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Commit | Line | Data |
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bc0c38d1 SR |
1 | /* |
2 | * ring buffer based function tracer | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
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 | |
12 | * Copyright (C) 2004 William Lee Irwin III | |
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> | |
405f5571 | 20 | #include <linux/smp_lock.h> |
3f5a54e3 | 21 | #include <linux/notifier.h> |
2cadf913 | 22 | #include <linux/irqflags.h> |
bc0c38d1 | 23 | #include <linux/debugfs.h> |
4c11d7ae | 24 | #include <linux/pagemap.h> |
bc0c38d1 SR |
25 | #include <linux/hardirq.h> |
26 | #include <linux/linkage.h> | |
27 | #include <linux/uaccess.h> | |
2cadf913 | 28 | #include <linux/kprobes.h> |
bc0c38d1 SR |
29 | #include <linux/ftrace.h> |
30 | #include <linux/module.h> | |
31 | #include <linux/percpu.h> | |
2cadf913 | 32 | #include <linux/splice.h> |
3f5a54e3 | 33 | #include <linux/kdebug.h> |
5f0c6c03 | 34 | #include <linux/string.h> |
7e53bd42 | 35 | #include <linux/rwsem.h> |
bc0c38d1 SR |
36 | #include <linux/ctype.h> |
37 | #include <linux/init.h> | |
2a2cc8f7 | 38 | #include <linux/poll.h> |
bc0c38d1 SR |
39 | #include <linux/gfp.h> |
40 | #include <linux/fs.h> | |
86387f7e | 41 | |
bc0c38d1 | 42 | #include "trace.h" |
f0868d1e | 43 | #include "trace_output.h" |
bc0c38d1 | 44 | |
3928a8a2 SR |
45 | #define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE) |
46 | ||
73c5162a SR |
47 | /* |
48 | * On boot up, the ring buffer is set to the minimum size, so that | |
49 | * we do not waste memory on systems that are not using tracing. | |
50 | */ | |
020e5f85 | 51 | int ring_buffer_expanded; |
73c5162a | 52 | |
8e1b82e0 FW |
53 | /* |
54 | * We need to change this state when a selftest is running. | |
ff32504f FW |
55 | * A selftest will lurk into the ring-buffer to count the |
56 | * entries inserted during the selftest although some concurrent | |
5e1607a0 | 57 | * insertions into the ring-buffer such as trace_printk could occurred |
ff32504f FW |
58 | * at the same time, giving false positive or negative results. |
59 | */ | |
8e1b82e0 | 60 | static bool __read_mostly tracing_selftest_running; |
ff32504f | 61 | |
b2821ae6 SR |
62 | /* |
63 | * If a tracer is running, we do not want to run SELFTEST. | |
64 | */ | |
020e5f85 | 65 | bool __read_mostly tracing_selftest_disabled; |
b2821ae6 | 66 | |
adf9f195 FW |
67 | /* For tracers that don't implement custom flags */ |
68 | static struct tracer_opt dummy_tracer_opt[] = { | |
69 | { } | |
70 | }; | |
71 | ||
72 | static struct tracer_flags dummy_tracer_flags = { | |
73 | .val = 0, | |
74 | .opts = dummy_tracer_opt | |
75 | }; | |
76 | ||
77 | static int dummy_set_flag(u32 old_flags, u32 bit, int set) | |
78 | { | |
79 | return 0; | |
80 | } | |
0f048701 SR |
81 | |
82 | /* | |
83 | * Kill all tracing for good (never come back). | |
84 | * It is initialized to 1 but will turn to zero if the initialization | |
85 | * of the tracer is successful. But that is the only place that sets | |
86 | * this back to zero. | |
87 | */ | |
4fd27358 | 88 | static int tracing_disabled = 1; |
0f048701 | 89 | |
9288f99a | 90 | DEFINE_PER_CPU(int, ftrace_cpu_disabled); |
d769041f SR |
91 | |
92 | static inline void ftrace_disable_cpu(void) | |
93 | { | |
94 | preempt_disable(); | |
9288f99a | 95 | __this_cpu_inc(per_cpu_var(ftrace_cpu_disabled)); |
d769041f SR |
96 | } |
97 | ||
98 | static inline void ftrace_enable_cpu(void) | |
99 | { | |
9288f99a | 100 | __this_cpu_dec(per_cpu_var(ftrace_cpu_disabled)); |
d769041f SR |
101 | preempt_enable(); |
102 | } | |
103 | ||
9e01c1b7 | 104 | static cpumask_var_t __read_mostly tracing_buffer_mask; |
ab46428c SR |
105 | |
106 | #define for_each_tracing_cpu(cpu) \ | |
9e01c1b7 | 107 | for_each_cpu(cpu, tracing_buffer_mask) |
ab46428c | 108 | |
944ac425 SR |
109 | /* |
110 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
111 | * | |
112 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
113 | * is set, then ftrace_dump is called. This will output the contents | |
114 | * of the ftrace buffers to the console. This is very useful for | |
115 | * capturing traces that lead to crashes and outputing it to a | |
116 | * serial console. | |
117 | * | |
118 | * It is default off, but you can enable it with either specifying | |
119 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
120 | * /proc/sys/kernel/ftrace_dump_on_oops to true. | |
121 | */ | |
122 | int ftrace_dump_on_oops; | |
123 | ||
b2821ae6 SR |
124 | static int tracing_set_tracer(const char *buf); |
125 | ||
ee6c2c1b LZ |
126 | #define MAX_TRACER_SIZE 100 |
127 | static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; | |
b2821ae6 | 128 | static char *default_bootup_tracer; |
d9e54076 | 129 | |
1beee96b | 130 | static int __init set_cmdline_ftrace(char *str) |
d9e54076 | 131 | { |
ee6c2c1b | 132 | strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); |
b2821ae6 | 133 | default_bootup_tracer = bootup_tracer_buf; |
73c5162a SR |
134 | /* We are using ftrace early, expand it */ |
135 | ring_buffer_expanded = 1; | |
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 | { | |
142 | ftrace_dump_on_oops = 1; | |
143 | return 1; | |
144 | } | |
145 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
60a11774 | 146 | |
cf8e3474 | 147 | unsigned long long ns2usecs(cycle_t nsec) |
bc0c38d1 SR |
148 | { |
149 | nsec += 500; | |
150 | do_div(nsec, 1000); | |
151 | return nsec; | |
152 | } | |
153 | ||
4fcdae83 SR |
154 | /* |
155 | * The global_trace is the descriptor that holds the tracing | |
156 | * buffers for the live tracing. For each CPU, it contains | |
157 | * a link list of pages that will store trace entries. The | |
158 | * page descriptor of the pages in the memory is used to hold | |
159 | * the link list by linking the lru item in the page descriptor | |
160 | * to each of the pages in the buffer per CPU. | |
161 | * | |
162 | * For each active CPU there is a data field that holds the | |
163 | * pages for the buffer for that CPU. Each CPU has the same number | |
164 | * of pages allocated for its buffer. | |
165 | */ | |
bc0c38d1 SR |
166 | static struct trace_array global_trace; |
167 | ||
168 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
169 | ||
e77405ad SR |
170 | int filter_current_check_discard(struct ring_buffer *buffer, |
171 | struct ftrace_event_call *call, void *rec, | |
eb02ce01 TZ |
172 | struct ring_buffer_event *event) |
173 | { | |
e77405ad | 174 | return filter_check_discard(call, rec, buffer, event); |
eb02ce01 | 175 | } |
17c873ec | 176 | EXPORT_SYMBOL_GPL(filter_current_check_discard); |
eb02ce01 | 177 | |
37886f6a SR |
178 | cycle_t ftrace_now(int cpu) |
179 | { | |
180 | u64 ts; | |
181 | ||
182 | /* Early boot up does not have a buffer yet */ | |
183 | if (!global_trace.buffer) | |
184 | return trace_clock_local(); | |
185 | ||
186 | ts = ring_buffer_time_stamp(global_trace.buffer, cpu); | |
187 | ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts); | |
188 | ||
189 | return ts; | |
190 | } | |
bc0c38d1 | 191 | |
4fcdae83 SR |
192 | /* |
193 | * The max_tr is used to snapshot the global_trace when a maximum | |
194 | * latency is reached. Some tracers will use this to store a maximum | |
195 | * trace while it continues examining live traces. | |
196 | * | |
197 | * The buffers for the max_tr are set up the same as the global_trace. | |
198 | * When a snapshot is taken, the link list of the max_tr is swapped | |
199 | * with the link list of the global_trace and the buffers are reset for | |
200 | * the global_trace so the tracing can continue. | |
201 | */ | |
bc0c38d1 SR |
202 | static struct trace_array max_tr; |
203 | ||
9705f69e | 204 | static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data); |
bc0c38d1 | 205 | |
4fcdae83 | 206 | /* tracer_enabled is used to toggle activation of a tracer */ |
26994ead | 207 | static int tracer_enabled = 1; |
4fcdae83 | 208 | |
9036990d SR |
209 | /** |
210 | * tracing_is_enabled - return tracer_enabled status | |
211 | * | |
212 | * This function is used by other tracers to know the status | |
213 | * of the tracer_enabled flag. Tracers may use this function | |
214 | * to know if it should enable their features when starting | |
215 | * up. See irqsoff tracer for an example (start_irqsoff_tracer). | |
216 | */ | |
217 | int tracing_is_enabled(void) | |
218 | { | |
219 | return tracer_enabled; | |
220 | } | |
221 | ||
4fcdae83 | 222 | /* |
3928a8a2 SR |
223 | * trace_buf_size is the size in bytes that is allocated |
224 | * for a buffer. Note, the number of bytes is always rounded | |
225 | * to page size. | |
3f5a54e3 SR |
226 | * |
227 | * This number is purposely set to a low number of 16384. | |
228 | * If the dump on oops happens, it will be much appreciated | |
229 | * to not have to wait for all that output. Anyway this can be | |
230 | * boot time and run time configurable. | |
4fcdae83 | 231 | */ |
3928a8a2 | 232 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 233 | |
3928a8a2 | 234 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 235 | |
4fcdae83 | 236 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 237 | static struct tracer *trace_types __read_mostly; |
4fcdae83 SR |
238 | |
239 | /* current_trace points to the tracer that is currently active */ | |
bc0c38d1 | 240 | static struct tracer *current_trace __read_mostly; |
4fcdae83 | 241 | |
4fcdae83 SR |
242 | /* |
243 | * trace_types_lock is used to protect the trace_types list. | |
4fcdae83 | 244 | */ |
bc0c38d1 | 245 | static DEFINE_MUTEX(trace_types_lock); |
4fcdae83 | 246 | |
7e53bd42 LJ |
247 | /* |
248 | * serialize the access of the ring buffer | |
249 | * | |
250 | * ring buffer serializes readers, but it is low level protection. | |
251 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
252 | * are not protected by ring buffer. | |
253 | * | |
254 | * The content of events may become garbage if we allow other process consumes | |
255 | * these events concurrently: | |
256 | * A) the page of the consumed events may become a normal page | |
257 | * (not reader page) in ring buffer, and this page will be rewrited | |
258 | * by events producer. | |
259 | * B) The page of the consumed events may become a page for splice_read, | |
260 | * and this page will be returned to system. | |
261 | * | |
262 | * These primitives allow multi process access to different cpu ring buffer | |
263 | * concurrently. | |
264 | * | |
265 | * These primitives don't distinguish read-only and read-consume access. | |
266 | * Multi read-only access are also serialized. | |
267 | */ | |
268 | ||
269 | #ifdef CONFIG_SMP | |
270 | static DECLARE_RWSEM(all_cpu_access_lock); | |
271 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
272 | ||
273 | static inline void trace_access_lock(int cpu) | |
274 | { | |
275 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
276 | /* gain it for accessing the whole ring buffer. */ | |
277 | down_write(&all_cpu_access_lock); | |
278 | } else { | |
279 | /* gain it for accessing a cpu ring buffer. */ | |
280 | ||
281 | /* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */ | |
282 | down_read(&all_cpu_access_lock); | |
283 | ||
284 | /* Secondly block other access to this @cpu ring buffer. */ | |
285 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
286 | } | |
287 | } | |
288 | ||
289 | static inline void trace_access_unlock(int cpu) | |
290 | { | |
291 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
292 | up_write(&all_cpu_access_lock); | |
293 | } else { | |
294 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
295 | up_read(&all_cpu_access_lock); | |
296 | } | |
297 | } | |
298 | ||
299 | static inline void trace_access_lock_init(void) | |
300 | { | |
301 | int cpu; | |
302 | ||
303 | for_each_possible_cpu(cpu) | |
304 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
305 | } | |
306 | ||
307 | #else | |
308 | ||
309 | static DEFINE_MUTEX(access_lock); | |
310 | ||
311 | static inline void trace_access_lock(int cpu) | |
312 | { | |
313 | (void)cpu; | |
314 | mutex_lock(&access_lock); | |
315 | } | |
316 | ||
317 | static inline void trace_access_unlock(int cpu) | |
318 | { | |
319 | (void)cpu; | |
320 | mutex_unlock(&access_lock); | |
321 | } | |
322 | ||
323 | static inline void trace_access_lock_init(void) | |
324 | { | |
325 | } | |
326 | ||
327 | #endif | |
328 | ||
4fcdae83 | 329 | /* trace_wait is a waitqueue for tasks blocked on trace_poll */ |
4e655519 IM |
330 | static DECLARE_WAIT_QUEUE_HEAD(trace_wait); |
331 | ||
ee6bce52 | 332 | /* trace_flags holds trace_options default values */ |
12ef7d44 | 333 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | |
a2a16d6a SR |
334 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | |
335 | TRACE_ITER_GRAPH_TIME; | |
4e655519 | 336 | |
b8de7bd1 SR |
337 | static int trace_stop_count; |
338 | static DEFINE_SPINLOCK(tracing_start_lock); | |
339 | ||
4fcdae83 SR |
340 | /** |
341 | * trace_wake_up - wake up tasks waiting for trace input | |
342 | * | |
343 | * Simply wakes up any task that is blocked on the trace_wait | |
344 | * queue. These is used with trace_poll for tasks polling the trace. | |
345 | */ | |
4e655519 IM |
346 | void trace_wake_up(void) |
347 | { | |
89f19f04 AM |
348 | int cpu; |
349 | ||
350 | if (trace_flags & TRACE_ITER_BLOCK) | |
351 | return; | |
017730c1 IM |
352 | /* |
353 | * The runqueue_is_locked() can fail, but this is the best we | |
354 | * have for now: | |
355 | */ | |
89f19f04 AM |
356 | cpu = get_cpu(); |
357 | if (!runqueue_is_locked(cpu)) | |
4e655519 | 358 | wake_up(&trace_wait); |
89f19f04 | 359 | put_cpu(); |
4e655519 | 360 | } |
bc0c38d1 | 361 | |
3928a8a2 | 362 | static int __init set_buf_size(char *str) |
bc0c38d1 | 363 | { |
3928a8a2 | 364 | unsigned long buf_size; |
c6caeeb1 | 365 | |
bc0c38d1 SR |
366 | if (!str) |
367 | return 0; | |
9d612bef | 368 | buf_size = memparse(str, &str); |
c6caeeb1 | 369 | /* nr_entries can not be zero */ |
9d612bef | 370 | if (buf_size == 0) |
c6caeeb1 | 371 | return 0; |
3928a8a2 | 372 | trace_buf_size = buf_size; |
bc0c38d1 SR |
373 | return 1; |
374 | } | |
3928a8a2 | 375 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 376 | |
57f50be1 SR |
377 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
378 | { | |
379 | return nsecs / 1000; | |
380 | } | |
381 | ||
4fcdae83 | 382 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 SR |
383 | static const char *trace_options[] = { |
384 | "print-parent", | |
385 | "sym-offset", | |
386 | "sym-addr", | |
387 | "verbose", | |
f9896bf3 | 388 | "raw", |
5e3ca0ec | 389 | "hex", |
cb0f12aa | 390 | "bin", |
2a2cc8f7 | 391 | "block", |
86387f7e | 392 | "stacktrace", |
5e1607a0 | 393 | "trace_printk", |
b2a866f9 | 394 | "ftrace_preempt", |
9f029e83 | 395 | "branch", |
12ef7d44 | 396 | "annotate", |
02b67518 | 397 | "userstacktrace", |
b54d3de9 | 398 | "sym-userobj", |
66896a85 | 399 | "printk-msg-only", |
c4a8e8be | 400 | "context-info", |
c032ef64 | 401 | "latency-format", |
be6f164a | 402 | "sleep-time", |
a2a16d6a | 403 | "graph-time", |
bc0c38d1 SR |
404 | NULL |
405 | }; | |
406 | ||
5079f326 Z |
407 | static struct { |
408 | u64 (*func)(void); | |
409 | const char *name; | |
410 | } trace_clocks[] = { | |
411 | { trace_clock_local, "local" }, | |
412 | { trace_clock_global, "global" }, | |
413 | }; | |
414 | ||
415 | int trace_clock_id; | |
416 | ||
b63f39ea | 417 | /* |
418 | * trace_parser_get_init - gets the buffer for trace parser | |
419 | */ | |
420 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
421 | { | |
422 | memset(parser, 0, sizeof(*parser)); | |
423 | ||
424 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
425 | if (!parser->buffer) | |
426 | return 1; | |
427 | ||
428 | parser->size = size; | |
429 | return 0; | |
430 | } | |
431 | ||
432 | /* | |
433 | * trace_parser_put - frees the buffer for trace parser | |
434 | */ | |
435 | void trace_parser_put(struct trace_parser *parser) | |
436 | { | |
437 | kfree(parser->buffer); | |
438 | } | |
439 | ||
440 | /* | |
441 | * trace_get_user - reads the user input string separated by space | |
442 | * (matched by isspace(ch)) | |
443 | * | |
444 | * For each string found the 'struct trace_parser' is updated, | |
445 | * and the function returns. | |
446 | * | |
447 | * Returns number of bytes read. | |
448 | * | |
449 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
450 | */ | |
451 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
452 | size_t cnt, loff_t *ppos) | |
453 | { | |
454 | char ch; | |
455 | size_t read = 0; | |
456 | ssize_t ret; | |
457 | ||
458 | if (!*ppos) | |
459 | trace_parser_clear(parser); | |
460 | ||
461 | ret = get_user(ch, ubuf++); | |
462 | if (ret) | |
463 | goto out; | |
464 | ||
465 | read++; | |
466 | cnt--; | |
467 | ||
468 | /* | |
469 | * The parser is not finished with the last write, | |
470 | * continue reading the user input without skipping spaces. | |
471 | */ | |
472 | if (!parser->cont) { | |
473 | /* skip white space */ | |
474 | while (cnt && isspace(ch)) { | |
475 | ret = get_user(ch, ubuf++); | |
476 | if (ret) | |
477 | goto out; | |
478 | read++; | |
479 | cnt--; | |
480 | } | |
481 | ||
482 | /* only spaces were written */ | |
483 | if (isspace(ch)) { | |
484 | *ppos += read; | |
485 | ret = read; | |
486 | goto out; | |
487 | } | |
488 | ||
489 | parser->idx = 0; | |
490 | } | |
491 | ||
492 | /* read the non-space input */ | |
493 | while (cnt && !isspace(ch)) { | |
3c235a33 | 494 | if (parser->idx < parser->size - 1) |
b63f39ea | 495 | parser->buffer[parser->idx++] = ch; |
496 | else { | |
497 | ret = -EINVAL; | |
498 | goto out; | |
499 | } | |
500 | ret = get_user(ch, ubuf++); | |
501 | if (ret) | |
502 | goto out; | |
503 | read++; | |
504 | cnt--; | |
505 | } | |
506 | ||
507 | /* We either got finished input or we have to wait for another call. */ | |
508 | if (isspace(ch)) { | |
509 | parser->buffer[parser->idx] = 0; | |
510 | parser->cont = false; | |
511 | } else { | |
512 | parser->cont = true; | |
513 | parser->buffer[parser->idx++] = ch; | |
514 | } | |
515 | ||
516 | *ppos += read; | |
517 | ret = read; | |
518 | ||
519 | out: | |
520 | return ret; | |
521 | } | |
522 | ||
6c6c2796 PP |
523 | ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) |
524 | { | |
525 | int len; | |
526 | int ret; | |
527 | ||
2dc5d12b SR |
528 | if (!cnt) |
529 | return 0; | |
530 | ||
6c6c2796 PP |
531 | if (s->len <= s->readpos) |
532 | return -EBUSY; | |
533 | ||
534 | len = s->len - s->readpos; | |
535 | if (cnt > len) | |
536 | cnt = len; | |
537 | ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); | |
2dc5d12b | 538 | if (ret == cnt) |
6c6c2796 PP |
539 | return -EFAULT; |
540 | ||
2dc5d12b SR |
541 | cnt -= ret; |
542 | ||
e74da523 | 543 | s->readpos += cnt; |
6c6c2796 | 544 | return cnt; |
214023c3 SR |
545 | } |
546 | ||
b8b94265 | 547 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
548 | { |
549 | int len; | |
550 | void *ret; | |
551 | ||
552 | if (s->len <= s->readpos) | |
553 | return -EBUSY; | |
554 | ||
555 | len = s->len - s->readpos; | |
556 | if (cnt > len) | |
557 | cnt = len; | |
558 | ret = memcpy(buf, s->buffer + s->readpos, cnt); | |
559 | if (!ret) | |
560 | return -EFAULT; | |
561 | ||
e74da523 | 562 | s->readpos += cnt; |
3c56819b EGM |
563 | return cnt; |
564 | } | |
565 | ||
5d4a9dba SR |
566 | /* |
567 | * ftrace_max_lock is used to protect the swapping of buffers | |
568 | * when taking a max snapshot. The buffers themselves are | |
569 | * protected by per_cpu spinlocks. But the action of the swap | |
570 | * needs its own lock. | |
571 | * | |
445c8951 | 572 | * This is defined as a arch_spinlock_t in order to help |
5d4a9dba SR |
573 | * with performance when lockdep debugging is enabled. |
574 | * | |
575 | * It is also used in other places outside the update_max_tr | |
576 | * so it needs to be defined outside of the | |
577 | * CONFIG_TRACER_MAX_TRACE. | |
578 | */ | |
445c8951 | 579 | static arch_spinlock_t ftrace_max_lock = |
edc35bd7 | 580 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
5d4a9dba SR |
581 | |
582 | #ifdef CONFIG_TRACER_MAX_TRACE | |
583 | unsigned long __read_mostly tracing_max_latency; | |
584 | unsigned long __read_mostly tracing_thresh; | |
585 | ||
586 | /* | |
587 | * Copy the new maximum trace into the separate maximum-trace | |
588 | * structure. (this way the maximum trace is permanently saved, | |
589 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
590 | */ | |
591 | static void | |
592 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
593 | { | |
594 | struct trace_array_cpu *data = tr->data[cpu]; | |
8248ac05 | 595 | struct trace_array_cpu *max_data = tr->data[cpu]; |
5d4a9dba SR |
596 | |
597 | max_tr.cpu = cpu; | |
598 | max_tr.time_start = data->preempt_timestamp; | |
599 | ||
8248ac05 SR |
600 | max_data = max_tr.data[cpu]; |
601 | max_data->saved_latency = tracing_max_latency; | |
602 | max_data->critical_start = data->critical_start; | |
603 | max_data->critical_end = data->critical_end; | |
5d4a9dba SR |
604 | |
605 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
8248ac05 SR |
606 | max_data->pid = tsk->pid; |
607 | max_data->uid = task_uid(tsk); | |
608 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
609 | max_data->policy = tsk->policy; | |
610 | max_data->rt_priority = tsk->rt_priority; | |
5d4a9dba SR |
611 | |
612 | /* record this tasks comm */ | |
613 | tracing_record_cmdline(tsk); | |
614 | } | |
615 | ||
4fcdae83 SR |
616 | /** |
617 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
618 | * @tr: tracer | |
619 | * @tsk: the task with the latency | |
620 | * @cpu: The cpu that initiated the trace. | |
621 | * | |
622 | * Flip the buffers between the @tr and the max_tr and record information | |
623 | * about which task was the cause of this latency. | |
624 | */ | |
e309b41d | 625 | void |
bc0c38d1 SR |
626 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
627 | { | |
3928a8a2 | 628 | struct ring_buffer *buf = tr->buffer; |
bc0c38d1 | 629 | |
b8de7bd1 SR |
630 | if (trace_stop_count) |
631 | return; | |
632 | ||
4c11d7ae | 633 | WARN_ON_ONCE(!irqs_disabled()); |
0199c4e6 | 634 | arch_spin_lock(&ftrace_max_lock); |
3928a8a2 SR |
635 | |
636 | tr->buffer = max_tr.buffer; | |
637 | max_tr.buffer = buf; | |
638 | ||
bc0c38d1 | 639 | __update_max_tr(tr, tsk, cpu); |
0199c4e6 | 640 | arch_spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
641 | } |
642 | ||
643 | /** | |
644 | * update_max_tr_single - only copy one trace over, and reset the rest | |
645 | * @tr - tracer | |
646 | * @tsk - task with the latency | |
647 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
648 | * |
649 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 650 | */ |
e309b41d | 651 | void |
bc0c38d1 SR |
652 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
653 | { | |
3928a8a2 | 654 | int ret; |
bc0c38d1 | 655 | |
b8de7bd1 SR |
656 | if (trace_stop_count) |
657 | return; | |
658 | ||
4c11d7ae | 659 | WARN_ON_ONCE(!irqs_disabled()); |
0199c4e6 | 660 | arch_spin_lock(&ftrace_max_lock); |
bc0c38d1 | 661 | |
d769041f SR |
662 | ftrace_disable_cpu(); |
663 | ||
3928a8a2 SR |
664 | ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); |
665 | ||
e8165dbb SR |
666 | if (ret == -EBUSY) { |
667 | /* | |
668 | * We failed to swap the buffer due to a commit taking | |
669 | * place on this CPU. We fail to record, but we reset | |
670 | * the max trace buffer (no one writes directly to it) | |
671 | * and flag that it failed. | |
672 | */ | |
673 | trace_array_printk(&max_tr, _THIS_IP_, | |
674 | "Failed to swap buffers due to commit in progress\n"); | |
675 | } | |
676 | ||
d769041f SR |
677 | ftrace_enable_cpu(); |
678 | ||
e8165dbb | 679 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
bc0c38d1 SR |
680 | |
681 | __update_max_tr(tr, tsk, cpu); | |
0199c4e6 | 682 | arch_spin_unlock(&ftrace_max_lock); |
bc0c38d1 | 683 | } |
5d4a9dba | 684 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
bc0c38d1 | 685 | |
4fcdae83 SR |
686 | /** |
687 | * register_tracer - register a tracer with the ftrace system. | |
688 | * @type - the plugin for the tracer | |
689 | * | |
690 | * Register a new plugin tracer. | |
691 | */ | |
bc0c38d1 | 692 | int register_tracer(struct tracer *type) |
e7669b8e HE |
693 | __releases(kernel_lock) |
694 | __acquires(kernel_lock) | |
bc0c38d1 SR |
695 | { |
696 | struct tracer *t; | |
bc0c38d1 SR |
697 | int ret = 0; |
698 | ||
699 | if (!type->name) { | |
700 | pr_info("Tracer must have a name\n"); | |
701 | return -1; | |
702 | } | |
703 | ||
ee6c2c1b LZ |
704 | if (strlen(type->name) > MAX_TRACER_SIZE) { |
705 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); | |
706 | return -1; | |
707 | } | |
708 | ||
86fa2f60 IM |
709 | /* |
710 | * When this gets called we hold the BKL which means that | |
711 | * preemption is disabled. Various trace selftests however | |
712 | * need to disable and enable preemption for successful tests. | |
713 | * So we drop the BKL here and grab it after the tests again. | |
714 | */ | |
715 | unlock_kernel(); | |
bc0c38d1 | 716 | mutex_lock(&trace_types_lock); |
86fa2f60 | 717 | |
8e1b82e0 FW |
718 | tracing_selftest_running = true; |
719 | ||
bc0c38d1 SR |
720 | for (t = trace_types; t; t = t->next) { |
721 | if (strcmp(type->name, t->name) == 0) { | |
722 | /* already found */ | |
ee6c2c1b | 723 | pr_info("Tracer %s already registered\n", |
bc0c38d1 SR |
724 | type->name); |
725 | ret = -1; | |
726 | goto out; | |
727 | } | |
728 | } | |
729 | ||
adf9f195 FW |
730 | if (!type->set_flag) |
731 | type->set_flag = &dummy_set_flag; | |
732 | if (!type->flags) | |
733 | type->flags = &dummy_tracer_flags; | |
734 | else | |
735 | if (!type->flags->opts) | |
736 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 FW |
737 | if (!type->wait_pipe) |
738 | type->wait_pipe = default_wait_pipe; | |
739 | ||
adf9f195 | 740 | |
60a11774 | 741 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
b2821ae6 | 742 | if (type->selftest && !tracing_selftest_disabled) { |
60a11774 | 743 | struct tracer *saved_tracer = current_trace; |
60a11774 | 744 | struct trace_array *tr = &global_trace; |
ff32504f | 745 | |
60a11774 SR |
746 | /* |
747 | * Run a selftest on this tracer. | |
748 | * Here we reset the trace buffer, and set the current | |
749 | * tracer to be this tracer. The tracer can then run some | |
750 | * internal tracing to verify that everything is in order. | |
751 | * If we fail, we do not register this tracer. | |
752 | */ | |
76f0d073 | 753 | tracing_reset_online_cpus(tr); |
86fa2f60 | 754 | |
60a11774 | 755 | current_trace = type; |
60a11774 SR |
756 | /* the test is responsible for initializing and enabling */ |
757 | pr_info("Testing tracer %s: ", type->name); | |
758 | ret = type->selftest(type, tr); | |
759 | /* the test is responsible for resetting too */ | |
760 | current_trace = saved_tracer; | |
60a11774 SR |
761 | if (ret) { |
762 | printk(KERN_CONT "FAILED!\n"); | |
763 | goto out; | |
764 | } | |
1d4db00a | 765 | /* Only reset on passing, to avoid touching corrupted buffers */ |
76f0d073 | 766 | tracing_reset_online_cpus(tr); |
86fa2f60 | 767 | |
60a11774 SR |
768 | printk(KERN_CONT "PASSED\n"); |
769 | } | |
770 | #endif | |
771 | ||
bc0c38d1 SR |
772 | type->next = trace_types; |
773 | trace_types = type; | |
60a11774 | 774 | |
bc0c38d1 | 775 | out: |
8e1b82e0 | 776 | tracing_selftest_running = false; |
bc0c38d1 SR |
777 | mutex_unlock(&trace_types_lock); |
778 | ||
dac74940 SR |
779 | if (ret || !default_bootup_tracer) |
780 | goto out_unlock; | |
781 | ||
ee6c2c1b | 782 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
dac74940 SR |
783 | goto out_unlock; |
784 | ||
785 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
786 | /* Do we want this tracer to start on bootup? */ | |
787 | tracing_set_tracer(type->name); | |
788 | default_bootup_tracer = NULL; | |
789 | /* disable other selftests, since this will break it. */ | |
790 | tracing_selftest_disabled = 1; | |
b2821ae6 | 791 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
792 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
793 | type->name); | |
b2821ae6 | 794 | #endif |
b2821ae6 | 795 | |
dac74940 | 796 | out_unlock: |
b2821ae6 | 797 | lock_kernel(); |
bc0c38d1 SR |
798 | return ret; |
799 | } | |
800 | ||
801 | void unregister_tracer(struct tracer *type) | |
802 | { | |
803 | struct tracer **t; | |
bc0c38d1 SR |
804 | |
805 | mutex_lock(&trace_types_lock); | |
806 | for (t = &trace_types; *t; t = &(*t)->next) { | |
807 | if (*t == type) | |
808 | goto found; | |
809 | } | |
ee6c2c1b | 810 | pr_info("Tracer %s not registered\n", type->name); |
bc0c38d1 SR |
811 | goto out; |
812 | ||
813 | found: | |
814 | *t = (*t)->next; | |
b5db03c4 ACM |
815 | |
816 | if (type == current_trace && tracer_enabled) { | |
817 | tracer_enabled = 0; | |
818 | tracing_stop(); | |
819 | if (current_trace->stop) | |
820 | current_trace->stop(&global_trace); | |
821 | current_trace = &nop_trace; | |
822 | } | |
ee6c2c1b | 823 | out: |
bc0c38d1 SR |
824 | mutex_unlock(&trace_types_lock); |
825 | } | |
826 | ||
f633903a | 827 | static void __tracing_reset(struct trace_array *tr, int cpu) |
bc0c38d1 | 828 | { |
d769041f | 829 | ftrace_disable_cpu(); |
3928a8a2 | 830 | ring_buffer_reset_cpu(tr->buffer, cpu); |
d769041f | 831 | ftrace_enable_cpu(); |
bc0c38d1 SR |
832 | } |
833 | ||
f633903a SR |
834 | void tracing_reset(struct trace_array *tr, int cpu) |
835 | { | |
836 | struct ring_buffer *buffer = tr->buffer; | |
837 | ||
838 | ring_buffer_record_disable(buffer); | |
839 | ||
840 | /* Make sure all commits have finished */ | |
841 | synchronize_sched(); | |
842 | __tracing_reset(tr, cpu); | |
843 | ||
844 | ring_buffer_record_enable(buffer); | |
845 | } | |
846 | ||
213cc060 PE |
847 | void tracing_reset_online_cpus(struct trace_array *tr) |
848 | { | |
621968cd | 849 | struct ring_buffer *buffer = tr->buffer; |
213cc060 PE |
850 | int cpu; |
851 | ||
621968cd SR |
852 | ring_buffer_record_disable(buffer); |
853 | ||
854 | /* Make sure all commits have finished */ | |
855 | synchronize_sched(); | |
856 | ||
213cc060 PE |
857 | tr->time_start = ftrace_now(tr->cpu); |
858 | ||
859 | for_each_online_cpu(cpu) | |
f633903a | 860 | __tracing_reset(tr, cpu); |
621968cd SR |
861 | |
862 | ring_buffer_record_enable(buffer); | |
213cc060 PE |
863 | } |
864 | ||
9456f0fa SR |
865 | void tracing_reset_current(int cpu) |
866 | { | |
867 | tracing_reset(&global_trace, cpu); | |
868 | } | |
869 | ||
870 | void tracing_reset_current_online_cpus(void) | |
871 | { | |
872 | tracing_reset_online_cpus(&global_trace); | |
873 | } | |
874 | ||
bc0c38d1 | 875 | #define SAVED_CMDLINES 128 |
2c7eea4c | 876 | #define NO_CMDLINE_MAP UINT_MAX |
bc0c38d1 SR |
877 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; |
878 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
879 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
880 | static int cmdline_idx; | |
edc35bd7 | 881 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
25b0b44a | 882 | |
25b0b44a | 883 | /* temporary disable recording */ |
4fd27358 | 884 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 SR |
885 | |
886 | static void trace_init_cmdlines(void) | |
887 | { | |
2c7eea4c TG |
888 | memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); |
889 | memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); | |
bc0c38d1 SR |
890 | cmdline_idx = 0; |
891 | } | |
892 | ||
b5130b1e CE |
893 | int is_tracing_stopped(void) |
894 | { | |
895 | return trace_stop_count; | |
896 | } | |
897 | ||
69bb54ec SR |
898 | /** |
899 | * ftrace_off_permanent - disable all ftrace code permanently | |
900 | * | |
901 | * This should only be called when a serious anomally has | |
902 | * been detected. This will turn off the function tracing, | |
903 | * ring buffers, and other tracing utilites. It takes no | |
904 | * locks and can be called from any context. | |
905 | */ | |
906 | void ftrace_off_permanent(void) | |
907 | { | |
908 | tracing_disabled = 1; | |
909 | ftrace_stop(); | |
910 | tracing_off_permanent(); | |
911 | } | |
912 | ||
0f048701 SR |
913 | /** |
914 | * tracing_start - quick start of the tracer | |
915 | * | |
916 | * If tracing is enabled but was stopped by tracing_stop, | |
917 | * this will start the tracer back up. | |
918 | */ | |
919 | void tracing_start(void) | |
920 | { | |
921 | struct ring_buffer *buffer; | |
922 | unsigned long flags; | |
923 | ||
924 | if (tracing_disabled) | |
925 | return; | |
926 | ||
927 | spin_lock_irqsave(&tracing_start_lock, flags); | |
b06a8301 SR |
928 | if (--trace_stop_count) { |
929 | if (trace_stop_count < 0) { | |
930 | /* Someone screwed up their debugging */ | |
931 | WARN_ON_ONCE(1); | |
932 | trace_stop_count = 0; | |
933 | } | |
0f048701 SR |
934 | goto out; |
935 | } | |
936 | ||
937 | ||
938 | buffer = global_trace.buffer; | |
939 | if (buffer) | |
940 | ring_buffer_record_enable(buffer); | |
941 | ||
942 | buffer = max_tr.buffer; | |
943 | if (buffer) | |
944 | ring_buffer_record_enable(buffer); | |
945 | ||
946 | ftrace_start(); | |
947 | out: | |
948 | spin_unlock_irqrestore(&tracing_start_lock, flags); | |
949 | } | |
950 | ||
951 | /** | |
952 | * tracing_stop - quick stop of the tracer | |
953 | * | |
954 | * Light weight way to stop tracing. Use in conjunction with | |
955 | * tracing_start. | |
956 | */ | |
957 | void tracing_stop(void) | |
958 | { | |
959 | struct ring_buffer *buffer; | |
960 | unsigned long flags; | |
961 | ||
962 | ftrace_stop(); | |
963 | spin_lock_irqsave(&tracing_start_lock, flags); | |
964 | if (trace_stop_count++) | |
965 | goto out; | |
966 | ||
967 | buffer = global_trace.buffer; | |
968 | if (buffer) | |
969 | ring_buffer_record_disable(buffer); | |
970 | ||
971 | buffer = max_tr.buffer; | |
972 | if (buffer) | |
973 | ring_buffer_record_disable(buffer); | |
974 | ||
975 | out: | |
976 | spin_unlock_irqrestore(&tracing_start_lock, flags); | |
977 | } | |
978 | ||
e309b41d | 979 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 980 | |
e309b41d | 981 | static void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 982 | { |
a635cf04 | 983 | unsigned pid, idx; |
bc0c38d1 SR |
984 | |
985 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
986 | return; | |
987 | ||
988 | /* | |
989 | * It's not the end of the world if we don't get | |
990 | * the lock, but we also don't want to spin | |
991 | * nor do we want to disable interrupts, | |
992 | * so if we miss here, then better luck next time. | |
993 | */ | |
0199c4e6 | 994 | if (!arch_spin_trylock(&trace_cmdline_lock)) |
bc0c38d1 SR |
995 | return; |
996 | ||
997 | idx = map_pid_to_cmdline[tsk->pid]; | |
2c7eea4c | 998 | if (idx == NO_CMDLINE_MAP) { |
bc0c38d1 SR |
999 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; |
1000 | ||
a635cf04 CE |
1001 | /* |
1002 | * Check whether the cmdline buffer at idx has a pid | |
1003 | * mapped. We are going to overwrite that entry so we | |
1004 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1005 | * would read the new comm for the old pid. | |
1006 | */ | |
1007 | pid = map_cmdline_to_pid[idx]; | |
1008 | if (pid != NO_CMDLINE_MAP) | |
1009 | map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; | |
bc0c38d1 | 1010 | |
a635cf04 | 1011 | map_cmdline_to_pid[idx] = tsk->pid; |
bc0c38d1 SR |
1012 | map_pid_to_cmdline[tsk->pid] = idx; |
1013 | ||
1014 | cmdline_idx = idx; | |
1015 | } | |
1016 | ||
1017 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
1018 | ||
0199c4e6 | 1019 | arch_spin_unlock(&trace_cmdline_lock); |
bc0c38d1 SR |
1020 | } |
1021 | ||
4ca53085 | 1022 | void trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 1023 | { |
bc0c38d1 SR |
1024 | unsigned map; |
1025 | ||
4ca53085 SR |
1026 | if (!pid) { |
1027 | strcpy(comm, "<idle>"); | |
1028 | return; | |
1029 | } | |
bc0c38d1 | 1030 | |
4ca53085 SR |
1031 | if (pid > PID_MAX_DEFAULT) { |
1032 | strcpy(comm, "<...>"); | |
1033 | return; | |
1034 | } | |
bc0c38d1 | 1035 | |
5b6045a9 | 1036 | preempt_disable(); |
0199c4e6 | 1037 | arch_spin_lock(&trace_cmdline_lock); |
bc0c38d1 | 1038 | map = map_pid_to_cmdline[pid]; |
50d88758 TG |
1039 | if (map != NO_CMDLINE_MAP) |
1040 | strcpy(comm, saved_cmdlines[map]); | |
1041 | else | |
1042 | strcpy(comm, "<...>"); | |
bc0c38d1 | 1043 | |
0199c4e6 | 1044 | arch_spin_unlock(&trace_cmdline_lock); |
5b6045a9 | 1045 | preempt_enable(); |
bc0c38d1 SR |
1046 | } |
1047 | ||
e309b41d | 1048 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1049 | { |
18aecd36 TG |
1050 | if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled || |
1051 | !tracing_is_on()) | |
bc0c38d1 SR |
1052 | return; |
1053 | ||
1054 | trace_save_cmdline(tsk); | |
1055 | } | |
1056 | ||
45dcd8b8 | 1057 | void |
38697053 SR |
1058 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
1059 | int pc) | |
bc0c38d1 SR |
1060 | { |
1061 | struct task_struct *tsk = current; | |
bc0c38d1 | 1062 | |
777e208d SR |
1063 | entry->preempt_count = pc & 0xff; |
1064 | entry->pid = (tsk) ? tsk->pid : 0; | |
637e7e86 | 1065 | entry->lock_depth = (tsk) ? tsk->lock_depth : 0; |
777e208d | 1066 | entry->flags = |
9244489a | 1067 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 1068 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
1069 | #else |
1070 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1071 | #endif | |
bc0c38d1 SR |
1072 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
1073 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
1074 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
1075 | } | |
f413cdb8 | 1076 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); |
bc0c38d1 | 1077 | |
e77405ad SR |
1078 | struct ring_buffer_event * |
1079 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1080 | int type, | |
1081 | unsigned long len, | |
1082 | unsigned long flags, int pc) | |
51a763dd ACM |
1083 | { |
1084 | struct ring_buffer_event *event; | |
1085 | ||
e77405ad | 1086 | event = ring_buffer_lock_reserve(buffer, len); |
51a763dd ACM |
1087 | if (event != NULL) { |
1088 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1089 | ||
1090 | tracing_generic_entry_update(ent, flags, pc); | |
1091 | ent->type = type; | |
1092 | } | |
1093 | ||
1094 | return event; | |
1095 | } | |
51a763dd | 1096 | |
e77405ad SR |
1097 | static inline void |
1098 | __trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1099 | struct ring_buffer_event *event, | |
1100 | unsigned long flags, int pc, | |
1101 | int wake) | |
51a763dd | 1102 | { |
e77405ad | 1103 | ring_buffer_unlock_commit(buffer, event); |
51a763dd | 1104 | |
e77405ad SR |
1105 | ftrace_trace_stack(buffer, flags, 6, pc); |
1106 | ftrace_trace_userstack(buffer, flags, pc); | |
07edf712 FW |
1107 | |
1108 | if (wake) | |
1109 | trace_wake_up(); | |
1110 | } | |
1111 | ||
e77405ad SR |
1112 | void trace_buffer_unlock_commit(struct ring_buffer *buffer, |
1113 | struct ring_buffer_event *event, | |
1114 | unsigned long flags, int pc) | |
07edf712 | 1115 | { |
e77405ad | 1116 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 1); |
51a763dd ACM |
1117 | } |
1118 | ||
ef5580d0 | 1119 | struct ring_buffer_event * |
e77405ad SR |
1120 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, |
1121 | int type, unsigned long len, | |
ef5580d0 SR |
1122 | unsigned long flags, int pc) |
1123 | { | |
e77405ad SR |
1124 | *current_rb = global_trace.buffer; |
1125 | return trace_buffer_lock_reserve(*current_rb, | |
ef5580d0 SR |
1126 | type, len, flags, pc); |
1127 | } | |
94487d6d | 1128 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); |
ef5580d0 | 1129 | |
e77405ad SR |
1130 | void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, |
1131 | struct ring_buffer_event *event, | |
ef5580d0 SR |
1132 | unsigned long flags, int pc) |
1133 | { | |
e77405ad | 1134 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 1); |
07edf712 | 1135 | } |
94487d6d | 1136 | EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit); |
07edf712 | 1137 | |
e77405ad SR |
1138 | void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer, |
1139 | struct ring_buffer_event *event, | |
1140 | unsigned long flags, int pc) | |
07edf712 | 1141 | { |
e77405ad | 1142 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 0); |
77d9f465 | 1143 | } |
94487d6d | 1144 | EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit); |
77d9f465 | 1145 | |
e77405ad SR |
1146 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, |
1147 | struct ring_buffer_event *event) | |
77d9f465 | 1148 | { |
e77405ad | 1149 | ring_buffer_discard_commit(buffer, event); |
ef5580d0 | 1150 | } |
12acd473 | 1151 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); |
ef5580d0 | 1152 | |
e309b41d | 1153 | void |
7be42151 | 1154 | trace_function(struct trace_array *tr, |
38697053 SR |
1155 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1156 | int pc) | |
bc0c38d1 | 1157 | { |
e1112b4d | 1158 | struct ftrace_event_call *call = &event_function; |
e77405ad | 1159 | struct ring_buffer *buffer = tr->buffer; |
3928a8a2 | 1160 | struct ring_buffer_event *event; |
777e208d | 1161 | struct ftrace_entry *entry; |
bc0c38d1 | 1162 | |
d769041f | 1163 | /* If we are reading the ring buffer, don't trace */ |
9288f99a | 1164 | if (unlikely(__this_cpu_read(per_cpu_var(ftrace_cpu_disabled)))) |
d769041f SR |
1165 | return; |
1166 | ||
e77405ad | 1167 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
51a763dd | 1168 | flags, pc); |
3928a8a2 SR |
1169 | if (!event) |
1170 | return; | |
1171 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1172 | entry->ip = ip; |
1173 | entry->parent_ip = parent_ip; | |
e1112b4d | 1174 | |
e77405ad SR |
1175 | if (!filter_check_discard(call, entry, buffer, event)) |
1176 | ring_buffer_unlock_commit(buffer, event); | |
bc0c38d1 SR |
1177 | } |
1178 | ||
e309b41d | 1179 | void |
2e0f5761 | 1180 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, |
38697053 SR |
1181 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1182 | int pc) | |
2e0f5761 IM |
1183 | { |
1184 | if (likely(!atomic_read(&data->disabled))) | |
7be42151 | 1185 | trace_function(tr, ip, parent_ip, flags, pc); |
2e0f5761 IM |
1186 | } |
1187 | ||
c0a0d0d3 | 1188 | #ifdef CONFIG_STACKTRACE |
e77405ad | 1189 | static void __ftrace_trace_stack(struct ring_buffer *buffer, |
53614991 SR |
1190 | unsigned long flags, |
1191 | int skip, int pc) | |
86387f7e | 1192 | { |
e1112b4d | 1193 | struct ftrace_event_call *call = &event_kernel_stack; |
3928a8a2 | 1194 | struct ring_buffer_event *event; |
777e208d | 1195 | struct stack_entry *entry; |
86387f7e IM |
1196 | struct stack_trace trace; |
1197 | ||
e77405ad | 1198 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, |
51a763dd | 1199 | sizeof(*entry), flags, pc); |
3928a8a2 SR |
1200 | if (!event) |
1201 | return; | |
1202 | entry = ring_buffer_event_data(event); | |
777e208d | 1203 | memset(&entry->caller, 0, sizeof(entry->caller)); |
86387f7e IM |
1204 | |
1205 | trace.nr_entries = 0; | |
1206 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1207 | trace.skip = skip; | |
777e208d | 1208 | trace.entries = entry->caller; |
86387f7e IM |
1209 | |
1210 | save_stack_trace(&trace); | |
e77405ad SR |
1211 | if (!filter_check_discard(call, entry, buffer, event)) |
1212 | ring_buffer_unlock_commit(buffer, event); | |
f0a920d5 IM |
1213 | } |
1214 | ||
e77405ad SR |
1215 | void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, |
1216 | int skip, int pc) | |
53614991 SR |
1217 | { |
1218 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1219 | return; | |
1220 | ||
e77405ad | 1221 | __ftrace_trace_stack(buffer, flags, skip, pc); |
53614991 SR |
1222 | } |
1223 | ||
c0a0d0d3 FW |
1224 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, |
1225 | int pc) | |
38697053 | 1226 | { |
e77405ad | 1227 | __ftrace_trace_stack(tr->buffer, flags, skip, pc); |
38697053 SR |
1228 | } |
1229 | ||
03889384 SR |
1230 | /** |
1231 | * trace_dump_stack - record a stack back trace in the trace buffer | |
1232 | */ | |
1233 | void trace_dump_stack(void) | |
1234 | { | |
1235 | unsigned long flags; | |
1236 | ||
1237 | if (tracing_disabled || tracing_selftest_running) | |
e36c5458 | 1238 | return; |
03889384 SR |
1239 | |
1240 | local_save_flags(flags); | |
1241 | ||
1242 | /* skipping 3 traces, seems to get us at the caller of this function */ | |
1243 | __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count()); | |
1244 | } | |
1245 | ||
e77405ad SR |
1246 | void |
1247 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
02b67518 | 1248 | { |
e1112b4d | 1249 | struct ftrace_event_call *call = &event_user_stack; |
8d7c6a96 | 1250 | struct ring_buffer_event *event; |
02b67518 TE |
1251 | struct userstack_entry *entry; |
1252 | struct stack_trace trace; | |
02b67518 TE |
1253 | |
1254 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1255 | return; | |
1256 | ||
e77405ad | 1257 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
51a763dd | 1258 | sizeof(*entry), flags, pc); |
02b67518 TE |
1259 | if (!event) |
1260 | return; | |
1261 | entry = ring_buffer_event_data(event); | |
02b67518 | 1262 | |
48659d31 | 1263 | entry->tgid = current->tgid; |
02b67518 TE |
1264 | memset(&entry->caller, 0, sizeof(entry->caller)); |
1265 | ||
1266 | trace.nr_entries = 0; | |
1267 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1268 | trace.skip = 0; | |
1269 | trace.entries = entry->caller; | |
1270 | ||
1271 | save_stack_trace_user(&trace); | |
e77405ad SR |
1272 | if (!filter_check_discard(call, entry, buffer, event)) |
1273 | ring_buffer_unlock_commit(buffer, event); | |
02b67518 TE |
1274 | } |
1275 | ||
4fd27358 HE |
1276 | #ifdef UNUSED |
1277 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1278 | { |
7be42151 | 1279 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1280 | } |
4fd27358 | 1281 | #endif /* UNUSED */ |
02b67518 | 1282 | |
c0a0d0d3 FW |
1283 | #endif /* CONFIG_STACKTRACE */ |
1284 | ||
38697053 | 1285 | static void |
7be42151 | 1286 | ftrace_trace_special(void *__tr, |
38697053 SR |
1287 | unsigned long arg1, unsigned long arg2, unsigned long arg3, |
1288 | int pc) | |
a4feb834 | 1289 | { |
60ba7702 | 1290 | struct ftrace_event_call *call = &event_special; |
3928a8a2 | 1291 | struct ring_buffer_event *event; |
a4feb834 | 1292 | struct trace_array *tr = __tr; |
e77405ad | 1293 | struct ring_buffer *buffer = tr->buffer; |
777e208d | 1294 | struct special_entry *entry; |
a4feb834 | 1295 | |
e77405ad | 1296 | event = trace_buffer_lock_reserve(buffer, TRACE_SPECIAL, |
51a763dd | 1297 | sizeof(*entry), 0, pc); |
3928a8a2 SR |
1298 | if (!event) |
1299 | return; | |
1300 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1301 | entry->arg1 = arg1; |
1302 | entry->arg2 = arg2; | |
1303 | entry->arg3 = arg3; | |
60ba7702 SR |
1304 | |
1305 | if (!filter_check_discard(call, entry, buffer, event)) | |
1306 | trace_buffer_unlock_commit(buffer, event, 0, pc); | |
a4feb834 IM |
1307 | } |
1308 | ||
38697053 SR |
1309 | void |
1310 | __trace_special(void *__tr, void *__data, | |
1311 | unsigned long arg1, unsigned long arg2, unsigned long arg3) | |
1312 | { | |
7be42151 | 1313 | ftrace_trace_special(__tr, arg1, arg2, arg3, preempt_count()); |
38697053 SR |
1314 | } |
1315 | ||
4902f884 SR |
1316 | void |
1317 | ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) | |
1318 | { | |
1319 | struct trace_array *tr = &global_trace; | |
1320 | struct trace_array_cpu *data; | |
5aa1ba6a | 1321 | unsigned long flags; |
4902f884 | 1322 | int cpu; |
38697053 | 1323 | int pc; |
4902f884 | 1324 | |
c76f0694 | 1325 | if (tracing_disabled) |
4902f884 SR |
1326 | return; |
1327 | ||
38697053 | 1328 | pc = preempt_count(); |
5aa1ba6a | 1329 | local_irq_save(flags); |
4902f884 SR |
1330 | cpu = raw_smp_processor_id(); |
1331 | data = tr->data[cpu]; | |
4902f884 | 1332 | |
5aa1ba6a | 1333 | if (likely(atomic_inc_return(&data->disabled) == 1)) |
7be42151 | 1334 | ftrace_trace_special(tr, arg1, arg2, arg3, pc); |
4902f884 | 1335 | |
5aa1ba6a SR |
1336 | atomic_dec(&data->disabled); |
1337 | local_irq_restore(flags); | |
4902f884 SR |
1338 | } |
1339 | ||
769b0441 | 1340 | /** |
48ead020 | 1341 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
1342 | * |
1343 | */ | |
40ce74f1 | 1344 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 1345 | { |
445c8951 | 1346 | static arch_spinlock_t trace_buf_lock = |
edc35bd7 | 1347 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
769b0441 FW |
1348 | static u32 trace_buf[TRACE_BUF_SIZE]; |
1349 | ||
e1112b4d | 1350 | struct ftrace_event_call *call = &event_bprint; |
769b0441 | 1351 | struct ring_buffer_event *event; |
e77405ad | 1352 | struct ring_buffer *buffer; |
769b0441 FW |
1353 | struct trace_array *tr = &global_trace; |
1354 | struct trace_array_cpu *data; | |
48ead020 | 1355 | struct bprint_entry *entry; |
769b0441 | 1356 | unsigned long flags; |
3189cdb3 | 1357 | int disable; |
769b0441 FW |
1358 | int resched; |
1359 | int cpu, len = 0, size, pc; | |
1360 | ||
1361 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
1362 | return 0; | |
1363 | ||
1364 | /* Don't pollute graph traces with trace_vprintk internals */ | |
1365 | pause_graph_tracing(); | |
1366 | ||
1367 | pc = preempt_count(); | |
1368 | resched = ftrace_preempt_disable(); | |
1369 | cpu = raw_smp_processor_id(); | |
1370 | data = tr->data[cpu]; | |
1371 | ||
3189cdb3 SR |
1372 | disable = atomic_inc_return(&data->disabled); |
1373 | if (unlikely(disable != 1)) | |
769b0441 FW |
1374 | goto out; |
1375 | ||
80370cb7 SR |
1376 | /* Lockdep uses trace_printk for lock tracing */ |
1377 | local_irq_save(flags); | |
0199c4e6 | 1378 | arch_spin_lock(&trace_buf_lock); |
769b0441 FW |
1379 | len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); |
1380 | ||
1381 | if (len > TRACE_BUF_SIZE || len < 0) | |
1382 | goto out_unlock; | |
1383 | ||
1384 | size = sizeof(*entry) + sizeof(u32) * len; | |
e77405ad SR |
1385 | buffer = tr->buffer; |
1386 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, | |
1387 | flags, pc); | |
769b0441 FW |
1388 | if (!event) |
1389 | goto out_unlock; | |
1390 | entry = ring_buffer_event_data(event); | |
1391 | entry->ip = ip; | |
769b0441 FW |
1392 | entry->fmt = fmt; |
1393 | ||
1394 | memcpy(entry->buf, trace_buf, sizeof(u32) * len); | |
e77405ad SR |
1395 | if (!filter_check_discard(call, entry, buffer, event)) |
1396 | ring_buffer_unlock_commit(buffer, event); | |
769b0441 FW |
1397 | |
1398 | out_unlock: | |
0199c4e6 | 1399 | arch_spin_unlock(&trace_buf_lock); |
80370cb7 | 1400 | local_irq_restore(flags); |
769b0441 FW |
1401 | |
1402 | out: | |
3189cdb3 | 1403 | atomic_dec_return(&data->disabled); |
769b0441 FW |
1404 | ftrace_preempt_enable(resched); |
1405 | unpause_graph_tracing(); | |
1406 | ||
1407 | return len; | |
1408 | } | |
48ead020 FW |
1409 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
1410 | ||
659372d3 SR |
1411 | int trace_array_printk(struct trace_array *tr, |
1412 | unsigned long ip, const char *fmt, ...) | |
1413 | { | |
1414 | int ret; | |
1415 | va_list ap; | |
1416 | ||
1417 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
1418 | return 0; | |
1419 | ||
1420 | va_start(ap, fmt); | |
1421 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
1422 | va_end(ap); | |
1423 | return ret; | |
1424 | } | |
1425 | ||
1426 | int trace_array_vprintk(struct trace_array *tr, | |
1427 | unsigned long ip, const char *fmt, va_list args) | |
48ead020 | 1428 | { |
edc35bd7 | 1429 | static arch_spinlock_t trace_buf_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
48ead020 FW |
1430 | static char trace_buf[TRACE_BUF_SIZE]; |
1431 | ||
e1112b4d | 1432 | struct ftrace_event_call *call = &event_print; |
48ead020 | 1433 | struct ring_buffer_event *event; |
e77405ad | 1434 | struct ring_buffer *buffer; |
48ead020 FW |
1435 | struct trace_array_cpu *data; |
1436 | int cpu, len = 0, size, pc; | |
1437 | struct print_entry *entry; | |
1438 | unsigned long irq_flags; | |
3189cdb3 | 1439 | int disable; |
48ead020 FW |
1440 | |
1441 | if (tracing_disabled || tracing_selftest_running) | |
1442 | return 0; | |
1443 | ||
1444 | pc = preempt_count(); | |
1445 | preempt_disable_notrace(); | |
1446 | cpu = raw_smp_processor_id(); | |
1447 | data = tr->data[cpu]; | |
1448 | ||
3189cdb3 SR |
1449 | disable = atomic_inc_return(&data->disabled); |
1450 | if (unlikely(disable != 1)) | |
48ead020 FW |
1451 | goto out; |
1452 | ||
1453 | pause_graph_tracing(); | |
1454 | raw_local_irq_save(irq_flags); | |
0199c4e6 | 1455 | arch_spin_lock(&trace_buf_lock); |
f2942487 | 1456 | len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); |
48ead020 FW |
1457 | |
1458 | size = sizeof(*entry) + len + 1; | |
e77405ad SR |
1459 | buffer = tr->buffer; |
1460 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
1461 | irq_flags, pc); | |
48ead020 FW |
1462 | if (!event) |
1463 | goto out_unlock; | |
1464 | entry = ring_buffer_event_data(event); | |
c13d2f7c | 1465 | entry->ip = ip; |
48ead020 FW |
1466 | |
1467 | memcpy(&entry->buf, trace_buf, len); | |
c13d2f7c | 1468 | entry->buf[len] = '\0'; |
e77405ad SR |
1469 | if (!filter_check_discard(call, entry, buffer, event)) |
1470 | ring_buffer_unlock_commit(buffer, event); | |
48ead020 FW |
1471 | |
1472 | out_unlock: | |
0199c4e6 | 1473 | arch_spin_unlock(&trace_buf_lock); |
48ead020 FW |
1474 | raw_local_irq_restore(irq_flags); |
1475 | unpause_graph_tracing(); | |
1476 | out: | |
3189cdb3 | 1477 | atomic_dec_return(&data->disabled); |
48ead020 FW |
1478 | preempt_enable_notrace(); |
1479 | ||
1480 | return len; | |
1481 | } | |
659372d3 SR |
1482 | |
1483 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) | |
1484 | { | |
a813a159 | 1485 | return trace_array_vprintk(&global_trace, ip, fmt, args); |
659372d3 | 1486 | } |
769b0441 FW |
1487 | EXPORT_SYMBOL_GPL(trace_vprintk); |
1488 | ||
bc0c38d1 SR |
1489 | enum trace_file_type { |
1490 | TRACE_FILE_LAT_FMT = 1, | |
12ef7d44 | 1491 | TRACE_FILE_ANNOTATE = 2, |
bc0c38d1 SR |
1492 | }; |
1493 | ||
e2ac8ef5 | 1494 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 1495 | { |
d769041f SR |
1496 | /* Don't allow ftrace to trace into the ring buffers */ |
1497 | ftrace_disable_cpu(); | |
1498 | ||
5a90f577 | 1499 | iter->idx++; |
d769041f SR |
1500 | if (iter->buffer_iter[iter->cpu]) |
1501 | ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); | |
1502 | ||
1503 | ftrace_enable_cpu(); | |
5a90f577 SR |
1504 | } |
1505 | ||
e309b41d | 1506 | static struct trace_entry * |
3928a8a2 | 1507 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) |
dd0e545f | 1508 | { |
3928a8a2 SR |
1509 | struct ring_buffer_event *event; |
1510 | struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; | |
dd0e545f | 1511 | |
d769041f SR |
1512 | /* Don't allow ftrace to trace into the ring buffers */ |
1513 | ftrace_disable_cpu(); | |
1514 | ||
1515 | if (buf_iter) | |
1516 | event = ring_buffer_iter_peek(buf_iter, ts); | |
1517 | else | |
1518 | event = ring_buffer_peek(iter->tr->buffer, cpu, ts); | |
1519 | ||
1520 | ftrace_enable_cpu(); | |
1521 | ||
3928a8a2 | 1522 | return event ? ring_buffer_event_data(event) : NULL; |
dd0e545f | 1523 | } |
d769041f | 1524 | |
dd0e545f | 1525 | static struct trace_entry * |
3928a8a2 | 1526 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) |
bc0c38d1 | 1527 | { |
3928a8a2 | 1528 | struct ring_buffer *buffer = iter->tr->buffer; |
bc0c38d1 | 1529 | struct trace_entry *ent, *next = NULL; |
b04cc6b1 | 1530 | int cpu_file = iter->cpu_file; |
3928a8a2 | 1531 | u64 next_ts = 0, ts; |
bc0c38d1 SR |
1532 | int next_cpu = -1; |
1533 | int cpu; | |
1534 | ||
b04cc6b1 FW |
1535 | /* |
1536 | * If we are in a per_cpu trace file, don't bother by iterating over | |
1537 | * all cpu and peek directly. | |
1538 | */ | |
1539 | if (cpu_file > TRACE_PIPE_ALL_CPU) { | |
1540 | if (ring_buffer_empty_cpu(buffer, cpu_file)) | |
1541 | return NULL; | |
1542 | ent = peek_next_entry(iter, cpu_file, ent_ts); | |
1543 | if (ent_cpu) | |
1544 | *ent_cpu = cpu_file; | |
1545 | ||
1546 | return ent; | |
1547 | } | |
1548 | ||
ab46428c | 1549 | for_each_tracing_cpu(cpu) { |
dd0e545f | 1550 | |
3928a8a2 SR |
1551 | if (ring_buffer_empty_cpu(buffer, cpu)) |
1552 | continue; | |
dd0e545f | 1553 | |
3928a8a2 | 1554 | ent = peek_next_entry(iter, cpu, &ts); |
dd0e545f | 1555 | |
cdd31cd2 IM |
1556 | /* |
1557 | * Pick the entry with the smallest timestamp: | |
1558 | */ | |
3928a8a2 | 1559 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
1560 | next = ent; |
1561 | next_cpu = cpu; | |
3928a8a2 | 1562 | next_ts = ts; |
bc0c38d1 SR |
1563 | } |
1564 | } | |
1565 | ||
1566 | if (ent_cpu) | |
1567 | *ent_cpu = next_cpu; | |
1568 | ||
3928a8a2 SR |
1569 | if (ent_ts) |
1570 | *ent_ts = next_ts; | |
1571 | ||
bc0c38d1 SR |
1572 | return next; |
1573 | } | |
1574 | ||
dd0e545f | 1575 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
1576 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
1577 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 1578 | { |
3928a8a2 | 1579 | return __find_next_entry(iter, ent_cpu, ent_ts); |
dd0e545f SR |
1580 | } |
1581 | ||
1582 | /* Find the next real entry, and increment the iterator to the next entry */ | |
1583 | static void *find_next_entry_inc(struct trace_iterator *iter) | |
1584 | { | |
3928a8a2 | 1585 | iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts); |
dd0e545f | 1586 | |
3928a8a2 | 1587 | if (iter->ent) |
e2ac8ef5 | 1588 | trace_iterator_increment(iter); |
dd0e545f | 1589 | |
3928a8a2 | 1590 | return iter->ent ? iter : NULL; |
b3806b43 | 1591 | } |
bc0c38d1 | 1592 | |
e309b41d | 1593 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 1594 | { |
d769041f SR |
1595 | /* Don't allow ftrace to trace into the ring buffers */ |
1596 | ftrace_disable_cpu(); | |
3928a8a2 | 1597 | ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts); |
d769041f | 1598 | ftrace_enable_cpu(); |
bc0c38d1 SR |
1599 | } |
1600 | ||
e309b41d | 1601 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
1602 | { |
1603 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 1604 | int i = (int)*pos; |
4e3c3333 | 1605 | void *ent; |
bc0c38d1 | 1606 | |
a63ce5b3 SR |
1607 | WARN_ON_ONCE(iter->leftover); |
1608 | ||
bc0c38d1 SR |
1609 | (*pos)++; |
1610 | ||
1611 | /* can't go backwards */ | |
1612 | if (iter->idx > i) | |
1613 | return NULL; | |
1614 | ||
1615 | if (iter->idx < 0) | |
1616 | ent = find_next_entry_inc(iter); | |
1617 | else | |
1618 | ent = iter; | |
1619 | ||
1620 | while (ent && iter->idx < i) | |
1621 | ent = find_next_entry_inc(iter); | |
1622 | ||
1623 | iter->pos = *pos; | |
1624 | ||
bc0c38d1 SR |
1625 | return ent; |
1626 | } | |
1627 | ||
2f26ebd5 SR |
1628 | static void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
1629 | { | |
1630 | struct trace_array *tr = iter->tr; | |
1631 | struct ring_buffer_event *event; | |
1632 | struct ring_buffer_iter *buf_iter; | |
1633 | unsigned long entries = 0; | |
1634 | u64 ts; | |
1635 | ||
1636 | tr->data[cpu]->skipped_entries = 0; | |
1637 | ||
1638 | if (!iter->buffer_iter[cpu]) | |
1639 | return; | |
1640 | ||
1641 | buf_iter = iter->buffer_iter[cpu]; | |
1642 | ring_buffer_iter_reset(buf_iter); | |
1643 | ||
1644 | /* | |
1645 | * We could have the case with the max latency tracers | |
1646 | * that a reset never took place on a cpu. This is evident | |
1647 | * by the timestamp being before the start of the buffer. | |
1648 | */ | |
1649 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
1650 | if (ts >= iter->tr->time_start) | |
1651 | break; | |
1652 | entries++; | |
1653 | ring_buffer_read(buf_iter, NULL); | |
1654 | } | |
1655 | ||
1656 | tr->data[cpu]->skipped_entries = entries; | |
1657 | } | |
1658 | ||
d7350c3f | 1659 | /* |
d7350c3f FW |
1660 | * The current tracer is copied to avoid a global locking |
1661 | * all around. | |
1662 | */ | |
bc0c38d1 SR |
1663 | static void *s_start(struct seq_file *m, loff_t *pos) |
1664 | { | |
1665 | struct trace_iterator *iter = m->private; | |
d7350c3f | 1666 | static struct tracer *old_tracer; |
b04cc6b1 | 1667 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
1668 | void *p = NULL; |
1669 | loff_t l = 0; | |
3928a8a2 | 1670 | int cpu; |
bc0c38d1 | 1671 | |
d7350c3f | 1672 | /* copy the tracer to avoid using a global lock all around */ |
bc0c38d1 | 1673 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
1674 | if (unlikely(old_tracer != current_trace && current_trace)) { |
1675 | old_tracer = current_trace; | |
1676 | *iter->trace = *current_trace; | |
d15f57f2 | 1677 | } |
d7350c3f | 1678 | mutex_unlock(&trace_types_lock); |
bc0c38d1 SR |
1679 | |
1680 | atomic_inc(&trace_record_cmdline_disabled); | |
1681 | ||
bc0c38d1 SR |
1682 | if (*pos != iter->pos) { |
1683 | iter->ent = NULL; | |
1684 | iter->cpu = 0; | |
1685 | iter->idx = -1; | |
1686 | ||
d769041f SR |
1687 | ftrace_disable_cpu(); |
1688 | ||
b04cc6b1 FW |
1689 | if (cpu_file == TRACE_PIPE_ALL_CPU) { |
1690 | for_each_tracing_cpu(cpu) | |
2f26ebd5 | 1691 | tracing_iter_reset(iter, cpu); |
b04cc6b1 | 1692 | } else |
2f26ebd5 | 1693 | tracing_iter_reset(iter, cpu_file); |
bc0c38d1 | 1694 | |
d769041f SR |
1695 | ftrace_enable_cpu(); |
1696 | ||
bc0c38d1 SR |
1697 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
1698 | ; | |
1699 | ||
1700 | } else { | |
a63ce5b3 SR |
1701 | /* |
1702 | * If we overflowed the seq_file before, then we want | |
1703 | * to just reuse the trace_seq buffer again. | |
1704 | */ | |
1705 | if (iter->leftover) | |
1706 | p = iter; | |
1707 | else { | |
1708 | l = *pos - 1; | |
1709 | p = s_next(m, p, &l); | |
1710 | } | |
bc0c38d1 SR |
1711 | } |
1712 | ||
4f535968 | 1713 | trace_event_read_lock(); |
7e53bd42 | 1714 | trace_access_lock(cpu_file); |
bc0c38d1 SR |
1715 | return p; |
1716 | } | |
1717 | ||
1718 | static void s_stop(struct seq_file *m, void *p) | |
1719 | { | |
7e53bd42 LJ |
1720 | struct trace_iterator *iter = m->private; |
1721 | ||
bc0c38d1 | 1722 | atomic_dec(&trace_record_cmdline_disabled); |
7e53bd42 | 1723 | trace_access_unlock(iter->cpu_file); |
4f535968 | 1724 | trace_event_read_unlock(); |
bc0c38d1 SR |
1725 | } |
1726 | ||
e309b41d | 1727 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 1728 | { |
a6168353 ME |
1729 | seq_puts(m, "# _------=> CPU# \n"); |
1730 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
1731 | seq_puts(m, "# | / _----=> need-resched \n"); | |
1732 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
1733 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
637e7e86 SR |
1734 | seq_puts(m, "# |||| /_--=> lock-depth \n"); |
1735 | seq_puts(m, "# |||||/ delay \n"); | |
1736 | seq_puts(m, "# cmd pid |||||| time | caller \n"); | |
1737 | seq_puts(m, "# \\ / |||||| \\ | / \n"); | |
bc0c38d1 SR |
1738 | } |
1739 | ||
e309b41d | 1740 | static void print_func_help_header(struct seq_file *m) |
bc0c38d1 | 1741 | { |
a6168353 ME |
1742 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); |
1743 | seq_puts(m, "# | | | | |\n"); | |
bc0c38d1 SR |
1744 | } |
1745 | ||
1746 | ||
e309b41d | 1747 | static void |
bc0c38d1 SR |
1748 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
1749 | { | |
1750 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
1751 | struct trace_array *tr = iter->tr; | |
1752 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
1753 | struct tracer *type = current_trace; | |
2f26ebd5 SR |
1754 | unsigned long entries = 0; |
1755 | unsigned long total = 0; | |
1756 | unsigned long count; | |
bc0c38d1 | 1757 | const char *name = "preemption"; |
2f26ebd5 | 1758 | int cpu; |
bc0c38d1 SR |
1759 | |
1760 | if (type) | |
1761 | name = type->name; | |
1762 | ||
2f26ebd5 SR |
1763 | |
1764 | for_each_tracing_cpu(cpu) { | |
1765 | count = ring_buffer_entries_cpu(tr->buffer, cpu); | |
1766 | /* | |
1767 | * If this buffer has skipped entries, then we hold all | |
1768 | * entries for the trace and we need to ignore the | |
1769 | * ones before the time stamp. | |
1770 | */ | |
1771 | if (tr->data[cpu]->skipped_entries) { | |
1772 | count -= tr->data[cpu]->skipped_entries; | |
1773 | /* total is the same as the entries */ | |
1774 | total += count; | |
1775 | } else | |
1776 | total += count + | |
1777 | ring_buffer_overrun_cpu(tr->buffer, cpu); | |
1778 | entries += count; | |
1779 | } | |
bc0c38d1 | 1780 | |
888b55dc | 1781 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 1782 | name, UTS_RELEASE); |
888b55dc | 1783 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 1784 | "---------------------------------\n"); |
888b55dc | 1785 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 1786 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 1787 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 1788 | entries, |
4c11d7ae | 1789 | total, |
bc0c38d1 SR |
1790 | tr->cpu, |
1791 | #if defined(CONFIG_PREEMPT_NONE) | |
1792 | "server", | |
1793 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
1794 | "desktop", | |
b5c21b45 | 1795 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
1796 | "preempt", |
1797 | #else | |
1798 | "unknown", | |
1799 | #endif | |
1800 | /* These are reserved for later use */ | |
1801 | 0, 0, 0, 0); | |
1802 | #ifdef CONFIG_SMP | |
1803 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
1804 | #else | |
1805 | seq_puts(m, ")\n"); | |
1806 | #endif | |
888b55dc KM |
1807 | seq_puts(m, "# -----------------\n"); |
1808 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 SR |
1809 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
1810 | data->comm, data->pid, data->uid, data->nice, | |
1811 | data->policy, data->rt_priority); | |
888b55dc | 1812 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
1813 | |
1814 | if (data->critical_start) { | |
888b55dc | 1815 | seq_puts(m, "# => started at: "); |
214023c3 SR |
1816 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
1817 | trace_print_seq(m, &iter->seq); | |
888b55dc | 1818 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
1819 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
1820 | trace_print_seq(m, &iter->seq); | |
8248ac05 | 1821 | seq_puts(m, "\n#\n"); |
bc0c38d1 SR |
1822 | } |
1823 | ||
888b55dc | 1824 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
1825 | } |
1826 | ||
a309720c SR |
1827 | static void test_cpu_buff_start(struct trace_iterator *iter) |
1828 | { | |
1829 | struct trace_seq *s = &iter->seq; | |
1830 | ||
12ef7d44 SR |
1831 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) |
1832 | return; | |
1833 | ||
1834 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
1835 | return; | |
1836 | ||
4462344e | 1837 | if (cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
1838 | return; |
1839 | ||
2f26ebd5 SR |
1840 | if (iter->tr->data[iter->cpu]->skipped_entries) |
1841 | return; | |
1842 | ||
4462344e | 1843 | cpumask_set_cpu(iter->cpu, iter->started); |
b0dfa978 FW |
1844 | |
1845 | /* Don't print started cpu buffer for the first entry of the trace */ | |
1846 | if (iter->idx > 1) | |
1847 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
1848 | iter->cpu); | |
a309720c SR |
1849 | } |
1850 | ||
2c4f035f | 1851 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 1852 | { |
214023c3 | 1853 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 1854 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 1855 | struct trace_entry *entry; |
f633cef0 | 1856 | struct trace_event *event; |
bc0c38d1 | 1857 | |
4e3c3333 | 1858 | entry = iter->ent; |
dd0e545f | 1859 | |
a309720c SR |
1860 | test_cpu_buff_start(iter); |
1861 | ||
c4a8e8be | 1862 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 1863 | |
c4a8e8be | 1864 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
27d48be8 SR |
1865 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
1866 | if (!trace_print_lat_context(iter)) | |
1867 | goto partial; | |
1868 | } else { | |
1869 | if (!trace_print_context(iter)) | |
1870 | goto partial; | |
1871 | } | |
c4a8e8be | 1872 | } |
bc0c38d1 | 1873 | |
268ccda0 | 1874 | if (event) |
d9793bd8 ACM |
1875 | return event->trace(iter, sym_flags); |
1876 | ||
1877 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
1878 | goto partial; | |
02b67518 | 1879 | |
2c4f035f | 1880 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
1881 | partial: |
1882 | return TRACE_TYPE_PARTIAL_LINE; | |
bc0c38d1 SR |
1883 | } |
1884 | ||
2c4f035f | 1885 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 IM |
1886 | { |
1887 | struct trace_seq *s = &iter->seq; | |
1888 | struct trace_entry *entry; | |
f633cef0 | 1889 | struct trace_event *event; |
f9896bf3 IM |
1890 | |
1891 | entry = iter->ent; | |
dd0e545f | 1892 | |
c4a8e8be | 1893 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
d9793bd8 ACM |
1894 | if (!trace_seq_printf(s, "%d %d %llu ", |
1895 | entry->pid, iter->cpu, iter->ts)) | |
1896 | goto partial; | |
c4a8e8be | 1897 | } |
f9896bf3 | 1898 | |
f633cef0 | 1899 | event = ftrace_find_event(entry->type); |
268ccda0 | 1900 | if (event) |
d9793bd8 ACM |
1901 | return event->raw(iter, 0); |
1902 | ||
1903 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
1904 | goto partial; | |
777e208d | 1905 | |
2c4f035f | 1906 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
1907 | partial: |
1908 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 IM |
1909 | } |
1910 | ||
2c4f035f | 1911 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec IM |
1912 | { |
1913 | struct trace_seq *s = &iter->seq; | |
1914 | unsigned char newline = '\n'; | |
1915 | struct trace_entry *entry; | |
f633cef0 | 1916 | struct trace_event *event; |
5e3ca0ec IM |
1917 | |
1918 | entry = iter->ent; | |
dd0e545f | 1919 | |
c4a8e8be FW |
1920 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
1921 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
1922 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
1923 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
1924 | } | |
5e3ca0ec | 1925 | |
f633cef0 | 1926 | event = ftrace_find_event(entry->type); |
268ccda0 | 1927 | if (event) { |
ae7462b4 | 1928 | enum print_line_t ret = event->hex(iter, 0); |
d9793bd8 ACM |
1929 | if (ret != TRACE_TYPE_HANDLED) |
1930 | return ret; | |
1931 | } | |
7104f300 | 1932 | |
5e3ca0ec IM |
1933 | SEQ_PUT_FIELD_RET(s, newline); |
1934 | ||
2c4f035f | 1935 | return TRACE_TYPE_HANDLED; |
5e3ca0ec IM |
1936 | } |
1937 | ||
2c4f035f | 1938 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa IM |
1939 | { |
1940 | struct trace_seq *s = &iter->seq; | |
1941 | struct trace_entry *entry; | |
f633cef0 | 1942 | struct trace_event *event; |
cb0f12aa IM |
1943 | |
1944 | entry = iter->ent; | |
dd0e545f | 1945 | |
c4a8e8be FW |
1946 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
1947 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
1830b52d | 1948 | SEQ_PUT_FIELD_RET(s, iter->cpu); |
c4a8e8be FW |
1949 | SEQ_PUT_FIELD_RET(s, iter->ts); |
1950 | } | |
cb0f12aa | 1951 | |
f633cef0 | 1952 | event = ftrace_find_event(entry->type); |
268ccda0 | 1953 | return event ? event->binary(iter, 0) : TRACE_TYPE_HANDLED; |
cb0f12aa IM |
1954 | } |
1955 | ||
bc0c38d1 SR |
1956 | static int trace_empty(struct trace_iterator *iter) |
1957 | { | |
bc0c38d1 SR |
1958 | int cpu; |
1959 | ||
9aba60fe SR |
1960 | /* If we are looking at one CPU buffer, only check that one */ |
1961 | if (iter->cpu_file != TRACE_PIPE_ALL_CPU) { | |
1962 | cpu = iter->cpu_file; | |
1963 | if (iter->buffer_iter[cpu]) { | |
1964 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
1965 | return 0; | |
1966 | } else { | |
1967 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
1968 | return 0; | |
1969 | } | |
1970 | return 1; | |
1971 | } | |
1972 | ||
ab46428c | 1973 | for_each_tracing_cpu(cpu) { |
d769041f SR |
1974 | if (iter->buffer_iter[cpu]) { |
1975 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
1976 | return 0; | |
1977 | } else { | |
1978 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
1979 | return 0; | |
1980 | } | |
bc0c38d1 | 1981 | } |
d769041f | 1982 | |
797d3712 | 1983 | return 1; |
bc0c38d1 SR |
1984 | } |
1985 | ||
4f535968 | 1986 | /* Called with trace_event_read_lock() held. */ |
2c4f035f | 1987 | static enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 1988 | { |
2c4f035f FW |
1989 | enum print_line_t ret; |
1990 | ||
1991 | if (iter->trace && iter->trace->print_line) { | |
1992 | ret = iter->trace->print_line(iter); | |
1993 | if (ret != TRACE_TYPE_UNHANDLED) | |
1994 | return ret; | |
1995 | } | |
72829bc3 | 1996 | |
48ead020 FW |
1997 | if (iter->ent->type == TRACE_BPRINT && |
1998 | trace_flags & TRACE_ITER_PRINTK && | |
1999 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2000 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 2001 | |
66896a85 FW |
2002 | if (iter->ent->type == TRACE_PRINT && |
2003 | trace_flags & TRACE_ITER_PRINTK && | |
2004 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2005 | return trace_print_printk_msg_only(iter); |
66896a85 | 2006 | |
cb0f12aa IM |
2007 | if (trace_flags & TRACE_ITER_BIN) |
2008 | return print_bin_fmt(iter); | |
2009 | ||
5e3ca0ec IM |
2010 | if (trace_flags & TRACE_ITER_HEX) |
2011 | return print_hex_fmt(iter); | |
2012 | ||
f9896bf3 IM |
2013 | if (trace_flags & TRACE_ITER_RAW) |
2014 | return print_raw_fmt(iter); | |
2015 | ||
f9896bf3 IM |
2016 | return print_trace_fmt(iter); |
2017 | } | |
2018 | ||
bc0c38d1 SR |
2019 | static int s_show(struct seq_file *m, void *v) |
2020 | { | |
2021 | struct trace_iterator *iter = v; | |
a63ce5b3 | 2022 | int ret; |
bc0c38d1 SR |
2023 | |
2024 | if (iter->ent == NULL) { | |
2025 | if (iter->tr) { | |
2026 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2027 | seq_puts(m, "#\n"); | |
2028 | } | |
8bba1bf5 MM |
2029 | if (iter->trace && iter->trace->print_header) |
2030 | iter->trace->print_header(m); | |
2031 | else if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
bc0c38d1 SR |
2032 | /* print nothing if the buffers are empty */ |
2033 | if (trace_empty(iter)) | |
2034 | return 0; | |
2035 | print_trace_header(m, iter); | |
2036 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2037 | print_lat_help_header(m); | |
2038 | } else { | |
2039 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2040 | print_func_help_header(m); | |
2041 | } | |
a63ce5b3 SR |
2042 | } else if (iter->leftover) { |
2043 | /* | |
2044 | * If we filled the seq_file buffer earlier, we | |
2045 | * want to just show it now. | |
2046 | */ | |
2047 | ret = trace_print_seq(m, &iter->seq); | |
2048 | ||
2049 | /* ret should this time be zero, but you never know */ | |
2050 | iter->leftover = ret; | |
2051 | ||
bc0c38d1 | 2052 | } else { |
f9896bf3 | 2053 | print_trace_line(iter); |
a63ce5b3 SR |
2054 | ret = trace_print_seq(m, &iter->seq); |
2055 | /* | |
2056 | * If we overflow the seq_file buffer, then it will | |
2057 | * ask us for this data again at start up. | |
2058 | * Use that instead. | |
2059 | * ret is 0 if seq_file write succeeded. | |
2060 | * -1 otherwise. | |
2061 | */ | |
2062 | iter->leftover = ret; | |
bc0c38d1 SR |
2063 | } |
2064 | ||
2065 | return 0; | |
2066 | } | |
2067 | ||
88e9d34c | 2068 | static const struct seq_operations tracer_seq_ops = { |
4bf39a94 IM |
2069 | .start = s_start, |
2070 | .next = s_next, | |
2071 | .stop = s_stop, | |
2072 | .show = s_show, | |
bc0c38d1 SR |
2073 | }; |
2074 | ||
e309b41d | 2075 | static struct trace_iterator * |
85a2f9b4 | 2076 | __tracing_open(struct inode *inode, struct file *file) |
bc0c38d1 | 2077 | { |
b04cc6b1 | 2078 | long cpu_file = (long) inode->i_private; |
85a2f9b4 | 2079 | void *fail_ret = ERR_PTR(-ENOMEM); |
bc0c38d1 | 2080 | struct trace_iterator *iter; |
3928a8a2 | 2081 | struct seq_file *m; |
85a2f9b4 | 2082 | int cpu, ret; |
bc0c38d1 | 2083 | |
85a2f9b4 SR |
2084 | if (tracing_disabled) |
2085 | return ERR_PTR(-ENODEV); | |
60a11774 | 2086 | |
bc0c38d1 | 2087 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
85a2f9b4 SR |
2088 | if (!iter) |
2089 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 2090 | |
d7350c3f FW |
2091 | /* |
2092 | * We make a copy of the current tracer to avoid concurrent | |
2093 | * changes on it while we are reading. | |
2094 | */ | |
bc0c38d1 | 2095 | mutex_lock(&trace_types_lock); |
d7350c3f | 2096 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 2097 | if (!iter->trace) |
d7350c3f | 2098 | goto fail; |
85a2f9b4 | 2099 | |
d7350c3f FW |
2100 | if (current_trace) |
2101 | *iter->trace = *current_trace; | |
2102 | ||
79f55997 | 2103 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
b0dfa978 FW |
2104 | goto fail; |
2105 | ||
bc0c38d1 SR |
2106 | if (current_trace && current_trace->print_max) |
2107 | iter->tr = &max_tr; | |
2108 | else | |
b04cc6b1 | 2109 | iter->tr = &global_trace; |
bc0c38d1 | 2110 | iter->pos = -1; |
d7350c3f | 2111 | mutex_init(&iter->mutex); |
b04cc6b1 | 2112 | iter->cpu_file = cpu_file; |
bc0c38d1 | 2113 | |
8bba1bf5 MM |
2114 | /* Notify the tracer early; before we stop tracing. */ |
2115 | if (iter->trace && iter->trace->open) | |
a93751ca | 2116 | iter->trace->open(iter); |
8bba1bf5 | 2117 | |
12ef7d44 SR |
2118 | /* Annotate start of buffers if we had overruns */ |
2119 | if (ring_buffer_overruns(iter->tr->buffer)) | |
2120 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
2121 | ||
2f26ebd5 SR |
2122 | /* stop the trace while dumping */ |
2123 | tracing_stop(); | |
2124 | ||
b04cc6b1 FW |
2125 | if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { |
2126 | for_each_tracing_cpu(cpu) { | |
12ef7d44 | 2127 | |
b04cc6b1 FW |
2128 | iter->buffer_iter[cpu] = |
2129 | ring_buffer_read_start(iter->tr->buffer, cpu); | |
2f26ebd5 | 2130 | tracing_iter_reset(iter, cpu); |
b04cc6b1 FW |
2131 | } |
2132 | } else { | |
2133 | cpu = iter->cpu_file; | |
3928a8a2 | 2134 | iter->buffer_iter[cpu] = |
b04cc6b1 | 2135 | ring_buffer_read_start(iter->tr->buffer, cpu); |
2f26ebd5 | 2136 | tracing_iter_reset(iter, cpu); |
3928a8a2 SR |
2137 | } |
2138 | ||
85a2f9b4 SR |
2139 | ret = seq_open(file, &tracer_seq_ops); |
2140 | if (ret < 0) { | |
2141 | fail_ret = ERR_PTR(ret); | |
3928a8a2 | 2142 | goto fail_buffer; |
85a2f9b4 | 2143 | } |
bc0c38d1 | 2144 | |
3928a8a2 SR |
2145 | m = file->private_data; |
2146 | m->private = iter; | |
bc0c38d1 | 2147 | |
bc0c38d1 SR |
2148 | mutex_unlock(&trace_types_lock); |
2149 | ||
bc0c38d1 | 2150 | return iter; |
3928a8a2 SR |
2151 | |
2152 | fail_buffer: | |
2153 | for_each_tracing_cpu(cpu) { | |
2154 | if (iter->buffer_iter[cpu]) | |
2155 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2156 | } | |
b0dfa978 | 2157 | free_cpumask_var(iter->started); |
2f26ebd5 | 2158 | tracing_start(); |
d7350c3f | 2159 | fail: |
3928a8a2 | 2160 | mutex_unlock(&trace_types_lock); |
d7350c3f | 2161 | kfree(iter->trace); |
0bb943c7 | 2162 | kfree(iter); |
3928a8a2 | 2163 | |
85a2f9b4 | 2164 | return fail_ret; |
bc0c38d1 SR |
2165 | } |
2166 | ||
2167 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
2168 | { | |
60a11774 SR |
2169 | if (tracing_disabled) |
2170 | return -ENODEV; | |
2171 | ||
bc0c38d1 SR |
2172 | filp->private_data = inode->i_private; |
2173 | return 0; | |
2174 | } | |
2175 | ||
4fd27358 | 2176 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 SR |
2177 | { |
2178 | struct seq_file *m = (struct seq_file *)file->private_data; | |
4acd4d00 | 2179 | struct trace_iterator *iter; |
3928a8a2 | 2180 | int cpu; |
bc0c38d1 | 2181 | |
4acd4d00 SR |
2182 | if (!(file->f_mode & FMODE_READ)) |
2183 | return 0; | |
2184 | ||
2185 | iter = m->private; | |
2186 | ||
bc0c38d1 | 2187 | mutex_lock(&trace_types_lock); |
3928a8a2 SR |
2188 | for_each_tracing_cpu(cpu) { |
2189 | if (iter->buffer_iter[cpu]) | |
2190 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2191 | } | |
2192 | ||
bc0c38d1 SR |
2193 | if (iter->trace && iter->trace->close) |
2194 | iter->trace->close(iter); | |
2195 | ||
2196 | /* reenable tracing if it was previously enabled */ | |
9036990d | 2197 | tracing_start(); |
bc0c38d1 SR |
2198 | mutex_unlock(&trace_types_lock); |
2199 | ||
2200 | seq_release(inode, file); | |
d7350c3f | 2201 | mutex_destroy(&iter->mutex); |
b0dfa978 | 2202 | free_cpumask_var(iter->started); |
d7350c3f | 2203 | kfree(iter->trace); |
bc0c38d1 SR |
2204 | kfree(iter); |
2205 | return 0; | |
2206 | } | |
2207 | ||
2208 | static int tracing_open(struct inode *inode, struct file *file) | |
2209 | { | |
85a2f9b4 SR |
2210 | struct trace_iterator *iter; |
2211 | int ret = 0; | |
bc0c38d1 | 2212 | |
4acd4d00 SR |
2213 | /* If this file was open for write, then erase contents */ |
2214 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2215 | (file->f_flags & O_TRUNC)) { |
4acd4d00 | 2216 | long cpu = (long) inode->i_private; |
bc0c38d1 | 2217 | |
4acd4d00 SR |
2218 | if (cpu == TRACE_PIPE_ALL_CPU) |
2219 | tracing_reset_online_cpus(&global_trace); | |
2220 | else | |
2221 | tracing_reset(&global_trace, cpu); | |
2222 | } | |
bc0c38d1 | 2223 | |
4acd4d00 SR |
2224 | if (file->f_mode & FMODE_READ) { |
2225 | iter = __tracing_open(inode, file); | |
2226 | if (IS_ERR(iter)) | |
2227 | ret = PTR_ERR(iter); | |
2228 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
2229 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
2230 | } | |
bc0c38d1 SR |
2231 | return ret; |
2232 | } | |
2233 | ||
e309b41d | 2234 | static void * |
bc0c38d1 SR |
2235 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2236 | { | |
f129e965 | 2237 | struct tracer *t = v; |
bc0c38d1 SR |
2238 | |
2239 | (*pos)++; | |
2240 | ||
2241 | if (t) | |
2242 | t = t->next; | |
2243 | ||
bc0c38d1 SR |
2244 | return t; |
2245 | } | |
2246 | ||
2247 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2248 | { | |
f129e965 | 2249 | struct tracer *t; |
bc0c38d1 SR |
2250 | loff_t l = 0; |
2251 | ||
2252 | mutex_lock(&trace_types_lock); | |
f129e965 | 2253 | for (t = trace_types; t && l < *pos; t = t_next(m, t, &l)) |
bc0c38d1 SR |
2254 | ; |
2255 | ||
2256 | return t; | |
2257 | } | |
2258 | ||
2259 | static void t_stop(struct seq_file *m, void *p) | |
2260 | { | |
2261 | mutex_unlock(&trace_types_lock); | |
2262 | } | |
2263 | ||
2264 | static int t_show(struct seq_file *m, void *v) | |
2265 | { | |
2266 | struct tracer *t = v; | |
2267 | ||
2268 | if (!t) | |
2269 | return 0; | |
2270 | ||
2271 | seq_printf(m, "%s", t->name); | |
2272 | if (t->next) | |
2273 | seq_putc(m, ' '); | |
2274 | else | |
2275 | seq_putc(m, '\n'); | |
2276 | ||
2277 | return 0; | |
2278 | } | |
2279 | ||
88e9d34c | 2280 | static const struct seq_operations show_traces_seq_ops = { |
4bf39a94 IM |
2281 | .start = t_start, |
2282 | .next = t_next, | |
2283 | .stop = t_stop, | |
2284 | .show = t_show, | |
bc0c38d1 SR |
2285 | }; |
2286 | ||
2287 | static int show_traces_open(struct inode *inode, struct file *file) | |
2288 | { | |
60a11774 SR |
2289 | if (tracing_disabled) |
2290 | return -ENODEV; | |
2291 | ||
f129e965 | 2292 | return seq_open(file, &show_traces_seq_ops); |
bc0c38d1 SR |
2293 | } |
2294 | ||
4acd4d00 SR |
2295 | static ssize_t |
2296 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
2297 | size_t count, loff_t *ppos) | |
2298 | { | |
2299 | return count; | |
2300 | } | |
2301 | ||
5e2336a0 | 2302 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
2303 | .open = tracing_open, |
2304 | .read = seq_read, | |
4acd4d00 | 2305 | .write = tracing_write_stub, |
4bf39a94 IM |
2306 | .llseek = seq_lseek, |
2307 | .release = tracing_release, | |
bc0c38d1 SR |
2308 | }; |
2309 | ||
5e2336a0 | 2310 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
2311 | .open = show_traces_open, |
2312 | .read = seq_read, | |
2313 | .release = seq_release, | |
2314 | }; | |
2315 | ||
36dfe925 IM |
2316 | /* |
2317 | * Only trace on a CPU if the bitmask is set: | |
2318 | */ | |
9e01c1b7 | 2319 | static cpumask_var_t tracing_cpumask; |
36dfe925 IM |
2320 | |
2321 | /* | |
2322 | * The tracer itself will not take this lock, but still we want | |
2323 | * to provide a consistent cpumask to user-space: | |
2324 | */ | |
2325 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
2326 | ||
2327 | /* | |
2328 | * Temporary storage for the character representation of the | |
2329 | * CPU bitmask (and one more byte for the newline): | |
2330 | */ | |
2331 | static char mask_str[NR_CPUS + 1]; | |
2332 | ||
c7078de1 IM |
2333 | static ssize_t |
2334 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
2335 | size_t count, loff_t *ppos) | |
2336 | { | |
36dfe925 | 2337 | int len; |
c7078de1 IM |
2338 | |
2339 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 2340 | |
9e01c1b7 | 2341 | len = cpumask_scnprintf(mask_str, count, tracing_cpumask); |
36dfe925 IM |
2342 | if (count - len < 2) { |
2343 | count = -EINVAL; | |
2344 | goto out_err; | |
2345 | } | |
2346 | len += sprintf(mask_str + len, "\n"); | |
2347 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
2348 | ||
2349 | out_err: | |
c7078de1 IM |
2350 | mutex_unlock(&tracing_cpumask_update_lock); |
2351 | ||
2352 | return count; | |
2353 | } | |
2354 | ||
2355 | static ssize_t | |
2356 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
2357 | size_t count, loff_t *ppos) | |
2358 | { | |
36dfe925 | 2359 | int err, cpu; |
9e01c1b7 RR |
2360 | cpumask_var_t tracing_cpumask_new; |
2361 | ||
2362 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
2363 | return -ENOMEM; | |
c7078de1 | 2364 | |
9e01c1b7 | 2365 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 2366 | if (err) |
36dfe925 IM |
2367 | goto err_unlock; |
2368 | ||
215368e8 LZ |
2369 | mutex_lock(&tracing_cpumask_update_lock); |
2370 | ||
a5e25883 | 2371 | local_irq_disable(); |
0199c4e6 | 2372 | arch_spin_lock(&ftrace_max_lock); |
ab46428c | 2373 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
2374 | /* |
2375 | * Increase/decrease the disabled counter if we are | |
2376 | * about to flip a bit in the cpumask: | |
2377 | */ | |
9e01c1b7 RR |
2378 | if (cpumask_test_cpu(cpu, tracing_cpumask) && |
2379 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 IM |
2380 | atomic_inc(&global_trace.data[cpu]->disabled); |
2381 | } | |
9e01c1b7 RR |
2382 | if (!cpumask_test_cpu(cpu, tracing_cpumask) && |
2383 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 IM |
2384 | atomic_dec(&global_trace.data[cpu]->disabled); |
2385 | } | |
2386 | } | |
0199c4e6 | 2387 | arch_spin_unlock(&ftrace_max_lock); |
a5e25883 | 2388 | local_irq_enable(); |
36dfe925 | 2389 | |
9e01c1b7 | 2390 | cpumask_copy(tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
2391 | |
2392 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 2393 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
2394 | |
2395 | return count; | |
36dfe925 IM |
2396 | |
2397 | err_unlock: | |
215368e8 | 2398 | free_cpumask_var(tracing_cpumask_new); |
36dfe925 IM |
2399 | |
2400 | return err; | |
c7078de1 IM |
2401 | } |
2402 | ||
5e2336a0 | 2403 | static const struct file_operations tracing_cpumask_fops = { |
c7078de1 IM |
2404 | .open = tracing_open_generic, |
2405 | .read = tracing_cpumask_read, | |
2406 | .write = tracing_cpumask_write, | |
bc0c38d1 SR |
2407 | }; |
2408 | ||
fdb372ed | 2409 | static int tracing_trace_options_show(struct seq_file *m, void *v) |
bc0c38d1 | 2410 | { |
d8e83d26 SR |
2411 | struct tracer_opt *trace_opts; |
2412 | u32 tracer_flags; | |
d8e83d26 | 2413 | int i; |
adf9f195 | 2414 | |
d8e83d26 SR |
2415 | mutex_lock(&trace_types_lock); |
2416 | tracer_flags = current_trace->flags->val; | |
2417 | trace_opts = current_trace->flags->opts; | |
2418 | ||
bc0c38d1 SR |
2419 | for (i = 0; trace_options[i]; i++) { |
2420 | if (trace_flags & (1 << i)) | |
fdb372ed | 2421 | seq_printf(m, "%s\n", trace_options[i]); |
bc0c38d1 | 2422 | else |
fdb372ed | 2423 | seq_printf(m, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
2424 | } |
2425 | ||
adf9f195 FW |
2426 | for (i = 0; trace_opts[i].name; i++) { |
2427 | if (tracer_flags & trace_opts[i].bit) | |
fdb372ed | 2428 | seq_printf(m, "%s\n", trace_opts[i].name); |
adf9f195 | 2429 | else |
fdb372ed | 2430 | seq_printf(m, "no%s\n", trace_opts[i].name); |
adf9f195 | 2431 | } |
d8e83d26 | 2432 | mutex_unlock(&trace_types_lock); |
adf9f195 | 2433 | |
fdb372ed | 2434 | return 0; |
bc0c38d1 | 2435 | } |
bc0c38d1 | 2436 | |
8d18eaaf LZ |
2437 | static int __set_tracer_option(struct tracer *trace, |
2438 | struct tracer_flags *tracer_flags, | |
2439 | struct tracer_opt *opts, int neg) | |
2440 | { | |
2441 | int ret; | |
bc0c38d1 | 2442 | |
8d18eaaf LZ |
2443 | ret = trace->set_flag(tracer_flags->val, opts->bit, !neg); |
2444 | if (ret) | |
2445 | return ret; | |
2446 | ||
2447 | if (neg) | |
2448 | tracer_flags->val &= ~opts->bit; | |
2449 | else | |
2450 | tracer_flags->val |= opts->bit; | |
2451 | return 0; | |
bc0c38d1 SR |
2452 | } |
2453 | ||
adf9f195 FW |
2454 | /* Try to assign a tracer specific option */ |
2455 | static int set_tracer_option(struct tracer *trace, char *cmp, int neg) | |
2456 | { | |
7770841e | 2457 | struct tracer_flags *tracer_flags = trace->flags; |
adf9f195 | 2458 | struct tracer_opt *opts = NULL; |
8d18eaaf | 2459 | int i; |
adf9f195 | 2460 | |
7770841e Z |
2461 | for (i = 0; tracer_flags->opts[i].name; i++) { |
2462 | opts = &tracer_flags->opts[i]; | |
adf9f195 | 2463 | |
8d18eaaf LZ |
2464 | if (strcmp(cmp, opts->name) == 0) |
2465 | return __set_tracer_option(trace, trace->flags, | |
2466 | opts, neg); | |
adf9f195 | 2467 | } |
adf9f195 | 2468 | |
8d18eaaf | 2469 | return -EINVAL; |
adf9f195 FW |
2470 | } |
2471 | ||
af4617bd SR |
2472 | static void set_tracer_flags(unsigned int mask, int enabled) |
2473 | { | |
2474 | /* do nothing if flag is already set */ | |
2475 | if (!!(trace_flags & mask) == !!enabled) | |
2476 | return; | |
2477 | ||
2478 | if (enabled) | |
2479 | trace_flags |= mask; | |
2480 | else | |
2481 | trace_flags &= ~mask; | |
af4617bd SR |
2482 | } |
2483 | ||
bc0c38d1 | 2484 | static ssize_t |
ee6bce52 | 2485 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, |
bc0c38d1 SR |
2486 | size_t cnt, loff_t *ppos) |
2487 | { | |
2488 | char buf[64]; | |
8d18eaaf | 2489 | char *cmp; |
bc0c38d1 | 2490 | int neg = 0; |
adf9f195 | 2491 | int ret; |
bc0c38d1 SR |
2492 | int i; |
2493 | ||
cffae437 SR |
2494 | if (cnt >= sizeof(buf)) |
2495 | return -EINVAL; | |
bc0c38d1 SR |
2496 | |
2497 | if (copy_from_user(&buf, ubuf, cnt)) | |
2498 | return -EFAULT; | |
2499 | ||
2500 | buf[cnt] = 0; | |
8d18eaaf | 2501 | cmp = strstrip(buf); |
bc0c38d1 | 2502 | |
8d18eaaf | 2503 | if (strncmp(cmp, "no", 2) == 0) { |
bc0c38d1 SR |
2504 | neg = 1; |
2505 | cmp += 2; | |
2506 | } | |
2507 | ||
2508 | for (i = 0; trace_options[i]; i++) { | |
8d18eaaf | 2509 | if (strcmp(cmp, trace_options[i]) == 0) { |
af4617bd | 2510 | set_tracer_flags(1 << i, !neg); |
bc0c38d1 SR |
2511 | break; |
2512 | } | |
2513 | } | |
adf9f195 FW |
2514 | |
2515 | /* If no option could be set, test the specific tracer options */ | |
2516 | if (!trace_options[i]) { | |
d8e83d26 | 2517 | mutex_lock(&trace_types_lock); |
adf9f195 | 2518 | ret = set_tracer_option(current_trace, cmp, neg); |
d8e83d26 | 2519 | mutex_unlock(&trace_types_lock); |
adf9f195 FW |
2520 | if (ret) |
2521 | return ret; | |
2522 | } | |
bc0c38d1 | 2523 | |
cf8517cf | 2524 | *ppos += cnt; |
bc0c38d1 SR |
2525 | |
2526 | return cnt; | |
2527 | } | |
2528 | ||
fdb372ed LZ |
2529 | static int tracing_trace_options_open(struct inode *inode, struct file *file) |
2530 | { | |
2531 | if (tracing_disabled) | |
2532 | return -ENODEV; | |
2533 | return single_open(file, tracing_trace_options_show, NULL); | |
2534 | } | |
2535 | ||
5e2336a0 | 2536 | static const struct file_operations tracing_iter_fops = { |
fdb372ed LZ |
2537 | .open = tracing_trace_options_open, |
2538 | .read = seq_read, | |
2539 | .llseek = seq_lseek, | |
2540 | .release = single_release, | |
ee6bce52 | 2541 | .write = tracing_trace_options_write, |
bc0c38d1 SR |
2542 | }; |
2543 | ||
7bd2f24c IM |
2544 | static const char readme_msg[] = |
2545 | "tracing mini-HOWTO:\n\n" | |
156f5a78 GL |
2546 | "# mount -t debugfs nodev /sys/kernel/debug\n\n" |
2547 | "# cat /sys/kernel/debug/tracing/available_tracers\n" | |
bc2b6871 | 2548 | "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n" |
156f5a78 | 2549 | "# cat /sys/kernel/debug/tracing/current_tracer\n" |
bc2b6871 | 2550 | "nop\n" |
156f5a78 GL |
2551 | "# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n" |
2552 | "# cat /sys/kernel/debug/tracing/current_tracer\n" | |
7bd2f24c | 2553 | "sched_switch\n" |
156f5a78 | 2554 | "# cat /sys/kernel/debug/tracing/trace_options\n" |
7bd2f24c | 2555 | "noprint-parent nosym-offset nosym-addr noverbose\n" |
156f5a78 GL |
2556 | "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n" |
2557 | "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n" | |
2558 | "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n" | |
2559 | "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n" | |
7bd2f24c IM |
2560 | ; |
2561 | ||
2562 | static ssize_t | |
2563 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
2564 | size_t cnt, loff_t *ppos) | |
2565 | { | |
2566 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
2567 | readme_msg, strlen(readme_msg)); | |
2568 | } | |
2569 | ||
5e2336a0 | 2570 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
2571 | .open = tracing_open_generic, |
2572 | .read = tracing_readme_read, | |
7bd2f24c IM |
2573 | }; |
2574 | ||
69abe6a5 AP |
2575 | static ssize_t |
2576 | tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, | |
2577 | size_t cnt, loff_t *ppos) | |
2578 | { | |
2579 | char *buf_comm; | |
2580 | char *file_buf; | |
2581 | char *buf; | |
2582 | int len = 0; | |
2583 | int pid; | |
2584 | int i; | |
2585 | ||
2586 | file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL); | |
2587 | if (!file_buf) | |
2588 | return -ENOMEM; | |
2589 | ||
2590 | buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL); | |
2591 | if (!buf_comm) { | |
2592 | kfree(file_buf); | |
2593 | return -ENOMEM; | |
2594 | } | |
2595 | ||
2596 | buf = file_buf; | |
2597 | ||
2598 | for (i = 0; i < SAVED_CMDLINES; i++) { | |
2599 | int r; | |
2600 | ||
2601 | pid = map_cmdline_to_pid[i]; | |
2602 | if (pid == -1 || pid == NO_CMDLINE_MAP) | |
2603 | continue; | |
2604 | ||
2605 | trace_find_cmdline(pid, buf_comm); | |
2606 | r = sprintf(buf, "%d %s\n", pid, buf_comm); | |
2607 | buf += r; | |
2608 | len += r; | |
2609 | } | |
2610 | ||
2611 | len = simple_read_from_buffer(ubuf, cnt, ppos, | |
2612 | file_buf, len); | |
2613 | ||
2614 | kfree(file_buf); | |
2615 | kfree(buf_comm); | |
2616 | ||
2617 | return len; | |
2618 | } | |
2619 | ||
2620 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
2621 | .open = tracing_open_generic, | |
2622 | .read = tracing_saved_cmdlines_read, | |
2623 | }; | |
2624 | ||
bc0c38d1 SR |
2625 | static ssize_t |
2626 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
2627 | size_t cnt, loff_t *ppos) | |
2628 | { | |
bc0c38d1 SR |
2629 | char buf[64]; |
2630 | int r; | |
2631 | ||
9036990d | 2632 | r = sprintf(buf, "%u\n", tracer_enabled); |
4e3c3333 | 2633 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2634 | } |
2635 | ||
2636 | static ssize_t | |
2637 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
2638 | size_t cnt, loff_t *ppos) | |
2639 | { | |
2640 | struct trace_array *tr = filp->private_data; | |
bc0c38d1 | 2641 | char buf[64]; |
5e39841c | 2642 | unsigned long val; |
c6caeeb1 | 2643 | int ret; |
bc0c38d1 | 2644 | |
cffae437 SR |
2645 | if (cnt >= sizeof(buf)) |
2646 | return -EINVAL; | |
bc0c38d1 SR |
2647 | |
2648 | if (copy_from_user(&buf, ubuf, cnt)) | |
2649 | return -EFAULT; | |
2650 | ||
2651 | buf[cnt] = 0; | |
2652 | ||
c6caeeb1 SR |
2653 | ret = strict_strtoul(buf, 10, &val); |
2654 | if (ret < 0) | |
2655 | return ret; | |
bc0c38d1 SR |
2656 | |
2657 | val = !!val; | |
2658 | ||
2659 | mutex_lock(&trace_types_lock); | |
9036990d SR |
2660 | if (tracer_enabled ^ val) { |
2661 | if (val) { | |
bc0c38d1 | 2662 | tracer_enabled = 1; |
9036990d SR |
2663 | if (current_trace->start) |
2664 | current_trace->start(tr); | |
2665 | tracing_start(); | |
2666 | } else { | |
bc0c38d1 | 2667 | tracer_enabled = 0; |
9036990d SR |
2668 | tracing_stop(); |
2669 | if (current_trace->stop) | |
2670 | current_trace->stop(tr); | |
2671 | } | |
bc0c38d1 SR |
2672 | } |
2673 | mutex_unlock(&trace_types_lock); | |
2674 | ||
cf8517cf | 2675 | *ppos += cnt; |
bc0c38d1 SR |
2676 | |
2677 | return cnt; | |
2678 | } | |
2679 | ||
2680 | static ssize_t | |
2681 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
2682 | size_t cnt, loff_t *ppos) | |
2683 | { | |
ee6c2c1b | 2684 | char buf[MAX_TRACER_SIZE+2]; |
bc0c38d1 SR |
2685 | int r; |
2686 | ||
2687 | mutex_lock(&trace_types_lock); | |
2688 | if (current_trace) | |
2689 | r = sprintf(buf, "%s\n", current_trace->name); | |
2690 | else | |
2691 | r = sprintf(buf, "\n"); | |
2692 | mutex_unlock(&trace_types_lock); | |
2693 | ||
4bf39a94 | 2694 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2695 | } |
2696 | ||
b6f11df2 ACM |
2697 | int tracer_init(struct tracer *t, struct trace_array *tr) |
2698 | { | |
2699 | tracing_reset_online_cpus(tr); | |
2700 | return t->init(tr); | |
2701 | } | |
2702 | ||
73c5162a SR |
2703 | static int tracing_resize_ring_buffer(unsigned long size) |
2704 | { | |
2705 | int ret; | |
2706 | ||
2707 | /* | |
2708 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
2709 | * we use the size that was given, and we can forget about |
2710 | * expanding it later. | |
73c5162a SR |
2711 | */ |
2712 | ring_buffer_expanded = 1; | |
2713 | ||
2714 | ret = ring_buffer_resize(global_trace.buffer, size); | |
2715 | if (ret < 0) | |
2716 | return ret; | |
2717 | ||
2718 | ret = ring_buffer_resize(max_tr.buffer, size); | |
2719 | if (ret < 0) { | |
2720 | int r; | |
2721 | ||
2722 | r = ring_buffer_resize(global_trace.buffer, | |
2723 | global_trace.entries); | |
2724 | if (r < 0) { | |
a123c52b SR |
2725 | /* |
2726 | * AARGH! We are left with different | |
2727 | * size max buffer!!!! | |
2728 | * The max buffer is our "snapshot" buffer. | |
2729 | * When a tracer needs a snapshot (one of the | |
2730 | * latency tracers), it swaps the max buffer | |
2731 | * with the saved snap shot. We succeeded to | |
2732 | * update the size of the main buffer, but failed to | |
2733 | * update the size of the max buffer. But when we tried | |
2734 | * to reset the main buffer to the original size, we | |
2735 | * failed there too. This is very unlikely to | |
2736 | * happen, but if it does, warn and kill all | |
2737 | * tracing. | |
2738 | */ | |
73c5162a SR |
2739 | WARN_ON(1); |
2740 | tracing_disabled = 1; | |
2741 | } | |
2742 | return ret; | |
2743 | } | |
2744 | ||
2745 | global_trace.entries = size; | |
2746 | ||
2747 | return ret; | |
2748 | } | |
2749 | ||
1852fcce SR |
2750 | /** |
2751 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
2752 | * | |
2753 | * To save on memory when the tracing is never used on a system with it | |
2754 | * configured in. The ring buffers are set to a minimum size. But once | |
2755 | * a user starts to use the tracing facility, then they need to grow | |
2756 | * to their default size. | |
2757 | * | |
2758 | * This function is to be called when a tracer is about to be used. | |
2759 | */ | |
2760 | int tracing_update_buffers(void) | |
2761 | { | |
2762 | int ret = 0; | |
2763 | ||
1027fcb2 | 2764 | mutex_lock(&trace_types_lock); |
1852fcce SR |
2765 | if (!ring_buffer_expanded) |
2766 | ret = tracing_resize_ring_buffer(trace_buf_size); | |
1027fcb2 | 2767 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
2768 | |
2769 | return ret; | |
2770 | } | |
2771 | ||
577b785f SR |
2772 | struct trace_option_dentry; |
2773 | ||
2774 | static struct trace_option_dentry * | |
2775 | create_trace_option_files(struct tracer *tracer); | |
2776 | ||
2777 | static void | |
2778 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
2779 | ||
b2821ae6 | 2780 | static int tracing_set_tracer(const char *buf) |
bc0c38d1 | 2781 | { |
577b785f | 2782 | static struct trace_option_dentry *topts; |
bc0c38d1 SR |
2783 | struct trace_array *tr = &global_trace; |
2784 | struct tracer *t; | |
d9e54076 | 2785 | int ret = 0; |
bc0c38d1 | 2786 | |
1027fcb2 SR |
2787 | mutex_lock(&trace_types_lock); |
2788 | ||
73c5162a SR |
2789 | if (!ring_buffer_expanded) { |
2790 | ret = tracing_resize_ring_buffer(trace_buf_size); | |
2791 | if (ret < 0) | |
59f586db | 2792 | goto out; |
73c5162a SR |
2793 | ret = 0; |
2794 | } | |
2795 | ||
bc0c38d1 SR |
2796 | for (t = trace_types; t; t = t->next) { |
2797 | if (strcmp(t->name, buf) == 0) | |
2798 | break; | |
2799 | } | |
c2931e05 FW |
2800 | if (!t) { |
2801 | ret = -EINVAL; | |
2802 | goto out; | |
2803 | } | |
2804 | if (t == current_trace) | |
bc0c38d1 SR |
2805 | goto out; |
2806 | ||
9f029e83 | 2807 | trace_branch_disable(); |
bc0c38d1 SR |
2808 | if (current_trace && current_trace->reset) |
2809 | current_trace->reset(tr); | |
2810 | ||
577b785f SR |
2811 | destroy_trace_option_files(topts); |
2812 | ||
bc0c38d1 | 2813 | current_trace = t; |
577b785f SR |
2814 | |
2815 | topts = create_trace_option_files(current_trace); | |
2816 | ||
1c80025a | 2817 | if (t->init) { |
b6f11df2 | 2818 | ret = tracer_init(t, tr); |
1c80025a FW |
2819 | if (ret) |
2820 | goto out; | |
2821 | } | |
bc0c38d1 | 2822 | |
9f029e83 | 2823 | trace_branch_enable(tr); |
bc0c38d1 SR |
2824 | out: |
2825 | mutex_unlock(&trace_types_lock); | |
2826 | ||
d9e54076 PZ |
2827 | return ret; |
2828 | } | |
2829 | ||
2830 | static ssize_t | |
2831 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
2832 | size_t cnt, loff_t *ppos) | |
2833 | { | |
ee6c2c1b | 2834 | char buf[MAX_TRACER_SIZE+1]; |
d9e54076 PZ |
2835 | int i; |
2836 | size_t ret; | |
e6e7a65a FW |
2837 | int err; |
2838 | ||
2839 | ret = cnt; | |
d9e54076 | 2840 | |
ee6c2c1b LZ |
2841 | if (cnt > MAX_TRACER_SIZE) |
2842 | cnt = MAX_TRACER_SIZE; | |
d9e54076 PZ |
2843 | |
2844 | if (copy_from_user(&buf, ubuf, cnt)) | |
2845 | return -EFAULT; | |
2846 | ||
2847 | buf[cnt] = 0; | |
2848 | ||
2849 | /* strip ending whitespace. */ | |
2850 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
2851 | buf[i] = 0; | |
2852 | ||
e6e7a65a FW |
2853 | err = tracing_set_tracer(buf); |
2854 | if (err) | |
2855 | return err; | |
d9e54076 | 2856 | |
cf8517cf | 2857 | *ppos += ret; |
bc0c38d1 | 2858 | |
c2931e05 | 2859 | return ret; |
bc0c38d1 SR |
2860 | } |
2861 | ||
2862 | static ssize_t | |
2863 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
2864 | size_t cnt, loff_t *ppos) | |
2865 | { | |
2866 | unsigned long *ptr = filp->private_data; | |
2867 | char buf[64]; | |
2868 | int r; | |
2869 | ||
cffae437 | 2870 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 2871 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
2872 | if (r > sizeof(buf)) |
2873 | r = sizeof(buf); | |
4bf39a94 | 2874 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2875 | } |
2876 | ||
2877 | static ssize_t | |
2878 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
2879 | size_t cnt, loff_t *ppos) | |
2880 | { | |
5e39841c | 2881 | unsigned long *ptr = filp->private_data; |
bc0c38d1 | 2882 | char buf[64]; |
5e39841c | 2883 | unsigned long val; |
c6caeeb1 | 2884 | int ret; |
bc0c38d1 | 2885 | |
cffae437 SR |
2886 | if (cnt >= sizeof(buf)) |
2887 | return -EINVAL; | |
bc0c38d1 SR |
2888 | |
2889 | if (copy_from_user(&buf, ubuf, cnt)) | |
2890 | return -EFAULT; | |
2891 | ||
2892 | buf[cnt] = 0; | |
2893 | ||
c6caeeb1 SR |
2894 | ret = strict_strtoul(buf, 10, &val); |
2895 | if (ret < 0) | |
2896 | return ret; | |
bc0c38d1 SR |
2897 | |
2898 | *ptr = val * 1000; | |
2899 | ||
2900 | return cnt; | |
2901 | } | |
2902 | ||
b3806b43 SR |
2903 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
2904 | { | |
b04cc6b1 | 2905 | long cpu_file = (long) inode->i_private; |
b3806b43 | 2906 | struct trace_iterator *iter; |
b04cc6b1 | 2907 | int ret = 0; |
b3806b43 SR |
2908 | |
2909 | if (tracing_disabled) | |
2910 | return -ENODEV; | |
2911 | ||
b04cc6b1 FW |
2912 | mutex_lock(&trace_types_lock); |
2913 | ||
b3806b43 SR |
2914 | /* create a buffer to store the information to pass to userspace */ |
2915 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
2916 | if (!iter) { |
2917 | ret = -ENOMEM; | |
2918 | goto out; | |
2919 | } | |
b3806b43 | 2920 | |
d7350c3f FW |
2921 | /* |
2922 | * We make a copy of the current tracer to avoid concurrent | |
2923 | * changes on it while we are reading. | |
2924 | */ | |
2925 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
2926 | if (!iter->trace) { | |
2927 | ret = -ENOMEM; | |
2928 | goto fail; | |
2929 | } | |
2930 | if (current_trace) | |
2931 | *iter->trace = *current_trace; | |
2932 | ||
4462344e | 2933 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 2934 | ret = -ENOMEM; |
d7350c3f | 2935 | goto fail; |
4462344e RR |
2936 | } |
2937 | ||
a309720c | 2938 | /* trace pipe does not show start of buffer */ |
4462344e | 2939 | cpumask_setall(iter->started); |
a309720c | 2940 | |
112f38a7 SR |
2941 | if (trace_flags & TRACE_ITER_LATENCY_FMT) |
2942 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
2943 | ||
b04cc6b1 | 2944 | iter->cpu_file = cpu_file; |
b3806b43 | 2945 | iter->tr = &global_trace; |
d7350c3f | 2946 | mutex_init(&iter->mutex); |
b3806b43 SR |
2947 | filp->private_data = iter; |
2948 | ||
107bad8b SR |
2949 | if (iter->trace->pipe_open) |
2950 | iter->trace->pipe_open(iter); | |
107bad8b | 2951 | |
b04cc6b1 FW |
2952 | out: |
2953 | mutex_unlock(&trace_types_lock); | |
2954 | return ret; | |
d7350c3f FW |
2955 | |
2956 | fail: | |
2957 | kfree(iter->trace); | |
2958 | kfree(iter); | |
2959 | mutex_unlock(&trace_types_lock); | |
2960 | return ret; | |
b3806b43 SR |
2961 | } |
2962 | ||
2963 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
2964 | { | |
2965 | struct trace_iterator *iter = file->private_data; | |
2966 | ||
b04cc6b1 FW |
2967 | mutex_lock(&trace_types_lock); |
2968 | ||
29bf4a5e | 2969 | if (iter->trace->pipe_close) |
c521efd1 SR |
2970 | iter->trace->pipe_close(iter); |
2971 | ||
b04cc6b1 FW |
2972 | mutex_unlock(&trace_types_lock); |
2973 | ||
4462344e | 2974 | free_cpumask_var(iter->started); |
d7350c3f FW |
2975 | mutex_destroy(&iter->mutex); |
2976 | kfree(iter->trace); | |
b3806b43 | 2977 | kfree(iter); |
b3806b43 SR |
2978 | |
2979 | return 0; | |
2980 | } | |
2981 | ||
2a2cc8f7 SSP |
2982 | static unsigned int |
2983 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
2984 | { | |
2985 | struct trace_iterator *iter = filp->private_data; | |
2986 | ||
2987 | if (trace_flags & TRACE_ITER_BLOCK) { | |
2988 | /* | |
2989 | * Always select as readable when in blocking mode | |
2990 | */ | |
2991 | return POLLIN | POLLRDNORM; | |
afc2abc0 | 2992 | } else { |
2a2cc8f7 SSP |
2993 | if (!trace_empty(iter)) |
2994 | return POLLIN | POLLRDNORM; | |
2995 | poll_wait(filp, &trace_wait, poll_table); | |
2996 | if (!trace_empty(iter)) | |
2997 | return POLLIN | POLLRDNORM; | |
2998 | ||
2999 | return 0; | |
3000 | } | |
3001 | } | |
3002 | ||
6eaaa5d5 FW |
3003 | |
3004 | void default_wait_pipe(struct trace_iterator *iter) | |
3005 | { | |
3006 | DEFINE_WAIT(wait); | |
3007 | ||
3008 | prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE); | |
3009 | ||
3010 | if (trace_empty(iter)) | |
3011 | schedule(); | |
3012 | ||
3013 | finish_wait(&trace_wait, &wait); | |
3014 | } | |
3015 | ||
3016 | /* | |
3017 | * This is a make-shift waitqueue. | |
3018 | * A tracer might use this callback on some rare cases: | |
3019 | * | |
3020 | * 1) the current tracer might hold the runqueue lock when it wakes up | |
3021 | * a reader, hence a deadlock (sched, function, and function graph tracers) | |
3022 | * 2) the function tracers, trace all functions, we don't want | |
3023 | * the overhead of calling wake_up and friends | |
3024 | * (and tracing them too) | |
3025 | * | |
3026 | * Anyway, this is really very primitive wakeup. | |
3027 | */ | |
3028 | void poll_wait_pipe(struct trace_iterator *iter) | |
3029 | { | |
3030 | set_current_state(TASK_INTERRUPTIBLE); | |
3031 | /* sleep for 100 msecs, and try again. */ | |
3032 | schedule_timeout(HZ / 10); | |
3033 | } | |
3034 | ||
ff98781b EGM |
3035 | /* Must be called with trace_types_lock mutex held. */ |
3036 | static int tracing_wait_pipe(struct file *filp) | |
b3806b43 SR |
3037 | { |
3038 | struct trace_iterator *iter = filp->private_data; | |
b3806b43 | 3039 | |
b3806b43 | 3040 | while (trace_empty(iter)) { |
2dc8f095 | 3041 | |
107bad8b | 3042 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 3043 | return -EAGAIN; |
107bad8b | 3044 | } |
2dc8f095 | 3045 | |
d7350c3f | 3046 | mutex_unlock(&iter->mutex); |
107bad8b | 3047 | |
6eaaa5d5 | 3048 | iter->trace->wait_pipe(iter); |
b3806b43 | 3049 | |
d7350c3f | 3050 | mutex_lock(&iter->mutex); |
107bad8b | 3051 | |
6eaaa5d5 | 3052 | if (signal_pending(current)) |
ff98781b | 3053 | return -EINTR; |
b3806b43 SR |
3054 | |
3055 | /* | |
3056 | * We block until we read something and tracing is disabled. | |
3057 | * We still block if tracing is disabled, but we have never | |
3058 | * read anything. This allows a user to cat this file, and | |
3059 | * then enable tracing. But after we have read something, | |
3060 | * we give an EOF when tracing is again disabled. | |
3061 | * | |
3062 | * iter->pos will be 0 if we haven't read anything. | |
3063 | */ | |
3064 | if (!tracer_enabled && iter->pos) | |
3065 | break; | |
b3806b43 SR |
3066 | } |
3067 | ||
ff98781b EGM |
3068 | return 1; |
3069 | } | |
3070 | ||
3071 | /* | |
3072 | * Consumer reader. | |
3073 | */ | |
3074 | static ssize_t | |
3075 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
3076 | size_t cnt, loff_t *ppos) | |
3077 | { | |
3078 | struct trace_iterator *iter = filp->private_data; | |
d7350c3f | 3079 | static struct tracer *old_tracer; |
ff98781b EGM |
3080 | ssize_t sret; |
3081 | ||
3082 | /* return any leftover data */ | |
3083 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
3084 | if (sret != -EBUSY) | |
3085 | return sret; | |
3086 | ||
f9520750 | 3087 | trace_seq_init(&iter->seq); |
ff98781b | 3088 | |
d7350c3f | 3089 | /* copy the tracer to avoid using a global lock all around */ |
ff98781b | 3090 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
3091 | if (unlikely(old_tracer != current_trace && current_trace)) { |
3092 | old_tracer = current_trace; | |
3093 | *iter->trace = *current_trace; | |
3094 | } | |
3095 | mutex_unlock(&trace_types_lock); | |
3096 | ||
3097 | /* | |
3098 | * Avoid more than one consumer on a single file descriptor | |
3099 | * This is just a matter of traces coherency, the ring buffer itself | |
3100 | * is protected. | |
3101 | */ | |
3102 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
3103 | if (iter->trace->read) { |
3104 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
3105 | if (sret) | |
3106 | goto out; | |
3107 | } | |
3108 | ||
3109 | waitagain: | |
3110 | sret = tracing_wait_pipe(filp); | |
3111 | if (sret <= 0) | |
3112 | goto out; | |
3113 | ||
b3806b43 | 3114 | /* stop when tracing is finished */ |
ff98781b EGM |
3115 | if (trace_empty(iter)) { |
3116 | sret = 0; | |
107bad8b | 3117 | goto out; |
ff98781b | 3118 | } |
b3806b43 SR |
3119 | |
3120 | if (cnt >= PAGE_SIZE) | |
3121 | cnt = PAGE_SIZE - 1; | |
3122 | ||
53d0aa77 | 3123 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
3124 | memset(&iter->seq, 0, |
3125 | sizeof(struct trace_iterator) - | |
3126 | offsetof(struct trace_iterator, seq)); | |
4823ed7e | 3127 | iter->pos = -1; |
b3806b43 | 3128 | |
4f535968 | 3129 | trace_event_read_lock(); |
7e53bd42 | 3130 | trace_access_lock(iter->cpu_file); |
088b1e42 | 3131 | while (find_next_entry_inc(iter) != NULL) { |
2c4f035f | 3132 | enum print_line_t ret; |
088b1e42 SR |
3133 | int len = iter->seq.len; |
3134 | ||
f9896bf3 | 3135 | ret = print_trace_line(iter); |
2c4f035f | 3136 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 SR |
3137 | /* don't print partial lines */ |
3138 | iter->seq.len = len; | |
b3806b43 | 3139 | break; |
088b1e42 | 3140 | } |
b91facc3 FW |
3141 | if (ret != TRACE_TYPE_NO_CONSUME) |
3142 | trace_consume(iter); | |
b3806b43 SR |
3143 | |
3144 | if (iter->seq.len >= cnt) | |
3145 | break; | |
b3806b43 | 3146 | } |
7e53bd42 | 3147 | trace_access_unlock(iter->cpu_file); |
4f535968 | 3148 | trace_event_read_unlock(); |
b3806b43 | 3149 | |
b3806b43 | 3150 | /* Now copy what we have to the user */ |
6c6c2796 PP |
3151 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
3152 | if (iter->seq.readpos >= iter->seq.len) | |
f9520750 | 3153 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
3154 | |
3155 | /* | |
3156 | * If there was nothing to send to user, inspite of consuming trace | |
3157 | * entries, go back to wait for more entries. | |
3158 | */ | |
6c6c2796 | 3159 | if (sret == -EBUSY) |
9ff4b974 | 3160 | goto waitagain; |
b3806b43 | 3161 | |
107bad8b | 3162 | out: |
d7350c3f | 3163 | mutex_unlock(&iter->mutex); |
107bad8b | 3164 | |
6c6c2796 | 3165 | return sret; |
b3806b43 SR |
3166 | } |
3167 | ||
3c56819b EGM |
3168 | static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, |
3169 | struct pipe_buffer *buf) | |
3170 | { | |
3171 | __free_page(buf->page); | |
3172 | } | |
3173 | ||
3174 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, | |
3175 | unsigned int idx) | |
3176 | { | |
3177 | __free_page(spd->pages[idx]); | |
3178 | } | |
3179 | ||
28dfef8f | 3180 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { |
34cd4998 SR |
3181 | .can_merge = 0, |
3182 | .map = generic_pipe_buf_map, | |
3183 | .unmap = generic_pipe_buf_unmap, | |
3184 | .confirm = generic_pipe_buf_confirm, | |
3185 | .release = tracing_pipe_buf_release, | |
3186 | .steal = generic_pipe_buf_steal, | |
3187 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
3188 | }; |
3189 | ||
34cd4998 | 3190 | static size_t |
fa7c7f6e | 3191 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
3192 | { |
3193 | size_t count; | |
3194 | int ret; | |
3195 | ||
3196 | /* Seq buffer is page-sized, exactly what we need. */ | |
3197 | for (;;) { | |
3198 | count = iter->seq.len; | |
3199 | ret = print_trace_line(iter); | |
3200 | count = iter->seq.len - count; | |
3201 | if (rem < count) { | |
3202 | rem = 0; | |
3203 | iter->seq.len -= count; | |
3204 | break; | |
3205 | } | |
3206 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
3207 | iter->seq.len -= count; | |
3208 | break; | |
3209 | } | |
3210 | ||
74e7ff8c LJ |
3211 | if (ret != TRACE_TYPE_NO_CONSUME) |
3212 | trace_consume(iter); | |
34cd4998 SR |
3213 | rem -= count; |
3214 | if (!find_next_entry_inc(iter)) { | |
3215 | rem = 0; | |
3216 | iter->ent = NULL; | |
3217 | break; | |
3218 | } | |
3219 | } | |
3220 | ||
3221 | return rem; | |
3222 | } | |
3223 | ||
3c56819b EGM |
3224 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
3225 | loff_t *ppos, | |
3226 | struct pipe_inode_info *pipe, | |
3227 | size_t len, | |
3228 | unsigned int flags) | |
3229 | { | |
3230 | struct page *pages[PIPE_BUFFERS]; | |
3231 | struct partial_page partial[PIPE_BUFFERS]; | |
3232 | struct trace_iterator *iter = filp->private_data; | |
3233 | struct splice_pipe_desc spd = { | |
34cd4998 SR |
3234 | .pages = pages, |
3235 | .partial = partial, | |
3236 | .nr_pages = 0, /* This gets updated below. */ | |
3237 | .flags = flags, | |
3238 | .ops = &tracing_pipe_buf_ops, | |
3239 | .spd_release = tracing_spd_release_pipe, | |
3c56819b | 3240 | }; |
d7350c3f | 3241 | static struct tracer *old_tracer; |
3c56819b | 3242 | ssize_t ret; |
34cd4998 | 3243 | size_t rem; |
3c56819b EGM |
3244 | unsigned int i; |
3245 | ||
d7350c3f | 3246 | /* copy the tracer to avoid using a global lock all around */ |
3c56819b | 3247 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
3248 | if (unlikely(old_tracer != current_trace && current_trace)) { |
3249 | old_tracer = current_trace; | |
3250 | *iter->trace = *current_trace; | |
3251 | } | |
3252 | mutex_unlock(&trace_types_lock); | |
3253 | ||
3254 | mutex_lock(&iter->mutex); | |
3c56819b EGM |
3255 | |
3256 | if (iter->trace->splice_read) { | |
3257 | ret = iter->trace->splice_read(iter, filp, | |
3258 | ppos, pipe, len, flags); | |
3259 | if (ret) | |
34cd4998 | 3260 | goto out_err; |
3c56819b EGM |
3261 | } |
3262 | ||
3263 | ret = tracing_wait_pipe(filp); | |
3264 | if (ret <= 0) | |
34cd4998 | 3265 | goto out_err; |
3c56819b EGM |
3266 | |
3267 | if (!iter->ent && !find_next_entry_inc(iter)) { | |
3268 | ret = -EFAULT; | |
34cd4998 | 3269 | goto out_err; |
3c56819b EGM |
3270 | } |
3271 | ||
4f535968 | 3272 | trace_event_read_lock(); |
7e53bd42 | 3273 | trace_access_lock(iter->cpu_file); |
4f535968 | 3274 | |
3c56819b EGM |
3275 | /* Fill as many pages as possible. */ |
3276 | for (i = 0, rem = len; i < PIPE_BUFFERS && rem; i++) { | |
3277 | pages[i] = alloc_page(GFP_KERNEL); | |
34cd4998 SR |
3278 | if (!pages[i]) |
3279 | break; | |
3c56819b | 3280 | |
fa7c7f6e | 3281 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
3282 | |
3283 | /* Copy the data into the page, so we can start over. */ | |
3284 | ret = trace_seq_to_buffer(&iter->seq, | |
3285 | page_address(pages[i]), | |
3286 | iter->seq.len); | |
3287 | if (ret < 0) { | |
3288 | __free_page(pages[i]); | |
3289 | break; | |
3290 | } | |
3291 | partial[i].offset = 0; | |
3292 | partial[i].len = iter->seq.len; | |
3293 | ||
f9520750 | 3294 | trace_seq_init(&iter->seq); |
3c56819b EGM |
3295 | } |
3296 | ||
7e53bd42 | 3297 | trace_access_unlock(iter->cpu_file); |
4f535968 | 3298 | trace_event_read_unlock(); |
d7350c3f | 3299 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
3300 | |
3301 | spd.nr_pages = i; | |
3302 | ||
3303 | return splice_to_pipe(pipe, &spd); | |
3304 | ||
34cd4998 | 3305 | out_err: |
d7350c3f | 3306 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
3307 | |
3308 | return ret; | |
3309 | } | |
3310 | ||
a98a3c3f SR |
3311 | static ssize_t |
3312 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
3313 | size_t cnt, loff_t *ppos) | |
3314 | { | |
3315 | struct trace_array *tr = filp->private_data; | |
db526ca3 | 3316 | char buf[96]; |
a98a3c3f SR |
3317 | int r; |
3318 | ||
db526ca3 SR |
3319 | mutex_lock(&trace_types_lock); |
3320 | if (!ring_buffer_expanded) | |
3321 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
3322 | tr->entries >> 10, | |
3323 | trace_buf_size >> 10); | |
3324 | else | |
3325 | r = sprintf(buf, "%lu\n", tr->entries >> 10); | |
3326 | mutex_unlock(&trace_types_lock); | |
3327 | ||
a98a3c3f SR |
3328 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
3329 | } | |
3330 | ||
3331 | static ssize_t | |
3332 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
3333 | size_t cnt, loff_t *ppos) | |
3334 | { | |
3335 | unsigned long val; | |
3336 | char buf[64]; | |
bf5e6519 | 3337 | int ret, cpu; |
a98a3c3f | 3338 | |
cffae437 SR |
3339 | if (cnt >= sizeof(buf)) |
3340 | return -EINVAL; | |
a98a3c3f SR |
3341 | |
3342 | if (copy_from_user(&buf, ubuf, cnt)) | |
3343 | return -EFAULT; | |
3344 | ||
3345 | buf[cnt] = 0; | |
3346 | ||
c6caeeb1 SR |
3347 | ret = strict_strtoul(buf, 10, &val); |
3348 | if (ret < 0) | |
3349 | return ret; | |
a98a3c3f SR |
3350 | |
3351 | /* must have at least 1 entry */ | |
3352 | if (!val) | |
3353 | return -EINVAL; | |
3354 | ||
3355 | mutex_lock(&trace_types_lock); | |
3356 | ||
c76f0694 | 3357 | tracing_stop(); |
a98a3c3f | 3358 | |
bf5e6519 SR |
3359 | /* disable all cpu buffers */ |
3360 | for_each_tracing_cpu(cpu) { | |
3361 | if (global_trace.data[cpu]) | |
3362 | atomic_inc(&global_trace.data[cpu]->disabled); | |
3363 | if (max_tr.data[cpu]) | |
3364 | atomic_inc(&max_tr.data[cpu]->disabled); | |
3365 | } | |
3366 | ||
1696b2b0 SR |
3367 | /* value is in KB */ |
3368 | val <<= 10; | |
3369 | ||
3928a8a2 | 3370 | if (val != global_trace.entries) { |
73c5162a | 3371 | ret = tracing_resize_ring_buffer(val); |
3928a8a2 SR |
3372 | if (ret < 0) { |
3373 | cnt = ret; | |
3eefae99 SR |
3374 | goto out; |
3375 | } | |
a98a3c3f SR |
3376 | } |
3377 | ||
cf8517cf | 3378 | *ppos += cnt; |
a98a3c3f | 3379 | |
19384c03 SR |
3380 | /* If check pages failed, return ENOMEM */ |
3381 | if (tracing_disabled) | |
3382 | cnt = -ENOMEM; | |
a98a3c3f | 3383 | out: |
bf5e6519 SR |
3384 | for_each_tracing_cpu(cpu) { |
3385 | if (global_trace.data[cpu]) | |
3386 | atomic_dec(&global_trace.data[cpu]->disabled); | |
3387 | if (max_tr.data[cpu]) | |
3388 | atomic_dec(&max_tr.data[cpu]->disabled); | |
3389 | } | |
3390 | ||
c76f0694 | 3391 | tracing_start(); |
a98a3c3f SR |
3392 | max_tr.entries = global_trace.entries; |
3393 | mutex_unlock(&trace_types_lock); | |
3394 | ||
3395 | return cnt; | |
3396 | } | |
3397 | ||
f2942487 CE |
3398 | static int mark_printk(const char *fmt, ...) |
3399 | { | |
3400 | int ret; | |
3401 | va_list args; | |
3402 | va_start(args, fmt); | |
3403 | ret = trace_vprintk(0, fmt, args); | |
3404 | va_end(args); | |
3405 | return ret; | |
3406 | } | |
3407 | ||
5bf9a1ee PP |
3408 | static ssize_t |
3409 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
3410 | size_t cnt, loff_t *fpos) | |
3411 | { | |
3412 | char *buf; | |
5bf9a1ee | 3413 | |
c76f0694 | 3414 | if (tracing_disabled) |
5bf9a1ee PP |
3415 | return -EINVAL; |
3416 | ||
3417 | if (cnt > TRACE_BUF_SIZE) | |
3418 | cnt = TRACE_BUF_SIZE; | |
3419 | ||
c13d2f7c | 3420 | buf = kmalloc(cnt + 2, GFP_KERNEL); |
5bf9a1ee PP |
3421 | if (buf == NULL) |
3422 | return -ENOMEM; | |
3423 | ||
3424 | if (copy_from_user(buf, ubuf, cnt)) { | |
3425 | kfree(buf); | |
3426 | return -EFAULT; | |
3427 | } | |
c13d2f7c CE |
3428 | if (buf[cnt-1] != '\n') { |
3429 | buf[cnt] = '\n'; | |
3430 | buf[cnt+1] = '\0'; | |
3431 | } else | |
3432 | buf[cnt] = '\0'; | |
5bf9a1ee | 3433 | |
f2942487 | 3434 | cnt = mark_printk("%s", buf); |
5bf9a1ee PP |
3435 | kfree(buf); |
3436 | *fpos += cnt; | |
3437 | ||
3438 | return cnt; | |
3439 | } | |
3440 | ||
13f16d20 | 3441 | static int tracing_clock_show(struct seq_file *m, void *v) |
5079f326 | 3442 | { |
5079f326 Z |
3443 | int i; |
3444 | ||
3445 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
13f16d20 | 3446 | seq_printf(m, |
5079f326 Z |
3447 | "%s%s%s%s", i ? " " : "", |
3448 | i == trace_clock_id ? "[" : "", trace_clocks[i].name, | |
3449 | i == trace_clock_id ? "]" : ""); | |
13f16d20 | 3450 | seq_putc(m, '\n'); |
5079f326 | 3451 | |
13f16d20 | 3452 | return 0; |
5079f326 Z |
3453 | } |
3454 | ||
3455 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
3456 | size_t cnt, loff_t *fpos) | |
3457 | { | |
3458 | char buf[64]; | |
3459 | const char *clockstr; | |
3460 | int i; | |
3461 | ||
3462 | if (cnt >= sizeof(buf)) | |
3463 | return -EINVAL; | |
3464 | ||
3465 | if (copy_from_user(&buf, ubuf, cnt)) | |
3466 | return -EFAULT; | |
3467 | ||
3468 | buf[cnt] = 0; | |
3469 | ||
3470 | clockstr = strstrip(buf); | |
3471 | ||
3472 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { | |
3473 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
3474 | break; | |
3475 | } | |
3476 | if (i == ARRAY_SIZE(trace_clocks)) | |
3477 | return -EINVAL; | |
3478 | ||
3479 | trace_clock_id = i; | |
3480 | ||
3481 | mutex_lock(&trace_types_lock); | |
3482 | ||
3483 | ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func); | |
3484 | if (max_tr.buffer) | |
3485 | ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); | |
3486 | ||
3487 | mutex_unlock(&trace_types_lock); | |
3488 | ||
3489 | *fpos += cnt; | |
3490 | ||
3491 | return cnt; | |
3492 | } | |
3493 | ||
13f16d20 LZ |
3494 | static int tracing_clock_open(struct inode *inode, struct file *file) |
3495 | { | |
3496 | if (tracing_disabled) | |
3497 | return -ENODEV; | |
3498 | return single_open(file, tracing_clock_show, NULL); | |
3499 | } | |
3500 | ||
5e2336a0 | 3501 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
3502 | .open = tracing_open_generic, |
3503 | .read = tracing_max_lat_read, | |
3504 | .write = tracing_max_lat_write, | |
bc0c38d1 SR |
3505 | }; |
3506 | ||
5e2336a0 | 3507 | static const struct file_operations tracing_ctrl_fops = { |
4bf39a94 IM |
3508 | .open = tracing_open_generic, |
3509 | .read = tracing_ctrl_read, | |
3510 | .write = tracing_ctrl_write, | |
bc0c38d1 SR |
3511 | }; |
3512 | ||
5e2336a0 | 3513 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
3514 | .open = tracing_open_generic, |
3515 | .read = tracing_set_trace_read, | |
3516 | .write = tracing_set_trace_write, | |
bc0c38d1 SR |
3517 | }; |
3518 | ||
5e2336a0 | 3519 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 3520 | .open = tracing_open_pipe, |
2a2cc8f7 | 3521 | .poll = tracing_poll_pipe, |
4bf39a94 | 3522 | .read = tracing_read_pipe, |
3c56819b | 3523 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 3524 | .release = tracing_release_pipe, |
b3806b43 SR |
3525 | }; |
3526 | ||
5e2336a0 | 3527 | static const struct file_operations tracing_entries_fops = { |
a98a3c3f SR |
3528 | .open = tracing_open_generic, |
3529 | .read = tracing_entries_read, | |
3530 | .write = tracing_entries_write, | |
3531 | }; | |
3532 | ||
5e2336a0 | 3533 | static const struct file_operations tracing_mark_fops = { |
43a15386 | 3534 | .open = tracing_open_generic, |
5bf9a1ee PP |
3535 | .write = tracing_mark_write, |
3536 | }; | |
3537 | ||
5079f326 | 3538 | static const struct file_operations trace_clock_fops = { |
13f16d20 LZ |
3539 | .open = tracing_clock_open, |
3540 | .read = seq_read, | |
3541 | .llseek = seq_lseek, | |
3542 | .release = single_release, | |
5079f326 Z |
3543 | .write = tracing_clock_write, |
3544 | }; | |
3545 | ||
2cadf913 SR |
3546 | struct ftrace_buffer_info { |
3547 | struct trace_array *tr; | |
3548 | void *spare; | |
3549 | int cpu; | |
3550 | unsigned int read; | |
3551 | }; | |
3552 | ||
3553 | static int tracing_buffers_open(struct inode *inode, struct file *filp) | |
3554 | { | |
3555 | int cpu = (int)(long)inode->i_private; | |
3556 | struct ftrace_buffer_info *info; | |
3557 | ||
3558 | if (tracing_disabled) | |
3559 | return -ENODEV; | |
3560 | ||
3561 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
3562 | if (!info) | |
3563 | return -ENOMEM; | |
3564 | ||
3565 | info->tr = &global_trace; | |
3566 | info->cpu = cpu; | |
ddd538f3 | 3567 | info->spare = NULL; |
2cadf913 SR |
3568 | /* Force reading ring buffer for first read */ |
3569 | info->read = (unsigned int)-1; | |
2cadf913 SR |
3570 | |
3571 | filp->private_data = info; | |
3572 | ||
d1e7e02f | 3573 | return nonseekable_open(inode, filp); |
2cadf913 SR |
3574 | } |
3575 | ||
3576 | static ssize_t | |
3577 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
3578 | size_t count, loff_t *ppos) | |
3579 | { | |
3580 | struct ftrace_buffer_info *info = filp->private_data; | |
3581 | unsigned int pos; | |
3582 | ssize_t ret; | |
3583 | size_t size; | |
3584 | ||
2dc5d12b SR |
3585 | if (!count) |
3586 | return 0; | |
3587 | ||
ddd538f3 LJ |
3588 | if (!info->spare) |
3589 | info->spare = ring_buffer_alloc_read_page(info->tr->buffer); | |
3590 | if (!info->spare) | |
3591 | return -ENOMEM; | |
3592 | ||
2cadf913 SR |
3593 | /* Do we have previous read data to read? */ |
3594 | if (info->read < PAGE_SIZE) | |
3595 | goto read; | |
3596 | ||
3597 | info->read = 0; | |
3598 | ||
7e53bd42 | 3599 | trace_access_lock(info->cpu); |
2cadf913 SR |
3600 | ret = ring_buffer_read_page(info->tr->buffer, |
3601 | &info->spare, | |
3602 | count, | |
3603 | info->cpu, 0); | |
7e53bd42 | 3604 | trace_access_unlock(info->cpu); |
2cadf913 SR |
3605 | if (ret < 0) |
3606 | return 0; | |
3607 | ||
3608 | pos = ring_buffer_page_len(info->spare); | |
3609 | ||
3610 | if (pos < PAGE_SIZE) | |
3611 | memset(info->spare + pos, 0, PAGE_SIZE - pos); | |
3612 | ||
3613 | read: | |
3614 | size = PAGE_SIZE - info->read; | |
3615 | if (size > count) | |
3616 | size = count; | |
3617 | ||
3618 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
2dc5d12b | 3619 | if (ret == size) |
2cadf913 | 3620 | return -EFAULT; |
2dc5d12b SR |
3621 | size -= ret; |
3622 | ||
2cadf913 SR |
3623 | *ppos += size; |
3624 | info->read += size; | |
3625 | ||
3626 | return size; | |
3627 | } | |
3628 | ||
3629 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
3630 | { | |
3631 | struct ftrace_buffer_info *info = file->private_data; | |
3632 | ||
ddd538f3 LJ |
3633 | if (info->spare) |
3634 | ring_buffer_free_read_page(info->tr->buffer, info->spare); | |
2cadf913 SR |
3635 | kfree(info); |
3636 | ||
3637 | return 0; | |
3638 | } | |
3639 | ||
3640 | struct buffer_ref { | |
3641 | struct ring_buffer *buffer; | |
3642 | void *page; | |
3643 | int ref; | |
3644 | }; | |
3645 | ||
3646 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
3647 | struct pipe_buffer *buf) | |
3648 | { | |
3649 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
3650 | ||
3651 | if (--ref->ref) | |
3652 | return; | |
3653 | ||
3654 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
3655 | kfree(ref); | |
3656 | buf->private = 0; | |
3657 | } | |
3658 | ||
3659 | static int buffer_pipe_buf_steal(struct pipe_inode_info *pipe, | |
3660 | struct pipe_buffer *buf) | |
3661 | { | |
3662 | return 1; | |
3663 | } | |
3664 | ||
3665 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, | |
3666 | struct pipe_buffer *buf) | |
3667 | { | |
3668 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
3669 | ||
3670 | ref->ref++; | |
3671 | } | |
3672 | ||
3673 | /* Pipe buffer operations for a buffer. */ | |
28dfef8f | 3674 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
2cadf913 SR |
3675 | .can_merge = 0, |
3676 | .map = generic_pipe_buf_map, | |
3677 | .unmap = generic_pipe_buf_unmap, | |
3678 | .confirm = generic_pipe_buf_confirm, | |
3679 | .release = buffer_pipe_buf_release, | |
3680 | .steal = buffer_pipe_buf_steal, | |
3681 | .get = buffer_pipe_buf_get, | |
3682 | }; | |
3683 | ||
3684 | /* | |
3685 | * Callback from splice_to_pipe(), if we need to release some pages | |
3686 | * at the end of the spd in case we error'ed out in filling the pipe. | |
3687 | */ | |
3688 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
3689 | { | |
3690 | struct buffer_ref *ref = | |
3691 | (struct buffer_ref *)spd->partial[i].private; | |
3692 | ||
3693 | if (--ref->ref) | |
3694 | return; | |
3695 | ||
3696 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
3697 | kfree(ref); | |
3698 | spd->partial[i].private = 0; | |
3699 | } | |
3700 | ||
3701 | static ssize_t | |
3702 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
3703 | struct pipe_inode_info *pipe, size_t len, | |
3704 | unsigned int flags) | |
3705 | { | |
3706 | struct ftrace_buffer_info *info = file->private_data; | |
3707 | struct partial_page partial[PIPE_BUFFERS]; | |
3708 | struct page *pages[PIPE_BUFFERS]; | |
3709 | struct splice_pipe_desc spd = { | |
3710 | .pages = pages, | |
3711 | .partial = partial, | |
3712 | .flags = flags, | |
3713 | .ops = &buffer_pipe_buf_ops, | |
3714 | .spd_release = buffer_spd_release, | |
3715 | }; | |
3716 | struct buffer_ref *ref; | |
93459c6c | 3717 | int entries, size, i; |
2cadf913 SR |
3718 | size_t ret; |
3719 | ||
93cfb3c9 LJ |
3720 | if (*ppos & (PAGE_SIZE - 1)) { |
3721 | WARN_ONCE(1, "Ftrace: previous read must page-align\n"); | |
3722 | return -EINVAL; | |
3723 | } | |
3724 | ||
3725 | if (len & (PAGE_SIZE - 1)) { | |
3726 | WARN_ONCE(1, "Ftrace: splice_read should page-align\n"); | |
3727 | if (len < PAGE_SIZE) | |
3728 | return -EINVAL; | |
3729 | len &= PAGE_MASK; | |
3730 | } | |
3731 | ||
7e53bd42 | 3732 | trace_access_lock(info->cpu); |
93459c6c SR |
3733 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); |
3734 | ||
3735 | for (i = 0; i < PIPE_BUFFERS && len && entries; i++, len -= PAGE_SIZE) { | |
2cadf913 SR |
3736 | struct page *page; |
3737 | int r; | |
3738 | ||
3739 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
3740 | if (!ref) | |
3741 | break; | |
3742 | ||
7267fa68 | 3743 | ref->ref = 1; |
2cadf913 SR |
3744 | ref->buffer = info->tr->buffer; |
3745 | ref->page = ring_buffer_alloc_read_page(ref->buffer); | |
3746 | if (!ref->page) { | |
3747 | kfree(ref); | |
3748 | break; | |
3749 | } | |
3750 | ||
3751 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
f2957f1f | 3752 | len, info->cpu, 1); |
2cadf913 SR |
3753 | if (r < 0) { |
3754 | ring_buffer_free_read_page(ref->buffer, | |
3755 | ref->page); | |
3756 | kfree(ref); | |
3757 | break; | |
3758 | } | |
3759 | ||
3760 | /* | |
3761 | * zero out any left over data, this is going to | |
3762 | * user land. | |
3763 | */ | |
3764 | size = ring_buffer_page_len(ref->page); | |
3765 | if (size < PAGE_SIZE) | |
3766 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
3767 | ||
3768 | page = virt_to_page(ref->page); | |
3769 | ||
3770 | spd.pages[i] = page; | |
3771 | spd.partial[i].len = PAGE_SIZE; | |
3772 | spd.partial[i].offset = 0; | |
3773 | spd.partial[i].private = (unsigned long)ref; | |
3774 | spd.nr_pages++; | |
93cfb3c9 | 3775 | *ppos += PAGE_SIZE; |
93459c6c SR |
3776 | |
3777 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); | |
2cadf913 SR |
3778 | } |
3779 | ||
7e53bd42 | 3780 | trace_access_unlock(info->cpu); |
2cadf913 SR |
3781 | spd.nr_pages = i; |
3782 | ||
3783 | /* did we read anything? */ | |
3784 | if (!spd.nr_pages) { | |
3785 | if (flags & SPLICE_F_NONBLOCK) | |
3786 | ret = -EAGAIN; | |
3787 | else | |
3788 | ret = 0; | |
3789 | /* TODO: block */ | |
3790 | return ret; | |
3791 | } | |
3792 | ||
3793 | ret = splice_to_pipe(pipe, &spd); | |
3794 | ||
3795 | return ret; | |
3796 | } | |
3797 | ||
3798 | static const struct file_operations tracing_buffers_fops = { | |
3799 | .open = tracing_buffers_open, | |
3800 | .read = tracing_buffers_read, | |
3801 | .release = tracing_buffers_release, | |
3802 | .splice_read = tracing_buffers_splice_read, | |
3803 | .llseek = no_llseek, | |
3804 | }; | |
3805 | ||
c8d77183 SR |
3806 | static ssize_t |
3807 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
3808 | size_t count, loff_t *ppos) | |
3809 | { | |
3810 | unsigned long cpu = (unsigned long)filp->private_data; | |
3811 | struct trace_array *tr = &global_trace; | |
3812 | struct trace_seq *s; | |
3813 | unsigned long cnt; | |
3814 | ||
e4f2d10f | 3815 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
c8d77183 | 3816 | if (!s) |
a646365c | 3817 | return -ENOMEM; |
c8d77183 SR |
3818 | |
3819 | trace_seq_init(s); | |
3820 | ||
3821 | cnt = ring_buffer_entries_cpu(tr->buffer, cpu); | |
3822 | trace_seq_printf(s, "entries: %ld\n", cnt); | |
3823 | ||
3824 | cnt = ring_buffer_overrun_cpu(tr->buffer, cpu); | |
3825 | trace_seq_printf(s, "overrun: %ld\n", cnt); | |
3826 | ||
3827 | cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); | |
3828 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); | |
3829 | ||
c8d77183 SR |
3830 | count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); |
3831 | ||
3832 | kfree(s); | |
3833 | ||
3834 | return count; | |
3835 | } | |
3836 | ||
3837 | static const struct file_operations tracing_stats_fops = { | |
3838 | .open = tracing_open_generic, | |
3839 | .read = tracing_stats_read, | |
3840 | }; | |
3841 | ||
bc0c38d1 SR |
3842 | #ifdef CONFIG_DYNAMIC_FTRACE |
3843 | ||
b807c3d0 SR |
3844 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
3845 | { | |
3846 | return 0; | |
3847 | } | |
3848 | ||
bc0c38d1 | 3849 | static ssize_t |
b807c3d0 | 3850 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
3851 | size_t cnt, loff_t *ppos) |
3852 | { | |
a26a2a27 SR |
3853 | static char ftrace_dyn_info_buffer[1024]; |
3854 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 3855 | unsigned long *p = filp->private_data; |
b807c3d0 | 3856 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 3857 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
3858 | int r; |
3859 | ||
b807c3d0 SR |
3860 | mutex_lock(&dyn_info_mutex); |
3861 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 3862 | |
a26a2a27 | 3863 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
3864 | buf[r++] = '\n'; |
3865 | ||
3866 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3867 | ||
3868 | mutex_unlock(&dyn_info_mutex); | |
3869 | ||
3870 | return r; | |
bc0c38d1 SR |
3871 | } |
3872 | ||
5e2336a0 | 3873 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 3874 | .open = tracing_open_generic, |
b807c3d0 | 3875 | .read = tracing_read_dyn_info, |
bc0c38d1 SR |
3876 | }; |
3877 | #endif | |
3878 | ||
3879 | static struct dentry *d_tracer; | |
3880 | ||
3881 | struct dentry *tracing_init_dentry(void) | |
3882 | { | |
3883 | static int once; | |
3884 | ||
3885 | if (d_tracer) | |
3886 | return d_tracer; | |
3887 | ||
3e1f60b8 FW |
3888 | if (!debugfs_initialized()) |
3889 | return NULL; | |
3890 | ||
bc0c38d1 SR |
3891 | d_tracer = debugfs_create_dir("tracing", NULL); |
3892 | ||
3893 | if (!d_tracer && !once) { | |
3894 | once = 1; | |
3895 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
3896 | return NULL; | |
3897 | } | |
3898 | ||
3899 | return d_tracer; | |
3900 | } | |
3901 | ||
b04cc6b1 FW |
3902 | static struct dentry *d_percpu; |
3903 | ||
3904 | struct dentry *tracing_dentry_percpu(void) | |
3905 | { | |
3906 | static int once; | |
3907 | struct dentry *d_tracer; | |
3908 | ||
3909 | if (d_percpu) | |
3910 | return d_percpu; | |
3911 | ||
3912 | d_tracer = tracing_init_dentry(); | |
3913 | ||
3914 | if (!d_tracer) | |
3915 | return NULL; | |
3916 | ||
3917 | d_percpu = debugfs_create_dir("per_cpu", d_tracer); | |
3918 | ||
3919 | if (!d_percpu && !once) { | |
3920 | once = 1; | |
3921 | pr_warning("Could not create debugfs directory 'per_cpu'\n"); | |
3922 | return NULL; | |
3923 | } | |
3924 | ||
3925 | return d_percpu; | |
3926 | } | |
3927 | ||
3928 | static void tracing_init_debugfs_percpu(long cpu) | |
3929 | { | |
3930 | struct dentry *d_percpu = tracing_dentry_percpu(); | |
5452af66 | 3931 | struct dentry *d_cpu; |
8656e7a2 FW |
3932 | /* strlen(cpu) + MAX(log10(cpu)) + '\0' */ |
3933 | char cpu_dir[7]; | |
b04cc6b1 FW |
3934 | |
3935 | if (cpu > 999 || cpu < 0) | |
3936 | return; | |
3937 | ||
8656e7a2 FW |
3938 | sprintf(cpu_dir, "cpu%ld", cpu); |
3939 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); | |
3940 | if (!d_cpu) { | |
3941 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
3942 | return; | |
3943 | } | |
b04cc6b1 | 3944 | |
8656e7a2 | 3945 | /* per cpu trace_pipe */ |
5452af66 FW |
3946 | trace_create_file("trace_pipe", 0444, d_cpu, |
3947 | (void *) cpu, &tracing_pipe_fops); | |
b04cc6b1 FW |
3948 | |
3949 | /* per cpu trace */ | |
5452af66 FW |
3950 | trace_create_file("trace", 0644, d_cpu, |
3951 | (void *) cpu, &tracing_fops); | |
7f96f93f | 3952 | |
5452af66 FW |
3953 | trace_create_file("trace_pipe_raw", 0444, d_cpu, |
3954 | (void *) cpu, &tracing_buffers_fops); | |
7f96f93f | 3955 | |
c8d77183 SR |
3956 | trace_create_file("stats", 0444, d_cpu, |
3957 | (void *) cpu, &tracing_stats_fops); | |
b04cc6b1 FW |
3958 | } |
3959 | ||
60a11774 SR |
3960 | #ifdef CONFIG_FTRACE_SELFTEST |
3961 | /* Let selftest have access to static functions in this file */ | |
3962 | #include "trace_selftest.c" | |
3963 | #endif | |
3964 | ||
577b785f SR |
3965 | struct trace_option_dentry { |
3966 | struct tracer_opt *opt; | |
3967 | struct tracer_flags *flags; | |
3968 | struct dentry *entry; | |
3969 | }; | |
3970 | ||
3971 | static ssize_t | |
3972 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
3973 | loff_t *ppos) | |
3974 | { | |
3975 | struct trace_option_dentry *topt = filp->private_data; | |
3976 | char *buf; | |
3977 | ||
3978 | if (topt->flags->val & topt->opt->bit) | |
3979 | buf = "1\n"; | |
3980 | else | |
3981 | buf = "0\n"; | |
3982 | ||
3983 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
3984 | } | |
3985 | ||
3986 | static ssize_t | |
3987 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
3988 | loff_t *ppos) | |
3989 | { | |
3990 | struct trace_option_dentry *topt = filp->private_data; | |
3991 | unsigned long val; | |
3992 | char buf[64]; | |
3993 | int ret; | |
3994 | ||
3995 | if (cnt >= sizeof(buf)) | |
3996 | return -EINVAL; | |
3997 | ||
3998 | if (copy_from_user(&buf, ubuf, cnt)) | |
3999 | return -EFAULT; | |
4000 | ||
4001 | buf[cnt] = 0; | |
4002 | ||
4003 | ret = strict_strtoul(buf, 10, &val); | |
4004 | if (ret < 0) | |
4005 | return ret; | |
4006 | ||
8d18eaaf LZ |
4007 | if (val != 0 && val != 1) |
4008 | return -EINVAL; | |
577b785f | 4009 | |
8d18eaaf | 4010 | if (!!(topt->flags->val & topt->opt->bit) != val) { |
577b785f | 4011 | mutex_lock(&trace_types_lock); |
8d18eaaf | 4012 | ret = __set_tracer_option(current_trace, topt->flags, |
c757bea9 | 4013 | topt->opt, !val); |
577b785f SR |
4014 | mutex_unlock(&trace_types_lock); |
4015 | if (ret) | |
4016 | return ret; | |
577b785f SR |
4017 | } |
4018 | ||
4019 | *ppos += cnt; | |
4020 | ||
4021 | return cnt; | |
4022 | } | |
4023 | ||
4024 | ||
4025 | static const struct file_operations trace_options_fops = { | |
4026 | .open = tracing_open_generic, | |
4027 | .read = trace_options_read, | |
4028 | .write = trace_options_write, | |
4029 | }; | |
4030 | ||
a8259075 SR |
4031 | static ssize_t |
4032 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4033 | loff_t *ppos) | |
4034 | { | |
4035 | long index = (long)filp->private_data; | |
4036 | char *buf; | |
4037 | ||
4038 | if (trace_flags & (1 << index)) | |
4039 | buf = "1\n"; | |
4040 | else | |
4041 | buf = "0\n"; | |
4042 | ||
4043 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4044 | } | |
4045 | ||
4046 | static ssize_t | |
4047 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4048 | loff_t *ppos) | |
4049 | { | |
4050 | long index = (long)filp->private_data; | |
4051 | char buf[64]; | |
4052 | unsigned long val; | |
4053 | int ret; | |
4054 | ||
4055 | if (cnt >= sizeof(buf)) | |
4056 | return -EINVAL; | |
4057 | ||
4058 | if (copy_from_user(&buf, ubuf, cnt)) | |
4059 | return -EFAULT; | |
4060 | ||
4061 | buf[cnt] = 0; | |
4062 | ||
4063 | ret = strict_strtoul(buf, 10, &val); | |
4064 | if (ret < 0) | |
4065 | return ret; | |
4066 | ||
f2d84b65 | 4067 | if (val != 0 && val != 1) |
a8259075 | 4068 | return -EINVAL; |
f2d84b65 | 4069 | set_tracer_flags(1 << index, val); |
a8259075 SR |
4070 | |
4071 | *ppos += cnt; | |
4072 | ||
4073 | return cnt; | |
4074 | } | |
4075 | ||
a8259075 SR |
4076 | static const struct file_operations trace_options_core_fops = { |
4077 | .open = tracing_open_generic, | |
4078 | .read = trace_options_core_read, | |
4079 | .write = trace_options_core_write, | |
4080 | }; | |
4081 | ||
5452af66 FW |
4082 | struct dentry *trace_create_file(const char *name, |
4083 | mode_t mode, | |
4084 | struct dentry *parent, | |
4085 | void *data, | |
4086 | const struct file_operations *fops) | |
4087 | { | |
4088 | struct dentry *ret; | |
4089 | ||
4090 | ret = debugfs_create_file(name, mode, parent, data, fops); | |
4091 | if (!ret) | |
4092 | pr_warning("Could not create debugfs '%s' entry\n", name); | |
4093 | ||
4094 | return ret; | |
4095 | } | |
4096 | ||
4097 | ||
a8259075 SR |
4098 | static struct dentry *trace_options_init_dentry(void) |
4099 | { | |
4100 | struct dentry *d_tracer; | |
4101 | static struct dentry *t_options; | |
4102 | ||
4103 | if (t_options) | |
4104 | return t_options; | |
4105 | ||
4106 | d_tracer = tracing_init_dentry(); | |
4107 | if (!d_tracer) | |
4108 | return NULL; | |
4109 | ||
4110 | t_options = debugfs_create_dir("options", d_tracer); | |
4111 | if (!t_options) { | |
4112 | pr_warning("Could not create debugfs directory 'options'\n"); | |
4113 | return NULL; | |
4114 | } | |
4115 | ||
4116 | return t_options; | |
4117 | } | |
4118 | ||
577b785f SR |
4119 | static void |
4120 | create_trace_option_file(struct trace_option_dentry *topt, | |
4121 | struct tracer_flags *flags, | |
4122 | struct tracer_opt *opt) | |
4123 | { | |
4124 | struct dentry *t_options; | |
577b785f SR |
4125 | |
4126 | t_options = trace_options_init_dentry(); | |
4127 | if (!t_options) | |
4128 | return; | |
4129 | ||
4130 | topt->flags = flags; | |
4131 | topt->opt = opt; | |
4132 | ||
5452af66 | 4133 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
577b785f SR |
4134 | &trace_options_fops); |
4135 | ||
577b785f SR |
4136 | } |
4137 | ||
4138 | static struct trace_option_dentry * | |
4139 | create_trace_option_files(struct tracer *tracer) | |
4140 | { | |
4141 | struct trace_option_dentry *topts; | |
4142 | struct tracer_flags *flags; | |
4143 | struct tracer_opt *opts; | |
4144 | int cnt; | |
4145 | ||
4146 | if (!tracer) | |
4147 | return NULL; | |
4148 | ||
4149 | flags = tracer->flags; | |
4150 | ||
4151 | if (!flags || !flags->opts) | |
4152 | return NULL; | |
4153 | ||
4154 | opts = flags->opts; | |
4155 | ||
4156 | for (cnt = 0; opts[cnt].name; cnt++) | |
4157 | ; | |
4158 | ||
0cfe8245 | 4159 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f SR |
4160 | if (!topts) |
4161 | return NULL; | |
4162 | ||
4163 | for (cnt = 0; opts[cnt].name; cnt++) | |
4164 | create_trace_option_file(&topts[cnt], flags, | |
4165 | &opts[cnt]); | |
4166 | ||
4167 | return topts; | |
4168 | } | |
4169 | ||
4170 | static void | |
4171 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
4172 | { | |
4173 | int cnt; | |
4174 | ||
4175 | if (!topts) | |
4176 | return; | |
4177 | ||
4178 | for (cnt = 0; topts[cnt].opt; cnt++) { | |
4179 | if (topts[cnt].entry) | |
4180 | debugfs_remove(topts[cnt].entry); | |
4181 | } | |
4182 | ||
4183 | kfree(topts); | |
4184 | } | |
4185 | ||
a8259075 SR |
4186 | static struct dentry * |
4187 | create_trace_option_core_file(const char *option, long index) | |
4188 | { | |
4189 | struct dentry *t_options; | |
a8259075 SR |
4190 | |
4191 | t_options = trace_options_init_dentry(); | |
4192 | if (!t_options) | |
4193 | return NULL; | |
4194 | ||
5452af66 | 4195 | return trace_create_file(option, 0644, t_options, (void *)index, |
a8259075 | 4196 | &trace_options_core_fops); |
a8259075 SR |
4197 | } |
4198 | ||
4199 | static __init void create_trace_options_dir(void) | |
4200 | { | |
4201 | struct dentry *t_options; | |
a8259075 SR |
4202 | int i; |
4203 | ||
4204 | t_options = trace_options_init_dentry(); | |
4205 | if (!t_options) | |
4206 | return; | |
4207 | ||
5452af66 FW |
4208 | for (i = 0; trace_options[i]; i++) |
4209 | create_trace_option_core_file(trace_options[i], i); | |
a8259075 SR |
4210 | } |
4211 | ||
b5ad384e | 4212 | static __init int tracer_init_debugfs(void) |
bc0c38d1 SR |
4213 | { |
4214 | struct dentry *d_tracer; | |
b04cc6b1 | 4215 | int cpu; |
bc0c38d1 | 4216 | |
7e53bd42 LJ |
4217 | trace_access_lock_init(); |
4218 | ||
bc0c38d1 SR |
4219 | d_tracer = tracing_init_dentry(); |
4220 | ||
5452af66 FW |
4221 | trace_create_file("tracing_enabled", 0644, d_tracer, |
4222 | &global_trace, &tracing_ctrl_fops); | |
bc0c38d1 | 4223 | |
5452af66 FW |
4224 | trace_create_file("trace_options", 0644, d_tracer, |
4225 | NULL, &tracing_iter_fops); | |
bc0c38d1 | 4226 | |
5452af66 FW |
4227 | trace_create_file("tracing_cpumask", 0644, d_tracer, |
4228 | NULL, &tracing_cpumask_fops); | |
4229 | ||
4230 | trace_create_file("trace", 0644, d_tracer, | |
4231 | (void *) TRACE_PIPE_ALL_CPU, &tracing_fops); | |
a8259075 | 4232 | |
5452af66 FW |
4233 | trace_create_file("available_tracers", 0444, d_tracer, |
4234 | &global_trace, &show_traces_fops); | |
4235 | ||
339ae5d3 | 4236 | trace_create_file("current_tracer", 0644, d_tracer, |
5452af66 FW |
4237 | &global_trace, &set_tracer_fops); |
4238 | ||
5d4a9dba | 4239 | #ifdef CONFIG_TRACER_MAX_TRACE |
5452af66 FW |
4240 | trace_create_file("tracing_max_latency", 0644, d_tracer, |
4241 | &tracing_max_latency, &tracing_max_lat_fops); | |
4242 | ||
4243 | trace_create_file("tracing_thresh", 0644, d_tracer, | |
4244 | &tracing_thresh, &tracing_max_lat_fops); | |
5d4a9dba | 4245 | #endif |
a8259075 | 4246 | |
339ae5d3 | 4247 | trace_create_file("README", 0444, d_tracer, |
5452af66 FW |
4248 | NULL, &tracing_readme_fops); |
4249 | ||
4250 | trace_create_file("trace_pipe", 0444, d_tracer, | |
b04cc6b1 | 4251 | (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); |
5452af66 FW |
4252 | |
4253 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
4254 | &global_trace, &tracing_entries_fops); | |
4255 | ||
4256 | trace_create_file("trace_marker", 0220, d_tracer, | |
4257 | NULL, &tracing_mark_fops); | |
5bf9a1ee | 4258 | |
69abe6a5 AP |
4259 | trace_create_file("saved_cmdlines", 0444, d_tracer, |
4260 | NULL, &tracing_saved_cmdlines_fops); | |
5bf9a1ee | 4261 | |
5079f326 Z |
4262 | trace_create_file("trace_clock", 0644, d_tracer, NULL, |
4263 | &trace_clock_fops); | |
4264 | ||
bc0c38d1 | 4265 | #ifdef CONFIG_DYNAMIC_FTRACE |
5452af66 FW |
4266 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
4267 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
bc0c38d1 | 4268 | #endif |
d618b3e6 IM |
4269 | #ifdef CONFIG_SYSPROF_TRACER |
4270 | init_tracer_sysprof_debugfs(d_tracer); | |
4271 | #endif | |
b04cc6b1 | 4272 | |
5452af66 FW |
4273 | create_trace_options_dir(); |
4274 | ||
b04cc6b1 FW |
4275 | for_each_tracing_cpu(cpu) |
4276 | tracing_init_debugfs_percpu(cpu); | |
4277 | ||
b5ad384e | 4278 | return 0; |
bc0c38d1 SR |
4279 | } |
4280 | ||
3f5a54e3 SR |
4281 | static int trace_panic_handler(struct notifier_block *this, |
4282 | unsigned long event, void *unused) | |
4283 | { | |
944ac425 SR |
4284 | if (ftrace_dump_on_oops) |
4285 | ftrace_dump(); | |
3f5a54e3 SR |
4286 | return NOTIFY_OK; |
4287 | } | |
4288 | ||
4289 | static struct notifier_block trace_panic_notifier = { | |
4290 | .notifier_call = trace_panic_handler, | |
4291 | .next = NULL, | |
4292 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
4293 | }; | |
4294 | ||
4295 | static int trace_die_handler(struct notifier_block *self, | |
4296 | unsigned long val, | |
4297 | void *data) | |
4298 | { | |
4299 | switch (val) { | |
4300 | case DIE_OOPS: | |
944ac425 SR |
4301 | if (ftrace_dump_on_oops) |
4302 | ftrace_dump(); | |
3f5a54e3 SR |
4303 | break; |
4304 | default: | |
4305 | break; | |
4306 | } | |
4307 | return NOTIFY_OK; | |
4308 | } | |
4309 | ||
4310 | static struct notifier_block trace_die_notifier = { | |
4311 | .notifier_call = trace_die_handler, | |
4312 | .priority = 200 | |
4313 | }; | |
4314 | ||
4315 | /* | |
4316 | * printk is set to max of 1024, we really don't need it that big. | |
4317 | * Nothing should be printing 1000 characters anyway. | |
4318 | */ | |
4319 | #define TRACE_MAX_PRINT 1000 | |
4320 | ||
4321 | /* | |
4322 | * Define here KERN_TRACE so that we have one place to modify | |
4323 | * it if we decide to change what log level the ftrace dump | |
4324 | * should be at. | |
4325 | */ | |
428aee14 | 4326 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 SR |
4327 | |
4328 | static void | |
4329 | trace_printk_seq(struct trace_seq *s) | |
4330 | { | |
4331 | /* Probably should print a warning here. */ | |
4332 | if (s->len >= 1000) | |
4333 | s->len = 1000; | |
4334 | ||
4335 | /* should be zero ended, but we are paranoid. */ | |
4336 | s->buffer[s->len] = 0; | |
4337 | ||
4338 | printk(KERN_TRACE "%s", s->buffer); | |
4339 | ||
f9520750 | 4340 | trace_seq_init(s); |
3f5a54e3 SR |
4341 | } |
4342 | ||
cf586b61 | 4343 | static void __ftrace_dump(bool disable_tracing) |
3f5a54e3 | 4344 | { |
445c8951 | 4345 | static arch_spinlock_t ftrace_dump_lock = |
edc35bd7 | 4346 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
3f5a54e3 SR |
4347 | /* use static because iter can be a bit big for the stack */ |
4348 | static struct trace_iterator iter; | |
cf586b61 | 4349 | unsigned int old_userobj; |
3f5a54e3 | 4350 | static int dump_ran; |
d769041f SR |
4351 | unsigned long flags; |
4352 | int cnt = 0, cpu; | |
3f5a54e3 SR |
4353 | |
4354 | /* only one dump */ | |
cd891ae0 | 4355 | local_irq_save(flags); |
0199c4e6 | 4356 | arch_spin_lock(&ftrace_dump_lock); |
3f5a54e3 SR |
4357 | if (dump_ran) |
4358 | goto out; | |
4359 | ||
4360 | dump_ran = 1; | |
4361 | ||
0ee6b6cf | 4362 | tracing_off(); |
cf586b61 FW |
4363 | |
4364 | if (disable_tracing) | |
4365 | ftrace_kill(); | |
3f5a54e3 | 4366 | |
d769041f SR |
4367 | for_each_tracing_cpu(cpu) { |
4368 | atomic_inc(&global_trace.data[cpu]->disabled); | |
4369 | } | |
4370 | ||
cf586b61 FW |
4371 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; |
4372 | ||
b54d3de9 TE |
4373 | /* don't look at user memory in panic mode */ |
4374 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
4375 | ||
3f5a54e3 SR |
4376 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); |
4377 | ||
e543ad76 | 4378 | /* Simulate the iterator */ |
3f5a54e3 SR |
4379 | iter.tr = &global_trace; |
4380 | iter.trace = current_trace; | |
e543ad76 | 4381 | iter.cpu_file = TRACE_PIPE_ALL_CPU; |
3f5a54e3 SR |
4382 | |
4383 | /* | |
4384 | * We need to stop all tracing on all CPUS to read the | |
4385 | * the next buffer. This is a bit expensive, but is | |
4386 | * not done often. We fill all what we can read, | |
4387 | * and then release the locks again. | |
4388 | */ | |
4389 | ||
3f5a54e3 SR |
4390 | while (!trace_empty(&iter)) { |
4391 | ||
4392 | if (!cnt) | |
4393 | printk(KERN_TRACE "---------------------------------\n"); | |
4394 | ||
4395 | cnt++; | |
4396 | ||
4397 | /* reset all but tr, trace, and overruns */ | |
4398 | memset(&iter.seq, 0, | |
4399 | sizeof(struct trace_iterator) - | |
4400 | offsetof(struct trace_iterator, seq)); | |
4401 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
4402 | iter.pos = -1; | |
4403 | ||
4404 | if (find_next_entry_inc(&iter) != NULL) { | |
74e7ff8c LJ |
4405 | int ret; |
4406 | ||
4407 | ret = print_trace_line(&iter); | |
4408 | if (ret != TRACE_TYPE_NO_CONSUME) | |
4409 | trace_consume(&iter); | |
3f5a54e3 SR |
4410 | } |
4411 | ||
4412 | trace_printk_seq(&iter.seq); | |
4413 | } | |
4414 | ||
4415 | if (!cnt) | |
4416 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
4417 | else | |
4418 | printk(KERN_TRACE "---------------------------------\n"); | |
4419 | ||
cf586b61 FW |
4420 | /* Re-enable tracing if requested */ |
4421 | if (!disable_tracing) { | |
4422 | trace_flags |= old_userobj; | |
4423 | ||
4424 | for_each_tracing_cpu(cpu) { | |
4425 | atomic_dec(&global_trace.data[cpu]->disabled); | |
4426 | } | |
4427 | tracing_on(); | |
4428 | } | |
4429 | ||
3f5a54e3 | 4430 | out: |
0199c4e6 | 4431 | arch_spin_unlock(&ftrace_dump_lock); |
cd891ae0 | 4432 | local_irq_restore(flags); |
3f5a54e3 SR |
4433 | } |
4434 | ||
cf586b61 FW |
4435 | /* By default: disable tracing after the dump */ |
4436 | void ftrace_dump(void) | |
4437 | { | |
4438 | __ftrace_dump(true); | |
4439 | } | |
4440 | ||
3928a8a2 | 4441 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 4442 | { |
73c5162a | 4443 | int ring_buf_size; |
4c11d7ae | 4444 | int i; |
9e01c1b7 | 4445 | int ret = -ENOMEM; |
4c11d7ae | 4446 | |
9e01c1b7 RR |
4447 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
4448 | goto out; | |
4449 | ||
4450 | if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) | |
4451 | goto out_free_buffer_mask; | |
4c11d7ae | 4452 | |
73c5162a SR |
4453 | /* To save memory, keep the ring buffer size to its minimum */ |
4454 | if (ring_buffer_expanded) | |
4455 | ring_buf_size = trace_buf_size; | |
4456 | else | |
4457 | ring_buf_size = 1; | |
4458 | ||
9e01c1b7 RR |
4459 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
4460 | cpumask_copy(tracing_cpumask, cpu_all_mask); | |
4461 | ||
4462 | /* TODO: make the number of buffers hot pluggable with CPUS */ | |
73c5162a | 4463 | global_trace.buffer = ring_buffer_alloc(ring_buf_size, |
3928a8a2 SR |
4464 | TRACE_BUFFER_FLAGS); |
4465 | if (!global_trace.buffer) { | |
4466 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); | |
4467 | WARN_ON(1); | |
9e01c1b7 | 4468 | goto out_free_cpumask; |
4c11d7ae | 4469 | } |
3928a8a2 | 4470 | global_trace.entries = ring_buffer_size(global_trace.buffer); |
4c11d7ae | 4471 | |
9e01c1b7 | 4472 | |
4c11d7ae | 4473 | #ifdef CONFIG_TRACER_MAX_TRACE |
73c5162a | 4474 | max_tr.buffer = ring_buffer_alloc(ring_buf_size, |
3928a8a2 SR |
4475 | TRACE_BUFFER_FLAGS); |
4476 | if (!max_tr.buffer) { | |
4477 | printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); | |
4478 | WARN_ON(1); | |
4479 | ring_buffer_free(global_trace.buffer); | |
9e01c1b7 | 4480 | goto out_free_cpumask; |
4c11d7ae | 4481 | } |
3928a8a2 SR |
4482 | max_tr.entries = ring_buffer_size(max_tr.buffer); |
4483 | WARN_ON(max_tr.entries != global_trace.entries); | |
a98a3c3f | 4484 | #endif |
ab46428c | 4485 | |
4c11d7ae | 4486 | /* Allocate the first page for all buffers */ |
ab46428c | 4487 | for_each_tracing_cpu(i) { |
566b0aaf | 4488 | global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
9705f69e | 4489 | max_tr.data[i] = &per_cpu(max_tr_data, i); |
4c11d7ae | 4490 | } |
bc0c38d1 | 4491 | |
bc0c38d1 SR |
4492 | trace_init_cmdlines(); |
4493 | ||
43a15386 | 4494 | register_tracer(&nop_trace); |
79fb0768 | 4495 | current_trace = &nop_trace; |
b5ad384e FW |
4496 | #ifdef CONFIG_BOOT_TRACER |
4497 | register_tracer(&boot_tracer); | |
b5ad384e | 4498 | #endif |
60a11774 SR |
4499 | /* All seems OK, enable tracing */ |
4500 | tracing_disabled = 0; | |
3928a8a2 | 4501 | |
3f5a54e3 SR |
4502 | atomic_notifier_chain_register(&panic_notifier_list, |
4503 | &trace_panic_notifier); | |
4504 | ||
4505 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe FW |
4506 | |
4507 | return 0; | |
3f5a54e3 | 4508 | |
9e01c1b7 RR |
4509 | out_free_cpumask: |
4510 | free_cpumask_var(tracing_cpumask); | |
4511 | out_free_buffer_mask: | |
4512 | free_cpumask_var(tracing_buffer_mask); | |
4513 | out: | |
4514 | return ret; | |
bc0c38d1 | 4515 | } |
b2821ae6 SR |
4516 | |
4517 | __init static int clear_boot_tracer(void) | |
4518 | { | |
4519 | /* | |
4520 | * The default tracer at boot buffer is an init section. | |
4521 | * This function is called in lateinit. If we did not | |
4522 | * find the boot tracer, then clear it out, to prevent | |
4523 | * later registration from accessing the buffer that is | |
4524 | * about to be freed. | |
4525 | */ | |
4526 | if (!default_bootup_tracer) | |
4527 | return 0; | |
4528 | ||
4529 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
4530 | default_bootup_tracer); | |
4531 | default_bootup_tracer = NULL; | |
4532 | ||
4533 | return 0; | |
4534 | } | |
4535 | ||
b5ad384e FW |
4536 | early_initcall(tracer_alloc_buffers); |
4537 | fs_initcall(tracer_init_debugfs); | |
b2821ae6 | 4538 | late_initcall(clear_boot_tracer); |