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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 | ||
256 | ||
4fcdae83 SR |
257 | /* |
258 | * The global_trace is the descriptor that holds the tracing | |
259 | * buffers for the live tracing. For each CPU, it contains | |
260 | * a link list of pages that will store trace entries. The | |
261 | * page descriptor of the pages in the memory is used to hold | |
262 | * the link list by linking the lru item in the page descriptor | |
263 | * to each of the pages in the buffer per CPU. | |
264 | * | |
265 | * For each active CPU there is a data field that holds the | |
266 | * pages for the buffer for that CPU. Each CPU has the same number | |
267 | * of pages allocated for its buffer. | |
268 | */ | |
983f938a SRRH |
269 | static struct trace_array global_trace = { |
270 | .trace_flags = TRACE_DEFAULT_FLAGS, | |
271 | }; | |
bc0c38d1 | 272 | |
ae63b31e | 273 | LIST_HEAD(ftrace_trace_arrays); |
bc0c38d1 | 274 | |
ff451961 SRRH |
275 | int trace_array_get(struct trace_array *this_tr) |
276 | { | |
277 | struct trace_array *tr; | |
278 | int ret = -ENODEV; | |
279 | ||
280 | mutex_lock(&trace_types_lock); | |
281 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
282 | if (tr == this_tr) { | |
283 | tr->ref++; | |
284 | ret = 0; | |
285 | break; | |
286 | } | |
287 | } | |
288 | mutex_unlock(&trace_types_lock); | |
289 | ||
290 | return ret; | |
291 | } | |
292 | ||
293 | static void __trace_array_put(struct trace_array *this_tr) | |
294 | { | |
295 | WARN_ON(!this_tr->ref); | |
296 | this_tr->ref--; | |
297 | } | |
298 | ||
299 | void trace_array_put(struct trace_array *this_tr) | |
300 | { | |
301 | mutex_lock(&trace_types_lock); | |
302 | __trace_array_put(this_tr); | |
303 | mutex_unlock(&trace_types_lock); | |
304 | } | |
305 | ||
7f1d2f82 | 306 | int filter_check_discard(struct trace_event_file *file, void *rec, |
f306cc82 TZ |
307 | struct ring_buffer *buffer, |
308 | struct ring_buffer_event *event) | |
eb02ce01 | 309 | { |
5d6ad960 | 310 | if (unlikely(file->flags & EVENT_FILE_FL_FILTERED) && |
f306cc82 TZ |
311 | !filter_match_preds(file->filter, rec)) { |
312 | ring_buffer_discard_commit(buffer, event); | |
313 | return 1; | |
314 | } | |
315 | ||
316 | return 0; | |
317 | } | |
318 | EXPORT_SYMBOL_GPL(filter_check_discard); | |
319 | ||
2425bcb9 | 320 | int call_filter_check_discard(struct trace_event_call *call, void *rec, |
f306cc82 TZ |
321 | struct ring_buffer *buffer, |
322 | struct ring_buffer_event *event) | |
323 | { | |
324 | if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) && | |
325 | !filter_match_preds(call->filter, rec)) { | |
326 | ring_buffer_discard_commit(buffer, event); | |
327 | return 1; | |
328 | } | |
329 | ||
330 | return 0; | |
eb02ce01 | 331 | } |
f306cc82 | 332 | EXPORT_SYMBOL_GPL(call_filter_check_discard); |
eb02ce01 | 333 | |
ad1438a0 | 334 | static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) |
37886f6a SR |
335 | { |
336 | u64 ts; | |
337 | ||
338 | /* Early boot up does not have a buffer yet */ | |
9457158b | 339 | if (!buf->buffer) |
37886f6a SR |
340 | return trace_clock_local(); |
341 | ||
9457158b AL |
342 | ts = ring_buffer_time_stamp(buf->buffer, cpu); |
343 | ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts); | |
37886f6a SR |
344 | |
345 | return ts; | |
346 | } | |
bc0c38d1 | 347 | |
9457158b AL |
348 | cycle_t ftrace_now(int cpu) |
349 | { | |
350 | return buffer_ftrace_now(&global_trace.trace_buffer, cpu); | |
351 | } | |
352 | ||
10246fa3 SRRH |
353 | /** |
354 | * tracing_is_enabled - Show if global_trace has been disabled | |
355 | * | |
356 | * Shows if the global trace has been enabled or not. It uses the | |
357 | * mirror flag "buffer_disabled" to be used in fast paths such as for | |
358 | * the irqsoff tracer. But it may be inaccurate due to races. If you | |
359 | * need to know the accurate state, use tracing_is_on() which is a little | |
360 | * slower, but accurate. | |
361 | */ | |
9036990d SR |
362 | int tracing_is_enabled(void) |
363 | { | |
10246fa3 SRRH |
364 | /* |
365 | * For quick access (irqsoff uses this in fast path), just | |
366 | * return the mirror variable of the state of the ring buffer. | |
367 | * It's a little racy, but we don't really care. | |
368 | */ | |
369 | smp_rmb(); | |
370 | return !global_trace.buffer_disabled; | |
9036990d SR |
371 | } |
372 | ||
4fcdae83 | 373 | /* |
3928a8a2 SR |
374 | * trace_buf_size is the size in bytes that is allocated |
375 | * for a buffer. Note, the number of bytes is always rounded | |
376 | * to page size. | |
3f5a54e3 SR |
377 | * |
378 | * This number is purposely set to a low number of 16384. | |
379 | * If the dump on oops happens, it will be much appreciated | |
380 | * to not have to wait for all that output. Anyway this can be | |
381 | * boot time and run time configurable. | |
4fcdae83 | 382 | */ |
3928a8a2 | 383 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 384 | |
3928a8a2 | 385 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 386 | |
4fcdae83 | 387 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 388 | static struct tracer *trace_types __read_mostly; |
4fcdae83 | 389 | |
4fcdae83 SR |
390 | /* |
391 | * trace_types_lock is used to protect the trace_types list. | |
4fcdae83 | 392 | */ |
a8227415 | 393 | DEFINE_MUTEX(trace_types_lock); |
4fcdae83 | 394 | |
7e53bd42 LJ |
395 | /* |
396 | * serialize the access of the ring buffer | |
397 | * | |
398 | * ring buffer serializes readers, but it is low level protection. | |
399 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
400 | * are not protected by ring buffer. | |
401 | * | |
402 | * The content of events may become garbage if we allow other process consumes | |
403 | * these events concurrently: | |
404 | * A) the page of the consumed events may become a normal page | |
405 | * (not reader page) in ring buffer, and this page will be rewrited | |
406 | * by events producer. | |
407 | * B) The page of the consumed events may become a page for splice_read, | |
408 | * and this page will be returned to system. | |
409 | * | |
410 | * These primitives allow multi process access to different cpu ring buffer | |
411 | * concurrently. | |
412 | * | |
413 | * These primitives don't distinguish read-only and read-consume access. | |
414 | * Multi read-only access are also serialized. | |
415 | */ | |
416 | ||
417 | #ifdef CONFIG_SMP | |
418 | static DECLARE_RWSEM(all_cpu_access_lock); | |
419 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
420 | ||
421 | static inline void trace_access_lock(int cpu) | |
422 | { | |
ae3b5093 | 423 | if (cpu == RING_BUFFER_ALL_CPUS) { |
7e53bd42 LJ |
424 | /* gain it for accessing the whole ring buffer. */ |
425 | down_write(&all_cpu_access_lock); | |
426 | } else { | |
427 | /* gain it for accessing a cpu ring buffer. */ | |
428 | ||
ae3b5093 | 429 | /* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */ |
7e53bd42 LJ |
430 | down_read(&all_cpu_access_lock); |
431 | ||
432 | /* Secondly block other access to this @cpu ring buffer. */ | |
433 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
434 | } | |
435 | } | |
436 | ||
437 | static inline void trace_access_unlock(int cpu) | |
438 | { | |
ae3b5093 | 439 | if (cpu == RING_BUFFER_ALL_CPUS) { |
7e53bd42 LJ |
440 | up_write(&all_cpu_access_lock); |
441 | } else { | |
442 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
443 | up_read(&all_cpu_access_lock); | |
444 | } | |
445 | } | |
446 | ||
447 | static inline void trace_access_lock_init(void) | |
448 | { | |
449 | int cpu; | |
450 | ||
451 | for_each_possible_cpu(cpu) | |
452 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
453 | } | |
454 | ||
455 | #else | |
456 | ||
457 | static DEFINE_MUTEX(access_lock); | |
458 | ||
459 | static inline void trace_access_lock(int cpu) | |
460 | { | |
461 | (void)cpu; | |
462 | mutex_lock(&access_lock); | |
463 | } | |
464 | ||
465 | static inline void trace_access_unlock(int cpu) | |
466 | { | |
467 | (void)cpu; | |
468 | mutex_unlock(&access_lock); | |
469 | } | |
470 | ||
471 | static inline void trace_access_lock_init(void) | |
472 | { | |
473 | } | |
474 | ||
475 | #endif | |
476 | ||
d78a4614 SRRH |
477 | #ifdef CONFIG_STACKTRACE |
478 | static void __ftrace_trace_stack(struct ring_buffer *buffer, | |
479 | unsigned long flags, | |
480 | int skip, int pc, struct pt_regs *regs); | |
2d34f489 SRRH |
481 | static inline void ftrace_trace_stack(struct trace_array *tr, |
482 | struct ring_buffer *buffer, | |
73dddbb5 SRRH |
483 | unsigned long flags, |
484 | int skip, int pc, struct pt_regs *regs); | |
ca475e83 | 485 | |
d78a4614 SRRH |
486 | #else |
487 | static inline void __ftrace_trace_stack(struct ring_buffer *buffer, | |
488 | unsigned long flags, | |
489 | int skip, int pc, struct pt_regs *regs) | |
490 | { | |
491 | } | |
2d34f489 SRRH |
492 | static inline void ftrace_trace_stack(struct trace_array *tr, |
493 | struct ring_buffer *buffer, | |
73dddbb5 SRRH |
494 | unsigned long flags, |
495 | int skip, int pc, struct pt_regs *regs) | |
ca475e83 SRRH |
496 | { |
497 | } | |
498 | ||
d78a4614 SRRH |
499 | #endif |
500 | ||
5280bcef | 501 | static void tracer_tracing_on(struct trace_array *tr) |
10246fa3 SRRH |
502 | { |
503 | if (tr->trace_buffer.buffer) | |
504 | ring_buffer_record_on(tr->trace_buffer.buffer); | |
505 | /* | |
506 | * This flag is looked at when buffers haven't been allocated | |
507 | * yet, or by some tracers (like irqsoff), that just want to | |
508 | * know if the ring buffer has been disabled, but it can handle | |
509 | * races of where it gets disabled but we still do a record. | |
510 | * As the check is in the fast path of the tracers, it is more | |
511 | * important to be fast than accurate. | |
512 | */ | |
513 | tr->buffer_disabled = 0; | |
514 | /* Make the flag seen by readers */ | |
515 | smp_wmb(); | |
516 | } | |
517 | ||
499e5470 SR |
518 | /** |
519 | * tracing_on - enable tracing buffers | |
520 | * | |
521 | * This function enables tracing buffers that may have been | |
522 | * disabled with tracing_off. | |
523 | */ | |
524 | void tracing_on(void) | |
525 | { | |
10246fa3 | 526 | tracer_tracing_on(&global_trace); |
499e5470 SR |
527 | } |
528 | EXPORT_SYMBOL_GPL(tracing_on); | |
529 | ||
09ae7234 SRRH |
530 | /** |
531 | * __trace_puts - write a constant string into the trace buffer. | |
532 | * @ip: The address of the caller | |
533 | * @str: The constant string to write | |
534 | * @size: The size of the string. | |
535 | */ | |
536 | int __trace_puts(unsigned long ip, const char *str, int size) | |
537 | { | |
538 | struct ring_buffer_event *event; | |
539 | struct ring_buffer *buffer; | |
540 | struct print_entry *entry; | |
541 | unsigned long irq_flags; | |
542 | int alloc; | |
8abfb872 J |
543 | int pc; |
544 | ||
983f938a | 545 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
f0160a5a J |
546 | return 0; |
547 | ||
8abfb872 | 548 | pc = preempt_count(); |
09ae7234 | 549 | |
3132e107 SRRH |
550 | if (unlikely(tracing_selftest_running || tracing_disabled)) |
551 | return 0; | |
552 | ||
09ae7234 SRRH |
553 | alloc = sizeof(*entry) + size + 2; /* possible \n added */ |
554 | ||
555 | local_save_flags(irq_flags); | |
556 | buffer = global_trace.trace_buffer.buffer; | |
557 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, | |
8abfb872 | 558 | irq_flags, pc); |
09ae7234 SRRH |
559 | if (!event) |
560 | return 0; | |
561 | ||
562 | entry = ring_buffer_event_data(event); | |
563 | entry->ip = ip; | |
564 | ||
565 | memcpy(&entry->buf, str, size); | |
566 | ||
567 | /* Add a newline if necessary */ | |
568 | if (entry->buf[size - 1] != '\n') { | |
569 | entry->buf[size] = '\n'; | |
570 | entry->buf[size + 1] = '\0'; | |
571 | } else | |
572 | entry->buf[size] = '\0'; | |
573 | ||
574 | __buffer_unlock_commit(buffer, event); | |
2d34f489 | 575 | ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL); |
09ae7234 SRRH |
576 | |
577 | return size; | |
578 | } | |
579 | EXPORT_SYMBOL_GPL(__trace_puts); | |
580 | ||
581 | /** | |
582 | * __trace_bputs - write the pointer to a constant string into trace buffer | |
583 | * @ip: The address of the caller | |
584 | * @str: The constant string to write to the buffer to | |
585 | */ | |
586 | int __trace_bputs(unsigned long ip, const char *str) | |
587 | { | |
588 | struct ring_buffer_event *event; | |
589 | struct ring_buffer *buffer; | |
590 | struct bputs_entry *entry; | |
591 | unsigned long irq_flags; | |
592 | int size = sizeof(struct bputs_entry); | |
8abfb872 J |
593 | int pc; |
594 | ||
983f938a | 595 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
f0160a5a J |
596 | return 0; |
597 | ||
8abfb872 | 598 | pc = preempt_count(); |
09ae7234 | 599 | |
3132e107 SRRH |
600 | if (unlikely(tracing_selftest_running || tracing_disabled)) |
601 | return 0; | |
602 | ||
09ae7234 SRRH |
603 | local_save_flags(irq_flags); |
604 | buffer = global_trace.trace_buffer.buffer; | |
605 | event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, | |
8abfb872 | 606 | irq_flags, pc); |
09ae7234 SRRH |
607 | if (!event) |
608 | return 0; | |
609 | ||
610 | entry = ring_buffer_event_data(event); | |
611 | entry->ip = ip; | |
612 | entry->str = str; | |
613 | ||
614 | __buffer_unlock_commit(buffer, event); | |
2d34f489 | 615 | ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL); |
09ae7234 SRRH |
616 | |
617 | return 1; | |
618 | } | |
619 | EXPORT_SYMBOL_GPL(__trace_bputs); | |
620 | ||
ad909e21 SRRH |
621 | #ifdef CONFIG_TRACER_SNAPSHOT |
622 | /** | |
623 | * trace_snapshot - take a snapshot of the current buffer. | |
624 | * | |
625 | * This causes a swap between the snapshot buffer and the current live | |
626 | * tracing buffer. You can use this to take snapshots of the live | |
627 | * trace when some condition is triggered, but continue to trace. | |
628 | * | |
629 | * Note, make sure to allocate the snapshot with either | |
630 | * a tracing_snapshot_alloc(), or by doing it manually | |
631 | * with: echo 1 > /sys/kernel/debug/tracing/snapshot | |
632 | * | |
633 | * If the snapshot buffer is not allocated, it will stop tracing. | |
634 | * Basically making a permanent snapshot. | |
635 | */ | |
636 | void tracing_snapshot(void) | |
637 | { | |
638 | struct trace_array *tr = &global_trace; | |
639 | struct tracer *tracer = tr->current_trace; | |
640 | unsigned long flags; | |
641 | ||
1b22e382 SRRH |
642 | if (in_nmi()) { |
643 | internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); | |
644 | internal_trace_puts("*** snapshot is being ignored ***\n"); | |
645 | return; | |
646 | } | |
647 | ||
ad909e21 | 648 | if (!tr->allocated_snapshot) { |
ca268da6 SRRH |
649 | internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); |
650 | internal_trace_puts("*** stopping trace here! ***\n"); | |
ad909e21 SRRH |
651 | tracing_off(); |
652 | return; | |
653 | } | |
654 | ||
655 | /* Note, snapshot can not be used when the tracer uses it */ | |
656 | if (tracer->use_max_tr) { | |
ca268da6 SRRH |
657 | internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); |
658 | internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); | |
ad909e21 SRRH |
659 | return; |
660 | } | |
661 | ||
662 | local_irq_save(flags); | |
663 | update_max_tr(tr, current, smp_processor_id()); | |
664 | local_irq_restore(flags); | |
665 | } | |
1b22e382 | 666 | EXPORT_SYMBOL_GPL(tracing_snapshot); |
ad909e21 SRRH |
667 | |
668 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, | |
669 | struct trace_buffer *size_buf, int cpu_id); | |
3209cff4 SRRH |
670 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val); |
671 | ||
672 | static int alloc_snapshot(struct trace_array *tr) | |
673 | { | |
674 | int ret; | |
675 | ||
676 | if (!tr->allocated_snapshot) { | |
677 | ||
678 | /* allocate spare buffer */ | |
679 | ret = resize_buffer_duplicate_size(&tr->max_buffer, | |
680 | &tr->trace_buffer, RING_BUFFER_ALL_CPUS); | |
681 | if (ret < 0) | |
682 | return ret; | |
683 | ||
684 | tr->allocated_snapshot = true; | |
685 | } | |
686 | ||
687 | return 0; | |
688 | } | |
689 | ||
ad1438a0 | 690 | static void free_snapshot(struct trace_array *tr) |
3209cff4 SRRH |
691 | { |
692 | /* | |
693 | * We don't free the ring buffer. instead, resize it because | |
694 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
695 | * we want preserve it. | |
696 | */ | |
697 | ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); | |
698 | set_buffer_entries(&tr->max_buffer, 1); | |
699 | tracing_reset_online_cpus(&tr->max_buffer); | |
700 | tr->allocated_snapshot = false; | |
701 | } | |
ad909e21 | 702 | |
93e31ffb TZ |
703 | /** |
704 | * tracing_alloc_snapshot - allocate snapshot buffer. | |
705 | * | |
706 | * This only allocates the snapshot buffer if it isn't already | |
707 | * allocated - it doesn't also take a snapshot. | |
708 | * | |
709 | * This is meant to be used in cases where the snapshot buffer needs | |
710 | * to be set up for events that can't sleep but need to be able to | |
711 | * trigger a snapshot. | |
712 | */ | |
713 | int tracing_alloc_snapshot(void) | |
714 | { | |
715 | struct trace_array *tr = &global_trace; | |
716 | int ret; | |
717 | ||
718 | ret = alloc_snapshot(tr); | |
719 | WARN_ON(ret < 0); | |
720 | ||
721 | return ret; | |
722 | } | |
723 | EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); | |
724 | ||
ad909e21 SRRH |
725 | /** |
726 | * trace_snapshot_alloc - allocate and take a snapshot of the current buffer. | |
727 | * | |
728 | * This is similar to trace_snapshot(), but it will allocate the | |
729 | * snapshot buffer if it isn't already allocated. Use this only | |
730 | * where it is safe to sleep, as the allocation may sleep. | |
731 | * | |
732 | * This causes a swap between the snapshot buffer and the current live | |
733 | * tracing buffer. You can use this to take snapshots of the live | |
734 | * trace when some condition is triggered, but continue to trace. | |
735 | */ | |
736 | void tracing_snapshot_alloc(void) | |
737 | { | |
ad909e21 SRRH |
738 | int ret; |
739 | ||
93e31ffb TZ |
740 | ret = tracing_alloc_snapshot(); |
741 | if (ret < 0) | |
3209cff4 | 742 | return; |
ad909e21 SRRH |
743 | |
744 | tracing_snapshot(); | |
745 | } | |
1b22e382 | 746 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
ad909e21 SRRH |
747 | #else |
748 | void tracing_snapshot(void) | |
749 | { | |
750 | WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); | |
751 | } | |
1b22e382 | 752 | EXPORT_SYMBOL_GPL(tracing_snapshot); |
93e31ffb TZ |
753 | int tracing_alloc_snapshot(void) |
754 | { | |
755 | WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used"); | |
756 | return -ENODEV; | |
757 | } | |
758 | EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); | |
ad909e21 SRRH |
759 | void tracing_snapshot_alloc(void) |
760 | { | |
761 | /* Give warning */ | |
762 | tracing_snapshot(); | |
763 | } | |
1b22e382 | 764 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
ad909e21 SRRH |
765 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
766 | ||
5280bcef | 767 | static void tracer_tracing_off(struct trace_array *tr) |
10246fa3 SRRH |
768 | { |
769 | if (tr->trace_buffer.buffer) | |
770 | ring_buffer_record_off(tr->trace_buffer.buffer); | |
771 | /* | |
772 | * This flag is looked at when buffers haven't been allocated | |
773 | * yet, or by some tracers (like irqsoff), that just want to | |
774 | * know if the ring buffer has been disabled, but it can handle | |
775 | * races of where it gets disabled but we still do a record. | |
776 | * As the check is in the fast path of the tracers, it is more | |
777 | * important to be fast than accurate. | |
778 | */ | |
779 | tr->buffer_disabled = 1; | |
780 | /* Make the flag seen by readers */ | |
781 | smp_wmb(); | |
782 | } | |
783 | ||
499e5470 SR |
784 | /** |
785 | * tracing_off - turn off tracing buffers | |
786 | * | |
787 | * This function stops the tracing buffers from recording data. | |
788 | * It does not disable any overhead the tracers themselves may | |
789 | * be causing. This function simply causes all recording to | |
790 | * the ring buffers to fail. | |
791 | */ | |
792 | void tracing_off(void) | |
793 | { | |
10246fa3 | 794 | tracer_tracing_off(&global_trace); |
499e5470 SR |
795 | } |
796 | EXPORT_SYMBOL_GPL(tracing_off); | |
797 | ||
de7edd31 SRRH |
798 | void disable_trace_on_warning(void) |
799 | { | |
800 | if (__disable_trace_on_warning) | |
801 | tracing_off(); | |
802 | } | |
803 | ||
10246fa3 SRRH |
804 | /** |
805 | * tracer_tracing_is_on - show real state of ring buffer enabled | |
806 | * @tr : the trace array to know if ring buffer is enabled | |
807 | * | |
808 | * Shows real state of the ring buffer if it is enabled or not. | |
809 | */ | |
5280bcef | 810 | static int tracer_tracing_is_on(struct trace_array *tr) |
10246fa3 SRRH |
811 | { |
812 | if (tr->trace_buffer.buffer) | |
813 | return ring_buffer_record_is_on(tr->trace_buffer.buffer); | |
814 | return !tr->buffer_disabled; | |
815 | } | |
816 | ||
499e5470 SR |
817 | /** |
818 | * tracing_is_on - show state of ring buffers enabled | |
819 | */ | |
820 | int tracing_is_on(void) | |
821 | { | |
10246fa3 | 822 | return tracer_tracing_is_on(&global_trace); |
499e5470 SR |
823 | } |
824 | EXPORT_SYMBOL_GPL(tracing_is_on); | |
825 | ||
3928a8a2 | 826 | static int __init set_buf_size(char *str) |
bc0c38d1 | 827 | { |
3928a8a2 | 828 | unsigned long buf_size; |
c6caeeb1 | 829 | |
bc0c38d1 SR |
830 | if (!str) |
831 | return 0; | |
9d612bef | 832 | buf_size = memparse(str, &str); |
c6caeeb1 | 833 | /* nr_entries can not be zero */ |
9d612bef | 834 | if (buf_size == 0) |
c6caeeb1 | 835 | return 0; |
3928a8a2 | 836 | trace_buf_size = buf_size; |
bc0c38d1 SR |
837 | return 1; |
838 | } | |
3928a8a2 | 839 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 840 | |
0e950173 TB |
841 | static int __init set_tracing_thresh(char *str) |
842 | { | |
87abb3b1 | 843 | unsigned long threshold; |
0e950173 TB |
844 | int ret; |
845 | ||
846 | if (!str) | |
847 | return 0; | |
bcd83ea6 | 848 | ret = kstrtoul(str, 0, &threshold); |
0e950173 TB |
849 | if (ret < 0) |
850 | return 0; | |
87abb3b1 | 851 | tracing_thresh = threshold * 1000; |
0e950173 TB |
852 | return 1; |
853 | } | |
854 | __setup("tracing_thresh=", set_tracing_thresh); | |
855 | ||
57f50be1 SR |
856 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
857 | { | |
858 | return nsecs / 1000; | |
859 | } | |
860 | ||
a3418a36 SRRH |
861 | /* |
862 | * TRACE_FLAGS is defined as a tuple matching bit masks with strings. | |
863 | * It uses C(a, b) where 'a' is the enum name and 'b' is the string that | |
864 | * matches it. By defining "C(a, b) b", TRACE_FLAGS becomes a list | |
865 | * of strings in the order that the enums were defined. | |
866 | */ | |
867 | #undef C | |
868 | #define C(a, b) b | |
869 | ||
4fcdae83 | 870 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 | 871 | static const char *trace_options[] = { |
a3418a36 | 872 | TRACE_FLAGS |
bc0c38d1 SR |
873 | NULL |
874 | }; | |
875 | ||
5079f326 Z |
876 | static struct { |
877 | u64 (*func)(void); | |
878 | const char *name; | |
8be0709f | 879 | int in_ns; /* is this clock in nanoseconds? */ |
5079f326 | 880 | } trace_clocks[] = { |
1b3e5c09 TG |
881 | { trace_clock_local, "local", 1 }, |
882 | { trace_clock_global, "global", 1 }, | |
883 | { trace_clock_counter, "counter", 0 }, | |
e7fda6c4 | 884 | { trace_clock_jiffies, "uptime", 0 }, |
1b3e5c09 TG |
885 | { trace_clock, "perf", 1 }, |
886 | { ktime_get_mono_fast_ns, "mono", 1 }, | |
aabfa5f2 | 887 | { ktime_get_raw_fast_ns, "mono_raw", 1 }, |
8cbd9cc6 | 888 | ARCH_TRACE_CLOCKS |
5079f326 Z |
889 | }; |
890 | ||
b63f39ea | 891 | /* |
892 | * trace_parser_get_init - gets the buffer for trace parser | |
893 | */ | |
894 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
895 | { | |
896 | memset(parser, 0, sizeof(*parser)); | |
897 | ||
898 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
899 | if (!parser->buffer) | |
900 | return 1; | |
901 | ||
902 | parser->size = size; | |
903 | return 0; | |
904 | } | |
905 | ||
906 | /* | |
907 | * trace_parser_put - frees the buffer for trace parser | |
908 | */ | |
909 | void trace_parser_put(struct trace_parser *parser) | |
910 | { | |
911 | kfree(parser->buffer); | |
912 | } | |
913 | ||
914 | /* | |
915 | * trace_get_user - reads the user input string separated by space | |
916 | * (matched by isspace(ch)) | |
917 | * | |
918 | * For each string found the 'struct trace_parser' is updated, | |
919 | * and the function returns. | |
920 | * | |
921 | * Returns number of bytes read. | |
922 | * | |
923 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
924 | */ | |
925 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
926 | size_t cnt, loff_t *ppos) | |
927 | { | |
928 | char ch; | |
929 | size_t read = 0; | |
930 | ssize_t ret; | |
931 | ||
932 | if (!*ppos) | |
933 | trace_parser_clear(parser); | |
934 | ||
935 | ret = get_user(ch, ubuf++); | |
936 | if (ret) | |
937 | goto out; | |
938 | ||
939 | read++; | |
940 | cnt--; | |
941 | ||
942 | /* | |
943 | * The parser is not finished with the last write, | |
944 | * continue reading the user input without skipping spaces. | |
945 | */ | |
946 | if (!parser->cont) { | |
947 | /* skip white space */ | |
948 | while (cnt && isspace(ch)) { | |
949 | ret = get_user(ch, ubuf++); | |
950 | if (ret) | |
951 | goto out; | |
952 | read++; | |
953 | cnt--; | |
954 | } | |
955 | ||
956 | /* only spaces were written */ | |
957 | if (isspace(ch)) { | |
958 | *ppos += read; | |
959 | ret = read; | |
960 | goto out; | |
961 | } | |
962 | ||
963 | parser->idx = 0; | |
964 | } | |
965 | ||
966 | /* read the non-space input */ | |
967 | while (cnt && !isspace(ch)) { | |
3c235a33 | 968 | if (parser->idx < parser->size - 1) |
b63f39ea | 969 | parser->buffer[parser->idx++] = ch; |
970 | else { | |
971 | ret = -EINVAL; | |
972 | goto out; | |
973 | } | |
974 | ret = get_user(ch, ubuf++); | |
975 | if (ret) | |
976 | goto out; | |
977 | read++; | |
978 | cnt--; | |
979 | } | |
980 | ||
981 | /* We either got finished input or we have to wait for another call. */ | |
982 | if (isspace(ch)) { | |
983 | parser->buffer[parser->idx] = 0; | |
984 | parser->cont = false; | |
057db848 | 985 | } else if (parser->idx < parser->size - 1) { |
b63f39ea | 986 | parser->cont = true; |
987 | parser->buffer[parser->idx++] = ch; | |
057db848 SR |
988 | } else { |
989 | ret = -EINVAL; | |
990 | goto out; | |
b63f39ea | 991 | } |
992 | ||
993 | *ppos += read; | |
994 | ret = read; | |
995 | ||
996 | out: | |
997 | return ret; | |
998 | } | |
999 | ||
3a161d99 | 1000 | /* TODO add a seq_buf_to_buffer() */ |
b8b94265 | 1001 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
1002 | { |
1003 | int len; | |
3c56819b | 1004 | |
5ac48378 | 1005 | if (trace_seq_used(s) <= s->seq.readpos) |
3c56819b EGM |
1006 | return -EBUSY; |
1007 | ||
5ac48378 | 1008 | len = trace_seq_used(s) - s->seq.readpos; |
3c56819b EGM |
1009 | if (cnt > len) |
1010 | cnt = len; | |
3a161d99 | 1011 | memcpy(buf, s->buffer + s->seq.readpos, cnt); |
3c56819b | 1012 | |
3a161d99 | 1013 | s->seq.readpos += cnt; |
3c56819b EGM |
1014 | return cnt; |
1015 | } | |
1016 | ||
0e950173 TB |
1017 | unsigned long __read_mostly tracing_thresh; |
1018 | ||
5d4a9dba | 1019 | #ifdef CONFIG_TRACER_MAX_TRACE |
5d4a9dba SR |
1020 | /* |
1021 | * Copy the new maximum trace into the separate maximum-trace | |
1022 | * structure. (this way the maximum trace is permanently saved, | |
1023 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
1024 | */ | |
1025 | static void | |
1026 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
1027 | { | |
12883efb SRRH |
1028 | struct trace_buffer *trace_buf = &tr->trace_buffer; |
1029 | struct trace_buffer *max_buf = &tr->max_buffer; | |
1030 | struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); | |
1031 | struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); | |
5d4a9dba | 1032 | |
12883efb SRRH |
1033 | max_buf->cpu = cpu; |
1034 | max_buf->time_start = data->preempt_timestamp; | |
5d4a9dba | 1035 | |
6d9b3fa5 | 1036 | max_data->saved_latency = tr->max_latency; |
8248ac05 SR |
1037 | max_data->critical_start = data->critical_start; |
1038 | max_data->critical_end = data->critical_end; | |
5d4a9dba | 1039 | |
1acaa1b2 | 1040 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); |
8248ac05 | 1041 | max_data->pid = tsk->pid; |
f17a5194 SRRH |
1042 | /* |
1043 | * If tsk == current, then use current_uid(), as that does not use | |
1044 | * RCU. The irq tracer can be called out of RCU scope. | |
1045 | */ | |
1046 | if (tsk == current) | |
1047 | max_data->uid = current_uid(); | |
1048 | else | |
1049 | max_data->uid = task_uid(tsk); | |
1050 | ||
8248ac05 SR |
1051 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; |
1052 | max_data->policy = tsk->policy; | |
1053 | max_data->rt_priority = tsk->rt_priority; | |
5d4a9dba SR |
1054 | |
1055 | /* record this tasks comm */ | |
1056 | tracing_record_cmdline(tsk); | |
1057 | } | |
1058 | ||
4fcdae83 SR |
1059 | /** |
1060 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
1061 | * @tr: tracer | |
1062 | * @tsk: the task with the latency | |
1063 | * @cpu: The cpu that initiated the trace. | |
1064 | * | |
1065 | * Flip the buffers between the @tr and the max_tr and record information | |
1066 | * about which task was the cause of this latency. | |
1067 | */ | |
e309b41d | 1068 | void |
bc0c38d1 SR |
1069 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
1070 | { | |
2721e72d | 1071 | struct ring_buffer *buf; |
bc0c38d1 | 1072 | |
2b6080f2 | 1073 | if (tr->stop_count) |
b8de7bd1 SR |
1074 | return; |
1075 | ||
4c11d7ae | 1076 | WARN_ON_ONCE(!irqs_disabled()); |
34600f0e | 1077 | |
45ad21ca | 1078 | if (!tr->allocated_snapshot) { |
debdd57f | 1079 | /* Only the nop tracer should hit this when disabling */ |
2b6080f2 | 1080 | WARN_ON_ONCE(tr->current_trace != &nop_trace); |
34600f0e | 1081 | return; |
debdd57f | 1082 | } |
34600f0e | 1083 | |
0b9b12c1 | 1084 | arch_spin_lock(&tr->max_lock); |
3928a8a2 | 1085 | |
12883efb SRRH |
1086 | buf = tr->trace_buffer.buffer; |
1087 | tr->trace_buffer.buffer = tr->max_buffer.buffer; | |
1088 | tr->max_buffer.buffer = buf; | |
3928a8a2 | 1089 | |
bc0c38d1 | 1090 | __update_max_tr(tr, tsk, cpu); |
0b9b12c1 | 1091 | arch_spin_unlock(&tr->max_lock); |
bc0c38d1 SR |
1092 | } |
1093 | ||
1094 | /** | |
1095 | * update_max_tr_single - only copy one trace over, and reset the rest | |
1096 | * @tr - tracer | |
1097 | * @tsk - task with the latency | |
1098 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
1099 | * |
1100 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 1101 | */ |
e309b41d | 1102 | void |
bc0c38d1 SR |
1103 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
1104 | { | |
3928a8a2 | 1105 | int ret; |
bc0c38d1 | 1106 | |
2b6080f2 | 1107 | if (tr->stop_count) |
b8de7bd1 SR |
1108 | return; |
1109 | ||
4c11d7ae | 1110 | WARN_ON_ONCE(!irqs_disabled()); |
6c24499f | 1111 | if (!tr->allocated_snapshot) { |
2930e04d | 1112 | /* Only the nop tracer should hit this when disabling */ |
9e8529af | 1113 | WARN_ON_ONCE(tr->current_trace != &nop_trace); |
ef710e10 | 1114 | return; |
2930e04d | 1115 | } |
ef710e10 | 1116 | |
0b9b12c1 | 1117 | arch_spin_lock(&tr->max_lock); |
bc0c38d1 | 1118 | |
12883efb | 1119 | ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu); |
3928a8a2 | 1120 | |
e8165dbb SR |
1121 | if (ret == -EBUSY) { |
1122 | /* | |
1123 | * We failed to swap the buffer due to a commit taking | |
1124 | * place on this CPU. We fail to record, but we reset | |
1125 | * the max trace buffer (no one writes directly to it) | |
1126 | * and flag that it failed. | |
1127 | */ | |
12883efb | 1128 | trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, |
e8165dbb SR |
1129 | "Failed to swap buffers due to commit in progress\n"); |
1130 | } | |
1131 | ||
e8165dbb | 1132 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
bc0c38d1 SR |
1133 | |
1134 | __update_max_tr(tr, tsk, cpu); | |
0b9b12c1 | 1135 | arch_spin_unlock(&tr->max_lock); |
bc0c38d1 | 1136 | } |
5d4a9dba | 1137 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
bc0c38d1 | 1138 | |
e30f53aa | 1139 | static int wait_on_pipe(struct trace_iterator *iter, bool full) |
0d5c6e1c | 1140 | { |
15693458 SRRH |
1141 | /* Iterators are static, they should be filled or empty */ |
1142 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
8b8b3683 | 1143 | return 0; |
0d5c6e1c | 1144 | |
e30f53aa RV |
1145 | return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file, |
1146 | full); | |
0d5c6e1c SR |
1147 | } |
1148 | ||
f4e781c0 SRRH |
1149 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
1150 | static int run_tracer_selftest(struct tracer *type) | |
1151 | { | |
1152 | struct trace_array *tr = &global_trace; | |
1153 | struct tracer *saved_tracer = tr->current_trace; | |
1154 | int ret; | |
0d5c6e1c | 1155 | |
f4e781c0 SRRH |
1156 | if (!type->selftest || tracing_selftest_disabled) |
1157 | return 0; | |
0d5c6e1c SR |
1158 | |
1159 | /* | |
f4e781c0 SRRH |
1160 | * Run a selftest on this tracer. |
1161 | * Here we reset the trace buffer, and set the current | |
1162 | * tracer to be this tracer. The tracer can then run some | |
1163 | * internal tracing to verify that everything is in order. | |
1164 | * If we fail, we do not register this tracer. | |
0d5c6e1c | 1165 | */ |
f4e781c0 | 1166 | tracing_reset_online_cpus(&tr->trace_buffer); |
0d5c6e1c | 1167 | |
f4e781c0 SRRH |
1168 | tr->current_trace = type; |
1169 | ||
1170 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1171 | if (type->use_max_tr) { | |
1172 | /* If we expanded the buffers, make sure the max is expanded too */ | |
1173 | if (ring_buffer_expanded) | |
1174 | ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, | |
1175 | RING_BUFFER_ALL_CPUS); | |
1176 | tr->allocated_snapshot = true; | |
1177 | } | |
1178 | #endif | |
1179 | ||
1180 | /* the test is responsible for initializing and enabling */ | |
1181 | pr_info("Testing tracer %s: ", type->name); | |
1182 | ret = type->selftest(type, tr); | |
1183 | /* the test is responsible for resetting too */ | |
1184 | tr->current_trace = saved_tracer; | |
1185 | if (ret) { | |
1186 | printk(KERN_CONT "FAILED!\n"); | |
1187 | /* Add the warning after printing 'FAILED' */ | |
1188 | WARN_ON(1); | |
1189 | return -1; | |
1190 | } | |
1191 | /* Only reset on passing, to avoid touching corrupted buffers */ | |
1192 | tracing_reset_online_cpus(&tr->trace_buffer); | |
1193 | ||
1194 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1195 | if (type->use_max_tr) { | |
1196 | tr->allocated_snapshot = false; | |
0d5c6e1c | 1197 | |
f4e781c0 SRRH |
1198 | /* Shrink the max buffer again */ |
1199 | if (ring_buffer_expanded) | |
1200 | ring_buffer_resize(tr->max_buffer.buffer, 1, | |
1201 | RING_BUFFER_ALL_CPUS); | |
1202 | } | |
1203 | #endif | |
1204 | ||
1205 | printk(KERN_CONT "PASSED\n"); | |
1206 | return 0; | |
1207 | } | |
1208 | #else | |
1209 | static inline int run_tracer_selftest(struct tracer *type) | |
1210 | { | |
1211 | return 0; | |
0d5c6e1c | 1212 | } |
f4e781c0 | 1213 | #endif /* CONFIG_FTRACE_STARTUP_TEST */ |
0d5c6e1c | 1214 | |
41d9c0be SRRH |
1215 | static void add_tracer_options(struct trace_array *tr, struct tracer *t); |
1216 | ||
a4d1e688 JW |
1217 | static void __init apply_trace_boot_options(void); |
1218 | ||
4fcdae83 SR |
1219 | /** |
1220 | * register_tracer - register a tracer with the ftrace system. | |
1221 | * @type - the plugin for the tracer | |
1222 | * | |
1223 | * Register a new plugin tracer. | |
1224 | */ | |
a4d1e688 | 1225 | int __init register_tracer(struct tracer *type) |
bc0c38d1 SR |
1226 | { |
1227 | struct tracer *t; | |
bc0c38d1 SR |
1228 | int ret = 0; |
1229 | ||
1230 | if (!type->name) { | |
1231 | pr_info("Tracer must have a name\n"); | |
1232 | return -1; | |
1233 | } | |
1234 | ||
24a461d5 | 1235 | if (strlen(type->name) >= MAX_TRACER_SIZE) { |
ee6c2c1b LZ |
1236 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); |
1237 | return -1; | |
1238 | } | |
1239 | ||
bc0c38d1 | 1240 | mutex_lock(&trace_types_lock); |
86fa2f60 | 1241 | |
8e1b82e0 FW |
1242 | tracing_selftest_running = true; |
1243 | ||
bc0c38d1 SR |
1244 | for (t = trace_types; t; t = t->next) { |
1245 | if (strcmp(type->name, t->name) == 0) { | |
1246 | /* already found */ | |
ee6c2c1b | 1247 | pr_info("Tracer %s already registered\n", |
bc0c38d1 SR |
1248 | type->name); |
1249 | ret = -1; | |
1250 | goto out; | |
1251 | } | |
1252 | } | |
1253 | ||
adf9f195 FW |
1254 | if (!type->set_flag) |
1255 | type->set_flag = &dummy_set_flag; | |
d39cdd20 CH |
1256 | if (!type->flags) { |
1257 | /*allocate a dummy tracer_flags*/ | |
1258 | type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL); | |
c8ca003b CH |
1259 | if (!type->flags) { |
1260 | ret = -ENOMEM; | |
1261 | goto out; | |
1262 | } | |
d39cdd20 CH |
1263 | type->flags->val = 0; |
1264 | type->flags->opts = dummy_tracer_opt; | |
1265 | } else | |
adf9f195 FW |
1266 | if (!type->flags->opts) |
1267 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 | 1268 | |
d39cdd20 CH |
1269 | /* store the tracer for __set_tracer_option */ |
1270 | type->flags->trace = type; | |
1271 | ||
f4e781c0 SRRH |
1272 | ret = run_tracer_selftest(type); |
1273 | if (ret < 0) | |
1274 | goto out; | |
60a11774 | 1275 | |
bc0c38d1 SR |
1276 | type->next = trace_types; |
1277 | trace_types = type; | |
41d9c0be | 1278 | add_tracer_options(&global_trace, type); |
60a11774 | 1279 | |
bc0c38d1 | 1280 | out: |
8e1b82e0 | 1281 | tracing_selftest_running = false; |
bc0c38d1 SR |
1282 | mutex_unlock(&trace_types_lock); |
1283 | ||
dac74940 SR |
1284 | if (ret || !default_bootup_tracer) |
1285 | goto out_unlock; | |
1286 | ||
ee6c2c1b | 1287 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
dac74940 SR |
1288 | goto out_unlock; |
1289 | ||
1290 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
1291 | /* Do we want this tracer to start on bootup? */ | |
607e2ea1 | 1292 | tracing_set_tracer(&global_trace, type->name); |
dac74940 | 1293 | default_bootup_tracer = NULL; |
a4d1e688 JW |
1294 | |
1295 | apply_trace_boot_options(); | |
1296 | ||
dac74940 | 1297 | /* disable other selftests, since this will break it. */ |
55034cd6 | 1298 | tracing_selftest_disabled = true; |
b2821ae6 | 1299 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
1300 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
1301 | type->name); | |
b2821ae6 | 1302 | #endif |
b2821ae6 | 1303 | |
dac74940 | 1304 | out_unlock: |
bc0c38d1 SR |
1305 | return ret; |
1306 | } | |
1307 | ||
12883efb | 1308 | void tracing_reset(struct trace_buffer *buf, int cpu) |
f633903a | 1309 | { |
12883efb | 1310 | struct ring_buffer *buffer = buf->buffer; |
f633903a | 1311 | |
a5416411 HT |
1312 | if (!buffer) |
1313 | return; | |
1314 | ||
f633903a SR |
1315 | ring_buffer_record_disable(buffer); |
1316 | ||
1317 | /* Make sure all commits have finished */ | |
1318 | synchronize_sched(); | |
68179686 | 1319 | ring_buffer_reset_cpu(buffer, cpu); |
f633903a SR |
1320 | |
1321 | ring_buffer_record_enable(buffer); | |
1322 | } | |
1323 | ||
12883efb | 1324 | void tracing_reset_online_cpus(struct trace_buffer *buf) |
213cc060 | 1325 | { |
12883efb | 1326 | struct ring_buffer *buffer = buf->buffer; |
213cc060 PE |
1327 | int cpu; |
1328 | ||
a5416411 HT |
1329 | if (!buffer) |
1330 | return; | |
1331 | ||
621968cd SR |
1332 | ring_buffer_record_disable(buffer); |
1333 | ||
1334 | /* Make sure all commits have finished */ | |
1335 | synchronize_sched(); | |
1336 | ||
9457158b | 1337 | buf->time_start = buffer_ftrace_now(buf, buf->cpu); |
213cc060 PE |
1338 | |
1339 | for_each_online_cpu(cpu) | |
68179686 | 1340 | ring_buffer_reset_cpu(buffer, cpu); |
621968cd SR |
1341 | |
1342 | ring_buffer_record_enable(buffer); | |
213cc060 PE |
1343 | } |
1344 | ||
09d8091c | 1345 | /* Must have trace_types_lock held */ |
873c642f | 1346 | void tracing_reset_all_online_cpus(void) |
9456f0fa | 1347 | { |
873c642f SRRH |
1348 | struct trace_array *tr; |
1349 | ||
873c642f | 1350 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
12883efb SRRH |
1351 | tracing_reset_online_cpus(&tr->trace_buffer); |
1352 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1353 | tracing_reset_online_cpus(&tr->max_buffer); | |
1354 | #endif | |
873c642f | 1355 | } |
9456f0fa SR |
1356 | } |
1357 | ||
939c7a4f | 1358 | #define SAVED_CMDLINES_DEFAULT 128 |
2c7eea4c | 1359 | #define NO_CMDLINE_MAP UINT_MAX |
edc35bd7 | 1360 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
939c7a4f YY |
1361 | struct saved_cmdlines_buffer { |
1362 | unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
1363 | unsigned *map_cmdline_to_pid; | |
1364 | unsigned cmdline_num; | |
1365 | int cmdline_idx; | |
1366 | char *saved_cmdlines; | |
1367 | }; | |
1368 | static struct saved_cmdlines_buffer *savedcmd; | |
25b0b44a | 1369 | |
25b0b44a | 1370 | /* temporary disable recording */ |
4fd27358 | 1371 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 | 1372 | |
939c7a4f YY |
1373 | static inline char *get_saved_cmdlines(int idx) |
1374 | { | |
1375 | return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN]; | |
1376 | } | |
1377 | ||
1378 | static inline void set_cmdline(int idx, const char *cmdline) | |
bc0c38d1 | 1379 | { |
939c7a4f YY |
1380 | memcpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); |
1381 | } | |
1382 | ||
1383 | static int allocate_cmdlines_buffer(unsigned int val, | |
1384 | struct saved_cmdlines_buffer *s) | |
1385 | { | |
1386 | s->map_cmdline_to_pid = kmalloc(val * sizeof(*s->map_cmdline_to_pid), | |
1387 | GFP_KERNEL); | |
1388 | if (!s->map_cmdline_to_pid) | |
1389 | return -ENOMEM; | |
1390 | ||
1391 | s->saved_cmdlines = kmalloc(val * TASK_COMM_LEN, GFP_KERNEL); | |
1392 | if (!s->saved_cmdlines) { | |
1393 | kfree(s->map_cmdline_to_pid); | |
1394 | return -ENOMEM; | |
1395 | } | |
1396 | ||
1397 | s->cmdline_idx = 0; | |
1398 | s->cmdline_num = val; | |
1399 | memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP, | |
1400 | sizeof(s->map_pid_to_cmdline)); | |
1401 | memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP, | |
1402 | val * sizeof(*s->map_cmdline_to_pid)); | |
1403 | ||
1404 | return 0; | |
1405 | } | |
1406 | ||
1407 | static int trace_create_savedcmd(void) | |
1408 | { | |
1409 | int ret; | |
1410 | ||
a6af8fbf | 1411 | savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL); |
939c7a4f YY |
1412 | if (!savedcmd) |
1413 | return -ENOMEM; | |
1414 | ||
1415 | ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd); | |
1416 | if (ret < 0) { | |
1417 | kfree(savedcmd); | |
1418 | savedcmd = NULL; | |
1419 | return -ENOMEM; | |
1420 | } | |
1421 | ||
1422 | return 0; | |
bc0c38d1 SR |
1423 | } |
1424 | ||
b5130b1e CE |
1425 | int is_tracing_stopped(void) |
1426 | { | |
2b6080f2 | 1427 | return global_trace.stop_count; |
b5130b1e CE |
1428 | } |
1429 | ||
0f048701 SR |
1430 | /** |
1431 | * tracing_start - quick start of the tracer | |
1432 | * | |
1433 | * If tracing is enabled but was stopped by tracing_stop, | |
1434 | * this will start the tracer back up. | |
1435 | */ | |
1436 | void tracing_start(void) | |
1437 | { | |
1438 | struct ring_buffer *buffer; | |
1439 | unsigned long flags; | |
1440 | ||
1441 | if (tracing_disabled) | |
1442 | return; | |
1443 | ||
2b6080f2 SR |
1444 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
1445 | if (--global_trace.stop_count) { | |
1446 | if (global_trace.stop_count < 0) { | |
b06a8301 SR |
1447 | /* Someone screwed up their debugging */ |
1448 | WARN_ON_ONCE(1); | |
2b6080f2 | 1449 | global_trace.stop_count = 0; |
b06a8301 | 1450 | } |
0f048701 SR |
1451 | goto out; |
1452 | } | |
1453 | ||
a2f80714 | 1454 | /* Prevent the buffers from switching */ |
0b9b12c1 | 1455 | arch_spin_lock(&global_trace.max_lock); |
0f048701 | 1456 | |
12883efb | 1457 | buffer = global_trace.trace_buffer.buffer; |
0f048701 SR |
1458 | if (buffer) |
1459 | ring_buffer_record_enable(buffer); | |
1460 | ||
12883efb SRRH |
1461 | #ifdef CONFIG_TRACER_MAX_TRACE |
1462 | buffer = global_trace.max_buffer.buffer; | |
0f048701 SR |
1463 | if (buffer) |
1464 | ring_buffer_record_enable(buffer); | |
12883efb | 1465 | #endif |
0f048701 | 1466 | |
0b9b12c1 | 1467 | arch_spin_unlock(&global_trace.max_lock); |
a2f80714 | 1468 | |
0f048701 | 1469 | out: |
2b6080f2 SR |
1470 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
1471 | } | |
1472 | ||
1473 | static void tracing_start_tr(struct trace_array *tr) | |
1474 | { | |
1475 | struct ring_buffer *buffer; | |
1476 | unsigned long flags; | |
1477 | ||
1478 | if (tracing_disabled) | |
1479 | return; | |
1480 | ||
1481 | /* If global, we need to also start the max tracer */ | |
1482 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1483 | return tracing_start(); | |
1484 | ||
1485 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1486 | ||
1487 | if (--tr->stop_count) { | |
1488 | if (tr->stop_count < 0) { | |
1489 | /* Someone screwed up their debugging */ | |
1490 | WARN_ON_ONCE(1); | |
1491 | tr->stop_count = 0; | |
1492 | } | |
1493 | goto out; | |
1494 | } | |
1495 | ||
12883efb | 1496 | buffer = tr->trace_buffer.buffer; |
2b6080f2 SR |
1497 | if (buffer) |
1498 | ring_buffer_record_enable(buffer); | |
1499 | ||
1500 | out: | |
1501 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
0f048701 SR |
1502 | } |
1503 | ||
1504 | /** | |
1505 | * tracing_stop - quick stop of the tracer | |
1506 | * | |
1507 | * Light weight way to stop tracing. Use in conjunction with | |
1508 | * tracing_start. | |
1509 | */ | |
1510 | void tracing_stop(void) | |
1511 | { | |
1512 | struct ring_buffer *buffer; | |
1513 | unsigned long flags; | |
1514 | ||
2b6080f2 SR |
1515 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
1516 | if (global_trace.stop_count++) | |
0f048701 SR |
1517 | goto out; |
1518 | ||
a2f80714 | 1519 | /* Prevent the buffers from switching */ |
0b9b12c1 | 1520 | arch_spin_lock(&global_trace.max_lock); |
a2f80714 | 1521 | |
12883efb | 1522 | buffer = global_trace.trace_buffer.buffer; |
0f048701 SR |
1523 | if (buffer) |
1524 | ring_buffer_record_disable(buffer); | |
1525 | ||
12883efb SRRH |
1526 | #ifdef CONFIG_TRACER_MAX_TRACE |
1527 | buffer = global_trace.max_buffer.buffer; | |
0f048701 SR |
1528 | if (buffer) |
1529 | ring_buffer_record_disable(buffer); | |
12883efb | 1530 | #endif |
0f048701 | 1531 | |
0b9b12c1 | 1532 | arch_spin_unlock(&global_trace.max_lock); |
a2f80714 | 1533 | |
0f048701 | 1534 | out: |
2b6080f2 SR |
1535 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
1536 | } | |
1537 | ||
1538 | static void tracing_stop_tr(struct trace_array *tr) | |
1539 | { | |
1540 | struct ring_buffer *buffer; | |
1541 | unsigned long flags; | |
1542 | ||
1543 | /* If global, we need to also stop the max tracer */ | |
1544 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1545 | return tracing_stop(); | |
1546 | ||
1547 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1548 | if (tr->stop_count++) | |
1549 | goto out; | |
1550 | ||
12883efb | 1551 | buffer = tr->trace_buffer.buffer; |
2b6080f2 SR |
1552 | if (buffer) |
1553 | ring_buffer_record_disable(buffer); | |
1554 | ||
1555 | out: | |
1556 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
0f048701 SR |
1557 | } |
1558 | ||
e309b41d | 1559 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 1560 | |
379cfdac | 1561 | static int trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1562 | { |
a635cf04 | 1563 | unsigned pid, idx; |
bc0c38d1 SR |
1564 | |
1565 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
379cfdac | 1566 | return 0; |
bc0c38d1 SR |
1567 | |
1568 | /* | |
1569 | * It's not the end of the world if we don't get | |
1570 | * the lock, but we also don't want to spin | |
1571 | * nor do we want to disable interrupts, | |
1572 | * so if we miss here, then better luck next time. | |
1573 | */ | |
0199c4e6 | 1574 | if (!arch_spin_trylock(&trace_cmdline_lock)) |
379cfdac | 1575 | return 0; |
bc0c38d1 | 1576 | |
939c7a4f | 1577 | idx = savedcmd->map_pid_to_cmdline[tsk->pid]; |
2c7eea4c | 1578 | if (idx == NO_CMDLINE_MAP) { |
939c7a4f | 1579 | idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num; |
bc0c38d1 | 1580 | |
a635cf04 CE |
1581 | /* |
1582 | * Check whether the cmdline buffer at idx has a pid | |
1583 | * mapped. We are going to overwrite that entry so we | |
1584 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1585 | * would read the new comm for the old pid. | |
1586 | */ | |
939c7a4f | 1587 | pid = savedcmd->map_cmdline_to_pid[idx]; |
a635cf04 | 1588 | if (pid != NO_CMDLINE_MAP) |
939c7a4f | 1589 | savedcmd->map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; |
bc0c38d1 | 1590 | |
939c7a4f YY |
1591 | savedcmd->map_cmdline_to_pid[idx] = tsk->pid; |
1592 | savedcmd->map_pid_to_cmdline[tsk->pid] = idx; | |
bc0c38d1 | 1593 | |
939c7a4f | 1594 | savedcmd->cmdline_idx = idx; |
bc0c38d1 SR |
1595 | } |
1596 | ||
939c7a4f | 1597 | set_cmdline(idx, tsk->comm); |
bc0c38d1 | 1598 | |
0199c4e6 | 1599 | arch_spin_unlock(&trace_cmdline_lock); |
379cfdac SRRH |
1600 | |
1601 | return 1; | |
bc0c38d1 SR |
1602 | } |
1603 | ||
4c27e756 | 1604 | static void __trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 1605 | { |
bc0c38d1 SR |
1606 | unsigned map; |
1607 | ||
4ca53085 SR |
1608 | if (!pid) { |
1609 | strcpy(comm, "<idle>"); | |
1610 | return; | |
1611 | } | |
bc0c38d1 | 1612 | |
74bf4076 SR |
1613 | if (WARN_ON_ONCE(pid < 0)) { |
1614 | strcpy(comm, "<XXX>"); | |
1615 | return; | |
1616 | } | |
1617 | ||
4ca53085 SR |
1618 | if (pid > PID_MAX_DEFAULT) { |
1619 | strcpy(comm, "<...>"); | |
1620 | return; | |
1621 | } | |
bc0c38d1 | 1622 | |
939c7a4f | 1623 | map = savedcmd->map_pid_to_cmdline[pid]; |
50d88758 | 1624 | if (map != NO_CMDLINE_MAP) |
939c7a4f | 1625 | strcpy(comm, get_saved_cmdlines(map)); |
50d88758 TG |
1626 | else |
1627 | strcpy(comm, "<...>"); | |
4c27e756 SRRH |
1628 | } |
1629 | ||
1630 | void trace_find_cmdline(int pid, char comm[]) | |
1631 | { | |
1632 | preempt_disable(); | |
1633 | arch_spin_lock(&trace_cmdline_lock); | |
1634 | ||
1635 | __trace_find_cmdline(pid, comm); | |
bc0c38d1 | 1636 | |
0199c4e6 | 1637 | arch_spin_unlock(&trace_cmdline_lock); |
5b6045a9 | 1638 | preempt_enable(); |
bc0c38d1 SR |
1639 | } |
1640 | ||
e309b41d | 1641 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1642 | { |
0fb9656d | 1643 | if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) |
bc0c38d1 SR |
1644 | return; |
1645 | ||
7ffbd48d SR |
1646 | if (!__this_cpu_read(trace_cmdline_save)) |
1647 | return; | |
1648 | ||
379cfdac SRRH |
1649 | if (trace_save_cmdline(tsk)) |
1650 | __this_cpu_write(trace_cmdline_save, false); | |
bc0c38d1 SR |
1651 | } |
1652 | ||
45dcd8b8 | 1653 | void |
38697053 SR |
1654 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
1655 | int pc) | |
bc0c38d1 SR |
1656 | { |
1657 | struct task_struct *tsk = current; | |
bc0c38d1 | 1658 | |
777e208d SR |
1659 | entry->preempt_count = pc & 0xff; |
1660 | entry->pid = (tsk) ? tsk->pid : 0; | |
1661 | entry->flags = | |
9244489a | 1662 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 1663 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
1664 | #else |
1665 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1666 | #endif | |
7e6867bf | 1667 | ((pc & NMI_MASK ) ? TRACE_FLAG_NMI : 0) | |
bc0c38d1 SR |
1668 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
1669 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
e5137b50 PZ |
1670 | (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | |
1671 | (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); | |
bc0c38d1 | 1672 | } |
f413cdb8 | 1673 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); |
bc0c38d1 | 1674 | |
e77405ad SR |
1675 | struct ring_buffer_event * |
1676 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1677 | int type, | |
1678 | unsigned long len, | |
1679 | unsigned long flags, int pc) | |
51a763dd ACM |
1680 | { |
1681 | struct ring_buffer_event *event; | |
1682 | ||
e77405ad | 1683 | event = ring_buffer_lock_reserve(buffer, len); |
51a763dd ACM |
1684 | if (event != NULL) { |
1685 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1686 | ||
1687 | tracing_generic_entry_update(ent, flags, pc); | |
1688 | ent->type = type; | |
1689 | } | |
1690 | ||
1691 | return event; | |
1692 | } | |
51a763dd | 1693 | |
7ffbd48d SR |
1694 | void |
1695 | __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) | |
1696 | { | |
1697 | __this_cpu_write(trace_cmdline_save, true); | |
1698 | ring_buffer_unlock_commit(buffer, event); | |
1699 | } | |
1700 | ||
b7f0c959 SRRH |
1701 | void trace_buffer_unlock_commit(struct trace_array *tr, |
1702 | struct ring_buffer *buffer, | |
1703 | struct ring_buffer_event *event, | |
1704 | unsigned long flags, int pc) | |
51a763dd | 1705 | { |
7ffbd48d | 1706 | __buffer_unlock_commit(buffer, event); |
51a763dd | 1707 | |
2d34f489 | 1708 | ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL); |
e77405ad | 1709 | ftrace_trace_userstack(buffer, flags, pc); |
07edf712 | 1710 | } |
0d5c6e1c | 1711 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); |
51a763dd | 1712 | |
2c4a33ab SRRH |
1713 | static struct ring_buffer *temp_buffer; |
1714 | ||
ccb469a1 SR |
1715 | struct ring_buffer_event * |
1716 | trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, | |
7f1d2f82 | 1717 | struct trace_event_file *trace_file, |
ccb469a1 SR |
1718 | int type, unsigned long len, |
1719 | unsigned long flags, int pc) | |
1720 | { | |
2c4a33ab SRRH |
1721 | struct ring_buffer_event *entry; |
1722 | ||
7f1d2f82 | 1723 | *current_rb = trace_file->tr->trace_buffer.buffer; |
2c4a33ab | 1724 | entry = trace_buffer_lock_reserve(*current_rb, |
ccb469a1 | 1725 | type, len, flags, pc); |
2c4a33ab SRRH |
1726 | /* |
1727 | * If tracing is off, but we have triggers enabled | |
1728 | * we still need to look at the event data. Use the temp_buffer | |
1729 | * to store the trace event for the tigger to use. It's recusive | |
1730 | * safe and will not be recorded anywhere. | |
1731 | */ | |
5d6ad960 | 1732 | if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) { |
2c4a33ab SRRH |
1733 | *current_rb = temp_buffer; |
1734 | entry = trace_buffer_lock_reserve(*current_rb, | |
1735 | type, len, flags, pc); | |
1736 | } | |
1737 | return entry; | |
ccb469a1 SR |
1738 | } |
1739 | EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); | |
1740 | ||
ef5580d0 | 1741 | struct ring_buffer_event * |
e77405ad SR |
1742 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, |
1743 | int type, unsigned long len, | |
ef5580d0 SR |
1744 | unsigned long flags, int pc) |
1745 | { | |
12883efb | 1746 | *current_rb = global_trace.trace_buffer.buffer; |
e77405ad | 1747 | return trace_buffer_lock_reserve(*current_rb, |
ef5580d0 SR |
1748 | type, len, flags, pc); |
1749 | } | |
94487d6d | 1750 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); |
ef5580d0 | 1751 | |
b7f0c959 SRRH |
1752 | void trace_buffer_unlock_commit_regs(struct trace_array *tr, |
1753 | struct ring_buffer *buffer, | |
0d5c6e1c SR |
1754 | struct ring_buffer_event *event, |
1755 | unsigned long flags, int pc, | |
1756 | struct pt_regs *regs) | |
1fd8df2c | 1757 | { |
7ffbd48d | 1758 | __buffer_unlock_commit(buffer, event); |
1fd8df2c | 1759 | |
7717c6be | 1760 | ftrace_trace_stack(tr, buffer, flags, 0, pc, regs); |
1fd8df2c MH |
1761 | ftrace_trace_userstack(buffer, flags, pc); |
1762 | } | |
0d5c6e1c | 1763 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); |
1fd8df2c | 1764 | |
e77405ad SR |
1765 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, |
1766 | struct ring_buffer_event *event) | |
77d9f465 | 1767 | { |
e77405ad | 1768 | ring_buffer_discard_commit(buffer, event); |
ef5580d0 | 1769 | } |
12acd473 | 1770 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); |
ef5580d0 | 1771 | |
e309b41d | 1772 | void |
7be42151 | 1773 | trace_function(struct trace_array *tr, |
38697053 SR |
1774 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1775 | int pc) | |
bc0c38d1 | 1776 | { |
2425bcb9 | 1777 | struct trace_event_call *call = &event_function; |
12883efb | 1778 | struct ring_buffer *buffer = tr->trace_buffer.buffer; |
3928a8a2 | 1779 | struct ring_buffer_event *event; |
777e208d | 1780 | struct ftrace_entry *entry; |
bc0c38d1 | 1781 | |
e77405ad | 1782 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
51a763dd | 1783 | flags, pc); |
3928a8a2 SR |
1784 | if (!event) |
1785 | return; | |
1786 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1787 | entry->ip = ip; |
1788 | entry->parent_ip = parent_ip; | |
e1112b4d | 1789 | |
f306cc82 | 1790 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1791 | __buffer_unlock_commit(buffer, event); |
bc0c38d1 SR |
1792 | } |
1793 | ||
c0a0d0d3 | 1794 | #ifdef CONFIG_STACKTRACE |
4a9bd3f1 SR |
1795 | |
1796 | #define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) | |
1797 | struct ftrace_stack { | |
1798 | unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; | |
1799 | }; | |
1800 | ||
1801 | static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); | |
1802 | static DEFINE_PER_CPU(int, ftrace_stack_reserve); | |
1803 | ||
e77405ad | 1804 | static void __ftrace_trace_stack(struct ring_buffer *buffer, |
53614991 | 1805 | unsigned long flags, |
1fd8df2c | 1806 | int skip, int pc, struct pt_regs *regs) |
86387f7e | 1807 | { |
2425bcb9 | 1808 | struct trace_event_call *call = &event_kernel_stack; |
3928a8a2 | 1809 | struct ring_buffer_event *event; |
777e208d | 1810 | struct stack_entry *entry; |
86387f7e | 1811 | struct stack_trace trace; |
4a9bd3f1 SR |
1812 | int use_stack; |
1813 | int size = FTRACE_STACK_ENTRIES; | |
1814 | ||
1815 | trace.nr_entries = 0; | |
1816 | trace.skip = skip; | |
1817 | ||
1818 | /* | |
1819 | * Since events can happen in NMIs there's no safe way to | |
1820 | * use the per cpu ftrace_stacks. We reserve it and if an interrupt | |
1821 | * or NMI comes in, it will just have to use the default | |
1822 | * FTRACE_STACK_SIZE. | |
1823 | */ | |
1824 | preempt_disable_notrace(); | |
1825 | ||
82146529 | 1826 | use_stack = __this_cpu_inc_return(ftrace_stack_reserve); |
4a9bd3f1 SR |
1827 | /* |
1828 | * We don't need any atomic variables, just a barrier. | |
1829 | * If an interrupt comes in, we don't care, because it would | |
1830 | * have exited and put the counter back to what we want. | |
1831 | * We just need a barrier to keep gcc from moving things | |
1832 | * around. | |
1833 | */ | |
1834 | barrier(); | |
1835 | if (use_stack == 1) { | |
bdffd893 | 1836 | trace.entries = this_cpu_ptr(ftrace_stack.calls); |
4a9bd3f1 SR |
1837 | trace.max_entries = FTRACE_STACK_MAX_ENTRIES; |
1838 | ||
1839 | if (regs) | |
1840 | save_stack_trace_regs(regs, &trace); | |
1841 | else | |
1842 | save_stack_trace(&trace); | |
1843 | ||
1844 | if (trace.nr_entries > size) | |
1845 | size = trace.nr_entries; | |
1846 | } else | |
1847 | /* From now on, use_stack is a boolean */ | |
1848 | use_stack = 0; | |
1849 | ||
1850 | size *= sizeof(unsigned long); | |
86387f7e | 1851 | |
e77405ad | 1852 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, |
4a9bd3f1 | 1853 | sizeof(*entry) + size, flags, pc); |
3928a8a2 | 1854 | if (!event) |
4a9bd3f1 SR |
1855 | goto out; |
1856 | entry = ring_buffer_event_data(event); | |
86387f7e | 1857 | |
4a9bd3f1 SR |
1858 | memset(&entry->caller, 0, size); |
1859 | ||
1860 | if (use_stack) | |
1861 | memcpy(&entry->caller, trace.entries, | |
1862 | trace.nr_entries * sizeof(unsigned long)); | |
1863 | else { | |
1864 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1865 | trace.entries = entry->caller; | |
1866 | if (regs) | |
1867 | save_stack_trace_regs(regs, &trace); | |
1868 | else | |
1869 | save_stack_trace(&trace); | |
1870 | } | |
1871 | ||
1872 | entry->size = trace.nr_entries; | |
86387f7e | 1873 | |
f306cc82 | 1874 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1875 | __buffer_unlock_commit(buffer, event); |
4a9bd3f1 SR |
1876 | |
1877 | out: | |
1878 | /* Again, don't let gcc optimize things here */ | |
1879 | barrier(); | |
82146529 | 1880 | __this_cpu_dec(ftrace_stack_reserve); |
4a9bd3f1 SR |
1881 | preempt_enable_notrace(); |
1882 | ||
f0a920d5 IM |
1883 | } |
1884 | ||
2d34f489 SRRH |
1885 | static inline void ftrace_trace_stack(struct trace_array *tr, |
1886 | struct ring_buffer *buffer, | |
73dddbb5 SRRH |
1887 | unsigned long flags, |
1888 | int skip, int pc, struct pt_regs *regs) | |
53614991 | 1889 | { |
2d34f489 | 1890 | if (!(tr->trace_flags & TRACE_ITER_STACKTRACE)) |
53614991 SR |
1891 | return; |
1892 | ||
73dddbb5 | 1893 | __ftrace_trace_stack(buffer, flags, skip, pc, regs); |
53614991 SR |
1894 | } |
1895 | ||
c0a0d0d3 FW |
1896 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, |
1897 | int pc) | |
38697053 | 1898 | { |
12883efb | 1899 | __ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL); |
38697053 SR |
1900 | } |
1901 | ||
03889384 SR |
1902 | /** |
1903 | * trace_dump_stack - record a stack back trace in the trace buffer | |
c142be8e | 1904 | * @skip: Number of functions to skip (helper handlers) |
03889384 | 1905 | */ |
c142be8e | 1906 | void trace_dump_stack(int skip) |
03889384 SR |
1907 | { |
1908 | unsigned long flags; | |
1909 | ||
1910 | if (tracing_disabled || tracing_selftest_running) | |
e36c5458 | 1911 | return; |
03889384 SR |
1912 | |
1913 | local_save_flags(flags); | |
1914 | ||
c142be8e SRRH |
1915 | /* |
1916 | * Skip 3 more, seems to get us at the caller of | |
1917 | * this function. | |
1918 | */ | |
1919 | skip += 3; | |
1920 | __ftrace_trace_stack(global_trace.trace_buffer.buffer, | |
1921 | flags, skip, preempt_count(), NULL); | |
03889384 SR |
1922 | } |
1923 | ||
91e86e56 SR |
1924 | static DEFINE_PER_CPU(int, user_stack_count); |
1925 | ||
e77405ad SR |
1926 | void |
1927 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
02b67518 | 1928 | { |
2425bcb9 | 1929 | struct trace_event_call *call = &event_user_stack; |
8d7c6a96 | 1930 | struct ring_buffer_event *event; |
02b67518 TE |
1931 | struct userstack_entry *entry; |
1932 | struct stack_trace trace; | |
02b67518 | 1933 | |
983f938a | 1934 | if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE)) |
02b67518 TE |
1935 | return; |
1936 | ||
b6345879 SR |
1937 | /* |
1938 | * NMIs can not handle page faults, even with fix ups. | |
1939 | * The save user stack can (and often does) fault. | |
1940 | */ | |
1941 | if (unlikely(in_nmi())) | |
1942 | return; | |
02b67518 | 1943 | |
91e86e56 SR |
1944 | /* |
1945 | * prevent recursion, since the user stack tracing may | |
1946 | * trigger other kernel events. | |
1947 | */ | |
1948 | preempt_disable(); | |
1949 | if (__this_cpu_read(user_stack_count)) | |
1950 | goto out; | |
1951 | ||
1952 | __this_cpu_inc(user_stack_count); | |
1953 | ||
e77405ad | 1954 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
51a763dd | 1955 | sizeof(*entry), flags, pc); |
02b67518 | 1956 | if (!event) |
1dbd1951 | 1957 | goto out_drop_count; |
02b67518 | 1958 | entry = ring_buffer_event_data(event); |
02b67518 | 1959 | |
48659d31 | 1960 | entry->tgid = current->tgid; |
02b67518 TE |
1961 | memset(&entry->caller, 0, sizeof(entry->caller)); |
1962 | ||
1963 | trace.nr_entries = 0; | |
1964 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1965 | trace.skip = 0; | |
1966 | trace.entries = entry->caller; | |
1967 | ||
1968 | save_stack_trace_user(&trace); | |
f306cc82 | 1969 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1970 | __buffer_unlock_commit(buffer, event); |
91e86e56 | 1971 | |
1dbd1951 | 1972 | out_drop_count: |
91e86e56 | 1973 | __this_cpu_dec(user_stack_count); |
91e86e56 SR |
1974 | out: |
1975 | preempt_enable(); | |
02b67518 TE |
1976 | } |
1977 | ||
4fd27358 HE |
1978 | #ifdef UNUSED |
1979 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1980 | { |
7be42151 | 1981 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1982 | } |
4fd27358 | 1983 | #endif /* UNUSED */ |
02b67518 | 1984 | |
c0a0d0d3 FW |
1985 | #endif /* CONFIG_STACKTRACE */ |
1986 | ||
07d777fe SR |
1987 | /* created for use with alloc_percpu */ |
1988 | struct trace_buffer_struct { | |
1989 | char buffer[TRACE_BUF_SIZE]; | |
1990 | }; | |
1991 | ||
1992 | static struct trace_buffer_struct *trace_percpu_buffer; | |
1993 | static struct trace_buffer_struct *trace_percpu_sirq_buffer; | |
1994 | static struct trace_buffer_struct *trace_percpu_irq_buffer; | |
1995 | static struct trace_buffer_struct *trace_percpu_nmi_buffer; | |
1996 | ||
1997 | /* | |
1998 | * The buffer used is dependent on the context. There is a per cpu | |
1999 | * buffer for normal context, softirq contex, hard irq context and | |
2000 | * for NMI context. Thise allows for lockless recording. | |
2001 | * | |
2002 | * Note, if the buffers failed to be allocated, then this returns NULL | |
2003 | */ | |
2004 | static char *get_trace_buf(void) | |
2005 | { | |
2006 | struct trace_buffer_struct *percpu_buffer; | |
07d777fe SR |
2007 | |
2008 | /* | |
2009 | * If we have allocated per cpu buffers, then we do not | |
2010 | * need to do any locking. | |
2011 | */ | |
2012 | if (in_nmi()) | |
2013 | percpu_buffer = trace_percpu_nmi_buffer; | |
2014 | else if (in_irq()) | |
2015 | percpu_buffer = trace_percpu_irq_buffer; | |
2016 | else if (in_softirq()) | |
2017 | percpu_buffer = trace_percpu_sirq_buffer; | |
2018 | else | |
2019 | percpu_buffer = trace_percpu_buffer; | |
2020 | ||
2021 | if (!percpu_buffer) | |
2022 | return NULL; | |
2023 | ||
d8a0349c | 2024 | return this_cpu_ptr(&percpu_buffer->buffer[0]); |
07d777fe SR |
2025 | } |
2026 | ||
2027 | static int alloc_percpu_trace_buffer(void) | |
2028 | { | |
2029 | struct trace_buffer_struct *buffers; | |
2030 | struct trace_buffer_struct *sirq_buffers; | |
2031 | struct trace_buffer_struct *irq_buffers; | |
2032 | struct trace_buffer_struct *nmi_buffers; | |
2033 | ||
2034 | buffers = alloc_percpu(struct trace_buffer_struct); | |
2035 | if (!buffers) | |
2036 | goto err_warn; | |
2037 | ||
2038 | sirq_buffers = alloc_percpu(struct trace_buffer_struct); | |
2039 | if (!sirq_buffers) | |
2040 | goto err_sirq; | |
2041 | ||
2042 | irq_buffers = alloc_percpu(struct trace_buffer_struct); | |
2043 | if (!irq_buffers) | |
2044 | goto err_irq; | |
2045 | ||
2046 | nmi_buffers = alloc_percpu(struct trace_buffer_struct); | |
2047 | if (!nmi_buffers) | |
2048 | goto err_nmi; | |
2049 | ||
2050 | trace_percpu_buffer = buffers; | |
2051 | trace_percpu_sirq_buffer = sirq_buffers; | |
2052 | trace_percpu_irq_buffer = irq_buffers; | |
2053 | trace_percpu_nmi_buffer = nmi_buffers; | |
2054 | ||
2055 | return 0; | |
2056 | ||
2057 | err_nmi: | |
2058 | free_percpu(irq_buffers); | |
2059 | err_irq: | |
2060 | free_percpu(sirq_buffers); | |
2061 | err_sirq: | |
2062 | free_percpu(buffers); | |
2063 | err_warn: | |
2064 | WARN(1, "Could not allocate percpu trace_printk buffer"); | |
2065 | return -ENOMEM; | |
2066 | } | |
2067 | ||
81698831 SR |
2068 | static int buffers_allocated; |
2069 | ||
07d777fe SR |
2070 | void trace_printk_init_buffers(void) |
2071 | { | |
07d777fe SR |
2072 | if (buffers_allocated) |
2073 | return; | |
2074 | ||
2075 | if (alloc_percpu_trace_buffer()) | |
2076 | return; | |
2077 | ||
2184db46 SR |
2078 | /* trace_printk() is for debug use only. Don't use it in production. */ |
2079 | ||
a395d6a7 JP |
2080 | pr_warn("\n"); |
2081 | pr_warn("**********************************************************\n"); | |
2082 | pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); | |
2083 | pr_warn("** **\n"); | |
2084 | pr_warn("** trace_printk() being used. Allocating extra memory. **\n"); | |
2085 | pr_warn("** **\n"); | |
2086 | pr_warn("** This means that this is a DEBUG kernel and it is **\n"); | |
2087 | pr_warn("** unsafe for production use. **\n"); | |
2088 | pr_warn("** **\n"); | |
2089 | pr_warn("** If you see this message and you are not debugging **\n"); | |
2090 | pr_warn("** the kernel, report this immediately to your vendor! **\n"); | |
2091 | pr_warn("** **\n"); | |
2092 | pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); | |
2093 | pr_warn("**********************************************************\n"); | |
07d777fe | 2094 | |
b382ede6 SR |
2095 | /* Expand the buffers to set size */ |
2096 | tracing_update_buffers(); | |
2097 | ||
07d777fe | 2098 | buffers_allocated = 1; |
81698831 SR |
2099 | |
2100 | /* | |
2101 | * trace_printk_init_buffers() can be called by modules. | |
2102 | * If that happens, then we need to start cmdline recording | |
2103 | * directly here. If the global_trace.buffer is already | |
2104 | * allocated here, then this was called by module code. | |
2105 | */ | |
12883efb | 2106 | if (global_trace.trace_buffer.buffer) |
81698831 SR |
2107 | tracing_start_cmdline_record(); |
2108 | } | |
2109 | ||
2110 | void trace_printk_start_comm(void) | |
2111 | { | |
2112 | /* Start tracing comms if trace printk is set */ | |
2113 | if (!buffers_allocated) | |
2114 | return; | |
2115 | tracing_start_cmdline_record(); | |
2116 | } | |
2117 | ||
2118 | static void trace_printk_start_stop_comm(int enabled) | |
2119 | { | |
2120 | if (!buffers_allocated) | |
2121 | return; | |
2122 | ||
2123 | if (enabled) | |
2124 | tracing_start_cmdline_record(); | |
2125 | else | |
2126 | tracing_stop_cmdline_record(); | |
07d777fe SR |
2127 | } |
2128 | ||
769b0441 | 2129 | /** |
48ead020 | 2130 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
2131 | * |
2132 | */ | |
40ce74f1 | 2133 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 2134 | { |
2425bcb9 | 2135 | struct trace_event_call *call = &event_bprint; |
769b0441 | 2136 | struct ring_buffer_event *event; |
e77405ad | 2137 | struct ring_buffer *buffer; |
769b0441 | 2138 | struct trace_array *tr = &global_trace; |
48ead020 | 2139 | struct bprint_entry *entry; |
769b0441 | 2140 | unsigned long flags; |
07d777fe SR |
2141 | char *tbuffer; |
2142 | int len = 0, size, pc; | |
769b0441 FW |
2143 | |
2144 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
2145 | return 0; | |
2146 | ||
2147 | /* Don't pollute graph traces with trace_vprintk internals */ | |
2148 | pause_graph_tracing(); | |
2149 | ||
2150 | pc = preempt_count(); | |
5168ae50 | 2151 | preempt_disable_notrace(); |
769b0441 | 2152 | |
07d777fe SR |
2153 | tbuffer = get_trace_buf(); |
2154 | if (!tbuffer) { | |
2155 | len = 0; | |
769b0441 | 2156 | goto out; |
07d777fe | 2157 | } |
769b0441 | 2158 | |
07d777fe | 2159 | len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); |
769b0441 | 2160 | |
07d777fe SR |
2161 | if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) |
2162 | goto out; | |
769b0441 | 2163 | |
07d777fe | 2164 | local_save_flags(flags); |
769b0441 | 2165 | size = sizeof(*entry) + sizeof(u32) * len; |
12883efb | 2166 | buffer = tr->trace_buffer.buffer; |
e77405ad SR |
2167 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, |
2168 | flags, pc); | |
769b0441 | 2169 | if (!event) |
07d777fe | 2170 | goto out; |
769b0441 FW |
2171 | entry = ring_buffer_event_data(event); |
2172 | entry->ip = ip; | |
769b0441 FW |
2173 | entry->fmt = fmt; |
2174 | ||
07d777fe | 2175 | memcpy(entry->buf, tbuffer, sizeof(u32) * len); |
f306cc82 | 2176 | if (!call_filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 2177 | __buffer_unlock_commit(buffer, event); |
2d34f489 | 2178 | ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL); |
d931369b | 2179 | } |
769b0441 | 2180 | |
769b0441 | 2181 | out: |
5168ae50 | 2182 | preempt_enable_notrace(); |
769b0441 FW |
2183 | unpause_graph_tracing(); |
2184 | ||
2185 | return len; | |
2186 | } | |
48ead020 FW |
2187 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
2188 | ||
12883efb SRRH |
2189 | static int |
2190 | __trace_array_vprintk(struct ring_buffer *buffer, | |
2191 | unsigned long ip, const char *fmt, va_list args) | |
48ead020 | 2192 | { |
2425bcb9 | 2193 | struct trace_event_call *call = &event_print; |
48ead020 | 2194 | struct ring_buffer_event *event; |
07d777fe | 2195 | int len = 0, size, pc; |
48ead020 | 2196 | struct print_entry *entry; |
07d777fe SR |
2197 | unsigned long flags; |
2198 | char *tbuffer; | |
48ead020 FW |
2199 | |
2200 | if (tracing_disabled || tracing_selftest_running) | |
2201 | return 0; | |
2202 | ||
07d777fe SR |
2203 | /* Don't pollute graph traces with trace_vprintk internals */ |
2204 | pause_graph_tracing(); | |
2205 | ||
48ead020 FW |
2206 | pc = preempt_count(); |
2207 | preempt_disable_notrace(); | |
48ead020 | 2208 | |
07d777fe SR |
2209 | |
2210 | tbuffer = get_trace_buf(); | |
2211 | if (!tbuffer) { | |
2212 | len = 0; | |
48ead020 | 2213 | goto out; |
07d777fe | 2214 | } |
48ead020 | 2215 | |
3558a5ac | 2216 | len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); |
48ead020 | 2217 | |
07d777fe | 2218 | local_save_flags(flags); |
48ead020 | 2219 | size = sizeof(*entry) + len + 1; |
e77405ad | 2220 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
07d777fe | 2221 | flags, pc); |
48ead020 | 2222 | if (!event) |
07d777fe | 2223 | goto out; |
48ead020 | 2224 | entry = ring_buffer_event_data(event); |
c13d2f7c | 2225 | entry->ip = ip; |
48ead020 | 2226 | |
3558a5ac | 2227 | memcpy(&entry->buf, tbuffer, len + 1); |
f306cc82 | 2228 | if (!call_filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 2229 | __buffer_unlock_commit(buffer, event); |
2d34f489 | 2230 | ftrace_trace_stack(&global_trace, buffer, flags, 6, pc, NULL); |
d931369b | 2231 | } |
48ead020 FW |
2232 | out: |
2233 | preempt_enable_notrace(); | |
07d777fe | 2234 | unpause_graph_tracing(); |
48ead020 FW |
2235 | |
2236 | return len; | |
2237 | } | |
659372d3 | 2238 | |
12883efb SRRH |
2239 | int trace_array_vprintk(struct trace_array *tr, |
2240 | unsigned long ip, const char *fmt, va_list args) | |
2241 | { | |
2242 | return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args); | |
2243 | } | |
2244 | ||
2245 | int trace_array_printk(struct trace_array *tr, | |
2246 | unsigned long ip, const char *fmt, ...) | |
2247 | { | |
2248 | int ret; | |
2249 | va_list ap; | |
2250 | ||
983f938a | 2251 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
12883efb SRRH |
2252 | return 0; |
2253 | ||
2254 | va_start(ap, fmt); | |
2255 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
2256 | va_end(ap); | |
2257 | return ret; | |
2258 | } | |
2259 | ||
2260 | int trace_array_printk_buf(struct ring_buffer *buffer, | |
2261 | unsigned long ip, const char *fmt, ...) | |
2262 | { | |
2263 | int ret; | |
2264 | va_list ap; | |
2265 | ||
983f938a | 2266 | if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
12883efb SRRH |
2267 | return 0; |
2268 | ||
2269 | va_start(ap, fmt); | |
2270 | ret = __trace_array_vprintk(buffer, ip, fmt, ap); | |
2271 | va_end(ap); | |
2272 | return ret; | |
2273 | } | |
2274 | ||
659372d3 SR |
2275 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) |
2276 | { | |
a813a159 | 2277 | return trace_array_vprintk(&global_trace, ip, fmt, args); |
659372d3 | 2278 | } |
769b0441 FW |
2279 | EXPORT_SYMBOL_GPL(trace_vprintk); |
2280 | ||
e2ac8ef5 | 2281 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 2282 | { |
6d158a81 SR |
2283 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); |
2284 | ||
5a90f577 | 2285 | iter->idx++; |
6d158a81 SR |
2286 | if (buf_iter) |
2287 | ring_buffer_read(buf_iter, NULL); | |
5a90f577 SR |
2288 | } |
2289 | ||
e309b41d | 2290 | static struct trace_entry * |
bc21b478 SR |
2291 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, |
2292 | unsigned long *lost_events) | |
dd0e545f | 2293 | { |
3928a8a2 | 2294 | struct ring_buffer_event *event; |
6d158a81 | 2295 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); |
dd0e545f | 2296 | |
d769041f SR |
2297 | if (buf_iter) |
2298 | event = ring_buffer_iter_peek(buf_iter, ts); | |
2299 | else | |
12883efb | 2300 | event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts, |
bc21b478 | 2301 | lost_events); |
d769041f | 2302 | |
4a9bd3f1 SR |
2303 | if (event) { |
2304 | iter->ent_size = ring_buffer_event_length(event); | |
2305 | return ring_buffer_event_data(event); | |
2306 | } | |
2307 | iter->ent_size = 0; | |
2308 | return NULL; | |
dd0e545f | 2309 | } |
d769041f | 2310 | |
dd0e545f | 2311 | static struct trace_entry * |
bc21b478 SR |
2312 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, |
2313 | unsigned long *missing_events, u64 *ent_ts) | |
bc0c38d1 | 2314 | { |
12883efb | 2315 | struct ring_buffer *buffer = iter->trace_buffer->buffer; |
bc0c38d1 | 2316 | struct trace_entry *ent, *next = NULL; |
aa27497c | 2317 | unsigned long lost_events = 0, next_lost = 0; |
b04cc6b1 | 2318 | int cpu_file = iter->cpu_file; |
3928a8a2 | 2319 | u64 next_ts = 0, ts; |
bc0c38d1 | 2320 | int next_cpu = -1; |
12b5da34 | 2321 | int next_size = 0; |
bc0c38d1 SR |
2322 | int cpu; |
2323 | ||
b04cc6b1 FW |
2324 | /* |
2325 | * If we are in a per_cpu trace file, don't bother by iterating over | |
2326 | * all cpu and peek directly. | |
2327 | */ | |
ae3b5093 | 2328 | if (cpu_file > RING_BUFFER_ALL_CPUS) { |
b04cc6b1 FW |
2329 | if (ring_buffer_empty_cpu(buffer, cpu_file)) |
2330 | return NULL; | |
bc21b478 | 2331 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); |
b04cc6b1 FW |
2332 | if (ent_cpu) |
2333 | *ent_cpu = cpu_file; | |
2334 | ||
2335 | return ent; | |
2336 | } | |
2337 | ||
ab46428c | 2338 | for_each_tracing_cpu(cpu) { |
dd0e545f | 2339 | |
3928a8a2 SR |
2340 | if (ring_buffer_empty_cpu(buffer, cpu)) |
2341 | continue; | |
dd0e545f | 2342 | |
bc21b478 | 2343 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); |
dd0e545f | 2344 | |
cdd31cd2 IM |
2345 | /* |
2346 | * Pick the entry with the smallest timestamp: | |
2347 | */ | |
3928a8a2 | 2348 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
2349 | next = ent; |
2350 | next_cpu = cpu; | |
3928a8a2 | 2351 | next_ts = ts; |
bc21b478 | 2352 | next_lost = lost_events; |
12b5da34 | 2353 | next_size = iter->ent_size; |
bc0c38d1 SR |
2354 | } |
2355 | } | |
2356 | ||
12b5da34 SR |
2357 | iter->ent_size = next_size; |
2358 | ||
bc0c38d1 SR |
2359 | if (ent_cpu) |
2360 | *ent_cpu = next_cpu; | |
2361 | ||
3928a8a2 SR |
2362 | if (ent_ts) |
2363 | *ent_ts = next_ts; | |
2364 | ||
bc21b478 SR |
2365 | if (missing_events) |
2366 | *missing_events = next_lost; | |
2367 | ||
bc0c38d1 SR |
2368 | return next; |
2369 | } | |
2370 | ||
dd0e545f | 2371 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
2372 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
2373 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 2374 | { |
bc21b478 | 2375 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); |
dd0e545f SR |
2376 | } |
2377 | ||
2378 | /* Find the next real entry, and increment the iterator to the next entry */ | |
955b61e5 | 2379 | void *trace_find_next_entry_inc(struct trace_iterator *iter) |
dd0e545f | 2380 | { |
bc21b478 SR |
2381 | iter->ent = __find_next_entry(iter, &iter->cpu, |
2382 | &iter->lost_events, &iter->ts); | |
dd0e545f | 2383 | |
3928a8a2 | 2384 | if (iter->ent) |
e2ac8ef5 | 2385 | trace_iterator_increment(iter); |
dd0e545f | 2386 | |
3928a8a2 | 2387 | return iter->ent ? iter : NULL; |
b3806b43 | 2388 | } |
bc0c38d1 | 2389 | |
e309b41d | 2390 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 2391 | { |
12883efb | 2392 | ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts, |
bc21b478 | 2393 | &iter->lost_events); |
bc0c38d1 SR |
2394 | } |
2395 | ||
e309b41d | 2396 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
2397 | { |
2398 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 2399 | int i = (int)*pos; |
4e3c3333 | 2400 | void *ent; |
bc0c38d1 | 2401 | |
a63ce5b3 SR |
2402 | WARN_ON_ONCE(iter->leftover); |
2403 | ||
bc0c38d1 SR |
2404 | (*pos)++; |
2405 | ||
2406 | /* can't go backwards */ | |
2407 | if (iter->idx > i) | |
2408 | return NULL; | |
2409 | ||
2410 | if (iter->idx < 0) | |
955b61e5 | 2411 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
2412 | else |
2413 | ent = iter; | |
2414 | ||
2415 | while (ent && iter->idx < i) | |
955b61e5 | 2416 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
2417 | |
2418 | iter->pos = *pos; | |
2419 | ||
bc0c38d1 SR |
2420 | return ent; |
2421 | } | |
2422 | ||
955b61e5 | 2423 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
2f26ebd5 | 2424 | { |
2f26ebd5 SR |
2425 | struct ring_buffer_event *event; |
2426 | struct ring_buffer_iter *buf_iter; | |
2427 | unsigned long entries = 0; | |
2428 | u64 ts; | |
2429 | ||
12883efb | 2430 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0; |
2f26ebd5 | 2431 | |
6d158a81 SR |
2432 | buf_iter = trace_buffer_iter(iter, cpu); |
2433 | if (!buf_iter) | |
2f26ebd5 SR |
2434 | return; |
2435 | ||
2f26ebd5 SR |
2436 | ring_buffer_iter_reset(buf_iter); |
2437 | ||
2438 | /* | |
2439 | * We could have the case with the max latency tracers | |
2440 | * that a reset never took place on a cpu. This is evident | |
2441 | * by the timestamp being before the start of the buffer. | |
2442 | */ | |
2443 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
12883efb | 2444 | if (ts >= iter->trace_buffer->time_start) |
2f26ebd5 SR |
2445 | break; |
2446 | entries++; | |
2447 | ring_buffer_read(buf_iter, NULL); | |
2448 | } | |
2449 | ||
12883efb | 2450 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries; |
2f26ebd5 SR |
2451 | } |
2452 | ||
d7350c3f | 2453 | /* |
d7350c3f FW |
2454 | * The current tracer is copied to avoid a global locking |
2455 | * all around. | |
2456 | */ | |
bc0c38d1 SR |
2457 | static void *s_start(struct seq_file *m, loff_t *pos) |
2458 | { | |
2459 | struct trace_iterator *iter = m->private; | |
2b6080f2 | 2460 | struct trace_array *tr = iter->tr; |
b04cc6b1 | 2461 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
2462 | void *p = NULL; |
2463 | loff_t l = 0; | |
3928a8a2 | 2464 | int cpu; |
bc0c38d1 | 2465 | |
2fd196ec HT |
2466 | /* |
2467 | * copy the tracer to avoid using a global lock all around. | |
2468 | * iter->trace is a copy of current_trace, the pointer to the | |
2469 | * name may be used instead of a strcmp(), as iter->trace->name | |
2470 | * will point to the same string as current_trace->name. | |
2471 | */ | |
bc0c38d1 | 2472 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
2473 | if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) |
2474 | *iter->trace = *tr->current_trace; | |
d7350c3f | 2475 | mutex_unlock(&trace_types_lock); |
bc0c38d1 | 2476 | |
12883efb | 2477 | #ifdef CONFIG_TRACER_MAX_TRACE |
debdd57f HT |
2478 | if (iter->snapshot && iter->trace->use_max_tr) |
2479 | return ERR_PTR(-EBUSY); | |
12883efb | 2480 | #endif |
debdd57f HT |
2481 | |
2482 | if (!iter->snapshot) | |
2483 | atomic_inc(&trace_record_cmdline_disabled); | |
bc0c38d1 | 2484 | |
bc0c38d1 SR |
2485 | if (*pos != iter->pos) { |
2486 | iter->ent = NULL; | |
2487 | iter->cpu = 0; | |
2488 | iter->idx = -1; | |
2489 | ||
ae3b5093 | 2490 | if (cpu_file == RING_BUFFER_ALL_CPUS) { |
b04cc6b1 | 2491 | for_each_tracing_cpu(cpu) |
2f26ebd5 | 2492 | tracing_iter_reset(iter, cpu); |
b04cc6b1 | 2493 | } else |
2f26ebd5 | 2494 | tracing_iter_reset(iter, cpu_file); |
bc0c38d1 | 2495 | |
ac91d854 | 2496 | iter->leftover = 0; |
bc0c38d1 SR |
2497 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
2498 | ; | |
2499 | ||
2500 | } else { | |
a63ce5b3 SR |
2501 | /* |
2502 | * If we overflowed the seq_file before, then we want | |
2503 | * to just reuse the trace_seq buffer again. | |
2504 | */ | |
2505 | if (iter->leftover) | |
2506 | p = iter; | |
2507 | else { | |
2508 | l = *pos - 1; | |
2509 | p = s_next(m, p, &l); | |
2510 | } | |
bc0c38d1 SR |
2511 | } |
2512 | ||
4f535968 | 2513 | trace_event_read_lock(); |
7e53bd42 | 2514 | trace_access_lock(cpu_file); |
bc0c38d1 SR |
2515 | return p; |
2516 | } | |
2517 | ||
2518 | static void s_stop(struct seq_file *m, void *p) | |
2519 | { | |
7e53bd42 LJ |
2520 | struct trace_iterator *iter = m->private; |
2521 | ||
12883efb | 2522 | #ifdef CONFIG_TRACER_MAX_TRACE |
debdd57f HT |
2523 | if (iter->snapshot && iter->trace->use_max_tr) |
2524 | return; | |
12883efb | 2525 | #endif |
debdd57f HT |
2526 | |
2527 | if (!iter->snapshot) | |
2528 | atomic_dec(&trace_record_cmdline_disabled); | |
12883efb | 2529 | |
7e53bd42 | 2530 | trace_access_unlock(iter->cpu_file); |
4f535968 | 2531 | trace_event_read_unlock(); |
bc0c38d1 SR |
2532 | } |
2533 | ||
39eaf7ef | 2534 | static void |
12883efb SRRH |
2535 | get_total_entries(struct trace_buffer *buf, |
2536 | unsigned long *total, unsigned long *entries) | |
39eaf7ef SR |
2537 | { |
2538 | unsigned long count; | |
2539 | int cpu; | |
2540 | ||
2541 | *total = 0; | |
2542 | *entries = 0; | |
2543 | ||
2544 | for_each_tracing_cpu(cpu) { | |
12883efb | 2545 | count = ring_buffer_entries_cpu(buf->buffer, cpu); |
39eaf7ef SR |
2546 | /* |
2547 | * If this buffer has skipped entries, then we hold all | |
2548 | * entries for the trace and we need to ignore the | |
2549 | * ones before the time stamp. | |
2550 | */ | |
12883efb SRRH |
2551 | if (per_cpu_ptr(buf->data, cpu)->skipped_entries) { |
2552 | count -= per_cpu_ptr(buf->data, cpu)->skipped_entries; | |
39eaf7ef SR |
2553 | /* total is the same as the entries */ |
2554 | *total += count; | |
2555 | } else | |
2556 | *total += count + | |
12883efb | 2557 | ring_buffer_overrun_cpu(buf->buffer, cpu); |
39eaf7ef SR |
2558 | *entries += count; |
2559 | } | |
2560 | } | |
2561 | ||
e309b41d | 2562 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 2563 | { |
d79ac28f RV |
2564 | seq_puts(m, "# _------=> CPU# \n" |
2565 | "# / _-----=> irqs-off \n" | |
2566 | "# | / _----=> need-resched \n" | |
2567 | "# || / _---=> hardirq/softirq \n" | |
2568 | "# ||| / _--=> preempt-depth \n" | |
2569 | "# |||| / delay \n" | |
2570 | "# cmd pid ||||| time | caller \n" | |
2571 | "# \\ / ||||| \\ | / \n"); | |
bc0c38d1 SR |
2572 | } |
2573 | ||
12883efb | 2574 | static void print_event_info(struct trace_buffer *buf, struct seq_file *m) |
bc0c38d1 | 2575 | { |
39eaf7ef SR |
2576 | unsigned long total; |
2577 | unsigned long entries; | |
2578 | ||
12883efb | 2579 | get_total_entries(buf, &total, &entries); |
39eaf7ef SR |
2580 | seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", |
2581 | entries, total, num_online_cpus()); | |
2582 | seq_puts(m, "#\n"); | |
2583 | } | |
2584 | ||
12883efb | 2585 | static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m) |
39eaf7ef | 2586 | { |
12883efb | 2587 | print_event_info(buf, m); |
d79ac28f RV |
2588 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n" |
2589 | "# | | | | |\n"); | |
bc0c38d1 SR |
2590 | } |
2591 | ||
12883efb | 2592 | static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m) |
77271ce4 | 2593 | { |
12883efb | 2594 | print_event_info(buf, m); |
d79ac28f RV |
2595 | seq_puts(m, "# _-----=> irqs-off\n" |
2596 | "# / _----=> need-resched\n" | |
2597 | "# | / _---=> hardirq/softirq\n" | |
2598 | "# || / _--=> preempt-depth\n" | |
2599 | "# ||| / delay\n" | |
2600 | "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n" | |
2601 | "# | | | |||| | |\n"); | |
77271ce4 | 2602 | } |
bc0c38d1 | 2603 | |
62b915f1 | 2604 | void |
bc0c38d1 SR |
2605 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
2606 | { | |
983f938a | 2607 | unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK); |
12883efb SRRH |
2608 | struct trace_buffer *buf = iter->trace_buffer; |
2609 | struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu); | |
2b6080f2 | 2610 | struct tracer *type = iter->trace; |
39eaf7ef SR |
2611 | unsigned long entries; |
2612 | unsigned long total; | |
bc0c38d1 SR |
2613 | const char *name = "preemption"; |
2614 | ||
d840f718 | 2615 | name = type->name; |
bc0c38d1 | 2616 | |
12883efb | 2617 | get_total_entries(buf, &total, &entries); |
bc0c38d1 | 2618 | |
888b55dc | 2619 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 2620 | name, UTS_RELEASE); |
888b55dc | 2621 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 2622 | "---------------------------------\n"); |
888b55dc | 2623 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 2624 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 2625 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 2626 | entries, |
4c11d7ae | 2627 | total, |
12883efb | 2628 | buf->cpu, |
bc0c38d1 SR |
2629 | #if defined(CONFIG_PREEMPT_NONE) |
2630 | "server", | |
2631 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
2632 | "desktop", | |
b5c21b45 | 2633 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
2634 | "preempt", |
2635 | #else | |
2636 | "unknown", | |
2637 | #endif | |
2638 | /* These are reserved for later use */ | |
2639 | 0, 0, 0, 0); | |
2640 | #ifdef CONFIG_SMP | |
2641 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
2642 | #else | |
2643 | seq_puts(m, ")\n"); | |
2644 | #endif | |
888b55dc KM |
2645 | seq_puts(m, "# -----------------\n"); |
2646 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 | 2647 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
d20b92ab EB |
2648 | data->comm, data->pid, |
2649 | from_kuid_munged(seq_user_ns(m), data->uid), data->nice, | |
bc0c38d1 | 2650 | data->policy, data->rt_priority); |
888b55dc | 2651 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
2652 | |
2653 | if (data->critical_start) { | |
888b55dc | 2654 | seq_puts(m, "# => started at: "); |
214023c3 SR |
2655 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
2656 | trace_print_seq(m, &iter->seq); | |
888b55dc | 2657 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
2658 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
2659 | trace_print_seq(m, &iter->seq); | |
8248ac05 | 2660 | seq_puts(m, "\n#\n"); |
bc0c38d1 SR |
2661 | } |
2662 | ||
888b55dc | 2663 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
2664 | } |
2665 | ||
a309720c SR |
2666 | static void test_cpu_buff_start(struct trace_iterator *iter) |
2667 | { | |
2668 | struct trace_seq *s = &iter->seq; | |
983f938a | 2669 | struct trace_array *tr = iter->tr; |
a309720c | 2670 | |
983f938a | 2671 | if (!(tr->trace_flags & TRACE_ITER_ANNOTATE)) |
12ef7d44 SR |
2672 | return; |
2673 | ||
2674 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
2675 | return; | |
2676 | ||
919cd979 | 2677 | if (iter->started && cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
2678 | return; |
2679 | ||
12883efb | 2680 | if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries) |
2f26ebd5 SR |
2681 | return; |
2682 | ||
919cd979 SL |
2683 | if (iter->started) |
2684 | cpumask_set_cpu(iter->cpu, iter->started); | |
b0dfa978 FW |
2685 | |
2686 | /* Don't print started cpu buffer for the first entry of the trace */ | |
2687 | if (iter->idx > 1) | |
2688 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
2689 | iter->cpu); | |
a309720c SR |
2690 | } |
2691 | ||
2c4f035f | 2692 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 2693 | { |
983f938a | 2694 | struct trace_array *tr = iter->tr; |
214023c3 | 2695 | struct trace_seq *s = &iter->seq; |
983f938a | 2696 | unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 2697 | struct trace_entry *entry; |
f633cef0 | 2698 | struct trace_event *event; |
bc0c38d1 | 2699 | |
4e3c3333 | 2700 | entry = iter->ent; |
dd0e545f | 2701 | |
a309720c SR |
2702 | test_cpu_buff_start(iter); |
2703 | ||
c4a8e8be | 2704 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 2705 | |
983f938a | 2706 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
19a7fe20 SRRH |
2707 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) |
2708 | trace_print_lat_context(iter); | |
2709 | else | |
2710 | trace_print_context(iter); | |
c4a8e8be | 2711 | } |
bc0c38d1 | 2712 | |
19a7fe20 SRRH |
2713 | if (trace_seq_has_overflowed(s)) |
2714 | return TRACE_TYPE_PARTIAL_LINE; | |
2715 | ||
268ccda0 | 2716 | if (event) |
a9a57763 | 2717 | return event->funcs->trace(iter, sym_flags, event); |
d9793bd8 | 2718 | |
19a7fe20 | 2719 | trace_seq_printf(s, "Unknown type %d\n", entry->type); |
02b67518 | 2720 | |
19a7fe20 | 2721 | return trace_handle_return(s); |
bc0c38d1 SR |
2722 | } |
2723 | ||
2c4f035f | 2724 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 | 2725 | { |
983f938a | 2726 | struct trace_array *tr = iter->tr; |
f9896bf3 IM |
2727 | struct trace_seq *s = &iter->seq; |
2728 | struct trace_entry *entry; | |
f633cef0 | 2729 | struct trace_event *event; |
f9896bf3 IM |
2730 | |
2731 | entry = iter->ent; | |
dd0e545f | 2732 | |
983f938a | 2733 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) |
19a7fe20 SRRH |
2734 | trace_seq_printf(s, "%d %d %llu ", |
2735 | entry->pid, iter->cpu, iter->ts); | |
2736 | ||
2737 | if (trace_seq_has_overflowed(s)) | |
2738 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 | 2739 | |
f633cef0 | 2740 | event = ftrace_find_event(entry->type); |
268ccda0 | 2741 | if (event) |
a9a57763 | 2742 | return event->funcs->raw(iter, 0, event); |
d9793bd8 | 2743 | |
19a7fe20 | 2744 | trace_seq_printf(s, "%d ?\n", entry->type); |
777e208d | 2745 | |
19a7fe20 | 2746 | return trace_handle_return(s); |
f9896bf3 IM |
2747 | } |
2748 | ||
2c4f035f | 2749 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec | 2750 | { |
983f938a | 2751 | struct trace_array *tr = iter->tr; |
5e3ca0ec IM |
2752 | struct trace_seq *s = &iter->seq; |
2753 | unsigned char newline = '\n'; | |
2754 | struct trace_entry *entry; | |
f633cef0 | 2755 | struct trace_event *event; |
5e3ca0ec IM |
2756 | |
2757 | entry = iter->ent; | |
dd0e545f | 2758 | |
983f938a | 2759 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
19a7fe20 SRRH |
2760 | SEQ_PUT_HEX_FIELD(s, entry->pid); |
2761 | SEQ_PUT_HEX_FIELD(s, iter->cpu); | |
2762 | SEQ_PUT_HEX_FIELD(s, iter->ts); | |
2763 | if (trace_seq_has_overflowed(s)) | |
2764 | return TRACE_TYPE_PARTIAL_LINE; | |
c4a8e8be | 2765 | } |
5e3ca0ec | 2766 | |
f633cef0 | 2767 | event = ftrace_find_event(entry->type); |
268ccda0 | 2768 | if (event) { |
a9a57763 | 2769 | enum print_line_t ret = event->funcs->hex(iter, 0, event); |
d9793bd8 ACM |
2770 | if (ret != TRACE_TYPE_HANDLED) |
2771 | return ret; | |
2772 | } | |
7104f300 | 2773 | |
19a7fe20 | 2774 | SEQ_PUT_FIELD(s, newline); |
5e3ca0ec | 2775 | |
19a7fe20 | 2776 | return trace_handle_return(s); |
5e3ca0ec IM |
2777 | } |
2778 | ||
2c4f035f | 2779 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa | 2780 | { |
983f938a | 2781 | struct trace_array *tr = iter->tr; |
cb0f12aa IM |
2782 | struct trace_seq *s = &iter->seq; |
2783 | struct trace_entry *entry; | |
f633cef0 | 2784 | struct trace_event *event; |
cb0f12aa IM |
2785 | |
2786 | entry = iter->ent; | |
dd0e545f | 2787 | |
983f938a | 2788 | if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
19a7fe20 SRRH |
2789 | SEQ_PUT_FIELD(s, entry->pid); |
2790 | SEQ_PUT_FIELD(s, iter->cpu); | |
2791 | SEQ_PUT_FIELD(s, iter->ts); | |
2792 | if (trace_seq_has_overflowed(s)) | |
2793 | return TRACE_TYPE_PARTIAL_LINE; | |
c4a8e8be | 2794 | } |
cb0f12aa | 2795 | |
f633cef0 | 2796 | event = ftrace_find_event(entry->type); |
a9a57763 SR |
2797 | return event ? event->funcs->binary(iter, 0, event) : |
2798 | TRACE_TYPE_HANDLED; | |
cb0f12aa IM |
2799 | } |
2800 | ||
62b915f1 | 2801 | int trace_empty(struct trace_iterator *iter) |
bc0c38d1 | 2802 | { |
6d158a81 | 2803 | struct ring_buffer_iter *buf_iter; |
bc0c38d1 SR |
2804 | int cpu; |
2805 | ||
9aba60fe | 2806 | /* If we are looking at one CPU buffer, only check that one */ |
ae3b5093 | 2807 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
9aba60fe | 2808 | cpu = iter->cpu_file; |
6d158a81 SR |
2809 | buf_iter = trace_buffer_iter(iter, cpu); |
2810 | if (buf_iter) { | |
2811 | if (!ring_buffer_iter_empty(buf_iter)) | |
9aba60fe SR |
2812 | return 0; |
2813 | } else { | |
12883efb | 2814 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) |
9aba60fe SR |
2815 | return 0; |
2816 | } | |
2817 | return 1; | |
2818 | } | |
2819 | ||
ab46428c | 2820 | for_each_tracing_cpu(cpu) { |
6d158a81 SR |
2821 | buf_iter = trace_buffer_iter(iter, cpu); |
2822 | if (buf_iter) { | |
2823 | if (!ring_buffer_iter_empty(buf_iter)) | |
d769041f SR |
2824 | return 0; |
2825 | } else { | |
12883efb | 2826 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) |
d769041f SR |
2827 | return 0; |
2828 | } | |
bc0c38d1 | 2829 | } |
d769041f | 2830 | |
797d3712 | 2831 | return 1; |
bc0c38d1 SR |
2832 | } |
2833 | ||
4f535968 | 2834 | /* Called with trace_event_read_lock() held. */ |
955b61e5 | 2835 | enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 2836 | { |
983f938a SRRH |
2837 | struct trace_array *tr = iter->tr; |
2838 | unsigned long trace_flags = tr->trace_flags; | |
2c4f035f FW |
2839 | enum print_line_t ret; |
2840 | ||
19a7fe20 SRRH |
2841 | if (iter->lost_events) { |
2842 | trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2843 | iter->cpu, iter->lost_events); | |
2844 | if (trace_seq_has_overflowed(&iter->seq)) | |
2845 | return TRACE_TYPE_PARTIAL_LINE; | |
2846 | } | |
bc21b478 | 2847 | |
2c4f035f FW |
2848 | if (iter->trace && iter->trace->print_line) { |
2849 | ret = iter->trace->print_line(iter); | |
2850 | if (ret != TRACE_TYPE_UNHANDLED) | |
2851 | return ret; | |
2852 | } | |
72829bc3 | 2853 | |
09ae7234 SRRH |
2854 | if (iter->ent->type == TRACE_BPUTS && |
2855 | trace_flags & TRACE_ITER_PRINTK && | |
2856 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2857 | return trace_print_bputs_msg_only(iter); | |
2858 | ||
48ead020 FW |
2859 | if (iter->ent->type == TRACE_BPRINT && |
2860 | trace_flags & TRACE_ITER_PRINTK && | |
2861 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2862 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 2863 | |
66896a85 FW |
2864 | if (iter->ent->type == TRACE_PRINT && |
2865 | trace_flags & TRACE_ITER_PRINTK && | |
2866 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2867 | return trace_print_printk_msg_only(iter); |
66896a85 | 2868 | |
cb0f12aa IM |
2869 | if (trace_flags & TRACE_ITER_BIN) |
2870 | return print_bin_fmt(iter); | |
2871 | ||
5e3ca0ec IM |
2872 | if (trace_flags & TRACE_ITER_HEX) |
2873 | return print_hex_fmt(iter); | |
2874 | ||
f9896bf3 IM |
2875 | if (trace_flags & TRACE_ITER_RAW) |
2876 | return print_raw_fmt(iter); | |
2877 | ||
f9896bf3 IM |
2878 | return print_trace_fmt(iter); |
2879 | } | |
2880 | ||
7e9a49ef JO |
2881 | void trace_latency_header(struct seq_file *m) |
2882 | { | |
2883 | struct trace_iterator *iter = m->private; | |
983f938a | 2884 | struct trace_array *tr = iter->tr; |
7e9a49ef JO |
2885 | |
2886 | /* print nothing if the buffers are empty */ | |
2887 | if (trace_empty(iter)) | |
2888 | return; | |
2889 | ||
2890 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
2891 | print_trace_header(m, iter); | |
2892 | ||
983f938a | 2893 | if (!(tr->trace_flags & TRACE_ITER_VERBOSE)) |
7e9a49ef JO |
2894 | print_lat_help_header(m); |
2895 | } | |
2896 | ||
62b915f1 JO |
2897 | void trace_default_header(struct seq_file *m) |
2898 | { | |
2899 | struct trace_iterator *iter = m->private; | |
983f938a SRRH |
2900 | struct trace_array *tr = iter->tr; |
2901 | unsigned long trace_flags = tr->trace_flags; | |
62b915f1 | 2902 | |
f56e7f8e JO |
2903 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
2904 | return; | |
2905 | ||
62b915f1 JO |
2906 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2907 | /* print nothing if the buffers are empty */ | |
2908 | if (trace_empty(iter)) | |
2909 | return; | |
2910 | print_trace_header(m, iter); | |
2911 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2912 | print_lat_help_header(m); | |
2913 | } else { | |
77271ce4 SR |
2914 | if (!(trace_flags & TRACE_ITER_VERBOSE)) { |
2915 | if (trace_flags & TRACE_ITER_IRQ_INFO) | |
12883efb | 2916 | print_func_help_header_irq(iter->trace_buffer, m); |
77271ce4 | 2917 | else |
12883efb | 2918 | print_func_help_header(iter->trace_buffer, m); |
77271ce4 | 2919 | } |
62b915f1 JO |
2920 | } |
2921 | } | |
2922 | ||
e0a413f6 SR |
2923 | static void test_ftrace_alive(struct seq_file *m) |
2924 | { | |
2925 | if (!ftrace_is_dead()) | |
2926 | return; | |
d79ac28f RV |
2927 | seq_puts(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n" |
2928 | "# MAY BE MISSING FUNCTION EVENTS\n"); | |
e0a413f6 SR |
2929 | } |
2930 | ||
d8741e2e | 2931 | #ifdef CONFIG_TRACER_MAX_TRACE |
f1affcaa | 2932 | static void show_snapshot_main_help(struct seq_file *m) |
d8741e2e | 2933 | { |
d79ac28f RV |
2934 | seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n" |
2935 | "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" | |
2936 | "# Takes a snapshot of the main buffer.\n" | |
2937 | "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n" | |
2938 | "# (Doesn't have to be '2' works with any number that\n" | |
2939 | "# is not a '0' or '1')\n"); | |
d8741e2e | 2940 | } |
f1affcaa SRRH |
2941 | |
2942 | static void show_snapshot_percpu_help(struct seq_file *m) | |
2943 | { | |
fa6f0cc7 | 2944 | seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); |
f1affcaa | 2945 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
d79ac28f RV |
2946 | seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" |
2947 | "# Takes a snapshot of the main buffer for this cpu.\n"); | |
f1affcaa | 2948 | #else |
d79ac28f RV |
2949 | seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n" |
2950 | "# Must use main snapshot file to allocate.\n"); | |
f1affcaa | 2951 | #endif |
d79ac28f RV |
2952 | seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n" |
2953 | "# (Doesn't have to be '2' works with any number that\n" | |
2954 | "# is not a '0' or '1')\n"); | |
f1affcaa SRRH |
2955 | } |
2956 | ||
d8741e2e SRRH |
2957 | static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) |
2958 | { | |
45ad21ca | 2959 | if (iter->tr->allocated_snapshot) |
fa6f0cc7 | 2960 | seq_puts(m, "#\n# * Snapshot is allocated *\n#\n"); |
d8741e2e | 2961 | else |
fa6f0cc7 | 2962 | seq_puts(m, "#\n# * Snapshot is freed *\n#\n"); |
d8741e2e | 2963 | |
fa6f0cc7 | 2964 | seq_puts(m, "# Snapshot commands:\n"); |
f1affcaa SRRH |
2965 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
2966 | show_snapshot_main_help(m); | |
2967 | else | |
2968 | show_snapshot_percpu_help(m); | |
d8741e2e SRRH |
2969 | } |
2970 | #else | |
2971 | /* Should never be called */ | |
2972 | static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } | |
2973 | #endif | |
2974 | ||
bc0c38d1 SR |
2975 | static int s_show(struct seq_file *m, void *v) |
2976 | { | |
2977 | struct trace_iterator *iter = v; | |
a63ce5b3 | 2978 | int ret; |
bc0c38d1 SR |
2979 | |
2980 | if (iter->ent == NULL) { | |
2981 | if (iter->tr) { | |
2982 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2983 | seq_puts(m, "#\n"); | |
e0a413f6 | 2984 | test_ftrace_alive(m); |
bc0c38d1 | 2985 | } |
d8741e2e SRRH |
2986 | if (iter->snapshot && trace_empty(iter)) |
2987 | print_snapshot_help(m, iter); | |
2988 | else if (iter->trace && iter->trace->print_header) | |
8bba1bf5 | 2989 | iter->trace->print_header(m); |
62b915f1 JO |
2990 | else |
2991 | trace_default_header(m); | |
2992 | ||
a63ce5b3 SR |
2993 | } else if (iter->leftover) { |
2994 | /* | |
2995 | * If we filled the seq_file buffer earlier, we | |
2996 | * want to just show it now. | |
2997 | */ | |
2998 | ret = trace_print_seq(m, &iter->seq); | |
2999 | ||
3000 | /* ret should this time be zero, but you never know */ | |
3001 | iter->leftover = ret; | |
3002 | ||
bc0c38d1 | 3003 | } else { |
f9896bf3 | 3004 | print_trace_line(iter); |
a63ce5b3 SR |
3005 | ret = trace_print_seq(m, &iter->seq); |
3006 | /* | |
3007 | * If we overflow the seq_file buffer, then it will | |
3008 | * ask us for this data again at start up. | |
3009 | * Use that instead. | |
3010 | * ret is 0 if seq_file write succeeded. | |
3011 | * -1 otherwise. | |
3012 | */ | |
3013 | iter->leftover = ret; | |
bc0c38d1 SR |
3014 | } |
3015 | ||
3016 | return 0; | |
3017 | } | |
3018 | ||
649e9c70 ON |
3019 | /* |
3020 | * Should be used after trace_array_get(), trace_types_lock | |
3021 | * ensures that i_cdev was already initialized. | |
3022 | */ | |
3023 | static inline int tracing_get_cpu(struct inode *inode) | |
3024 | { | |
3025 | if (inode->i_cdev) /* See trace_create_cpu_file() */ | |
3026 | return (long)inode->i_cdev - 1; | |
3027 | return RING_BUFFER_ALL_CPUS; | |
3028 | } | |
3029 | ||
88e9d34c | 3030 | static const struct seq_operations tracer_seq_ops = { |
4bf39a94 IM |
3031 | .start = s_start, |
3032 | .next = s_next, | |
3033 | .stop = s_stop, | |
3034 | .show = s_show, | |
bc0c38d1 SR |
3035 | }; |
3036 | ||
e309b41d | 3037 | static struct trace_iterator * |
6484c71c | 3038 | __tracing_open(struct inode *inode, struct file *file, bool snapshot) |
bc0c38d1 | 3039 | { |
6484c71c | 3040 | struct trace_array *tr = inode->i_private; |
bc0c38d1 | 3041 | struct trace_iterator *iter; |
50e18b94 | 3042 | int cpu; |
bc0c38d1 | 3043 | |
85a2f9b4 SR |
3044 | if (tracing_disabled) |
3045 | return ERR_PTR(-ENODEV); | |
60a11774 | 3046 | |
50e18b94 | 3047 | iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); |
85a2f9b4 SR |
3048 | if (!iter) |
3049 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 3050 | |
72917235 | 3051 | iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter), |
6d158a81 | 3052 | GFP_KERNEL); |
93574fcc DC |
3053 | if (!iter->buffer_iter) |
3054 | goto release; | |
3055 | ||
d7350c3f FW |
3056 | /* |
3057 | * We make a copy of the current tracer to avoid concurrent | |
3058 | * changes on it while we are reading. | |
3059 | */ | |
bc0c38d1 | 3060 | mutex_lock(&trace_types_lock); |
d7350c3f | 3061 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 3062 | if (!iter->trace) |
d7350c3f | 3063 | goto fail; |
85a2f9b4 | 3064 | |
2b6080f2 | 3065 | *iter->trace = *tr->current_trace; |
d7350c3f | 3066 | |
79f55997 | 3067 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
b0dfa978 FW |
3068 | goto fail; |
3069 | ||
12883efb SRRH |
3070 | iter->tr = tr; |
3071 | ||
3072 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2b6080f2 SR |
3073 | /* Currently only the top directory has a snapshot */ |
3074 | if (tr->current_trace->print_max || snapshot) | |
12883efb | 3075 | iter->trace_buffer = &tr->max_buffer; |
bc0c38d1 | 3076 | else |
12883efb SRRH |
3077 | #endif |
3078 | iter->trace_buffer = &tr->trace_buffer; | |
debdd57f | 3079 | iter->snapshot = snapshot; |
bc0c38d1 | 3080 | iter->pos = -1; |
6484c71c | 3081 | iter->cpu_file = tracing_get_cpu(inode); |
d7350c3f | 3082 | mutex_init(&iter->mutex); |
bc0c38d1 | 3083 | |
8bba1bf5 MM |
3084 | /* Notify the tracer early; before we stop tracing. */ |
3085 | if (iter->trace && iter->trace->open) | |
a93751ca | 3086 | iter->trace->open(iter); |
8bba1bf5 | 3087 | |
12ef7d44 | 3088 | /* Annotate start of buffers if we had overruns */ |
12883efb | 3089 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) |
12ef7d44 SR |
3090 | iter->iter_flags |= TRACE_FILE_ANNOTATE; |
3091 | ||
8be0709f | 3092 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
58e8eedf | 3093 | if (trace_clocks[tr->clock_id].in_ns) |
8be0709f DS |
3094 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
3095 | ||
debdd57f HT |
3096 | /* stop the trace while dumping if we are not opening "snapshot" */ |
3097 | if (!iter->snapshot) | |
2b6080f2 | 3098 | tracing_stop_tr(tr); |
2f26ebd5 | 3099 | |
ae3b5093 | 3100 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { |
b04cc6b1 | 3101 | for_each_tracing_cpu(cpu) { |
b04cc6b1 | 3102 | iter->buffer_iter[cpu] = |
12883efb | 3103 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); |
72c9ddfd DM |
3104 | } |
3105 | ring_buffer_read_prepare_sync(); | |
3106 | for_each_tracing_cpu(cpu) { | |
3107 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 3108 | tracing_iter_reset(iter, cpu); |
b04cc6b1 FW |
3109 | } |
3110 | } else { | |
3111 | cpu = iter->cpu_file; | |
3928a8a2 | 3112 | iter->buffer_iter[cpu] = |
12883efb | 3113 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); |
72c9ddfd DM |
3114 | ring_buffer_read_prepare_sync(); |
3115 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 3116 | tracing_iter_reset(iter, cpu); |
3928a8a2 SR |
3117 | } |
3118 | ||
bc0c38d1 SR |
3119 | mutex_unlock(&trace_types_lock); |
3120 | ||
bc0c38d1 | 3121 | return iter; |
3928a8a2 | 3122 | |
d7350c3f | 3123 | fail: |
3928a8a2 | 3124 | mutex_unlock(&trace_types_lock); |
d7350c3f | 3125 | kfree(iter->trace); |
6d158a81 | 3126 | kfree(iter->buffer_iter); |
93574fcc | 3127 | release: |
50e18b94 JO |
3128 | seq_release_private(inode, file); |
3129 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 SR |
3130 | } |
3131 | ||
3132 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
3133 | { | |
60a11774 SR |
3134 | if (tracing_disabled) |
3135 | return -ENODEV; | |
3136 | ||
bc0c38d1 SR |
3137 | filp->private_data = inode->i_private; |
3138 | return 0; | |
3139 | } | |
3140 | ||
2e86421d GB |
3141 | bool tracing_is_disabled(void) |
3142 | { | |
3143 | return (tracing_disabled) ? true: false; | |
3144 | } | |
3145 | ||
7b85af63 SRRH |
3146 | /* |
3147 | * Open and update trace_array ref count. | |
3148 | * Must have the current trace_array passed to it. | |
3149 | */ | |
dcc30223 | 3150 | static int tracing_open_generic_tr(struct inode *inode, struct file *filp) |
7b85af63 SRRH |
3151 | { |
3152 | struct trace_array *tr = inode->i_private; | |
3153 | ||
3154 | if (tracing_disabled) | |
3155 | return -ENODEV; | |
3156 | ||
3157 | if (trace_array_get(tr) < 0) | |
3158 | return -ENODEV; | |
3159 | ||
3160 | filp->private_data = inode->i_private; | |
3161 | ||
3162 | return 0; | |
7b85af63 SRRH |
3163 | } |
3164 | ||
4fd27358 | 3165 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 | 3166 | { |
6484c71c | 3167 | struct trace_array *tr = inode->i_private; |
907f2784 | 3168 | struct seq_file *m = file->private_data; |
4acd4d00 | 3169 | struct trace_iterator *iter; |
3928a8a2 | 3170 | int cpu; |
bc0c38d1 | 3171 | |
ff451961 | 3172 | if (!(file->f_mode & FMODE_READ)) { |
6484c71c | 3173 | trace_array_put(tr); |
4acd4d00 | 3174 | return 0; |
ff451961 | 3175 | } |
4acd4d00 | 3176 | |
6484c71c | 3177 | /* Writes do not use seq_file */ |
4acd4d00 | 3178 | iter = m->private; |
bc0c38d1 | 3179 | mutex_lock(&trace_types_lock); |
a695cb58 | 3180 | |
3928a8a2 SR |
3181 | for_each_tracing_cpu(cpu) { |
3182 | if (iter->buffer_iter[cpu]) | |
3183 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
3184 | } | |
3185 | ||
bc0c38d1 SR |
3186 | if (iter->trace && iter->trace->close) |
3187 | iter->trace->close(iter); | |
3188 | ||
debdd57f HT |
3189 | if (!iter->snapshot) |
3190 | /* reenable tracing if it was previously enabled */ | |
2b6080f2 | 3191 | tracing_start_tr(tr); |
f77d09a3 AL |
3192 | |
3193 | __trace_array_put(tr); | |
3194 | ||
bc0c38d1 SR |
3195 | mutex_unlock(&trace_types_lock); |
3196 | ||
d7350c3f | 3197 | mutex_destroy(&iter->mutex); |
b0dfa978 | 3198 | free_cpumask_var(iter->started); |
d7350c3f | 3199 | kfree(iter->trace); |
6d158a81 | 3200 | kfree(iter->buffer_iter); |
50e18b94 | 3201 | seq_release_private(inode, file); |
ff451961 | 3202 | |
bc0c38d1 SR |
3203 | return 0; |
3204 | } | |
3205 | ||
7b85af63 SRRH |
3206 | static int tracing_release_generic_tr(struct inode *inode, struct file *file) |
3207 | { | |
3208 | struct trace_array *tr = inode->i_private; | |
3209 | ||
3210 | trace_array_put(tr); | |
bc0c38d1 SR |
3211 | return 0; |
3212 | } | |
3213 | ||
7b85af63 SRRH |
3214 | static int tracing_single_release_tr(struct inode *inode, struct file *file) |
3215 | { | |
3216 | struct trace_array *tr = inode->i_private; | |
3217 | ||
3218 | trace_array_put(tr); | |
3219 | ||
3220 | return single_release(inode, file); | |
3221 | } | |
3222 | ||
bc0c38d1 SR |
3223 | static int tracing_open(struct inode *inode, struct file *file) |
3224 | { | |
6484c71c | 3225 | struct trace_array *tr = inode->i_private; |
85a2f9b4 SR |
3226 | struct trace_iterator *iter; |
3227 | int ret = 0; | |
bc0c38d1 | 3228 | |
ff451961 SRRH |
3229 | if (trace_array_get(tr) < 0) |
3230 | return -ENODEV; | |
3231 | ||
4acd4d00 | 3232 | /* If this file was open for write, then erase contents */ |
6484c71c ON |
3233 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
3234 | int cpu = tracing_get_cpu(inode); | |
3235 | ||
3236 | if (cpu == RING_BUFFER_ALL_CPUS) | |
12883efb | 3237 | tracing_reset_online_cpus(&tr->trace_buffer); |
4acd4d00 | 3238 | else |
6484c71c | 3239 | tracing_reset(&tr->trace_buffer, cpu); |
4acd4d00 | 3240 | } |
bc0c38d1 | 3241 | |
4acd4d00 | 3242 | if (file->f_mode & FMODE_READ) { |
6484c71c | 3243 | iter = __tracing_open(inode, file, false); |
4acd4d00 SR |
3244 | if (IS_ERR(iter)) |
3245 | ret = PTR_ERR(iter); | |
983f938a | 3246 | else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
4acd4d00 SR |
3247 | iter->iter_flags |= TRACE_FILE_LAT_FMT; |
3248 | } | |
ff451961 SRRH |
3249 | |
3250 | if (ret < 0) | |
3251 | trace_array_put(tr); | |
3252 | ||
bc0c38d1 SR |
3253 | return ret; |
3254 | } | |
3255 | ||
607e2ea1 SRRH |
3256 | /* |
3257 | * Some tracers are not suitable for instance buffers. | |
3258 | * A tracer is always available for the global array (toplevel) | |
3259 | * or if it explicitly states that it is. | |
3260 | */ | |
3261 | static bool | |
3262 | trace_ok_for_array(struct tracer *t, struct trace_array *tr) | |
3263 | { | |
3264 | return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances; | |
3265 | } | |
3266 | ||
3267 | /* Find the next tracer that this trace array may use */ | |
3268 | static struct tracer * | |
3269 | get_tracer_for_array(struct trace_array *tr, struct tracer *t) | |
3270 | { | |
3271 | while (t && !trace_ok_for_array(t, tr)) | |
3272 | t = t->next; | |
3273 | ||
3274 | return t; | |
3275 | } | |
3276 | ||
e309b41d | 3277 | static void * |
bc0c38d1 SR |
3278 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3279 | { | |
607e2ea1 | 3280 | struct trace_array *tr = m->private; |
f129e965 | 3281 | struct tracer *t = v; |
bc0c38d1 SR |
3282 | |
3283 | (*pos)++; | |
3284 | ||
3285 | if (t) | |
607e2ea1 | 3286 | t = get_tracer_for_array(tr, t->next); |
bc0c38d1 | 3287 | |
bc0c38d1 SR |
3288 | return t; |
3289 | } | |
3290 | ||
3291 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3292 | { | |
607e2ea1 | 3293 | struct trace_array *tr = m->private; |
f129e965 | 3294 | struct tracer *t; |
bc0c38d1 SR |
3295 | loff_t l = 0; |
3296 | ||
3297 | mutex_lock(&trace_types_lock); | |
607e2ea1 SRRH |
3298 | |
3299 | t = get_tracer_for_array(tr, trace_types); | |
3300 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
3301 | ; | |
bc0c38d1 SR |
3302 | |
3303 | return t; | |
3304 | } | |
3305 | ||
3306 | static void t_stop(struct seq_file *m, void *p) | |
3307 | { | |
3308 | mutex_unlock(&trace_types_lock); | |
3309 | } | |
3310 | ||
3311 | static int t_show(struct seq_file *m, void *v) | |
3312 | { | |
3313 | struct tracer *t = v; | |
3314 | ||
3315 | if (!t) | |
3316 | return 0; | |
3317 | ||
fa6f0cc7 | 3318 | seq_puts(m, t->name); |
bc0c38d1 SR |
3319 | if (t->next) |
3320 | seq_putc(m, ' '); | |
3321 | else | |
3322 | seq_putc(m, '\n'); | |
3323 | ||
3324 | return 0; | |
3325 | } | |
3326 | ||
88e9d34c | 3327 | static const struct seq_operations show_traces_seq_ops = { |
4bf39a94 IM |
3328 | .start = t_start, |
3329 | .next = t_next, | |
3330 | .stop = t_stop, | |
3331 | .show = t_show, | |
bc0c38d1 SR |
3332 | }; |
3333 | ||
3334 | static int show_traces_open(struct inode *inode, struct file *file) | |
3335 | { | |
607e2ea1 SRRH |
3336 | struct trace_array *tr = inode->i_private; |
3337 | struct seq_file *m; | |
3338 | int ret; | |
3339 | ||
60a11774 SR |
3340 | if (tracing_disabled) |
3341 | return -ENODEV; | |
3342 | ||
607e2ea1 SRRH |
3343 | ret = seq_open(file, &show_traces_seq_ops); |
3344 | if (ret) | |
3345 | return ret; | |
3346 | ||
3347 | m = file->private_data; | |
3348 | m->private = tr; | |
3349 | ||
3350 | return 0; | |
bc0c38d1 SR |
3351 | } |
3352 | ||
4acd4d00 SR |
3353 | static ssize_t |
3354 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
3355 | size_t count, loff_t *ppos) | |
3356 | { | |
3357 | return count; | |
3358 | } | |
3359 | ||
098c879e | 3360 | loff_t tracing_lseek(struct file *file, loff_t offset, int whence) |
364829b1 | 3361 | { |
098c879e SRRH |
3362 | int ret; |
3363 | ||
364829b1 | 3364 | if (file->f_mode & FMODE_READ) |
098c879e | 3365 | ret = seq_lseek(file, offset, whence); |
364829b1 | 3366 | else |
098c879e SRRH |
3367 | file->f_pos = ret = 0; |
3368 | ||
3369 | return ret; | |
364829b1 SP |
3370 | } |
3371 | ||
5e2336a0 | 3372 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
3373 | .open = tracing_open, |
3374 | .read = seq_read, | |
4acd4d00 | 3375 | .write = tracing_write_stub, |
098c879e | 3376 | .llseek = tracing_lseek, |
4bf39a94 | 3377 | .release = tracing_release, |
bc0c38d1 SR |
3378 | }; |
3379 | ||
5e2336a0 | 3380 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
3381 | .open = show_traces_open, |
3382 | .read = seq_read, | |
3383 | .release = seq_release, | |
b444786f | 3384 | .llseek = seq_lseek, |
c7078de1 IM |
3385 | }; |
3386 | ||
36dfe925 IM |
3387 | /* |
3388 | * The tracer itself will not take this lock, but still we want | |
3389 | * to provide a consistent cpumask to user-space: | |
3390 | */ | |
3391 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
3392 | ||
3393 | /* | |
3394 | * Temporary storage for the character representation of the | |
3395 | * CPU bitmask (and one more byte for the newline): | |
3396 | */ | |
3397 | static char mask_str[NR_CPUS + 1]; | |
3398 | ||
c7078de1 IM |
3399 | static ssize_t |
3400 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
3401 | size_t count, loff_t *ppos) | |
3402 | { | |
ccfe9e42 | 3403 | struct trace_array *tr = file_inode(filp)->i_private; |
36dfe925 | 3404 | int len; |
c7078de1 IM |
3405 | |
3406 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 3407 | |
1a40243b TH |
3408 | len = snprintf(mask_str, count, "%*pb\n", |
3409 | cpumask_pr_args(tr->tracing_cpumask)); | |
3410 | if (len >= count) { | |
36dfe925 IM |
3411 | count = -EINVAL; |
3412 | goto out_err; | |
3413 | } | |
36dfe925 IM |
3414 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); |
3415 | ||
3416 | out_err: | |
c7078de1 IM |
3417 | mutex_unlock(&tracing_cpumask_update_lock); |
3418 | ||
3419 | return count; | |
3420 | } | |
3421 | ||
3422 | static ssize_t | |
3423 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
3424 | size_t count, loff_t *ppos) | |
3425 | { | |
ccfe9e42 | 3426 | struct trace_array *tr = file_inode(filp)->i_private; |
9e01c1b7 | 3427 | cpumask_var_t tracing_cpumask_new; |
2b6080f2 | 3428 | int err, cpu; |
9e01c1b7 RR |
3429 | |
3430 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
3431 | return -ENOMEM; | |
c7078de1 | 3432 | |
9e01c1b7 | 3433 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 3434 | if (err) |
36dfe925 IM |
3435 | goto err_unlock; |
3436 | ||
215368e8 LZ |
3437 | mutex_lock(&tracing_cpumask_update_lock); |
3438 | ||
a5e25883 | 3439 | local_irq_disable(); |
0b9b12c1 | 3440 | arch_spin_lock(&tr->max_lock); |
ab46428c | 3441 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
3442 | /* |
3443 | * Increase/decrease the disabled counter if we are | |
3444 | * about to flip a bit in the cpumask: | |
3445 | */ | |
ccfe9e42 | 3446 | if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
9e01c1b7 | 3447 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
12883efb SRRH |
3448 | atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); |
3449 | ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu); | |
36dfe925 | 3450 | } |
ccfe9e42 | 3451 | if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
9e01c1b7 | 3452 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
12883efb SRRH |
3453 | atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); |
3454 | ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu); | |
36dfe925 IM |
3455 | } |
3456 | } | |
0b9b12c1 | 3457 | arch_spin_unlock(&tr->max_lock); |
a5e25883 | 3458 | local_irq_enable(); |
36dfe925 | 3459 | |
ccfe9e42 | 3460 | cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
3461 | |
3462 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 3463 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
3464 | |
3465 | return count; | |
36dfe925 IM |
3466 | |
3467 | err_unlock: | |
215368e8 | 3468 | free_cpumask_var(tracing_cpumask_new); |
36dfe925 IM |
3469 | |
3470 | return err; | |
c7078de1 IM |
3471 | } |
3472 | ||
5e2336a0 | 3473 | static const struct file_operations tracing_cpumask_fops = { |
ccfe9e42 | 3474 | .open = tracing_open_generic_tr, |
c7078de1 IM |
3475 | .read = tracing_cpumask_read, |
3476 | .write = tracing_cpumask_write, | |
ccfe9e42 | 3477 | .release = tracing_release_generic_tr, |
b444786f | 3478 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
3479 | }; |
3480 | ||
fdb372ed | 3481 | static int tracing_trace_options_show(struct seq_file *m, void *v) |
bc0c38d1 | 3482 | { |
d8e83d26 | 3483 | struct tracer_opt *trace_opts; |
2b6080f2 | 3484 | struct trace_array *tr = m->private; |
d8e83d26 | 3485 | u32 tracer_flags; |
d8e83d26 | 3486 | int i; |
adf9f195 | 3487 | |
d8e83d26 | 3488 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
3489 | tracer_flags = tr->current_trace->flags->val; |
3490 | trace_opts = tr->current_trace->flags->opts; | |
d8e83d26 | 3491 | |
bc0c38d1 | 3492 | for (i = 0; trace_options[i]; i++) { |
983f938a | 3493 | if (tr->trace_flags & (1 << i)) |
fdb372ed | 3494 | seq_printf(m, "%s\n", trace_options[i]); |
bc0c38d1 | 3495 | else |
fdb372ed | 3496 | seq_printf(m, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
3497 | } |
3498 | ||
adf9f195 FW |
3499 | for (i = 0; trace_opts[i].name; i++) { |
3500 | if (tracer_flags & trace_opts[i].bit) | |
fdb372ed | 3501 | seq_printf(m, "%s\n", trace_opts[i].name); |
adf9f195 | 3502 | else |
fdb372ed | 3503 | seq_printf(m, "no%s\n", trace_opts[i].name); |
adf9f195 | 3504 | } |
d8e83d26 | 3505 | mutex_unlock(&trace_types_lock); |
adf9f195 | 3506 | |
fdb372ed | 3507 | return 0; |
bc0c38d1 | 3508 | } |
bc0c38d1 | 3509 | |
8c1a49ae | 3510 | static int __set_tracer_option(struct trace_array *tr, |
8d18eaaf LZ |
3511 | struct tracer_flags *tracer_flags, |
3512 | struct tracer_opt *opts, int neg) | |
3513 | { | |
d39cdd20 | 3514 | struct tracer *trace = tracer_flags->trace; |
8d18eaaf | 3515 | int ret; |
bc0c38d1 | 3516 | |
8c1a49ae | 3517 | ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg); |
8d18eaaf LZ |
3518 | if (ret) |
3519 | return ret; | |
3520 | ||
3521 | if (neg) | |
3522 | tracer_flags->val &= ~opts->bit; | |
3523 | else | |
3524 | tracer_flags->val |= opts->bit; | |
3525 | return 0; | |
bc0c38d1 SR |
3526 | } |
3527 | ||
adf9f195 | 3528 | /* Try to assign a tracer specific option */ |
8c1a49ae | 3529 | static int set_tracer_option(struct trace_array *tr, char *cmp, int neg) |
adf9f195 | 3530 | { |
8c1a49ae | 3531 | struct tracer *trace = tr->current_trace; |
7770841e | 3532 | struct tracer_flags *tracer_flags = trace->flags; |
adf9f195 | 3533 | struct tracer_opt *opts = NULL; |
8d18eaaf | 3534 | int i; |
adf9f195 | 3535 | |
7770841e Z |
3536 | for (i = 0; tracer_flags->opts[i].name; i++) { |
3537 | opts = &tracer_flags->opts[i]; | |
adf9f195 | 3538 | |
8d18eaaf | 3539 | if (strcmp(cmp, opts->name) == 0) |
8c1a49ae | 3540 | return __set_tracer_option(tr, trace->flags, opts, neg); |
adf9f195 | 3541 | } |
adf9f195 | 3542 | |
8d18eaaf | 3543 | return -EINVAL; |
adf9f195 FW |
3544 | } |
3545 | ||
613f04a0 SRRH |
3546 | /* Some tracers require overwrite to stay enabled */ |
3547 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) | |
3548 | { | |
3549 | if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) | |
3550 | return -1; | |
3551 | ||
3552 | return 0; | |
3553 | } | |
3554 | ||
2b6080f2 | 3555 | int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) |
af4617bd SR |
3556 | { |
3557 | /* do nothing if flag is already set */ | |
983f938a | 3558 | if (!!(tr->trace_flags & mask) == !!enabled) |
613f04a0 SRRH |
3559 | return 0; |
3560 | ||
3561 | /* Give the tracer a chance to approve the change */ | |
2b6080f2 | 3562 | if (tr->current_trace->flag_changed) |
bf6065b5 | 3563 | if (tr->current_trace->flag_changed(tr, mask, !!enabled)) |
613f04a0 | 3564 | return -EINVAL; |
af4617bd SR |
3565 | |
3566 | if (enabled) | |
983f938a | 3567 | tr->trace_flags |= mask; |
af4617bd | 3568 | else |
983f938a | 3569 | tr->trace_flags &= ~mask; |
e870e9a1 LZ |
3570 | |
3571 | if (mask == TRACE_ITER_RECORD_CMD) | |
3572 | trace_event_enable_cmd_record(enabled); | |
750912fa | 3573 | |
c37775d5 SR |
3574 | if (mask == TRACE_ITER_EVENT_FORK) |
3575 | trace_event_follow_fork(tr, enabled); | |
3576 | ||
80902822 | 3577 | if (mask == TRACE_ITER_OVERWRITE) { |
12883efb | 3578 | ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); |
80902822 | 3579 | #ifdef CONFIG_TRACER_MAX_TRACE |
12883efb | 3580 | ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled); |
80902822 SRRH |
3581 | #endif |
3582 | } | |
81698831 | 3583 | |
b9f9108c | 3584 | if (mask == TRACE_ITER_PRINTK) { |
81698831 | 3585 | trace_printk_start_stop_comm(enabled); |
b9f9108c SRRH |
3586 | trace_printk_control(enabled); |
3587 | } | |
613f04a0 SRRH |
3588 | |
3589 | return 0; | |
af4617bd SR |
3590 | } |
3591 | ||
2b6080f2 | 3592 | static int trace_set_options(struct trace_array *tr, char *option) |
bc0c38d1 | 3593 | { |
8d18eaaf | 3594 | char *cmp; |
bc0c38d1 | 3595 | int neg = 0; |
613f04a0 | 3596 | int ret = -ENODEV; |
bc0c38d1 | 3597 | int i; |
a4d1e688 | 3598 | size_t orig_len = strlen(option); |
bc0c38d1 | 3599 | |
7bcfaf54 | 3600 | cmp = strstrip(option); |
bc0c38d1 | 3601 | |
8d18eaaf | 3602 | if (strncmp(cmp, "no", 2) == 0) { |
bc0c38d1 SR |
3603 | neg = 1; |
3604 | cmp += 2; | |
3605 | } | |
3606 | ||
69d34da2 SRRH |
3607 | mutex_lock(&trace_types_lock); |
3608 | ||
bc0c38d1 | 3609 | for (i = 0; trace_options[i]; i++) { |
8d18eaaf | 3610 | if (strcmp(cmp, trace_options[i]) == 0) { |
2b6080f2 | 3611 | ret = set_tracer_flag(tr, 1 << i, !neg); |
bc0c38d1 SR |
3612 | break; |
3613 | } | |
3614 | } | |
adf9f195 FW |
3615 | |
3616 | /* If no option could be set, test the specific tracer options */ | |
69d34da2 | 3617 | if (!trace_options[i]) |
8c1a49ae | 3618 | ret = set_tracer_option(tr, cmp, neg); |
69d34da2 SRRH |
3619 | |
3620 | mutex_unlock(&trace_types_lock); | |
bc0c38d1 | 3621 | |
a4d1e688 JW |
3622 | /* |
3623 | * If the first trailing whitespace is replaced with '\0' by strstrip, | |
3624 | * turn it back into a space. | |
3625 | */ | |
3626 | if (orig_len > strlen(option)) | |
3627 | option[strlen(option)] = ' '; | |
3628 | ||
7bcfaf54 SR |
3629 | return ret; |
3630 | } | |
3631 | ||
a4d1e688 JW |
3632 | static void __init apply_trace_boot_options(void) |
3633 | { | |
3634 | char *buf = trace_boot_options_buf; | |
3635 | char *option; | |
3636 | ||
3637 | while (true) { | |
3638 | option = strsep(&buf, ","); | |
3639 | ||
3640 | if (!option) | |
3641 | break; | |
a4d1e688 | 3642 | |
43ed3843 SRRH |
3643 | if (*option) |
3644 | trace_set_options(&global_trace, option); | |
a4d1e688 JW |
3645 | |
3646 | /* Put back the comma to allow this to be called again */ | |
3647 | if (buf) | |
3648 | *(buf - 1) = ','; | |
3649 | } | |
3650 | } | |
3651 | ||
7bcfaf54 SR |
3652 | static ssize_t |
3653 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, | |
3654 | size_t cnt, loff_t *ppos) | |
3655 | { | |
2b6080f2 SR |
3656 | struct seq_file *m = filp->private_data; |
3657 | struct trace_array *tr = m->private; | |
7bcfaf54 | 3658 | char buf[64]; |
613f04a0 | 3659 | int ret; |
7bcfaf54 SR |
3660 | |
3661 | if (cnt >= sizeof(buf)) | |
3662 | return -EINVAL; | |
3663 | ||
3664 | if (copy_from_user(&buf, ubuf, cnt)) | |
3665 | return -EFAULT; | |
3666 | ||
a8dd2176 SR |
3667 | buf[cnt] = 0; |
3668 | ||
2b6080f2 | 3669 | ret = trace_set_options(tr, buf); |
613f04a0 SRRH |
3670 | if (ret < 0) |
3671 | return ret; | |
7bcfaf54 | 3672 | |
cf8517cf | 3673 | *ppos += cnt; |
bc0c38d1 SR |
3674 | |
3675 | return cnt; | |
3676 | } | |
3677 | ||
fdb372ed LZ |
3678 | static int tracing_trace_options_open(struct inode *inode, struct file *file) |
3679 | { | |
7b85af63 | 3680 | struct trace_array *tr = inode->i_private; |
f77d09a3 | 3681 | int ret; |
7b85af63 | 3682 | |
fdb372ed LZ |
3683 | if (tracing_disabled) |
3684 | return -ENODEV; | |
2b6080f2 | 3685 | |
7b85af63 SRRH |
3686 | if (trace_array_get(tr) < 0) |
3687 | return -ENODEV; | |
3688 | ||
f77d09a3 AL |
3689 | ret = single_open(file, tracing_trace_options_show, inode->i_private); |
3690 | if (ret < 0) | |
3691 | trace_array_put(tr); | |
3692 | ||
3693 | return ret; | |
fdb372ed LZ |
3694 | } |
3695 | ||
5e2336a0 | 3696 | static const struct file_operations tracing_iter_fops = { |
fdb372ed LZ |
3697 | .open = tracing_trace_options_open, |
3698 | .read = seq_read, | |
3699 | .llseek = seq_lseek, | |
7b85af63 | 3700 | .release = tracing_single_release_tr, |
ee6bce52 | 3701 | .write = tracing_trace_options_write, |
bc0c38d1 SR |
3702 | }; |
3703 | ||
7bd2f24c IM |
3704 | static const char readme_msg[] = |
3705 | "tracing mini-HOWTO:\n\n" | |
22f45649 SRRH |
3706 | "# echo 0 > tracing_on : quick way to disable tracing\n" |
3707 | "# echo 1 > tracing_on : quick way to re-enable tracing\n\n" | |
3708 | " Important files:\n" | |
3709 | " trace\t\t\t- The static contents of the buffer\n" | |
3710 | "\t\t\t To clear the buffer write into this file: echo > trace\n" | |
3711 | " trace_pipe\t\t- A consuming read to see the contents of the buffer\n" | |
3712 | " current_tracer\t- function and latency tracers\n" | |
3713 | " available_tracers\t- list of configured tracers for current_tracer\n" | |
3714 | " buffer_size_kb\t- view and modify size of per cpu buffer\n" | |
3715 | " buffer_total_size_kb - view total size of all cpu buffers\n\n" | |
3716 | " trace_clock\t\t-change the clock used to order events\n" | |
3717 | " local: Per cpu clock but may not be synced across CPUs\n" | |
3718 | " global: Synced across CPUs but slows tracing down.\n" | |
3719 | " counter: Not a clock, but just an increment\n" | |
3720 | " uptime: Jiffy counter from time of boot\n" | |
3721 | " perf: Same clock that perf events use\n" | |
3722 | #ifdef CONFIG_X86_64 | |
3723 | " x86-tsc: TSC cycle counter\n" | |
3724 | #endif | |
3725 | "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" | |
3726 | " tracing_cpumask\t- Limit which CPUs to trace\n" | |
3727 | " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" | |
3728 | "\t\t\t Remove sub-buffer with rmdir\n" | |
3729 | " trace_options\t\t- Set format or modify how tracing happens\n" | |
71485c45 SRRH |
3730 | "\t\t\t Disable an option by adding a suffix 'no' to the\n" |
3731 | "\t\t\t option name\n" | |
939c7a4f | 3732 | " saved_cmdlines_size\t- echo command number in here to store comm-pid list\n" |
22f45649 SRRH |
3733 | #ifdef CONFIG_DYNAMIC_FTRACE |
3734 | "\n available_filter_functions - list of functions that can be filtered on\n" | |
71485c45 SRRH |
3735 | " set_ftrace_filter\t- echo function name in here to only trace these\n" |
3736 | "\t\t\t functions\n" | |
3737 | "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" | |
3738 | "\t modules: Can select a group via module\n" | |
3739 | "\t Format: :mod:<module-name>\n" | |
3740 | "\t example: echo :mod:ext3 > set_ftrace_filter\n" | |
3741 | "\t triggers: a command to perform when function is hit\n" | |
3742 | "\t Format: <function>:<trigger>[:count]\n" | |
3743 | "\t trigger: traceon, traceoff\n" | |
3744 | "\t\t enable_event:<system>:<event>\n" | |
3745 | "\t\t disable_event:<system>:<event>\n" | |
22f45649 | 3746 | #ifdef CONFIG_STACKTRACE |
71485c45 | 3747 | "\t\t stacktrace\n" |
22f45649 SRRH |
3748 | #endif |
3749 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 | 3750 | "\t\t snapshot\n" |
22f45649 | 3751 | #endif |
17a280ea SRRH |
3752 | "\t\t dump\n" |
3753 | "\t\t cpudump\n" | |
71485c45 SRRH |
3754 | "\t example: echo do_fault:traceoff > set_ftrace_filter\n" |
3755 | "\t echo do_trap:traceoff:3 > set_ftrace_filter\n" | |
3756 | "\t The first one will disable tracing every time do_fault is hit\n" | |
3757 | "\t The second will disable tracing at most 3 times when do_trap is hit\n" | |
3758 | "\t The first time do trap is hit and it disables tracing, the\n" | |
3759 | "\t counter will decrement to 2. If tracing is already disabled,\n" | |
3760 | "\t the counter will not decrement. It only decrements when the\n" | |
3761 | "\t trigger did work\n" | |
3762 | "\t To remove trigger without count:\n" | |
3763 | "\t echo '!<function>:<trigger> > set_ftrace_filter\n" | |
3764 | "\t To remove trigger with a count:\n" | |
3765 | "\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n" | |
22f45649 | 3766 | " set_ftrace_notrace\t- echo function name in here to never trace.\n" |
71485c45 SRRH |
3767 | "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" |
3768 | "\t modules: Can select a group via module command :mod:\n" | |
3769 | "\t Does not accept triggers\n" | |
22f45649 SRRH |
3770 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3771 | #ifdef CONFIG_FUNCTION_TRACER | |
71485c45 SRRH |
3772 | " set_ftrace_pid\t- Write pid(s) to only function trace those pids\n" |
3773 | "\t\t (function)\n" | |
22f45649 SRRH |
3774 | #endif |
3775 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
3776 | " set_graph_function\t- Trace the nested calls of a function (function_graph)\n" | |
d048a8c7 | 3777 | " set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n" |
22f45649 SRRH |
3778 | " max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n" |
3779 | #endif | |
3780 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 SRRH |
3781 | "\n snapshot\t\t- Like 'trace' but shows the content of the static\n" |
3782 | "\t\t\t snapshot buffer. Read the contents for more\n" | |
3783 | "\t\t\t information\n" | |
22f45649 | 3784 | #endif |
991821c8 | 3785 | #ifdef CONFIG_STACK_TRACER |
22f45649 SRRH |
3786 | " stack_trace\t\t- Shows the max stack trace when active\n" |
3787 | " stack_max_size\t- Shows current max stack size that was traced\n" | |
71485c45 SRRH |
3788 | "\t\t\t Write into this file to reset the max size (trigger a\n" |
3789 | "\t\t\t new trace)\n" | |
22f45649 | 3790 | #ifdef CONFIG_DYNAMIC_FTRACE |
71485c45 SRRH |
3791 | " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n" |
3792 | "\t\t\t traces\n" | |
22f45649 | 3793 | #endif |
991821c8 | 3794 | #endif /* CONFIG_STACK_TRACER */ |
26f25564 TZ |
3795 | " events/\t\t- Directory containing all trace event subsystems:\n" |
3796 | " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" | |
3797 | " events/<system>/\t- Directory containing all trace events for <system>:\n" | |
71485c45 SRRH |
3798 | " enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n" |
3799 | "\t\t\t events\n" | |
26f25564 | 3800 | " filter\t\t- If set, only events passing filter are traced\n" |
71485c45 SRRH |
3801 | " events/<system>/<event>/\t- Directory containing control files for\n" |
3802 | "\t\t\t <event>:\n" | |
26f25564 TZ |
3803 | " enable\t\t- Write 0/1 to enable/disable tracing of <event>\n" |
3804 | " filter\t\t- If set, only events passing filter are traced\n" | |
3805 | " trigger\t\t- If set, a command to perform when event is hit\n" | |
71485c45 SRRH |
3806 | "\t Format: <trigger>[:count][if <filter>]\n" |
3807 | "\t trigger: traceon, traceoff\n" | |
3808 | "\t enable_event:<system>:<event>\n" | |
3809 | "\t disable_event:<system>:<event>\n" | |
26f25564 | 3810 | #ifdef CONFIG_STACKTRACE |
71485c45 | 3811 | "\t\t stacktrace\n" |
26f25564 TZ |
3812 | #endif |
3813 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 | 3814 | "\t\t snapshot\n" |
7ef224d1 TZ |
3815 | #endif |
3816 | #ifdef CONFIG_HIST_TRIGGERS | |
3817 | "\t\t hist (see below)\n" | |
26f25564 | 3818 | #endif |
71485c45 SRRH |
3819 | "\t example: echo traceoff > events/block/block_unplug/trigger\n" |
3820 | "\t echo traceoff:3 > events/block/block_unplug/trigger\n" | |
3821 | "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n" | |
3822 | "\t events/block/block_unplug/trigger\n" | |
3823 | "\t The first disables tracing every time block_unplug is hit.\n" | |
3824 | "\t The second disables tracing the first 3 times block_unplug is hit.\n" | |
3825 | "\t The third enables the kmalloc event the first 3 times block_unplug\n" | |
3826 | "\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n" | |
3827 | "\t Like function triggers, the counter is only decremented if it\n" | |
3828 | "\t enabled or disabled tracing.\n" | |
3829 | "\t To remove a trigger without a count:\n" | |
3830 | "\t echo '!<trigger> > <system>/<event>/trigger\n" | |
3831 | "\t To remove a trigger with a count:\n" | |
3832 | "\t echo '!<trigger>:0 > <system>/<event>/trigger\n" | |
3833 | "\t Filters can be ignored when removing a trigger.\n" | |
7ef224d1 TZ |
3834 | #ifdef CONFIG_HIST_TRIGGERS |
3835 | " hist trigger\t- If set, event hits are aggregated into a hash table\n" | |
76a3b0c8 | 3836 | "\t Format: hist:keys=<field1[,field2,...]>\n" |
f2606835 | 3837 | "\t [:values=<field1[,field2,...]>]\n" |
e62347d2 | 3838 | "\t [:sort=<field1[,field2,...]>]\n" |
7ef224d1 | 3839 | "\t [:size=#entries]\n" |
83e99914 | 3840 | "\t [:pause][:continue]\n" |
7ef224d1 TZ |
3841 | "\t [if <filter>]\n\n" |
3842 | "\t When a matching event is hit, an entry is added to a hash\n" | |
f2606835 TZ |
3843 | "\t table using the key(s) and value(s) named, and the value of a\n" |
3844 | "\t sum called 'hitcount' is incremented. Keys and values\n" | |
3845 | "\t correspond to fields in the event's format description. Keys\n" | |
76a3b0c8 TZ |
3846 | "\t can be any field. Compound keys consisting of up to two\n" |
3847 | "\t fields can be specified by the 'keys' keyword. Values must\n" | |
e62347d2 TZ |
3848 | "\t correspond to numeric fields. Sort keys consisting of up to\n" |
3849 | "\t two fields can be specified using the 'sort' keyword. The\n" | |
3850 | "\t sort direction can be modified by appending '.descending' or\n" | |
3851 | "\t '.ascending' to a sort field. The 'size' parameter can be\n" | |
76a3b0c8 TZ |
3852 | "\t used to specify more or fewer than the default 2048 entries\n" |
3853 | "\t for the hashtable size.\n\n" | |
7ef224d1 | 3854 | "\t Reading the 'hist' file for the event will dump the hash\n" |
83e99914 TZ |
3855 | "\t table in its entirety to stdout.\n\n" |
3856 | "\t The 'pause' parameter can be used to pause an existing hist\n" | |
3857 | "\t trigger or to start a hist trigger but not log any events\n" | |
3858 | "\t until told to do so. 'continue' can be used to start or\n" | |
3859 | "\t restart a paused hist trigger.\n\n" | |
7ef224d1 | 3860 | #endif |
7bd2f24c IM |
3861 | ; |
3862 | ||
3863 | static ssize_t | |
3864 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
3865 | size_t cnt, loff_t *ppos) | |
3866 | { | |
3867 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
3868 | readme_msg, strlen(readme_msg)); | |
3869 | } | |
3870 | ||
5e2336a0 | 3871 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
3872 | .open = tracing_open_generic, |
3873 | .read = tracing_readme_read, | |
b444786f | 3874 | .llseek = generic_file_llseek, |
7bd2f24c IM |
3875 | }; |
3876 | ||
42584c81 YY |
3877 | static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos) |
3878 | { | |
3879 | unsigned int *ptr = v; | |
69abe6a5 | 3880 | |
42584c81 YY |
3881 | if (*pos || m->count) |
3882 | ptr++; | |
69abe6a5 | 3883 | |
42584c81 | 3884 | (*pos)++; |
69abe6a5 | 3885 | |
939c7a4f YY |
3886 | for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num]; |
3887 | ptr++) { | |
42584c81 YY |
3888 | if (*ptr == -1 || *ptr == NO_CMDLINE_MAP) |
3889 | continue; | |
69abe6a5 | 3890 | |
42584c81 YY |
3891 | return ptr; |
3892 | } | |
69abe6a5 | 3893 | |
42584c81 YY |
3894 | return NULL; |
3895 | } | |
3896 | ||
3897 | static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos) | |
3898 | { | |
3899 | void *v; | |
3900 | loff_t l = 0; | |
69abe6a5 | 3901 | |
4c27e756 SRRH |
3902 | preempt_disable(); |
3903 | arch_spin_lock(&trace_cmdline_lock); | |
3904 | ||
939c7a4f | 3905 | v = &savedcmd->map_cmdline_to_pid[0]; |
42584c81 YY |
3906 | while (l <= *pos) { |
3907 | v = saved_cmdlines_next(m, v, &l); | |
3908 | if (!v) | |
3909 | return NULL; | |
69abe6a5 AP |
3910 | } |
3911 | ||
42584c81 YY |
3912 | return v; |
3913 | } | |
3914 | ||
3915 | static void saved_cmdlines_stop(struct seq_file *m, void *v) | |
3916 | { | |
4c27e756 SRRH |
3917 | arch_spin_unlock(&trace_cmdline_lock); |
3918 | preempt_enable(); | |
42584c81 | 3919 | } |
69abe6a5 | 3920 | |
42584c81 YY |
3921 | static int saved_cmdlines_show(struct seq_file *m, void *v) |
3922 | { | |
3923 | char buf[TASK_COMM_LEN]; | |
3924 | unsigned int *pid = v; | |
69abe6a5 | 3925 | |
4c27e756 | 3926 | __trace_find_cmdline(*pid, buf); |
42584c81 YY |
3927 | seq_printf(m, "%d %s\n", *pid, buf); |
3928 | return 0; | |
3929 | } | |
3930 | ||
3931 | static const struct seq_operations tracing_saved_cmdlines_seq_ops = { | |
3932 | .start = saved_cmdlines_start, | |
3933 | .next = saved_cmdlines_next, | |
3934 | .stop = saved_cmdlines_stop, | |
3935 | .show = saved_cmdlines_show, | |
3936 | }; | |
3937 | ||
3938 | static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp) | |
3939 | { | |
3940 | if (tracing_disabled) | |
3941 | return -ENODEV; | |
3942 | ||
3943 | return seq_open(filp, &tracing_saved_cmdlines_seq_ops); | |
69abe6a5 AP |
3944 | } |
3945 | ||
3946 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
42584c81 YY |
3947 | .open = tracing_saved_cmdlines_open, |
3948 | .read = seq_read, | |
3949 | .llseek = seq_lseek, | |
3950 | .release = seq_release, | |
69abe6a5 AP |
3951 | }; |
3952 | ||
939c7a4f YY |
3953 | static ssize_t |
3954 | tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf, | |
3955 | size_t cnt, loff_t *ppos) | |
3956 | { | |
3957 | char buf[64]; | |
3958 | int r; | |
3959 | ||
3960 | arch_spin_lock(&trace_cmdline_lock); | |
a6af8fbf | 3961 | r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num); |
939c7a4f YY |
3962 | arch_spin_unlock(&trace_cmdline_lock); |
3963 | ||
3964 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3965 | } | |
3966 | ||
3967 | static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s) | |
3968 | { | |
3969 | kfree(s->saved_cmdlines); | |
3970 | kfree(s->map_cmdline_to_pid); | |
3971 | kfree(s); | |
3972 | } | |
3973 | ||
3974 | static int tracing_resize_saved_cmdlines(unsigned int val) | |
3975 | { | |
3976 | struct saved_cmdlines_buffer *s, *savedcmd_temp; | |
3977 | ||
a6af8fbf | 3978 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
939c7a4f YY |
3979 | if (!s) |
3980 | return -ENOMEM; | |
3981 | ||
3982 | if (allocate_cmdlines_buffer(val, s) < 0) { | |
3983 | kfree(s); | |
3984 | return -ENOMEM; | |
3985 | } | |
3986 | ||
3987 | arch_spin_lock(&trace_cmdline_lock); | |
3988 | savedcmd_temp = savedcmd; | |
3989 | savedcmd = s; | |
3990 | arch_spin_unlock(&trace_cmdline_lock); | |
3991 | free_saved_cmdlines_buffer(savedcmd_temp); | |
3992 | ||
3993 | return 0; | |
3994 | } | |
3995 | ||
3996 | static ssize_t | |
3997 | tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf, | |
3998 | size_t cnt, loff_t *ppos) | |
3999 | { | |
4000 | unsigned long val; | |
4001 | int ret; | |
4002 | ||
4003 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
4004 | if (ret) | |
4005 | return ret; | |
4006 | ||
4007 | /* must have at least 1 entry or less than PID_MAX_DEFAULT */ | |
4008 | if (!val || val > PID_MAX_DEFAULT) | |
4009 | return -EINVAL; | |
4010 | ||
4011 | ret = tracing_resize_saved_cmdlines((unsigned int)val); | |
4012 | if (ret < 0) | |
4013 | return ret; | |
4014 | ||
4015 | *ppos += cnt; | |
4016 | ||
4017 | return cnt; | |
4018 | } | |
4019 | ||
4020 | static const struct file_operations tracing_saved_cmdlines_size_fops = { | |
4021 | .open = tracing_open_generic, | |
4022 | .read = tracing_saved_cmdlines_size_read, | |
4023 | .write = tracing_saved_cmdlines_size_write, | |
4024 | }; | |
4025 | ||
9828413d SRRH |
4026 | #ifdef CONFIG_TRACE_ENUM_MAP_FILE |
4027 | static union trace_enum_map_item * | |
4028 | update_enum_map(union trace_enum_map_item *ptr) | |
4029 | { | |
4030 | if (!ptr->map.enum_string) { | |
4031 | if (ptr->tail.next) { | |
4032 | ptr = ptr->tail.next; | |
4033 | /* Set ptr to the next real item (skip head) */ | |
4034 | ptr++; | |
4035 | } else | |
4036 | return NULL; | |
4037 | } | |
4038 | return ptr; | |
4039 | } | |
4040 | ||
4041 | static void *enum_map_next(struct seq_file *m, void *v, loff_t *pos) | |
4042 | { | |
4043 | union trace_enum_map_item *ptr = v; | |
4044 | ||
4045 | /* | |
4046 | * Paranoid! If ptr points to end, we don't want to increment past it. | |
4047 | * This really should never happen. | |
4048 | */ | |
4049 | ptr = update_enum_map(ptr); | |
4050 | if (WARN_ON_ONCE(!ptr)) | |
4051 | return NULL; | |
4052 | ||
4053 | ptr++; | |
4054 | ||
4055 | (*pos)++; | |
4056 | ||
4057 | ptr = update_enum_map(ptr); | |
4058 | ||
4059 | return ptr; | |
4060 | } | |
4061 | ||
4062 | static void *enum_map_start(struct seq_file *m, loff_t *pos) | |
4063 | { | |
4064 | union trace_enum_map_item *v; | |
4065 | loff_t l = 0; | |
4066 | ||
4067 | mutex_lock(&trace_enum_mutex); | |
4068 | ||
4069 | v = trace_enum_maps; | |
4070 | if (v) | |
4071 | v++; | |
4072 | ||
4073 | while (v && l < *pos) { | |
4074 | v = enum_map_next(m, v, &l); | |
4075 | } | |
4076 | ||
4077 | return v; | |
4078 | } | |
4079 | ||
4080 | static void enum_map_stop(struct seq_file *m, void *v) | |
4081 | { | |
4082 | mutex_unlock(&trace_enum_mutex); | |
4083 | } | |
4084 | ||
4085 | static int enum_map_show(struct seq_file *m, void *v) | |
4086 | { | |
4087 | union trace_enum_map_item *ptr = v; | |
4088 | ||
4089 | seq_printf(m, "%s %ld (%s)\n", | |
4090 | ptr->map.enum_string, ptr->map.enum_value, | |
4091 | ptr->map.system); | |
4092 | ||
4093 | return 0; | |
4094 | } | |
4095 | ||
4096 | static const struct seq_operations tracing_enum_map_seq_ops = { | |
4097 | .start = enum_map_start, | |
4098 | .next = enum_map_next, | |
4099 | .stop = enum_map_stop, | |
4100 | .show = enum_map_show, | |
4101 | }; | |
4102 | ||
4103 | static int tracing_enum_map_open(struct inode *inode, struct file *filp) | |
4104 | { | |
4105 | if (tracing_disabled) | |
4106 | return -ENODEV; | |
4107 | ||
4108 | return seq_open(filp, &tracing_enum_map_seq_ops); | |
4109 | } | |
4110 | ||
4111 | static const struct file_operations tracing_enum_map_fops = { | |
4112 | .open = tracing_enum_map_open, | |
4113 | .read = seq_read, | |
4114 | .llseek = seq_lseek, | |
4115 | .release = seq_release, | |
4116 | }; | |
4117 | ||
4118 | static inline union trace_enum_map_item * | |
4119 | trace_enum_jmp_to_tail(union trace_enum_map_item *ptr) | |
4120 | { | |
4121 | /* Return tail of array given the head */ | |
4122 | return ptr + ptr->head.length + 1; | |
4123 | } | |
4124 | ||
4125 | static void | |
4126 | trace_insert_enum_map_file(struct module *mod, struct trace_enum_map **start, | |
4127 | int len) | |
4128 | { | |
4129 | struct trace_enum_map **stop; | |
4130 | struct trace_enum_map **map; | |
4131 | union trace_enum_map_item *map_array; | |
4132 | union trace_enum_map_item *ptr; | |
4133 | ||
4134 | stop = start + len; | |
4135 | ||
4136 | /* | |
4137 | * The trace_enum_maps contains the map plus a head and tail item, | |
4138 | * where the head holds the module and length of array, and the | |
4139 | * tail holds a pointer to the next list. | |
4140 | */ | |
4141 | map_array = kmalloc(sizeof(*map_array) * (len + 2), GFP_KERNEL); | |
4142 | if (!map_array) { | |
a395d6a7 | 4143 | pr_warn("Unable to allocate trace enum mapping\n"); |
9828413d SRRH |
4144 | return; |
4145 | } | |
4146 | ||
4147 | mutex_lock(&trace_enum_mutex); | |
4148 | ||
4149 | if (!trace_enum_maps) | |
4150 | trace_enum_maps = map_array; | |
4151 | else { | |
4152 | ptr = trace_enum_maps; | |
4153 | for (;;) { | |
4154 | ptr = trace_enum_jmp_to_tail(ptr); | |
4155 | if (!ptr->tail.next) | |
4156 | break; | |
4157 | ptr = ptr->tail.next; | |
4158 | ||
4159 | } | |
4160 | ptr->tail.next = map_array; | |
4161 | } | |
4162 | map_array->head.mod = mod; | |
4163 | map_array->head.length = len; | |
4164 | map_array++; | |
4165 | ||
4166 | for (map = start; (unsigned long)map < (unsigned long)stop; map++) { | |
4167 | map_array->map = **map; | |
4168 | map_array++; | |
4169 | } | |
4170 | memset(map_array, 0, sizeof(*map_array)); | |
4171 | ||
4172 | mutex_unlock(&trace_enum_mutex); | |
4173 | } | |
4174 | ||
4175 | static void trace_create_enum_file(struct dentry *d_tracer) | |
4176 | { | |
4177 | trace_create_file("enum_map", 0444, d_tracer, | |
4178 | NULL, &tracing_enum_map_fops); | |
4179 | } | |
4180 | ||
4181 | #else /* CONFIG_TRACE_ENUM_MAP_FILE */ | |
4182 | static inline void trace_create_enum_file(struct dentry *d_tracer) { } | |
4183 | static inline void trace_insert_enum_map_file(struct module *mod, | |
4184 | struct trace_enum_map **start, int len) { } | |
4185 | #endif /* !CONFIG_TRACE_ENUM_MAP_FILE */ | |
4186 | ||
4187 | static void trace_insert_enum_map(struct module *mod, | |
4188 | struct trace_enum_map **start, int len) | |
0c564a53 SRRH |
4189 | { |
4190 | struct trace_enum_map **map; | |
0c564a53 SRRH |
4191 | |
4192 | if (len <= 0) | |
4193 | return; | |
4194 | ||
4195 | map = start; | |
4196 | ||
4197 | trace_event_enum_update(map, len); | |
9828413d SRRH |
4198 | |
4199 | trace_insert_enum_map_file(mod, start, len); | |
0c564a53 SRRH |
4200 | } |
4201 | ||
bc0c38d1 SR |
4202 | static ssize_t |
4203 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
4204 | size_t cnt, loff_t *ppos) | |
4205 | { | |
2b6080f2 | 4206 | struct trace_array *tr = filp->private_data; |
ee6c2c1b | 4207 | char buf[MAX_TRACER_SIZE+2]; |
bc0c38d1 SR |
4208 | int r; |
4209 | ||
4210 | mutex_lock(&trace_types_lock); | |
2b6080f2 | 4211 | r = sprintf(buf, "%s\n", tr->current_trace->name); |
bc0c38d1 SR |
4212 | mutex_unlock(&trace_types_lock); |
4213 | ||
4bf39a94 | 4214 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
4215 | } |
4216 | ||
b6f11df2 ACM |
4217 | int tracer_init(struct tracer *t, struct trace_array *tr) |
4218 | { | |
12883efb | 4219 | tracing_reset_online_cpus(&tr->trace_buffer); |
b6f11df2 ACM |
4220 | return t->init(tr); |
4221 | } | |
4222 | ||
12883efb | 4223 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val) |
438ced17 VN |
4224 | { |
4225 | int cpu; | |
737223fb | 4226 | |
438ced17 | 4227 | for_each_tracing_cpu(cpu) |
12883efb | 4228 | per_cpu_ptr(buf->data, cpu)->entries = val; |
438ced17 VN |
4229 | } |
4230 | ||
12883efb | 4231 | #ifdef CONFIG_TRACER_MAX_TRACE |
d60da506 | 4232 | /* resize @tr's buffer to the size of @size_tr's entries */ |
12883efb SRRH |
4233 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, |
4234 | struct trace_buffer *size_buf, int cpu_id) | |
d60da506 HT |
4235 | { |
4236 | int cpu, ret = 0; | |
4237 | ||
4238 | if (cpu_id == RING_BUFFER_ALL_CPUS) { | |
4239 | for_each_tracing_cpu(cpu) { | |
12883efb SRRH |
4240 | ret = ring_buffer_resize(trace_buf->buffer, |
4241 | per_cpu_ptr(size_buf->data, cpu)->entries, cpu); | |
d60da506 HT |
4242 | if (ret < 0) |
4243 | break; | |
12883efb SRRH |
4244 | per_cpu_ptr(trace_buf->data, cpu)->entries = |
4245 | per_cpu_ptr(size_buf->data, cpu)->entries; | |
d60da506 HT |
4246 | } |
4247 | } else { | |
12883efb SRRH |
4248 | ret = ring_buffer_resize(trace_buf->buffer, |
4249 | per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); | |
d60da506 | 4250 | if (ret == 0) |
12883efb SRRH |
4251 | per_cpu_ptr(trace_buf->data, cpu_id)->entries = |
4252 | per_cpu_ptr(size_buf->data, cpu_id)->entries; | |
d60da506 HT |
4253 | } |
4254 | ||
4255 | return ret; | |
4256 | } | |
12883efb | 4257 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
d60da506 | 4258 | |
2b6080f2 SR |
4259 | static int __tracing_resize_ring_buffer(struct trace_array *tr, |
4260 | unsigned long size, int cpu) | |
73c5162a SR |
4261 | { |
4262 | int ret; | |
4263 | ||
4264 | /* | |
4265 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
4266 | * we use the size that was given, and we can forget about |
4267 | * expanding it later. | |
73c5162a | 4268 | */ |
55034cd6 | 4269 | ring_buffer_expanded = true; |
73c5162a | 4270 | |
b382ede6 | 4271 | /* May be called before buffers are initialized */ |
12883efb | 4272 | if (!tr->trace_buffer.buffer) |
b382ede6 SR |
4273 | return 0; |
4274 | ||
12883efb | 4275 | ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu); |
73c5162a SR |
4276 | if (ret < 0) |
4277 | return ret; | |
4278 | ||
12883efb | 4279 | #ifdef CONFIG_TRACER_MAX_TRACE |
2b6080f2 SR |
4280 | if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || |
4281 | !tr->current_trace->use_max_tr) | |
ef710e10 KM |
4282 | goto out; |
4283 | ||
12883efb | 4284 | ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); |
73c5162a | 4285 | if (ret < 0) { |
12883efb SRRH |
4286 | int r = resize_buffer_duplicate_size(&tr->trace_buffer, |
4287 | &tr->trace_buffer, cpu); | |
73c5162a | 4288 | if (r < 0) { |
a123c52b SR |
4289 | /* |
4290 | * AARGH! We are left with different | |
4291 | * size max buffer!!!! | |
4292 | * The max buffer is our "snapshot" buffer. | |
4293 | * When a tracer needs a snapshot (one of the | |
4294 | * latency tracers), it swaps the max buffer | |
4295 | * with the saved snap shot. We succeeded to | |
4296 | * update the size of the main buffer, but failed to | |
4297 | * update the size of the max buffer. But when we tried | |
4298 | * to reset the main buffer to the original size, we | |
4299 | * failed there too. This is very unlikely to | |
4300 | * happen, but if it does, warn and kill all | |
4301 | * tracing. | |
4302 | */ | |
73c5162a SR |
4303 | WARN_ON(1); |
4304 | tracing_disabled = 1; | |
4305 | } | |
4306 | return ret; | |
4307 | } | |
4308 | ||
438ced17 | 4309 | if (cpu == RING_BUFFER_ALL_CPUS) |
12883efb | 4310 | set_buffer_entries(&tr->max_buffer, size); |
438ced17 | 4311 | else |
12883efb | 4312 | per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size; |
438ced17 | 4313 | |
ef710e10 | 4314 | out: |
12883efb SRRH |
4315 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
4316 | ||
438ced17 | 4317 | if (cpu == RING_BUFFER_ALL_CPUS) |
12883efb | 4318 | set_buffer_entries(&tr->trace_buffer, size); |
438ced17 | 4319 | else |
12883efb | 4320 | per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size; |
73c5162a SR |
4321 | |
4322 | return ret; | |
4323 | } | |
4324 | ||
2b6080f2 SR |
4325 | static ssize_t tracing_resize_ring_buffer(struct trace_array *tr, |
4326 | unsigned long size, int cpu_id) | |
4f271a2a | 4327 | { |
83f40318 | 4328 | int ret = size; |
4f271a2a VN |
4329 | |
4330 | mutex_lock(&trace_types_lock); | |
4331 | ||
438ced17 VN |
4332 | if (cpu_id != RING_BUFFER_ALL_CPUS) { |
4333 | /* make sure, this cpu is enabled in the mask */ | |
4334 | if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { | |
4335 | ret = -EINVAL; | |
4336 | goto out; | |
4337 | } | |
4338 | } | |
4f271a2a | 4339 | |
2b6080f2 | 4340 | ret = __tracing_resize_ring_buffer(tr, size, cpu_id); |
4f271a2a VN |
4341 | if (ret < 0) |
4342 | ret = -ENOMEM; | |
4343 | ||
438ced17 | 4344 | out: |
4f271a2a VN |
4345 | mutex_unlock(&trace_types_lock); |
4346 | ||
4347 | return ret; | |
4348 | } | |
4349 | ||
ef710e10 | 4350 | |
1852fcce SR |
4351 | /** |
4352 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
4353 | * | |
4354 | * To save on memory when the tracing is never used on a system with it | |
4355 | * configured in. The ring buffers are set to a minimum size. But once | |
4356 | * a user starts to use the tracing facility, then they need to grow | |
4357 | * to their default size. | |
4358 | * | |
4359 | * This function is to be called when a tracer is about to be used. | |
4360 | */ | |
4361 | int tracing_update_buffers(void) | |
4362 | { | |
4363 | int ret = 0; | |
4364 | ||
1027fcb2 | 4365 | mutex_lock(&trace_types_lock); |
1852fcce | 4366 | if (!ring_buffer_expanded) |
2b6080f2 | 4367 | ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, |
438ced17 | 4368 | RING_BUFFER_ALL_CPUS); |
1027fcb2 | 4369 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
4370 | |
4371 | return ret; | |
4372 | } | |
4373 | ||
577b785f SR |
4374 | struct trace_option_dentry; |
4375 | ||
37aea98b | 4376 | static void |
2b6080f2 | 4377 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer); |
577b785f | 4378 | |
6b450d25 SRRH |
4379 | /* |
4380 | * Used to clear out the tracer before deletion of an instance. | |
4381 | * Must have trace_types_lock held. | |
4382 | */ | |
4383 | static void tracing_set_nop(struct trace_array *tr) | |
4384 | { | |
4385 | if (tr->current_trace == &nop_trace) | |
4386 | return; | |
4387 | ||
50512ab5 | 4388 | tr->current_trace->enabled--; |
6b450d25 SRRH |
4389 | |
4390 | if (tr->current_trace->reset) | |
4391 | tr->current_trace->reset(tr); | |
4392 | ||
4393 | tr->current_trace = &nop_trace; | |
4394 | } | |
4395 | ||
41d9c0be | 4396 | static void add_tracer_options(struct trace_array *tr, struct tracer *t) |
bc0c38d1 | 4397 | { |
09d23a1d SRRH |
4398 | /* Only enable if the directory has been created already. */ |
4399 | if (!tr->dir) | |
4400 | return; | |
4401 | ||
37aea98b | 4402 | create_trace_option_files(tr, t); |
09d23a1d SRRH |
4403 | } |
4404 | ||
4405 | static int tracing_set_tracer(struct trace_array *tr, const char *buf) | |
4406 | { | |
bc0c38d1 | 4407 | struct tracer *t; |
12883efb | 4408 | #ifdef CONFIG_TRACER_MAX_TRACE |
34600f0e | 4409 | bool had_max_tr; |
12883efb | 4410 | #endif |
d9e54076 | 4411 | int ret = 0; |
bc0c38d1 | 4412 | |
1027fcb2 SR |
4413 | mutex_lock(&trace_types_lock); |
4414 | ||
73c5162a | 4415 | if (!ring_buffer_expanded) { |
2b6080f2 | 4416 | ret = __tracing_resize_ring_buffer(tr, trace_buf_size, |
438ced17 | 4417 | RING_BUFFER_ALL_CPUS); |
73c5162a | 4418 | if (ret < 0) |
59f586db | 4419 | goto out; |
73c5162a SR |
4420 | ret = 0; |
4421 | } | |
4422 | ||
bc0c38d1 SR |
4423 | for (t = trace_types; t; t = t->next) { |
4424 | if (strcmp(t->name, buf) == 0) | |
4425 | break; | |
4426 | } | |
c2931e05 FW |
4427 | if (!t) { |
4428 | ret = -EINVAL; | |
4429 | goto out; | |
4430 | } | |
2b6080f2 | 4431 | if (t == tr->current_trace) |
bc0c38d1 SR |
4432 | goto out; |
4433 | ||
607e2ea1 SRRH |
4434 | /* Some tracers are only allowed for the top level buffer */ |
4435 | if (!trace_ok_for_array(t, tr)) { | |
4436 | ret = -EINVAL; | |
4437 | goto out; | |
4438 | } | |
4439 | ||
cf6ab6d9 SRRH |
4440 | /* If trace pipe files are being read, we can't change the tracer */ |
4441 | if (tr->current_trace->ref) { | |
4442 | ret = -EBUSY; | |
4443 | goto out; | |
4444 | } | |
4445 | ||
9f029e83 | 4446 | trace_branch_disable(); |
613f04a0 | 4447 | |
50512ab5 | 4448 | tr->current_trace->enabled--; |
613f04a0 | 4449 | |
2b6080f2 SR |
4450 | if (tr->current_trace->reset) |
4451 | tr->current_trace->reset(tr); | |
34600f0e | 4452 | |
12883efb | 4453 | /* Current trace needs to be nop_trace before synchronize_sched */ |
2b6080f2 | 4454 | tr->current_trace = &nop_trace; |
34600f0e | 4455 | |
45ad21ca SRRH |
4456 | #ifdef CONFIG_TRACER_MAX_TRACE |
4457 | had_max_tr = tr->allocated_snapshot; | |
34600f0e SR |
4458 | |
4459 | if (had_max_tr && !t->use_max_tr) { | |
4460 | /* | |
4461 | * We need to make sure that the update_max_tr sees that | |
4462 | * current_trace changed to nop_trace to keep it from | |
4463 | * swapping the buffers after we resize it. | |
4464 | * The update_max_tr is called from interrupts disabled | |
4465 | * so a synchronized_sched() is sufficient. | |
4466 | */ | |
4467 | synchronize_sched(); | |
3209cff4 | 4468 | free_snapshot(tr); |
ef710e10 | 4469 | } |
12883efb | 4470 | #endif |
12883efb SRRH |
4471 | |
4472 | #ifdef CONFIG_TRACER_MAX_TRACE | |
34600f0e | 4473 | if (t->use_max_tr && !had_max_tr) { |
3209cff4 | 4474 | ret = alloc_snapshot(tr); |
d60da506 HT |
4475 | if (ret < 0) |
4476 | goto out; | |
ef710e10 | 4477 | } |
12883efb | 4478 | #endif |
577b785f | 4479 | |
1c80025a | 4480 | if (t->init) { |
b6f11df2 | 4481 | ret = tracer_init(t, tr); |
1c80025a FW |
4482 | if (ret) |
4483 | goto out; | |
4484 | } | |
bc0c38d1 | 4485 | |
2b6080f2 | 4486 | tr->current_trace = t; |
50512ab5 | 4487 | tr->current_trace->enabled++; |
9f029e83 | 4488 | trace_branch_enable(tr); |
bc0c38d1 SR |
4489 | out: |
4490 | mutex_unlock(&trace_types_lock); | |
4491 | ||
d9e54076 PZ |
4492 | return ret; |
4493 | } | |
4494 | ||
4495 | static ssize_t | |
4496 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
4497 | size_t cnt, loff_t *ppos) | |
4498 | { | |
607e2ea1 | 4499 | struct trace_array *tr = filp->private_data; |
ee6c2c1b | 4500 | char buf[MAX_TRACER_SIZE+1]; |
d9e54076 PZ |
4501 | int i; |
4502 | size_t ret; | |
e6e7a65a FW |
4503 | int err; |
4504 | ||
4505 | ret = cnt; | |
d9e54076 | 4506 | |
ee6c2c1b LZ |
4507 | if (cnt > MAX_TRACER_SIZE) |
4508 | cnt = MAX_TRACER_SIZE; | |
d9e54076 PZ |
4509 | |
4510 | if (copy_from_user(&buf, ubuf, cnt)) | |
4511 | return -EFAULT; | |
4512 | ||
4513 | buf[cnt] = 0; | |
4514 | ||
4515 | /* strip ending whitespace. */ | |
4516 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
4517 | buf[i] = 0; | |
4518 | ||
607e2ea1 | 4519 | err = tracing_set_tracer(tr, buf); |
e6e7a65a FW |
4520 | if (err) |
4521 | return err; | |
d9e54076 | 4522 | |
cf8517cf | 4523 | *ppos += ret; |
bc0c38d1 | 4524 | |
c2931e05 | 4525 | return ret; |
bc0c38d1 SR |
4526 | } |
4527 | ||
4528 | static ssize_t | |
6508fa76 SF |
4529 | tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, |
4530 | size_t cnt, loff_t *ppos) | |
bc0c38d1 | 4531 | { |
bc0c38d1 SR |
4532 | char buf[64]; |
4533 | int r; | |
4534 | ||
cffae437 | 4535 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 4536 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
4537 | if (r > sizeof(buf)) |
4538 | r = sizeof(buf); | |
4bf39a94 | 4539 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
4540 | } |
4541 | ||
4542 | static ssize_t | |
6508fa76 SF |
4543 | tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf, |
4544 | size_t cnt, loff_t *ppos) | |
bc0c38d1 | 4545 | { |
5e39841c | 4546 | unsigned long val; |
c6caeeb1 | 4547 | int ret; |
bc0c38d1 | 4548 | |
22fe9b54 PH |
4549 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4550 | if (ret) | |
c6caeeb1 | 4551 | return ret; |
bc0c38d1 SR |
4552 | |
4553 | *ptr = val * 1000; | |
4554 | ||
4555 | return cnt; | |
4556 | } | |
4557 | ||
6508fa76 SF |
4558 | static ssize_t |
4559 | tracing_thresh_read(struct file *filp, char __user *ubuf, | |
4560 | size_t cnt, loff_t *ppos) | |
4561 | { | |
4562 | return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos); | |
4563 | } | |
4564 | ||
4565 | static ssize_t | |
4566 | tracing_thresh_write(struct file *filp, const char __user *ubuf, | |
4567 | size_t cnt, loff_t *ppos) | |
4568 | { | |
4569 | struct trace_array *tr = filp->private_data; | |
4570 | int ret; | |
4571 | ||
4572 | mutex_lock(&trace_types_lock); | |
4573 | ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos); | |
4574 | if (ret < 0) | |
4575 | goto out; | |
4576 | ||
4577 | if (tr->current_trace->update_thresh) { | |
4578 | ret = tr->current_trace->update_thresh(tr); | |
4579 | if (ret < 0) | |
4580 | goto out; | |
4581 | } | |
4582 | ||
4583 | ret = cnt; | |
4584 | out: | |
4585 | mutex_unlock(&trace_types_lock); | |
4586 | ||
4587 | return ret; | |
4588 | } | |
4589 | ||
e428abbb CG |
4590 | #ifdef CONFIG_TRACER_MAX_TRACE |
4591 | ||
6508fa76 SF |
4592 | static ssize_t |
4593 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
4594 | size_t cnt, loff_t *ppos) | |
4595 | { | |
4596 | return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos); | |
4597 | } | |
4598 | ||
4599 | static ssize_t | |
4600 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
4601 | size_t cnt, loff_t *ppos) | |
4602 | { | |
4603 | return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos); | |
4604 | } | |
4605 | ||
e428abbb CG |
4606 | #endif |
4607 | ||
b3806b43 SR |
4608 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
4609 | { | |
15544209 | 4610 | struct trace_array *tr = inode->i_private; |
b3806b43 | 4611 | struct trace_iterator *iter; |
b04cc6b1 | 4612 | int ret = 0; |
b3806b43 SR |
4613 | |
4614 | if (tracing_disabled) | |
4615 | return -ENODEV; | |
4616 | ||
7b85af63 SRRH |
4617 | if (trace_array_get(tr) < 0) |
4618 | return -ENODEV; | |
4619 | ||
b04cc6b1 FW |
4620 | mutex_lock(&trace_types_lock); |
4621 | ||
b3806b43 SR |
4622 | /* create a buffer to store the information to pass to userspace */ |
4623 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
4624 | if (!iter) { |
4625 | ret = -ENOMEM; | |
f77d09a3 | 4626 | __trace_array_put(tr); |
b04cc6b1 FW |
4627 | goto out; |
4628 | } | |
b3806b43 | 4629 | |
3a161d99 | 4630 | trace_seq_init(&iter->seq); |
d716ff71 | 4631 | iter->trace = tr->current_trace; |
d7350c3f | 4632 | |
4462344e | 4633 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 4634 | ret = -ENOMEM; |
d7350c3f | 4635 | goto fail; |
4462344e RR |
4636 | } |
4637 | ||
a309720c | 4638 | /* trace pipe does not show start of buffer */ |
4462344e | 4639 | cpumask_setall(iter->started); |
a309720c | 4640 | |
983f938a | 4641 | if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
112f38a7 SR |
4642 | iter->iter_flags |= TRACE_FILE_LAT_FMT; |
4643 | ||
8be0709f | 4644 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
58e8eedf | 4645 | if (trace_clocks[tr->clock_id].in_ns) |
8be0709f DS |
4646 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
4647 | ||
15544209 ON |
4648 | iter->tr = tr; |
4649 | iter->trace_buffer = &tr->trace_buffer; | |
4650 | iter->cpu_file = tracing_get_cpu(inode); | |
d7350c3f | 4651 | mutex_init(&iter->mutex); |
b3806b43 SR |
4652 | filp->private_data = iter; |
4653 | ||
107bad8b SR |
4654 | if (iter->trace->pipe_open) |
4655 | iter->trace->pipe_open(iter); | |
107bad8b | 4656 | |
b444786f | 4657 | nonseekable_open(inode, filp); |
cf6ab6d9 SRRH |
4658 | |
4659 | tr->current_trace->ref++; | |
b04cc6b1 FW |
4660 | out: |
4661 | mutex_unlock(&trace_types_lock); | |
4662 | return ret; | |
d7350c3f FW |
4663 | |
4664 | fail: | |
4665 | kfree(iter->trace); | |
4666 | kfree(iter); | |
7b85af63 | 4667 | __trace_array_put(tr); |
d7350c3f FW |
4668 | mutex_unlock(&trace_types_lock); |
4669 | return ret; | |
b3806b43 SR |
4670 | } |
4671 | ||
4672 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
4673 | { | |
4674 | struct trace_iterator *iter = file->private_data; | |
15544209 | 4675 | struct trace_array *tr = inode->i_private; |
b3806b43 | 4676 | |
b04cc6b1 FW |
4677 | mutex_lock(&trace_types_lock); |
4678 | ||
cf6ab6d9 SRRH |
4679 | tr->current_trace->ref--; |
4680 | ||
29bf4a5e | 4681 | if (iter->trace->pipe_close) |
c521efd1 SR |
4682 | iter->trace->pipe_close(iter); |
4683 | ||
b04cc6b1 FW |
4684 | mutex_unlock(&trace_types_lock); |
4685 | ||
4462344e | 4686 | free_cpumask_var(iter->started); |
d7350c3f | 4687 | mutex_destroy(&iter->mutex); |
b3806b43 | 4688 | kfree(iter); |
b3806b43 | 4689 | |
7b85af63 SRRH |
4690 | trace_array_put(tr); |
4691 | ||
b3806b43 SR |
4692 | return 0; |
4693 | } | |
4694 | ||
2a2cc8f7 | 4695 | static unsigned int |
cc60cdc9 | 4696 | trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table) |
2a2cc8f7 | 4697 | { |
983f938a SRRH |
4698 | struct trace_array *tr = iter->tr; |
4699 | ||
15693458 SRRH |
4700 | /* Iterators are static, they should be filled or empty */ |
4701 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
4702 | return POLLIN | POLLRDNORM; | |
2a2cc8f7 | 4703 | |
983f938a | 4704 | if (tr->trace_flags & TRACE_ITER_BLOCK) |
2a2cc8f7 SSP |
4705 | /* |
4706 | * Always select as readable when in blocking mode | |
4707 | */ | |
4708 | return POLLIN | POLLRDNORM; | |
15693458 | 4709 | else |
12883efb | 4710 | return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file, |
15693458 | 4711 | filp, poll_table); |
2a2cc8f7 | 4712 | } |
2a2cc8f7 | 4713 | |
cc60cdc9 SR |
4714 | static unsigned int |
4715 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
4716 | { | |
4717 | struct trace_iterator *iter = filp->private_data; | |
4718 | ||
4719 | return trace_poll(iter, filp, poll_table); | |
2a2cc8f7 SSP |
4720 | } |
4721 | ||
d716ff71 | 4722 | /* Must be called with iter->mutex held. */ |
ff98781b | 4723 | static int tracing_wait_pipe(struct file *filp) |
b3806b43 SR |
4724 | { |
4725 | struct trace_iterator *iter = filp->private_data; | |
8b8b3683 | 4726 | int ret; |
b3806b43 | 4727 | |
b3806b43 | 4728 | while (trace_empty(iter)) { |
2dc8f095 | 4729 | |
107bad8b | 4730 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 4731 | return -EAGAIN; |
107bad8b | 4732 | } |
2dc8f095 | 4733 | |
b3806b43 | 4734 | /* |
250bfd3d | 4735 | * We block until we read something and tracing is disabled. |
b3806b43 SR |
4736 | * We still block if tracing is disabled, but we have never |
4737 | * read anything. This allows a user to cat this file, and | |
4738 | * then enable tracing. But after we have read something, | |
4739 | * we give an EOF when tracing is again disabled. | |
4740 | * | |
4741 | * iter->pos will be 0 if we haven't read anything. | |
4742 | */ | |
10246fa3 | 4743 | if (!tracing_is_on() && iter->pos) |
b3806b43 | 4744 | break; |
f4874261 SRRH |
4745 | |
4746 | mutex_unlock(&iter->mutex); | |
4747 | ||
e30f53aa | 4748 | ret = wait_on_pipe(iter, false); |
f4874261 SRRH |
4749 | |
4750 | mutex_lock(&iter->mutex); | |
4751 | ||
8b8b3683 SRRH |
4752 | if (ret) |
4753 | return ret; | |
b3806b43 SR |
4754 | } |
4755 | ||
ff98781b EGM |
4756 | return 1; |
4757 | } | |
4758 | ||
4759 | /* | |
4760 | * Consumer reader. | |
4761 | */ | |
4762 | static ssize_t | |
4763 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
4764 | size_t cnt, loff_t *ppos) | |
4765 | { | |
4766 | struct trace_iterator *iter = filp->private_data; | |
4767 | ssize_t sret; | |
4768 | ||
4769 | /* return any leftover data */ | |
4770 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
4771 | if (sret != -EBUSY) | |
4772 | return sret; | |
4773 | ||
f9520750 | 4774 | trace_seq_init(&iter->seq); |
ff98781b | 4775 | |
d7350c3f FW |
4776 | /* |
4777 | * Avoid more than one consumer on a single file descriptor | |
4778 | * This is just a matter of traces coherency, the ring buffer itself | |
4779 | * is protected. | |
4780 | */ | |
4781 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
4782 | if (iter->trace->read) { |
4783 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
4784 | if (sret) | |
4785 | goto out; | |
4786 | } | |
4787 | ||
4788 | waitagain: | |
4789 | sret = tracing_wait_pipe(filp); | |
4790 | if (sret <= 0) | |
4791 | goto out; | |
4792 | ||
b3806b43 | 4793 | /* stop when tracing is finished */ |
ff98781b EGM |
4794 | if (trace_empty(iter)) { |
4795 | sret = 0; | |
107bad8b | 4796 | goto out; |
ff98781b | 4797 | } |
b3806b43 SR |
4798 | |
4799 | if (cnt >= PAGE_SIZE) | |
4800 | cnt = PAGE_SIZE - 1; | |
4801 | ||
53d0aa77 | 4802 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
4803 | memset(&iter->seq, 0, |
4804 | sizeof(struct trace_iterator) - | |
4805 | offsetof(struct trace_iterator, seq)); | |
ed5467da | 4806 | cpumask_clear(iter->started); |
4823ed7e | 4807 | iter->pos = -1; |
b3806b43 | 4808 | |
4f535968 | 4809 | trace_event_read_lock(); |
7e53bd42 | 4810 | trace_access_lock(iter->cpu_file); |
955b61e5 | 4811 | while (trace_find_next_entry_inc(iter) != NULL) { |
2c4f035f | 4812 | enum print_line_t ret; |
5ac48378 | 4813 | int save_len = iter->seq.seq.len; |
088b1e42 | 4814 | |
f9896bf3 | 4815 | ret = print_trace_line(iter); |
2c4f035f | 4816 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 | 4817 | /* don't print partial lines */ |
5ac48378 | 4818 | iter->seq.seq.len = save_len; |
b3806b43 | 4819 | break; |
088b1e42 | 4820 | } |
b91facc3 FW |
4821 | if (ret != TRACE_TYPE_NO_CONSUME) |
4822 | trace_consume(iter); | |
b3806b43 | 4823 | |
5ac48378 | 4824 | if (trace_seq_used(&iter->seq) >= cnt) |
b3806b43 | 4825 | break; |
ee5e51f5 JO |
4826 | |
4827 | /* | |
4828 | * Setting the full flag means we reached the trace_seq buffer | |
4829 | * size and we should leave by partial output condition above. | |
4830 | * One of the trace_seq_* functions is not used properly. | |
4831 | */ | |
4832 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
4833 | iter->ent->type); | |
b3806b43 | 4834 | } |
7e53bd42 | 4835 | trace_access_unlock(iter->cpu_file); |
4f535968 | 4836 | trace_event_read_unlock(); |
b3806b43 | 4837 | |
b3806b43 | 4838 | /* Now copy what we have to the user */ |
6c6c2796 | 4839 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
5ac48378 | 4840 | if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq)) |
f9520750 | 4841 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
4842 | |
4843 | /* | |
25985edc | 4844 | * If there was nothing to send to user, in spite of consuming trace |
9ff4b974 PP |
4845 | * entries, go back to wait for more entries. |
4846 | */ | |
6c6c2796 | 4847 | if (sret == -EBUSY) |
9ff4b974 | 4848 | goto waitagain; |
b3806b43 | 4849 | |
107bad8b | 4850 | out: |
d7350c3f | 4851 | mutex_unlock(&iter->mutex); |
107bad8b | 4852 | |
6c6c2796 | 4853 | return sret; |
b3806b43 SR |
4854 | } |
4855 | ||
3c56819b EGM |
4856 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, |
4857 | unsigned int idx) | |
4858 | { | |
4859 | __free_page(spd->pages[idx]); | |
4860 | } | |
4861 | ||
28dfef8f | 4862 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { |
34cd4998 | 4863 | .can_merge = 0, |
34cd4998 | 4864 | .confirm = generic_pipe_buf_confirm, |
92fdd98c | 4865 | .release = generic_pipe_buf_release, |
34cd4998 SR |
4866 | .steal = generic_pipe_buf_steal, |
4867 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
4868 | }; |
4869 | ||
34cd4998 | 4870 | static size_t |
fa7c7f6e | 4871 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
4872 | { |
4873 | size_t count; | |
74f06bb7 | 4874 | int save_len; |
34cd4998 SR |
4875 | int ret; |
4876 | ||
4877 | /* Seq buffer is page-sized, exactly what we need. */ | |
4878 | for (;;) { | |
74f06bb7 | 4879 | save_len = iter->seq.seq.len; |
34cd4998 | 4880 | ret = print_trace_line(iter); |
74f06bb7 SRRH |
4881 | |
4882 | if (trace_seq_has_overflowed(&iter->seq)) { | |
4883 | iter->seq.seq.len = save_len; | |
34cd4998 SR |
4884 | break; |
4885 | } | |
74f06bb7 SRRH |
4886 | |
4887 | /* | |
4888 | * This should not be hit, because it should only | |
4889 | * be set if the iter->seq overflowed. But check it | |
4890 | * anyway to be safe. | |
4891 | */ | |
34cd4998 | 4892 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
74f06bb7 SRRH |
4893 | iter->seq.seq.len = save_len; |
4894 | break; | |
4895 | } | |
4896 | ||
5ac48378 | 4897 | count = trace_seq_used(&iter->seq) - save_len; |
74f06bb7 SRRH |
4898 | if (rem < count) { |
4899 | rem = 0; | |
4900 | iter->seq.seq.len = save_len; | |
34cd4998 SR |
4901 | break; |
4902 | } | |
4903 | ||
74e7ff8c LJ |
4904 | if (ret != TRACE_TYPE_NO_CONSUME) |
4905 | trace_consume(iter); | |
34cd4998 | 4906 | rem -= count; |
955b61e5 | 4907 | if (!trace_find_next_entry_inc(iter)) { |
34cd4998 SR |
4908 | rem = 0; |
4909 | iter->ent = NULL; | |
4910 | break; | |
4911 | } | |
4912 | } | |
4913 | ||
4914 | return rem; | |
4915 | } | |
4916 | ||
3c56819b EGM |
4917 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
4918 | loff_t *ppos, | |
4919 | struct pipe_inode_info *pipe, | |
4920 | size_t len, | |
4921 | unsigned int flags) | |
4922 | { | |
35f3d14d JA |
4923 | struct page *pages_def[PIPE_DEF_BUFFERS]; |
4924 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3c56819b EGM |
4925 | struct trace_iterator *iter = filp->private_data; |
4926 | struct splice_pipe_desc spd = { | |
35f3d14d JA |
4927 | .pages = pages_def, |
4928 | .partial = partial_def, | |
34cd4998 | 4929 | .nr_pages = 0, /* This gets updated below. */ |
047fe360 | 4930 | .nr_pages_max = PIPE_DEF_BUFFERS, |
34cd4998 SR |
4931 | .flags = flags, |
4932 | .ops = &tracing_pipe_buf_ops, | |
4933 | .spd_release = tracing_spd_release_pipe, | |
3c56819b EGM |
4934 | }; |
4935 | ssize_t ret; | |
34cd4998 | 4936 | size_t rem; |
3c56819b EGM |
4937 | unsigned int i; |
4938 | ||
35f3d14d JA |
4939 | if (splice_grow_spd(pipe, &spd)) |
4940 | return -ENOMEM; | |
4941 | ||
d7350c3f | 4942 | mutex_lock(&iter->mutex); |
3c56819b EGM |
4943 | |
4944 | if (iter->trace->splice_read) { | |
4945 | ret = iter->trace->splice_read(iter, filp, | |
4946 | ppos, pipe, len, flags); | |
4947 | if (ret) | |
34cd4998 | 4948 | goto out_err; |
3c56819b EGM |
4949 | } |
4950 | ||
4951 | ret = tracing_wait_pipe(filp); | |
4952 | if (ret <= 0) | |
34cd4998 | 4953 | goto out_err; |
3c56819b | 4954 | |
955b61e5 | 4955 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { |
3c56819b | 4956 | ret = -EFAULT; |
34cd4998 | 4957 | goto out_err; |
3c56819b EGM |
4958 | } |
4959 | ||
4f535968 | 4960 | trace_event_read_lock(); |
7e53bd42 | 4961 | trace_access_lock(iter->cpu_file); |
4f535968 | 4962 | |
3c56819b | 4963 | /* Fill as many pages as possible. */ |
a786c06d | 4964 | for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) { |
35f3d14d JA |
4965 | spd.pages[i] = alloc_page(GFP_KERNEL); |
4966 | if (!spd.pages[i]) | |
34cd4998 | 4967 | break; |
3c56819b | 4968 | |
fa7c7f6e | 4969 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
4970 | |
4971 | /* Copy the data into the page, so we can start over. */ | |
4972 | ret = trace_seq_to_buffer(&iter->seq, | |
35f3d14d | 4973 | page_address(spd.pages[i]), |
5ac48378 | 4974 | trace_seq_used(&iter->seq)); |
3c56819b | 4975 | if (ret < 0) { |
35f3d14d | 4976 | __free_page(spd.pages[i]); |
3c56819b EGM |
4977 | break; |
4978 | } | |
35f3d14d | 4979 | spd.partial[i].offset = 0; |
5ac48378 | 4980 | spd.partial[i].len = trace_seq_used(&iter->seq); |
3c56819b | 4981 | |
f9520750 | 4982 | trace_seq_init(&iter->seq); |
3c56819b EGM |
4983 | } |
4984 | ||
7e53bd42 | 4985 | trace_access_unlock(iter->cpu_file); |
4f535968 | 4986 | trace_event_read_unlock(); |
d7350c3f | 4987 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
4988 | |
4989 | spd.nr_pages = i; | |
4990 | ||
a29054d9 SRRH |
4991 | if (i) |
4992 | ret = splice_to_pipe(pipe, &spd); | |
4993 | else | |
4994 | ret = 0; | |
35f3d14d | 4995 | out: |
047fe360 | 4996 | splice_shrink_spd(&spd); |
35f3d14d | 4997 | return ret; |
3c56819b | 4998 | |
34cd4998 | 4999 | out_err: |
d7350c3f | 5000 | mutex_unlock(&iter->mutex); |
35f3d14d | 5001 | goto out; |
3c56819b EGM |
5002 | } |
5003 | ||
a98a3c3f SR |
5004 | static ssize_t |
5005 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
5006 | size_t cnt, loff_t *ppos) | |
5007 | { | |
0bc392ee ON |
5008 | struct inode *inode = file_inode(filp); |
5009 | struct trace_array *tr = inode->i_private; | |
5010 | int cpu = tracing_get_cpu(inode); | |
438ced17 VN |
5011 | char buf[64]; |
5012 | int r = 0; | |
5013 | ssize_t ret; | |
a98a3c3f | 5014 | |
db526ca3 | 5015 | mutex_lock(&trace_types_lock); |
438ced17 | 5016 | |
0bc392ee | 5017 | if (cpu == RING_BUFFER_ALL_CPUS) { |
438ced17 VN |
5018 | int cpu, buf_size_same; |
5019 | unsigned long size; | |
5020 | ||
5021 | size = 0; | |
5022 | buf_size_same = 1; | |
5023 | /* check if all cpu sizes are same */ | |
5024 | for_each_tracing_cpu(cpu) { | |
5025 | /* fill in the size from first enabled cpu */ | |
5026 | if (size == 0) | |
12883efb SRRH |
5027 | size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries; |
5028 | if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) { | |
438ced17 VN |
5029 | buf_size_same = 0; |
5030 | break; | |
5031 | } | |
5032 | } | |
5033 | ||
5034 | if (buf_size_same) { | |
5035 | if (!ring_buffer_expanded) | |
5036 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
5037 | size >> 10, | |
5038 | trace_buf_size >> 10); | |
5039 | else | |
5040 | r = sprintf(buf, "%lu\n", size >> 10); | |
5041 | } else | |
5042 | r = sprintf(buf, "X\n"); | |
5043 | } else | |
0bc392ee | 5044 | r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10); |
438ced17 | 5045 | |
db526ca3 SR |
5046 | mutex_unlock(&trace_types_lock); |
5047 | ||
438ced17 VN |
5048 | ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
5049 | return ret; | |
a98a3c3f SR |
5050 | } |
5051 | ||
5052 | static ssize_t | |
5053 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
5054 | size_t cnt, loff_t *ppos) | |
5055 | { | |
0bc392ee ON |
5056 | struct inode *inode = file_inode(filp); |
5057 | struct trace_array *tr = inode->i_private; | |
a98a3c3f | 5058 | unsigned long val; |
4f271a2a | 5059 | int ret; |
a98a3c3f | 5060 | |
22fe9b54 PH |
5061 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
5062 | if (ret) | |
c6caeeb1 | 5063 | return ret; |
a98a3c3f SR |
5064 | |
5065 | /* must have at least 1 entry */ | |
5066 | if (!val) | |
5067 | return -EINVAL; | |
5068 | ||
1696b2b0 SR |
5069 | /* value is in KB */ |
5070 | val <<= 10; | |
0bc392ee | 5071 | ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode)); |
4f271a2a VN |
5072 | if (ret < 0) |
5073 | return ret; | |
a98a3c3f | 5074 | |
cf8517cf | 5075 | *ppos += cnt; |
a98a3c3f | 5076 | |
4f271a2a VN |
5077 | return cnt; |
5078 | } | |
bf5e6519 | 5079 | |
f81ab074 VN |
5080 | static ssize_t |
5081 | tracing_total_entries_read(struct file *filp, char __user *ubuf, | |
5082 | size_t cnt, loff_t *ppos) | |
5083 | { | |
5084 | struct trace_array *tr = filp->private_data; | |
5085 | char buf[64]; | |
5086 | int r, cpu; | |
5087 | unsigned long size = 0, expanded_size = 0; | |
5088 | ||
5089 | mutex_lock(&trace_types_lock); | |
5090 | for_each_tracing_cpu(cpu) { | |
12883efb | 5091 | size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10; |
f81ab074 VN |
5092 | if (!ring_buffer_expanded) |
5093 | expanded_size += trace_buf_size >> 10; | |
5094 | } | |
5095 | if (ring_buffer_expanded) | |
5096 | r = sprintf(buf, "%lu\n", size); | |
5097 | else | |
5098 | r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); | |
5099 | mutex_unlock(&trace_types_lock); | |
5100 | ||
5101 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
5102 | } | |
5103 | ||
4f271a2a VN |
5104 | static ssize_t |
5105 | tracing_free_buffer_write(struct file *filp, const char __user *ubuf, | |
5106 | size_t cnt, loff_t *ppos) | |
5107 | { | |
5108 | /* | |
5109 | * There is no need to read what the user has written, this function | |
5110 | * is just to make sure that there is no error when "echo" is used | |
5111 | */ | |
5112 | ||
5113 | *ppos += cnt; | |
a98a3c3f SR |
5114 | |
5115 | return cnt; | |
5116 | } | |
5117 | ||
4f271a2a VN |
5118 | static int |
5119 | tracing_free_buffer_release(struct inode *inode, struct file *filp) | |
5120 | { | |
2b6080f2 SR |
5121 | struct trace_array *tr = inode->i_private; |
5122 | ||
cf30cf67 | 5123 | /* disable tracing ? */ |
983f938a | 5124 | if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE) |
711e1243 | 5125 | tracer_tracing_off(tr); |
4f271a2a | 5126 | /* resize the ring buffer to 0 */ |
2b6080f2 | 5127 | tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS); |
4f271a2a | 5128 | |
7b85af63 SRRH |
5129 | trace_array_put(tr); |
5130 | ||
4f271a2a VN |
5131 | return 0; |
5132 | } | |
5133 | ||
5bf9a1ee PP |
5134 | static ssize_t |
5135 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
5136 | size_t cnt, loff_t *fpos) | |
5137 | { | |
d696b58c | 5138 | unsigned long addr = (unsigned long)ubuf; |
2d71619c | 5139 | struct trace_array *tr = filp->private_data; |
d696b58c SR |
5140 | struct ring_buffer_event *event; |
5141 | struct ring_buffer *buffer; | |
5142 | struct print_entry *entry; | |
5143 | unsigned long irq_flags; | |
5144 | struct page *pages[2]; | |
6edb2a8a | 5145 | void *map_page[2]; |
d696b58c SR |
5146 | int nr_pages = 1; |
5147 | ssize_t written; | |
d696b58c SR |
5148 | int offset; |
5149 | int size; | |
5150 | int len; | |
5151 | int ret; | |
6edb2a8a | 5152 | int i; |
5bf9a1ee | 5153 | |
c76f0694 | 5154 | if (tracing_disabled) |
5bf9a1ee PP |
5155 | return -EINVAL; |
5156 | ||
983f938a | 5157 | if (!(tr->trace_flags & TRACE_ITER_MARKERS)) |
5224c3a3 MSB |
5158 | return -EINVAL; |
5159 | ||
5bf9a1ee PP |
5160 | if (cnt > TRACE_BUF_SIZE) |
5161 | cnt = TRACE_BUF_SIZE; | |
5162 | ||
d696b58c SR |
5163 | /* |
5164 | * Userspace is injecting traces into the kernel trace buffer. | |
5165 | * We want to be as non intrusive as possible. | |
5166 | * To do so, we do not want to allocate any special buffers | |
5167 | * or take any locks, but instead write the userspace data | |
5168 | * straight into the ring buffer. | |
5169 | * | |
5170 | * First we need to pin the userspace buffer into memory, | |
5171 | * which, most likely it is, because it just referenced it. | |
5172 | * But there's no guarantee that it is. By using get_user_pages_fast() | |
5173 | * and kmap_atomic/kunmap_atomic() we can get access to the | |
5174 | * pages directly. We then write the data directly into the | |
5175 | * ring buffer. | |
5176 | */ | |
5177 | BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); | |
5bf9a1ee | 5178 | |
d696b58c SR |
5179 | /* check if we cross pages */ |
5180 | if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) | |
5181 | nr_pages = 2; | |
5182 | ||
5183 | offset = addr & (PAGE_SIZE - 1); | |
5184 | addr &= PAGE_MASK; | |
5185 | ||
5186 | ret = get_user_pages_fast(addr, nr_pages, 0, pages); | |
5187 | if (ret < nr_pages) { | |
5188 | while (--ret >= 0) | |
5189 | put_page(pages[ret]); | |
5190 | written = -EFAULT; | |
5191 | goto out; | |
5bf9a1ee | 5192 | } |
d696b58c | 5193 | |
6edb2a8a SR |
5194 | for (i = 0; i < nr_pages; i++) |
5195 | map_page[i] = kmap_atomic(pages[i]); | |
d696b58c SR |
5196 | |
5197 | local_save_flags(irq_flags); | |
5198 | size = sizeof(*entry) + cnt + 2; /* possible \n added */ | |
2d71619c | 5199 | buffer = tr->trace_buffer.buffer; |
d696b58c SR |
5200 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
5201 | irq_flags, preempt_count()); | |
5202 | if (!event) { | |
5203 | /* Ring buffer disabled, return as if not open for write */ | |
5204 | written = -EBADF; | |
5205 | goto out_unlock; | |
5bf9a1ee | 5206 | } |
d696b58c SR |
5207 | |
5208 | entry = ring_buffer_event_data(event); | |
5209 | entry->ip = _THIS_IP_; | |
5210 | ||
5211 | if (nr_pages == 2) { | |
5212 | len = PAGE_SIZE - offset; | |
6edb2a8a SR |
5213 | memcpy(&entry->buf, map_page[0] + offset, len); |
5214 | memcpy(&entry->buf[len], map_page[1], cnt - len); | |
c13d2f7c | 5215 | } else |
6edb2a8a | 5216 | memcpy(&entry->buf, map_page[0] + offset, cnt); |
5bf9a1ee | 5217 | |
d696b58c SR |
5218 | if (entry->buf[cnt - 1] != '\n') { |
5219 | entry->buf[cnt] = '\n'; | |
5220 | entry->buf[cnt + 1] = '\0'; | |
5221 | } else | |
5222 | entry->buf[cnt] = '\0'; | |
5223 | ||
7ffbd48d | 5224 | __buffer_unlock_commit(buffer, event); |
5bf9a1ee | 5225 | |
d696b58c | 5226 | written = cnt; |
5bf9a1ee | 5227 | |
d696b58c | 5228 | *fpos += written; |
1aa54bca | 5229 | |
d696b58c | 5230 | out_unlock: |
7215853e | 5231 | for (i = nr_pages - 1; i >= 0; i--) { |
6edb2a8a SR |
5232 | kunmap_atomic(map_page[i]); |
5233 | put_page(pages[i]); | |
5234 | } | |
d696b58c | 5235 | out: |
1aa54bca | 5236 | return written; |
5bf9a1ee PP |
5237 | } |
5238 | ||
13f16d20 | 5239 | static int tracing_clock_show(struct seq_file *m, void *v) |
5079f326 | 5240 | { |
2b6080f2 | 5241 | struct trace_array *tr = m->private; |
5079f326 Z |
5242 | int i; |
5243 | ||
5244 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
13f16d20 | 5245 | seq_printf(m, |
5079f326 | 5246 | "%s%s%s%s", i ? " " : "", |
2b6080f2 SR |
5247 | i == tr->clock_id ? "[" : "", trace_clocks[i].name, |
5248 | i == tr->clock_id ? "]" : ""); | |
13f16d20 | 5249 | seq_putc(m, '\n'); |
5079f326 | 5250 | |
13f16d20 | 5251 | return 0; |
5079f326 Z |
5252 | } |
5253 | ||
e1e232ca | 5254 | static int tracing_set_clock(struct trace_array *tr, const char *clockstr) |
5079f326 | 5255 | { |
5079f326 Z |
5256 | int i; |
5257 | ||
5079f326 Z |
5258 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { |
5259 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
5260 | break; | |
5261 | } | |
5262 | if (i == ARRAY_SIZE(trace_clocks)) | |
5263 | return -EINVAL; | |
5264 | ||
5079f326 Z |
5265 | mutex_lock(&trace_types_lock); |
5266 | ||
2b6080f2 SR |
5267 | tr->clock_id = i; |
5268 | ||
12883efb | 5269 | ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func); |
5079f326 | 5270 | |
60303ed3 DS |
5271 | /* |
5272 | * New clock may not be consistent with the previous clock. | |
5273 | * Reset the buffer so that it doesn't have incomparable timestamps. | |
5274 | */ | |
9457158b | 5275 | tracing_reset_online_cpus(&tr->trace_buffer); |
12883efb SRRH |
5276 | |
5277 | #ifdef CONFIG_TRACER_MAX_TRACE | |
5278 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer) | |
5279 | ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); | |
9457158b | 5280 | tracing_reset_online_cpus(&tr->max_buffer); |
12883efb | 5281 | #endif |
60303ed3 | 5282 | |
5079f326 Z |
5283 | mutex_unlock(&trace_types_lock); |
5284 | ||
e1e232ca SR |
5285 | return 0; |
5286 | } | |
5287 | ||
5288 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
5289 | size_t cnt, loff_t *fpos) | |
5290 | { | |
5291 | struct seq_file *m = filp->private_data; | |
5292 | struct trace_array *tr = m->private; | |
5293 | char buf[64]; | |
5294 | const char *clockstr; | |
5295 | int ret; | |
5296 | ||
5297 | if (cnt >= sizeof(buf)) | |
5298 | return -EINVAL; | |
5299 | ||
5300 | if (copy_from_user(&buf, ubuf, cnt)) | |
5301 | return -EFAULT; | |
5302 | ||
5303 | buf[cnt] = 0; | |
5304 | ||
5305 | clockstr = strstrip(buf); | |
5306 | ||
5307 | ret = tracing_set_clock(tr, clockstr); | |
5308 | if (ret) | |
5309 | return ret; | |
5310 | ||
5079f326 Z |
5311 | *fpos += cnt; |
5312 | ||
5313 | return cnt; | |
5314 | } | |
5315 | ||
13f16d20 LZ |
5316 | static int tracing_clock_open(struct inode *inode, struct file *file) |
5317 | { | |
7b85af63 SRRH |
5318 | struct trace_array *tr = inode->i_private; |
5319 | int ret; | |
5320 | ||
13f16d20 LZ |
5321 | if (tracing_disabled) |
5322 | return -ENODEV; | |
2b6080f2 | 5323 | |
7b85af63 SRRH |
5324 | if (trace_array_get(tr)) |
5325 | return -ENODEV; | |
5326 | ||
5327 | ret = single_open(file, tracing_clock_show, inode->i_private); | |
5328 | if (ret < 0) | |
5329 | trace_array_put(tr); | |
5330 | ||
5331 | return ret; | |
13f16d20 LZ |
5332 | } |
5333 | ||
6de58e62 SRRH |
5334 | struct ftrace_buffer_info { |
5335 | struct trace_iterator iter; | |
5336 | void *spare; | |
5337 | unsigned int read; | |
5338 | }; | |
5339 | ||
debdd57f HT |
5340 | #ifdef CONFIG_TRACER_SNAPSHOT |
5341 | static int tracing_snapshot_open(struct inode *inode, struct file *file) | |
5342 | { | |
6484c71c | 5343 | struct trace_array *tr = inode->i_private; |
debdd57f | 5344 | struct trace_iterator *iter; |
2b6080f2 | 5345 | struct seq_file *m; |
debdd57f HT |
5346 | int ret = 0; |
5347 | ||
ff451961 SRRH |
5348 | if (trace_array_get(tr) < 0) |
5349 | return -ENODEV; | |
5350 | ||
debdd57f | 5351 | if (file->f_mode & FMODE_READ) { |
6484c71c | 5352 | iter = __tracing_open(inode, file, true); |
debdd57f HT |
5353 | if (IS_ERR(iter)) |
5354 | ret = PTR_ERR(iter); | |
2b6080f2 SR |
5355 | } else { |
5356 | /* Writes still need the seq_file to hold the private data */ | |
f77d09a3 | 5357 | ret = -ENOMEM; |
2b6080f2 SR |
5358 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
5359 | if (!m) | |
f77d09a3 | 5360 | goto out; |
2b6080f2 SR |
5361 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
5362 | if (!iter) { | |
5363 | kfree(m); | |
f77d09a3 | 5364 | goto out; |
2b6080f2 | 5365 | } |
f77d09a3 AL |
5366 | ret = 0; |
5367 | ||
ff451961 | 5368 | iter->tr = tr; |
6484c71c ON |
5369 | iter->trace_buffer = &tr->max_buffer; |
5370 | iter->cpu_file = tracing_get_cpu(inode); | |
2b6080f2 SR |
5371 | m->private = iter; |
5372 | file->private_data = m; | |
debdd57f | 5373 | } |
f77d09a3 | 5374 | out: |
ff451961 SRRH |
5375 | if (ret < 0) |
5376 | trace_array_put(tr); | |
5377 | ||
debdd57f HT |
5378 | return ret; |
5379 | } | |
5380 | ||
5381 | static ssize_t | |
5382 | tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
5383 | loff_t *ppos) | |
5384 | { | |
2b6080f2 SR |
5385 | struct seq_file *m = filp->private_data; |
5386 | struct trace_iterator *iter = m->private; | |
5387 | struct trace_array *tr = iter->tr; | |
debdd57f HT |
5388 | unsigned long val; |
5389 | int ret; | |
5390 | ||
5391 | ret = tracing_update_buffers(); | |
5392 | if (ret < 0) | |
5393 | return ret; | |
5394 | ||
5395 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
5396 | if (ret) | |
5397 | return ret; | |
5398 | ||
5399 | mutex_lock(&trace_types_lock); | |
5400 | ||
2b6080f2 | 5401 | if (tr->current_trace->use_max_tr) { |
debdd57f HT |
5402 | ret = -EBUSY; |
5403 | goto out; | |
5404 | } | |
5405 | ||
5406 | switch (val) { | |
5407 | case 0: | |
f1affcaa SRRH |
5408 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
5409 | ret = -EINVAL; | |
5410 | break; | |
debdd57f | 5411 | } |
3209cff4 SRRH |
5412 | if (tr->allocated_snapshot) |
5413 | free_snapshot(tr); | |
debdd57f HT |
5414 | break; |
5415 | case 1: | |
f1affcaa SRRH |
5416 | /* Only allow per-cpu swap if the ring buffer supports it */ |
5417 | #ifndef CONFIG_RING_BUFFER_ALLOW_SWAP | |
5418 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { | |
5419 | ret = -EINVAL; | |
5420 | break; | |
5421 | } | |
5422 | #endif | |
45ad21ca | 5423 | if (!tr->allocated_snapshot) { |
3209cff4 | 5424 | ret = alloc_snapshot(tr); |
debdd57f HT |
5425 | if (ret < 0) |
5426 | break; | |
debdd57f | 5427 | } |
debdd57f HT |
5428 | local_irq_disable(); |
5429 | /* Now, we're going to swap */ | |
f1affcaa | 5430 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
ce9bae55 | 5431 | update_max_tr(tr, current, smp_processor_id()); |
f1affcaa | 5432 | else |
ce9bae55 | 5433 | update_max_tr_single(tr, current, iter->cpu_file); |
debdd57f HT |
5434 | local_irq_enable(); |
5435 | break; | |
5436 | default: | |
45ad21ca | 5437 | if (tr->allocated_snapshot) { |
f1affcaa SRRH |
5438 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
5439 | tracing_reset_online_cpus(&tr->max_buffer); | |
5440 | else | |
5441 | tracing_reset(&tr->max_buffer, iter->cpu_file); | |
5442 | } | |
debdd57f HT |
5443 | break; |
5444 | } | |
5445 | ||
5446 | if (ret >= 0) { | |
5447 | *ppos += cnt; | |
5448 | ret = cnt; | |
5449 | } | |
5450 | out: | |
5451 | mutex_unlock(&trace_types_lock); | |
5452 | return ret; | |
5453 | } | |
2b6080f2 SR |
5454 | |
5455 | static int tracing_snapshot_release(struct inode *inode, struct file *file) | |
5456 | { | |
5457 | struct seq_file *m = file->private_data; | |
ff451961 SRRH |
5458 | int ret; |
5459 | ||
5460 | ret = tracing_release(inode, file); | |
2b6080f2 SR |
5461 | |
5462 | if (file->f_mode & FMODE_READ) | |
ff451961 | 5463 | return ret; |
2b6080f2 SR |
5464 | |
5465 | /* If write only, the seq_file is just a stub */ | |
5466 | if (m) | |
5467 | kfree(m->private); | |
5468 | kfree(m); | |
5469 | ||
5470 | return 0; | |
5471 | } | |
5472 | ||
6de58e62 SRRH |
5473 | static int tracing_buffers_open(struct inode *inode, struct file *filp); |
5474 | static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, | |
5475 | size_t count, loff_t *ppos); | |
5476 | static int tracing_buffers_release(struct inode *inode, struct file *file); | |
5477 | static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5478 | struct pipe_inode_info *pipe, size_t len, unsigned int flags); | |
5479 | ||
5480 | static int snapshot_raw_open(struct inode *inode, struct file *filp) | |
5481 | { | |
5482 | struct ftrace_buffer_info *info; | |
5483 | int ret; | |
5484 | ||
5485 | ret = tracing_buffers_open(inode, filp); | |
5486 | if (ret < 0) | |
5487 | return ret; | |
5488 | ||
5489 | info = filp->private_data; | |
5490 | ||
5491 | if (info->iter.trace->use_max_tr) { | |
5492 | tracing_buffers_release(inode, filp); | |
5493 | return -EBUSY; | |
5494 | } | |
5495 | ||
5496 | info->iter.snapshot = true; | |
5497 | info->iter.trace_buffer = &info->iter.tr->max_buffer; | |
5498 | ||
5499 | return ret; | |
5500 | } | |
5501 | ||
debdd57f HT |
5502 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
5503 | ||
5504 | ||
6508fa76 SF |
5505 | static const struct file_operations tracing_thresh_fops = { |
5506 | .open = tracing_open_generic, | |
5507 | .read = tracing_thresh_read, | |
5508 | .write = tracing_thresh_write, | |
5509 | .llseek = generic_file_llseek, | |
5510 | }; | |
5511 | ||
e428abbb | 5512 | #ifdef CONFIG_TRACER_MAX_TRACE |
5e2336a0 | 5513 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
5514 | .open = tracing_open_generic, |
5515 | .read = tracing_max_lat_read, | |
5516 | .write = tracing_max_lat_write, | |
b444786f | 5517 | .llseek = generic_file_llseek, |
bc0c38d1 | 5518 | }; |
e428abbb | 5519 | #endif |
bc0c38d1 | 5520 | |
5e2336a0 | 5521 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
5522 | .open = tracing_open_generic, |
5523 | .read = tracing_set_trace_read, | |
5524 | .write = tracing_set_trace_write, | |
b444786f | 5525 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
5526 | }; |
5527 | ||
5e2336a0 | 5528 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 5529 | .open = tracing_open_pipe, |
2a2cc8f7 | 5530 | .poll = tracing_poll_pipe, |
4bf39a94 | 5531 | .read = tracing_read_pipe, |
3c56819b | 5532 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 5533 | .release = tracing_release_pipe, |
b444786f | 5534 | .llseek = no_llseek, |
b3806b43 SR |
5535 | }; |
5536 | ||
5e2336a0 | 5537 | static const struct file_operations tracing_entries_fops = { |
0bc392ee | 5538 | .open = tracing_open_generic_tr, |
a98a3c3f SR |
5539 | .read = tracing_entries_read, |
5540 | .write = tracing_entries_write, | |
b444786f | 5541 | .llseek = generic_file_llseek, |
0bc392ee | 5542 | .release = tracing_release_generic_tr, |
a98a3c3f SR |
5543 | }; |
5544 | ||
f81ab074 | 5545 | static const struct file_operations tracing_total_entries_fops = { |
7b85af63 | 5546 | .open = tracing_open_generic_tr, |
f81ab074 VN |
5547 | .read = tracing_total_entries_read, |
5548 | .llseek = generic_file_llseek, | |
7b85af63 | 5549 | .release = tracing_release_generic_tr, |
f81ab074 VN |
5550 | }; |
5551 | ||
4f271a2a | 5552 | static const struct file_operations tracing_free_buffer_fops = { |
7b85af63 | 5553 | .open = tracing_open_generic_tr, |
4f271a2a VN |
5554 | .write = tracing_free_buffer_write, |
5555 | .release = tracing_free_buffer_release, | |
5556 | }; | |
5557 | ||
5e2336a0 | 5558 | static const struct file_operations tracing_mark_fops = { |
7b85af63 | 5559 | .open = tracing_open_generic_tr, |
5bf9a1ee | 5560 | .write = tracing_mark_write, |
b444786f | 5561 | .llseek = generic_file_llseek, |
7b85af63 | 5562 | .release = tracing_release_generic_tr, |
5bf9a1ee PP |
5563 | }; |
5564 | ||
5079f326 | 5565 | static const struct file_operations trace_clock_fops = { |
13f16d20 LZ |
5566 | .open = tracing_clock_open, |
5567 | .read = seq_read, | |
5568 | .llseek = seq_lseek, | |
7b85af63 | 5569 | .release = tracing_single_release_tr, |
5079f326 Z |
5570 | .write = tracing_clock_write, |
5571 | }; | |
5572 | ||
debdd57f HT |
5573 | #ifdef CONFIG_TRACER_SNAPSHOT |
5574 | static const struct file_operations snapshot_fops = { | |
5575 | .open = tracing_snapshot_open, | |
5576 | .read = seq_read, | |
5577 | .write = tracing_snapshot_write, | |
098c879e | 5578 | .llseek = tracing_lseek, |
2b6080f2 | 5579 | .release = tracing_snapshot_release, |
debdd57f | 5580 | }; |
debdd57f | 5581 | |
6de58e62 SRRH |
5582 | static const struct file_operations snapshot_raw_fops = { |
5583 | .open = snapshot_raw_open, | |
5584 | .read = tracing_buffers_read, | |
5585 | .release = tracing_buffers_release, | |
5586 | .splice_read = tracing_buffers_splice_read, | |
5587 | .llseek = no_llseek, | |
2cadf913 SR |
5588 | }; |
5589 | ||
6de58e62 SRRH |
5590 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
5591 | ||
2cadf913 SR |
5592 | static int tracing_buffers_open(struct inode *inode, struct file *filp) |
5593 | { | |
46ef2be0 | 5594 | struct trace_array *tr = inode->i_private; |
2cadf913 | 5595 | struct ftrace_buffer_info *info; |
7b85af63 | 5596 | int ret; |
2cadf913 SR |
5597 | |
5598 | if (tracing_disabled) | |
5599 | return -ENODEV; | |
5600 | ||
7b85af63 SRRH |
5601 | if (trace_array_get(tr) < 0) |
5602 | return -ENODEV; | |
5603 | ||
2cadf913 | 5604 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
7b85af63 SRRH |
5605 | if (!info) { |
5606 | trace_array_put(tr); | |
2cadf913 | 5607 | return -ENOMEM; |
7b85af63 | 5608 | } |
2cadf913 | 5609 | |
a695cb58 SRRH |
5610 | mutex_lock(&trace_types_lock); |
5611 | ||
cc60cdc9 | 5612 | info->iter.tr = tr; |
46ef2be0 | 5613 | info->iter.cpu_file = tracing_get_cpu(inode); |
b627344f | 5614 | info->iter.trace = tr->current_trace; |
12883efb | 5615 | info->iter.trace_buffer = &tr->trace_buffer; |
cc60cdc9 | 5616 | info->spare = NULL; |
2cadf913 | 5617 | /* Force reading ring buffer for first read */ |
cc60cdc9 | 5618 | info->read = (unsigned int)-1; |
2cadf913 SR |
5619 | |
5620 | filp->private_data = info; | |
5621 | ||
cf6ab6d9 SRRH |
5622 | tr->current_trace->ref++; |
5623 | ||
a695cb58 SRRH |
5624 | mutex_unlock(&trace_types_lock); |
5625 | ||
7b85af63 SRRH |
5626 | ret = nonseekable_open(inode, filp); |
5627 | if (ret < 0) | |
5628 | trace_array_put(tr); | |
5629 | ||
5630 | return ret; | |
2cadf913 SR |
5631 | } |
5632 | ||
cc60cdc9 SR |
5633 | static unsigned int |
5634 | tracing_buffers_poll(struct file *filp, poll_table *poll_table) | |
5635 | { | |
5636 | struct ftrace_buffer_info *info = filp->private_data; | |
5637 | struct trace_iterator *iter = &info->iter; | |
5638 | ||
5639 | return trace_poll(iter, filp, poll_table); | |
5640 | } | |
5641 | ||
2cadf913 SR |
5642 | static ssize_t |
5643 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
5644 | size_t count, loff_t *ppos) | |
5645 | { | |
5646 | struct ftrace_buffer_info *info = filp->private_data; | |
cc60cdc9 | 5647 | struct trace_iterator *iter = &info->iter; |
2cadf913 | 5648 | ssize_t ret; |
6de58e62 | 5649 | ssize_t size; |
2cadf913 | 5650 | |
2dc5d12b SR |
5651 | if (!count) |
5652 | return 0; | |
5653 | ||
6de58e62 | 5654 | #ifdef CONFIG_TRACER_MAX_TRACE |
d716ff71 SRRH |
5655 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) |
5656 | return -EBUSY; | |
6de58e62 SRRH |
5657 | #endif |
5658 | ||
ddd538f3 | 5659 | if (!info->spare) |
12883efb SRRH |
5660 | info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer, |
5661 | iter->cpu_file); | |
ddd538f3 | 5662 | if (!info->spare) |
d716ff71 | 5663 | return -ENOMEM; |
ddd538f3 | 5664 | |
2cadf913 SR |
5665 | /* Do we have previous read data to read? */ |
5666 | if (info->read < PAGE_SIZE) | |
5667 | goto read; | |
5668 | ||
b627344f | 5669 | again: |
cc60cdc9 | 5670 | trace_access_lock(iter->cpu_file); |
12883efb | 5671 | ret = ring_buffer_read_page(iter->trace_buffer->buffer, |
2cadf913 SR |
5672 | &info->spare, |
5673 | count, | |
cc60cdc9 SR |
5674 | iter->cpu_file, 0); |
5675 | trace_access_unlock(iter->cpu_file); | |
2cadf913 | 5676 | |
b627344f SR |
5677 | if (ret < 0) { |
5678 | if (trace_empty(iter)) { | |
d716ff71 SRRH |
5679 | if ((filp->f_flags & O_NONBLOCK)) |
5680 | return -EAGAIN; | |
5681 | ||
e30f53aa | 5682 | ret = wait_on_pipe(iter, false); |
d716ff71 SRRH |
5683 | if (ret) |
5684 | return ret; | |
5685 | ||
b627344f SR |
5686 | goto again; |
5687 | } | |
d716ff71 | 5688 | return 0; |
b627344f | 5689 | } |
436fc280 | 5690 | |
436fc280 | 5691 | info->read = 0; |
b627344f | 5692 | read: |
2cadf913 SR |
5693 | size = PAGE_SIZE - info->read; |
5694 | if (size > count) | |
5695 | size = count; | |
5696 | ||
5697 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
d716ff71 SRRH |
5698 | if (ret == size) |
5699 | return -EFAULT; | |
5700 | ||
2dc5d12b SR |
5701 | size -= ret; |
5702 | ||
2cadf913 SR |
5703 | *ppos += size; |
5704 | info->read += size; | |
5705 | ||
5706 | return size; | |
5707 | } | |
5708 | ||
5709 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
5710 | { | |
5711 | struct ftrace_buffer_info *info = file->private_data; | |
cc60cdc9 | 5712 | struct trace_iterator *iter = &info->iter; |
2cadf913 | 5713 | |
a695cb58 SRRH |
5714 | mutex_lock(&trace_types_lock); |
5715 | ||
cf6ab6d9 SRRH |
5716 | iter->tr->current_trace->ref--; |
5717 | ||
ff451961 | 5718 | __trace_array_put(iter->tr); |
2cadf913 | 5719 | |
ddd538f3 | 5720 | if (info->spare) |
12883efb | 5721 | ring_buffer_free_read_page(iter->trace_buffer->buffer, info->spare); |
2cadf913 SR |
5722 | kfree(info); |
5723 | ||
a695cb58 SRRH |
5724 | mutex_unlock(&trace_types_lock); |
5725 | ||
2cadf913 SR |
5726 | return 0; |
5727 | } | |
5728 | ||
5729 | struct buffer_ref { | |
5730 | struct ring_buffer *buffer; | |
5731 | void *page; | |
5732 | int ref; | |
5733 | }; | |
5734 | ||
5735 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
5736 | struct pipe_buffer *buf) | |
5737 | { | |
5738 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5739 | ||
5740 | if (--ref->ref) | |
5741 | return; | |
5742 | ||
5743 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5744 | kfree(ref); | |
5745 | buf->private = 0; | |
5746 | } | |
5747 | ||
2cadf913 SR |
5748 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, |
5749 | struct pipe_buffer *buf) | |
5750 | { | |
5751 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5752 | ||
5753 | ref->ref++; | |
5754 | } | |
5755 | ||
5756 | /* Pipe buffer operations for a buffer. */ | |
28dfef8f | 5757 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
2cadf913 | 5758 | .can_merge = 0, |
2cadf913 SR |
5759 | .confirm = generic_pipe_buf_confirm, |
5760 | .release = buffer_pipe_buf_release, | |
d55cb6cf | 5761 | .steal = generic_pipe_buf_steal, |
2cadf913 SR |
5762 | .get = buffer_pipe_buf_get, |
5763 | }; | |
5764 | ||
5765 | /* | |
5766 | * Callback from splice_to_pipe(), if we need to release some pages | |
5767 | * at the end of the spd in case we error'ed out in filling the pipe. | |
5768 | */ | |
5769 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
5770 | { | |
5771 | struct buffer_ref *ref = | |
5772 | (struct buffer_ref *)spd->partial[i].private; | |
5773 | ||
5774 | if (--ref->ref) | |
5775 | return; | |
5776 | ||
5777 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5778 | kfree(ref); | |
5779 | spd->partial[i].private = 0; | |
5780 | } | |
5781 | ||
5782 | static ssize_t | |
5783 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5784 | struct pipe_inode_info *pipe, size_t len, | |
5785 | unsigned int flags) | |
5786 | { | |
5787 | struct ftrace_buffer_info *info = file->private_data; | |
cc60cdc9 | 5788 | struct trace_iterator *iter = &info->iter; |
35f3d14d JA |
5789 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
5790 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
2cadf913 | 5791 | struct splice_pipe_desc spd = { |
35f3d14d JA |
5792 | .pages = pages_def, |
5793 | .partial = partial_def, | |
047fe360 | 5794 | .nr_pages_max = PIPE_DEF_BUFFERS, |
2cadf913 SR |
5795 | .flags = flags, |
5796 | .ops = &buffer_pipe_buf_ops, | |
5797 | .spd_release = buffer_spd_release, | |
5798 | }; | |
5799 | struct buffer_ref *ref; | |
93459c6c | 5800 | int entries, size, i; |
07906da7 | 5801 | ssize_t ret = 0; |
2cadf913 | 5802 | |
6de58e62 | 5803 | #ifdef CONFIG_TRACER_MAX_TRACE |
d716ff71 SRRH |
5804 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) |
5805 | return -EBUSY; | |
6de58e62 SRRH |
5806 | #endif |
5807 | ||
d716ff71 SRRH |
5808 | if (splice_grow_spd(pipe, &spd)) |
5809 | return -ENOMEM; | |
35f3d14d | 5810 | |
d716ff71 SRRH |
5811 | if (*ppos & (PAGE_SIZE - 1)) |
5812 | return -EINVAL; | |
93cfb3c9 LJ |
5813 | |
5814 | if (len & (PAGE_SIZE - 1)) { | |
d716ff71 SRRH |
5815 | if (len < PAGE_SIZE) |
5816 | return -EINVAL; | |
93cfb3c9 LJ |
5817 | len &= PAGE_MASK; |
5818 | } | |
5819 | ||
cc60cdc9 SR |
5820 | again: |
5821 | trace_access_lock(iter->cpu_file); | |
12883efb | 5822 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); |
93459c6c | 5823 | |
a786c06d | 5824 | for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) { |
2cadf913 SR |
5825 | struct page *page; |
5826 | int r; | |
5827 | ||
5828 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
07906da7 RV |
5829 | if (!ref) { |
5830 | ret = -ENOMEM; | |
2cadf913 | 5831 | break; |
07906da7 | 5832 | } |
2cadf913 | 5833 | |
7267fa68 | 5834 | ref->ref = 1; |
12883efb | 5835 | ref->buffer = iter->trace_buffer->buffer; |
cc60cdc9 | 5836 | ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); |
2cadf913 | 5837 | if (!ref->page) { |
07906da7 | 5838 | ret = -ENOMEM; |
2cadf913 SR |
5839 | kfree(ref); |
5840 | break; | |
5841 | } | |
5842 | ||
5843 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
cc60cdc9 | 5844 | len, iter->cpu_file, 1); |
2cadf913 | 5845 | if (r < 0) { |
7ea59064 | 5846 | ring_buffer_free_read_page(ref->buffer, ref->page); |
2cadf913 SR |
5847 | kfree(ref); |
5848 | break; | |
5849 | } | |
5850 | ||
5851 | /* | |
5852 | * zero out any left over data, this is going to | |
5853 | * user land. | |
5854 | */ | |
5855 | size = ring_buffer_page_len(ref->page); | |
5856 | if (size < PAGE_SIZE) | |
5857 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
5858 | ||
5859 | page = virt_to_page(ref->page); | |
5860 | ||
5861 | spd.pages[i] = page; | |
5862 | spd.partial[i].len = PAGE_SIZE; | |
5863 | spd.partial[i].offset = 0; | |
5864 | spd.partial[i].private = (unsigned long)ref; | |
5865 | spd.nr_pages++; | |
93cfb3c9 | 5866 | *ppos += PAGE_SIZE; |
93459c6c | 5867 | |
12883efb | 5868 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); |
2cadf913 SR |
5869 | } |
5870 | ||
cc60cdc9 | 5871 | trace_access_unlock(iter->cpu_file); |
2cadf913 SR |
5872 | spd.nr_pages = i; |
5873 | ||
5874 | /* did we read anything? */ | |
5875 | if (!spd.nr_pages) { | |
07906da7 | 5876 | if (ret) |
d716ff71 SRRH |
5877 | return ret; |
5878 | ||
5879 | if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) | |
5880 | return -EAGAIN; | |
07906da7 | 5881 | |
e30f53aa | 5882 | ret = wait_on_pipe(iter, true); |
8b8b3683 | 5883 | if (ret) |
d716ff71 | 5884 | return ret; |
e30f53aa | 5885 | |
cc60cdc9 | 5886 | goto again; |
2cadf913 SR |
5887 | } |
5888 | ||
5889 | ret = splice_to_pipe(pipe, &spd); | |
047fe360 | 5890 | splice_shrink_spd(&spd); |
6de58e62 | 5891 | |
2cadf913 SR |
5892 | return ret; |
5893 | } | |
5894 | ||
5895 | static const struct file_operations tracing_buffers_fops = { | |
5896 | .open = tracing_buffers_open, | |
5897 | .read = tracing_buffers_read, | |
cc60cdc9 | 5898 | .poll = tracing_buffers_poll, |
2cadf913 SR |
5899 | .release = tracing_buffers_release, |
5900 | .splice_read = tracing_buffers_splice_read, | |
5901 | .llseek = no_llseek, | |
5902 | }; | |
5903 | ||
c8d77183 SR |
5904 | static ssize_t |
5905 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
5906 | size_t count, loff_t *ppos) | |
5907 | { | |
4d3435b8 ON |
5908 | struct inode *inode = file_inode(filp); |
5909 | struct trace_array *tr = inode->i_private; | |
12883efb | 5910 | struct trace_buffer *trace_buf = &tr->trace_buffer; |
4d3435b8 | 5911 | int cpu = tracing_get_cpu(inode); |
c8d77183 SR |
5912 | struct trace_seq *s; |
5913 | unsigned long cnt; | |
c64e148a VN |
5914 | unsigned long long t; |
5915 | unsigned long usec_rem; | |
c8d77183 | 5916 | |
e4f2d10f | 5917 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
c8d77183 | 5918 | if (!s) |
a646365c | 5919 | return -ENOMEM; |
c8d77183 SR |
5920 | |
5921 | trace_seq_init(s); | |
5922 | ||
12883efb | 5923 | cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5924 | trace_seq_printf(s, "entries: %ld\n", cnt); |
5925 | ||
12883efb | 5926 | cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5927 | trace_seq_printf(s, "overrun: %ld\n", cnt); |
5928 | ||
12883efb | 5929 | cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5930 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); |
5931 | ||
12883efb | 5932 | cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu); |
c64e148a VN |
5933 | trace_seq_printf(s, "bytes: %ld\n", cnt); |
5934 | ||
58e8eedf | 5935 | if (trace_clocks[tr->clock_id].in_ns) { |
11043d8b | 5936 | /* local or global for trace_clock */ |
12883efb | 5937 | t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
11043d8b YY |
5938 | usec_rem = do_div(t, USEC_PER_SEC); |
5939 | trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", | |
5940 | t, usec_rem); | |
5941 | ||
12883efb | 5942 | t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
11043d8b YY |
5943 | usec_rem = do_div(t, USEC_PER_SEC); |
5944 | trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); | |
5945 | } else { | |
5946 | /* counter or tsc mode for trace_clock */ | |
5947 | trace_seq_printf(s, "oldest event ts: %llu\n", | |
12883efb | 5948 | ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
c64e148a | 5949 | |
11043d8b | 5950 | trace_seq_printf(s, "now ts: %llu\n", |
12883efb | 5951 | ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
11043d8b | 5952 | } |
c64e148a | 5953 | |
12883efb | 5954 | cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu); |
884bfe89 SP |
5955 | trace_seq_printf(s, "dropped events: %ld\n", cnt); |
5956 | ||
12883efb | 5957 | cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); |
ad964704 SRRH |
5958 | trace_seq_printf(s, "read events: %ld\n", cnt); |
5959 | ||
5ac48378 SRRH |
5960 | count = simple_read_from_buffer(ubuf, count, ppos, |
5961 | s->buffer, trace_seq_used(s)); | |
c8d77183 SR |
5962 | |
5963 | kfree(s); | |
5964 | ||
5965 | return count; | |
5966 | } | |
5967 | ||
5968 | static const struct file_operations tracing_stats_fops = { | |
4d3435b8 | 5969 | .open = tracing_open_generic_tr, |
c8d77183 | 5970 | .read = tracing_stats_read, |
b444786f | 5971 | .llseek = generic_file_llseek, |
4d3435b8 | 5972 | .release = tracing_release_generic_tr, |
c8d77183 SR |
5973 | }; |
5974 | ||
bc0c38d1 SR |
5975 | #ifdef CONFIG_DYNAMIC_FTRACE |
5976 | ||
b807c3d0 SR |
5977 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
5978 | { | |
5979 | return 0; | |
5980 | } | |
5981 | ||
bc0c38d1 | 5982 | static ssize_t |
b807c3d0 | 5983 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
5984 | size_t cnt, loff_t *ppos) |
5985 | { | |
a26a2a27 SR |
5986 | static char ftrace_dyn_info_buffer[1024]; |
5987 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 5988 | unsigned long *p = filp->private_data; |
b807c3d0 | 5989 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 5990 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
5991 | int r; |
5992 | ||
b807c3d0 SR |
5993 | mutex_lock(&dyn_info_mutex); |
5994 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 5995 | |
a26a2a27 | 5996 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
5997 | buf[r++] = '\n'; |
5998 | ||
5999 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
6000 | ||
6001 | mutex_unlock(&dyn_info_mutex); | |
6002 | ||
6003 | return r; | |
bc0c38d1 SR |
6004 | } |
6005 | ||
5e2336a0 | 6006 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 6007 | .open = tracing_open_generic, |
b807c3d0 | 6008 | .read = tracing_read_dyn_info, |
b444786f | 6009 | .llseek = generic_file_llseek, |
bc0c38d1 | 6010 | }; |
77fd5c15 | 6011 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
bc0c38d1 | 6012 | |
77fd5c15 SRRH |
6013 | #if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) |
6014 | static void | |
6015 | ftrace_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
6016 | { | |
6017 | tracing_snapshot(); | |
6018 | } | |
bc0c38d1 | 6019 | |
77fd5c15 SRRH |
6020 | static void |
6021 | ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
bc0c38d1 | 6022 | { |
77fd5c15 SRRH |
6023 | unsigned long *count = (long *)data; |
6024 | ||
6025 | if (!*count) | |
6026 | return; | |
bc0c38d1 | 6027 | |
77fd5c15 SRRH |
6028 | if (*count != -1) |
6029 | (*count)--; | |
6030 | ||
6031 | tracing_snapshot(); | |
6032 | } | |
6033 | ||
6034 | static int | |
6035 | ftrace_snapshot_print(struct seq_file *m, unsigned long ip, | |
6036 | struct ftrace_probe_ops *ops, void *data) | |
6037 | { | |
6038 | long count = (long)data; | |
6039 | ||
6040 | seq_printf(m, "%ps:", (void *)ip); | |
6041 | ||
fa6f0cc7 | 6042 | seq_puts(m, "snapshot"); |
77fd5c15 SRRH |
6043 | |
6044 | if (count == -1) | |
fa6f0cc7 | 6045 | seq_puts(m, ":unlimited\n"); |
77fd5c15 SRRH |
6046 | else |
6047 | seq_printf(m, ":count=%ld\n", count); | |
6048 | ||
6049 | return 0; | |
6050 | } | |
6051 | ||
6052 | static struct ftrace_probe_ops snapshot_probe_ops = { | |
6053 | .func = ftrace_snapshot, | |
6054 | .print = ftrace_snapshot_print, | |
6055 | }; | |
6056 | ||
6057 | static struct ftrace_probe_ops snapshot_count_probe_ops = { | |
6058 | .func = ftrace_count_snapshot, | |
6059 | .print = ftrace_snapshot_print, | |
6060 | }; | |
6061 | ||
6062 | static int | |
6063 | ftrace_trace_snapshot_callback(struct ftrace_hash *hash, | |
6064 | char *glob, char *cmd, char *param, int enable) | |
6065 | { | |
6066 | struct ftrace_probe_ops *ops; | |
6067 | void *count = (void *)-1; | |
6068 | char *number; | |
6069 | int ret; | |
6070 | ||
6071 | /* hash funcs only work with set_ftrace_filter */ | |
6072 | if (!enable) | |
6073 | return -EINVAL; | |
6074 | ||
6075 | ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; | |
6076 | ||
6077 | if (glob[0] == '!') { | |
6078 | unregister_ftrace_function_probe_func(glob+1, ops); | |
6079 | return 0; | |
6080 | } | |
6081 | ||
6082 | if (!param) | |
6083 | goto out_reg; | |
6084 | ||
6085 | number = strsep(¶m, ":"); | |
6086 | ||
6087 | if (!strlen(number)) | |
6088 | goto out_reg; | |
6089 | ||
6090 | /* | |
6091 | * We use the callback data field (which is a pointer) | |
6092 | * as our counter. | |
6093 | */ | |
6094 | ret = kstrtoul(number, 0, (unsigned long *)&count); | |
6095 | if (ret) | |
6096 | return ret; | |
6097 | ||
6098 | out_reg: | |
6099 | ret = register_ftrace_function_probe(glob, ops, count); | |
6100 | ||
6101 | if (ret >= 0) | |
6102 | alloc_snapshot(&global_trace); | |
6103 | ||
6104 | return ret < 0 ? ret : 0; | |
6105 | } | |
6106 | ||
6107 | static struct ftrace_func_command ftrace_snapshot_cmd = { | |
6108 | .name = "snapshot", | |
6109 | .func = ftrace_trace_snapshot_callback, | |
6110 | }; | |
6111 | ||
38de93ab | 6112 | static __init int register_snapshot_cmd(void) |
77fd5c15 SRRH |
6113 | { |
6114 | return register_ftrace_command(&ftrace_snapshot_cmd); | |
6115 | } | |
6116 | #else | |
38de93ab | 6117 | static inline __init int register_snapshot_cmd(void) { return 0; } |
77fd5c15 | 6118 | #endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ |
bc0c38d1 | 6119 | |
7eeafbca | 6120 | static struct dentry *tracing_get_dentry(struct trace_array *tr) |
bc0c38d1 | 6121 | { |
8434dc93 SRRH |
6122 | if (WARN_ON(!tr->dir)) |
6123 | return ERR_PTR(-ENODEV); | |
6124 | ||
6125 | /* Top directory uses NULL as the parent */ | |
6126 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
6127 | return NULL; | |
6128 | ||
6129 | /* All sub buffers have a descriptor */ | |
2b6080f2 | 6130 | return tr->dir; |
bc0c38d1 SR |
6131 | } |
6132 | ||
2b6080f2 | 6133 | static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) |
b04cc6b1 | 6134 | { |
b04cc6b1 FW |
6135 | struct dentry *d_tracer; |
6136 | ||
2b6080f2 SR |
6137 | if (tr->percpu_dir) |
6138 | return tr->percpu_dir; | |
b04cc6b1 | 6139 | |
7eeafbca | 6140 | d_tracer = tracing_get_dentry(tr); |
14a5ae40 | 6141 | if (IS_ERR(d_tracer)) |
b04cc6b1 FW |
6142 | return NULL; |
6143 | ||
8434dc93 | 6144 | tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer); |
b04cc6b1 | 6145 | |
2b6080f2 | 6146 | WARN_ONCE(!tr->percpu_dir, |
8434dc93 | 6147 | "Could not create tracefs directory 'per_cpu/%d'\n", cpu); |
b04cc6b1 | 6148 | |
2b6080f2 | 6149 | return tr->percpu_dir; |
b04cc6b1 FW |
6150 | } |
6151 | ||
649e9c70 ON |
6152 | static struct dentry * |
6153 | trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent, | |
6154 | void *data, long cpu, const struct file_operations *fops) | |
6155 | { | |
6156 | struct dentry *ret = trace_create_file(name, mode, parent, data, fops); | |
6157 | ||
6158 | if (ret) /* See tracing_get_cpu() */ | |
7682c918 | 6159 | d_inode(ret)->i_cdev = (void *)(cpu + 1); |
649e9c70 ON |
6160 | return ret; |
6161 | } | |
6162 | ||
2b6080f2 | 6163 | static void |
8434dc93 | 6164 | tracing_init_tracefs_percpu(struct trace_array *tr, long cpu) |
b04cc6b1 | 6165 | { |
2b6080f2 | 6166 | struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu); |
5452af66 | 6167 | struct dentry *d_cpu; |
dd49a38c | 6168 | char cpu_dir[30]; /* 30 characters should be more than enough */ |
b04cc6b1 | 6169 | |
0a3d7ce7 NK |
6170 | if (!d_percpu) |
6171 | return; | |
6172 | ||
dd49a38c | 6173 | snprintf(cpu_dir, 30, "cpu%ld", cpu); |
8434dc93 | 6174 | d_cpu = tracefs_create_dir(cpu_dir, d_percpu); |
8656e7a2 | 6175 | if (!d_cpu) { |
a395d6a7 | 6176 | pr_warn("Could not create tracefs '%s' entry\n", cpu_dir); |
8656e7a2 FW |
6177 | return; |
6178 | } | |
b04cc6b1 | 6179 | |
8656e7a2 | 6180 | /* per cpu trace_pipe */ |
649e9c70 | 6181 | trace_create_cpu_file("trace_pipe", 0444, d_cpu, |
15544209 | 6182 | tr, cpu, &tracing_pipe_fops); |
b04cc6b1 FW |
6183 | |
6184 | /* per cpu trace */ | |
649e9c70 | 6185 | trace_create_cpu_file("trace", 0644, d_cpu, |
6484c71c | 6186 | tr, cpu, &tracing_fops); |
7f96f93f | 6187 | |
649e9c70 | 6188 | trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu, |
46ef2be0 | 6189 | tr, cpu, &tracing_buffers_fops); |
7f96f93f | 6190 | |
649e9c70 | 6191 | trace_create_cpu_file("stats", 0444, d_cpu, |
4d3435b8 | 6192 | tr, cpu, &tracing_stats_fops); |
438ced17 | 6193 | |
649e9c70 | 6194 | trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, |
0bc392ee | 6195 | tr, cpu, &tracing_entries_fops); |
f1affcaa SRRH |
6196 | |
6197 | #ifdef CONFIG_TRACER_SNAPSHOT | |
649e9c70 | 6198 | trace_create_cpu_file("snapshot", 0644, d_cpu, |
6484c71c | 6199 | tr, cpu, &snapshot_fops); |
6de58e62 | 6200 | |
649e9c70 | 6201 | trace_create_cpu_file("snapshot_raw", 0444, d_cpu, |
46ef2be0 | 6202 | tr, cpu, &snapshot_raw_fops); |
f1affcaa | 6203 | #endif |
b04cc6b1 FW |
6204 | } |
6205 | ||
60a11774 SR |
6206 | #ifdef CONFIG_FTRACE_SELFTEST |
6207 | /* Let selftest have access to static functions in this file */ | |
6208 | #include "trace_selftest.c" | |
6209 | #endif | |
6210 | ||
577b785f SR |
6211 | static ssize_t |
6212 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
6213 | loff_t *ppos) | |
6214 | { | |
6215 | struct trace_option_dentry *topt = filp->private_data; | |
6216 | char *buf; | |
6217 | ||
6218 | if (topt->flags->val & topt->opt->bit) | |
6219 | buf = "1\n"; | |
6220 | else | |
6221 | buf = "0\n"; | |
6222 | ||
6223 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
6224 | } | |
6225 | ||
6226 | static ssize_t | |
6227 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
6228 | loff_t *ppos) | |
6229 | { | |
6230 | struct trace_option_dentry *topt = filp->private_data; | |
6231 | unsigned long val; | |
577b785f SR |
6232 | int ret; |
6233 | ||
22fe9b54 PH |
6234 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
6235 | if (ret) | |
577b785f SR |
6236 | return ret; |
6237 | ||
8d18eaaf LZ |
6238 | if (val != 0 && val != 1) |
6239 | return -EINVAL; | |
577b785f | 6240 | |
8d18eaaf | 6241 | if (!!(topt->flags->val & topt->opt->bit) != val) { |
577b785f | 6242 | mutex_lock(&trace_types_lock); |
8c1a49ae | 6243 | ret = __set_tracer_option(topt->tr, topt->flags, |
c757bea9 | 6244 | topt->opt, !val); |
577b785f SR |
6245 | mutex_unlock(&trace_types_lock); |
6246 | if (ret) | |
6247 | return ret; | |
577b785f SR |
6248 | } |
6249 | ||
6250 | *ppos += cnt; | |
6251 | ||
6252 | return cnt; | |
6253 | } | |
6254 | ||
6255 | ||
6256 | static const struct file_operations trace_options_fops = { | |
6257 | .open = tracing_open_generic, | |
6258 | .read = trace_options_read, | |
6259 | .write = trace_options_write, | |
b444786f | 6260 | .llseek = generic_file_llseek, |
577b785f SR |
6261 | }; |
6262 | ||
9a38a885 SRRH |
6263 | /* |
6264 | * In order to pass in both the trace_array descriptor as well as the index | |
6265 | * to the flag that the trace option file represents, the trace_array | |
6266 | * has a character array of trace_flags_index[], which holds the index | |
6267 | * of the bit for the flag it represents. index[0] == 0, index[1] == 1, etc. | |
6268 | * The address of this character array is passed to the flag option file | |
6269 | * read/write callbacks. | |
6270 | * | |
6271 | * In order to extract both the index and the trace_array descriptor, | |
6272 | * get_tr_index() uses the following algorithm. | |
6273 | * | |
6274 | * idx = *ptr; | |
6275 | * | |
6276 | * As the pointer itself contains the address of the index (remember | |
6277 | * index[1] == 1). | |
6278 | * | |
6279 | * Then to get the trace_array descriptor, by subtracting that index | |
6280 | * from the ptr, we get to the start of the index itself. | |
6281 | * | |
6282 | * ptr - idx == &index[0] | |
6283 | * | |
6284 | * Then a simple container_of() from that pointer gets us to the | |
6285 | * trace_array descriptor. | |
6286 | */ | |
6287 | static void get_tr_index(void *data, struct trace_array **ptr, | |
6288 | unsigned int *pindex) | |
6289 | { | |
6290 | *pindex = *(unsigned char *)data; | |
6291 | ||
6292 | *ptr = container_of(data - *pindex, struct trace_array, | |
6293 | trace_flags_index); | |
6294 | } | |
6295 | ||
a8259075 SR |
6296 | static ssize_t |
6297 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
6298 | loff_t *ppos) | |
6299 | { | |
9a38a885 SRRH |
6300 | void *tr_index = filp->private_data; |
6301 | struct trace_array *tr; | |
6302 | unsigned int index; | |
a8259075 SR |
6303 | char *buf; |
6304 | ||
9a38a885 SRRH |
6305 | get_tr_index(tr_index, &tr, &index); |
6306 | ||
6307 | if (tr->trace_flags & (1 << index)) | |
a8259075 SR |
6308 | buf = "1\n"; |
6309 | else | |
6310 | buf = "0\n"; | |
6311 | ||
6312 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
6313 | } | |
6314 | ||
6315 | static ssize_t | |
6316 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
6317 | loff_t *ppos) | |
6318 | { | |
9a38a885 SRRH |
6319 | void *tr_index = filp->private_data; |
6320 | struct trace_array *tr; | |
6321 | unsigned int index; | |
a8259075 SR |
6322 | unsigned long val; |
6323 | int ret; | |
6324 | ||
9a38a885 SRRH |
6325 | get_tr_index(tr_index, &tr, &index); |
6326 | ||
22fe9b54 PH |
6327 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
6328 | if (ret) | |
a8259075 SR |
6329 | return ret; |
6330 | ||
f2d84b65 | 6331 | if (val != 0 && val != 1) |
a8259075 | 6332 | return -EINVAL; |
69d34da2 SRRH |
6333 | |
6334 | mutex_lock(&trace_types_lock); | |
2b6080f2 | 6335 | ret = set_tracer_flag(tr, 1 << index, val); |
69d34da2 | 6336 | mutex_unlock(&trace_types_lock); |
a8259075 | 6337 | |
613f04a0 SRRH |
6338 | if (ret < 0) |
6339 | return ret; | |
6340 | ||
a8259075 SR |
6341 | *ppos += cnt; |
6342 | ||
6343 | return cnt; | |
6344 | } | |
6345 | ||
a8259075 SR |
6346 | static const struct file_operations trace_options_core_fops = { |
6347 | .open = tracing_open_generic, | |
6348 | .read = trace_options_core_read, | |
6349 | .write = trace_options_core_write, | |
b444786f | 6350 | .llseek = generic_file_llseek, |
a8259075 SR |
6351 | }; |
6352 | ||
5452af66 | 6353 | struct dentry *trace_create_file(const char *name, |
f4ae40a6 | 6354 | umode_t mode, |
5452af66 FW |
6355 | struct dentry *parent, |
6356 | void *data, | |
6357 | const struct file_operations *fops) | |
6358 | { | |
6359 | struct dentry *ret; | |
6360 | ||
8434dc93 | 6361 | ret = tracefs_create_file(name, mode, parent, data, fops); |
5452af66 | 6362 | if (!ret) |
a395d6a7 | 6363 | pr_warn("Could not create tracefs '%s' entry\n", name); |
5452af66 FW |
6364 | |
6365 | return ret; | |
6366 | } | |
6367 | ||
6368 | ||
2b6080f2 | 6369 | static struct dentry *trace_options_init_dentry(struct trace_array *tr) |
a8259075 SR |
6370 | { |
6371 | struct dentry *d_tracer; | |
a8259075 | 6372 | |
2b6080f2 SR |
6373 | if (tr->options) |
6374 | return tr->options; | |
a8259075 | 6375 | |
7eeafbca | 6376 | d_tracer = tracing_get_dentry(tr); |
14a5ae40 | 6377 | if (IS_ERR(d_tracer)) |
a8259075 SR |
6378 | return NULL; |
6379 | ||
8434dc93 | 6380 | tr->options = tracefs_create_dir("options", d_tracer); |
2b6080f2 | 6381 | if (!tr->options) { |
a395d6a7 | 6382 | pr_warn("Could not create tracefs directory 'options'\n"); |
a8259075 SR |
6383 | return NULL; |
6384 | } | |
6385 | ||
2b6080f2 | 6386 | return tr->options; |
a8259075 SR |
6387 | } |
6388 | ||
577b785f | 6389 | static void |
2b6080f2 SR |
6390 | create_trace_option_file(struct trace_array *tr, |
6391 | struct trace_option_dentry *topt, | |
577b785f SR |
6392 | struct tracer_flags *flags, |
6393 | struct tracer_opt *opt) | |
6394 | { | |
6395 | struct dentry *t_options; | |
577b785f | 6396 | |
2b6080f2 | 6397 | t_options = trace_options_init_dentry(tr); |
577b785f SR |
6398 | if (!t_options) |
6399 | return; | |
6400 | ||
6401 | topt->flags = flags; | |
6402 | topt->opt = opt; | |
2b6080f2 | 6403 | topt->tr = tr; |
577b785f | 6404 | |
5452af66 | 6405 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
577b785f SR |
6406 | &trace_options_fops); |
6407 | ||
577b785f SR |
6408 | } |
6409 | ||
37aea98b | 6410 | static void |
2b6080f2 | 6411 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer) |
577b785f SR |
6412 | { |
6413 | struct trace_option_dentry *topts; | |
37aea98b | 6414 | struct trace_options *tr_topts; |
577b785f SR |
6415 | struct tracer_flags *flags; |
6416 | struct tracer_opt *opts; | |
6417 | int cnt; | |
37aea98b | 6418 | int i; |
577b785f SR |
6419 | |
6420 | if (!tracer) | |
37aea98b | 6421 | return; |
577b785f SR |
6422 | |
6423 | flags = tracer->flags; | |
6424 | ||
6425 | if (!flags || !flags->opts) | |
37aea98b SRRH |
6426 | return; |
6427 | ||
6428 | /* | |
6429 | * If this is an instance, only create flags for tracers | |
6430 | * the instance may have. | |
6431 | */ | |
6432 | if (!trace_ok_for_array(tracer, tr)) | |
6433 | return; | |
6434 | ||
6435 | for (i = 0; i < tr->nr_topts; i++) { | |
d39cdd20 CH |
6436 | /* Make sure there's no duplicate flags. */ |
6437 | if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags)) | |
37aea98b SRRH |
6438 | return; |
6439 | } | |
577b785f SR |
6440 | |
6441 | opts = flags->opts; | |
6442 | ||
6443 | for (cnt = 0; opts[cnt].name; cnt++) | |
6444 | ; | |
6445 | ||
0cfe8245 | 6446 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f | 6447 | if (!topts) |
37aea98b SRRH |
6448 | return; |
6449 | ||
6450 | tr_topts = krealloc(tr->topts, sizeof(*tr->topts) * (tr->nr_topts + 1), | |
6451 | GFP_KERNEL); | |
6452 | if (!tr_topts) { | |
6453 | kfree(topts); | |
6454 | return; | |
6455 | } | |
6456 | ||
6457 | tr->topts = tr_topts; | |
6458 | tr->topts[tr->nr_topts].tracer = tracer; | |
6459 | tr->topts[tr->nr_topts].topts = topts; | |
6460 | tr->nr_topts++; | |
577b785f | 6461 | |
41d9c0be | 6462 | for (cnt = 0; opts[cnt].name; cnt++) { |
2b6080f2 | 6463 | create_trace_option_file(tr, &topts[cnt], flags, |
577b785f | 6464 | &opts[cnt]); |
41d9c0be SRRH |
6465 | WARN_ONCE(topts[cnt].entry == NULL, |
6466 | "Failed to create trace option: %s", | |
6467 | opts[cnt].name); | |
6468 | } | |
577b785f SR |
6469 | } |
6470 | ||
a8259075 | 6471 | static struct dentry * |
2b6080f2 SR |
6472 | create_trace_option_core_file(struct trace_array *tr, |
6473 | const char *option, long index) | |
a8259075 SR |
6474 | { |
6475 | struct dentry *t_options; | |
a8259075 | 6476 | |
2b6080f2 | 6477 | t_options = trace_options_init_dentry(tr); |
a8259075 SR |
6478 | if (!t_options) |
6479 | return NULL; | |
6480 | ||
9a38a885 SRRH |
6481 | return trace_create_file(option, 0644, t_options, |
6482 | (void *)&tr->trace_flags_index[index], | |
6483 | &trace_options_core_fops); | |
a8259075 SR |
6484 | } |
6485 | ||
16270145 | 6486 | static void create_trace_options_dir(struct trace_array *tr) |
a8259075 SR |
6487 | { |
6488 | struct dentry *t_options; | |
16270145 | 6489 | bool top_level = tr == &global_trace; |
a8259075 SR |
6490 | int i; |
6491 | ||
2b6080f2 | 6492 | t_options = trace_options_init_dentry(tr); |
a8259075 SR |
6493 | if (!t_options) |
6494 | return; | |
6495 | ||
16270145 SRRH |
6496 | for (i = 0; trace_options[i]; i++) { |
6497 | if (top_level || | |
6498 | !((1 << i) & TOP_LEVEL_TRACE_FLAGS)) | |
6499 | create_trace_option_core_file(tr, trace_options[i], i); | |
6500 | } | |
a8259075 SR |
6501 | } |
6502 | ||
499e5470 SR |
6503 | static ssize_t |
6504 | rb_simple_read(struct file *filp, char __user *ubuf, | |
6505 | size_t cnt, loff_t *ppos) | |
6506 | { | |
348f0fc2 | 6507 | struct trace_array *tr = filp->private_data; |
499e5470 SR |
6508 | char buf[64]; |
6509 | int r; | |
6510 | ||
10246fa3 | 6511 | r = tracer_tracing_is_on(tr); |
499e5470 SR |
6512 | r = sprintf(buf, "%d\n", r); |
6513 | ||
6514 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
6515 | } | |
6516 | ||
6517 | static ssize_t | |
6518 | rb_simple_write(struct file *filp, const char __user *ubuf, | |
6519 | size_t cnt, loff_t *ppos) | |
6520 | { | |
348f0fc2 | 6521 | struct trace_array *tr = filp->private_data; |
12883efb | 6522 | struct ring_buffer *buffer = tr->trace_buffer.buffer; |
499e5470 SR |
6523 | unsigned long val; |
6524 | int ret; | |
6525 | ||
6526 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
6527 | if (ret) | |
6528 | return ret; | |
6529 | ||
6530 | if (buffer) { | |
2df8f8a6 SR |
6531 | mutex_lock(&trace_types_lock); |
6532 | if (val) { | |
10246fa3 | 6533 | tracer_tracing_on(tr); |
2b6080f2 SR |
6534 | if (tr->current_trace->start) |
6535 | tr->current_trace->start(tr); | |
2df8f8a6 | 6536 | } else { |
10246fa3 | 6537 | tracer_tracing_off(tr); |
2b6080f2 SR |
6538 | if (tr->current_trace->stop) |
6539 | tr->current_trace->stop(tr); | |
2df8f8a6 SR |
6540 | } |
6541 | mutex_unlock(&trace_types_lock); | |
499e5470 SR |
6542 | } |
6543 | ||
6544 | (*ppos)++; | |
6545 | ||
6546 | return cnt; | |
6547 | } | |
6548 | ||
6549 | static const struct file_operations rb_simple_fops = { | |
7b85af63 | 6550 | .open = tracing_open_generic_tr, |
499e5470 SR |
6551 | .read = rb_simple_read, |
6552 | .write = rb_simple_write, | |
7b85af63 | 6553 | .release = tracing_release_generic_tr, |
499e5470 SR |
6554 | .llseek = default_llseek, |
6555 | }; | |
6556 | ||
277ba044 SR |
6557 | struct dentry *trace_instance_dir; |
6558 | ||
6559 | static void | |
8434dc93 | 6560 | init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer); |
277ba044 | 6561 | |
55034cd6 SRRH |
6562 | static int |
6563 | allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size) | |
277ba044 SR |
6564 | { |
6565 | enum ring_buffer_flags rb_flags; | |
737223fb | 6566 | |
983f938a | 6567 | rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; |
737223fb | 6568 | |
dced341b SRRH |
6569 | buf->tr = tr; |
6570 | ||
55034cd6 SRRH |
6571 | buf->buffer = ring_buffer_alloc(size, rb_flags); |
6572 | if (!buf->buffer) | |
6573 | return -ENOMEM; | |
737223fb | 6574 | |
55034cd6 SRRH |
6575 | buf->data = alloc_percpu(struct trace_array_cpu); |
6576 | if (!buf->data) { | |
6577 | ring_buffer_free(buf->buffer); | |
6578 | return -ENOMEM; | |
6579 | } | |
737223fb | 6580 | |
737223fb SRRH |
6581 | /* Allocate the first page for all buffers */ |
6582 | set_buffer_entries(&tr->trace_buffer, | |
6583 | ring_buffer_size(tr->trace_buffer.buffer, 0)); | |
6584 | ||
55034cd6 SRRH |
6585 | return 0; |
6586 | } | |
737223fb | 6587 | |
55034cd6 SRRH |
6588 | static int allocate_trace_buffers(struct trace_array *tr, int size) |
6589 | { | |
6590 | int ret; | |
737223fb | 6591 | |
55034cd6 SRRH |
6592 | ret = allocate_trace_buffer(tr, &tr->trace_buffer, size); |
6593 | if (ret) | |
6594 | return ret; | |
737223fb | 6595 | |
55034cd6 SRRH |
6596 | #ifdef CONFIG_TRACER_MAX_TRACE |
6597 | ret = allocate_trace_buffer(tr, &tr->max_buffer, | |
6598 | allocate_snapshot ? size : 1); | |
6599 | if (WARN_ON(ret)) { | |
737223fb | 6600 | ring_buffer_free(tr->trace_buffer.buffer); |
55034cd6 SRRH |
6601 | free_percpu(tr->trace_buffer.data); |
6602 | return -ENOMEM; | |
6603 | } | |
6604 | tr->allocated_snapshot = allocate_snapshot; | |
737223fb | 6605 | |
55034cd6 SRRH |
6606 | /* |
6607 | * Only the top level trace array gets its snapshot allocated | |
6608 | * from the kernel command line. | |
6609 | */ | |
6610 | allocate_snapshot = false; | |
737223fb | 6611 | #endif |
55034cd6 | 6612 | return 0; |
737223fb SRRH |
6613 | } |
6614 | ||
f0b70cc4 SRRH |
6615 | static void free_trace_buffer(struct trace_buffer *buf) |
6616 | { | |
6617 | if (buf->buffer) { | |
6618 | ring_buffer_free(buf->buffer); | |
6619 | buf->buffer = NULL; | |
6620 | free_percpu(buf->data); | |
6621 | buf->data = NULL; | |
6622 | } | |
6623 | } | |
6624 | ||
23aaa3c1 SRRH |
6625 | static void free_trace_buffers(struct trace_array *tr) |
6626 | { | |
6627 | if (!tr) | |
6628 | return; | |
6629 | ||
f0b70cc4 | 6630 | free_trace_buffer(&tr->trace_buffer); |
23aaa3c1 SRRH |
6631 | |
6632 | #ifdef CONFIG_TRACER_MAX_TRACE | |
f0b70cc4 | 6633 | free_trace_buffer(&tr->max_buffer); |
23aaa3c1 SRRH |
6634 | #endif |
6635 | } | |
6636 | ||
9a38a885 SRRH |
6637 | static void init_trace_flags_index(struct trace_array *tr) |
6638 | { | |
6639 | int i; | |
6640 | ||
6641 | /* Used by the trace options files */ | |
6642 | for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) | |
6643 | tr->trace_flags_index[i] = i; | |
6644 | } | |
6645 | ||
37aea98b SRRH |
6646 | static void __update_tracer_options(struct trace_array *tr) |
6647 | { | |
6648 | struct tracer *t; | |
6649 | ||
6650 | for (t = trace_types; t; t = t->next) | |
6651 | add_tracer_options(tr, t); | |
6652 | } | |
6653 | ||
6654 | static void update_tracer_options(struct trace_array *tr) | |
6655 | { | |
6656 | mutex_lock(&trace_types_lock); | |
6657 | __update_tracer_options(tr); | |
6658 | mutex_unlock(&trace_types_lock); | |
6659 | } | |
6660 | ||
eae47358 | 6661 | static int instance_mkdir(const char *name) |
737223fb | 6662 | { |
277ba044 SR |
6663 | struct trace_array *tr; |
6664 | int ret; | |
277ba044 SR |
6665 | |
6666 | mutex_lock(&trace_types_lock); | |
6667 | ||
6668 | ret = -EEXIST; | |
6669 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6670 | if (tr->name && strcmp(tr->name, name) == 0) | |
6671 | goto out_unlock; | |
6672 | } | |
6673 | ||
6674 | ret = -ENOMEM; | |
6675 | tr = kzalloc(sizeof(*tr), GFP_KERNEL); | |
6676 | if (!tr) | |
6677 | goto out_unlock; | |
6678 | ||
6679 | tr->name = kstrdup(name, GFP_KERNEL); | |
6680 | if (!tr->name) | |
6681 | goto out_free_tr; | |
6682 | ||
ccfe9e42 AL |
6683 | if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL)) |
6684 | goto out_free_tr; | |
6685 | ||
983f938a SRRH |
6686 | tr->trace_flags = global_trace.trace_flags; |
6687 | ||
ccfe9e42 AL |
6688 | cpumask_copy(tr->tracing_cpumask, cpu_all_mask); |
6689 | ||
277ba044 SR |
6690 | raw_spin_lock_init(&tr->start_lock); |
6691 | ||
0b9b12c1 SRRH |
6692 | tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
6693 | ||
277ba044 SR |
6694 | tr->current_trace = &nop_trace; |
6695 | ||
6696 | INIT_LIST_HEAD(&tr->systems); | |
6697 | INIT_LIST_HEAD(&tr->events); | |
6698 | ||
737223fb | 6699 | if (allocate_trace_buffers(tr, trace_buf_size) < 0) |
277ba044 SR |
6700 | goto out_free_tr; |
6701 | ||
8434dc93 | 6702 | tr->dir = tracefs_create_dir(name, trace_instance_dir); |
277ba044 SR |
6703 | if (!tr->dir) |
6704 | goto out_free_tr; | |
6705 | ||
6706 | ret = event_trace_add_tracer(tr->dir, tr); | |
609e85a7 | 6707 | if (ret) { |
8434dc93 | 6708 | tracefs_remove_recursive(tr->dir); |
277ba044 | 6709 | goto out_free_tr; |
609e85a7 | 6710 | } |
277ba044 | 6711 | |
8434dc93 | 6712 | init_tracer_tracefs(tr, tr->dir); |
9a38a885 | 6713 | init_trace_flags_index(tr); |
37aea98b | 6714 | __update_tracer_options(tr); |
277ba044 SR |
6715 | |
6716 | list_add(&tr->list, &ftrace_trace_arrays); | |
6717 | ||
6718 | mutex_unlock(&trace_types_lock); | |
6719 | ||
6720 | return 0; | |
6721 | ||
6722 | out_free_tr: | |
23aaa3c1 | 6723 | free_trace_buffers(tr); |
ccfe9e42 | 6724 | free_cpumask_var(tr->tracing_cpumask); |
277ba044 SR |
6725 | kfree(tr->name); |
6726 | kfree(tr); | |
6727 | ||
6728 | out_unlock: | |
6729 | mutex_unlock(&trace_types_lock); | |
6730 | ||
6731 | return ret; | |
6732 | ||
6733 | } | |
6734 | ||
eae47358 | 6735 | static int instance_rmdir(const char *name) |
0c8916c3 SR |
6736 | { |
6737 | struct trace_array *tr; | |
6738 | int found = 0; | |
6739 | int ret; | |
37aea98b | 6740 | int i; |
0c8916c3 SR |
6741 | |
6742 | mutex_lock(&trace_types_lock); | |
6743 | ||
6744 | ret = -ENODEV; | |
6745 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6746 | if (tr->name && strcmp(tr->name, name) == 0) { | |
6747 | found = 1; | |
6748 | break; | |
6749 | } | |
6750 | } | |
6751 | if (!found) | |
6752 | goto out_unlock; | |
6753 | ||
a695cb58 | 6754 | ret = -EBUSY; |
cf6ab6d9 | 6755 | if (tr->ref || (tr->current_trace && tr->current_trace->ref)) |
a695cb58 SRRH |
6756 | goto out_unlock; |
6757 | ||
0c8916c3 SR |
6758 | list_del(&tr->list); |
6759 | ||
6b450d25 | 6760 | tracing_set_nop(tr); |
0c8916c3 | 6761 | event_trace_del_tracer(tr); |
591dffda | 6762 | ftrace_destroy_function_files(tr); |
681a4a2f | 6763 | tracefs_remove_recursive(tr->dir); |
a9fcaaac | 6764 | free_trace_buffers(tr); |
0c8916c3 | 6765 | |
37aea98b SRRH |
6766 | for (i = 0; i < tr->nr_topts; i++) { |
6767 | kfree(tr->topts[i].topts); | |
6768 | } | |
6769 | kfree(tr->topts); | |
6770 | ||
0c8916c3 SR |
6771 | kfree(tr->name); |
6772 | kfree(tr); | |
6773 | ||
6774 | ret = 0; | |
6775 | ||
6776 | out_unlock: | |
6777 | mutex_unlock(&trace_types_lock); | |
6778 | ||
6779 | return ret; | |
6780 | } | |
6781 | ||
277ba044 SR |
6782 | static __init void create_trace_instances(struct dentry *d_tracer) |
6783 | { | |
eae47358 SRRH |
6784 | trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, |
6785 | instance_mkdir, | |
6786 | instance_rmdir); | |
277ba044 SR |
6787 | if (WARN_ON(!trace_instance_dir)) |
6788 | return; | |
277ba044 SR |
6789 | } |
6790 | ||
2b6080f2 | 6791 | static void |
8434dc93 | 6792 | init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
2b6080f2 | 6793 | { |
121aaee7 | 6794 | int cpu; |
2b6080f2 | 6795 | |
607e2ea1 SRRH |
6796 | trace_create_file("available_tracers", 0444, d_tracer, |
6797 | tr, &show_traces_fops); | |
6798 | ||
6799 | trace_create_file("current_tracer", 0644, d_tracer, | |
6800 | tr, &set_tracer_fops); | |
6801 | ||
ccfe9e42 AL |
6802 | trace_create_file("tracing_cpumask", 0644, d_tracer, |
6803 | tr, &tracing_cpumask_fops); | |
6804 | ||
2b6080f2 SR |
6805 | trace_create_file("trace_options", 0644, d_tracer, |
6806 | tr, &tracing_iter_fops); | |
6807 | ||
6808 | trace_create_file("trace", 0644, d_tracer, | |
6484c71c | 6809 | tr, &tracing_fops); |
2b6080f2 SR |
6810 | |
6811 | trace_create_file("trace_pipe", 0444, d_tracer, | |
15544209 | 6812 | tr, &tracing_pipe_fops); |
2b6080f2 SR |
6813 | |
6814 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
0bc392ee | 6815 | tr, &tracing_entries_fops); |
2b6080f2 SR |
6816 | |
6817 | trace_create_file("buffer_total_size_kb", 0444, d_tracer, | |
6818 | tr, &tracing_total_entries_fops); | |
6819 | ||
238ae93d | 6820 | trace_create_file("free_buffer", 0200, d_tracer, |
2b6080f2 SR |
6821 | tr, &tracing_free_buffer_fops); |
6822 | ||
6823 | trace_create_file("trace_marker", 0220, d_tracer, | |
6824 | tr, &tracing_mark_fops); | |
6825 | ||
6826 | trace_create_file("trace_clock", 0644, d_tracer, tr, | |
6827 | &trace_clock_fops); | |
6828 | ||
6829 | trace_create_file("tracing_on", 0644, d_tracer, | |
6484c71c | 6830 | tr, &rb_simple_fops); |
ce9bae55 | 6831 | |
16270145 SRRH |
6832 | create_trace_options_dir(tr); |
6833 | ||
6d9b3fa5 SRRH |
6834 | #ifdef CONFIG_TRACER_MAX_TRACE |
6835 | trace_create_file("tracing_max_latency", 0644, d_tracer, | |
6836 | &tr->max_latency, &tracing_max_lat_fops); | |
6837 | #endif | |
6838 | ||
591dffda SRRH |
6839 | if (ftrace_create_function_files(tr, d_tracer)) |
6840 | WARN(1, "Could not allocate function filter files"); | |
6841 | ||
ce9bae55 SRRH |
6842 | #ifdef CONFIG_TRACER_SNAPSHOT |
6843 | trace_create_file("snapshot", 0644, d_tracer, | |
6484c71c | 6844 | tr, &snapshot_fops); |
ce9bae55 | 6845 | #endif |
121aaee7 SRRH |
6846 | |
6847 | for_each_tracing_cpu(cpu) | |
8434dc93 | 6848 | tracing_init_tracefs_percpu(tr, cpu); |
121aaee7 | 6849 | |
2b6080f2 SR |
6850 | } |
6851 | ||
f76180bc SRRH |
6852 | static struct vfsmount *trace_automount(void *ingore) |
6853 | { | |
6854 | struct vfsmount *mnt; | |
6855 | struct file_system_type *type; | |
6856 | ||
6857 | /* | |
6858 | * To maintain backward compatibility for tools that mount | |
6859 | * debugfs to get to the tracing facility, tracefs is automatically | |
6860 | * mounted to the debugfs/tracing directory. | |
6861 | */ | |
6862 | type = get_fs_type("tracefs"); | |
6863 | if (!type) | |
6864 | return NULL; | |
6865 | mnt = vfs_kern_mount(type, 0, "tracefs", NULL); | |
6866 | put_filesystem(type); | |
6867 | if (IS_ERR(mnt)) | |
6868 | return NULL; | |
6869 | mntget(mnt); | |
6870 | ||
6871 | return mnt; | |
6872 | } | |
6873 | ||
7eeafbca SRRH |
6874 | /** |
6875 | * tracing_init_dentry - initialize top level trace array | |
6876 | * | |
6877 | * This is called when creating files or directories in the tracing | |
6878 | * directory. It is called via fs_initcall() by any of the boot up code | |
6879 | * and expects to return the dentry of the top level tracing directory. | |
6880 | */ | |
6881 | struct dentry *tracing_init_dentry(void) | |
6882 | { | |
6883 | struct trace_array *tr = &global_trace; | |
6884 | ||
f76180bc | 6885 | /* The top level trace array uses NULL as parent */ |
7eeafbca | 6886 | if (tr->dir) |
f76180bc | 6887 | return NULL; |
7eeafbca | 6888 | |
8b129199 JW |
6889 | if (WARN_ON(!tracefs_initialized()) || |
6890 | (IS_ENABLED(CONFIG_DEBUG_FS) && | |
6891 | WARN_ON(!debugfs_initialized()))) | |
7eeafbca SRRH |
6892 | return ERR_PTR(-ENODEV); |
6893 | ||
f76180bc SRRH |
6894 | /* |
6895 | * As there may still be users that expect the tracing | |
6896 | * files to exist in debugfs/tracing, we must automount | |
6897 | * the tracefs file system there, so older tools still | |
6898 | * work with the newer kerenl. | |
6899 | */ | |
6900 | tr->dir = debugfs_create_automount("tracing", NULL, | |
6901 | trace_automount, NULL); | |
7eeafbca SRRH |
6902 | if (!tr->dir) { |
6903 | pr_warn_once("Could not create debugfs directory 'tracing'\n"); | |
6904 | return ERR_PTR(-ENOMEM); | |
6905 | } | |
6906 | ||
8434dc93 | 6907 | return NULL; |
7eeafbca SRRH |
6908 | } |
6909 | ||
0c564a53 SRRH |
6910 | extern struct trace_enum_map *__start_ftrace_enum_maps[]; |
6911 | extern struct trace_enum_map *__stop_ftrace_enum_maps[]; | |
6912 | ||
6913 | static void __init trace_enum_init(void) | |
6914 | { | |
3673b8e4 SRRH |
6915 | int len; |
6916 | ||
6917 | len = __stop_ftrace_enum_maps - __start_ftrace_enum_maps; | |
9828413d | 6918 | trace_insert_enum_map(NULL, __start_ftrace_enum_maps, len); |
3673b8e4 SRRH |
6919 | } |
6920 | ||
6921 | #ifdef CONFIG_MODULES | |
6922 | static void trace_module_add_enums(struct module *mod) | |
6923 | { | |
6924 | if (!mod->num_trace_enums) | |
6925 | return; | |
6926 | ||
6927 | /* | |
6928 | * Modules with bad taint do not have events created, do | |
6929 | * not bother with enums either. | |
6930 | */ | |
6931 | if (trace_module_has_bad_taint(mod)) | |
6932 | return; | |
6933 | ||
9828413d | 6934 | trace_insert_enum_map(mod, mod->trace_enums, mod->num_trace_enums); |
3673b8e4 SRRH |
6935 | } |
6936 | ||
9828413d SRRH |
6937 | #ifdef CONFIG_TRACE_ENUM_MAP_FILE |
6938 | static void trace_module_remove_enums(struct module *mod) | |
6939 | { | |
6940 | union trace_enum_map_item *map; | |
6941 | union trace_enum_map_item **last = &trace_enum_maps; | |
6942 | ||
6943 | if (!mod->num_trace_enums) | |
6944 | return; | |
6945 | ||
6946 | mutex_lock(&trace_enum_mutex); | |
6947 | ||
6948 | map = trace_enum_maps; | |
6949 | ||
6950 | while (map) { | |
6951 | if (map->head.mod == mod) | |
6952 | break; | |
6953 | map = trace_enum_jmp_to_tail(map); | |
6954 | last = &map->tail.next; | |
6955 | map = map->tail.next; | |
6956 | } | |
6957 | if (!map) | |
6958 | goto out; | |
6959 | ||
6960 | *last = trace_enum_jmp_to_tail(map)->tail.next; | |
6961 | kfree(map); | |
6962 | out: | |
6963 | mutex_unlock(&trace_enum_mutex); | |
6964 | } | |
6965 | #else | |
6966 | static inline void trace_module_remove_enums(struct module *mod) { } | |
6967 | #endif /* CONFIG_TRACE_ENUM_MAP_FILE */ | |
6968 | ||
3673b8e4 SRRH |
6969 | static int trace_module_notify(struct notifier_block *self, |
6970 | unsigned long val, void *data) | |
6971 | { | |
6972 | struct module *mod = data; | |
6973 | ||
6974 | switch (val) { | |
6975 | case MODULE_STATE_COMING: | |
6976 | trace_module_add_enums(mod); | |
6977 | break; | |
9828413d SRRH |
6978 | case MODULE_STATE_GOING: |
6979 | trace_module_remove_enums(mod); | |
6980 | break; | |
3673b8e4 SRRH |
6981 | } |
6982 | ||
6983 | return 0; | |
0c564a53 SRRH |
6984 | } |
6985 | ||
3673b8e4 SRRH |
6986 | static struct notifier_block trace_module_nb = { |
6987 | .notifier_call = trace_module_notify, | |
6988 | .priority = 0, | |
6989 | }; | |
9828413d | 6990 | #endif /* CONFIG_MODULES */ |
3673b8e4 | 6991 | |
8434dc93 | 6992 | static __init int tracer_init_tracefs(void) |
bc0c38d1 SR |
6993 | { |
6994 | struct dentry *d_tracer; | |
bc0c38d1 | 6995 | |
7e53bd42 LJ |
6996 | trace_access_lock_init(); |
6997 | ||
bc0c38d1 | 6998 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 6999 | if (IS_ERR(d_tracer)) |
ed6f1c99 | 7000 | return 0; |
bc0c38d1 | 7001 | |
8434dc93 | 7002 | init_tracer_tracefs(&global_trace, d_tracer); |
bc0c38d1 | 7003 | |
5452af66 | 7004 | trace_create_file("tracing_thresh", 0644, d_tracer, |
6508fa76 | 7005 | &global_trace, &tracing_thresh_fops); |
a8259075 | 7006 | |
339ae5d3 | 7007 | trace_create_file("README", 0444, d_tracer, |
5452af66 FW |
7008 | NULL, &tracing_readme_fops); |
7009 | ||
69abe6a5 AP |
7010 | trace_create_file("saved_cmdlines", 0444, d_tracer, |
7011 | NULL, &tracing_saved_cmdlines_fops); | |
5bf9a1ee | 7012 | |
939c7a4f YY |
7013 | trace_create_file("saved_cmdlines_size", 0644, d_tracer, |
7014 | NULL, &tracing_saved_cmdlines_size_fops); | |
7015 | ||
0c564a53 SRRH |
7016 | trace_enum_init(); |
7017 | ||
9828413d SRRH |
7018 | trace_create_enum_file(d_tracer); |
7019 | ||
3673b8e4 SRRH |
7020 | #ifdef CONFIG_MODULES |
7021 | register_module_notifier(&trace_module_nb); | |
7022 | #endif | |
7023 | ||
bc0c38d1 | 7024 | #ifdef CONFIG_DYNAMIC_FTRACE |
5452af66 FW |
7025 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
7026 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
bc0c38d1 | 7027 | #endif |
b04cc6b1 | 7028 | |
277ba044 | 7029 | create_trace_instances(d_tracer); |
5452af66 | 7030 | |
37aea98b | 7031 | update_tracer_options(&global_trace); |
09d23a1d | 7032 | |
b5ad384e | 7033 | return 0; |
bc0c38d1 SR |
7034 | } |
7035 | ||
3f5a54e3 SR |
7036 | static int trace_panic_handler(struct notifier_block *this, |
7037 | unsigned long event, void *unused) | |
7038 | { | |
944ac425 | 7039 | if (ftrace_dump_on_oops) |
cecbca96 | 7040 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
7041 | return NOTIFY_OK; |
7042 | } | |
7043 | ||
7044 | static struct notifier_block trace_panic_notifier = { | |
7045 | .notifier_call = trace_panic_handler, | |
7046 | .next = NULL, | |
7047 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
7048 | }; | |
7049 | ||
7050 | static int trace_die_handler(struct notifier_block *self, | |
7051 | unsigned long val, | |
7052 | void *data) | |
7053 | { | |
7054 | switch (val) { | |
7055 | case DIE_OOPS: | |
944ac425 | 7056 | if (ftrace_dump_on_oops) |
cecbca96 | 7057 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
7058 | break; |
7059 | default: | |
7060 | break; | |
7061 | } | |
7062 | return NOTIFY_OK; | |
7063 | } | |
7064 | ||
7065 | static struct notifier_block trace_die_notifier = { | |
7066 | .notifier_call = trace_die_handler, | |
7067 | .priority = 200 | |
7068 | }; | |
7069 | ||
7070 | /* | |
7071 | * printk is set to max of 1024, we really don't need it that big. | |
7072 | * Nothing should be printing 1000 characters anyway. | |
7073 | */ | |
7074 | #define TRACE_MAX_PRINT 1000 | |
7075 | ||
7076 | /* | |
7077 | * Define here KERN_TRACE so that we have one place to modify | |
7078 | * it if we decide to change what log level the ftrace dump | |
7079 | * should be at. | |
7080 | */ | |
428aee14 | 7081 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 | 7082 | |
955b61e5 | 7083 | void |
3f5a54e3 SR |
7084 | trace_printk_seq(struct trace_seq *s) |
7085 | { | |
7086 | /* Probably should print a warning here. */ | |
3a161d99 SRRH |
7087 | if (s->seq.len >= TRACE_MAX_PRINT) |
7088 | s->seq.len = TRACE_MAX_PRINT; | |
3f5a54e3 | 7089 | |
820b75f6 SRRH |
7090 | /* |
7091 | * More paranoid code. Although the buffer size is set to | |
7092 | * PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just | |
7093 | * an extra layer of protection. | |
7094 | */ | |
7095 | if (WARN_ON_ONCE(s->seq.len >= s->seq.size)) | |
7096 | s->seq.len = s->seq.size - 1; | |
3f5a54e3 SR |
7097 | |
7098 | /* should be zero ended, but we are paranoid. */ | |
3a161d99 | 7099 | s->buffer[s->seq.len] = 0; |
3f5a54e3 SR |
7100 | |
7101 | printk(KERN_TRACE "%s", s->buffer); | |
7102 | ||
f9520750 | 7103 | trace_seq_init(s); |
3f5a54e3 SR |
7104 | } |
7105 | ||
955b61e5 JW |
7106 | void trace_init_global_iter(struct trace_iterator *iter) |
7107 | { | |
7108 | iter->tr = &global_trace; | |
2b6080f2 | 7109 | iter->trace = iter->tr->current_trace; |
ae3b5093 | 7110 | iter->cpu_file = RING_BUFFER_ALL_CPUS; |
12883efb | 7111 | iter->trace_buffer = &global_trace.trace_buffer; |
b2f974d6 CS |
7112 | |
7113 | if (iter->trace && iter->trace->open) | |
7114 | iter->trace->open(iter); | |
7115 | ||
7116 | /* Annotate start of buffers if we had overruns */ | |
7117 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) | |
7118 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
7119 | ||
7120 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ | |
7121 | if (trace_clocks[iter->tr->clock_id].in_ns) | |
7122 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
955b61e5 JW |
7123 | } |
7124 | ||
7fe70b57 | 7125 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) |
3f5a54e3 | 7126 | { |
3f5a54e3 SR |
7127 | /* use static because iter can be a bit big for the stack */ |
7128 | static struct trace_iterator iter; | |
7fe70b57 | 7129 | static atomic_t dump_running; |
983f938a | 7130 | struct trace_array *tr = &global_trace; |
cf586b61 | 7131 | unsigned int old_userobj; |
d769041f SR |
7132 | unsigned long flags; |
7133 | int cnt = 0, cpu; | |
3f5a54e3 | 7134 | |
7fe70b57 SRRH |
7135 | /* Only allow one dump user at a time. */ |
7136 | if (atomic_inc_return(&dump_running) != 1) { | |
7137 | atomic_dec(&dump_running); | |
7138 | return; | |
7139 | } | |
3f5a54e3 | 7140 | |
7fe70b57 SRRH |
7141 | /* |
7142 | * Always turn off tracing when we dump. | |
7143 | * We don't need to show trace output of what happens | |
7144 | * between multiple crashes. | |
7145 | * | |
7146 | * If the user does a sysrq-z, then they can re-enable | |
7147 | * tracing with echo 1 > tracing_on. | |
7148 | */ | |
0ee6b6cf | 7149 | tracing_off(); |
cf586b61 | 7150 | |
7fe70b57 | 7151 | local_irq_save(flags); |
3f5a54e3 | 7152 | |
38dbe0b1 | 7153 | /* Simulate the iterator */ |
955b61e5 JW |
7154 | trace_init_global_iter(&iter); |
7155 | ||
d769041f | 7156 | for_each_tracing_cpu(cpu) { |
5e2d5ef8 | 7157 | atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); |
d769041f SR |
7158 | } |
7159 | ||
983f938a | 7160 | old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ; |
cf586b61 | 7161 | |
b54d3de9 | 7162 | /* don't look at user memory in panic mode */ |
983f938a | 7163 | tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ; |
b54d3de9 | 7164 | |
cecbca96 FW |
7165 | switch (oops_dump_mode) { |
7166 | case DUMP_ALL: | |
ae3b5093 | 7167 | iter.cpu_file = RING_BUFFER_ALL_CPUS; |
cecbca96 FW |
7168 | break; |
7169 | case DUMP_ORIG: | |
7170 | iter.cpu_file = raw_smp_processor_id(); | |
7171 | break; | |
7172 | case DUMP_NONE: | |
7173 | goto out_enable; | |
7174 | default: | |
7175 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
ae3b5093 | 7176 | iter.cpu_file = RING_BUFFER_ALL_CPUS; |
cecbca96 FW |
7177 | } |
7178 | ||
7179 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
3f5a54e3 | 7180 | |
7fe70b57 SRRH |
7181 | /* Did function tracer already get disabled? */ |
7182 | if (ftrace_is_dead()) { | |
7183 | printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
7184 | printk("# MAY BE MISSING FUNCTION EVENTS\n"); | |
7185 | } | |
7186 | ||
3f5a54e3 SR |
7187 | /* |
7188 | * We need to stop all tracing on all CPUS to read the | |
7189 | * the next buffer. This is a bit expensive, but is | |
7190 | * not done often. We fill all what we can read, | |
7191 | * and then release the locks again. | |
7192 | */ | |
7193 | ||
3f5a54e3 SR |
7194 | while (!trace_empty(&iter)) { |
7195 | ||
7196 | if (!cnt) | |
7197 | printk(KERN_TRACE "---------------------------------\n"); | |
7198 | ||
7199 | cnt++; | |
7200 | ||
7201 | /* reset all but tr, trace, and overruns */ | |
7202 | memset(&iter.seq, 0, | |
7203 | sizeof(struct trace_iterator) - | |
7204 | offsetof(struct trace_iterator, seq)); | |
7205 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
7206 | iter.pos = -1; | |
7207 | ||
955b61e5 | 7208 | if (trace_find_next_entry_inc(&iter) != NULL) { |
74e7ff8c LJ |
7209 | int ret; |
7210 | ||
7211 | ret = print_trace_line(&iter); | |
7212 | if (ret != TRACE_TYPE_NO_CONSUME) | |
7213 | trace_consume(&iter); | |
3f5a54e3 | 7214 | } |
b892e5c8 | 7215 | touch_nmi_watchdog(); |
3f5a54e3 SR |
7216 | |
7217 | trace_printk_seq(&iter.seq); | |
7218 | } | |
7219 | ||
7220 | if (!cnt) | |
7221 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
7222 | else | |
7223 | printk(KERN_TRACE "---------------------------------\n"); | |
7224 | ||
cecbca96 | 7225 | out_enable: |
983f938a | 7226 | tr->trace_flags |= old_userobj; |
cf586b61 | 7227 | |
7fe70b57 SRRH |
7228 | for_each_tracing_cpu(cpu) { |
7229 | atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); | |
cf586b61 | 7230 | } |
7fe70b57 | 7231 | atomic_dec(&dump_running); |
cd891ae0 | 7232 | local_irq_restore(flags); |
3f5a54e3 | 7233 | } |
a8eecf22 | 7234 | EXPORT_SYMBOL_GPL(ftrace_dump); |
cf586b61 | 7235 | |
3928a8a2 | 7236 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 7237 | { |
73c5162a | 7238 | int ring_buf_size; |
9e01c1b7 | 7239 | int ret = -ENOMEM; |
4c11d7ae | 7240 | |
b5e87c05 SRRH |
7241 | /* |
7242 | * Make sure we don't accidently add more trace options | |
7243 | * than we have bits for. | |
7244 | */ | |
9a38a885 | 7245 | BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE); |
b5e87c05 | 7246 | |
9e01c1b7 RR |
7247 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
7248 | goto out; | |
7249 | ||
ccfe9e42 | 7250 | if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL)) |
9e01c1b7 | 7251 | goto out_free_buffer_mask; |
4c11d7ae | 7252 | |
07d777fe SR |
7253 | /* Only allocate trace_printk buffers if a trace_printk exists */ |
7254 | if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) | |
81698831 | 7255 | /* Must be called before global_trace.buffer is allocated */ |
07d777fe SR |
7256 | trace_printk_init_buffers(); |
7257 | ||
73c5162a SR |
7258 | /* To save memory, keep the ring buffer size to its minimum */ |
7259 | if (ring_buffer_expanded) | |
7260 | ring_buf_size = trace_buf_size; | |
7261 | else | |
7262 | ring_buf_size = 1; | |
7263 | ||
9e01c1b7 | 7264 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
ccfe9e42 | 7265 | cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask); |
9e01c1b7 | 7266 | |
2b6080f2 SR |
7267 | raw_spin_lock_init(&global_trace.start_lock); |
7268 | ||
2c4a33ab SRRH |
7269 | /* Used for event triggers */ |
7270 | temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE); | |
7271 | if (!temp_buffer) | |
7272 | goto out_free_cpumask; | |
7273 | ||
939c7a4f YY |
7274 | if (trace_create_savedcmd() < 0) |
7275 | goto out_free_temp_buffer; | |
7276 | ||
9e01c1b7 | 7277 | /* TODO: make the number of buffers hot pluggable with CPUS */ |
737223fb | 7278 | if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { |
3928a8a2 SR |
7279 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); |
7280 | WARN_ON(1); | |
939c7a4f | 7281 | goto out_free_savedcmd; |
4c11d7ae | 7282 | } |
a7603ff4 | 7283 | |
499e5470 SR |
7284 | if (global_trace.buffer_disabled) |
7285 | tracing_off(); | |
4c11d7ae | 7286 | |
e1e232ca SR |
7287 | if (trace_boot_clock) { |
7288 | ret = tracing_set_clock(&global_trace, trace_boot_clock); | |
7289 | if (ret < 0) | |
a395d6a7 JP |
7290 | pr_warn("Trace clock %s not defined, going back to default\n", |
7291 | trace_boot_clock); | |
e1e232ca SR |
7292 | } |
7293 | ||
ca164318 SRRH |
7294 | /* |
7295 | * register_tracer() might reference current_trace, so it | |
7296 | * needs to be set before we register anything. This is | |
7297 | * just a bootstrap of current_trace anyway. | |
7298 | */ | |
2b6080f2 SR |
7299 | global_trace.current_trace = &nop_trace; |
7300 | ||
0b9b12c1 SRRH |
7301 | global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
7302 | ||
4104d326 SRRH |
7303 | ftrace_init_global_array_ops(&global_trace); |
7304 | ||
9a38a885 SRRH |
7305 | init_trace_flags_index(&global_trace); |
7306 | ||
ca164318 SRRH |
7307 | register_tracer(&nop_trace); |
7308 | ||
60a11774 SR |
7309 | /* All seems OK, enable tracing */ |
7310 | tracing_disabled = 0; | |
3928a8a2 | 7311 | |
3f5a54e3 SR |
7312 | atomic_notifier_chain_register(&panic_notifier_list, |
7313 | &trace_panic_notifier); | |
7314 | ||
7315 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe | 7316 | |
ae63b31e SR |
7317 | global_trace.flags = TRACE_ARRAY_FL_GLOBAL; |
7318 | ||
7319 | INIT_LIST_HEAD(&global_trace.systems); | |
7320 | INIT_LIST_HEAD(&global_trace.events); | |
7321 | list_add(&global_trace.list, &ftrace_trace_arrays); | |
7322 | ||
a4d1e688 | 7323 | apply_trace_boot_options(); |
7bcfaf54 | 7324 | |
77fd5c15 SRRH |
7325 | register_snapshot_cmd(); |
7326 | ||
2fc1dfbe | 7327 | return 0; |
3f5a54e3 | 7328 | |
939c7a4f YY |
7329 | out_free_savedcmd: |
7330 | free_saved_cmdlines_buffer(savedcmd); | |
2c4a33ab SRRH |
7331 | out_free_temp_buffer: |
7332 | ring_buffer_free(temp_buffer); | |
9e01c1b7 | 7333 | out_free_cpumask: |
ccfe9e42 | 7334 | free_cpumask_var(global_trace.tracing_cpumask); |
9e01c1b7 RR |
7335 | out_free_buffer_mask: |
7336 | free_cpumask_var(tracing_buffer_mask); | |
7337 | out: | |
7338 | return ret; | |
bc0c38d1 | 7339 | } |
b2821ae6 | 7340 | |
5f893b26 SRRH |
7341 | void __init trace_init(void) |
7342 | { | |
0daa2302 SRRH |
7343 | if (tracepoint_printk) { |
7344 | tracepoint_print_iter = | |
7345 | kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL); | |
7346 | if (WARN_ON(!tracepoint_print_iter)) | |
7347 | tracepoint_printk = 0; | |
7348 | } | |
5f893b26 | 7349 | tracer_alloc_buffers(); |
0c564a53 | 7350 | trace_event_init(); |
5f893b26 SRRH |
7351 | } |
7352 | ||
b2821ae6 SR |
7353 | __init static int clear_boot_tracer(void) |
7354 | { | |
7355 | /* | |
7356 | * The default tracer at boot buffer is an init section. | |
7357 | * This function is called in lateinit. If we did not | |
7358 | * find the boot tracer, then clear it out, to prevent | |
7359 | * later registration from accessing the buffer that is | |
7360 | * about to be freed. | |
7361 | */ | |
7362 | if (!default_bootup_tracer) | |
7363 | return 0; | |
7364 | ||
7365 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
7366 | default_bootup_tracer); | |
7367 | default_bootup_tracer = NULL; | |
7368 | ||
7369 | return 0; | |
7370 | } | |
7371 | ||
8434dc93 | 7372 | fs_initcall(tracer_init_tracefs); |
b2821ae6 | 7373 | late_initcall(clear_boot_tracer); |