Commit | Line | Data |
---|---|---|
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> | |
3f5a54e3 | 20 | #include <linux/notifier.h> |
2cadf913 | 21 | #include <linux/irqflags.h> |
bc0c38d1 | 22 | #include <linux/debugfs.h> |
4c11d7ae | 23 | #include <linux/pagemap.h> |
bc0c38d1 SR |
24 | #include <linux/hardirq.h> |
25 | #include <linux/linkage.h> | |
26 | #include <linux/uaccess.h> | |
2cadf913 | 27 | #include <linux/kprobes.h> |
bc0c38d1 SR |
28 | #include <linux/ftrace.h> |
29 | #include <linux/module.h> | |
30 | #include <linux/percpu.h> | |
2cadf913 | 31 | #include <linux/splice.h> |
3f5a54e3 | 32 | #include <linux/kdebug.h> |
5f0c6c03 | 33 | #include <linux/string.h> |
7e53bd42 | 34 | #include <linux/rwsem.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
bc0c38d1 SR |
36 | #include <linux/ctype.h> |
37 | #include <linux/init.h> | |
2a2cc8f7 | 38 | #include <linux/poll.h> |
b892e5c8 | 39 | #include <linux/nmi.h> |
bc0c38d1 | 40 | #include <linux/fs.h> |
86387f7e | 41 | |
bc0c38d1 | 42 | #include "trace.h" |
f0868d1e | 43 | #include "trace_output.h" |
bc0c38d1 | 44 | |
73c5162a SR |
45 | /* |
46 | * On boot up, the ring buffer is set to the minimum size, so that | |
47 | * we do not waste memory on systems that are not using tracing. | |
48 | */ | |
020e5f85 | 49 | int ring_buffer_expanded; |
73c5162a | 50 | |
8e1b82e0 FW |
51 | /* |
52 | * We need to change this state when a selftest is running. | |
ff32504f FW |
53 | * A selftest will lurk into the ring-buffer to count the |
54 | * entries inserted during the selftest although some concurrent | |
5e1607a0 | 55 | * insertions into the ring-buffer such as trace_printk could occurred |
ff32504f FW |
56 | * at the same time, giving false positive or negative results. |
57 | */ | |
8e1b82e0 | 58 | static bool __read_mostly tracing_selftest_running; |
ff32504f | 59 | |
b2821ae6 SR |
60 | /* |
61 | * If a tracer is running, we do not want to run SELFTEST. | |
62 | */ | |
020e5f85 | 63 | bool __read_mostly tracing_selftest_disabled; |
b2821ae6 | 64 | |
adf9f195 FW |
65 | /* For tracers that don't implement custom flags */ |
66 | static struct tracer_opt dummy_tracer_opt[] = { | |
67 | { } | |
68 | }; | |
69 | ||
70 | static struct tracer_flags dummy_tracer_flags = { | |
71 | .val = 0, | |
72 | .opts = dummy_tracer_opt | |
73 | }; | |
74 | ||
75 | static int dummy_set_flag(u32 old_flags, u32 bit, int set) | |
76 | { | |
77 | return 0; | |
78 | } | |
0f048701 SR |
79 | |
80 | /* | |
81 | * Kill all tracing for good (never come back). | |
82 | * It is initialized to 1 but will turn to zero if the initialization | |
83 | * of the tracer is successful. But that is the only place that sets | |
84 | * this back to zero. | |
85 | */ | |
4fd27358 | 86 | static int tracing_disabled = 1; |
0f048701 | 87 | |
9288f99a | 88 | DEFINE_PER_CPU(int, ftrace_cpu_disabled); |
d769041f SR |
89 | |
90 | static inline void ftrace_disable_cpu(void) | |
91 | { | |
92 | preempt_disable(); | |
dd17c8f7 | 93 | __this_cpu_inc(ftrace_cpu_disabled); |
d769041f SR |
94 | } |
95 | ||
96 | static inline void ftrace_enable_cpu(void) | |
97 | { | |
dd17c8f7 | 98 | __this_cpu_dec(ftrace_cpu_disabled); |
d769041f SR |
99 | preempt_enable(); |
100 | } | |
101 | ||
955b61e5 | 102 | cpumask_var_t __read_mostly tracing_buffer_mask; |
ab46428c | 103 | |
944ac425 SR |
104 | /* |
105 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
106 | * | |
107 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
108 | * is set, then ftrace_dump is called. This will output the contents | |
109 | * of the ftrace buffers to the console. This is very useful for | |
110 | * capturing traces that lead to crashes and outputing it to a | |
111 | * serial console. | |
112 | * | |
113 | * It is default off, but you can enable it with either specifying | |
114 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
cecbca96 FW |
115 | * /proc/sys/kernel/ftrace_dump_on_oops |
116 | * Set 1 if you want to dump buffers of all CPUs | |
117 | * Set 2 if you want to dump the buffer of the CPU that triggered oops | |
944ac425 | 118 | */ |
cecbca96 FW |
119 | |
120 | enum ftrace_dump_mode ftrace_dump_on_oops; | |
944ac425 | 121 | |
b2821ae6 SR |
122 | static int tracing_set_tracer(const char *buf); |
123 | ||
ee6c2c1b LZ |
124 | #define MAX_TRACER_SIZE 100 |
125 | static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; | |
b2821ae6 | 126 | static char *default_bootup_tracer; |
d9e54076 | 127 | |
1beee96b | 128 | static int __init set_cmdline_ftrace(char *str) |
d9e54076 | 129 | { |
ee6c2c1b | 130 | strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); |
b2821ae6 | 131 | default_bootup_tracer = bootup_tracer_buf; |
73c5162a SR |
132 | /* We are using ftrace early, expand it */ |
133 | ring_buffer_expanded = 1; | |
d9e54076 PZ |
134 | return 1; |
135 | } | |
1beee96b | 136 | __setup("ftrace=", set_cmdline_ftrace); |
d9e54076 | 137 | |
944ac425 SR |
138 | static int __init set_ftrace_dump_on_oops(char *str) |
139 | { | |
cecbca96 FW |
140 | if (*str++ != '=' || !*str) { |
141 | ftrace_dump_on_oops = DUMP_ALL; | |
142 | return 1; | |
143 | } | |
144 | ||
145 | if (!strcmp("orig_cpu", str)) { | |
146 | ftrace_dump_on_oops = DUMP_ORIG; | |
147 | return 1; | |
148 | } | |
149 | ||
150 | return 0; | |
944ac425 SR |
151 | } |
152 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
60a11774 | 153 | |
cf8e3474 | 154 | unsigned long long ns2usecs(cycle_t nsec) |
bc0c38d1 SR |
155 | { |
156 | nsec += 500; | |
157 | do_div(nsec, 1000); | |
158 | return nsec; | |
159 | } | |
160 | ||
4fcdae83 SR |
161 | /* |
162 | * The global_trace is the descriptor that holds the tracing | |
163 | * buffers for the live tracing. For each CPU, it contains | |
164 | * a link list of pages that will store trace entries. The | |
165 | * page descriptor of the pages in the memory is used to hold | |
166 | * the link list by linking the lru item in the page descriptor | |
167 | * to each of the pages in the buffer per CPU. | |
168 | * | |
169 | * For each active CPU there is a data field that holds the | |
170 | * pages for the buffer for that CPU. Each CPU has the same number | |
171 | * of pages allocated for its buffer. | |
172 | */ | |
bc0c38d1 SR |
173 | static struct trace_array global_trace; |
174 | ||
175 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
176 | ||
e77405ad SR |
177 | int filter_current_check_discard(struct ring_buffer *buffer, |
178 | struct ftrace_event_call *call, void *rec, | |
eb02ce01 TZ |
179 | struct ring_buffer_event *event) |
180 | { | |
e77405ad | 181 | return filter_check_discard(call, rec, buffer, event); |
eb02ce01 | 182 | } |
17c873ec | 183 | EXPORT_SYMBOL_GPL(filter_current_check_discard); |
eb02ce01 | 184 | |
37886f6a SR |
185 | cycle_t ftrace_now(int cpu) |
186 | { | |
187 | u64 ts; | |
188 | ||
189 | /* Early boot up does not have a buffer yet */ | |
190 | if (!global_trace.buffer) | |
191 | return trace_clock_local(); | |
192 | ||
193 | ts = ring_buffer_time_stamp(global_trace.buffer, cpu); | |
194 | ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts); | |
195 | ||
196 | return ts; | |
197 | } | |
bc0c38d1 | 198 | |
4fcdae83 SR |
199 | /* |
200 | * The max_tr is used to snapshot the global_trace when a maximum | |
201 | * latency is reached. Some tracers will use this to store a maximum | |
202 | * trace while it continues examining live traces. | |
203 | * | |
204 | * The buffers for the max_tr are set up the same as the global_trace. | |
205 | * When a snapshot is taken, the link list of the max_tr is swapped | |
206 | * with the link list of the global_trace and the buffers are reset for | |
207 | * the global_trace so the tracing can continue. | |
208 | */ | |
bc0c38d1 SR |
209 | static struct trace_array max_tr; |
210 | ||
9705f69e | 211 | static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data); |
bc0c38d1 | 212 | |
4fcdae83 | 213 | /* tracer_enabled is used to toggle activation of a tracer */ |
26994ead | 214 | static int tracer_enabled = 1; |
4fcdae83 | 215 | |
9036990d SR |
216 | /** |
217 | * tracing_is_enabled - return tracer_enabled status | |
218 | * | |
219 | * This function is used by other tracers to know the status | |
220 | * of the tracer_enabled flag. Tracers may use this function | |
221 | * to know if it should enable their features when starting | |
222 | * up. See irqsoff tracer for an example (start_irqsoff_tracer). | |
223 | */ | |
224 | int tracing_is_enabled(void) | |
225 | { | |
226 | return tracer_enabled; | |
227 | } | |
228 | ||
4fcdae83 | 229 | /* |
3928a8a2 SR |
230 | * trace_buf_size is the size in bytes that is allocated |
231 | * for a buffer. Note, the number of bytes is always rounded | |
232 | * to page size. | |
3f5a54e3 SR |
233 | * |
234 | * This number is purposely set to a low number of 16384. | |
235 | * If the dump on oops happens, it will be much appreciated | |
236 | * to not have to wait for all that output. Anyway this can be | |
237 | * boot time and run time configurable. | |
4fcdae83 | 238 | */ |
3928a8a2 | 239 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 240 | |
3928a8a2 | 241 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 242 | |
4fcdae83 | 243 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 244 | static struct tracer *trace_types __read_mostly; |
4fcdae83 SR |
245 | |
246 | /* current_trace points to the tracer that is currently active */ | |
bc0c38d1 | 247 | static struct tracer *current_trace __read_mostly; |
4fcdae83 | 248 | |
4fcdae83 SR |
249 | /* |
250 | * trace_types_lock is used to protect the trace_types list. | |
4fcdae83 | 251 | */ |
bc0c38d1 | 252 | static DEFINE_MUTEX(trace_types_lock); |
4fcdae83 | 253 | |
7e53bd42 LJ |
254 | /* |
255 | * serialize the access of the ring buffer | |
256 | * | |
257 | * ring buffer serializes readers, but it is low level protection. | |
258 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
259 | * are not protected by ring buffer. | |
260 | * | |
261 | * The content of events may become garbage if we allow other process consumes | |
262 | * these events concurrently: | |
263 | * A) the page of the consumed events may become a normal page | |
264 | * (not reader page) in ring buffer, and this page will be rewrited | |
265 | * by events producer. | |
266 | * B) The page of the consumed events may become a page for splice_read, | |
267 | * and this page will be returned to system. | |
268 | * | |
269 | * These primitives allow multi process access to different cpu ring buffer | |
270 | * concurrently. | |
271 | * | |
272 | * These primitives don't distinguish read-only and read-consume access. | |
273 | * Multi read-only access are also serialized. | |
274 | */ | |
275 | ||
276 | #ifdef CONFIG_SMP | |
277 | static DECLARE_RWSEM(all_cpu_access_lock); | |
278 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
279 | ||
280 | static inline void trace_access_lock(int cpu) | |
281 | { | |
282 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
283 | /* gain it for accessing the whole ring buffer. */ | |
284 | down_write(&all_cpu_access_lock); | |
285 | } else { | |
286 | /* gain it for accessing a cpu ring buffer. */ | |
287 | ||
288 | /* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */ | |
289 | down_read(&all_cpu_access_lock); | |
290 | ||
291 | /* Secondly block other access to this @cpu ring buffer. */ | |
292 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
293 | } | |
294 | } | |
295 | ||
296 | static inline void trace_access_unlock(int cpu) | |
297 | { | |
298 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
299 | up_write(&all_cpu_access_lock); | |
300 | } else { | |
301 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
302 | up_read(&all_cpu_access_lock); | |
303 | } | |
304 | } | |
305 | ||
306 | static inline void trace_access_lock_init(void) | |
307 | { | |
308 | int cpu; | |
309 | ||
310 | for_each_possible_cpu(cpu) | |
311 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
312 | } | |
313 | ||
314 | #else | |
315 | ||
316 | static DEFINE_MUTEX(access_lock); | |
317 | ||
318 | static inline void trace_access_lock(int cpu) | |
319 | { | |
320 | (void)cpu; | |
321 | mutex_lock(&access_lock); | |
322 | } | |
323 | ||
324 | static inline void trace_access_unlock(int cpu) | |
325 | { | |
326 | (void)cpu; | |
327 | mutex_unlock(&access_lock); | |
328 | } | |
329 | ||
330 | static inline void trace_access_lock_init(void) | |
331 | { | |
332 | } | |
333 | ||
334 | #endif | |
335 | ||
4fcdae83 | 336 | /* trace_wait is a waitqueue for tasks blocked on trace_poll */ |
4e655519 IM |
337 | static DECLARE_WAIT_QUEUE_HEAD(trace_wait); |
338 | ||
ee6bce52 | 339 | /* trace_flags holds trace_options default values */ |
12ef7d44 | 340 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | |
a2a16d6a | 341 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | |
77271ce4 SR |
342 | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | |
343 | TRACE_ITER_IRQ_INFO; | |
4e655519 | 344 | |
b8de7bd1 | 345 | static int trace_stop_count; |
5389f6fa | 346 | static DEFINE_RAW_SPINLOCK(tracing_start_lock); |
b8de7bd1 | 347 | |
e7e2ee89 VN |
348 | static void wakeup_work_handler(struct work_struct *work) |
349 | { | |
350 | wake_up(&trace_wait); | |
351 | } | |
352 | ||
353 | static DECLARE_DELAYED_WORK(wakeup_work, wakeup_work_handler); | |
354 | ||
499e5470 SR |
355 | /** |
356 | * tracing_on - enable tracing buffers | |
357 | * | |
358 | * This function enables tracing buffers that may have been | |
359 | * disabled with tracing_off. | |
360 | */ | |
361 | void tracing_on(void) | |
362 | { | |
363 | if (global_trace.buffer) | |
364 | ring_buffer_record_on(global_trace.buffer); | |
365 | /* | |
366 | * This flag is only looked at when buffers haven't been | |
367 | * allocated yet. We don't really care about the race | |
368 | * between setting this flag and actually turning | |
369 | * on the buffer. | |
370 | */ | |
371 | global_trace.buffer_disabled = 0; | |
372 | } | |
373 | EXPORT_SYMBOL_GPL(tracing_on); | |
374 | ||
375 | /** | |
376 | * tracing_off - turn off tracing buffers | |
377 | * | |
378 | * This function stops the tracing buffers from recording data. | |
379 | * It does not disable any overhead the tracers themselves may | |
380 | * be causing. This function simply causes all recording to | |
381 | * the ring buffers to fail. | |
382 | */ | |
383 | void tracing_off(void) | |
384 | { | |
385 | if (global_trace.buffer) | |
386 | ring_buffer_record_on(global_trace.buffer); | |
387 | /* | |
388 | * This flag is only looked at when buffers haven't been | |
389 | * allocated yet. We don't really care about the race | |
390 | * between setting this flag and actually turning | |
391 | * on the buffer. | |
392 | */ | |
393 | global_trace.buffer_disabled = 1; | |
394 | } | |
395 | EXPORT_SYMBOL_GPL(tracing_off); | |
396 | ||
397 | /** | |
398 | * tracing_is_on - show state of ring buffers enabled | |
399 | */ | |
400 | int tracing_is_on(void) | |
401 | { | |
402 | if (global_trace.buffer) | |
403 | return ring_buffer_record_is_on(global_trace.buffer); | |
404 | return !global_trace.buffer_disabled; | |
405 | } | |
406 | EXPORT_SYMBOL_GPL(tracing_is_on); | |
407 | ||
4fcdae83 SR |
408 | /** |
409 | * trace_wake_up - wake up tasks waiting for trace input | |
410 | * | |
e7e2ee89 VN |
411 | * Schedules a delayed work to wake up any task that is blocked on the |
412 | * trace_wait queue. These is used with trace_poll for tasks polling the | |
413 | * trace. | |
4fcdae83 | 414 | */ |
4e655519 IM |
415 | void trace_wake_up(void) |
416 | { | |
e7e2ee89 | 417 | const unsigned long delay = msecs_to_jiffies(2); |
89f19f04 AM |
418 | |
419 | if (trace_flags & TRACE_ITER_BLOCK) | |
420 | return; | |
e7e2ee89 | 421 | schedule_delayed_work(&wakeup_work, delay); |
4e655519 | 422 | } |
bc0c38d1 | 423 | |
3928a8a2 | 424 | static int __init set_buf_size(char *str) |
bc0c38d1 | 425 | { |
3928a8a2 | 426 | unsigned long buf_size; |
c6caeeb1 | 427 | |
bc0c38d1 SR |
428 | if (!str) |
429 | return 0; | |
9d612bef | 430 | buf_size = memparse(str, &str); |
c6caeeb1 | 431 | /* nr_entries can not be zero */ |
9d612bef | 432 | if (buf_size == 0) |
c6caeeb1 | 433 | return 0; |
3928a8a2 | 434 | trace_buf_size = buf_size; |
bc0c38d1 SR |
435 | return 1; |
436 | } | |
3928a8a2 | 437 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 438 | |
0e950173 TB |
439 | static int __init set_tracing_thresh(char *str) |
440 | { | |
441 | unsigned long threshhold; | |
442 | int ret; | |
443 | ||
444 | if (!str) | |
445 | return 0; | |
446 | ret = strict_strtoul(str, 0, &threshhold); | |
447 | if (ret < 0) | |
448 | return 0; | |
449 | tracing_thresh = threshhold * 1000; | |
450 | return 1; | |
451 | } | |
452 | __setup("tracing_thresh=", set_tracing_thresh); | |
453 | ||
57f50be1 SR |
454 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
455 | { | |
456 | return nsecs / 1000; | |
457 | } | |
458 | ||
4fcdae83 | 459 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 SR |
460 | static const char *trace_options[] = { |
461 | "print-parent", | |
462 | "sym-offset", | |
463 | "sym-addr", | |
464 | "verbose", | |
f9896bf3 | 465 | "raw", |
5e3ca0ec | 466 | "hex", |
cb0f12aa | 467 | "bin", |
2a2cc8f7 | 468 | "block", |
86387f7e | 469 | "stacktrace", |
5e1607a0 | 470 | "trace_printk", |
b2a866f9 | 471 | "ftrace_preempt", |
9f029e83 | 472 | "branch", |
12ef7d44 | 473 | "annotate", |
02b67518 | 474 | "userstacktrace", |
b54d3de9 | 475 | "sym-userobj", |
66896a85 | 476 | "printk-msg-only", |
c4a8e8be | 477 | "context-info", |
c032ef64 | 478 | "latency-format", |
be6f164a | 479 | "sleep-time", |
a2a16d6a | 480 | "graph-time", |
e870e9a1 | 481 | "record-cmd", |
750912fa | 482 | "overwrite", |
cf30cf67 | 483 | "disable_on_free", |
77271ce4 | 484 | "irq-info", |
bc0c38d1 SR |
485 | NULL |
486 | }; | |
487 | ||
5079f326 Z |
488 | static struct { |
489 | u64 (*func)(void); | |
490 | const char *name; | |
491 | } trace_clocks[] = { | |
492 | { trace_clock_local, "local" }, | |
493 | { trace_clock_global, "global" }, | |
6249687f | 494 | { trace_clock_counter, "counter" }, |
5079f326 Z |
495 | }; |
496 | ||
497 | int trace_clock_id; | |
498 | ||
b63f39ea | 499 | /* |
500 | * trace_parser_get_init - gets the buffer for trace parser | |
501 | */ | |
502 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
503 | { | |
504 | memset(parser, 0, sizeof(*parser)); | |
505 | ||
506 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
507 | if (!parser->buffer) | |
508 | return 1; | |
509 | ||
510 | parser->size = size; | |
511 | return 0; | |
512 | } | |
513 | ||
514 | /* | |
515 | * trace_parser_put - frees the buffer for trace parser | |
516 | */ | |
517 | void trace_parser_put(struct trace_parser *parser) | |
518 | { | |
519 | kfree(parser->buffer); | |
520 | } | |
521 | ||
522 | /* | |
523 | * trace_get_user - reads the user input string separated by space | |
524 | * (matched by isspace(ch)) | |
525 | * | |
526 | * For each string found the 'struct trace_parser' is updated, | |
527 | * and the function returns. | |
528 | * | |
529 | * Returns number of bytes read. | |
530 | * | |
531 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
532 | */ | |
533 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
534 | size_t cnt, loff_t *ppos) | |
535 | { | |
536 | char ch; | |
537 | size_t read = 0; | |
538 | ssize_t ret; | |
539 | ||
540 | if (!*ppos) | |
541 | trace_parser_clear(parser); | |
542 | ||
543 | ret = get_user(ch, ubuf++); | |
544 | if (ret) | |
545 | goto out; | |
546 | ||
547 | read++; | |
548 | cnt--; | |
549 | ||
550 | /* | |
551 | * The parser is not finished with the last write, | |
552 | * continue reading the user input without skipping spaces. | |
553 | */ | |
554 | if (!parser->cont) { | |
555 | /* skip white space */ | |
556 | while (cnt && isspace(ch)) { | |
557 | ret = get_user(ch, ubuf++); | |
558 | if (ret) | |
559 | goto out; | |
560 | read++; | |
561 | cnt--; | |
562 | } | |
563 | ||
564 | /* only spaces were written */ | |
565 | if (isspace(ch)) { | |
566 | *ppos += read; | |
567 | ret = read; | |
568 | goto out; | |
569 | } | |
570 | ||
571 | parser->idx = 0; | |
572 | } | |
573 | ||
574 | /* read the non-space input */ | |
575 | while (cnt && !isspace(ch)) { | |
3c235a33 | 576 | if (parser->idx < parser->size - 1) |
b63f39ea | 577 | parser->buffer[parser->idx++] = ch; |
578 | else { | |
579 | ret = -EINVAL; | |
580 | goto out; | |
581 | } | |
582 | ret = get_user(ch, ubuf++); | |
583 | if (ret) | |
584 | goto out; | |
585 | read++; | |
586 | cnt--; | |
587 | } | |
588 | ||
589 | /* We either got finished input or we have to wait for another call. */ | |
590 | if (isspace(ch)) { | |
591 | parser->buffer[parser->idx] = 0; | |
592 | parser->cont = false; | |
593 | } else { | |
594 | parser->cont = true; | |
595 | parser->buffer[parser->idx++] = ch; | |
596 | } | |
597 | ||
598 | *ppos += read; | |
599 | ret = read; | |
600 | ||
601 | out: | |
602 | return ret; | |
603 | } | |
604 | ||
6c6c2796 PP |
605 | ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) |
606 | { | |
607 | int len; | |
608 | int ret; | |
609 | ||
2dc5d12b SR |
610 | if (!cnt) |
611 | return 0; | |
612 | ||
6c6c2796 PP |
613 | if (s->len <= s->readpos) |
614 | return -EBUSY; | |
615 | ||
616 | len = s->len - s->readpos; | |
617 | if (cnt > len) | |
618 | cnt = len; | |
619 | ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); | |
2dc5d12b | 620 | if (ret == cnt) |
6c6c2796 PP |
621 | return -EFAULT; |
622 | ||
2dc5d12b SR |
623 | cnt -= ret; |
624 | ||
e74da523 | 625 | s->readpos += cnt; |
6c6c2796 | 626 | return cnt; |
214023c3 SR |
627 | } |
628 | ||
b8b94265 | 629 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
630 | { |
631 | int len; | |
632 | void *ret; | |
633 | ||
634 | if (s->len <= s->readpos) | |
635 | return -EBUSY; | |
636 | ||
637 | len = s->len - s->readpos; | |
638 | if (cnt > len) | |
639 | cnt = len; | |
640 | ret = memcpy(buf, s->buffer + s->readpos, cnt); | |
641 | if (!ret) | |
642 | return -EFAULT; | |
643 | ||
e74da523 | 644 | s->readpos += cnt; |
3c56819b EGM |
645 | return cnt; |
646 | } | |
647 | ||
5d4a9dba SR |
648 | /* |
649 | * ftrace_max_lock is used to protect the swapping of buffers | |
650 | * when taking a max snapshot. The buffers themselves are | |
651 | * protected by per_cpu spinlocks. But the action of the swap | |
652 | * needs its own lock. | |
653 | * | |
445c8951 | 654 | * This is defined as a arch_spinlock_t in order to help |
5d4a9dba SR |
655 | * with performance when lockdep debugging is enabled. |
656 | * | |
657 | * It is also used in other places outside the update_max_tr | |
658 | * so it needs to be defined outside of the | |
659 | * CONFIG_TRACER_MAX_TRACE. | |
660 | */ | |
445c8951 | 661 | static arch_spinlock_t ftrace_max_lock = |
edc35bd7 | 662 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
5d4a9dba | 663 | |
0e950173 TB |
664 | unsigned long __read_mostly tracing_thresh; |
665 | ||
5d4a9dba SR |
666 | #ifdef CONFIG_TRACER_MAX_TRACE |
667 | unsigned long __read_mostly tracing_max_latency; | |
5d4a9dba SR |
668 | |
669 | /* | |
670 | * Copy the new maximum trace into the separate maximum-trace | |
671 | * structure. (this way the maximum trace is permanently saved, | |
672 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
673 | */ | |
674 | static void | |
675 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
676 | { | |
677 | struct trace_array_cpu *data = tr->data[cpu]; | |
1acaa1b2 | 678 | struct trace_array_cpu *max_data; |
5d4a9dba SR |
679 | |
680 | max_tr.cpu = cpu; | |
681 | max_tr.time_start = data->preempt_timestamp; | |
682 | ||
8248ac05 SR |
683 | max_data = max_tr.data[cpu]; |
684 | max_data->saved_latency = tracing_max_latency; | |
685 | max_data->critical_start = data->critical_start; | |
686 | max_data->critical_end = data->critical_end; | |
5d4a9dba | 687 | |
1acaa1b2 | 688 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); |
8248ac05 SR |
689 | max_data->pid = tsk->pid; |
690 | max_data->uid = task_uid(tsk); | |
691 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
692 | max_data->policy = tsk->policy; | |
693 | max_data->rt_priority = tsk->rt_priority; | |
5d4a9dba SR |
694 | |
695 | /* record this tasks comm */ | |
696 | tracing_record_cmdline(tsk); | |
697 | } | |
698 | ||
4fcdae83 SR |
699 | /** |
700 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
701 | * @tr: tracer | |
702 | * @tsk: the task with the latency | |
703 | * @cpu: The cpu that initiated the trace. | |
704 | * | |
705 | * Flip the buffers between the @tr and the max_tr and record information | |
706 | * about which task was the cause of this latency. | |
707 | */ | |
e309b41d | 708 | void |
bc0c38d1 SR |
709 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
710 | { | |
3928a8a2 | 711 | struct ring_buffer *buf = tr->buffer; |
bc0c38d1 | 712 | |
b8de7bd1 SR |
713 | if (trace_stop_count) |
714 | return; | |
715 | ||
4c11d7ae | 716 | WARN_ON_ONCE(!irqs_disabled()); |
ef710e10 KM |
717 | if (!current_trace->use_max_tr) { |
718 | WARN_ON_ONCE(1); | |
719 | return; | |
720 | } | |
0199c4e6 | 721 | arch_spin_lock(&ftrace_max_lock); |
3928a8a2 SR |
722 | |
723 | tr->buffer = max_tr.buffer; | |
724 | max_tr.buffer = buf; | |
725 | ||
bc0c38d1 | 726 | __update_max_tr(tr, tsk, cpu); |
0199c4e6 | 727 | arch_spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
728 | } |
729 | ||
730 | /** | |
731 | * update_max_tr_single - only copy one trace over, and reset the rest | |
732 | * @tr - tracer | |
733 | * @tsk - task with the latency | |
734 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
735 | * |
736 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 737 | */ |
e309b41d | 738 | void |
bc0c38d1 SR |
739 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
740 | { | |
3928a8a2 | 741 | int ret; |
bc0c38d1 | 742 | |
b8de7bd1 SR |
743 | if (trace_stop_count) |
744 | return; | |
745 | ||
4c11d7ae | 746 | WARN_ON_ONCE(!irqs_disabled()); |
ef710e10 KM |
747 | if (!current_trace->use_max_tr) { |
748 | WARN_ON_ONCE(1); | |
749 | return; | |
750 | } | |
751 | ||
0199c4e6 | 752 | arch_spin_lock(&ftrace_max_lock); |
bc0c38d1 | 753 | |
d769041f SR |
754 | ftrace_disable_cpu(); |
755 | ||
3928a8a2 SR |
756 | ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); |
757 | ||
e8165dbb SR |
758 | if (ret == -EBUSY) { |
759 | /* | |
760 | * We failed to swap the buffer due to a commit taking | |
761 | * place on this CPU. We fail to record, but we reset | |
762 | * the max trace buffer (no one writes directly to it) | |
763 | * and flag that it failed. | |
764 | */ | |
765 | trace_array_printk(&max_tr, _THIS_IP_, | |
766 | "Failed to swap buffers due to commit in progress\n"); | |
767 | } | |
768 | ||
d769041f SR |
769 | ftrace_enable_cpu(); |
770 | ||
e8165dbb | 771 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
bc0c38d1 SR |
772 | |
773 | __update_max_tr(tr, tsk, cpu); | |
0199c4e6 | 774 | arch_spin_unlock(&ftrace_max_lock); |
bc0c38d1 | 775 | } |
5d4a9dba | 776 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
bc0c38d1 | 777 | |
4fcdae83 SR |
778 | /** |
779 | * register_tracer - register a tracer with the ftrace system. | |
780 | * @type - the plugin for the tracer | |
781 | * | |
782 | * Register a new plugin tracer. | |
783 | */ | |
bc0c38d1 | 784 | int register_tracer(struct tracer *type) |
e7669b8e HE |
785 | __releases(kernel_lock) |
786 | __acquires(kernel_lock) | |
bc0c38d1 SR |
787 | { |
788 | struct tracer *t; | |
bc0c38d1 SR |
789 | int ret = 0; |
790 | ||
791 | if (!type->name) { | |
792 | pr_info("Tracer must have a name\n"); | |
793 | return -1; | |
794 | } | |
795 | ||
24a461d5 | 796 | if (strlen(type->name) >= MAX_TRACER_SIZE) { |
ee6c2c1b LZ |
797 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); |
798 | return -1; | |
799 | } | |
800 | ||
bc0c38d1 | 801 | mutex_lock(&trace_types_lock); |
86fa2f60 | 802 | |
8e1b82e0 FW |
803 | tracing_selftest_running = true; |
804 | ||
bc0c38d1 SR |
805 | for (t = trace_types; t; t = t->next) { |
806 | if (strcmp(type->name, t->name) == 0) { | |
807 | /* already found */ | |
ee6c2c1b | 808 | pr_info("Tracer %s already registered\n", |
bc0c38d1 SR |
809 | type->name); |
810 | ret = -1; | |
811 | goto out; | |
812 | } | |
813 | } | |
814 | ||
adf9f195 FW |
815 | if (!type->set_flag) |
816 | type->set_flag = &dummy_set_flag; | |
817 | if (!type->flags) | |
818 | type->flags = &dummy_tracer_flags; | |
819 | else | |
820 | if (!type->flags->opts) | |
821 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 FW |
822 | if (!type->wait_pipe) |
823 | type->wait_pipe = default_wait_pipe; | |
824 | ||
adf9f195 | 825 | |
60a11774 | 826 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
b2821ae6 | 827 | if (type->selftest && !tracing_selftest_disabled) { |
60a11774 | 828 | struct tracer *saved_tracer = current_trace; |
60a11774 | 829 | struct trace_array *tr = &global_trace; |
ff32504f | 830 | |
60a11774 SR |
831 | /* |
832 | * Run a selftest on this tracer. | |
833 | * Here we reset the trace buffer, and set the current | |
834 | * tracer to be this tracer. The tracer can then run some | |
835 | * internal tracing to verify that everything is in order. | |
836 | * If we fail, we do not register this tracer. | |
837 | */ | |
76f0d073 | 838 | tracing_reset_online_cpus(tr); |
86fa2f60 | 839 | |
60a11774 | 840 | current_trace = type; |
4a0b1665 SR |
841 | |
842 | /* If we expanded the buffers, make sure the max is expanded too */ | |
843 | if (ring_buffer_expanded && type->use_max_tr) | |
844 | ring_buffer_resize(max_tr.buffer, trace_buf_size); | |
845 | ||
60a11774 SR |
846 | /* the test is responsible for initializing and enabling */ |
847 | pr_info("Testing tracer %s: ", type->name); | |
848 | ret = type->selftest(type, tr); | |
849 | /* the test is responsible for resetting too */ | |
850 | current_trace = saved_tracer; | |
60a11774 SR |
851 | if (ret) { |
852 | printk(KERN_CONT "FAILED!\n"); | |
853 | goto out; | |
854 | } | |
1d4db00a | 855 | /* Only reset on passing, to avoid touching corrupted buffers */ |
76f0d073 | 856 | tracing_reset_online_cpus(tr); |
86fa2f60 | 857 | |
4a0b1665 SR |
858 | /* Shrink the max buffer again */ |
859 | if (ring_buffer_expanded && type->use_max_tr) | |
860 | ring_buffer_resize(max_tr.buffer, 1); | |
861 | ||
60a11774 SR |
862 | printk(KERN_CONT "PASSED\n"); |
863 | } | |
864 | #endif | |
865 | ||
bc0c38d1 SR |
866 | type->next = trace_types; |
867 | trace_types = type; | |
60a11774 | 868 | |
bc0c38d1 | 869 | out: |
8e1b82e0 | 870 | tracing_selftest_running = false; |
bc0c38d1 SR |
871 | mutex_unlock(&trace_types_lock); |
872 | ||
dac74940 SR |
873 | if (ret || !default_bootup_tracer) |
874 | goto out_unlock; | |
875 | ||
ee6c2c1b | 876 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
dac74940 SR |
877 | goto out_unlock; |
878 | ||
879 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
880 | /* Do we want this tracer to start on bootup? */ | |
881 | tracing_set_tracer(type->name); | |
882 | default_bootup_tracer = NULL; | |
883 | /* disable other selftests, since this will break it. */ | |
884 | tracing_selftest_disabled = 1; | |
b2821ae6 | 885 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
886 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
887 | type->name); | |
b2821ae6 | 888 | #endif |
b2821ae6 | 889 | |
dac74940 | 890 | out_unlock: |
bc0c38d1 SR |
891 | return ret; |
892 | } | |
893 | ||
894 | void unregister_tracer(struct tracer *type) | |
895 | { | |
896 | struct tracer **t; | |
bc0c38d1 SR |
897 | |
898 | mutex_lock(&trace_types_lock); | |
899 | for (t = &trace_types; *t; t = &(*t)->next) { | |
900 | if (*t == type) | |
901 | goto found; | |
902 | } | |
ee6c2c1b | 903 | pr_info("Tracer %s not registered\n", type->name); |
bc0c38d1 SR |
904 | goto out; |
905 | ||
906 | found: | |
907 | *t = (*t)->next; | |
b5db03c4 ACM |
908 | |
909 | if (type == current_trace && tracer_enabled) { | |
910 | tracer_enabled = 0; | |
911 | tracing_stop(); | |
912 | if (current_trace->stop) | |
913 | current_trace->stop(&global_trace); | |
914 | current_trace = &nop_trace; | |
915 | } | |
ee6c2c1b | 916 | out: |
bc0c38d1 SR |
917 | mutex_unlock(&trace_types_lock); |
918 | } | |
919 | ||
283740c6 | 920 | static void __tracing_reset(struct ring_buffer *buffer, int cpu) |
bc0c38d1 | 921 | { |
d769041f | 922 | ftrace_disable_cpu(); |
283740c6 | 923 | ring_buffer_reset_cpu(buffer, cpu); |
d769041f | 924 | ftrace_enable_cpu(); |
bc0c38d1 SR |
925 | } |
926 | ||
f633903a SR |
927 | void tracing_reset(struct trace_array *tr, int cpu) |
928 | { | |
929 | struct ring_buffer *buffer = tr->buffer; | |
930 | ||
931 | ring_buffer_record_disable(buffer); | |
932 | ||
933 | /* Make sure all commits have finished */ | |
934 | synchronize_sched(); | |
283740c6 | 935 | __tracing_reset(buffer, cpu); |
f633903a SR |
936 | |
937 | ring_buffer_record_enable(buffer); | |
938 | } | |
939 | ||
213cc060 PE |
940 | void tracing_reset_online_cpus(struct trace_array *tr) |
941 | { | |
621968cd | 942 | struct ring_buffer *buffer = tr->buffer; |
213cc060 PE |
943 | int cpu; |
944 | ||
621968cd SR |
945 | ring_buffer_record_disable(buffer); |
946 | ||
947 | /* Make sure all commits have finished */ | |
948 | synchronize_sched(); | |
949 | ||
213cc060 PE |
950 | tr->time_start = ftrace_now(tr->cpu); |
951 | ||
952 | for_each_online_cpu(cpu) | |
283740c6 | 953 | __tracing_reset(buffer, cpu); |
621968cd SR |
954 | |
955 | ring_buffer_record_enable(buffer); | |
213cc060 PE |
956 | } |
957 | ||
9456f0fa SR |
958 | void tracing_reset_current(int cpu) |
959 | { | |
960 | tracing_reset(&global_trace, cpu); | |
961 | } | |
962 | ||
963 | void tracing_reset_current_online_cpus(void) | |
964 | { | |
965 | tracing_reset_online_cpus(&global_trace); | |
966 | } | |
967 | ||
bc0c38d1 | 968 | #define SAVED_CMDLINES 128 |
2c7eea4c | 969 | #define NO_CMDLINE_MAP UINT_MAX |
bc0c38d1 SR |
970 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; |
971 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
972 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
973 | static int cmdline_idx; | |
edc35bd7 | 974 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
25b0b44a | 975 | |
25b0b44a | 976 | /* temporary disable recording */ |
4fd27358 | 977 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 SR |
978 | |
979 | static void trace_init_cmdlines(void) | |
980 | { | |
2c7eea4c TG |
981 | memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); |
982 | memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); | |
bc0c38d1 SR |
983 | cmdline_idx = 0; |
984 | } | |
985 | ||
b5130b1e CE |
986 | int is_tracing_stopped(void) |
987 | { | |
988 | return trace_stop_count; | |
989 | } | |
990 | ||
69bb54ec SR |
991 | /** |
992 | * ftrace_off_permanent - disable all ftrace code permanently | |
993 | * | |
994 | * This should only be called when a serious anomally has | |
995 | * been detected. This will turn off the function tracing, | |
996 | * ring buffers, and other tracing utilites. It takes no | |
997 | * locks and can be called from any context. | |
998 | */ | |
999 | void ftrace_off_permanent(void) | |
1000 | { | |
1001 | tracing_disabled = 1; | |
1002 | ftrace_stop(); | |
1003 | tracing_off_permanent(); | |
1004 | } | |
1005 | ||
0f048701 SR |
1006 | /** |
1007 | * tracing_start - quick start of the tracer | |
1008 | * | |
1009 | * If tracing is enabled but was stopped by tracing_stop, | |
1010 | * this will start the tracer back up. | |
1011 | */ | |
1012 | void tracing_start(void) | |
1013 | { | |
1014 | struct ring_buffer *buffer; | |
1015 | unsigned long flags; | |
1016 | ||
1017 | if (tracing_disabled) | |
1018 | return; | |
1019 | ||
5389f6fa | 1020 | raw_spin_lock_irqsave(&tracing_start_lock, flags); |
b06a8301 SR |
1021 | if (--trace_stop_count) { |
1022 | if (trace_stop_count < 0) { | |
1023 | /* Someone screwed up their debugging */ | |
1024 | WARN_ON_ONCE(1); | |
1025 | trace_stop_count = 0; | |
1026 | } | |
0f048701 SR |
1027 | goto out; |
1028 | } | |
1029 | ||
a2f80714 SR |
1030 | /* Prevent the buffers from switching */ |
1031 | arch_spin_lock(&ftrace_max_lock); | |
0f048701 SR |
1032 | |
1033 | buffer = global_trace.buffer; | |
1034 | if (buffer) | |
1035 | ring_buffer_record_enable(buffer); | |
1036 | ||
1037 | buffer = max_tr.buffer; | |
1038 | if (buffer) | |
1039 | ring_buffer_record_enable(buffer); | |
1040 | ||
a2f80714 SR |
1041 | arch_spin_unlock(&ftrace_max_lock); |
1042 | ||
0f048701 SR |
1043 | ftrace_start(); |
1044 | out: | |
5389f6fa | 1045 | raw_spin_unlock_irqrestore(&tracing_start_lock, flags); |
0f048701 SR |
1046 | } |
1047 | ||
1048 | /** | |
1049 | * tracing_stop - quick stop of the tracer | |
1050 | * | |
1051 | * Light weight way to stop tracing. Use in conjunction with | |
1052 | * tracing_start. | |
1053 | */ | |
1054 | void tracing_stop(void) | |
1055 | { | |
1056 | struct ring_buffer *buffer; | |
1057 | unsigned long flags; | |
1058 | ||
1059 | ftrace_stop(); | |
5389f6fa | 1060 | raw_spin_lock_irqsave(&tracing_start_lock, flags); |
0f048701 SR |
1061 | if (trace_stop_count++) |
1062 | goto out; | |
1063 | ||
a2f80714 SR |
1064 | /* Prevent the buffers from switching */ |
1065 | arch_spin_lock(&ftrace_max_lock); | |
1066 | ||
0f048701 SR |
1067 | buffer = global_trace.buffer; |
1068 | if (buffer) | |
1069 | ring_buffer_record_disable(buffer); | |
1070 | ||
1071 | buffer = max_tr.buffer; | |
1072 | if (buffer) | |
1073 | ring_buffer_record_disable(buffer); | |
1074 | ||
a2f80714 SR |
1075 | arch_spin_unlock(&ftrace_max_lock); |
1076 | ||
0f048701 | 1077 | out: |
5389f6fa | 1078 | raw_spin_unlock_irqrestore(&tracing_start_lock, flags); |
0f048701 SR |
1079 | } |
1080 | ||
e309b41d | 1081 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 1082 | |
e309b41d | 1083 | static void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1084 | { |
a635cf04 | 1085 | unsigned pid, idx; |
bc0c38d1 SR |
1086 | |
1087 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
1088 | return; | |
1089 | ||
1090 | /* | |
1091 | * It's not the end of the world if we don't get | |
1092 | * the lock, but we also don't want to spin | |
1093 | * nor do we want to disable interrupts, | |
1094 | * so if we miss here, then better luck next time. | |
1095 | */ | |
0199c4e6 | 1096 | if (!arch_spin_trylock(&trace_cmdline_lock)) |
bc0c38d1 SR |
1097 | return; |
1098 | ||
1099 | idx = map_pid_to_cmdline[tsk->pid]; | |
2c7eea4c | 1100 | if (idx == NO_CMDLINE_MAP) { |
bc0c38d1 SR |
1101 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; |
1102 | ||
a635cf04 CE |
1103 | /* |
1104 | * Check whether the cmdline buffer at idx has a pid | |
1105 | * mapped. We are going to overwrite that entry so we | |
1106 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1107 | * would read the new comm for the old pid. | |
1108 | */ | |
1109 | pid = map_cmdline_to_pid[idx]; | |
1110 | if (pid != NO_CMDLINE_MAP) | |
1111 | map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; | |
bc0c38d1 | 1112 | |
a635cf04 | 1113 | map_cmdline_to_pid[idx] = tsk->pid; |
bc0c38d1 SR |
1114 | map_pid_to_cmdline[tsk->pid] = idx; |
1115 | ||
1116 | cmdline_idx = idx; | |
1117 | } | |
1118 | ||
1119 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
1120 | ||
0199c4e6 | 1121 | arch_spin_unlock(&trace_cmdline_lock); |
bc0c38d1 SR |
1122 | } |
1123 | ||
4ca53085 | 1124 | void trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 1125 | { |
bc0c38d1 SR |
1126 | unsigned map; |
1127 | ||
4ca53085 SR |
1128 | if (!pid) { |
1129 | strcpy(comm, "<idle>"); | |
1130 | return; | |
1131 | } | |
bc0c38d1 | 1132 | |
74bf4076 SR |
1133 | if (WARN_ON_ONCE(pid < 0)) { |
1134 | strcpy(comm, "<XXX>"); | |
1135 | return; | |
1136 | } | |
1137 | ||
4ca53085 SR |
1138 | if (pid > PID_MAX_DEFAULT) { |
1139 | strcpy(comm, "<...>"); | |
1140 | return; | |
1141 | } | |
bc0c38d1 | 1142 | |
5b6045a9 | 1143 | preempt_disable(); |
0199c4e6 | 1144 | arch_spin_lock(&trace_cmdline_lock); |
bc0c38d1 | 1145 | map = map_pid_to_cmdline[pid]; |
50d88758 TG |
1146 | if (map != NO_CMDLINE_MAP) |
1147 | strcpy(comm, saved_cmdlines[map]); | |
1148 | else | |
1149 | strcpy(comm, "<...>"); | |
bc0c38d1 | 1150 | |
0199c4e6 | 1151 | arch_spin_unlock(&trace_cmdline_lock); |
5b6045a9 | 1152 | preempt_enable(); |
bc0c38d1 SR |
1153 | } |
1154 | ||
e309b41d | 1155 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1156 | { |
18aecd36 TG |
1157 | if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled || |
1158 | !tracing_is_on()) | |
bc0c38d1 SR |
1159 | return; |
1160 | ||
1161 | trace_save_cmdline(tsk); | |
1162 | } | |
1163 | ||
45dcd8b8 | 1164 | void |
38697053 SR |
1165 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
1166 | int pc) | |
bc0c38d1 SR |
1167 | { |
1168 | struct task_struct *tsk = current; | |
bc0c38d1 | 1169 | |
777e208d SR |
1170 | entry->preempt_count = pc & 0xff; |
1171 | entry->pid = (tsk) ? tsk->pid : 0; | |
a3a4a5ac | 1172 | entry->padding = 0; |
777e208d | 1173 | entry->flags = |
9244489a | 1174 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 1175 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
1176 | #else |
1177 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1178 | #endif | |
bc0c38d1 SR |
1179 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
1180 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
1181 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
1182 | } | |
f413cdb8 | 1183 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); |
bc0c38d1 | 1184 | |
e77405ad SR |
1185 | struct ring_buffer_event * |
1186 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1187 | int type, | |
1188 | unsigned long len, | |
1189 | unsigned long flags, int pc) | |
51a763dd ACM |
1190 | { |
1191 | struct ring_buffer_event *event; | |
1192 | ||
e77405ad | 1193 | event = ring_buffer_lock_reserve(buffer, len); |
51a763dd ACM |
1194 | if (event != NULL) { |
1195 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1196 | ||
1197 | tracing_generic_entry_update(ent, flags, pc); | |
1198 | ent->type = type; | |
1199 | } | |
1200 | ||
1201 | return event; | |
1202 | } | |
51a763dd | 1203 | |
e77405ad SR |
1204 | static inline void |
1205 | __trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1206 | struct ring_buffer_event *event, | |
1207 | unsigned long flags, int pc, | |
1208 | int wake) | |
51a763dd | 1209 | { |
e77405ad | 1210 | ring_buffer_unlock_commit(buffer, event); |
51a763dd | 1211 | |
e77405ad SR |
1212 | ftrace_trace_stack(buffer, flags, 6, pc); |
1213 | ftrace_trace_userstack(buffer, flags, pc); | |
07edf712 FW |
1214 | |
1215 | if (wake) | |
1216 | trace_wake_up(); | |
1217 | } | |
1218 | ||
e77405ad SR |
1219 | void trace_buffer_unlock_commit(struct ring_buffer *buffer, |
1220 | struct ring_buffer_event *event, | |
1221 | unsigned long flags, int pc) | |
07edf712 | 1222 | { |
e77405ad | 1223 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 1); |
51a763dd ACM |
1224 | } |
1225 | ||
ef5580d0 | 1226 | struct ring_buffer_event * |
e77405ad SR |
1227 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, |
1228 | int type, unsigned long len, | |
ef5580d0 SR |
1229 | unsigned long flags, int pc) |
1230 | { | |
e77405ad SR |
1231 | *current_rb = global_trace.buffer; |
1232 | return trace_buffer_lock_reserve(*current_rb, | |
ef5580d0 SR |
1233 | type, len, flags, pc); |
1234 | } | |
94487d6d | 1235 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); |
ef5580d0 | 1236 | |
e77405ad SR |
1237 | void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, |
1238 | struct ring_buffer_event *event, | |
ef5580d0 SR |
1239 | unsigned long flags, int pc) |
1240 | { | |
e77405ad | 1241 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 1); |
07edf712 | 1242 | } |
94487d6d | 1243 | EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit); |
07edf712 | 1244 | |
e77405ad SR |
1245 | void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer, |
1246 | struct ring_buffer_event *event, | |
1247 | unsigned long flags, int pc) | |
07edf712 | 1248 | { |
e77405ad | 1249 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 0); |
77d9f465 | 1250 | } |
94487d6d | 1251 | EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit); |
77d9f465 | 1252 | |
1fd8df2c MH |
1253 | void trace_nowake_buffer_unlock_commit_regs(struct ring_buffer *buffer, |
1254 | struct ring_buffer_event *event, | |
1255 | unsigned long flags, int pc, | |
1256 | struct pt_regs *regs) | |
1257 | { | |
1258 | ring_buffer_unlock_commit(buffer, event); | |
1259 | ||
1260 | ftrace_trace_stack_regs(buffer, flags, 0, pc, regs); | |
1261 | ftrace_trace_userstack(buffer, flags, pc); | |
1262 | } | |
1263 | EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit_regs); | |
1264 | ||
e77405ad SR |
1265 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, |
1266 | struct ring_buffer_event *event) | |
77d9f465 | 1267 | { |
e77405ad | 1268 | ring_buffer_discard_commit(buffer, event); |
ef5580d0 | 1269 | } |
12acd473 | 1270 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); |
ef5580d0 | 1271 | |
e309b41d | 1272 | void |
7be42151 | 1273 | trace_function(struct trace_array *tr, |
38697053 SR |
1274 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1275 | int pc) | |
bc0c38d1 | 1276 | { |
e1112b4d | 1277 | struct ftrace_event_call *call = &event_function; |
e77405ad | 1278 | struct ring_buffer *buffer = tr->buffer; |
3928a8a2 | 1279 | struct ring_buffer_event *event; |
777e208d | 1280 | struct ftrace_entry *entry; |
bc0c38d1 | 1281 | |
d769041f | 1282 | /* If we are reading the ring buffer, don't trace */ |
dd17c8f7 | 1283 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) |
d769041f SR |
1284 | return; |
1285 | ||
e77405ad | 1286 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
51a763dd | 1287 | flags, pc); |
3928a8a2 SR |
1288 | if (!event) |
1289 | return; | |
1290 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1291 | entry->ip = ip; |
1292 | entry->parent_ip = parent_ip; | |
e1112b4d | 1293 | |
e77405ad SR |
1294 | if (!filter_check_discard(call, entry, buffer, event)) |
1295 | ring_buffer_unlock_commit(buffer, event); | |
bc0c38d1 SR |
1296 | } |
1297 | ||
e309b41d | 1298 | void |
2e0f5761 | 1299 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, |
38697053 SR |
1300 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1301 | int pc) | |
2e0f5761 IM |
1302 | { |
1303 | if (likely(!atomic_read(&data->disabled))) | |
7be42151 | 1304 | trace_function(tr, ip, parent_ip, flags, pc); |
2e0f5761 IM |
1305 | } |
1306 | ||
c0a0d0d3 | 1307 | #ifdef CONFIG_STACKTRACE |
4a9bd3f1 SR |
1308 | |
1309 | #define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) | |
1310 | struct ftrace_stack { | |
1311 | unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; | |
1312 | }; | |
1313 | ||
1314 | static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); | |
1315 | static DEFINE_PER_CPU(int, ftrace_stack_reserve); | |
1316 | ||
e77405ad | 1317 | static void __ftrace_trace_stack(struct ring_buffer *buffer, |
53614991 | 1318 | unsigned long flags, |
1fd8df2c | 1319 | int skip, int pc, struct pt_regs *regs) |
86387f7e | 1320 | { |
e1112b4d | 1321 | struct ftrace_event_call *call = &event_kernel_stack; |
3928a8a2 | 1322 | struct ring_buffer_event *event; |
777e208d | 1323 | struct stack_entry *entry; |
86387f7e | 1324 | struct stack_trace trace; |
4a9bd3f1 SR |
1325 | int use_stack; |
1326 | int size = FTRACE_STACK_ENTRIES; | |
1327 | ||
1328 | trace.nr_entries = 0; | |
1329 | trace.skip = skip; | |
1330 | ||
1331 | /* | |
1332 | * Since events can happen in NMIs there's no safe way to | |
1333 | * use the per cpu ftrace_stacks. We reserve it and if an interrupt | |
1334 | * or NMI comes in, it will just have to use the default | |
1335 | * FTRACE_STACK_SIZE. | |
1336 | */ | |
1337 | preempt_disable_notrace(); | |
1338 | ||
1339 | use_stack = ++__get_cpu_var(ftrace_stack_reserve); | |
1340 | /* | |
1341 | * We don't need any atomic variables, just a barrier. | |
1342 | * If an interrupt comes in, we don't care, because it would | |
1343 | * have exited and put the counter back to what we want. | |
1344 | * We just need a barrier to keep gcc from moving things | |
1345 | * around. | |
1346 | */ | |
1347 | barrier(); | |
1348 | if (use_stack == 1) { | |
1349 | trace.entries = &__get_cpu_var(ftrace_stack).calls[0]; | |
1350 | trace.max_entries = FTRACE_STACK_MAX_ENTRIES; | |
1351 | ||
1352 | if (regs) | |
1353 | save_stack_trace_regs(regs, &trace); | |
1354 | else | |
1355 | save_stack_trace(&trace); | |
1356 | ||
1357 | if (trace.nr_entries > size) | |
1358 | size = trace.nr_entries; | |
1359 | } else | |
1360 | /* From now on, use_stack is a boolean */ | |
1361 | use_stack = 0; | |
1362 | ||
1363 | size *= sizeof(unsigned long); | |
86387f7e | 1364 | |
e77405ad | 1365 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, |
4a9bd3f1 | 1366 | sizeof(*entry) + size, flags, pc); |
3928a8a2 | 1367 | if (!event) |
4a9bd3f1 SR |
1368 | goto out; |
1369 | entry = ring_buffer_event_data(event); | |
86387f7e | 1370 | |
4a9bd3f1 SR |
1371 | memset(&entry->caller, 0, size); |
1372 | ||
1373 | if (use_stack) | |
1374 | memcpy(&entry->caller, trace.entries, | |
1375 | trace.nr_entries * sizeof(unsigned long)); | |
1376 | else { | |
1377 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1378 | trace.entries = entry->caller; | |
1379 | if (regs) | |
1380 | save_stack_trace_regs(regs, &trace); | |
1381 | else | |
1382 | save_stack_trace(&trace); | |
1383 | } | |
1384 | ||
1385 | entry->size = trace.nr_entries; | |
86387f7e | 1386 | |
e77405ad SR |
1387 | if (!filter_check_discard(call, entry, buffer, event)) |
1388 | ring_buffer_unlock_commit(buffer, event); | |
4a9bd3f1 SR |
1389 | |
1390 | out: | |
1391 | /* Again, don't let gcc optimize things here */ | |
1392 | barrier(); | |
1393 | __get_cpu_var(ftrace_stack_reserve)--; | |
1394 | preempt_enable_notrace(); | |
1395 | ||
f0a920d5 IM |
1396 | } |
1397 | ||
1fd8df2c MH |
1398 | void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags, |
1399 | int skip, int pc, struct pt_regs *regs) | |
1400 | { | |
1401 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1402 | return; | |
1403 | ||
1404 | __ftrace_trace_stack(buffer, flags, skip, pc, regs); | |
1405 | } | |
1406 | ||
e77405ad SR |
1407 | void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, |
1408 | int skip, int pc) | |
53614991 SR |
1409 | { |
1410 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1411 | return; | |
1412 | ||
1fd8df2c | 1413 | __ftrace_trace_stack(buffer, flags, skip, pc, NULL); |
53614991 SR |
1414 | } |
1415 | ||
c0a0d0d3 FW |
1416 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, |
1417 | int pc) | |
38697053 | 1418 | { |
1fd8df2c | 1419 | __ftrace_trace_stack(tr->buffer, flags, skip, pc, NULL); |
38697053 SR |
1420 | } |
1421 | ||
03889384 SR |
1422 | /** |
1423 | * trace_dump_stack - record a stack back trace in the trace buffer | |
1424 | */ | |
1425 | void trace_dump_stack(void) | |
1426 | { | |
1427 | unsigned long flags; | |
1428 | ||
1429 | if (tracing_disabled || tracing_selftest_running) | |
e36c5458 | 1430 | return; |
03889384 SR |
1431 | |
1432 | local_save_flags(flags); | |
1433 | ||
1434 | /* skipping 3 traces, seems to get us at the caller of this function */ | |
1fd8df2c | 1435 | __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count(), NULL); |
03889384 SR |
1436 | } |
1437 | ||
91e86e56 SR |
1438 | static DEFINE_PER_CPU(int, user_stack_count); |
1439 | ||
e77405ad SR |
1440 | void |
1441 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
02b67518 | 1442 | { |
e1112b4d | 1443 | struct ftrace_event_call *call = &event_user_stack; |
8d7c6a96 | 1444 | struct ring_buffer_event *event; |
02b67518 TE |
1445 | struct userstack_entry *entry; |
1446 | struct stack_trace trace; | |
02b67518 TE |
1447 | |
1448 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1449 | return; | |
1450 | ||
b6345879 SR |
1451 | /* |
1452 | * NMIs can not handle page faults, even with fix ups. | |
1453 | * The save user stack can (and often does) fault. | |
1454 | */ | |
1455 | if (unlikely(in_nmi())) | |
1456 | return; | |
02b67518 | 1457 | |
91e86e56 SR |
1458 | /* |
1459 | * prevent recursion, since the user stack tracing may | |
1460 | * trigger other kernel events. | |
1461 | */ | |
1462 | preempt_disable(); | |
1463 | if (__this_cpu_read(user_stack_count)) | |
1464 | goto out; | |
1465 | ||
1466 | __this_cpu_inc(user_stack_count); | |
1467 | ||
e77405ad | 1468 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
51a763dd | 1469 | sizeof(*entry), flags, pc); |
02b67518 | 1470 | if (!event) |
1dbd1951 | 1471 | goto out_drop_count; |
02b67518 | 1472 | entry = ring_buffer_event_data(event); |
02b67518 | 1473 | |
48659d31 | 1474 | entry->tgid = current->tgid; |
02b67518 TE |
1475 | memset(&entry->caller, 0, sizeof(entry->caller)); |
1476 | ||
1477 | trace.nr_entries = 0; | |
1478 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1479 | trace.skip = 0; | |
1480 | trace.entries = entry->caller; | |
1481 | ||
1482 | save_stack_trace_user(&trace); | |
e77405ad SR |
1483 | if (!filter_check_discard(call, entry, buffer, event)) |
1484 | ring_buffer_unlock_commit(buffer, event); | |
91e86e56 | 1485 | |
1dbd1951 | 1486 | out_drop_count: |
91e86e56 | 1487 | __this_cpu_dec(user_stack_count); |
91e86e56 SR |
1488 | out: |
1489 | preempt_enable(); | |
02b67518 TE |
1490 | } |
1491 | ||
4fd27358 HE |
1492 | #ifdef UNUSED |
1493 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1494 | { |
7be42151 | 1495 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1496 | } |
4fd27358 | 1497 | #endif /* UNUSED */ |
02b67518 | 1498 | |
c0a0d0d3 FW |
1499 | #endif /* CONFIG_STACKTRACE */ |
1500 | ||
769b0441 | 1501 | /** |
48ead020 | 1502 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
1503 | * |
1504 | */ | |
40ce74f1 | 1505 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 1506 | { |
445c8951 | 1507 | static arch_spinlock_t trace_buf_lock = |
edc35bd7 | 1508 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
769b0441 FW |
1509 | static u32 trace_buf[TRACE_BUF_SIZE]; |
1510 | ||
e1112b4d | 1511 | struct ftrace_event_call *call = &event_bprint; |
769b0441 | 1512 | struct ring_buffer_event *event; |
e77405ad | 1513 | struct ring_buffer *buffer; |
769b0441 FW |
1514 | struct trace_array *tr = &global_trace; |
1515 | struct trace_array_cpu *data; | |
48ead020 | 1516 | struct bprint_entry *entry; |
769b0441 | 1517 | unsigned long flags; |
3189cdb3 | 1518 | int disable; |
769b0441 FW |
1519 | int cpu, len = 0, size, pc; |
1520 | ||
1521 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
1522 | return 0; | |
1523 | ||
1524 | /* Don't pollute graph traces with trace_vprintk internals */ | |
1525 | pause_graph_tracing(); | |
1526 | ||
1527 | pc = preempt_count(); | |
5168ae50 | 1528 | preempt_disable_notrace(); |
769b0441 FW |
1529 | cpu = raw_smp_processor_id(); |
1530 | data = tr->data[cpu]; | |
1531 | ||
3189cdb3 SR |
1532 | disable = atomic_inc_return(&data->disabled); |
1533 | if (unlikely(disable != 1)) | |
769b0441 FW |
1534 | goto out; |
1535 | ||
80370cb7 SR |
1536 | /* Lockdep uses trace_printk for lock tracing */ |
1537 | local_irq_save(flags); | |
0199c4e6 | 1538 | arch_spin_lock(&trace_buf_lock); |
769b0441 FW |
1539 | len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); |
1540 | ||
1541 | if (len > TRACE_BUF_SIZE || len < 0) | |
1542 | goto out_unlock; | |
1543 | ||
1544 | size = sizeof(*entry) + sizeof(u32) * len; | |
e77405ad SR |
1545 | buffer = tr->buffer; |
1546 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, | |
1547 | flags, pc); | |
769b0441 FW |
1548 | if (!event) |
1549 | goto out_unlock; | |
1550 | entry = ring_buffer_event_data(event); | |
1551 | entry->ip = ip; | |
769b0441 FW |
1552 | entry->fmt = fmt; |
1553 | ||
1554 | memcpy(entry->buf, trace_buf, sizeof(u32) * len); | |
d931369b | 1555 | if (!filter_check_discard(call, entry, buffer, event)) { |
e77405ad | 1556 | ring_buffer_unlock_commit(buffer, event); |
d931369b SR |
1557 | ftrace_trace_stack(buffer, flags, 6, pc); |
1558 | } | |
769b0441 FW |
1559 | |
1560 | out_unlock: | |
0199c4e6 | 1561 | arch_spin_unlock(&trace_buf_lock); |
80370cb7 | 1562 | local_irq_restore(flags); |
769b0441 FW |
1563 | |
1564 | out: | |
3189cdb3 | 1565 | atomic_dec_return(&data->disabled); |
5168ae50 | 1566 | preempt_enable_notrace(); |
769b0441 FW |
1567 | unpause_graph_tracing(); |
1568 | ||
1569 | return len; | |
1570 | } | |
48ead020 FW |
1571 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
1572 | ||
659372d3 SR |
1573 | int trace_array_printk(struct trace_array *tr, |
1574 | unsigned long ip, const char *fmt, ...) | |
1575 | { | |
1576 | int ret; | |
1577 | va_list ap; | |
1578 | ||
1579 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
1580 | return 0; | |
1581 | ||
1582 | va_start(ap, fmt); | |
1583 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
1584 | va_end(ap); | |
1585 | return ret; | |
1586 | } | |
1587 | ||
1588 | int trace_array_vprintk(struct trace_array *tr, | |
1589 | unsigned long ip, const char *fmt, va_list args) | |
48ead020 | 1590 | { |
edc35bd7 | 1591 | static arch_spinlock_t trace_buf_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
48ead020 FW |
1592 | static char trace_buf[TRACE_BUF_SIZE]; |
1593 | ||
e1112b4d | 1594 | struct ftrace_event_call *call = &event_print; |
48ead020 | 1595 | struct ring_buffer_event *event; |
e77405ad | 1596 | struct ring_buffer *buffer; |
48ead020 FW |
1597 | struct trace_array_cpu *data; |
1598 | int cpu, len = 0, size, pc; | |
1599 | struct print_entry *entry; | |
1600 | unsigned long irq_flags; | |
3189cdb3 | 1601 | int disable; |
48ead020 FW |
1602 | |
1603 | if (tracing_disabled || tracing_selftest_running) | |
1604 | return 0; | |
1605 | ||
1606 | pc = preempt_count(); | |
1607 | preempt_disable_notrace(); | |
1608 | cpu = raw_smp_processor_id(); | |
1609 | data = tr->data[cpu]; | |
1610 | ||
3189cdb3 SR |
1611 | disable = atomic_inc_return(&data->disabled); |
1612 | if (unlikely(disable != 1)) | |
48ead020 FW |
1613 | goto out; |
1614 | ||
1615 | pause_graph_tracing(); | |
1616 | raw_local_irq_save(irq_flags); | |
0199c4e6 | 1617 | arch_spin_lock(&trace_buf_lock); |
f2942487 | 1618 | len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); |
48ead020 FW |
1619 | |
1620 | size = sizeof(*entry) + len + 1; | |
e77405ad SR |
1621 | buffer = tr->buffer; |
1622 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
1623 | irq_flags, pc); | |
48ead020 FW |
1624 | if (!event) |
1625 | goto out_unlock; | |
1626 | entry = ring_buffer_event_data(event); | |
c13d2f7c | 1627 | entry->ip = ip; |
48ead020 FW |
1628 | |
1629 | memcpy(&entry->buf, trace_buf, len); | |
c13d2f7c | 1630 | entry->buf[len] = '\0'; |
d931369b | 1631 | if (!filter_check_discard(call, entry, buffer, event)) { |
e77405ad | 1632 | ring_buffer_unlock_commit(buffer, event); |
d931369b SR |
1633 | ftrace_trace_stack(buffer, irq_flags, 6, pc); |
1634 | } | |
48ead020 FW |
1635 | |
1636 | out_unlock: | |
0199c4e6 | 1637 | arch_spin_unlock(&trace_buf_lock); |
48ead020 FW |
1638 | raw_local_irq_restore(irq_flags); |
1639 | unpause_graph_tracing(); | |
1640 | out: | |
3189cdb3 | 1641 | atomic_dec_return(&data->disabled); |
48ead020 FW |
1642 | preempt_enable_notrace(); |
1643 | ||
1644 | return len; | |
1645 | } | |
659372d3 SR |
1646 | |
1647 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) | |
1648 | { | |
a813a159 | 1649 | return trace_array_vprintk(&global_trace, ip, fmt, args); |
659372d3 | 1650 | } |
769b0441 FW |
1651 | EXPORT_SYMBOL_GPL(trace_vprintk); |
1652 | ||
e2ac8ef5 | 1653 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 1654 | { |
d769041f SR |
1655 | /* Don't allow ftrace to trace into the ring buffers */ |
1656 | ftrace_disable_cpu(); | |
1657 | ||
5a90f577 | 1658 | iter->idx++; |
d769041f SR |
1659 | if (iter->buffer_iter[iter->cpu]) |
1660 | ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); | |
1661 | ||
1662 | ftrace_enable_cpu(); | |
5a90f577 SR |
1663 | } |
1664 | ||
e309b41d | 1665 | static struct trace_entry * |
bc21b478 SR |
1666 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, |
1667 | unsigned long *lost_events) | |
dd0e545f | 1668 | { |
3928a8a2 SR |
1669 | struct ring_buffer_event *event; |
1670 | struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; | |
dd0e545f | 1671 | |
d769041f SR |
1672 | /* Don't allow ftrace to trace into the ring buffers */ |
1673 | ftrace_disable_cpu(); | |
1674 | ||
1675 | if (buf_iter) | |
1676 | event = ring_buffer_iter_peek(buf_iter, ts); | |
1677 | else | |
bc21b478 SR |
1678 | event = ring_buffer_peek(iter->tr->buffer, cpu, ts, |
1679 | lost_events); | |
d769041f SR |
1680 | |
1681 | ftrace_enable_cpu(); | |
1682 | ||
4a9bd3f1 SR |
1683 | if (event) { |
1684 | iter->ent_size = ring_buffer_event_length(event); | |
1685 | return ring_buffer_event_data(event); | |
1686 | } | |
1687 | iter->ent_size = 0; | |
1688 | return NULL; | |
dd0e545f | 1689 | } |
d769041f | 1690 | |
dd0e545f | 1691 | static struct trace_entry * |
bc21b478 SR |
1692 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, |
1693 | unsigned long *missing_events, u64 *ent_ts) | |
bc0c38d1 | 1694 | { |
3928a8a2 | 1695 | struct ring_buffer *buffer = iter->tr->buffer; |
bc0c38d1 | 1696 | struct trace_entry *ent, *next = NULL; |
aa27497c | 1697 | unsigned long lost_events = 0, next_lost = 0; |
b04cc6b1 | 1698 | int cpu_file = iter->cpu_file; |
3928a8a2 | 1699 | u64 next_ts = 0, ts; |
bc0c38d1 SR |
1700 | int next_cpu = -1; |
1701 | int cpu; | |
1702 | ||
b04cc6b1 FW |
1703 | /* |
1704 | * If we are in a per_cpu trace file, don't bother by iterating over | |
1705 | * all cpu and peek directly. | |
1706 | */ | |
1707 | if (cpu_file > TRACE_PIPE_ALL_CPU) { | |
1708 | if (ring_buffer_empty_cpu(buffer, cpu_file)) | |
1709 | return NULL; | |
bc21b478 | 1710 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); |
b04cc6b1 FW |
1711 | if (ent_cpu) |
1712 | *ent_cpu = cpu_file; | |
1713 | ||
1714 | return ent; | |
1715 | } | |
1716 | ||
ab46428c | 1717 | for_each_tracing_cpu(cpu) { |
dd0e545f | 1718 | |
3928a8a2 SR |
1719 | if (ring_buffer_empty_cpu(buffer, cpu)) |
1720 | continue; | |
dd0e545f | 1721 | |
bc21b478 | 1722 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); |
dd0e545f | 1723 | |
cdd31cd2 IM |
1724 | /* |
1725 | * Pick the entry with the smallest timestamp: | |
1726 | */ | |
3928a8a2 | 1727 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
1728 | next = ent; |
1729 | next_cpu = cpu; | |
3928a8a2 | 1730 | next_ts = ts; |
bc21b478 | 1731 | next_lost = lost_events; |
bc0c38d1 SR |
1732 | } |
1733 | } | |
1734 | ||
1735 | if (ent_cpu) | |
1736 | *ent_cpu = next_cpu; | |
1737 | ||
3928a8a2 SR |
1738 | if (ent_ts) |
1739 | *ent_ts = next_ts; | |
1740 | ||
bc21b478 SR |
1741 | if (missing_events) |
1742 | *missing_events = next_lost; | |
1743 | ||
bc0c38d1 SR |
1744 | return next; |
1745 | } | |
1746 | ||
dd0e545f | 1747 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
1748 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
1749 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 1750 | { |
bc21b478 | 1751 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); |
dd0e545f SR |
1752 | } |
1753 | ||
1754 | /* Find the next real entry, and increment the iterator to the next entry */ | |
955b61e5 | 1755 | void *trace_find_next_entry_inc(struct trace_iterator *iter) |
dd0e545f | 1756 | { |
bc21b478 SR |
1757 | iter->ent = __find_next_entry(iter, &iter->cpu, |
1758 | &iter->lost_events, &iter->ts); | |
dd0e545f | 1759 | |
3928a8a2 | 1760 | if (iter->ent) |
e2ac8ef5 | 1761 | trace_iterator_increment(iter); |
dd0e545f | 1762 | |
3928a8a2 | 1763 | return iter->ent ? iter : NULL; |
b3806b43 | 1764 | } |
bc0c38d1 | 1765 | |
e309b41d | 1766 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 1767 | { |
d769041f SR |
1768 | /* Don't allow ftrace to trace into the ring buffers */ |
1769 | ftrace_disable_cpu(); | |
bc21b478 SR |
1770 | ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, |
1771 | &iter->lost_events); | |
d769041f | 1772 | ftrace_enable_cpu(); |
bc0c38d1 SR |
1773 | } |
1774 | ||
e309b41d | 1775 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
1776 | { |
1777 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 1778 | int i = (int)*pos; |
4e3c3333 | 1779 | void *ent; |
bc0c38d1 | 1780 | |
a63ce5b3 SR |
1781 | WARN_ON_ONCE(iter->leftover); |
1782 | ||
bc0c38d1 SR |
1783 | (*pos)++; |
1784 | ||
1785 | /* can't go backwards */ | |
1786 | if (iter->idx > i) | |
1787 | return NULL; | |
1788 | ||
1789 | if (iter->idx < 0) | |
955b61e5 | 1790 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
1791 | else |
1792 | ent = iter; | |
1793 | ||
1794 | while (ent && iter->idx < i) | |
955b61e5 | 1795 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
1796 | |
1797 | iter->pos = *pos; | |
1798 | ||
bc0c38d1 SR |
1799 | return ent; |
1800 | } | |
1801 | ||
955b61e5 | 1802 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
2f26ebd5 SR |
1803 | { |
1804 | struct trace_array *tr = iter->tr; | |
1805 | struct ring_buffer_event *event; | |
1806 | struct ring_buffer_iter *buf_iter; | |
1807 | unsigned long entries = 0; | |
1808 | u64 ts; | |
1809 | ||
1810 | tr->data[cpu]->skipped_entries = 0; | |
1811 | ||
1812 | if (!iter->buffer_iter[cpu]) | |
1813 | return; | |
1814 | ||
1815 | buf_iter = iter->buffer_iter[cpu]; | |
1816 | ring_buffer_iter_reset(buf_iter); | |
1817 | ||
1818 | /* | |
1819 | * We could have the case with the max latency tracers | |
1820 | * that a reset never took place on a cpu. This is evident | |
1821 | * by the timestamp being before the start of the buffer. | |
1822 | */ | |
1823 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
1824 | if (ts >= iter->tr->time_start) | |
1825 | break; | |
1826 | entries++; | |
1827 | ring_buffer_read(buf_iter, NULL); | |
1828 | } | |
1829 | ||
1830 | tr->data[cpu]->skipped_entries = entries; | |
1831 | } | |
1832 | ||
d7350c3f | 1833 | /* |
d7350c3f FW |
1834 | * The current tracer is copied to avoid a global locking |
1835 | * all around. | |
1836 | */ | |
bc0c38d1 SR |
1837 | static void *s_start(struct seq_file *m, loff_t *pos) |
1838 | { | |
1839 | struct trace_iterator *iter = m->private; | |
d7350c3f | 1840 | static struct tracer *old_tracer; |
b04cc6b1 | 1841 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
1842 | void *p = NULL; |
1843 | loff_t l = 0; | |
3928a8a2 | 1844 | int cpu; |
bc0c38d1 | 1845 | |
d7350c3f | 1846 | /* copy the tracer to avoid using a global lock all around */ |
bc0c38d1 | 1847 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
1848 | if (unlikely(old_tracer != current_trace && current_trace)) { |
1849 | old_tracer = current_trace; | |
1850 | *iter->trace = *current_trace; | |
d15f57f2 | 1851 | } |
d7350c3f | 1852 | mutex_unlock(&trace_types_lock); |
bc0c38d1 SR |
1853 | |
1854 | atomic_inc(&trace_record_cmdline_disabled); | |
1855 | ||
bc0c38d1 SR |
1856 | if (*pos != iter->pos) { |
1857 | iter->ent = NULL; | |
1858 | iter->cpu = 0; | |
1859 | iter->idx = -1; | |
1860 | ||
d769041f SR |
1861 | ftrace_disable_cpu(); |
1862 | ||
b04cc6b1 FW |
1863 | if (cpu_file == TRACE_PIPE_ALL_CPU) { |
1864 | for_each_tracing_cpu(cpu) | |
2f26ebd5 | 1865 | tracing_iter_reset(iter, cpu); |
b04cc6b1 | 1866 | } else |
2f26ebd5 | 1867 | tracing_iter_reset(iter, cpu_file); |
bc0c38d1 | 1868 | |
d769041f SR |
1869 | ftrace_enable_cpu(); |
1870 | ||
ac91d854 | 1871 | iter->leftover = 0; |
bc0c38d1 SR |
1872 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
1873 | ; | |
1874 | ||
1875 | } else { | |
a63ce5b3 SR |
1876 | /* |
1877 | * If we overflowed the seq_file before, then we want | |
1878 | * to just reuse the trace_seq buffer again. | |
1879 | */ | |
1880 | if (iter->leftover) | |
1881 | p = iter; | |
1882 | else { | |
1883 | l = *pos - 1; | |
1884 | p = s_next(m, p, &l); | |
1885 | } | |
bc0c38d1 SR |
1886 | } |
1887 | ||
4f535968 | 1888 | trace_event_read_lock(); |
7e53bd42 | 1889 | trace_access_lock(cpu_file); |
bc0c38d1 SR |
1890 | return p; |
1891 | } | |
1892 | ||
1893 | static void s_stop(struct seq_file *m, void *p) | |
1894 | { | |
7e53bd42 LJ |
1895 | struct trace_iterator *iter = m->private; |
1896 | ||
bc0c38d1 | 1897 | atomic_dec(&trace_record_cmdline_disabled); |
7e53bd42 | 1898 | trace_access_unlock(iter->cpu_file); |
4f535968 | 1899 | trace_event_read_unlock(); |
bc0c38d1 SR |
1900 | } |
1901 | ||
39eaf7ef SR |
1902 | static void |
1903 | get_total_entries(struct trace_array *tr, unsigned long *total, unsigned long *entries) | |
1904 | { | |
1905 | unsigned long count; | |
1906 | int cpu; | |
1907 | ||
1908 | *total = 0; | |
1909 | *entries = 0; | |
1910 | ||
1911 | for_each_tracing_cpu(cpu) { | |
1912 | count = ring_buffer_entries_cpu(tr->buffer, cpu); | |
1913 | /* | |
1914 | * If this buffer has skipped entries, then we hold all | |
1915 | * entries for the trace and we need to ignore the | |
1916 | * ones before the time stamp. | |
1917 | */ | |
1918 | if (tr->data[cpu]->skipped_entries) { | |
1919 | count -= tr->data[cpu]->skipped_entries; | |
1920 | /* total is the same as the entries */ | |
1921 | *total += count; | |
1922 | } else | |
1923 | *total += count + | |
1924 | ring_buffer_overrun_cpu(tr->buffer, cpu); | |
1925 | *entries += count; | |
1926 | } | |
1927 | } | |
1928 | ||
e309b41d | 1929 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 1930 | { |
a6168353 ME |
1931 | seq_puts(m, "# _------=> CPU# \n"); |
1932 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
1933 | seq_puts(m, "# | / _----=> need-resched \n"); | |
1934 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
1935 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
e6e1e259 SR |
1936 | seq_puts(m, "# |||| / delay \n"); |
1937 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
1938 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
bc0c38d1 SR |
1939 | } |
1940 | ||
39eaf7ef | 1941 | static void print_event_info(struct trace_array *tr, struct seq_file *m) |
bc0c38d1 | 1942 | { |
39eaf7ef SR |
1943 | unsigned long total; |
1944 | unsigned long entries; | |
1945 | ||
1946 | get_total_entries(tr, &total, &entries); | |
1947 | seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", | |
1948 | entries, total, num_online_cpus()); | |
1949 | seq_puts(m, "#\n"); | |
1950 | } | |
1951 | ||
1952 | static void print_func_help_header(struct trace_array *tr, struct seq_file *m) | |
1953 | { | |
1954 | print_event_info(tr, m); | |
77271ce4 | 1955 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); |
a6168353 | 1956 | seq_puts(m, "# | | | | |\n"); |
bc0c38d1 SR |
1957 | } |
1958 | ||
39eaf7ef | 1959 | static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *m) |
77271ce4 | 1960 | { |
39eaf7ef | 1961 | print_event_info(tr, m); |
77271ce4 SR |
1962 | seq_puts(m, "# _-----=> irqs-off\n"); |
1963 | seq_puts(m, "# / _----=> need-resched\n"); | |
1964 | seq_puts(m, "# | / _---=> hardirq/softirq\n"); | |
1965 | seq_puts(m, "# || / _--=> preempt-depth\n"); | |
1966 | seq_puts(m, "# ||| / delay\n"); | |
1967 | seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"); | |
1968 | seq_puts(m, "# | | | |||| | |\n"); | |
1969 | } | |
bc0c38d1 | 1970 | |
62b915f1 | 1971 | void |
bc0c38d1 SR |
1972 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
1973 | { | |
1974 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
1975 | struct trace_array *tr = iter->tr; | |
1976 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
1977 | struct tracer *type = current_trace; | |
39eaf7ef SR |
1978 | unsigned long entries; |
1979 | unsigned long total; | |
bc0c38d1 SR |
1980 | const char *name = "preemption"; |
1981 | ||
1982 | if (type) | |
1983 | name = type->name; | |
1984 | ||
39eaf7ef | 1985 | get_total_entries(tr, &total, &entries); |
bc0c38d1 | 1986 | |
888b55dc | 1987 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 1988 | name, UTS_RELEASE); |
888b55dc | 1989 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 1990 | "---------------------------------\n"); |
888b55dc | 1991 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 1992 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 1993 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 1994 | entries, |
4c11d7ae | 1995 | total, |
bc0c38d1 SR |
1996 | tr->cpu, |
1997 | #if defined(CONFIG_PREEMPT_NONE) | |
1998 | "server", | |
1999 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
2000 | "desktop", | |
b5c21b45 | 2001 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
2002 | "preempt", |
2003 | #else | |
2004 | "unknown", | |
2005 | #endif | |
2006 | /* These are reserved for later use */ | |
2007 | 0, 0, 0, 0); | |
2008 | #ifdef CONFIG_SMP | |
2009 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
2010 | #else | |
2011 | seq_puts(m, ")\n"); | |
2012 | #endif | |
888b55dc KM |
2013 | seq_puts(m, "# -----------------\n"); |
2014 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 SR |
2015 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
2016 | data->comm, data->pid, data->uid, data->nice, | |
2017 | data->policy, data->rt_priority); | |
888b55dc | 2018 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
2019 | |
2020 | if (data->critical_start) { | |
888b55dc | 2021 | seq_puts(m, "# => started at: "); |
214023c3 SR |
2022 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
2023 | trace_print_seq(m, &iter->seq); | |
888b55dc | 2024 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
2025 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
2026 | trace_print_seq(m, &iter->seq); | |
8248ac05 | 2027 | seq_puts(m, "\n#\n"); |
bc0c38d1 SR |
2028 | } |
2029 | ||
888b55dc | 2030 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
2031 | } |
2032 | ||
a309720c SR |
2033 | static void test_cpu_buff_start(struct trace_iterator *iter) |
2034 | { | |
2035 | struct trace_seq *s = &iter->seq; | |
2036 | ||
12ef7d44 SR |
2037 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) |
2038 | return; | |
2039 | ||
2040 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
2041 | return; | |
2042 | ||
4462344e | 2043 | if (cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
2044 | return; |
2045 | ||
2f26ebd5 SR |
2046 | if (iter->tr->data[iter->cpu]->skipped_entries) |
2047 | return; | |
2048 | ||
4462344e | 2049 | cpumask_set_cpu(iter->cpu, iter->started); |
b0dfa978 FW |
2050 | |
2051 | /* Don't print started cpu buffer for the first entry of the trace */ | |
2052 | if (iter->idx > 1) | |
2053 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
2054 | iter->cpu); | |
a309720c SR |
2055 | } |
2056 | ||
2c4f035f | 2057 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 2058 | { |
214023c3 | 2059 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 2060 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 2061 | struct trace_entry *entry; |
f633cef0 | 2062 | struct trace_event *event; |
bc0c38d1 | 2063 | |
4e3c3333 | 2064 | entry = iter->ent; |
dd0e545f | 2065 | |
a309720c SR |
2066 | test_cpu_buff_start(iter); |
2067 | ||
c4a8e8be | 2068 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 2069 | |
c4a8e8be | 2070 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
27d48be8 SR |
2071 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2072 | if (!trace_print_lat_context(iter)) | |
2073 | goto partial; | |
2074 | } else { | |
2075 | if (!trace_print_context(iter)) | |
2076 | goto partial; | |
2077 | } | |
c4a8e8be | 2078 | } |
bc0c38d1 | 2079 | |
268ccda0 | 2080 | if (event) |
a9a57763 | 2081 | return event->funcs->trace(iter, sym_flags, event); |
d9793bd8 ACM |
2082 | |
2083 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
2084 | goto partial; | |
02b67518 | 2085 | |
2c4f035f | 2086 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
2087 | partial: |
2088 | return TRACE_TYPE_PARTIAL_LINE; | |
bc0c38d1 SR |
2089 | } |
2090 | ||
2c4f035f | 2091 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 IM |
2092 | { |
2093 | struct trace_seq *s = &iter->seq; | |
2094 | struct trace_entry *entry; | |
f633cef0 | 2095 | struct trace_event *event; |
f9896bf3 IM |
2096 | |
2097 | entry = iter->ent; | |
dd0e545f | 2098 | |
c4a8e8be | 2099 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
d9793bd8 ACM |
2100 | if (!trace_seq_printf(s, "%d %d %llu ", |
2101 | entry->pid, iter->cpu, iter->ts)) | |
2102 | goto partial; | |
c4a8e8be | 2103 | } |
f9896bf3 | 2104 | |
f633cef0 | 2105 | event = ftrace_find_event(entry->type); |
268ccda0 | 2106 | if (event) |
a9a57763 | 2107 | return event->funcs->raw(iter, 0, event); |
d9793bd8 ACM |
2108 | |
2109 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
2110 | goto partial; | |
777e208d | 2111 | |
2c4f035f | 2112 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
2113 | partial: |
2114 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 IM |
2115 | } |
2116 | ||
2c4f035f | 2117 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec IM |
2118 | { |
2119 | struct trace_seq *s = &iter->seq; | |
2120 | unsigned char newline = '\n'; | |
2121 | struct trace_entry *entry; | |
f633cef0 | 2122 | struct trace_event *event; |
5e3ca0ec IM |
2123 | |
2124 | entry = iter->ent; | |
dd0e545f | 2125 | |
c4a8e8be FW |
2126 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
2127 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
2128 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
2129 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
2130 | } | |
5e3ca0ec | 2131 | |
f633cef0 | 2132 | event = ftrace_find_event(entry->type); |
268ccda0 | 2133 | if (event) { |
a9a57763 | 2134 | enum print_line_t ret = event->funcs->hex(iter, 0, event); |
d9793bd8 ACM |
2135 | if (ret != TRACE_TYPE_HANDLED) |
2136 | return ret; | |
2137 | } | |
7104f300 | 2138 | |
5e3ca0ec IM |
2139 | SEQ_PUT_FIELD_RET(s, newline); |
2140 | ||
2c4f035f | 2141 | return TRACE_TYPE_HANDLED; |
5e3ca0ec IM |
2142 | } |
2143 | ||
2c4f035f | 2144 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa IM |
2145 | { |
2146 | struct trace_seq *s = &iter->seq; | |
2147 | struct trace_entry *entry; | |
f633cef0 | 2148 | struct trace_event *event; |
cb0f12aa IM |
2149 | |
2150 | entry = iter->ent; | |
dd0e545f | 2151 | |
c4a8e8be FW |
2152 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
2153 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
1830b52d | 2154 | SEQ_PUT_FIELD_RET(s, iter->cpu); |
c4a8e8be FW |
2155 | SEQ_PUT_FIELD_RET(s, iter->ts); |
2156 | } | |
cb0f12aa | 2157 | |
f633cef0 | 2158 | event = ftrace_find_event(entry->type); |
a9a57763 SR |
2159 | return event ? event->funcs->binary(iter, 0, event) : |
2160 | TRACE_TYPE_HANDLED; | |
cb0f12aa IM |
2161 | } |
2162 | ||
62b915f1 | 2163 | int trace_empty(struct trace_iterator *iter) |
bc0c38d1 | 2164 | { |
bc0c38d1 SR |
2165 | int cpu; |
2166 | ||
9aba60fe SR |
2167 | /* If we are looking at one CPU buffer, only check that one */ |
2168 | if (iter->cpu_file != TRACE_PIPE_ALL_CPU) { | |
2169 | cpu = iter->cpu_file; | |
2170 | if (iter->buffer_iter[cpu]) { | |
2171 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
2172 | return 0; | |
2173 | } else { | |
2174 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
2175 | return 0; | |
2176 | } | |
2177 | return 1; | |
2178 | } | |
2179 | ||
ab46428c | 2180 | for_each_tracing_cpu(cpu) { |
d769041f SR |
2181 | if (iter->buffer_iter[cpu]) { |
2182 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
2183 | return 0; | |
2184 | } else { | |
2185 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
2186 | return 0; | |
2187 | } | |
bc0c38d1 | 2188 | } |
d769041f | 2189 | |
797d3712 | 2190 | return 1; |
bc0c38d1 SR |
2191 | } |
2192 | ||
4f535968 | 2193 | /* Called with trace_event_read_lock() held. */ |
955b61e5 | 2194 | enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 2195 | { |
2c4f035f FW |
2196 | enum print_line_t ret; |
2197 | ||
ee5e51f5 JO |
2198 | if (iter->lost_events && |
2199 | !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2200 | iter->cpu, iter->lost_events)) | |
2201 | return TRACE_TYPE_PARTIAL_LINE; | |
bc21b478 | 2202 | |
2c4f035f FW |
2203 | if (iter->trace && iter->trace->print_line) { |
2204 | ret = iter->trace->print_line(iter); | |
2205 | if (ret != TRACE_TYPE_UNHANDLED) | |
2206 | return ret; | |
2207 | } | |
72829bc3 | 2208 | |
48ead020 FW |
2209 | if (iter->ent->type == TRACE_BPRINT && |
2210 | trace_flags & TRACE_ITER_PRINTK && | |
2211 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2212 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 2213 | |
66896a85 FW |
2214 | if (iter->ent->type == TRACE_PRINT && |
2215 | trace_flags & TRACE_ITER_PRINTK && | |
2216 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2217 | return trace_print_printk_msg_only(iter); |
66896a85 | 2218 | |
cb0f12aa IM |
2219 | if (trace_flags & TRACE_ITER_BIN) |
2220 | return print_bin_fmt(iter); | |
2221 | ||
5e3ca0ec IM |
2222 | if (trace_flags & TRACE_ITER_HEX) |
2223 | return print_hex_fmt(iter); | |
2224 | ||
f9896bf3 IM |
2225 | if (trace_flags & TRACE_ITER_RAW) |
2226 | return print_raw_fmt(iter); | |
2227 | ||
f9896bf3 IM |
2228 | return print_trace_fmt(iter); |
2229 | } | |
2230 | ||
7e9a49ef JO |
2231 | void trace_latency_header(struct seq_file *m) |
2232 | { | |
2233 | struct trace_iterator *iter = m->private; | |
2234 | ||
2235 | /* print nothing if the buffers are empty */ | |
2236 | if (trace_empty(iter)) | |
2237 | return; | |
2238 | ||
2239 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
2240 | print_trace_header(m, iter); | |
2241 | ||
2242 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2243 | print_lat_help_header(m); | |
2244 | } | |
2245 | ||
62b915f1 JO |
2246 | void trace_default_header(struct seq_file *m) |
2247 | { | |
2248 | struct trace_iterator *iter = m->private; | |
2249 | ||
f56e7f8e JO |
2250 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
2251 | return; | |
2252 | ||
62b915f1 JO |
2253 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2254 | /* print nothing if the buffers are empty */ | |
2255 | if (trace_empty(iter)) | |
2256 | return; | |
2257 | print_trace_header(m, iter); | |
2258 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2259 | print_lat_help_header(m); | |
2260 | } else { | |
77271ce4 SR |
2261 | if (!(trace_flags & TRACE_ITER_VERBOSE)) { |
2262 | if (trace_flags & TRACE_ITER_IRQ_INFO) | |
39eaf7ef | 2263 | print_func_help_header_irq(iter->tr, m); |
77271ce4 | 2264 | else |
39eaf7ef | 2265 | print_func_help_header(iter->tr, m); |
77271ce4 | 2266 | } |
62b915f1 JO |
2267 | } |
2268 | } | |
2269 | ||
e0a413f6 SR |
2270 | static void test_ftrace_alive(struct seq_file *m) |
2271 | { | |
2272 | if (!ftrace_is_dead()) | |
2273 | return; | |
2274 | seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
2275 | seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n"); | |
2276 | } | |
2277 | ||
bc0c38d1 SR |
2278 | static int s_show(struct seq_file *m, void *v) |
2279 | { | |
2280 | struct trace_iterator *iter = v; | |
a63ce5b3 | 2281 | int ret; |
bc0c38d1 SR |
2282 | |
2283 | if (iter->ent == NULL) { | |
2284 | if (iter->tr) { | |
2285 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2286 | seq_puts(m, "#\n"); | |
e0a413f6 | 2287 | test_ftrace_alive(m); |
bc0c38d1 | 2288 | } |
8bba1bf5 MM |
2289 | if (iter->trace && iter->trace->print_header) |
2290 | iter->trace->print_header(m); | |
62b915f1 JO |
2291 | else |
2292 | trace_default_header(m); | |
2293 | ||
a63ce5b3 SR |
2294 | } else if (iter->leftover) { |
2295 | /* | |
2296 | * If we filled the seq_file buffer earlier, we | |
2297 | * want to just show it now. | |
2298 | */ | |
2299 | ret = trace_print_seq(m, &iter->seq); | |
2300 | ||
2301 | /* ret should this time be zero, but you never know */ | |
2302 | iter->leftover = ret; | |
2303 | ||
bc0c38d1 | 2304 | } else { |
f9896bf3 | 2305 | print_trace_line(iter); |
a63ce5b3 SR |
2306 | ret = trace_print_seq(m, &iter->seq); |
2307 | /* | |
2308 | * If we overflow the seq_file buffer, then it will | |
2309 | * ask us for this data again at start up. | |
2310 | * Use that instead. | |
2311 | * ret is 0 if seq_file write succeeded. | |
2312 | * -1 otherwise. | |
2313 | */ | |
2314 | iter->leftover = ret; | |
bc0c38d1 SR |
2315 | } |
2316 | ||
2317 | return 0; | |
2318 | } | |
2319 | ||
88e9d34c | 2320 | static const struct seq_operations tracer_seq_ops = { |
4bf39a94 IM |
2321 | .start = s_start, |
2322 | .next = s_next, | |
2323 | .stop = s_stop, | |
2324 | .show = s_show, | |
bc0c38d1 SR |
2325 | }; |
2326 | ||
e309b41d | 2327 | static struct trace_iterator * |
85a2f9b4 | 2328 | __tracing_open(struct inode *inode, struct file *file) |
bc0c38d1 | 2329 | { |
b04cc6b1 | 2330 | long cpu_file = (long) inode->i_private; |
85a2f9b4 | 2331 | void *fail_ret = ERR_PTR(-ENOMEM); |
bc0c38d1 | 2332 | struct trace_iterator *iter; |
3928a8a2 | 2333 | struct seq_file *m; |
85a2f9b4 | 2334 | int cpu, ret; |
bc0c38d1 | 2335 | |
85a2f9b4 SR |
2336 | if (tracing_disabled) |
2337 | return ERR_PTR(-ENODEV); | |
60a11774 | 2338 | |
bc0c38d1 | 2339 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
85a2f9b4 SR |
2340 | if (!iter) |
2341 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 2342 | |
d7350c3f FW |
2343 | /* |
2344 | * We make a copy of the current tracer to avoid concurrent | |
2345 | * changes on it while we are reading. | |
2346 | */ | |
bc0c38d1 | 2347 | mutex_lock(&trace_types_lock); |
d7350c3f | 2348 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 2349 | if (!iter->trace) |
d7350c3f | 2350 | goto fail; |
85a2f9b4 | 2351 | |
d7350c3f FW |
2352 | if (current_trace) |
2353 | *iter->trace = *current_trace; | |
2354 | ||
79f55997 | 2355 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
b0dfa978 FW |
2356 | goto fail; |
2357 | ||
bc0c38d1 SR |
2358 | if (current_trace && current_trace->print_max) |
2359 | iter->tr = &max_tr; | |
2360 | else | |
b04cc6b1 | 2361 | iter->tr = &global_trace; |
bc0c38d1 | 2362 | iter->pos = -1; |
d7350c3f | 2363 | mutex_init(&iter->mutex); |
b04cc6b1 | 2364 | iter->cpu_file = cpu_file; |
bc0c38d1 | 2365 | |
8bba1bf5 MM |
2366 | /* Notify the tracer early; before we stop tracing. */ |
2367 | if (iter->trace && iter->trace->open) | |
a93751ca | 2368 | iter->trace->open(iter); |
8bba1bf5 | 2369 | |
12ef7d44 SR |
2370 | /* Annotate start of buffers if we had overruns */ |
2371 | if (ring_buffer_overruns(iter->tr->buffer)) | |
2372 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
2373 | ||
2f26ebd5 SR |
2374 | /* stop the trace while dumping */ |
2375 | tracing_stop(); | |
2376 | ||
b04cc6b1 FW |
2377 | if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { |
2378 | for_each_tracing_cpu(cpu) { | |
b04cc6b1 | 2379 | iter->buffer_iter[cpu] = |
72c9ddfd DM |
2380 | ring_buffer_read_prepare(iter->tr->buffer, cpu); |
2381 | } | |
2382 | ring_buffer_read_prepare_sync(); | |
2383 | for_each_tracing_cpu(cpu) { | |
2384 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 2385 | tracing_iter_reset(iter, cpu); |
b04cc6b1 FW |
2386 | } |
2387 | } else { | |
2388 | cpu = iter->cpu_file; | |
3928a8a2 | 2389 | iter->buffer_iter[cpu] = |
72c9ddfd DM |
2390 | ring_buffer_read_prepare(iter->tr->buffer, cpu); |
2391 | ring_buffer_read_prepare_sync(); | |
2392 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 2393 | tracing_iter_reset(iter, cpu); |
3928a8a2 SR |
2394 | } |
2395 | ||
85a2f9b4 SR |
2396 | ret = seq_open(file, &tracer_seq_ops); |
2397 | if (ret < 0) { | |
2398 | fail_ret = ERR_PTR(ret); | |
3928a8a2 | 2399 | goto fail_buffer; |
85a2f9b4 | 2400 | } |
bc0c38d1 | 2401 | |
3928a8a2 SR |
2402 | m = file->private_data; |
2403 | m->private = iter; | |
bc0c38d1 | 2404 | |
bc0c38d1 SR |
2405 | mutex_unlock(&trace_types_lock); |
2406 | ||
bc0c38d1 | 2407 | return iter; |
3928a8a2 SR |
2408 | |
2409 | fail_buffer: | |
2410 | for_each_tracing_cpu(cpu) { | |
2411 | if (iter->buffer_iter[cpu]) | |
2412 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2413 | } | |
b0dfa978 | 2414 | free_cpumask_var(iter->started); |
2f26ebd5 | 2415 | tracing_start(); |
d7350c3f | 2416 | fail: |
3928a8a2 | 2417 | mutex_unlock(&trace_types_lock); |
d7350c3f | 2418 | kfree(iter->trace); |
0bb943c7 | 2419 | kfree(iter); |
3928a8a2 | 2420 | |
85a2f9b4 | 2421 | return fail_ret; |
bc0c38d1 SR |
2422 | } |
2423 | ||
2424 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
2425 | { | |
60a11774 SR |
2426 | if (tracing_disabled) |
2427 | return -ENODEV; | |
2428 | ||
bc0c38d1 SR |
2429 | filp->private_data = inode->i_private; |
2430 | return 0; | |
2431 | } | |
2432 | ||
4fd27358 | 2433 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 | 2434 | { |
907f2784 | 2435 | struct seq_file *m = file->private_data; |
4acd4d00 | 2436 | struct trace_iterator *iter; |
3928a8a2 | 2437 | int cpu; |
bc0c38d1 | 2438 | |
4acd4d00 SR |
2439 | if (!(file->f_mode & FMODE_READ)) |
2440 | return 0; | |
2441 | ||
2442 | iter = m->private; | |
2443 | ||
bc0c38d1 | 2444 | mutex_lock(&trace_types_lock); |
3928a8a2 SR |
2445 | for_each_tracing_cpu(cpu) { |
2446 | if (iter->buffer_iter[cpu]) | |
2447 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2448 | } | |
2449 | ||
bc0c38d1 SR |
2450 | if (iter->trace && iter->trace->close) |
2451 | iter->trace->close(iter); | |
2452 | ||
2453 | /* reenable tracing if it was previously enabled */ | |
9036990d | 2454 | tracing_start(); |
bc0c38d1 SR |
2455 | mutex_unlock(&trace_types_lock); |
2456 | ||
2457 | seq_release(inode, file); | |
d7350c3f | 2458 | mutex_destroy(&iter->mutex); |
b0dfa978 | 2459 | free_cpumask_var(iter->started); |
d7350c3f | 2460 | kfree(iter->trace); |
bc0c38d1 SR |
2461 | kfree(iter); |
2462 | return 0; | |
2463 | } | |
2464 | ||
2465 | static int tracing_open(struct inode *inode, struct file *file) | |
2466 | { | |
85a2f9b4 SR |
2467 | struct trace_iterator *iter; |
2468 | int ret = 0; | |
bc0c38d1 | 2469 | |
4acd4d00 SR |
2470 | /* If this file was open for write, then erase contents */ |
2471 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2472 | (file->f_flags & O_TRUNC)) { |
4acd4d00 | 2473 | long cpu = (long) inode->i_private; |
bc0c38d1 | 2474 | |
4acd4d00 SR |
2475 | if (cpu == TRACE_PIPE_ALL_CPU) |
2476 | tracing_reset_online_cpus(&global_trace); | |
2477 | else | |
2478 | tracing_reset(&global_trace, cpu); | |
2479 | } | |
bc0c38d1 | 2480 | |
4acd4d00 SR |
2481 | if (file->f_mode & FMODE_READ) { |
2482 | iter = __tracing_open(inode, file); | |
2483 | if (IS_ERR(iter)) | |
2484 | ret = PTR_ERR(iter); | |
2485 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
2486 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
2487 | } | |
bc0c38d1 SR |
2488 | return ret; |
2489 | } | |
2490 | ||
e309b41d | 2491 | static void * |
bc0c38d1 SR |
2492 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2493 | { | |
f129e965 | 2494 | struct tracer *t = v; |
bc0c38d1 SR |
2495 | |
2496 | (*pos)++; | |
2497 | ||
2498 | if (t) | |
2499 | t = t->next; | |
2500 | ||
bc0c38d1 SR |
2501 | return t; |
2502 | } | |
2503 | ||
2504 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2505 | { | |
f129e965 | 2506 | struct tracer *t; |
bc0c38d1 SR |
2507 | loff_t l = 0; |
2508 | ||
2509 | mutex_lock(&trace_types_lock); | |
f129e965 | 2510 | for (t = trace_types; t && l < *pos; t = t_next(m, t, &l)) |
bc0c38d1 SR |
2511 | ; |
2512 | ||
2513 | return t; | |
2514 | } | |
2515 | ||
2516 | static void t_stop(struct seq_file *m, void *p) | |
2517 | { | |
2518 | mutex_unlock(&trace_types_lock); | |
2519 | } | |
2520 | ||
2521 | static int t_show(struct seq_file *m, void *v) | |
2522 | { | |
2523 | struct tracer *t = v; | |
2524 | ||
2525 | if (!t) | |
2526 | return 0; | |
2527 | ||
2528 | seq_printf(m, "%s", t->name); | |
2529 | if (t->next) | |
2530 | seq_putc(m, ' '); | |
2531 | else | |
2532 | seq_putc(m, '\n'); | |
2533 | ||
2534 | return 0; | |
2535 | } | |
2536 | ||
88e9d34c | 2537 | static const struct seq_operations show_traces_seq_ops = { |
4bf39a94 IM |
2538 | .start = t_start, |
2539 | .next = t_next, | |
2540 | .stop = t_stop, | |
2541 | .show = t_show, | |
bc0c38d1 SR |
2542 | }; |
2543 | ||
2544 | static int show_traces_open(struct inode *inode, struct file *file) | |
2545 | { | |
60a11774 SR |
2546 | if (tracing_disabled) |
2547 | return -ENODEV; | |
2548 | ||
f129e965 | 2549 | return seq_open(file, &show_traces_seq_ops); |
bc0c38d1 SR |
2550 | } |
2551 | ||
4acd4d00 SR |
2552 | static ssize_t |
2553 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
2554 | size_t count, loff_t *ppos) | |
2555 | { | |
2556 | return count; | |
2557 | } | |
2558 | ||
364829b1 SP |
2559 | static loff_t tracing_seek(struct file *file, loff_t offset, int origin) |
2560 | { | |
2561 | if (file->f_mode & FMODE_READ) | |
2562 | return seq_lseek(file, offset, origin); | |
2563 | else | |
2564 | return 0; | |
2565 | } | |
2566 | ||
5e2336a0 | 2567 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
2568 | .open = tracing_open, |
2569 | .read = seq_read, | |
4acd4d00 | 2570 | .write = tracing_write_stub, |
364829b1 | 2571 | .llseek = tracing_seek, |
4bf39a94 | 2572 | .release = tracing_release, |
bc0c38d1 SR |
2573 | }; |
2574 | ||
5e2336a0 | 2575 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
2576 | .open = show_traces_open, |
2577 | .read = seq_read, | |
2578 | .release = seq_release, | |
b444786f | 2579 | .llseek = seq_lseek, |
c7078de1 IM |
2580 | }; |
2581 | ||
36dfe925 IM |
2582 | /* |
2583 | * Only trace on a CPU if the bitmask is set: | |
2584 | */ | |
9e01c1b7 | 2585 | static cpumask_var_t tracing_cpumask; |
36dfe925 IM |
2586 | |
2587 | /* | |
2588 | * The tracer itself will not take this lock, but still we want | |
2589 | * to provide a consistent cpumask to user-space: | |
2590 | */ | |
2591 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
2592 | ||
2593 | /* | |
2594 | * Temporary storage for the character representation of the | |
2595 | * CPU bitmask (and one more byte for the newline): | |
2596 | */ | |
2597 | static char mask_str[NR_CPUS + 1]; | |
2598 | ||
c7078de1 IM |
2599 | static ssize_t |
2600 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
2601 | size_t count, loff_t *ppos) | |
2602 | { | |
36dfe925 | 2603 | int len; |
c7078de1 IM |
2604 | |
2605 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 2606 | |
9e01c1b7 | 2607 | len = cpumask_scnprintf(mask_str, count, tracing_cpumask); |
36dfe925 IM |
2608 | if (count - len < 2) { |
2609 | count = -EINVAL; | |
2610 | goto out_err; | |
2611 | } | |
2612 | len += sprintf(mask_str + len, "\n"); | |
2613 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
2614 | ||
2615 | out_err: | |
c7078de1 IM |
2616 | mutex_unlock(&tracing_cpumask_update_lock); |
2617 | ||
2618 | return count; | |
2619 | } | |
2620 | ||
2621 | static ssize_t | |
2622 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
2623 | size_t count, loff_t *ppos) | |
2624 | { | |
36dfe925 | 2625 | int err, cpu; |
9e01c1b7 RR |
2626 | cpumask_var_t tracing_cpumask_new; |
2627 | ||
2628 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
2629 | return -ENOMEM; | |
c7078de1 | 2630 | |
9e01c1b7 | 2631 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 2632 | if (err) |
36dfe925 IM |
2633 | goto err_unlock; |
2634 | ||
215368e8 LZ |
2635 | mutex_lock(&tracing_cpumask_update_lock); |
2636 | ||
a5e25883 | 2637 | local_irq_disable(); |
0199c4e6 | 2638 | arch_spin_lock(&ftrace_max_lock); |
ab46428c | 2639 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
2640 | /* |
2641 | * Increase/decrease the disabled counter if we are | |
2642 | * about to flip a bit in the cpumask: | |
2643 | */ | |
9e01c1b7 RR |
2644 | if (cpumask_test_cpu(cpu, tracing_cpumask) && |
2645 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 IM |
2646 | atomic_inc(&global_trace.data[cpu]->disabled); |
2647 | } | |
9e01c1b7 RR |
2648 | if (!cpumask_test_cpu(cpu, tracing_cpumask) && |
2649 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 IM |
2650 | atomic_dec(&global_trace.data[cpu]->disabled); |
2651 | } | |
2652 | } | |
0199c4e6 | 2653 | arch_spin_unlock(&ftrace_max_lock); |
a5e25883 | 2654 | local_irq_enable(); |
36dfe925 | 2655 | |
9e01c1b7 | 2656 | cpumask_copy(tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
2657 | |
2658 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 2659 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
2660 | |
2661 | return count; | |
36dfe925 IM |
2662 | |
2663 | err_unlock: | |
215368e8 | 2664 | free_cpumask_var(tracing_cpumask_new); |
36dfe925 IM |
2665 | |
2666 | return err; | |
c7078de1 IM |
2667 | } |
2668 | ||
5e2336a0 | 2669 | static const struct file_operations tracing_cpumask_fops = { |
c7078de1 IM |
2670 | .open = tracing_open_generic, |
2671 | .read = tracing_cpumask_read, | |
2672 | .write = tracing_cpumask_write, | |
b444786f | 2673 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
2674 | }; |
2675 | ||
fdb372ed | 2676 | static int tracing_trace_options_show(struct seq_file *m, void *v) |
bc0c38d1 | 2677 | { |
d8e83d26 SR |
2678 | struct tracer_opt *trace_opts; |
2679 | u32 tracer_flags; | |
d8e83d26 | 2680 | int i; |
adf9f195 | 2681 | |
d8e83d26 SR |
2682 | mutex_lock(&trace_types_lock); |
2683 | tracer_flags = current_trace->flags->val; | |
2684 | trace_opts = current_trace->flags->opts; | |
2685 | ||
bc0c38d1 SR |
2686 | for (i = 0; trace_options[i]; i++) { |
2687 | if (trace_flags & (1 << i)) | |
fdb372ed | 2688 | seq_printf(m, "%s\n", trace_options[i]); |
bc0c38d1 | 2689 | else |
fdb372ed | 2690 | seq_printf(m, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
2691 | } |
2692 | ||
adf9f195 FW |
2693 | for (i = 0; trace_opts[i].name; i++) { |
2694 | if (tracer_flags & trace_opts[i].bit) | |
fdb372ed | 2695 | seq_printf(m, "%s\n", trace_opts[i].name); |
adf9f195 | 2696 | else |
fdb372ed | 2697 | seq_printf(m, "no%s\n", trace_opts[i].name); |
adf9f195 | 2698 | } |
d8e83d26 | 2699 | mutex_unlock(&trace_types_lock); |
adf9f195 | 2700 | |
fdb372ed | 2701 | return 0; |
bc0c38d1 | 2702 | } |
bc0c38d1 | 2703 | |
8d18eaaf LZ |
2704 | static int __set_tracer_option(struct tracer *trace, |
2705 | struct tracer_flags *tracer_flags, | |
2706 | struct tracer_opt *opts, int neg) | |
2707 | { | |
2708 | int ret; | |
bc0c38d1 | 2709 | |
8d18eaaf LZ |
2710 | ret = trace->set_flag(tracer_flags->val, opts->bit, !neg); |
2711 | if (ret) | |
2712 | return ret; | |
2713 | ||
2714 | if (neg) | |
2715 | tracer_flags->val &= ~opts->bit; | |
2716 | else | |
2717 | tracer_flags->val |= opts->bit; | |
2718 | return 0; | |
bc0c38d1 SR |
2719 | } |
2720 | ||
adf9f195 FW |
2721 | /* Try to assign a tracer specific option */ |
2722 | static int set_tracer_option(struct tracer *trace, char *cmp, int neg) | |
2723 | { | |
7770841e | 2724 | struct tracer_flags *tracer_flags = trace->flags; |
adf9f195 | 2725 | struct tracer_opt *opts = NULL; |
8d18eaaf | 2726 | int i; |
adf9f195 | 2727 | |
7770841e Z |
2728 | for (i = 0; tracer_flags->opts[i].name; i++) { |
2729 | opts = &tracer_flags->opts[i]; | |
adf9f195 | 2730 | |
8d18eaaf LZ |
2731 | if (strcmp(cmp, opts->name) == 0) |
2732 | return __set_tracer_option(trace, trace->flags, | |
2733 | opts, neg); | |
adf9f195 | 2734 | } |
adf9f195 | 2735 | |
8d18eaaf | 2736 | return -EINVAL; |
adf9f195 FW |
2737 | } |
2738 | ||
af4617bd SR |
2739 | static void set_tracer_flags(unsigned int mask, int enabled) |
2740 | { | |
2741 | /* do nothing if flag is already set */ | |
2742 | if (!!(trace_flags & mask) == !!enabled) | |
2743 | return; | |
2744 | ||
2745 | if (enabled) | |
2746 | trace_flags |= mask; | |
2747 | else | |
2748 | trace_flags &= ~mask; | |
e870e9a1 LZ |
2749 | |
2750 | if (mask == TRACE_ITER_RECORD_CMD) | |
2751 | trace_event_enable_cmd_record(enabled); | |
750912fa DS |
2752 | |
2753 | if (mask == TRACE_ITER_OVERWRITE) | |
2754 | ring_buffer_change_overwrite(global_trace.buffer, enabled); | |
af4617bd SR |
2755 | } |
2756 | ||
bc0c38d1 | 2757 | static ssize_t |
ee6bce52 | 2758 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, |
bc0c38d1 SR |
2759 | size_t cnt, loff_t *ppos) |
2760 | { | |
2761 | char buf[64]; | |
8d18eaaf | 2762 | char *cmp; |
bc0c38d1 | 2763 | int neg = 0; |
adf9f195 | 2764 | int ret; |
bc0c38d1 SR |
2765 | int i; |
2766 | ||
cffae437 SR |
2767 | if (cnt >= sizeof(buf)) |
2768 | return -EINVAL; | |
bc0c38d1 SR |
2769 | |
2770 | if (copy_from_user(&buf, ubuf, cnt)) | |
2771 | return -EFAULT; | |
2772 | ||
2773 | buf[cnt] = 0; | |
8d18eaaf | 2774 | cmp = strstrip(buf); |
bc0c38d1 | 2775 | |
8d18eaaf | 2776 | if (strncmp(cmp, "no", 2) == 0) { |
bc0c38d1 SR |
2777 | neg = 1; |
2778 | cmp += 2; | |
2779 | } | |
2780 | ||
2781 | for (i = 0; trace_options[i]; i++) { | |
8d18eaaf | 2782 | if (strcmp(cmp, trace_options[i]) == 0) { |
af4617bd | 2783 | set_tracer_flags(1 << i, !neg); |
bc0c38d1 SR |
2784 | break; |
2785 | } | |
2786 | } | |
adf9f195 FW |
2787 | |
2788 | /* If no option could be set, test the specific tracer options */ | |
2789 | if (!trace_options[i]) { | |
d8e83d26 | 2790 | mutex_lock(&trace_types_lock); |
adf9f195 | 2791 | ret = set_tracer_option(current_trace, cmp, neg); |
d8e83d26 | 2792 | mutex_unlock(&trace_types_lock); |
adf9f195 FW |
2793 | if (ret) |
2794 | return ret; | |
2795 | } | |
bc0c38d1 | 2796 | |
cf8517cf | 2797 | *ppos += cnt; |
bc0c38d1 SR |
2798 | |
2799 | return cnt; | |
2800 | } | |
2801 | ||
fdb372ed LZ |
2802 | static int tracing_trace_options_open(struct inode *inode, struct file *file) |
2803 | { | |
2804 | if (tracing_disabled) | |
2805 | return -ENODEV; | |
2806 | return single_open(file, tracing_trace_options_show, NULL); | |
2807 | } | |
2808 | ||
5e2336a0 | 2809 | static const struct file_operations tracing_iter_fops = { |
fdb372ed LZ |
2810 | .open = tracing_trace_options_open, |
2811 | .read = seq_read, | |
2812 | .llseek = seq_lseek, | |
2813 | .release = single_release, | |
ee6bce52 | 2814 | .write = tracing_trace_options_write, |
bc0c38d1 SR |
2815 | }; |
2816 | ||
7bd2f24c IM |
2817 | static const char readme_msg[] = |
2818 | "tracing mini-HOWTO:\n\n" | |
156f5a78 GL |
2819 | "# mount -t debugfs nodev /sys/kernel/debug\n\n" |
2820 | "# cat /sys/kernel/debug/tracing/available_tracers\n" | |
1e42e83f | 2821 | "wakeup wakeup_rt preemptirqsoff preemptoff irqsoff function nop\n\n" |
156f5a78 | 2822 | "# cat /sys/kernel/debug/tracing/current_tracer\n" |
bc2b6871 | 2823 | "nop\n" |
1e42e83f | 2824 | "# echo wakeup > /sys/kernel/debug/tracing/current_tracer\n" |
156f5a78 | 2825 | "# cat /sys/kernel/debug/tracing/current_tracer\n" |
1e42e83f | 2826 | "wakeup\n" |
156f5a78 | 2827 | "# cat /sys/kernel/debug/tracing/trace_options\n" |
7bd2f24c | 2828 | "noprint-parent nosym-offset nosym-addr noverbose\n" |
156f5a78 | 2829 | "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n" |
9b5f8b31 | 2830 | "# echo 1 > /sys/kernel/debug/tracing/tracing_on\n" |
156f5a78 | 2831 | "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n" |
9b5f8b31 | 2832 | "# echo 0 > /sys/kernel/debug/tracing/tracing_on\n" |
7bd2f24c IM |
2833 | ; |
2834 | ||
2835 | static ssize_t | |
2836 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
2837 | size_t cnt, loff_t *ppos) | |
2838 | { | |
2839 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
2840 | readme_msg, strlen(readme_msg)); | |
2841 | } | |
2842 | ||
5e2336a0 | 2843 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
2844 | .open = tracing_open_generic, |
2845 | .read = tracing_readme_read, | |
b444786f | 2846 | .llseek = generic_file_llseek, |
7bd2f24c IM |
2847 | }; |
2848 | ||
69abe6a5 AP |
2849 | static ssize_t |
2850 | tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, | |
2851 | size_t cnt, loff_t *ppos) | |
2852 | { | |
2853 | char *buf_comm; | |
2854 | char *file_buf; | |
2855 | char *buf; | |
2856 | int len = 0; | |
2857 | int pid; | |
2858 | int i; | |
2859 | ||
2860 | file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL); | |
2861 | if (!file_buf) | |
2862 | return -ENOMEM; | |
2863 | ||
2864 | buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL); | |
2865 | if (!buf_comm) { | |
2866 | kfree(file_buf); | |
2867 | return -ENOMEM; | |
2868 | } | |
2869 | ||
2870 | buf = file_buf; | |
2871 | ||
2872 | for (i = 0; i < SAVED_CMDLINES; i++) { | |
2873 | int r; | |
2874 | ||
2875 | pid = map_cmdline_to_pid[i]; | |
2876 | if (pid == -1 || pid == NO_CMDLINE_MAP) | |
2877 | continue; | |
2878 | ||
2879 | trace_find_cmdline(pid, buf_comm); | |
2880 | r = sprintf(buf, "%d %s\n", pid, buf_comm); | |
2881 | buf += r; | |
2882 | len += r; | |
2883 | } | |
2884 | ||
2885 | len = simple_read_from_buffer(ubuf, cnt, ppos, | |
2886 | file_buf, len); | |
2887 | ||
2888 | kfree(file_buf); | |
2889 | kfree(buf_comm); | |
2890 | ||
2891 | return len; | |
2892 | } | |
2893 | ||
2894 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
2895 | .open = tracing_open_generic, | |
2896 | .read = tracing_saved_cmdlines_read, | |
b444786f | 2897 | .llseek = generic_file_llseek, |
69abe6a5 AP |
2898 | }; |
2899 | ||
bc0c38d1 SR |
2900 | static ssize_t |
2901 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
2902 | size_t cnt, loff_t *ppos) | |
2903 | { | |
bc0c38d1 SR |
2904 | char buf[64]; |
2905 | int r; | |
2906 | ||
9036990d | 2907 | r = sprintf(buf, "%u\n", tracer_enabled); |
4e3c3333 | 2908 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2909 | } |
2910 | ||
2911 | static ssize_t | |
2912 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
2913 | size_t cnt, loff_t *ppos) | |
2914 | { | |
2915 | struct trace_array *tr = filp->private_data; | |
5e39841c | 2916 | unsigned long val; |
c6caeeb1 | 2917 | int ret; |
bc0c38d1 | 2918 | |
22fe9b54 PH |
2919 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
2920 | if (ret) | |
c6caeeb1 | 2921 | return ret; |
bc0c38d1 SR |
2922 | |
2923 | val = !!val; | |
2924 | ||
2925 | mutex_lock(&trace_types_lock); | |
9036990d | 2926 | if (tracer_enabled ^ val) { |
6752ab4a SR |
2927 | |
2928 | /* Only need to warn if this is used to change the state */ | |
2929 | WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on"); | |
2930 | ||
9036990d | 2931 | if (val) { |
bc0c38d1 | 2932 | tracer_enabled = 1; |
9036990d SR |
2933 | if (current_trace->start) |
2934 | current_trace->start(tr); | |
2935 | tracing_start(); | |
2936 | } else { | |
bc0c38d1 | 2937 | tracer_enabled = 0; |
9036990d SR |
2938 | tracing_stop(); |
2939 | if (current_trace->stop) | |
2940 | current_trace->stop(tr); | |
2941 | } | |
bc0c38d1 SR |
2942 | } |
2943 | mutex_unlock(&trace_types_lock); | |
2944 | ||
cf8517cf | 2945 | *ppos += cnt; |
bc0c38d1 SR |
2946 | |
2947 | return cnt; | |
2948 | } | |
2949 | ||
2950 | static ssize_t | |
2951 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
2952 | size_t cnt, loff_t *ppos) | |
2953 | { | |
ee6c2c1b | 2954 | char buf[MAX_TRACER_SIZE+2]; |
bc0c38d1 SR |
2955 | int r; |
2956 | ||
2957 | mutex_lock(&trace_types_lock); | |
2958 | if (current_trace) | |
2959 | r = sprintf(buf, "%s\n", current_trace->name); | |
2960 | else | |
2961 | r = sprintf(buf, "\n"); | |
2962 | mutex_unlock(&trace_types_lock); | |
2963 | ||
4bf39a94 | 2964 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2965 | } |
2966 | ||
b6f11df2 ACM |
2967 | int tracer_init(struct tracer *t, struct trace_array *tr) |
2968 | { | |
2969 | tracing_reset_online_cpus(tr); | |
2970 | return t->init(tr); | |
2971 | } | |
2972 | ||
4f271a2a | 2973 | static int __tracing_resize_ring_buffer(unsigned long size) |
73c5162a SR |
2974 | { |
2975 | int ret; | |
2976 | ||
2977 | /* | |
2978 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
2979 | * we use the size that was given, and we can forget about |
2980 | * expanding it later. | |
73c5162a SR |
2981 | */ |
2982 | ring_buffer_expanded = 1; | |
2983 | ||
2984 | ret = ring_buffer_resize(global_trace.buffer, size); | |
2985 | if (ret < 0) | |
2986 | return ret; | |
2987 | ||
ef710e10 KM |
2988 | if (!current_trace->use_max_tr) |
2989 | goto out; | |
2990 | ||
73c5162a SR |
2991 | ret = ring_buffer_resize(max_tr.buffer, size); |
2992 | if (ret < 0) { | |
2993 | int r; | |
2994 | ||
2995 | r = ring_buffer_resize(global_trace.buffer, | |
2996 | global_trace.entries); | |
2997 | if (r < 0) { | |
a123c52b SR |
2998 | /* |
2999 | * AARGH! We are left with different | |
3000 | * size max buffer!!!! | |
3001 | * The max buffer is our "snapshot" buffer. | |
3002 | * When a tracer needs a snapshot (one of the | |
3003 | * latency tracers), it swaps the max buffer | |
3004 | * with the saved snap shot. We succeeded to | |
3005 | * update the size of the main buffer, but failed to | |
3006 | * update the size of the max buffer. But when we tried | |
3007 | * to reset the main buffer to the original size, we | |
3008 | * failed there too. This is very unlikely to | |
3009 | * happen, but if it does, warn and kill all | |
3010 | * tracing. | |
3011 | */ | |
73c5162a SR |
3012 | WARN_ON(1); |
3013 | tracing_disabled = 1; | |
3014 | } | |
3015 | return ret; | |
3016 | } | |
3017 | ||
ef710e10 KM |
3018 | max_tr.entries = size; |
3019 | out: | |
73c5162a SR |
3020 | global_trace.entries = size; |
3021 | ||
3022 | return ret; | |
3023 | } | |
3024 | ||
4f271a2a VN |
3025 | static ssize_t tracing_resize_ring_buffer(unsigned long size) |
3026 | { | |
3027 | int cpu, ret = size; | |
3028 | ||
3029 | mutex_lock(&trace_types_lock); | |
3030 | ||
3031 | tracing_stop(); | |
3032 | ||
3033 | /* disable all cpu buffers */ | |
3034 | for_each_tracing_cpu(cpu) { | |
3035 | if (global_trace.data[cpu]) | |
3036 | atomic_inc(&global_trace.data[cpu]->disabled); | |
3037 | if (max_tr.data[cpu]) | |
3038 | atomic_inc(&max_tr.data[cpu]->disabled); | |
3039 | } | |
3040 | ||
3041 | if (size != global_trace.entries) | |
3042 | ret = __tracing_resize_ring_buffer(size); | |
3043 | ||
3044 | if (ret < 0) | |
3045 | ret = -ENOMEM; | |
3046 | ||
3047 | for_each_tracing_cpu(cpu) { | |
3048 | if (global_trace.data[cpu]) | |
3049 | atomic_dec(&global_trace.data[cpu]->disabled); | |
3050 | if (max_tr.data[cpu]) | |
3051 | atomic_dec(&max_tr.data[cpu]->disabled); | |
3052 | } | |
3053 | ||
3054 | tracing_start(); | |
3055 | mutex_unlock(&trace_types_lock); | |
3056 | ||
3057 | return ret; | |
3058 | } | |
3059 | ||
ef710e10 | 3060 | |
1852fcce SR |
3061 | /** |
3062 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
3063 | * | |
3064 | * To save on memory when the tracing is never used on a system with it | |
3065 | * configured in. The ring buffers are set to a minimum size. But once | |
3066 | * a user starts to use the tracing facility, then they need to grow | |
3067 | * to their default size. | |
3068 | * | |
3069 | * This function is to be called when a tracer is about to be used. | |
3070 | */ | |
3071 | int tracing_update_buffers(void) | |
3072 | { | |
3073 | int ret = 0; | |
3074 | ||
1027fcb2 | 3075 | mutex_lock(&trace_types_lock); |
1852fcce | 3076 | if (!ring_buffer_expanded) |
4f271a2a | 3077 | ret = __tracing_resize_ring_buffer(trace_buf_size); |
1027fcb2 | 3078 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
3079 | |
3080 | return ret; | |
3081 | } | |
3082 | ||
577b785f SR |
3083 | struct trace_option_dentry; |
3084 | ||
3085 | static struct trace_option_dentry * | |
3086 | create_trace_option_files(struct tracer *tracer); | |
3087 | ||
3088 | static void | |
3089 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
3090 | ||
b2821ae6 | 3091 | static int tracing_set_tracer(const char *buf) |
bc0c38d1 | 3092 | { |
577b785f | 3093 | static struct trace_option_dentry *topts; |
bc0c38d1 SR |
3094 | struct trace_array *tr = &global_trace; |
3095 | struct tracer *t; | |
d9e54076 | 3096 | int ret = 0; |
bc0c38d1 | 3097 | |
1027fcb2 SR |
3098 | mutex_lock(&trace_types_lock); |
3099 | ||
73c5162a | 3100 | if (!ring_buffer_expanded) { |
4f271a2a | 3101 | ret = __tracing_resize_ring_buffer(trace_buf_size); |
73c5162a | 3102 | if (ret < 0) |
59f586db | 3103 | goto out; |
73c5162a SR |
3104 | ret = 0; |
3105 | } | |
3106 | ||
bc0c38d1 SR |
3107 | for (t = trace_types; t; t = t->next) { |
3108 | if (strcmp(t->name, buf) == 0) | |
3109 | break; | |
3110 | } | |
c2931e05 FW |
3111 | if (!t) { |
3112 | ret = -EINVAL; | |
3113 | goto out; | |
3114 | } | |
3115 | if (t == current_trace) | |
bc0c38d1 SR |
3116 | goto out; |
3117 | ||
9f029e83 | 3118 | trace_branch_disable(); |
bc0c38d1 SR |
3119 | if (current_trace && current_trace->reset) |
3120 | current_trace->reset(tr); | |
ef710e10 KM |
3121 | if (current_trace && current_trace->use_max_tr) { |
3122 | /* | |
3123 | * We don't free the ring buffer. instead, resize it because | |
3124 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
3125 | * we want preserve it. | |
3126 | */ | |
3127 | ring_buffer_resize(max_tr.buffer, 1); | |
3128 | max_tr.entries = 1; | |
3129 | } | |
577b785f SR |
3130 | destroy_trace_option_files(topts); |
3131 | ||
bc0c38d1 | 3132 | current_trace = t; |
577b785f SR |
3133 | |
3134 | topts = create_trace_option_files(current_trace); | |
ef710e10 KM |
3135 | if (current_trace->use_max_tr) { |
3136 | ret = ring_buffer_resize(max_tr.buffer, global_trace.entries); | |
3137 | if (ret < 0) | |
3138 | goto out; | |
3139 | max_tr.entries = global_trace.entries; | |
3140 | } | |
577b785f | 3141 | |
1c80025a | 3142 | if (t->init) { |
b6f11df2 | 3143 | ret = tracer_init(t, tr); |
1c80025a FW |
3144 | if (ret) |
3145 | goto out; | |
3146 | } | |
bc0c38d1 | 3147 | |
9f029e83 | 3148 | trace_branch_enable(tr); |
bc0c38d1 SR |
3149 | out: |
3150 | mutex_unlock(&trace_types_lock); | |
3151 | ||
d9e54076 PZ |
3152 | return ret; |
3153 | } | |
3154 | ||
3155 | static ssize_t | |
3156 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
3157 | size_t cnt, loff_t *ppos) | |
3158 | { | |
ee6c2c1b | 3159 | char buf[MAX_TRACER_SIZE+1]; |
d9e54076 PZ |
3160 | int i; |
3161 | size_t ret; | |
e6e7a65a FW |
3162 | int err; |
3163 | ||
3164 | ret = cnt; | |
d9e54076 | 3165 | |
ee6c2c1b LZ |
3166 | if (cnt > MAX_TRACER_SIZE) |
3167 | cnt = MAX_TRACER_SIZE; | |
d9e54076 PZ |
3168 | |
3169 | if (copy_from_user(&buf, ubuf, cnt)) | |
3170 | return -EFAULT; | |
3171 | ||
3172 | buf[cnt] = 0; | |
3173 | ||
3174 | /* strip ending whitespace. */ | |
3175 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
3176 | buf[i] = 0; | |
3177 | ||
e6e7a65a FW |
3178 | err = tracing_set_tracer(buf); |
3179 | if (err) | |
3180 | return err; | |
d9e54076 | 3181 | |
cf8517cf | 3182 | *ppos += ret; |
bc0c38d1 | 3183 | |
c2931e05 | 3184 | return ret; |
bc0c38d1 SR |
3185 | } |
3186 | ||
3187 | static ssize_t | |
3188 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
3189 | size_t cnt, loff_t *ppos) | |
3190 | { | |
3191 | unsigned long *ptr = filp->private_data; | |
3192 | char buf[64]; | |
3193 | int r; | |
3194 | ||
cffae437 | 3195 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 3196 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
3197 | if (r > sizeof(buf)) |
3198 | r = sizeof(buf); | |
4bf39a94 | 3199 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
3200 | } |
3201 | ||
3202 | static ssize_t | |
3203 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
3204 | size_t cnt, loff_t *ppos) | |
3205 | { | |
5e39841c | 3206 | unsigned long *ptr = filp->private_data; |
5e39841c | 3207 | unsigned long val; |
c6caeeb1 | 3208 | int ret; |
bc0c38d1 | 3209 | |
22fe9b54 PH |
3210 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
3211 | if (ret) | |
c6caeeb1 | 3212 | return ret; |
bc0c38d1 SR |
3213 | |
3214 | *ptr = val * 1000; | |
3215 | ||
3216 | return cnt; | |
3217 | } | |
3218 | ||
b3806b43 SR |
3219 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
3220 | { | |
b04cc6b1 | 3221 | long cpu_file = (long) inode->i_private; |
b3806b43 | 3222 | struct trace_iterator *iter; |
b04cc6b1 | 3223 | int ret = 0; |
b3806b43 SR |
3224 | |
3225 | if (tracing_disabled) | |
3226 | return -ENODEV; | |
3227 | ||
b04cc6b1 FW |
3228 | mutex_lock(&trace_types_lock); |
3229 | ||
b3806b43 SR |
3230 | /* create a buffer to store the information to pass to userspace */ |
3231 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
3232 | if (!iter) { |
3233 | ret = -ENOMEM; | |
3234 | goto out; | |
3235 | } | |
b3806b43 | 3236 | |
d7350c3f FW |
3237 | /* |
3238 | * We make a copy of the current tracer to avoid concurrent | |
3239 | * changes on it while we are reading. | |
3240 | */ | |
3241 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
3242 | if (!iter->trace) { | |
3243 | ret = -ENOMEM; | |
3244 | goto fail; | |
3245 | } | |
3246 | if (current_trace) | |
3247 | *iter->trace = *current_trace; | |
3248 | ||
4462344e | 3249 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 3250 | ret = -ENOMEM; |
d7350c3f | 3251 | goto fail; |
4462344e RR |
3252 | } |
3253 | ||
a309720c | 3254 | /* trace pipe does not show start of buffer */ |
4462344e | 3255 | cpumask_setall(iter->started); |
a309720c | 3256 | |
112f38a7 SR |
3257 | if (trace_flags & TRACE_ITER_LATENCY_FMT) |
3258 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
3259 | ||
b04cc6b1 | 3260 | iter->cpu_file = cpu_file; |
b3806b43 | 3261 | iter->tr = &global_trace; |
d7350c3f | 3262 | mutex_init(&iter->mutex); |
b3806b43 SR |
3263 | filp->private_data = iter; |
3264 | ||
107bad8b SR |
3265 | if (iter->trace->pipe_open) |
3266 | iter->trace->pipe_open(iter); | |
107bad8b | 3267 | |
b444786f | 3268 | nonseekable_open(inode, filp); |
b04cc6b1 FW |
3269 | out: |
3270 | mutex_unlock(&trace_types_lock); | |
3271 | return ret; | |
d7350c3f FW |
3272 | |
3273 | fail: | |
3274 | kfree(iter->trace); | |
3275 | kfree(iter); | |
3276 | mutex_unlock(&trace_types_lock); | |
3277 | return ret; | |
b3806b43 SR |
3278 | } |
3279 | ||
3280 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
3281 | { | |
3282 | struct trace_iterator *iter = file->private_data; | |
3283 | ||
b04cc6b1 FW |
3284 | mutex_lock(&trace_types_lock); |
3285 | ||
29bf4a5e | 3286 | if (iter->trace->pipe_close) |
c521efd1 SR |
3287 | iter->trace->pipe_close(iter); |
3288 | ||
b04cc6b1 FW |
3289 | mutex_unlock(&trace_types_lock); |
3290 | ||
4462344e | 3291 | free_cpumask_var(iter->started); |
d7350c3f FW |
3292 | mutex_destroy(&iter->mutex); |
3293 | kfree(iter->trace); | |
b3806b43 | 3294 | kfree(iter); |
b3806b43 SR |
3295 | |
3296 | return 0; | |
3297 | } | |
3298 | ||
2a2cc8f7 SSP |
3299 | static unsigned int |
3300 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
3301 | { | |
3302 | struct trace_iterator *iter = filp->private_data; | |
3303 | ||
3304 | if (trace_flags & TRACE_ITER_BLOCK) { | |
3305 | /* | |
3306 | * Always select as readable when in blocking mode | |
3307 | */ | |
3308 | return POLLIN | POLLRDNORM; | |
afc2abc0 | 3309 | } else { |
2a2cc8f7 SSP |
3310 | if (!trace_empty(iter)) |
3311 | return POLLIN | POLLRDNORM; | |
3312 | poll_wait(filp, &trace_wait, poll_table); | |
3313 | if (!trace_empty(iter)) | |
3314 | return POLLIN | POLLRDNORM; | |
3315 | ||
3316 | return 0; | |
3317 | } | |
3318 | } | |
3319 | ||
6eaaa5d5 FW |
3320 | |
3321 | void default_wait_pipe(struct trace_iterator *iter) | |
3322 | { | |
3323 | DEFINE_WAIT(wait); | |
3324 | ||
3325 | prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE); | |
3326 | ||
3327 | if (trace_empty(iter)) | |
3328 | schedule(); | |
3329 | ||
3330 | finish_wait(&trace_wait, &wait); | |
3331 | } | |
3332 | ||
3333 | /* | |
3334 | * This is a make-shift waitqueue. | |
3335 | * A tracer might use this callback on some rare cases: | |
3336 | * | |
3337 | * 1) the current tracer might hold the runqueue lock when it wakes up | |
3338 | * a reader, hence a deadlock (sched, function, and function graph tracers) | |
3339 | * 2) the function tracers, trace all functions, we don't want | |
3340 | * the overhead of calling wake_up and friends | |
3341 | * (and tracing them too) | |
3342 | * | |
3343 | * Anyway, this is really very primitive wakeup. | |
3344 | */ | |
3345 | void poll_wait_pipe(struct trace_iterator *iter) | |
3346 | { | |
3347 | set_current_state(TASK_INTERRUPTIBLE); | |
3348 | /* sleep for 100 msecs, and try again. */ | |
3349 | schedule_timeout(HZ / 10); | |
3350 | } | |
3351 | ||
ff98781b EGM |
3352 | /* Must be called with trace_types_lock mutex held. */ |
3353 | static int tracing_wait_pipe(struct file *filp) | |
b3806b43 SR |
3354 | { |
3355 | struct trace_iterator *iter = filp->private_data; | |
b3806b43 | 3356 | |
b3806b43 | 3357 | while (trace_empty(iter)) { |
2dc8f095 | 3358 | |
107bad8b | 3359 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 3360 | return -EAGAIN; |
107bad8b | 3361 | } |
2dc8f095 | 3362 | |
d7350c3f | 3363 | mutex_unlock(&iter->mutex); |
107bad8b | 3364 | |
6eaaa5d5 | 3365 | iter->trace->wait_pipe(iter); |
b3806b43 | 3366 | |
d7350c3f | 3367 | mutex_lock(&iter->mutex); |
107bad8b | 3368 | |
6eaaa5d5 | 3369 | if (signal_pending(current)) |
ff98781b | 3370 | return -EINTR; |
b3806b43 SR |
3371 | |
3372 | /* | |
3373 | * We block until we read something and tracing is disabled. | |
3374 | * We still block if tracing is disabled, but we have never | |
3375 | * read anything. This allows a user to cat this file, and | |
3376 | * then enable tracing. But after we have read something, | |
3377 | * we give an EOF when tracing is again disabled. | |
3378 | * | |
3379 | * iter->pos will be 0 if we haven't read anything. | |
3380 | */ | |
3381 | if (!tracer_enabled && iter->pos) | |
3382 | break; | |
b3806b43 SR |
3383 | } |
3384 | ||
ff98781b EGM |
3385 | return 1; |
3386 | } | |
3387 | ||
3388 | /* | |
3389 | * Consumer reader. | |
3390 | */ | |
3391 | static ssize_t | |
3392 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
3393 | size_t cnt, loff_t *ppos) | |
3394 | { | |
3395 | struct trace_iterator *iter = filp->private_data; | |
d7350c3f | 3396 | static struct tracer *old_tracer; |
ff98781b EGM |
3397 | ssize_t sret; |
3398 | ||
3399 | /* return any leftover data */ | |
3400 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
3401 | if (sret != -EBUSY) | |
3402 | return sret; | |
3403 | ||
f9520750 | 3404 | trace_seq_init(&iter->seq); |
ff98781b | 3405 | |
d7350c3f | 3406 | /* copy the tracer to avoid using a global lock all around */ |
ff98781b | 3407 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
3408 | if (unlikely(old_tracer != current_trace && current_trace)) { |
3409 | old_tracer = current_trace; | |
3410 | *iter->trace = *current_trace; | |
3411 | } | |
3412 | mutex_unlock(&trace_types_lock); | |
3413 | ||
3414 | /* | |
3415 | * Avoid more than one consumer on a single file descriptor | |
3416 | * This is just a matter of traces coherency, the ring buffer itself | |
3417 | * is protected. | |
3418 | */ | |
3419 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
3420 | if (iter->trace->read) { |
3421 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
3422 | if (sret) | |
3423 | goto out; | |
3424 | } | |
3425 | ||
3426 | waitagain: | |
3427 | sret = tracing_wait_pipe(filp); | |
3428 | if (sret <= 0) | |
3429 | goto out; | |
3430 | ||
b3806b43 | 3431 | /* stop when tracing is finished */ |
ff98781b EGM |
3432 | if (trace_empty(iter)) { |
3433 | sret = 0; | |
107bad8b | 3434 | goto out; |
ff98781b | 3435 | } |
b3806b43 SR |
3436 | |
3437 | if (cnt >= PAGE_SIZE) | |
3438 | cnt = PAGE_SIZE - 1; | |
3439 | ||
53d0aa77 | 3440 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
3441 | memset(&iter->seq, 0, |
3442 | sizeof(struct trace_iterator) - | |
3443 | offsetof(struct trace_iterator, seq)); | |
4823ed7e | 3444 | iter->pos = -1; |
b3806b43 | 3445 | |
4f535968 | 3446 | trace_event_read_lock(); |
7e53bd42 | 3447 | trace_access_lock(iter->cpu_file); |
955b61e5 | 3448 | while (trace_find_next_entry_inc(iter) != NULL) { |
2c4f035f | 3449 | enum print_line_t ret; |
088b1e42 SR |
3450 | int len = iter->seq.len; |
3451 | ||
f9896bf3 | 3452 | ret = print_trace_line(iter); |
2c4f035f | 3453 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 SR |
3454 | /* don't print partial lines */ |
3455 | iter->seq.len = len; | |
b3806b43 | 3456 | break; |
088b1e42 | 3457 | } |
b91facc3 FW |
3458 | if (ret != TRACE_TYPE_NO_CONSUME) |
3459 | trace_consume(iter); | |
b3806b43 SR |
3460 | |
3461 | if (iter->seq.len >= cnt) | |
3462 | break; | |
ee5e51f5 JO |
3463 | |
3464 | /* | |
3465 | * Setting the full flag means we reached the trace_seq buffer | |
3466 | * size and we should leave by partial output condition above. | |
3467 | * One of the trace_seq_* functions is not used properly. | |
3468 | */ | |
3469 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
3470 | iter->ent->type); | |
b3806b43 | 3471 | } |
7e53bd42 | 3472 | trace_access_unlock(iter->cpu_file); |
4f535968 | 3473 | trace_event_read_unlock(); |
b3806b43 | 3474 | |
b3806b43 | 3475 | /* Now copy what we have to the user */ |
6c6c2796 PP |
3476 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
3477 | if (iter->seq.readpos >= iter->seq.len) | |
f9520750 | 3478 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
3479 | |
3480 | /* | |
25985edc | 3481 | * If there was nothing to send to user, in spite of consuming trace |
9ff4b974 PP |
3482 | * entries, go back to wait for more entries. |
3483 | */ | |
6c6c2796 | 3484 | if (sret == -EBUSY) |
9ff4b974 | 3485 | goto waitagain; |
b3806b43 | 3486 | |
107bad8b | 3487 | out: |
d7350c3f | 3488 | mutex_unlock(&iter->mutex); |
107bad8b | 3489 | |
6c6c2796 | 3490 | return sret; |
b3806b43 SR |
3491 | } |
3492 | ||
3c56819b EGM |
3493 | static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, |
3494 | struct pipe_buffer *buf) | |
3495 | { | |
3496 | __free_page(buf->page); | |
3497 | } | |
3498 | ||
3499 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, | |
3500 | unsigned int idx) | |
3501 | { | |
3502 | __free_page(spd->pages[idx]); | |
3503 | } | |
3504 | ||
28dfef8f | 3505 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { |
34cd4998 SR |
3506 | .can_merge = 0, |
3507 | .map = generic_pipe_buf_map, | |
3508 | .unmap = generic_pipe_buf_unmap, | |
3509 | .confirm = generic_pipe_buf_confirm, | |
3510 | .release = tracing_pipe_buf_release, | |
3511 | .steal = generic_pipe_buf_steal, | |
3512 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
3513 | }; |
3514 | ||
34cd4998 | 3515 | static size_t |
fa7c7f6e | 3516 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
3517 | { |
3518 | size_t count; | |
3519 | int ret; | |
3520 | ||
3521 | /* Seq buffer is page-sized, exactly what we need. */ | |
3522 | for (;;) { | |
3523 | count = iter->seq.len; | |
3524 | ret = print_trace_line(iter); | |
3525 | count = iter->seq.len - count; | |
3526 | if (rem < count) { | |
3527 | rem = 0; | |
3528 | iter->seq.len -= count; | |
3529 | break; | |
3530 | } | |
3531 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
3532 | iter->seq.len -= count; | |
3533 | break; | |
3534 | } | |
3535 | ||
74e7ff8c LJ |
3536 | if (ret != TRACE_TYPE_NO_CONSUME) |
3537 | trace_consume(iter); | |
34cd4998 | 3538 | rem -= count; |
955b61e5 | 3539 | if (!trace_find_next_entry_inc(iter)) { |
34cd4998 SR |
3540 | rem = 0; |
3541 | iter->ent = NULL; | |
3542 | break; | |
3543 | } | |
3544 | } | |
3545 | ||
3546 | return rem; | |
3547 | } | |
3548 | ||
3c56819b EGM |
3549 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
3550 | loff_t *ppos, | |
3551 | struct pipe_inode_info *pipe, | |
3552 | size_t len, | |
3553 | unsigned int flags) | |
3554 | { | |
35f3d14d JA |
3555 | struct page *pages_def[PIPE_DEF_BUFFERS]; |
3556 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3c56819b EGM |
3557 | struct trace_iterator *iter = filp->private_data; |
3558 | struct splice_pipe_desc spd = { | |
35f3d14d JA |
3559 | .pages = pages_def, |
3560 | .partial = partial_def, | |
34cd4998 SR |
3561 | .nr_pages = 0, /* This gets updated below. */ |
3562 | .flags = flags, | |
3563 | .ops = &tracing_pipe_buf_ops, | |
3564 | .spd_release = tracing_spd_release_pipe, | |
3c56819b | 3565 | }; |
d7350c3f | 3566 | static struct tracer *old_tracer; |
3c56819b | 3567 | ssize_t ret; |
34cd4998 | 3568 | size_t rem; |
3c56819b EGM |
3569 | unsigned int i; |
3570 | ||
35f3d14d JA |
3571 | if (splice_grow_spd(pipe, &spd)) |
3572 | return -ENOMEM; | |
3573 | ||
d7350c3f | 3574 | /* copy the tracer to avoid using a global lock all around */ |
3c56819b | 3575 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
3576 | if (unlikely(old_tracer != current_trace && current_trace)) { |
3577 | old_tracer = current_trace; | |
3578 | *iter->trace = *current_trace; | |
3579 | } | |
3580 | mutex_unlock(&trace_types_lock); | |
3581 | ||
3582 | mutex_lock(&iter->mutex); | |
3c56819b EGM |
3583 | |
3584 | if (iter->trace->splice_read) { | |
3585 | ret = iter->trace->splice_read(iter, filp, | |
3586 | ppos, pipe, len, flags); | |
3587 | if (ret) | |
34cd4998 | 3588 | goto out_err; |
3c56819b EGM |
3589 | } |
3590 | ||
3591 | ret = tracing_wait_pipe(filp); | |
3592 | if (ret <= 0) | |
34cd4998 | 3593 | goto out_err; |
3c56819b | 3594 | |
955b61e5 | 3595 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { |
3c56819b | 3596 | ret = -EFAULT; |
34cd4998 | 3597 | goto out_err; |
3c56819b EGM |
3598 | } |
3599 | ||
4f535968 | 3600 | trace_event_read_lock(); |
7e53bd42 | 3601 | trace_access_lock(iter->cpu_file); |
4f535968 | 3602 | |
3c56819b | 3603 | /* Fill as many pages as possible. */ |
35f3d14d JA |
3604 | for (i = 0, rem = len; i < pipe->buffers && rem; i++) { |
3605 | spd.pages[i] = alloc_page(GFP_KERNEL); | |
3606 | if (!spd.pages[i]) | |
34cd4998 | 3607 | break; |
3c56819b | 3608 | |
fa7c7f6e | 3609 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
3610 | |
3611 | /* Copy the data into the page, so we can start over. */ | |
3612 | ret = trace_seq_to_buffer(&iter->seq, | |
35f3d14d | 3613 | page_address(spd.pages[i]), |
3c56819b EGM |
3614 | iter->seq.len); |
3615 | if (ret < 0) { | |
35f3d14d | 3616 | __free_page(spd.pages[i]); |
3c56819b EGM |
3617 | break; |
3618 | } | |
35f3d14d JA |
3619 | spd.partial[i].offset = 0; |
3620 | spd.partial[i].len = iter->seq.len; | |
3c56819b | 3621 | |
f9520750 | 3622 | trace_seq_init(&iter->seq); |
3c56819b EGM |
3623 | } |
3624 | ||
7e53bd42 | 3625 | trace_access_unlock(iter->cpu_file); |
4f535968 | 3626 | trace_event_read_unlock(); |
d7350c3f | 3627 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
3628 | |
3629 | spd.nr_pages = i; | |
3630 | ||
35f3d14d JA |
3631 | ret = splice_to_pipe(pipe, &spd); |
3632 | out: | |
3633 | splice_shrink_spd(pipe, &spd); | |
3634 | return ret; | |
3c56819b | 3635 | |
34cd4998 | 3636 | out_err: |
d7350c3f | 3637 | mutex_unlock(&iter->mutex); |
35f3d14d | 3638 | goto out; |
3c56819b EGM |
3639 | } |
3640 | ||
a98a3c3f SR |
3641 | static ssize_t |
3642 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
3643 | size_t cnt, loff_t *ppos) | |
3644 | { | |
3645 | struct trace_array *tr = filp->private_data; | |
db526ca3 | 3646 | char buf[96]; |
a98a3c3f SR |
3647 | int r; |
3648 | ||
db526ca3 SR |
3649 | mutex_lock(&trace_types_lock); |
3650 | if (!ring_buffer_expanded) | |
3651 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
3652 | tr->entries >> 10, | |
3653 | trace_buf_size >> 10); | |
3654 | else | |
3655 | r = sprintf(buf, "%lu\n", tr->entries >> 10); | |
3656 | mutex_unlock(&trace_types_lock); | |
3657 | ||
a98a3c3f SR |
3658 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
3659 | } | |
3660 | ||
3661 | static ssize_t | |
3662 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
3663 | size_t cnt, loff_t *ppos) | |
3664 | { | |
3665 | unsigned long val; | |
4f271a2a | 3666 | int ret; |
a98a3c3f | 3667 | |
22fe9b54 PH |
3668 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
3669 | if (ret) | |
c6caeeb1 | 3670 | return ret; |
a98a3c3f SR |
3671 | |
3672 | /* must have at least 1 entry */ | |
3673 | if (!val) | |
3674 | return -EINVAL; | |
3675 | ||
1696b2b0 SR |
3676 | /* value is in KB */ |
3677 | val <<= 10; | |
3678 | ||
4f271a2a VN |
3679 | ret = tracing_resize_ring_buffer(val); |
3680 | if (ret < 0) | |
3681 | return ret; | |
a98a3c3f | 3682 | |
cf8517cf | 3683 | *ppos += cnt; |
a98a3c3f | 3684 | |
4f271a2a VN |
3685 | return cnt; |
3686 | } | |
bf5e6519 | 3687 | |
f81ab074 VN |
3688 | static ssize_t |
3689 | tracing_total_entries_read(struct file *filp, char __user *ubuf, | |
3690 | size_t cnt, loff_t *ppos) | |
3691 | { | |
3692 | struct trace_array *tr = filp->private_data; | |
3693 | char buf[64]; | |
3694 | int r, cpu; | |
3695 | unsigned long size = 0, expanded_size = 0; | |
3696 | ||
3697 | mutex_lock(&trace_types_lock); | |
3698 | for_each_tracing_cpu(cpu) { | |
3699 | size += tr->entries >> 10; | |
3700 | if (!ring_buffer_expanded) | |
3701 | expanded_size += trace_buf_size >> 10; | |
3702 | } | |
3703 | if (ring_buffer_expanded) | |
3704 | r = sprintf(buf, "%lu\n", size); | |
3705 | else | |
3706 | r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); | |
3707 | mutex_unlock(&trace_types_lock); | |
3708 | ||
3709 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3710 | } | |
3711 | ||
4f271a2a VN |
3712 | static ssize_t |
3713 | tracing_free_buffer_write(struct file *filp, const char __user *ubuf, | |
3714 | size_t cnt, loff_t *ppos) | |
3715 | { | |
3716 | /* | |
3717 | * There is no need to read what the user has written, this function | |
3718 | * is just to make sure that there is no error when "echo" is used | |
3719 | */ | |
3720 | ||
3721 | *ppos += cnt; | |
a98a3c3f SR |
3722 | |
3723 | return cnt; | |
3724 | } | |
3725 | ||
4f271a2a VN |
3726 | static int |
3727 | tracing_free_buffer_release(struct inode *inode, struct file *filp) | |
3728 | { | |
cf30cf67 SR |
3729 | /* disable tracing ? */ |
3730 | if (trace_flags & TRACE_ITER_STOP_ON_FREE) | |
3731 | tracing_off(); | |
4f271a2a VN |
3732 | /* resize the ring buffer to 0 */ |
3733 | tracing_resize_ring_buffer(0); | |
3734 | ||
3735 | return 0; | |
3736 | } | |
3737 | ||
5bf9a1ee PP |
3738 | static ssize_t |
3739 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
3740 | size_t cnt, loff_t *fpos) | |
3741 | { | |
d696b58c SR |
3742 | unsigned long addr = (unsigned long)ubuf; |
3743 | struct ring_buffer_event *event; | |
3744 | struct ring_buffer *buffer; | |
3745 | struct print_entry *entry; | |
3746 | unsigned long irq_flags; | |
3747 | struct page *pages[2]; | |
3748 | int nr_pages = 1; | |
3749 | ssize_t written; | |
3750 | void *page1; | |
3751 | void *page2; | |
3752 | int offset; | |
3753 | int size; | |
3754 | int len; | |
3755 | int ret; | |
5bf9a1ee | 3756 | |
c76f0694 | 3757 | if (tracing_disabled) |
5bf9a1ee PP |
3758 | return -EINVAL; |
3759 | ||
3760 | if (cnt > TRACE_BUF_SIZE) | |
3761 | cnt = TRACE_BUF_SIZE; | |
3762 | ||
d696b58c SR |
3763 | /* |
3764 | * Userspace is injecting traces into the kernel trace buffer. | |
3765 | * We want to be as non intrusive as possible. | |
3766 | * To do so, we do not want to allocate any special buffers | |
3767 | * or take any locks, but instead write the userspace data | |
3768 | * straight into the ring buffer. | |
3769 | * | |
3770 | * First we need to pin the userspace buffer into memory, | |
3771 | * which, most likely it is, because it just referenced it. | |
3772 | * But there's no guarantee that it is. By using get_user_pages_fast() | |
3773 | * and kmap_atomic/kunmap_atomic() we can get access to the | |
3774 | * pages directly. We then write the data directly into the | |
3775 | * ring buffer. | |
3776 | */ | |
3777 | BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); | |
5bf9a1ee | 3778 | |
d696b58c SR |
3779 | /* check if we cross pages */ |
3780 | if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) | |
3781 | nr_pages = 2; | |
3782 | ||
3783 | offset = addr & (PAGE_SIZE - 1); | |
3784 | addr &= PAGE_MASK; | |
3785 | ||
3786 | ret = get_user_pages_fast(addr, nr_pages, 0, pages); | |
3787 | if (ret < nr_pages) { | |
3788 | while (--ret >= 0) | |
3789 | put_page(pages[ret]); | |
3790 | written = -EFAULT; | |
3791 | goto out; | |
5bf9a1ee | 3792 | } |
d696b58c SR |
3793 | |
3794 | page1 = kmap_atomic(pages[0]); | |
3795 | if (nr_pages == 2) | |
3796 | page2 = kmap_atomic(pages[1]); | |
3797 | ||
3798 | local_save_flags(irq_flags); | |
3799 | size = sizeof(*entry) + cnt + 2; /* possible \n added */ | |
3800 | buffer = global_trace.buffer; | |
3801 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
3802 | irq_flags, preempt_count()); | |
3803 | if (!event) { | |
3804 | /* Ring buffer disabled, return as if not open for write */ | |
3805 | written = -EBADF; | |
3806 | goto out_unlock; | |
5bf9a1ee | 3807 | } |
d696b58c SR |
3808 | |
3809 | entry = ring_buffer_event_data(event); | |
3810 | entry->ip = _THIS_IP_; | |
3811 | ||
3812 | if (nr_pages == 2) { | |
3813 | len = PAGE_SIZE - offset; | |
3814 | memcpy(&entry->buf, page1 + offset, len); | |
3815 | memcpy(&entry->buf[len], page2, cnt - len); | |
c13d2f7c | 3816 | } else |
d696b58c | 3817 | memcpy(&entry->buf, page1 + offset, cnt); |
5bf9a1ee | 3818 | |
d696b58c SR |
3819 | if (entry->buf[cnt - 1] != '\n') { |
3820 | entry->buf[cnt] = '\n'; | |
3821 | entry->buf[cnt + 1] = '\0'; | |
3822 | } else | |
3823 | entry->buf[cnt] = '\0'; | |
3824 | ||
3825 | ring_buffer_unlock_commit(buffer, event); | |
5bf9a1ee | 3826 | |
d696b58c | 3827 | written = cnt; |
5bf9a1ee | 3828 | |
d696b58c | 3829 | *fpos += written; |
1aa54bca | 3830 | |
d696b58c SR |
3831 | out_unlock: |
3832 | if (nr_pages == 2) | |
3833 | kunmap_atomic(page2); | |
3834 | kunmap_atomic(page1); | |
3835 | while (nr_pages > 0) | |
3836 | put_page(pages[--nr_pages]); | |
3837 | out: | |
1aa54bca | 3838 | return written; |
5bf9a1ee PP |
3839 | } |
3840 | ||
13f16d20 | 3841 | static int tracing_clock_show(struct seq_file *m, void *v) |
5079f326 | 3842 | { |
5079f326 Z |
3843 | int i; |
3844 | ||
3845 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
13f16d20 | 3846 | seq_printf(m, |
5079f326 Z |
3847 | "%s%s%s%s", i ? " " : "", |
3848 | i == trace_clock_id ? "[" : "", trace_clocks[i].name, | |
3849 | i == trace_clock_id ? "]" : ""); | |
13f16d20 | 3850 | seq_putc(m, '\n'); |
5079f326 | 3851 | |
13f16d20 | 3852 | return 0; |
5079f326 Z |
3853 | } |
3854 | ||
3855 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
3856 | size_t cnt, loff_t *fpos) | |
3857 | { | |
3858 | char buf[64]; | |
3859 | const char *clockstr; | |
3860 | int i; | |
3861 | ||
3862 | if (cnt >= sizeof(buf)) | |
3863 | return -EINVAL; | |
3864 | ||
3865 | if (copy_from_user(&buf, ubuf, cnt)) | |
3866 | return -EFAULT; | |
3867 | ||
3868 | buf[cnt] = 0; | |
3869 | ||
3870 | clockstr = strstrip(buf); | |
3871 | ||
3872 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { | |
3873 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
3874 | break; | |
3875 | } | |
3876 | if (i == ARRAY_SIZE(trace_clocks)) | |
3877 | return -EINVAL; | |
3878 | ||
3879 | trace_clock_id = i; | |
3880 | ||
3881 | mutex_lock(&trace_types_lock); | |
3882 | ||
3883 | ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func); | |
3884 | if (max_tr.buffer) | |
3885 | ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); | |
3886 | ||
3887 | mutex_unlock(&trace_types_lock); | |
3888 | ||
3889 | *fpos += cnt; | |
3890 | ||
3891 | return cnt; | |
3892 | } | |
3893 | ||
13f16d20 LZ |
3894 | static int tracing_clock_open(struct inode *inode, struct file *file) |
3895 | { | |
3896 | if (tracing_disabled) | |
3897 | return -ENODEV; | |
3898 | return single_open(file, tracing_clock_show, NULL); | |
3899 | } | |
3900 | ||
5e2336a0 | 3901 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
3902 | .open = tracing_open_generic, |
3903 | .read = tracing_max_lat_read, | |
3904 | .write = tracing_max_lat_write, | |
b444786f | 3905 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
3906 | }; |
3907 | ||
5e2336a0 | 3908 | static const struct file_operations tracing_ctrl_fops = { |
4bf39a94 IM |
3909 | .open = tracing_open_generic, |
3910 | .read = tracing_ctrl_read, | |
3911 | .write = tracing_ctrl_write, | |
b444786f | 3912 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
3913 | }; |
3914 | ||
5e2336a0 | 3915 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
3916 | .open = tracing_open_generic, |
3917 | .read = tracing_set_trace_read, | |
3918 | .write = tracing_set_trace_write, | |
b444786f | 3919 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
3920 | }; |
3921 | ||
5e2336a0 | 3922 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 3923 | .open = tracing_open_pipe, |
2a2cc8f7 | 3924 | .poll = tracing_poll_pipe, |
4bf39a94 | 3925 | .read = tracing_read_pipe, |
3c56819b | 3926 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 3927 | .release = tracing_release_pipe, |
b444786f | 3928 | .llseek = no_llseek, |
b3806b43 SR |
3929 | }; |
3930 | ||
5e2336a0 | 3931 | static const struct file_operations tracing_entries_fops = { |
a98a3c3f SR |
3932 | .open = tracing_open_generic, |
3933 | .read = tracing_entries_read, | |
3934 | .write = tracing_entries_write, | |
b444786f | 3935 | .llseek = generic_file_llseek, |
a98a3c3f SR |
3936 | }; |
3937 | ||
f81ab074 VN |
3938 | static const struct file_operations tracing_total_entries_fops = { |
3939 | .open = tracing_open_generic, | |
3940 | .read = tracing_total_entries_read, | |
3941 | .llseek = generic_file_llseek, | |
3942 | }; | |
3943 | ||
4f271a2a VN |
3944 | static const struct file_operations tracing_free_buffer_fops = { |
3945 | .write = tracing_free_buffer_write, | |
3946 | .release = tracing_free_buffer_release, | |
3947 | }; | |
3948 | ||
5e2336a0 | 3949 | static const struct file_operations tracing_mark_fops = { |
43a15386 | 3950 | .open = tracing_open_generic, |
5bf9a1ee | 3951 | .write = tracing_mark_write, |
b444786f | 3952 | .llseek = generic_file_llseek, |
5bf9a1ee PP |
3953 | }; |
3954 | ||
5079f326 | 3955 | static const struct file_operations trace_clock_fops = { |
13f16d20 LZ |
3956 | .open = tracing_clock_open, |
3957 | .read = seq_read, | |
3958 | .llseek = seq_lseek, | |
3959 | .release = single_release, | |
5079f326 Z |
3960 | .write = tracing_clock_write, |
3961 | }; | |
3962 | ||
2cadf913 SR |
3963 | struct ftrace_buffer_info { |
3964 | struct trace_array *tr; | |
3965 | void *spare; | |
3966 | int cpu; | |
3967 | unsigned int read; | |
3968 | }; | |
3969 | ||
3970 | static int tracing_buffers_open(struct inode *inode, struct file *filp) | |
3971 | { | |
3972 | int cpu = (int)(long)inode->i_private; | |
3973 | struct ftrace_buffer_info *info; | |
3974 | ||
3975 | if (tracing_disabled) | |
3976 | return -ENODEV; | |
3977 | ||
3978 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
3979 | if (!info) | |
3980 | return -ENOMEM; | |
3981 | ||
3982 | info->tr = &global_trace; | |
3983 | info->cpu = cpu; | |
ddd538f3 | 3984 | info->spare = NULL; |
2cadf913 SR |
3985 | /* Force reading ring buffer for first read */ |
3986 | info->read = (unsigned int)-1; | |
2cadf913 SR |
3987 | |
3988 | filp->private_data = info; | |
3989 | ||
d1e7e02f | 3990 | return nonseekable_open(inode, filp); |
2cadf913 SR |
3991 | } |
3992 | ||
3993 | static ssize_t | |
3994 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
3995 | size_t count, loff_t *ppos) | |
3996 | { | |
3997 | struct ftrace_buffer_info *info = filp->private_data; | |
2cadf913 SR |
3998 | ssize_t ret; |
3999 | size_t size; | |
4000 | ||
2dc5d12b SR |
4001 | if (!count) |
4002 | return 0; | |
4003 | ||
ddd538f3 | 4004 | if (!info->spare) |
7ea59064 | 4005 | info->spare = ring_buffer_alloc_read_page(info->tr->buffer, info->cpu); |
ddd538f3 LJ |
4006 | if (!info->spare) |
4007 | return -ENOMEM; | |
4008 | ||
2cadf913 SR |
4009 | /* Do we have previous read data to read? */ |
4010 | if (info->read < PAGE_SIZE) | |
4011 | goto read; | |
4012 | ||
7e53bd42 | 4013 | trace_access_lock(info->cpu); |
2cadf913 SR |
4014 | ret = ring_buffer_read_page(info->tr->buffer, |
4015 | &info->spare, | |
4016 | count, | |
4017 | info->cpu, 0); | |
7e53bd42 | 4018 | trace_access_unlock(info->cpu); |
2cadf913 SR |
4019 | if (ret < 0) |
4020 | return 0; | |
4021 | ||
436fc280 SR |
4022 | info->read = 0; |
4023 | ||
2cadf913 SR |
4024 | read: |
4025 | size = PAGE_SIZE - info->read; | |
4026 | if (size > count) | |
4027 | size = count; | |
4028 | ||
4029 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
2dc5d12b | 4030 | if (ret == size) |
2cadf913 | 4031 | return -EFAULT; |
2dc5d12b SR |
4032 | size -= ret; |
4033 | ||
2cadf913 SR |
4034 | *ppos += size; |
4035 | info->read += size; | |
4036 | ||
4037 | return size; | |
4038 | } | |
4039 | ||
4040 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
4041 | { | |
4042 | struct ftrace_buffer_info *info = file->private_data; | |
4043 | ||
ddd538f3 LJ |
4044 | if (info->spare) |
4045 | ring_buffer_free_read_page(info->tr->buffer, info->spare); | |
2cadf913 SR |
4046 | kfree(info); |
4047 | ||
4048 | return 0; | |
4049 | } | |
4050 | ||
4051 | struct buffer_ref { | |
4052 | struct ring_buffer *buffer; | |
4053 | void *page; | |
4054 | int ref; | |
4055 | }; | |
4056 | ||
4057 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
4058 | struct pipe_buffer *buf) | |
4059 | { | |
4060 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
4061 | ||
4062 | if (--ref->ref) | |
4063 | return; | |
4064 | ||
4065 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
4066 | kfree(ref); | |
4067 | buf->private = 0; | |
4068 | } | |
4069 | ||
4070 | static int buffer_pipe_buf_steal(struct pipe_inode_info *pipe, | |
4071 | struct pipe_buffer *buf) | |
4072 | { | |
4073 | return 1; | |
4074 | } | |
4075 | ||
4076 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, | |
4077 | struct pipe_buffer *buf) | |
4078 | { | |
4079 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
4080 | ||
4081 | ref->ref++; | |
4082 | } | |
4083 | ||
4084 | /* Pipe buffer operations for a buffer. */ | |
28dfef8f | 4085 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
2cadf913 SR |
4086 | .can_merge = 0, |
4087 | .map = generic_pipe_buf_map, | |
4088 | .unmap = generic_pipe_buf_unmap, | |
4089 | .confirm = generic_pipe_buf_confirm, | |
4090 | .release = buffer_pipe_buf_release, | |
4091 | .steal = buffer_pipe_buf_steal, | |
4092 | .get = buffer_pipe_buf_get, | |
4093 | }; | |
4094 | ||
4095 | /* | |
4096 | * Callback from splice_to_pipe(), if we need to release some pages | |
4097 | * at the end of the spd in case we error'ed out in filling the pipe. | |
4098 | */ | |
4099 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
4100 | { | |
4101 | struct buffer_ref *ref = | |
4102 | (struct buffer_ref *)spd->partial[i].private; | |
4103 | ||
4104 | if (--ref->ref) | |
4105 | return; | |
4106 | ||
4107 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
4108 | kfree(ref); | |
4109 | spd->partial[i].private = 0; | |
4110 | } | |
4111 | ||
4112 | static ssize_t | |
4113 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
4114 | struct pipe_inode_info *pipe, size_t len, | |
4115 | unsigned int flags) | |
4116 | { | |
4117 | struct ftrace_buffer_info *info = file->private_data; | |
35f3d14d JA |
4118 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
4119 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
2cadf913 | 4120 | struct splice_pipe_desc spd = { |
35f3d14d JA |
4121 | .pages = pages_def, |
4122 | .partial = partial_def, | |
2cadf913 SR |
4123 | .flags = flags, |
4124 | .ops = &buffer_pipe_buf_ops, | |
4125 | .spd_release = buffer_spd_release, | |
4126 | }; | |
4127 | struct buffer_ref *ref; | |
93459c6c | 4128 | int entries, size, i; |
2cadf913 SR |
4129 | size_t ret; |
4130 | ||
35f3d14d JA |
4131 | if (splice_grow_spd(pipe, &spd)) |
4132 | return -ENOMEM; | |
4133 | ||
93cfb3c9 LJ |
4134 | if (*ppos & (PAGE_SIZE - 1)) { |
4135 | WARN_ONCE(1, "Ftrace: previous read must page-align\n"); | |
35f3d14d JA |
4136 | ret = -EINVAL; |
4137 | goto out; | |
93cfb3c9 LJ |
4138 | } |
4139 | ||
4140 | if (len & (PAGE_SIZE - 1)) { | |
4141 | WARN_ONCE(1, "Ftrace: splice_read should page-align\n"); | |
35f3d14d JA |
4142 | if (len < PAGE_SIZE) { |
4143 | ret = -EINVAL; | |
4144 | goto out; | |
4145 | } | |
93cfb3c9 LJ |
4146 | len &= PAGE_MASK; |
4147 | } | |
4148 | ||
7e53bd42 | 4149 | trace_access_lock(info->cpu); |
93459c6c SR |
4150 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); |
4151 | ||
35f3d14d | 4152 | for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { |
2cadf913 SR |
4153 | struct page *page; |
4154 | int r; | |
4155 | ||
4156 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
4157 | if (!ref) | |
4158 | break; | |
4159 | ||
7267fa68 | 4160 | ref->ref = 1; |
2cadf913 | 4161 | ref->buffer = info->tr->buffer; |
7ea59064 | 4162 | ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu); |
2cadf913 SR |
4163 | if (!ref->page) { |
4164 | kfree(ref); | |
4165 | break; | |
4166 | } | |
4167 | ||
4168 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
f2957f1f | 4169 | len, info->cpu, 1); |
2cadf913 | 4170 | if (r < 0) { |
7ea59064 | 4171 | ring_buffer_free_read_page(ref->buffer, ref->page); |
2cadf913 SR |
4172 | kfree(ref); |
4173 | break; | |
4174 | } | |
4175 | ||
4176 | /* | |
4177 | * zero out any left over data, this is going to | |
4178 | * user land. | |
4179 | */ | |
4180 | size = ring_buffer_page_len(ref->page); | |
4181 | if (size < PAGE_SIZE) | |
4182 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
4183 | ||
4184 | page = virt_to_page(ref->page); | |
4185 | ||
4186 | spd.pages[i] = page; | |
4187 | spd.partial[i].len = PAGE_SIZE; | |
4188 | spd.partial[i].offset = 0; | |
4189 | spd.partial[i].private = (unsigned long)ref; | |
4190 | spd.nr_pages++; | |
93cfb3c9 | 4191 | *ppos += PAGE_SIZE; |
93459c6c SR |
4192 | |
4193 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); | |
2cadf913 SR |
4194 | } |
4195 | ||
7e53bd42 | 4196 | trace_access_unlock(info->cpu); |
2cadf913 SR |
4197 | spd.nr_pages = i; |
4198 | ||
4199 | /* did we read anything? */ | |
4200 | if (!spd.nr_pages) { | |
4201 | if (flags & SPLICE_F_NONBLOCK) | |
4202 | ret = -EAGAIN; | |
4203 | else | |
4204 | ret = 0; | |
4205 | /* TODO: block */ | |
35f3d14d | 4206 | goto out; |
2cadf913 SR |
4207 | } |
4208 | ||
4209 | ret = splice_to_pipe(pipe, &spd); | |
35f3d14d JA |
4210 | splice_shrink_spd(pipe, &spd); |
4211 | out: | |
2cadf913 SR |
4212 | return ret; |
4213 | } | |
4214 | ||
4215 | static const struct file_operations tracing_buffers_fops = { | |
4216 | .open = tracing_buffers_open, | |
4217 | .read = tracing_buffers_read, | |
4218 | .release = tracing_buffers_release, | |
4219 | .splice_read = tracing_buffers_splice_read, | |
4220 | .llseek = no_llseek, | |
4221 | }; | |
4222 | ||
c8d77183 SR |
4223 | static ssize_t |
4224 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
4225 | size_t count, loff_t *ppos) | |
4226 | { | |
4227 | unsigned long cpu = (unsigned long)filp->private_data; | |
4228 | struct trace_array *tr = &global_trace; | |
4229 | struct trace_seq *s; | |
4230 | unsigned long cnt; | |
c64e148a VN |
4231 | unsigned long long t; |
4232 | unsigned long usec_rem; | |
c8d77183 | 4233 | |
e4f2d10f | 4234 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
c8d77183 | 4235 | if (!s) |
a646365c | 4236 | return -ENOMEM; |
c8d77183 SR |
4237 | |
4238 | trace_seq_init(s); | |
4239 | ||
4240 | cnt = ring_buffer_entries_cpu(tr->buffer, cpu); | |
4241 | trace_seq_printf(s, "entries: %ld\n", cnt); | |
4242 | ||
4243 | cnt = ring_buffer_overrun_cpu(tr->buffer, cpu); | |
4244 | trace_seq_printf(s, "overrun: %ld\n", cnt); | |
4245 | ||
4246 | cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); | |
4247 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); | |
4248 | ||
c64e148a VN |
4249 | cnt = ring_buffer_bytes_cpu(tr->buffer, cpu); |
4250 | trace_seq_printf(s, "bytes: %ld\n", cnt); | |
4251 | ||
4252 | t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu)); | |
4253 | usec_rem = do_div(t, USEC_PER_SEC); | |
4254 | trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", t, usec_rem); | |
4255 | ||
4256 | t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu)); | |
4257 | usec_rem = do_div(t, USEC_PER_SEC); | |
4258 | trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); | |
4259 | ||
c8d77183 SR |
4260 | count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); |
4261 | ||
4262 | kfree(s); | |
4263 | ||
4264 | return count; | |
4265 | } | |
4266 | ||
4267 | static const struct file_operations tracing_stats_fops = { | |
4268 | .open = tracing_open_generic, | |
4269 | .read = tracing_stats_read, | |
b444786f | 4270 | .llseek = generic_file_llseek, |
c8d77183 SR |
4271 | }; |
4272 | ||
bc0c38d1 SR |
4273 | #ifdef CONFIG_DYNAMIC_FTRACE |
4274 | ||
b807c3d0 SR |
4275 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
4276 | { | |
4277 | return 0; | |
4278 | } | |
4279 | ||
bc0c38d1 | 4280 | static ssize_t |
b807c3d0 | 4281 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
4282 | size_t cnt, loff_t *ppos) |
4283 | { | |
a26a2a27 SR |
4284 | static char ftrace_dyn_info_buffer[1024]; |
4285 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 4286 | unsigned long *p = filp->private_data; |
b807c3d0 | 4287 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 4288 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
4289 | int r; |
4290 | ||
b807c3d0 SR |
4291 | mutex_lock(&dyn_info_mutex); |
4292 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 4293 | |
a26a2a27 | 4294 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
4295 | buf[r++] = '\n'; |
4296 | ||
4297 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4298 | ||
4299 | mutex_unlock(&dyn_info_mutex); | |
4300 | ||
4301 | return r; | |
bc0c38d1 SR |
4302 | } |
4303 | ||
5e2336a0 | 4304 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 4305 | .open = tracing_open_generic, |
b807c3d0 | 4306 | .read = tracing_read_dyn_info, |
b444786f | 4307 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
4308 | }; |
4309 | #endif | |
4310 | ||
4311 | static struct dentry *d_tracer; | |
4312 | ||
4313 | struct dentry *tracing_init_dentry(void) | |
4314 | { | |
4315 | static int once; | |
4316 | ||
4317 | if (d_tracer) | |
4318 | return d_tracer; | |
4319 | ||
3e1f60b8 FW |
4320 | if (!debugfs_initialized()) |
4321 | return NULL; | |
4322 | ||
bc0c38d1 SR |
4323 | d_tracer = debugfs_create_dir("tracing", NULL); |
4324 | ||
4325 | if (!d_tracer && !once) { | |
4326 | once = 1; | |
4327 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
4328 | return NULL; | |
4329 | } | |
4330 | ||
4331 | return d_tracer; | |
4332 | } | |
4333 | ||
b04cc6b1 FW |
4334 | static struct dentry *d_percpu; |
4335 | ||
4336 | struct dentry *tracing_dentry_percpu(void) | |
4337 | { | |
4338 | static int once; | |
4339 | struct dentry *d_tracer; | |
4340 | ||
4341 | if (d_percpu) | |
4342 | return d_percpu; | |
4343 | ||
4344 | d_tracer = tracing_init_dentry(); | |
4345 | ||
4346 | if (!d_tracer) | |
4347 | return NULL; | |
4348 | ||
4349 | d_percpu = debugfs_create_dir("per_cpu", d_tracer); | |
4350 | ||
4351 | if (!d_percpu && !once) { | |
4352 | once = 1; | |
4353 | pr_warning("Could not create debugfs directory 'per_cpu'\n"); | |
4354 | return NULL; | |
4355 | } | |
4356 | ||
4357 | return d_percpu; | |
4358 | } | |
4359 | ||
4360 | static void tracing_init_debugfs_percpu(long cpu) | |
4361 | { | |
4362 | struct dentry *d_percpu = tracing_dentry_percpu(); | |
5452af66 | 4363 | struct dentry *d_cpu; |
dd49a38c | 4364 | char cpu_dir[30]; /* 30 characters should be more than enough */ |
b04cc6b1 | 4365 | |
dd49a38c | 4366 | snprintf(cpu_dir, 30, "cpu%ld", cpu); |
8656e7a2 FW |
4367 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); |
4368 | if (!d_cpu) { | |
4369 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
4370 | return; | |
4371 | } | |
b04cc6b1 | 4372 | |
8656e7a2 | 4373 | /* per cpu trace_pipe */ |
5452af66 FW |
4374 | trace_create_file("trace_pipe", 0444, d_cpu, |
4375 | (void *) cpu, &tracing_pipe_fops); | |
b04cc6b1 FW |
4376 | |
4377 | /* per cpu trace */ | |
5452af66 FW |
4378 | trace_create_file("trace", 0644, d_cpu, |
4379 | (void *) cpu, &tracing_fops); | |
7f96f93f | 4380 | |
5452af66 FW |
4381 | trace_create_file("trace_pipe_raw", 0444, d_cpu, |
4382 | (void *) cpu, &tracing_buffers_fops); | |
7f96f93f | 4383 | |
c8d77183 SR |
4384 | trace_create_file("stats", 0444, d_cpu, |
4385 | (void *) cpu, &tracing_stats_fops); | |
b04cc6b1 FW |
4386 | } |
4387 | ||
60a11774 SR |
4388 | #ifdef CONFIG_FTRACE_SELFTEST |
4389 | /* Let selftest have access to static functions in this file */ | |
4390 | #include "trace_selftest.c" | |
4391 | #endif | |
4392 | ||
577b785f SR |
4393 | struct trace_option_dentry { |
4394 | struct tracer_opt *opt; | |
4395 | struct tracer_flags *flags; | |
4396 | struct dentry *entry; | |
4397 | }; | |
4398 | ||
4399 | static ssize_t | |
4400 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4401 | loff_t *ppos) | |
4402 | { | |
4403 | struct trace_option_dentry *topt = filp->private_data; | |
4404 | char *buf; | |
4405 | ||
4406 | if (topt->flags->val & topt->opt->bit) | |
4407 | buf = "1\n"; | |
4408 | else | |
4409 | buf = "0\n"; | |
4410 | ||
4411 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4412 | } | |
4413 | ||
4414 | static ssize_t | |
4415 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4416 | loff_t *ppos) | |
4417 | { | |
4418 | struct trace_option_dentry *topt = filp->private_data; | |
4419 | unsigned long val; | |
577b785f SR |
4420 | int ret; |
4421 | ||
22fe9b54 PH |
4422 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4423 | if (ret) | |
577b785f SR |
4424 | return ret; |
4425 | ||
8d18eaaf LZ |
4426 | if (val != 0 && val != 1) |
4427 | return -EINVAL; | |
577b785f | 4428 | |
8d18eaaf | 4429 | if (!!(topt->flags->val & topt->opt->bit) != val) { |
577b785f | 4430 | mutex_lock(&trace_types_lock); |
8d18eaaf | 4431 | ret = __set_tracer_option(current_trace, topt->flags, |
c757bea9 | 4432 | topt->opt, !val); |
577b785f SR |
4433 | mutex_unlock(&trace_types_lock); |
4434 | if (ret) | |
4435 | return ret; | |
577b785f SR |
4436 | } |
4437 | ||
4438 | *ppos += cnt; | |
4439 | ||
4440 | return cnt; | |
4441 | } | |
4442 | ||
4443 | ||
4444 | static const struct file_operations trace_options_fops = { | |
4445 | .open = tracing_open_generic, | |
4446 | .read = trace_options_read, | |
4447 | .write = trace_options_write, | |
b444786f | 4448 | .llseek = generic_file_llseek, |
577b785f SR |
4449 | }; |
4450 | ||
a8259075 SR |
4451 | static ssize_t |
4452 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4453 | loff_t *ppos) | |
4454 | { | |
4455 | long index = (long)filp->private_data; | |
4456 | char *buf; | |
4457 | ||
4458 | if (trace_flags & (1 << index)) | |
4459 | buf = "1\n"; | |
4460 | else | |
4461 | buf = "0\n"; | |
4462 | ||
4463 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4464 | } | |
4465 | ||
4466 | static ssize_t | |
4467 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4468 | loff_t *ppos) | |
4469 | { | |
4470 | long index = (long)filp->private_data; | |
a8259075 SR |
4471 | unsigned long val; |
4472 | int ret; | |
4473 | ||
22fe9b54 PH |
4474 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4475 | if (ret) | |
a8259075 SR |
4476 | return ret; |
4477 | ||
f2d84b65 | 4478 | if (val != 0 && val != 1) |
a8259075 | 4479 | return -EINVAL; |
f2d84b65 | 4480 | set_tracer_flags(1 << index, val); |
a8259075 SR |
4481 | |
4482 | *ppos += cnt; | |
4483 | ||
4484 | return cnt; | |
4485 | } | |
4486 | ||
a8259075 SR |
4487 | static const struct file_operations trace_options_core_fops = { |
4488 | .open = tracing_open_generic, | |
4489 | .read = trace_options_core_read, | |
4490 | .write = trace_options_core_write, | |
b444786f | 4491 | .llseek = generic_file_llseek, |
a8259075 SR |
4492 | }; |
4493 | ||
5452af66 | 4494 | struct dentry *trace_create_file(const char *name, |
f4ae40a6 | 4495 | umode_t mode, |
5452af66 FW |
4496 | struct dentry *parent, |
4497 | void *data, | |
4498 | const struct file_operations *fops) | |
4499 | { | |
4500 | struct dentry *ret; | |
4501 | ||
4502 | ret = debugfs_create_file(name, mode, parent, data, fops); | |
4503 | if (!ret) | |
4504 | pr_warning("Could not create debugfs '%s' entry\n", name); | |
4505 | ||
4506 | return ret; | |
4507 | } | |
4508 | ||
4509 | ||
a8259075 SR |
4510 | static struct dentry *trace_options_init_dentry(void) |
4511 | { | |
4512 | struct dentry *d_tracer; | |
4513 | static struct dentry *t_options; | |
4514 | ||
4515 | if (t_options) | |
4516 | return t_options; | |
4517 | ||
4518 | d_tracer = tracing_init_dentry(); | |
4519 | if (!d_tracer) | |
4520 | return NULL; | |
4521 | ||
4522 | t_options = debugfs_create_dir("options", d_tracer); | |
4523 | if (!t_options) { | |
4524 | pr_warning("Could not create debugfs directory 'options'\n"); | |
4525 | return NULL; | |
4526 | } | |
4527 | ||
4528 | return t_options; | |
4529 | } | |
4530 | ||
577b785f SR |
4531 | static void |
4532 | create_trace_option_file(struct trace_option_dentry *topt, | |
4533 | struct tracer_flags *flags, | |
4534 | struct tracer_opt *opt) | |
4535 | { | |
4536 | struct dentry *t_options; | |
577b785f SR |
4537 | |
4538 | t_options = trace_options_init_dentry(); | |
4539 | if (!t_options) | |
4540 | return; | |
4541 | ||
4542 | topt->flags = flags; | |
4543 | topt->opt = opt; | |
4544 | ||
5452af66 | 4545 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
577b785f SR |
4546 | &trace_options_fops); |
4547 | ||
577b785f SR |
4548 | } |
4549 | ||
4550 | static struct trace_option_dentry * | |
4551 | create_trace_option_files(struct tracer *tracer) | |
4552 | { | |
4553 | struct trace_option_dentry *topts; | |
4554 | struct tracer_flags *flags; | |
4555 | struct tracer_opt *opts; | |
4556 | int cnt; | |
4557 | ||
4558 | if (!tracer) | |
4559 | return NULL; | |
4560 | ||
4561 | flags = tracer->flags; | |
4562 | ||
4563 | if (!flags || !flags->opts) | |
4564 | return NULL; | |
4565 | ||
4566 | opts = flags->opts; | |
4567 | ||
4568 | for (cnt = 0; opts[cnt].name; cnt++) | |
4569 | ; | |
4570 | ||
0cfe8245 | 4571 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f SR |
4572 | if (!topts) |
4573 | return NULL; | |
4574 | ||
4575 | for (cnt = 0; opts[cnt].name; cnt++) | |
4576 | create_trace_option_file(&topts[cnt], flags, | |
4577 | &opts[cnt]); | |
4578 | ||
4579 | return topts; | |
4580 | } | |
4581 | ||
4582 | static void | |
4583 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
4584 | { | |
4585 | int cnt; | |
4586 | ||
4587 | if (!topts) | |
4588 | return; | |
4589 | ||
4590 | for (cnt = 0; topts[cnt].opt; cnt++) { | |
4591 | if (topts[cnt].entry) | |
4592 | debugfs_remove(topts[cnt].entry); | |
4593 | } | |
4594 | ||
4595 | kfree(topts); | |
4596 | } | |
4597 | ||
a8259075 SR |
4598 | static struct dentry * |
4599 | create_trace_option_core_file(const char *option, long index) | |
4600 | { | |
4601 | struct dentry *t_options; | |
a8259075 SR |
4602 | |
4603 | t_options = trace_options_init_dentry(); | |
4604 | if (!t_options) | |
4605 | return NULL; | |
4606 | ||
5452af66 | 4607 | return trace_create_file(option, 0644, t_options, (void *)index, |
a8259075 | 4608 | &trace_options_core_fops); |
a8259075 SR |
4609 | } |
4610 | ||
4611 | static __init void create_trace_options_dir(void) | |
4612 | { | |
4613 | struct dentry *t_options; | |
a8259075 SR |
4614 | int i; |
4615 | ||
4616 | t_options = trace_options_init_dentry(); | |
4617 | if (!t_options) | |
4618 | return; | |
4619 | ||
5452af66 FW |
4620 | for (i = 0; trace_options[i]; i++) |
4621 | create_trace_option_core_file(trace_options[i], i); | |
a8259075 SR |
4622 | } |
4623 | ||
499e5470 SR |
4624 | static ssize_t |
4625 | rb_simple_read(struct file *filp, char __user *ubuf, | |
4626 | size_t cnt, loff_t *ppos) | |
4627 | { | |
4628 | struct ring_buffer *buffer = filp->private_data; | |
4629 | char buf[64]; | |
4630 | int r; | |
4631 | ||
4632 | if (buffer) | |
4633 | r = ring_buffer_record_is_on(buffer); | |
4634 | else | |
4635 | r = 0; | |
4636 | ||
4637 | r = sprintf(buf, "%d\n", r); | |
4638 | ||
4639 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4640 | } | |
4641 | ||
4642 | static ssize_t | |
4643 | rb_simple_write(struct file *filp, const char __user *ubuf, | |
4644 | size_t cnt, loff_t *ppos) | |
4645 | { | |
4646 | struct ring_buffer *buffer = filp->private_data; | |
4647 | unsigned long val; | |
4648 | int ret; | |
4649 | ||
4650 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
4651 | if (ret) | |
4652 | return ret; | |
4653 | ||
4654 | if (buffer) { | |
4655 | if (val) | |
4656 | ring_buffer_record_on(buffer); | |
4657 | else | |
4658 | ring_buffer_record_off(buffer); | |
4659 | } | |
4660 | ||
4661 | (*ppos)++; | |
4662 | ||
4663 | return cnt; | |
4664 | } | |
4665 | ||
4666 | static const struct file_operations rb_simple_fops = { | |
4667 | .open = tracing_open_generic, | |
4668 | .read = rb_simple_read, | |
4669 | .write = rb_simple_write, | |
4670 | .llseek = default_llseek, | |
4671 | }; | |
4672 | ||
b5ad384e | 4673 | static __init int tracer_init_debugfs(void) |
bc0c38d1 SR |
4674 | { |
4675 | struct dentry *d_tracer; | |
b04cc6b1 | 4676 | int cpu; |
bc0c38d1 | 4677 | |
7e53bd42 LJ |
4678 | trace_access_lock_init(); |
4679 | ||
bc0c38d1 SR |
4680 | d_tracer = tracing_init_dentry(); |
4681 | ||
5452af66 FW |
4682 | trace_create_file("tracing_enabled", 0644, d_tracer, |
4683 | &global_trace, &tracing_ctrl_fops); | |
bc0c38d1 | 4684 | |
5452af66 FW |
4685 | trace_create_file("trace_options", 0644, d_tracer, |
4686 | NULL, &tracing_iter_fops); | |
bc0c38d1 | 4687 | |
5452af66 FW |
4688 | trace_create_file("tracing_cpumask", 0644, d_tracer, |
4689 | NULL, &tracing_cpumask_fops); | |
4690 | ||
4691 | trace_create_file("trace", 0644, d_tracer, | |
4692 | (void *) TRACE_PIPE_ALL_CPU, &tracing_fops); | |
a8259075 | 4693 | |
5452af66 FW |
4694 | trace_create_file("available_tracers", 0444, d_tracer, |
4695 | &global_trace, &show_traces_fops); | |
4696 | ||
339ae5d3 | 4697 | trace_create_file("current_tracer", 0644, d_tracer, |
5452af66 FW |
4698 | &global_trace, &set_tracer_fops); |
4699 | ||
5d4a9dba | 4700 | #ifdef CONFIG_TRACER_MAX_TRACE |
5452af66 FW |
4701 | trace_create_file("tracing_max_latency", 0644, d_tracer, |
4702 | &tracing_max_latency, &tracing_max_lat_fops); | |
0e950173 | 4703 | #endif |
5452af66 FW |
4704 | |
4705 | trace_create_file("tracing_thresh", 0644, d_tracer, | |
4706 | &tracing_thresh, &tracing_max_lat_fops); | |
a8259075 | 4707 | |
339ae5d3 | 4708 | trace_create_file("README", 0444, d_tracer, |
5452af66 FW |
4709 | NULL, &tracing_readme_fops); |
4710 | ||
4711 | trace_create_file("trace_pipe", 0444, d_tracer, | |
b04cc6b1 | 4712 | (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); |
5452af66 FW |
4713 | |
4714 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
4715 | &global_trace, &tracing_entries_fops); | |
4716 | ||
f81ab074 VN |
4717 | trace_create_file("buffer_total_size_kb", 0444, d_tracer, |
4718 | &global_trace, &tracing_total_entries_fops); | |
4719 | ||
4f271a2a VN |
4720 | trace_create_file("free_buffer", 0644, d_tracer, |
4721 | &global_trace, &tracing_free_buffer_fops); | |
4722 | ||
5452af66 FW |
4723 | trace_create_file("trace_marker", 0220, d_tracer, |
4724 | NULL, &tracing_mark_fops); | |
5bf9a1ee | 4725 | |
69abe6a5 AP |
4726 | trace_create_file("saved_cmdlines", 0444, d_tracer, |
4727 | NULL, &tracing_saved_cmdlines_fops); | |
5bf9a1ee | 4728 | |
5079f326 Z |
4729 | trace_create_file("trace_clock", 0644, d_tracer, NULL, |
4730 | &trace_clock_fops); | |
4731 | ||
499e5470 SR |
4732 | trace_create_file("tracing_on", 0644, d_tracer, |
4733 | global_trace.buffer, &rb_simple_fops); | |
4734 | ||
bc0c38d1 | 4735 | #ifdef CONFIG_DYNAMIC_FTRACE |
5452af66 FW |
4736 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
4737 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
bc0c38d1 | 4738 | #endif |
b04cc6b1 | 4739 | |
5452af66 FW |
4740 | create_trace_options_dir(); |
4741 | ||
b04cc6b1 FW |
4742 | for_each_tracing_cpu(cpu) |
4743 | tracing_init_debugfs_percpu(cpu); | |
4744 | ||
b5ad384e | 4745 | return 0; |
bc0c38d1 SR |
4746 | } |
4747 | ||
3f5a54e3 SR |
4748 | static int trace_panic_handler(struct notifier_block *this, |
4749 | unsigned long event, void *unused) | |
4750 | { | |
944ac425 | 4751 | if (ftrace_dump_on_oops) |
cecbca96 | 4752 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
4753 | return NOTIFY_OK; |
4754 | } | |
4755 | ||
4756 | static struct notifier_block trace_panic_notifier = { | |
4757 | .notifier_call = trace_panic_handler, | |
4758 | .next = NULL, | |
4759 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
4760 | }; | |
4761 | ||
4762 | static int trace_die_handler(struct notifier_block *self, | |
4763 | unsigned long val, | |
4764 | void *data) | |
4765 | { | |
4766 | switch (val) { | |
4767 | case DIE_OOPS: | |
944ac425 | 4768 | if (ftrace_dump_on_oops) |
cecbca96 | 4769 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
4770 | break; |
4771 | default: | |
4772 | break; | |
4773 | } | |
4774 | return NOTIFY_OK; | |
4775 | } | |
4776 | ||
4777 | static struct notifier_block trace_die_notifier = { | |
4778 | .notifier_call = trace_die_handler, | |
4779 | .priority = 200 | |
4780 | }; | |
4781 | ||
4782 | /* | |
4783 | * printk is set to max of 1024, we really don't need it that big. | |
4784 | * Nothing should be printing 1000 characters anyway. | |
4785 | */ | |
4786 | #define TRACE_MAX_PRINT 1000 | |
4787 | ||
4788 | /* | |
4789 | * Define here KERN_TRACE so that we have one place to modify | |
4790 | * it if we decide to change what log level the ftrace dump | |
4791 | * should be at. | |
4792 | */ | |
428aee14 | 4793 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 | 4794 | |
955b61e5 | 4795 | void |
3f5a54e3 SR |
4796 | trace_printk_seq(struct trace_seq *s) |
4797 | { | |
4798 | /* Probably should print a warning here. */ | |
4799 | if (s->len >= 1000) | |
4800 | s->len = 1000; | |
4801 | ||
4802 | /* should be zero ended, but we are paranoid. */ | |
4803 | s->buffer[s->len] = 0; | |
4804 | ||
4805 | printk(KERN_TRACE "%s", s->buffer); | |
4806 | ||
f9520750 | 4807 | trace_seq_init(s); |
3f5a54e3 SR |
4808 | } |
4809 | ||
955b61e5 JW |
4810 | void trace_init_global_iter(struct trace_iterator *iter) |
4811 | { | |
4812 | iter->tr = &global_trace; | |
4813 | iter->trace = current_trace; | |
4814 | iter->cpu_file = TRACE_PIPE_ALL_CPU; | |
4815 | } | |
4816 | ||
cecbca96 FW |
4817 | static void |
4818 | __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) | |
3f5a54e3 | 4819 | { |
445c8951 | 4820 | static arch_spinlock_t ftrace_dump_lock = |
edc35bd7 | 4821 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
3f5a54e3 SR |
4822 | /* use static because iter can be a bit big for the stack */ |
4823 | static struct trace_iterator iter; | |
cf586b61 | 4824 | unsigned int old_userobj; |
3f5a54e3 | 4825 | static int dump_ran; |
d769041f SR |
4826 | unsigned long flags; |
4827 | int cnt = 0, cpu; | |
3f5a54e3 SR |
4828 | |
4829 | /* only one dump */ | |
cd891ae0 | 4830 | local_irq_save(flags); |
0199c4e6 | 4831 | arch_spin_lock(&ftrace_dump_lock); |
3f5a54e3 SR |
4832 | if (dump_ran) |
4833 | goto out; | |
4834 | ||
4835 | dump_ran = 1; | |
4836 | ||
0ee6b6cf | 4837 | tracing_off(); |
cf586b61 | 4838 | |
e0a413f6 SR |
4839 | /* Did function tracer already get disabled? */ |
4840 | if (ftrace_is_dead()) { | |
4841 | printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
4842 | printk("# MAY BE MISSING FUNCTION EVENTS\n"); | |
4843 | } | |
4844 | ||
cf586b61 FW |
4845 | if (disable_tracing) |
4846 | ftrace_kill(); | |
3f5a54e3 | 4847 | |
955b61e5 JW |
4848 | trace_init_global_iter(&iter); |
4849 | ||
d769041f | 4850 | for_each_tracing_cpu(cpu) { |
955b61e5 | 4851 | atomic_inc(&iter.tr->data[cpu]->disabled); |
d769041f SR |
4852 | } |
4853 | ||
cf586b61 FW |
4854 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; |
4855 | ||
b54d3de9 TE |
4856 | /* don't look at user memory in panic mode */ |
4857 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
4858 | ||
e543ad76 | 4859 | /* Simulate the iterator */ |
3f5a54e3 SR |
4860 | iter.tr = &global_trace; |
4861 | iter.trace = current_trace; | |
cecbca96 FW |
4862 | |
4863 | switch (oops_dump_mode) { | |
4864 | case DUMP_ALL: | |
4865 | iter.cpu_file = TRACE_PIPE_ALL_CPU; | |
4866 | break; | |
4867 | case DUMP_ORIG: | |
4868 | iter.cpu_file = raw_smp_processor_id(); | |
4869 | break; | |
4870 | case DUMP_NONE: | |
4871 | goto out_enable; | |
4872 | default: | |
4873 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
4874 | iter.cpu_file = TRACE_PIPE_ALL_CPU; | |
4875 | } | |
4876 | ||
4877 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
3f5a54e3 SR |
4878 | |
4879 | /* | |
4880 | * We need to stop all tracing on all CPUS to read the | |
4881 | * the next buffer. This is a bit expensive, but is | |
4882 | * not done often. We fill all what we can read, | |
4883 | * and then release the locks again. | |
4884 | */ | |
4885 | ||
3f5a54e3 SR |
4886 | while (!trace_empty(&iter)) { |
4887 | ||
4888 | if (!cnt) | |
4889 | printk(KERN_TRACE "---------------------------------\n"); | |
4890 | ||
4891 | cnt++; | |
4892 | ||
4893 | /* reset all but tr, trace, and overruns */ | |
4894 | memset(&iter.seq, 0, | |
4895 | sizeof(struct trace_iterator) - | |
4896 | offsetof(struct trace_iterator, seq)); | |
4897 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
4898 | iter.pos = -1; | |
4899 | ||
955b61e5 | 4900 | if (trace_find_next_entry_inc(&iter) != NULL) { |
74e7ff8c LJ |
4901 | int ret; |
4902 | ||
4903 | ret = print_trace_line(&iter); | |
4904 | if (ret != TRACE_TYPE_NO_CONSUME) | |
4905 | trace_consume(&iter); | |
3f5a54e3 | 4906 | } |
b892e5c8 | 4907 | touch_nmi_watchdog(); |
3f5a54e3 SR |
4908 | |
4909 | trace_printk_seq(&iter.seq); | |
4910 | } | |
4911 | ||
4912 | if (!cnt) | |
4913 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
4914 | else | |
4915 | printk(KERN_TRACE "---------------------------------\n"); | |
4916 | ||
cecbca96 | 4917 | out_enable: |
cf586b61 FW |
4918 | /* Re-enable tracing if requested */ |
4919 | if (!disable_tracing) { | |
4920 | trace_flags |= old_userobj; | |
4921 | ||
4922 | for_each_tracing_cpu(cpu) { | |
955b61e5 | 4923 | atomic_dec(&iter.tr->data[cpu]->disabled); |
cf586b61 FW |
4924 | } |
4925 | tracing_on(); | |
4926 | } | |
4927 | ||
3f5a54e3 | 4928 | out: |
0199c4e6 | 4929 | arch_spin_unlock(&ftrace_dump_lock); |
cd891ae0 | 4930 | local_irq_restore(flags); |
3f5a54e3 SR |
4931 | } |
4932 | ||
cf586b61 | 4933 | /* By default: disable tracing after the dump */ |
cecbca96 | 4934 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) |
cf586b61 | 4935 | { |
cecbca96 | 4936 | __ftrace_dump(true, oops_dump_mode); |
cf586b61 | 4937 | } |
a8eecf22 | 4938 | EXPORT_SYMBOL_GPL(ftrace_dump); |
cf586b61 | 4939 | |
3928a8a2 | 4940 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 4941 | { |
73c5162a | 4942 | int ring_buf_size; |
750912fa | 4943 | enum ring_buffer_flags rb_flags; |
4c11d7ae | 4944 | int i; |
9e01c1b7 | 4945 | int ret = -ENOMEM; |
4c11d7ae | 4946 | |
750912fa | 4947 | |
9e01c1b7 RR |
4948 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
4949 | goto out; | |
4950 | ||
4951 | if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) | |
4952 | goto out_free_buffer_mask; | |
4c11d7ae | 4953 | |
73c5162a SR |
4954 | /* To save memory, keep the ring buffer size to its minimum */ |
4955 | if (ring_buffer_expanded) | |
4956 | ring_buf_size = trace_buf_size; | |
4957 | else | |
4958 | ring_buf_size = 1; | |
4959 | ||
750912fa DS |
4960 | rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; |
4961 | ||
9e01c1b7 RR |
4962 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
4963 | cpumask_copy(tracing_cpumask, cpu_all_mask); | |
4964 | ||
4965 | /* TODO: make the number of buffers hot pluggable with CPUS */ | |
750912fa | 4966 | global_trace.buffer = ring_buffer_alloc(ring_buf_size, rb_flags); |
3928a8a2 SR |
4967 | if (!global_trace.buffer) { |
4968 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); | |
4969 | WARN_ON(1); | |
9e01c1b7 | 4970 | goto out_free_cpumask; |
4c11d7ae | 4971 | } |
3928a8a2 | 4972 | global_trace.entries = ring_buffer_size(global_trace.buffer); |
499e5470 SR |
4973 | if (global_trace.buffer_disabled) |
4974 | tracing_off(); | |
4c11d7ae | 4975 | |
9e01c1b7 | 4976 | |
4c11d7ae | 4977 | #ifdef CONFIG_TRACER_MAX_TRACE |
750912fa | 4978 | max_tr.buffer = ring_buffer_alloc(1, rb_flags); |
3928a8a2 SR |
4979 | if (!max_tr.buffer) { |
4980 | printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); | |
4981 | WARN_ON(1); | |
4982 | ring_buffer_free(global_trace.buffer); | |
9e01c1b7 | 4983 | goto out_free_cpumask; |
4c11d7ae | 4984 | } |
ef710e10 | 4985 | max_tr.entries = 1; |
a98a3c3f | 4986 | #endif |
ab46428c | 4987 | |
4c11d7ae | 4988 | /* Allocate the first page for all buffers */ |
ab46428c | 4989 | for_each_tracing_cpu(i) { |
566b0aaf | 4990 | global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
9705f69e | 4991 | max_tr.data[i] = &per_cpu(max_tr_data, i); |
4c11d7ae | 4992 | } |
bc0c38d1 | 4993 | |
bc0c38d1 SR |
4994 | trace_init_cmdlines(); |
4995 | ||
43a15386 | 4996 | register_tracer(&nop_trace); |
79fb0768 | 4997 | current_trace = &nop_trace; |
60a11774 SR |
4998 | /* All seems OK, enable tracing */ |
4999 | tracing_disabled = 0; | |
3928a8a2 | 5000 | |
3f5a54e3 SR |
5001 | atomic_notifier_chain_register(&panic_notifier_list, |
5002 | &trace_panic_notifier); | |
5003 | ||
5004 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe FW |
5005 | |
5006 | return 0; | |
3f5a54e3 | 5007 | |
9e01c1b7 RR |
5008 | out_free_cpumask: |
5009 | free_cpumask_var(tracing_cpumask); | |
5010 | out_free_buffer_mask: | |
5011 | free_cpumask_var(tracing_buffer_mask); | |
5012 | out: | |
5013 | return ret; | |
bc0c38d1 | 5014 | } |
b2821ae6 SR |
5015 | |
5016 | __init static int clear_boot_tracer(void) | |
5017 | { | |
5018 | /* | |
5019 | * The default tracer at boot buffer is an init section. | |
5020 | * This function is called in lateinit. If we did not | |
5021 | * find the boot tracer, then clear it out, to prevent | |
5022 | * later registration from accessing the buffer that is | |
5023 | * about to be freed. | |
5024 | */ | |
5025 | if (!default_bootup_tracer) | |
5026 | return 0; | |
5027 | ||
5028 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
5029 | default_bootup_tracer); | |
5030 | default_bootup_tracer = NULL; | |
5031 | ||
5032 | return 0; | |
5033 | } | |
5034 | ||
b5ad384e FW |
5035 | early_initcall(tracer_alloc_buffers); |
5036 | fs_initcall(tracer_init_debugfs); | |
b2821ae6 | 5037 | late_initcall(clear_boot_tracer); |