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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> |
4c11d7ae | 23 | #include <linux/pagemap.h> |
bc0c38d1 SR |
24 | #include <linux/hardirq.h> |
25 | #include <linux/linkage.h> | |
26 | #include <linux/uaccess.h> | |
2cadf913 | 27 | #include <linux/kprobes.h> |
bc0c38d1 SR |
28 | #include <linux/ftrace.h> |
29 | #include <linux/module.h> | |
30 | #include <linux/percpu.h> | |
2cadf913 | 31 | #include <linux/splice.h> |
3f5a54e3 | 32 | #include <linux/kdebug.h> |
5f0c6c03 | 33 | #include <linux/string.h> |
7e53bd42 | 34 | #include <linux/rwsem.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
bc0c38d1 SR |
36 | #include <linux/ctype.h> |
37 | #include <linux/init.h> | |
2a2cc8f7 | 38 | #include <linux/poll.h> |
b892e5c8 | 39 | #include <linux/nmi.h> |
bc0c38d1 | 40 | #include <linux/fs.h> |
8bd75c77 | 41 | #include <linux/sched/rt.h> |
86387f7e | 42 | |
bc0c38d1 | 43 | #include "trace.h" |
f0868d1e | 44 | #include "trace_output.h" |
bc0c38d1 | 45 | |
73c5162a SR |
46 | /* |
47 | * On boot up, the ring buffer is set to the minimum size, so that | |
48 | * we do not waste memory on systems that are not using tracing. | |
49 | */ | |
55034cd6 | 50 | bool ring_buffer_expanded; |
73c5162a | 51 | |
8e1b82e0 FW |
52 | /* |
53 | * We need to change this state when a selftest is running. | |
ff32504f FW |
54 | * A selftest will lurk into the ring-buffer to count the |
55 | * entries inserted during the selftest although some concurrent | |
5e1607a0 | 56 | * insertions into the ring-buffer such as trace_printk could occurred |
ff32504f FW |
57 | * at the same time, giving false positive or negative results. |
58 | */ | |
8e1b82e0 | 59 | static bool __read_mostly tracing_selftest_running; |
ff32504f | 60 | |
b2821ae6 SR |
61 | /* |
62 | * If a tracer is running, we do not want to run SELFTEST. | |
63 | */ | |
020e5f85 | 64 | bool __read_mostly tracing_selftest_disabled; |
b2821ae6 | 65 | |
adf9f195 FW |
66 | /* For tracers that don't implement custom flags */ |
67 | static struct tracer_opt dummy_tracer_opt[] = { | |
68 | { } | |
69 | }; | |
70 | ||
71 | static struct tracer_flags dummy_tracer_flags = { | |
72 | .val = 0, | |
73 | .opts = dummy_tracer_opt | |
74 | }; | |
75 | ||
8c1a49ae SRRH |
76 | static int |
77 | dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
adf9f195 FW |
78 | { |
79 | return 0; | |
80 | } | |
0f048701 | 81 | |
7ffbd48d SR |
82 | /* |
83 | * To prevent the comm cache from being overwritten when no | |
84 | * tracing is active, only save the comm when a trace event | |
85 | * occurred. | |
86 | */ | |
87 | static DEFINE_PER_CPU(bool, trace_cmdline_save); | |
88 | ||
0f048701 SR |
89 | /* |
90 | * Kill all tracing for good (never come back). | |
91 | * It is initialized to 1 but will turn to zero if the initialization | |
92 | * of the tracer is successful. But that is the only place that sets | |
93 | * this back to zero. | |
94 | */ | |
4fd27358 | 95 | static int tracing_disabled = 1; |
0f048701 | 96 | |
9288f99a | 97 | DEFINE_PER_CPU(int, ftrace_cpu_disabled); |
d769041f | 98 | |
955b61e5 | 99 | cpumask_var_t __read_mostly tracing_buffer_mask; |
ab46428c | 100 | |
944ac425 SR |
101 | /* |
102 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
103 | * | |
104 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
105 | * is set, then ftrace_dump is called. This will output the contents | |
106 | * of the ftrace buffers to the console. This is very useful for | |
107 | * capturing traces that lead to crashes and outputing it to a | |
108 | * serial console. | |
109 | * | |
110 | * It is default off, but you can enable it with either specifying | |
111 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
cecbca96 FW |
112 | * /proc/sys/kernel/ftrace_dump_on_oops |
113 | * Set 1 if you want to dump buffers of all CPUs | |
114 | * Set 2 if you want to dump the buffer of the CPU that triggered oops | |
944ac425 | 115 | */ |
cecbca96 FW |
116 | |
117 | enum ftrace_dump_mode ftrace_dump_on_oops; | |
944ac425 | 118 | |
de7edd31 SRRH |
119 | /* When set, tracing will stop when a WARN*() is hit */ |
120 | int __disable_trace_on_warning; | |
121 | ||
607e2ea1 | 122 | static int tracing_set_tracer(struct trace_array *tr, const char *buf); |
b2821ae6 | 123 | |
ee6c2c1b LZ |
124 | #define MAX_TRACER_SIZE 100 |
125 | static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; | |
b2821ae6 | 126 | static char *default_bootup_tracer; |
d9e54076 | 127 | |
55034cd6 SRRH |
128 | static bool allocate_snapshot; |
129 | ||
1beee96b | 130 | static int __init set_cmdline_ftrace(char *str) |
d9e54076 | 131 | { |
67012ab1 | 132 | strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); |
b2821ae6 | 133 | default_bootup_tracer = bootup_tracer_buf; |
73c5162a | 134 | /* We are using ftrace early, expand it */ |
55034cd6 | 135 | ring_buffer_expanded = true; |
d9e54076 PZ |
136 | return 1; |
137 | } | |
1beee96b | 138 | __setup("ftrace=", set_cmdline_ftrace); |
d9e54076 | 139 | |
944ac425 SR |
140 | static int __init set_ftrace_dump_on_oops(char *str) |
141 | { | |
cecbca96 FW |
142 | if (*str++ != '=' || !*str) { |
143 | ftrace_dump_on_oops = DUMP_ALL; | |
144 | return 1; | |
145 | } | |
146 | ||
147 | if (!strcmp("orig_cpu", str)) { | |
148 | ftrace_dump_on_oops = DUMP_ORIG; | |
149 | return 1; | |
150 | } | |
151 | ||
152 | return 0; | |
944ac425 SR |
153 | } |
154 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
60a11774 | 155 | |
de7edd31 SRRH |
156 | static int __init stop_trace_on_warning(char *str) |
157 | { | |
158 | __disable_trace_on_warning = 1; | |
159 | return 1; | |
160 | } | |
161 | __setup("traceoff_on_warning=", stop_trace_on_warning); | |
162 | ||
3209cff4 | 163 | static int __init boot_alloc_snapshot(char *str) |
55034cd6 SRRH |
164 | { |
165 | allocate_snapshot = true; | |
166 | /* We also need the main ring buffer expanded */ | |
167 | ring_buffer_expanded = true; | |
168 | return 1; | |
169 | } | |
3209cff4 | 170 | __setup("alloc_snapshot", boot_alloc_snapshot); |
55034cd6 | 171 | |
7bcfaf54 SR |
172 | |
173 | static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; | |
174 | static char *trace_boot_options __initdata; | |
175 | ||
176 | static int __init set_trace_boot_options(char *str) | |
177 | { | |
67012ab1 | 178 | strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); |
7bcfaf54 SR |
179 | trace_boot_options = trace_boot_options_buf; |
180 | return 0; | |
181 | } | |
182 | __setup("trace_options=", set_trace_boot_options); | |
183 | ||
e1e232ca SR |
184 | static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata; |
185 | static char *trace_boot_clock __initdata; | |
186 | ||
187 | static int __init set_trace_boot_clock(char *str) | |
188 | { | |
189 | strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE); | |
190 | trace_boot_clock = trace_boot_clock_buf; | |
191 | return 0; | |
192 | } | |
193 | __setup("trace_clock=", set_trace_boot_clock); | |
194 | ||
de7edd31 | 195 | |
cf8e3474 | 196 | unsigned long long ns2usecs(cycle_t nsec) |
bc0c38d1 SR |
197 | { |
198 | nsec += 500; | |
199 | do_div(nsec, 1000); | |
200 | return nsec; | |
201 | } | |
202 | ||
4fcdae83 SR |
203 | /* |
204 | * The global_trace is the descriptor that holds the tracing | |
205 | * buffers for the live tracing. For each CPU, it contains | |
206 | * a link list of pages that will store trace entries. The | |
207 | * page descriptor of the pages in the memory is used to hold | |
208 | * the link list by linking the lru item in the page descriptor | |
209 | * to each of the pages in the buffer per CPU. | |
210 | * | |
211 | * For each active CPU there is a data field that holds the | |
212 | * pages for the buffer for that CPU. Each CPU has the same number | |
213 | * of pages allocated for its buffer. | |
214 | */ | |
bc0c38d1 SR |
215 | static struct trace_array global_trace; |
216 | ||
ae63b31e | 217 | LIST_HEAD(ftrace_trace_arrays); |
bc0c38d1 | 218 | |
ff451961 SRRH |
219 | int trace_array_get(struct trace_array *this_tr) |
220 | { | |
221 | struct trace_array *tr; | |
222 | int ret = -ENODEV; | |
223 | ||
224 | mutex_lock(&trace_types_lock); | |
225 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
226 | if (tr == this_tr) { | |
227 | tr->ref++; | |
228 | ret = 0; | |
229 | break; | |
230 | } | |
231 | } | |
232 | mutex_unlock(&trace_types_lock); | |
233 | ||
234 | return ret; | |
235 | } | |
236 | ||
237 | static void __trace_array_put(struct trace_array *this_tr) | |
238 | { | |
239 | WARN_ON(!this_tr->ref); | |
240 | this_tr->ref--; | |
241 | } | |
242 | ||
243 | void trace_array_put(struct trace_array *this_tr) | |
244 | { | |
245 | mutex_lock(&trace_types_lock); | |
246 | __trace_array_put(this_tr); | |
247 | mutex_unlock(&trace_types_lock); | |
248 | } | |
249 | ||
f306cc82 TZ |
250 | int filter_check_discard(struct ftrace_event_file *file, void *rec, |
251 | struct ring_buffer *buffer, | |
252 | struct ring_buffer_event *event) | |
eb02ce01 | 253 | { |
f306cc82 TZ |
254 | if (unlikely(file->flags & FTRACE_EVENT_FL_FILTERED) && |
255 | !filter_match_preds(file->filter, rec)) { | |
256 | ring_buffer_discard_commit(buffer, event); | |
257 | return 1; | |
258 | } | |
259 | ||
260 | return 0; | |
261 | } | |
262 | EXPORT_SYMBOL_GPL(filter_check_discard); | |
263 | ||
264 | int call_filter_check_discard(struct ftrace_event_call *call, void *rec, | |
265 | struct ring_buffer *buffer, | |
266 | struct ring_buffer_event *event) | |
267 | { | |
268 | if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) && | |
269 | !filter_match_preds(call->filter, rec)) { | |
270 | ring_buffer_discard_commit(buffer, event); | |
271 | return 1; | |
272 | } | |
273 | ||
274 | return 0; | |
eb02ce01 | 275 | } |
f306cc82 | 276 | EXPORT_SYMBOL_GPL(call_filter_check_discard); |
eb02ce01 | 277 | |
ad1438a0 | 278 | static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) |
37886f6a SR |
279 | { |
280 | u64 ts; | |
281 | ||
282 | /* Early boot up does not have a buffer yet */ | |
9457158b | 283 | if (!buf->buffer) |
37886f6a SR |
284 | return trace_clock_local(); |
285 | ||
9457158b AL |
286 | ts = ring_buffer_time_stamp(buf->buffer, cpu); |
287 | ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts); | |
37886f6a SR |
288 | |
289 | return ts; | |
290 | } | |
bc0c38d1 | 291 | |
9457158b AL |
292 | cycle_t ftrace_now(int cpu) |
293 | { | |
294 | return buffer_ftrace_now(&global_trace.trace_buffer, cpu); | |
295 | } | |
296 | ||
10246fa3 SRRH |
297 | /** |
298 | * tracing_is_enabled - Show if global_trace has been disabled | |
299 | * | |
300 | * Shows if the global trace has been enabled or not. It uses the | |
301 | * mirror flag "buffer_disabled" to be used in fast paths such as for | |
302 | * the irqsoff tracer. But it may be inaccurate due to races. If you | |
303 | * need to know the accurate state, use tracing_is_on() which is a little | |
304 | * slower, but accurate. | |
305 | */ | |
9036990d SR |
306 | int tracing_is_enabled(void) |
307 | { | |
10246fa3 SRRH |
308 | /* |
309 | * For quick access (irqsoff uses this in fast path), just | |
310 | * return the mirror variable of the state of the ring buffer. | |
311 | * It's a little racy, but we don't really care. | |
312 | */ | |
313 | smp_rmb(); | |
314 | return !global_trace.buffer_disabled; | |
9036990d SR |
315 | } |
316 | ||
4fcdae83 | 317 | /* |
3928a8a2 SR |
318 | * trace_buf_size is the size in bytes that is allocated |
319 | * for a buffer. Note, the number of bytes is always rounded | |
320 | * to page size. | |
3f5a54e3 SR |
321 | * |
322 | * This number is purposely set to a low number of 16384. | |
323 | * If the dump on oops happens, it will be much appreciated | |
324 | * to not have to wait for all that output. Anyway this can be | |
325 | * boot time and run time configurable. | |
4fcdae83 | 326 | */ |
3928a8a2 | 327 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 328 | |
3928a8a2 | 329 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 330 | |
4fcdae83 | 331 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 332 | static struct tracer *trace_types __read_mostly; |
4fcdae83 | 333 | |
4fcdae83 SR |
334 | /* |
335 | * trace_types_lock is used to protect the trace_types list. | |
4fcdae83 | 336 | */ |
a8227415 | 337 | DEFINE_MUTEX(trace_types_lock); |
4fcdae83 | 338 | |
7e53bd42 LJ |
339 | /* |
340 | * serialize the access of the ring buffer | |
341 | * | |
342 | * ring buffer serializes readers, but it is low level protection. | |
343 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
344 | * are not protected by ring buffer. | |
345 | * | |
346 | * The content of events may become garbage if we allow other process consumes | |
347 | * these events concurrently: | |
348 | * A) the page of the consumed events may become a normal page | |
349 | * (not reader page) in ring buffer, and this page will be rewrited | |
350 | * by events producer. | |
351 | * B) The page of the consumed events may become a page for splice_read, | |
352 | * and this page will be returned to system. | |
353 | * | |
354 | * These primitives allow multi process access to different cpu ring buffer | |
355 | * concurrently. | |
356 | * | |
357 | * These primitives don't distinguish read-only and read-consume access. | |
358 | * Multi read-only access are also serialized. | |
359 | */ | |
360 | ||
361 | #ifdef CONFIG_SMP | |
362 | static DECLARE_RWSEM(all_cpu_access_lock); | |
363 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
364 | ||
365 | static inline void trace_access_lock(int cpu) | |
366 | { | |
ae3b5093 | 367 | if (cpu == RING_BUFFER_ALL_CPUS) { |
7e53bd42 LJ |
368 | /* gain it for accessing the whole ring buffer. */ |
369 | down_write(&all_cpu_access_lock); | |
370 | } else { | |
371 | /* gain it for accessing a cpu ring buffer. */ | |
372 | ||
ae3b5093 | 373 | /* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */ |
7e53bd42 LJ |
374 | down_read(&all_cpu_access_lock); |
375 | ||
376 | /* Secondly block other access to this @cpu ring buffer. */ | |
377 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
378 | } | |
379 | } | |
380 | ||
381 | static inline void trace_access_unlock(int cpu) | |
382 | { | |
ae3b5093 | 383 | if (cpu == RING_BUFFER_ALL_CPUS) { |
7e53bd42 LJ |
384 | up_write(&all_cpu_access_lock); |
385 | } else { | |
386 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
387 | up_read(&all_cpu_access_lock); | |
388 | } | |
389 | } | |
390 | ||
391 | static inline void trace_access_lock_init(void) | |
392 | { | |
393 | int cpu; | |
394 | ||
395 | for_each_possible_cpu(cpu) | |
396 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
397 | } | |
398 | ||
399 | #else | |
400 | ||
401 | static DEFINE_MUTEX(access_lock); | |
402 | ||
403 | static inline void trace_access_lock(int cpu) | |
404 | { | |
405 | (void)cpu; | |
406 | mutex_lock(&access_lock); | |
407 | } | |
408 | ||
409 | static inline void trace_access_unlock(int cpu) | |
410 | { | |
411 | (void)cpu; | |
412 | mutex_unlock(&access_lock); | |
413 | } | |
414 | ||
415 | static inline void trace_access_lock_init(void) | |
416 | { | |
417 | } | |
418 | ||
419 | #endif | |
420 | ||
ee6bce52 | 421 | /* trace_flags holds trace_options default values */ |
12ef7d44 | 422 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | |
a2a16d6a | 423 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | |
77271ce4 | 424 | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | |
328df475 | 425 | TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | TRACE_ITER_FUNCTION; |
e7e2ee89 | 426 | |
5280bcef | 427 | static void tracer_tracing_on(struct trace_array *tr) |
10246fa3 SRRH |
428 | { |
429 | if (tr->trace_buffer.buffer) | |
430 | ring_buffer_record_on(tr->trace_buffer.buffer); | |
431 | /* | |
432 | * This flag is looked at when buffers haven't been allocated | |
433 | * yet, or by some tracers (like irqsoff), that just want to | |
434 | * know if the ring buffer has been disabled, but it can handle | |
435 | * races of where it gets disabled but we still do a record. | |
436 | * As the check is in the fast path of the tracers, it is more | |
437 | * important to be fast than accurate. | |
438 | */ | |
439 | tr->buffer_disabled = 0; | |
440 | /* Make the flag seen by readers */ | |
441 | smp_wmb(); | |
442 | } | |
443 | ||
499e5470 SR |
444 | /** |
445 | * tracing_on - enable tracing buffers | |
446 | * | |
447 | * This function enables tracing buffers that may have been | |
448 | * disabled with tracing_off. | |
449 | */ | |
450 | void tracing_on(void) | |
451 | { | |
10246fa3 | 452 | tracer_tracing_on(&global_trace); |
499e5470 SR |
453 | } |
454 | EXPORT_SYMBOL_GPL(tracing_on); | |
455 | ||
09ae7234 SRRH |
456 | /** |
457 | * __trace_puts - write a constant string into the trace buffer. | |
458 | * @ip: The address of the caller | |
459 | * @str: The constant string to write | |
460 | * @size: The size of the string. | |
461 | */ | |
462 | int __trace_puts(unsigned long ip, const char *str, int size) | |
463 | { | |
464 | struct ring_buffer_event *event; | |
465 | struct ring_buffer *buffer; | |
466 | struct print_entry *entry; | |
467 | unsigned long irq_flags; | |
468 | int alloc; | |
8abfb872 J |
469 | int pc; |
470 | ||
f0160a5a J |
471 | if (!(trace_flags & TRACE_ITER_PRINTK)) |
472 | return 0; | |
473 | ||
8abfb872 | 474 | pc = preempt_count(); |
09ae7234 | 475 | |
3132e107 SRRH |
476 | if (unlikely(tracing_selftest_running || tracing_disabled)) |
477 | return 0; | |
478 | ||
09ae7234 SRRH |
479 | alloc = sizeof(*entry) + size + 2; /* possible \n added */ |
480 | ||
481 | local_save_flags(irq_flags); | |
482 | buffer = global_trace.trace_buffer.buffer; | |
483 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, | |
8abfb872 | 484 | irq_flags, pc); |
09ae7234 SRRH |
485 | if (!event) |
486 | return 0; | |
487 | ||
488 | entry = ring_buffer_event_data(event); | |
489 | entry->ip = ip; | |
490 | ||
491 | memcpy(&entry->buf, str, size); | |
492 | ||
493 | /* Add a newline if necessary */ | |
494 | if (entry->buf[size - 1] != '\n') { | |
495 | entry->buf[size] = '\n'; | |
496 | entry->buf[size + 1] = '\0'; | |
497 | } else | |
498 | entry->buf[size] = '\0'; | |
499 | ||
500 | __buffer_unlock_commit(buffer, event); | |
8abfb872 | 501 | ftrace_trace_stack(buffer, irq_flags, 4, pc); |
09ae7234 SRRH |
502 | |
503 | return size; | |
504 | } | |
505 | EXPORT_SYMBOL_GPL(__trace_puts); | |
506 | ||
507 | /** | |
508 | * __trace_bputs - write the pointer to a constant string into trace buffer | |
509 | * @ip: The address of the caller | |
510 | * @str: The constant string to write to the buffer to | |
511 | */ | |
512 | int __trace_bputs(unsigned long ip, const char *str) | |
513 | { | |
514 | struct ring_buffer_event *event; | |
515 | struct ring_buffer *buffer; | |
516 | struct bputs_entry *entry; | |
517 | unsigned long irq_flags; | |
518 | int size = sizeof(struct bputs_entry); | |
8abfb872 J |
519 | int pc; |
520 | ||
f0160a5a J |
521 | if (!(trace_flags & TRACE_ITER_PRINTK)) |
522 | return 0; | |
523 | ||
8abfb872 | 524 | pc = preempt_count(); |
09ae7234 | 525 | |
3132e107 SRRH |
526 | if (unlikely(tracing_selftest_running || tracing_disabled)) |
527 | return 0; | |
528 | ||
09ae7234 SRRH |
529 | local_save_flags(irq_flags); |
530 | buffer = global_trace.trace_buffer.buffer; | |
531 | event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, | |
8abfb872 | 532 | irq_flags, pc); |
09ae7234 SRRH |
533 | if (!event) |
534 | return 0; | |
535 | ||
536 | entry = ring_buffer_event_data(event); | |
537 | entry->ip = ip; | |
538 | entry->str = str; | |
539 | ||
540 | __buffer_unlock_commit(buffer, event); | |
8abfb872 | 541 | ftrace_trace_stack(buffer, irq_flags, 4, pc); |
09ae7234 SRRH |
542 | |
543 | return 1; | |
544 | } | |
545 | EXPORT_SYMBOL_GPL(__trace_bputs); | |
546 | ||
ad909e21 SRRH |
547 | #ifdef CONFIG_TRACER_SNAPSHOT |
548 | /** | |
549 | * trace_snapshot - take a snapshot of the current buffer. | |
550 | * | |
551 | * This causes a swap between the snapshot buffer and the current live | |
552 | * tracing buffer. You can use this to take snapshots of the live | |
553 | * trace when some condition is triggered, but continue to trace. | |
554 | * | |
555 | * Note, make sure to allocate the snapshot with either | |
556 | * a tracing_snapshot_alloc(), or by doing it manually | |
557 | * with: echo 1 > /sys/kernel/debug/tracing/snapshot | |
558 | * | |
559 | * If the snapshot buffer is not allocated, it will stop tracing. | |
560 | * Basically making a permanent snapshot. | |
561 | */ | |
562 | void tracing_snapshot(void) | |
563 | { | |
564 | struct trace_array *tr = &global_trace; | |
565 | struct tracer *tracer = tr->current_trace; | |
566 | unsigned long flags; | |
567 | ||
1b22e382 SRRH |
568 | if (in_nmi()) { |
569 | internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); | |
570 | internal_trace_puts("*** snapshot is being ignored ***\n"); | |
571 | return; | |
572 | } | |
573 | ||
ad909e21 | 574 | if (!tr->allocated_snapshot) { |
ca268da6 SRRH |
575 | internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); |
576 | internal_trace_puts("*** stopping trace here! ***\n"); | |
ad909e21 SRRH |
577 | tracing_off(); |
578 | return; | |
579 | } | |
580 | ||
581 | /* Note, snapshot can not be used when the tracer uses it */ | |
582 | if (tracer->use_max_tr) { | |
ca268da6 SRRH |
583 | internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); |
584 | internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); | |
ad909e21 SRRH |
585 | return; |
586 | } | |
587 | ||
588 | local_irq_save(flags); | |
589 | update_max_tr(tr, current, smp_processor_id()); | |
590 | local_irq_restore(flags); | |
591 | } | |
1b22e382 | 592 | EXPORT_SYMBOL_GPL(tracing_snapshot); |
ad909e21 SRRH |
593 | |
594 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, | |
595 | struct trace_buffer *size_buf, int cpu_id); | |
3209cff4 SRRH |
596 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val); |
597 | ||
598 | static int alloc_snapshot(struct trace_array *tr) | |
599 | { | |
600 | int ret; | |
601 | ||
602 | if (!tr->allocated_snapshot) { | |
603 | ||
604 | /* allocate spare buffer */ | |
605 | ret = resize_buffer_duplicate_size(&tr->max_buffer, | |
606 | &tr->trace_buffer, RING_BUFFER_ALL_CPUS); | |
607 | if (ret < 0) | |
608 | return ret; | |
609 | ||
610 | tr->allocated_snapshot = true; | |
611 | } | |
612 | ||
613 | return 0; | |
614 | } | |
615 | ||
ad1438a0 | 616 | static void free_snapshot(struct trace_array *tr) |
3209cff4 SRRH |
617 | { |
618 | /* | |
619 | * We don't free the ring buffer. instead, resize it because | |
620 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
621 | * we want preserve it. | |
622 | */ | |
623 | ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); | |
624 | set_buffer_entries(&tr->max_buffer, 1); | |
625 | tracing_reset_online_cpus(&tr->max_buffer); | |
626 | tr->allocated_snapshot = false; | |
627 | } | |
ad909e21 | 628 | |
93e31ffb TZ |
629 | /** |
630 | * tracing_alloc_snapshot - allocate snapshot buffer. | |
631 | * | |
632 | * This only allocates the snapshot buffer if it isn't already | |
633 | * allocated - it doesn't also take a snapshot. | |
634 | * | |
635 | * This is meant to be used in cases where the snapshot buffer needs | |
636 | * to be set up for events that can't sleep but need to be able to | |
637 | * trigger a snapshot. | |
638 | */ | |
639 | int tracing_alloc_snapshot(void) | |
640 | { | |
641 | struct trace_array *tr = &global_trace; | |
642 | int ret; | |
643 | ||
644 | ret = alloc_snapshot(tr); | |
645 | WARN_ON(ret < 0); | |
646 | ||
647 | return ret; | |
648 | } | |
649 | EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); | |
650 | ||
ad909e21 SRRH |
651 | /** |
652 | * trace_snapshot_alloc - allocate and take a snapshot of the current buffer. | |
653 | * | |
654 | * This is similar to trace_snapshot(), but it will allocate the | |
655 | * snapshot buffer if it isn't already allocated. Use this only | |
656 | * where it is safe to sleep, as the allocation may sleep. | |
657 | * | |
658 | * This causes a swap between the snapshot buffer and the current live | |
659 | * tracing buffer. You can use this to take snapshots of the live | |
660 | * trace when some condition is triggered, but continue to trace. | |
661 | */ | |
662 | void tracing_snapshot_alloc(void) | |
663 | { | |
ad909e21 SRRH |
664 | int ret; |
665 | ||
93e31ffb TZ |
666 | ret = tracing_alloc_snapshot(); |
667 | if (ret < 0) | |
3209cff4 | 668 | return; |
ad909e21 SRRH |
669 | |
670 | tracing_snapshot(); | |
671 | } | |
1b22e382 | 672 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
ad909e21 SRRH |
673 | #else |
674 | void tracing_snapshot(void) | |
675 | { | |
676 | WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); | |
677 | } | |
1b22e382 | 678 | EXPORT_SYMBOL_GPL(tracing_snapshot); |
93e31ffb TZ |
679 | int tracing_alloc_snapshot(void) |
680 | { | |
681 | WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used"); | |
682 | return -ENODEV; | |
683 | } | |
684 | EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); | |
ad909e21 SRRH |
685 | void tracing_snapshot_alloc(void) |
686 | { | |
687 | /* Give warning */ | |
688 | tracing_snapshot(); | |
689 | } | |
1b22e382 | 690 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
ad909e21 SRRH |
691 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
692 | ||
5280bcef | 693 | static void tracer_tracing_off(struct trace_array *tr) |
10246fa3 SRRH |
694 | { |
695 | if (tr->trace_buffer.buffer) | |
696 | ring_buffer_record_off(tr->trace_buffer.buffer); | |
697 | /* | |
698 | * This flag is looked at when buffers haven't been allocated | |
699 | * yet, or by some tracers (like irqsoff), that just want to | |
700 | * know if the ring buffer has been disabled, but it can handle | |
701 | * races of where it gets disabled but we still do a record. | |
702 | * As the check is in the fast path of the tracers, it is more | |
703 | * important to be fast than accurate. | |
704 | */ | |
705 | tr->buffer_disabled = 1; | |
706 | /* Make the flag seen by readers */ | |
707 | smp_wmb(); | |
708 | } | |
709 | ||
499e5470 SR |
710 | /** |
711 | * tracing_off - turn off tracing buffers | |
712 | * | |
713 | * This function stops the tracing buffers from recording data. | |
714 | * It does not disable any overhead the tracers themselves may | |
715 | * be causing. This function simply causes all recording to | |
716 | * the ring buffers to fail. | |
717 | */ | |
718 | void tracing_off(void) | |
719 | { | |
10246fa3 | 720 | tracer_tracing_off(&global_trace); |
499e5470 SR |
721 | } |
722 | EXPORT_SYMBOL_GPL(tracing_off); | |
723 | ||
de7edd31 SRRH |
724 | void disable_trace_on_warning(void) |
725 | { | |
726 | if (__disable_trace_on_warning) | |
727 | tracing_off(); | |
728 | } | |
729 | ||
10246fa3 SRRH |
730 | /** |
731 | * tracer_tracing_is_on - show real state of ring buffer enabled | |
732 | * @tr : the trace array to know if ring buffer is enabled | |
733 | * | |
734 | * Shows real state of the ring buffer if it is enabled or not. | |
735 | */ | |
5280bcef | 736 | static int tracer_tracing_is_on(struct trace_array *tr) |
10246fa3 SRRH |
737 | { |
738 | if (tr->trace_buffer.buffer) | |
739 | return ring_buffer_record_is_on(tr->trace_buffer.buffer); | |
740 | return !tr->buffer_disabled; | |
741 | } | |
742 | ||
499e5470 SR |
743 | /** |
744 | * tracing_is_on - show state of ring buffers enabled | |
745 | */ | |
746 | int tracing_is_on(void) | |
747 | { | |
10246fa3 | 748 | return tracer_tracing_is_on(&global_trace); |
499e5470 SR |
749 | } |
750 | EXPORT_SYMBOL_GPL(tracing_is_on); | |
751 | ||
3928a8a2 | 752 | static int __init set_buf_size(char *str) |
bc0c38d1 | 753 | { |
3928a8a2 | 754 | unsigned long buf_size; |
c6caeeb1 | 755 | |
bc0c38d1 SR |
756 | if (!str) |
757 | return 0; | |
9d612bef | 758 | buf_size = memparse(str, &str); |
c6caeeb1 | 759 | /* nr_entries can not be zero */ |
9d612bef | 760 | if (buf_size == 0) |
c6caeeb1 | 761 | return 0; |
3928a8a2 | 762 | trace_buf_size = buf_size; |
bc0c38d1 SR |
763 | return 1; |
764 | } | |
3928a8a2 | 765 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 766 | |
0e950173 TB |
767 | static int __init set_tracing_thresh(char *str) |
768 | { | |
87abb3b1 | 769 | unsigned long threshold; |
0e950173 TB |
770 | int ret; |
771 | ||
772 | if (!str) | |
773 | return 0; | |
bcd83ea6 | 774 | ret = kstrtoul(str, 0, &threshold); |
0e950173 TB |
775 | if (ret < 0) |
776 | return 0; | |
87abb3b1 | 777 | tracing_thresh = threshold * 1000; |
0e950173 TB |
778 | return 1; |
779 | } | |
780 | __setup("tracing_thresh=", set_tracing_thresh); | |
781 | ||
57f50be1 SR |
782 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
783 | { | |
784 | return nsecs / 1000; | |
785 | } | |
786 | ||
4fcdae83 | 787 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 SR |
788 | static const char *trace_options[] = { |
789 | "print-parent", | |
790 | "sym-offset", | |
791 | "sym-addr", | |
792 | "verbose", | |
f9896bf3 | 793 | "raw", |
5e3ca0ec | 794 | "hex", |
cb0f12aa | 795 | "bin", |
2a2cc8f7 | 796 | "block", |
86387f7e | 797 | "stacktrace", |
5e1607a0 | 798 | "trace_printk", |
b2a866f9 | 799 | "ftrace_preempt", |
9f029e83 | 800 | "branch", |
12ef7d44 | 801 | "annotate", |
02b67518 | 802 | "userstacktrace", |
b54d3de9 | 803 | "sym-userobj", |
66896a85 | 804 | "printk-msg-only", |
c4a8e8be | 805 | "context-info", |
c032ef64 | 806 | "latency-format", |
be6f164a | 807 | "sleep-time", |
a2a16d6a | 808 | "graph-time", |
e870e9a1 | 809 | "record-cmd", |
750912fa | 810 | "overwrite", |
cf30cf67 | 811 | "disable_on_free", |
77271ce4 | 812 | "irq-info", |
5224c3a3 | 813 | "markers", |
328df475 | 814 | "function-trace", |
bc0c38d1 SR |
815 | NULL |
816 | }; | |
817 | ||
5079f326 Z |
818 | static struct { |
819 | u64 (*func)(void); | |
820 | const char *name; | |
8be0709f | 821 | int in_ns; /* is this clock in nanoseconds? */ |
5079f326 | 822 | } trace_clocks[] = { |
1b3e5c09 TG |
823 | { trace_clock_local, "local", 1 }, |
824 | { trace_clock_global, "global", 1 }, | |
825 | { trace_clock_counter, "counter", 0 }, | |
e7fda6c4 | 826 | { trace_clock_jiffies, "uptime", 0 }, |
1b3e5c09 TG |
827 | { trace_clock, "perf", 1 }, |
828 | { ktime_get_mono_fast_ns, "mono", 1 }, | |
8cbd9cc6 | 829 | ARCH_TRACE_CLOCKS |
5079f326 Z |
830 | }; |
831 | ||
b63f39ea | 832 | /* |
833 | * trace_parser_get_init - gets the buffer for trace parser | |
834 | */ | |
835 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
836 | { | |
837 | memset(parser, 0, sizeof(*parser)); | |
838 | ||
839 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
840 | if (!parser->buffer) | |
841 | return 1; | |
842 | ||
843 | parser->size = size; | |
844 | return 0; | |
845 | } | |
846 | ||
847 | /* | |
848 | * trace_parser_put - frees the buffer for trace parser | |
849 | */ | |
850 | void trace_parser_put(struct trace_parser *parser) | |
851 | { | |
852 | kfree(parser->buffer); | |
853 | } | |
854 | ||
855 | /* | |
856 | * trace_get_user - reads the user input string separated by space | |
857 | * (matched by isspace(ch)) | |
858 | * | |
859 | * For each string found the 'struct trace_parser' is updated, | |
860 | * and the function returns. | |
861 | * | |
862 | * Returns number of bytes read. | |
863 | * | |
864 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
865 | */ | |
866 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
867 | size_t cnt, loff_t *ppos) | |
868 | { | |
869 | char ch; | |
870 | size_t read = 0; | |
871 | ssize_t ret; | |
872 | ||
873 | if (!*ppos) | |
874 | trace_parser_clear(parser); | |
875 | ||
876 | ret = get_user(ch, ubuf++); | |
877 | if (ret) | |
878 | goto out; | |
879 | ||
880 | read++; | |
881 | cnt--; | |
882 | ||
883 | /* | |
884 | * The parser is not finished with the last write, | |
885 | * continue reading the user input without skipping spaces. | |
886 | */ | |
887 | if (!parser->cont) { | |
888 | /* skip white space */ | |
889 | while (cnt && isspace(ch)) { | |
890 | ret = get_user(ch, ubuf++); | |
891 | if (ret) | |
892 | goto out; | |
893 | read++; | |
894 | cnt--; | |
895 | } | |
896 | ||
897 | /* only spaces were written */ | |
898 | if (isspace(ch)) { | |
899 | *ppos += read; | |
900 | ret = read; | |
901 | goto out; | |
902 | } | |
903 | ||
904 | parser->idx = 0; | |
905 | } | |
906 | ||
907 | /* read the non-space input */ | |
908 | while (cnt && !isspace(ch)) { | |
3c235a33 | 909 | if (parser->idx < parser->size - 1) |
b63f39ea | 910 | parser->buffer[parser->idx++] = ch; |
911 | else { | |
912 | ret = -EINVAL; | |
913 | goto out; | |
914 | } | |
915 | ret = get_user(ch, ubuf++); | |
916 | if (ret) | |
917 | goto out; | |
918 | read++; | |
919 | cnt--; | |
920 | } | |
921 | ||
922 | /* We either got finished input or we have to wait for another call. */ | |
923 | if (isspace(ch)) { | |
924 | parser->buffer[parser->idx] = 0; | |
925 | parser->cont = false; | |
057db848 | 926 | } else if (parser->idx < parser->size - 1) { |
b63f39ea | 927 | parser->cont = true; |
928 | parser->buffer[parser->idx++] = ch; | |
057db848 SR |
929 | } else { |
930 | ret = -EINVAL; | |
931 | goto out; | |
b63f39ea | 932 | } |
933 | ||
934 | *ppos += read; | |
935 | ret = read; | |
936 | ||
937 | out: | |
938 | return ret; | |
939 | } | |
940 | ||
b8b94265 | 941 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
942 | { |
943 | int len; | |
3c56819b EGM |
944 | |
945 | if (s->len <= s->readpos) | |
946 | return -EBUSY; | |
947 | ||
948 | len = s->len - s->readpos; | |
949 | if (cnt > len) | |
950 | cnt = len; | |
5a26c8f0 | 951 | memcpy(buf, s->buffer + s->readpos, cnt); |
3c56819b | 952 | |
e74da523 | 953 | s->readpos += cnt; |
3c56819b EGM |
954 | return cnt; |
955 | } | |
956 | ||
0e950173 TB |
957 | unsigned long __read_mostly tracing_thresh; |
958 | ||
5d4a9dba | 959 | #ifdef CONFIG_TRACER_MAX_TRACE |
5d4a9dba SR |
960 | /* |
961 | * Copy the new maximum trace into the separate maximum-trace | |
962 | * structure. (this way the maximum trace is permanently saved, | |
963 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
964 | */ | |
965 | static void | |
966 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
967 | { | |
12883efb SRRH |
968 | struct trace_buffer *trace_buf = &tr->trace_buffer; |
969 | struct trace_buffer *max_buf = &tr->max_buffer; | |
970 | struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); | |
971 | struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); | |
5d4a9dba | 972 | |
12883efb SRRH |
973 | max_buf->cpu = cpu; |
974 | max_buf->time_start = data->preempt_timestamp; | |
5d4a9dba | 975 | |
6d9b3fa5 | 976 | max_data->saved_latency = tr->max_latency; |
8248ac05 SR |
977 | max_data->critical_start = data->critical_start; |
978 | max_data->critical_end = data->critical_end; | |
5d4a9dba | 979 | |
1acaa1b2 | 980 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); |
8248ac05 | 981 | max_data->pid = tsk->pid; |
f17a5194 SRRH |
982 | /* |
983 | * If tsk == current, then use current_uid(), as that does not use | |
984 | * RCU. The irq tracer can be called out of RCU scope. | |
985 | */ | |
986 | if (tsk == current) | |
987 | max_data->uid = current_uid(); | |
988 | else | |
989 | max_data->uid = task_uid(tsk); | |
990 | ||
8248ac05 SR |
991 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; |
992 | max_data->policy = tsk->policy; | |
993 | max_data->rt_priority = tsk->rt_priority; | |
5d4a9dba SR |
994 | |
995 | /* record this tasks comm */ | |
996 | tracing_record_cmdline(tsk); | |
997 | } | |
998 | ||
4fcdae83 SR |
999 | /** |
1000 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
1001 | * @tr: tracer | |
1002 | * @tsk: the task with the latency | |
1003 | * @cpu: The cpu that initiated the trace. | |
1004 | * | |
1005 | * Flip the buffers between the @tr and the max_tr and record information | |
1006 | * about which task was the cause of this latency. | |
1007 | */ | |
e309b41d | 1008 | void |
bc0c38d1 SR |
1009 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
1010 | { | |
2721e72d | 1011 | struct ring_buffer *buf; |
bc0c38d1 | 1012 | |
2b6080f2 | 1013 | if (tr->stop_count) |
b8de7bd1 SR |
1014 | return; |
1015 | ||
4c11d7ae | 1016 | WARN_ON_ONCE(!irqs_disabled()); |
34600f0e | 1017 | |
45ad21ca | 1018 | if (!tr->allocated_snapshot) { |
debdd57f | 1019 | /* Only the nop tracer should hit this when disabling */ |
2b6080f2 | 1020 | WARN_ON_ONCE(tr->current_trace != &nop_trace); |
34600f0e | 1021 | return; |
debdd57f | 1022 | } |
34600f0e | 1023 | |
0b9b12c1 | 1024 | arch_spin_lock(&tr->max_lock); |
3928a8a2 | 1025 | |
12883efb SRRH |
1026 | buf = tr->trace_buffer.buffer; |
1027 | tr->trace_buffer.buffer = tr->max_buffer.buffer; | |
1028 | tr->max_buffer.buffer = buf; | |
3928a8a2 | 1029 | |
bc0c38d1 | 1030 | __update_max_tr(tr, tsk, cpu); |
0b9b12c1 | 1031 | arch_spin_unlock(&tr->max_lock); |
bc0c38d1 SR |
1032 | } |
1033 | ||
1034 | /** | |
1035 | * update_max_tr_single - only copy one trace over, and reset the rest | |
1036 | * @tr - tracer | |
1037 | * @tsk - task with the latency | |
1038 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
1039 | * |
1040 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 1041 | */ |
e309b41d | 1042 | void |
bc0c38d1 SR |
1043 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
1044 | { | |
3928a8a2 | 1045 | int ret; |
bc0c38d1 | 1046 | |
2b6080f2 | 1047 | if (tr->stop_count) |
b8de7bd1 SR |
1048 | return; |
1049 | ||
4c11d7ae | 1050 | WARN_ON_ONCE(!irqs_disabled()); |
6c24499f | 1051 | if (!tr->allocated_snapshot) { |
2930e04d | 1052 | /* Only the nop tracer should hit this when disabling */ |
9e8529af | 1053 | WARN_ON_ONCE(tr->current_trace != &nop_trace); |
ef710e10 | 1054 | return; |
2930e04d | 1055 | } |
ef710e10 | 1056 | |
0b9b12c1 | 1057 | arch_spin_lock(&tr->max_lock); |
bc0c38d1 | 1058 | |
12883efb | 1059 | ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu); |
3928a8a2 | 1060 | |
e8165dbb SR |
1061 | if (ret == -EBUSY) { |
1062 | /* | |
1063 | * We failed to swap the buffer due to a commit taking | |
1064 | * place on this CPU. We fail to record, but we reset | |
1065 | * the max trace buffer (no one writes directly to it) | |
1066 | * and flag that it failed. | |
1067 | */ | |
12883efb | 1068 | trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, |
e8165dbb SR |
1069 | "Failed to swap buffers due to commit in progress\n"); |
1070 | } | |
1071 | ||
e8165dbb | 1072 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
bc0c38d1 SR |
1073 | |
1074 | __update_max_tr(tr, tsk, cpu); | |
0b9b12c1 | 1075 | arch_spin_unlock(&tr->max_lock); |
bc0c38d1 | 1076 | } |
5d4a9dba | 1077 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
bc0c38d1 | 1078 | |
8b8b3683 | 1079 | static int wait_on_pipe(struct trace_iterator *iter) |
0d5c6e1c | 1080 | { |
15693458 SRRH |
1081 | /* Iterators are static, they should be filled or empty */ |
1082 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
8b8b3683 | 1083 | return 0; |
0d5c6e1c | 1084 | |
8b8b3683 | 1085 | return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file); |
0d5c6e1c SR |
1086 | } |
1087 | ||
f4e781c0 SRRH |
1088 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
1089 | static int run_tracer_selftest(struct tracer *type) | |
1090 | { | |
1091 | struct trace_array *tr = &global_trace; | |
1092 | struct tracer *saved_tracer = tr->current_trace; | |
1093 | int ret; | |
0d5c6e1c | 1094 | |
f4e781c0 SRRH |
1095 | if (!type->selftest || tracing_selftest_disabled) |
1096 | return 0; | |
0d5c6e1c SR |
1097 | |
1098 | /* | |
f4e781c0 SRRH |
1099 | * Run a selftest on this tracer. |
1100 | * Here we reset the trace buffer, and set the current | |
1101 | * tracer to be this tracer. The tracer can then run some | |
1102 | * internal tracing to verify that everything is in order. | |
1103 | * If we fail, we do not register this tracer. | |
0d5c6e1c | 1104 | */ |
f4e781c0 | 1105 | tracing_reset_online_cpus(&tr->trace_buffer); |
0d5c6e1c | 1106 | |
f4e781c0 SRRH |
1107 | tr->current_trace = type; |
1108 | ||
1109 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1110 | if (type->use_max_tr) { | |
1111 | /* If we expanded the buffers, make sure the max is expanded too */ | |
1112 | if (ring_buffer_expanded) | |
1113 | ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, | |
1114 | RING_BUFFER_ALL_CPUS); | |
1115 | tr->allocated_snapshot = true; | |
1116 | } | |
1117 | #endif | |
1118 | ||
1119 | /* the test is responsible for initializing and enabling */ | |
1120 | pr_info("Testing tracer %s: ", type->name); | |
1121 | ret = type->selftest(type, tr); | |
1122 | /* the test is responsible for resetting too */ | |
1123 | tr->current_trace = saved_tracer; | |
1124 | if (ret) { | |
1125 | printk(KERN_CONT "FAILED!\n"); | |
1126 | /* Add the warning after printing 'FAILED' */ | |
1127 | WARN_ON(1); | |
1128 | return -1; | |
1129 | } | |
1130 | /* Only reset on passing, to avoid touching corrupted buffers */ | |
1131 | tracing_reset_online_cpus(&tr->trace_buffer); | |
1132 | ||
1133 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1134 | if (type->use_max_tr) { | |
1135 | tr->allocated_snapshot = false; | |
0d5c6e1c | 1136 | |
f4e781c0 SRRH |
1137 | /* Shrink the max buffer again */ |
1138 | if (ring_buffer_expanded) | |
1139 | ring_buffer_resize(tr->max_buffer.buffer, 1, | |
1140 | RING_BUFFER_ALL_CPUS); | |
1141 | } | |
1142 | #endif | |
1143 | ||
1144 | printk(KERN_CONT "PASSED\n"); | |
1145 | return 0; | |
1146 | } | |
1147 | #else | |
1148 | static inline int run_tracer_selftest(struct tracer *type) | |
1149 | { | |
1150 | return 0; | |
0d5c6e1c | 1151 | } |
f4e781c0 | 1152 | #endif /* CONFIG_FTRACE_STARTUP_TEST */ |
0d5c6e1c | 1153 | |
4fcdae83 SR |
1154 | /** |
1155 | * register_tracer - register a tracer with the ftrace system. | |
1156 | * @type - the plugin for the tracer | |
1157 | * | |
1158 | * Register a new plugin tracer. | |
1159 | */ | |
bc0c38d1 SR |
1160 | int register_tracer(struct tracer *type) |
1161 | { | |
1162 | struct tracer *t; | |
bc0c38d1 SR |
1163 | int ret = 0; |
1164 | ||
1165 | if (!type->name) { | |
1166 | pr_info("Tracer must have a name\n"); | |
1167 | return -1; | |
1168 | } | |
1169 | ||
24a461d5 | 1170 | if (strlen(type->name) >= MAX_TRACER_SIZE) { |
ee6c2c1b LZ |
1171 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); |
1172 | return -1; | |
1173 | } | |
1174 | ||
bc0c38d1 | 1175 | mutex_lock(&trace_types_lock); |
86fa2f60 | 1176 | |
8e1b82e0 FW |
1177 | tracing_selftest_running = true; |
1178 | ||
bc0c38d1 SR |
1179 | for (t = trace_types; t; t = t->next) { |
1180 | if (strcmp(type->name, t->name) == 0) { | |
1181 | /* already found */ | |
ee6c2c1b | 1182 | pr_info("Tracer %s already registered\n", |
bc0c38d1 SR |
1183 | type->name); |
1184 | ret = -1; | |
1185 | goto out; | |
1186 | } | |
1187 | } | |
1188 | ||
adf9f195 FW |
1189 | if (!type->set_flag) |
1190 | type->set_flag = &dummy_set_flag; | |
1191 | if (!type->flags) | |
1192 | type->flags = &dummy_tracer_flags; | |
1193 | else | |
1194 | if (!type->flags->opts) | |
1195 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 | 1196 | |
f4e781c0 SRRH |
1197 | ret = run_tracer_selftest(type); |
1198 | if (ret < 0) | |
1199 | goto out; | |
60a11774 | 1200 | |
bc0c38d1 SR |
1201 | type->next = trace_types; |
1202 | trace_types = type; | |
60a11774 | 1203 | |
bc0c38d1 | 1204 | out: |
8e1b82e0 | 1205 | tracing_selftest_running = false; |
bc0c38d1 SR |
1206 | mutex_unlock(&trace_types_lock); |
1207 | ||
dac74940 SR |
1208 | if (ret || !default_bootup_tracer) |
1209 | goto out_unlock; | |
1210 | ||
ee6c2c1b | 1211 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
dac74940 SR |
1212 | goto out_unlock; |
1213 | ||
1214 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
1215 | /* Do we want this tracer to start on bootup? */ | |
607e2ea1 | 1216 | tracing_set_tracer(&global_trace, type->name); |
dac74940 SR |
1217 | default_bootup_tracer = NULL; |
1218 | /* disable other selftests, since this will break it. */ | |
55034cd6 | 1219 | tracing_selftest_disabled = true; |
b2821ae6 | 1220 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
1221 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
1222 | type->name); | |
b2821ae6 | 1223 | #endif |
b2821ae6 | 1224 | |
dac74940 | 1225 | out_unlock: |
bc0c38d1 SR |
1226 | return ret; |
1227 | } | |
1228 | ||
12883efb | 1229 | void tracing_reset(struct trace_buffer *buf, int cpu) |
f633903a | 1230 | { |
12883efb | 1231 | struct ring_buffer *buffer = buf->buffer; |
f633903a | 1232 | |
a5416411 HT |
1233 | if (!buffer) |
1234 | return; | |
1235 | ||
f633903a SR |
1236 | ring_buffer_record_disable(buffer); |
1237 | ||
1238 | /* Make sure all commits have finished */ | |
1239 | synchronize_sched(); | |
68179686 | 1240 | ring_buffer_reset_cpu(buffer, cpu); |
f633903a SR |
1241 | |
1242 | ring_buffer_record_enable(buffer); | |
1243 | } | |
1244 | ||
12883efb | 1245 | void tracing_reset_online_cpus(struct trace_buffer *buf) |
213cc060 | 1246 | { |
12883efb | 1247 | struct ring_buffer *buffer = buf->buffer; |
213cc060 PE |
1248 | int cpu; |
1249 | ||
a5416411 HT |
1250 | if (!buffer) |
1251 | return; | |
1252 | ||
621968cd SR |
1253 | ring_buffer_record_disable(buffer); |
1254 | ||
1255 | /* Make sure all commits have finished */ | |
1256 | synchronize_sched(); | |
1257 | ||
9457158b | 1258 | buf->time_start = buffer_ftrace_now(buf, buf->cpu); |
213cc060 PE |
1259 | |
1260 | for_each_online_cpu(cpu) | |
68179686 | 1261 | ring_buffer_reset_cpu(buffer, cpu); |
621968cd SR |
1262 | |
1263 | ring_buffer_record_enable(buffer); | |
213cc060 PE |
1264 | } |
1265 | ||
09d8091c | 1266 | /* Must have trace_types_lock held */ |
873c642f | 1267 | void tracing_reset_all_online_cpus(void) |
9456f0fa | 1268 | { |
873c642f SRRH |
1269 | struct trace_array *tr; |
1270 | ||
873c642f | 1271 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
12883efb SRRH |
1272 | tracing_reset_online_cpus(&tr->trace_buffer); |
1273 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1274 | tracing_reset_online_cpus(&tr->max_buffer); | |
1275 | #endif | |
873c642f | 1276 | } |
9456f0fa SR |
1277 | } |
1278 | ||
939c7a4f | 1279 | #define SAVED_CMDLINES_DEFAULT 128 |
2c7eea4c | 1280 | #define NO_CMDLINE_MAP UINT_MAX |
edc35bd7 | 1281 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
939c7a4f YY |
1282 | struct saved_cmdlines_buffer { |
1283 | unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
1284 | unsigned *map_cmdline_to_pid; | |
1285 | unsigned cmdline_num; | |
1286 | int cmdline_idx; | |
1287 | char *saved_cmdlines; | |
1288 | }; | |
1289 | static struct saved_cmdlines_buffer *savedcmd; | |
25b0b44a | 1290 | |
25b0b44a | 1291 | /* temporary disable recording */ |
4fd27358 | 1292 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 | 1293 | |
939c7a4f YY |
1294 | static inline char *get_saved_cmdlines(int idx) |
1295 | { | |
1296 | return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN]; | |
1297 | } | |
1298 | ||
1299 | static inline void set_cmdline(int idx, const char *cmdline) | |
bc0c38d1 | 1300 | { |
939c7a4f YY |
1301 | memcpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); |
1302 | } | |
1303 | ||
1304 | static int allocate_cmdlines_buffer(unsigned int val, | |
1305 | struct saved_cmdlines_buffer *s) | |
1306 | { | |
1307 | s->map_cmdline_to_pid = kmalloc(val * sizeof(*s->map_cmdline_to_pid), | |
1308 | GFP_KERNEL); | |
1309 | if (!s->map_cmdline_to_pid) | |
1310 | return -ENOMEM; | |
1311 | ||
1312 | s->saved_cmdlines = kmalloc(val * TASK_COMM_LEN, GFP_KERNEL); | |
1313 | if (!s->saved_cmdlines) { | |
1314 | kfree(s->map_cmdline_to_pid); | |
1315 | return -ENOMEM; | |
1316 | } | |
1317 | ||
1318 | s->cmdline_idx = 0; | |
1319 | s->cmdline_num = val; | |
1320 | memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP, | |
1321 | sizeof(s->map_pid_to_cmdline)); | |
1322 | memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP, | |
1323 | val * sizeof(*s->map_cmdline_to_pid)); | |
1324 | ||
1325 | return 0; | |
1326 | } | |
1327 | ||
1328 | static int trace_create_savedcmd(void) | |
1329 | { | |
1330 | int ret; | |
1331 | ||
a6af8fbf | 1332 | savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL); |
939c7a4f YY |
1333 | if (!savedcmd) |
1334 | return -ENOMEM; | |
1335 | ||
1336 | ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd); | |
1337 | if (ret < 0) { | |
1338 | kfree(savedcmd); | |
1339 | savedcmd = NULL; | |
1340 | return -ENOMEM; | |
1341 | } | |
1342 | ||
1343 | return 0; | |
bc0c38d1 SR |
1344 | } |
1345 | ||
b5130b1e CE |
1346 | int is_tracing_stopped(void) |
1347 | { | |
2b6080f2 | 1348 | return global_trace.stop_count; |
b5130b1e CE |
1349 | } |
1350 | ||
0f048701 SR |
1351 | /** |
1352 | * tracing_start - quick start of the tracer | |
1353 | * | |
1354 | * If tracing is enabled but was stopped by tracing_stop, | |
1355 | * this will start the tracer back up. | |
1356 | */ | |
1357 | void tracing_start(void) | |
1358 | { | |
1359 | struct ring_buffer *buffer; | |
1360 | unsigned long flags; | |
1361 | ||
1362 | if (tracing_disabled) | |
1363 | return; | |
1364 | ||
2b6080f2 SR |
1365 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
1366 | if (--global_trace.stop_count) { | |
1367 | if (global_trace.stop_count < 0) { | |
b06a8301 SR |
1368 | /* Someone screwed up their debugging */ |
1369 | WARN_ON_ONCE(1); | |
2b6080f2 | 1370 | global_trace.stop_count = 0; |
b06a8301 | 1371 | } |
0f048701 SR |
1372 | goto out; |
1373 | } | |
1374 | ||
a2f80714 | 1375 | /* Prevent the buffers from switching */ |
0b9b12c1 | 1376 | arch_spin_lock(&global_trace.max_lock); |
0f048701 | 1377 | |
12883efb | 1378 | buffer = global_trace.trace_buffer.buffer; |
0f048701 SR |
1379 | if (buffer) |
1380 | ring_buffer_record_enable(buffer); | |
1381 | ||
12883efb SRRH |
1382 | #ifdef CONFIG_TRACER_MAX_TRACE |
1383 | buffer = global_trace.max_buffer.buffer; | |
0f048701 SR |
1384 | if (buffer) |
1385 | ring_buffer_record_enable(buffer); | |
12883efb | 1386 | #endif |
0f048701 | 1387 | |
0b9b12c1 | 1388 | arch_spin_unlock(&global_trace.max_lock); |
a2f80714 | 1389 | |
0f048701 | 1390 | out: |
2b6080f2 SR |
1391 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
1392 | } | |
1393 | ||
1394 | static void tracing_start_tr(struct trace_array *tr) | |
1395 | { | |
1396 | struct ring_buffer *buffer; | |
1397 | unsigned long flags; | |
1398 | ||
1399 | if (tracing_disabled) | |
1400 | return; | |
1401 | ||
1402 | /* If global, we need to also start the max tracer */ | |
1403 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1404 | return tracing_start(); | |
1405 | ||
1406 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1407 | ||
1408 | if (--tr->stop_count) { | |
1409 | if (tr->stop_count < 0) { | |
1410 | /* Someone screwed up their debugging */ | |
1411 | WARN_ON_ONCE(1); | |
1412 | tr->stop_count = 0; | |
1413 | } | |
1414 | goto out; | |
1415 | } | |
1416 | ||
12883efb | 1417 | buffer = tr->trace_buffer.buffer; |
2b6080f2 SR |
1418 | if (buffer) |
1419 | ring_buffer_record_enable(buffer); | |
1420 | ||
1421 | out: | |
1422 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
0f048701 SR |
1423 | } |
1424 | ||
1425 | /** | |
1426 | * tracing_stop - quick stop of the tracer | |
1427 | * | |
1428 | * Light weight way to stop tracing. Use in conjunction with | |
1429 | * tracing_start. | |
1430 | */ | |
1431 | void tracing_stop(void) | |
1432 | { | |
1433 | struct ring_buffer *buffer; | |
1434 | unsigned long flags; | |
1435 | ||
2b6080f2 SR |
1436 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
1437 | if (global_trace.stop_count++) | |
0f048701 SR |
1438 | goto out; |
1439 | ||
a2f80714 | 1440 | /* Prevent the buffers from switching */ |
0b9b12c1 | 1441 | arch_spin_lock(&global_trace.max_lock); |
a2f80714 | 1442 | |
12883efb | 1443 | buffer = global_trace.trace_buffer.buffer; |
0f048701 SR |
1444 | if (buffer) |
1445 | ring_buffer_record_disable(buffer); | |
1446 | ||
12883efb SRRH |
1447 | #ifdef CONFIG_TRACER_MAX_TRACE |
1448 | buffer = global_trace.max_buffer.buffer; | |
0f048701 SR |
1449 | if (buffer) |
1450 | ring_buffer_record_disable(buffer); | |
12883efb | 1451 | #endif |
0f048701 | 1452 | |
0b9b12c1 | 1453 | arch_spin_unlock(&global_trace.max_lock); |
a2f80714 | 1454 | |
0f048701 | 1455 | out: |
2b6080f2 SR |
1456 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
1457 | } | |
1458 | ||
1459 | static void tracing_stop_tr(struct trace_array *tr) | |
1460 | { | |
1461 | struct ring_buffer *buffer; | |
1462 | unsigned long flags; | |
1463 | ||
1464 | /* If global, we need to also stop the max tracer */ | |
1465 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1466 | return tracing_stop(); | |
1467 | ||
1468 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1469 | if (tr->stop_count++) | |
1470 | goto out; | |
1471 | ||
12883efb | 1472 | buffer = tr->trace_buffer.buffer; |
2b6080f2 SR |
1473 | if (buffer) |
1474 | ring_buffer_record_disable(buffer); | |
1475 | ||
1476 | out: | |
1477 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
0f048701 SR |
1478 | } |
1479 | ||
e309b41d | 1480 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 1481 | |
379cfdac | 1482 | static int trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1483 | { |
a635cf04 | 1484 | unsigned pid, idx; |
bc0c38d1 SR |
1485 | |
1486 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
379cfdac | 1487 | return 0; |
bc0c38d1 SR |
1488 | |
1489 | /* | |
1490 | * It's not the end of the world if we don't get | |
1491 | * the lock, but we also don't want to spin | |
1492 | * nor do we want to disable interrupts, | |
1493 | * so if we miss here, then better luck next time. | |
1494 | */ | |
0199c4e6 | 1495 | if (!arch_spin_trylock(&trace_cmdline_lock)) |
379cfdac | 1496 | return 0; |
bc0c38d1 | 1497 | |
939c7a4f | 1498 | idx = savedcmd->map_pid_to_cmdline[tsk->pid]; |
2c7eea4c | 1499 | if (idx == NO_CMDLINE_MAP) { |
939c7a4f | 1500 | idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num; |
bc0c38d1 | 1501 | |
a635cf04 CE |
1502 | /* |
1503 | * Check whether the cmdline buffer at idx has a pid | |
1504 | * mapped. We are going to overwrite that entry so we | |
1505 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1506 | * would read the new comm for the old pid. | |
1507 | */ | |
939c7a4f | 1508 | pid = savedcmd->map_cmdline_to_pid[idx]; |
a635cf04 | 1509 | if (pid != NO_CMDLINE_MAP) |
939c7a4f | 1510 | savedcmd->map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; |
bc0c38d1 | 1511 | |
939c7a4f YY |
1512 | savedcmd->map_cmdline_to_pid[idx] = tsk->pid; |
1513 | savedcmd->map_pid_to_cmdline[tsk->pid] = idx; | |
bc0c38d1 | 1514 | |
939c7a4f | 1515 | savedcmd->cmdline_idx = idx; |
bc0c38d1 SR |
1516 | } |
1517 | ||
939c7a4f | 1518 | set_cmdline(idx, tsk->comm); |
bc0c38d1 | 1519 | |
0199c4e6 | 1520 | arch_spin_unlock(&trace_cmdline_lock); |
379cfdac SRRH |
1521 | |
1522 | return 1; | |
bc0c38d1 SR |
1523 | } |
1524 | ||
4c27e756 | 1525 | static void __trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 1526 | { |
bc0c38d1 SR |
1527 | unsigned map; |
1528 | ||
4ca53085 SR |
1529 | if (!pid) { |
1530 | strcpy(comm, "<idle>"); | |
1531 | return; | |
1532 | } | |
bc0c38d1 | 1533 | |
74bf4076 SR |
1534 | if (WARN_ON_ONCE(pid < 0)) { |
1535 | strcpy(comm, "<XXX>"); | |
1536 | return; | |
1537 | } | |
1538 | ||
4ca53085 SR |
1539 | if (pid > PID_MAX_DEFAULT) { |
1540 | strcpy(comm, "<...>"); | |
1541 | return; | |
1542 | } | |
bc0c38d1 | 1543 | |
939c7a4f | 1544 | map = savedcmd->map_pid_to_cmdline[pid]; |
50d88758 | 1545 | if (map != NO_CMDLINE_MAP) |
939c7a4f | 1546 | strcpy(comm, get_saved_cmdlines(map)); |
50d88758 TG |
1547 | else |
1548 | strcpy(comm, "<...>"); | |
4c27e756 SRRH |
1549 | } |
1550 | ||
1551 | void trace_find_cmdline(int pid, char comm[]) | |
1552 | { | |
1553 | preempt_disable(); | |
1554 | arch_spin_lock(&trace_cmdline_lock); | |
1555 | ||
1556 | __trace_find_cmdline(pid, comm); | |
bc0c38d1 | 1557 | |
0199c4e6 | 1558 | arch_spin_unlock(&trace_cmdline_lock); |
5b6045a9 | 1559 | preempt_enable(); |
bc0c38d1 SR |
1560 | } |
1561 | ||
e309b41d | 1562 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1563 | { |
0fb9656d | 1564 | if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) |
bc0c38d1 SR |
1565 | return; |
1566 | ||
7ffbd48d SR |
1567 | if (!__this_cpu_read(trace_cmdline_save)) |
1568 | return; | |
1569 | ||
379cfdac SRRH |
1570 | if (trace_save_cmdline(tsk)) |
1571 | __this_cpu_write(trace_cmdline_save, false); | |
bc0c38d1 SR |
1572 | } |
1573 | ||
45dcd8b8 | 1574 | void |
38697053 SR |
1575 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
1576 | int pc) | |
bc0c38d1 SR |
1577 | { |
1578 | struct task_struct *tsk = current; | |
bc0c38d1 | 1579 | |
777e208d SR |
1580 | entry->preempt_count = pc & 0xff; |
1581 | entry->pid = (tsk) ? tsk->pid : 0; | |
1582 | entry->flags = | |
9244489a | 1583 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 1584 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
1585 | #else |
1586 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1587 | #endif | |
bc0c38d1 SR |
1588 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
1589 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
e5137b50 PZ |
1590 | (tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) | |
1591 | (test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0); | |
bc0c38d1 | 1592 | } |
f413cdb8 | 1593 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); |
bc0c38d1 | 1594 | |
e77405ad SR |
1595 | struct ring_buffer_event * |
1596 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1597 | int type, | |
1598 | unsigned long len, | |
1599 | unsigned long flags, int pc) | |
51a763dd ACM |
1600 | { |
1601 | struct ring_buffer_event *event; | |
1602 | ||
e77405ad | 1603 | event = ring_buffer_lock_reserve(buffer, len); |
51a763dd ACM |
1604 | if (event != NULL) { |
1605 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1606 | ||
1607 | tracing_generic_entry_update(ent, flags, pc); | |
1608 | ent->type = type; | |
1609 | } | |
1610 | ||
1611 | return event; | |
1612 | } | |
51a763dd | 1613 | |
7ffbd48d SR |
1614 | void |
1615 | __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) | |
1616 | { | |
1617 | __this_cpu_write(trace_cmdline_save, true); | |
1618 | ring_buffer_unlock_commit(buffer, event); | |
1619 | } | |
1620 | ||
e77405ad SR |
1621 | static inline void |
1622 | __trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1623 | struct ring_buffer_event *event, | |
0d5c6e1c | 1624 | unsigned long flags, int pc) |
51a763dd | 1625 | { |
7ffbd48d | 1626 | __buffer_unlock_commit(buffer, event); |
51a763dd | 1627 | |
e77405ad SR |
1628 | ftrace_trace_stack(buffer, flags, 6, pc); |
1629 | ftrace_trace_userstack(buffer, flags, pc); | |
07edf712 FW |
1630 | } |
1631 | ||
e77405ad SR |
1632 | void trace_buffer_unlock_commit(struct ring_buffer *buffer, |
1633 | struct ring_buffer_event *event, | |
1634 | unsigned long flags, int pc) | |
07edf712 | 1635 | { |
0d5c6e1c | 1636 | __trace_buffer_unlock_commit(buffer, event, flags, pc); |
51a763dd | 1637 | } |
0d5c6e1c | 1638 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); |
51a763dd | 1639 | |
2c4a33ab SRRH |
1640 | static struct ring_buffer *temp_buffer; |
1641 | ||
ccb469a1 SR |
1642 | struct ring_buffer_event * |
1643 | trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, | |
1644 | struct ftrace_event_file *ftrace_file, | |
1645 | int type, unsigned long len, | |
1646 | unsigned long flags, int pc) | |
1647 | { | |
2c4a33ab SRRH |
1648 | struct ring_buffer_event *entry; |
1649 | ||
12883efb | 1650 | *current_rb = ftrace_file->tr->trace_buffer.buffer; |
2c4a33ab | 1651 | entry = trace_buffer_lock_reserve(*current_rb, |
ccb469a1 | 1652 | type, len, flags, pc); |
2c4a33ab SRRH |
1653 | /* |
1654 | * If tracing is off, but we have triggers enabled | |
1655 | * we still need to look at the event data. Use the temp_buffer | |
1656 | * to store the trace event for the tigger to use. It's recusive | |
1657 | * safe and will not be recorded anywhere. | |
1658 | */ | |
1659 | if (!entry && ftrace_file->flags & FTRACE_EVENT_FL_TRIGGER_COND) { | |
1660 | *current_rb = temp_buffer; | |
1661 | entry = trace_buffer_lock_reserve(*current_rb, | |
1662 | type, len, flags, pc); | |
1663 | } | |
1664 | return entry; | |
ccb469a1 SR |
1665 | } |
1666 | EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); | |
1667 | ||
ef5580d0 | 1668 | struct ring_buffer_event * |
e77405ad SR |
1669 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, |
1670 | int type, unsigned long len, | |
ef5580d0 SR |
1671 | unsigned long flags, int pc) |
1672 | { | |
12883efb | 1673 | *current_rb = global_trace.trace_buffer.buffer; |
e77405ad | 1674 | return trace_buffer_lock_reserve(*current_rb, |
ef5580d0 SR |
1675 | type, len, flags, pc); |
1676 | } | |
94487d6d | 1677 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); |
ef5580d0 | 1678 | |
e77405ad SR |
1679 | void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, |
1680 | struct ring_buffer_event *event, | |
ef5580d0 SR |
1681 | unsigned long flags, int pc) |
1682 | { | |
0d5c6e1c | 1683 | __trace_buffer_unlock_commit(buffer, event, flags, pc); |
07edf712 | 1684 | } |
94487d6d | 1685 | EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit); |
07edf712 | 1686 | |
0d5c6e1c SR |
1687 | void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer, |
1688 | struct ring_buffer_event *event, | |
1689 | unsigned long flags, int pc, | |
1690 | struct pt_regs *regs) | |
1fd8df2c | 1691 | { |
7ffbd48d | 1692 | __buffer_unlock_commit(buffer, event); |
1fd8df2c MH |
1693 | |
1694 | ftrace_trace_stack_regs(buffer, flags, 0, pc, regs); | |
1695 | ftrace_trace_userstack(buffer, flags, pc); | |
1696 | } | |
0d5c6e1c | 1697 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); |
1fd8df2c | 1698 | |
e77405ad SR |
1699 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, |
1700 | struct ring_buffer_event *event) | |
77d9f465 | 1701 | { |
e77405ad | 1702 | ring_buffer_discard_commit(buffer, event); |
ef5580d0 | 1703 | } |
12acd473 | 1704 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); |
ef5580d0 | 1705 | |
e309b41d | 1706 | void |
7be42151 | 1707 | trace_function(struct trace_array *tr, |
38697053 SR |
1708 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1709 | int pc) | |
bc0c38d1 | 1710 | { |
e1112b4d | 1711 | struct ftrace_event_call *call = &event_function; |
12883efb | 1712 | struct ring_buffer *buffer = tr->trace_buffer.buffer; |
3928a8a2 | 1713 | struct ring_buffer_event *event; |
777e208d | 1714 | struct ftrace_entry *entry; |
bc0c38d1 | 1715 | |
d769041f | 1716 | /* If we are reading the ring buffer, don't trace */ |
dd17c8f7 | 1717 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) |
d769041f SR |
1718 | return; |
1719 | ||
e77405ad | 1720 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
51a763dd | 1721 | flags, pc); |
3928a8a2 SR |
1722 | if (!event) |
1723 | return; | |
1724 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1725 | entry->ip = ip; |
1726 | entry->parent_ip = parent_ip; | |
e1112b4d | 1727 | |
f306cc82 | 1728 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1729 | __buffer_unlock_commit(buffer, event); |
bc0c38d1 SR |
1730 | } |
1731 | ||
c0a0d0d3 | 1732 | #ifdef CONFIG_STACKTRACE |
4a9bd3f1 SR |
1733 | |
1734 | #define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) | |
1735 | struct ftrace_stack { | |
1736 | unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; | |
1737 | }; | |
1738 | ||
1739 | static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); | |
1740 | static DEFINE_PER_CPU(int, ftrace_stack_reserve); | |
1741 | ||
e77405ad | 1742 | static void __ftrace_trace_stack(struct ring_buffer *buffer, |
53614991 | 1743 | unsigned long flags, |
1fd8df2c | 1744 | int skip, int pc, struct pt_regs *regs) |
86387f7e | 1745 | { |
e1112b4d | 1746 | struct ftrace_event_call *call = &event_kernel_stack; |
3928a8a2 | 1747 | struct ring_buffer_event *event; |
777e208d | 1748 | struct stack_entry *entry; |
86387f7e | 1749 | struct stack_trace trace; |
4a9bd3f1 SR |
1750 | int use_stack; |
1751 | int size = FTRACE_STACK_ENTRIES; | |
1752 | ||
1753 | trace.nr_entries = 0; | |
1754 | trace.skip = skip; | |
1755 | ||
1756 | /* | |
1757 | * Since events can happen in NMIs there's no safe way to | |
1758 | * use the per cpu ftrace_stacks. We reserve it and if an interrupt | |
1759 | * or NMI comes in, it will just have to use the default | |
1760 | * FTRACE_STACK_SIZE. | |
1761 | */ | |
1762 | preempt_disable_notrace(); | |
1763 | ||
82146529 | 1764 | use_stack = __this_cpu_inc_return(ftrace_stack_reserve); |
4a9bd3f1 SR |
1765 | /* |
1766 | * We don't need any atomic variables, just a barrier. | |
1767 | * If an interrupt comes in, we don't care, because it would | |
1768 | * have exited and put the counter back to what we want. | |
1769 | * We just need a barrier to keep gcc from moving things | |
1770 | * around. | |
1771 | */ | |
1772 | barrier(); | |
1773 | if (use_stack == 1) { | |
bdffd893 | 1774 | trace.entries = this_cpu_ptr(ftrace_stack.calls); |
4a9bd3f1 SR |
1775 | trace.max_entries = FTRACE_STACK_MAX_ENTRIES; |
1776 | ||
1777 | if (regs) | |
1778 | save_stack_trace_regs(regs, &trace); | |
1779 | else | |
1780 | save_stack_trace(&trace); | |
1781 | ||
1782 | if (trace.nr_entries > size) | |
1783 | size = trace.nr_entries; | |
1784 | } else | |
1785 | /* From now on, use_stack is a boolean */ | |
1786 | use_stack = 0; | |
1787 | ||
1788 | size *= sizeof(unsigned long); | |
86387f7e | 1789 | |
e77405ad | 1790 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, |
4a9bd3f1 | 1791 | sizeof(*entry) + size, flags, pc); |
3928a8a2 | 1792 | if (!event) |
4a9bd3f1 SR |
1793 | goto out; |
1794 | entry = ring_buffer_event_data(event); | |
86387f7e | 1795 | |
4a9bd3f1 SR |
1796 | memset(&entry->caller, 0, size); |
1797 | ||
1798 | if (use_stack) | |
1799 | memcpy(&entry->caller, trace.entries, | |
1800 | trace.nr_entries * sizeof(unsigned long)); | |
1801 | else { | |
1802 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1803 | trace.entries = entry->caller; | |
1804 | if (regs) | |
1805 | save_stack_trace_regs(regs, &trace); | |
1806 | else | |
1807 | save_stack_trace(&trace); | |
1808 | } | |
1809 | ||
1810 | entry->size = trace.nr_entries; | |
86387f7e | 1811 | |
f306cc82 | 1812 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1813 | __buffer_unlock_commit(buffer, event); |
4a9bd3f1 SR |
1814 | |
1815 | out: | |
1816 | /* Again, don't let gcc optimize things here */ | |
1817 | barrier(); | |
82146529 | 1818 | __this_cpu_dec(ftrace_stack_reserve); |
4a9bd3f1 SR |
1819 | preempt_enable_notrace(); |
1820 | ||
f0a920d5 IM |
1821 | } |
1822 | ||
1fd8df2c MH |
1823 | void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags, |
1824 | int skip, int pc, struct pt_regs *regs) | |
1825 | { | |
1826 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1827 | return; | |
1828 | ||
1829 | __ftrace_trace_stack(buffer, flags, skip, pc, regs); | |
1830 | } | |
1831 | ||
e77405ad SR |
1832 | void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, |
1833 | int skip, int pc) | |
53614991 SR |
1834 | { |
1835 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1836 | return; | |
1837 | ||
1fd8df2c | 1838 | __ftrace_trace_stack(buffer, flags, skip, pc, NULL); |
53614991 SR |
1839 | } |
1840 | ||
c0a0d0d3 FW |
1841 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, |
1842 | int pc) | |
38697053 | 1843 | { |
12883efb | 1844 | __ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL); |
38697053 SR |
1845 | } |
1846 | ||
03889384 SR |
1847 | /** |
1848 | * trace_dump_stack - record a stack back trace in the trace buffer | |
c142be8e | 1849 | * @skip: Number of functions to skip (helper handlers) |
03889384 | 1850 | */ |
c142be8e | 1851 | void trace_dump_stack(int skip) |
03889384 SR |
1852 | { |
1853 | unsigned long flags; | |
1854 | ||
1855 | if (tracing_disabled || tracing_selftest_running) | |
e36c5458 | 1856 | return; |
03889384 SR |
1857 | |
1858 | local_save_flags(flags); | |
1859 | ||
c142be8e SRRH |
1860 | /* |
1861 | * Skip 3 more, seems to get us at the caller of | |
1862 | * this function. | |
1863 | */ | |
1864 | skip += 3; | |
1865 | __ftrace_trace_stack(global_trace.trace_buffer.buffer, | |
1866 | flags, skip, preempt_count(), NULL); | |
03889384 SR |
1867 | } |
1868 | ||
91e86e56 SR |
1869 | static DEFINE_PER_CPU(int, user_stack_count); |
1870 | ||
e77405ad SR |
1871 | void |
1872 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
02b67518 | 1873 | { |
e1112b4d | 1874 | struct ftrace_event_call *call = &event_user_stack; |
8d7c6a96 | 1875 | struct ring_buffer_event *event; |
02b67518 TE |
1876 | struct userstack_entry *entry; |
1877 | struct stack_trace trace; | |
02b67518 TE |
1878 | |
1879 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1880 | return; | |
1881 | ||
b6345879 SR |
1882 | /* |
1883 | * NMIs can not handle page faults, even with fix ups. | |
1884 | * The save user stack can (and often does) fault. | |
1885 | */ | |
1886 | if (unlikely(in_nmi())) | |
1887 | return; | |
02b67518 | 1888 | |
91e86e56 SR |
1889 | /* |
1890 | * prevent recursion, since the user stack tracing may | |
1891 | * trigger other kernel events. | |
1892 | */ | |
1893 | preempt_disable(); | |
1894 | if (__this_cpu_read(user_stack_count)) | |
1895 | goto out; | |
1896 | ||
1897 | __this_cpu_inc(user_stack_count); | |
1898 | ||
e77405ad | 1899 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
51a763dd | 1900 | sizeof(*entry), flags, pc); |
02b67518 | 1901 | if (!event) |
1dbd1951 | 1902 | goto out_drop_count; |
02b67518 | 1903 | entry = ring_buffer_event_data(event); |
02b67518 | 1904 | |
48659d31 | 1905 | entry->tgid = current->tgid; |
02b67518 TE |
1906 | memset(&entry->caller, 0, sizeof(entry->caller)); |
1907 | ||
1908 | trace.nr_entries = 0; | |
1909 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1910 | trace.skip = 0; | |
1911 | trace.entries = entry->caller; | |
1912 | ||
1913 | save_stack_trace_user(&trace); | |
f306cc82 | 1914 | if (!call_filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1915 | __buffer_unlock_commit(buffer, event); |
91e86e56 | 1916 | |
1dbd1951 | 1917 | out_drop_count: |
91e86e56 | 1918 | __this_cpu_dec(user_stack_count); |
91e86e56 SR |
1919 | out: |
1920 | preempt_enable(); | |
02b67518 TE |
1921 | } |
1922 | ||
4fd27358 HE |
1923 | #ifdef UNUSED |
1924 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1925 | { |
7be42151 | 1926 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1927 | } |
4fd27358 | 1928 | #endif /* UNUSED */ |
02b67518 | 1929 | |
c0a0d0d3 FW |
1930 | #endif /* CONFIG_STACKTRACE */ |
1931 | ||
07d777fe SR |
1932 | /* created for use with alloc_percpu */ |
1933 | struct trace_buffer_struct { | |
1934 | char buffer[TRACE_BUF_SIZE]; | |
1935 | }; | |
1936 | ||
1937 | static struct trace_buffer_struct *trace_percpu_buffer; | |
1938 | static struct trace_buffer_struct *trace_percpu_sirq_buffer; | |
1939 | static struct trace_buffer_struct *trace_percpu_irq_buffer; | |
1940 | static struct trace_buffer_struct *trace_percpu_nmi_buffer; | |
1941 | ||
1942 | /* | |
1943 | * The buffer used is dependent on the context. There is a per cpu | |
1944 | * buffer for normal context, softirq contex, hard irq context and | |
1945 | * for NMI context. Thise allows for lockless recording. | |
1946 | * | |
1947 | * Note, if the buffers failed to be allocated, then this returns NULL | |
1948 | */ | |
1949 | static char *get_trace_buf(void) | |
1950 | { | |
1951 | struct trace_buffer_struct *percpu_buffer; | |
07d777fe SR |
1952 | |
1953 | /* | |
1954 | * If we have allocated per cpu buffers, then we do not | |
1955 | * need to do any locking. | |
1956 | */ | |
1957 | if (in_nmi()) | |
1958 | percpu_buffer = trace_percpu_nmi_buffer; | |
1959 | else if (in_irq()) | |
1960 | percpu_buffer = trace_percpu_irq_buffer; | |
1961 | else if (in_softirq()) | |
1962 | percpu_buffer = trace_percpu_sirq_buffer; | |
1963 | else | |
1964 | percpu_buffer = trace_percpu_buffer; | |
1965 | ||
1966 | if (!percpu_buffer) | |
1967 | return NULL; | |
1968 | ||
d8a0349c | 1969 | return this_cpu_ptr(&percpu_buffer->buffer[0]); |
07d777fe SR |
1970 | } |
1971 | ||
1972 | static int alloc_percpu_trace_buffer(void) | |
1973 | { | |
1974 | struct trace_buffer_struct *buffers; | |
1975 | struct trace_buffer_struct *sirq_buffers; | |
1976 | struct trace_buffer_struct *irq_buffers; | |
1977 | struct trace_buffer_struct *nmi_buffers; | |
1978 | ||
1979 | buffers = alloc_percpu(struct trace_buffer_struct); | |
1980 | if (!buffers) | |
1981 | goto err_warn; | |
1982 | ||
1983 | sirq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1984 | if (!sirq_buffers) | |
1985 | goto err_sirq; | |
1986 | ||
1987 | irq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1988 | if (!irq_buffers) | |
1989 | goto err_irq; | |
1990 | ||
1991 | nmi_buffers = alloc_percpu(struct trace_buffer_struct); | |
1992 | if (!nmi_buffers) | |
1993 | goto err_nmi; | |
1994 | ||
1995 | trace_percpu_buffer = buffers; | |
1996 | trace_percpu_sirq_buffer = sirq_buffers; | |
1997 | trace_percpu_irq_buffer = irq_buffers; | |
1998 | trace_percpu_nmi_buffer = nmi_buffers; | |
1999 | ||
2000 | return 0; | |
2001 | ||
2002 | err_nmi: | |
2003 | free_percpu(irq_buffers); | |
2004 | err_irq: | |
2005 | free_percpu(sirq_buffers); | |
2006 | err_sirq: | |
2007 | free_percpu(buffers); | |
2008 | err_warn: | |
2009 | WARN(1, "Could not allocate percpu trace_printk buffer"); | |
2010 | return -ENOMEM; | |
2011 | } | |
2012 | ||
81698831 SR |
2013 | static int buffers_allocated; |
2014 | ||
07d777fe SR |
2015 | void trace_printk_init_buffers(void) |
2016 | { | |
07d777fe SR |
2017 | if (buffers_allocated) |
2018 | return; | |
2019 | ||
2020 | if (alloc_percpu_trace_buffer()) | |
2021 | return; | |
2022 | ||
2184db46 SR |
2023 | /* trace_printk() is for debug use only. Don't use it in production. */ |
2024 | ||
2025 | pr_warning("\n**********************************************************\n"); | |
2026 | pr_warning("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); | |
2027 | pr_warning("** **\n"); | |
2028 | pr_warning("** trace_printk() being used. Allocating extra memory. **\n"); | |
2029 | pr_warning("** **\n"); | |
2030 | pr_warning("** This means that this is a DEBUG kernel and it is **\n"); | |
2031 | pr_warning("** unsafe for produciton use. **\n"); | |
2032 | pr_warning("** **\n"); | |
2033 | pr_warning("** If you see this message and you are not debugging **\n"); | |
2034 | pr_warning("** the kernel, report this immediately to your vendor! **\n"); | |
2035 | pr_warning("** **\n"); | |
2036 | pr_warning("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); | |
2037 | pr_warning("**********************************************************\n"); | |
07d777fe | 2038 | |
b382ede6 SR |
2039 | /* Expand the buffers to set size */ |
2040 | tracing_update_buffers(); | |
2041 | ||
07d777fe | 2042 | buffers_allocated = 1; |
81698831 SR |
2043 | |
2044 | /* | |
2045 | * trace_printk_init_buffers() can be called by modules. | |
2046 | * If that happens, then we need to start cmdline recording | |
2047 | * directly here. If the global_trace.buffer is already | |
2048 | * allocated here, then this was called by module code. | |
2049 | */ | |
12883efb | 2050 | if (global_trace.trace_buffer.buffer) |
81698831 SR |
2051 | tracing_start_cmdline_record(); |
2052 | } | |
2053 | ||
2054 | void trace_printk_start_comm(void) | |
2055 | { | |
2056 | /* Start tracing comms if trace printk is set */ | |
2057 | if (!buffers_allocated) | |
2058 | return; | |
2059 | tracing_start_cmdline_record(); | |
2060 | } | |
2061 | ||
2062 | static void trace_printk_start_stop_comm(int enabled) | |
2063 | { | |
2064 | if (!buffers_allocated) | |
2065 | return; | |
2066 | ||
2067 | if (enabled) | |
2068 | tracing_start_cmdline_record(); | |
2069 | else | |
2070 | tracing_stop_cmdline_record(); | |
07d777fe SR |
2071 | } |
2072 | ||
769b0441 | 2073 | /** |
48ead020 | 2074 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
2075 | * |
2076 | */ | |
40ce74f1 | 2077 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 2078 | { |
e1112b4d | 2079 | struct ftrace_event_call *call = &event_bprint; |
769b0441 | 2080 | struct ring_buffer_event *event; |
e77405ad | 2081 | struct ring_buffer *buffer; |
769b0441 | 2082 | struct trace_array *tr = &global_trace; |
48ead020 | 2083 | struct bprint_entry *entry; |
769b0441 | 2084 | unsigned long flags; |
07d777fe SR |
2085 | char *tbuffer; |
2086 | int len = 0, size, pc; | |
769b0441 FW |
2087 | |
2088 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
2089 | return 0; | |
2090 | ||
2091 | /* Don't pollute graph traces with trace_vprintk internals */ | |
2092 | pause_graph_tracing(); | |
2093 | ||
2094 | pc = preempt_count(); | |
5168ae50 | 2095 | preempt_disable_notrace(); |
769b0441 | 2096 | |
07d777fe SR |
2097 | tbuffer = get_trace_buf(); |
2098 | if (!tbuffer) { | |
2099 | len = 0; | |
769b0441 | 2100 | goto out; |
07d777fe | 2101 | } |
769b0441 | 2102 | |
07d777fe | 2103 | len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); |
769b0441 | 2104 | |
07d777fe SR |
2105 | if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) |
2106 | goto out; | |
769b0441 | 2107 | |
07d777fe | 2108 | local_save_flags(flags); |
769b0441 | 2109 | size = sizeof(*entry) + sizeof(u32) * len; |
12883efb | 2110 | buffer = tr->trace_buffer.buffer; |
e77405ad SR |
2111 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, |
2112 | flags, pc); | |
769b0441 | 2113 | if (!event) |
07d777fe | 2114 | goto out; |
769b0441 FW |
2115 | entry = ring_buffer_event_data(event); |
2116 | entry->ip = ip; | |
769b0441 FW |
2117 | entry->fmt = fmt; |
2118 | ||
07d777fe | 2119 | memcpy(entry->buf, tbuffer, sizeof(u32) * len); |
f306cc82 | 2120 | if (!call_filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 2121 | __buffer_unlock_commit(buffer, event); |
d931369b SR |
2122 | ftrace_trace_stack(buffer, flags, 6, pc); |
2123 | } | |
769b0441 | 2124 | |
769b0441 | 2125 | out: |
5168ae50 | 2126 | preempt_enable_notrace(); |
769b0441 FW |
2127 | unpause_graph_tracing(); |
2128 | ||
2129 | return len; | |
2130 | } | |
48ead020 FW |
2131 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
2132 | ||
12883efb SRRH |
2133 | static int |
2134 | __trace_array_vprintk(struct ring_buffer *buffer, | |
2135 | unsigned long ip, const char *fmt, va_list args) | |
48ead020 | 2136 | { |
e1112b4d | 2137 | struct ftrace_event_call *call = &event_print; |
48ead020 | 2138 | struct ring_buffer_event *event; |
07d777fe | 2139 | int len = 0, size, pc; |
48ead020 | 2140 | struct print_entry *entry; |
07d777fe SR |
2141 | unsigned long flags; |
2142 | char *tbuffer; | |
48ead020 FW |
2143 | |
2144 | if (tracing_disabled || tracing_selftest_running) | |
2145 | return 0; | |
2146 | ||
07d777fe SR |
2147 | /* Don't pollute graph traces with trace_vprintk internals */ |
2148 | pause_graph_tracing(); | |
2149 | ||
48ead020 FW |
2150 | pc = preempt_count(); |
2151 | preempt_disable_notrace(); | |
48ead020 | 2152 | |
07d777fe SR |
2153 | |
2154 | tbuffer = get_trace_buf(); | |
2155 | if (!tbuffer) { | |
2156 | len = 0; | |
48ead020 | 2157 | goto out; |
07d777fe | 2158 | } |
48ead020 | 2159 | |
07d777fe SR |
2160 | len = vsnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); |
2161 | if (len > TRACE_BUF_SIZE) | |
2162 | goto out; | |
48ead020 | 2163 | |
07d777fe | 2164 | local_save_flags(flags); |
48ead020 | 2165 | size = sizeof(*entry) + len + 1; |
e77405ad | 2166 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
07d777fe | 2167 | flags, pc); |
48ead020 | 2168 | if (!event) |
07d777fe | 2169 | goto out; |
48ead020 | 2170 | entry = ring_buffer_event_data(event); |
c13d2f7c | 2171 | entry->ip = ip; |
48ead020 | 2172 | |
07d777fe | 2173 | memcpy(&entry->buf, tbuffer, len); |
c13d2f7c | 2174 | entry->buf[len] = '\0'; |
f306cc82 | 2175 | if (!call_filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 2176 | __buffer_unlock_commit(buffer, event); |
07d777fe | 2177 | ftrace_trace_stack(buffer, flags, 6, pc); |
d931369b | 2178 | } |
48ead020 FW |
2179 | out: |
2180 | preempt_enable_notrace(); | |
07d777fe | 2181 | unpause_graph_tracing(); |
48ead020 FW |
2182 | |
2183 | return len; | |
2184 | } | |
659372d3 | 2185 | |
12883efb SRRH |
2186 | int trace_array_vprintk(struct trace_array *tr, |
2187 | unsigned long ip, const char *fmt, va_list args) | |
2188 | { | |
2189 | return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args); | |
2190 | } | |
2191 | ||
2192 | int trace_array_printk(struct trace_array *tr, | |
2193 | unsigned long ip, const char *fmt, ...) | |
2194 | { | |
2195 | int ret; | |
2196 | va_list ap; | |
2197 | ||
2198 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
2199 | return 0; | |
2200 | ||
2201 | va_start(ap, fmt); | |
2202 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
2203 | va_end(ap); | |
2204 | return ret; | |
2205 | } | |
2206 | ||
2207 | int trace_array_printk_buf(struct ring_buffer *buffer, | |
2208 | unsigned long ip, const char *fmt, ...) | |
2209 | { | |
2210 | int ret; | |
2211 | va_list ap; | |
2212 | ||
2213 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
2214 | return 0; | |
2215 | ||
2216 | va_start(ap, fmt); | |
2217 | ret = __trace_array_vprintk(buffer, ip, fmt, ap); | |
2218 | va_end(ap); | |
2219 | return ret; | |
2220 | } | |
2221 | ||
659372d3 SR |
2222 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) |
2223 | { | |
a813a159 | 2224 | return trace_array_vprintk(&global_trace, ip, fmt, args); |
659372d3 | 2225 | } |
769b0441 FW |
2226 | EXPORT_SYMBOL_GPL(trace_vprintk); |
2227 | ||
e2ac8ef5 | 2228 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 2229 | { |
6d158a81 SR |
2230 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); |
2231 | ||
5a90f577 | 2232 | iter->idx++; |
6d158a81 SR |
2233 | if (buf_iter) |
2234 | ring_buffer_read(buf_iter, NULL); | |
5a90f577 SR |
2235 | } |
2236 | ||
e309b41d | 2237 | static struct trace_entry * |
bc21b478 SR |
2238 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, |
2239 | unsigned long *lost_events) | |
dd0e545f | 2240 | { |
3928a8a2 | 2241 | struct ring_buffer_event *event; |
6d158a81 | 2242 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); |
dd0e545f | 2243 | |
d769041f SR |
2244 | if (buf_iter) |
2245 | event = ring_buffer_iter_peek(buf_iter, ts); | |
2246 | else | |
12883efb | 2247 | event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts, |
bc21b478 | 2248 | lost_events); |
d769041f | 2249 | |
4a9bd3f1 SR |
2250 | if (event) { |
2251 | iter->ent_size = ring_buffer_event_length(event); | |
2252 | return ring_buffer_event_data(event); | |
2253 | } | |
2254 | iter->ent_size = 0; | |
2255 | return NULL; | |
dd0e545f | 2256 | } |
d769041f | 2257 | |
dd0e545f | 2258 | static struct trace_entry * |
bc21b478 SR |
2259 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, |
2260 | unsigned long *missing_events, u64 *ent_ts) | |
bc0c38d1 | 2261 | { |
12883efb | 2262 | struct ring_buffer *buffer = iter->trace_buffer->buffer; |
bc0c38d1 | 2263 | struct trace_entry *ent, *next = NULL; |
aa27497c | 2264 | unsigned long lost_events = 0, next_lost = 0; |
b04cc6b1 | 2265 | int cpu_file = iter->cpu_file; |
3928a8a2 | 2266 | u64 next_ts = 0, ts; |
bc0c38d1 | 2267 | int next_cpu = -1; |
12b5da34 | 2268 | int next_size = 0; |
bc0c38d1 SR |
2269 | int cpu; |
2270 | ||
b04cc6b1 FW |
2271 | /* |
2272 | * If we are in a per_cpu trace file, don't bother by iterating over | |
2273 | * all cpu and peek directly. | |
2274 | */ | |
ae3b5093 | 2275 | if (cpu_file > RING_BUFFER_ALL_CPUS) { |
b04cc6b1 FW |
2276 | if (ring_buffer_empty_cpu(buffer, cpu_file)) |
2277 | return NULL; | |
bc21b478 | 2278 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); |
b04cc6b1 FW |
2279 | if (ent_cpu) |
2280 | *ent_cpu = cpu_file; | |
2281 | ||
2282 | return ent; | |
2283 | } | |
2284 | ||
ab46428c | 2285 | for_each_tracing_cpu(cpu) { |
dd0e545f | 2286 | |
3928a8a2 SR |
2287 | if (ring_buffer_empty_cpu(buffer, cpu)) |
2288 | continue; | |
dd0e545f | 2289 | |
bc21b478 | 2290 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); |
dd0e545f | 2291 | |
cdd31cd2 IM |
2292 | /* |
2293 | * Pick the entry with the smallest timestamp: | |
2294 | */ | |
3928a8a2 | 2295 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
2296 | next = ent; |
2297 | next_cpu = cpu; | |
3928a8a2 | 2298 | next_ts = ts; |
bc21b478 | 2299 | next_lost = lost_events; |
12b5da34 | 2300 | next_size = iter->ent_size; |
bc0c38d1 SR |
2301 | } |
2302 | } | |
2303 | ||
12b5da34 SR |
2304 | iter->ent_size = next_size; |
2305 | ||
bc0c38d1 SR |
2306 | if (ent_cpu) |
2307 | *ent_cpu = next_cpu; | |
2308 | ||
3928a8a2 SR |
2309 | if (ent_ts) |
2310 | *ent_ts = next_ts; | |
2311 | ||
bc21b478 SR |
2312 | if (missing_events) |
2313 | *missing_events = next_lost; | |
2314 | ||
bc0c38d1 SR |
2315 | return next; |
2316 | } | |
2317 | ||
dd0e545f | 2318 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
2319 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
2320 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 2321 | { |
bc21b478 | 2322 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); |
dd0e545f SR |
2323 | } |
2324 | ||
2325 | /* Find the next real entry, and increment the iterator to the next entry */ | |
955b61e5 | 2326 | void *trace_find_next_entry_inc(struct trace_iterator *iter) |
dd0e545f | 2327 | { |
bc21b478 SR |
2328 | iter->ent = __find_next_entry(iter, &iter->cpu, |
2329 | &iter->lost_events, &iter->ts); | |
dd0e545f | 2330 | |
3928a8a2 | 2331 | if (iter->ent) |
e2ac8ef5 | 2332 | trace_iterator_increment(iter); |
dd0e545f | 2333 | |
3928a8a2 | 2334 | return iter->ent ? iter : NULL; |
b3806b43 | 2335 | } |
bc0c38d1 | 2336 | |
e309b41d | 2337 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 2338 | { |
12883efb | 2339 | ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts, |
bc21b478 | 2340 | &iter->lost_events); |
bc0c38d1 SR |
2341 | } |
2342 | ||
e309b41d | 2343 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
2344 | { |
2345 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 2346 | int i = (int)*pos; |
4e3c3333 | 2347 | void *ent; |
bc0c38d1 | 2348 | |
a63ce5b3 SR |
2349 | WARN_ON_ONCE(iter->leftover); |
2350 | ||
bc0c38d1 SR |
2351 | (*pos)++; |
2352 | ||
2353 | /* can't go backwards */ | |
2354 | if (iter->idx > i) | |
2355 | return NULL; | |
2356 | ||
2357 | if (iter->idx < 0) | |
955b61e5 | 2358 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
2359 | else |
2360 | ent = iter; | |
2361 | ||
2362 | while (ent && iter->idx < i) | |
955b61e5 | 2363 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
2364 | |
2365 | iter->pos = *pos; | |
2366 | ||
bc0c38d1 SR |
2367 | return ent; |
2368 | } | |
2369 | ||
955b61e5 | 2370 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
2f26ebd5 | 2371 | { |
2f26ebd5 SR |
2372 | struct ring_buffer_event *event; |
2373 | struct ring_buffer_iter *buf_iter; | |
2374 | unsigned long entries = 0; | |
2375 | u64 ts; | |
2376 | ||
12883efb | 2377 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0; |
2f26ebd5 | 2378 | |
6d158a81 SR |
2379 | buf_iter = trace_buffer_iter(iter, cpu); |
2380 | if (!buf_iter) | |
2f26ebd5 SR |
2381 | return; |
2382 | ||
2f26ebd5 SR |
2383 | ring_buffer_iter_reset(buf_iter); |
2384 | ||
2385 | /* | |
2386 | * We could have the case with the max latency tracers | |
2387 | * that a reset never took place on a cpu. This is evident | |
2388 | * by the timestamp being before the start of the buffer. | |
2389 | */ | |
2390 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
12883efb | 2391 | if (ts >= iter->trace_buffer->time_start) |
2f26ebd5 SR |
2392 | break; |
2393 | entries++; | |
2394 | ring_buffer_read(buf_iter, NULL); | |
2395 | } | |
2396 | ||
12883efb | 2397 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries; |
2f26ebd5 SR |
2398 | } |
2399 | ||
d7350c3f | 2400 | /* |
d7350c3f FW |
2401 | * The current tracer is copied to avoid a global locking |
2402 | * all around. | |
2403 | */ | |
bc0c38d1 SR |
2404 | static void *s_start(struct seq_file *m, loff_t *pos) |
2405 | { | |
2406 | struct trace_iterator *iter = m->private; | |
2b6080f2 | 2407 | struct trace_array *tr = iter->tr; |
b04cc6b1 | 2408 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
2409 | void *p = NULL; |
2410 | loff_t l = 0; | |
3928a8a2 | 2411 | int cpu; |
bc0c38d1 | 2412 | |
2fd196ec HT |
2413 | /* |
2414 | * copy the tracer to avoid using a global lock all around. | |
2415 | * iter->trace is a copy of current_trace, the pointer to the | |
2416 | * name may be used instead of a strcmp(), as iter->trace->name | |
2417 | * will point to the same string as current_trace->name. | |
2418 | */ | |
bc0c38d1 | 2419 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
2420 | if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) |
2421 | *iter->trace = *tr->current_trace; | |
d7350c3f | 2422 | mutex_unlock(&trace_types_lock); |
bc0c38d1 | 2423 | |
12883efb | 2424 | #ifdef CONFIG_TRACER_MAX_TRACE |
debdd57f HT |
2425 | if (iter->snapshot && iter->trace->use_max_tr) |
2426 | return ERR_PTR(-EBUSY); | |
12883efb | 2427 | #endif |
debdd57f HT |
2428 | |
2429 | if (!iter->snapshot) | |
2430 | atomic_inc(&trace_record_cmdline_disabled); | |
bc0c38d1 | 2431 | |
bc0c38d1 SR |
2432 | if (*pos != iter->pos) { |
2433 | iter->ent = NULL; | |
2434 | iter->cpu = 0; | |
2435 | iter->idx = -1; | |
2436 | ||
ae3b5093 | 2437 | if (cpu_file == RING_BUFFER_ALL_CPUS) { |
b04cc6b1 | 2438 | for_each_tracing_cpu(cpu) |
2f26ebd5 | 2439 | tracing_iter_reset(iter, cpu); |
b04cc6b1 | 2440 | } else |
2f26ebd5 | 2441 | tracing_iter_reset(iter, cpu_file); |
bc0c38d1 | 2442 | |
ac91d854 | 2443 | iter->leftover = 0; |
bc0c38d1 SR |
2444 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
2445 | ; | |
2446 | ||
2447 | } else { | |
a63ce5b3 SR |
2448 | /* |
2449 | * If we overflowed the seq_file before, then we want | |
2450 | * to just reuse the trace_seq buffer again. | |
2451 | */ | |
2452 | if (iter->leftover) | |
2453 | p = iter; | |
2454 | else { | |
2455 | l = *pos - 1; | |
2456 | p = s_next(m, p, &l); | |
2457 | } | |
bc0c38d1 SR |
2458 | } |
2459 | ||
4f535968 | 2460 | trace_event_read_lock(); |
7e53bd42 | 2461 | trace_access_lock(cpu_file); |
bc0c38d1 SR |
2462 | return p; |
2463 | } | |
2464 | ||
2465 | static void s_stop(struct seq_file *m, void *p) | |
2466 | { | |
7e53bd42 LJ |
2467 | struct trace_iterator *iter = m->private; |
2468 | ||
12883efb | 2469 | #ifdef CONFIG_TRACER_MAX_TRACE |
debdd57f HT |
2470 | if (iter->snapshot && iter->trace->use_max_tr) |
2471 | return; | |
12883efb | 2472 | #endif |
debdd57f HT |
2473 | |
2474 | if (!iter->snapshot) | |
2475 | atomic_dec(&trace_record_cmdline_disabled); | |
12883efb | 2476 | |
7e53bd42 | 2477 | trace_access_unlock(iter->cpu_file); |
4f535968 | 2478 | trace_event_read_unlock(); |
bc0c38d1 SR |
2479 | } |
2480 | ||
39eaf7ef | 2481 | static void |
12883efb SRRH |
2482 | get_total_entries(struct trace_buffer *buf, |
2483 | unsigned long *total, unsigned long *entries) | |
39eaf7ef SR |
2484 | { |
2485 | unsigned long count; | |
2486 | int cpu; | |
2487 | ||
2488 | *total = 0; | |
2489 | *entries = 0; | |
2490 | ||
2491 | for_each_tracing_cpu(cpu) { | |
12883efb | 2492 | count = ring_buffer_entries_cpu(buf->buffer, cpu); |
39eaf7ef SR |
2493 | /* |
2494 | * If this buffer has skipped entries, then we hold all | |
2495 | * entries for the trace and we need to ignore the | |
2496 | * ones before the time stamp. | |
2497 | */ | |
12883efb SRRH |
2498 | if (per_cpu_ptr(buf->data, cpu)->skipped_entries) { |
2499 | count -= per_cpu_ptr(buf->data, cpu)->skipped_entries; | |
39eaf7ef SR |
2500 | /* total is the same as the entries */ |
2501 | *total += count; | |
2502 | } else | |
2503 | *total += count + | |
12883efb | 2504 | ring_buffer_overrun_cpu(buf->buffer, cpu); |
39eaf7ef SR |
2505 | *entries += count; |
2506 | } | |
2507 | } | |
2508 | ||
e309b41d | 2509 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 2510 | { |
a6168353 ME |
2511 | seq_puts(m, "# _------=> CPU# \n"); |
2512 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
2513 | seq_puts(m, "# | / _----=> need-resched \n"); | |
2514 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
2515 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
e6e1e259 SR |
2516 | seq_puts(m, "# |||| / delay \n"); |
2517 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
2518 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
bc0c38d1 SR |
2519 | } |
2520 | ||
12883efb | 2521 | static void print_event_info(struct trace_buffer *buf, struct seq_file *m) |
bc0c38d1 | 2522 | { |
39eaf7ef SR |
2523 | unsigned long total; |
2524 | unsigned long entries; | |
2525 | ||
12883efb | 2526 | get_total_entries(buf, &total, &entries); |
39eaf7ef SR |
2527 | seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", |
2528 | entries, total, num_online_cpus()); | |
2529 | seq_puts(m, "#\n"); | |
2530 | } | |
2531 | ||
12883efb | 2532 | static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m) |
39eaf7ef | 2533 | { |
12883efb | 2534 | print_event_info(buf, m); |
77271ce4 | 2535 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); |
a6168353 | 2536 | seq_puts(m, "# | | | | |\n"); |
bc0c38d1 SR |
2537 | } |
2538 | ||
12883efb | 2539 | static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m) |
77271ce4 | 2540 | { |
12883efb | 2541 | print_event_info(buf, m); |
77271ce4 SR |
2542 | seq_puts(m, "# _-----=> irqs-off\n"); |
2543 | seq_puts(m, "# / _----=> need-resched\n"); | |
2544 | seq_puts(m, "# | / _---=> hardirq/softirq\n"); | |
2545 | seq_puts(m, "# || / _--=> preempt-depth\n"); | |
2546 | seq_puts(m, "# ||| / delay\n"); | |
2547 | seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"); | |
2548 | seq_puts(m, "# | | | |||| | |\n"); | |
2549 | } | |
bc0c38d1 | 2550 | |
62b915f1 | 2551 | void |
bc0c38d1 SR |
2552 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
2553 | { | |
2554 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
12883efb SRRH |
2555 | struct trace_buffer *buf = iter->trace_buffer; |
2556 | struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu); | |
2b6080f2 | 2557 | struct tracer *type = iter->trace; |
39eaf7ef SR |
2558 | unsigned long entries; |
2559 | unsigned long total; | |
bc0c38d1 SR |
2560 | const char *name = "preemption"; |
2561 | ||
d840f718 | 2562 | name = type->name; |
bc0c38d1 | 2563 | |
12883efb | 2564 | get_total_entries(buf, &total, &entries); |
bc0c38d1 | 2565 | |
888b55dc | 2566 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 2567 | name, UTS_RELEASE); |
888b55dc | 2568 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 2569 | "---------------------------------\n"); |
888b55dc | 2570 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 2571 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 2572 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 2573 | entries, |
4c11d7ae | 2574 | total, |
12883efb | 2575 | buf->cpu, |
bc0c38d1 SR |
2576 | #if defined(CONFIG_PREEMPT_NONE) |
2577 | "server", | |
2578 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
2579 | "desktop", | |
b5c21b45 | 2580 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
2581 | "preempt", |
2582 | #else | |
2583 | "unknown", | |
2584 | #endif | |
2585 | /* These are reserved for later use */ | |
2586 | 0, 0, 0, 0); | |
2587 | #ifdef CONFIG_SMP | |
2588 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
2589 | #else | |
2590 | seq_puts(m, ")\n"); | |
2591 | #endif | |
888b55dc KM |
2592 | seq_puts(m, "# -----------------\n"); |
2593 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 | 2594 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
d20b92ab EB |
2595 | data->comm, data->pid, |
2596 | from_kuid_munged(seq_user_ns(m), data->uid), data->nice, | |
bc0c38d1 | 2597 | data->policy, data->rt_priority); |
888b55dc | 2598 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
2599 | |
2600 | if (data->critical_start) { | |
888b55dc | 2601 | seq_puts(m, "# => started at: "); |
214023c3 SR |
2602 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
2603 | trace_print_seq(m, &iter->seq); | |
888b55dc | 2604 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
2605 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
2606 | trace_print_seq(m, &iter->seq); | |
8248ac05 | 2607 | seq_puts(m, "\n#\n"); |
bc0c38d1 SR |
2608 | } |
2609 | ||
888b55dc | 2610 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
2611 | } |
2612 | ||
a309720c SR |
2613 | static void test_cpu_buff_start(struct trace_iterator *iter) |
2614 | { | |
2615 | struct trace_seq *s = &iter->seq; | |
2616 | ||
12ef7d44 SR |
2617 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) |
2618 | return; | |
2619 | ||
2620 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
2621 | return; | |
2622 | ||
4462344e | 2623 | if (cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
2624 | return; |
2625 | ||
12883efb | 2626 | if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries) |
2f26ebd5 SR |
2627 | return; |
2628 | ||
4462344e | 2629 | cpumask_set_cpu(iter->cpu, iter->started); |
b0dfa978 FW |
2630 | |
2631 | /* Don't print started cpu buffer for the first entry of the trace */ | |
2632 | if (iter->idx > 1) | |
2633 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
2634 | iter->cpu); | |
a309720c SR |
2635 | } |
2636 | ||
2c4f035f | 2637 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 2638 | { |
214023c3 | 2639 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 2640 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 2641 | struct trace_entry *entry; |
f633cef0 | 2642 | struct trace_event *event; |
bc0c38d1 | 2643 | |
4e3c3333 | 2644 | entry = iter->ent; |
dd0e545f | 2645 | |
a309720c SR |
2646 | test_cpu_buff_start(iter); |
2647 | ||
c4a8e8be | 2648 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 2649 | |
c4a8e8be | 2650 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
27d48be8 SR |
2651 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2652 | if (!trace_print_lat_context(iter)) | |
2653 | goto partial; | |
2654 | } else { | |
2655 | if (!trace_print_context(iter)) | |
2656 | goto partial; | |
2657 | } | |
c4a8e8be | 2658 | } |
bc0c38d1 | 2659 | |
268ccda0 | 2660 | if (event) |
a9a57763 | 2661 | return event->funcs->trace(iter, sym_flags, event); |
d9793bd8 ACM |
2662 | |
2663 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
2664 | goto partial; | |
02b67518 | 2665 | |
2c4f035f | 2666 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
2667 | partial: |
2668 | return TRACE_TYPE_PARTIAL_LINE; | |
bc0c38d1 SR |
2669 | } |
2670 | ||
2c4f035f | 2671 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 IM |
2672 | { |
2673 | struct trace_seq *s = &iter->seq; | |
2674 | struct trace_entry *entry; | |
f633cef0 | 2675 | struct trace_event *event; |
f9896bf3 IM |
2676 | |
2677 | entry = iter->ent; | |
dd0e545f | 2678 | |
c4a8e8be | 2679 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
d9793bd8 ACM |
2680 | if (!trace_seq_printf(s, "%d %d %llu ", |
2681 | entry->pid, iter->cpu, iter->ts)) | |
2682 | goto partial; | |
c4a8e8be | 2683 | } |
f9896bf3 | 2684 | |
f633cef0 | 2685 | event = ftrace_find_event(entry->type); |
268ccda0 | 2686 | if (event) |
a9a57763 | 2687 | return event->funcs->raw(iter, 0, event); |
d9793bd8 ACM |
2688 | |
2689 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
2690 | goto partial; | |
777e208d | 2691 | |
2c4f035f | 2692 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
2693 | partial: |
2694 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 IM |
2695 | } |
2696 | ||
2c4f035f | 2697 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec IM |
2698 | { |
2699 | struct trace_seq *s = &iter->seq; | |
2700 | unsigned char newline = '\n'; | |
2701 | struct trace_entry *entry; | |
f633cef0 | 2702 | struct trace_event *event; |
5e3ca0ec IM |
2703 | |
2704 | entry = iter->ent; | |
dd0e545f | 2705 | |
c4a8e8be FW |
2706 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
2707 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
2708 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
2709 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
2710 | } | |
5e3ca0ec | 2711 | |
f633cef0 | 2712 | event = ftrace_find_event(entry->type); |
268ccda0 | 2713 | if (event) { |
a9a57763 | 2714 | enum print_line_t ret = event->funcs->hex(iter, 0, event); |
d9793bd8 ACM |
2715 | if (ret != TRACE_TYPE_HANDLED) |
2716 | return ret; | |
2717 | } | |
7104f300 | 2718 | |
5e3ca0ec IM |
2719 | SEQ_PUT_FIELD_RET(s, newline); |
2720 | ||
2c4f035f | 2721 | return TRACE_TYPE_HANDLED; |
5e3ca0ec IM |
2722 | } |
2723 | ||
2c4f035f | 2724 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa IM |
2725 | { |
2726 | struct trace_seq *s = &iter->seq; | |
2727 | struct trace_entry *entry; | |
f633cef0 | 2728 | struct trace_event *event; |
cb0f12aa IM |
2729 | |
2730 | entry = iter->ent; | |
dd0e545f | 2731 | |
c4a8e8be FW |
2732 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
2733 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
1830b52d | 2734 | SEQ_PUT_FIELD_RET(s, iter->cpu); |
c4a8e8be FW |
2735 | SEQ_PUT_FIELD_RET(s, iter->ts); |
2736 | } | |
cb0f12aa | 2737 | |
f633cef0 | 2738 | event = ftrace_find_event(entry->type); |
a9a57763 SR |
2739 | return event ? event->funcs->binary(iter, 0, event) : |
2740 | TRACE_TYPE_HANDLED; | |
cb0f12aa IM |
2741 | } |
2742 | ||
62b915f1 | 2743 | int trace_empty(struct trace_iterator *iter) |
bc0c38d1 | 2744 | { |
6d158a81 | 2745 | struct ring_buffer_iter *buf_iter; |
bc0c38d1 SR |
2746 | int cpu; |
2747 | ||
9aba60fe | 2748 | /* If we are looking at one CPU buffer, only check that one */ |
ae3b5093 | 2749 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
9aba60fe | 2750 | cpu = iter->cpu_file; |
6d158a81 SR |
2751 | buf_iter = trace_buffer_iter(iter, cpu); |
2752 | if (buf_iter) { | |
2753 | if (!ring_buffer_iter_empty(buf_iter)) | |
9aba60fe SR |
2754 | return 0; |
2755 | } else { | |
12883efb | 2756 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) |
9aba60fe SR |
2757 | return 0; |
2758 | } | |
2759 | return 1; | |
2760 | } | |
2761 | ||
ab46428c | 2762 | for_each_tracing_cpu(cpu) { |
6d158a81 SR |
2763 | buf_iter = trace_buffer_iter(iter, cpu); |
2764 | if (buf_iter) { | |
2765 | if (!ring_buffer_iter_empty(buf_iter)) | |
d769041f SR |
2766 | return 0; |
2767 | } else { | |
12883efb | 2768 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) |
d769041f SR |
2769 | return 0; |
2770 | } | |
bc0c38d1 | 2771 | } |
d769041f | 2772 | |
797d3712 | 2773 | return 1; |
bc0c38d1 SR |
2774 | } |
2775 | ||
4f535968 | 2776 | /* Called with trace_event_read_lock() held. */ |
955b61e5 | 2777 | enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 2778 | { |
2c4f035f FW |
2779 | enum print_line_t ret; |
2780 | ||
ee5e51f5 JO |
2781 | if (iter->lost_events && |
2782 | !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2783 | iter->cpu, iter->lost_events)) | |
2784 | return TRACE_TYPE_PARTIAL_LINE; | |
bc21b478 | 2785 | |
2c4f035f FW |
2786 | if (iter->trace && iter->trace->print_line) { |
2787 | ret = iter->trace->print_line(iter); | |
2788 | if (ret != TRACE_TYPE_UNHANDLED) | |
2789 | return ret; | |
2790 | } | |
72829bc3 | 2791 | |
09ae7234 SRRH |
2792 | if (iter->ent->type == TRACE_BPUTS && |
2793 | trace_flags & TRACE_ITER_PRINTK && | |
2794 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2795 | return trace_print_bputs_msg_only(iter); | |
2796 | ||
48ead020 FW |
2797 | if (iter->ent->type == TRACE_BPRINT && |
2798 | trace_flags & TRACE_ITER_PRINTK && | |
2799 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2800 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 2801 | |
66896a85 FW |
2802 | if (iter->ent->type == TRACE_PRINT && |
2803 | trace_flags & TRACE_ITER_PRINTK && | |
2804 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2805 | return trace_print_printk_msg_only(iter); |
66896a85 | 2806 | |
cb0f12aa IM |
2807 | if (trace_flags & TRACE_ITER_BIN) |
2808 | return print_bin_fmt(iter); | |
2809 | ||
5e3ca0ec IM |
2810 | if (trace_flags & TRACE_ITER_HEX) |
2811 | return print_hex_fmt(iter); | |
2812 | ||
f9896bf3 IM |
2813 | if (trace_flags & TRACE_ITER_RAW) |
2814 | return print_raw_fmt(iter); | |
2815 | ||
f9896bf3 IM |
2816 | return print_trace_fmt(iter); |
2817 | } | |
2818 | ||
7e9a49ef JO |
2819 | void trace_latency_header(struct seq_file *m) |
2820 | { | |
2821 | struct trace_iterator *iter = m->private; | |
2822 | ||
2823 | /* print nothing if the buffers are empty */ | |
2824 | if (trace_empty(iter)) | |
2825 | return; | |
2826 | ||
2827 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
2828 | print_trace_header(m, iter); | |
2829 | ||
2830 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2831 | print_lat_help_header(m); | |
2832 | } | |
2833 | ||
62b915f1 JO |
2834 | void trace_default_header(struct seq_file *m) |
2835 | { | |
2836 | struct trace_iterator *iter = m->private; | |
2837 | ||
f56e7f8e JO |
2838 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
2839 | return; | |
2840 | ||
62b915f1 JO |
2841 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2842 | /* print nothing if the buffers are empty */ | |
2843 | if (trace_empty(iter)) | |
2844 | return; | |
2845 | print_trace_header(m, iter); | |
2846 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2847 | print_lat_help_header(m); | |
2848 | } else { | |
77271ce4 SR |
2849 | if (!(trace_flags & TRACE_ITER_VERBOSE)) { |
2850 | if (trace_flags & TRACE_ITER_IRQ_INFO) | |
12883efb | 2851 | print_func_help_header_irq(iter->trace_buffer, m); |
77271ce4 | 2852 | else |
12883efb | 2853 | print_func_help_header(iter->trace_buffer, m); |
77271ce4 | 2854 | } |
62b915f1 JO |
2855 | } |
2856 | } | |
2857 | ||
e0a413f6 SR |
2858 | static void test_ftrace_alive(struct seq_file *m) |
2859 | { | |
2860 | if (!ftrace_is_dead()) | |
2861 | return; | |
2862 | seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
2863 | seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n"); | |
2864 | } | |
2865 | ||
d8741e2e | 2866 | #ifdef CONFIG_TRACER_MAX_TRACE |
f1affcaa | 2867 | static void show_snapshot_main_help(struct seq_file *m) |
d8741e2e | 2868 | { |
d8741e2e SRRH |
2869 | seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"); |
2870 | seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); | |
2871 | seq_printf(m, "# Takes a snapshot of the main buffer.\n"); | |
b9be6d02 | 2872 | seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n"); |
d8741e2e SRRH |
2873 | seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); |
2874 | seq_printf(m, "# is not a '0' or '1')\n"); | |
2875 | } | |
f1affcaa SRRH |
2876 | |
2877 | static void show_snapshot_percpu_help(struct seq_file *m) | |
2878 | { | |
2879 | seq_printf(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); | |
2880 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP | |
2881 | seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); | |
2882 | seq_printf(m, "# Takes a snapshot of the main buffer for this cpu.\n"); | |
2883 | #else | |
2884 | seq_printf(m, "# echo 1 > snapshot : Not supported with this kernel.\n"); | |
2885 | seq_printf(m, "# Must use main snapshot file to allocate.\n"); | |
2886 | #endif | |
2887 | seq_printf(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n"); | |
2888 | seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); | |
2889 | seq_printf(m, "# is not a '0' or '1')\n"); | |
2890 | } | |
2891 | ||
d8741e2e SRRH |
2892 | static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) |
2893 | { | |
45ad21ca | 2894 | if (iter->tr->allocated_snapshot) |
d8741e2e SRRH |
2895 | seq_printf(m, "#\n# * Snapshot is allocated *\n#\n"); |
2896 | else | |
2897 | seq_printf(m, "#\n# * Snapshot is freed *\n#\n"); | |
2898 | ||
2899 | seq_printf(m, "# Snapshot commands:\n"); | |
f1affcaa SRRH |
2900 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
2901 | show_snapshot_main_help(m); | |
2902 | else | |
2903 | show_snapshot_percpu_help(m); | |
d8741e2e SRRH |
2904 | } |
2905 | #else | |
2906 | /* Should never be called */ | |
2907 | static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } | |
2908 | #endif | |
2909 | ||
bc0c38d1 SR |
2910 | static int s_show(struct seq_file *m, void *v) |
2911 | { | |
2912 | struct trace_iterator *iter = v; | |
a63ce5b3 | 2913 | int ret; |
bc0c38d1 SR |
2914 | |
2915 | if (iter->ent == NULL) { | |
2916 | if (iter->tr) { | |
2917 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2918 | seq_puts(m, "#\n"); | |
e0a413f6 | 2919 | test_ftrace_alive(m); |
bc0c38d1 | 2920 | } |
d8741e2e SRRH |
2921 | if (iter->snapshot && trace_empty(iter)) |
2922 | print_snapshot_help(m, iter); | |
2923 | else if (iter->trace && iter->trace->print_header) | |
8bba1bf5 | 2924 | iter->trace->print_header(m); |
62b915f1 JO |
2925 | else |
2926 | trace_default_header(m); | |
2927 | ||
a63ce5b3 SR |
2928 | } else if (iter->leftover) { |
2929 | /* | |
2930 | * If we filled the seq_file buffer earlier, we | |
2931 | * want to just show it now. | |
2932 | */ | |
2933 | ret = trace_print_seq(m, &iter->seq); | |
2934 | ||
2935 | /* ret should this time be zero, but you never know */ | |
2936 | iter->leftover = ret; | |
2937 | ||
bc0c38d1 | 2938 | } else { |
f9896bf3 | 2939 | print_trace_line(iter); |
a63ce5b3 SR |
2940 | ret = trace_print_seq(m, &iter->seq); |
2941 | /* | |
2942 | * If we overflow the seq_file buffer, then it will | |
2943 | * ask us for this data again at start up. | |
2944 | * Use that instead. | |
2945 | * ret is 0 if seq_file write succeeded. | |
2946 | * -1 otherwise. | |
2947 | */ | |
2948 | iter->leftover = ret; | |
bc0c38d1 SR |
2949 | } |
2950 | ||
2951 | return 0; | |
2952 | } | |
2953 | ||
649e9c70 ON |
2954 | /* |
2955 | * Should be used after trace_array_get(), trace_types_lock | |
2956 | * ensures that i_cdev was already initialized. | |
2957 | */ | |
2958 | static inline int tracing_get_cpu(struct inode *inode) | |
2959 | { | |
2960 | if (inode->i_cdev) /* See trace_create_cpu_file() */ | |
2961 | return (long)inode->i_cdev - 1; | |
2962 | return RING_BUFFER_ALL_CPUS; | |
2963 | } | |
2964 | ||
88e9d34c | 2965 | static const struct seq_operations tracer_seq_ops = { |
4bf39a94 IM |
2966 | .start = s_start, |
2967 | .next = s_next, | |
2968 | .stop = s_stop, | |
2969 | .show = s_show, | |
bc0c38d1 SR |
2970 | }; |
2971 | ||
e309b41d | 2972 | static struct trace_iterator * |
6484c71c | 2973 | __tracing_open(struct inode *inode, struct file *file, bool snapshot) |
bc0c38d1 | 2974 | { |
6484c71c | 2975 | struct trace_array *tr = inode->i_private; |
bc0c38d1 | 2976 | struct trace_iterator *iter; |
50e18b94 | 2977 | int cpu; |
bc0c38d1 | 2978 | |
85a2f9b4 SR |
2979 | if (tracing_disabled) |
2980 | return ERR_PTR(-ENODEV); | |
60a11774 | 2981 | |
50e18b94 | 2982 | iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); |
85a2f9b4 SR |
2983 | if (!iter) |
2984 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 2985 | |
6d158a81 SR |
2986 | iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(), |
2987 | GFP_KERNEL); | |
93574fcc DC |
2988 | if (!iter->buffer_iter) |
2989 | goto release; | |
2990 | ||
d7350c3f FW |
2991 | /* |
2992 | * We make a copy of the current tracer to avoid concurrent | |
2993 | * changes on it while we are reading. | |
2994 | */ | |
bc0c38d1 | 2995 | mutex_lock(&trace_types_lock); |
d7350c3f | 2996 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 2997 | if (!iter->trace) |
d7350c3f | 2998 | goto fail; |
85a2f9b4 | 2999 | |
2b6080f2 | 3000 | *iter->trace = *tr->current_trace; |
d7350c3f | 3001 | |
79f55997 | 3002 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
b0dfa978 FW |
3003 | goto fail; |
3004 | ||
12883efb SRRH |
3005 | iter->tr = tr; |
3006 | ||
3007 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2b6080f2 SR |
3008 | /* Currently only the top directory has a snapshot */ |
3009 | if (tr->current_trace->print_max || snapshot) | |
12883efb | 3010 | iter->trace_buffer = &tr->max_buffer; |
bc0c38d1 | 3011 | else |
12883efb SRRH |
3012 | #endif |
3013 | iter->trace_buffer = &tr->trace_buffer; | |
debdd57f | 3014 | iter->snapshot = snapshot; |
bc0c38d1 | 3015 | iter->pos = -1; |
6484c71c | 3016 | iter->cpu_file = tracing_get_cpu(inode); |
d7350c3f | 3017 | mutex_init(&iter->mutex); |
bc0c38d1 | 3018 | |
8bba1bf5 MM |
3019 | /* Notify the tracer early; before we stop tracing. */ |
3020 | if (iter->trace && iter->trace->open) | |
a93751ca | 3021 | iter->trace->open(iter); |
8bba1bf5 | 3022 | |
12ef7d44 | 3023 | /* Annotate start of buffers if we had overruns */ |
12883efb | 3024 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) |
12ef7d44 SR |
3025 | iter->iter_flags |= TRACE_FILE_ANNOTATE; |
3026 | ||
8be0709f | 3027 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
58e8eedf | 3028 | if (trace_clocks[tr->clock_id].in_ns) |
8be0709f DS |
3029 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
3030 | ||
debdd57f HT |
3031 | /* stop the trace while dumping if we are not opening "snapshot" */ |
3032 | if (!iter->snapshot) | |
2b6080f2 | 3033 | tracing_stop_tr(tr); |
2f26ebd5 | 3034 | |
ae3b5093 | 3035 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { |
b04cc6b1 | 3036 | for_each_tracing_cpu(cpu) { |
b04cc6b1 | 3037 | iter->buffer_iter[cpu] = |
12883efb | 3038 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); |
72c9ddfd DM |
3039 | } |
3040 | ring_buffer_read_prepare_sync(); | |
3041 | for_each_tracing_cpu(cpu) { | |
3042 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 3043 | tracing_iter_reset(iter, cpu); |
b04cc6b1 FW |
3044 | } |
3045 | } else { | |
3046 | cpu = iter->cpu_file; | |
3928a8a2 | 3047 | iter->buffer_iter[cpu] = |
12883efb | 3048 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); |
72c9ddfd DM |
3049 | ring_buffer_read_prepare_sync(); |
3050 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 3051 | tracing_iter_reset(iter, cpu); |
3928a8a2 SR |
3052 | } |
3053 | ||
bc0c38d1 SR |
3054 | mutex_unlock(&trace_types_lock); |
3055 | ||
bc0c38d1 | 3056 | return iter; |
3928a8a2 | 3057 | |
d7350c3f | 3058 | fail: |
3928a8a2 | 3059 | mutex_unlock(&trace_types_lock); |
d7350c3f | 3060 | kfree(iter->trace); |
6d158a81 | 3061 | kfree(iter->buffer_iter); |
93574fcc | 3062 | release: |
50e18b94 JO |
3063 | seq_release_private(inode, file); |
3064 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 SR |
3065 | } |
3066 | ||
3067 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
3068 | { | |
60a11774 SR |
3069 | if (tracing_disabled) |
3070 | return -ENODEV; | |
3071 | ||
bc0c38d1 SR |
3072 | filp->private_data = inode->i_private; |
3073 | return 0; | |
3074 | } | |
3075 | ||
2e86421d GB |
3076 | bool tracing_is_disabled(void) |
3077 | { | |
3078 | return (tracing_disabled) ? true: false; | |
3079 | } | |
3080 | ||
7b85af63 SRRH |
3081 | /* |
3082 | * Open and update trace_array ref count. | |
3083 | * Must have the current trace_array passed to it. | |
3084 | */ | |
dcc30223 | 3085 | static int tracing_open_generic_tr(struct inode *inode, struct file *filp) |
7b85af63 SRRH |
3086 | { |
3087 | struct trace_array *tr = inode->i_private; | |
3088 | ||
3089 | if (tracing_disabled) | |
3090 | return -ENODEV; | |
3091 | ||
3092 | if (trace_array_get(tr) < 0) | |
3093 | return -ENODEV; | |
3094 | ||
3095 | filp->private_data = inode->i_private; | |
3096 | ||
3097 | return 0; | |
7b85af63 SRRH |
3098 | } |
3099 | ||
4fd27358 | 3100 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 | 3101 | { |
6484c71c | 3102 | struct trace_array *tr = inode->i_private; |
907f2784 | 3103 | struct seq_file *m = file->private_data; |
4acd4d00 | 3104 | struct trace_iterator *iter; |
3928a8a2 | 3105 | int cpu; |
bc0c38d1 | 3106 | |
ff451961 | 3107 | if (!(file->f_mode & FMODE_READ)) { |
6484c71c | 3108 | trace_array_put(tr); |
4acd4d00 | 3109 | return 0; |
ff451961 | 3110 | } |
4acd4d00 | 3111 | |
6484c71c | 3112 | /* Writes do not use seq_file */ |
4acd4d00 | 3113 | iter = m->private; |
bc0c38d1 | 3114 | mutex_lock(&trace_types_lock); |
a695cb58 | 3115 | |
3928a8a2 SR |
3116 | for_each_tracing_cpu(cpu) { |
3117 | if (iter->buffer_iter[cpu]) | |
3118 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
3119 | } | |
3120 | ||
bc0c38d1 SR |
3121 | if (iter->trace && iter->trace->close) |
3122 | iter->trace->close(iter); | |
3123 | ||
debdd57f HT |
3124 | if (!iter->snapshot) |
3125 | /* reenable tracing if it was previously enabled */ | |
2b6080f2 | 3126 | tracing_start_tr(tr); |
f77d09a3 AL |
3127 | |
3128 | __trace_array_put(tr); | |
3129 | ||
bc0c38d1 SR |
3130 | mutex_unlock(&trace_types_lock); |
3131 | ||
d7350c3f | 3132 | mutex_destroy(&iter->mutex); |
b0dfa978 | 3133 | free_cpumask_var(iter->started); |
d7350c3f | 3134 | kfree(iter->trace); |
6d158a81 | 3135 | kfree(iter->buffer_iter); |
50e18b94 | 3136 | seq_release_private(inode, file); |
ff451961 | 3137 | |
bc0c38d1 SR |
3138 | return 0; |
3139 | } | |
3140 | ||
7b85af63 SRRH |
3141 | static int tracing_release_generic_tr(struct inode *inode, struct file *file) |
3142 | { | |
3143 | struct trace_array *tr = inode->i_private; | |
3144 | ||
3145 | trace_array_put(tr); | |
bc0c38d1 SR |
3146 | return 0; |
3147 | } | |
3148 | ||
7b85af63 SRRH |
3149 | static int tracing_single_release_tr(struct inode *inode, struct file *file) |
3150 | { | |
3151 | struct trace_array *tr = inode->i_private; | |
3152 | ||
3153 | trace_array_put(tr); | |
3154 | ||
3155 | return single_release(inode, file); | |
3156 | } | |
3157 | ||
bc0c38d1 SR |
3158 | static int tracing_open(struct inode *inode, struct file *file) |
3159 | { | |
6484c71c | 3160 | struct trace_array *tr = inode->i_private; |
85a2f9b4 SR |
3161 | struct trace_iterator *iter; |
3162 | int ret = 0; | |
bc0c38d1 | 3163 | |
ff451961 SRRH |
3164 | if (trace_array_get(tr) < 0) |
3165 | return -ENODEV; | |
3166 | ||
4acd4d00 | 3167 | /* If this file was open for write, then erase contents */ |
6484c71c ON |
3168 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
3169 | int cpu = tracing_get_cpu(inode); | |
3170 | ||
3171 | if (cpu == RING_BUFFER_ALL_CPUS) | |
12883efb | 3172 | tracing_reset_online_cpus(&tr->trace_buffer); |
4acd4d00 | 3173 | else |
6484c71c | 3174 | tracing_reset(&tr->trace_buffer, cpu); |
4acd4d00 | 3175 | } |
bc0c38d1 | 3176 | |
4acd4d00 | 3177 | if (file->f_mode & FMODE_READ) { |
6484c71c | 3178 | iter = __tracing_open(inode, file, false); |
4acd4d00 SR |
3179 | if (IS_ERR(iter)) |
3180 | ret = PTR_ERR(iter); | |
3181 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
3182 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
3183 | } | |
ff451961 SRRH |
3184 | |
3185 | if (ret < 0) | |
3186 | trace_array_put(tr); | |
3187 | ||
bc0c38d1 SR |
3188 | return ret; |
3189 | } | |
3190 | ||
607e2ea1 SRRH |
3191 | /* |
3192 | * Some tracers are not suitable for instance buffers. | |
3193 | * A tracer is always available for the global array (toplevel) | |
3194 | * or if it explicitly states that it is. | |
3195 | */ | |
3196 | static bool | |
3197 | trace_ok_for_array(struct tracer *t, struct trace_array *tr) | |
3198 | { | |
3199 | return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances; | |
3200 | } | |
3201 | ||
3202 | /* Find the next tracer that this trace array may use */ | |
3203 | static struct tracer * | |
3204 | get_tracer_for_array(struct trace_array *tr, struct tracer *t) | |
3205 | { | |
3206 | while (t && !trace_ok_for_array(t, tr)) | |
3207 | t = t->next; | |
3208 | ||
3209 | return t; | |
3210 | } | |
3211 | ||
e309b41d | 3212 | static void * |
bc0c38d1 SR |
3213 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3214 | { | |
607e2ea1 | 3215 | struct trace_array *tr = m->private; |
f129e965 | 3216 | struct tracer *t = v; |
bc0c38d1 SR |
3217 | |
3218 | (*pos)++; | |
3219 | ||
3220 | if (t) | |
607e2ea1 | 3221 | t = get_tracer_for_array(tr, t->next); |
bc0c38d1 | 3222 | |
bc0c38d1 SR |
3223 | return t; |
3224 | } | |
3225 | ||
3226 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3227 | { | |
607e2ea1 | 3228 | struct trace_array *tr = m->private; |
f129e965 | 3229 | struct tracer *t; |
bc0c38d1 SR |
3230 | loff_t l = 0; |
3231 | ||
3232 | mutex_lock(&trace_types_lock); | |
607e2ea1 SRRH |
3233 | |
3234 | t = get_tracer_for_array(tr, trace_types); | |
3235 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
3236 | ; | |
bc0c38d1 SR |
3237 | |
3238 | return t; | |
3239 | } | |
3240 | ||
3241 | static void t_stop(struct seq_file *m, void *p) | |
3242 | { | |
3243 | mutex_unlock(&trace_types_lock); | |
3244 | } | |
3245 | ||
3246 | static int t_show(struct seq_file *m, void *v) | |
3247 | { | |
3248 | struct tracer *t = v; | |
3249 | ||
3250 | if (!t) | |
3251 | return 0; | |
3252 | ||
3253 | seq_printf(m, "%s", t->name); | |
3254 | if (t->next) | |
3255 | seq_putc(m, ' '); | |
3256 | else | |
3257 | seq_putc(m, '\n'); | |
3258 | ||
3259 | return 0; | |
3260 | } | |
3261 | ||
88e9d34c | 3262 | static const struct seq_operations show_traces_seq_ops = { |
4bf39a94 IM |
3263 | .start = t_start, |
3264 | .next = t_next, | |
3265 | .stop = t_stop, | |
3266 | .show = t_show, | |
bc0c38d1 SR |
3267 | }; |
3268 | ||
3269 | static int show_traces_open(struct inode *inode, struct file *file) | |
3270 | { | |
607e2ea1 SRRH |
3271 | struct trace_array *tr = inode->i_private; |
3272 | struct seq_file *m; | |
3273 | int ret; | |
3274 | ||
60a11774 SR |
3275 | if (tracing_disabled) |
3276 | return -ENODEV; | |
3277 | ||
607e2ea1 SRRH |
3278 | ret = seq_open(file, &show_traces_seq_ops); |
3279 | if (ret) | |
3280 | return ret; | |
3281 | ||
3282 | m = file->private_data; | |
3283 | m->private = tr; | |
3284 | ||
3285 | return 0; | |
bc0c38d1 SR |
3286 | } |
3287 | ||
4acd4d00 SR |
3288 | static ssize_t |
3289 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
3290 | size_t count, loff_t *ppos) | |
3291 | { | |
3292 | return count; | |
3293 | } | |
3294 | ||
098c879e | 3295 | loff_t tracing_lseek(struct file *file, loff_t offset, int whence) |
364829b1 | 3296 | { |
098c879e SRRH |
3297 | int ret; |
3298 | ||
364829b1 | 3299 | if (file->f_mode & FMODE_READ) |
098c879e | 3300 | ret = seq_lseek(file, offset, whence); |
364829b1 | 3301 | else |
098c879e SRRH |
3302 | file->f_pos = ret = 0; |
3303 | ||
3304 | return ret; | |
364829b1 SP |
3305 | } |
3306 | ||
5e2336a0 | 3307 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
3308 | .open = tracing_open, |
3309 | .read = seq_read, | |
4acd4d00 | 3310 | .write = tracing_write_stub, |
098c879e | 3311 | .llseek = tracing_lseek, |
4bf39a94 | 3312 | .release = tracing_release, |
bc0c38d1 SR |
3313 | }; |
3314 | ||
5e2336a0 | 3315 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
3316 | .open = show_traces_open, |
3317 | .read = seq_read, | |
3318 | .release = seq_release, | |
b444786f | 3319 | .llseek = seq_lseek, |
c7078de1 IM |
3320 | }; |
3321 | ||
36dfe925 IM |
3322 | /* |
3323 | * The tracer itself will not take this lock, but still we want | |
3324 | * to provide a consistent cpumask to user-space: | |
3325 | */ | |
3326 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
3327 | ||
3328 | /* | |
3329 | * Temporary storage for the character representation of the | |
3330 | * CPU bitmask (and one more byte for the newline): | |
3331 | */ | |
3332 | static char mask_str[NR_CPUS + 1]; | |
3333 | ||
c7078de1 IM |
3334 | static ssize_t |
3335 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
3336 | size_t count, loff_t *ppos) | |
3337 | { | |
ccfe9e42 | 3338 | struct trace_array *tr = file_inode(filp)->i_private; |
36dfe925 | 3339 | int len; |
c7078de1 IM |
3340 | |
3341 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 3342 | |
ccfe9e42 | 3343 | len = cpumask_scnprintf(mask_str, count, tr->tracing_cpumask); |
36dfe925 IM |
3344 | if (count - len < 2) { |
3345 | count = -EINVAL; | |
3346 | goto out_err; | |
3347 | } | |
3348 | len += sprintf(mask_str + len, "\n"); | |
3349 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
3350 | ||
3351 | out_err: | |
c7078de1 IM |
3352 | mutex_unlock(&tracing_cpumask_update_lock); |
3353 | ||
3354 | return count; | |
3355 | } | |
3356 | ||
3357 | static ssize_t | |
3358 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
3359 | size_t count, loff_t *ppos) | |
3360 | { | |
ccfe9e42 | 3361 | struct trace_array *tr = file_inode(filp)->i_private; |
9e01c1b7 | 3362 | cpumask_var_t tracing_cpumask_new; |
2b6080f2 | 3363 | int err, cpu; |
9e01c1b7 RR |
3364 | |
3365 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
3366 | return -ENOMEM; | |
c7078de1 | 3367 | |
9e01c1b7 | 3368 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 3369 | if (err) |
36dfe925 IM |
3370 | goto err_unlock; |
3371 | ||
215368e8 LZ |
3372 | mutex_lock(&tracing_cpumask_update_lock); |
3373 | ||
a5e25883 | 3374 | local_irq_disable(); |
0b9b12c1 | 3375 | arch_spin_lock(&tr->max_lock); |
ab46428c | 3376 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
3377 | /* |
3378 | * Increase/decrease the disabled counter if we are | |
3379 | * about to flip a bit in the cpumask: | |
3380 | */ | |
ccfe9e42 | 3381 | if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
9e01c1b7 | 3382 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
12883efb SRRH |
3383 | atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); |
3384 | ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu); | |
36dfe925 | 3385 | } |
ccfe9e42 | 3386 | if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
9e01c1b7 | 3387 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
12883efb SRRH |
3388 | atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); |
3389 | ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu); | |
36dfe925 IM |
3390 | } |
3391 | } | |
0b9b12c1 | 3392 | arch_spin_unlock(&tr->max_lock); |
a5e25883 | 3393 | local_irq_enable(); |
36dfe925 | 3394 | |
ccfe9e42 | 3395 | cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
3396 | |
3397 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 3398 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
3399 | |
3400 | return count; | |
36dfe925 IM |
3401 | |
3402 | err_unlock: | |
215368e8 | 3403 | free_cpumask_var(tracing_cpumask_new); |
36dfe925 IM |
3404 | |
3405 | return err; | |
c7078de1 IM |
3406 | } |
3407 | ||
5e2336a0 | 3408 | static const struct file_operations tracing_cpumask_fops = { |
ccfe9e42 | 3409 | .open = tracing_open_generic_tr, |
c7078de1 IM |
3410 | .read = tracing_cpumask_read, |
3411 | .write = tracing_cpumask_write, | |
ccfe9e42 | 3412 | .release = tracing_release_generic_tr, |
b444786f | 3413 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
3414 | }; |
3415 | ||
fdb372ed | 3416 | static int tracing_trace_options_show(struct seq_file *m, void *v) |
bc0c38d1 | 3417 | { |
d8e83d26 | 3418 | struct tracer_opt *trace_opts; |
2b6080f2 | 3419 | struct trace_array *tr = m->private; |
d8e83d26 | 3420 | u32 tracer_flags; |
d8e83d26 | 3421 | int i; |
adf9f195 | 3422 | |
d8e83d26 | 3423 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
3424 | tracer_flags = tr->current_trace->flags->val; |
3425 | trace_opts = tr->current_trace->flags->opts; | |
d8e83d26 | 3426 | |
bc0c38d1 SR |
3427 | for (i = 0; trace_options[i]; i++) { |
3428 | if (trace_flags & (1 << i)) | |
fdb372ed | 3429 | seq_printf(m, "%s\n", trace_options[i]); |
bc0c38d1 | 3430 | else |
fdb372ed | 3431 | seq_printf(m, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
3432 | } |
3433 | ||
adf9f195 FW |
3434 | for (i = 0; trace_opts[i].name; i++) { |
3435 | if (tracer_flags & trace_opts[i].bit) | |
fdb372ed | 3436 | seq_printf(m, "%s\n", trace_opts[i].name); |
adf9f195 | 3437 | else |
fdb372ed | 3438 | seq_printf(m, "no%s\n", trace_opts[i].name); |
adf9f195 | 3439 | } |
d8e83d26 | 3440 | mutex_unlock(&trace_types_lock); |
adf9f195 | 3441 | |
fdb372ed | 3442 | return 0; |
bc0c38d1 | 3443 | } |
bc0c38d1 | 3444 | |
8c1a49ae | 3445 | static int __set_tracer_option(struct trace_array *tr, |
8d18eaaf LZ |
3446 | struct tracer_flags *tracer_flags, |
3447 | struct tracer_opt *opts, int neg) | |
3448 | { | |
8c1a49ae | 3449 | struct tracer *trace = tr->current_trace; |
8d18eaaf | 3450 | int ret; |
bc0c38d1 | 3451 | |
8c1a49ae | 3452 | ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg); |
8d18eaaf LZ |
3453 | if (ret) |
3454 | return ret; | |
3455 | ||
3456 | if (neg) | |
3457 | tracer_flags->val &= ~opts->bit; | |
3458 | else | |
3459 | tracer_flags->val |= opts->bit; | |
3460 | return 0; | |
bc0c38d1 SR |
3461 | } |
3462 | ||
adf9f195 | 3463 | /* Try to assign a tracer specific option */ |
8c1a49ae | 3464 | static int set_tracer_option(struct trace_array *tr, char *cmp, int neg) |
adf9f195 | 3465 | { |
8c1a49ae | 3466 | struct tracer *trace = tr->current_trace; |
7770841e | 3467 | struct tracer_flags *tracer_flags = trace->flags; |
adf9f195 | 3468 | struct tracer_opt *opts = NULL; |
8d18eaaf | 3469 | int i; |
adf9f195 | 3470 | |
7770841e Z |
3471 | for (i = 0; tracer_flags->opts[i].name; i++) { |
3472 | opts = &tracer_flags->opts[i]; | |
adf9f195 | 3473 | |
8d18eaaf | 3474 | if (strcmp(cmp, opts->name) == 0) |
8c1a49ae | 3475 | return __set_tracer_option(tr, trace->flags, opts, neg); |
adf9f195 | 3476 | } |
adf9f195 | 3477 | |
8d18eaaf | 3478 | return -EINVAL; |
adf9f195 FW |
3479 | } |
3480 | ||
613f04a0 SRRH |
3481 | /* Some tracers require overwrite to stay enabled */ |
3482 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) | |
3483 | { | |
3484 | if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) | |
3485 | return -1; | |
3486 | ||
3487 | return 0; | |
3488 | } | |
3489 | ||
2b6080f2 | 3490 | int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) |
af4617bd SR |
3491 | { |
3492 | /* do nothing if flag is already set */ | |
3493 | if (!!(trace_flags & mask) == !!enabled) | |
613f04a0 SRRH |
3494 | return 0; |
3495 | ||
3496 | /* Give the tracer a chance to approve the change */ | |
2b6080f2 | 3497 | if (tr->current_trace->flag_changed) |
bf6065b5 | 3498 | if (tr->current_trace->flag_changed(tr, mask, !!enabled)) |
613f04a0 | 3499 | return -EINVAL; |
af4617bd SR |
3500 | |
3501 | if (enabled) | |
3502 | trace_flags |= mask; | |
3503 | else | |
3504 | trace_flags &= ~mask; | |
e870e9a1 LZ |
3505 | |
3506 | if (mask == TRACE_ITER_RECORD_CMD) | |
3507 | trace_event_enable_cmd_record(enabled); | |
750912fa | 3508 | |
80902822 | 3509 | if (mask == TRACE_ITER_OVERWRITE) { |
12883efb | 3510 | ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); |
80902822 | 3511 | #ifdef CONFIG_TRACER_MAX_TRACE |
12883efb | 3512 | ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled); |
80902822 SRRH |
3513 | #endif |
3514 | } | |
81698831 SR |
3515 | |
3516 | if (mask == TRACE_ITER_PRINTK) | |
3517 | trace_printk_start_stop_comm(enabled); | |
613f04a0 SRRH |
3518 | |
3519 | return 0; | |
af4617bd SR |
3520 | } |
3521 | ||
2b6080f2 | 3522 | static int trace_set_options(struct trace_array *tr, char *option) |
bc0c38d1 | 3523 | { |
8d18eaaf | 3524 | char *cmp; |
bc0c38d1 | 3525 | int neg = 0; |
613f04a0 | 3526 | int ret = -ENODEV; |
bc0c38d1 SR |
3527 | int i; |
3528 | ||
7bcfaf54 | 3529 | cmp = strstrip(option); |
bc0c38d1 | 3530 | |
8d18eaaf | 3531 | if (strncmp(cmp, "no", 2) == 0) { |
bc0c38d1 SR |
3532 | neg = 1; |
3533 | cmp += 2; | |
3534 | } | |
3535 | ||
69d34da2 SRRH |
3536 | mutex_lock(&trace_types_lock); |
3537 | ||
bc0c38d1 | 3538 | for (i = 0; trace_options[i]; i++) { |
8d18eaaf | 3539 | if (strcmp(cmp, trace_options[i]) == 0) { |
2b6080f2 | 3540 | ret = set_tracer_flag(tr, 1 << i, !neg); |
bc0c38d1 SR |
3541 | break; |
3542 | } | |
3543 | } | |
adf9f195 FW |
3544 | |
3545 | /* If no option could be set, test the specific tracer options */ | |
69d34da2 | 3546 | if (!trace_options[i]) |
8c1a49ae | 3547 | ret = set_tracer_option(tr, cmp, neg); |
69d34da2 SRRH |
3548 | |
3549 | mutex_unlock(&trace_types_lock); | |
bc0c38d1 | 3550 | |
7bcfaf54 SR |
3551 | return ret; |
3552 | } | |
3553 | ||
3554 | static ssize_t | |
3555 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, | |
3556 | size_t cnt, loff_t *ppos) | |
3557 | { | |
2b6080f2 SR |
3558 | struct seq_file *m = filp->private_data; |
3559 | struct trace_array *tr = m->private; | |
7bcfaf54 | 3560 | char buf[64]; |
613f04a0 | 3561 | int ret; |
7bcfaf54 SR |
3562 | |
3563 | if (cnt >= sizeof(buf)) | |
3564 | return -EINVAL; | |
3565 | ||
3566 | if (copy_from_user(&buf, ubuf, cnt)) | |
3567 | return -EFAULT; | |
3568 | ||
a8dd2176 SR |
3569 | buf[cnt] = 0; |
3570 | ||
2b6080f2 | 3571 | ret = trace_set_options(tr, buf); |
613f04a0 SRRH |
3572 | if (ret < 0) |
3573 | return ret; | |
7bcfaf54 | 3574 | |
cf8517cf | 3575 | *ppos += cnt; |
bc0c38d1 SR |
3576 | |
3577 | return cnt; | |
3578 | } | |
3579 | ||
fdb372ed LZ |
3580 | static int tracing_trace_options_open(struct inode *inode, struct file *file) |
3581 | { | |
7b85af63 | 3582 | struct trace_array *tr = inode->i_private; |
f77d09a3 | 3583 | int ret; |
7b85af63 | 3584 | |
fdb372ed LZ |
3585 | if (tracing_disabled) |
3586 | return -ENODEV; | |
2b6080f2 | 3587 | |
7b85af63 SRRH |
3588 | if (trace_array_get(tr) < 0) |
3589 | return -ENODEV; | |
3590 | ||
f77d09a3 AL |
3591 | ret = single_open(file, tracing_trace_options_show, inode->i_private); |
3592 | if (ret < 0) | |
3593 | trace_array_put(tr); | |
3594 | ||
3595 | return ret; | |
fdb372ed LZ |
3596 | } |
3597 | ||
5e2336a0 | 3598 | static const struct file_operations tracing_iter_fops = { |
fdb372ed LZ |
3599 | .open = tracing_trace_options_open, |
3600 | .read = seq_read, | |
3601 | .llseek = seq_lseek, | |
7b85af63 | 3602 | .release = tracing_single_release_tr, |
ee6bce52 | 3603 | .write = tracing_trace_options_write, |
bc0c38d1 SR |
3604 | }; |
3605 | ||
7bd2f24c IM |
3606 | static const char readme_msg[] = |
3607 | "tracing mini-HOWTO:\n\n" | |
22f45649 SRRH |
3608 | "# echo 0 > tracing_on : quick way to disable tracing\n" |
3609 | "# echo 1 > tracing_on : quick way to re-enable tracing\n\n" | |
3610 | " Important files:\n" | |
3611 | " trace\t\t\t- The static contents of the buffer\n" | |
3612 | "\t\t\t To clear the buffer write into this file: echo > trace\n" | |
3613 | " trace_pipe\t\t- A consuming read to see the contents of the buffer\n" | |
3614 | " current_tracer\t- function and latency tracers\n" | |
3615 | " available_tracers\t- list of configured tracers for current_tracer\n" | |
3616 | " buffer_size_kb\t- view and modify size of per cpu buffer\n" | |
3617 | " buffer_total_size_kb - view total size of all cpu buffers\n\n" | |
3618 | " trace_clock\t\t-change the clock used to order events\n" | |
3619 | " local: Per cpu clock but may not be synced across CPUs\n" | |
3620 | " global: Synced across CPUs but slows tracing down.\n" | |
3621 | " counter: Not a clock, but just an increment\n" | |
3622 | " uptime: Jiffy counter from time of boot\n" | |
3623 | " perf: Same clock that perf events use\n" | |
3624 | #ifdef CONFIG_X86_64 | |
3625 | " x86-tsc: TSC cycle counter\n" | |
3626 | #endif | |
3627 | "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" | |
3628 | " tracing_cpumask\t- Limit which CPUs to trace\n" | |
3629 | " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" | |
3630 | "\t\t\t Remove sub-buffer with rmdir\n" | |
3631 | " trace_options\t\t- Set format or modify how tracing happens\n" | |
71485c45 SRRH |
3632 | "\t\t\t Disable an option by adding a suffix 'no' to the\n" |
3633 | "\t\t\t option name\n" | |
939c7a4f | 3634 | " saved_cmdlines_size\t- echo command number in here to store comm-pid list\n" |
22f45649 SRRH |
3635 | #ifdef CONFIG_DYNAMIC_FTRACE |
3636 | "\n available_filter_functions - list of functions that can be filtered on\n" | |
71485c45 SRRH |
3637 | " set_ftrace_filter\t- echo function name in here to only trace these\n" |
3638 | "\t\t\t functions\n" | |
3639 | "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" | |
3640 | "\t modules: Can select a group via module\n" | |
3641 | "\t Format: :mod:<module-name>\n" | |
3642 | "\t example: echo :mod:ext3 > set_ftrace_filter\n" | |
3643 | "\t triggers: a command to perform when function is hit\n" | |
3644 | "\t Format: <function>:<trigger>[:count]\n" | |
3645 | "\t trigger: traceon, traceoff\n" | |
3646 | "\t\t enable_event:<system>:<event>\n" | |
3647 | "\t\t disable_event:<system>:<event>\n" | |
22f45649 | 3648 | #ifdef CONFIG_STACKTRACE |
71485c45 | 3649 | "\t\t stacktrace\n" |
22f45649 SRRH |
3650 | #endif |
3651 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 | 3652 | "\t\t snapshot\n" |
22f45649 | 3653 | #endif |
17a280ea SRRH |
3654 | "\t\t dump\n" |
3655 | "\t\t cpudump\n" | |
71485c45 SRRH |
3656 | "\t example: echo do_fault:traceoff > set_ftrace_filter\n" |
3657 | "\t echo do_trap:traceoff:3 > set_ftrace_filter\n" | |
3658 | "\t The first one will disable tracing every time do_fault is hit\n" | |
3659 | "\t The second will disable tracing at most 3 times when do_trap is hit\n" | |
3660 | "\t The first time do trap is hit and it disables tracing, the\n" | |
3661 | "\t counter will decrement to 2. If tracing is already disabled,\n" | |
3662 | "\t the counter will not decrement. It only decrements when the\n" | |
3663 | "\t trigger did work\n" | |
3664 | "\t To remove trigger without count:\n" | |
3665 | "\t echo '!<function>:<trigger> > set_ftrace_filter\n" | |
3666 | "\t To remove trigger with a count:\n" | |
3667 | "\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n" | |
22f45649 | 3668 | " set_ftrace_notrace\t- echo function name in here to never trace.\n" |
71485c45 SRRH |
3669 | "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" |
3670 | "\t modules: Can select a group via module command :mod:\n" | |
3671 | "\t Does not accept triggers\n" | |
22f45649 SRRH |
3672 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
3673 | #ifdef CONFIG_FUNCTION_TRACER | |
71485c45 SRRH |
3674 | " set_ftrace_pid\t- Write pid(s) to only function trace those pids\n" |
3675 | "\t\t (function)\n" | |
22f45649 SRRH |
3676 | #endif |
3677 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
3678 | " set_graph_function\t- Trace the nested calls of a function (function_graph)\n" | |
d048a8c7 | 3679 | " set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n" |
22f45649 SRRH |
3680 | " max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n" |
3681 | #endif | |
3682 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 SRRH |
3683 | "\n snapshot\t\t- Like 'trace' but shows the content of the static\n" |
3684 | "\t\t\t snapshot buffer. Read the contents for more\n" | |
3685 | "\t\t\t information\n" | |
22f45649 | 3686 | #endif |
991821c8 | 3687 | #ifdef CONFIG_STACK_TRACER |
22f45649 SRRH |
3688 | " stack_trace\t\t- Shows the max stack trace when active\n" |
3689 | " stack_max_size\t- Shows current max stack size that was traced\n" | |
71485c45 SRRH |
3690 | "\t\t\t Write into this file to reset the max size (trigger a\n" |
3691 | "\t\t\t new trace)\n" | |
22f45649 | 3692 | #ifdef CONFIG_DYNAMIC_FTRACE |
71485c45 SRRH |
3693 | " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n" |
3694 | "\t\t\t traces\n" | |
22f45649 | 3695 | #endif |
991821c8 | 3696 | #endif /* CONFIG_STACK_TRACER */ |
26f25564 TZ |
3697 | " events/\t\t- Directory containing all trace event subsystems:\n" |
3698 | " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" | |
3699 | " events/<system>/\t- Directory containing all trace events for <system>:\n" | |
71485c45 SRRH |
3700 | " enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n" |
3701 | "\t\t\t events\n" | |
26f25564 | 3702 | " filter\t\t- If set, only events passing filter are traced\n" |
71485c45 SRRH |
3703 | " events/<system>/<event>/\t- Directory containing control files for\n" |
3704 | "\t\t\t <event>:\n" | |
26f25564 TZ |
3705 | " enable\t\t- Write 0/1 to enable/disable tracing of <event>\n" |
3706 | " filter\t\t- If set, only events passing filter are traced\n" | |
3707 | " trigger\t\t- If set, a command to perform when event is hit\n" | |
71485c45 SRRH |
3708 | "\t Format: <trigger>[:count][if <filter>]\n" |
3709 | "\t trigger: traceon, traceoff\n" | |
3710 | "\t enable_event:<system>:<event>\n" | |
3711 | "\t disable_event:<system>:<event>\n" | |
26f25564 | 3712 | #ifdef CONFIG_STACKTRACE |
71485c45 | 3713 | "\t\t stacktrace\n" |
26f25564 TZ |
3714 | #endif |
3715 | #ifdef CONFIG_TRACER_SNAPSHOT | |
71485c45 | 3716 | "\t\t snapshot\n" |
26f25564 | 3717 | #endif |
71485c45 SRRH |
3718 | "\t example: echo traceoff > events/block/block_unplug/trigger\n" |
3719 | "\t echo traceoff:3 > events/block/block_unplug/trigger\n" | |
3720 | "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n" | |
3721 | "\t events/block/block_unplug/trigger\n" | |
3722 | "\t The first disables tracing every time block_unplug is hit.\n" | |
3723 | "\t The second disables tracing the first 3 times block_unplug is hit.\n" | |
3724 | "\t The third enables the kmalloc event the first 3 times block_unplug\n" | |
3725 | "\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n" | |
3726 | "\t Like function triggers, the counter is only decremented if it\n" | |
3727 | "\t enabled or disabled tracing.\n" | |
3728 | "\t To remove a trigger without a count:\n" | |
3729 | "\t echo '!<trigger> > <system>/<event>/trigger\n" | |
3730 | "\t To remove a trigger with a count:\n" | |
3731 | "\t echo '!<trigger>:0 > <system>/<event>/trigger\n" | |
3732 | "\t Filters can be ignored when removing a trigger.\n" | |
7bd2f24c IM |
3733 | ; |
3734 | ||
3735 | static ssize_t | |
3736 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
3737 | size_t cnt, loff_t *ppos) | |
3738 | { | |
3739 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
3740 | readme_msg, strlen(readme_msg)); | |
3741 | } | |
3742 | ||
5e2336a0 | 3743 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
3744 | .open = tracing_open_generic, |
3745 | .read = tracing_readme_read, | |
b444786f | 3746 | .llseek = generic_file_llseek, |
7bd2f24c IM |
3747 | }; |
3748 | ||
42584c81 YY |
3749 | static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos) |
3750 | { | |
3751 | unsigned int *ptr = v; | |
69abe6a5 | 3752 | |
42584c81 YY |
3753 | if (*pos || m->count) |
3754 | ptr++; | |
69abe6a5 | 3755 | |
42584c81 | 3756 | (*pos)++; |
69abe6a5 | 3757 | |
939c7a4f YY |
3758 | for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num]; |
3759 | ptr++) { | |
42584c81 YY |
3760 | if (*ptr == -1 || *ptr == NO_CMDLINE_MAP) |
3761 | continue; | |
69abe6a5 | 3762 | |
42584c81 YY |
3763 | return ptr; |
3764 | } | |
69abe6a5 | 3765 | |
42584c81 YY |
3766 | return NULL; |
3767 | } | |
3768 | ||
3769 | static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos) | |
3770 | { | |
3771 | void *v; | |
3772 | loff_t l = 0; | |
69abe6a5 | 3773 | |
4c27e756 SRRH |
3774 | preempt_disable(); |
3775 | arch_spin_lock(&trace_cmdline_lock); | |
3776 | ||
939c7a4f | 3777 | v = &savedcmd->map_cmdline_to_pid[0]; |
42584c81 YY |
3778 | while (l <= *pos) { |
3779 | v = saved_cmdlines_next(m, v, &l); | |
3780 | if (!v) | |
3781 | return NULL; | |
69abe6a5 AP |
3782 | } |
3783 | ||
42584c81 YY |
3784 | return v; |
3785 | } | |
3786 | ||
3787 | static void saved_cmdlines_stop(struct seq_file *m, void *v) | |
3788 | { | |
4c27e756 SRRH |
3789 | arch_spin_unlock(&trace_cmdline_lock); |
3790 | preempt_enable(); | |
42584c81 | 3791 | } |
69abe6a5 | 3792 | |
42584c81 YY |
3793 | static int saved_cmdlines_show(struct seq_file *m, void *v) |
3794 | { | |
3795 | char buf[TASK_COMM_LEN]; | |
3796 | unsigned int *pid = v; | |
69abe6a5 | 3797 | |
4c27e756 | 3798 | __trace_find_cmdline(*pid, buf); |
42584c81 YY |
3799 | seq_printf(m, "%d %s\n", *pid, buf); |
3800 | return 0; | |
3801 | } | |
3802 | ||
3803 | static const struct seq_operations tracing_saved_cmdlines_seq_ops = { | |
3804 | .start = saved_cmdlines_start, | |
3805 | .next = saved_cmdlines_next, | |
3806 | .stop = saved_cmdlines_stop, | |
3807 | .show = saved_cmdlines_show, | |
3808 | }; | |
3809 | ||
3810 | static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp) | |
3811 | { | |
3812 | if (tracing_disabled) | |
3813 | return -ENODEV; | |
3814 | ||
3815 | return seq_open(filp, &tracing_saved_cmdlines_seq_ops); | |
69abe6a5 AP |
3816 | } |
3817 | ||
3818 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
42584c81 YY |
3819 | .open = tracing_saved_cmdlines_open, |
3820 | .read = seq_read, | |
3821 | .llseek = seq_lseek, | |
3822 | .release = seq_release, | |
69abe6a5 AP |
3823 | }; |
3824 | ||
939c7a4f YY |
3825 | static ssize_t |
3826 | tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf, | |
3827 | size_t cnt, loff_t *ppos) | |
3828 | { | |
3829 | char buf[64]; | |
3830 | int r; | |
3831 | ||
3832 | arch_spin_lock(&trace_cmdline_lock); | |
a6af8fbf | 3833 | r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num); |
939c7a4f YY |
3834 | arch_spin_unlock(&trace_cmdline_lock); |
3835 | ||
3836 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3837 | } | |
3838 | ||
3839 | static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s) | |
3840 | { | |
3841 | kfree(s->saved_cmdlines); | |
3842 | kfree(s->map_cmdline_to_pid); | |
3843 | kfree(s); | |
3844 | } | |
3845 | ||
3846 | static int tracing_resize_saved_cmdlines(unsigned int val) | |
3847 | { | |
3848 | struct saved_cmdlines_buffer *s, *savedcmd_temp; | |
3849 | ||
a6af8fbf | 3850 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
939c7a4f YY |
3851 | if (!s) |
3852 | return -ENOMEM; | |
3853 | ||
3854 | if (allocate_cmdlines_buffer(val, s) < 0) { | |
3855 | kfree(s); | |
3856 | return -ENOMEM; | |
3857 | } | |
3858 | ||
3859 | arch_spin_lock(&trace_cmdline_lock); | |
3860 | savedcmd_temp = savedcmd; | |
3861 | savedcmd = s; | |
3862 | arch_spin_unlock(&trace_cmdline_lock); | |
3863 | free_saved_cmdlines_buffer(savedcmd_temp); | |
3864 | ||
3865 | return 0; | |
3866 | } | |
3867 | ||
3868 | static ssize_t | |
3869 | tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf, | |
3870 | size_t cnt, loff_t *ppos) | |
3871 | { | |
3872 | unsigned long val; | |
3873 | int ret; | |
3874 | ||
3875 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
3876 | if (ret) | |
3877 | return ret; | |
3878 | ||
3879 | /* must have at least 1 entry or less than PID_MAX_DEFAULT */ | |
3880 | if (!val || val > PID_MAX_DEFAULT) | |
3881 | return -EINVAL; | |
3882 | ||
3883 | ret = tracing_resize_saved_cmdlines((unsigned int)val); | |
3884 | if (ret < 0) | |
3885 | return ret; | |
3886 | ||
3887 | *ppos += cnt; | |
3888 | ||
3889 | return cnt; | |
3890 | } | |
3891 | ||
3892 | static const struct file_operations tracing_saved_cmdlines_size_fops = { | |
3893 | .open = tracing_open_generic, | |
3894 | .read = tracing_saved_cmdlines_size_read, | |
3895 | .write = tracing_saved_cmdlines_size_write, | |
3896 | }; | |
3897 | ||
bc0c38d1 SR |
3898 | static ssize_t |
3899 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
3900 | size_t cnt, loff_t *ppos) | |
3901 | { | |
2b6080f2 | 3902 | struct trace_array *tr = filp->private_data; |
ee6c2c1b | 3903 | char buf[MAX_TRACER_SIZE+2]; |
bc0c38d1 SR |
3904 | int r; |
3905 | ||
3906 | mutex_lock(&trace_types_lock); | |
2b6080f2 | 3907 | r = sprintf(buf, "%s\n", tr->current_trace->name); |
bc0c38d1 SR |
3908 | mutex_unlock(&trace_types_lock); |
3909 | ||
4bf39a94 | 3910 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
3911 | } |
3912 | ||
b6f11df2 ACM |
3913 | int tracer_init(struct tracer *t, struct trace_array *tr) |
3914 | { | |
12883efb | 3915 | tracing_reset_online_cpus(&tr->trace_buffer); |
b6f11df2 ACM |
3916 | return t->init(tr); |
3917 | } | |
3918 | ||
12883efb | 3919 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val) |
438ced17 VN |
3920 | { |
3921 | int cpu; | |
737223fb | 3922 | |
438ced17 | 3923 | for_each_tracing_cpu(cpu) |
12883efb | 3924 | per_cpu_ptr(buf->data, cpu)->entries = val; |
438ced17 VN |
3925 | } |
3926 | ||
12883efb | 3927 | #ifdef CONFIG_TRACER_MAX_TRACE |
d60da506 | 3928 | /* resize @tr's buffer to the size of @size_tr's entries */ |
12883efb SRRH |
3929 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, |
3930 | struct trace_buffer *size_buf, int cpu_id) | |
d60da506 HT |
3931 | { |
3932 | int cpu, ret = 0; | |
3933 | ||
3934 | if (cpu_id == RING_BUFFER_ALL_CPUS) { | |
3935 | for_each_tracing_cpu(cpu) { | |
12883efb SRRH |
3936 | ret = ring_buffer_resize(trace_buf->buffer, |
3937 | per_cpu_ptr(size_buf->data, cpu)->entries, cpu); | |
d60da506 HT |
3938 | if (ret < 0) |
3939 | break; | |
12883efb SRRH |
3940 | per_cpu_ptr(trace_buf->data, cpu)->entries = |
3941 | per_cpu_ptr(size_buf->data, cpu)->entries; | |
d60da506 HT |
3942 | } |
3943 | } else { | |
12883efb SRRH |
3944 | ret = ring_buffer_resize(trace_buf->buffer, |
3945 | per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); | |
d60da506 | 3946 | if (ret == 0) |
12883efb SRRH |
3947 | per_cpu_ptr(trace_buf->data, cpu_id)->entries = |
3948 | per_cpu_ptr(size_buf->data, cpu_id)->entries; | |
d60da506 HT |
3949 | } |
3950 | ||
3951 | return ret; | |
3952 | } | |
12883efb | 3953 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
d60da506 | 3954 | |
2b6080f2 SR |
3955 | static int __tracing_resize_ring_buffer(struct trace_array *tr, |
3956 | unsigned long size, int cpu) | |
73c5162a SR |
3957 | { |
3958 | int ret; | |
3959 | ||
3960 | /* | |
3961 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
3962 | * we use the size that was given, and we can forget about |
3963 | * expanding it later. | |
73c5162a | 3964 | */ |
55034cd6 | 3965 | ring_buffer_expanded = true; |
73c5162a | 3966 | |
b382ede6 | 3967 | /* May be called before buffers are initialized */ |
12883efb | 3968 | if (!tr->trace_buffer.buffer) |
b382ede6 SR |
3969 | return 0; |
3970 | ||
12883efb | 3971 | ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu); |
73c5162a SR |
3972 | if (ret < 0) |
3973 | return ret; | |
3974 | ||
12883efb | 3975 | #ifdef CONFIG_TRACER_MAX_TRACE |
2b6080f2 SR |
3976 | if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || |
3977 | !tr->current_trace->use_max_tr) | |
ef710e10 KM |
3978 | goto out; |
3979 | ||
12883efb | 3980 | ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); |
73c5162a | 3981 | if (ret < 0) { |
12883efb SRRH |
3982 | int r = resize_buffer_duplicate_size(&tr->trace_buffer, |
3983 | &tr->trace_buffer, cpu); | |
73c5162a | 3984 | if (r < 0) { |
a123c52b SR |
3985 | /* |
3986 | * AARGH! We are left with different | |
3987 | * size max buffer!!!! | |
3988 | * The max buffer is our "snapshot" buffer. | |
3989 | * When a tracer needs a snapshot (one of the | |
3990 | * latency tracers), it swaps the max buffer | |
3991 | * with the saved snap shot. We succeeded to | |
3992 | * update the size of the main buffer, but failed to | |
3993 | * update the size of the max buffer. But when we tried | |
3994 | * to reset the main buffer to the original size, we | |
3995 | * failed there too. This is very unlikely to | |
3996 | * happen, but if it does, warn and kill all | |
3997 | * tracing. | |
3998 | */ | |
73c5162a SR |
3999 | WARN_ON(1); |
4000 | tracing_disabled = 1; | |
4001 | } | |
4002 | return ret; | |
4003 | } | |
4004 | ||
438ced17 | 4005 | if (cpu == RING_BUFFER_ALL_CPUS) |
12883efb | 4006 | set_buffer_entries(&tr->max_buffer, size); |
438ced17 | 4007 | else |
12883efb | 4008 | per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size; |
438ced17 | 4009 | |
ef710e10 | 4010 | out: |
12883efb SRRH |
4011 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
4012 | ||
438ced17 | 4013 | if (cpu == RING_BUFFER_ALL_CPUS) |
12883efb | 4014 | set_buffer_entries(&tr->trace_buffer, size); |
438ced17 | 4015 | else |
12883efb | 4016 | per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size; |
73c5162a SR |
4017 | |
4018 | return ret; | |
4019 | } | |
4020 | ||
2b6080f2 SR |
4021 | static ssize_t tracing_resize_ring_buffer(struct trace_array *tr, |
4022 | unsigned long size, int cpu_id) | |
4f271a2a | 4023 | { |
83f40318 | 4024 | int ret = size; |
4f271a2a VN |
4025 | |
4026 | mutex_lock(&trace_types_lock); | |
4027 | ||
438ced17 VN |
4028 | if (cpu_id != RING_BUFFER_ALL_CPUS) { |
4029 | /* make sure, this cpu is enabled in the mask */ | |
4030 | if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { | |
4031 | ret = -EINVAL; | |
4032 | goto out; | |
4033 | } | |
4034 | } | |
4f271a2a | 4035 | |
2b6080f2 | 4036 | ret = __tracing_resize_ring_buffer(tr, size, cpu_id); |
4f271a2a VN |
4037 | if (ret < 0) |
4038 | ret = -ENOMEM; | |
4039 | ||
438ced17 | 4040 | out: |
4f271a2a VN |
4041 | mutex_unlock(&trace_types_lock); |
4042 | ||
4043 | return ret; | |
4044 | } | |
4045 | ||
ef710e10 | 4046 | |
1852fcce SR |
4047 | /** |
4048 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
4049 | * | |
4050 | * To save on memory when the tracing is never used on a system with it | |
4051 | * configured in. The ring buffers are set to a minimum size. But once | |
4052 | * a user starts to use the tracing facility, then they need to grow | |
4053 | * to their default size. | |
4054 | * | |
4055 | * This function is to be called when a tracer is about to be used. | |
4056 | */ | |
4057 | int tracing_update_buffers(void) | |
4058 | { | |
4059 | int ret = 0; | |
4060 | ||
1027fcb2 | 4061 | mutex_lock(&trace_types_lock); |
1852fcce | 4062 | if (!ring_buffer_expanded) |
2b6080f2 | 4063 | ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, |
438ced17 | 4064 | RING_BUFFER_ALL_CPUS); |
1027fcb2 | 4065 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
4066 | |
4067 | return ret; | |
4068 | } | |
4069 | ||
577b785f SR |
4070 | struct trace_option_dentry; |
4071 | ||
4072 | static struct trace_option_dentry * | |
2b6080f2 | 4073 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer); |
577b785f SR |
4074 | |
4075 | static void | |
4076 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
4077 | ||
6b450d25 SRRH |
4078 | /* |
4079 | * Used to clear out the tracer before deletion of an instance. | |
4080 | * Must have trace_types_lock held. | |
4081 | */ | |
4082 | static void tracing_set_nop(struct trace_array *tr) | |
4083 | { | |
4084 | if (tr->current_trace == &nop_trace) | |
4085 | return; | |
4086 | ||
50512ab5 | 4087 | tr->current_trace->enabled--; |
6b450d25 SRRH |
4088 | |
4089 | if (tr->current_trace->reset) | |
4090 | tr->current_trace->reset(tr); | |
4091 | ||
4092 | tr->current_trace = &nop_trace; | |
4093 | } | |
4094 | ||
607e2ea1 | 4095 | static int tracing_set_tracer(struct trace_array *tr, const char *buf) |
bc0c38d1 | 4096 | { |
577b785f | 4097 | static struct trace_option_dentry *topts; |
bc0c38d1 | 4098 | struct tracer *t; |
12883efb | 4099 | #ifdef CONFIG_TRACER_MAX_TRACE |
34600f0e | 4100 | bool had_max_tr; |
12883efb | 4101 | #endif |
d9e54076 | 4102 | int ret = 0; |
bc0c38d1 | 4103 | |
1027fcb2 SR |
4104 | mutex_lock(&trace_types_lock); |
4105 | ||
73c5162a | 4106 | if (!ring_buffer_expanded) { |
2b6080f2 | 4107 | ret = __tracing_resize_ring_buffer(tr, trace_buf_size, |
438ced17 | 4108 | RING_BUFFER_ALL_CPUS); |
73c5162a | 4109 | if (ret < 0) |
59f586db | 4110 | goto out; |
73c5162a SR |
4111 | ret = 0; |
4112 | } | |
4113 | ||
bc0c38d1 SR |
4114 | for (t = trace_types; t; t = t->next) { |
4115 | if (strcmp(t->name, buf) == 0) | |
4116 | break; | |
4117 | } | |
c2931e05 FW |
4118 | if (!t) { |
4119 | ret = -EINVAL; | |
4120 | goto out; | |
4121 | } | |
2b6080f2 | 4122 | if (t == tr->current_trace) |
bc0c38d1 SR |
4123 | goto out; |
4124 | ||
607e2ea1 SRRH |
4125 | /* Some tracers are only allowed for the top level buffer */ |
4126 | if (!trace_ok_for_array(t, tr)) { | |
4127 | ret = -EINVAL; | |
4128 | goto out; | |
4129 | } | |
4130 | ||
9f029e83 | 4131 | trace_branch_disable(); |
613f04a0 | 4132 | |
50512ab5 | 4133 | tr->current_trace->enabled--; |
613f04a0 | 4134 | |
2b6080f2 SR |
4135 | if (tr->current_trace->reset) |
4136 | tr->current_trace->reset(tr); | |
34600f0e | 4137 | |
12883efb | 4138 | /* Current trace needs to be nop_trace before synchronize_sched */ |
2b6080f2 | 4139 | tr->current_trace = &nop_trace; |
34600f0e | 4140 | |
45ad21ca SRRH |
4141 | #ifdef CONFIG_TRACER_MAX_TRACE |
4142 | had_max_tr = tr->allocated_snapshot; | |
34600f0e SR |
4143 | |
4144 | if (had_max_tr && !t->use_max_tr) { | |
4145 | /* | |
4146 | * We need to make sure that the update_max_tr sees that | |
4147 | * current_trace changed to nop_trace to keep it from | |
4148 | * swapping the buffers after we resize it. | |
4149 | * The update_max_tr is called from interrupts disabled | |
4150 | * so a synchronized_sched() is sufficient. | |
4151 | */ | |
4152 | synchronize_sched(); | |
3209cff4 | 4153 | free_snapshot(tr); |
ef710e10 | 4154 | } |
12883efb | 4155 | #endif |
f1b21c9a SRRH |
4156 | /* Currently, only the top instance has options */ |
4157 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
4158 | destroy_trace_option_files(topts); | |
4159 | topts = create_trace_option_files(tr, t); | |
4160 | } | |
12883efb SRRH |
4161 | |
4162 | #ifdef CONFIG_TRACER_MAX_TRACE | |
34600f0e | 4163 | if (t->use_max_tr && !had_max_tr) { |
3209cff4 | 4164 | ret = alloc_snapshot(tr); |
d60da506 HT |
4165 | if (ret < 0) |
4166 | goto out; | |
ef710e10 | 4167 | } |
12883efb | 4168 | #endif |
577b785f | 4169 | |
1c80025a | 4170 | if (t->init) { |
b6f11df2 | 4171 | ret = tracer_init(t, tr); |
1c80025a FW |
4172 | if (ret) |
4173 | goto out; | |
4174 | } | |
bc0c38d1 | 4175 | |
2b6080f2 | 4176 | tr->current_trace = t; |
50512ab5 | 4177 | tr->current_trace->enabled++; |
9f029e83 | 4178 | trace_branch_enable(tr); |
bc0c38d1 SR |
4179 | out: |
4180 | mutex_unlock(&trace_types_lock); | |
4181 | ||
d9e54076 PZ |
4182 | return ret; |
4183 | } | |
4184 | ||
4185 | static ssize_t | |
4186 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
4187 | size_t cnt, loff_t *ppos) | |
4188 | { | |
607e2ea1 | 4189 | struct trace_array *tr = filp->private_data; |
ee6c2c1b | 4190 | char buf[MAX_TRACER_SIZE+1]; |
d9e54076 PZ |
4191 | int i; |
4192 | size_t ret; | |
e6e7a65a FW |
4193 | int err; |
4194 | ||
4195 | ret = cnt; | |
d9e54076 | 4196 | |
ee6c2c1b LZ |
4197 | if (cnt > MAX_TRACER_SIZE) |
4198 | cnt = MAX_TRACER_SIZE; | |
d9e54076 PZ |
4199 | |
4200 | if (copy_from_user(&buf, ubuf, cnt)) | |
4201 | return -EFAULT; | |
4202 | ||
4203 | buf[cnt] = 0; | |
4204 | ||
4205 | /* strip ending whitespace. */ | |
4206 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
4207 | buf[i] = 0; | |
4208 | ||
607e2ea1 | 4209 | err = tracing_set_tracer(tr, buf); |
e6e7a65a FW |
4210 | if (err) |
4211 | return err; | |
d9e54076 | 4212 | |
cf8517cf | 4213 | *ppos += ret; |
bc0c38d1 | 4214 | |
c2931e05 | 4215 | return ret; |
bc0c38d1 SR |
4216 | } |
4217 | ||
4218 | static ssize_t | |
6508fa76 SF |
4219 | tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, |
4220 | size_t cnt, loff_t *ppos) | |
bc0c38d1 | 4221 | { |
bc0c38d1 SR |
4222 | char buf[64]; |
4223 | int r; | |
4224 | ||
cffae437 | 4225 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 4226 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
4227 | if (r > sizeof(buf)) |
4228 | r = sizeof(buf); | |
4bf39a94 | 4229 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
4230 | } |
4231 | ||
4232 | static ssize_t | |
6508fa76 SF |
4233 | tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf, |
4234 | size_t cnt, loff_t *ppos) | |
bc0c38d1 | 4235 | { |
5e39841c | 4236 | unsigned long val; |
c6caeeb1 | 4237 | int ret; |
bc0c38d1 | 4238 | |
22fe9b54 PH |
4239 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4240 | if (ret) | |
c6caeeb1 | 4241 | return ret; |
bc0c38d1 SR |
4242 | |
4243 | *ptr = val * 1000; | |
4244 | ||
4245 | return cnt; | |
4246 | } | |
4247 | ||
6508fa76 SF |
4248 | static ssize_t |
4249 | tracing_thresh_read(struct file *filp, char __user *ubuf, | |
4250 | size_t cnt, loff_t *ppos) | |
4251 | { | |
4252 | return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos); | |
4253 | } | |
4254 | ||
4255 | static ssize_t | |
4256 | tracing_thresh_write(struct file *filp, const char __user *ubuf, | |
4257 | size_t cnt, loff_t *ppos) | |
4258 | { | |
4259 | struct trace_array *tr = filp->private_data; | |
4260 | int ret; | |
4261 | ||
4262 | mutex_lock(&trace_types_lock); | |
4263 | ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos); | |
4264 | if (ret < 0) | |
4265 | goto out; | |
4266 | ||
4267 | if (tr->current_trace->update_thresh) { | |
4268 | ret = tr->current_trace->update_thresh(tr); | |
4269 | if (ret < 0) | |
4270 | goto out; | |
4271 | } | |
4272 | ||
4273 | ret = cnt; | |
4274 | out: | |
4275 | mutex_unlock(&trace_types_lock); | |
4276 | ||
4277 | return ret; | |
4278 | } | |
4279 | ||
4280 | static ssize_t | |
4281 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
4282 | size_t cnt, loff_t *ppos) | |
4283 | { | |
4284 | return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos); | |
4285 | } | |
4286 | ||
4287 | static ssize_t | |
4288 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
4289 | size_t cnt, loff_t *ppos) | |
4290 | { | |
4291 | return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos); | |
4292 | } | |
4293 | ||
b3806b43 SR |
4294 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
4295 | { | |
15544209 | 4296 | struct trace_array *tr = inode->i_private; |
b3806b43 | 4297 | struct trace_iterator *iter; |
b04cc6b1 | 4298 | int ret = 0; |
b3806b43 SR |
4299 | |
4300 | if (tracing_disabled) | |
4301 | return -ENODEV; | |
4302 | ||
7b85af63 SRRH |
4303 | if (trace_array_get(tr) < 0) |
4304 | return -ENODEV; | |
4305 | ||
b04cc6b1 FW |
4306 | mutex_lock(&trace_types_lock); |
4307 | ||
b3806b43 SR |
4308 | /* create a buffer to store the information to pass to userspace */ |
4309 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
4310 | if (!iter) { |
4311 | ret = -ENOMEM; | |
f77d09a3 | 4312 | __trace_array_put(tr); |
b04cc6b1 FW |
4313 | goto out; |
4314 | } | |
b3806b43 | 4315 | |
d7350c3f FW |
4316 | /* |
4317 | * We make a copy of the current tracer to avoid concurrent | |
4318 | * changes on it while we are reading. | |
4319 | */ | |
4320 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
4321 | if (!iter->trace) { | |
4322 | ret = -ENOMEM; | |
4323 | goto fail; | |
4324 | } | |
2b6080f2 | 4325 | *iter->trace = *tr->current_trace; |
d7350c3f | 4326 | |
4462344e | 4327 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 4328 | ret = -ENOMEM; |
d7350c3f | 4329 | goto fail; |
4462344e RR |
4330 | } |
4331 | ||
a309720c | 4332 | /* trace pipe does not show start of buffer */ |
4462344e | 4333 | cpumask_setall(iter->started); |
a309720c | 4334 | |
112f38a7 SR |
4335 | if (trace_flags & TRACE_ITER_LATENCY_FMT) |
4336 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
4337 | ||
8be0709f | 4338 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
58e8eedf | 4339 | if (trace_clocks[tr->clock_id].in_ns) |
8be0709f DS |
4340 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
4341 | ||
15544209 ON |
4342 | iter->tr = tr; |
4343 | iter->trace_buffer = &tr->trace_buffer; | |
4344 | iter->cpu_file = tracing_get_cpu(inode); | |
d7350c3f | 4345 | mutex_init(&iter->mutex); |
b3806b43 SR |
4346 | filp->private_data = iter; |
4347 | ||
107bad8b SR |
4348 | if (iter->trace->pipe_open) |
4349 | iter->trace->pipe_open(iter); | |
107bad8b | 4350 | |
b444786f | 4351 | nonseekable_open(inode, filp); |
b04cc6b1 FW |
4352 | out: |
4353 | mutex_unlock(&trace_types_lock); | |
4354 | return ret; | |
d7350c3f FW |
4355 | |
4356 | fail: | |
4357 | kfree(iter->trace); | |
4358 | kfree(iter); | |
7b85af63 | 4359 | __trace_array_put(tr); |
d7350c3f FW |
4360 | mutex_unlock(&trace_types_lock); |
4361 | return ret; | |
b3806b43 SR |
4362 | } |
4363 | ||
4364 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
4365 | { | |
4366 | struct trace_iterator *iter = file->private_data; | |
15544209 | 4367 | struct trace_array *tr = inode->i_private; |
b3806b43 | 4368 | |
b04cc6b1 FW |
4369 | mutex_lock(&trace_types_lock); |
4370 | ||
29bf4a5e | 4371 | if (iter->trace->pipe_close) |
c521efd1 SR |
4372 | iter->trace->pipe_close(iter); |
4373 | ||
b04cc6b1 FW |
4374 | mutex_unlock(&trace_types_lock); |
4375 | ||
4462344e | 4376 | free_cpumask_var(iter->started); |
d7350c3f FW |
4377 | mutex_destroy(&iter->mutex); |
4378 | kfree(iter->trace); | |
b3806b43 | 4379 | kfree(iter); |
b3806b43 | 4380 | |
7b85af63 SRRH |
4381 | trace_array_put(tr); |
4382 | ||
b3806b43 SR |
4383 | return 0; |
4384 | } | |
4385 | ||
2a2cc8f7 | 4386 | static unsigned int |
cc60cdc9 | 4387 | trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table) |
2a2cc8f7 | 4388 | { |
15693458 SRRH |
4389 | /* Iterators are static, they should be filled or empty */ |
4390 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
4391 | return POLLIN | POLLRDNORM; | |
2a2cc8f7 | 4392 | |
15693458 | 4393 | if (trace_flags & TRACE_ITER_BLOCK) |
2a2cc8f7 SSP |
4394 | /* |
4395 | * Always select as readable when in blocking mode | |
4396 | */ | |
4397 | return POLLIN | POLLRDNORM; | |
15693458 | 4398 | else |
12883efb | 4399 | return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file, |
15693458 | 4400 | filp, poll_table); |
2a2cc8f7 | 4401 | } |
2a2cc8f7 | 4402 | |
cc60cdc9 SR |
4403 | static unsigned int |
4404 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
4405 | { | |
4406 | struct trace_iterator *iter = filp->private_data; | |
4407 | ||
4408 | return trace_poll(iter, filp, poll_table); | |
2a2cc8f7 SSP |
4409 | } |
4410 | ||
ff98781b EGM |
4411 | /* Must be called with trace_types_lock mutex held. */ |
4412 | static int tracing_wait_pipe(struct file *filp) | |
b3806b43 SR |
4413 | { |
4414 | struct trace_iterator *iter = filp->private_data; | |
8b8b3683 | 4415 | int ret; |
b3806b43 | 4416 | |
b3806b43 | 4417 | while (trace_empty(iter)) { |
2dc8f095 | 4418 | |
107bad8b | 4419 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 4420 | return -EAGAIN; |
107bad8b | 4421 | } |
2dc8f095 | 4422 | |
b3806b43 | 4423 | /* |
250bfd3d | 4424 | * We block until we read something and tracing is disabled. |
b3806b43 SR |
4425 | * We still block if tracing is disabled, but we have never |
4426 | * read anything. This allows a user to cat this file, and | |
4427 | * then enable tracing. But after we have read something, | |
4428 | * we give an EOF when tracing is again disabled. | |
4429 | * | |
4430 | * iter->pos will be 0 if we haven't read anything. | |
4431 | */ | |
10246fa3 | 4432 | if (!tracing_is_on() && iter->pos) |
b3806b43 | 4433 | break; |
f4874261 SRRH |
4434 | |
4435 | mutex_unlock(&iter->mutex); | |
4436 | ||
8b8b3683 | 4437 | ret = wait_on_pipe(iter); |
f4874261 SRRH |
4438 | |
4439 | mutex_lock(&iter->mutex); | |
4440 | ||
8b8b3683 SRRH |
4441 | if (ret) |
4442 | return ret; | |
4443 | ||
f4874261 SRRH |
4444 | if (signal_pending(current)) |
4445 | return -EINTR; | |
b3806b43 SR |
4446 | } |
4447 | ||
ff98781b EGM |
4448 | return 1; |
4449 | } | |
4450 | ||
4451 | /* | |
4452 | * Consumer reader. | |
4453 | */ | |
4454 | static ssize_t | |
4455 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
4456 | size_t cnt, loff_t *ppos) | |
4457 | { | |
4458 | struct trace_iterator *iter = filp->private_data; | |
2b6080f2 | 4459 | struct trace_array *tr = iter->tr; |
ff98781b EGM |
4460 | ssize_t sret; |
4461 | ||
4462 | /* return any leftover data */ | |
4463 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
4464 | if (sret != -EBUSY) | |
4465 | return sret; | |
4466 | ||
f9520750 | 4467 | trace_seq_init(&iter->seq); |
ff98781b | 4468 | |
d7350c3f | 4469 | /* copy the tracer to avoid using a global lock all around */ |
ff98781b | 4470 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
4471 | if (unlikely(iter->trace->name != tr->current_trace->name)) |
4472 | *iter->trace = *tr->current_trace; | |
d7350c3f FW |
4473 | mutex_unlock(&trace_types_lock); |
4474 | ||
4475 | /* | |
4476 | * Avoid more than one consumer on a single file descriptor | |
4477 | * This is just a matter of traces coherency, the ring buffer itself | |
4478 | * is protected. | |
4479 | */ | |
4480 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
4481 | if (iter->trace->read) { |
4482 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
4483 | if (sret) | |
4484 | goto out; | |
4485 | } | |
4486 | ||
4487 | waitagain: | |
4488 | sret = tracing_wait_pipe(filp); | |
4489 | if (sret <= 0) | |
4490 | goto out; | |
4491 | ||
b3806b43 | 4492 | /* stop when tracing is finished */ |
ff98781b EGM |
4493 | if (trace_empty(iter)) { |
4494 | sret = 0; | |
107bad8b | 4495 | goto out; |
ff98781b | 4496 | } |
b3806b43 SR |
4497 | |
4498 | if (cnt >= PAGE_SIZE) | |
4499 | cnt = PAGE_SIZE - 1; | |
4500 | ||
53d0aa77 | 4501 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
4502 | memset(&iter->seq, 0, |
4503 | sizeof(struct trace_iterator) - | |
4504 | offsetof(struct trace_iterator, seq)); | |
ed5467da | 4505 | cpumask_clear(iter->started); |
4823ed7e | 4506 | iter->pos = -1; |
b3806b43 | 4507 | |
4f535968 | 4508 | trace_event_read_lock(); |
7e53bd42 | 4509 | trace_access_lock(iter->cpu_file); |
955b61e5 | 4510 | while (trace_find_next_entry_inc(iter) != NULL) { |
2c4f035f | 4511 | enum print_line_t ret; |
088b1e42 SR |
4512 | int len = iter->seq.len; |
4513 | ||
f9896bf3 | 4514 | ret = print_trace_line(iter); |
2c4f035f | 4515 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 SR |
4516 | /* don't print partial lines */ |
4517 | iter->seq.len = len; | |
b3806b43 | 4518 | break; |
088b1e42 | 4519 | } |
b91facc3 FW |
4520 | if (ret != TRACE_TYPE_NO_CONSUME) |
4521 | trace_consume(iter); | |
b3806b43 SR |
4522 | |
4523 | if (iter->seq.len >= cnt) | |
4524 | break; | |
ee5e51f5 JO |
4525 | |
4526 | /* | |
4527 | * Setting the full flag means we reached the trace_seq buffer | |
4528 | * size and we should leave by partial output condition above. | |
4529 | * One of the trace_seq_* functions is not used properly. | |
4530 | */ | |
4531 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
4532 | iter->ent->type); | |
b3806b43 | 4533 | } |
7e53bd42 | 4534 | trace_access_unlock(iter->cpu_file); |
4f535968 | 4535 | trace_event_read_unlock(); |
b3806b43 | 4536 | |
b3806b43 | 4537 | /* Now copy what we have to the user */ |
6c6c2796 PP |
4538 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
4539 | if (iter->seq.readpos >= iter->seq.len) | |
f9520750 | 4540 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
4541 | |
4542 | /* | |
25985edc | 4543 | * If there was nothing to send to user, in spite of consuming trace |
9ff4b974 PP |
4544 | * entries, go back to wait for more entries. |
4545 | */ | |
6c6c2796 | 4546 | if (sret == -EBUSY) |
9ff4b974 | 4547 | goto waitagain; |
b3806b43 | 4548 | |
107bad8b | 4549 | out: |
d7350c3f | 4550 | mutex_unlock(&iter->mutex); |
107bad8b | 4551 | |
6c6c2796 | 4552 | return sret; |
b3806b43 SR |
4553 | } |
4554 | ||
3c56819b EGM |
4555 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, |
4556 | unsigned int idx) | |
4557 | { | |
4558 | __free_page(spd->pages[idx]); | |
4559 | } | |
4560 | ||
28dfef8f | 4561 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { |
34cd4998 | 4562 | .can_merge = 0, |
34cd4998 | 4563 | .confirm = generic_pipe_buf_confirm, |
92fdd98c | 4564 | .release = generic_pipe_buf_release, |
34cd4998 SR |
4565 | .steal = generic_pipe_buf_steal, |
4566 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
4567 | }; |
4568 | ||
34cd4998 | 4569 | static size_t |
fa7c7f6e | 4570 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
4571 | { |
4572 | size_t count; | |
4573 | int ret; | |
4574 | ||
4575 | /* Seq buffer is page-sized, exactly what we need. */ | |
4576 | for (;;) { | |
4577 | count = iter->seq.len; | |
4578 | ret = print_trace_line(iter); | |
4579 | count = iter->seq.len - count; | |
4580 | if (rem < count) { | |
4581 | rem = 0; | |
4582 | iter->seq.len -= count; | |
4583 | break; | |
4584 | } | |
4585 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
4586 | iter->seq.len -= count; | |
4587 | break; | |
4588 | } | |
4589 | ||
74e7ff8c LJ |
4590 | if (ret != TRACE_TYPE_NO_CONSUME) |
4591 | trace_consume(iter); | |
34cd4998 | 4592 | rem -= count; |
955b61e5 | 4593 | if (!trace_find_next_entry_inc(iter)) { |
34cd4998 SR |
4594 | rem = 0; |
4595 | iter->ent = NULL; | |
4596 | break; | |
4597 | } | |
4598 | } | |
4599 | ||
4600 | return rem; | |
4601 | } | |
4602 | ||
3c56819b EGM |
4603 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
4604 | loff_t *ppos, | |
4605 | struct pipe_inode_info *pipe, | |
4606 | size_t len, | |
4607 | unsigned int flags) | |
4608 | { | |
35f3d14d JA |
4609 | struct page *pages_def[PIPE_DEF_BUFFERS]; |
4610 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3c56819b EGM |
4611 | struct trace_iterator *iter = filp->private_data; |
4612 | struct splice_pipe_desc spd = { | |
35f3d14d JA |
4613 | .pages = pages_def, |
4614 | .partial = partial_def, | |
34cd4998 | 4615 | .nr_pages = 0, /* This gets updated below. */ |
047fe360 | 4616 | .nr_pages_max = PIPE_DEF_BUFFERS, |
34cd4998 SR |
4617 | .flags = flags, |
4618 | .ops = &tracing_pipe_buf_ops, | |
4619 | .spd_release = tracing_spd_release_pipe, | |
3c56819b | 4620 | }; |
2b6080f2 | 4621 | struct trace_array *tr = iter->tr; |
3c56819b | 4622 | ssize_t ret; |
34cd4998 | 4623 | size_t rem; |
3c56819b EGM |
4624 | unsigned int i; |
4625 | ||
35f3d14d JA |
4626 | if (splice_grow_spd(pipe, &spd)) |
4627 | return -ENOMEM; | |
4628 | ||
d7350c3f | 4629 | /* copy the tracer to avoid using a global lock all around */ |
3c56819b | 4630 | mutex_lock(&trace_types_lock); |
2b6080f2 SR |
4631 | if (unlikely(iter->trace->name != tr->current_trace->name)) |
4632 | *iter->trace = *tr->current_trace; | |
d7350c3f FW |
4633 | mutex_unlock(&trace_types_lock); |
4634 | ||
4635 | mutex_lock(&iter->mutex); | |
3c56819b EGM |
4636 | |
4637 | if (iter->trace->splice_read) { | |
4638 | ret = iter->trace->splice_read(iter, filp, | |
4639 | ppos, pipe, len, flags); | |
4640 | if (ret) | |
34cd4998 | 4641 | goto out_err; |
3c56819b EGM |
4642 | } |
4643 | ||
4644 | ret = tracing_wait_pipe(filp); | |
4645 | if (ret <= 0) | |
34cd4998 | 4646 | goto out_err; |
3c56819b | 4647 | |
955b61e5 | 4648 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { |
3c56819b | 4649 | ret = -EFAULT; |
34cd4998 | 4650 | goto out_err; |
3c56819b EGM |
4651 | } |
4652 | ||
4f535968 | 4653 | trace_event_read_lock(); |
7e53bd42 | 4654 | trace_access_lock(iter->cpu_file); |
4f535968 | 4655 | |
3c56819b | 4656 | /* Fill as many pages as possible. */ |
a786c06d | 4657 | for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) { |
35f3d14d JA |
4658 | spd.pages[i] = alloc_page(GFP_KERNEL); |
4659 | if (!spd.pages[i]) | |
34cd4998 | 4660 | break; |
3c56819b | 4661 | |
fa7c7f6e | 4662 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
4663 | |
4664 | /* Copy the data into the page, so we can start over. */ | |
4665 | ret = trace_seq_to_buffer(&iter->seq, | |
35f3d14d | 4666 | page_address(spd.pages[i]), |
3c56819b EGM |
4667 | iter->seq.len); |
4668 | if (ret < 0) { | |
35f3d14d | 4669 | __free_page(spd.pages[i]); |
3c56819b EGM |
4670 | break; |
4671 | } | |
35f3d14d JA |
4672 | spd.partial[i].offset = 0; |
4673 | spd.partial[i].len = iter->seq.len; | |
3c56819b | 4674 | |
f9520750 | 4675 | trace_seq_init(&iter->seq); |
3c56819b EGM |
4676 | } |
4677 | ||
7e53bd42 | 4678 | trace_access_unlock(iter->cpu_file); |
4f535968 | 4679 | trace_event_read_unlock(); |
d7350c3f | 4680 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
4681 | |
4682 | spd.nr_pages = i; | |
4683 | ||
35f3d14d JA |
4684 | ret = splice_to_pipe(pipe, &spd); |
4685 | out: | |
047fe360 | 4686 | splice_shrink_spd(&spd); |
35f3d14d | 4687 | return ret; |
3c56819b | 4688 | |
34cd4998 | 4689 | out_err: |
d7350c3f | 4690 | mutex_unlock(&iter->mutex); |
35f3d14d | 4691 | goto out; |
3c56819b EGM |
4692 | } |
4693 | ||
a98a3c3f SR |
4694 | static ssize_t |
4695 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
4696 | size_t cnt, loff_t *ppos) | |
4697 | { | |
0bc392ee ON |
4698 | struct inode *inode = file_inode(filp); |
4699 | struct trace_array *tr = inode->i_private; | |
4700 | int cpu = tracing_get_cpu(inode); | |
438ced17 VN |
4701 | char buf[64]; |
4702 | int r = 0; | |
4703 | ssize_t ret; | |
a98a3c3f | 4704 | |
db526ca3 | 4705 | mutex_lock(&trace_types_lock); |
438ced17 | 4706 | |
0bc392ee | 4707 | if (cpu == RING_BUFFER_ALL_CPUS) { |
438ced17 VN |
4708 | int cpu, buf_size_same; |
4709 | unsigned long size; | |
4710 | ||
4711 | size = 0; | |
4712 | buf_size_same = 1; | |
4713 | /* check if all cpu sizes are same */ | |
4714 | for_each_tracing_cpu(cpu) { | |
4715 | /* fill in the size from first enabled cpu */ | |
4716 | if (size == 0) | |
12883efb SRRH |
4717 | size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries; |
4718 | if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) { | |
438ced17 VN |
4719 | buf_size_same = 0; |
4720 | break; | |
4721 | } | |
4722 | } | |
4723 | ||
4724 | if (buf_size_same) { | |
4725 | if (!ring_buffer_expanded) | |
4726 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
4727 | size >> 10, | |
4728 | trace_buf_size >> 10); | |
4729 | else | |
4730 | r = sprintf(buf, "%lu\n", size >> 10); | |
4731 | } else | |
4732 | r = sprintf(buf, "X\n"); | |
4733 | } else | |
0bc392ee | 4734 | r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10); |
438ced17 | 4735 | |
db526ca3 SR |
4736 | mutex_unlock(&trace_types_lock); |
4737 | ||
438ced17 VN |
4738 | ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
4739 | return ret; | |
a98a3c3f SR |
4740 | } |
4741 | ||
4742 | static ssize_t | |
4743 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
4744 | size_t cnt, loff_t *ppos) | |
4745 | { | |
0bc392ee ON |
4746 | struct inode *inode = file_inode(filp); |
4747 | struct trace_array *tr = inode->i_private; | |
a98a3c3f | 4748 | unsigned long val; |
4f271a2a | 4749 | int ret; |
a98a3c3f | 4750 | |
22fe9b54 PH |
4751 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4752 | if (ret) | |
c6caeeb1 | 4753 | return ret; |
a98a3c3f SR |
4754 | |
4755 | /* must have at least 1 entry */ | |
4756 | if (!val) | |
4757 | return -EINVAL; | |
4758 | ||
1696b2b0 SR |
4759 | /* value is in KB */ |
4760 | val <<= 10; | |
0bc392ee | 4761 | ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode)); |
4f271a2a VN |
4762 | if (ret < 0) |
4763 | return ret; | |
a98a3c3f | 4764 | |
cf8517cf | 4765 | *ppos += cnt; |
a98a3c3f | 4766 | |
4f271a2a VN |
4767 | return cnt; |
4768 | } | |
bf5e6519 | 4769 | |
f81ab074 VN |
4770 | static ssize_t |
4771 | tracing_total_entries_read(struct file *filp, char __user *ubuf, | |
4772 | size_t cnt, loff_t *ppos) | |
4773 | { | |
4774 | struct trace_array *tr = filp->private_data; | |
4775 | char buf[64]; | |
4776 | int r, cpu; | |
4777 | unsigned long size = 0, expanded_size = 0; | |
4778 | ||
4779 | mutex_lock(&trace_types_lock); | |
4780 | for_each_tracing_cpu(cpu) { | |
12883efb | 4781 | size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10; |
f81ab074 VN |
4782 | if (!ring_buffer_expanded) |
4783 | expanded_size += trace_buf_size >> 10; | |
4784 | } | |
4785 | if (ring_buffer_expanded) | |
4786 | r = sprintf(buf, "%lu\n", size); | |
4787 | else | |
4788 | r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); | |
4789 | mutex_unlock(&trace_types_lock); | |
4790 | ||
4791 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4792 | } | |
4793 | ||
4f271a2a VN |
4794 | static ssize_t |
4795 | tracing_free_buffer_write(struct file *filp, const char __user *ubuf, | |
4796 | size_t cnt, loff_t *ppos) | |
4797 | { | |
4798 | /* | |
4799 | * There is no need to read what the user has written, this function | |
4800 | * is just to make sure that there is no error when "echo" is used | |
4801 | */ | |
4802 | ||
4803 | *ppos += cnt; | |
a98a3c3f SR |
4804 | |
4805 | return cnt; | |
4806 | } | |
4807 | ||
4f271a2a VN |
4808 | static int |
4809 | tracing_free_buffer_release(struct inode *inode, struct file *filp) | |
4810 | { | |
2b6080f2 SR |
4811 | struct trace_array *tr = inode->i_private; |
4812 | ||
cf30cf67 SR |
4813 | /* disable tracing ? */ |
4814 | if (trace_flags & TRACE_ITER_STOP_ON_FREE) | |
711e1243 | 4815 | tracer_tracing_off(tr); |
4f271a2a | 4816 | /* resize the ring buffer to 0 */ |
2b6080f2 | 4817 | tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS); |
4f271a2a | 4818 | |
7b85af63 SRRH |
4819 | trace_array_put(tr); |
4820 | ||
4f271a2a VN |
4821 | return 0; |
4822 | } | |
4823 | ||
5bf9a1ee PP |
4824 | static ssize_t |
4825 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
4826 | size_t cnt, loff_t *fpos) | |
4827 | { | |
d696b58c | 4828 | unsigned long addr = (unsigned long)ubuf; |
2d71619c | 4829 | struct trace_array *tr = filp->private_data; |
d696b58c SR |
4830 | struct ring_buffer_event *event; |
4831 | struct ring_buffer *buffer; | |
4832 | struct print_entry *entry; | |
4833 | unsigned long irq_flags; | |
4834 | struct page *pages[2]; | |
6edb2a8a | 4835 | void *map_page[2]; |
d696b58c SR |
4836 | int nr_pages = 1; |
4837 | ssize_t written; | |
d696b58c SR |
4838 | int offset; |
4839 | int size; | |
4840 | int len; | |
4841 | int ret; | |
6edb2a8a | 4842 | int i; |
5bf9a1ee | 4843 | |
c76f0694 | 4844 | if (tracing_disabled) |
5bf9a1ee PP |
4845 | return -EINVAL; |
4846 | ||
5224c3a3 MSB |
4847 | if (!(trace_flags & TRACE_ITER_MARKERS)) |
4848 | return -EINVAL; | |
4849 | ||
5bf9a1ee PP |
4850 | if (cnt > TRACE_BUF_SIZE) |
4851 | cnt = TRACE_BUF_SIZE; | |
4852 | ||
d696b58c SR |
4853 | /* |
4854 | * Userspace is injecting traces into the kernel trace buffer. | |
4855 | * We want to be as non intrusive as possible. | |
4856 | * To do so, we do not want to allocate any special buffers | |
4857 | * or take any locks, but instead write the userspace data | |
4858 | * straight into the ring buffer. | |
4859 | * | |
4860 | * First we need to pin the userspace buffer into memory, | |
4861 | * which, most likely it is, because it just referenced it. | |
4862 | * But there's no guarantee that it is. By using get_user_pages_fast() | |
4863 | * and kmap_atomic/kunmap_atomic() we can get access to the | |
4864 | * pages directly. We then write the data directly into the | |
4865 | * ring buffer. | |
4866 | */ | |
4867 | BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); | |
5bf9a1ee | 4868 | |
d696b58c SR |
4869 | /* check if we cross pages */ |
4870 | if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) | |
4871 | nr_pages = 2; | |
4872 | ||
4873 | offset = addr & (PAGE_SIZE - 1); | |
4874 | addr &= PAGE_MASK; | |
4875 | ||
4876 | ret = get_user_pages_fast(addr, nr_pages, 0, pages); | |
4877 | if (ret < nr_pages) { | |
4878 | while (--ret >= 0) | |
4879 | put_page(pages[ret]); | |
4880 | written = -EFAULT; | |
4881 | goto out; | |
5bf9a1ee | 4882 | } |
d696b58c | 4883 | |
6edb2a8a SR |
4884 | for (i = 0; i < nr_pages; i++) |
4885 | map_page[i] = kmap_atomic(pages[i]); | |
d696b58c SR |
4886 | |
4887 | local_save_flags(irq_flags); | |
4888 | size = sizeof(*entry) + cnt + 2; /* possible \n added */ | |
2d71619c | 4889 | buffer = tr->trace_buffer.buffer; |
d696b58c SR |
4890 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
4891 | irq_flags, preempt_count()); | |
4892 | if (!event) { | |
4893 | /* Ring buffer disabled, return as if not open for write */ | |
4894 | written = -EBADF; | |
4895 | goto out_unlock; | |
5bf9a1ee | 4896 | } |
d696b58c SR |
4897 | |
4898 | entry = ring_buffer_event_data(event); | |
4899 | entry->ip = _THIS_IP_; | |
4900 | ||
4901 | if (nr_pages == 2) { | |
4902 | len = PAGE_SIZE - offset; | |
6edb2a8a SR |
4903 | memcpy(&entry->buf, map_page[0] + offset, len); |
4904 | memcpy(&entry->buf[len], map_page[1], cnt - len); | |
c13d2f7c | 4905 | } else |
6edb2a8a | 4906 | memcpy(&entry->buf, map_page[0] + offset, cnt); |
5bf9a1ee | 4907 | |
d696b58c SR |
4908 | if (entry->buf[cnt - 1] != '\n') { |
4909 | entry->buf[cnt] = '\n'; | |
4910 | entry->buf[cnt + 1] = '\0'; | |
4911 | } else | |
4912 | entry->buf[cnt] = '\0'; | |
4913 | ||
7ffbd48d | 4914 | __buffer_unlock_commit(buffer, event); |
5bf9a1ee | 4915 | |
d696b58c | 4916 | written = cnt; |
5bf9a1ee | 4917 | |
d696b58c | 4918 | *fpos += written; |
1aa54bca | 4919 | |
d696b58c | 4920 | out_unlock: |
6edb2a8a SR |
4921 | for (i = 0; i < nr_pages; i++){ |
4922 | kunmap_atomic(map_page[i]); | |
4923 | put_page(pages[i]); | |
4924 | } | |
d696b58c | 4925 | out: |
1aa54bca | 4926 | return written; |
5bf9a1ee PP |
4927 | } |
4928 | ||
13f16d20 | 4929 | static int tracing_clock_show(struct seq_file *m, void *v) |
5079f326 | 4930 | { |
2b6080f2 | 4931 | struct trace_array *tr = m->private; |
5079f326 Z |
4932 | int i; |
4933 | ||
4934 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
13f16d20 | 4935 | seq_printf(m, |
5079f326 | 4936 | "%s%s%s%s", i ? " " : "", |
2b6080f2 SR |
4937 | i == tr->clock_id ? "[" : "", trace_clocks[i].name, |
4938 | i == tr->clock_id ? "]" : ""); | |
13f16d20 | 4939 | seq_putc(m, '\n'); |
5079f326 | 4940 | |
13f16d20 | 4941 | return 0; |
5079f326 Z |
4942 | } |
4943 | ||
e1e232ca | 4944 | static int tracing_set_clock(struct trace_array *tr, const char *clockstr) |
5079f326 | 4945 | { |
5079f326 Z |
4946 | int i; |
4947 | ||
5079f326 Z |
4948 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { |
4949 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
4950 | break; | |
4951 | } | |
4952 | if (i == ARRAY_SIZE(trace_clocks)) | |
4953 | return -EINVAL; | |
4954 | ||
5079f326 Z |
4955 | mutex_lock(&trace_types_lock); |
4956 | ||
2b6080f2 SR |
4957 | tr->clock_id = i; |
4958 | ||
12883efb | 4959 | ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func); |
5079f326 | 4960 | |
60303ed3 DS |
4961 | /* |
4962 | * New clock may not be consistent with the previous clock. | |
4963 | * Reset the buffer so that it doesn't have incomparable timestamps. | |
4964 | */ | |
9457158b | 4965 | tracing_reset_online_cpus(&tr->trace_buffer); |
12883efb SRRH |
4966 | |
4967 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4968 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer) | |
4969 | ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); | |
9457158b | 4970 | tracing_reset_online_cpus(&tr->max_buffer); |
12883efb | 4971 | #endif |
60303ed3 | 4972 | |
5079f326 Z |
4973 | mutex_unlock(&trace_types_lock); |
4974 | ||
e1e232ca SR |
4975 | return 0; |
4976 | } | |
4977 | ||
4978 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
4979 | size_t cnt, loff_t *fpos) | |
4980 | { | |
4981 | struct seq_file *m = filp->private_data; | |
4982 | struct trace_array *tr = m->private; | |
4983 | char buf[64]; | |
4984 | const char *clockstr; | |
4985 | int ret; | |
4986 | ||
4987 | if (cnt >= sizeof(buf)) | |
4988 | return -EINVAL; | |
4989 | ||
4990 | if (copy_from_user(&buf, ubuf, cnt)) | |
4991 | return -EFAULT; | |
4992 | ||
4993 | buf[cnt] = 0; | |
4994 | ||
4995 | clockstr = strstrip(buf); | |
4996 | ||
4997 | ret = tracing_set_clock(tr, clockstr); | |
4998 | if (ret) | |
4999 | return ret; | |
5000 | ||
5079f326 Z |
5001 | *fpos += cnt; |
5002 | ||
5003 | return cnt; | |
5004 | } | |
5005 | ||
13f16d20 LZ |
5006 | static int tracing_clock_open(struct inode *inode, struct file *file) |
5007 | { | |
7b85af63 SRRH |
5008 | struct trace_array *tr = inode->i_private; |
5009 | int ret; | |
5010 | ||
13f16d20 LZ |
5011 | if (tracing_disabled) |
5012 | return -ENODEV; | |
2b6080f2 | 5013 | |
7b85af63 SRRH |
5014 | if (trace_array_get(tr)) |
5015 | return -ENODEV; | |
5016 | ||
5017 | ret = single_open(file, tracing_clock_show, inode->i_private); | |
5018 | if (ret < 0) | |
5019 | trace_array_put(tr); | |
5020 | ||
5021 | return ret; | |
13f16d20 LZ |
5022 | } |
5023 | ||
6de58e62 SRRH |
5024 | struct ftrace_buffer_info { |
5025 | struct trace_iterator iter; | |
5026 | void *spare; | |
5027 | unsigned int read; | |
5028 | }; | |
5029 | ||
debdd57f HT |
5030 | #ifdef CONFIG_TRACER_SNAPSHOT |
5031 | static int tracing_snapshot_open(struct inode *inode, struct file *file) | |
5032 | { | |
6484c71c | 5033 | struct trace_array *tr = inode->i_private; |
debdd57f | 5034 | struct trace_iterator *iter; |
2b6080f2 | 5035 | struct seq_file *m; |
debdd57f HT |
5036 | int ret = 0; |
5037 | ||
ff451961 SRRH |
5038 | if (trace_array_get(tr) < 0) |
5039 | return -ENODEV; | |
5040 | ||
debdd57f | 5041 | if (file->f_mode & FMODE_READ) { |
6484c71c | 5042 | iter = __tracing_open(inode, file, true); |
debdd57f HT |
5043 | if (IS_ERR(iter)) |
5044 | ret = PTR_ERR(iter); | |
2b6080f2 SR |
5045 | } else { |
5046 | /* Writes still need the seq_file to hold the private data */ | |
f77d09a3 | 5047 | ret = -ENOMEM; |
2b6080f2 SR |
5048 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
5049 | if (!m) | |
f77d09a3 | 5050 | goto out; |
2b6080f2 SR |
5051 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
5052 | if (!iter) { | |
5053 | kfree(m); | |
f77d09a3 | 5054 | goto out; |
2b6080f2 | 5055 | } |
f77d09a3 AL |
5056 | ret = 0; |
5057 | ||
ff451961 | 5058 | iter->tr = tr; |
6484c71c ON |
5059 | iter->trace_buffer = &tr->max_buffer; |
5060 | iter->cpu_file = tracing_get_cpu(inode); | |
2b6080f2 SR |
5061 | m->private = iter; |
5062 | file->private_data = m; | |
debdd57f | 5063 | } |
f77d09a3 | 5064 | out: |
ff451961 SRRH |
5065 | if (ret < 0) |
5066 | trace_array_put(tr); | |
5067 | ||
debdd57f HT |
5068 | return ret; |
5069 | } | |
5070 | ||
5071 | static ssize_t | |
5072 | tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
5073 | loff_t *ppos) | |
5074 | { | |
2b6080f2 SR |
5075 | struct seq_file *m = filp->private_data; |
5076 | struct trace_iterator *iter = m->private; | |
5077 | struct trace_array *tr = iter->tr; | |
debdd57f HT |
5078 | unsigned long val; |
5079 | int ret; | |
5080 | ||
5081 | ret = tracing_update_buffers(); | |
5082 | if (ret < 0) | |
5083 | return ret; | |
5084 | ||
5085 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
5086 | if (ret) | |
5087 | return ret; | |
5088 | ||
5089 | mutex_lock(&trace_types_lock); | |
5090 | ||
2b6080f2 | 5091 | if (tr->current_trace->use_max_tr) { |
debdd57f HT |
5092 | ret = -EBUSY; |
5093 | goto out; | |
5094 | } | |
5095 | ||
5096 | switch (val) { | |
5097 | case 0: | |
f1affcaa SRRH |
5098 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
5099 | ret = -EINVAL; | |
5100 | break; | |
debdd57f | 5101 | } |
3209cff4 SRRH |
5102 | if (tr->allocated_snapshot) |
5103 | free_snapshot(tr); | |
debdd57f HT |
5104 | break; |
5105 | case 1: | |
f1affcaa SRRH |
5106 | /* Only allow per-cpu swap if the ring buffer supports it */ |
5107 | #ifndef CONFIG_RING_BUFFER_ALLOW_SWAP | |
5108 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { | |
5109 | ret = -EINVAL; | |
5110 | break; | |
5111 | } | |
5112 | #endif | |
45ad21ca | 5113 | if (!tr->allocated_snapshot) { |
3209cff4 | 5114 | ret = alloc_snapshot(tr); |
debdd57f HT |
5115 | if (ret < 0) |
5116 | break; | |
debdd57f | 5117 | } |
debdd57f HT |
5118 | local_irq_disable(); |
5119 | /* Now, we're going to swap */ | |
f1affcaa | 5120 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
ce9bae55 | 5121 | update_max_tr(tr, current, smp_processor_id()); |
f1affcaa | 5122 | else |
ce9bae55 | 5123 | update_max_tr_single(tr, current, iter->cpu_file); |
debdd57f HT |
5124 | local_irq_enable(); |
5125 | break; | |
5126 | default: | |
45ad21ca | 5127 | if (tr->allocated_snapshot) { |
f1affcaa SRRH |
5128 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
5129 | tracing_reset_online_cpus(&tr->max_buffer); | |
5130 | else | |
5131 | tracing_reset(&tr->max_buffer, iter->cpu_file); | |
5132 | } | |
debdd57f HT |
5133 | break; |
5134 | } | |
5135 | ||
5136 | if (ret >= 0) { | |
5137 | *ppos += cnt; | |
5138 | ret = cnt; | |
5139 | } | |
5140 | out: | |
5141 | mutex_unlock(&trace_types_lock); | |
5142 | return ret; | |
5143 | } | |
2b6080f2 SR |
5144 | |
5145 | static int tracing_snapshot_release(struct inode *inode, struct file *file) | |
5146 | { | |
5147 | struct seq_file *m = file->private_data; | |
ff451961 SRRH |
5148 | int ret; |
5149 | ||
5150 | ret = tracing_release(inode, file); | |
2b6080f2 SR |
5151 | |
5152 | if (file->f_mode & FMODE_READ) | |
ff451961 | 5153 | return ret; |
2b6080f2 SR |
5154 | |
5155 | /* If write only, the seq_file is just a stub */ | |
5156 | if (m) | |
5157 | kfree(m->private); | |
5158 | kfree(m); | |
5159 | ||
5160 | return 0; | |
5161 | } | |
5162 | ||
6de58e62 SRRH |
5163 | static int tracing_buffers_open(struct inode *inode, struct file *filp); |
5164 | static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, | |
5165 | size_t count, loff_t *ppos); | |
5166 | static int tracing_buffers_release(struct inode *inode, struct file *file); | |
5167 | static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5168 | struct pipe_inode_info *pipe, size_t len, unsigned int flags); | |
5169 | ||
5170 | static int snapshot_raw_open(struct inode *inode, struct file *filp) | |
5171 | { | |
5172 | struct ftrace_buffer_info *info; | |
5173 | int ret; | |
5174 | ||
5175 | ret = tracing_buffers_open(inode, filp); | |
5176 | if (ret < 0) | |
5177 | return ret; | |
5178 | ||
5179 | info = filp->private_data; | |
5180 | ||
5181 | if (info->iter.trace->use_max_tr) { | |
5182 | tracing_buffers_release(inode, filp); | |
5183 | return -EBUSY; | |
5184 | } | |
5185 | ||
5186 | info->iter.snapshot = true; | |
5187 | info->iter.trace_buffer = &info->iter.tr->max_buffer; | |
5188 | ||
5189 | return ret; | |
5190 | } | |
5191 | ||
debdd57f HT |
5192 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
5193 | ||
5194 | ||
6508fa76 SF |
5195 | static const struct file_operations tracing_thresh_fops = { |
5196 | .open = tracing_open_generic, | |
5197 | .read = tracing_thresh_read, | |
5198 | .write = tracing_thresh_write, | |
5199 | .llseek = generic_file_llseek, | |
5200 | }; | |
5201 | ||
5e2336a0 | 5202 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
5203 | .open = tracing_open_generic, |
5204 | .read = tracing_max_lat_read, | |
5205 | .write = tracing_max_lat_write, | |
b444786f | 5206 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
5207 | }; |
5208 | ||
5e2336a0 | 5209 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
5210 | .open = tracing_open_generic, |
5211 | .read = tracing_set_trace_read, | |
5212 | .write = tracing_set_trace_write, | |
b444786f | 5213 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
5214 | }; |
5215 | ||
5e2336a0 | 5216 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 5217 | .open = tracing_open_pipe, |
2a2cc8f7 | 5218 | .poll = tracing_poll_pipe, |
4bf39a94 | 5219 | .read = tracing_read_pipe, |
3c56819b | 5220 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 5221 | .release = tracing_release_pipe, |
b444786f | 5222 | .llseek = no_llseek, |
b3806b43 SR |
5223 | }; |
5224 | ||
5e2336a0 | 5225 | static const struct file_operations tracing_entries_fops = { |
0bc392ee | 5226 | .open = tracing_open_generic_tr, |
a98a3c3f SR |
5227 | .read = tracing_entries_read, |
5228 | .write = tracing_entries_write, | |
b444786f | 5229 | .llseek = generic_file_llseek, |
0bc392ee | 5230 | .release = tracing_release_generic_tr, |
a98a3c3f SR |
5231 | }; |
5232 | ||
f81ab074 | 5233 | static const struct file_operations tracing_total_entries_fops = { |
7b85af63 | 5234 | .open = tracing_open_generic_tr, |
f81ab074 VN |
5235 | .read = tracing_total_entries_read, |
5236 | .llseek = generic_file_llseek, | |
7b85af63 | 5237 | .release = tracing_release_generic_tr, |
f81ab074 VN |
5238 | }; |
5239 | ||
4f271a2a | 5240 | static const struct file_operations tracing_free_buffer_fops = { |
7b85af63 | 5241 | .open = tracing_open_generic_tr, |
4f271a2a VN |
5242 | .write = tracing_free_buffer_write, |
5243 | .release = tracing_free_buffer_release, | |
5244 | }; | |
5245 | ||
5e2336a0 | 5246 | static const struct file_operations tracing_mark_fops = { |
7b85af63 | 5247 | .open = tracing_open_generic_tr, |
5bf9a1ee | 5248 | .write = tracing_mark_write, |
b444786f | 5249 | .llseek = generic_file_llseek, |
7b85af63 | 5250 | .release = tracing_release_generic_tr, |
5bf9a1ee PP |
5251 | }; |
5252 | ||
5079f326 | 5253 | static const struct file_operations trace_clock_fops = { |
13f16d20 LZ |
5254 | .open = tracing_clock_open, |
5255 | .read = seq_read, | |
5256 | .llseek = seq_lseek, | |
7b85af63 | 5257 | .release = tracing_single_release_tr, |
5079f326 Z |
5258 | .write = tracing_clock_write, |
5259 | }; | |
5260 | ||
debdd57f HT |
5261 | #ifdef CONFIG_TRACER_SNAPSHOT |
5262 | static const struct file_operations snapshot_fops = { | |
5263 | .open = tracing_snapshot_open, | |
5264 | .read = seq_read, | |
5265 | .write = tracing_snapshot_write, | |
098c879e | 5266 | .llseek = tracing_lseek, |
2b6080f2 | 5267 | .release = tracing_snapshot_release, |
debdd57f | 5268 | }; |
debdd57f | 5269 | |
6de58e62 SRRH |
5270 | static const struct file_operations snapshot_raw_fops = { |
5271 | .open = snapshot_raw_open, | |
5272 | .read = tracing_buffers_read, | |
5273 | .release = tracing_buffers_release, | |
5274 | .splice_read = tracing_buffers_splice_read, | |
5275 | .llseek = no_llseek, | |
2cadf913 SR |
5276 | }; |
5277 | ||
6de58e62 SRRH |
5278 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
5279 | ||
2cadf913 SR |
5280 | static int tracing_buffers_open(struct inode *inode, struct file *filp) |
5281 | { | |
46ef2be0 | 5282 | struct trace_array *tr = inode->i_private; |
2cadf913 | 5283 | struct ftrace_buffer_info *info; |
7b85af63 | 5284 | int ret; |
2cadf913 SR |
5285 | |
5286 | if (tracing_disabled) | |
5287 | return -ENODEV; | |
5288 | ||
7b85af63 SRRH |
5289 | if (trace_array_get(tr) < 0) |
5290 | return -ENODEV; | |
5291 | ||
2cadf913 | 5292 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
7b85af63 SRRH |
5293 | if (!info) { |
5294 | trace_array_put(tr); | |
2cadf913 | 5295 | return -ENOMEM; |
7b85af63 | 5296 | } |
2cadf913 | 5297 | |
a695cb58 SRRH |
5298 | mutex_lock(&trace_types_lock); |
5299 | ||
cc60cdc9 | 5300 | info->iter.tr = tr; |
46ef2be0 | 5301 | info->iter.cpu_file = tracing_get_cpu(inode); |
b627344f | 5302 | info->iter.trace = tr->current_trace; |
12883efb | 5303 | info->iter.trace_buffer = &tr->trace_buffer; |
cc60cdc9 | 5304 | info->spare = NULL; |
2cadf913 | 5305 | /* Force reading ring buffer for first read */ |
cc60cdc9 | 5306 | info->read = (unsigned int)-1; |
2cadf913 SR |
5307 | |
5308 | filp->private_data = info; | |
5309 | ||
a695cb58 SRRH |
5310 | mutex_unlock(&trace_types_lock); |
5311 | ||
7b85af63 SRRH |
5312 | ret = nonseekable_open(inode, filp); |
5313 | if (ret < 0) | |
5314 | trace_array_put(tr); | |
5315 | ||
5316 | return ret; | |
2cadf913 SR |
5317 | } |
5318 | ||
cc60cdc9 SR |
5319 | static unsigned int |
5320 | tracing_buffers_poll(struct file *filp, poll_table *poll_table) | |
5321 | { | |
5322 | struct ftrace_buffer_info *info = filp->private_data; | |
5323 | struct trace_iterator *iter = &info->iter; | |
5324 | ||
5325 | return trace_poll(iter, filp, poll_table); | |
5326 | } | |
5327 | ||
2cadf913 SR |
5328 | static ssize_t |
5329 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
5330 | size_t count, loff_t *ppos) | |
5331 | { | |
5332 | struct ftrace_buffer_info *info = filp->private_data; | |
cc60cdc9 | 5333 | struct trace_iterator *iter = &info->iter; |
2cadf913 | 5334 | ssize_t ret; |
6de58e62 | 5335 | ssize_t size; |
2cadf913 | 5336 | |
2dc5d12b SR |
5337 | if (!count) |
5338 | return 0; | |
5339 | ||
6de58e62 SRRH |
5340 | mutex_lock(&trace_types_lock); |
5341 | ||
5342 | #ifdef CONFIG_TRACER_MAX_TRACE | |
5343 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) { | |
5344 | size = -EBUSY; | |
5345 | goto out_unlock; | |
5346 | } | |
5347 | #endif | |
5348 | ||
ddd538f3 | 5349 | if (!info->spare) |
12883efb SRRH |
5350 | info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer, |
5351 | iter->cpu_file); | |
6de58e62 | 5352 | size = -ENOMEM; |
ddd538f3 | 5353 | if (!info->spare) |
6de58e62 | 5354 | goto out_unlock; |
ddd538f3 | 5355 | |
2cadf913 SR |
5356 | /* Do we have previous read data to read? */ |
5357 | if (info->read < PAGE_SIZE) | |
5358 | goto read; | |
5359 | ||
b627344f | 5360 | again: |
cc60cdc9 | 5361 | trace_access_lock(iter->cpu_file); |
12883efb | 5362 | ret = ring_buffer_read_page(iter->trace_buffer->buffer, |
2cadf913 SR |
5363 | &info->spare, |
5364 | count, | |
cc60cdc9 SR |
5365 | iter->cpu_file, 0); |
5366 | trace_access_unlock(iter->cpu_file); | |
2cadf913 | 5367 | |
b627344f SR |
5368 | if (ret < 0) { |
5369 | if (trace_empty(iter)) { | |
6de58e62 SRRH |
5370 | if ((filp->f_flags & O_NONBLOCK)) { |
5371 | size = -EAGAIN; | |
5372 | goto out_unlock; | |
5373 | } | |
5374 | mutex_unlock(&trace_types_lock); | |
8b8b3683 | 5375 | ret = wait_on_pipe(iter); |
6de58e62 | 5376 | mutex_lock(&trace_types_lock); |
8b8b3683 SRRH |
5377 | if (ret) { |
5378 | size = ret; | |
5379 | goto out_unlock; | |
5380 | } | |
6de58e62 SRRH |
5381 | if (signal_pending(current)) { |
5382 | size = -EINTR; | |
5383 | goto out_unlock; | |
5384 | } | |
b627344f SR |
5385 | goto again; |
5386 | } | |
6de58e62 SRRH |
5387 | size = 0; |
5388 | goto out_unlock; | |
b627344f | 5389 | } |
436fc280 | 5390 | |
436fc280 | 5391 | info->read = 0; |
b627344f | 5392 | read: |
2cadf913 SR |
5393 | size = PAGE_SIZE - info->read; |
5394 | if (size > count) | |
5395 | size = count; | |
5396 | ||
5397 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
6de58e62 SRRH |
5398 | if (ret == size) { |
5399 | size = -EFAULT; | |
5400 | goto out_unlock; | |
5401 | } | |
2dc5d12b SR |
5402 | size -= ret; |
5403 | ||
2cadf913 SR |
5404 | *ppos += size; |
5405 | info->read += size; | |
5406 | ||
6de58e62 SRRH |
5407 | out_unlock: |
5408 | mutex_unlock(&trace_types_lock); | |
5409 | ||
2cadf913 SR |
5410 | return size; |
5411 | } | |
5412 | ||
5413 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
5414 | { | |
5415 | struct ftrace_buffer_info *info = file->private_data; | |
cc60cdc9 | 5416 | struct trace_iterator *iter = &info->iter; |
2cadf913 | 5417 | |
a695cb58 SRRH |
5418 | mutex_lock(&trace_types_lock); |
5419 | ||
ff451961 | 5420 | __trace_array_put(iter->tr); |
2cadf913 | 5421 | |
ddd538f3 | 5422 | if (info->spare) |
12883efb | 5423 | ring_buffer_free_read_page(iter->trace_buffer->buffer, info->spare); |
2cadf913 SR |
5424 | kfree(info); |
5425 | ||
a695cb58 SRRH |
5426 | mutex_unlock(&trace_types_lock); |
5427 | ||
2cadf913 SR |
5428 | return 0; |
5429 | } | |
5430 | ||
5431 | struct buffer_ref { | |
5432 | struct ring_buffer *buffer; | |
5433 | void *page; | |
5434 | int ref; | |
5435 | }; | |
5436 | ||
5437 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
5438 | struct pipe_buffer *buf) | |
5439 | { | |
5440 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5441 | ||
5442 | if (--ref->ref) | |
5443 | return; | |
5444 | ||
5445 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5446 | kfree(ref); | |
5447 | buf->private = 0; | |
5448 | } | |
5449 | ||
2cadf913 SR |
5450 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, |
5451 | struct pipe_buffer *buf) | |
5452 | { | |
5453 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5454 | ||
5455 | ref->ref++; | |
5456 | } | |
5457 | ||
5458 | /* Pipe buffer operations for a buffer. */ | |
28dfef8f | 5459 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
2cadf913 | 5460 | .can_merge = 0, |
2cadf913 SR |
5461 | .confirm = generic_pipe_buf_confirm, |
5462 | .release = buffer_pipe_buf_release, | |
d55cb6cf | 5463 | .steal = generic_pipe_buf_steal, |
2cadf913 SR |
5464 | .get = buffer_pipe_buf_get, |
5465 | }; | |
5466 | ||
5467 | /* | |
5468 | * Callback from splice_to_pipe(), if we need to release some pages | |
5469 | * at the end of the spd in case we error'ed out in filling the pipe. | |
5470 | */ | |
5471 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
5472 | { | |
5473 | struct buffer_ref *ref = | |
5474 | (struct buffer_ref *)spd->partial[i].private; | |
5475 | ||
5476 | if (--ref->ref) | |
5477 | return; | |
5478 | ||
5479 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5480 | kfree(ref); | |
5481 | spd->partial[i].private = 0; | |
5482 | } | |
5483 | ||
5484 | static ssize_t | |
5485 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5486 | struct pipe_inode_info *pipe, size_t len, | |
5487 | unsigned int flags) | |
5488 | { | |
5489 | struct ftrace_buffer_info *info = file->private_data; | |
cc60cdc9 | 5490 | struct trace_iterator *iter = &info->iter; |
35f3d14d JA |
5491 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
5492 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
2cadf913 | 5493 | struct splice_pipe_desc spd = { |
35f3d14d JA |
5494 | .pages = pages_def, |
5495 | .partial = partial_def, | |
047fe360 | 5496 | .nr_pages_max = PIPE_DEF_BUFFERS, |
2cadf913 SR |
5497 | .flags = flags, |
5498 | .ops = &buffer_pipe_buf_ops, | |
5499 | .spd_release = buffer_spd_release, | |
5500 | }; | |
5501 | struct buffer_ref *ref; | |
93459c6c | 5502 | int entries, size, i; |
6de58e62 | 5503 | ssize_t ret; |
2cadf913 | 5504 | |
6de58e62 SRRH |
5505 | mutex_lock(&trace_types_lock); |
5506 | ||
5507 | #ifdef CONFIG_TRACER_MAX_TRACE | |
5508 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) { | |
5509 | ret = -EBUSY; | |
5510 | goto out; | |
5511 | } | |
5512 | #endif | |
5513 | ||
5514 | if (splice_grow_spd(pipe, &spd)) { | |
5515 | ret = -ENOMEM; | |
5516 | goto out; | |
5517 | } | |
35f3d14d | 5518 | |
93cfb3c9 | 5519 | if (*ppos & (PAGE_SIZE - 1)) { |
35f3d14d JA |
5520 | ret = -EINVAL; |
5521 | goto out; | |
93cfb3c9 LJ |
5522 | } |
5523 | ||
5524 | if (len & (PAGE_SIZE - 1)) { | |
35f3d14d JA |
5525 | if (len < PAGE_SIZE) { |
5526 | ret = -EINVAL; | |
5527 | goto out; | |
5528 | } | |
93cfb3c9 LJ |
5529 | len &= PAGE_MASK; |
5530 | } | |
5531 | ||
cc60cdc9 SR |
5532 | again: |
5533 | trace_access_lock(iter->cpu_file); | |
12883efb | 5534 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); |
93459c6c | 5535 | |
a786c06d | 5536 | for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) { |
2cadf913 SR |
5537 | struct page *page; |
5538 | int r; | |
5539 | ||
5540 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
5541 | if (!ref) | |
5542 | break; | |
5543 | ||
7267fa68 | 5544 | ref->ref = 1; |
12883efb | 5545 | ref->buffer = iter->trace_buffer->buffer; |
cc60cdc9 | 5546 | ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); |
2cadf913 SR |
5547 | if (!ref->page) { |
5548 | kfree(ref); | |
5549 | break; | |
5550 | } | |
5551 | ||
5552 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
cc60cdc9 | 5553 | len, iter->cpu_file, 1); |
2cadf913 | 5554 | if (r < 0) { |
7ea59064 | 5555 | ring_buffer_free_read_page(ref->buffer, ref->page); |
2cadf913 SR |
5556 | kfree(ref); |
5557 | break; | |
5558 | } | |
5559 | ||
5560 | /* | |
5561 | * zero out any left over data, this is going to | |
5562 | * user land. | |
5563 | */ | |
5564 | size = ring_buffer_page_len(ref->page); | |
5565 | if (size < PAGE_SIZE) | |
5566 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
5567 | ||
5568 | page = virt_to_page(ref->page); | |
5569 | ||
5570 | spd.pages[i] = page; | |
5571 | spd.partial[i].len = PAGE_SIZE; | |
5572 | spd.partial[i].offset = 0; | |
5573 | spd.partial[i].private = (unsigned long)ref; | |
5574 | spd.nr_pages++; | |
93cfb3c9 | 5575 | *ppos += PAGE_SIZE; |
93459c6c | 5576 | |
12883efb | 5577 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); |
2cadf913 SR |
5578 | } |
5579 | ||
cc60cdc9 | 5580 | trace_access_unlock(iter->cpu_file); |
2cadf913 SR |
5581 | spd.nr_pages = i; |
5582 | ||
5583 | /* did we read anything? */ | |
5584 | if (!spd.nr_pages) { | |
cc60cdc9 | 5585 | if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) { |
2cadf913 | 5586 | ret = -EAGAIN; |
cc60cdc9 SR |
5587 | goto out; |
5588 | } | |
6de58e62 | 5589 | mutex_unlock(&trace_types_lock); |
8b8b3683 | 5590 | ret = wait_on_pipe(iter); |
6de58e62 | 5591 | mutex_lock(&trace_types_lock); |
8b8b3683 SRRH |
5592 | if (ret) |
5593 | goto out; | |
cc60cdc9 SR |
5594 | if (signal_pending(current)) { |
5595 | ret = -EINTR; | |
5596 | goto out; | |
5597 | } | |
5598 | goto again; | |
2cadf913 SR |
5599 | } |
5600 | ||
5601 | ret = splice_to_pipe(pipe, &spd); | |
047fe360 | 5602 | splice_shrink_spd(&spd); |
35f3d14d | 5603 | out: |
6de58e62 SRRH |
5604 | mutex_unlock(&trace_types_lock); |
5605 | ||
2cadf913 SR |
5606 | return ret; |
5607 | } | |
5608 | ||
5609 | static const struct file_operations tracing_buffers_fops = { | |
5610 | .open = tracing_buffers_open, | |
5611 | .read = tracing_buffers_read, | |
cc60cdc9 | 5612 | .poll = tracing_buffers_poll, |
2cadf913 SR |
5613 | .release = tracing_buffers_release, |
5614 | .splice_read = tracing_buffers_splice_read, | |
5615 | .llseek = no_llseek, | |
5616 | }; | |
5617 | ||
c8d77183 SR |
5618 | static ssize_t |
5619 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
5620 | size_t count, loff_t *ppos) | |
5621 | { | |
4d3435b8 ON |
5622 | struct inode *inode = file_inode(filp); |
5623 | struct trace_array *tr = inode->i_private; | |
12883efb | 5624 | struct trace_buffer *trace_buf = &tr->trace_buffer; |
4d3435b8 | 5625 | int cpu = tracing_get_cpu(inode); |
c8d77183 SR |
5626 | struct trace_seq *s; |
5627 | unsigned long cnt; | |
c64e148a VN |
5628 | unsigned long long t; |
5629 | unsigned long usec_rem; | |
c8d77183 | 5630 | |
e4f2d10f | 5631 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
c8d77183 | 5632 | if (!s) |
a646365c | 5633 | return -ENOMEM; |
c8d77183 SR |
5634 | |
5635 | trace_seq_init(s); | |
5636 | ||
12883efb | 5637 | cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5638 | trace_seq_printf(s, "entries: %ld\n", cnt); |
5639 | ||
12883efb | 5640 | cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5641 | trace_seq_printf(s, "overrun: %ld\n", cnt); |
5642 | ||
12883efb | 5643 | cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu); |
c8d77183 SR |
5644 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); |
5645 | ||
12883efb | 5646 | cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu); |
c64e148a VN |
5647 | trace_seq_printf(s, "bytes: %ld\n", cnt); |
5648 | ||
58e8eedf | 5649 | if (trace_clocks[tr->clock_id].in_ns) { |
11043d8b | 5650 | /* local or global for trace_clock */ |
12883efb | 5651 | t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
11043d8b YY |
5652 | usec_rem = do_div(t, USEC_PER_SEC); |
5653 | trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", | |
5654 | t, usec_rem); | |
5655 | ||
12883efb | 5656 | t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
11043d8b YY |
5657 | usec_rem = do_div(t, USEC_PER_SEC); |
5658 | trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); | |
5659 | } else { | |
5660 | /* counter or tsc mode for trace_clock */ | |
5661 | trace_seq_printf(s, "oldest event ts: %llu\n", | |
12883efb | 5662 | ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
c64e148a | 5663 | |
11043d8b | 5664 | trace_seq_printf(s, "now ts: %llu\n", |
12883efb | 5665 | ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
11043d8b | 5666 | } |
c64e148a | 5667 | |
12883efb | 5668 | cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu); |
884bfe89 SP |
5669 | trace_seq_printf(s, "dropped events: %ld\n", cnt); |
5670 | ||
12883efb | 5671 | cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); |
ad964704 SRRH |
5672 | trace_seq_printf(s, "read events: %ld\n", cnt); |
5673 | ||
c8d77183 SR |
5674 | count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); |
5675 | ||
5676 | kfree(s); | |
5677 | ||
5678 | return count; | |
5679 | } | |
5680 | ||
5681 | static const struct file_operations tracing_stats_fops = { | |
4d3435b8 | 5682 | .open = tracing_open_generic_tr, |
c8d77183 | 5683 | .read = tracing_stats_read, |
b444786f | 5684 | .llseek = generic_file_llseek, |
4d3435b8 | 5685 | .release = tracing_release_generic_tr, |
c8d77183 SR |
5686 | }; |
5687 | ||
bc0c38d1 SR |
5688 | #ifdef CONFIG_DYNAMIC_FTRACE |
5689 | ||
b807c3d0 SR |
5690 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
5691 | { | |
5692 | return 0; | |
5693 | } | |
5694 | ||
bc0c38d1 | 5695 | static ssize_t |
b807c3d0 | 5696 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
5697 | size_t cnt, loff_t *ppos) |
5698 | { | |
a26a2a27 SR |
5699 | static char ftrace_dyn_info_buffer[1024]; |
5700 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 5701 | unsigned long *p = filp->private_data; |
b807c3d0 | 5702 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 5703 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
5704 | int r; |
5705 | ||
b807c3d0 SR |
5706 | mutex_lock(&dyn_info_mutex); |
5707 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 5708 | |
a26a2a27 | 5709 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
5710 | buf[r++] = '\n'; |
5711 | ||
5712 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
5713 | ||
5714 | mutex_unlock(&dyn_info_mutex); | |
5715 | ||
5716 | return r; | |
bc0c38d1 SR |
5717 | } |
5718 | ||
5e2336a0 | 5719 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 5720 | .open = tracing_open_generic, |
b807c3d0 | 5721 | .read = tracing_read_dyn_info, |
b444786f | 5722 | .llseek = generic_file_llseek, |
bc0c38d1 | 5723 | }; |
77fd5c15 | 5724 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
bc0c38d1 | 5725 | |
77fd5c15 SRRH |
5726 | #if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) |
5727 | static void | |
5728 | ftrace_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
5729 | { | |
5730 | tracing_snapshot(); | |
5731 | } | |
bc0c38d1 | 5732 | |
77fd5c15 SRRH |
5733 | static void |
5734 | ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
bc0c38d1 | 5735 | { |
77fd5c15 SRRH |
5736 | unsigned long *count = (long *)data; |
5737 | ||
5738 | if (!*count) | |
5739 | return; | |
bc0c38d1 | 5740 | |
77fd5c15 SRRH |
5741 | if (*count != -1) |
5742 | (*count)--; | |
5743 | ||
5744 | tracing_snapshot(); | |
5745 | } | |
5746 | ||
5747 | static int | |
5748 | ftrace_snapshot_print(struct seq_file *m, unsigned long ip, | |
5749 | struct ftrace_probe_ops *ops, void *data) | |
5750 | { | |
5751 | long count = (long)data; | |
5752 | ||
5753 | seq_printf(m, "%ps:", (void *)ip); | |
5754 | ||
5755 | seq_printf(m, "snapshot"); | |
5756 | ||
5757 | if (count == -1) | |
5758 | seq_printf(m, ":unlimited\n"); | |
5759 | else | |
5760 | seq_printf(m, ":count=%ld\n", count); | |
5761 | ||
5762 | return 0; | |
5763 | } | |
5764 | ||
5765 | static struct ftrace_probe_ops snapshot_probe_ops = { | |
5766 | .func = ftrace_snapshot, | |
5767 | .print = ftrace_snapshot_print, | |
5768 | }; | |
5769 | ||
5770 | static struct ftrace_probe_ops snapshot_count_probe_ops = { | |
5771 | .func = ftrace_count_snapshot, | |
5772 | .print = ftrace_snapshot_print, | |
5773 | }; | |
5774 | ||
5775 | static int | |
5776 | ftrace_trace_snapshot_callback(struct ftrace_hash *hash, | |
5777 | char *glob, char *cmd, char *param, int enable) | |
5778 | { | |
5779 | struct ftrace_probe_ops *ops; | |
5780 | void *count = (void *)-1; | |
5781 | char *number; | |
5782 | int ret; | |
5783 | ||
5784 | /* hash funcs only work with set_ftrace_filter */ | |
5785 | if (!enable) | |
5786 | return -EINVAL; | |
5787 | ||
5788 | ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; | |
5789 | ||
5790 | if (glob[0] == '!') { | |
5791 | unregister_ftrace_function_probe_func(glob+1, ops); | |
5792 | return 0; | |
5793 | } | |
5794 | ||
5795 | if (!param) | |
5796 | goto out_reg; | |
5797 | ||
5798 | number = strsep(¶m, ":"); | |
5799 | ||
5800 | if (!strlen(number)) | |
5801 | goto out_reg; | |
5802 | ||
5803 | /* | |
5804 | * We use the callback data field (which is a pointer) | |
5805 | * as our counter. | |
5806 | */ | |
5807 | ret = kstrtoul(number, 0, (unsigned long *)&count); | |
5808 | if (ret) | |
5809 | return ret; | |
5810 | ||
5811 | out_reg: | |
5812 | ret = register_ftrace_function_probe(glob, ops, count); | |
5813 | ||
5814 | if (ret >= 0) | |
5815 | alloc_snapshot(&global_trace); | |
5816 | ||
5817 | return ret < 0 ? ret : 0; | |
5818 | } | |
5819 | ||
5820 | static struct ftrace_func_command ftrace_snapshot_cmd = { | |
5821 | .name = "snapshot", | |
5822 | .func = ftrace_trace_snapshot_callback, | |
5823 | }; | |
5824 | ||
38de93ab | 5825 | static __init int register_snapshot_cmd(void) |
77fd5c15 SRRH |
5826 | { |
5827 | return register_ftrace_command(&ftrace_snapshot_cmd); | |
5828 | } | |
5829 | #else | |
38de93ab | 5830 | static inline __init int register_snapshot_cmd(void) { return 0; } |
77fd5c15 | 5831 | #endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ |
bc0c38d1 | 5832 | |
2b6080f2 | 5833 | struct dentry *tracing_init_dentry_tr(struct trace_array *tr) |
bc0c38d1 | 5834 | { |
2b6080f2 SR |
5835 | if (tr->dir) |
5836 | return tr->dir; | |
bc0c38d1 | 5837 | |
3e1f60b8 FW |
5838 | if (!debugfs_initialized()) |
5839 | return NULL; | |
5840 | ||
2b6080f2 SR |
5841 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) |
5842 | tr->dir = debugfs_create_dir("tracing", NULL); | |
bc0c38d1 | 5843 | |
687c878a J |
5844 | if (!tr->dir) |
5845 | pr_warn_once("Could not create debugfs directory 'tracing'\n"); | |
bc0c38d1 | 5846 | |
2b6080f2 | 5847 | return tr->dir; |
bc0c38d1 SR |
5848 | } |
5849 | ||
2b6080f2 SR |
5850 | struct dentry *tracing_init_dentry(void) |
5851 | { | |
5852 | return tracing_init_dentry_tr(&global_trace); | |
5853 | } | |
b04cc6b1 | 5854 | |
2b6080f2 | 5855 | static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) |
b04cc6b1 | 5856 | { |
b04cc6b1 FW |
5857 | struct dentry *d_tracer; |
5858 | ||
2b6080f2 SR |
5859 | if (tr->percpu_dir) |
5860 | return tr->percpu_dir; | |
b04cc6b1 | 5861 | |
2b6080f2 | 5862 | d_tracer = tracing_init_dentry_tr(tr); |
b04cc6b1 FW |
5863 | if (!d_tracer) |
5864 | return NULL; | |
5865 | ||
2b6080f2 | 5866 | tr->percpu_dir = debugfs_create_dir("per_cpu", d_tracer); |
b04cc6b1 | 5867 | |
2b6080f2 SR |
5868 | WARN_ONCE(!tr->percpu_dir, |
5869 | "Could not create debugfs directory 'per_cpu/%d'\n", cpu); | |
b04cc6b1 | 5870 | |
2b6080f2 | 5871 | return tr->percpu_dir; |
b04cc6b1 FW |
5872 | } |
5873 | ||
649e9c70 ON |
5874 | static struct dentry * |
5875 | trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent, | |
5876 | void *data, long cpu, const struct file_operations *fops) | |
5877 | { | |
5878 | struct dentry *ret = trace_create_file(name, mode, parent, data, fops); | |
5879 | ||
5880 | if (ret) /* See tracing_get_cpu() */ | |
5881 | ret->d_inode->i_cdev = (void *)(cpu + 1); | |
5882 | return ret; | |
5883 | } | |
5884 | ||
2b6080f2 SR |
5885 | static void |
5886 | tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) | |
b04cc6b1 | 5887 | { |
2b6080f2 | 5888 | struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu); |
5452af66 | 5889 | struct dentry *d_cpu; |
dd49a38c | 5890 | char cpu_dir[30]; /* 30 characters should be more than enough */ |
b04cc6b1 | 5891 | |
0a3d7ce7 NK |
5892 | if (!d_percpu) |
5893 | return; | |
5894 | ||
dd49a38c | 5895 | snprintf(cpu_dir, 30, "cpu%ld", cpu); |
8656e7a2 FW |
5896 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); |
5897 | if (!d_cpu) { | |
5898 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
5899 | return; | |
5900 | } | |
b04cc6b1 | 5901 | |
8656e7a2 | 5902 | /* per cpu trace_pipe */ |
649e9c70 | 5903 | trace_create_cpu_file("trace_pipe", 0444, d_cpu, |
15544209 | 5904 | tr, cpu, &tracing_pipe_fops); |
b04cc6b1 FW |
5905 | |
5906 | /* per cpu trace */ | |
649e9c70 | 5907 | trace_create_cpu_file("trace", 0644, d_cpu, |
6484c71c | 5908 | tr, cpu, &tracing_fops); |
7f96f93f | 5909 | |
649e9c70 | 5910 | trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu, |
46ef2be0 | 5911 | tr, cpu, &tracing_buffers_fops); |
7f96f93f | 5912 | |
649e9c70 | 5913 | trace_create_cpu_file("stats", 0444, d_cpu, |
4d3435b8 | 5914 | tr, cpu, &tracing_stats_fops); |
438ced17 | 5915 | |
649e9c70 | 5916 | trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, |
0bc392ee | 5917 | tr, cpu, &tracing_entries_fops); |
f1affcaa SRRH |
5918 | |
5919 | #ifdef CONFIG_TRACER_SNAPSHOT | |
649e9c70 | 5920 | trace_create_cpu_file("snapshot", 0644, d_cpu, |
6484c71c | 5921 | tr, cpu, &snapshot_fops); |
6de58e62 | 5922 | |
649e9c70 | 5923 | trace_create_cpu_file("snapshot_raw", 0444, d_cpu, |
46ef2be0 | 5924 | tr, cpu, &snapshot_raw_fops); |
f1affcaa | 5925 | #endif |
b04cc6b1 FW |
5926 | } |
5927 | ||
60a11774 SR |
5928 | #ifdef CONFIG_FTRACE_SELFTEST |
5929 | /* Let selftest have access to static functions in this file */ | |
5930 | #include "trace_selftest.c" | |
5931 | #endif | |
5932 | ||
577b785f SR |
5933 | struct trace_option_dentry { |
5934 | struct tracer_opt *opt; | |
5935 | struct tracer_flags *flags; | |
2b6080f2 | 5936 | struct trace_array *tr; |
577b785f SR |
5937 | struct dentry *entry; |
5938 | }; | |
5939 | ||
5940 | static ssize_t | |
5941 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
5942 | loff_t *ppos) | |
5943 | { | |
5944 | struct trace_option_dentry *topt = filp->private_data; | |
5945 | char *buf; | |
5946 | ||
5947 | if (topt->flags->val & topt->opt->bit) | |
5948 | buf = "1\n"; | |
5949 | else | |
5950 | buf = "0\n"; | |
5951 | ||
5952 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
5953 | } | |
5954 | ||
5955 | static ssize_t | |
5956 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
5957 | loff_t *ppos) | |
5958 | { | |
5959 | struct trace_option_dentry *topt = filp->private_data; | |
5960 | unsigned long val; | |
577b785f SR |
5961 | int ret; |
5962 | ||
22fe9b54 PH |
5963 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
5964 | if (ret) | |
577b785f SR |
5965 | return ret; |
5966 | ||
8d18eaaf LZ |
5967 | if (val != 0 && val != 1) |
5968 | return -EINVAL; | |
577b785f | 5969 | |
8d18eaaf | 5970 | if (!!(topt->flags->val & topt->opt->bit) != val) { |
577b785f | 5971 | mutex_lock(&trace_types_lock); |
8c1a49ae | 5972 | ret = __set_tracer_option(topt->tr, topt->flags, |
c757bea9 | 5973 | topt->opt, !val); |
577b785f SR |
5974 | mutex_unlock(&trace_types_lock); |
5975 | if (ret) | |
5976 | return ret; | |
577b785f SR |
5977 | } |
5978 | ||
5979 | *ppos += cnt; | |
5980 | ||
5981 | return cnt; | |
5982 | } | |
5983 | ||
5984 | ||
5985 | static const struct file_operations trace_options_fops = { | |
5986 | .open = tracing_open_generic, | |
5987 | .read = trace_options_read, | |
5988 | .write = trace_options_write, | |
b444786f | 5989 | .llseek = generic_file_llseek, |
577b785f SR |
5990 | }; |
5991 | ||
a8259075 SR |
5992 | static ssize_t |
5993 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
5994 | loff_t *ppos) | |
5995 | { | |
5996 | long index = (long)filp->private_data; | |
5997 | char *buf; | |
5998 | ||
5999 | if (trace_flags & (1 << index)) | |
6000 | buf = "1\n"; | |
6001 | else | |
6002 | buf = "0\n"; | |
6003 | ||
6004 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
6005 | } | |
6006 | ||
6007 | static ssize_t | |
6008 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
6009 | loff_t *ppos) | |
6010 | { | |
2b6080f2 | 6011 | struct trace_array *tr = &global_trace; |
a8259075 | 6012 | long index = (long)filp->private_data; |
a8259075 SR |
6013 | unsigned long val; |
6014 | int ret; | |
6015 | ||
22fe9b54 PH |
6016 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
6017 | if (ret) | |
a8259075 SR |
6018 | return ret; |
6019 | ||
f2d84b65 | 6020 | if (val != 0 && val != 1) |
a8259075 | 6021 | return -EINVAL; |
69d34da2 SRRH |
6022 | |
6023 | mutex_lock(&trace_types_lock); | |
2b6080f2 | 6024 | ret = set_tracer_flag(tr, 1 << index, val); |
69d34da2 | 6025 | mutex_unlock(&trace_types_lock); |
a8259075 | 6026 | |
613f04a0 SRRH |
6027 | if (ret < 0) |
6028 | return ret; | |
6029 | ||
a8259075 SR |
6030 | *ppos += cnt; |
6031 | ||
6032 | return cnt; | |
6033 | } | |
6034 | ||
a8259075 SR |
6035 | static const struct file_operations trace_options_core_fops = { |
6036 | .open = tracing_open_generic, | |
6037 | .read = trace_options_core_read, | |
6038 | .write = trace_options_core_write, | |
b444786f | 6039 | .llseek = generic_file_llseek, |
a8259075 SR |
6040 | }; |
6041 | ||
5452af66 | 6042 | struct dentry *trace_create_file(const char *name, |
f4ae40a6 | 6043 | umode_t mode, |
5452af66 FW |
6044 | struct dentry *parent, |
6045 | void *data, | |
6046 | const struct file_operations *fops) | |
6047 | { | |
6048 | struct dentry *ret; | |
6049 | ||
6050 | ret = debugfs_create_file(name, mode, parent, data, fops); | |
6051 | if (!ret) | |
6052 | pr_warning("Could not create debugfs '%s' entry\n", name); | |
6053 | ||
6054 | return ret; | |
6055 | } | |
6056 | ||
6057 | ||
2b6080f2 | 6058 | static struct dentry *trace_options_init_dentry(struct trace_array *tr) |
a8259075 SR |
6059 | { |
6060 | struct dentry *d_tracer; | |
a8259075 | 6061 | |
2b6080f2 SR |
6062 | if (tr->options) |
6063 | return tr->options; | |
a8259075 | 6064 | |
2b6080f2 | 6065 | d_tracer = tracing_init_dentry_tr(tr); |
a8259075 SR |
6066 | if (!d_tracer) |
6067 | return NULL; | |
6068 | ||
2b6080f2 SR |
6069 | tr->options = debugfs_create_dir("options", d_tracer); |
6070 | if (!tr->options) { | |
a8259075 SR |
6071 | pr_warning("Could not create debugfs directory 'options'\n"); |
6072 | return NULL; | |
6073 | } | |
6074 | ||
2b6080f2 | 6075 | return tr->options; |
a8259075 SR |
6076 | } |
6077 | ||
577b785f | 6078 | static void |
2b6080f2 SR |
6079 | create_trace_option_file(struct trace_array *tr, |
6080 | struct trace_option_dentry *topt, | |
577b785f SR |
6081 | struct tracer_flags *flags, |
6082 | struct tracer_opt *opt) | |
6083 | { | |
6084 | struct dentry *t_options; | |
577b785f | 6085 | |
2b6080f2 | 6086 | t_options = trace_options_init_dentry(tr); |
577b785f SR |
6087 | if (!t_options) |
6088 | return; | |
6089 | ||
6090 | topt->flags = flags; | |
6091 | topt->opt = opt; | |
2b6080f2 | 6092 | topt->tr = tr; |
577b785f | 6093 | |
5452af66 | 6094 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
577b785f SR |
6095 | &trace_options_fops); |
6096 | ||
577b785f SR |
6097 | } |
6098 | ||
6099 | static struct trace_option_dentry * | |
2b6080f2 | 6100 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer) |
577b785f SR |
6101 | { |
6102 | struct trace_option_dentry *topts; | |
6103 | struct tracer_flags *flags; | |
6104 | struct tracer_opt *opts; | |
6105 | int cnt; | |
6106 | ||
6107 | if (!tracer) | |
6108 | return NULL; | |
6109 | ||
6110 | flags = tracer->flags; | |
6111 | ||
6112 | if (!flags || !flags->opts) | |
6113 | return NULL; | |
6114 | ||
6115 | opts = flags->opts; | |
6116 | ||
6117 | for (cnt = 0; opts[cnt].name; cnt++) | |
6118 | ; | |
6119 | ||
0cfe8245 | 6120 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f SR |
6121 | if (!topts) |
6122 | return NULL; | |
6123 | ||
6124 | for (cnt = 0; opts[cnt].name; cnt++) | |
2b6080f2 | 6125 | create_trace_option_file(tr, &topts[cnt], flags, |
577b785f SR |
6126 | &opts[cnt]); |
6127 | ||
6128 | return topts; | |
6129 | } | |
6130 | ||
6131 | static void | |
6132 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
6133 | { | |
6134 | int cnt; | |
6135 | ||
6136 | if (!topts) | |
6137 | return; | |
6138 | ||
3f4d8f78 FF |
6139 | for (cnt = 0; topts[cnt].opt; cnt++) |
6140 | debugfs_remove(topts[cnt].entry); | |
577b785f SR |
6141 | |
6142 | kfree(topts); | |
6143 | } | |
6144 | ||
a8259075 | 6145 | static struct dentry * |
2b6080f2 SR |
6146 | create_trace_option_core_file(struct trace_array *tr, |
6147 | const char *option, long index) | |
a8259075 SR |
6148 | { |
6149 | struct dentry *t_options; | |
a8259075 | 6150 | |
2b6080f2 | 6151 | t_options = trace_options_init_dentry(tr); |
a8259075 SR |
6152 | if (!t_options) |
6153 | return NULL; | |
6154 | ||
5452af66 | 6155 | return trace_create_file(option, 0644, t_options, (void *)index, |
a8259075 | 6156 | &trace_options_core_fops); |
a8259075 SR |
6157 | } |
6158 | ||
2b6080f2 | 6159 | static __init void create_trace_options_dir(struct trace_array *tr) |
a8259075 SR |
6160 | { |
6161 | struct dentry *t_options; | |
a8259075 SR |
6162 | int i; |
6163 | ||
2b6080f2 | 6164 | t_options = trace_options_init_dentry(tr); |
a8259075 SR |
6165 | if (!t_options) |
6166 | return; | |
6167 | ||
5452af66 | 6168 | for (i = 0; trace_options[i]; i++) |
2b6080f2 | 6169 | create_trace_option_core_file(tr, trace_options[i], i); |
a8259075 SR |
6170 | } |
6171 | ||
499e5470 SR |
6172 | static ssize_t |
6173 | rb_simple_read(struct file *filp, char __user *ubuf, | |
6174 | size_t cnt, loff_t *ppos) | |
6175 | { | |
348f0fc2 | 6176 | struct trace_array *tr = filp->private_data; |
499e5470 SR |
6177 | char buf[64]; |
6178 | int r; | |
6179 | ||
10246fa3 | 6180 | r = tracer_tracing_is_on(tr); |
499e5470 SR |
6181 | r = sprintf(buf, "%d\n", r); |
6182 | ||
6183 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
6184 | } | |
6185 | ||
6186 | static ssize_t | |
6187 | rb_simple_write(struct file *filp, const char __user *ubuf, | |
6188 | size_t cnt, loff_t *ppos) | |
6189 | { | |
348f0fc2 | 6190 | struct trace_array *tr = filp->private_data; |
12883efb | 6191 | struct ring_buffer *buffer = tr->trace_buffer.buffer; |
499e5470 SR |
6192 | unsigned long val; |
6193 | int ret; | |
6194 | ||
6195 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
6196 | if (ret) | |
6197 | return ret; | |
6198 | ||
6199 | if (buffer) { | |
2df8f8a6 SR |
6200 | mutex_lock(&trace_types_lock); |
6201 | if (val) { | |
10246fa3 | 6202 | tracer_tracing_on(tr); |
2b6080f2 SR |
6203 | if (tr->current_trace->start) |
6204 | tr->current_trace->start(tr); | |
2df8f8a6 | 6205 | } else { |
10246fa3 | 6206 | tracer_tracing_off(tr); |
2b6080f2 SR |
6207 | if (tr->current_trace->stop) |
6208 | tr->current_trace->stop(tr); | |
2df8f8a6 SR |
6209 | } |
6210 | mutex_unlock(&trace_types_lock); | |
499e5470 SR |
6211 | } |
6212 | ||
6213 | (*ppos)++; | |
6214 | ||
6215 | return cnt; | |
6216 | } | |
6217 | ||
6218 | static const struct file_operations rb_simple_fops = { | |
7b85af63 | 6219 | .open = tracing_open_generic_tr, |
499e5470 SR |
6220 | .read = rb_simple_read, |
6221 | .write = rb_simple_write, | |
7b85af63 | 6222 | .release = tracing_release_generic_tr, |
499e5470 SR |
6223 | .llseek = default_llseek, |
6224 | }; | |
6225 | ||
277ba044 SR |
6226 | struct dentry *trace_instance_dir; |
6227 | ||
6228 | static void | |
6229 | init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer); | |
6230 | ||
55034cd6 SRRH |
6231 | static int |
6232 | allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size) | |
277ba044 SR |
6233 | { |
6234 | enum ring_buffer_flags rb_flags; | |
737223fb SRRH |
6235 | |
6236 | rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; | |
6237 | ||
dced341b SRRH |
6238 | buf->tr = tr; |
6239 | ||
55034cd6 SRRH |
6240 | buf->buffer = ring_buffer_alloc(size, rb_flags); |
6241 | if (!buf->buffer) | |
6242 | return -ENOMEM; | |
737223fb | 6243 | |
55034cd6 SRRH |
6244 | buf->data = alloc_percpu(struct trace_array_cpu); |
6245 | if (!buf->data) { | |
6246 | ring_buffer_free(buf->buffer); | |
6247 | return -ENOMEM; | |
6248 | } | |
737223fb | 6249 | |
737223fb SRRH |
6250 | /* Allocate the first page for all buffers */ |
6251 | set_buffer_entries(&tr->trace_buffer, | |
6252 | ring_buffer_size(tr->trace_buffer.buffer, 0)); | |
6253 | ||
55034cd6 SRRH |
6254 | return 0; |
6255 | } | |
737223fb | 6256 | |
55034cd6 SRRH |
6257 | static int allocate_trace_buffers(struct trace_array *tr, int size) |
6258 | { | |
6259 | int ret; | |
737223fb | 6260 | |
55034cd6 SRRH |
6261 | ret = allocate_trace_buffer(tr, &tr->trace_buffer, size); |
6262 | if (ret) | |
6263 | return ret; | |
737223fb | 6264 | |
55034cd6 SRRH |
6265 | #ifdef CONFIG_TRACER_MAX_TRACE |
6266 | ret = allocate_trace_buffer(tr, &tr->max_buffer, | |
6267 | allocate_snapshot ? size : 1); | |
6268 | if (WARN_ON(ret)) { | |
737223fb | 6269 | ring_buffer_free(tr->trace_buffer.buffer); |
55034cd6 SRRH |
6270 | free_percpu(tr->trace_buffer.data); |
6271 | return -ENOMEM; | |
6272 | } | |
6273 | tr->allocated_snapshot = allocate_snapshot; | |
737223fb | 6274 | |
55034cd6 SRRH |
6275 | /* |
6276 | * Only the top level trace array gets its snapshot allocated | |
6277 | * from the kernel command line. | |
6278 | */ | |
6279 | allocate_snapshot = false; | |
737223fb | 6280 | #endif |
55034cd6 | 6281 | return 0; |
737223fb SRRH |
6282 | } |
6283 | ||
f0b70cc4 SRRH |
6284 | static void free_trace_buffer(struct trace_buffer *buf) |
6285 | { | |
6286 | if (buf->buffer) { | |
6287 | ring_buffer_free(buf->buffer); | |
6288 | buf->buffer = NULL; | |
6289 | free_percpu(buf->data); | |
6290 | buf->data = NULL; | |
6291 | } | |
6292 | } | |
6293 | ||
23aaa3c1 SRRH |
6294 | static void free_trace_buffers(struct trace_array *tr) |
6295 | { | |
6296 | if (!tr) | |
6297 | return; | |
6298 | ||
f0b70cc4 | 6299 | free_trace_buffer(&tr->trace_buffer); |
23aaa3c1 SRRH |
6300 | |
6301 | #ifdef CONFIG_TRACER_MAX_TRACE | |
f0b70cc4 | 6302 | free_trace_buffer(&tr->max_buffer); |
23aaa3c1 SRRH |
6303 | #endif |
6304 | } | |
6305 | ||
737223fb SRRH |
6306 | static int new_instance_create(const char *name) |
6307 | { | |
277ba044 SR |
6308 | struct trace_array *tr; |
6309 | int ret; | |
277ba044 SR |
6310 | |
6311 | mutex_lock(&trace_types_lock); | |
6312 | ||
6313 | ret = -EEXIST; | |
6314 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6315 | if (tr->name && strcmp(tr->name, name) == 0) | |
6316 | goto out_unlock; | |
6317 | } | |
6318 | ||
6319 | ret = -ENOMEM; | |
6320 | tr = kzalloc(sizeof(*tr), GFP_KERNEL); | |
6321 | if (!tr) | |
6322 | goto out_unlock; | |
6323 | ||
6324 | tr->name = kstrdup(name, GFP_KERNEL); | |
6325 | if (!tr->name) | |
6326 | goto out_free_tr; | |
6327 | ||
ccfe9e42 AL |
6328 | if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL)) |
6329 | goto out_free_tr; | |
6330 | ||
6331 | cpumask_copy(tr->tracing_cpumask, cpu_all_mask); | |
6332 | ||
277ba044 SR |
6333 | raw_spin_lock_init(&tr->start_lock); |
6334 | ||
0b9b12c1 SRRH |
6335 | tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
6336 | ||
277ba044 SR |
6337 | tr->current_trace = &nop_trace; |
6338 | ||
6339 | INIT_LIST_HEAD(&tr->systems); | |
6340 | INIT_LIST_HEAD(&tr->events); | |
6341 | ||
737223fb | 6342 | if (allocate_trace_buffers(tr, trace_buf_size) < 0) |
277ba044 SR |
6343 | goto out_free_tr; |
6344 | ||
277ba044 SR |
6345 | tr->dir = debugfs_create_dir(name, trace_instance_dir); |
6346 | if (!tr->dir) | |
6347 | goto out_free_tr; | |
6348 | ||
6349 | ret = event_trace_add_tracer(tr->dir, tr); | |
609e85a7 AL |
6350 | if (ret) { |
6351 | debugfs_remove_recursive(tr->dir); | |
277ba044 | 6352 | goto out_free_tr; |
609e85a7 | 6353 | } |
277ba044 SR |
6354 | |
6355 | init_tracer_debugfs(tr, tr->dir); | |
6356 | ||
6357 | list_add(&tr->list, &ftrace_trace_arrays); | |
6358 | ||
6359 | mutex_unlock(&trace_types_lock); | |
6360 | ||
6361 | return 0; | |
6362 | ||
6363 | out_free_tr: | |
23aaa3c1 | 6364 | free_trace_buffers(tr); |
ccfe9e42 | 6365 | free_cpumask_var(tr->tracing_cpumask); |
277ba044 SR |
6366 | kfree(tr->name); |
6367 | kfree(tr); | |
6368 | ||
6369 | out_unlock: | |
6370 | mutex_unlock(&trace_types_lock); | |
6371 | ||
6372 | return ret; | |
6373 | ||
6374 | } | |
6375 | ||
0c8916c3 SR |
6376 | static int instance_delete(const char *name) |
6377 | { | |
6378 | struct trace_array *tr; | |
6379 | int found = 0; | |
6380 | int ret; | |
6381 | ||
6382 | mutex_lock(&trace_types_lock); | |
6383 | ||
6384 | ret = -ENODEV; | |
6385 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6386 | if (tr->name && strcmp(tr->name, name) == 0) { | |
6387 | found = 1; | |
6388 | break; | |
6389 | } | |
6390 | } | |
6391 | if (!found) | |
6392 | goto out_unlock; | |
6393 | ||
a695cb58 SRRH |
6394 | ret = -EBUSY; |
6395 | if (tr->ref) | |
6396 | goto out_unlock; | |
6397 | ||
0c8916c3 SR |
6398 | list_del(&tr->list); |
6399 | ||
6b450d25 | 6400 | tracing_set_nop(tr); |
0c8916c3 | 6401 | event_trace_del_tracer(tr); |
591dffda | 6402 | ftrace_destroy_function_files(tr); |
0c8916c3 | 6403 | debugfs_remove_recursive(tr->dir); |
a9fcaaac | 6404 | free_trace_buffers(tr); |
0c8916c3 SR |
6405 | |
6406 | kfree(tr->name); | |
6407 | kfree(tr); | |
6408 | ||
6409 | ret = 0; | |
6410 | ||
6411 | out_unlock: | |
6412 | mutex_unlock(&trace_types_lock); | |
6413 | ||
6414 | return ret; | |
6415 | } | |
6416 | ||
277ba044 SR |
6417 | static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t mode) |
6418 | { | |
6419 | struct dentry *parent; | |
6420 | int ret; | |
6421 | ||
6422 | /* Paranoid: Make sure the parent is the "instances" directory */ | |
6423 | parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias); | |
6424 | if (WARN_ON_ONCE(parent != trace_instance_dir)) | |
6425 | return -ENOENT; | |
6426 | ||
6427 | /* | |
6428 | * The inode mutex is locked, but debugfs_create_dir() will also | |
6429 | * take the mutex. As the instances directory can not be destroyed | |
6430 | * or changed in any other way, it is safe to unlock it, and | |
6431 | * let the dentry try. If two users try to make the same dir at | |
6432 | * the same time, then the new_instance_create() will determine the | |
6433 | * winner. | |
6434 | */ | |
6435 | mutex_unlock(&inode->i_mutex); | |
6436 | ||
6437 | ret = new_instance_create(dentry->d_iname); | |
6438 | ||
6439 | mutex_lock(&inode->i_mutex); | |
6440 | ||
6441 | return ret; | |
6442 | } | |
6443 | ||
0c8916c3 SR |
6444 | static int instance_rmdir(struct inode *inode, struct dentry *dentry) |
6445 | { | |
6446 | struct dentry *parent; | |
6447 | int ret; | |
6448 | ||
6449 | /* Paranoid: Make sure the parent is the "instances" directory */ | |
6450 | parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias); | |
6451 | if (WARN_ON_ONCE(parent != trace_instance_dir)) | |
6452 | return -ENOENT; | |
6453 | ||
6454 | /* The caller did a dget() on dentry */ | |
6455 | mutex_unlock(&dentry->d_inode->i_mutex); | |
6456 | ||
6457 | /* | |
6458 | * The inode mutex is locked, but debugfs_create_dir() will also | |
6459 | * take the mutex. As the instances directory can not be destroyed | |
6460 | * or changed in any other way, it is safe to unlock it, and | |
6461 | * let the dentry try. If two users try to make the same dir at | |
6462 | * the same time, then the instance_delete() will determine the | |
6463 | * winner. | |
6464 | */ | |
6465 | mutex_unlock(&inode->i_mutex); | |
6466 | ||
6467 | ret = instance_delete(dentry->d_iname); | |
6468 | ||
6469 | mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); | |
6470 | mutex_lock(&dentry->d_inode->i_mutex); | |
6471 | ||
6472 | return ret; | |
6473 | } | |
6474 | ||
277ba044 SR |
6475 | static const struct inode_operations instance_dir_inode_operations = { |
6476 | .lookup = simple_lookup, | |
6477 | .mkdir = instance_mkdir, | |
0c8916c3 | 6478 | .rmdir = instance_rmdir, |
277ba044 SR |
6479 | }; |
6480 | ||
6481 | static __init void create_trace_instances(struct dentry *d_tracer) | |
6482 | { | |
6483 | trace_instance_dir = debugfs_create_dir("instances", d_tracer); | |
6484 | if (WARN_ON(!trace_instance_dir)) | |
6485 | return; | |
6486 | ||
6487 | /* Hijack the dir inode operations, to allow mkdir */ | |
6488 | trace_instance_dir->d_inode->i_op = &instance_dir_inode_operations; | |
6489 | } | |
6490 | ||
2b6080f2 SR |
6491 | static void |
6492 | init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) | |
6493 | { | |
121aaee7 | 6494 | int cpu; |
2b6080f2 | 6495 | |
607e2ea1 SRRH |
6496 | trace_create_file("available_tracers", 0444, d_tracer, |
6497 | tr, &show_traces_fops); | |
6498 | ||
6499 | trace_create_file("current_tracer", 0644, d_tracer, | |
6500 | tr, &set_tracer_fops); | |
6501 | ||
ccfe9e42 AL |
6502 | trace_create_file("tracing_cpumask", 0644, d_tracer, |
6503 | tr, &tracing_cpumask_fops); | |
6504 | ||
2b6080f2 SR |
6505 | trace_create_file("trace_options", 0644, d_tracer, |
6506 | tr, &tracing_iter_fops); | |
6507 | ||
6508 | trace_create_file("trace", 0644, d_tracer, | |
6484c71c | 6509 | tr, &tracing_fops); |
2b6080f2 SR |
6510 | |
6511 | trace_create_file("trace_pipe", 0444, d_tracer, | |
15544209 | 6512 | tr, &tracing_pipe_fops); |
2b6080f2 SR |
6513 | |
6514 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
0bc392ee | 6515 | tr, &tracing_entries_fops); |
2b6080f2 SR |
6516 | |
6517 | trace_create_file("buffer_total_size_kb", 0444, d_tracer, | |
6518 | tr, &tracing_total_entries_fops); | |
6519 | ||
238ae93d | 6520 | trace_create_file("free_buffer", 0200, d_tracer, |
2b6080f2 SR |
6521 | tr, &tracing_free_buffer_fops); |
6522 | ||
6523 | trace_create_file("trace_marker", 0220, d_tracer, | |
6524 | tr, &tracing_mark_fops); | |
6525 | ||
6526 | trace_create_file("trace_clock", 0644, d_tracer, tr, | |
6527 | &trace_clock_fops); | |
6528 | ||
6529 | trace_create_file("tracing_on", 0644, d_tracer, | |
6484c71c | 6530 | tr, &rb_simple_fops); |
ce9bae55 | 6531 | |
6d9b3fa5 SRRH |
6532 | #ifdef CONFIG_TRACER_MAX_TRACE |
6533 | trace_create_file("tracing_max_latency", 0644, d_tracer, | |
6534 | &tr->max_latency, &tracing_max_lat_fops); | |
6535 | #endif | |
6536 | ||
591dffda SRRH |
6537 | if (ftrace_create_function_files(tr, d_tracer)) |
6538 | WARN(1, "Could not allocate function filter files"); | |
6539 | ||
ce9bae55 SRRH |
6540 | #ifdef CONFIG_TRACER_SNAPSHOT |
6541 | trace_create_file("snapshot", 0644, d_tracer, | |
6484c71c | 6542 | tr, &snapshot_fops); |
ce9bae55 | 6543 | #endif |
121aaee7 SRRH |
6544 | |
6545 | for_each_tracing_cpu(cpu) | |
6546 | tracing_init_debugfs_percpu(tr, cpu); | |
6547 | ||
2b6080f2 SR |
6548 | } |
6549 | ||
b5ad384e | 6550 | static __init int tracer_init_debugfs(void) |
bc0c38d1 SR |
6551 | { |
6552 | struct dentry *d_tracer; | |
bc0c38d1 | 6553 | |
7e53bd42 LJ |
6554 | trace_access_lock_init(); |
6555 | ||
bc0c38d1 | 6556 | d_tracer = tracing_init_dentry(); |
ed6f1c99 NK |
6557 | if (!d_tracer) |
6558 | return 0; | |
bc0c38d1 | 6559 | |
2b6080f2 | 6560 | init_tracer_debugfs(&global_trace, d_tracer); |
bc0c38d1 | 6561 | |
5452af66 | 6562 | trace_create_file("tracing_thresh", 0644, d_tracer, |
6508fa76 | 6563 | &global_trace, &tracing_thresh_fops); |
a8259075 | 6564 | |
339ae5d3 | 6565 | trace_create_file("README", 0444, d_tracer, |
5452af66 FW |
6566 | NULL, &tracing_readme_fops); |
6567 | ||
69abe6a5 AP |
6568 | trace_create_file("saved_cmdlines", 0444, d_tracer, |
6569 | NULL, &tracing_saved_cmdlines_fops); | |
5bf9a1ee | 6570 | |
939c7a4f YY |
6571 | trace_create_file("saved_cmdlines_size", 0644, d_tracer, |
6572 | NULL, &tracing_saved_cmdlines_size_fops); | |
6573 | ||
bc0c38d1 | 6574 | #ifdef CONFIG_DYNAMIC_FTRACE |
5452af66 FW |
6575 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
6576 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
bc0c38d1 | 6577 | #endif |
b04cc6b1 | 6578 | |
277ba044 | 6579 | create_trace_instances(d_tracer); |
5452af66 | 6580 | |
2b6080f2 | 6581 | create_trace_options_dir(&global_trace); |
b04cc6b1 | 6582 | |
b5ad384e | 6583 | return 0; |
bc0c38d1 SR |
6584 | } |
6585 | ||
3f5a54e3 SR |
6586 | static int trace_panic_handler(struct notifier_block *this, |
6587 | unsigned long event, void *unused) | |
6588 | { | |
944ac425 | 6589 | if (ftrace_dump_on_oops) |
cecbca96 | 6590 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
6591 | return NOTIFY_OK; |
6592 | } | |
6593 | ||
6594 | static struct notifier_block trace_panic_notifier = { | |
6595 | .notifier_call = trace_panic_handler, | |
6596 | .next = NULL, | |
6597 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
6598 | }; | |
6599 | ||
6600 | static int trace_die_handler(struct notifier_block *self, | |
6601 | unsigned long val, | |
6602 | void *data) | |
6603 | { | |
6604 | switch (val) { | |
6605 | case DIE_OOPS: | |
944ac425 | 6606 | if (ftrace_dump_on_oops) |
cecbca96 | 6607 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
6608 | break; |
6609 | default: | |
6610 | break; | |
6611 | } | |
6612 | return NOTIFY_OK; | |
6613 | } | |
6614 | ||
6615 | static struct notifier_block trace_die_notifier = { | |
6616 | .notifier_call = trace_die_handler, | |
6617 | .priority = 200 | |
6618 | }; | |
6619 | ||
6620 | /* | |
6621 | * printk is set to max of 1024, we really don't need it that big. | |
6622 | * Nothing should be printing 1000 characters anyway. | |
6623 | */ | |
6624 | #define TRACE_MAX_PRINT 1000 | |
6625 | ||
6626 | /* | |
6627 | * Define here KERN_TRACE so that we have one place to modify | |
6628 | * it if we decide to change what log level the ftrace dump | |
6629 | * should be at. | |
6630 | */ | |
428aee14 | 6631 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 | 6632 | |
955b61e5 | 6633 | void |
3f5a54e3 SR |
6634 | trace_printk_seq(struct trace_seq *s) |
6635 | { | |
6636 | /* Probably should print a warning here. */ | |
bd6df187 J |
6637 | if (s->len >= TRACE_MAX_PRINT) |
6638 | s->len = TRACE_MAX_PRINT; | |
3f5a54e3 SR |
6639 | |
6640 | /* should be zero ended, but we are paranoid. */ | |
6641 | s->buffer[s->len] = 0; | |
6642 | ||
6643 | printk(KERN_TRACE "%s", s->buffer); | |
6644 | ||
f9520750 | 6645 | trace_seq_init(s); |
3f5a54e3 SR |
6646 | } |
6647 | ||
955b61e5 JW |
6648 | void trace_init_global_iter(struct trace_iterator *iter) |
6649 | { | |
6650 | iter->tr = &global_trace; | |
2b6080f2 | 6651 | iter->trace = iter->tr->current_trace; |
ae3b5093 | 6652 | iter->cpu_file = RING_BUFFER_ALL_CPUS; |
12883efb | 6653 | iter->trace_buffer = &global_trace.trace_buffer; |
b2f974d6 CS |
6654 | |
6655 | if (iter->trace && iter->trace->open) | |
6656 | iter->trace->open(iter); | |
6657 | ||
6658 | /* Annotate start of buffers if we had overruns */ | |
6659 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) | |
6660 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
6661 | ||
6662 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ | |
6663 | if (trace_clocks[iter->tr->clock_id].in_ns) | |
6664 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
955b61e5 JW |
6665 | } |
6666 | ||
7fe70b57 | 6667 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) |
3f5a54e3 | 6668 | { |
3f5a54e3 SR |
6669 | /* use static because iter can be a bit big for the stack */ |
6670 | static struct trace_iterator iter; | |
7fe70b57 | 6671 | static atomic_t dump_running; |
cf586b61 | 6672 | unsigned int old_userobj; |
d769041f SR |
6673 | unsigned long flags; |
6674 | int cnt = 0, cpu; | |
3f5a54e3 | 6675 | |
7fe70b57 SRRH |
6676 | /* Only allow one dump user at a time. */ |
6677 | if (atomic_inc_return(&dump_running) != 1) { | |
6678 | atomic_dec(&dump_running); | |
6679 | return; | |
6680 | } | |
3f5a54e3 | 6681 | |
7fe70b57 SRRH |
6682 | /* |
6683 | * Always turn off tracing when we dump. | |
6684 | * We don't need to show trace output of what happens | |
6685 | * between multiple crashes. | |
6686 | * | |
6687 | * If the user does a sysrq-z, then they can re-enable | |
6688 | * tracing with echo 1 > tracing_on. | |
6689 | */ | |
0ee6b6cf | 6690 | tracing_off(); |
cf586b61 | 6691 | |
7fe70b57 | 6692 | local_irq_save(flags); |
3f5a54e3 | 6693 | |
38dbe0b1 | 6694 | /* Simulate the iterator */ |
955b61e5 JW |
6695 | trace_init_global_iter(&iter); |
6696 | ||
d769041f | 6697 | for_each_tracing_cpu(cpu) { |
12883efb | 6698 | atomic_inc(&per_cpu_ptr(iter.tr->trace_buffer.data, cpu)->disabled); |
d769041f SR |
6699 | } |
6700 | ||
cf586b61 FW |
6701 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; |
6702 | ||
b54d3de9 TE |
6703 | /* don't look at user memory in panic mode */ |
6704 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
6705 | ||
cecbca96 FW |
6706 | switch (oops_dump_mode) { |
6707 | case DUMP_ALL: | |
ae3b5093 | 6708 | iter.cpu_file = RING_BUFFER_ALL_CPUS; |
cecbca96 FW |
6709 | break; |
6710 | case DUMP_ORIG: | |
6711 | iter.cpu_file = raw_smp_processor_id(); | |
6712 | break; | |
6713 | case DUMP_NONE: | |
6714 | goto out_enable; | |
6715 | default: | |
6716 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
ae3b5093 | 6717 | iter.cpu_file = RING_BUFFER_ALL_CPUS; |
cecbca96 FW |
6718 | } |
6719 | ||
6720 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
3f5a54e3 | 6721 | |
7fe70b57 SRRH |
6722 | /* Did function tracer already get disabled? */ |
6723 | if (ftrace_is_dead()) { | |
6724 | printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
6725 | printk("# MAY BE MISSING FUNCTION EVENTS\n"); | |
6726 | } | |
6727 | ||
3f5a54e3 SR |
6728 | /* |
6729 | * We need to stop all tracing on all CPUS to read the | |
6730 | * the next buffer. This is a bit expensive, but is | |
6731 | * not done often. We fill all what we can read, | |
6732 | * and then release the locks again. | |
6733 | */ | |
6734 | ||
3f5a54e3 SR |
6735 | while (!trace_empty(&iter)) { |
6736 | ||
6737 | if (!cnt) | |
6738 | printk(KERN_TRACE "---------------------------------\n"); | |
6739 | ||
6740 | cnt++; | |
6741 | ||
6742 | /* reset all but tr, trace, and overruns */ | |
6743 | memset(&iter.seq, 0, | |
6744 | sizeof(struct trace_iterator) - | |
6745 | offsetof(struct trace_iterator, seq)); | |
6746 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
6747 | iter.pos = -1; | |
6748 | ||
955b61e5 | 6749 | if (trace_find_next_entry_inc(&iter) != NULL) { |
74e7ff8c LJ |
6750 | int ret; |
6751 | ||
6752 | ret = print_trace_line(&iter); | |
6753 | if (ret != TRACE_TYPE_NO_CONSUME) | |
6754 | trace_consume(&iter); | |
3f5a54e3 | 6755 | } |
b892e5c8 | 6756 | touch_nmi_watchdog(); |
3f5a54e3 SR |
6757 | |
6758 | trace_printk_seq(&iter.seq); | |
6759 | } | |
6760 | ||
6761 | if (!cnt) | |
6762 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
6763 | else | |
6764 | printk(KERN_TRACE "---------------------------------\n"); | |
6765 | ||
cecbca96 | 6766 | out_enable: |
7fe70b57 | 6767 | trace_flags |= old_userobj; |
cf586b61 | 6768 | |
7fe70b57 SRRH |
6769 | for_each_tracing_cpu(cpu) { |
6770 | atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); | |
cf586b61 | 6771 | } |
7fe70b57 | 6772 | atomic_dec(&dump_running); |
cd891ae0 | 6773 | local_irq_restore(flags); |
3f5a54e3 | 6774 | } |
a8eecf22 | 6775 | EXPORT_SYMBOL_GPL(ftrace_dump); |
cf586b61 | 6776 | |
3928a8a2 | 6777 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 6778 | { |
73c5162a | 6779 | int ring_buf_size; |
9e01c1b7 | 6780 | int ret = -ENOMEM; |
4c11d7ae | 6781 | |
750912fa | 6782 | |
9e01c1b7 RR |
6783 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
6784 | goto out; | |
6785 | ||
ccfe9e42 | 6786 | if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL)) |
9e01c1b7 | 6787 | goto out_free_buffer_mask; |
4c11d7ae | 6788 | |
07d777fe SR |
6789 | /* Only allocate trace_printk buffers if a trace_printk exists */ |
6790 | if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) | |
81698831 | 6791 | /* Must be called before global_trace.buffer is allocated */ |
07d777fe SR |
6792 | trace_printk_init_buffers(); |
6793 | ||
73c5162a SR |
6794 | /* To save memory, keep the ring buffer size to its minimum */ |
6795 | if (ring_buffer_expanded) | |
6796 | ring_buf_size = trace_buf_size; | |
6797 | else | |
6798 | ring_buf_size = 1; | |
6799 | ||
9e01c1b7 | 6800 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
ccfe9e42 | 6801 | cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask); |
9e01c1b7 | 6802 | |
2b6080f2 SR |
6803 | raw_spin_lock_init(&global_trace.start_lock); |
6804 | ||
2c4a33ab SRRH |
6805 | /* Used for event triggers */ |
6806 | temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE); | |
6807 | if (!temp_buffer) | |
6808 | goto out_free_cpumask; | |
6809 | ||
939c7a4f YY |
6810 | if (trace_create_savedcmd() < 0) |
6811 | goto out_free_temp_buffer; | |
6812 | ||
9e01c1b7 | 6813 | /* TODO: make the number of buffers hot pluggable with CPUS */ |
737223fb | 6814 | if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { |
3928a8a2 SR |
6815 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); |
6816 | WARN_ON(1); | |
939c7a4f | 6817 | goto out_free_savedcmd; |
4c11d7ae | 6818 | } |
a7603ff4 | 6819 | |
499e5470 SR |
6820 | if (global_trace.buffer_disabled) |
6821 | tracing_off(); | |
4c11d7ae | 6822 | |
e1e232ca SR |
6823 | if (trace_boot_clock) { |
6824 | ret = tracing_set_clock(&global_trace, trace_boot_clock); | |
6825 | if (ret < 0) | |
6826 | pr_warning("Trace clock %s not defined, going back to default\n", | |
6827 | trace_boot_clock); | |
6828 | } | |
6829 | ||
ca164318 SRRH |
6830 | /* |
6831 | * register_tracer() might reference current_trace, so it | |
6832 | * needs to be set before we register anything. This is | |
6833 | * just a bootstrap of current_trace anyway. | |
6834 | */ | |
2b6080f2 SR |
6835 | global_trace.current_trace = &nop_trace; |
6836 | ||
0b9b12c1 SRRH |
6837 | global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
6838 | ||
4104d326 SRRH |
6839 | ftrace_init_global_array_ops(&global_trace); |
6840 | ||
ca164318 SRRH |
6841 | register_tracer(&nop_trace); |
6842 | ||
60a11774 SR |
6843 | /* All seems OK, enable tracing */ |
6844 | tracing_disabled = 0; | |
3928a8a2 | 6845 | |
3f5a54e3 SR |
6846 | atomic_notifier_chain_register(&panic_notifier_list, |
6847 | &trace_panic_notifier); | |
6848 | ||
6849 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe | 6850 | |
ae63b31e SR |
6851 | global_trace.flags = TRACE_ARRAY_FL_GLOBAL; |
6852 | ||
6853 | INIT_LIST_HEAD(&global_trace.systems); | |
6854 | INIT_LIST_HEAD(&global_trace.events); | |
6855 | list_add(&global_trace.list, &ftrace_trace_arrays); | |
6856 | ||
7bcfaf54 SR |
6857 | while (trace_boot_options) { |
6858 | char *option; | |
6859 | ||
6860 | option = strsep(&trace_boot_options, ","); | |
2b6080f2 | 6861 | trace_set_options(&global_trace, option); |
7bcfaf54 SR |
6862 | } |
6863 | ||
77fd5c15 SRRH |
6864 | register_snapshot_cmd(); |
6865 | ||
2fc1dfbe | 6866 | return 0; |
3f5a54e3 | 6867 | |
939c7a4f YY |
6868 | out_free_savedcmd: |
6869 | free_saved_cmdlines_buffer(savedcmd); | |
2c4a33ab SRRH |
6870 | out_free_temp_buffer: |
6871 | ring_buffer_free(temp_buffer); | |
9e01c1b7 | 6872 | out_free_cpumask: |
ccfe9e42 | 6873 | free_cpumask_var(global_trace.tracing_cpumask); |
9e01c1b7 RR |
6874 | out_free_buffer_mask: |
6875 | free_cpumask_var(tracing_buffer_mask); | |
6876 | out: | |
6877 | return ret; | |
bc0c38d1 | 6878 | } |
b2821ae6 SR |
6879 | |
6880 | __init static int clear_boot_tracer(void) | |
6881 | { | |
6882 | /* | |
6883 | * The default tracer at boot buffer is an init section. | |
6884 | * This function is called in lateinit. If we did not | |
6885 | * find the boot tracer, then clear it out, to prevent | |
6886 | * later registration from accessing the buffer that is | |
6887 | * about to be freed. | |
6888 | */ | |
6889 | if (!default_bootup_tracer) | |
6890 | return 0; | |
6891 | ||
6892 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
6893 | default_bootup_tracer); | |
6894 | default_bootup_tracer = NULL; | |
6895 | ||
6896 | return 0; | |
6897 | } | |
6898 | ||
b5ad384e FW |
6899 | early_initcall(tracer_alloc_buffers); |
6900 | fs_initcall(tracer_init_debugfs); | |
b2821ae6 | 6901 | late_initcall(clear_boot_tracer); |