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Commit | Line | Data |
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bc0c38d1 SR |
1 | /* |
2 | * ring buffer based function tracer | |
3 | * | |
2b6080f2 | 4 | * Copyright (C) 2007-2012 Steven Rostedt <srostedt@redhat.com> |
bc0c38d1 SR |
5 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> |
6 | * | |
7 | * Originally taken from the RT patch by: | |
8 | * Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code from the latency_tracer, that is: | |
11 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 12 | * Copyright (C) 2004 Nadia Yvette Chambers |
bc0c38d1 | 13 | */ |
2cadf913 | 14 | #include <linux/ring_buffer.h> |
273b281f | 15 | #include <generated/utsrelease.h> |
2cadf913 SR |
16 | #include <linux/stacktrace.h> |
17 | #include <linux/writeback.h> | |
bc0c38d1 SR |
18 | #include <linux/kallsyms.h> |
19 | #include <linux/seq_file.h> | |
3f5a54e3 | 20 | #include <linux/notifier.h> |
2cadf913 | 21 | #include <linux/irqflags.h> |
bc0c38d1 | 22 | #include <linux/debugfs.h> |
8434dc93 | 23 | #include <linux/tracefs.h> |
4c11d7ae | 24 | #include <linux/pagemap.h> |
bc0c38d1 SR |
25 | #include <linux/hardirq.h> |
26 | #include <linux/linkage.h> | |
27 | #include <linux/uaccess.h> | |
2cadf913 | 28 | #include <linux/kprobes.h> |
bc0c38d1 SR |
29 | #include <linux/ftrace.h> |
30 | #include <linux/module.h> | |
31 | #include <linux/percpu.h> | |
2cadf913 | 32 | #include <linux/splice.h> |
3f5a54e3 | 33 | #include <linux/kdebug.h> |
5f0c6c03 | 34 | #include <linux/string.h> |
f76180bc | 35 | #include <linux/mount.h> |
7e53bd42 | 36 | #include <linux/rwsem.h> |
5a0e3ad6 | 37 | #include <linux/slab.h> |
bc0c38d1 SR |
38 | #include <linux/ctype.h> |
39 | #include <linux/init.h> | |
2a2cc8f7 | 40 | #include <linux/poll.h> |
b892e5c8 | 41 | #include <linux/nmi.h> |
bc0c38d1 | 42 | #include <linux/fs.h> |
8bd75c77 | 43 | #include <linux/sched/rt.h> |
86387f7e | 44 | |
bc0c38d1 | 45 | #include "trace.h" |
f0868d1e | 46 | #include "trace_output.h" |
bc0c38d1 | 47 | |
73c5162a SR |
48 | /* |
49 | * On boot up, the ring buffer is set to the minimum size, so that | |
50 | * we do not waste memory on systems that are not using tracing. | |
51 | */ | |
55034cd6 | 52 | bool ring_buffer_expanded; |
73c5162a | 53 | |
8e1b82e0 FW |
54 | /* |
55 | * We need to change this state when a selftest is running. | |
ff32504f FW |
56 | * A selftest will lurk into the ring-buffer to count the |
57 | * entries inserted during the selftest although some concurrent | |
5e1607a0 | 58 | * insertions into the ring-buffer such as trace_printk could occurred |
ff32504f FW |
59 | * at the same time, giving false positive or negative results. |
60 | */ | |
8e1b82e0 | 61 | static bool __read_mostly tracing_selftest_running; |
ff32504f | 62 | |
b2821ae6 SR |
63 | /* |
64 | * If a tracer is running, we do not want to run SELFTEST. | |
65 | */ | |
020e5f85 | 66 | bool __read_mostly tracing_selftest_disabled; |
b2821ae6 | 67 | |
0daa2302 SRRH |
68 | /* Pipe tracepoints to printk */ |
69 | struct trace_iterator *tracepoint_print_iter; | |
70 | int tracepoint_printk; | |
71 | ||
adf9f195 FW |
72 | /* For tracers that don't implement custom flags */ |
73 | static struct tracer_opt dummy_tracer_opt[] = { | |
74 | { } | |
75 | }; | |
76 | ||
8c1a49ae SRRH |
77 | static int |
78 | dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
adf9f195 FW |
79 | { |
80 | return 0; | |
81 | } | |
0f048701 | 82 | |
7ffbd48d SR |
83 | /* |
84 | * To prevent the comm cache from being overwritten when no | |
85 | * tracing is active, only save the comm when a trace event | |
86 | * occurred. | |
87 | */ | |
88 | static DEFINE_PER_CPU(bool, trace_cmdline_save); | |
89 | ||
0f048701 SR |
90 | /* |
91 | * Kill all tracing for good (never come back). | |
92 | * It is initialized to 1 but will turn to zero if the initialization | |
93 | * of the tracer is successful. But that is the only place that sets | |
94 | * this back to zero. | |
95 | */ | |
4fd27358 | 96 | static int tracing_disabled = 1; |
0f048701 | 97 | |
955b61e5 | 98 | cpumask_var_t __read_mostly tracing_buffer_mask; |
ab46428c | 99 | |
944ac425 SR |
100 | /* |
101 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
102 | * | |
103 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
104 | * is set, then ftrace_dump is called. This will output the contents | |
105 | * of the ftrace buffers to the console. This is very useful for | |
106 | * capturing traces that lead to crashes and outputing it to a | |
107 | * serial console. | |
108 | * | |
109 | * It is default off, but you can enable it with either specifying | |
110 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
cecbca96 FW |
111 | * /proc/sys/kernel/ftrace_dump_on_oops |
112 | * Set 1 if you want to dump buffers of all CPUs | |
113 | * Set 2 if you want to dump the buffer of the CPU that triggered oops | |
944ac425 | 114 | */ |
cecbca96 FW |
115 | |
116 | enum ftrace_dump_mode ftrace_dump_on_oops; | |
944ac425 | 117 | |
de7edd31 SRRH |
118 | /* When set, tracing will stop when a WARN*() is hit */ |
119 | int __disable_trace_on_warning; | |
120 | ||
9828413d SRRH |
121 | #ifdef CONFIG_TRACE_ENUM_MAP_FILE |
122 | /* Map of enums to their values, for "enum_map" file */ | |
123 | struct trace_enum_map_head { | |
124 | struct module *mod; | |
125 | unsigned long length; | |
126 | }; | |
127 | ||
128 | union trace_enum_map_item; | |
129 | ||
130 | struct trace_enum_map_tail { | |
131 | /* | |
132 | * "end" is first and points to NULL as it must be different | |
133 | * than "mod" or "enum_string" | |
134 | */ | |
135 | union trace_enum_map_item *next; | |
136 | const char *end; /* points to NULL */ | |
137 | }; | |
138 | ||
139 | static DEFINE_MUTEX(trace_enum_mutex); | |
140 | ||
141 | /* | |
142 | * The trace_enum_maps are saved in an array with two extra elements, | |
143 | * one at the beginning, and one at the end. The beginning item contains | |
144 | * the count of the saved maps (head.length), and the module they | |
145 | * belong to if not built in (head.mod). The ending item contains a | |
146 | * pointer to the next array of saved enum_map items. | |
147 | */ | |
148 | union trace_enum_map_item { | |
149 | struct trace_enum_map map; | |
150 | struct trace_enum_map_head head; | |
151 | struct trace_enum_map_tail tail; | |
152 | }; | |
153 | ||
154 | static union trace_enum_map_item *trace_enum_maps; | |
155 | #endif /* CONFIG_TRACE_ENUM_MAP_FILE */ | |
156 | ||
607e2ea1 | 157 | static int tracing_set_tracer(struct trace_array *tr, const char *buf); |
b2821ae6 | 158 | |
ee6c2c1b LZ |
159 | #define MAX_TRACER_SIZE 100 |
160 | static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; | |
b2821ae6 | 161 | static char *default_bootup_tracer; |
d9e54076 | 162 | |
55034cd6 SRRH |
163 | static bool allocate_snapshot; |
164 | ||
1beee96b | 165 | static int __init set_cmdline_ftrace(char *str) |
d9e54076 | 166 | { |
67012ab1 | 167 | strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); |
b2821ae6 | 168 | default_bootup_tracer = bootup_tracer_buf; |
73c5162a | 169 | /* We are using ftrace early, expand it */ |
55034cd6 | 170 | ring_buffer_expanded = true; |
d9e54076 PZ |
171 | return 1; |
172 | } | |
1beee96b | 173 | __setup("ftrace=", set_cmdline_ftrace); |
d9e54076 | 174 | |
944ac425 SR |
175 | static int __init set_ftrace_dump_on_oops(char *str) |
176 | { | |
cecbca96 FW |
177 | if (*str++ != '=' || !*str) { |
178 | ftrace_dump_on_oops = DUMP_ALL; | |
179 | return 1; | |
180 | } | |
181 | ||
182 | if (!strcmp("orig_cpu", str)) { | |
183 | ftrace_dump_on_oops = DUMP_ORIG; | |
184 | return 1; | |
185 | } | |
186 | ||
187 | return 0; | |
944ac425 SR |
188 | } |
189 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
60a11774 | 190 | |
de7edd31 SRRH |
191 | static int __init stop_trace_on_warning(char *str) |
192 | { | |
933ff9f2 LCG |
193 | if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0)) |
194 | __disable_trace_on_warning = 1; | |
de7edd31 SRRH |
195 | return 1; |
196 | } | |
933ff9f2 | 197 | __setup("traceoff_on_warning", stop_trace_on_warning); |
de7edd31 | 198 | |
3209cff4 | 199 | static int __init boot_alloc_snapshot(char *str) |
55034cd6 SRRH |
200 | { |
201 | allocate_snapshot = true; | |
202 | /* We also need the main ring buffer expanded */ | |
203 | ring_buffer_expanded = true; | |
204 | return 1; | |
205 | } | |
3209cff4 | 206 | __setup("alloc_snapshot", boot_alloc_snapshot); |
55034cd6 | 207 | |
7bcfaf54 SR |
208 | |
209 | static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; | |
7bcfaf54 SR |
210 | |
211 | static int __init set_trace_boot_options(char *str) | |
212 | { | |
67012ab1 | 213 | strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); |
7bcfaf54 SR |
214 | return 0; |
215 | } | |
216 | __setup("trace_options=", set_trace_boot_options); | |
217 | ||
e1e232ca SR |
218 | static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata; |
219 | static char *trace_boot_clock __initdata; | |
220 | ||
221 | static int __init set_trace_boot_clock(char *str) | |
222 | { | |
223 | strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE); | |
224 | trace_boot_clock = trace_boot_clock_buf; | |
225 | return 0; | |
226 | } | |
227 | __setup("trace_clock=", set_trace_boot_clock); | |
228 | ||
0daa2302 SRRH |
229 | static int __init set_tracepoint_printk(char *str) |
230 | { | |
231 | if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0)) | |
232 | tracepoint_printk = 1; | |
233 | return 1; | |
234 | } | |
235 | __setup("tp_printk", set_tracepoint_printk); | |
de7edd31 | 236 | |
cf8e3474 | 237 | unsigned long long ns2usecs(cycle_t nsec) |
bc0c38d1 SR |
238 | { |
239 | nsec += 500; | |
240 | do_div(nsec, 1000); | |
241 | return nsec; | |
242 | } | |
243 | ||
983f938a SRRH |
244 | /* trace_flags holds trace_options default values */ |
245 | #define TRACE_DEFAULT_FLAGS \ | |
246 | (FUNCTION_DEFAULT_FLAGS | \ | |
247 | TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | \ | |
248 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | \ | |
249 | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | \ | |
250 | TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS) | |
251 | ||
16270145 SRRH |
252 | /* trace_options that are only supported by global_trace */ |
253 | #define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \ | |
254 | TRACE_ITER_PRINTK_MSGONLY | TRACE_ITER_RECORD_CMD) | |
255 | ||
20550622 SRRH |
256 | /* trace_flags that are default zero for instances */ |
257 | #define ZEROED_TRACE_FLAGS \ | |
258 | TRACE_ITER_EVENT_FORK | |
16270145 | 259 | |
4fcdae83 SR |
260 | /* |
261 | * The global_trace is the descriptor that holds the tracing | |
262 | * buffers for the live tracing. For each CPU, it contains | |
263 | * a link list of pages that will store trace entries. The | |
264 | * page descriptor of the pages in the memory is used to hold | |
265 | * the link list by linking the lru item in the page descriptor | |
266 | * to each of the pages in the buffer per CPU. | |
267 | * | |
268 | * For each active CPU there is a data field that holds the | |
269 | * pages for the buffer for that CPU. Each CPU has the same number | |
270 | * of pages allocated for its buffer. | |
271 | */ | |
983f938a SRRH |
272 | static struct trace_array global_trace = { |
273 | .trace_flags = TRACE_DEFAULT_FLAGS, | |
274 | }; | |
bc0c38d1 | 275 | |
ae63b31e | 276 | LIST_HEAD(ftrace_trace_arrays); |
bc0c38d1 | 277 | |
ff451961 SRRH |
278 | int trace_array_get(struct trace_array *this_tr) |
279 | { | |
280 | struct trace_array *tr; | |
281 | int ret = -ENODEV; | |
282 | ||
283 | mutex_lock(&trace_types_lock); | |
284 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
285 | if (tr == this_tr) { | |
286 | tr->ref++; | |
287 | ret = 0; | |
288 | break; | |
289 | } | |
290 | } | |
291 | mutex_unlock(&trace_types_lock); | |
292 | ||
293 | return ret; | |
294 | } | |
295 | ||
296 | static void __trace_array_put(struct trace_array *this_tr) | |
297 | { | |
298 | WARN_ON(!this_tr->ref); | |
299 | this_tr->ref--; | |
300 | } | |
301 | ||
302 | void trace_array_put(struct trace_array *this_tr) | |
303 | { | |
304 | mutex_lock(&trace_types_lock); | |
305 | __trace_array_put(this_tr); | |
306 | mutex_unlock(&trace_types_lock); | |
307 | } | |
308 | ||
2425bcb9 | 309 | int call_filter_check_discard(struct trace_event_call *call, void *rec, |
f306cc82 TZ |
310 | struct ring_buffer *buffer, |
311 | struct ring_buffer_event *event) | |
312 | { | |
313 | if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) && | |
314 | !filter_match_preds(call->filter, rec)) { | |
315 | ring_buffer_discard_commit(buffer, event); | |
316 | return 1; | |
317 | } | |
318 | ||
319 | return 0; | |
eb02ce01 TZ |
320 | } |
321 | ||
ad1438a0 | 322 | static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) |
37886f6a SR |
323 | { |
324 | u64 ts; | |
325 | ||
326 | /* Early boot up does not have a buffer yet */ | |
9457158b | 327 | if (!buf->buffer) |
37886f6a SR |
328 | return trace_clock_local(); |
329 | ||
9457158b AL |
330 | ts = ring_buffer_time_stamp(buf->buffer, cpu); |
331 | ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts); | |
37886f6a SR |
332 | |
333 | return ts; | |
334 | } | |
bc0c38d1 | 335 | |
9457158b AL |
336 | cycle_t ftrace_now(int cpu) |
337 | { | |
338 | return buffer_ftrace_now(&global_trace.trace_buffer, cpu); | |
339 | } | |
340 | ||
10246fa3 SRRH |
341 | /** |
342 | * tracing_is_enabled - Show if global_trace has been disabled | |
343 | * | |
344 | * Shows if the global trace has been enabled or not. It uses the | |
345 | * mirror flag "buffer_disabled" to be used in fast paths such as for | |
346 | * the irqsoff tracer. But it may be inaccurate due to races. If you | |
347 | * need to know the accurate state, use tracing_is_on() which is a little | |
348 | * slower, but accurate. | |
349 | */ | |
9036990d SR |
350 | int tracing_is_enabled(void) |
351 | { | |
10246fa3 SRRH |
352 | /* |
353 | * For quick access (irqsoff uses this in fast path), just | |
354 | * return the mirror variable of the state of the ring buffer. | |
355 | * It's a little racy, but we don't really care. | |
356 | */ | |
357 | smp_rmb(); | |
358 | return !global_trace.buffer_disabled; | |
9036990d SR |
359 | } |
360 | ||
4fcdae83 | 361 | /* |
3928a8a2 SR |
362 | * trace_buf_size is the size in bytes that is allocated |
363 | * for a buffer. Note, the number of bytes is always rounded | |
364 | * to page size. | |
3f5a54e3 SR |
365 | * |
366 | * This number is purposely set to a low number of 16384. | |
367 | * If the dump on oops happens, it will be much appreciated | |
368 | * to not have to wait for all that output. Anyway this can be | |
369 | * boot time and run time configurable. | |
4fcdae83 | 370 | */ |
3928a8a2 | 371 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 372 | |
3928a8a2 | 373 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 374 | |
4fcdae83 | 375 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 376 | static struct tracer *trace_types __read_mostly; |
4fcdae83 | 377 | |
4fcdae83 SR |
378 | /* |
379 | * trace_types_lock is used to protect the trace_types list. | |
4fcdae83 | 380 | */ |
a8227415 | 381 | DEFINE_MUTEX(trace_types_lock); |
4fcdae83 | 382 | |
7e53bd42 LJ |
383 | /* |
384 | * serialize the access of the ring buffer | |
385 | * | |
386 | * ring buffer serializes readers, but it is low level protection. | |
387 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
388 | * are not protected by ring buffer. | |
389 | * | |
390 | * The content of events may become garbage if we allow other process consumes | |
391 | * these events concurrently: | |
392 | * A) the page of the consumed events may become a normal page | |
393 | * (not reader page) in ring buffer, and this page will be rewrited | |
394 | * by events producer. | |
395 | * B) The page of the consumed events may become a page for splice_read, | |
396 | * and this page will be returned to system. | |
397 | * | |
398 | * These primitives allow multi process access to different cpu ring buffer | |
399 | * concurrently. | |
400 | * | |
401 | * These primitives don't distinguish read-only and read-consume access. | |
402 | * Multi read-only access are also serialized. | |
403 | */ | |
404 | ||
405 | #ifdef CONFIG_SMP | |
406 | static DECLARE_RWSEM(all_cpu_access_lock); | |
407 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
408 | ||
409 | static inline void trace_access_lock(int cpu) | |
410 | { | |
ae3b5093 | 411 | if (cpu == RING_BUFFER_ALL_CPUS) { |
7e53bd42 LJ |
412 | /* gain it for accessing the whole ring buffer. */ |
413 | down_write(&all_cpu_access_lock); | |
414 | } else { | |
415 | /* gain it for accessing a cpu ring buffer. */ | |
416 | ||
ae3b5093 | 417 | /* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */ |
7e53bd42 LJ |
418 | down_read(&all_cpu_access_lock); |
419 | ||
420 | /* Secondly block other access to this @cpu ring buffer. */ | |
421 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
422 | } | |
423 | } | |
424 | ||
425 | static inline void trace_access_unlock(int cpu) | |
426 | { | |
ae3b5093 | 427 | if (cpu == RING_BUFFER_ALL_CPUS) { |
7e53bd42 LJ |
428 | up_write(&all_cpu_access_lock); |
429 | } else { | |
430 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
431 | up_read(&all_cpu_access_lock); | |
432 | } | |
433 | } | |
434 | ||
435 | static inline void trace_access_lock_init(void) | |
436 | { | |
437 | int cpu; | |
438 | ||
439 | for_each_possible_cpu(cpu) | |
440 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
441 | } | |
442 | ||
443 | #else | |
444 | ||
445 | static DEFINE_MUTEX(access_lock); | |
446 | ||
447 | static inline void trace_access_lock(int cpu) | |
448 | { | |
449 | (void)cpu; | |
450 | mutex_lock(&access_lock); | |
451 | } | |
452 | ||
453 | static inline void trace_access_unlock(int cpu) | |
454 | { | |
455 | (void)cpu; | |
456 | mutex_unlock(&access_lock); | |
457 | } | |
458 | ||
459 | static inline void trace_access_lock_init(void) | |
460 | { | |
461 | } | |
462 | ||
463 | #endif | |
464 | ||
d78a4614 SRRH |
465 | #ifdef CONFIG_STACKTRACE |
466 | static void __ftrace_trace_stack(struct ring_buffer *buffer, | |
467 | unsigned long flags, | |
468 | int skip, int pc, struct pt_regs *regs); | |
2d34f489 SRRH |
469 | static inline void ftrace_trace_stack(struct trace_array *tr, |
470 | struct ring_buffer *buffer, | |
73dddbb5 SRRH |
471 | unsigned long flags, |
472 | int skip, int pc, struct pt_regs *regs); | |
ca475e83 | 473 | |
d78a4614 SRRH |
474 | #else |
475 | static inline void __ftrace_trace_stack(struct ring_buffer *buffer, | |
476 | unsigned long flags, | |
477 | int skip, int pc, struct pt_regs *regs) | |
478 | { | |
479 | } | |
2d34f489 SRRH |
480 | static inline void ftrace_trace_stack(struct trace_array *tr, |
481 | struct ring_buffer *buffer, | |
73dddbb5 SRRH |
482 | unsigned long flags, |
483 | int skip, int pc, struct pt_regs *regs) | |
ca475e83 SRRH |
484 | { |
485 | } | |
486 | ||
d78a4614 SRRH |
487 | #endif |
488 | ||
5280bcef | 489 | static void tracer_tracing_on(struct trace_array *tr) |
10246fa3 SRRH |
490 | { |
491 | if (tr->trace_buffer.buffer) | |
492 | ring_buffer_record_on(tr->trace_buffer.buffer); | |
493 | /* | |
494 | * This flag is looked at when buffers haven't been allocated | |
495 | * yet, or by some tracers (like irqsoff), that just want to | |
496 | * know if the ring buffer has been disabled, but it can handle | |
497 | * races of where it gets disabled but we still do a record. | |
498 | * As the check is in the fast path of the tracers, it is more | |
499 | * important to be fast than accurate. | |
500 | */ | |
501 | tr->buffer_disabled = 0; | |
502 | /* Make the flag seen by readers */ | |
503 | smp_wmb(); | |
504 | } | |
505 | ||
499e5470 SR |
506 | /** |
507 | * tracing_on - enable tracing buffers | |
508 | * | |
509 | * This function enables tracing buffers that may have been | |
510 | * disabled with tracing_off. | |
511 | */ | |
512 | void tracing_on(void) | |
513 | { | |
10246fa3 | 514 | tracer_tracing_on(&global_trace); |
499e5470 SR |
515 | } |
516 | EXPORT_SYMBOL_GPL(tracing_on); | |
517 | ||
09ae7234 SRRH |
518 | /** |
519 | * __trace_puts - write a constant string into the trace buffer. | |
520 | * @ip: The address of the caller | |
521 | * @str: The constant string to write | |
522 | * @size: The size of the string. | |
523 | */ | |
524 | int __trace_puts(unsigned long ip, const char *str, int size) | |
525 | { | |
526 | struct ring_buffer_event *event; | |
527 | struct ring_buffer *buffer; | |
528 | struct print_entry *entry; | |
529 | unsigned long irq_flags; | |
530 | int alloc; | |
8abfb872 J |
531 | int pc; |
532 | ||
983f938a | 533 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
f0160a5a J |
534 | return 0; |
535 | ||
8abfb872 | 536 | pc = preempt_count(); |
09ae7234 | 537 | |
3132e107 SRRH |
538 | if (unlikely(tracing_selftest_running || tracing_disabled)) |
539 | return 0; | |
540 | ||
09ae7234 SRRH |
541 | alloc = sizeof(*entry) + size + 2; /* possible \n added */ |
542 | ||
543 | local_save_flags(irq_flags); | |
544 | buffer = global_trace.trace_buffer.buffer; | |
545 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, | |
8abfb872 | 546 | irq_flags, pc); |
09ae7234 SRRH |
547 | if (!event) |
548 | return 0; | |
549 | ||
550 | entry = ring_buffer_event_data(event); | |
551 | entry->ip = ip; | |
552 | ||
553 | memcpy(&entry->buf, str, size); | |
554 | ||
555 | /* Add a newline if necessary */ | |
556 | if (entry->buf[size - 1] != '\n') { | |
557 | entry->buf[size] = '\n'; | |
558 | entry->buf[size + 1] = '\0'; | |
559 | } else | |
560 | entry->buf[size] = '\0'; | |
561 | ||
562 | __buffer_unlock_commit(buffer, event); | |
2d34f489 | 563 | ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL); |
09ae7234 SRRH |
564 | |
565 | return size; | |
566 | } | |
567 | EXPORT_SYMBOL_GPL(__trace_puts); | |
568 | ||
569 | /** | |
570 | * __trace_bputs - write the pointer to a constant string into trace buffer | |
571 | * @ip: The address of the caller | |
572 | * @str: The constant string to write to the buffer to | |
573 | */ | |
574 | int __trace_bputs(unsigned long ip, const char *str) | |
575 | { | |
576 | struct ring_buffer_event *event; | |
577 | struct ring_buffer *buffer; | |
578 | struct bputs_entry *entry; | |
579 | unsigned long irq_flags; | |
580 | int size = sizeof(struct bputs_entry); | |
8abfb872 J |
581 | int pc; |
582 | ||
983f938a | 583 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
f0160a5a J |
584 | return 0; |
585 | ||
8abfb872 | 586 | pc = preempt_count(); |
09ae7234 | 587 | |
3132e107 SRRH |
588 | if (unlikely(tracing_selftest_running || tracing_disabled)) |
589 | return 0; | |
590 | ||
09ae7234 SRRH |
591 | local_save_flags(irq_flags); |
592 | buffer = global_trace.trace_buffer.buffer; | |
593 | event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, | |
8abfb872 | 594 | irq_flags, pc); |
09ae7234 SRRH |
595 | if (!event) |
596 | return 0; | |
597 | ||
598 | entry = ring_buffer_event_data(event); | |
599 | entry->ip = ip; | |
600 | entry->str = str; | |
601 | ||
602 | __buffer_unlock_commit(buffer, event); | |
2d34f489 | 603 | ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL); |
09ae7234 SRRH |
604 | |
605 | return 1; | |
606 | } | |
607 | EXPORT_SYMBOL_GPL(__trace_bputs); | |
608 | ||
ad909e21 SRRH |
609 | #ifdef CONFIG_TRACER_SNAPSHOT |
610 | /** | |
611 | * trace_snapshot - take a snapshot of the current buffer. | |
612 | * | |
613 | * This causes a swap between the snapshot buffer and the current live | |
614 | * tracing buffer. You can use this to take snapshots of the live | |
615 | * trace when some condition is triggered, but continue to trace. | |
616 | * | |
617 | * Note, make sure to allocate the snapshot with either | |
618 | * a tracing_snapshot_alloc(), or by doing it manually | |
619 | * with: echo 1 > /sys/kernel/debug/tracing/snapshot | |
620 | * | |
621 | * If the snapshot buffer is not allocated, it will stop tracing. | |
622 | * Basically making a permanent snapshot. | |
623 | */ | |
624 | void tracing_snapshot(void) | |
625 | { | |
626 | struct trace_array *tr = &global_trace; | |
627 | struct tracer *tracer = tr->current_trace; | |
628 | unsigned long flags; | |
629 | ||
1b22e382 SRRH |
630 | if (in_nmi()) { |
631 | internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); | |
632 | internal_trace_puts("*** snapshot is being ignored ***\n"); | |
633 | return; | |
634 | } | |
635 | ||
ad909e21 | 636 | if (!tr->allocated_snapshot) { |
ca268da6 SRRH |
637 | internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); |
638 | internal_trace_puts("*** stopping trace here! ***\n"); | |
ad909e21 SRRH |
639 | tracing_off(); |
640 | return; | |
641 | } | |
642 | ||
643 | /* Note, snapshot can not be used when the tracer uses it */ | |
644 | if (tracer->use_max_tr) { | |
ca268da6 SRRH |
645 | internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); |
646 | internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); | |
ad909e21 SRRH |
647 | return; |
648 | } | |
649 | ||
650 | local_irq_save(flags); | |
651 | update_max_tr(tr, current, smp_processor_id()); | |
652 | local_irq_restore(flags); | |
653 | } | |
1b22e382 | 654 | EXPORT_SYMBOL_GPL(tracing_snapshot); |
ad909e21 SRRH |
655 | |
656 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, | |
657 | struct trace_buffer *size_buf, int cpu_id); | |
3209cff4 SRRH |
658 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val); |
659 | ||
660 | static int alloc_snapshot(struct trace_array *tr) | |
661 | { | |
662 | int ret; | |
663 | ||
664 | if (!tr->allocated_snapshot) { | |
665 | ||
666 | /* allocate spare buffer */ | |
667 | ret = resize_buffer_duplicate_size(&tr->max_buffer, | |
668 | &tr->trace_buffer, RING_BUFFER_ALL_CPUS); | |
669 | if (ret < 0) | |
670 | return ret; | |
671 | ||
672 | tr->allocated_snapshot = true; | |
673 | } | |
674 | ||
675 | return 0; | |
676 | } | |
677 | ||
ad1438a0 | 678 | static void free_snapshot(struct trace_array *tr) |
3209cff4 SRRH |
679 | { |
680 | /* | |
681 | * We don't free the ring buffer. instead, resize it because | |
682 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
683 | * we want preserve it. | |
684 | */ | |
685 | ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); | |
686 | set_buffer_entries(&tr->max_buffer, 1); | |
687 | tracing_reset_online_cpus(&tr->max_buffer); | |
688 | tr->allocated_snapshot = false; | |
689 | } | |
ad909e21 | 690 | |
93e31ffb TZ |
691 | /** |
692 | * tracing_alloc_snapshot - allocate snapshot buffer. | |
693 | * | |
694 | * This only allocates the snapshot buffer if it isn't already | |
695 | * allocated - it doesn't also take a snapshot. | |
696 | * | |
697 | * This is meant to be used in cases where the snapshot buffer needs | |
698 | * to be set up for events that can't sleep but need to be able to | |
699 | * trigger a snapshot. | |
700 | */ | |
701 | int tracing_alloc_snapshot(void) | |
702 | { | |
703 | struct trace_array *tr = &global_trace; | |
704 | int ret; | |
705 | ||
706 | ret = alloc_snapshot(tr); | |
707 | WARN_ON(ret < 0); | |
708 | ||
709 | return ret; | |
710 | } | |
711 | EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); | |
712 | ||
ad909e21 SRRH |
713 | /** |
714 | * trace_snapshot_alloc - allocate and take a snapshot of the current buffer. | |
715 | * | |
716 | * This is similar to trace_snapshot(), but it will allocate the | |
717 | * snapshot buffer if it isn't already allocated. Use this only | |
718 | * where it is safe to sleep, as the allocation may sleep. | |
719 | * | |
720 | * This causes a swap between the snapshot buffer and the current live | |
721 | * tracing buffer. You can use this to take snapshots of the live | |
722 | * trace when some condition is triggered, but continue to trace. | |
723 | */ | |
724 | void tracing_snapshot_alloc(void) | |
725 | { | |
ad909e21 SRRH |
726 | int ret; |
727 | ||
93e31ffb TZ |
728 | ret = tracing_alloc_snapshot(); |
729 | if (ret < 0) | |
3209cff4 | 730 | return; |
ad909e21 SRRH |
731 | |
732 | tracing_snapshot(); | |
733 | } | |
1b22e382 | 734 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
ad909e21 SRRH |
735 | #else |
736 | void tracing_snapshot(void) | |
737 | { | |
738 | WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); | |
739 | } | |
1b22e382 | 740 | EXPORT_SYMBOL_GPL(tracing_snapshot); |
93e31ffb TZ |
741 | int tracing_alloc_snapshot(void) |
742 | { | |
743 | WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used"); | |
744 | return -ENODEV; | |
745 | } | |
746 | EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); | |
ad909e21 SRRH |
747 | void tracing_snapshot_alloc(void) |
748 | { | |
749 | /* Give warning */ | |
750 | tracing_snapshot(); | |
751 | } | |
1b22e382 | 752 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
ad909e21 SRRH |
753 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
754 | ||
5280bcef | 755 | static void tracer_tracing_off(struct trace_array *tr) |
10246fa3 SRRH |
756 | { |
757 | if (tr->trace_buffer.buffer) | |
758 | ring_buffer_record_off(tr->trace_buffer.buffer); | |
759 | /* | |
760 | * This flag is looked at when buffers haven't been allocated | |
761 | * yet, or by some tracers (like irqsoff), that just want to | |
762 | * know if the ring buffer has been disabled, but it can handle | |
763 | * races of where it gets disabled but we still do a record. | |
764 | * As the check is in the fast path of the tracers, it is more | |
765 | * important to be fast than accurate. | |
766 | */ | |
767 | tr->buffer_disabled = 1; | |
768 | /* Make the flag seen by readers */ | |
769 | smp_wmb(); | |
770 | } | |
771 | ||
499e5470 SR |
772 | /** |
773 | * tracing_off - turn off tracing buffers | |
774 | * | |
775 | * This function stops the tracing buffers from recording data. | |
776 | * It does not disable any overhead the tracers themselves may | |
777 | * be causing. This function simply causes all recording to | |
778 | * the ring buffers to fail. | |
779 | */ | |
780 | void tracing_off(void) | |
781 | { | |
10246fa3 | 782 | tracer_tracing_off(&global_trace); |
499e5470 SR |
783 | } |
784 | EXPORT_SYMBOL_GPL(tracing_off); | |
785 | ||
de7edd31 SRRH |
786 | void disable_trace_on_warning(void) |
787 | { | |
788 | if (__disable_trace_on_warning) | |
789 | tracing_off(); | |
790 | } | |
791 | ||
10246fa3 SRRH |
792 | /** |
793 | * tracer_tracing_is_on - show real state of ring buffer enabled | |
794 | * @tr : the trace array to know if ring buffer is enabled | |
795 | * | |
796 | * Shows real state of the ring buffer if it is enabled or not. | |
797 | */ | |
5280bcef | 798 | static int tracer_tracing_is_on(struct trace_array *tr) |
10246fa3 SRRH |
799 | { |
800 | if (tr->trace_buffer.buffer) | |
801 | return ring_buffer_record_is_on(tr->trace_buffer.buffer); | |
802 | return !tr->buffer_disabled; | |
803 | } | |
804 | ||
499e5470 SR |
805 | /** |
806 | * tracing_is_on - show state of ring buffers enabled | |
807 | */ | |
808 | int tracing_is_on(void) | |
809 | { | |
10246fa3 | 810 | return tracer_tracing_is_on(&global_trace); |
499e5470 SR |
811 | } |
812 | EXPORT_SYMBOL_GPL(tracing_is_on); | |
813 | ||
3928a8a2 | 814 | static int __init set_buf_size(char *str) |
bc0c38d1 | 815 | { |
3928a8a2 | 816 | unsigned long buf_size; |
c6caeeb1 | 817 | |
bc0c38d1 SR |
818 | if (!str) |
819 | return 0; | |
9d612bef | 820 | buf_size = memparse(str, &str); |
c6caeeb1 | 821 | /* nr_entries can not be zero */ |
9d612bef | 822 | if (buf_size == 0) |
c6caeeb1 | 823 | return 0; |
3928a8a2 | 824 | trace_buf_size = buf_size; |
bc0c38d1 SR |
825 | return 1; |
826 | } | |
3928a8a2 | 827 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 828 | |
0e950173 TB |
829 | static int __init set_tracing_thresh(char *str) |
830 | { | |
87abb3b1 | 831 | unsigned long threshold; |
0e950173 TB |
832 | int ret; |
833 | ||
834 | if (!str) | |
835 | return 0; | |
bcd83ea6 | 836 | ret = kstrtoul(str, 0, &threshold); |
0e950173 TB |
837 | if (ret < 0) |
838 | return 0; | |
87abb3b1 | 839 | tracing_thresh = threshold * 1000; |
0e950173 TB |
840 | return 1; |
841 | } | |
842 | __setup("tracing_thresh=", set_tracing_thresh); | |
843 | ||
57f50be1 SR |
844 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
845 | { | |
846 | return nsecs / 1000; | |
847 | } | |
848 | ||
a3418a36 SRRH |
849 | /* |
850 | * TRACE_FLAGS is defined as a tuple matching bit masks with strings. | |
851 | * It uses C(a, b) where 'a' is the enum name and 'b' is the string that | |
852 | * matches it. By defining "C(a, b) b", TRACE_FLAGS becomes a list | |
853 | * of strings in the order that the enums were defined. | |
854 | */ | |
855 | #undef C | |
856 | #define C(a, b) b | |
857 | ||
4fcdae83 | 858 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 | 859 | static const char *trace_options[] = { |
a3418a36 | 860 | TRACE_FLAGS |
bc0c38d1 SR |
861 | NULL |
862 | }; | |
863 | ||
5079f326 Z |
864 | static struct { |
865 | u64 (*func)(void); | |
866 | const char *name; | |
8be0709f | 867 | int in_ns; /* is this clock in nanoseconds? */ |
5079f326 | 868 | } trace_clocks[] = { |
1b3e5c09 TG |
869 | { trace_clock_local, "local", 1 }, |
870 | { trace_clock_global, "global", 1 }, | |
871 | { trace_clock_counter, "counter", 0 }, | |
e7fda6c4 | 872 | { trace_clock_jiffies, "uptime", 0 }, |
1b3e5c09 TG |
873 | { trace_clock, "perf", 1 }, |
874 | { ktime_get_mono_fast_ns, "mono", 1 }, | |
aabfa5f2 | 875 | { ktime_get_raw_fast_ns, "mono_raw", 1 }, |
8cbd9cc6 | 876 | ARCH_TRACE_CLOCKS |
5079f326 Z |
877 | }; |
878 | ||
b63f39ea | 879 | /* |
880 | * trace_parser_get_init - gets the buffer for trace parser | |
881 | */ | |
882 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
883 | { | |
884 | memset(parser, 0, sizeof(*parser)); | |
885 | ||
886 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
887 | if (!parser->buffer) | |
888 | return 1; | |
889 | ||
890 | parser->size = size; | |
891 | return 0; | |
892 | } | |
893 | ||
894 | /* | |
895 | * trace_parser_put - frees the buffer for trace parser | |
896 | */ | |
897 | void trace_parser_put(struct trace_parser *parser) | |
898 | { | |
899 | kfree(parser->buffer); | |
900 | } | |
901 | ||
902 | /* | |
903 | * trace_get_user - reads the user input string separated by space | |
904 | * (matched by isspace(ch)) | |
905 | * | |
906 | * For each string found the 'struct trace_parser' is updated, | |
907 | * and the function returns. | |
908 | * | |
909 | * Returns number of bytes read. | |
910 | * | |
911 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
912 | */ | |
913 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
914 | size_t cnt, loff_t *ppos) | |
915 | { | |
916 | char ch; | |
917 | size_t read = 0; | |
918 | ssize_t ret; | |
919 | ||
920 | if (!*ppos) | |
921 | trace_parser_clear(parser); | |
922 | ||
923 | ret = get_user(ch, ubuf++); | |
924 | if (ret) | |
925 | goto out; | |
926 | ||
927 | read++; | |
928 | cnt--; | |
929 | ||
930 | /* | |
931 | * The parser is not finished with the last write, | |
932 | * continue reading the user input without skipping spaces. | |
933 | */ | |
934 | if (!parser->cont) { | |
935 | /* skip white space */ | |
936 | while (cnt && isspace(ch)) { | |
937 | ret = get_user(ch, ubuf++); | |
938 | if (ret) | |
939 | goto out; | |
940 | read++; | |
941 | cnt--; | |
942 | } | |
943 | ||
944 | /* only spaces were written */ | |
945 | if (isspace(ch)) { | |
946 | *ppos += read; | |
947 | ret = read; | |
948 | goto out; | |
949 | } | |
950 | ||
951 | parser->idx = 0; | |
952 | } | |
953 | ||
954 | /* read the non-space input */ | |
955 | while (cnt && !isspace(ch)) { | |
3c235a33 | 956 | if (parser->idx < parser->size - 1) |
b63f39ea | 957 | parser->buffer[parser->idx++] = ch; |
958 | else { | |
959 | ret = -EINVAL; | |
960 | goto out; | |
961 | } | |
962 | ret = get_user(ch, ubuf++); | |
963 | if (ret) | |
964 | goto out; | |
965 | read++; | |
966 | cnt--; | |
967 | } | |
968 | ||
969 | /* We either got finished input or we have to wait for another call. */ | |
970 | if (isspace(ch)) { | |
971 | parser->buffer[parser->idx] = 0; | |
972 | parser->cont = false; | |
057db848 | 973 | } else if (parser->idx < parser->size - 1) { |
b63f39ea | 974 | parser->cont = true; |
975 | parser->buffer[parser->idx++] = ch; | |
057db848 SR |
976 | } else { |
977 | ret = -EINVAL; | |
978 | goto out; | |
b63f39ea | 979 | } |
980 | ||
981 | *ppos += read; | |
982 | ret = read; | |
983 | ||
984 | out: | |
985 | return ret; | |
986 | } | |
987 | ||
3a161d99 | 988 | /* TODO add a seq_buf_to_buffer() */ |
b8b94265 | 989 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
990 | { |
991 | int len; | |
3c56819b | 992 | |
5ac48378 | 993 | if (trace_seq_used(s) <= s->seq.readpos) |
3c56819b EGM |
994 | return -EBUSY; |
995 | ||
5ac48378 | 996 | len = trace_seq_used(s) - s->seq.readpos; |
3c56819b EGM |
997 | if (cnt > len) |
998 | cnt = len; | |
3a161d99 | 999 | memcpy(buf, s->buffer + s->seq.readpos, cnt); |
3c56819b | 1000 | |
3a161d99 | 1001 | s->seq.readpos += cnt; |
3c56819b EGM |
1002 | return cnt; |
1003 | } | |
1004 | ||
0e950173 TB |
1005 | unsigned long __read_mostly tracing_thresh; |
1006 | ||
5d4a9dba | 1007 | #ifdef CONFIG_TRACER_MAX_TRACE |
5d4a9dba SR |
1008 | /* |
1009 | * Copy the new maximum trace into the separate maximum-trace | |
1010 | * structure. (this way the maximum trace is permanently saved, | |
1011 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
1012 | */ | |
1013 | static void | |
1014 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
1015 | { | |
12883efb SRRH |
1016 | struct trace_buffer *trace_buf = &tr->trace_buffer; |
1017 | struct trace_buffer *max_buf = &tr->max_buffer; | |
1018 | struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); | |
1019 | struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); | |
5d4a9dba | 1020 | |
12883efb SRRH |
1021 | max_buf->cpu = cpu; |
1022 | max_buf->time_start = data->preempt_timestamp; | |
5d4a9dba | 1023 | |
6d9b3fa5 | 1024 | max_data->saved_latency = tr->max_latency; |
8248ac05 SR |
1025 | max_data->critical_start = data->critical_start; |
1026 | max_data->critical_end = data->critical_end; | |
5d4a9dba | 1027 | |
1acaa1b2 | 1028 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); |
8248ac05 | 1029 | max_data->pid = tsk->pid; |
f17a5194 SRRH |
1030 | /* |
1031 | * If tsk == current, then use current_uid(), as that does not use | |
1032 | * RCU. The irq tracer can be called out of RCU scope. | |
1033 | */ | |
1034 | if (tsk == current) | |
1035 | max_data->uid = current_uid(); | |
1036 | else | |
1037 | max_data->uid = task_uid(tsk); | |
1038 | ||
8248ac05 SR |
1039 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; |
1040 | max_data->policy = tsk->policy; | |
1041 | max_data->rt_priority = tsk->rt_priority; | |
5d4a9dba SR |
1042 | |
1043 | /* record this tasks comm */ | |
1044 | tracing_record_cmdline(tsk); | |
1045 | } | |
1046 | ||
4fcdae83 SR |
1047 | /** |
1048 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
1049 | * @tr: tracer | |
1050 | * @tsk: the task with the latency | |
1051 | * @cpu: The cpu that initiated the trace. | |
1052 | * | |
1053 | * Flip the buffers between the @tr and the max_tr and record information | |
1054 | * about which task was the cause of this latency. | |
1055 | */ | |
e309b41d | 1056 | void |
bc0c38d1 SR |
1057 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
1058 | { | |
2721e72d | 1059 | struct ring_buffer *buf; |
bc0c38d1 | 1060 | |
2b6080f2 | 1061 | if (tr->stop_count) |
b8de7bd1 SR |
1062 | return; |
1063 | ||
4c11d7ae | 1064 | WARN_ON_ONCE(!irqs_disabled()); |
34600f0e | 1065 | |
45ad21ca | 1066 | if (!tr->allocated_snapshot) { |
debdd57f | 1067 | /* Only the nop tracer should hit this when disabling */ |
2b6080f2 | 1068 | WARN_ON_ONCE(tr->current_trace != &nop_trace); |
34600f0e | 1069 | return; |
debdd57f | 1070 | } |
34600f0e | 1071 | |
0b9b12c1 | 1072 | arch_spin_lock(&tr->max_lock); |
3928a8a2 | 1073 | |
12883efb SRRH |
1074 | buf = tr->trace_buffer.buffer; |
1075 | tr->trace_buffer.buffer = tr->max_buffer.buffer; | |
1076 | tr->max_buffer.buffer = buf; | |
3928a8a2 | 1077 | |
bc0c38d1 | 1078 | __update_max_tr(tr, tsk, cpu); |
0b9b12c1 | 1079 | arch_spin_unlock(&tr->max_lock); |
bc0c38d1 SR |
1080 | } |
1081 | ||
1082 | /** | |
1083 | * update_max_tr_single - only copy one trace over, and reset the rest | |
1084 | * @tr - tracer | |
1085 | * @tsk - task with the latency | |
1086 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
1087 | * |
1088 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 1089 | */ |
e309b41d | 1090 | void |
bc0c38d1 SR |
1091 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
1092 | { | |
3928a8a2 | 1093 | int ret; |
bc0c38d1 | 1094 | |
2b6080f2 | 1095 | if (tr->stop_count) |
b8de7bd1 SR |
1096 | return; |
1097 | ||
4c11d7ae | 1098 | WARN_ON_ONCE(!irqs_disabled()); |
6c24499f | 1099 | if (!tr->allocated_snapshot) { |
2930e04d | 1100 | /* Only the nop tracer should hit this when disabling */ |
9e8529af | 1101 | WARN_ON_ONCE(tr->current_trace != &nop_trace); |
ef710e10 | 1102 | return; |
2930e04d | 1103 | } |
ef710e10 | 1104 | |
0b9b12c1 | 1105 | arch_spin_lock(&tr->max_lock); |
bc0c38d1 | 1106 | |
12883efb | 1107 | ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu); |
3928a8a2 | 1108 | |
e8165dbb SR |
1109 | if (ret == -EBUSY) { |
1110 | /* | |
1111 | * We failed to swap the buffer due to a commit taking | |
1112 | * place on this CPU. We fail to record, but we reset | |
1113 | * the max trace buffer (no one writes directly to it) | |
1114 | * and flag that it failed. | |
1115 | */ | |
12883efb | 1116 | trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, |
e8165dbb SR |
1117 | "Failed to swap buffers due to commit in progress\n"); |
1118 | } | |
1119 | ||
e8165dbb | 1120 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
bc0c38d1 SR |
1121 | |
1122 | __update_max_tr(tr, tsk, cpu); | |
0b9b12c1 | 1123 | arch_spin_unlock(&tr->max_lock); |
bc0c38d1 | 1124 | } |
5d4a9dba | 1125 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
bc0c38d1 | 1126 | |
e30f53aa | 1127 | static int wait_on_pipe(struct trace_iterator *iter, bool full) |
0d5c6e1c | 1128 | { |
15693458 SRRH |
1129 | /* Iterators are static, they should be filled or empty */ |
1130 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
8b8b3683 | 1131 | return 0; |
0d5c6e1c | 1132 | |
e30f53aa RV |
1133 | return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file, |
1134 | full); | |
0d5c6e1c SR |
1135 | } |
1136 | ||
f4e781c0 SRRH |
1137 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
1138 | static int run_tracer_selftest(struct tracer *type) | |
1139 | { | |
1140 | struct trace_array *tr = &global_trace; | |
1141 | struct tracer *saved_tracer = tr->current_trace; | |
1142 | int ret; | |
0d5c6e1c | 1143 | |
f4e781c0 SRRH |
1144 | if (!type->selftest || tracing_selftest_disabled) |
1145 | return 0; | |
0d5c6e1c SR |
1146 | |
1147 | /* | |
f4e781c0 SRRH |
1148 | * Run a selftest on this tracer. |
1149 | * Here we reset the trace buffer, and set the current | |
1150 | * tracer to be this tracer. The tracer can then run some | |
1151 | * internal tracing to verify that everything is in order. | |
1152 | * If we fail, we do not register this tracer. | |
0d5c6e1c | 1153 | */ |
f4e781c0 | 1154 | tracing_reset_online_cpus(&tr->trace_buffer); |
0d5c6e1c | 1155 | |
f4e781c0 SRRH |
1156 | tr->current_trace = type; |
1157 | ||
1158 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1159 | if (type->use_max_tr) { | |
1160 | /* If we expanded the buffers, make sure the max is expanded too */ | |
1161 | if (ring_buffer_expanded) | |
1162 | ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, | |
1163 | RING_BUFFER_ALL_CPUS); | |
1164 | tr->allocated_snapshot = true; | |
1165 | } | |
1166 | #endif | |
1167 | ||
1168 | /* the test is responsible for initializing and enabling */ | |
1169 | pr_info("Testing tracer %s: ", type->name); | |
1170 | ret = type->selftest(type, tr); | |
1171 | /* the test is responsible for resetting too */ | |
1172 | tr->current_trace = saved_tracer; | |
1173 | if (ret) { | |
1174 | printk(KERN_CONT "FAILED!\n"); | |
1175 | /* Add the warning after printing 'FAILED' */ | |
1176 | WARN_ON(1); | |
1177 | return -1; | |
1178 | } | |
1179 | /* Only reset on passing, to avoid touching corrupted buffers */ | |
1180 | tracing_reset_online_cpus(&tr->trace_buffer); | |
1181 | ||
1182 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1183 | if (type->use_max_tr) { | |
1184 | tr->allocated_snapshot = false; | |
0d5c6e1c | 1185 | |
f4e781c0 SRRH |
1186 | /* Shrink the max buffer again */ |
1187 | if (ring_buffer_expanded) | |
1188 | ring_buffer_resize(tr->max_buffer.buffer, 1, | |
1189 | RING_BUFFER_ALL_CPUS); | |
1190 | } | |
1191 | #endif | |
1192 | ||
1193 | printk(KERN_CONT "PASSED\n"); | |
1194 | return 0; | |
1195 | } | |
1196 | #else | |
1197 | static inline int run_tracer_selftest(struct tracer *type) | |
1198 | { | |
1199 | return 0; | |
0d5c6e1c | 1200 | } |
f4e781c0 | 1201 | #endif /* CONFIG_FTRACE_STARTUP_TEST */ |
0d5c6e1c | 1202 | |
41d9c0be SRRH |
1203 | static void add_tracer_options(struct trace_array *tr, struct tracer *t); |
1204 | ||
a4d1e688 JW |
1205 | static void __init apply_trace_boot_options(void); |
1206 | ||
4fcdae83 SR |
1207 | /** |
1208 | * register_tracer - register a tracer with the ftrace system. | |
1209 | * @type - the plugin for the tracer | |
1210 | * | |
1211 | * Register a new plugin tracer. | |
1212 | */ | |
a4d1e688 | 1213 | int __init register_tracer(struct tracer *type) |
bc0c38d1 SR |
1214 | { |
1215 | struct tracer *t; | |
bc0c38d1 SR |
1216 | int ret = 0; |
1217 | ||
1218 | if (!type->name) { | |
1219 | pr_info("Tracer must have a name\n"); | |
1220 | return -1; | |
1221 | } | |
1222 | ||
24a461d5 | 1223 | if (strlen(type->name) >= MAX_TRACER_SIZE) { |
ee6c2c1b LZ |
1224 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); |
1225 | return -1; | |
1226 | } | |
1227 | ||
bc0c38d1 | 1228 | mutex_lock(&trace_types_lock); |
86fa2f60 | 1229 | |
8e1b82e0 FW |
1230 | tracing_selftest_running = true; |
1231 | ||
bc0c38d1 SR |
1232 | for (t = trace_types; t; t = t->next) { |
1233 | if (strcmp(type->name, t->name) == 0) { | |
1234 | /* already found */ | |
ee6c2c1b | 1235 | pr_info("Tracer %s already registered\n", |
bc0c38d1 SR |
1236 | type->name); |
1237 | ret = -1; | |
1238 | goto out; | |
1239 | } | |
1240 | } | |
1241 | ||
adf9f195 FW |
1242 | if (!type->set_flag) |
1243 | type->set_flag = &dummy_set_flag; | |
d39cdd20 CH |
1244 | if (!type->flags) { |
1245 | /*allocate a dummy tracer_flags*/ | |
1246 | type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL); | |
c8ca003b CH |
1247 | if (!type->flags) { |
1248 | ret = -ENOMEM; | |
1249 | goto out; | |
1250 | } | |
d39cdd20 CH |
1251 | type->flags->val = 0; |
1252 | type->flags->opts = dummy_tracer_opt; | |
1253 | } else | |
adf9f195 FW |
1254 | if (!type->flags->opts) |
1255 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 | 1256 | |
d39cdd20 CH |
1257 | /* store the tracer for __set_tracer_option */ |
1258 | type->flags->trace = type; | |
1259 | ||
f4e781c0 SRRH |
1260 | ret = run_tracer_selftest(type); |
1261 | if (ret < 0) | |
1262 | goto out; | |
60a11774 | 1263 | |
bc0c38d1 SR |
1264 | type->next = trace_types; |
1265 | trace_types = type; | |
41d9c0be | 1266 | add_tracer_options(&global_trace, type); |
60a11774 | 1267 | |
bc0c38d1 | 1268 | out: |
8e1b82e0 | 1269 | tracing_selftest_running = false; |
bc0c38d1 SR |
1270 | mutex_unlock(&trace_types_lock); |
1271 | ||
dac74940 SR |
1272 | if (ret || !default_bootup_tracer) |
1273 | goto out_unlock; | |
1274 | ||
ee6c2c1b | 1275 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
dac74940 SR |
1276 | goto out_unlock; |
1277 | ||
1278 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
1279 | /* Do we want this tracer to start on bootup? */ | |
607e2ea1 | 1280 | tracing_set_tracer(&global_trace, type->name); |
dac74940 | 1281 | default_bootup_tracer = NULL; |
a4d1e688 JW |
1282 | |
1283 | apply_trace_boot_options(); | |
1284 | ||
dac74940 | 1285 | /* disable other selftests, since this will break it. */ |
55034cd6 | 1286 | tracing_selftest_disabled = true; |
b2821ae6 | 1287 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
1288 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
1289 | type->name); | |
b2821ae6 | 1290 | #endif |
b2821ae6 | 1291 | |
dac74940 | 1292 | out_unlock: |
bc0c38d1 SR |
1293 | return ret; |
1294 | } | |
1295 | ||
12883efb | 1296 | void tracing_reset(struct trace_buffer *buf, int cpu) |
f633903a | 1297 | { |
12883efb | 1298 | struct ring_buffer *buffer = buf->buffer; |
f633903a | 1299 | |
a5416411 HT |
1300 | if (!buffer) |
1301 | return; | |
1302 | ||
f633903a SR |
1303 | ring_buffer_record_disable(buffer); |
1304 | ||
1305 | /* Make sure all commits have finished */ | |
1306 | synchronize_sched(); | |
68179686 | 1307 | ring_buffer_reset_cpu(buffer, cpu); |
f633903a SR |
1308 | |
1309 | ring_buffer_record_enable(buffer); | |
1310 | } | |
1311 | ||
12883efb | 1312 | void tracing_reset_online_cpus(struct trace_buffer *buf) |
213cc060 | 1313 | { |
12883efb | 1314 | struct ring_buffer *buffer = buf->buffer; |
213cc060 PE |
1315 | int cpu; |
1316 | ||
a5416411 HT |
1317 | if (!buffer) |
1318 | return; | |
1319 | ||
621968cd SR |
1320 | ring_buffer_record_disable(buffer); |
1321 | ||
1322 | /* Make sure all commits have finished */ | |
1323 | synchronize_sched(); | |
1324 | ||
9457158b | 1325 | buf->time_start = buffer_ftrace_now(buf, buf->cpu); |
213cc060 PE |
1326 | |
1327 | for_each_online_cpu(cpu) | |
68179686 | 1328 | ring_buffer_reset_cpu(buffer, cpu); |
621968cd SR |
1329 | |
1330 | ring_buffer_record_enable(buffer); | |
213cc060 PE |
1331 | } |
1332 | ||
09d8091c | 1333 | /* Must have trace_types_lock held */ |
873c642f | 1334 | void tracing_reset_all_online_cpus(void) |
9456f0fa | 1335 | { |
873c642f SRRH |
1336 | struct trace_array *tr; |
1337 | ||
873c642f | 1338 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
12883efb SRRH |
1339 | tracing_reset_online_cpus(&tr->trace_buffer); |
1340 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1341 | tracing_reset_online_cpus(&tr->max_buffer); | |
1342 | #endif | |
873c642f | 1343 | } |
9456f0fa SR |
1344 | } |
1345 | ||
939c7a4f | 1346 | #define SAVED_CMDLINES_DEFAULT 128 |
2c7eea4c | 1347 | #define NO_CMDLINE_MAP UINT_MAX |
edc35bd7 | 1348 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
939c7a4f YY |
1349 | struct saved_cmdlines_buffer { |
1350 | unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
1351 | unsigned *map_cmdline_to_pid; | |
1352 | unsigned cmdline_num; | |
1353 | int cmdline_idx; | |
1354 | char *saved_cmdlines; | |
1355 | }; | |
1356 | static struct saved_cmdlines_buffer *savedcmd; | |
25b0b44a | 1357 | |
25b0b44a | 1358 | /* temporary disable recording */ |
4fd27358 | 1359 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 | 1360 | |
939c7a4f YY |
1361 | static inline char *get_saved_cmdlines(int idx) |
1362 | { | |
1363 | return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN]; | |
1364 | } | |
1365 | ||
1366 | static inline void set_cmdline(int idx, const char *cmdline) | |
bc0c38d1 | 1367 | { |
939c7a4f YY |
1368 | memcpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); |
1369 | } | |
1370 | ||
1371 | static int allocate_cmdlines_buffer(unsigned int val, | |
1372 | struct saved_cmdlines_buffer *s) | |
1373 | { | |
1374 | s->map_cmdline_to_pid = kmalloc(val * sizeof(*s->map_cmdline_to_pid), | |
1375 | GFP_KERNEL); | |
1376 | if (!s->map_cmdline_to_pid) | |
1377 | return -ENOMEM; | |
1378 | ||
1379 | s->saved_cmdlines = kmalloc(val * TASK_COMM_LEN, GFP_KERNEL); | |
1380 | if (!s->saved_cmdlines) { | |
1381 | kfree(s->map_cmdline_to_pid); | |
1382 | return -ENOMEM; | |
1383 | } | |
1384 | ||
1385 | s->cmdline_idx = 0; | |
1386 | s->cmdline_num = val; | |
1387 | memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP, | |
1388 | sizeof(s->map_pid_to_cmdline)); | |
1389 | memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP, | |
1390 | val * sizeof(*s->map_cmdline_to_pid)); | |
1391 | ||
1392 | return 0; | |
1393 | } | |
1394 | ||
1395 | static int trace_create_savedcmd(void) | |
1396 | { | |
1397 | int ret; | |
1398 | ||
a6af8fbf | 1399 | savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL); |
939c7a4f YY |
1400 | if (!savedcmd) |
1401 | return -ENOMEM; | |
1402 | ||
1403 | ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd); | |
1404 | if (ret < 0) { | |
1405 | kfree(savedcmd); | |
1406 | savedcmd = NULL; | |
1407 | return -ENOMEM; | |
1408 | } | |
1409 | ||
1410 | return 0; | |
bc0c38d1 SR |
1411 | } |
1412 | ||
b5130b1e CE |
1413 | int is_tracing_stopped(void) |
1414 | { | |
2b6080f2 | 1415 | return global_trace.stop_count; |
b5130b1e CE |
1416 | } |
1417 | ||
0f048701 SR |
1418 | /** |
1419 | * tracing_start - quick start of the tracer | |
1420 | * | |
1421 | * If tracing is enabled but was stopped by tracing_stop, | |
1422 | * this will start the tracer back up. | |
1423 | */ | |
1424 | void tracing_start(void) | |
1425 | { | |
1426 | struct ring_buffer *buffer; | |
1427 | unsigned long flags; | |
1428 | ||
1429 | if (tracing_disabled) | |
1430 | return; | |
1431 | ||
2b6080f2 SR |
1432 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
1433 | if (--global_trace.stop_count) { | |
1434 | if (global_trace.stop_count < 0) { | |
b06a8301 SR |
1435 | /* Someone screwed up their debugging */ |
1436 | WARN_ON_ONCE(1); | |
2b6080f2 | 1437 | global_trace.stop_count = 0; |
b06a8301 | 1438 | } |
0f048701 SR |
1439 | goto out; |
1440 | } | |
1441 | ||
a2f80714 | 1442 | /* Prevent the buffers from switching */ |
0b9b12c1 | 1443 | arch_spin_lock(&global_trace.max_lock); |
0f048701 | 1444 | |
12883efb | 1445 | buffer = global_trace.trace_buffer.buffer; |
0f048701 SR |
1446 | if (buffer) |
1447 | ring_buffer_record_enable(buffer); | |
1448 | ||
12883efb SRRH |
1449 | #ifdef CONFIG_TRACER_MAX_TRACE |
1450 | buffer = global_trace.max_buffer.buffer; | |
0f048701 SR |
1451 | if (buffer) |
1452 | ring_buffer_record_enable(buffer); | |
12883efb | 1453 | #endif |
0f048701 | 1454 | |
0b9b12c1 | 1455 | arch_spin_unlock(&global_trace.max_lock); |
a2f80714 | 1456 | |
0f048701 | 1457 | out: |
2b6080f2 SR |
1458 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
1459 | } | |
1460 | ||
1461 | static void tracing_start_tr(struct trace_array *tr) | |
1462 | { | |
1463 | struct ring_buffer *buffer; | |
1464 | unsigned long flags; | |
1465 | ||
1466 | if (tracing_disabled) | |
1467 | return; | |
1468 | ||
1469 | /* If global, we need to also start the max tracer */ | |
1470 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1471 | return tracing_start(); | |
1472 | ||
1473 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1474 | ||
1475 | if (--tr->stop_count) { | |
1476 | if (tr->stop_count < 0) { | |
1477 | /* Someone screwed up their debugging */ | |
1478 | WARN_ON_ONCE(1); | |
1479 | tr->stop_count = 0; | |
1480 | } | |
1481 | goto out; | |
1482 | } | |
1483 | ||
12883efb | 1484 | buffer = tr->trace_buffer.buffer; |
2b6080f2 SR |
1485 | if (buffer) |
1486 | ring_buffer_record_enable(buffer); | |
1487 | ||
1488 | out: | |
1489 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
0f048701 SR |
1490 | } |
1491 | ||
1492 | /** | |
1493 | * tracing_stop - quick stop of the tracer | |
1494 | * | |
1495 | * Light weight way to stop tracing. Use in conjunction with | |
1496 | * tracing_start. | |
1497 | */ | |
1498 | void tracing_stop(void) | |
1499 | { | |
1500 | struct ring_buffer *buffer; | |
1501 | unsigned long flags; | |
1502 | ||
2b6080f2 SR |
1503 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
1504 | if (global_trace.stop_count++) | |
0f048701 SR |
1505 | goto out; |
1506 | ||
a2f80714 | 1507 | /* Prevent the buffers from switching */ |
0b9b12c1 | 1508 | arch_spin_lock(&global_trace.max_lock); |
a2f80714 | 1509 | |
12883efb | 1510 | buffer = global_trace.trace_buffer.buffer; |
0f048701 SR |
1511 | if (buffer) |
1512 | ring_buffer_record_disable(buffer); | |
1513 | ||
12883efb SRRH |
1514 | #ifdef CONFIG_TRACER_MAX_TRACE |
1515 | buffer = global_trace.max_buffer.buffer; | |
0f048701 SR |
1516 | if (buffer) |
1517 | ring_buffer_record_disable(buffer); | |
12883efb | 1518 | #endif |
0f048701 | 1519 | |
0b9b12c1 | 1520 | arch_spin_unlock(&global_trace.max_lock); |
a2f80714 | 1521 | |
0f048701 | 1522 | out: |
2b6080f2 SR |
1523 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
1524 | } | |
1525 | ||
1526 | static void tracing_stop_tr(struct trace_array *tr) | |
1527 | { | |
1528 | struct ring_buffer *buffer; | |
1529 | unsigned long flags; | |
1530 | ||
1531 | /* If global, we need to also stop the max tracer */ | |
1532 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1533 | return tracing_stop(); | |
1534 | ||
1535 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1536 | if (tr->stop_count++) | |
1537 | goto out; | |
1538 | ||
12883efb | 1539 | buffer = tr->trace_buffer.buffer; |
2b6080f2 SR |
1540 | if (buffer) |
1541 | ring_buffer_record_disable(buffer); | |
1542 | ||
1543 | out: | |
1544 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
0f048701 SR |
1545 | } |
1546 | ||
e309b41d | 1547 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 1548 | |
379cfdac | 1549 | static int trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1550 | { |
a635cf04 | 1551 | unsigned pid, idx; |
bc0c38d1 SR |
1552 | |
1553 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
379cfdac | 1554 | return 0; |
bc0c38d1 SR |
1555 | |
1556 | /* | |
1557 | * It's not the end of the world if we don't get | |
1558 | * the lock, but we also don't want to spin | |
1559 | * nor do we want to disable interrupts, | |
1560 | * so if we miss here, then better luck next time. | |
1561 | */ | |
0199c4e6 | 1562 | if (!arch_spin_trylock(&trace_cmdline_lock)) |
379cfdac | 1563 | return 0; |
bc0c38d1 | 1564 | |
939c7a4f | 1565 | idx = savedcmd->map_pid_to_cmdline[tsk->pid]; |
2c7eea4c | 1566 | if (idx == NO_CMDLINE_MAP) { |
939c7a4f | 1567 | idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num; |
bc0c38d1 | 1568 | |
a635cf04 CE |
1569 | /* |
1570 | * Check whether the cmdline buffer at idx has a pid | |
1571 | * mapped. We are going to overwrite that entry so we | |
1572 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1573 | * would read the new comm for the old pid. | |
1574 | */ | |
939c7a4f | 1575 | pid = savedcmd->map_cmdline_to_pid[idx]; |
a635cf04 | 1576 | if (pid != NO_CMDLINE_MAP) |
939c7a4f | 1577 | savedcmd->map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; |
bc0c38d1 | 1578 | |
939c7a4f YY |
1579 | savedcmd->map_cmdline_to_pid[idx] = tsk->pid; |
1580 | savedcmd->map_pid_to_cmdline[tsk->pid] = idx; | |
bc0c38d1 | 1581 | |
939c7a4f | 1582 | savedcmd->cmdline_idx = idx; |
bc0c38d1 SR |
1583 | } |
1584 | ||
939c7a4f | 1585 | set_cmdline(idx, tsk->comm); |
bc0c38d1 | 1586 | |
0199c4e6 | 1587 | arch_spin_unlock(&trace_cmdline_lock); |
379cfdac SRRH |
1588 | |
1589 | return 1; | |
bc0c38d1 SR |
1590 | } |
1591 | ||
4c27e756 | 1592 | static void __trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 1593 | { |
bc0c38d1 SR |
1594 | unsigned map; |
1595 | ||
4ca53085 SR |
1596 | if (!pid) { |
1597 | strcpy(comm, "<idle>"); | |
1598 | return; | |
1599 | } | |
bc0c38d1 | 1600 | |
74bf4076 SR |
1601 | if (WARN_ON_ONCE(pid < 0)) { |
1602 | strcpy(comm, "<XXX>"); | |
1603 | return; | |
1604 | } | |
1605 | ||
4ca53085 SR |
1606 | if (pid > PID_MAX_DEFAULT) { |
1607 | strcpy(comm, "<...>"); | |
1608 | return; | |
1609 | } | |
bc0c38d1 | 1610 | |
939c7a4f | 1611 | map = savedcmd->map_pid_to_cmdline[pid]; |
50d88758 | 1612 | if (map != NO_CMDLINE_MAP) |
939c7a4f | 1613 | strcpy(comm, get_saved_cmdlines(map)); |
50d88758 TG |
1614 | else |
1615 | strcpy(comm, "<...>"); | |
4c27e756 SRRH |
1616 | } |
1617 | ||
1618 | void trace_find_cmdline(int pid, char comm[]) | |
1619 | { | |
1620 | preempt_disable(); | |
1621 | arch_spin_lock(&trace_cmdline_lock); | |
1622 | ||
1623 | __trace_find_cmdline(pid, comm); | |
bc0c38d1 | 1624 | |
0199c4e6 | 1625 | arch_spin_unlock(&trace_cmdline_lock); |
5b6045a9 | 1626 | preempt_enable(); |
bc0c38d1 SR |
1627 | } |
1628 | ||
e309b41d | 1629 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1630 | { |
0fb9656d | 1631 | if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) |
bc0c38d1 SR |
1632 | return; |
1633 | ||
7ffbd48d SR |
1634 | if (!__this_cpu_read(trace_cmdline_save)) |
1635 | return; | |
1636 | ||
379cfdac SRRH |
1637 | if (trace_save_cmdline(tsk)) |
1638 | __this_cpu_write(trace_cmdline_save, false); | |
bc0c38d1 SR |
1639 | } |
1640 | ||
45dcd8b8 | 1641 | void |
38697053 SR |
1642 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
1643 | int pc) | |
bc0c38d1 SR |
1644 | { |
1645 | struct task_struct *tsk = current; | |
bc0c38d1 | 1646 | |
777e208d SR |
1647 | entry->preempt_count = pc & 0xff; |
1648 | entry->pid = (tsk) ? tsk->pid : 0; | |
1649 | entry->flags = | |
9244489a | 1650 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 1651 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
1652 | #else |
1653 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1654 | #endif | |
7e6867bf | 1655 | ((pc & NMI_MASK ) ? TRACE_FLAG_NMI : 0) | |
bc0c38d1 SR |
1656 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
1657 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
e5137b50 PZ |
1658 | (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | |
1659 | (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); | |
bc0c38d1 | 1660 | } |
f413cdb8 | 1661 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); |
bc0c38d1 | 1662 | |
e77405ad SR |
1663 | struct ring_buffer_event * |
1664 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1665 | int type, | |
1666 | unsigned long len, | |
1667 | unsigned long flags, int pc) | |
51a763dd ACM |
1668 | { |
1669 | struct ring_buffer_event *event; | |
1670 | ||
e77405ad | 1671 | event = ring_buffer_lock_reserve(buffer, len); |
51a763dd ACM |
1672 | if (event != NULL) { |
1673 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1674 | ||
1675 | tracing_generic_entry_update(ent, flags, pc); | |
1676 | ent->type = type; | |
1677 | } | |
1678 | ||
1679 | return event; | |
1680 | } | |
51a763dd | 1681 | |
7ffbd48d SR |
1682 | void |
1683 | __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) | |
1684 | { | |
1685 | __this_cpu_write(trace_cmdline_save, true); | |
1686 | ring_buffer_unlock_commit(buffer, event); | |
1687 | } | |
1688 | ||
2c4a33ab SRRH |
1689 | static struct ring_buffer *temp_buffer; |
1690 | ||
ccb469a1 SR |
1691 | struct ring_buffer_event * |
1692 | trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, | |
7f1d2f82 | 1693 | struct trace_event_file *trace_file, |
ccb469a1 SR |
1694 | int type, unsigned long len, |
1695 | unsigned long flags, int pc) | |
1696 | { | |
2c4a33ab SRRH |
1697 | struct ring_buffer_event *entry; |
1698 | ||
7f1d2f82 | 1699 | *current_rb = trace_file->tr->trace_buffer.buffer; |
2c4a33ab | 1700 | entry = trace_buffer_lock_reserve(*current_rb, |
ccb469a1 | 1701 | type, len, flags, pc); |
2c4a33ab SRRH |
1702 | /* |
1703 | * If tracing is off, but we have triggers enabled | |
1704 | * we still need to look at the event data. Use the temp_buffer | |
1705 | * to store the trace event for the tigger to use. It's recusive | |
1706 | * safe and will not be recorded anywhere. | |
1707 | */ | |
5d6ad960 | 1708 | if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) { |
2c4a33ab SRRH |
1709 | *current_rb = temp_buffer; |
1710 | entry = trace_buffer_lock_reserve(*current_rb, | |
1711 | type, len, flags, pc); | |
1712 | } | |
1713 | return entry; | |
ccb469a1 SR |
1714 | } |
1715 | EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); | |
1716 | ||
b7f0c959 SRRH |
1717 | void trace_buffer_unlock_commit_regs(struct trace_array *tr, |
1718 | struct ring_buffer *buffer, | |
0d5c6e1c SR |
1719 | struct ring_buffer_event *event, |
1720 | unsigned long flags, int pc, | |
1721 | struct pt_regs *regs) | |
1fd8df2c | 1722 | { |
7ffbd48d | 1723 | __buffer_unlock_commit(buffer, event); |
1fd8df2c | 1724 | |
7717c6be | 1725 | ftrace_trace_stack(tr, buffer, flags, 0, pc, regs); |
1fd8df2c MH |
1726 | ftrace_trace_userstack(buffer, flags, pc); |
1727 | } | |
1fd8df2c | 1728 | |
e309b41d | 1729 | void |
7be42151 | 1730 | trace_function(struct trace_array *tr, |
38697053 SR |
1731 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1732 | int pc) | |
bc0c38d1 | 1733 | { |
2425bcb9 | 1734 | struct trace_event_call *call = &event_function; |
12883efb | 1735 | struct ring_buffer *buffer = tr->trace_buffer.buffer; |
3928a8a2 | 1736 | struct ring_buffer_event *event; |
777e208d | 1737 | struct ftrace_entry *entry; |
bc0c38d1 | 1738 | |
e77405ad | 1739 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
51a763dd | 1740 | flags, pc); |
3928a8a2 SR |
1741 | if (!event) |
1742 | return; | |
1743 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1744 | entry->ip = ip; |
1745 | entry->parent_ip = parent_ip; | |
e1112b4d | 1746 | |
f306cc82 | 1747 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1748 | __buffer_unlock_commit(buffer, event); |
bc0c38d1 SR |
1749 | } |
1750 | ||
c0a0d0d3 | 1751 | #ifdef CONFIG_STACKTRACE |
4a9bd3f1 SR |
1752 | |
1753 | #define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) | |
1754 | struct ftrace_stack { | |
1755 | unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; | |
1756 | }; | |
1757 | ||
1758 | static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); | |
1759 | static DEFINE_PER_CPU(int, ftrace_stack_reserve); | |
1760 | ||
e77405ad | 1761 | static void __ftrace_trace_stack(struct ring_buffer *buffer, |
53614991 | 1762 | unsigned long flags, |
1fd8df2c | 1763 | int skip, int pc, struct pt_regs *regs) |
86387f7e | 1764 | { |
2425bcb9 | 1765 | struct trace_event_call *call = &event_kernel_stack; |
3928a8a2 | 1766 | struct ring_buffer_event *event; |
777e208d | 1767 | struct stack_entry *entry; |
86387f7e | 1768 | struct stack_trace trace; |
4a9bd3f1 SR |
1769 | int use_stack; |
1770 | int size = FTRACE_STACK_ENTRIES; | |
1771 | ||
1772 | trace.nr_entries = 0; | |
1773 | trace.skip = skip; | |
1774 | ||
1775 | /* | |
1776 | * Since events can happen in NMIs there's no safe way to | |
1777 | * use the per cpu ftrace_stacks. We reserve it and if an interrupt | |
1778 | * or NMI comes in, it will just have to use the default | |
1779 | * FTRACE_STACK_SIZE. | |
1780 | */ | |
1781 | preempt_disable_notrace(); | |
1782 | ||
82146529 | 1783 | use_stack = __this_cpu_inc_return(ftrace_stack_reserve); |
4a9bd3f1 SR |
1784 | /* |
1785 | * We don't need any atomic variables, just a barrier. | |
1786 | * If an interrupt comes in, we don't care, because it would | |
1787 | * have exited and put the counter back to what we want. | |
1788 | * We just need a barrier to keep gcc from moving things | |
1789 | * around. | |
1790 | */ | |
1791 | barrier(); | |
1792 | if (use_stack == 1) { | |
bdffd893 | 1793 | trace.entries = this_cpu_ptr(ftrace_stack.calls); |
4a9bd3f1 SR |
1794 | trace.max_entries = FTRACE_STACK_MAX_ENTRIES; |
1795 | ||
1796 | if (regs) | |
1797 | save_stack_trace_regs(regs, &trace); | |
1798 | else | |
1799 | save_stack_trace(&trace); | |
1800 | ||
1801 | if (trace.nr_entries > size) | |
1802 | size = trace.nr_entries; | |
1803 | } else | |
1804 | /* From now on, use_stack is a boolean */ | |
1805 | use_stack = 0; | |
1806 | ||
1807 | size *= sizeof(unsigned long); | |
86387f7e | 1808 | |
e77405ad | 1809 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, |
4a9bd3f1 | 1810 | sizeof(*entry) + size, flags, pc); |
3928a8a2 | 1811 | if (!event) |
4a9bd3f1 SR |
1812 | goto out; |
1813 | entry = ring_buffer_event_data(event); | |
86387f7e | 1814 | |
4a9bd3f1 SR |
1815 | memset(&entry->caller, 0, size); |
1816 | ||
1817 | if (use_stack) | |
1818 | memcpy(&entry->caller, trace.entries, | |
1819 | trace.nr_entries * sizeof(unsigned long)); | |
1820 | else { | |
1821 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1822 | trace.entries = entry->caller; | |
1823 | if (regs) | |
1824 | save_stack_trace_regs(regs, &trace); | |
1825 | else | |
1826 | save_stack_trace(&trace); | |
1827 | } | |
1828 | ||
1829 | entry->size = trace.nr_entries; | |
86387f7e | 1830 | |
f306cc82 | 1831 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1832 | __buffer_unlock_commit(buffer, event); |
4a9bd3f1 SR |
1833 | |
1834 | out: | |
1835 | /* Again, don't let gcc optimize things here */ | |
1836 | barrier(); | |
82146529 | 1837 | __this_cpu_dec(ftrace_stack_reserve); |
4a9bd3f1 SR |
1838 | preempt_enable_notrace(); |
1839 | ||
f0a920d5 IM |
1840 | } |
1841 | ||
2d34f489 SRRH |
1842 | static inline void ftrace_trace_stack(struct trace_array *tr, |
1843 | struct ring_buffer *buffer, | |
73dddbb5 SRRH |
1844 | unsigned long flags, |
1845 | int skip, int pc, struct pt_regs *regs) | |
53614991 | 1846 | { |
2d34f489 | 1847 | if (!(tr->trace_flags & TRACE_ITER_STACKTRACE)) |
53614991 SR |
1848 | return; |
1849 | ||
73dddbb5 | 1850 | __ftrace_trace_stack(buffer, flags, skip, pc, regs); |
53614991 SR |
1851 | } |
1852 | ||
c0a0d0d3 FW |
1853 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, |
1854 | int pc) | |
38697053 | 1855 | { |
12883efb | 1856 | __ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL); |
38697053 SR |
1857 | } |
1858 | ||
03889384 SR |
1859 | /** |
1860 | * trace_dump_stack - record a stack back trace in the trace buffer | |
c142be8e | 1861 | * @skip: Number of functions to skip (helper handlers) |
03889384 | 1862 | */ |
c142be8e | 1863 | void trace_dump_stack(int skip) |
03889384 SR |
1864 | { |
1865 | unsigned long flags; | |
1866 | ||
1867 | if (tracing_disabled || tracing_selftest_running) | |
e36c5458 | 1868 | return; |
03889384 SR |
1869 | |
1870 | local_save_flags(flags); | |
1871 | ||
c142be8e SRRH |
1872 | /* |
1873 | * Skip 3 more, seems to get us at the caller of | |
1874 | * this function. | |
1875 | */ | |
1876 | skip += 3; | |
1877 | __ftrace_trace_stack(global_trace.trace_buffer.buffer, | |
1878 | flags, skip, preempt_count(), NULL); | |
03889384 SR |
1879 | } |
1880 | ||
91e86e56 SR |
1881 | static DEFINE_PER_CPU(int, user_stack_count); |
1882 | ||
e77405ad SR |
1883 | void |
1884 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
02b67518 | 1885 | { |
2425bcb9 | 1886 | struct trace_event_call *call = &event_user_stack; |
8d7c6a96 | 1887 | struct ring_buffer_event *event; |
02b67518 TE |
1888 | struct userstack_entry *entry; |
1889 | struct stack_trace trace; | |
02b67518 | 1890 | |
983f938a | 1891 | if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE)) |
02b67518 TE |
1892 | return; |
1893 | ||
b6345879 SR |
1894 | /* |
1895 | * NMIs can not handle page faults, even with fix ups. | |
1896 | * The save user stack can (and often does) fault. | |
1897 | */ | |
1898 | if (unlikely(in_nmi())) | |
1899 | return; | |
02b67518 | 1900 | |
91e86e56 SR |
1901 | /* |
1902 | * prevent recursion, since the user stack tracing may | |
1903 | * trigger other kernel events. | |
1904 | */ | |
1905 | preempt_disable(); | |
1906 | if (__this_cpu_read(user_stack_count)) | |
1907 | goto out; | |
1908 | ||
1909 | __this_cpu_inc(user_stack_count); | |
1910 | ||
e77405ad | 1911 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
51a763dd | 1912 | sizeof(*entry), flags, pc); |
02b67518 | 1913 | if (!event) |
1dbd1951 | 1914 | goto out_drop_count; |
02b67518 | 1915 | entry = ring_buffer_event_data(event); |
02b67518 | 1916 | |
48659d31 | 1917 | entry->tgid = current->tgid; |
02b67518 TE |
1918 | memset(&entry->caller, 0, sizeof(entry->caller)); |
1919 | ||
1920 | trace.nr_entries = 0; | |
1921 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1922 | trace.skip = 0; | |
1923 | trace.entries = entry->caller; | |
1924 | ||
1925 | save_stack_trace_user(&trace); | |
f306cc82 | 1926 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1927 | __buffer_unlock_commit(buffer, event); |
91e86e56 | 1928 | |
1dbd1951 | 1929 | out_drop_count: |
91e86e56 | 1930 | __this_cpu_dec(user_stack_count); |
91e86e56 SR |
1931 | out: |
1932 | preempt_enable(); | |
02b67518 TE |
1933 | } |
1934 | ||
4fd27358 HE |
1935 | #ifdef UNUSED |
1936 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1937 | { |
7be42151 | 1938 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1939 | } |
4fd27358 | 1940 | #endif /* UNUSED */ |
02b67518 | 1941 | |
c0a0d0d3 FW |
1942 | #endif /* CONFIG_STACKTRACE */ |
1943 | ||
07d777fe SR |
1944 | /* created for use with alloc_percpu */ |
1945 | struct trace_buffer_struct { | |
1946 | char buffer[TRACE_BUF_SIZE]; | |
1947 | }; | |
1948 | ||
1949 | static struct trace_buffer_struct *trace_percpu_buffer; | |
1950 | static struct trace_buffer_struct *trace_percpu_sirq_buffer; | |
1951 | static struct trace_buffer_struct *trace_percpu_irq_buffer; | |
1952 | static struct trace_buffer_struct *trace_percpu_nmi_buffer; | |
1953 | ||
1954 | /* | |
1955 | * The buffer used is dependent on the context. There is a per cpu | |
1956 | * buffer for normal context, softirq contex, hard irq context and | |
1957 | * for NMI context. Thise allows for lockless recording. | |
1958 | * | |
1959 | * Note, if the buffers failed to be allocated, then this returns NULL | |
1960 | */ | |
1961 | static char *get_trace_buf(void) | |
1962 | { | |
1963 | struct trace_buffer_struct *percpu_buffer; | |
07d777fe SR |
1964 | |
1965 | /* | |
1966 | * If we have allocated per cpu buffers, then we do not | |
1967 | * need to do any locking. | |
1968 | */ | |
1969 | if (in_nmi()) | |
1970 | percpu_buffer = trace_percpu_nmi_buffer; | |
1971 | else if (in_irq()) | |
1972 | percpu_buffer = trace_percpu_irq_buffer; | |
1973 | else if (in_softirq()) | |
1974 | percpu_buffer = trace_percpu_sirq_buffer; | |
1975 | else | |
1976 | percpu_buffer = trace_percpu_buffer; | |
1977 | ||
1978 | if (!percpu_buffer) | |
1979 | return NULL; | |
1980 | ||
d8a0349c | 1981 | return this_cpu_ptr(&percpu_buffer->buffer[0]); |
07d777fe SR |
1982 | } |
1983 | ||
1984 | static int alloc_percpu_trace_buffer(void) | |
1985 | { | |
1986 | struct trace_buffer_struct *buffers; | |
1987 | struct trace_buffer_struct *sirq_buffers; | |
1988 | struct trace_buffer_struct *irq_buffers; | |
1989 | struct trace_buffer_struct *nmi_buffers; | |
1990 | ||
1991 | buffers = alloc_percpu(struct trace_buffer_struct); | |
1992 | if (!buffers) | |
1993 | goto err_warn; | |
1994 | ||
1995 | sirq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1996 | if (!sirq_buffers) | |
1997 | goto err_sirq; | |
1998 | ||
1999 | irq_buffers = alloc_percpu(struct trace_buffer_struct); | |
2000 | if (!irq_buffers) | |
2001 | goto err_irq; | |
2002 | ||
2003 | nmi_buffers = alloc_percpu(struct trace_buffer_struct); | |
2004 | if (!nmi_buffers) | |
2005 | goto err_nmi; | |
2006 | ||
2007 | trace_percpu_buffer = buffers; | |
2008 | trace_percpu_sirq_buffer = sirq_buffers; | |
2009 | trace_percpu_irq_buffer = irq_buffers; | |
2010 | trace_percpu_nmi_buffer = nmi_buffers; | |
2011 | ||
2012 | return 0; | |
2013 | ||
2014 | err_nmi: | |
2015 | free_percpu(irq_buffers); | |
2016 | err_irq: | |
2017 | free_percpu(sirq_buffers); | |
2018 | err_sirq: | |
2019 | free_percpu(buffers); | |
2020 | err_warn: | |
2021 | WARN(1, "Could not allocate percpu trace_printk buffer"); | |
2022 | return -ENOMEM; | |
2023 | } | |
2024 | ||
81698831 SR |
2025 | static int buffers_allocated; |
2026 | ||
07d777fe SR |
2027 | void trace_printk_init_buffers(void) |
2028 | { | |
07d777fe SR |
2029 | if (buffers_allocated) |
2030 | return; | |
2031 | ||
2032 | if (alloc_percpu_trace_buffer()) | |
2033 | return; | |
2034 | ||
2184db46 SR |
2035 | /* trace_printk() is for debug use only. Don't use it in production. */ |
2036 | ||
a395d6a7 JP |
2037 | pr_warn("\n"); |
2038 | pr_warn("**********************************************************\n"); | |
2039 | pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); | |
2040 | pr_warn("** **\n"); | |
2041 | pr_warn("** trace_printk() being used. Allocating extra memory. **\n"); | |
2042 | pr_warn("** **\n"); | |
2043 | pr_warn("** This means that this is a DEBUG kernel and it is **\n"); | |
2044 | pr_warn("** unsafe for production use. **\n"); | |
2045 | pr_warn("** **\n"); | |
2046 | pr_warn("** If you see this message and you are not debugging **\n"); | |
2047 | pr_warn("** the kernel, report this immediately to your vendor! **\n"); | |
2048 | pr_warn("** **\n"); | |
2049 | pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); | |
2050 | pr_warn("**********************************************************\n"); | |
07d777fe | 2051 | |
b382ede6 SR |
2052 | /* Expand the buffers to set size */ |
2053 | tracing_update_buffers(); | |
2054 | ||
07d777fe | 2055 | buffers_allocated = 1; |
81698831 SR |
2056 | |
2057 | /* | |
2058 | * trace_printk_init_buffers() can be called by modules. | |
2059 | * If that happens, then we need to start cmdline recording | |
2060 | * directly here. If the global_trace.buffer is already | |
2061 | * allocated here, then this was called by module code. | |
2062 | */ | |
12883efb | 2063 | if (global_trace.trace_buffer.buffer) |
81698831 SR |
2064 | tracing_start_cmdline_record(); |
2065 | } | |
2066 | ||
2067 | void trace_printk_start_comm(void) | |
2068 | { | |
2069 | /* Start tracing comms if trace printk is set */ | |
2070 | if (!buffers_allocated) | |
2071 | return; | |
2072 | tracing_start_cmdline_record(); | |
2073 | } | |
2074 | ||
2075 | static void trace_printk_start_stop_comm(int enabled) | |
2076 | { | |
2077 | if (!buffers_allocated) | |
2078 | return; | |
2079 | ||
2080 | if (enabled) | |
2081 | tracing_start_cmdline_record(); | |
2082 | else | |
2083 | tracing_stop_cmdline_record(); | |
07d777fe SR |
2084 | } |
2085 | ||
769b0441 | 2086 | /** |
48ead020 | 2087 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
2088 | * |
2089 | */ | |
40ce74f1 | 2090 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 2091 | { |
2425bcb9 | 2092 | struct trace_event_call *call = &event_bprint; |
769b0441 | 2093 | struct ring_buffer_event *event; |
e77405ad | 2094 | struct ring_buffer *buffer; |
769b0441 | 2095 | struct trace_array *tr = &global_trace; |
48ead020 | 2096 | struct bprint_entry *entry; |
769b0441 | 2097 | unsigned long flags; |
07d777fe SR |
2098 | char *tbuffer; |
2099 | int len = 0, size, pc; | |
769b0441 FW |
2100 | |
2101 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
2102 | return 0; | |
2103 | ||
2104 | /* Don't pollute graph traces with trace_vprintk internals */ | |
2105 | pause_graph_tracing(); | |
2106 | ||
2107 | pc = preempt_count(); | |
5168ae50 | 2108 | preempt_disable_notrace(); |
769b0441 | 2109 | |
07d777fe SR |
2110 | tbuffer = get_trace_buf(); |
2111 | if (!tbuffer) { | |
2112 | len = 0; | |
769b0441 | 2113 | goto out; |
07d777fe | 2114 | } |
769b0441 | 2115 | |
07d777fe | 2116 | len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); |
769b0441 | 2117 | |
07d777fe SR |
2118 | if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) |
2119 | goto out; | |
769b0441 | 2120 | |
07d777fe | 2121 | local_save_flags(flags); |
769b0441 | 2122 | size = sizeof(*entry) + sizeof(u32) * len; |
12883efb | 2123 | buffer = tr->trace_buffer.buffer; |
e77405ad SR |
2124 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, |
2125 | flags, pc); | |
769b0441 | 2126 | if (!event) |
07d777fe | 2127 | goto out; |
769b0441 FW |
2128 | entry = ring_buffer_event_data(event); |
2129 | entry->ip = ip; | |
769b0441 FW |
2130 | entry->fmt = fmt; |
2131 | ||
07d777fe | 2132 | memcpy(entry->buf, tbuffer, sizeof(u32) * len); |
f306cc82 | 2133 | if (!call_filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 2134 | __buffer_unlock_commit(buffer, event); |
2d34f489 | 2135 | ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL); |
d931369b | 2136 | } |
769b0441 | 2137 | |
769b0441 | 2138 | out: |
5168ae50 | 2139 | preempt_enable_notrace(); |
769b0441 FW |
2140 | unpause_graph_tracing(); |
2141 | ||
2142 | return len; | |
2143 | } | |
48ead020 FW |
2144 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
2145 | ||
12883efb SRRH |
2146 | static int |
2147 | __trace_array_vprintk(struct ring_buffer *buffer, | |
2148 | unsigned long ip, const char *fmt, va_list args) | |
48ead020 | 2149 | { |
2425bcb9 | 2150 | struct trace_event_call *call = &event_print; |
48ead020 | 2151 | struct ring_buffer_event *event; |
07d777fe | 2152 | int len = 0, size, pc; |
48ead020 | 2153 | struct print_entry *entry; |
07d777fe SR |
2154 | unsigned long flags; |
2155 | char *tbuffer; | |
48ead020 FW |
2156 | |
2157 | if (tracing_disabled || tracing_selftest_running) | |
2158 | return 0; | |
2159 | ||
07d777fe SR |
2160 | /* Don't pollute graph traces with trace_vprintk internals */ |
2161 | pause_graph_tracing(); | |
2162 | ||
48ead020 FW |
2163 | pc = preempt_count(); |
2164 | preempt_disable_notrace(); | |
48ead020 | 2165 | |
07d777fe SR |
2166 | |
2167 | tbuffer = get_trace_buf(); | |
2168 | if (!tbuffer) { | |
2169 | len = 0; | |
48ead020 | 2170 | goto out; |
07d777fe | 2171 | } |
48ead020 | 2172 | |
3558a5ac | 2173 | len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); |
48ead020 | 2174 | |
07d777fe | 2175 | local_save_flags(flags); |
48ead020 | 2176 | size = sizeof(*entry) + len + 1; |
e77405ad | 2177 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
07d777fe | 2178 | flags, pc); |
48ead020 | 2179 | if (!event) |
07d777fe | 2180 | goto out; |
48ead020 | 2181 | entry = ring_buffer_event_data(event); |
c13d2f7c | 2182 | entry->ip = ip; |
48ead020 | 2183 | |
3558a5ac | 2184 | memcpy(&entry->buf, tbuffer, len + 1); |
f306cc82 | 2185 | if (!call_filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 2186 | __buffer_unlock_commit(buffer, event); |
2d34f489 | 2187 | ftrace_trace_stack(&global_trace, buffer, flags, 6, pc, NULL); |
d931369b | 2188 | } |
48ead020 FW |
2189 | out: |
2190 | preempt_enable_notrace(); | |
07d777fe | 2191 | unpause_graph_tracing(); |
48ead020 FW |
2192 | |
2193 | return len; | |
2194 | } | |
659372d3 | 2195 | |
12883efb SRRH |
2196 | int trace_array_vprintk(struct trace_array *tr, |
2197 | unsigned long ip, const char *fmt, va_list args) | |
2198 | { | |
2199 | return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args); | |
2200 | } | |
2201 | ||
2202 | int trace_array_printk(struct trace_array *tr, | |
2203 | unsigned long ip, const char *fmt, ...) | |
2204 | { | |
2205 | int ret; | |
2206 | va_list ap; | |
2207 | ||
983f938a | 2208 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
12883efb SRRH |
2209 | return 0; |
2210 | ||
2211 | va_start(ap, fmt); | |
2212 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
2213 | va_end(ap); | |
2214 | return ret; | |
2215 | } | |
2216 | ||
2217 | int trace_array_printk_buf(struct ring_buffer *buffer, | |
2218 | unsigned long ip, const char *fmt, ...) | |
2219 | { | |
2220 | int ret; | |
2221 | va_list ap; | |
2222 | ||
983f938a | 2223 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
12883efb SRRH |
2224 | return 0; |
2225 | ||
2226 | va_start(ap, fmt); | |
2227 | ret = __trace_array_vprintk(buffer, ip, fmt, ap); | |
2228 | va_end(ap); | |
2229 | return ret; | |
2230 | } | |
2231 | ||
659372d3 SR |
2232 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) |
2233 | { | |
a813a159 | 2234 | return trace_array_vprintk(&global_trace, ip, fmt, args); |
659372d3 | 2235 | } |
769b0441 FW |
2236 | EXPORT_SYMBOL_GPL(trace_vprintk); |
2237 | ||
e2ac8ef5 | 2238 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 2239 | { |
6d158a81 SR |
2240 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); |
2241 | ||
5a90f577 | 2242 | iter->idx++; |
6d158a81 SR |
2243 | if (buf_iter) |
2244 | ring_buffer_read(buf_iter, NULL); | |
5a90f577 SR |
2245 | } |
2246 | ||
e309b41d | 2247 | static struct trace_entry * |
bc21b478 SR |
2248 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, |
2249 | unsigned long *lost_events) | |
dd0e545f | 2250 | { |
3928a8a2 | 2251 | struct ring_buffer_event *event; |
6d158a81 | 2252 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); |
dd0e545f | 2253 | |
d769041f SR |
2254 | if (buf_iter) |
2255 | event = ring_buffer_iter_peek(buf_iter, ts); | |
2256 | else | |
12883efb | 2257 | event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts, |
bc21b478 | 2258 | lost_events); |
d769041f | 2259 | |
4a9bd3f1 SR |
2260 | if (event) { |
2261 | iter->ent_size = ring_buffer_event_length(event); | |
2262 | return ring_buffer_event_data(event); | |
2263 | } | |
2264 | iter->ent_size = 0; | |
2265 | return NULL; | |
dd0e545f | 2266 | } |
d769041f | 2267 | |
dd0e545f | 2268 | static struct trace_entry * |
bc21b478 SR |
2269 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, |
2270 | unsigned long *missing_events, u64 *ent_ts) | |
bc0c38d1 | 2271 | { |
12883efb | 2272 | struct ring_buffer *buffer = iter->trace_buffer->buffer; |
bc0c38d1 | 2273 | struct trace_entry *ent, *next = NULL; |
aa27497c | 2274 | unsigned long lost_events = 0, next_lost = 0; |
b04cc6b1 | 2275 | int cpu_file = iter->cpu_file; |
3928a8a2 | 2276 | u64 next_ts = 0, ts; |
bc0c38d1 | 2277 | int next_cpu = -1; |
12b5da34 | 2278 | int next_size = 0; |
bc0c38d1 SR |
2279 | int cpu; |
2280 | ||
b04cc6b1 FW |
2281 | /* |
2282 | * If we are in a per_cpu trace file, don't bother by iterating over | |
2283 | * all cpu and peek directly. | |
2284 | */ | |
ae3b5093 | 2285 | if (cpu_file > RING_BUFFER_ALL_CPUS) { |
b04cc6b1 FW |
2286 | if (ring_buffer_empty_cpu(buffer, cpu_file)) |
2287 | return NULL; | |
bc21b478 | 2288 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); |
b04cc6b1 FW |
2289 | if (ent_cpu) |
2290 | *ent_cpu = cpu_file; | |
2291 | ||
2292 | return ent; | |
2293 | } | |
2294 | ||
ab46428c | 2295 | for_each_tracing_cpu(cpu) { |
dd0e545f | 2296 | |
3928a8a2 SR |
2297 | if (ring_buffer_empty_cpu(buffer, cpu)) |
2298 | continue; | |
dd0e545f | 2299 | |
bc21b478 | 2300 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); |
dd0e545f | 2301 | |
cdd31cd2 IM |
2302 | /* |
2303 | * Pick the entry with the smallest timestamp: | |
2304 | */ | |
3928a8a2 | 2305 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
2306 | next = ent; |
2307 | next_cpu = cpu; | |
3928a8a2 | 2308 | next_ts = ts; |
bc21b478 | 2309 | next_lost = lost_events; |
12b5da34 | 2310 | next_size = iter->ent_size; |
bc0c38d1 SR |
2311 | } |
2312 | } | |
2313 | ||
12b5da34 SR |
2314 | iter->ent_size = next_size; |
2315 | ||
bc0c38d1 SR |
2316 | if (ent_cpu) |
2317 | *ent_cpu = next_cpu; | |
2318 | ||
3928a8a2 SR |
2319 | if (ent_ts) |
2320 | *ent_ts = next_ts; | |
2321 | ||
bc21b478 SR |
2322 | if (missing_events) |
2323 | *missing_events = next_lost; | |
2324 | ||
bc0c38d1 SR |
2325 | return next; |
2326 | } | |
2327 | ||
dd0e545f | 2328 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
2329 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
2330 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 2331 | { |
bc21b478 | 2332 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); |
dd0e545f SR |
2333 | } |
2334 | ||
2335 | /* Find the next real entry, and increment the iterator to the next entry */ | |
955b61e5 | 2336 | void *trace_find_next_entry_inc(struct trace_iterator *iter) |
dd0e545f | 2337 | { |
bc21b478 SR |
2338 | iter->ent = __find_next_entry(iter, &iter->cpu, |
2339 | &iter->lost_events, &iter->ts); | |
dd0e545f | 2340 | |
3928a8a2 | 2341 | if (iter->ent) |
e2ac8ef5 | 2342 | trace_iterator_increment(iter); |
dd0e545f | 2343 | |
3928a8a2 | 2344 | return iter->ent ? iter : NULL; |
b3806b43 | 2345 | } |
bc0c38d1 | 2346 | |
e309b41d | 2347 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 2348 | { |
12883efb | 2349 | ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts, |
bc21b478 | 2350 | &iter->lost_events); |
bc0c38d1 SR |
2351 | } |
2352 | ||
e309b41d | 2353 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
2354 | { |
2355 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 2356 | int i = (int)*pos; |
4e3c3333 | 2357 | void *ent; |
bc0c38d1 | 2358 | |
a63ce5b3 SR |
2359 | WARN_ON_ONCE(iter->leftover); |
2360 | ||
bc0c38d1 SR |
2361 | (*pos)++; |
2362 | ||
2363 | /* can't go backwards */ | |
2364 | if (iter->idx > i) | |
2365 | return NULL; | |
2366 | ||
2367 | if (iter->idx < 0) | |
955b61e5 | 2368 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
2369 | else |
2370 | ent = iter; | |
2371 | ||
2372 | while (ent && iter->idx < i) | |
955b61e5 | 2373 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
2374 | |
2375 | iter->pos = *pos; | |
2376 | ||
bc0c38d1 SR |
2377 | return ent; |
2378 | } | |
2379 | ||
955b61e5 | 2380 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
2f26ebd5 | 2381 | { |
2f26ebd5 SR |
2382 | struct ring_buffer_event *event; |
2383 | struct ring_buffer_iter *buf_iter; | |
2384 | unsigned long entries = 0; | |
2385 | u64 ts; | |
2386 | ||
12883efb | 2387 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0; |
2f26ebd5 | 2388 | |
6d158a81 SR |
2389 | buf_iter = trace_buffer_iter(iter, cpu); |
2390 | if (!buf_iter) | |
2f26ebd5 SR |
2391 | return; |
2392 | ||
2f26ebd5 SR |
2393 | ring_buffer_iter_reset(buf_iter); |
2394 | ||
2395 | /* | |
2396 | * We could have the case with the max latency tracers | |
2397 | * that a reset never took place on a cpu. This is evident | |
2398 | * by the timestamp being before the start of the buffer. | |
2399 | */ | |
2400 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
12883efb | 2401 | if (ts >= iter->trace_buffer->time_start) |
2f26ebd5 SR |
2402 | break; |
2403 | entries++; | |
2404 | ring_buffer_read(buf_iter, NULL); | |
2405 | } | |
2406 | ||
12883efb | 2407 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries; |
2f26ebd5 SR |
2408 | } |
2409 | ||
d7350c3f | 2410 | /* |
d7350c3f FW |
2411 | * The current tracer is copied to avoid a global locking |
2412 | * all around. | |
2413 | */ | |
bc0c38d1 SR |
2414 | static void *s_start(struct seq_file *m, loff_t *pos) |
2415 | { | |
2416 | struct trace_iterator *iter = m->private; | |
2b6080f2 | 2417 | struct trace_array *tr = iter->tr; |
b04cc6b1 | 2418 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
2419 | void *p = NULL; |
2420 | loff_t l = 0; | |
3928a8a2 | 2421 | int cpu; |
bc0c38d1 | 2422 | |
2fd196ec HT |
2423 | /* |
2424 | * copy the tracer to avoid using a global lock all around. | |
2425 | * iter->trace is a copy of current_trace, the pointer to the | |
2426 | * name may be used instead of a strcmp(), as iter->trace->name | |
2427 | * will point to the same string as current_trace->name. | |
2428 | */ | |
bc0c38d1 | 2429 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
2430 | if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) |
2431 | *iter->trace = *tr->current_trace; | |
d7350c3f | 2432 | mutex_unlock(&trace_types_lock); |
bc0c38d1 | 2433 | |
12883efb | 2434 | #ifdef CONFIG_TRACER_MAX_TRACE |
debdd57f HT |
2435 | if (iter->snapshot && iter->trace->use_max_tr) |
2436 | return ERR_PTR(-EBUSY); | |
12883efb | 2437 | #endif |
debdd57f HT |
2438 | |
2439 | if (!iter->snapshot) | |
2440 | atomic_inc(&trace_record_cmdline_disabled); | |
bc0c38d1 | 2441 | |
bc0c38d1 SR |
2442 | if (*pos != iter->pos) { |
2443 | iter->ent = NULL; | |
2444 | iter->cpu = 0; | |
2445 | iter->idx = -1; | |
2446 | ||
ae3b5093 | 2447 | if (cpu_file == RING_BUFFER_ALL_CPUS) { |
b04cc6b1 | 2448 | for_each_tracing_cpu(cpu) |
2f26ebd5 | 2449 | tracing_iter_reset(iter, cpu); |
b04cc6b1 | 2450 | } else |
2f26ebd5 | 2451 | tracing_iter_reset(iter, cpu_file); |
bc0c38d1 | 2452 | |
ac91d854 | 2453 | iter->leftover = 0; |
bc0c38d1 SR |
2454 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
2455 | ; | |
2456 | ||
2457 | } else { | |
a63ce5b3 SR |
2458 | /* |
2459 | * If we overflowed the seq_file before, then we want | |
2460 | * to just reuse the trace_seq buffer again. | |
2461 | */ | |
2462 | if (iter->leftover) | |
2463 | p = iter; | |
2464 | else { | |
2465 | l = *pos - 1; | |
2466 | p = s_next(m, p, &l); | |
2467 | } | |
bc0c38d1 SR |
2468 | } |
2469 | ||
4f535968 | 2470 | trace_event_read_lock(); |
7e53bd42 | 2471 | trace_access_lock(cpu_file); |
bc0c38d1 SR |
2472 | return p; |
2473 | } | |
2474 | ||
2475 | static void s_stop(struct seq_file *m, void *p) | |
2476 | { | |
7e53bd42 LJ |
2477 | struct trace_iterator *iter = m->private; |
2478 | ||
12883efb | 2479 | #ifdef CONFIG_TRACER_MAX_TRACE |
debdd57f HT |
2480 | if (iter->snapshot && iter->trace->use_max_tr) |
2481 | return; | |
12883efb | 2482 | #endif |
debdd57f HT |
2483 | |
2484 | if (!iter->snapshot) | |
2485 | atomic_dec(&trace_record_cmdline_disabled); | |
12883efb | 2486 | |
7e53bd42 | 2487 | trace_access_unlock(iter->cpu_file); |
4f535968 | 2488 | trace_event_read_unlock(); |
bc0c38d1 SR |
2489 | } |
2490 | ||
39eaf7ef | 2491 | static void |
12883efb SRRH |
2492 | get_total_entries(struct trace_buffer *buf, |
2493 | unsigned long *total, unsigned long *entries) | |
39eaf7ef SR |
2494 | { |
2495 | unsigned long count; | |
2496 | int cpu; | |
2497 | ||
2498 | *total = 0; | |
2499 | *entries = 0; | |
2500 | ||
2501 | for_each_tracing_cpu(cpu) { | |
12883efb | 2502 | count = ring_buffer_entries_cpu(buf->buffer, cpu); |
39eaf7ef SR |
2503 | /* |
2504 | * If this buffer has skipped entries, then we hold all | |
2505 | * entries for the trace and we need to ignore the | |
2506 | * ones before the time stamp. | |
2507 | */ | |
12883efb SRRH |
2508 | if (per_cpu_ptr(buf->data, cpu)->skipped_entries) { |
2509 | count -= per_cpu_ptr(buf->data, cpu)->skipped_entries; | |
39eaf7ef SR |
2510 | /* total is the same as the entries */ |
2511 | *total += count; | |
2512 | } else | |
2513 | *total += count + | |
12883efb | 2514 | ring_buffer_overrun_cpu(buf->buffer, cpu); |
39eaf7ef SR |
2515 | *entries += count; |
2516 | } | |
2517 | } | |
2518 | ||
e309b41d | 2519 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 2520 | { |
d79ac28f RV |
2521 | seq_puts(m, "# _------=> CPU# \n" |
2522 | "# / _-----=> irqs-off \n" | |
2523 | "# | / _----=> need-resched \n" | |
2524 | "# || / _---=> hardirq/softirq \n" | |
2525 | "# ||| / _--=> preempt-depth \n" | |
2526 | "# |||| / delay \n" | |
2527 | "# cmd pid ||||| time | caller \n" | |
2528 | "# \\ / ||||| \\ | / \n"); | |
bc0c38d1 SR |
2529 | } |
2530 | ||
12883efb | 2531 | static void print_event_info(struct trace_buffer *buf, struct seq_file *m) |
bc0c38d1 | 2532 | { |
39eaf7ef SR |
2533 | unsigned long total; |
2534 | unsigned long entries; | |
2535 | ||
12883efb | 2536 | get_total_entries(buf, &total, &entries); |
39eaf7ef SR |
2537 | seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", |
2538 | entries, total, num_online_cpus()); | |
2539 | seq_puts(m, "#\n"); | |
2540 | } | |
2541 | ||
12883efb | 2542 | static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m) |
39eaf7ef | 2543 | { |
12883efb | 2544 | print_event_info(buf, m); |
d79ac28f RV |
2545 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n" |
2546 | "# | | | | |\n"); | |
bc0c38d1 SR |
2547 | } |
2548 | ||
12883efb | 2549 | static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m) |
77271ce4 | 2550 | { |
12883efb | 2551 | print_event_info(buf, m); |
d79ac28f RV |
2552 | seq_puts(m, "# _-----=> irqs-off\n" |
2553 | "# / _----=> need-resched\n" | |
2554 | "# | / _---=> hardirq/softirq\n" | |
2555 | "# || / _--=> preempt-depth\n" | |
2556 | "# ||| / delay\n" | |
2557 | "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n" | |
2558 | "# | | | |||| | |\n"); | |
77271ce4 | 2559 | } |
bc0c38d1 | 2560 | |
62b915f1 | 2561 | void |
bc0c38d1 SR |
2562 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
2563 | { | |
983f938a | 2564 | unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK); |
12883efb SRRH |
2565 | struct trace_buffer *buf = iter->trace_buffer; |
2566 | struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu); | |
2b6080f2 | 2567 | struct tracer *type = iter->trace; |
39eaf7ef SR |
2568 | unsigned long entries; |
2569 | unsigned long total; | |
bc0c38d1 SR |
2570 | const char *name = "preemption"; |
2571 | ||
d840f718 | 2572 | name = type->name; |
bc0c38d1 | 2573 | |
12883efb | 2574 | get_total_entries(buf, &total, &entries); |
bc0c38d1 | 2575 | |
888b55dc | 2576 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 2577 | name, UTS_RELEASE); |
888b55dc | 2578 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 2579 | "---------------------------------\n"); |
888b55dc | 2580 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 2581 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 2582 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 2583 | entries, |
4c11d7ae | 2584 | total, |
12883efb | 2585 | buf->cpu, |
bc0c38d1 SR |
2586 | #if defined(CONFIG_PREEMPT_NONE) |
2587 | "server", | |
2588 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
2589 | "desktop", | |
b5c21b45 | 2590 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
2591 | "preempt", |
2592 | #else | |
2593 | "unknown", | |
2594 | #endif | |
2595 | /* These are reserved for later use */ | |
2596 | 0, 0, 0, 0); | |
2597 | #ifdef CONFIG_SMP | |
2598 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
2599 | #else | |
2600 | seq_puts(m, ")\n"); | |
2601 | #endif | |
888b55dc KM |
2602 | seq_puts(m, "# -----------------\n"); |
2603 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 | 2604 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
d20b92ab EB |
2605 | data->comm, data->pid, |
2606 | from_kuid_munged(seq_user_ns(m), data->uid), data->nice, | |
bc0c38d1 | 2607 | data->policy, data->rt_priority); |
888b55dc | 2608 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
2609 | |
2610 | if (data->critical_start) { | |
888b55dc | 2611 | seq_puts(m, "# => started at: "); |
214023c3 SR |
2612 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
2613 | trace_print_seq(m, &iter->seq); | |
888b55dc | 2614 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
2615 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
2616 | trace_print_seq(m, &iter->seq); | |
8248ac05 | 2617 | seq_puts(m, "\n#\n"); |
bc0c38d1 SR |
2618 | } |
2619 | ||
888b55dc | 2620 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
2621 | } |
2622 | ||
a309720c SR |
2623 | static void test_cpu_buff_start(struct trace_iterator *iter) |
2624 | { | |
2625 | struct trace_seq *s = &iter->seq; | |
983f938a | 2626 | struct trace_array *tr = iter->tr; |
a309720c | 2627 | |
983f938a | 2628 | if (!(tr->trace_flags & TRACE_ITER_ANNOTATE)) |
12ef7d44 SR |
2629 | return; |
2630 | ||
2631 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
2632 | return; | |
2633 | ||
919cd979 | 2634 | if (iter->started && cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
2635 | return; |
2636 | ||
12883efb | 2637 | if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries) |
2f26ebd5 SR |
2638 | return; |
2639 | ||
919cd979 SL |
2640 | if (iter->started) |
2641 | cpumask_set_cpu(iter->cpu, iter->started); | |
b0dfa978 FW |
2642 | |
2643 | /* Don't print started cpu buffer for the first entry of the trace */ | |
2644 | if (iter->idx > 1) | |
2645 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
2646 | iter->cpu); | |
a309720c SR |
2647 | } |
2648 | ||
2c4f035f | 2649 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 2650 | { |
983f938a | 2651 | struct trace_array *tr = iter->tr; |
214023c3 | 2652 | struct trace_seq *s = &iter->seq; |
983f938a | 2653 | unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 2654 | struct trace_entry *entry; |
f633cef0 | 2655 | struct trace_event *event; |
bc0c38d1 | 2656 | |
4e3c3333 | 2657 | entry = iter->ent; |
dd0e545f | 2658 | |
a309720c SR |
2659 | test_cpu_buff_start(iter); |
2660 | ||
c4a8e8be | 2661 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 2662 | |
983f938a | 2663 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
19a7fe20 SRRH |
2664 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) |
2665 | trace_print_lat_context(iter); | |
2666 | else | |
2667 | trace_print_context(iter); | |
c4a8e8be | 2668 | } |
bc0c38d1 | 2669 | |
19a7fe20 SRRH |
2670 | if (trace_seq_has_overflowed(s)) |
2671 | return TRACE_TYPE_PARTIAL_LINE; | |
2672 | ||
268ccda0 | 2673 | if (event) |
a9a57763 | 2674 | return event->funcs->trace(iter, sym_flags, event); |
d9793bd8 | 2675 | |
19a7fe20 | 2676 | trace_seq_printf(s, "Unknown type %d\n", entry->type); |
02b67518 | 2677 | |
19a7fe20 | 2678 | return trace_handle_return(s); |
bc0c38d1 SR |
2679 | } |
2680 | ||
2c4f035f | 2681 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 | 2682 | { |
983f938a | 2683 | struct trace_array *tr = iter->tr; |
f9896bf3 IM |
2684 | struct trace_seq *s = &iter->seq; |
2685 | struct trace_entry *entry; | |
f633cef0 | 2686 | struct trace_event *event; |
f9896bf3 IM |
2687 | |
2688 | entry = iter->ent; | |
dd0e545f | 2689 | |
983f938a | 2690 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) |
19a7fe20 SRRH |
2691 | trace_seq_printf(s, "%d %d %llu ", |
2692 | entry->pid, iter->cpu, iter->ts); | |
2693 | ||
2694 | if (trace_seq_has_overflowed(s)) | |
2695 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 | 2696 | |
f633cef0 | 2697 | event = ftrace_find_event(entry->type); |
268ccda0 | 2698 | if (event) |
a9a57763 | 2699 | return event->funcs->raw(iter, 0, event); |
d9793bd8 | 2700 | |
19a7fe20 | 2701 | trace_seq_printf(s, "%d ?\n", entry->type); |
777e208d | 2702 | |
19a7fe20 | 2703 | return trace_handle_return(s); |
f9896bf3 IM |
2704 | } |
2705 | ||
2c4f035f | 2706 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec | 2707 | { |
983f938a | 2708 | struct trace_array *tr = iter->tr; |
5e3ca0ec IM |
2709 | struct trace_seq *s = &iter->seq; |
2710 | unsigned char newline = '\n'; | |
2711 | struct trace_entry *entry; | |
f633cef0 | 2712 | struct trace_event *event; |
5e3ca0ec IM |
2713 | |
2714 | entry = iter->ent; | |
dd0e545f | 2715 | |
983f938a | 2716 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
19a7fe20 SRRH |
2717 | SEQ_PUT_HEX_FIELD(s, entry->pid); |
2718 | SEQ_PUT_HEX_FIELD(s, iter->cpu); | |
2719 | SEQ_PUT_HEX_FIELD(s, iter->ts); | |
2720 | if (trace_seq_has_overflowed(s)) | |
2721 | return TRACE_TYPE_PARTIAL_LINE; | |
c4a8e8be | 2722 | } |
5e3ca0ec | 2723 | |
f633cef0 | 2724 | event = ftrace_find_event(entry->type); |
268ccda0 | 2725 | if (event) { |
a9a57763 | 2726 | enum print_line_t ret = event->funcs->hex(iter, 0, event); |
d9793bd8 ACM |
2727 | if (ret != TRACE_TYPE_HANDLED) |
2728 | return ret; | |
2729 | } | |
7104f300 | 2730 | |
19a7fe20 | 2731 | SEQ_PUT_FIELD(s, newline); |
5e3ca0ec | 2732 | |
19a7fe20 | 2733 | return trace_handle_return(s); |
5e3ca0ec IM |
2734 | } |
2735 | ||
2c4f035f | 2736 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa | 2737 | { |
983f938a | 2738 | struct trace_array *tr = iter->tr; |
cb0f12aa IM |
2739 | struct trace_seq *s = &iter->seq; |
2740 | struct trace_entry *entry; | |
f633cef0 | 2741 | struct trace_event *event; |
cb0f12aa IM |
2742 | |
2743 | entry = iter->ent; | |
dd0e545f | 2744 | |
983f938a | 2745 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
19a7fe20 SRRH |
2746 | SEQ_PUT_FIELD(s, entry->pid); |
2747 | SEQ_PUT_FIELD(s, iter->cpu); | |
2748 | SEQ_PUT_FIELD(s, iter->ts); | |
2749 | if (trace_seq_has_overflowed(s)) | |
2750 | return TRACE_TYPE_PARTIAL_LINE; | |
c4a8e8be | 2751 | } |
cb0f12aa | 2752 | |
f633cef0 | 2753 | event = ftrace_find_event(entry->type); |
a9a57763 SR |
2754 | return event ? event->funcs->binary(iter, 0, event) : |
2755 | TRACE_TYPE_HANDLED; | |
cb0f12aa IM |
2756 | } |
2757 | ||
62b915f1 | 2758 | int trace_empty(struct trace_iterator *iter) |
bc0c38d1 | 2759 | { |
6d158a81 | 2760 | struct ring_buffer_iter *buf_iter; |
bc0c38d1 SR |
2761 | int cpu; |
2762 | ||
9aba60fe | 2763 | /* If we are looking at one CPU buffer, only check that one */ |
ae3b5093 | 2764 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
9aba60fe | 2765 | cpu = iter->cpu_file; |
6d158a81 SR |
2766 | buf_iter = trace_buffer_iter(iter, cpu); |
2767 | if (buf_iter) { | |
2768 | if (!ring_buffer_iter_empty(buf_iter)) | |
9aba60fe SR |
2769 | return 0; |
2770 | } else { | |
12883efb | 2771 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) |
9aba60fe SR |
2772 | return 0; |
2773 | } | |
2774 | return 1; | |
2775 | } | |
2776 | ||
ab46428c | 2777 | for_each_tracing_cpu(cpu) { |
6d158a81 SR |
2778 | buf_iter = trace_buffer_iter(iter, cpu); |
2779 | if (buf_iter) { | |
2780 | if (!ring_buffer_iter_empty(buf_iter)) | |
d769041f SR |
2781 | return 0; |
2782 | } else { | |
12883efb | 2783 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) |
d769041f SR |
2784 | return 0; |
2785 | } | |
bc0c38d1 | 2786 | } |
d769041f | 2787 | |
797d3712 | 2788 | return 1; |
bc0c38d1 SR |
2789 | } |
2790 | ||
4f535968 | 2791 | /* Called with trace_event_read_lock() held. */ |
955b61e5 | 2792 | enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 2793 | { |
983f938a SRRH |
2794 | struct trace_array *tr = iter->tr; |
2795 | unsigned long trace_flags = tr->trace_flags; | |
2c4f035f FW |
2796 | enum print_line_t ret; |
2797 | ||
19a7fe20 SRRH |
2798 | if (iter->lost_events) { |
2799 | trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2800 | iter->cpu, iter->lost_events); | |
2801 | if (trace_seq_has_overflowed(&iter->seq)) | |
2802 | return TRACE_TYPE_PARTIAL_LINE; | |
2803 | } | |
bc21b478 | 2804 | |
2c4f035f FW |
2805 | if (iter->trace && iter->trace->print_line) { |
2806 | ret = iter->trace->print_line(iter); | |
2807 | if (ret != TRACE_TYPE_UNHANDLED) | |
2808 | return ret; | |
2809 | } | |
72829bc3 | 2810 | |
09ae7234 SRRH |
2811 | if (iter->ent->type == TRACE_BPUTS && |
2812 | trace_flags & TRACE_ITER_PRINTK && | |
2813 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2814 | return trace_print_bputs_msg_only(iter); | |
2815 | ||
48ead020 FW |
2816 | if (iter->ent->type == TRACE_BPRINT && |
2817 | trace_flags & TRACE_ITER_PRINTK && | |
2818 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2819 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 2820 | |
66896a85 FW |
2821 | if (iter->ent->type == TRACE_PRINT && |
2822 | trace_flags & TRACE_ITER_PRINTK && | |
2823 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2824 | return trace_print_printk_msg_only(iter); |
66896a85 | 2825 | |
cb0f12aa IM |
2826 | if (trace_flags & TRACE_ITER_BIN) |
2827 | return print_bin_fmt(iter); | |
2828 | ||
5e3ca0ec IM |
2829 | if (trace_flags & TRACE_ITER_HEX) |
2830 | return print_hex_fmt(iter); | |
2831 | ||
f9896bf3 IM |
2832 | if (trace_flags & TRACE_ITER_RAW) |
2833 | return print_raw_fmt(iter); | |
2834 | ||
f9896bf3 IM |
2835 | return print_trace_fmt(iter); |
2836 | } | |
2837 | ||
7e9a49ef JO |
2838 | void trace_latency_header(struct seq_file *m) |
2839 | { | |
2840 | struct trace_iterator *iter = m->private; | |
983f938a | 2841 | struct trace_array *tr = iter->tr; |
7e9a49ef JO |
2842 | |
2843 | /* print nothing if the buffers are empty */ | |
2844 | if (trace_empty(iter)) | |
2845 | return; | |
2846 | ||
2847 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
2848 | print_trace_header(m, iter); | |
2849 | ||
983f938a | 2850 | if (!(tr->trace_flags & TRACE_ITER_VERBOSE)) |
7e9a49ef JO |
2851 | print_lat_help_header(m); |
2852 | } | |
2853 | ||
62b915f1 JO |
2854 | void trace_default_header(struct seq_file *m) |
2855 | { | |
2856 | struct trace_iterator *iter = m->private; | |
983f938a SRRH |
2857 | struct trace_array *tr = iter->tr; |
2858 | unsigned long trace_flags = tr->trace_flags; | |
62b915f1 | 2859 | |
f56e7f8e JO |
2860 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
2861 | return; | |
2862 | ||
62b915f1 JO |
2863 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2864 | /* print nothing if the buffers are empty */ | |
2865 | if (trace_empty(iter)) | |
2866 | return; | |
2867 | print_trace_header(m, iter); | |
2868 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2869 | print_lat_help_header(m); | |
2870 | } else { | |
77271ce4 SR |
2871 | if (!(trace_flags & TRACE_ITER_VERBOSE)) { |
2872 | if (trace_flags & TRACE_ITER_IRQ_INFO) | |
12883efb | 2873 | print_func_help_header_irq(iter->trace_buffer, m); |
77271ce4 | 2874 | else |
12883efb | 2875 | print_func_help_header(iter->trace_buffer, m); |
77271ce4 | 2876 | } |
62b915f1 JO |
2877 | } |
2878 | } | |
2879 | ||
e0a413f6 SR |
2880 | static void test_ftrace_alive(struct seq_file *m) |
2881 | { | |
2882 | if (!ftrace_is_dead()) | |
2883 | return; | |
d79ac28f RV |
2884 | seq_puts(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n" |
2885 | "# MAY BE MISSING FUNCTION EVENTS\n"); | |
e0a413f6 SR |
2886 | } |
2887 | ||
d8741e2e | 2888 | #ifdef CONFIG_TRACER_MAX_TRACE |
f1affcaa | 2889 | static void show_snapshot_main_help(struct seq_file *m) |
d8741e2e | 2890 | { |
d79ac28f RV |
2891 | seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n" |
2892 | "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" | |
2893 | "# Takes a snapshot of the main buffer.\n" | |
2894 | "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n" | |
2895 | "# (Doesn't have to be '2' works with any number that\n" | |
2896 | "# is not a '0' or '1')\n"); | |
d8741e2e | 2897 | } |
f1affcaa SRRH |
2898 | |
2899 | static void show_snapshot_percpu_help(struct seq_file *m) | |
2900 | { | |
fa6f0cc7 | 2901 | seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); |
f1affcaa | 2902 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
d79ac28f RV |
2903 | seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" |
2904 | "# Takes a snapshot of the main buffer for this cpu.\n"); | |
f1affcaa | 2905 | #else |
d79ac28f RV |
2906 | seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n" |
2907 | "# Must use main snapshot file to allocate.\n"); | |
f1affcaa | 2908 | #endif |
d79ac28f RV |
2909 | seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n" |
2910 | "# (Doesn't have to be '2' works with any number that\n" | |
2911 | "# is not a '0' or '1')\n"); | |
f1affcaa SRRH |
2912 | } |
2913 | ||
d8741e2e SRRH |
2914 | static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) |
2915 | { | |
45ad21ca | 2916 | if (iter->tr->allocated_snapshot) |
fa6f0cc7 | 2917 | seq_puts(m, "#\n# * Snapshot is allocated *\n#\n"); |
d8741e2e | 2918 | else |
fa6f0cc7 | 2919 | seq_puts(m, "#\n# * Snapshot is freed *\n#\n"); |
d8741e2e | 2920 | |
fa6f0cc7 | 2921 | seq_puts(m, "# Snapshot commands:\n"); |
f1affcaa SRRH |
2922 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
2923 | show_snapshot_main_help(m); | |
2924 | else | |
2925 | show_snapshot_percpu_help(m); | |
d8741e2e SRRH |
2926 | } |
2927 | #else | |
2928 | /* Should never be called */ | |
2929 | static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } | |
2930 | #endif | |
2931 | ||
bc0c38d1 SR |
2932 | static int s_show(struct seq_file *m, void *v) |
2933 | { | |
2934 | struct trace_iterator *iter = v; | |
a63ce5b3 | 2935 | int ret; |
bc0c38d1 SR |
2936 | |
2937 | if (iter->ent == NULL) { | |
2938 | if (iter->tr) { | |
2939 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2940 | seq_puts(m, "#\n"); | |
e0a413f6 | 2941 | test_ftrace_alive(m); |
bc0c38d1 | 2942 | } |
d8741e2e SRRH |
2943 | if (iter->snapshot && trace_empty(iter)) |
2944 | print_snapshot_help(m, iter); | |
2945 | else if (iter->trace && iter->trace->print_header) | |
8bba1bf5 | 2946 | iter->trace->print_header(m); |
62b915f1 JO |
2947 | else |
2948 | trace_default_header(m); | |
2949 | ||
a63ce5b3 SR |
2950 | } else if (iter->leftover) { |
2951 | /* | |
2952 | * If we filled the seq_file buffer earlier, we | |
2953 | * want to just show it now. | |
2954 | */ | |
2955 | ret = trace_print_seq(m, &iter->seq); | |
2956 | ||
2957 | /* ret should this time be zero, but you never know */ | |
2958 | iter->leftover = ret; | |
2959 | ||
bc0c38d1 | 2960 | } else { |
f9896bf3 | 2961 | print_trace_line(iter); |
a63ce5b3 SR |
2962 | ret = trace_print_seq(m, &iter->seq); |
2963 | /* | |
2964 | * If we overflow the seq_file buffer, then it will | |
2965 | * ask us for this data again at start up. | |
2966 | * Use that instead. | |
2967 | * ret is 0 if seq_file write succeeded. | |
2968 | * -1 otherwise. | |
2969 | */ | |
2970 | iter->leftover = ret; | |
bc0c38d1 SR |
2971 | } |
2972 | ||
2973 | return 0; | |
2974 | } | |
2975 | ||
649e9c70 ON |
2976 | /* |
2977 | * Should be used after trace_array_get(), trace_types_lock | |
2978 | * ensures that i_cdev was already initialized. | |
2979 | */ | |
2980 | static inline int tracing_get_cpu(struct inode *inode) | |
2981 | { | |
2982 | if (inode->i_cdev) /* See trace_create_cpu_file() */ | |
2983 | return (long)inode->i_cdev - 1; | |
2984 | return RING_BUFFER_ALL_CPUS; | |
2985 | } | |
2986 | ||
88e9d34c | 2987 | static const struct seq_operations tracer_seq_ops = { |
4bf39a94 IM |
2988 | .start = s_start, |
2989 | .next = s_next, | |
2990 | .stop = s_stop, | |
2991 | .show = s_show, | |
bc0c38d1 SR |
2992 | }; |
2993 | ||
e309b41d | 2994 | static struct trace_iterator * |
6484c71c | 2995 | __tracing_open(struct inode *inode, struct file *file, bool snapshot) |
bc0c38d1 | 2996 | { |
6484c71c | 2997 | struct trace_array *tr = inode->i_private; |
bc0c38d1 | 2998 | struct trace_iterator *iter; |
50e18b94 | 2999 | int cpu; |
bc0c38d1 | 3000 | |
85a2f9b4 SR |
3001 | if (tracing_disabled) |
3002 | return ERR_PTR(-ENODEV); | |
60a11774 | 3003 | |
50e18b94 | 3004 | iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); |
85a2f9b4 SR |
3005 | if (!iter) |
3006 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 3007 | |
72917235 | 3008 | iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter), |
6d158a81 | 3009 | GFP_KERNEL); |
93574fcc DC |
3010 | if (!iter->buffer_iter) |
3011 | goto release; | |
3012 | ||
d7350c3f FW |
3013 | /* |
3014 | * We make a copy of the current tracer to avoid concurrent | |
3015 | * changes on it while we are reading. | |
3016 | */ | |
bc0c38d1 | 3017 | mutex_lock(&trace_types_lock); |
d7350c3f | 3018 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 3019 | if (!iter->trace) |
d7350c3f | 3020 | goto fail; |
85a2f9b4 | 3021 | |
2b6080f2 | 3022 | *iter->trace = *tr->current_trace; |
d7350c3f | 3023 | |
79f55997 | 3024 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
b0dfa978 FW |
3025 | goto fail; |
3026 | ||
12883efb SRRH |
3027 | iter->tr = tr; |
3028 | ||
3029 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2b6080f2 SR |
3030 | /* Currently only the top directory has a snapshot */ |
3031 | if (tr->current_trace->print_max || snapshot) | |
12883efb | 3032 | iter->trace_buffer = &tr->max_buffer; |
bc0c38d1 | 3033 | else |
12883efb SRRH |
3034 | #endif |
3035 | iter->trace_buffer = &tr->trace_buffer; | |
debdd57f | 3036 | iter->snapshot = snapshot; |
bc0c38d1 | 3037 | iter->pos = -1; |
6484c71c | 3038 | iter->cpu_file = tracing_get_cpu(inode); |
d7350c3f | 3039 | mutex_init(&iter->mutex); |
bc0c38d1 | 3040 | |
8bba1bf5 MM |
3041 | /* Notify the tracer early; before we stop tracing. */ |
3042 | if (iter->trace && iter->trace->open) | |
a93751ca | 3043 | iter->trace->open(iter); |
8bba1bf5 | 3044 | |
12ef7d44 | 3045 | /* Annotate start of buffers if we had overruns */ |
12883efb | 3046 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) |
12ef7d44 SR |
3047 | iter->iter_flags |= TRACE_FILE_ANNOTATE; |
3048 | ||
8be0709f | 3049 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
58e8eedf | 3050 | if (trace_clocks[tr->clock_id].in_ns) |
8be0709f DS |
3051 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
3052 | ||
debdd57f HT |
3053 | /* stop the trace while dumping if we are not opening "snapshot" */ |
3054 | if (!iter->snapshot) | |
2b6080f2 | 3055 | tracing_stop_tr(tr); |
2f26ebd5 | 3056 | |
ae3b5093 | 3057 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { |
b04cc6b1 | 3058 | for_each_tracing_cpu(cpu) { |
b04cc6b1 | 3059 | iter->buffer_iter[cpu] = |
12883efb | 3060 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); |
72c9ddfd DM |
3061 | } |
3062 | ring_buffer_read_prepare_sync(); | |
3063 | for_each_tracing_cpu(cpu) { | |
3064 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 3065 | tracing_iter_reset(iter, cpu); |
b04cc6b1 FW |
3066 | } |
3067 | } else { | |
3068 | cpu = iter->cpu_file; | |
3928a8a2 | 3069 | iter->buffer_iter[cpu] = |
12883efb | 3070 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); |
72c9ddfd DM |
3071 | ring_buffer_read_prepare_sync(); |
3072 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 3073 | tracing_iter_reset(iter, cpu); |
3928a8a2 SR |
3074 | } |
3075 | ||
bc0c38d1 SR |
3076 | mutex_unlock(&trace_types_lock); |
3077 | ||
bc0c38d1 | 3078 | return iter; |
3928a8a2 | 3079 | |
d7350c3f | 3080 | fail: |
3928a8a2 | 3081 | mutex_unlock(&trace_types_lock); |
d7350c3f | 3082 | kfree(iter->trace); |
6d158a81 | 3083 | kfree(iter->buffer_iter); |
93574fcc | 3084 | release: |
50e18b94 JO |
3085 | seq_release_private(inode, file); |
3086 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 SR |
3087 | } |
3088 | ||
3089 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
3090 | { | |
60a11774 SR |
3091 | if (tracing_disabled) |
3092 | return -ENODEV; | |
3093 | ||
bc0c38d1 SR |
3094 | filp->private_data = inode->i_private; |
3095 | return 0; | |
3096 | } | |
3097 | ||
2e86421d GB |
3098 | bool tracing_is_disabled(void) |
3099 | { | |
3100 | return (tracing_disabled) ? true: false; | |
3101 | } | |
3102 | ||
7b85af63 SRRH |
3103 | /* |
3104 | * Open and update trace_array ref count. | |
3105 | * Must have the current trace_array passed to it. | |
3106 | */ | |
dcc30223 | 3107 | static int tracing_open_generic_tr(struct inode *inode, struct file *filp) |
7b85af63 SRRH |
3108 | { |
3109 | struct trace_array *tr = inode->i_private; | |
3110 | ||
3111 | if (tracing_disabled) | |
3112 | return -ENODEV; | |
3113 | ||
3114 | if (trace_array_get(tr) < 0) | |
3115 | return -ENODEV; | |
3116 | ||
3117 | filp->private_data = inode->i_private; | |
3118 | ||
3119 | return 0; | |
7b85af63 SRRH |
3120 | } |
3121 | ||
4fd27358 | 3122 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 | 3123 | { |
6484c71c | 3124 | struct trace_array *tr = inode->i_private; |
907f2784 | 3125 | struct seq_file *m = file->private_data; |
4acd4d00 | 3126 | struct trace_iterator *iter; |
3928a8a2 | 3127 | int cpu; |
bc0c38d1 | 3128 | |
ff451961 | 3129 | if (!(file->f_mode & FMODE_READ)) { |
6484c71c | 3130 | trace_array_put(tr); |
4acd4d00 | 3131 | return 0; |
ff451961 | 3132 | } |
4acd4d00 | 3133 | |
6484c71c | 3134 | /* Writes do not use seq_file */ |
4acd4d00 | 3135 | iter = m->private; |
bc0c38d1 | 3136 | mutex_lock(&trace_types_lock); |
a695cb58 | 3137 | |
3928a8a2 SR |
3138 | for_each_tracing_cpu(cpu) { |
3139 | if (iter->buffer_iter[cpu]) | |
3140 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
3141 | } | |
3142 | ||
bc0c38d1 SR |
3143 | if (iter->trace && iter->trace->close) |
3144 | iter->trace->close(iter); | |
3145 | ||
debdd57f HT |
3146 | if (!iter->snapshot) |
3147 | /* reenable tracing if it was previously enabled */ | |
2b6080f2 | 3148 | tracing_start_tr(tr); |
f77d09a3 AL |
3149 | |
3150 | __trace_array_put(tr); | |
3151 | ||
bc0c38d1 SR |
3152 | mutex_unlock(&trace_types_lock); |
3153 | ||
d7350c3f | 3154 | mutex_destroy(&iter->mutex); |
b0dfa978 | 3155 | free_cpumask_var(iter->started); |
d7350c3f | 3156 | kfree(iter->trace); |
6d158a81 | 3157 | kfree(iter->buffer_iter); |
50e18b94 | 3158 | seq_release_private(inode, file); |
ff451961 | 3159 | |
bc0c38d1 SR |
3160 | return 0; |
3161 | } | |
3162 | ||
7b85af63 SRRH |
3163 | static int tracing_release_generic_tr(struct inode *inode, struct file *file) |
3164 | { | |
3165 | struct trace_array *tr = inode->i_private; | |
3166 | ||
3167 | trace_array_put(tr); | |
bc0c38d1 SR |
3168 | return 0; |
3169 | } | |
3170 | ||
7b85af63 SRRH |
3171 | static int tracing_single_release_tr(struct inode *inode, struct file *file) |
3172 | { | |
3173 | struct trace_array *tr = inode->i_private; | |
3174 | ||
3175 | trace_array_put(tr); | |
3176 | ||
3177 | return single_release(inode, file); | |
3178 | } | |
3179 | ||
bc0c38d1 SR |
3180 | static int tracing_open(struct inode *inode, struct file *file) |
3181 | { | |
6484c71c | 3182 | struct trace_array *tr = inode->i_private; |
85a2f9b4 SR |
3183 | struct trace_iterator *iter; |
3184 | int ret = 0; | |
bc0c38d1 | 3185 | |
ff451961 SRRH |
3186 | if (trace_array_get(tr) < 0) |
3187 | return -ENODEV; | |
3188 | ||
4acd4d00 | 3189 | /* If this file was open for write, then erase contents */ |
6484c71c ON |
3190 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
3191 | int cpu = tracing_get_cpu(inode); | |
3192 | ||
3193 | if (cpu == RING_BUFFER_ALL_CPUS) | |
12883efb | 3194 | tracing_reset_online_cpus(&tr->trace_buffer); |
4acd4d00 | 3195 | else |
6484c71c | 3196 | tracing_reset(&tr->trace_buffer, cpu); |
4acd4d00 | 3197 | } |
bc0c38d1 | 3198 | |
4acd4d00 | 3199 | if (file->f_mode & FMODE_READ) { |
6484c71c | 3200 | iter = __tracing_open(inode, file, false); |
4acd4d00 SR |
3201 | if (IS_ERR(iter)) |
3202 | ret = PTR_ERR(iter); | |
983f938a | 3203 | else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
4acd4d00 SR |
3204 | iter->iter_flags |= TRACE_FILE_LAT_FMT; |
3205 | } | |
ff451961 SRRH |
3206 | |
3207 | if (ret < 0) | |
3208 | trace_array_put(tr); | |
3209 | ||
bc0c38d1 SR |
3210 | return ret; |
3211 | } | |
3212 | ||
607e2ea1 SRRH |
3213 | /* |
3214 | * Some tracers are not suitable for instance buffers. | |
3215 | * A tracer is always available for the global array (toplevel) | |
3216 | * or if it explicitly states that it is. | |
3217 | */ | |
3218 | static bool | |
3219 | trace_ok_for_array(struct tracer *t, struct trace_array *tr) | |
3220 | { | |
3221 | return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances; | |
3222 | } | |
3223 | ||
3224 | /* Find the next tracer that this trace array may use */ | |
3225 | static struct tracer * | |
3226 | get_tracer_for_array(struct trace_array *tr, struct tracer *t) | |
3227 | { | |
3228 | while (t && !trace_ok_for_array(t, tr)) | |
3229 | t = t->next; | |
3230 | ||
3231 | return t; | |
3232 | } | |
3233 | ||
e309b41d | 3234 | static void * |
bc0c38d1 SR |
3235 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3236 | { | |
607e2ea1 | 3237 | struct trace_array *tr = m->private; |
f129e965 | 3238 | struct tracer *t = v; |
bc0c38d1 SR |
3239 | |
3240 | (*pos)++; | |
3241 | ||
3242 | if (t) | |
607e2ea1 | 3243 | t = get_tracer_for_array(tr, t->next); |
bc0c38d1 | 3244 | |
bc0c38d1 SR |
3245 | return t; |
3246 | } | |
3247 | ||
3248 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3249 | { | |
607e2ea1 | 3250 | struct trace_array *tr = m->private; |
f129e965 | 3251 | struct tracer *t; |
bc0c38d1 SR |
3252 | loff_t l = 0; |
3253 | ||
3254 | mutex_lock(&trace_types_lock); | |
607e2ea1 SRRH |
3255 | |
3256 | t = get_tracer_for_array(tr, trace_types); | |
3257 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
3258 | ; | |
bc0c38d1 SR |
3259 | |
3260 | return t; | |
3261 | } | |
3262 | ||
3263 | static void t_stop(struct seq_file *m, void *p) | |
3264 | { | |
3265 | mutex_unlock(&trace_types_lock); | |
3266 | } | |
3267 | ||
3268 | static int t_show(struct seq_file *m, void *v) | |
3269 | { | |
3270 | struct tracer *t = v; | |
3271 | ||
3272 | if (!t) | |
3273 | return 0; | |
3274 | ||
fa6f0cc7 | 3275 | seq_puts(m, t->name); |
bc0c38d1 SR |
3276 | if (t->next) |
3277 | seq_putc(m, ' '); | |
3278 | else | |
3279 | seq_putc(m, '\n'); | |
3280 | ||
3281 | return 0; | |
3282 | } | |
3283 | ||
88e9d34c | 3284 | static const struct seq_operations show_traces_seq_ops = { |
4bf39a94 IM |
3285 | .start = t_start, |
3286 | .next = t_next, | |
3287 | .stop = t_stop, | |
3288 | .show = t_show, | |
bc0c38d1 SR |
3289 | }; |
3290 | ||
3291 | static int show_traces_open(struct inode *inode, struct file *file) | |
3292 | { | |
607e2ea1 SRRH |
3293 | struct trace_array *tr = inode->i_private; |
3294 | struct seq_file *m; | |
3295 | int ret; | |
3296 | ||
60a11774 SR |
3297 | if (tracing_disabled) |
3298 | return -ENODEV; | |
3299 | ||
607e2ea1 SRRH |
3300 | ret = seq_open(file, &show_traces_seq_ops); |
3301 | if (ret) | |
3302 | return ret; | |
3303 | ||
3304 | m = file->private_data; | |
3305 | m->private = tr; | |
3306 | ||
3307 | return 0; | |
bc0c38d1 SR |
3308 | } |
3309 | ||
4acd4d00 SR |
3310 | static ssize_t |
3311 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
3312 | size_t count, loff_t *ppos) | |
3313 | { | |
3314 | return count; | |
3315 | } | |
3316 | ||
098c879e | 3317 | loff_t tracing_lseek(struct file *file, loff_t offset, int whence) |
364829b1 | 3318 | { |
098c879e SRRH |
3319 | int ret; |
3320 | ||
364829b1 | 3321 | if (file->f_mode & FMODE_READ) |
098c879e | 3322 | ret = seq_lseek(file, offset, whence); |
364829b1 | 3323 | else |
098c879e SRRH |
3324 | file->f_pos = ret = 0; |
3325 | ||
3326 | return ret; | |
364829b1 SP |
3327 | } |
3328 | ||
5e2336a0 | 3329 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
3330 | .open = tracing_open, |
3331 | .read = seq_read, | |
4acd4d00 | 3332 | .write = tracing_write_stub, |
098c879e | 3333 | .llseek = tracing_lseek, |
4bf39a94 | 3334 | .release = tracing_release, |
bc0c38d1 SR |
3335 | }; |
3336 | ||
5e2336a0 | 3337 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
3338 | .open = show_traces_open, |
3339 | .read = seq_read, | |
3340 | .release = seq_release, | |
b444786f | 3341 | .llseek = seq_lseek, |
c7078de1 IM |
3342 | }; |
3343 | ||
36dfe925 IM |
3344 | /* |
3345 | * The tracer itself will not take this lock, but still we want | |
3346 | * to provide a consistent cpumask to user-space: | |
3347 | */ | |
3348 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
3349 | ||
3350 | /* | |
3351 | * Temporary storage for the character representation of the | |
3352 | * CPU bitmask (and one more byte for the newline): | |
3353 | */ | |
3354 | static char mask_str[NR_CPUS + 1]; | |
3355 | ||
c7078de1 IM |
3356 | static ssize_t |
3357 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
3358 | size_t count, loff_t *ppos) | |
3359 | { | |
ccfe9e42 | 3360 | struct trace_array *tr = file_inode(filp)->i_private; |
36dfe925 | 3361 | int len; |
c7078de1 IM |
3362 | |
3363 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 3364 | |
1a40243b TH |
3365 | len = snprintf(mask_str, count, "%*pb\n", |
3366 | cpumask_pr_args(tr->tracing_cpumask)); | |
3367 | if (len >= count) { | |
36dfe925 IM |
3368 | count = -EINVAL; |
3369 | goto out_err; | |
3370 | } | |
36dfe925 IM |
3371 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); |
3372 | ||
3373 | out_err: | |
c7078de1 IM |
3374 | mutex_unlock(&tracing_cpumask_update_lock); |
3375 | ||
3376 | return count; | |
3377 | } | |
3378 | ||
3379 | static ssize_t | |
3380 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
3381 | size_t count, loff_t *ppos) | |
3382 | { | |
ccfe9e42 | 3383 | struct trace_array *tr = file_inode(filp)->i_private; |
9e01c1b7 | 3384 | cpumask_var_t tracing_cpumask_new; |
2b6080f2 | 3385 | int err, cpu; |
9e01c1b7 RR |
3386 | |
3387 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
3388 | return -ENOMEM; | |
c7078de1 | 3389 | |
9e01c1b7 | 3390 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 3391 | if (err) |
36dfe925 IM |
3392 | goto err_unlock; |
3393 | ||
215368e8 LZ |
3394 | mutex_lock(&tracing_cpumask_update_lock); |
3395 | ||
a5e25883 | 3396 | local_irq_disable(); |
0b9b12c1 | 3397 | arch_spin_lock(&tr->max_lock); |
ab46428c | 3398 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
3399 | /* |
3400 | * Increase/decrease the disabled counter if we are | |
3401 | * about to flip a bit in the cpumask: | |
3402 | */ | |
ccfe9e42 | 3403 | if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
9e01c1b7 | 3404 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
12883efb SRRH |
3405 | atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); |
3406 | ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu); | |
36dfe925 | 3407 | } |
ccfe9e42 | 3408 | if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
9e01c1b7 | 3409 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
12883efb SRRH |
3410 | atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); |
3411 | ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu); | |
36dfe925 IM |
3412 | } |
3413 | } | |
0b9b12c1 | 3414 | arch_spin_unlock(&tr->max_lock); |
a5e25883 | 3415 | local_irq_enable(); |
36dfe925 | 3416 | |
ccfe9e42 | 3417 | cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
3418 | |
3419 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 3420 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
3421 | |
3422 | return count; | |
36dfe925 IM |
3423 | |
3424 | err_unlock: | |
215368e8 | 3425 | free_cpumask_var(tracing_cpumask_new); |
36dfe925 IM |
3426 | |
3427 | return err; | |
c7078de1 IM |
3428 | } |
3429 | ||
5e2336a0 | 3430 | static const struct file_operations tracing_cpumask_fops = { |
ccfe9e42 | 3431 | .open = tracing_open_generic_tr, |
c7078de1 IM |
3432 | .read = tracing_cpumask_read, |
3433 | .write = tracing_cpumask_write, | |
ccfe9e42 | 3434 | .release = tracing_release_generic_tr, |
b444786f | 3435 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
3436 | }; |
3437 | ||
fdb372ed | 3438 | static int tracing_trace_options_show(struct seq_file *m, void *v) |
bc0c38d1 | 3439 | { |
d8e83d26 | 3440 | struct tracer_opt *trace_opts; |
2b6080f2 | 3441 | struct trace_array *tr = m->private; |
d8e83d26 | 3442 | u32 tracer_flags; |
d8e83d26 | 3443 | int i; |
adf9f195 | 3444 | |
d8e83d26 | 3445 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
3446 | tracer_flags = tr->current_trace->flags->val; |
3447 | trace_opts = tr->current_trace->flags->opts; | |
d8e83d26 | 3448 | |
bc0c38d1 | 3449 | for (i = 0; trace_options[i]; i++) { |
983f938a | 3450 | if (tr->trace_flags & (1 << i)) |
fdb372ed | 3451 | seq_printf(m, "%s\n", trace_options[i]); |
bc0c38d1 | 3452 | else |
fdb372ed | 3453 | seq_printf(m, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
3454 | } |
3455 | ||
adf9f195 FW |
3456 | for (i = 0; trace_opts[i].name; i++) { |
3457 | if (tracer_flags & trace_opts[i].bit) | |
fdb372ed | 3458 | seq_printf(m, "%s\n", trace_opts[i].name); |
adf9f195 | 3459 | else |
fdb372ed | 3460 | seq_printf(m, "no%s\n", trace_opts[i].name); |
adf9f195 | 3461 | } |
d8e83d26 | 3462 | mutex_unlock(&trace_types_lock); |
adf9f195 | 3463 | |
fdb372ed | 3464 | return 0; |
bc0c38d1 | 3465 | } |
bc0c38d1 | 3466 | |
8c1a49ae | 3467 | static int __set_tracer_option(struct trace_array *tr, |
8d18eaaf LZ |
3468 | struct tracer_flags *tracer_flags, |
3469 | struct tracer_opt *opts, int neg) | |
3470 | { | |
d39cdd20 | 3471 | struct tracer *trace = tracer_flags->trace; |
8d18eaaf | 3472 | int ret; |
bc0c38d1 | 3473 | |
8c1a49ae | 3474 | ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg); |
8d18eaaf LZ |
3475 | if (ret) |
3476 | return ret; | |
3477 | ||
3478 | if (neg) | |
3479 | tracer_flags->val &= ~opts->bit; | |
3480 | else | |
3481 | tracer_flags->val |= opts->bit; | |
3482 | return 0; | |
bc0c38d1 SR |
3483 | } |
3484 | ||
adf9f195 | 3485 | /* Try to assign a tracer specific option */ |
8c1a49ae | 3486 | static int set_tracer_option(struct trace_array *tr, char *cmp, int neg) |
adf9f195 | 3487 | { |
8c1a49ae | 3488 | struct tracer *trace = tr->current_trace; |
7770841e | 3489 | struct tracer_flags *tracer_flags = trace->flags; |
adf9f195 | 3490 | struct tracer_opt *opts = NULL; |
8d18eaaf | 3491 | int i; |
adf9f195 | 3492 | |
7770841e Z |
3493 | for (i = 0; tracer_flags->opts[i].name; i++) { |
3494 | opts = &tracer_flags->opts[i]; | |
adf9f195 | 3495 | |
8d18eaaf | 3496 | if (strcmp(cmp, opts->name) == 0) |
8c1a49ae | 3497 | return __set_tracer_option(tr, trace->flags, opts, neg); |
adf9f195 | 3498 | } |
adf9f195 | 3499 | |
8d18eaaf | 3500 | return -EINVAL; |
adf9f195 FW |
3501 | } |
3502 | ||
613f04a0 SRRH |
3503 | /* Some tracers require overwrite to stay enabled */ |
3504 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) | |
3505 | { | |
3506 | if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) | |
3507 | return -1; | |
3508 | ||
3509 | return 0; | |
3510 | } | |
3511 | ||
2b6080f2 | 3512 | int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) |
af4617bd SR |
3513 | { |
3514 | /* do nothing if flag is already set */ | |
983f938a | 3515 | if (!!(tr->trace_flags & mask) == !!enabled) |
613f04a0 SRRH |
3516 | return 0; |
3517 | ||
3518 | /* Give the tracer a chance to approve the change */ | |
2b6080f2 | 3519 | if (tr->current_trace->flag_changed) |
bf6065b5 | 3520 | if (tr->current_trace->flag_changed(tr, mask, !!enabled)) |
613f04a0 | 3521 | return -EINVAL; |
af4617bd SR |
3522 | |
3523 | if (enabled) | |
983f938a | 3524 | tr->trace_flags |= mask; |
af4617bd | 3525 | else |
983f938a | 3526 | tr->trace_flags &= ~mask; |
e870e9a1 LZ |
3527 | |
3528 | if (mask == TRACE_ITER_RECORD_CMD) | |
3529 | trace_event_enable_cmd_record(enabled); | |
750912fa | 3530 | |
c37775d5 SR |
3531 | if (mask == TRACE_ITER_EVENT_FORK) |
3532 | trace_event_follow_fork(tr, enabled); | |
3533 | ||
80902822 | 3534 | if (mask == TRACE_ITER_OVERWRITE) { |
12883efb | 3535 | ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); |
80902822 | 3536 | #ifdef CONFIG_TRACER_MAX_TRACE |
12883efb | 3537 | ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled); |
80902822 SRRH |
3538 | #endif |
3539 | } | |
81698831 | 3540 | |
b9f9108c | 3541 | if (mask == TRACE_ITER_PRINTK) { |
81698831 | 3542 | trace_printk_start_stop_comm(enabled); |
b9f9108c SRRH |
3543 | trace_printk_control(enabled); |
3544 | } | |
613f04a0 SRRH |
3545 | |
3546 | return 0; | |
af4617bd SR |
3547 | } |
3548 | ||
2b6080f2 | 3549 | static int trace_set_options(struct trace_array *tr, char *option) |
bc0c38d1 | 3550 | { |
8d18eaaf | 3551 | char *cmp; |
bc0c38d1 | 3552 | int neg = 0; |
613f04a0 | 3553 | int ret = -ENODEV; |
bc0c38d1 | 3554 | int i; |
a4d1e688 | 3555 | size_t orig_len = strlen(option); |
bc0c38d1 | 3556 | |
7bcfaf54 | 3557 | cmp = strstrip(option); |
bc0c38d1 | 3558 | |
8d18eaaf | 3559 | if (strncmp(cmp, "no", 2) == 0) { |
bc0c38d1 SR |
3560 | neg = 1; |
3561 | cmp += 2; | |
3562 | } | |
3563 | ||
69d34da2 SRRH |
3564 | mutex_lock(&trace_types_lock); |
3565 | ||
bc0c38d1 | 3566 | for (i = 0; trace_options[i]; i++) { |
8d18eaaf | 3567 | if (strcmp(cmp, trace_options[i]) == 0) { |
2b6080f2 | 3568 | ret = set_tracer_flag(tr, 1 << i, !neg); |
bc0c38d1 SR |
3569 | break; |
3570 | } | |
3571 | } | |
adf9f195 FW |
3572 | |
3573 | /* If no option could be set, test the specific tracer options */ | |
69d34da2 | 3574 | if (!trace_options[i]) |
8c1a49ae | 3575 | ret = set_tracer_option(tr, cmp, neg); |
69d34da2 SRRH |
3576 | |
3577 | mutex_unlock(&trace_types_lock); | |
bc0c38d1 | 3578 | |
a4d1e688 JW |
3579 | /* |
3580 | * If the first trailing whitespace is replaced with '\0' by strstrip, | |
3581 | * turn it back into a space. | |
3582 | */ | |
3583 | if (orig_len > strlen(option)) | |
3584 | option[strlen(option)] = ' '; | |
3585 | ||
7bcfaf54 SR |
3586 | return ret; |
3587 | } | |
3588 | ||
a4d1e688 JW |
3589 | static void __init apply_trace_boot_options(void) |
3590 | { | |
3591 | char *buf = trace_boot_options_buf; | |
3592 | char *option; | |
3593 | ||
3594 | while (true) { | |
3595 | option = strsep(&buf, ","); | |
3596 | ||
3597 | if (!option) | |
3598 | break; | |
a4d1e688 | 3599 | |
43ed3843 SRRH |
3600 | if (*option) |
3601 | trace_set_options(&global_trace, option); | |
a4d1e688 JW |
3602 | |
3603 | /* Put back the comma to allow this to be called again */ | |
3604 | if (buf) | |
3605 | *(buf - 1) = ','; | |
3606 | } | |
3607 | } | |
3608 | ||
7bcfaf54 SR |
3609 | static ssize_t |
3610 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, | |
3611 | size_t cnt, loff_t *ppos) | |
3612 | { | |
2b6080f2 SR |
3613 | struct seq_file *m = filp->private_data; |
3614 | struct trace_array *tr = m->private; | |
7bcfaf54 | 3615 | char buf[64]; |
613f04a0 | 3616 | int ret; |
7bcfaf54 SR |
3617 | |
3618 | if (cnt >= sizeof(buf)) | |
3619 | return -EINVAL; | |
3620 | ||
4afe6495 | 3621 | if (copy_from_user(buf, ubuf, cnt)) |
7bcfaf54 SR |
3622 | return -EFAULT; |
3623 | ||
a8dd2176 SR |
3624 | buf[cnt] = 0; |
3625 | ||
2b6080f2 | 3626 | ret = trace_set_options(tr, buf); |
613f04a0 SRRH |
3627 | if (ret < 0) |
3628 | return ret; | |
7bcfaf54 | 3629 | |
cf8517cf | 3630 | *ppos += cnt; |
bc0c38d1 SR |
3631 | |
3632 | return cnt; | |
3633 | } | |
3634 | ||
fdb372ed LZ |
3635 | static int tracing_trace_options_open(struct inode *inode, struct file *file) |
3636 | { | |
7b85af63 | 3637 | struct trace_array *tr = inode->i_private; |
f77d09a3 | 3638 | int ret; |
7b85af63 | 3639 | |
fdb372ed LZ |
3640 | if (tracing_disabled) |
3641 | return -ENODEV; | |
2b6080f2 | 3642 | |
7b85af63 SRRH |
3643 | if (trace_array_get(tr) < 0) |
3644 | return -ENODEV; | |
3645 | ||
f77d09a3 AL |
3646 | ret = single_open(file, tracing_trace_options_show, inode->i_private); |
3647 | if (ret < 0) | |
3648 | trace_array_put(tr); | |
3649 | ||
3650 | return ret; | |
fdb372ed LZ |
3651 | } |
3652 | ||
5e2336a0 | 3653 | static const struct file_operations tracing_iter_fops = { |
fdb372ed LZ |
3654 | .open = tracing_trace_options_open, |
3655 | .read = seq_read, | |
3656 | .llseek = seq_lseek, | |
7b85af63 | 3657 | .release = tracing_single_release_tr, |
ee6bce52 | 3658 | .write = tracing_trace_options_write, |
bc0c38d1 SR |
3659 | }; |
3660 | ||
7bd2f24c IM |
3661 | static const char readme_msg[] = |
3662 | "tracing mini-HOWTO:\n\n" | |
22f45649 SRRH |
3663 | "# echo 0 > tracing_on : quick way to disable tracing\n" |
3664 | "# echo 1 > tracing_on : quick way to re-enable tracing\n\n" | |
3665 | " Important files:\n" | |
3666 | " trace\t\t\t- The static contents of the buffer\n" | |
3667 | "\t\t\t To clear the buffer write into this file: echo > trace\n" | |
3668 | " trace_pipe\t\t- A consuming read to see the contents of the buffer\n" | |
3669 | " current_tracer\t- function and latency tracers\n" | |
3670 | " available_tracers\t- list of configured tracers for current_tracer\n" | |
3671 | " buffer_size_kb\t- view and modify size of per cpu buffer\n" | |
3672 | " buffer_total_size_kb - view total size of all cpu buffers\n\n" | |
3673 | " trace_clock\t\t-change the clock used to order events\n" | |
3674 | " local: Per cpu clock but may not be synced across CPUs\n" | |
3675 | " global: Synced across CPUs but slows tracing down.\n" | |
3676 | " counter: Not a clock, but just an increment\n" | |
3677 | " uptime: Jiffy counter from time of boot\n" | |
3678 | " perf: Same clock that perf events use\n" | |
3679 | #ifdef CONFIG_X86_64 | |
3680 | " x86-tsc: TSC cycle counter\n" | |
3681 | #endif | |
3682 | "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" | |
3683 | " tracing_cpumask\t- Limit which CPUs to trace\n" | |
3684 | " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" | |
3685 | "\t\t\t Remove sub-buffer with rmdir\n" | |
3686 | " trace_options\t\t- Set format or modify how tracing happens\n" | |
71485c45 SRRH |
3687 | "\t\t\t Disable an option by adding a suffix 'no' to the\n" |
3688 | "\t\t\t option name\n" | |
939c7a4f | 3689 | " saved_cmdlines_size\t- echo command number in here to store comm-pid list\n" |
22f45649 SRRH |
3690 | #ifdef CONFIG_DYNAMIC_FTRACE |
3691 | "\n available_filter_functions - list of functions that can be filtered on\n" | |
71485c45 SRRH |
3692 | " set_ftrace_filter\t- echo function name in here to only trace these\n" |
3693 | "\t\t\t functions\n" | |
3694 | "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" | |
3695 | "\t modules: Can select a group via module\n" | |
3696 | "\t Format: :mod:<module-name>\n" | |
3697 | "\t example: echo :mod:ext3 > set_ftrace_filter\n" | |
3698 | "\t triggers: a command to perform when function is hit\n" | |
3699 | "\t Format: <function>:<trigger>[:count]\n" | |
3700 | "\t trigger: traceon, traceoff\n" | |
3701 | "\t\t enable_event:<system>:<event>\n" | |
3702 | "\t\t disable_event:<system>:<event>\n" | |
22f45649 | 3703 | #ifdef CONFIG_STACKTRACE |
71485c45 | 3704 | "\t\t stacktrace\n" |
22f45649 SRRH |
3705 | #endif |
3706 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 | 3707 | "\t\t snapshot\n" |
22f45649 | 3708 | #endif |
17a280ea SRRH |
3709 | "\t\t dump\n" |
3710 | "\t\t cpudump\n" | |
71485c45 SRRH |
3711 | "\t example: echo do_fault:traceoff > set_ftrace_filter\n" |
3712 | "\t echo do_trap:traceoff:3 > set_ftrace_filter\n" | |
3713 | "\t The first one will disable tracing every time do_fault is hit\n" | |
3714 | "\t The second will disable tracing at most 3 times when do_trap is hit\n" | |
3715 | "\t The first time do trap is hit and it disables tracing, the\n" | |
3716 | "\t counter will decrement to 2. If tracing is already disabled,\n" | |
3717 | "\t the counter will not decrement. It only decrements when the\n" | |
3718 | "\t trigger did work\n" | |
3719 | "\t To remove trigger without count:\n" | |
3720 | "\t echo '!<function>:<trigger> > set_ftrace_filter\n" | |
3721 | "\t To remove trigger with a count:\n" | |
3722 | "\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n" | |
22f45649 | 3723 | " set_ftrace_notrace\t- echo function name in here to never trace.\n" |
71485c45 SRRH |
3724 | "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" |
3725 | "\t modules: Can select a group via module command :mod:\n" | |
3726 | "\t Does not accept triggers\n" | |
22f45649 SRRH |
3727 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3728 | #ifdef CONFIG_FUNCTION_TRACER | |
71485c45 SRRH |
3729 | " set_ftrace_pid\t- Write pid(s) to only function trace those pids\n" |
3730 | "\t\t (function)\n" | |
22f45649 SRRH |
3731 | #endif |
3732 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
3733 | " set_graph_function\t- Trace the nested calls of a function (function_graph)\n" | |
d048a8c7 | 3734 | " set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n" |
22f45649 SRRH |
3735 | " max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n" |
3736 | #endif | |
3737 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 SRRH |
3738 | "\n snapshot\t\t- Like 'trace' but shows the content of the static\n" |
3739 | "\t\t\t snapshot buffer. Read the contents for more\n" | |
3740 | "\t\t\t information\n" | |
22f45649 | 3741 | #endif |
991821c8 | 3742 | #ifdef CONFIG_STACK_TRACER |
22f45649 SRRH |
3743 | " stack_trace\t\t- Shows the max stack trace when active\n" |
3744 | " stack_max_size\t- Shows current max stack size that was traced\n" | |
71485c45 SRRH |
3745 | "\t\t\t Write into this file to reset the max size (trigger a\n" |
3746 | "\t\t\t new trace)\n" | |
22f45649 | 3747 | #ifdef CONFIG_DYNAMIC_FTRACE |
71485c45 SRRH |
3748 | " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n" |
3749 | "\t\t\t traces\n" | |
22f45649 | 3750 | #endif |
991821c8 | 3751 | #endif /* CONFIG_STACK_TRACER */ |
26f25564 TZ |
3752 | " events/\t\t- Directory containing all trace event subsystems:\n" |
3753 | " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" | |
3754 | " events/<system>/\t- Directory containing all trace events for <system>:\n" | |
71485c45 SRRH |
3755 | " enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n" |
3756 | "\t\t\t events\n" | |
26f25564 | 3757 | " filter\t\t- If set, only events passing filter are traced\n" |
71485c45 SRRH |
3758 | " events/<system>/<event>/\t- Directory containing control files for\n" |
3759 | "\t\t\t <event>:\n" | |
26f25564 TZ |
3760 | " enable\t\t- Write 0/1 to enable/disable tracing of <event>\n" |
3761 | " filter\t\t- If set, only events passing filter are traced\n" | |
3762 | " trigger\t\t- If set, a command to perform when event is hit\n" | |
71485c45 SRRH |
3763 | "\t Format: <trigger>[:count][if <filter>]\n" |
3764 | "\t trigger: traceon, traceoff\n" | |
3765 | "\t enable_event:<system>:<event>\n" | |
3766 | "\t disable_event:<system>:<event>\n" | |
d0bad49b TZ |
3767 | #ifdef CONFIG_HIST_TRIGGERS |
3768 | "\t enable_hist:<system>:<event>\n" | |
3769 | "\t disable_hist:<system>:<event>\n" | |
3770 | #endif | |
26f25564 | 3771 | #ifdef CONFIG_STACKTRACE |
71485c45 | 3772 | "\t\t stacktrace\n" |
26f25564 TZ |
3773 | #endif |
3774 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 | 3775 | "\t\t snapshot\n" |
7ef224d1 TZ |
3776 | #endif |
3777 | #ifdef CONFIG_HIST_TRIGGERS | |
3778 | "\t\t hist (see below)\n" | |
26f25564 | 3779 | #endif |
71485c45 SRRH |
3780 | "\t example: echo traceoff > events/block/block_unplug/trigger\n" |
3781 | "\t echo traceoff:3 > events/block/block_unplug/trigger\n" | |
3782 | "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n" | |
3783 | "\t events/block/block_unplug/trigger\n" | |
3784 | "\t The first disables tracing every time block_unplug is hit.\n" | |
3785 | "\t The second disables tracing the first 3 times block_unplug is hit.\n" | |
3786 | "\t The third enables the kmalloc event the first 3 times block_unplug\n" | |
3787 | "\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n" | |
3788 | "\t Like function triggers, the counter is only decremented if it\n" | |
3789 | "\t enabled or disabled tracing.\n" | |
3790 | "\t To remove a trigger without a count:\n" | |
3791 | "\t echo '!<trigger> > <system>/<event>/trigger\n" | |
3792 | "\t To remove a trigger with a count:\n" | |
3793 | "\t echo '!<trigger>:0 > <system>/<event>/trigger\n" | |
3794 | "\t Filters can be ignored when removing a trigger.\n" | |
7ef224d1 TZ |
3795 | #ifdef CONFIG_HIST_TRIGGERS |
3796 | " hist trigger\t- If set, event hits are aggregated into a hash table\n" | |
76a3b0c8 | 3797 | "\t Format: hist:keys=<field1[,field2,...]>\n" |
f2606835 | 3798 | "\t [:values=<field1[,field2,...]>]\n" |
e62347d2 | 3799 | "\t [:sort=<field1[,field2,...]>]\n" |
7ef224d1 | 3800 | "\t [:size=#entries]\n" |
e86ae9ba | 3801 | "\t [:pause][:continue][:clear]\n" |
5463bfda | 3802 | "\t [:name=histname1]\n" |
7ef224d1 TZ |
3803 | "\t [if <filter>]\n\n" |
3804 | "\t When a matching event is hit, an entry is added to a hash\n" | |
f2606835 TZ |
3805 | "\t table using the key(s) and value(s) named, and the value of a\n" |
3806 | "\t sum called 'hitcount' is incremented. Keys and values\n" | |
3807 | "\t correspond to fields in the event's format description. Keys\n" | |
69a0200c TZ |
3808 | "\t can be any field, or the special string 'stacktrace'.\n" |
3809 | "\t Compound keys consisting of up to two fields can be specified\n" | |
3810 | "\t by the 'keys' keyword. Values must correspond to numeric\n" | |
3811 | "\t fields. Sort keys consisting of up to two fields can be\n" | |
3812 | "\t specified using the 'sort' keyword. The sort direction can\n" | |
3813 | "\t be modified by appending '.descending' or '.ascending' to a\n" | |
3814 | "\t sort field. The 'size' parameter can be used to specify more\n" | |
5463bfda TZ |
3815 | "\t or fewer than the default 2048 entries for the hashtable size.\n" |
3816 | "\t If a hist trigger is given a name using the 'name' parameter,\n" | |
3817 | "\t its histogram data will be shared with other triggers of the\n" | |
3818 | "\t same name, and trigger hits will update this common data.\n\n" | |
7ef224d1 | 3819 | "\t Reading the 'hist' file for the event will dump the hash\n" |
52a7f16d TZ |
3820 | "\t table in its entirety to stdout. If there are multiple hist\n" |
3821 | "\t triggers attached to an event, there will be a table for each\n" | |
5463bfda TZ |
3822 | "\t trigger in the output. The table displayed for a named\n" |
3823 | "\t trigger will be the same as any other instance having the\n" | |
3824 | "\t same name. The default format used to display a given field\n" | |
3825 | "\t can be modified by appending any of the following modifiers\n" | |
3826 | "\t to the field name, as applicable:\n\n" | |
c6afad49 TZ |
3827 | "\t .hex display a number as a hex value\n" |
3828 | "\t .sym display an address as a symbol\n" | |
6b4827ad | 3829 | "\t .sym-offset display an address as a symbol and offset\n" |
31696198 TZ |
3830 | "\t .execname display a common_pid as a program name\n" |
3831 | "\t .syscall display a syscall id as a syscall name\n\n" | |
4b94f5b7 | 3832 | "\t .log2 display log2 value rather than raw number\n\n" |
83e99914 TZ |
3833 | "\t The 'pause' parameter can be used to pause an existing hist\n" |
3834 | "\t trigger or to start a hist trigger but not log any events\n" | |
3835 | "\t until told to do so. 'continue' can be used to start or\n" | |
3836 | "\t restart a paused hist trigger.\n\n" | |
e86ae9ba TZ |
3837 | "\t The 'clear' parameter will clear the contents of a running\n" |
3838 | "\t hist trigger and leave its current paused/active state\n" | |
3839 | "\t unchanged.\n\n" | |
d0bad49b TZ |
3840 | "\t The enable_hist and disable_hist triggers can be used to\n" |
3841 | "\t have one event conditionally start and stop another event's\n" | |
3842 | "\t already-attached hist trigger. The syntax is analagous to\n" | |
3843 | "\t the enable_event and disable_event triggers.\n" | |
7ef224d1 | 3844 | #endif |
7bd2f24c IM |
3845 | ; |
3846 | ||
3847 | static ssize_t | |
3848 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
3849 | size_t cnt, loff_t *ppos) | |
3850 | { | |
3851 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
3852 | readme_msg, strlen(readme_msg)); | |
3853 | } | |
3854 | ||
5e2336a0 | 3855 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
3856 | .open = tracing_open_generic, |
3857 | .read = tracing_readme_read, | |
b444786f | 3858 | .llseek = generic_file_llseek, |
7bd2f24c IM |
3859 | }; |
3860 | ||
42584c81 YY |
3861 | static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos) |
3862 | { | |
3863 | unsigned int *ptr = v; | |
69abe6a5 | 3864 | |
42584c81 YY |
3865 | if (*pos || m->count) |
3866 | ptr++; | |
69abe6a5 | 3867 | |
42584c81 | 3868 | (*pos)++; |
69abe6a5 | 3869 | |
939c7a4f YY |
3870 | for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num]; |
3871 | ptr++) { | |
42584c81 YY |
3872 | if (*ptr == -1 || *ptr == NO_CMDLINE_MAP) |
3873 | continue; | |
69abe6a5 | 3874 | |
42584c81 YY |
3875 | return ptr; |
3876 | } | |
69abe6a5 | 3877 | |
42584c81 YY |
3878 | return NULL; |
3879 | } | |
3880 | ||
3881 | static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos) | |
3882 | { | |
3883 | void *v; | |
3884 | loff_t l = 0; | |
69abe6a5 | 3885 | |
4c27e756 SRRH |
3886 | preempt_disable(); |
3887 | arch_spin_lock(&trace_cmdline_lock); | |
3888 | ||
939c7a4f | 3889 | v = &savedcmd->map_cmdline_to_pid[0]; |
42584c81 YY |
3890 | while (l <= *pos) { |
3891 | v = saved_cmdlines_next(m, v, &l); | |
3892 | if (!v) | |
3893 | return NULL; | |
69abe6a5 AP |
3894 | } |
3895 | ||
42584c81 YY |
3896 | return v; |
3897 | } | |
3898 | ||
3899 | static void saved_cmdlines_stop(struct seq_file *m, void *v) | |
3900 | { | |
4c27e756 SRRH |
3901 | arch_spin_unlock(&trace_cmdline_lock); |
3902 | preempt_enable(); | |
42584c81 | 3903 | } |
69abe6a5 | 3904 | |
42584c81 YY |
3905 | static int saved_cmdlines_show(struct seq_file *m, void *v) |
3906 | { | |
3907 | char buf[TASK_COMM_LEN]; | |
3908 | unsigned int *pid = v; | |
69abe6a5 | 3909 | |
4c27e756 | 3910 | __trace_find_cmdline(*pid, buf); |
42584c81 YY |
3911 | seq_printf(m, "%d %s\n", *pid, buf); |
3912 | return 0; | |
3913 | } | |
3914 | ||
3915 | static const struct seq_operations tracing_saved_cmdlines_seq_ops = { | |
3916 | .start = saved_cmdlines_start, | |
3917 | .next = saved_cmdlines_next, | |
3918 | .stop = saved_cmdlines_stop, | |
3919 | .show = saved_cmdlines_show, | |
3920 | }; | |
3921 | ||
3922 | static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp) | |
3923 | { | |
3924 | if (tracing_disabled) | |
3925 | return -ENODEV; | |
3926 | ||
3927 | return seq_open(filp, &tracing_saved_cmdlines_seq_ops); | |
69abe6a5 AP |
3928 | } |
3929 | ||
3930 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
42584c81 YY |
3931 | .open = tracing_saved_cmdlines_open, |
3932 | .read = seq_read, | |
3933 | .llseek = seq_lseek, | |
3934 | .release = seq_release, | |
69abe6a5 AP |
3935 | }; |
3936 | ||
939c7a4f YY |
3937 | static ssize_t |
3938 | tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf, | |
3939 | size_t cnt, loff_t *ppos) | |
3940 | { | |
3941 | char buf[64]; | |
3942 | int r; | |
3943 | ||
3944 | arch_spin_lock(&trace_cmdline_lock); | |
a6af8fbf | 3945 | r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num); |
939c7a4f YY |
3946 | arch_spin_unlock(&trace_cmdline_lock); |
3947 | ||
3948 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3949 | } | |
3950 | ||
3951 | static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s) | |
3952 | { | |
3953 | kfree(s->saved_cmdlines); | |
3954 | kfree(s->map_cmdline_to_pid); | |
3955 | kfree(s); | |
3956 | } | |
3957 | ||
3958 | static int tracing_resize_saved_cmdlines(unsigned int val) | |
3959 | { | |
3960 | struct saved_cmdlines_buffer *s, *savedcmd_temp; | |
3961 | ||
a6af8fbf | 3962 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
939c7a4f YY |
3963 | if (!s) |
3964 | return -ENOMEM; | |
3965 | ||
3966 | if (allocate_cmdlines_buffer(val, s) < 0) { | |
3967 | kfree(s); | |
3968 | return -ENOMEM; | |
3969 | } | |
3970 | ||
3971 | arch_spin_lock(&trace_cmdline_lock); | |
3972 | savedcmd_temp = savedcmd; | |
3973 | savedcmd = s; | |
3974 | arch_spin_unlock(&trace_cmdline_lock); | |
3975 | free_saved_cmdlines_buffer(savedcmd_temp); | |
3976 | ||
3977 | return 0; | |
3978 | } | |
3979 | ||
3980 | static ssize_t | |
3981 | tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf, | |
3982 | size_t cnt, loff_t *ppos) | |
3983 | { | |
3984 | unsigned long val; | |
3985 | int ret; | |
3986 | ||
3987 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
3988 | if (ret) | |
3989 | return ret; | |
3990 | ||
3991 | /* must have at least 1 entry or less than PID_MAX_DEFAULT */ | |
3992 | if (!val || val > PID_MAX_DEFAULT) | |
3993 | return -EINVAL; | |
3994 | ||
3995 | ret = tracing_resize_saved_cmdlines((unsigned int)val); | |
3996 | if (ret < 0) | |
3997 | return ret; | |
3998 | ||
3999 | *ppos += cnt; | |
4000 | ||
4001 | return cnt; | |
4002 | } | |
4003 | ||
4004 | static const struct file_operations tracing_saved_cmdlines_size_fops = { | |
4005 | .open = tracing_open_generic, | |
4006 | .read = tracing_saved_cmdlines_size_read, | |
4007 | .write = tracing_saved_cmdlines_size_write, | |
4008 | }; | |
4009 | ||
9828413d SRRH |
4010 | #ifdef CONFIG_TRACE_ENUM_MAP_FILE |
4011 | static union trace_enum_map_item * | |
4012 | update_enum_map(union trace_enum_map_item *ptr) | |
4013 | { | |
4014 | if (!ptr->map.enum_string) { | |
4015 | if (ptr->tail.next) { | |
4016 | ptr = ptr->tail.next; | |
4017 | /* Set ptr to the next real item (skip head) */ | |
4018 | ptr++; | |
4019 | } else | |
4020 | return NULL; | |
4021 | } | |
4022 | return ptr; | |
4023 | } | |
4024 | ||
4025 | static void *enum_map_next(struct seq_file *m, void *v, loff_t *pos) | |
4026 | { | |
4027 | union trace_enum_map_item *ptr = v; | |
4028 | ||
4029 | /* | |
4030 | * Paranoid! If ptr points to end, we don't want to increment past it. | |
4031 | * This really should never happen. | |
4032 | */ | |
4033 | ptr = update_enum_map(ptr); | |
4034 | if (WARN_ON_ONCE(!ptr)) | |
4035 | return NULL; | |
4036 | ||
4037 | ptr++; | |
4038 | ||
4039 | (*pos)++; | |
4040 | ||
4041 | ptr = update_enum_map(ptr); | |
4042 | ||
4043 | return ptr; | |
4044 | } | |
4045 | ||
4046 | static void *enum_map_start(struct seq_file *m, loff_t *pos) | |
4047 | { | |
4048 | union trace_enum_map_item *v; | |
4049 | loff_t l = 0; | |
4050 | ||
4051 | mutex_lock(&trace_enum_mutex); | |
4052 | ||
4053 | v = trace_enum_maps; | |
4054 | if (v) | |
4055 | v++; | |
4056 | ||
4057 | while (v && l < *pos) { | |
4058 | v = enum_map_next(m, v, &l); | |
4059 | } | |
4060 | ||
4061 | return v; | |
4062 | } | |
4063 | ||
4064 | static void enum_map_stop(struct seq_file *m, void *v) | |
4065 | { | |
4066 | mutex_unlock(&trace_enum_mutex); | |
4067 | } | |
4068 | ||
4069 | static int enum_map_show(struct seq_file *m, void *v) | |
4070 | { | |
4071 | union trace_enum_map_item *ptr = v; | |
4072 | ||
4073 | seq_printf(m, "%s %ld (%s)\n", | |
4074 | ptr->map.enum_string, ptr->map.enum_value, | |
4075 | ptr->map.system); | |
4076 | ||
4077 | return 0; | |
4078 | } | |
4079 | ||
4080 | static const struct seq_operations tracing_enum_map_seq_ops = { | |
4081 | .start = enum_map_start, | |
4082 | .next = enum_map_next, | |
4083 | .stop = enum_map_stop, | |
4084 | .show = enum_map_show, | |
4085 | }; | |
4086 | ||
4087 | static int tracing_enum_map_open(struct inode *inode, struct file *filp) | |
4088 | { | |
4089 | if (tracing_disabled) | |
4090 | return -ENODEV; | |
4091 | ||
4092 | return seq_open(filp, &tracing_enum_map_seq_ops); | |
4093 | } | |
4094 | ||
4095 | static const struct file_operations tracing_enum_map_fops = { | |
4096 | .open = tracing_enum_map_open, | |
4097 | .read = seq_read, | |
4098 | .llseek = seq_lseek, | |
4099 | .release = seq_release, | |
4100 | }; | |
4101 | ||
4102 | static inline union trace_enum_map_item * | |
4103 | trace_enum_jmp_to_tail(union trace_enum_map_item *ptr) | |
4104 | { | |
4105 | /* Return tail of array given the head */ | |
4106 | return ptr + ptr->head.length + 1; | |
4107 | } | |
4108 | ||
4109 | static void | |
4110 | trace_insert_enum_map_file(struct module *mod, struct trace_enum_map **start, | |
4111 | int len) | |
4112 | { | |
4113 | struct trace_enum_map **stop; | |
4114 | struct trace_enum_map **map; | |
4115 | union trace_enum_map_item *map_array; | |
4116 | union trace_enum_map_item *ptr; | |
4117 | ||
4118 | stop = start + len; | |
4119 | ||
4120 | /* | |
4121 | * The trace_enum_maps contains the map plus a head and tail item, | |
4122 | * where the head holds the module and length of array, and the | |
4123 | * tail holds a pointer to the next list. | |
4124 | */ | |
4125 | map_array = kmalloc(sizeof(*map_array) * (len + 2), GFP_KERNEL); | |
4126 | if (!map_array) { | |
a395d6a7 | 4127 | pr_warn("Unable to allocate trace enum mapping\n"); |
9828413d SRRH |
4128 | return; |
4129 | } | |
4130 | ||
4131 | mutex_lock(&trace_enum_mutex); | |
4132 | ||
4133 | if (!trace_enum_maps) | |
4134 | trace_enum_maps = map_array; | |
4135 | else { | |
4136 | ptr = trace_enum_maps; | |
4137 | for (;;) { | |
4138 | ptr = trace_enum_jmp_to_tail(ptr); | |
4139 | if (!ptr->tail.next) | |
4140 | break; | |
4141 | ptr = ptr->tail.next; | |
4142 | ||
4143 | } | |
4144 | ptr->tail.next = map_array; | |
4145 | } | |
4146 | map_array->head.mod = mod; | |
4147 | map_array->head.length = len; | |
4148 | map_array++; | |
4149 | ||
4150 | for (map = start; (unsigned long)map < (unsigned long)stop; map++) { | |
4151 | map_array->map = **map; | |
4152 | map_array++; | |
4153 | } | |
4154 | memset(map_array, 0, sizeof(*map_array)); | |
4155 | ||
4156 | mutex_unlock(&trace_enum_mutex); | |
4157 | } | |
4158 | ||
4159 | static void trace_create_enum_file(struct dentry *d_tracer) | |
4160 | { | |
4161 | trace_create_file("enum_map", 0444, d_tracer, | |
4162 | NULL, &tracing_enum_map_fops); | |
4163 | } | |
4164 | ||
4165 | #else /* CONFIG_TRACE_ENUM_MAP_FILE */ | |
4166 | static inline void trace_create_enum_file(struct dentry *d_tracer) { } | |
4167 | static inline void trace_insert_enum_map_file(struct module *mod, | |
4168 | struct trace_enum_map **start, int len) { } | |
4169 | #endif /* !CONFIG_TRACE_ENUM_MAP_FILE */ | |
4170 | ||
4171 | static void trace_insert_enum_map(struct module *mod, | |
4172 | struct trace_enum_map **start, int len) | |
0c564a53 SRRH |
4173 | { |
4174 | struct trace_enum_map **map; | |
0c564a53 SRRH |
4175 | |
4176 | if (len <= 0) | |
4177 | return; | |
4178 | ||
4179 | map = start; | |
4180 | ||
4181 | trace_event_enum_update(map, len); | |
9828413d SRRH |
4182 | |
4183 | trace_insert_enum_map_file(mod, start, len); | |
0c564a53 SRRH |
4184 | } |
4185 | ||
bc0c38d1 SR |
4186 | static ssize_t |
4187 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
4188 | size_t cnt, loff_t *ppos) | |
4189 | { | |
2b6080f2 | 4190 | struct trace_array *tr = filp->private_data; |
ee6c2c1b | 4191 | char buf[MAX_TRACER_SIZE+2]; |
bc0c38d1 SR |
4192 | int r; |
4193 | ||
4194 | mutex_lock(&trace_types_lock); | |
2b6080f2 | 4195 | r = sprintf(buf, "%s\n", tr->current_trace->name); |
bc0c38d1 SR |
4196 | mutex_unlock(&trace_types_lock); |
4197 | ||
4bf39a94 | 4198 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
4199 | } |
4200 | ||
b6f11df2 ACM |
4201 | int tracer_init(struct tracer *t, struct trace_array *tr) |
4202 | { | |
12883efb | 4203 | tracing_reset_online_cpus(&tr->trace_buffer); |
b6f11df2 ACM |
4204 | return t->init(tr); |
4205 | } | |
4206 | ||
12883efb | 4207 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val) |
438ced17 VN |
4208 | { |
4209 | int cpu; | |
737223fb | 4210 | |
438ced17 | 4211 | for_each_tracing_cpu(cpu) |
12883efb | 4212 | per_cpu_ptr(buf->data, cpu)->entries = val; |
438ced17 VN |
4213 | } |
4214 | ||
12883efb | 4215 | #ifdef CONFIG_TRACER_MAX_TRACE |
d60da506 | 4216 | /* resize @tr's buffer to the size of @size_tr's entries */ |
12883efb SRRH |
4217 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, |
4218 | struct trace_buffer *size_buf, int cpu_id) | |
d60da506 HT |
4219 | { |
4220 | int cpu, ret = 0; | |
4221 | ||
4222 | if (cpu_id == RING_BUFFER_ALL_CPUS) { | |
4223 | for_each_tracing_cpu(cpu) { | |
12883efb SRRH |
4224 | ret = ring_buffer_resize(trace_buf->buffer, |
4225 | per_cpu_ptr(size_buf->data, cpu)->entries, cpu); | |
d60da506 HT |
4226 | if (ret < 0) |
4227 | break; | |
12883efb SRRH |
4228 | per_cpu_ptr(trace_buf->data, cpu)->entries = |
4229 | per_cpu_ptr(size_buf->data, cpu)->entries; | |
d60da506 HT |
4230 | } |
4231 | } else { | |
12883efb SRRH |
4232 | ret = ring_buffer_resize(trace_buf->buffer, |
4233 | per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); | |
d60da506 | 4234 | if (ret == 0) |
12883efb SRRH |
4235 | per_cpu_ptr(trace_buf->data, cpu_id)->entries = |
4236 | per_cpu_ptr(size_buf->data, cpu_id)->entries; | |
d60da506 HT |
4237 | } |
4238 | ||
4239 | return ret; | |
4240 | } | |
12883efb | 4241 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
d60da506 | 4242 | |
2b6080f2 SR |
4243 | static int __tracing_resize_ring_buffer(struct trace_array *tr, |
4244 | unsigned long size, int cpu) | |
73c5162a SR |
4245 | { |
4246 | int ret; | |
4247 | ||
4248 | /* | |
4249 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
4250 | * we use the size that was given, and we can forget about |
4251 | * expanding it later. | |
73c5162a | 4252 | */ |
55034cd6 | 4253 | ring_buffer_expanded = true; |
73c5162a | 4254 | |
b382ede6 | 4255 | /* May be called before buffers are initialized */ |
12883efb | 4256 | if (!tr->trace_buffer.buffer) |
b382ede6 SR |
4257 | return 0; |
4258 | ||
12883efb | 4259 | ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu); |
73c5162a SR |
4260 | if (ret < 0) |
4261 | return ret; | |
4262 | ||
12883efb | 4263 | #ifdef CONFIG_TRACER_MAX_TRACE |
2b6080f2 SR |
4264 | if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || |
4265 | !tr->current_trace->use_max_tr) | |
ef710e10 KM |
4266 | goto out; |
4267 | ||
12883efb | 4268 | ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); |
73c5162a | 4269 | if (ret < 0) { |
12883efb SRRH |
4270 | int r = resize_buffer_duplicate_size(&tr->trace_buffer, |
4271 | &tr->trace_buffer, cpu); | |
73c5162a | 4272 | if (r < 0) { |
a123c52b SR |
4273 | /* |
4274 | * AARGH! We are left with different | |
4275 | * size max buffer!!!! | |
4276 | * The max buffer is our "snapshot" buffer. | |
4277 | * When a tracer needs a snapshot (one of the | |
4278 | * latency tracers), it swaps the max buffer | |
4279 | * with the saved snap shot. We succeeded to | |
4280 | * update the size of the main buffer, but failed to | |
4281 | * update the size of the max buffer. But when we tried | |
4282 | * to reset the main buffer to the original size, we | |
4283 | * failed there too. This is very unlikely to | |
4284 | * happen, but if it does, warn and kill all | |
4285 | * tracing. | |
4286 | */ | |
73c5162a SR |
4287 | WARN_ON(1); |
4288 | tracing_disabled = 1; | |
4289 | } | |
4290 | return ret; | |
4291 | } | |
4292 | ||
438ced17 | 4293 | if (cpu == RING_BUFFER_ALL_CPUS) |
12883efb | 4294 | set_buffer_entries(&tr->max_buffer, size); |
438ced17 | 4295 | else |
12883efb | 4296 | per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size; |
438ced17 | 4297 | |
ef710e10 | 4298 | out: |
12883efb SRRH |
4299 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
4300 | ||
438ced17 | 4301 | if (cpu == RING_BUFFER_ALL_CPUS) |
12883efb | 4302 | set_buffer_entries(&tr->trace_buffer, size); |
438ced17 | 4303 | else |
12883efb | 4304 | per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size; |
73c5162a SR |
4305 | |
4306 | return ret; | |
4307 | } | |
4308 | ||
2b6080f2 SR |
4309 | static ssize_t tracing_resize_ring_buffer(struct trace_array *tr, |
4310 | unsigned long size, int cpu_id) | |
4f271a2a | 4311 | { |
83f40318 | 4312 | int ret = size; |
4f271a2a VN |
4313 | |
4314 | mutex_lock(&trace_types_lock); | |
4315 | ||
438ced17 VN |
4316 | if (cpu_id != RING_BUFFER_ALL_CPUS) { |
4317 | /* make sure, this cpu is enabled in the mask */ | |
4318 | if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { | |
4319 | ret = -EINVAL; | |
4320 | goto out; | |
4321 | } | |
4322 | } | |
4f271a2a | 4323 | |
2b6080f2 | 4324 | ret = __tracing_resize_ring_buffer(tr, size, cpu_id); |
4f271a2a VN |
4325 | if (ret < 0) |
4326 | ret = -ENOMEM; | |
4327 | ||
438ced17 | 4328 | out: |
4f271a2a VN |
4329 | mutex_unlock(&trace_types_lock); |
4330 | ||
4331 | return ret; | |
4332 | } | |
4333 | ||
ef710e10 | 4334 | |
1852fcce SR |
4335 | /** |
4336 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
4337 | * | |
4338 | * To save on memory when the tracing is never used on a system with it | |
4339 | * configured in. The ring buffers are set to a minimum size. But once | |
4340 | * a user starts to use the tracing facility, then they need to grow | |
4341 | * to their default size. | |
4342 | * | |
4343 | * This function is to be called when a tracer is about to be used. | |
4344 | */ | |
4345 | int tracing_update_buffers(void) | |
4346 | { | |
4347 | int ret = 0; | |
4348 | ||
1027fcb2 | 4349 | mutex_lock(&trace_types_lock); |
1852fcce | 4350 | if (!ring_buffer_expanded) |
2b6080f2 | 4351 | ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, |
438ced17 | 4352 | RING_BUFFER_ALL_CPUS); |
1027fcb2 | 4353 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
4354 | |
4355 | return ret; | |
4356 | } | |
4357 | ||
577b785f SR |
4358 | struct trace_option_dentry; |
4359 | ||
37aea98b | 4360 | static void |
2b6080f2 | 4361 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer); |
577b785f | 4362 | |
6b450d25 SRRH |
4363 | /* |
4364 | * Used to clear out the tracer before deletion of an instance. | |
4365 | * Must have trace_types_lock held. | |
4366 | */ | |
4367 | static void tracing_set_nop(struct trace_array *tr) | |
4368 | { | |
4369 | if (tr->current_trace == &nop_trace) | |
4370 | return; | |
4371 | ||
50512ab5 | 4372 | tr->current_trace->enabled--; |
6b450d25 SRRH |
4373 | |
4374 | if (tr->current_trace->reset) | |
4375 | tr->current_trace->reset(tr); | |
4376 | ||
4377 | tr->current_trace = &nop_trace; | |
4378 | } | |
4379 | ||
41d9c0be | 4380 | static void add_tracer_options(struct trace_array *tr, struct tracer *t) |
bc0c38d1 | 4381 | { |
09d23a1d SRRH |
4382 | /* Only enable if the directory has been created already. */ |
4383 | if (!tr->dir) | |
4384 | return; | |
4385 | ||
37aea98b | 4386 | create_trace_option_files(tr, t); |
09d23a1d SRRH |
4387 | } |
4388 | ||
4389 | static int tracing_set_tracer(struct trace_array *tr, const char *buf) | |
4390 | { | |
bc0c38d1 | 4391 | struct tracer *t; |
12883efb | 4392 | #ifdef CONFIG_TRACER_MAX_TRACE |
34600f0e | 4393 | bool had_max_tr; |
12883efb | 4394 | #endif |
d9e54076 | 4395 | int ret = 0; |
bc0c38d1 | 4396 | |
1027fcb2 SR |
4397 | mutex_lock(&trace_types_lock); |
4398 | ||
73c5162a | 4399 | if (!ring_buffer_expanded) { |
2b6080f2 | 4400 | ret = __tracing_resize_ring_buffer(tr, trace_buf_size, |
438ced17 | 4401 | RING_BUFFER_ALL_CPUS); |
73c5162a | 4402 | if (ret < 0) |
59f586db | 4403 | goto out; |
73c5162a SR |
4404 | ret = 0; |
4405 | } | |
4406 | ||
bc0c38d1 SR |
4407 | for (t = trace_types; t; t = t->next) { |
4408 | if (strcmp(t->name, buf) == 0) | |
4409 | break; | |
4410 | } | |
c2931e05 FW |
4411 | if (!t) { |
4412 | ret = -EINVAL; | |
4413 | goto out; | |
4414 | } | |
2b6080f2 | 4415 | if (t == tr->current_trace) |
bc0c38d1 SR |
4416 | goto out; |
4417 | ||
607e2ea1 SRRH |
4418 | /* Some tracers are only allowed for the top level buffer */ |
4419 | if (!trace_ok_for_array(t, tr)) { | |
4420 | ret = -EINVAL; | |
4421 | goto out; | |
4422 | } | |
4423 | ||
cf6ab6d9 SRRH |
4424 | /* If trace pipe files are being read, we can't change the tracer */ |
4425 | if (tr->current_trace->ref) { | |
4426 | ret = -EBUSY; | |
4427 | goto out; | |
4428 | } | |
4429 | ||
9f029e83 | 4430 | trace_branch_disable(); |
613f04a0 | 4431 | |
50512ab5 | 4432 | tr->current_trace->enabled--; |
613f04a0 | 4433 | |
2b6080f2 SR |
4434 | if (tr->current_trace->reset) |
4435 | tr->current_trace->reset(tr); | |
34600f0e | 4436 | |
12883efb | 4437 | /* Current trace needs to be nop_trace before synchronize_sched */ |
2b6080f2 | 4438 | tr->current_trace = &nop_trace; |
34600f0e | 4439 | |
45ad21ca SRRH |
4440 | #ifdef CONFIG_TRACER_MAX_TRACE |
4441 | had_max_tr = tr->allocated_snapshot; | |
34600f0e SR |
4442 | |
4443 | if (had_max_tr && !t->use_max_tr) { | |
4444 | /* | |
4445 | * We need to make sure that the update_max_tr sees that | |
4446 | * current_trace changed to nop_trace to keep it from | |
4447 | * swapping the buffers after we resize it. | |
4448 | * The update_max_tr is called from interrupts disabled | |
4449 | * so a synchronized_sched() is sufficient. | |
4450 | */ | |
4451 | synchronize_sched(); | |
3209cff4 | 4452 | free_snapshot(tr); |
ef710e10 | 4453 | } |
12883efb | 4454 | #endif |
12883efb SRRH |
4455 | |
4456 | #ifdef CONFIG_TRACER_MAX_TRACE | |
34600f0e | 4457 | if (t->use_max_tr && !had_max_tr) { |
3209cff4 | 4458 | ret = alloc_snapshot(tr); |
d60da506 HT |
4459 | if (ret < 0) |
4460 | goto out; | |
ef710e10 | 4461 | } |
12883efb | 4462 | #endif |
577b785f | 4463 | |
1c80025a | 4464 | if (t->init) { |
b6f11df2 | 4465 | ret = tracer_init(t, tr); |
1c80025a FW |
4466 | if (ret) |
4467 | goto out; | |
4468 | } | |
bc0c38d1 | 4469 | |
2b6080f2 | 4470 | tr->current_trace = t; |
50512ab5 | 4471 | tr->current_trace->enabled++; |
9f029e83 | 4472 | trace_branch_enable(tr); |
bc0c38d1 SR |
4473 | out: |
4474 | mutex_unlock(&trace_types_lock); | |
4475 | ||
d9e54076 PZ |
4476 | return ret; |
4477 | } | |
4478 | ||
4479 | static ssize_t | |
4480 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
4481 | size_t cnt, loff_t *ppos) | |
4482 | { | |
607e2ea1 | 4483 | struct trace_array *tr = filp->private_data; |
ee6c2c1b | 4484 | char buf[MAX_TRACER_SIZE+1]; |
d9e54076 PZ |
4485 | int i; |
4486 | size_t ret; | |
e6e7a65a FW |
4487 | int err; |
4488 | ||
4489 | ret = cnt; | |
d9e54076 | 4490 | |
ee6c2c1b LZ |
4491 | if (cnt > MAX_TRACER_SIZE) |
4492 | cnt = MAX_TRACER_SIZE; | |
d9e54076 | 4493 | |
4afe6495 | 4494 | if (copy_from_user(buf, ubuf, cnt)) |
d9e54076 PZ |
4495 | return -EFAULT; |
4496 | ||
4497 | buf[cnt] = 0; | |
4498 | ||
4499 | /* strip ending whitespace. */ | |
4500 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
4501 | buf[i] = 0; | |
4502 | ||
607e2ea1 | 4503 | err = tracing_set_tracer(tr, buf); |
e6e7a65a FW |
4504 | if (err) |
4505 | return err; | |
d9e54076 | 4506 | |
cf8517cf | 4507 | *ppos += ret; |
bc0c38d1 | 4508 | |
c2931e05 | 4509 | return ret; |
bc0c38d1 SR |
4510 | } |
4511 | ||
4512 | static ssize_t | |
6508fa76 SF |
4513 | tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, |
4514 | size_t cnt, loff_t *ppos) | |
bc0c38d1 | 4515 | { |
bc0c38d1 SR |
4516 | char buf[64]; |
4517 | int r; | |
4518 | ||
cffae437 | 4519 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 4520 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
4521 | if (r > sizeof(buf)) |
4522 | r = sizeof(buf); | |
4bf39a94 | 4523 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
4524 | } |
4525 | ||
4526 | static ssize_t | |
6508fa76 SF |
4527 | tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf, |
4528 | size_t cnt, loff_t *ppos) | |
bc0c38d1 | 4529 | { |
5e39841c | 4530 | unsigned long val; |
c6caeeb1 | 4531 | int ret; |
bc0c38d1 | 4532 | |
22fe9b54 PH |
4533 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4534 | if (ret) | |
c6caeeb1 | 4535 | return ret; |
bc0c38d1 SR |
4536 | |
4537 | *ptr = val * 1000; | |
4538 | ||
4539 | return cnt; | |
4540 | } | |
4541 | ||
6508fa76 SF |
4542 | static ssize_t |
4543 | tracing_thresh_read(struct file *filp, char __user *ubuf, | |
4544 | size_t cnt, loff_t *ppos) | |
4545 | { | |
4546 | return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos); | |
4547 | } | |
4548 | ||
4549 | static ssize_t | |
4550 | tracing_thresh_write(struct file *filp, const char __user *ubuf, | |
4551 | size_t cnt, loff_t *ppos) | |
4552 | { | |
4553 | struct trace_array *tr = filp->private_data; | |
4554 | int ret; | |
4555 | ||
4556 | mutex_lock(&trace_types_lock); | |
4557 | ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos); | |
4558 | if (ret < 0) | |
4559 | goto out; | |
4560 | ||
4561 | if (tr->current_trace->update_thresh) { | |
4562 | ret = tr->current_trace->update_thresh(tr); | |
4563 | if (ret < 0) | |
4564 | goto out; | |
4565 | } | |
4566 | ||
4567 | ret = cnt; | |
4568 | out: | |
4569 | mutex_unlock(&trace_types_lock); | |
4570 | ||
4571 | return ret; | |
4572 | } | |
4573 | ||
e428abbb CG |
4574 | #ifdef CONFIG_TRACER_MAX_TRACE |
4575 | ||
6508fa76 SF |
4576 | static ssize_t |
4577 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
4578 | size_t cnt, loff_t *ppos) | |
4579 | { | |
4580 | return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos); | |
4581 | } | |
4582 | ||
4583 | static ssize_t | |
4584 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
4585 | size_t cnt, loff_t *ppos) | |
4586 | { | |
4587 | return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos); | |
4588 | } | |
4589 | ||
e428abbb CG |
4590 | #endif |
4591 | ||
b3806b43 SR |
4592 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
4593 | { | |
15544209 | 4594 | struct trace_array *tr = inode->i_private; |
b3806b43 | 4595 | struct trace_iterator *iter; |
b04cc6b1 | 4596 | int ret = 0; |
b3806b43 SR |
4597 | |
4598 | if (tracing_disabled) | |
4599 | return -ENODEV; | |
4600 | ||
7b85af63 SRRH |
4601 | if (trace_array_get(tr) < 0) |
4602 | return -ENODEV; | |
4603 | ||
b04cc6b1 FW |
4604 | mutex_lock(&trace_types_lock); |
4605 | ||
b3806b43 SR |
4606 | /* create a buffer to store the information to pass to userspace */ |
4607 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
4608 | if (!iter) { |
4609 | ret = -ENOMEM; | |
f77d09a3 | 4610 | __trace_array_put(tr); |
b04cc6b1 FW |
4611 | goto out; |
4612 | } | |
b3806b43 | 4613 | |
3a161d99 | 4614 | trace_seq_init(&iter->seq); |
d716ff71 | 4615 | iter->trace = tr->current_trace; |
d7350c3f | 4616 | |
4462344e | 4617 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 4618 | ret = -ENOMEM; |
d7350c3f | 4619 | goto fail; |
4462344e RR |
4620 | } |
4621 | ||
a309720c | 4622 | /* trace pipe does not show start of buffer */ |
4462344e | 4623 | cpumask_setall(iter->started); |
a309720c | 4624 | |
983f938a | 4625 | if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
112f38a7 SR |
4626 | iter->iter_flags |= TRACE_FILE_LAT_FMT; |
4627 | ||
8be0709f | 4628 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
58e8eedf | 4629 | if (trace_clocks[tr->clock_id].in_ns) |
8be0709f DS |
4630 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
4631 | ||
15544209 ON |
4632 | iter->tr = tr; |
4633 | iter->trace_buffer = &tr->trace_buffer; | |
4634 | iter->cpu_file = tracing_get_cpu(inode); | |
d7350c3f | 4635 | mutex_init(&iter->mutex); |
b3806b43 SR |
4636 | filp->private_data = iter; |
4637 | ||
107bad8b SR |
4638 | if (iter->trace->pipe_open) |
4639 | iter->trace->pipe_open(iter); | |
107bad8b | 4640 | |
b444786f | 4641 | nonseekable_open(inode, filp); |
cf6ab6d9 SRRH |
4642 | |
4643 | tr->current_trace->ref++; | |
b04cc6b1 FW |
4644 | out: |
4645 | mutex_unlock(&trace_types_lock); | |
4646 | return ret; | |
d7350c3f FW |
4647 | |
4648 | fail: | |
4649 | kfree(iter->trace); | |
4650 | kfree(iter); | |
7b85af63 | 4651 | __trace_array_put(tr); |
d7350c3f FW |
4652 | mutex_unlock(&trace_types_lock); |
4653 | return ret; | |
b3806b43 SR |
4654 | } |
4655 | ||
4656 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
4657 | { | |
4658 | struct trace_iterator *iter = file->private_data; | |
15544209 | 4659 | struct trace_array *tr = inode->i_private; |
b3806b43 | 4660 | |
b04cc6b1 FW |
4661 | mutex_lock(&trace_types_lock); |
4662 | ||
cf6ab6d9 SRRH |
4663 | tr->current_trace->ref--; |
4664 | ||
29bf4a5e | 4665 | if (iter->trace->pipe_close) |
c521efd1 SR |
4666 | iter->trace->pipe_close(iter); |
4667 | ||
b04cc6b1 FW |
4668 | mutex_unlock(&trace_types_lock); |
4669 | ||
4462344e | 4670 | free_cpumask_var(iter->started); |
d7350c3f | 4671 | mutex_destroy(&iter->mutex); |
b3806b43 | 4672 | kfree(iter); |
b3806b43 | 4673 | |
7b85af63 SRRH |
4674 | trace_array_put(tr); |
4675 | ||
b3806b43 SR |
4676 | return 0; |
4677 | } | |
4678 | ||
2a2cc8f7 | 4679 | static unsigned int |
cc60cdc9 | 4680 | trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table) |
2a2cc8f7 | 4681 | { |
983f938a SRRH |
4682 | struct trace_array *tr = iter->tr; |
4683 | ||
15693458 SRRH |
4684 | /* Iterators are static, they should be filled or empty */ |
4685 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
4686 | return POLLIN | POLLRDNORM; | |
2a2cc8f7 | 4687 | |
983f938a | 4688 | if (tr->trace_flags & TRACE_ITER_BLOCK) |
2a2cc8f7 SSP |
4689 | /* |
4690 | * Always select as readable when in blocking mode | |
4691 | */ | |
4692 | return POLLIN | POLLRDNORM; | |
15693458 | 4693 | else |
12883efb | 4694 | return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file, |
15693458 | 4695 | filp, poll_table); |
2a2cc8f7 | 4696 | } |
2a2cc8f7 | 4697 | |
cc60cdc9 SR |
4698 | static unsigned int |
4699 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
4700 | { | |
4701 | struct trace_iterator *iter = filp->private_data; | |
4702 | ||
4703 | return trace_poll(iter, filp, poll_table); | |
2a2cc8f7 SSP |
4704 | } |
4705 | ||
d716ff71 | 4706 | /* Must be called with iter->mutex held. */ |
ff98781b | 4707 | static int tracing_wait_pipe(struct file *filp) |
b3806b43 SR |
4708 | { |
4709 | struct trace_iterator *iter = filp->private_data; | |
8b8b3683 | 4710 | int ret; |
b3806b43 | 4711 | |
b3806b43 | 4712 | while (trace_empty(iter)) { |
2dc8f095 | 4713 | |
107bad8b | 4714 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 4715 | return -EAGAIN; |
107bad8b | 4716 | } |
2dc8f095 | 4717 | |
b3806b43 | 4718 | /* |
250bfd3d | 4719 | * We block until we read something and tracing is disabled. |
b3806b43 SR |
4720 | * We still block if tracing is disabled, but we have never |
4721 | * read anything. This allows a user to cat this file, and | |
4722 | * then enable tracing. But after we have read something, | |
4723 | * we give an EOF when tracing is again disabled. | |
4724 | * | |
4725 | * iter->pos will be 0 if we haven't read anything. | |
4726 | */ | |
10246fa3 | 4727 | if (!tracing_is_on() && iter->pos) |
b3806b43 | 4728 | break; |
f4874261 SRRH |
4729 | |
4730 | mutex_unlock(&iter->mutex); | |
4731 | ||
e30f53aa | 4732 | ret = wait_on_pipe(iter, false); |
f4874261 SRRH |
4733 | |
4734 | mutex_lock(&iter->mutex); | |
4735 | ||
8b8b3683 SRRH |
4736 | if (ret) |
4737 | return ret; | |
b3806b43 SR |
4738 | } |
4739 | ||
ff98781b EGM |
4740 | return 1; |
4741 | } | |
4742 | ||
4743 | /* | |
4744 | * Consumer reader. | |
4745 | */ | |
4746 | static ssize_t | |
4747 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
4748 | size_t cnt, loff_t *ppos) | |
4749 | { | |
4750 | struct trace_iterator *iter = filp->private_data; | |
4751 | ssize_t sret; | |
4752 | ||
4753 | /* return any leftover data */ | |
4754 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
4755 | if (sret != -EBUSY) | |
4756 | return sret; | |
4757 | ||
f9520750 | 4758 | trace_seq_init(&iter->seq); |
ff98781b | 4759 | |
d7350c3f FW |
4760 | /* |
4761 | * Avoid more than one consumer on a single file descriptor | |
4762 | * This is just a matter of traces coherency, the ring buffer itself | |
4763 | * is protected. | |
4764 | */ | |
4765 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
4766 | if (iter->trace->read) { |
4767 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
4768 | if (sret) | |
4769 | goto out; | |
4770 | } | |
4771 | ||
4772 | waitagain: | |
4773 | sret = tracing_wait_pipe(filp); | |
4774 | if (sret <= 0) | |
4775 | goto out; | |
4776 | ||
b3806b43 | 4777 | /* stop when tracing is finished */ |
ff98781b EGM |
4778 | if (trace_empty(iter)) { |
4779 | sret = 0; | |
107bad8b | 4780 | goto out; |
ff98781b | 4781 | } |
b3806b43 SR |
4782 | |
4783 | if (cnt >= PAGE_SIZE) | |
4784 | cnt = PAGE_SIZE - 1; | |
4785 | ||
53d0aa77 | 4786 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
4787 | memset(&iter->seq, 0, |
4788 | sizeof(struct trace_iterator) - | |
4789 | offsetof(struct trace_iterator, seq)); | |
ed5467da | 4790 | cpumask_clear(iter->started); |
4823ed7e | 4791 | iter->pos = -1; |
b3806b43 | 4792 | |
4f535968 | 4793 | trace_event_read_lock(); |
7e53bd42 | 4794 | trace_access_lock(iter->cpu_file); |
955b61e5 | 4795 | while (trace_find_next_entry_inc(iter) != NULL) { |
2c4f035f | 4796 | enum print_line_t ret; |
5ac48378 | 4797 | int save_len = iter->seq.seq.len; |
088b1e42 | 4798 | |
f9896bf3 | 4799 | ret = print_trace_line(iter); |
2c4f035f | 4800 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 | 4801 | /* don't print partial lines */ |
5ac48378 | 4802 | iter->seq.seq.len = save_len; |
b3806b43 | 4803 | break; |
088b1e42 | 4804 | } |
b91facc3 FW |
4805 | if (ret != TRACE_TYPE_NO_CONSUME) |
4806 | trace_consume(iter); | |
b3806b43 | 4807 | |
5ac48378 | 4808 | if (trace_seq_used(&iter->seq) >= cnt) |
b3806b43 | 4809 | break; |
ee5e51f5 JO |
4810 | |
4811 | /* | |
4812 | * Setting the full flag means we reached the trace_seq buffer | |
4813 | * size and we should leave by partial output condition above. | |
4814 | * One of the trace_seq_* functions is not used properly. | |
4815 | */ | |
4816 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
4817 | iter->ent->type); | |
b3806b43 | 4818 | } |
7e53bd42 | 4819 | trace_access_unlock(iter->cpu_file); |
4f535968 | 4820 | trace_event_read_unlock(); |
b3806b43 | 4821 | |
b3806b43 | 4822 | /* Now copy what we have to the user */ |
6c6c2796 | 4823 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
5ac48378 | 4824 | if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq)) |
f9520750 | 4825 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
4826 | |
4827 | /* | |
25985edc | 4828 | * If there was nothing to send to user, in spite of consuming trace |
9ff4b974 PP |
4829 | * entries, go back to wait for more entries. |
4830 | */ | |
6c6c2796 | 4831 | if (sret == -EBUSY) |
9ff4b974 | 4832 | goto waitagain; |
b3806b43 | 4833 | |
107bad8b | 4834 | out: |
d7350c3f | 4835 | mutex_unlock(&iter->mutex); |
107bad8b | 4836 | |
6c6c2796 | 4837 | return sret; |
b3806b43 SR |
4838 | } |
4839 | ||
3c56819b EGM |
4840 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, |
4841 | unsigned int idx) | |
4842 | { | |
4843 | __free_page(spd->pages[idx]); | |
4844 | } | |
4845 | ||
28dfef8f | 4846 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { |
34cd4998 | 4847 | .can_merge = 0, |
34cd4998 | 4848 | .confirm = generic_pipe_buf_confirm, |
92fdd98c | 4849 | .release = generic_pipe_buf_release, |
34cd4998 SR |
4850 | .steal = generic_pipe_buf_steal, |
4851 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
4852 | }; |
4853 | ||
34cd4998 | 4854 | static size_t |
fa7c7f6e | 4855 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
4856 | { |
4857 | size_t count; | |
74f06bb7 | 4858 | int save_len; |
34cd4998 SR |
4859 | int ret; |
4860 | ||
4861 | /* Seq buffer is page-sized, exactly what we need. */ | |
4862 | for (;;) { | |
74f06bb7 | 4863 | save_len = iter->seq.seq.len; |
34cd4998 | 4864 | ret = print_trace_line(iter); |
74f06bb7 SRRH |
4865 | |
4866 | if (trace_seq_has_overflowed(&iter->seq)) { | |
4867 | iter->seq.seq.len = save_len; | |
34cd4998 SR |
4868 | break; |
4869 | } | |
74f06bb7 SRRH |
4870 | |
4871 | /* | |
4872 | * This should not be hit, because it should only | |
4873 | * be set if the iter->seq overflowed. But check it | |
4874 | * anyway to be safe. | |
4875 | */ | |
34cd4998 | 4876 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
74f06bb7 SRRH |
4877 | iter->seq.seq.len = save_len; |
4878 | break; | |
4879 | } | |
4880 | ||
5ac48378 | 4881 | count = trace_seq_used(&iter->seq) - save_len; |
74f06bb7 SRRH |
4882 | if (rem < count) { |
4883 | rem = 0; | |
4884 | iter->seq.seq.len = save_len; | |
34cd4998 SR |
4885 | break; |
4886 | } | |
4887 | ||
74e7ff8c LJ |
4888 | if (ret != TRACE_TYPE_NO_CONSUME) |
4889 | trace_consume(iter); | |
34cd4998 | 4890 | rem -= count; |
955b61e5 | 4891 | if (!trace_find_next_entry_inc(iter)) { |
34cd4998 SR |
4892 | rem = 0; |
4893 | iter->ent = NULL; | |
4894 | break; | |
4895 | } | |
4896 | } | |
4897 | ||
4898 | return rem; | |
4899 | } | |
4900 | ||
3c56819b EGM |
4901 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
4902 | loff_t *ppos, | |
4903 | struct pipe_inode_info *pipe, | |
4904 | size_t len, | |
4905 | unsigned int flags) | |
4906 | { | |
35f3d14d JA |
4907 | struct page *pages_def[PIPE_DEF_BUFFERS]; |
4908 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3c56819b EGM |
4909 | struct trace_iterator *iter = filp->private_data; |
4910 | struct splice_pipe_desc spd = { | |
35f3d14d JA |
4911 | .pages = pages_def, |
4912 | .partial = partial_def, | |
34cd4998 | 4913 | .nr_pages = 0, /* This gets updated below. */ |
047fe360 | 4914 | .nr_pages_max = PIPE_DEF_BUFFERS, |
34cd4998 SR |
4915 | .flags = flags, |
4916 | .ops = &tracing_pipe_buf_ops, | |
4917 | .spd_release = tracing_spd_release_pipe, | |
3c56819b EGM |
4918 | }; |
4919 | ssize_t ret; | |
34cd4998 | 4920 | size_t rem; |
3c56819b EGM |
4921 | unsigned int i; |
4922 | ||
35f3d14d JA |
4923 | if (splice_grow_spd(pipe, &spd)) |
4924 | return -ENOMEM; | |
4925 | ||
d7350c3f | 4926 | mutex_lock(&iter->mutex); |
3c56819b EGM |
4927 | |
4928 | if (iter->trace->splice_read) { | |
4929 | ret = iter->trace->splice_read(iter, filp, | |
4930 | ppos, pipe, len, flags); | |
4931 | if (ret) | |
34cd4998 | 4932 | goto out_err; |
3c56819b EGM |
4933 | } |
4934 | ||
4935 | ret = tracing_wait_pipe(filp); | |
4936 | if (ret <= 0) | |
34cd4998 | 4937 | goto out_err; |
3c56819b | 4938 | |
955b61e5 | 4939 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { |
3c56819b | 4940 | ret = -EFAULT; |
34cd4998 | 4941 | goto out_err; |
3c56819b EGM |
4942 | } |
4943 | ||
4f535968 | 4944 | trace_event_read_lock(); |
7e53bd42 | 4945 | trace_access_lock(iter->cpu_file); |
4f535968 | 4946 | |
3c56819b | 4947 | /* Fill as many pages as possible. */ |
a786c06d | 4948 | for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) { |
35f3d14d JA |
4949 | spd.pages[i] = alloc_page(GFP_KERNEL); |
4950 | if (!spd.pages[i]) | |
34cd4998 | 4951 | break; |
3c56819b | 4952 | |
fa7c7f6e | 4953 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
4954 | |
4955 | /* Copy the data into the page, so we can start over. */ | |
4956 | ret = trace_seq_to_buffer(&iter->seq, | |
35f3d14d | 4957 | page_address(spd.pages[i]), |
5ac48378 | 4958 | trace_seq_used(&iter->seq)); |
3c56819b | 4959 | if (ret < 0) { |
35f3d14d | 4960 | __free_page(spd.pages[i]); |
3c56819b EGM |
4961 | break; |
4962 | } | |
35f3d14d | 4963 | spd.partial[i].offset = 0; |
5ac48378 | 4964 | spd.partial[i].len = trace_seq_used(&iter->seq); |
3c56819b | 4965 | |
f9520750 | 4966 | trace_seq_init(&iter->seq); |
3c56819b EGM |
4967 | } |
4968 | ||
7e53bd42 | 4969 | trace_access_unlock(iter->cpu_file); |
4f535968 | 4970 | trace_event_read_unlock(); |
d7350c3f | 4971 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
4972 | |
4973 | spd.nr_pages = i; | |
4974 | ||
a29054d9 SRRH |
4975 | if (i) |
4976 | ret = splice_to_pipe(pipe, &spd); | |
4977 | else | |
4978 | ret = 0; | |
35f3d14d | 4979 | out: |
047fe360 | 4980 | splice_shrink_spd(&spd); |
35f3d14d | 4981 | return ret; |
3c56819b | 4982 | |
34cd4998 | 4983 | out_err: |
d7350c3f | 4984 | mutex_unlock(&iter->mutex); |
35f3d14d | 4985 | goto out; |
3c56819b EGM |
4986 | } |
4987 | ||
a98a3c3f SR |
4988 | static ssize_t |
4989 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
4990 | size_t cnt, loff_t *ppos) | |
4991 | { | |
0bc392ee ON |
4992 | struct inode *inode = file_inode(filp); |
4993 | struct trace_array *tr = inode->i_private; | |
4994 | int cpu = tracing_get_cpu(inode); | |
438ced17 VN |
4995 | char buf[64]; |
4996 | int r = 0; | |
4997 | ssize_t ret; | |
a98a3c3f | 4998 | |
db526ca3 | 4999 | mutex_lock(&trace_types_lock); |
438ced17 | 5000 | |
0bc392ee | 5001 | if (cpu == RING_BUFFER_ALL_CPUS) { |
438ced17 VN |
5002 | int cpu, buf_size_same; |
5003 | unsigned long size; | |
5004 | ||
5005 | size = 0; | |
5006 | buf_size_same = 1; | |
5007 | /* check if all cpu sizes are same */ | |
5008 | for_each_tracing_cpu(cpu) { | |
5009 | /* fill in the size from first enabled cpu */ | |
5010 | if (size == 0) | |
12883efb SRRH |
5011 | size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries; |
5012 | if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) { | |
438ced17 VN |
5013 | buf_size_same = 0; |
5014 | break; | |
5015 | } | |
5016 | } | |
5017 | ||
5018 | if (buf_size_same) { | |
5019 | if (!ring_buffer_expanded) | |
5020 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
5021 | size >> 10, | |
5022 | trace_buf_size >> 10); | |
5023 | else | |
5024 | r = sprintf(buf, "%lu\n", size >> 10); | |
5025 | } else | |
5026 | r = sprintf(buf, "X\n"); | |
5027 | } else | |
0bc392ee | 5028 | r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10); |
438ced17 | 5029 | |
db526ca3 SR |
5030 | mutex_unlock(&trace_types_lock); |
5031 | ||
438ced17 VN |
5032 | ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
5033 | return ret; | |
a98a3c3f SR |
5034 | } |
5035 | ||
5036 | static ssize_t | |
5037 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
5038 | size_t cnt, loff_t *ppos) | |
5039 | { | |
0bc392ee ON |
5040 | struct inode *inode = file_inode(filp); |
5041 | struct trace_array *tr = inode->i_private; | |
a98a3c3f | 5042 | unsigned long val; |
4f271a2a | 5043 | int ret; |
a98a3c3f | 5044 | |
22fe9b54 PH |
5045 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
5046 | if (ret) | |
c6caeeb1 | 5047 | return ret; |
a98a3c3f SR |
5048 | |
5049 | /* must have at least 1 entry */ | |
5050 | if (!val) | |
5051 | return -EINVAL; | |
5052 | ||
1696b2b0 SR |
5053 | /* value is in KB */ |
5054 | val <<= 10; | |
0bc392ee | 5055 | ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode)); |
4f271a2a VN |
5056 | if (ret < 0) |
5057 | return ret; | |
a98a3c3f | 5058 | |
cf8517cf | 5059 | *ppos += cnt; |
a98a3c3f | 5060 | |
4f271a2a VN |
5061 | return cnt; |
5062 | } | |
bf5e6519 | 5063 | |
f81ab074 VN |
5064 | static ssize_t |
5065 | tracing_total_entries_read(struct file *filp, char __user *ubuf, | |
5066 | size_t cnt, loff_t *ppos) | |
5067 | { | |
5068 | struct trace_array *tr = filp->private_data; | |
5069 | char buf[64]; | |
5070 | int r, cpu; | |
5071 | unsigned long size = 0, expanded_size = 0; | |
5072 | ||
5073 | mutex_lock(&trace_types_lock); | |
5074 | for_each_tracing_cpu(cpu) { | |
12883efb | 5075 | size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10; |
f81ab074 VN |
5076 | if (!ring_buffer_expanded) |
5077 | expanded_size += trace_buf_size >> 10; | |
5078 | } | |
5079 | if (ring_buffer_expanded) | |
5080 | r = sprintf(buf, "%lu\n", size); | |
5081 | else | |
5082 | r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); | |
5083 | mutex_unlock(&trace_types_lock); | |
5084 | ||
5085 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
5086 | } | |
5087 | ||
4f271a2a VN |
5088 | static ssize_t |
5089 | tracing_free_buffer_write(struct file *filp, const char __user *ubuf, | |
5090 | size_t cnt, loff_t *ppos) | |
5091 | { | |
5092 | /* | |
5093 | * There is no need to read what the user has written, this function | |
5094 | * is just to make sure that there is no error when "echo" is used | |
5095 | */ | |
5096 | ||
5097 | *ppos += cnt; | |
a98a3c3f SR |
5098 | |
5099 | return cnt; | |
5100 | } | |
5101 | ||
4f271a2a VN |
5102 | static int |
5103 | tracing_free_buffer_release(struct inode *inode, struct file *filp) | |
5104 | { | |
2b6080f2 SR |
5105 | struct trace_array *tr = inode->i_private; |
5106 | ||
cf30cf67 | 5107 | /* disable tracing ? */ |
983f938a | 5108 | if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE) |
711e1243 | 5109 | tracer_tracing_off(tr); |
4f271a2a | 5110 | /* resize the ring buffer to 0 */ |
2b6080f2 | 5111 | tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS); |
4f271a2a | 5112 | |
7b85af63 SRRH |
5113 | trace_array_put(tr); |
5114 | ||
4f271a2a VN |
5115 | return 0; |
5116 | } | |
5117 | ||
5bf9a1ee PP |
5118 | static ssize_t |
5119 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
5120 | size_t cnt, loff_t *fpos) | |
5121 | { | |
d696b58c | 5122 | unsigned long addr = (unsigned long)ubuf; |
2d71619c | 5123 | struct trace_array *tr = filp->private_data; |
d696b58c SR |
5124 | struct ring_buffer_event *event; |
5125 | struct ring_buffer *buffer; | |
5126 | struct print_entry *entry; | |
5127 | unsigned long irq_flags; | |
5128 | struct page *pages[2]; | |
6edb2a8a | 5129 | void *map_page[2]; |
d696b58c SR |
5130 | int nr_pages = 1; |
5131 | ssize_t written; | |
d696b58c SR |
5132 | int offset; |
5133 | int size; | |
5134 | int len; | |
5135 | int ret; | |
6edb2a8a | 5136 | int i; |
5bf9a1ee | 5137 | |
c76f0694 | 5138 | if (tracing_disabled) |
5bf9a1ee PP |
5139 | return -EINVAL; |
5140 | ||
983f938a | 5141 | if (!(tr->trace_flags & TRACE_ITER_MARKERS)) |
5224c3a3 MSB |
5142 | return -EINVAL; |
5143 | ||
5bf9a1ee PP |
5144 | if (cnt > TRACE_BUF_SIZE) |
5145 | cnt = TRACE_BUF_SIZE; | |
5146 | ||
d696b58c SR |
5147 | /* |
5148 | * Userspace is injecting traces into the kernel trace buffer. | |
5149 | * We want to be as non intrusive as possible. | |
5150 | * To do so, we do not want to allocate any special buffers | |
5151 | * or take any locks, but instead write the userspace data | |
5152 | * straight into the ring buffer. | |
5153 | * | |
5154 | * First we need to pin the userspace buffer into memory, | |
5155 | * which, most likely it is, because it just referenced it. | |
5156 | * But there's no guarantee that it is. By using get_user_pages_fast() | |
5157 | * and kmap_atomic/kunmap_atomic() we can get access to the | |
5158 | * pages directly. We then write the data directly into the | |
5159 | * ring buffer. | |
5160 | */ | |
5161 | BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); | |
5bf9a1ee | 5162 | |
d696b58c SR |
5163 | /* check if we cross pages */ |
5164 | if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) | |
5165 | nr_pages = 2; | |
5166 | ||
5167 | offset = addr & (PAGE_SIZE - 1); | |
5168 | addr &= PAGE_MASK; | |
5169 | ||
5170 | ret = get_user_pages_fast(addr, nr_pages, 0, pages); | |
5171 | if (ret < nr_pages) { | |
5172 | while (--ret >= 0) | |
5173 | put_page(pages[ret]); | |
5174 | written = -EFAULT; | |
5175 | goto out; | |
5bf9a1ee | 5176 | } |
d696b58c | 5177 | |
6edb2a8a SR |
5178 | for (i = 0; i < nr_pages; i++) |
5179 | map_page[i] = kmap_atomic(pages[i]); | |
d696b58c SR |
5180 | |
5181 | local_save_flags(irq_flags); | |
5182 | size = sizeof(*entry) + cnt + 2; /* possible \n added */ | |
2d71619c | 5183 | buffer = tr->trace_buffer.buffer; |
d696b58c SR |
5184 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
5185 | irq_flags, preempt_count()); | |
5186 | if (!event) { | |
5187 | /* Ring buffer disabled, return as if not open for write */ | |
5188 | written = -EBADF; | |
5189 | goto out_unlock; | |
5bf9a1ee | 5190 | } |
d696b58c SR |
5191 | |
5192 | entry = ring_buffer_event_data(event); | |
5193 | entry->ip = _THIS_IP_; | |
5194 | ||
5195 | if (nr_pages == 2) { | |
5196 | len = PAGE_SIZE - offset; | |
6edb2a8a SR |
5197 | memcpy(&entry->buf, map_page[0] + offset, len); |
5198 | memcpy(&entry->buf[len], map_page[1], cnt - len); | |
c13d2f7c | 5199 | } else |
6edb2a8a | 5200 | memcpy(&entry->buf, map_page[0] + offset, cnt); |
5bf9a1ee | 5201 | |
d696b58c SR |
5202 | if (entry->buf[cnt - 1] != '\n') { |
5203 | entry->buf[cnt] = '\n'; | |
5204 | entry->buf[cnt + 1] = '\0'; | |
5205 | } else | |
5206 | entry->buf[cnt] = '\0'; | |
5207 | ||
7ffbd48d | 5208 | __buffer_unlock_commit(buffer, event); |
5bf9a1ee | 5209 | |
d696b58c | 5210 | written = cnt; |
5bf9a1ee | 5211 | |
d696b58c | 5212 | *fpos += written; |
1aa54bca | 5213 | |
d696b58c | 5214 | out_unlock: |
7215853e | 5215 | for (i = nr_pages - 1; i >= 0; i--) { |
6edb2a8a SR |
5216 | kunmap_atomic(map_page[i]); |
5217 | put_page(pages[i]); | |
5218 | } | |
d696b58c | 5219 | out: |
1aa54bca | 5220 | return written; |
5bf9a1ee PP |
5221 | } |
5222 | ||
13f16d20 | 5223 | static int tracing_clock_show(struct seq_file *m, void *v) |
5079f326 | 5224 | { |
2b6080f2 | 5225 | struct trace_array *tr = m->private; |
5079f326 Z |
5226 | int i; |
5227 | ||
5228 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
13f16d20 | 5229 | seq_printf(m, |
5079f326 | 5230 | "%s%s%s%s", i ? " " : "", |
2b6080f2 SR |
5231 | i == tr->clock_id ? "[" : "", trace_clocks[i].name, |
5232 | i == tr->clock_id ? "]" : ""); | |
13f16d20 | 5233 | seq_putc(m, '\n'); |
5079f326 | 5234 | |
13f16d20 | 5235 | return 0; |
5079f326 Z |
5236 | } |
5237 | ||
e1e232ca | 5238 | static int tracing_set_clock(struct trace_array *tr, const char *clockstr) |
5079f326 | 5239 | { |
5079f326 Z |
5240 | int i; |
5241 | ||
5079f326 Z |
5242 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { |
5243 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
5244 | break; | |
5245 | } | |
5246 | if (i == ARRAY_SIZE(trace_clocks)) | |
5247 | return -EINVAL; | |
5248 | ||
5079f326 Z |
5249 | mutex_lock(&trace_types_lock); |
5250 | ||
2b6080f2 SR |
5251 | tr->clock_id = i; |
5252 | ||
12883efb | 5253 | ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func); |
5079f326 | 5254 | |
60303ed3 DS |
5255 | /* |
5256 | * New clock may not be consistent with the previous clock. | |
5257 | * Reset the buffer so that it doesn't have incomparable timestamps. | |
5258 | */ | |
9457158b | 5259 | tracing_reset_online_cpus(&tr->trace_buffer); |
12883efb SRRH |
5260 | |
5261 | #ifdef CONFIG_TRACER_MAX_TRACE | |
5262 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer) | |
5263 | ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); | |
9457158b | 5264 | tracing_reset_online_cpus(&tr->max_buffer); |
12883efb | 5265 | #endif |
60303ed3 | 5266 | |
5079f326 Z |
5267 | mutex_unlock(&trace_types_lock); |
5268 | ||
e1e232ca SR |
5269 | return 0; |
5270 | } | |
5271 | ||
5272 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
5273 | size_t cnt, loff_t *fpos) | |
5274 | { | |
5275 | struct seq_file *m = filp->private_data; | |
5276 | struct trace_array *tr = m->private; | |
5277 | char buf[64]; | |
5278 | const char *clockstr; | |
5279 | int ret; | |
5280 | ||
5281 | if (cnt >= sizeof(buf)) | |
5282 | return -EINVAL; | |
5283 | ||
4afe6495 | 5284 | if (copy_from_user(buf, ubuf, cnt)) |
e1e232ca SR |
5285 | return -EFAULT; |
5286 | ||
5287 | buf[cnt] = 0; | |
5288 | ||
5289 | clockstr = strstrip(buf); | |
5290 | ||
5291 | ret = tracing_set_clock(tr, clockstr); | |
5292 | if (ret) | |
5293 | return ret; | |
5294 | ||
5079f326 Z |
5295 | *fpos += cnt; |
5296 | ||
5297 | return cnt; | |
5298 | } | |
5299 | ||
13f16d20 LZ |
5300 | static int tracing_clock_open(struct inode *inode, struct file *file) |
5301 | { | |
7b85af63 SRRH |
5302 | struct trace_array *tr = inode->i_private; |
5303 | int ret; | |
5304 | ||
13f16d20 LZ |
5305 | if (tracing_disabled) |
5306 | return -ENODEV; | |
2b6080f2 | 5307 | |
7b85af63 SRRH |
5308 | if (trace_array_get(tr)) |
5309 | return -ENODEV; | |
5310 | ||
5311 | ret = single_open(file, tracing_clock_show, inode->i_private); | |
5312 | if (ret < 0) | |
5313 | trace_array_put(tr); | |
5314 | ||
5315 | return ret; | |
13f16d20 LZ |
5316 | } |
5317 | ||
6de58e62 SRRH |
5318 | struct ftrace_buffer_info { |
5319 | struct trace_iterator iter; | |
5320 | void *spare; | |
5321 | unsigned int read; | |
5322 | }; | |
5323 | ||
debdd57f HT |
5324 | #ifdef CONFIG_TRACER_SNAPSHOT |
5325 | static int tracing_snapshot_open(struct inode *inode, struct file *file) | |
5326 | { | |
6484c71c | 5327 | struct trace_array *tr = inode->i_private; |
debdd57f | 5328 | struct trace_iterator *iter; |
2b6080f2 | 5329 | struct seq_file *m; |
debdd57f HT |
5330 | int ret = 0; |
5331 | ||
ff451961 SRRH |
5332 | if (trace_array_get(tr) < 0) |
5333 | return -ENODEV; | |
5334 | ||
debdd57f | 5335 | if (file->f_mode & FMODE_READ) { |
6484c71c | 5336 | iter = __tracing_open(inode, file, true); |
debdd57f HT |
5337 | if (IS_ERR(iter)) |
5338 | ret = PTR_ERR(iter); | |
2b6080f2 SR |
5339 | } else { |
5340 | /* Writes still need the seq_file to hold the private data */ | |
f77d09a3 | 5341 | ret = -ENOMEM; |
2b6080f2 SR |
5342 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
5343 | if (!m) | |
f77d09a3 | 5344 | goto out; |
2b6080f2 SR |
5345 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
5346 | if (!iter) { | |
5347 | kfree(m); | |
f77d09a3 | 5348 | goto out; |
2b6080f2 | 5349 | } |
f77d09a3 AL |
5350 | ret = 0; |
5351 | ||
ff451961 | 5352 | iter->tr = tr; |
6484c71c ON |
5353 | iter->trace_buffer = &tr->max_buffer; |
5354 | iter->cpu_file = tracing_get_cpu(inode); | |
2b6080f2 SR |
5355 | m->private = iter; |
5356 | file->private_data = m; | |
debdd57f | 5357 | } |
f77d09a3 | 5358 | out: |
ff451961 SRRH |
5359 | if (ret < 0) |
5360 | trace_array_put(tr); | |
5361 | ||
debdd57f HT |
5362 | return ret; |
5363 | } | |
5364 | ||
5365 | static ssize_t | |
5366 | tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
5367 | loff_t *ppos) | |
5368 | { | |
2b6080f2 SR |
5369 | struct seq_file *m = filp->private_data; |
5370 | struct trace_iterator *iter = m->private; | |
5371 | struct trace_array *tr = iter->tr; | |
debdd57f HT |
5372 | unsigned long val; |
5373 | int ret; | |
5374 | ||
5375 | ret = tracing_update_buffers(); | |
5376 | if (ret < 0) | |
5377 | return ret; | |
5378 | ||
5379 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
5380 | if (ret) | |
5381 | return ret; | |
5382 | ||
5383 | mutex_lock(&trace_types_lock); | |
5384 | ||
2b6080f2 | 5385 | if (tr->current_trace->use_max_tr) { |
debdd57f HT |
5386 | ret = -EBUSY; |
5387 | goto out; | |
5388 | } | |
5389 | ||
5390 | switch (val) { | |
5391 | case 0: | |
f1affcaa SRRH |
5392 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
5393 | ret = -EINVAL; | |
5394 | break; | |
debdd57f | 5395 | } |
3209cff4 SRRH |
5396 | if (tr->allocated_snapshot) |
5397 | free_snapshot(tr); | |
debdd57f HT |
5398 | break; |
5399 | case 1: | |
f1affcaa SRRH |
5400 | /* Only allow per-cpu swap if the ring buffer supports it */ |
5401 | #ifndef CONFIG_RING_BUFFER_ALLOW_SWAP | |
5402 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { | |
5403 | ret = -EINVAL; | |
5404 | break; | |
5405 | } | |
5406 | #endif | |
45ad21ca | 5407 | if (!tr->allocated_snapshot) { |
3209cff4 | 5408 | ret = alloc_snapshot(tr); |
debdd57f HT |
5409 | if (ret < 0) |
5410 | break; | |
debdd57f | 5411 | } |
debdd57f HT |
5412 | local_irq_disable(); |
5413 | /* Now, we're going to swap */ | |
f1affcaa | 5414 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
ce9bae55 | 5415 | update_max_tr(tr, current, smp_processor_id()); |
f1affcaa | 5416 | else |
ce9bae55 | 5417 | update_max_tr_single(tr, current, iter->cpu_file); |
debdd57f HT |
5418 | local_irq_enable(); |
5419 | break; | |
5420 | default: | |
45ad21ca | 5421 | if (tr->allocated_snapshot) { |
f1affcaa SRRH |
5422 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
5423 | tracing_reset_online_cpus(&tr->max_buffer); | |
5424 | else | |
5425 | tracing_reset(&tr->max_buffer, iter->cpu_file); | |
5426 | } | |
debdd57f HT |
5427 | break; |
5428 | } | |
5429 | ||
5430 | if (ret >= 0) { | |
5431 | *ppos += cnt; | |
5432 | ret = cnt; | |
5433 | } | |
5434 | out: | |
5435 | mutex_unlock(&trace_types_lock); | |
5436 | return ret; | |
5437 | } | |
2b6080f2 SR |
5438 | |
5439 | static int tracing_snapshot_release(struct inode *inode, struct file *file) | |
5440 | { | |
5441 | struct seq_file *m = file->private_data; | |
ff451961 SRRH |
5442 | int ret; |
5443 | ||
5444 | ret = tracing_release(inode, file); | |
2b6080f2 SR |
5445 | |
5446 | if (file->f_mode & FMODE_READ) | |
ff451961 | 5447 | return ret; |
2b6080f2 SR |
5448 | |
5449 | /* If write only, the seq_file is just a stub */ | |
5450 | if (m) | |
5451 | kfree(m->private); | |
5452 | kfree(m); | |
5453 | ||
5454 | return 0; | |
5455 | } | |
5456 | ||
6de58e62 SRRH |
5457 | static int tracing_buffers_open(struct inode *inode, struct file *filp); |
5458 | static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, | |
5459 | size_t count, loff_t *ppos); | |
5460 | static int tracing_buffers_release(struct inode *inode, struct file *file); | |
5461 | static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5462 | struct pipe_inode_info *pipe, size_t len, unsigned int flags); | |
5463 | ||
5464 | static int snapshot_raw_open(struct inode *inode, struct file *filp) | |
5465 | { | |
5466 | struct ftrace_buffer_info *info; | |
5467 | int ret; | |
5468 | ||
5469 | ret = tracing_buffers_open(inode, filp); | |
5470 | if (ret < 0) | |
5471 | return ret; | |
5472 | ||
5473 | info = filp->private_data; | |
5474 | ||
5475 | if (info->iter.trace->use_max_tr) { | |
5476 | tracing_buffers_release(inode, filp); | |
5477 | return -EBUSY; | |
5478 | } | |
5479 | ||
5480 | info->iter.snapshot = true; | |
5481 | info->iter.trace_buffer = &info->iter.tr->max_buffer; | |
5482 | ||
5483 | return ret; | |
5484 | } | |
5485 | ||
debdd57f HT |
5486 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
5487 | ||
5488 | ||
6508fa76 SF |
5489 | static const struct file_operations tracing_thresh_fops = { |
5490 | .open = tracing_open_generic, | |
5491 | .read = tracing_thresh_read, | |
5492 | .write = tracing_thresh_write, | |
5493 | .llseek = generic_file_llseek, | |
5494 | }; | |
5495 | ||
e428abbb | 5496 | #ifdef CONFIG_TRACER_MAX_TRACE |
5e2336a0 | 5497 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
5498 | .open = tracing_open_generic, |
5499 | .read = tracing_max_lat_read, | |
5500 | .write = tracing_max_lat_write, | |
b444786f | 5501 | .llseek = generic_file_llseek, |
bc0c38d1 | 5502 | }; |
e428abbb | 5503 | #endif |
bc0c38d1 | 5504 | |
5e2336a0 | 5505 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
5506 | .open = tracing_open_generic, |
5507 | .read = tracing_set_trace_read, | |
5508 | .write = tracing_set_trace_write, | |
b444786f | 5509 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
5510 | }; |
5511 | ||
5e2336a0 | 5512 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 5513 | .open = tracing_open_pipe, |
2a2cc8f7 | 5514 | .poll = tracing_poll_pipe, |
4bf39a94 | 5515 | .read = tracing_read_pipe, |
3c56819b | 5516 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 5517 | .release = tracing_release_pipe, |
b444786f | 5518 | .llseek = no_llseek, |
b3806b43 SR |
5519 | }; |
5520 | ||
5e2336a0 | 5521 | static const struct file_operations tracing_entries_fops = { |
0bc392ee | 5522 | .open = tracing_open_generic_tr, |
a98a3c3f SR |
5523 | .read = tracing_entries_read, |
5524 | .write = tracing_entries_write, | |
b444786f | 5525 | .llseek = generic_file_llseek, |
0bc392ee | 5526 | .release = tracing_release_generic_tr, |
a98a3c3f SR |
5527 | }; |
5528 | ||
f81ab074 | 5529 | static const struct file_operations tracing_total_entries_fops = { |
7b85af63 | 5530 | .open = tracing_open_generic_tr, |
f81ab074 VN |
5531 | .read = tracing_total_entries_read, |
5532 | .llseek = generic_file_llseek, | |
7b85af63 | 5533 | .release = tracing_release_generic_tr, |
f81ab074 VN |
5534 | }; |
5535 | ||
4f271a2a | 5536 | static const struct file_operations tracing_free_buffer_fops = { |
7b85af63 | 5537 | .open = tracing_open_generic_tr, |
4f271a2a VN |
5538 | .write = tracing_free_buffer_write, |
5539 | .release = tracing_free_buffer_release, | |
5540 | }; | |
5541 | ||
5e2336a0 | 5542 | static const struct file_operations tracing_mark_fops = { |
7b85af63 | 5543 | .open = tracing_open_generic_tr, |
5bf9a1ee | 5544 | .write = tracing_mark_write, |
b444786f | 5545 | .llseek = generic_file_llseek, |
7b85af63 | 5546 | .release = tracing_release_generic_tr, |
5bf9a1ee PP |
5547 | }; |
5548 | ||
5079f326 | 5549 | static const struct file_operations trace_clock_fops = { |
13f16d20 LZ |
5550 | .open = tracing_clock_open, |
5551 | .read = seq_read, | |
5552 | .llseek = seq_lseek, | |
7b85af63 | 5553 | .release = tracing_single_release_tr, |
5079f326 Z |
5554 | .write = tracing_clock_write, |
5555 | }; | |
5556 | ||
debdd57f HT |
5557 | #ifdef CONFIG_TRACER_SNAPSHOT |
5558 | static const struct file_operations snapshot_fops = { | |
5559 | .open = tracing_snapshot_open, | |
5560 | .read = seq_read, | |
5561 | .write = tracing_snapshot_write, | |
098c879e | 5562 | .llseek = tracing_lseek, |
2b6080f2 | 5563 | .release = tracing_snapshot_release, |
debdd57f | 5564 | }; |
debdd57f | 5565 | |
6de58e62 SRRH |
5566 | static const struct file_operations snapshot_raw_fops = { |
5567 | .open = snapshot_raw_open, | |
5568 | .read = tracing_buffers_read, | |
5569 | .release = tracing_buffers_release, | |
5570 | .splice_read = tracing_buffers_splice_read, | |
5571 | .llseek = no_llseek, | |
2cadf913 SR |
5572 | }; |
5573 | ||
6de58e62 SRRH |
5574 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
5575 | ||
2cadf913 SR |
5576 | static int tracing_buffers_open(struct inode *inode, struct file *filp) |
5577 | { | |
46ef2be0 | 5578 | struct trace_array *tr = inode->i_private; |
2cadf913 | 5579 | struct ftrace_buffer_info *info; |
7b85af63 | 5580 | int ret; |
2cadf913 SR |
5581 | |
5582 | if (tracing_disabled) | |
5583 | return -ENODEV; | |
5584 | ||
7b85af63 SRRH |
5585 | if (trace_array_get(tr) < 0) |
5586 | return -ENODEV; | |
5587 | ||
2cadf913 | 5588 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
7b85af63 SRRH |
5589 | if (!info) { |
5590 | trace_array_put(tr); | |
2cadf913 | 5591 | return -ENOMEM; |
7b85af63 | 5592 | } |
2cadf913 | 5593 | |
a695cb58 SRRH |
5594 | mutex_lock(&trace_types_lock); |
5595 | ||
cc60cdc9 | 5596 | info->iter.tr = tr; |
46ef2be0 | 5597 | info->iter.cpu_file = tracing_get_cpu(inode); |
b627344f | 5598 | info->iter.trace = tr->current_trace; |
12883efb | 5599 | info->iter.trace_buffer = &tr->trace_buffer; |
cc60cdc9 | 5600 | info->spare = NULL; |
2cadf913 | 5601 | /* Force reading ring buffer for first read */ |
cc60cdc9 | 5602 | info->read = (unsigned int)-1; |
2cadf913 SR |
5603 | |
5604 | filp->private_data = info; | |
5605 | ||
cf6ab6d9 SRRH |
5606 | tr->current_trace->ref++; |
5607 | ||
a695cb58 SRRH |
5608 | mutex_unlock(&trace_types_lock); |
5609 | ||
7b85af63 SRRH |
5610 | ret = nonseekable_open(inode, filp); |
5611 | if (ret < 0) | |
5612 | trace_array_put(tr); | |
5613 | ||
5614 | return ret; | |
2cadf913 SR |
5615 | } |
5616 | ||
cc60cdc9 SR |
5617 | static unsigned int |
5618 | tracing_buffers_poll(struct file *filp, poll_table *poll_table) | |
5619 | { | |
5620 | struct ftrace_buffer_info *info = filp->private_data; | |
5621 | struct trace_iterator *iter = &info->iter; | |
5622 | ||
5623 | return trace_poll(iter, filp, poll_table); | |
5624 | } | |
5625 | ||
2cadf913 SR |
5626 | static ssize_t |
5627 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
5628 | size_t count, loff_t *ppos) | |
5629 | { | |
5630 | struct ftrace_buffer_info *info = filp->private_data; | |
cc60cdc9 | 5631 | struct trace_iterator *iter = &info->iter; |
2cadf913 | 5632 | ssize_t ret; |
6de58e62 | 5633 | ssize_t size; |
2cadf913 | 5634 | |
2dc5d12b SR |
5635 | if (!count) |
5636 | return 0; | |
5637 | ||
6de58e62 | 5638 | #ifdef CONFIG_TRACER_MAX_TRACE |
d716ff71 SRRH |
5639 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) |
5640 | return -EBUSY; | |
6de58e62 SRRH |
5641 | #endif |
5642 | ||
ddd538f3 | 5643 | if (!info->spare) |
12883efb SRRH |
5644 | info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer, |
5645 | iter->cpu_file); | |
ddd538f3 | 5646 | if (!info->spare) |
d716ff71 | 5647 | return -ENOMEM; |
ddd538f3 | 5648 | |
2cadf913 SR |
5649 | /* Do we have previous read data to read? */ |
5650 | if (info->read < PAGE_SIZE) | |
5651 | goto read; | |
5652 | ||
b627344f | 5653 | again: |
cc60cdc9 | 5654 | trace_access_lock(iter->cpu_file); |
12883efb | 5655 | ret = ring_buffer_read_page(iter->trace_buffer->buffer, |
2cadf913 SR |
5656 | &info->spare, |
5657 | count, | |
cc60cdc9 SR |
5658 | iter->cpu_file, 0); |
5659 | trace_access_unlock(iter->cpu_file); | |
2cadf913 | 5660 | |
b627344f SR |
5661 | if (ret < 0) { |
5662 | if (trace_empty(iter)) { | |
d716ff71 SRRH |
5663 | if ((filp->f_flags & O_NONBLOCK)) |
5664 | return -EAGAIN; | |
5665 | ||
e30f53aa | 5666 | ret = wait_on_pipe(iter, false); |
d716ff71 SRRH |
5667 | if (ret) |
5668 | return ret; | |
5669 | ||
b627344f SR |
5670 | goto again; |
5671 | } | |
d716ff71 | 5672 | return 0; |
b627344f | 5673 | } |
436fc280 | 5674 | |
436fc280 | 5675 | info->read = 0; |
b627344f | 5676 | read: |
2cadf913 SR |
5677 | size = PAGE_SIZE - info->read; |
5678 | if (size > count) | |
5679 | size = count; | |
5680 | ||
5681 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
d716ff71 SRRH |
5682 | if (ret == size) |
5683 | return -EFAULT; | |
5684 | ||
2dc5d12b SR |
5685 | size -= ret; |
5686 | ||
2cadf913 SR |
5687 | *ppos += size; |
5688 | info->read += size; | |
5689 | ||
5690 | return size; | |
5691 | } | |
5692 | ||
5693 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
5694 | { | |
5695 | struct ftrace_buffer_info *info = file->private_data; | |
cc60cdc9 | 5696 | struct trace_iterator *iter = &info->iter; |
2cadf913 | 5697 | |
a695cb58 SRRH |
5698 | mutex_lock(&trace_types_lock); |
5699 | ||
cf6ab6d9 SRRH |
5700 | iter->tr->current_trace->ref--; |
5701 | ||
ff451961 | 5702 | __trace_array_put(iter->tr); |
2cadf913 | 5703 | |
ddd538f3 | 5704 | if (info->spare) |
12883efb | 5705 | ring_buffer_free_read_page(iter->trace_buffer->buffer, info->spare); |
2cadf913 SR |
5706 | kfree(info); |
5707 | ||
a695cb58 SRRH |
5708 | mutex_unlock(&trace_types_lock); |
5709 | ||
2cadf913 SR |
5710 | return 0; |
5711 | } | |
5712 | ||
5713 | struct buffer_ref { | |
5714 | struct ring_buffer *buffer; | |
5715 | void *page; | |
5716 | int ref; | |
5717 | }; | |
5718 | ||
5719 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
5720 | struct pipe_buffer *buf) | |
5721 | { | |
5722 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5723 | ||
5724 | if (--ref->ref) | |
5725 | return; | |
5726 | ||
5727 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5728 | kfree(ref); | |
5729 | buf->private = 0; | |
5730 | } | |
5731 | ||
2cadf913 SR |
5732 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, |
5733 | struct pipe_buffer *buf) | |
5734 | { | |
5735 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5736 | ||
5737 | ref->ref++; | |
5738 | } | |
5739 | ||
5740 | /* Pipe buffer operations for a buffer. */ | |
28dfef8f | 5741 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
2cadf913 | 5742 | .can_merge = 0, |
2cadf913 SR |
5743 | .confirm = generic_pipe_buf_confirm, |
5744 | .release = buffer_pipe_buf_release, | |
d55cb6cf | 5745 | .steal = generic_pipe_buf_steal, |
2cadf913 SR |
5746 | .get = buffer_pipe_buf_get, |
5747 | }; | |
5748 | ||
5749 | /* | |
5750 | * Callback from splice_to_pipe(), if we need to release some pages | |
5751 | * at the end of the spd in case we error'ed out in filling the pipe. | |
5752 | */ | |
5753 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
5754 | { | |
5755 | struct buffer_ref *ref = | |
5756 | (struct buffer_ref *)spd->partial[i].private; | |
5757 | ||
5758 | if (--ref->ref) | |
5759 | return; | |
5760 | ||
5761 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5762 | kfree(ref); | |
5763 | spd->partial[i].private = 0; | |
5764 | } | |
5765 | ||
5766 | static ssize_t | |
5767 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5768 | struct pipe_inode_info *pipe, size_t len, | |
5769 | unsigned int flags) | |
5770 | { | |
5771 | struct ftrace_buffer_info *info = file->private_data; | |
cc60cdc9 | 5772 | struct trace_iterator *iter = &info->iter; |
35f3d14d JA |
5773 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
5774 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
2cadf913 | 5775 | struct splice_pipe_desc spd = { |
35f3d14d JA |
5776 | .pages = pages_def, |
5777 | .partial = partial_def, | |
047fe360 | 5778 | .nr_pages_max = PIPE_DEF_BUFFERS, |
2cadf913 SR |
5779 | .flags = flags, |
5780 | .ops = &buffer_pipe_buf_ops, | |
5781 | .spd_release = buffer_spd_release, | |
5782 | }; | |
5783 | struct buffer_ref *ref; | |
93459c6c | 5784 | int entries, size, i; |
07906da7 | 5785 | ssize_t ret = 0; |
2cadf913 | 5786 | |
6de58e62 | 5787 | #ifdef CONFIG_TRACER_MAX_TRACE |
d716ff71 SRRH |
5788 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) |
5789 | return -EBUSY; | |
6de58e62 SRRH |
5790 | #endif |
5791 | ||
d716ff71 SRRH |
5792 | if (splice_grow_spd(pipe, &spd)) |
5793 | return -ENOMEM; | |
35f3d14d | 5794 | |
d716ff71 SRRH |
5795 | if (*ppos & (PAGE_SIZE - 1)) |
5796 | return -EINVAL; | |
93cfb3c9 LJ |
5797 | |
5798 | if (len & (PAGE_SIZE - 1)) { | |
d716ff71 SRRH |
5799 | if (len < PAGE_SIZE) |
5800 | return -EINVAL; | |
93cfb3c9 LJ |
5801 | len &= PAGE_MASK; |
5802 | } | |
5803 | ||
cc60cdc9 SR |
5804 | again: |
5805 | trace_access_lock(iter->cpu_file); | |
12883efb | 5806 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); |
93459c6c | 5807 | |
a786c06d | 5808 | for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) { |
2cadf913 SR |
5809 | struct page *page; |
5810 | int r; | |
5811 | ||
5812 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
07906da7 RV |
5813 | if (!ref) { |
5814 | ret = -ENOMEM; | |
2cadf913 | 5815 | break; |
07906da7 | 5816 | } |
2cadf913 | 5817 | |
7267fa68 | 5818 | ref->ref = 1; |
12883efb | 5819 | ref->buffer = iter->trace_buffer->buffer; |
cc60cdc9 | 5820 | ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); |
2cadf913 | 5821 | if (!ref->page) { |
07906da7 | 5822 | ret = -ENOMEM; |
2cadf913 SR |
5823 | kfree(ref); |
5824 | break; | |
5825 | } | |
5826 | ||
5827 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
cc60cdc9 | 5828 | len, iter->cpu_file, 1); |
2cadf913 | 5829 | if (r < 0) { |
7ea59064 | 5830 | ring_buffer_free_read_page(ref->buffer, ref->page); |
2cadf913 SR |
5831 | kfree(ref); |
5832 | break; | |
5833 | } | |
5834 | ||
5835 | /* | |
5836 | * zero out any left over data, this is going to | |
5837 | * user land. | |
5838 | */ | |
5839 | size = ring_buffer_page_len(ref->page); | |
5840 | if (size < PAGE_SIZE) | |
5841 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
5842 | ||
5843 | page = virt_to_page(ref->page); | |
5844 | ||
5845 | spd.pages[i] = page; | |
5846 | spd.partial[i].len = PAGE_SIZE; | |
5847 | spd.partial[i].offset = 0; | |
5848 | spd.partial[i].private = (unsigned long)ref; | |
5849 | spd.nr_pages++; | |
93cfb3c9 | 5850 | *ppos += PAGE_SIZE; |
93459c6c | 5851 | |
12883efb | 5852 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); |
2cadf913 SR |
5853 | } |
5854 | ||
cc60cdc9 | 5855 | trace_access_unlock(iter->cpu_file); |
2cadf913 SR |
5856 | spd.nr_pages = i; |
5857 | ||
5858 | /* did we read anything? */ | |
5859 | if (!spd.nr_pages) { | |
07906da7 | 5860 | if (ret) |
d716ff71 SRRH |
5861 | return ret; |
5862 | ||
5863 | if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) | |
5864 | return -EAGAIN; | |
07906da7 | 5865 | |
e30f53aa | 5866 | ret = wait_on_pipe(iter, true); |
8b8b3683 | 5867 | if (ret) |
d716ff71 | 5868 | return ret; |
e30f53aa | 5869 | |
cc60cdc9 | 5870 | goto again; |
2cadf913 SR |
5871 | } |
5872 | ||
5873 | ret = splice_to_pipe(pipe, &spd); | |
047fe360 | 5874 | splice_shrink_spd(&spd); |
6de58e62 | 5875 | |
2cadf913 SR |
5876 | return ret; |
5877 | } | |
5878 | ||
5879 | static const struct file_operations tracing_buffers_fops = { | |
5880 | .open = tracing_buffers_open, | |
5881 | .read = tracing_buffers_read, | |
cc60cdc9 | 5882 | .poll = tracing_buffers_poll, |
2cadf913 SR |
5883 | .release = tracing_buffers_release, |
5884 | .splice_read = tracing_buffers_splice_read, | |
5885 | .llseek = no_llseek, | |
5886 | }; | |
5887 | ||
c8d77183 SR |
5888 | static ssize_t |
5889 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
5890 | size_t count, loff_t *ppos) | |
5891 | { | |
4d3435b8 ON |
5892 | struct inode *inode = file_inode(filp); |
5893 | struct trace_array *tr = inode->i_private; | |
12883efb | 5894 | struct trace_buffer *trace_buf = &tr->trace_buffer; |
4d3435b8 | 5895 | int cpu = tracing_get_cpu(inode); |
c8d77183 SR |
5896 | struct trace_seq *s; |
5897 | unsigned long cnt; | |
c64e148a VN |
5898 | unsigned long long t; |
5899 | unsigned long usec_rem; | |
c8d77183 | 5900 | |
e4f2d10f | 5901 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
c8d77183 | 5902 | if (!s) |
a646365c | 5903 | return -ENOMEM; |
c8d77183 SR |
5904 | |
5905 | trace_seq_init(s); | |
5906 | ||
12883efb | 5907 | cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5908 | trace_seq_printf(s, "entries: %ld\n", cnt); |
5909 | ||
12883efb | 5910 | cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5911 | trace_seq_printf(s, "overrun: %ld\n", cnt); |
5912 | ||
12883efb | 5913 | cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5914 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); |
5915 | ||
12883efb | 5916 | cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu); |
c64e148a VN |
5917 | trace_seq_printf(s, "bytes: %ld\n", cnt); |
5918 | ||
58e8eedf | 5919 | if (trace_clocks[tr->clock_id].in_ns) { |
11043d8b | 5920 | /* local or global for trace_clock */ |
12883efb | 5921 | t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
11043d8b YY |
5922 | usec_rem = do_div(t, USEC_PER_SEC); |
5923 | trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", | |
5924 | t, usec_rem); | |
5925 | ||
12883efb | 5926 | t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
11043d8b YY |
5927 | usec_rem = do_div(t, USEC_PER_SEC); |
5928 | trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); | |
5929 | } else { | |
5930 | /* counter or tsc mode for trace_clock */ | |
5931 | trace_seq_printf(s, "oldest event ts: %llu\n", | |
12883efb | 5932 | ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
c64e148a | 5933 | |
11043d8b | 5934 | trace_seq_printf(s, "now ts: %llu\n", |
12883efb | 5935 | ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
11043d8b | 5936 | } |
c64e148a | 5937 | |
12883efb | 5938 | cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu); |
884bfe89 SP |
5939 | trace_seq_printf(s, "dropped events: %ld\n", cnt); |
5940 | ||
12883efb | 5941 | cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); |
ad964704 SRRH |
5942 | trace_seq_printf(s, "read events: %ld\n", cnt); |
5943 | ||
5ac48378 SRRH |
5944 | count = simple_read_from_buffer(ubuf, count, ppos, |
5945 | s->buffer, trace_seq_used(s)); | |
c8d77183 SR |
5946 | |
5947 | kfree(s); | |
5948 | ||
5949 | return count; | |
5950 | } | |
5951 | ||
5952 | static const struct file_operations tracing_stats_fops = { | |
4d3435b8 | 5953 | .open = tracing_open_generic_tr, |
c8d77183 | 5954 | .read = tracing_stats_read, |
b444786f | 5955 | .llseek = generic_file_llseek, |
4d3435b8 | 5956 | .release = tracing_release_generic_tr, |
c8d77183 SR |
5957 | }; |
5958 | ||
bc0c38d1 SR |
5959 | #ifdef CONFIG_DYNAMIC_FTRACE |
5960 | ||
b807c3d0 SR |
5961 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
5962 | { | |
5963 | return 0; | |
5964 | } | |
5965 | ||
bc0c38d1 | 5966 | static ssize_t |
b807c3d0 | 5967 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
5968 | size_t cnt, loff_t *ppos) |
5969 | { | |
a26a2a27 SR |
5970 | static char ftrace_dyn_info_buffer[1024]; |
5971 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 5972 | unsigned long *p = filp->private_data; |
b807c3d0 | 5973 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 5974 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
5975 | int r; |
5976 | ||
b807c3d0 SR |
5977 | mutex_lock(&dyn_info_mutex); |
5978 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 5979 | |
a26a2a27 | 5980 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
5981 | buf[r++] = '\n'; |
5982 | ||
5983 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
5984 | ||
5985 | mutex_unlock(&dyn_info_mutex); | |
5986 | ||
5987 | return r; | |
bc0c38d1 SR |
5988 | } |
5989 | ||
5e2336a0 | 5990 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 5991 | .open = tracing_open_generic, |
b807c3d0 | 5992 | .read = tracing_read_dyn_info, |
b444786f | 5993 | .llseek = generic_file_llseek, |
bc0c38d1 | 5994 | }; |
77fd5c15 | 5995 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
bc0c38d1 | 5996 | |
77fd5c15 SRRH |
5997 | #if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) |
5998 | static void | |
5999 | ftrace_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
6000 | { | |
6001 | tracing_snapshot(); | |
6002 | } | |
bc0c38d1 | 6003 | |
77fd5c15 SRRH |
6004 | static void |
6005 | ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
bc0c38d1 | 6006 | { |
77fd5c15 SRRH |
6007 | unsigned long *count = (long *)data; |
6008 | ||
6009 | if (!*count) | |
6010 | return; | |
bc0c38d1 | 6011 | |
77fd5c15 SRRH |
6012 | if (*count != -1) |
6013 | (*count)--; | |
6014 | ||
6015 | tracing_snapshot(); | |
6016 | } | |
6017 | ||
6018 | static int | |
6019 | ftrace_snapshot_print(struct seq_file *m, unsigned long ip, | |
6020 | struct ftrace_probe_ops *ops, void *data) | |
6021 | { | |
6022 | long count = (long)data; | |
6023 | ||
6024 | seq_printf(m, "%ps:", (void *)ip); | |
6025 | ||
fa6f0cc7 | 6026 | seq_puts(m, "snapshot"); |
77fd5c15 SRRH |
6027 | |
6028 | if (count == -1) | |
fa6f0cc7 | 6029 | seq_puts(m, ":unlimited\n"); |
77fd5c15 SRRH |
6030 | else |
6031 | seq_printf(m, ":count=%ld\n", count); | |
6032 | ||
6033 | return 0; | |
6034 | } | |
6035 | ||
6036 | static struct ftrace_probe_ops snapshot_probe_ops = { | |
6037 | .func = ftrace_snapshot, | |
6038 | .print = ftrace_snapshot_print, | |
6039 | }; | |
6040 | ||
6041 | static struct ftrace_probe_ops snapshot_count_probe_ops = { | |
6042 | .func = ftrace_count_snapshot, | |
6043 | .print = ftrace_snapshot_print, | |
6044 | }; | |
6045 | ||
6046 | static int | |
6047 | ftrace_trace_snapshot_callback(struct ftrace_hash *hash, | |
6048 | char *glob, char *cmd, char *param, int enable) | |
6049 | { | |
6050 | struct ftrace_probe_ops *ops; | |
6051 | void *count = (void *)-1; | |
6052 | char *number; | |
6053 | int ret; | |
6054 | ||
6055 | /* hash funcs only work with set_ftrace_filter */ | |
6056 | if (!enable) | |
6057 | return -EINVAL; | |
6058 | ||
6059 | ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; | |
6060 | ||
6061 | if (glob[0] == '!') { | |
6062 | unregister_ftrace_function_probe_func(glob+1, ops); | |
6063 | return 0; | |
6064 | } | |
6065 | ||
6066 | if (!param) | |
6067 | goto out_reg; | |
6068 | ||
6069 | number = strsep(¶m, ":"); | |
6070 | ||
6071 | if (!strlen(number)) | |
6072 | goto out_reg; | |
6073 | ||
6074 | /* | |
6075 | * We use the callback data field (which is a pointer) | |
6076 | * as our counter. | |
6077 | */ | |
6078 | ret = kstrtoul(number, 0, (unsigned long *)&count); | |
6079 | if (ret) | |
6080 | return ret; | |
6081 | ||
6082 | out_reg: | |
6083 | ret = register_ftrace_function_probe(glob, ops, count); | |
6084 | ||
6085 | if (ret >= 0) | |
6086 | alloc_snapshot(&global_trace); | |
6087 | ||
6088 | return ret < 0 ? ret : 0; | |
6089 | } | |
6090 | ||
6091 | static struct ftrace_func_command ftrace_snapshot_cmd = { | |
6092 | .name = "snapshot", | |
6093 | .func = ftrace_trace_snapshot_callback, | |
6094 | }; | |
6095 | ||
38de93ab | 6096 | static __init int register_snapshot_cmd(void) |
77fd5c15 SRRH |
6097 | { |
6098 | return register_ftrace_command(&ftrace_snapshot_cmd); | |
6099 | } | |
6100 | #else | |
38de93ab | 6101 | static inline __init int register_snapshot_cmd(void) { return 0; } |
77fd5c15 | 6102 | #endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ |
bc0c38d1 | 6103 | |
7eeafbca | 6104 | static struct dentry *tracing_get_dentry(struct trace_array *tr) |
bc0c38d1 | 6105 | { |
8434dc93 SRRH |
6106 | if (WARN_ON(!tr->dir)) |
6107 | return ERR_PTR(-ENODEV); | |
6108 | ||
6109 | /* Top directory uses NULL as the parent */ | |
6110 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
6111 | return NULL; | |
6112 | ||
6113 | /* All sub buffers have a descriptor */ | |
2b6080f2 | 6114 | return tr->dir; |
bc0c38d1 SR |
6115 | } |
6116 | ||
2b6080f2 | 6117 | static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) |
b04cc6b1 | 6118 | { |
b04cc6b1 FW |
6119 | struct dentry *d_tracer; |
6120 | ||
2b6080f2 SR |
6121 | if (tr->percpu_dir) |
6122 | return tr->percpu_dir; | |
b04cc6b1 | 6123 | |
7eeafbca | 6124 | d_tracer = tracing_get_dentry(tr); |
14a5ae40 | 6125 | if (IS_ERR(d_tracer)) |
b04cc6b1 FW |
6126 | return NULL; |
6127 | ||
8434dc93 | 6128 | tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer); |
b04cc6b1 | 6129 | |
2b6080f2 | 6130 | WARN_ONCE(!tr->percpu_dir, |
8434dc93 | 6131 | "Could not create tracefs directory 'per_cpu/%d'\n", cpu); |
b04cc6b1 | 6132 | |
2b6080f2 | 6133 | return tr->percpu_dir; |
b04cc6b1 FW |
6134 | } |
6135 | ||
649e9c70 ON |
6136 | static struct dentry * |
6137 | trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent, | |
6138 | void *data, long cpu, const struct file_operations *fops) | |
6139 | { | |
6140 | struct dentry *ret = trace_create_file(name, mode, parent, data, fops); | |
6141 | ||
6142 | if (ret) /* See tracing_get_cpu() */ | |
7682c918 | 6143 | d_inode(ret)->i_cdev = (void *)(cpu + 1); |
649e9c70 ON |
6144 | return ret; |
6145 | } | |
6146 | ||
2b6080f2 | 6147 | static void |
8434dc93 | 6148 | tracing_init_tracefs_percpu(struct trace_array *tr, long cpu) |
b04cc6b1 | 6149 | { |
2b6080f2 | 6150 | struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu); |
5452af66 | 6151 | struct dentry *d_cpu; |
dd49a38c | 6152 | char cpu_dir[30]; /* 30 characters should be more than enough */ |
b04cc6b1 | 6153 | |
0a3d7ce7 NK |
6154 | if (!d_percpu) |
6155 | return; | |
6156 | ||
dd49a38c | 6157 | snprintf(cpu_dir, 30, "cpu%ld", cpu); |
8434dc93 | 6158 | d_cpu = tracefs_create_dir(cpu_dir, d_percpu); |
8656e7a2 | 6159 | if (!d_cpu) { |
a395d6a7 | 6160 | pr_warn("Could not create tracefs '%s' entry\n", cpu_dir); |
8656e7a2 FW |
6161 | return; |
6162 | } | |
b04cc6b1 | 6163 | |
8656e7a2 | 6164 | /* per cpu trace_pipe */ |
649e9c70 | 6165 | trace_create_cpu_file("trace_pipe", 0444, d_cpu, |
15544209 | 6166 | tr, cpu, &tracing_pipe_fops); |
b04cc6b1 FW |
6167 | |
6168 | /* per cpu trace */ | |
649e9c70 | 6169 | trace_create_cpu_file("trace", 0644, d_cpu, |
6484c71c | 6170 | tr, cpu, &tracing_fops); |
7f96f93f | 6171 | |
649e9c70 | 6172 | trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu, |
46ef2be0 | 6173 | tr, cpu, &tracing_buffers_fops); |
7f96f93f | 6174 | |
649e9c70 | 6175 | trace_create_cpu_file("stats", 0444, d_cpu, |
4d3435b8 | 6176 | tr, cpu, &tracing_stats_fops); |
438ced17 | 6177 | |
649e9c70 | 6178 | trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, |
0bc392ee | 6179 | tr, cpu, &tracing_entries_fops); |
f1affcaa SRRH |
6180 | |
6181 | #ifdef CONFIG_TRACER_SNAPSHOT | |
649e9c70 | 6182 | trace_create_cpu_file("snapshot", 0644, d_cpu, |
6484c71c | 6183 | tr, cpu, &snapshot_fops); |
6de58e62 | 6184 | |
649e9c70 | 6185 | trace_create_cpu_file("snapshot_raw", 0444, d_cpu, |
46ef2be0 | 6186 | tr, cpu, &snapshot_raw_fops); |
f1affcaa | 6187 | #endif |
b04cc6b1 FW |
6188 | } |
6189 | ||
60a11774 SR |
6190 | #ifdef CONFIG_FTRACE_SELFTEST |
6191 | /* Let selftest have access to static functions in this file */ | |
6192 | #include "trace_selftest.c" | |
6193 | #endif | |
6194 | ||
577b785f SR |
6195 | static ssize_t |
6196 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
6197 | loff_t *ppos) | |
6198 | { | |
6199 | struct trace_option_dentry *topt = filp->private_data; | |
6200 | char *buf; | |
6201 | ||
6202 | if (topt->flags->val & topt->opt->bit) | |
6203 | buf = "1\n"; | |
6204 | else | |
6205 | buf = "0\n"; | |
6206 | ||
6207 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
6208 | } | |
6209 | ||
6210 | static ssize_t | |
6211 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
6212 | loff_t *ppos) | |
6213 | { | |
6214 | struct trace_option_dentry *topt = filp->private_data; | |
6215 | unsigned long val; | |
577b785f SR |
6216 | int ret; |
6217 | ||
22fe9b54 PH |
6218 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
6219 | if (ret) | |
577b785f SR |
6220 | return ret; |
6221 | ||
8d18eaaf LZ |
6222 | if (val != 0 && val != 1) |
6223 | return -EINVAL; | |
577b785f | 6224 | |
8d18eaaf | 6225 | if (!!(topt->flags->val & topt->opt->bit) != val) { |
577b785f | 6226 | mutex_lock(&trace_types_lock); |
8c1a49ae | 6227 | ret = __set_tracer_option(topt->tr, topt->flags, |
c757bea9 | 6228 | topt->opt, !val); |
577b785f SR |
6229 | mutex_unlock(&trace_types_lock); |
6230 | if (ret) | |
6231 | return ret; | |
577b785f SR |
6232 | } |
6233 | ||
6234 | *ppos += cnt; | |
6235 | ||
6236 | return cnt; | |
6237 | } | |
6238 | ||
6239 | ||
6240 | static const struct file_operations trace_options_fops = { | |
6241 | .open = tracing_open_generic, | |
6242 | .read = trace_options_read, | |
6243 | .write = trace_options_write, | |
b444786f | 6244 | .llseek = generic_file_llseek, |
577b785f SR |
6245 | }; |
6246 | ||
9a38a885 SRRH |
6247 | /* |
6248 | * In order to pass in both the trace_array descriptor as well as the index | |
6249 | * to the flag that the trace option file represents, the trace_array | |
6250 | * has a character array of trace_flags_index[], which holds the index | |
6251 | * of the bit for the flag it represents. index[0] == 0, index[1] == 1, etc. | |
6252 | * The address of this character array is passed to the flag option file | |
6253 | * read/write callbacks. | |
6254 | * | |
6255 | * In order to extract both the index and the trace_array descriptor, | |
6256 | * get_tr_index() uses the following algorithm. | |
6257 | * | |
6258 | * idx = *ptr; | |
6259 | * | |
6260 | * As the pointer itself contains the address of the index (remember | |
6261 | * index[1] == 1). | |
6262 | * | |
6263 | * Then to get the trace_array descriptor, by subtracting that index | |
6264 | * from the ptr, we get to the start of the index itself. | |
6265 | * | |
6266 | * ptr - idx == &index[0] | |
6267 | * | |
6268 | * Then a simple container_of() from that pointer gets us to the | |
6269 | * trace_array descriptor. | |
6270 | */ | |
6271 | static void get_tr_index(void *data, struct trace_array **ptr, | |
6272 | unsigned int *pindex) | |
6273 | { | |
6274 | *pindex = *(unsigned char *)data; | |
6275 | ||
6276 | *ptr = container_of(data - *pindex, struct trace_array, | |
6277 | trace_flags_index); | |
6278 | } | |
6279 | ||
a8259075 SR |
6280 | static ssize_t |
6281 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
6282 | loff_t *ppos) | |
6283 | { | |
9a38a885 SRRH |
6284 | void *tr_index = filp->private_data; |
6285 | struct trace_array *tr; | |
6286 | unsigned int index; | |
a8259075 SR |
6287 | char *buf; |
6288 | ||
9a38a885 SRRH |
6289 | get_tr_index(tr_index, &tr, &index); |
6290 | ||
6291 | if (tr->trace_flags & (1 << index)) | |
a8259075 SR |
6292 | buf = "1\n"; |
6293 | else | |
6294 | buf = "0\n"; | |
6295 | ||
6296 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
6297 | } | |
6298 | ||
6299 | static ssize_t | |
6300 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
6301 | loff_t *ppos) | |
6302 | { | |
9a38a885 SRRH |
6303 | void *tr_index = filp->private_data; |
6304 | struct trace_array *tr; | |
6305 | unsigned int index; | |
a8259075 SR |
6306 | unsigned long val; |
6307 | int ret; | |
6308 | ||
9a38a885 SRRH |
6309 | get_tr_index(tr_index, &tr, &index); |
6310 | ||
22fe9b54 PH |
6311 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
6312 | if (ret) | |
a8259075 SR |
6313 | return ret; |
6314 | ||
f2d84b65 | 6315 | if (val != 0 && val != 1) |
a8259075 | 6316 | return -EINVAL; |
69d34da2 SRRH |
6317 | |
6318 | mutex_lock(&trace_types_lock); | |
2b6080f2 | 6319 | ret = set_tracer_flag(tr, 1 << index, val); |
69d34da2 | 6320 | mutex_unlock(&trace_types_lock); |
a8259075 | 6321 | |
613f04a0 SRRH |
6322 | if (ret < 0) |
6323 | return ret; | |
6324 | ||
a8259075 SR |
6325 | *ppos += cnt; |
6326 | ||
6327 | return cnt; | |
6328 | } | |
6329 | ||
a8259075 SR |
6330 | static const struct file_operations trace_options_core_fops = { |
6331 | .open = tracing_open_generic, | |
6332 | .read = trace_options_core_read, | |
6333 | .write = trace_options_core_write, | |
b444786f | 6334 | .llseek = generic_file_llseek, |
a8259075 SR |
6335 | }; |
6336 | ||
5452af66 | 6337 | struct dentry *trace_create_file(const char *name, |
f4ae40a6 | 6338 | umode_t mode, |
5452af66 FW |
6339 | struct dentry *parent, |
6340 | void *data, | |
6341 | const struct file_operations *fops) | |
6342 | { | |
6343 | struct dentry *ret; | |
6344 | ||
8434dc93 | 6345 | ret = tracefs_create_file(name, mode, parent, data, fops); |
5452af66 | 6346 | if (!ret) |
a395d6a7 | 6347 | pr_warn("Could not create tracefs '%s' entry\n", name); |
5452af66 FW |
6348 | |
6349 | return ret; | |
6350 | } | |
6351 | ||
6352 | ||
2b6080f2 | 6353 | static struct dentry *trace_options_init_dentry(struct trace_array *tr) |
a8259075 SR |
6354 | { |
6355 | struct dentry *d_tracer; | |
a8259075 | 6356 | |
2b6080f2 SR |
6357 | if (tr->options) |
6358 | return tr->options; | |
a8259075 | 6359 | |
7eeafbca | 6360 | d_tracer = tracing_get_dentry(tr); |
14a5ae40 | 6361 | if (IS_ERR(d_tracer)) |
a8259075 SR |
6362 | return NULL; |
6363 | ||
8434dc93 | 6364 | tr->options = tracefs_create_dir("options", d_tracer); |
2b6080f2 | 6365 | if (!tr->options) { |
a395d6a7 | 6366 | pr_warn("Could not create tracefs directory 'options'\n"); |
a8259075 SR |
6367 | return NULL; |
6368 | } | |
6369 | ||
2b6080f2 | 6370 | return tr->options; |
a8259075 SR |
6371 | } |
6372 | ||
577b785f | 6373 | static void |
2b6080f2 SR |
6374 | create_trace_option_file(struct trace_array *tr, |
6375 | struct trace_option_dentry *topt, | |
577b785f SR |
6376 | struct tracer_flags *flags, |
6377 | struct tracer_opt *opt) | |
6378 | { | |
6379 | struct dentry *t_options; | |
577b785f | 6380 | |
2b6080f2 | 6381 | t_options = trace_options_init_dentry(tr); |
577b785f SR |
6382 | if (!t_options) |
6383 | return; | |
6384 | ||
6385 | topt->flags = flags; | |
6386 | topt->opt = opt; | |
2b6080f2 | 6387 | topt->tr = tr; |
577b785f | 6388 | |
5452af66 | 6389 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
577b785f SR |
6390 | &trace_options_fops); |
6391 | ||
577b785f SR |
6392 | } |
6393 | ||
37aea98b | 6394 | static void |
2b6080f2 | 6395 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer) |
577b785f SR |
6396 | { |
6397 | struct trace_option_dentry *topts; | |
37aea98b | 6398 | struct trace_options *tr_topts; |
577b785f SR |
6399 | struct tracer_flags *flags; |
6400 | struct tracer_opt *opts; | |
6401 | int cnt; | |
37aea98b | 6402 | int i; |
577b785f SR |
6403 | |
6404 | if (!tracer) | |
37aea98b | 6405 | return; |
577b785f SR |
6406 | |
6407 | flags = tracer->flags; | |
6408 | ||
6409 | if (!flags || !flags->opts) | |
37aea98b SRRH |
6410 | return; |
6411 | ||
6412 | /* | |
6413 | * If this is an instance, only create flags for tracers | |
6414 | * the instance may have. | |
6415 | */ | |
6416 | if (!trace_ok_for_array(tracer, tr)) | |
6417 | return; | |
6418 | ||
6419 | for (i = 0; i < tr->nr_topts; i++) { | |
d39cdd20 CH |
6420 | /* Make sure there's no duplicate flags. */ |
6421 | if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags)) | |
37aea98b SRRH |
6422 | return; |
6423 | } | |
577b785f SR |
6424 | |
6425 | opts = flags->opts; | |
6426 | ||
6427 | for (cnt = 0; opts[cnt].name; cnt++) | |
6428 | ; | |
6429 | ||
0cfe8245 | 6430 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f | 6431 | if (!topts) |
37aea98b SRRH |
6432 | return; |
6433 | ||
6434 | tr_topts = krealloc(tr->topts, sizeof(*tr->topts) * (tr->nr_topts + 1), | |
6435 | GFP_KERNEL); | |
6436 | if (!tr_topts) { | |
6437 | kfree(topts); | |
6438 | return; | |
6439 | } | |
6440 | ||
6441 | tr->topts = tr_topts; | |
6442 | tr->topts[tr->nr_topts].tracer = tracer; | |
6443 | tr->topts[tr->nr_topts].topts = topts; | |
6444 | tr->nr_topts++; | |
577b785f | 6445 | |
41d9c0be | 6446 | for (cnt = 0; opts[cnt].name; cnt++) { |
2b6080f2 | 6447 | create_trace_option_file(tr, &topts[cnt], flags, |
577b785f | 6448 | &opts[cnt]); |
41d9c0be SRRH |
6449 | WARN_ONCE(topts[cnt].entry == NULL, |
6450 | "Failed to create trace option: %s", | |
6451 | opts[cnt].name); | |
6452 | } | |
577b785f SR |
6453 | } |
6454 | ||
a8259075 | 6455 | static struct dentry * |
2b6080f2 SR |
6456 | create_trace_option_core_file(struct trace_array *tr, |
6457 | const char *option, long index) | |
a8259075 SR |
6458 | { |
6459 | struct dentry *t_options; | |
a8259075 | 6460 | |
2b6080f2 | 6461 | t_options = trace_options_init_dentry(tr); |
a8259075 SR |
6462 | if (!t_options) |
6463 | return NULL; | |
6464 | ||
9a38a885 SRRH |
6465 | return trace_create_file(option, 0644, t_options, |
6466 | (void *)&tr->trace_flags_index[index], | |
6467 | &trace_options_core_fops); | |
a8259075 SR |
6468 | } |
6469 | ||
16270145 | 6470 | static void create_trace_options_dir(struct trace_array *tr) |
a8259075 SR |
6471 | { |
6472 | struct dentry *t_options; | |
16270145 | 6473 | bool top_level = tr == &global_trace; |
a8259075 SR |
6474 | int i; |
6475 | ||
2b6080f2 | 6476 | t_options = trace_options_init_dentry(tr); |
a8259075 SR |
6477 | if (!t_options) |
6478 | return; | |
6479 | ||
16270145 SRRH |
6480 | for (i = 0; trace_options[i]; i++) { |
6481 | if (top_level || | |
6482 | !((1 << i) & TOP_LEVEL_TRACE_FLAGS)) | |
6483 | create_trace_option_core_file(tr, trace_options[i], i); | |
6484 | } | |
a8259075 SR |
6485 | } |
6486 | ||
499e5470 SR |
6487 | static ssize_t |
6488 | rb_simple_read(struct file *filp, char __user *ubuf, | |
6489 | size_t cnt, loff_t *ppos) | |
6490 | { | |
348f0fc2 | 6491 | struct trace_array *tr = filp->private_data; |
499e5470 SR |
6492 | char buf[64]; |
6493 | int r; | |
6494 | ||
10246fa3 | 6495 | r = tracer_tracing_is_on(tr); |
499e5470 SR |
6496 | r = sprintf(buf, "%d\n", r); |
6497 | ||
6498 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
6499 | } | |
6500 | ||
6501 | static ssize_t | |
6502 | rb_simple_write(struct file *filp, const char __user *ubuf, | |
6503 | size_t cnt, loff_t *ppos) | |
6504 | { | |
348f0fc2 | 6505 | struct trace_array *tr = filp->private_data; |
12883efb | 6506 | struct ring_buffer *buffer = tr->trace_buffer.buffer; |
499e5470 SR |
6507 | unsigned long val; |
6508 | int ret; | |
6509 | ||
6510 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
6511 | if (ret) | |
6512 | return ret; | |
6513 | ||
6514 | if (buffer) { | |
2df8f8a6 SR |
6515 | mutex_lock(&trace_types_lock); |
6516 | if (val) { | |
10246fa3 | 6517 | tracer_tracing_on(tr); |
2b6080f2 SR |
6518 | if (tr->current_trace->start) |
6519 | tr->current_trace->start(tr); | |
2df8f8a6 | 6520 | } else { |
10246fa3 | 6521 | tracer_tracing_off(tr); |
2b6080f2 SR |
6522 | if (tr->current_trace->stop) |
6523 | tr->current_trace->stop(tr); | |
2df8f8a6 SR |
6524 | } |
6525 | mutex_unlock(&trace_types_lock); | |
499e5470 SR |
6526 | } |
6527 | ||
6528 | (*ppos)++; | |
6529 | ||
6530 | return cnt; | |
6531 | } | |
6532 | ||
6533 | static const struct file_operations rb_simple_fops = { | |
7b85af63 | 6534 | .open = tracing_open_generic_tr, |
499e5470 SR |
6535 | .read = rb_simple_read, |
6536 | .write = rb_simple_write, | |
7b85af63 | 6537 | .release = tracing_release_generic_tr, |
499e5470 SR |
6538 | .llseek = default_llseek, |
6539 | }; | |
6540 | ||
277ba044 SR |
6541 | struct dentry *trace_instance_dir; |
6542 | ||
6543 | static void | |
8434dc93 | 6544 | init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer); |
277ba044 | 6545 | |
55034cd6 SRRH |
6546 | static int |
6547 | allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size) | |
277ba044 SR |
6548 | { |
6549 | enum ring_buffer_flags rb_flags; | |
737223fb | 6550 | |
983f938a | 6551 | rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; |
737223fb | 6552 | |
dced341b SRRH |
6553 | buf->tr = tr; |
6554 | ||
55034cd6 SRRH |
6555 | buf->buffer = ring_buffer_alloc(size, rb_flags); |
6556 | if (!buf->buffer) | |
6557 | return -ENOMEM; | |
737223fb | 6558 | |
55034cd6 SRRH |
6559 | buf->data = alloc_percpu(struct trace_array_cpu); |
6560 | if (!buf->data) { | |
6561 | ring_buffer_free(buf->buffer); | |
6562 | return -ENOMEM; | |
6563 | } | |
737223fb | 6564 | |
737223fb SRRH |
6565 | /* Allocate the first page for all buffers */ |
6566 | set_buffer_entries(&tr->trace_buffer, | |
6567 | ring_buffer_size(tr->trace_buffer.buffer, 0)); | |
6568 | ||
55034cd6 SRRH |
6569 | return 0; |
6570 | } | |
737223fb | 6571 | |
55034cd6 SRRH |
6572 | static int allocate_trace_buffers(struct trace_array *tr, int size) |
6573 | { | |
6574 | int ret; | |
737223fb | 6575 | |
55034cd6 SRRH |
6576 | ret = allocate_trace_buffer(tr, &tr->trace_buffer, size); |
6577 | if (ret) | |
6578 | return ret; | |
737223fb | 6579 | |
55034cd6 SRRH |
6580 | #ifdef CONFIG_TRACER_MAX_TRACE |
6581 | ret = allocate_trace_buffer(tr, &tr->max_buffer, | |
6582 | allocate_snapshot ? size : 1); | |
6583 | if (WARN_ON(ret)) { | |
737223fb | 6584 | ring_buffer_free(tr->trace_buffer.buffer); |
55034cd6 SRRH |
6585 | free_percpu(tr->trace_buffer.data); |
6586 | return -ENOMEM; | |
6587 | } | |
6588 | tr->allocated_snapshot = allocate_snapshot; | |
737223fb | 6589 | |
55034cd6 SRRH |
6590 | /* |
6591 | * Only the top level trace array gets its snapshot allocated | |
6592 | * from the kernel command line. | |
6593 | */ | |
6594 | allocate_snapshot = false; | |
737223fb | 6595 | #endif |
55034cd6 | 6596 | return 0; |
737223fb SRRH |
6597 | } |
6598 | ||
f0b70cc4 SRRH |
6599 | static void free_trace_buffer(struct trace_buffer *buf) |
6600 | { | |
6601 | if (buf->buffer) { | |
6602 | ring_buffer_free(buf->buffer); | |
6603 | buf->buffer = NULL; | |
6604 | free_percpu(buf->data); | |
6605 | buf->data = NULL; | |
6606 | } | |
6607 | } | |
6608 | ||
23aaa3c1 SRRH |
6609 | static void free_trace_buffers(struct trace_array *tr) |
6610 | { | |
6611 | if (!tr) | |
6612 | return; | |
6613 | ||
f0b70cc4 | 6614 | free_trace_buffer(&tr->trace_buffer); |
23aaa3c1 SRRH |
6615 | |
6616 | #ifdef CONFIG_TRACER_MAX_TRACE | |
f0b70cc4 | 6617 | free_trace_buffer(&tr->max_buffer); |
23aaa3c1 SRRH |
6618 | #endif |
6619 | } | |
6620 | ||
9a38a885 SRRH |
6621 | static void init_trace_flags_index(struct trace_array *tr) |
6622 | { | |
6623 | int i; | |
6624 | ||
6625 | /* Used by the trace options files */ | |
6626 | for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) | |
6627 | tr->trace_flags_index[i] = i; | |
6628 | } | |
6629 | ||
37aea98b SRRH |
6630 | static void __update_tracer_options(struct trace_array *tr) |
6631 | { | |
6632 | struct tracer *t; | |
6633 | ||
6634 | for (t = trace_types; t; t = t->next) | |
6635 | add_tracer_options(tr, t); | |
6636 | } | |
6637 | ||
6638 | static void update_tracer_options(struct trace_array *tr) | |
6639 | { | |
6640 | mutex_lock(&trace_types_lock); | |
6641 | __update_tracer_options(tr); | |
6642 | mutex_unlock(&trace_types_lock); | |
6643 | } | |
6644 | ||
eae47358 | 6645 | static int instance_mkdir(const char *name) |
737223fb | 6646 | { |
277ba044 SR |
6647 | struct trace_array *tr; |
6648 | int ret; | |
277ba044 SR |
6649 | |
6650 | mutex_lock(&trace_types_lock); | |
6651 | ||
6652 | ret = -EEXIST; | |
6653 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6654 | if (tr->name && strcmp(tr->name, name) == 0) | |
6655 | goto out_unlock; | |
6656 | } | |
6657 | ||
6658 | ret = -ENOMEM; | |
6659 | tr = kzalloc(sizeof(*tr), GFP_KERNEL); | |
6660 | if (!tr) | |
6661 | goto out_unlock; | |
6662 | ||
6663 | tr->name = kstrdup(name, GFP_KERNEL); | |
6664 | if (!tr->name) | |
6665 | goto out_free_tr; | |
6666 | ||
ccfe9e42 AL |
6667 | if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL)) |
6668 | goto out_free_tr; | |
6669 | ||
20550622 | 6670 | tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS; |
983f938a | 6671 | |
ccfe9e42 AL |
6672 | cpumask_copy(tr->tracing_cpumask, cpu_all_mask); |
6673 | ||
277ba044 SR |
6674 | raw_spin_lock_init(&tr->start_lock); |
6675 | ||
0b9b12c1 SRRH |
6676 | tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
6677 | ||
277ba044 SR |
6678 | tr->current_trace = &nop_trace; |
6679 | ||
6680 | INIT_LIST_HEAD(&tr->systems); | |
6681 | INIT_LIST_HEAD(&tr->events); | |
6682 | ||
737223fb | 6683 | if (allocate_trace_buffers(tr, trace_buf_size) < 0) |
277ba044 SR |
6684 | goto out_free_tr; |
6685 | ||
8434dc93 | 6686 | tr->dir = tracefs_create_dir(name, trace_instance_dir); |
277ba044 SR |
6687 | if (!tr->dir) |
6688 | goto out_free_tr; | |
6689 | ||
6690 | ret = event_trace_add_tracer(tr->dir, tr); | |
609e85a7 | 6691 | if (ret) { |
8434dc93 | 6692 | tracefs_remove_recursive(tr->dir); |
277ba044 | 6693 | goto out_free_tr; |
609e85a7 | 6694 | } |
277ba044 | 6695 | |
8434dc93 | 6696 | init_tracer_tracefs(tr, tr->dir); |
9a38a885 | 6697 | init_trace_flags_index(tr); |
37aea98b | 6698 | __update_tracer_options(tr); |
277ba044 SR |
6699 | |
6700 | list_add(&tr->list, &ftrace_trace_arrays); | |
6701 | ||
6702 | mutex_unlock(&trace_types_lock); | |
6703 | ||
6704 | return 0; | |
6705 | ||
6706 | out_free_tr: | |
23aaa3c1 | 6707 | free_trace_buffers(tr); |
ccfe9e42 | 6708 | free_cpumask_var(tr->tracing_cpumask); |
277ba044 SR |
6709 | kfree(tr->name); |
6710 | kfree(tr); | |
6711 | ||
6712 | out_unlock: | |
6713 | mutex_unlock(&trace_types_lock); | |
6714 | ||
6715 | return ret; | |
6716 | ||
6717 | } | |
6718 | ||
eae47358 | 6719 | static int instance_rmdir(const char *name) |
0c8916c3 SR |
6720 | { |
6721 | struct trace_array *tr; | |
6722 | int found = 0; | |
6723 | int ret; | |
37aea98b | 6724 | int i; |
0c8916c3 SR |
6725 | |
6726 | mutex_lock(&trace_types_lock); | |
6727 | ||
6728 | ret = -ENODEV; | |
6729 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6730 | if (tr->name && strcmp(tr->name, name) == 0) { | |
6731 | found = 1; | |
6732 | break; | |
6733 | } | |
6734 | } | |
6735 | if (!found) | |
6736 | goto out_unlock; | |
6737 | ||
a695cb58 | 6738 | ret = -EBUSY; |
cf6ab6d9 | 6739 | if (tr->ref || (tr->current_trace && tr->current_trace->ref)) |
a695cb58 SRRH |
6740 | goto out_unlock; |
6741 | ||
0c8916c3 SR |
6742 | list_del(&tr->list); |
6743 | ||
20550622 SRRH |
6744 | /* Disable all the flags that were enabled coming in */ |
6745 | for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) { | |
6746 | if ((1 << i) & ZEROED_TRACE_FLAGS) | |
6747 | set_tracer_flag(tr, 1 << i, 0); | |
6748 | } | |
6749 | ||
6b450d25 | 6750 | tracing_set_nop(tr); |
0c8916c3 | 6751 | event_trace_del_tracer(tr); |
591dffda | 6752 | ftrace_destroy_function_files(tr); |
681a4a2f | 6753 | tracefs_remove_recursive(tr->dir); |
a9fcaaac | 6754 | free_trace_buffers(tr); |
0c8916c3 | 6755 | |
37aea98b SRRH |
6756 | for (i = 0; i < tr->nr_topts; i++) { |
6757 | kfree(tr->topts[i].topts); | |
6758 | } | |
6759 | kfree(tr->topts); | |
6760 | ||
0c8916c3 SR |
6761 | kfree(tr->name); |
6762 | kfree(tr); | |
6763 | ||
6764 | ret = 0; | |
6765 | ||
6766 | out_unlock: | |
6767 | mutex_unlock(&trace_types_lock); | |
6768 | ||
6769 | return ret; | |
6770 | } | |
6771 | ||
277ba044 SR |
6772 | static __init void create_trace_instances(struct dentry *d_tracer) |
6773 | { | |
eae47358 SRRH |
6774 | trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, |
6775 | instance_mkdir, | |
6776 | instance_rmdir); | |
277ba044 SR |
6777 | if (WARN_ON(!trace_instance_dir)) |
6778 | return; | |
277ba044 SR |
6779 | } |
6780 | ||
2b6080f2 | 6781 | static void |
8434dc93 | 6782 | init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
2b6080f2 | 6783 | { |
121aaee7 | 6784 | int cpu; |
2b6080f2 | 6785 | |
607e2ea1 SRRH |
6786 | trace_create_file("available_tracers", 0444, d_tracer, |
6787 | tr, &show_traces_fops); | |
6788 | ||
6789 | trace_create_file("current_tracer", 0644, d_tracer, | |
6790 | tr, &set_tracer_fops); | |
6791 | ||
ccfe9e42 AL |
6792 | trace_create_file("tracing_cpumask", 0644, d_tracer, |
6793 | tr, &tracing_cpumask_fops); | |
6794 | ||
2b6080f2 SR |
6795 | trace_create_file("trace_options", 0644, d_tracer, |
6796 | tr, &tracing_iter_fops); | |
6797 | ||
6798 | trace_create_file("trace", 0644, d_tracer, | |
6484c71c | 6799 | tr, &tracing_fops); |
2b6080f2 SR |
6800 | |
6801 | trace_create_file("trace_pipe", 0444, d_tracer, | |
15544209 | 6802 | tr, &tracing_pipe_fops); |
2b6080f2 SR |
6803 | |
6804 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
0bc392ee | 6805 | tr, &tracing_entries_fops); |
2b6080f2 SR |
6806 | |
6807 | trace_create_file("buffer_total_size_kb", 0444, d_tracer, | |
6808 | tr, &tracing_total_entries_fops); | |
6809 | ||
238ae93d | 6810 | trace_create_file("free_buffer", 0200, d_tracer, |
2b6080f2 SR |
6811 | tr, &tracing_free_buffer_fops); |
6812 | ||
6813 | trace_create_file("trace_marker", 0220, d_tracer, | |
6814 | tr, &tracing_mark_fops); | |
6815 | ||
6816 | trace_create_file("trace_clock", 0644, d_tracer, tr, | |
6817 | &trace_clock_fops); | |
6818 | ||
6819 | trace_create_file("tracing_on", 0644, d_tracer, | |
6484c71c | 6820 | tr, &rb_simple_fops); |
ce9bae55 | 6821 | |
16270145 SRRH |
6822 | create_trace_options_dir(tr); |
6823 | ||
6d9b3fa5 SRRH |
6824 | #ifdef CONFIG_TRACER_MAX_TRACE |
6825 | trace_create_file("tracing_max_latency", 0644, d_tracer, | |
6826 | &tr->max_latency, &tracing_max_lat_fops); | |
6827 | #endif | |
6828 | ||
591dffda SRRH |
6829 | if (ftrace_create_function_files(tr, d_tracer)) |
6830 | WARN(1, "Could not allocate function filter files"); | |
6831 | ||
ce9bae55 SRRH |
6832 | #ifdef CONFIG_TRACER_SNAPSHOT |
6833 | trace_create_file("snapshot", 0644, d_tracer, | |
6484c71c | 6834 | tr, &snapshot_fops); |
ce9bae55 | 6835 | #endif |
121aaee7 SRRH |
6836 | |
6837 | for_each_tracing_cpu(cpu) | |
8434dc93 | 6838 | tracing_init_tracefs_percpu(tr, cpu); |
121aaee7 | 6839 | |
2b6080f2 SR |
6840 | } |
6841 | ||
f76180bc SRRH |
6842 | static struct vfsmount *trace_automount(void *ingore) |
6843 | { | |
6844 | struct vfsmount *mnt; | |
6845 | struct file_system_type *type; | |
6846 | ||
6847 | /* | |
6848 | * To maintain backward compatibility for tools that mount | |
6849 | * debugfs to get to the tracing facility, tracefs is automatically | |
6850 | * mounted to the debugfs/tracing directory. | |
6851 | */ | |
6852 | type = get_fs_type("tracefs"); | |
6853 | if (!type) | |
6854 | return NULL; | |
6855 | mnt = vfs_kern_mount(type, 0, "tracefs", NULL); | |
6856 | put_filesystem(type); | |
6857 | if (IS_ERR(mnt)) | |
6858 | return NULL; | |
6859 | mntget(mnt); | |
6860 | ||
6861 | return mnt; | |
6862 | } | |
6863 | ||
7eeafbca SRRH |
6864 | /** |
6865 | * tracing_init_dentry - initialize top level trace array | |
6866 | * | |
6867 | * This is called when creating files or directories in the tracing | |
6868 | * directory. It is called via fs_initcall() by any of the boot up code | |
6869 | * and expects to return the dentry of the top level tracing directory. | |
6870 | */ | |
6871 | struct dentry *tracing_init_dentry(void) | |
6872 | { | |
6873 | struct trace_array *tr = &global_trace; | |
6874 | ||
f76180bc | 6875 | /* The top level trace array uses NULL as parent */ |
7eeafbca | 6876 | if (tr->dir) |
f76180bc | 6877 | return NULL; |
7eeafbca | 6878 | |
8b129199 JW |
6879 | if (WARN_ON(!tracefs_initialized()) || |
6880 | (IS_ENABLED(CONFIG_DEBUG_FS) && | |
6881 | WARN_ON(!debugfs_initialized()))) | |
7eeafbca SRRH |
6882 | return ERR_PTR(-ENODEV); |
6883 | ||
f76180bc SRRH |
6884 | /* |
6885 | * As there may still be users that expect the tracing | |
6886 | * files to exist in debugfs/tracing, we must automount | |
6887 | * the tracefs file system there, so older tools still | |
6888 | * work with the newer kerenl. | |
6889 | */ | |
6890 | tr->dir = debugfs_create_automount("tracing", NULL, | |
6891 | trace_automount, NULL); | |
7eeafbca SRRH |
6892 | if (!tr->dir) { |
6893 | pr_warn_once("Could not create debugfs directory 'tracing'\n"); | |
6894 | return ERR_PTR(-ENOMEM); | |
6895 | } | |
6896 | ||
8434dc93 | 6897 | return NULL; |
7eeafbca SRRH |
6898 | } |
6899 | ||
0c564a53 SRRH |
6900 | extern struct trace_enum_map *__start_ftrace_enum_maps[]; |
6901 | extern struct trace_enum_map *__stop_ftrace_enum_maps[]; | |
6902 | ||
6903 | static void __init trace_enum_init(void) | |
6904 | { | |
3673b8e4 SRRH |
6905 | int len; |
6906 | ||
6907 | len = __stop_ftrace_enum_maps - __start_ftrace_enum_maps; | |
9828413d | 6908 | trace_insert_enum_map(NULL, __start_ftrace_enum_maps, len); |
3673b8e4 SRRH |
6909 | } |
6910 | ||
6911 | #ifdef CONFIG_MODULES | |
6912 | static void trace_module_add_enums(struct module *mod) | |
6913 | { | |
6914 | if (!mod->num_trace_enums) | |
6915 | return; | |
6916 | ||
6917 | /* | |
6918 | * Modules with bad taint do not have events created, do | |
6919 | * not bother with enums either. | |
6920 | */ | |
6921 | if (trace_module_has_bad_taint(mod)) | |
6922 | return; | |
6923 | ||
9828413d | 6924 | trace_insert_enum_map(mod, mod->trace_enums, mod->num_trace_enums); |
3673b8e4 SRRH |
6925 | } |
6926 | ||
9828413d SRRH |
6927 | #ifdef CONFIG_TRACE_ENUM_MAP_FILE |
6928 | static void trace_module_remove_enums(struct module *mod) | |
6929 | { | |
6930 | union trace_enum_map_item *map; | |
6931 | union trace_enum_map_item **last = &trace_enum_maps; | |
6932 | ||
6933 | if (!mod->num_trace_enums) | |
6934 | return; | |
6935 | ||
6936 | mutex_lock(&trace_enum_mutex); | |
6937 | ||
6938 | map = trace_enum_maps; | |
6939 | ||
6940 | while (map) { | |
6941 | if (map->head.mod == mod) | |
6942 | break; | |
6943 | map = trace_enum_jmp_to_tail(map); | |
6944 | last = &map->tail.next; | |
6945 | map = map->tail.next; | |
6946 | } | |
6947 | if (!map) | |
6948 | goto out; | |
6949 | ||
6950 | *last = trace_enum_jmp_to_tail(map)->tail.next; | |
6951 | kfree(map); | |
6952 | out: | |
6953 | mutex_unlock(&trace_enum_mutex); | |
6954 | } | |
6955 | #else | |
6956 | static inline void trace_module_remove_enums(struct module *mod) { } | |
6957 | #endif /* CONFIG_TRACE_ENUM_MAP_FILE */ | |
6958 | ||
3673b8e4 SRRH |
6959 | static int trace_module_notify(struct notifier_block *self, |
6960 | unsigned long val, void *data) | |
6961 | { | |
6962 | struct module *mod = data; | |
6963 | ||
6964 | switch (val) { | |
6965 | case MODULE_STATE_COMING: | |
6966 | trace_module_add_enums(mod); | |
6967 | break; | |
9828413d SRRH |
6968 | case MODULE_STATE_GOING: |
6969 | trace_module_remove_enums(mod); | |
6970 | break; | |
3673b8e4 SRRH |
6971 | } |
6972 | ||
6973 | return 0; | |
0c564a53 SRRH |
6974 | } |
6975 | ||
3673b8e4 SRRH |
6976 | static struct notifier_block trace_module_nb = { |
6977 | .notifier_call = trace_module_notify, | |
6978 | .priority = 0, | |
6979 | }; | |
9828413d | 6980 | #endif /* CONFIG_MODULES */ |
3673b8e4 | 6981 | |
8434dc93 | 6982 | static __init int tracer_init_tracefs(void) |
bc0c38d1 SR |
6983 | { |
6984 | struct dentry *d_tracer; | |
bc0c38d1 | 6985 | |
7e53bd42 LJ |
6986 | trace_access_lock_init(); |
6987 | ||
bc0c38d1 | 6988 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 6989 | if (IS_ERR(d_tracer)) |
ed6f1c99 | 6990 | return 0; |
bc0c38d1 | 6991 | |
8434dc93 | 6992 | init_tracer_tracefs(&global_trace, d_tracer); |
bc0c38d1 | 6993 | |
5452af66 | 6994 | trace_create_file("tracing_thresh", 0644, d_tracer, |
6508fa76 | 6995 | &global_trace, &tracing_thresh_fops); |
a8259075 | 6996 | |
339ae5d3 | 6997 | trace_create_file("README", 0444, d_tracer, |
5452af66 FW |
6998 | NULL, &tracing_readme_fops); |
6999 | ||
69abe6a5 AP |
7000 | trace_create_file("saved_cmdlines", 0444, d_tracer, |
7001 | NULL, &tracing_saved_cmdlines_fops); | |
5bf9a1ee | 7002 | |
939c7a4f YY |
7003 | trace_create_file("saved_cmdlines_size", 0644, d_tracer, |
7004 | NULL, &tracing_saved_cmdlines_size_fops); | |
7005 | ||
0c564a53 SRRH |
7006 | trace_enum_init(); |
7007 | ||
9828413d SRRH |
7008 | trace_create_enum_file(d_tracer); |
7009 | ||
3673b8e4 SRRH |
7010 | #ifdef CONFIG_MODULES |
7011 | register_module_notifier(&trace_module_nb); | |
7012 | #endif | |
7013 | ||
bc0c38d1 | 7014 | #ifdef CONFIG_DYNAMIC_FTRACE |
5452af66 FW |
7015 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
7016 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
bc0c38d1 | 7017 | #endif |
b04cc6b1 | 7018 | |
277ba044 | 7019 | create_trace_instances(d_tracer); |
5452af66 | 7020 | |
37aea98b | 7021 | update_tracer_options(&global_trace); |
09d23a1d | 7022 | |
b5ad384e | 7023 | return 0; |
bc0c38d1 SR |
7024 | } |
7025 | ||
3f5a54e3 SR |
7026 | static int trace_panic_handler(struct notifier_block *this, |
7027 | unsigned long event, void *unused) | |
7028 | { | |
944ac425 | 7029 | if (ftrace_dump_on_oops) |
cecbca96 | 7030 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
7031 | return NOTIFY_OK; |
7032 | } | |
7033 | ||
7034 | static struct notifier_block trace_panic_notifier = { | |
7035 | .notifier_call = trace_panic_handler, | |
7036 | .next = NULL, | |
7037 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
7038 | }; | |
7039 | ||
7040 | static int trace_die_handler(struct notifier_block *self, | |
7041 | unsigned long val, | |
7042 | void *data) | |
7043 | { | |
7044 | switch (val) { | |
7045 | case DIE_OOPS: | |
944ac425 | 7046 | if (ftrace_dump_on_oops) |
cecbca96 | 7047 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
7048 | break; |
7049 | default: | |
7050 | break; | |
7051 | } | |
7052 | return NOTIFY_OK; | |
7053 | } | |
7054 | ||
7055 | static struct notifier_block trace_die_notifier = { | |
7056 | .notifier_call = trace_die_handler, | |
7057 | .priority = 200 | |
7058 | }; | |
7059 | ||
7060 | /* | |
7061 | * printk is set to max of 1024, we really don't need it that big. | |
7062 | * Nothing should be printing 1000 characters anyway. | |
7063 | */ | |
7064 | #define TRACE_MAX_PRINT 1000 | |
7065 | ||
7066 | /* | |
7067 | * Define here KERN_TRACE so that we have one place to modify | |
7068 | * it if we decide to change what log level the ftrace dump | |
7069 | * should be at. | |
7070 | */ | |
428aee14 | 7071 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 | 7072 | |
955b61e5 | 7073 | void |
3f5a54e3 SR |
7074 | trace_printk_seq(struct trace_seq *s) |
7075 | { | |
7076 | /* Probably should print a warning here. */ | |
3a161d99 SRRH |
7077 | if (s->seq.len >= TRACE_MAX_PRINT) |
7078 | s->seq.len = TRACE_MAX_PRINT; | |
3f5a54e3 | 7079 | |
820b75f6 SRRH |
7080 | /* |
7081 | * More paranoid code. Although the buffer size is set to | |
7082 | * PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just | |
7083 | * an extra layer of protection. | |
7084 | */ | |
7085 | if (WARN_ON_ONCE(s->seq.len >= s->seq.size)) | |
7086 | s->seq.len = s->seq.size - 1; | |
3f5a54e3 SR |
7087 | |
7088 | /* should be zero ended, but we are paranoid. */ | |
3a161d99 | 7089 | s->buffer[s->seq.len] = 0; |
3f5a54e3 SR |
7090 | |
7091 | printk(KERN_TRACE "%s", s->buffer); | |
7092 | ||
f9520750 | 7093 | trace_seq_init(s); |
3f5a54e3 SR |
7094 | } |
7095 | ||
955b61e5 JW |
7096 | void trace_init_global_iter(struct trace_iterator *iter) |
7097 | { | |
7098 | iter->tr = &global_trace; | |
2b6080f2 | 7099 | iter->trace = iter->tr->current_trace; |
ae3b5093 | 7100 | iter->cpu_file = RING_BUFFER_ALL_CPUS; |
12883efb | 7101 | iter->trace_buffer = &global_trace.trace_buffer; |
b2f974d6 CS |
7102 | |
7103 | if (iter->trace && iter->trace->open) | |
7104 | iter->trace->open(iter); | |
7105 | ||
7106 | /* Annotate start of buffers if we had overruns */ | |
7107 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) | |
7108 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
7109 | ||
7110 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ | |
7111 | if (trace_clocks[iter->tr->clock_id].in_ns) | |
7112 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
955b61e5 JW |
7113 | } |
7114 | ||
7fe70b57 | 7115 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) |
3f5a54e3 | 7116 | { |
3f5a54e3 SR |
7117 | /* use static because iter can be a bit big for the stack */ |
7118 | static struct trace_iterator iter; | |
7fe70b57 | 7119 | static atomic_t dump_running; |
983f938a | 7120 | struct trace_array *tr = &global_trace; |
cf586b61 | 7121 | unsigned int old_userobj; |
d769041f SR |
7122 | unsigned long flags; |
7123 | int cnt = 0, cpu; | |
3f5a54e3 | 7124 | |
7fe70b57 SRRH |
7125 | /* Only allow one dump user at a time. */ |
7126 | if (atomic_inc_return(&dump_running) != 1) { | |
7127 | atomic_dec(&dump_running); | |
7128 | return; | |
7129 | } | |
3f5a54e3 | 7130 | |
7fe70b57 SRRH |
7131 | /* |
7132 | * Always turn off tracing when we dump. | |
7133 | * We don't need to show trace output of what happens | |
7134 | * between multiple crashes. | |
7135 | * | |
7136 | * If the user does a sysrq-z, then they can re-enable | |
7137 | * tracing with echo 1 > tracing_on. | |
7138 | */ | |
0ee6b6cf | 7139 | tracing_off(); |
cf586b61 | 7140 | |
7fe70b57 | 7141 | local_irq_save(flags); |
3f5a54e3 | 7142 | |
38dbe0b1 | 7143 | /* Simulate the iterator */ |
955b61e5 JW |
7144 | trace_init_global_iter(&iter); |
7145 | ||
d769041f | 7146 | for_each_tracing_cpu(cpu) { |
5e2d5ef8 | 7147 | atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); |
d769041f SR |
7148 | } |
7149 | ||
983f938a | 7150 | old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ; |
cf586b61 | 7151 | |
b54d3de9 | 7152 | /* don't look at user memory in panic mode */ |
983f938a | 7153 | tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ; |
b54d3de9 | 7154 | |
cecbca96 FW |
7155 | switch (oops_dump_mode) { |
7156 | case DUMP_ALL: | |
ae3b5093 | 7157 | iter.cpu_file = RING_BUFFER_ALL_CPUS; |
cecbca96 FW |
7158 | break; |
7159 | case DUMP_ORIG: | |
7160 | iter.cpu_file = raw_smp_processor_id(); | |
7161 | break; | |
7162 | case DUMP_NONE: | |
7163 | goto out_enable; | |
7164 | default: | |
7165 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
ae3b5093 | 7166 | iter.cpu_file = RING_BUFFER_ALL_CPUS; |
cecbca96 FW |
7167 | } |
7168 | ||
7169 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
3f5a54e3 | 7170 | |
7fe70b57 SRRH |
7171 | /* Did function tracer already get disabled? */ |
7172 | if (ftrace_is_dead()) { | |
7173 | printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
7174 | printk("# MAY BE MISSING FUNCTION EVENTS\n"); | |
7175 | } | |
7176 | ||
3f5a54e3 SR |
7177 | /* |
7178 | * We need to stop all tracing on all CPUS to read the | |
7179 | * the next buffer. This is a bit expensive, but is | |
7180 | * not done often. We fill all what we can read, | |
7181 | * and then release the locks again. | |
7182 | */ | |
7183 | ||
3f5a54e3 SR |
7184 | while (!trace_empty(&iter)) { |
7185 | ||
7186 | if (!cnt) | |
7187 | printk(KERN_TRACE "---------------------------------\n"); | |
7188 | ||
7189 | cnt++; | |
7190 | ||
7191 | /* reset all but tr, trace, and overruns */ | |
7192 | memset(&iter.seq, 0, | |
7193 | sizeof(struct trace_iterator) - | |
7194 | offsetof(struct trace_iterator, seq)); | |
7195 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
7196 | iter.pos = -1; | |
7197 | ||
955b61e5 | 7198 | if (trace_find_next_entry_inc(&iter) != NULL) { |
74e7ff8c LJ |
7199 | int ret; |
7200 | ||
7201 | ret = print_trace_line(&iter); | |
7202 | if (ret != TRACE_TYPE_NO_CONSUME) | |
7203 | trace_consume(&iter); | |
3f5a54e3 | 7204 | } |
b892e5c8 | 7205 | touch_nmi_watchdog(); |
3f5a54e3 SR |
7206 | |
7207 | trace_printk_seq(&iter.seq); | |
7208 | } | |
7209 | ||
7210 | if (!cnt) | |
7211 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
7212 | else | |
7213 | printk(KERN_TRACE "---------------------------------\n"); | |
7214 | ||
cecbca96 | 7215 | out_enable: |
983f938a | 7216 | tr->trace_flags |= old_userobj; |
cf586b61 | 7217 | |
7fe70b57 SRRH |
7218 | for_each_tracing_cpu(cpu) { |
7219 | atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); | |
cf586b61 | 7220 | } |
7fe70b57 | 7221 | atomic_dec(&dump_running); |
cd891ae0 | 7222 | local_irq_restore(flags); |
3f5a54e3 | 7223 | } |
a8eecf22 | 7224 | EXPORT_SYMBOL_GPL(ftrace_dump); |
cf586b61 | 7225 | |
3928a8a2 | 7226 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 7227 | { |
73c5162a | 7228 | int ring_buf_size; |
9e01c1b7 | 7229 | int ret = -ENOMEM; |
4c11d7ae | 7230 | |
b5e87c05 SRRH |
7231 | /* |
7232 | * Make sure we don't accidently add more trace options | |
7233 | * than we have bits for. | |
7234 | */ | |
9a38a885 | 7235 | BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE); |
b5e87c05 | 7236 | |
9e01c1b7 RR |
7237 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
7238 | goto out; | |
7239 | ||
ccfe9e42 | 7240 | if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL)) |
9e01c1b7 | 7241 | goto out_free_buffer_mask; |
4c11d7ae | 7242 | |
07d777fe SR |
7243 | /* Only allocate trace_printk buffers if a trace_printk exists */ |
7244 | if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) | |
81698831 | 7245 | /* Must be called before global_trace.buffer is allocated */ |
07d777fe SR |
7246 | trace_printk_init_buffers(); |
7247 | ||
73c5162a SR |
7248 | /* To save memory, keep the ring buffer size to its minimum */ |
7249 | if (ring_buffer_expanded) | |
7250 | ring_buf_size = trace_buf_size; | |
7251 | else | |
7252 | ring_buf_size = 1; | |
7253 | ||
9e01c1b7 | 7254 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
ccfe9e42 | 7255 | cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask); |
9e01c1b7 | 7256 | |
2b6080f2 SR |
7257 | raw_spin_lock_init(&global_trace.start_lock); |
7258 | ||
2c4a33ab SRRH |
7259 | /* Used for event triggers */ |
7260 | temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE); | |
7261 | if (!temp_buffer) | |
7262 | goto out_free_cpumask; | |
7263 | ||
939c7a4f YY |
7264 | if (trace_create_savedcmd() < 0) |
7265 | goto out_free_temp_buffer; | |
7266 | ||
9e01c1b7 | 7267 | /* TODO: make the number of buffers hot pluggable with CPUS */ |
737223fb | 7268 | if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { |
3928a8a2 SR |
7269 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); |
7270 | WARN_ON(1); | |
939c7a4f | 7271 | goto out_free_savedcmd; |
4c11d7ae | 7272 | } |
a7603ff4 | 7273 | |
499e5470 SR |
7274 | if (global_trace.buffer_disabled) |
7275 | tracing_off(); | |
4c11d7ae | 7276 | |
e1e232ca SR |
7277 | if (trace_boot_clock) { |
7278 | ret = tracing_set_clock(&global_trace, trace_boot_clock); | |
7279 | if (ret < 0) | |
a395d6a7 JP |
7280 | pr_warn("Trace clock %s not defined, going back to default\n", |
7281 | trace_boot_clock); | |
e1e232ca SR |
7282 | } |
7283 | ||
ca164318 SRRH |
7284 | /* |
7285 | * register_tracer() might reference current_trace, so it | |
7286 | * needs to be set before we register anything. This is | |
7287 | * just a bootstrap of current_trace anyway. | |
7288 | */ | |
2b6080f2 SR |
7289 | global_trace.current_trace = &nop_trace; |
7290 | ||
0b9b12c1 SRRH |
7291 | global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
7292 | ||
4104d326 SRRH |
7293 | ftrace_init_global_array_ops(&global_trace); |
7294 | ||
9a38a885 SRRH |
7295 | init_trace_flags_index(&global_trace); |
7296 | ||
ca164318 SRRH |
7297 | register_tracer(&nop_trace); |
7298 | ||
60a11774 SR |
7299 | /* All seems OK, enable tracing */ |
7300 | tracing_disabled = 0; | |
3928a8a2 | 7301 | |
3f5a54e3 SR |
7302 | atomic_notifier_chain_register(&panic_notifier_list, |
7303 | &trace_panic_notifier); | |
7304 | ||
7305 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe | 7306 | |
ae63b31e SR |
7307 | global_trace.flags = TRACE_ARRAY_FL_GLOBAL; |
7308 | ||
7309 | INIT_LIST_HEAD(&global_trace.systems); | |
7310 | INIT_LIST_HEAD(&global_trace.events); | |
7311 | list_add(&global_trace.list, &ftrace_trace_arrays); | |
7312 | ||
a4d1e688 | 7313 | apply_trace_boot_options(); |
7bcfaf54 | 7314 | |
77fd5c15 SRRH |
7315 | register_snapshot_cmd(); |
7316 | ||
2fc1dfbe | 7317 | return 0; |
3f5a54e3 | 7318 | |
939c7a4f YY |
7319 | out_free_savedcmd: |
7320 | free_saved_cmdlines_buffer(savedcmd); | |
2c4a33ab SRRH |
7321 | out_free_temp_buffer: |
7322 | ring_buffer_free(temp_buffer); | |
9e01c1b7 | 7323 | out_free_cpumask: |
ccfe9e42 | 7324 | free_cpumask_var(global_trace.tracing_cpumask); |
9e01c1b7 RR |
7325 | out_free_buffer_mask: |
7326 | free_cpumask_var(tracing_buffer_mask); | |
7327 | out: | |
7328 | return ret; | |
bc0c38d1 | 7329 | } |
b2821ae6 | 7330 | |
5f893b26 SRRH |
7331 | void __init trace_init(void) |
7332 | { | |
0daa2302 SRRH |
7333 | if (tracepoint_printk) { |
7334 | tracepoint_print_iter = | |
7335 | kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL); | |
7336 | if (WARN_ON(!tracepoint_print_iter)) | |
7337 | tracepoint_printk = 0; | |
7338 | } | |
5f893b26 | 7339 | tracer_alloc_buffers(); |
0c564a53 | 7340 | trace_event_init(); |
5f893b26 SRRH |
7341 | } |
7342 | ||
b2821ae6 SR |
7343 | __init static int clear_boot_tracer(void) |
7344 | { | |
7345 | /* | |
7346 | * The default tracer at boot buffer is an init section. | |
7347 | * This function is called in lateinit. If we did not | |
7348 | * find the boot tracer, then clear it out, to prevent | |
7349 | * later registration from accessing the buffer that is | |
7350 | * about to be freed. | |
7351 | */ | |
7352 | if (!default_bootup_tracer) | |
7353 | return 0; | |
7354 | ||
7355 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
7356 | default_bootup_tracer); | |
7357 | default_bootup_tracer = NULL; | |
7358 | ||
7359 | return 0; | |
7360 | } | |
7361 | ||
8434dc93 | 7362 | fs_initcall(tracer_init_tracefs); |
b2821ae6 | 7363 | late_initcall(clear_boot_tracer); |