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 | |
6d49e352 | 12 | * Copyright (C) 2004 Nadia Yvette Chambers |
bc0c38d1 | 13 | */ |
2cadf913 | 14 | #include <linux/ring_buffer.h> |
273b281f | 15 | #include <generated/utsrelease.h> |
2cadf913 SR |
16 | #include <linux/stacktrace.h> |
17 | #include <linux/writeback.h> | |
bc0c38d1 SR |
18 | #include <linux/kallsyms.h> |
19 | #include <linux/seq_file.h> | |
3f5a54e3 | 20 | #include <linux/notifier.h> |
2cadf913 | 21 | #include <linux/irqflags.h> |
0d5c6e1c | 22 | #include <linux/irq_work.h> |
bc0c38d1 | 23 | #include <linux/debugfs.h> |
4c11d7ae | 24 | #include <linux/pagemap.h> |
bc0c38d1 SR |
25 | #include <linux/hardirq.h> |
26 | #include <linux/linkage.h> | |
27 | #include <linux/uaccess.h> | |
2cadf913 | 28 | #include <linux/kprobes.h> |
bc0c38d1 SR |
29 | #include <linux/ftrace.h> |
30 | #include <linux/module.h> | |
31 | #include <linux/percpu.h> | |
2cadf913 | 32 | #include <linux/splice.h> |
3f5a54e3 | 33 | #include <linux/kdebug.h> |
5f0c6c03 | 34 | #include <linux/string.h> |
7e53bd42 | 35 | #include <linux/rwsem.h> |
5a0e3ad6 | 36 | #include <linux/slab.h> |
bc0c38d1 SR |
37 | #include <linux/ctype.h> |
38 | #include <linux/init.h> | |
2a2cc8f7 | 39 | #include <linux/poll.h> |
b892e5c8 | 40 | #include <linux/nmi.h> |
bc0c38d1 | 41 | #include <linux/fs.h> |
8bd75c77 | 42 | #include <linux/sched/rt.h> |
86387f7e | 43 | |
bc0c38d1 | 44 | #include "trace.h" |
f0868d1e | 45 | #include "trace_output.h" |
bc0c38d1 | 46 | |
73c5162a SR |
47 | /* |
48 | * On boot up, the ring buffer is set to the minimum size, so that | |
49 | * we do not waste memory on systems that are not using tracing. | |
50 | */ | |
020e5f85 | 51 | int ring_buffer_expanded; |
73c5162a | 52 | |
8e1b82e0 FW |
53 | /* |
54 | * We need to change this state when a selftest is running. | |
ff32504f FW |
55 | * A selftest will lurk into the ring-buffer to count the |
56 | * entries inserted during the selftest although some concurrent | |
5e1607a0 | 57 | * insertions into the ring-buffer such as trace_printk could occurred |
ff32504f FW |
58 | * at the same time, giving false positive or negative results. |
59 | */ | |
8e1b82e0 | 60 | static bool __read_mostly tracing_selftest_running; |
ff32504f | 61 | |
b2821ae6 SR |
62 | /* |
63 | * If a tracer is running, we do not want to run SELFTEST. | |
64 | */ | |
020e5f85 | 65 | bool __read_mostly tracing_selftest_disabled; |
b2821ae6 | 66 | |
adf9f195 FW |
67 | /* For tracers that don't implement custom flags */ |
68 | static struct tracer_opt dummy_tracer_opt[] = { | |
69 | { } | |
70 | }; | |
71 | ||
72 | static struct tracer_flags dummy_tracer_flags = { | |
73 | .val = 0, | |
74 | .opts = dummy_tracer_opt | |
75 | }; | |
76 | ||
77 | static int dummy_set_flag(u32 old_flags, u32 bit, int set) | |
78 | { | |
79 | return 0; | |
80 | } | |
0f048701 | 81 | |
7ffbd48d SR |
82 | /* |
83 | * To prevent the comm cache from being overwritten when no | |
84 | * tracing is active, only save the comm when a trace event | |
85 | * occurred. | |
86 | */ | |
87 | static DEFINE_PER_CPU(bool, trace_cmdline_save); | |
88 | ||
0d5c6e1c SR |
89 | /* |
90 | * When a reader is waiting for data, then this variable is | |
91 | * set to true. | |
92 | */ | |
93 | static bool trace_wakeup_needed; | |
94 | ||
95 | static struct irq_work trace_work_wakeup; | |
96 | ||
0f048701 SR |
97 | /* |
98 | * Kill all tracing for good (never come back). | |
99 | * It is initialized to 1 but will turn to zero if the initialization | |
100 | * of the tracer is successful. But that is the only place that sets | |
101 | * this back to zero. | |
102 | */ | |
4fd27358 | 103 | static int tracing_disabled = 1; |
0f048701 | 104 | |
9288f99a | 105 | DEFINE_PER_CPU(int, ftrace_cpu_disabled); |
d769041f | 106 | |
955b61e5 | 107 | cpumask_var_t __read_mostly tracing_buffer_mask; |
ab46428c | 108 | |
944ac425 SR |
109 | /* |
110 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
111 | * | |
112 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
113 | * is set, then ftrace_dump is called. This will output the contents | |
114 | * of the ftrace buffers to the console. This is very useful for | |
115 | * capturing traces that lead to crashes and outputing it to a | |
116 | * serial console. | |
117 | * | |
118 | * It is default off, but you can enable it with either specifying | |
119 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
cecbca96 FW |
120 | * /proc/sys/kernel/ftrace_dump_on_oops |
121 | * Set 1 if you want to dump buffers of all CPUs | |
122 | * Set 2 if you want to dump the buffer of the CPU that triggered oops | |
944ac425 | 123 | */ |
cecbca96 FW |
124 | |
125 | enum ftrace_dump_mode ftrace_dump_on_oops; | |
944ac425 | 126 | |
b2821ae6 SR |
127 | static int tracing_set_tracer(const char *buf); |
128 | ||
ee6c2c1b LZ |
129 | #define MAX_TRACER_SIZE 100 |
130 | static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; | |
b2821ae6 | 131 | static char *default_bootup_tracer; |
d9e54076 | 132 | |
1beee96b | 133 | static int __init set_cmdline_ftrace(char *str) |
d9e54076 | 134 | { |
ee6c2c1b | 135 | strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); |
b2821ae6 | 136 | default_bootup_tracer = bootup_tracer_buf; |
73c5162a SR |
137 | /* We are using ftrace early, expand it */ |
138 | ring_buffer_expanded = 1; | |
d9e54076 PZ |
139 | return 1; |
140 | } | |
1beee96b | 141 | __setup("ftrace=", set_cmdline_ftrace); |
d9e54076 | 142 | |
944ac425 SR |
143 | static int __init set_ftrace_dump_on_oops(char *str) |
144 | { | |
cecbca96 FW |
145 | if (*str++ != '=' || !*str) { |
146 | ftrace_dump_on_oops = DUMP_ALL; | |
147 | return 1; | |
148 | } | |
149 | ||
150 | if (!strcmp("orig_cpu", str)) { | |
151 | ftrace_dump_on_oops = DUMP_ORIG; | |
152 | return 1; | |
153 | } | |
154 | ||
155 | return 0; | |
944ac425 SR |
156 | } |
157 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
60a11774 | 158 | |
7bcfaf54 SR |
159 | |
160 | static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; | |
161 | static char *trace_boot_options __initdata; | |
162 | ||
163 | static int __init set_trace_boot_options(char *str) | |
164 | { | |
165 | strncpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); | |
166 | trace_boot_options = trace_boot_options_buf; | |
167 | return 0; | |
168 | } | |
169 | __setup("trace_options=", set_trace_boot_options); | |
170 | ||
cf8e3474 | 171 | unsigned long long ns2usecs(cycle_t nsec) |
bc0c38d1 SR |
172 | { |
173 | nsec += 500; | |
174 | do_div(nsec, 1000); | |
175 | return nsec; | |
176 | } | |
177 | ||
4fcdae83 SR |
178 | /* |
179 | * The global_trace is the descriptor that holds the tracing | |
180 | * buffers for the live tracing. For each CPU, it contains | |
181 | * a link list of pages that will store trace entries. The | |
182 | * page descriptor of the pages in the memory is used to hold | |
183 | * the link list by linking the lru item in the page descriptor | |
184 | * to each of the pages in the buffer per CPU. | |
185 | * | |
186 | * For each active CPU there is a data field that holds the | |
187 | * pages for the buffer for that CPU. Each CPU has the same number | |
188 | * of pages allocated for its buffer. | |
189 | */ | |
bc0c38d1 SR |
190 | static struct trace_array global_trace; |
191 | ||
ae63b31e SR |
192 | LIST_HEAD(ftrace_trace_arrays); |
193 | ||
bc0c38d1 SR |
194 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); |
195 | ||
e77405ad SR |
196 | int filter_current_check_discard(struct ring_buffer *buffer, |
197 | struct ftrace_event_call *call, void *rec, | |
eb02ce01 TZ |
198 | struct ring_buffer_event *event) |
199 | { | |
e77405ad | 200 | return filter_check_discard(call, rec, buffer, event); |
eb02ce01 | 201 | } |
17c873ec | 202 | EXPORT_SYMBOL_GPL(filter_current_check_discard); |
eb02ce01 | 203 | |
37886f6a SR |
204 | cycle_t ftrace_now(int cpu) |
205 | { | |
206 | u64 ts; | |
207 | ||
208 | /* Early boot up does not have a buffer yet */ | |
209 | if (!global_trace.buffer) | |
210 | return trace_clock_local(); | |
211 | ||
212 | ts = ring_buffer_time_stamp(global_trace.buffer, cpu); | |
213 | ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts); | |
214 | ||
215 | return ts; | |
216 | } | |
bc0c38d1 | 217 | |
4fcdae83 SR |
218 | /* |
219 | * The max_tr is used to snapshot the global_trace when a maximum | |
220 | * latency is reached. Some tracers will use this to store a maximum | |
221 | * trace while it continues examining live traces. | |
222 | * | |
223 | * The buffers for the max_tr are set up the same as the global_trace. | |
224 | * When a snapshot is taken, the link list of the max_tr is swapped | |
225 | * with the link list of the global_trace and the buffers are reset for | |
226 | * the global_trace so the tracing can continue. | |
227 | */ | |
bc0c38d1 SR |
228 | static struct trace_array max_tr; |
229 | ||
9705f69e | 230 | static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data); |
bc0c38d1 | 231 | |
9036990d SR |
232 | int tracing_is_enabled(void) |
233 | { | |
0fb9656d | 234 | return tracing_is_on(); |
9036990d SR |
235 | } |
236 | ||
4fcdae83 | 237 | /* |
3928a8a2 SR |
238 | * trace_buf_size is the size in bytes that is allocated |
239 | * for a buffer. Note, the number of bytes is always rounded | |
240 | * to page size. | |
3f5a54e3 SR |
241 | * |
242 | * This number is purposely set to a low number of 16384. | |
243 | * If the dump on oops happens, it will be much appreciated | |
244 | * to not have to wait for all that output. Anyway this can be | |
245 | * boot time and run time configurable. | |
4fcdae83 | 246 | */ |
3928a8a2 | 247 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 248 | |
3928a8a2 | 249 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 250 | |
4fcdae83 | 251 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 252 | static struct tracer *trace_types __read_mostly; |
4fcdae83 SR |
253 | |
254 | /* current_trace points to the tracer that is currently active */ | |
d840f718 | 255 | static struct tracer *current_trace __read_mostly = &nop_trace; |
4fcdae83 | 256 | |
4fcdae83 SR |
257 | /* |
258 | * trace_types_lock is used to protect the trace_types list. | |
4fcdae83 | 259 | */ |
bc0c38d1 | 260 | static DEFINE_MUTEX(trace_types_lock); |
4fcdae83 | 261 | |
7e53bd42 LJ |
262 | /* |
263 | * serialize the access of the ring buffer | |
264 | * | |
265 | * ring buffer serializes readers, but it is low level protection. | |
266 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
267 | * are not protected by ring buffer. | |
268 | * | |
269 | * The content of events may become garbage if we allow other process consumes | |
270 | * these events concurrently: | |
271 | * A) the page of the consumed events may become a normal page | |
272 | * (not reader page) in ring buffer, and this page will be rewrited | |
273 | * by events producer. | |
274 | * B) The page of the consumed events may become a page for splice_read, | |
275 | * and this page will be returned to system. | |
276 | * | |
277 | * These primitives allow multi process access to different cpu ring buffer | |
278 | * concurrently. | |
279 | * | |
280 | * These primitives don't distinguish read-only and read-consume access. | |
281 | * Multi read-only access are also serialized. | |
282 | */ | |
283 | ||
284 | #ifdef CONFIG_SMP | |
285 | static DECLARE_RWSEM(all_cpu_access_lock); | |
286 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
287 | ||
288 | static inline void trace_access_lock(int cpu) | |
289 | { | |
290 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
291 | /* gain it for accessing the whole ring buffer. */ | |
292 | down_write(&all_cpu_access_lock); | |
293 | } else { | |
294 | /* gain it for accessing a cpu ring buffer. */ | |
295 | ||
296 | /* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */ | |
297 | down_read(&all_cpu_access_lock); | |
298 | ||
299 | /* Secondly block other access to this @cpu ring buffer. */ | |
300 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
301 | } | |
302 | } | |
303 | ||
304 | static inline void trace_access_unlock(int cpu) | |
305 | { | |
306 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
307 | up_write(&all_cpu_access_lock); | |
308 | } else { | |
309 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
310 | up_read(&all_cpu_access_lock); | |
311 | } | |
312 | } | |
313 | ||
314 | static inline void trace_access_lock_init(void) | |
315 | { | |
316 | int cpu; | |
317 | ||
318 | for_each_possible_cpu(cpu) | |
319 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
320 | } | |
321 | ||
322 | #else | |
323 | ||
324 | static DEFINE_MUTEX(access_lock); | |
325 | ||
326 | static inline void trace_access_lock(int cpu) | |
327 | { | |
328 | (void)cpu; | |
329 | mutex_lock(&access_lock); | |
330 | } | |
331 | ||
332 | static inline void trace_access_unlock(int cpu) | |
333 | { | |
334 | (void)cpu; | |
335 | mutex_unlock(&access_lock); | |
336 | } | |
337 | ||
338 | static inline void trace_access_lock_init(void) | |
339 | { | |
340 | } | |
341 | ||
342 | #endif | |
343 | ||
4fcdae83 | 344 | /* trace_wait is a waitqueue for tasks blocked on trace_poll */ |
4e655519 IM |
345 | static DECLARE_WAIT_QUEUE_HEAD(trace_wait); |
346 | ||
ee6bce52 | 347 | /* trace_flags holds trace_options default values */ |
12ef7d44 | 348 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | |
a2a16d6a | 349 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | |
77271ce4 | 350 | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | |
5224c3a3 | 351 | TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS; |
4e655519 | 352 | |
b8de7bd1 | 353 | static int trace_stop_count; |
5389f6fa | 354 | static DEFINE_RAW_SPINLOCK(tracing_start_lock); |
b8de7bd1 | 355 | |
0d5c6e1c SR |
356 | /** |
357 | * trace_wake_up - wake up tasks waiting for trace input | |
358 | * | |
359 | * Schedules a delayed work to wake up any task that is blocked on the | |
360 | * trace_wait queue. These is used with trace_poll for tasks polling the | |
361 | * trace. | |
362 | */ | |
363 | static void trace_wake_up(struct irq_work *work) | |
e7e2ee89 | 364 | { |
0d5c6e1c | 365 | wake_up_all(&trace_wait); |
e7e2ee89 | 366 | |
0d5c6e1c | 367 | } |
e7e2ee89 | 368 | |
499e5470 SR |
369 | /** |
370 | * tracing_on - enable tracing buffers | |
371 | * | |
372 | * This function enables tracing buffers that may have been | |
373 | * disabled with tracing_off. | |
374 | */ | |
375 | void tracing_on(void) | |
376 | { | |
377 | if (global_trace.buffer) | |
378 | ring_buffer_record_on(global_trace.buffer); | |
379 | /* | |
380 | * This flag is only looked at when buffers haven't been | |
381 | * allocated yet. We don't really care about the race | |
382 | * between setting this flag and actually turning | |
383 | * on the buffer. | |
384 | */ | |
385 | global_trace.buffer_disabled = 0; | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(tracing_on); | |
388 | ||
389 | /** | |
390 | * tracing_off - turn off tracing buffers | |
391 | * | |
392 | * This function stops the tracing buffers from recording data. | |
393 | * It does not disable any overhead the tracers themselves may | |
394 | * be causing. This function simply causes all recording to | |
395 | * the ring buffers to fail. | |
396 | */ | |
397 | void tracing_off(void) | |
398 | { | |
399 | if (global_trace.buffer) | |
f2bf1f6f | 400 | ring_buffer_record_off(global_trace.buffer); |
499e5470 SR |
401 | /* |
402 | * This flag is only looked at when buffers haven't been | |
403 | * allocated yet. We don't really care about the race | |
404 | * between setting this flag and actually turning | |
405 | * on the buffer. | |
406 | */ | |
407 | global_trace.buffer_disabled = 1; | |
408 | } | |
409 | EXPORT_SYMBOL_GPL(tracing_off); | |
410 | ||
411 | /** | |
412 | * tracing_is_on - show state of ring buffers enabled | |
413 | */ | |
414 | int tracing_is_on(void) | |
415 | { | |
416 | if (global_trace.buffer) | |
417 | return ring_buffer_record_is_on(global_trace.buffer); | |
418 | return !global_trace.buffer_disabled; | |
419 | } | |
420 | EXPORT_SYMBOL_GPL(tracing_is_on); | |
421 | ||
3928a8a2 | 422 | static int __init set_buf_size(char *str) |
bc0c38d1 | 423 | { |
3928a8a2 | 424 | unsigned long buf_size; |
c6caeeb1 | 425 | |
bc0c38d1 SR |
426 | if (!str) |
427 | return 0; | |
9d612bef | 428 | buf_size = memparse(str, &str); |
c6caeeb1 | 429 | /* nr_entries can not be zero */ |
9d612bef | 430 | if (buf_size == 0) |
c6caeeb1 | 431 | return 0; |
3928a8a2 | 432 | trace_buf_size = buf_size; |
bc0c38d1 SR |
433 | return 1; |
434 | } | |
3928a8a2 | 435 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 436 | |
0e950173 TB |
437 | static int __init set_tracing_thresh(char *str) |
438 | { | |
87abb3b1 | 439 | unsigned long threshold; |
0e950173 TB |
440 | int ret; |
441 | ||
442 | if (!str) | |
443 | return 0; | |
bcd83ea6 | 444 | ret = kstrtoul(str, 0, &threshold); |
0e950173 TB |
445 | if (ret < 0) |
446 | return 0; | |
87abb3b1 | 447 | tracing_thresh = threshold * 1000; |
0e950173 TB |
448 | return 1; |
449 | } | |
450 | __setup("tracing_thresh=", set_tracing_thresh); | |
451 | ||
57f50be1 SR |
452 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
453 | { | |
454 | return nsecs / 1000; | |
455 | } | |
456 | ||
4fcdae83 | 457 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 SR |
458 | static const char *trace_options[] = { |
459 | "print-parent", | |
460 | "sym-offset", | |
461 | "sym-addr", | |
462 | "verbose", | |
f9896bf3 | 463 | "raw", |
5e3ca0ec | 464 | "hex", |
cb0f12aa | 465 | "bin", |
2a2cc8f7 | 466 | "block", |
86387f7e | 467 | "stacktrace", |
5e1607a0 | 468 | "trace_printk", |
b2a866f9 | 469 | "ftrace_preempt", |
9f029e83 | 470 | "branch", |
12ef7d44 | 471 | "annotate", |
02b67518 | 472 | "userstacktrace", |
b54d3de9 | 473 | "sym-userobj", |
66896a85 | 474 | "printk-msg-only", |
c4a8e8be | 475 | "context-info", |
c032ef64 | 476 | "latency-format", |
be6f164a | 477 | "sleep-time", |
a2a16d6a | 478 | "graph-time", |
e870e9a1 | 479 | "record-cmd", |
750912fa | 480 | "overwrite", |
cf30cf67 | 481 | "disable_on_free", |
77271ce4 | 482 | "irq-info", |
5224c3a3 | 483 | "markers", |
bc0c38d1 SR |
484 | NULL |
485 | }; | |
486 | ||
5079f326 Z |
487 | static struct { |
488 | u64 (*func)(void); | |
489 | const char *name; | |
8be0709f | 490 | int in_ns; /* is this clock in nanoseconds? */ |
5079f326 | 491 | } trace_clocks[] = { |
8be0709f DS |
492 | { trace_clock_local, "local", 1 }, |
493 | { trace_clock_global, "global", 1 }, | |
494 | { trace_clock_counter, "counter", 0 }, | |
8cbd9cc6 | 495 | ARCH_TRACE_CLOCKS |
5079f326 Z |
496 | }; |
497 | ||
498 | int trace_clock_id; | |
499 | ||
b63f39ea | 500 | /* |
501 | * trace_parser_get_init - gets the buffer for trace parser | |
502 | */ | |
503 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
504 | { | |
505 | memset(parser, 0, sizeof(*parser)); | |
506 | ||
507 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
508 | if (!parser->buffer) | |
509 | return 1; | |
510 | ||
511 | parser->size = size; | |
512 | return 0; | |
513 | } | |
514 | ||
515 | /* | |
516 | * trace_parser_put - frees the buffer for trace parser | |
517 | */ | |
518 | void trace_parser_put(struct trace_parser *parser) | |
519 | { | |
520 | kfree(parser->buffer); | |
521 | } | |
522 | ||
523 | /* | |
524 | * trace_get_user - reads the user input string separated by space | |
525 | * (matched by isspace(ch)) | |
526 | * | |
527 | * For each string found the 'struct trace_parser' is updated, | |
528 | * and the function returns. | |
529 | * | |
530 | * Returns number of bytes read. | |
531 | * | |
532 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
533 | */ | |
534 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
535 | size_t cnt, loff_t *ppos) | |
536 | { | |
537 | char ch; | |
538 | size_t read = 0; | |
539 | ssize_t ret; | |
540 | ||
541 | if (!*ppos) | |
542 | trace_parser_clear(parser); | |
543 | ||
544 | ret = get_user(ch, ubuf++); | |
545 | if (ret) | |
546 | goto out; | |
547 | ||
548 | read++; | |
549 | cnt--; | |
550 | ||
551 | /* | |
552 | * The parser is not finished with the last write, | |
553 | * continue reading the user input without skipping spaces. | |
554 | */ | |
555 | if (!parser->cont) { | |
556 | /* skip white space */ | |
557 | while (cnt && isspace(ch)) { | |
558 | ret = get_user(ch, ubuf++); | |
559 | if (ret) | |
560 | goto out; | |
561 | read++; | |
562 | cnt--; | |
563 | } | |
564 | ||
565 | /* only spaces were written */ | |
566 | if (isspace(ch)) { | |
567 | *ppos += read; | |
568 | ret = read; | |
569 | goto out; | |
570 | } | |
571 | ||
572 | parser->idx = 0; | |
573 | } | |
574 | ||
575 | /* read the non-space input */ | |
576 | while (cnt && !isspace(ch)) { | |
3c235a33 | 577 | if (parser->idx < parser->size - 1) |
b63f39ea | 578 | parser->buffer[parser->idx++] = ch; |
579 | else { | |
580 | ret = -EINVAL; | |
581 | goto out; | |
582 | } | |
583 | ret = get_user(ch, ubuf++); | |
584 | if (ret) | |
585 | goto out; | |
586 | read++; | |
587 | cnt--; | |
588 | } | |
589 | ||
590 | /* We either got finished input or we have to wait for another call. */ | |
591 | if (isspace(ch)) { | |
592 | parser->buffer[parser->idx] = 0; | |
593 | parser->cont = false; | |
594 | } else { | |
595 | parser->cont = true; | |
596 | parser->buffer[parser->idx++] = ch; | |
597 | } | |
598 | ||
599 | *ppos += read; | |
600 | ret = read; | |
601 | ||
602 | out: | |
603 | return ret; | |
604 | } | |
605 | ||
6c6c2796 PP |
606 | ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) |
607 | { | |
608 | int len; | |
609 | int ret; | |
610 | ||
2dc5d12b SR |
611 | if (!cnt) |
612 | return 0; | |
613 | ||
6c6c2796 PP |
614 | if (s->len <= s->readpos) |
615 | return -EBUSY; | |
616 | ||
617 | len = s->len - s->readpos; | |
618 | if (cnt > len) | |
619 | cnt = len; | |
620 | ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); | |
2dc5d12b | 621 | if (ret == cnt) |
6c6c2796 PP |
622 | return -EFAULT; |
623 | ||
2dc5d12b SR |
624 | cnt -= ret; |
625 | ||
e74da523 | 626 | s->readpos += cnt; |
6c6c2796 | 627 | return cnt; |
214023c3 SR |
628 | } |
629 | ||
b8b94265 | 630 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
631 | { |
632 | int len; | |
3c56819b EGM |
633 | |
634 | if (s->len <= s->readpos) | |
635 | return -EBUSY; | |
636 | ||
637 | len = s->len - s->readpos; | |
638 | if (cnt > len) | |
639 | cnt = len; | |
5a26c8f0 | 640 | memcpy(buf, s->buffer + s->readpos, cnt); |
3c56819b | 641 | |
e74da523 | 642 | s->readpos += cnt; |
3c56819b EGM |
643 | return cnt; |
644 | } | |
645 | ||
5d4a9dba SR |
646 | /* |
647 | * ftrace_max_lock is used to protect the swapping of buffers | |
648 | * when taking a max snapshot. The buffers themselves are | |
649 | * protected by per_cpu spinlocks. But the action of the swap | |
650 | * needs its own lock. | |
651 | * | |
445c8951 | 652 | * This is defined as a arch_spinlock_t in order to help |
5d4a9dba SR |
653 | * with performance when lockdep debugging is enabled. |
654 | * | |
655 | * It is also used in other places outside the update_max_tr | |
656 | * so it needs to be defined outside of the | |
657 | * CONFIG_TRACER_MAX_TRACE. | |
658 | */ | |
445c8951 | 659 | static arch_spinlock_t ftrace_max_lock = |
edc35bd7 | 660 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
5d4a9dba | 661 | |
0e950173 TB |
662 | unsigned long __read_mostly tracing_thresh; |
663 | ||
5d4a9dba SR |
664 | #ifdef CONFIG_TRACER_MAX_TRACE |
665 | unsigned long __read_mostly tracing_max_latency; | |
5d4a9dba SR |
666 | |
667 | /* | |
668 | * Copy the new maximum trace into the separate maximum-trace | |
669 | * structure. (this way the maximum trace is permanently saved, | |
670 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
671 | */ | |
672 | static void | |
673 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
674 | { | |
675 | struct trace_array_cpu *data = tr->data[cpu]; | |
1acaa1b2 | 676 | struct trace_array_cpu *max_data; |
5d4a9dba SR |
677 | |
678 | max_tr.cpu = cpu; | |
679 | max_tr.time_start = data->preempt_timestamp; | |
680 | ||
8248ac05 SR |
681 | max_data = max_tr.data[cpu]; |
682 | max_data->saved_latency = tracing_max_latency; | |
683 | max_data->critical_start = data->critical_start; | |
684 | max_data->critical_end = data->critical_end; | |
5d4a9dba | 685 | |
1acaa1b2 | 686 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); |
8248ac05 SR |
687 | max_data->pid = tsk->pid; |
688 | max_data->uid = task_uid(tsk); | |
689 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
690 | max_data->policy = tsk->policy; | |
691 | max_data->rt_priority = tsk->rt_priority; | |
5d4a9dba SR |
692 | |
693 | /* record this tasks comm */ | |
694 | tracing_record_cmdline(tsk); | |
695 | } | |
696 | ||
4fcdae83 SR |
697 | /** |
698 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
699 | * @tr: tracer | |
700 | * @tsk: the task with the latency | |
701 | * @cpu: The cpu that initiated the trace. | |
702 | * | |
703 | * Flip the buffers between the @tr and the max_tr and record information | |
704 | * about which task was the cause of this latency. | |
705 | */ | |
e309b41d | 706 | void |
bc0c38d1 SR |
707 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
708 | { | |
2721e72d | 709 | struct ring_buffer *buf; |
bc0c38d1 | 710 | |
b8de7bd1 SR |
711 | if (trace_stop_count) |
712 | return; | |
713 | ||
4c11d7ae | 714 | WARN_ON_ONCE(!irqs_disabled()); |
34600f0e | 715 | |
debdd57f HT |
716 | if (!current_trace->allocated_snapshot) { |
717 | /* Only the nop tracer should hit this when disabling */ | |
718 | WARN_ON_ONCE(current_trace != &nop_trace); | |
34600f0e | 719 | return; |
debdd57f | 720 | } |
34600f0e | 721 | |
0199c4e6 | 722 | arch_spin_lock(&ftrace_max_lock); |
3928a8a2 | 723 | |
2721e72d | 724 | buf = tr->buffer; |
3928a8a2 SR |
725 | tr->buffer = max_tr.buffer; |
726 | max_tr.buffer = buf; | |
727 | ||
bc0c38d1 | 728 | __update_max_tr(tr, tsk, cpu); |
0199c4e6 | 729 | arch_spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
730 | } |
731 | ||
732 | /** | |
733 | * update_max_tr_single - only copy one trace over, and reset the rest | |
734 | * @tr - tracer | |
735 | * @tsk - task with the latency | |
736 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
737 | * |
738 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 739 | */ |
e309b41d | 740 | void |
bc0c38d1 SR |
741 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
742 | { | |
3928a8a2 | 743 | int ret; |
bc0c38d1 | 744 | |
b8de7bd1 SR |
745 | if (trace_stop_count) |
746 | return; | |
747 | ||
4c11d7ae | 748 | WARN_ON_ONCE(!irqs_disabled()); |
debdd57f | 749 | if (WARN_ON_ONCE(!current_trace->allocated_snapshot)) |
ef710e10 | 750 | return; |
ef710e10 | 751 | |
0199c4e6 | 752 | arch_spin_lock(&ftrace_max_lock); |
bc0c38d1 | 753 | |
3928a8a2 SR |
754 | ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); |
755 | ||
e8165dbb SR |
756 | if (ret == -EBUSY) { |
757 | /* | |
758 | * We failed to swap the buffer due to a commit taking | |
759 | * place on this CPU. We fail to record, but we reset | |
760 | * the max trace buffer (no one writes directly to it) | |
761 | * and flag that it failed. | |
762 | */ | |
763 | trace_array_printk(&max_tr, _THIS_IP_, | |
764 | "Failed to swap buffers due to commit in progress\n"); | |
765 | } | |
766 | ||
e8165dbb | 767 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
bc0c38d1 SR |
768 | |
769 | __update_max_tr(tr, tsk, cpu); | |
0199c4e6 | 770 | arch_spin_unlock(&ftrace_max_lock); |
bc0c38d1 | 771 | } |
5d4a9dba | 772 | #endif /* CONFIG_TRACER_MAX_TRACE */ |
bc0c38d1 | 773 | |
0d5c6e1c SR |
774 | static void default_wait_pipe(struct trace_iterator *iter) |
775 | { | |
776 | DEFINE_WAIT(wait); | |
777 | ||
778 | prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE); | |
779 | ||
780 | /* | |
781 | * The events can happen in critical sections where | |
782 | * checking a work queue can cause deadlocks. | |
783 | * After adding a task to the queue, this flag is set | |
784 | * only to notify events to try to wake up the queue | |
785 | * using irq_work. | |
786 | * | |
787 | * We don't clear it even if the buffer is no longer | |
788 | * empty. The flag only causes the next event to run | |
789 | * irq_work to do the work queue wake up. The worse | |
790 | * that can happen if we race with !trace_empty() is that | |
791 | * an event will cause an irq_work to try to wake up | |
792 | * an empty queue. | |
793 | * | |
794 | * There's no reason to protect this flag either, as | |
795 | * the work queue and irq_work logic will do the necessary | |
796 | * synchronization for the wake ups. The only thing | |
797 | * that is necessary is that the wake up happens after | |
798 | * a task has been queued. It's OK for spurious wake ups. | |
799 | */ | |
800 | trace_wakeup_needed = true; | |
801 | ||
802 | if (trace_empty(iter)) | |
803 | schedule(); | |
804 | ||
805 | finish_wait(&trace_wait, &wait); | |
806 | } | |
807 | ||
4fcdae83 SR |
808 | /** |
809 | * register_tracer - register a tracer with the ftrace system. | |
810 | * @type - the plugin for the tracer | |
811 | * | |
812 | * Register a new plugin tracer. | |
813 | */ | |
bc0c38d1 SR |
814 | int register_tracer(struct tracer *type) |
815 | { | |
816 | struct tracer *t; | |
bc0c38d1 SR |
817 | int ret = 0; |
818 | ||
819 | if (!type->name) { | |
820 | pr_info("Tracer must have a name\n"); | |
821 | return -1; | |
822 | } | |
823 | ||
24a461d5 | 824 | if (strlen(type->name) >= MAX_TRACER_SIZE) { |
ee6c2c1b LZ |
825 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); |
826 | return -1; | |
827 | } | |
828 | ||
bc0c38d1 | 829 | mutex_lock(&trace_types_lock); |
86fa2f60 | 830 | |
8e1b82e0 FW |
831 | tracing_selftest_running = true; |
832 | ||
bc0c38d1 SR |
833 | for (t = trace_types; t; t = t->next) { |
834 | if (strcmp(type->name, t->name) == 0) { | |
835 | /* already found */ | |
ee6c2c1b | 836 | pr_info("Tracer %s already registered\n", |
bc0c38d1 SR |
837 | type->name); |
838 | ret = -1; | |
839 | goto out; | |
840 | } | |
841 | } | |
842 | ||
adf9f195 FW |
843 | if (!type->set_flag) |
844 | type->set_flag = &dummy_set_flag; | |
845 | if (!type->flags) | |
846 | type->flags = &dummy_tracer_flags; | |
847 | else | |
848 | if (!type->flags->opts) | |
849 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 FW |
850 | if (!type->wait_pipe) |
851 | type->wait_pipe = default_wait_pipe; | |
852 | ||
adf9f195 | 853 | |
60a11774 | 854 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
b2821ae6 | 855 | if (type->selftest && !tracing_selftest_disabled) { |
60a11774 | 856 | struct tracer *saved_tracer = current_trace; |
60a11774 | 857 | struct trace_array *tr = &global_trace; |
ff32504f | 858 | |
60a11774 SR |
859 | /* |
860 | * Run a selftest on this tracer. | |
861 | * Here we reset the trace buffer, and set the current | |
862 | * tracer to be this tracer. The tracer can then run some | |
863 | * internal tracing to verify that everything is in order. | |
864 | * If we fail, we do not register this tracer. | |
865 | */ | |
76f0d073 | 866 | tracing_reset_online_cpus(tr); |
86fa2f60 | 867 | |
60a11774 | 868 | current_trace = type; |
4a0b1665 | 869 | |
debdd57f HT |
870 | if (type->use_max_tr) { |
871 | /* If we expanded the buffers, make sure the max is expanded too */ | |
872 | if (ring_buffer_expanded) | |
873 | ring_buffer_resize(max_tr.buffer, trace_buf_size, | |
874 | RING_BUFFER_ALL_CPUS); | |
875 | type->allocated_snapshot = true; | |
876 | } | |
4a0b1665 | 877 | |
60a11774 SR |
878 | /* the test is responsible for initializing and enabling */ |
879 | pr_info("Testing tracer %s: ", type->name); | |
880 | ret = type->selftest(type, tr); | |
881 | /* the test is responsible for resetting too */ | |
882 | current_trace = saved_tracer; | |
60a11774 SR |
883 | if (ret) { |
884 | printk(KERN_CONT "FAILED!\n"); | |
0be61ebc SR |
885 | /* Add the warning after printing 'FAILED' */ |
886 | WARN_ON(1); | |
60a11774 SR |
887 | goto out; |
888 | } | |
1d4db00a | 889 | /* Only reset on passing, to avoid touching corrupted buffers */ |
76f0d073 | 890 | tracing_reset_online_cpus(tr); |
86fa2f60 | 891 | |
debdd57f HT |
892 | if (type->use_max_tr) { |
893 | type->allocated_snapshot = false; | |
894 | ||
895 | /* Shrink the max buffer again */ | |
896 | if (ring_buffer_expanded) | |
897 | ring_buffer_resize(max_tr.buffer, 1, | |
898 | RING_BUFFER_ALL_CPUS); | |
899 | } | |
4a0b1665 | 900 | |
60a11774 SR |
901 | printk(KERN_CONT "PASSED\n"); |
902 | } | |
903 | #endif | |
904 | ||
bc0c38d1 SR |
905 | type->next = trace_types; |
906 | trace_types = type; | |
60a11774 | 907 | |
bc0c38d1 | 908 | out: |
8e1b82e0 | 909 | tracing_selftest_running = false; |
bc0c38d1 SR |
910 | mutex_unlock(&trace_types_lock); |
911 | ||
dac74940 SR |
912 | if (ret || !default_bootup_tracer) |
913 | goto out_unlock; | |
914 | ||
ee6c2c1b | 915 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
dac74940 SR |
916 | goto out_unlock; |
917 | ||
918 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
919 | /* Do we want this tracer to start on bootup? */ | |
920 | tracing_set_tracer(type->name); | |
921 | default_bootup_tracer = NULL; | |
922 | /* disable other selftests, since this will break it. */ | |
923 | tracing_selftest_disabled = 1; | |
b2821ae6 | 924 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
925 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
926 | type->name); | |
b2821ae6 | 927 | #endif |
b2821ae6 | 928 | |
dac74940 | 929 | out_unlock: |
bc0c38d1 SR |
930 | return ret; |
931 | } | |
932 | ||
f633903a SR |
933 | void tracing_reset(struct trace_array *tr, int cpu) |
934 | { | |
935 | struct ring_buffer *buffer = tr->buffer; | |
936 | ||
a5416411 HT |
937 | if (!buffer) |
938 | return; | |
939 | ||
f633903a SR |
940 | ring_buffer_record_disable(buffer); |
941 | ||
942 | /* Make sure all commits have finished */ | |
943 | synchronize_sched(); | |
68179686 | 944 | ring_buffer_reset_cpu(buffer, cpu); |
f633903a SR |
945 | |
946 | ring_buffer_record_enable(buffer); | |
947 | } | |
948 | ||
213cc060 PE |
949 | void tracing_reset_online_cpus(struct trace_array *tr) |
950 | { | |
621968cd | 951 | struct ring_buffer *buffer = tr->buffer; |
213cc060 PE |
952 | int cpu; |
953 | ||
a5416411 HT |
954 | if (!buffer) |
955 | return; | |
956 | ||
621968cd SR |
957 | ring_buffer_record_disable(buffer); |
958 | ||
959 | /* Make sure all commits have finished */ | |
960 | synchronize_sched(); | |
961 | ||
213cc060 PE |
962 | tr->time_start = ftrace_now(tr->cpu); |
963 | ||
964 | for_each_online_cpu(cpu) | |
68179686 | 965 | ring_buffer_reset_cpu(buffer, cpu); |
621968cd SR |
966 | |
967 | ring_buffer_record_enable(buffer); | |
213cc060 PE |
968 | } |
969 | ||
9456f0fa SR |
970 | void tracing_reset_current(int cpu) |
971 | { | |
972 | tracing_reset(&global_trace, cpu); | |
973 | } | |
974 | ||
975 | void tracing_reset_current_online_cpus(void) | |
976 | { | |
977 | tracing_reset_online_cpus(&global_trace); | |
978 | } | |
979 | ||
bc0c38d1 | 980 | #define SAVED_CMDLINES 128 |
2c7eea4c | 981 | #define NO_CMDLINE_MAP UINT_MAX |
bc0c38d1 SR |
982 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; |
983 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
984 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
985 | static int cmdline_idx; | |
edc35bd7 | 986 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
25b0b44a | 987 | |
25b0b44a | 988 | /* temporary disable recording */ |
4fd27358 | 989 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 SR |
990 | |
991 | static void trace_init_cmdlines(void) | |
992 | { | |
2c7eea4c TG |
993 | memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); |
994 | memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); | |
bc0c38d1 SR |
995 | cmdline_idx = 0; |
996 | } | |
997 | ||
b5130b1e CE |
998 | int is_tracing_stopped(void) |
999 | { | |
1000 | return trace_stop_count; | |
1001 | } | |
1002 | ||
69bb54ec SR |
1003 | /** |
1004 | * ftrace_off_permanent - disable all ftrace code permanently | |
1005 | * | |
1006 | * This should only be called when a serious anomally has | |
1007 | * been detected. This will turn off the function tracing, | |
1008 | * ring buffers, and other tracing utilites. It takes no | |
1009 | * locks and can be called from any context. | |
1010 | */ | |
1011 | void ftrace_off_permanent(void) | |
1012 | { | |
1013 | tracing_disabled = 1; | |
1014 | ftrace_stop(); | |
1015 | tracing_off_permanent(); | |
1016 | } | |
1017 | ||
0f048701 SR |
1018 | /** |
1019 | * tracing_start - quick start of the tracer | |
1020 | * | |
1021 | * If tracing is enabled but was stopped by tracing_stop, | |
1022 | * this will start the tracer back up. | |
1023 | */ | |
1024 | void tracing_start(void) | |
1025 | { | |
1026 | struct ring_buffer *buffer; | |
1027 | unsigned long flags; | |
1028 | ||
1029 | if (tracing_disabled) | |
1030 | return; | |
1031 | ||
5389f6fa | 1032 | raw_spin_lock_irqsave(&tracing_start_lock, flags); |
b06a8301 SR |
1033 | if (--trace_stop_count) { |
1034 | if (trace_stop_count < 0) { | |
1035 | /* Someone screwed up their debugging */ | |
1036 | WARN_ON_ONCE(1); | |
1037 | trace_stop_count = 0; | |
1038 | } | |
0f048701 SR |
1039 | goto out; |
1040 | } | |
1041 | ||
a2f80714 SR |
1042 | /* Prevent the buffers from switching */ |
1043 | arch_spin_lock(&ftrace_max_lock); | |
0f048701 SR |
1044 | |
1045 | buffer = global_trace.buffer; | |
1046 | if (buffer) | |
1047 | ring_buffer_record_enable(buffer); | |
1048 | ||
1049 | buffer = max_tr.buffer; | |
1050 | if (buffer) | |
1051 | ring_buffer_record_enable(buffer); | |
1052 | ||
a2f80714 SR |
1053 | arch_spin_unlock(&ftrace_max_lock); |
1054 | ||
0f048701 SR |
1055 | ftrace_start(); |
1056 | out: | |
5389f6fa | 1057 | raw_spin_unlock_irqrestore(&tracing_start_lock, flags); |
0f048701 SR |
1058 | } |
1059 | ||
1060 | /** | |
1061 | * tracing_stop - quick stop of the tracer | |
1062 | * | |
1063 | * Light weight way to stop tracing. Use in conjunction with | |
1064 | * tracing_start. | |
1065 | */ | |
1066 | void tracing_stop(void) | |
1067 | { | |
1068 | struct ring_buffer *buffer; | |
1069 | unsigned long flags; | |
1070 | ||
1071 | ftrace_stop(); | |
5389f6fa | 1072 | raw_spin_lock_irqsave(&tracing_start_lock, flags); |
0f048701 SR |
1073 | if (trace_stop_count++) |
1074 | goto out; | |
1075 | ||
a2f80714 SR |
1076 | /* Prevent the buffers from switching */ |
1077 | arch_spin_lock(&ftrace_max_lock); | |
1078 | ||
0f048701 SR |
1079 | buffer = global_trace.buffer; |
1080 | if (buffer) | |
1081 | ring_buffer_record_disable(buffer); | |
1082 | ||
1083 | buffer = max_tr.buffer; | |
1084 | if (buffer) | |
1085 | ring_buffer_record_disable(buffer); | |
1086 | ||
a2f80714 SR |
1087 | arch_spin_unlock(&ftrace_max_lock); |
1088 | ||
0f048701 | 1089 | out: |
5389f6fa | 1090 | raw_spin_unlock_irqrestore(&tracing_start_lock, flags); |
0f048701 SR |
1091 | } |
1092 | ||
e309b41d | 1093 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 1094 | |
e309b41d | 1095 | static void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1096 | { |
a635cf04 | 1097 | unsigned pid, idx; |
bc0c38d1 SR |
1098 | |
1099 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
1100 | return; | |
1101 | ||
1102 | /* | |
1103 | * It's not the end of the world if we don't get | |
1104 | * the lock, but we also don't want to spin | |
1105 | * nor do we want to disable interrupts, | |
1106 | * so if we miss here, then better luck next time. | |
1107 | */ | |
0199c4e6 | 1108 | if (!arch_spin_trylock(&trace_cmdline_lock)) |
bc0c38d1 SR |
1109 | return; |
1110 | ||
1111 | idx = map_pid_to_cmdline[tsk->pid]; | |
2c7eea4c | 1112 | if (idx == NO_CMDLINE_MAP) { |
bc0c38d1 SR |
1113 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; |
1114 | ||
a635cf04 CE |
1115 | /* |
1116 | * Check whether the cmdline buffer at idx has a pid | |
1117 | * mapped. We are going to overwrite that entry so we | |
1118 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1119 | * would read the new comm for the old pid. | |
1120 | */ | |
1121 | pid = map_cmdline_to_pid[idx]; | |
1122 | if (pid != NO_CMDLINE_MAP) | |
1123 | map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; | |
bc0c38d1 | 1124 | |
a635cf04 | 1125 | map_cmdline_to_pid[idx] = tsk->pid; |
bc0c38d1 SR |
1126 | map_pid_to_cmdline[tsk->pid] = idx; |
1127 | ||
1128 | cmdline_idx = idx; | |
1129 | } | |
1130 | ||
1131 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
1132 | ||
0199c4e6 | 1133 | arch_spin_unlock(&trace_cmdline_lock); |
bc0c38d1 SR |
1134 | } |
1135 | ||
4ca53085 | 1136 | void trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 1137 | { |
bc0c38d1 SR |
1138 | unsigned map; |
1139 | ||
4ca53085 SR |
1140 | if (!pid) { |
1141 | strcpy(comm, "<idle>"); | |
1142 | return; | |
1143 | } | |
bc0c38d1 | 1144 | |
74bf4076 SR |
1145 | if (WARN_ON_ONCE(pid < 0)) { |
1146 | strcpy(comm, "<XXX>"); | |
1147 | return; | |
1148 | } | |
1149 | ||
4ca53085 SR |
1150 | if (pid > PID_MAX_DEFAULT) { |
1151 | strcpy(comm, "<...>"); | |
1152 | return; | |
1153 | } | |
bc0c38d1 | 1154 | |
5b6045a9 | 1155 | preempt_disable(); |
0199c4e6 | 1156 | arch_spin_lock(&trace_cmdline_lock); |
bc0c38d1 | 1157 | map = map_pid_to_cmdline[pid]; |
50d88758 TG |
1158 | if (map != NO_CMDLINE_MAP) |
1159 | strcpy(comm, saved_cmdlines[map]); | |
1160 | else | |
1161 | strcpy(comm, "<...>"); | |
bc0c38d1 | 1162 | |
0199c4e6 | 1163 | arch_spin_unlock(&trace_cmdline_lock); |
5b6045a9 | 1164 | preempt_enable(); |
bc0c38d1 SR |
1165 | } |
1166 | ||
e309b41d | 1167 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 1168 | { |
0fb9656d | 1169 | if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) |
bc0c38d1 SR |
1170 | return; |
1171 | ||
7ffbd48d SR |
1172 | if (!__this_cpu_read(trace_cmdline_save)) |
1173 | return; | |
1174 | ||
1175 | __this_cpu_write(trace_cmdline_save, false); | |
1176 | ||
bc0c38d1 SR |
1177 | trace_save_cmdline(tsk); |
1178 | } | |
1179 | ||
45dcd8b8 | 1180 | void |
38697053 SR |
1181 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
1182 | int pc) | |
bc0c38d1 SR |
1183 | { |
1184 | struct task_struct *tsk = current; | |
bc0c38d1 | 1185 | |
777e208d SR |
1186 | entry->preempt_count = pc & 0xff; |
1187 | entry->pid = (tsk) ? tsk->pid : 0; | |
1188 | entry->flags = | |
9244489a | 1189 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 1190 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
1191 | #else |
1192 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1193 | #endif | |
bc0c38d1 SR |
1194 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
1195 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
1196 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
1197 | } | |
f413cdb8 | 1198 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); |
bc0c38d1 | 1199 | |
e77405ad SR |
1200 | struct ring_buffer_event * |
1201 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1202 | int type, | |
1203 | unsigned long len, | |
1204 | unsigned long flags, int pc) | |
51a763dd ACM |
1205 | { |
1206 | struct ring_buffer_event *event; | |
1207 | ||
e77405ad | 1208 | event = ring_buffer_lock_reserve(buffer, len); |
51a763dd ACM |
1209 | if (event != NULL) { |
1210 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1211 | ||
1212 | tracing_generic_entry_update(ent, flags, pc); | |
1213 | ent->type = type; | |
1214 | } | |
1215 | ||
1216 | return event; | |
1217 | } | |
51a763dd | 1218 | |
7ffbd48d SR |
1219 | void |
1220 | __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) | |
1221 | { | |
1222 | __this_cpu_write(trace_cmdline_save, true); | |
0d5c6e1c SR |
1223 | if (trace_wakeup_needed) { |
1224 | trace_wakeup_needed = false; | |
1225 | /* irq_work_queue() supplies it's own memory barriers */ | |
1226 | irq_work_queue(&trace_work_wakeup); | |
1227 | } | |
7ffbd48d SR |
1228 | ring_buffer_unlock_commit(buffer, event); |
1229 | } | |
1230 | ||
e77405ad SR |
1231 | static inline void |
1232 | __trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1233 | struct ring_buffer_event *event, | |
0d5c6e1c | 1234 | unsigned long flags, int pc) |
51a763dd | 1235 | { |
7ffbd48d | 1236 | __buffer_unlock_commit(buffer, event); |
51a763dd | 1237 | |
e77405ad SR |
1238 | ftrace_trace_stack(buffer, flags, 6, pc); |
1239 | ftrace_trace_userstack(buffer, flags, pc); | |
07edf712 FW |
1240 | } |
1241 | ||
e77405ad SR |
1242 | void trace_buffer_unlock_commit(struct ring_buffer *buffer, |
1243 | struct ring_buffer_event *event, | |
1244 | unsigned long flags, int pc) | |
07edf712 | 1245 | { |
0d5c6e1c | 1246 | __trace_buffer_unlock_commit(buffer, event, flags, pc); |
51a763dd | 1247 | } |
0d5c6e1c | 1248 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); |
51a763dd | 1249 | |
ef5580d0 | 1250 | struct ring_buffer_event * |
e77405ad SR |
1251 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, |
1252 | int type, unsigned long len, | |
ef5580d0 SR |
1253 | unsigned long flags, int pc) |
1254 | { | |
e77405ad SR |
1255 | *current_rb = global_trace.buffer; |
1256 | return trace_buffer_lock_reserve(*current_rb, | |
ef5580d0 SR |
1257 | type, len, flags, pc); |
1258 | } | |
94487d6d | 1259 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); |
ef5580d0 | 1260 | |
e77405ad SR |
1261 | void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, |
1262 | struct ring_buffer_event *event, | |
ef5580d0 SR |
1263 | unsigned long flags, int pc) |
1264 | { | |
0d5c6e1c | 1265 | __trace_buffer_unlock_commit(buffer, event, flags, pc); |
07edf712 | 1266 | } |
94487d6d | 1267 | EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit); |
07edf712 | 1268 | |
0d5c6e1c SR |
1269 | void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer, |
1270 | struct ring_buffer_event *event, | |
1271 | unsigned long flags, int pc, | |
1272 | struct pt_regs *regs) | |
1fd8df2c | 1273 | { |
7ffbd48d | 1274 | __buffer_unlock_commit(buffer, event); |
1fd8df2c MH |
1275 | |
1276 | ftrace_trace_stack_regs(buffer, flags, 0, pc, regs); | |
1277 | ftrace_trace_userstack(buffer, flags, pc); | |
1278 | } | |
0d5c6e1c | 1279 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); |
1fd8df2c | 1280 | |
e77405ad SR |
1281 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, |
1282 | struct ring_buffer_event *event) | |
77d9f465 | 1283 | { |
e77405ad | 1284 | ring_buffer_discard_commit(buffer, event); |
ef5580d0 | 1285 | } |
12acd473 | 1286 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); |
ef5580d0 | 1287 | |
e309b41d | 1288 | void |
7be42151 | 1289 | trace_function(struct trace_array *tr, |
38697053 SR |
1290 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1291 | int pc) | |
bc0c38d1 | 1292 | { |
e1112b4d | 1293 | struct ftrace_event_call *call = &event_function; |
e77405ad | 1294 | struct ring_buffer *buffer = tr->buffer; |
3928a8a2 | 1295 | struct ring_buffer_event *event; |
777e208d | 1296 | struct ftrace_entry *entry; |
bc0c38d1 | 1297 | |
d769041f | 1298 | /* If we are reading the ring buffer, don't trace */ |
dd17c8f7 | 1299 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) |
d769041f SR |
1300 | return; |
1301 | ||
e77405ad | 1302 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
51a763dd | 1303 | flags, pc); |
3928a8a2 SR |
1304 | if (!event) |
1305 | return; | |
1306 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1307 | entry->ip = ip; |
1308 | entry->parent_ip = parent_ip; | |
e1112b4d | 1309 | |
e77405ad | 1310 | if (!filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1311 | __buffer_unlock_commit(buffer, event); |
bc0c38d1 SR |
1312 | } |
1313 | ||
e309b41d | 1314 | void |
2e0f5761 | 1315 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, |
38697053 SR |
1316 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
1317 | int pc) | |
2e0f5761 IM |
1318 | { |
1319 | if (likely(!atomic_read(&data->disabled))) | |
7be42151 | 1320 | trace_function(tr, ip, parent_ip, flags, pc); |
2e0f5761 IM |
1321 | } |
1322 | ||
c0a0d0d3 | 1323 | #ifdef CONFIG_STACKTRACE |
4a9bd3f1 SR |
1324 | |
1325 | #define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) | |
1326 | struct ftrace_stack { | |
1327 | unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; | |
1328 | }; | |
1329 | ||
1330 | static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); | |
1331 | static DEFINE_PER_CPU(int, ftrace_stack_reserve); | |
1332 | ||
e77405ad | 1333 | static void __ftrace_trace_stack(struct ring_buffer *buffer, |
53614991 | 1334 | unsigned long flags, |
1fd8df2c | 1335 | int skip, int pc, struct pt_regs *regs) |
86387f7e | 1336 | { |
e1112b4d | 1337 | struct ftrace_event_call *call = &event_kernel_stack; |
3928a8a2 | 1338 | struct ring_buffer_event *event; |
777e208d | 1339 | struct stack_entry *entry; |
86387f7e | 1340 | struct stack_trace trace; |
4a9bd3f1 SR |
1341 | int use_stack; |
1342 | int size = FTRACE_STACK_ENTRIES; | |
1343 | ||
1344 | trace.nr_entries = 0; | |
1345 | trace.skip = skip; | |
1346 | ||
1347 | /* | |
1348 | * Since events can happen in NMIs there's no safe way to | |
1349 | * use the per cpu ftrace_stacks. We reserve it and if an interrupt | |
1350 | * or NMI comes in, it will just have to use the default | |
1351 | * FTRACE_STACK_SIZE. | |
1352 | */ | |
1353 | preempt_disable_notrace(); | |
1354 | ||
82146529 | 1355 | use_stack = __this_cpu_inc_return(ftrace_stack_reserve); |
4a9bd3f1 SR |
1356 | /* |
1357 | * We don't need any atomic variables, just a barrier. | |
1358 | * If an interrupt comes in, we don't care, because it would | |
1359 | * have exited and put the counter back to what we want. | |
1360 | * We just need a barrier to keep gcc from moving things | |
1361 | * around. | |
1362 | */ | |
1363 | barrier(); | |
1364 | if (use_stack == 1) { | |
1365 | trace.entries = &__get_cpu_var(ftrace_stack).calls[0]; | |
1366 | trace.max_entries = FTRACE_STACK_MAX_ENTRIES; | |
1367 | ||
1368 | if (regs) | |
1369 | save_stack_trace_regs(regs, &trace); | |
1370 | else | |
1371 | save_stack_trace(&trace); | |
1372 | ||
1373 | if (trace.nr_entries > size) | |
1374 | size = trace.nr_entries; | |
1375 | } else | |
1376 | /* From now on, use_stack is a boolean */ | |
1377 | use_stack = 0; | |
1378 | ||
1379 | size *= sizeof(unsigned long); | |
86387f7e | 1380 | |
e77405ad | 1381 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, |
4a9bd3f1 | 1382 | sizeof(*entry) + size, flags, pc); |
3928a8a2 | 1383 | if (!event) |
4a9bd3f1 SR |
1384 | goto out; |
1385 | entry = ring_buffer_event_data(event); | |
86387f7e | 1386 | |
4a9bd3f1 SR |
1387 | memset(&entry->caller, 0, size); |
1388 | ||
1389 | if (use_stack) | |
1390 | memcpy(&entry->caller, trace.entries, | |
1391 | trace.nr_entries * sizeof(unsigned long)); | |
1392 | else { | |
1393 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1394 | trace.entries = entry->caller; | |
1395 | if (regs) | |
1396 | save_stack_trace_regs(regs, &trace); | |
1397 | else | |
1398 | save_stack_trace(&trace); | |
1399 | } | |
1400 | ||
1401 | entry->size = trace.nr_entries; | |
86387f7e | 1402 | |
e77405ad | 1403 | if (!filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1404 | __buffer_unlock_commit(buffer, event); |
4a9bd3f1 SR |
1405 | |
1406 | out: | |
1407 | /* Again, don't let gcc optimize things here */ | |
1408 | barrier(); | |
82146529 | 1409 | __this_cpu_dec(ftrace_stack_reserve); |
4a9bd3f1 SR |
1410 | preempt_enable_notrace(); |
1411 | ||
f0a920d5 IM |
1412 | } |
1413 | ||
1fd8df2c MH |
1414 | void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags, |
1415 | int skip, int pc, struct pt_regs *regs) | |
1416 | { | |
1417 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1418 | return; | |
1419 | ||
1420 | __ftrace_trace_stack(buffer, flags, skip, pc, regs); | |
1421 | } | |
1422 | ||
e77405ad SR |
1423 | void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, |
1424 | int skip, int pc) | |
53614991 SR |
1425 | { |
1426 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1427 | return; | |
1428 | ||
1fd8df2c | 1429 | __ftrace_trace_stack(buffer, flags, skip, pc, NULL); |
53614991 SR |
1430 | } |
1431 | ||
c0a0d0d3 FW |
1432 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, |
1433 | int pc) | |
38697053 | 1434 | { |
1fd8df2c | 1435 | __ftrace_trace_stack(tr->buffer, flags, skip, pc, NULL); |
38697053 SR |
1436 | } |
1437 | ||
03889384 SR |
1438 | /** |
1439 | * trace_dump_stack - record a stack back trace in the trace buffer | |
1440 | */ | |
1441 | void trace_dump_stack(void) | |
1442 | { | |
1443 | unsigned long flags; | |
1444 | ||
1445 | if (tracing_disabled || tracing_selftest_running) | |
e36c5458 | 1446 | return; |
03889384 SR |
1447 | |
1448 | local_save_flags(flags); | |
1449 | ||
1450 | /* skipping 3 traces, seems to get us at the caller of this function */ | |
1fd8df2c | 1451 | __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count(), NULL); |
03889384 SR |
1452 | } |
1453 | ||
91e86e56 SR |
1454 | static DEFINE_PER_CPU(int, user_stack_count); |
1455 | ||
e77405ad SR |
1456 | void |
1457 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
02b67518 | 1458 | { |
e1112b4d | 1459 | struct ftrace_event_call *call = &event_user_stack; |
8d7c6a96 | 1460 | struct ring_buffer_event *event; |
02b67518 TE |
1461 | struct userstack_entry *entry; |
1462 | struct stack_trace trace; | |
02b67518 TE |
1463 | |
1464 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1465 | return; | |
1466 | ||
b6345879 SR |
1467 | /* |
1468 | * NMIs can not handle page faults, even with fix ups. | |
1469 | * The save user stack can (and often does) fault. | |
1470 | */ | |
1471 | if (unlikely(in_nmi())) | |
1472 | return; | |
02b67518 | 1473 | |
91e86e56 SR |
1474 | /* |
1475 | * prevent recursion, since the user stack tracing may | |
1476 | * trigger other kernel events. | |
1477 | */ | |
1478 | preempt_disable(); | |
1479 | if (__this_cpu_read(user_stack_count)) | |
1480 | goto out; | |
1481 | ||
1482 | __this_cpu_inc(user_stack_count); | |
1483 | ||
e77405ad | 1484 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
51a763dd | 1485 | sizeof(*entry), flags, pc); |
02b67518 | 1486 | if (!event) |
1dbd1951 | 1487 | goto out_drop_count; |
02b67518 | 1488 | entry = ring_buffer_event_data(event); |
02b67518 | 1489 | |
48659d31 | 1490 | entry->tgid = current->tgid; |
02b67518 TE |
1491 | memset(&entry->caller, 0, sizeof(entry->caller)); |
1492 | ||
1493 | trace.nr_entries = 0; | |
1494 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1495 | trace.skip = 0; | |
1496 | trace.entries = entry->caller; | |
1497 | ||
1498 | save_stack_trace_user(&trace); | |
e77405ad | 1499 | if (!filter_check_discard(call, entry, buffer, event)) |
7ffbd48d | 1500 | __buffer_unlock_commit(buffer, event); |
91e86e56 | 1501 | |
1dbd1951 | 1502 | out_drop_count: |
91e86e56 | 1503 | __this_cpu_dec(user_stack_count); |
91e86e56 SR |
1504 | out: |
1505 | preempt_enable(); | |
02b67518 TE |
1506 | } |
1507 | ||
4fd27358 HE |
1508 | #ifdef UNUSED |
1509 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1510 | { |
7be42151 | 1511 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1512 | } |
4fd27358 | 1513 | #endif /* UNUSED */ |
02b67518 | 1514 | |
c0a0d0d3 FW |
1515 | #endif /* CONFIG_STACKTRACE */ |
1516 | ||
07d777fe SR |
1517 | /* created for use with alloc_percpu */ |
1518 | struct trace_buffer_struct { | |
1519 | char buffer[TRACE_BUF_SIZE]; | |
1520 | }; | |
1521 | ||
1522 | static struct trace_buffer_struct *trace_percpu_buffer; | |
1523 | static struct trace_buffer_struct *trace_percpu_sirq_buffer; | |
1524 | static struct trace_buffer_struct *trace_percpu_irq_buffer; | |
1525 | static struct trace_buffer_struct *trace_percpu_nmi_buffer; | |
1526 | ||
1527 | /* | |
1528 | * The buffer used is dependent on the context. There is a per cpu | |
1529 | * buffer for normal context, softirq contex, hard irq context and | |
1530 | * for NMI context. Thise allows for lockless recording. | |
1531 | * | |
1532 | * Note, if the buffers failed to be allocated, then this returns NULL | |
1533 | */ | |
1534 | static char *get_trace_buf(void) | |
1535 | { | |
1536 | struct trace_buffer_struct *percpu_buffer; | |
07d777fe SR |
1537 | |
1538 | /* | |
1539 | * If we have allocated per cpu buffers, then we do not | |
1540 | * need to do any locking. | |
1541 | */ | |
1542 | if (in_nmi()) | |
1543 | percpu_buffer = trace_percpu_nmi_buffer; | |
1544 | else if (in_irq()) | |
1545 | percpu_buffer = trace_percpu_irq_buffer; | |
1546 | else if (in_softirq()) | |
1547 | percpu_buffer = trace_percpu_sirq_buffer; | |
1548 | else | |
1549 | percpu_buffer = trace_percpu_buffer; | |
1550 | ||
1551 | if (!percpu_buffer) | |
1552 | return NULL; | |
1553 | ||
d8a0349c | 1554 | return this_cpu_ptr(&percpu_buffer->buffer[0]); |
07d777fe SR |
1555 | } |
1556 | ||
1557 | static int alloc_percpu_trace_buffer(void) | |
1558 | { | |
1559 | struct trace_buffer_struct *buffers; | |
1560 | struct trace_buffer_struct *sirq_buffers; | |
1561 | struct trace_buffer_struct *irq_buffers; | |
1562 | struct trace_buffer_struct *nmi_buffers; | |
1563 | ||
1564 | buffers = alloc_percpu(struct trace_buffer_struct); | |
1565 | if (!buffers) | |
1566 | goto err_warn; | |
1567 | ||
1568 | sirq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1569 | if (!sirq_buffers) | |
1570 | goto err_sirq; | |
1571 | ||
1572 | irq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1573 | if (!irq_buffers) | |
1574 | goto err_irq; | |
1575 | ||
1576 | nmi_buffers = alloc_percpu(struct trace_buffer_struct); | |
1577 | if (!nmi_buffers) | |
1578 | goto err_nmi; | |
1579 | ||
1580 | trace_percpu_buffer = buffers; | |
1581 | trace_percpu_sirq_buffer = sirq_buffers; | |
1582 | trace_percpu_irq_buffer = irq_buffers; | |
1583 | trace_percpu_nmi_buffer = nmi_buffers; | |
1584 | ||
1585 | return 0; | |
1586 | ||
1587 | err_nmi: | |
1588 | free_percpu(irq_buffers); | |
1589 | err_irq: | |
1590 | free_percpu(sirq_buffers); | |
1591 | err_sirq: | |
1592 | free_percpu(buffers); | |
1593 | err_warn: | |
1594 | WARN(1, "Could not allocate percpu trace_printk buffer"); | |
1595 | return -ENOMEM; | |
1596 | } | |
1597 | ||
81698831 SR |
1598 | static int buffers_allocated; |
1599 | ||
07d777fe SR |
1600 | void trace_printk_init_buffers(void) |
1601 | { | |
07d777fe SR |
1602 | if (buffers_allocated) |
1603 | return; | |
1604 | ||
1605 | if (alloc_percpu_trace_buffer()) | |
1606 | return; | |
1607 | ||
1608 | pr_info("ftrace: Allocated trace_printk buffers\n"); | |
1609 | ||
b382ede6 SR |
1610 | /* Expand the buffers to set size */ |
1611 | tracing_update_buffers(); | |
1612 | ||
07d777fe | 1613 | buffers_allocated = 1; |
81698831 SR |
1614 | |
1615 | /* | |
1616 | * trace_printk_init_buffers() can be called by modules. | |
1617 | * If that happens, then we need to start cmdline recording | |
1618 | * directly here. If the global_trace.buffer is already | |
1619 | * allocated here, then this was called by module code. | |
1620 | */ | |
1621 | if (global_trace.buffer) | |
1622 | tracing_start_cmdline_record(); | |
1623 | } | |
1624 | ||
1625 | void trace_printk_start_comm(void) | |
1626 | { | |
1627 | /* Start tracing comms if trace printk is set */ | |
1628 | if (!buffers_allocated) | |
1629 | return; | |
1630 | tracing_start_cmdline_record(); | |
1631 | } | |
1632 | ||
1633 | static void trace_printk_start_stop_comm(int enabled) | |
1634 | { | |
1635 | if (!buffers_allocated) | |
1636 | return; | |
1637 | ||
1638 | if (enabled) | |
1639 | tracing_start_cmdline_record(); | |
1640 | else | |
1641 | tracing_stop_cmdline_record(); | |
07d777fe SR |
1642 | } |
1643 | ||
769b0441 | 1644 | /** |
48ead020 | 1645 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
1646 | * |
1647 | */ | |
40ce74f1 | 1648 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 1649 | { |
e1112b4d | 1650 | struct ftrace_event_call *call = &event_bprint; |
769b0441 | 1651 | struct ring_buffer_event *event; |
e77405ad | 1652 | struct ring_buffer *buffer; |
769b0441 | 1653 | struct trace_array *tr = &global_trace; |
48ead020 | 1654 | struct bprint_entry *entry; |
769b0441 | 1655 | unsigned long flags; |
07d777fe SR |
1656 | char *tbuffer; |
1657 | int len = 0, size, pc; | |
769b0441 FW |
1658 | |
1659 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
1660 | return 0; | |
1661 | ||
1662 | /* Don't pollute graph traces with trace_vprintk internals */ | |
1663 | pause_graph_tracing(); | |
1664 | ||
1665 | pc = preempt_count(); | |
5168ae50 | 1666 | preempt_disable_notrace(); |
769b0441 | 1667 | |
07d777fe SR |
1668 | tbuffer = get_trace_buf(); |
1669 | if (!tbuffer) { | |
1670 | len = 0; | |
769b0441 | 1671 | goto out; |
07d777fe | 1672 | } |
769b0441 | 1673 | |
07d777fe | 1674 | len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); |
769b0441 | 1675 | |
07d777fe SR |
1676 | if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) |
1677 | goto out; | |
769b0441 | 1678 | |
07d777fe | 1679 | local_save_flags(flags); |
769b0441 | 1680 | size = sizeof(*entry) + sizeof(u32) * len; |
e77405ad SR |
1681 | buffer = tr->buffer; |
1682 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, | |
1683 | flags, pc); | |
769b0441 | 1684 | if (!event) |
07d777fe | 1685 | goto out; |
769b0441 FW |
1686 | entry = ring_buffer_event_data(event); |
1687 | entry->ip = ip; | |
769b0441 FW |
1688 | entry->fmt = fmt; |
1689 | ||
07d777fe | 1690 | memcpy(entry->buf, tbuffer, sizeof(u32) * len); |
d931369b | 1691 | if (!filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 1692 | __buffer_unlock_commit(buffer, event); |
d931369b SR |
1693 | ftrace_trace_stack(buffer, flags, 6, pc); |
1694 | } | |
769b0441 | 1695 | |
769b0441 | 1696 | out: |
5168ae50 | 1697 | preempt_enable_notrace(); |
769b0441 FW |
1698 | unpause_graph_tracing(); |
1699 | ||
1700 | return len; | |
1701 | } | |
48ead020 FW |
1702 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
1703 | ||
659372d3 SR |
1704 | int trace_array_printk(struct trace_array *tr, |
1705 | unsigned long ip, const char *fmt, ...) | |
1706 | { | |
1707 | int ret; | |
1708 | va_list ap; | |
1709 | ||
1710 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
1711 | return 0; | |
1712 | ||
1713 | va_start(ap, fmt); | |
1714 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
1715 | va_end(ap); | |
1716 | return ret; | |
1717 | } | |
1718 | ||
1719 | int trace_array_vprintk(struct trace_array *tr, | |
1720 | unsigned long ip, const char *fmt, va_list args) | |
48ead020 | 1721 | { |
e1112b4d | 1722 | struct ftrace_event_call *call = &event_print; |
48ead020 | 1723 | struct ring_buffer_event *event; |
e77405ad | 1724 | struct ring_buffer *buffer; |
07d777fe | 1725 | int len = 0, size, pc; |
48ead020 | 1726 | struct print_entry *entry; |
07d777fe SR |
1727 | unsigned long flags; |
1728 | char *tbuffer; | |
48ead020 FW |
1729 | |
1730 | if (tracing_disabled || tracing_selftest_running) | |
1731 | return 0; | |
1732 | ||
07d777fe SR |
1733 | /* Don't pollute graph traces with trace_vprintk internals */ |
1734 | pause_graph_tracing(); | |
1735 | ||
48ead020 FW |
1736 | pc = preempt_count(); |
1737 | preempt_disable_notrace(); | |
48ead020 | 1738 | |
07d777fe SR |
1739 | |
1740 | tbuffer = get_trace_buf(); | |
1741 | if (!tbuffer) { | |
1742 | len = 0; | |
48ead020 | 1743 | goto out; |
07d777fe | 1744 | } |
48ead020 | 1745 | |
07d777fe SR |
1746 | len = vsnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); |
1747 | if (len > TRACE_BUF_SIZE) | |
1748 | goto out; | |
48ead020 | 1749 | |
07d777fe | 1750 | local_save_flags(flags); |
48ead020 | 1751 | size = sizeof(*entry) + len + 1; |
e77405ad SR |
1752 | buffer = tr->buffer; |
1753 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
07d777fe | 1754 | flags, pc); |
48ead020 | 1755 | if (!event) |
07d777fe | 1756 | goto out; |
48ead020 | 1757 | entry = ring_buffer_event_data(event); |
c13d2f7c | 1758 | entry->ip = ip; |
48ead020 | 1759 | |
07d777fe | 1760 | memcpy(&entry->buf, tbuffer, len); |
c13d2f7c | 1761 | entry->buf[len] = '\0'; |
d931369b | 1762 | if (!filter_check_discard(call, entry, buffer, event)) { |
7ffbd48d | 1763 | __buffer_unlock_commit(buffer, event); |
07d777fe | 1764 | ftrace_trace_stack(buffer, flags, 6, pc); |
d931369b | 1765 | } |
48ead020 FW |
1766 | out: |
1767 | preempt_enable_notrace(); | |
07d777fe | 1768 | unpause_graph_tracing(); |
48ead020 FW |
1769 | |
1770 | return len; | |
1771 | } | |
659372d3 SR |
1772 | |
1773 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) | |
1774 | { | |
a813a159 | 1775 | return trace_array_vprintk(&global_trace, ip, fmt, args); |
659372d3 | 1776 | } |
769b0441 FW |
1777 | EXPORT_SYMBOL_GPL(trace_vprintk); |
1778 | ||
e2ac8ef5 | 1779 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 1780 | { |
6d158a81 SR |
1781 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); |
1782 | ||
5a90f577 | 1783 | iter->idx++; |
6d158a81 SR |
1784 | if (buf_iter) |
1785 | ring_buffer_read(buf_iter, NULL); | |
5a90f577 SR |
1786 | } |
1787 | ||
e309b41d | 1788 | static struct trace_entry * |
bc21b478 SR |
1789 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, |
1790 | unsigned long *lost_events) | |
dd0e545f | 1791 | { |
3928a8a2 | 1792 | struct ring_buffer_event *event; |
6d158a81 | 1793 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); |
dd0e545f | 1794 | |
d769041f SR |
1795 | if (buf_iter) |
1796 | event = ring_buffer_iter_peek(buf_iter, ts); | |
1797 | else | |
bc21b478 SR |
1798 | event = ring_buffer_peek(iter->tr->buffer, cpu, ts, |
1799 | lost_events); | |
d769041f | 1800 | |
4a9bd3f1 SR |
1801 | if (event) { |
1802 | iter->ent_size = ring_buffer_event_length(event); | |
1803 | return ring_buffer_event_data(event); | |
1804 | } | |
1805 | iter->ent_size = 0; | |
1806 | return NULL; | |
dd0e545f | 1807 | } |
d769041f | 1808 | |
dd0e545f | 1809 | static struct trace_entry * |
bc21b478 SR |
1810 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, |
1811 | unsigned long *missing_events, u64 *ent_ts) | |
bc0c38d1 | 1812 | { |
3928a8a2 | 1813 | struct ring_buffer *buffer = iter->tr->buffer; |
bc0c38d1 | 1814 | struct trace_entry *ent, *next = NULL; |
aa27497c | 1815 | unsigned long lost_events = 0, next_lost = 0; |
b04cc6b1 | 1816 | int cpu_file = iter->cpu_file; |
3928a8a2 | 1817 | u64 next_ts = 0, ts; |
bc0c38d1 | 1818 | int next_cpu = -1; |
12b5da34 | 1819 | int next_size = 0; |
bc0c38d1 SR |
1820 | int cpu; |
1821 | ||
b04cc6b1 FW |
1822 | /* |
1823 | * If we are in a per_cpu trace file, don't bother by iterating over | |
1824 | * all cpu and peek directly. | |
1825 | */ | |
1826 | if (cpu_file > TRACE_PIPE_ALL_CPU) { | |
1827 | if (ring_buffer_empty_cpu(buffer, cpu_file)) | |
1828 | return NULL; | |
bc21b478 | 1829 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); |
b04cc6b1 FW |
1830 | if (ent_cpu) |
1831 | *ent_cpu = cpu_file; | |
1832 | ||
1833 | return ent; | |
1834 | } | |
1835 | ||
ab46428c | 1836 | for_each_tracing_cpu(cpu) { |
dd0e545f | 1837 | |
3928a8a2 SR |
1838 | if (ring_buffer_empty_cpu(buffer, cpu)) |
1839 | continue; | |
dd0e545f | 1840 | |
bc21b478 | 1841 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); |
dd0e545f | 1842 | |
cdd31cd2 IM |
1843 | /* |
1844 | * Pick the entry with the smallest timestamp: | |
1845 | */ | |
3928a8a2 | 1846 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
1847 | next = ent; |
1848 | next_cpu = cpu; | |
3928a8a2 | 1849 | next_ts = ts; |
bc21b478 | 1850 | next_lost = lost_events; |
12b5da34 | 1851 | next_size = iter->ent_size; |
bc0c38d1 SR |
1852 | } |
1853 | } | |
1854 | ||
12b5da34 SR |
1855 | iter->ent_size = next_size; |
1856 | ||
bc0c38d1 SR |
1857 | if (ent_cpu) |
1858 | *ent_cpu = next_cpu; | |
1859 | ||
3928a8a2 SR |
1860 | if (ent_ts) |
1861 | *ent_ts = next_ts; | |
1862 | ||
bc21b478 SR |
1863 | if (missing_events) |
1864 | *missing_events = next_lost; | |
1865 | ||
bc0c38d1 SR |
1866 | return next; |
1867 | } | |
1868 | ||
dd0e545f | 1869 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
1870 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
1871 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 1872 | { |
bc21b478 | 1873 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); |
dd0e545f SR |
1874 | } |
1875 | ||
1876 | /* Find the next real entry, and increment the iterator to the next entry */ | |
955b61e5 | 1877 | void *trace_find_next_entry_inc(struct trace_iterator *iter) |
dd0e545f | 1878 | { |
bc21b478 SR |
1879 | iter->ent = __find_next_entry(iter, &iter->cpu, |
1880 | &iter->lost_events, &iter->ts); | |
dd0e545f | 1881 | |
3928a8a2 | 1882 | if (iter->ent) |
e2ac8ef5 | 1883 | trace_iterator_increment(iter); |
dd0e545f | 1884 | |
3928a8a2 | 1885 | return iter->ent ? iter : NULL; |
b3806b43 | 1886 | } |
bc0c38d1 | 1887 | |
e309b41d | 1888 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 1889 | { |
bc21b478 SR |
1890 | ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, |
1891 | &iter->lost_events); | |
bc0c38d1 SR |
1892 | } |
1893 | ||
e309b41d | 1894 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
1895 | { |
1896 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 1897 | int i = (int)*pos; |
4e3c3333 | 1898 | void *ent; |
bc0c38d1 | 1899 | |
a63ce5b3 SR |
1900 | WARN_ON_ONCE(iter->leftover); |
1901 | ||
bc0c38d1 SR |
1902 | (*pos)++; |
1903 | ||
1904 | /* can't go backwards */ | |
1905 | if (iter->idx > i) | |
1906 | return NULL; | |
1907 | ||
1908 | if (iter->idx < 0) | |
955b61e5 | 1909 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
1910 | else |
1911 | ent = iter; | |
1912 | ||
1913 | while (ent && iter->idx < i) | |
955b61e5 | 1914 | ent = trace_find_next_entry_inc(iter); |
bc0c38d1 SR |
1915 | |
1916 | iter->pos = *pos; | |
1917 | ||
bc0c38d1 SR |
1918 | return ent; |
1919 | } | |
1920 | ||
955b61e5 | 1921 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
2f26ebd5 SR |
1922 | { |
1923 | struct trace_array *tr = iter->tr; | |
1924 | struct ring_buffer_event *event; | |
1925 | struct ring_buffer_iter *buf_iter; | |
1926 | unsigned long entries = 0; | |
1927 | u64 ts; | |
1928 | ||
1929 | tr->data[cpu]->skipped_entries = 0; | |
1930 | ||
6d158a81 SR |
1931 | buf_iter = trace_buffer_iter(iter, cpu); |
1932 | if (!buf_iter) | |
2f26ebd5 SR |
1933 | return; |
1934 | ||
2f26ebd5 SR |
1935 | ring_buffer_iter_reset(buf_iter); |
1936 | ||
1937 | /* | |
1938 | * We could have the case with the max latency tracers | |
1939 | * that a reset never took place on a cpu. This is evident | |
1940 | * by the timestamp being before the start of the buffer. | |
1941 | */ | |
1942 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
1943 | if (ts >= iter->tr->time_start) | |
1944 | break; | |
1945 | entries++; | |
1946 | ring_buffer_read(buf_iter, NULL); | |
1947 | } | |
1948 | ||
1949 | tr->data[cpu]->skipped_entries = entries; | |
1950 | } | |
1951 | ||
d7350c3f | 1952 | /* |
d7350c3f FW |
1953 | * The current tracer is copied to avoid a global locking |
1954 | * all around. | |
1955 | */ | |
bc0c38d1 SR |
1956 | static void *s_start(struct seq_file *m, loff_t *pos) |
1957 | { | |
1958 | struct trace_iterator *iter = m->private; | |
b04cc6b1 | 1959 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
1960 | void *p = NULL; |
1961 | loff_t l = 0; | |
3928a8a2 | 1962 | int cpu; |
bc0c38d1 | 1963 | |
2fd196ec HT |
1964 | /* |
1965 | * copy the tracer to avoid using a global lock all around. | |
1966 | * iter->trace is a copy of current_trace, the pointer to the | |
1967 | * name may be used instead of a strcmp(), as iter->trace->name | |
1968 | * will point to the same string as current_trace->name. | |
1969 | */ | |
bc0c38d1 | 1970 | mutex_lock(&trace_types_lock); |
2fd196ec | 1971 | if (unlikely(current_trace && iter->trace->name != current_trace->name)) |
d7350c3f | 1972 | *iter->trace = *current_trace; |
d7350c3f | 1973 | mutex_unlock(&trace_types_lock); |
bc0c38d1 | 1974 | |
debdd57f HT |
1975 | if (iter->snapshot && iter->trace->use_max_tr) |
1976 | return ERR_PTR(-EBUSY); | |
1977 | ||
1978 | if (!iter->snapshot) | |
1979 | atomic_inc(&trace_record_cmdline_disabled); | |
bc0c38d1 | 1980 | |
bc0c38d1 SR |
1981 | if (*pos != iter->pos) { |
1982 | iter->ent = NULL; | |
1983 | iter->cpu = 0; | |
1984 | iter->idx = -1; | |
1985 | ||
b04cc6b1 FW |
1986 | if (cpu_file == TRACE_PIPE_ALL_CPU) { |
1987 | for_each_tracing_cpu(cpu) | |
2f26ebd5 | 1988 | tracing_iter_reset(iter, cpu); |
b04cc6b1 | 1989 | } else |
2f26ebd5 | 1990 | tracing_iter_reset(iter, cpu_file); |
bc0c38d1 | 1991 | |
ac91d854 | 1992 | iter->leftover = 0; |
bc0c38d1 SR |
1993 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
1994 | ; | |
1995 | ||
1996 | } else { | |
a63ce5b3 SR |
1997 | /* |
1998 | * If we overflowed the seq_file before, then we want | |
1999 | * to just reuse the trace_seq buffer again. | |
2000 | */ | |
2001 | if (iter->leftover) | |
2002 | p = iter; | |
2003 | else { | |
2004 | l = *pos - 1; | |
2005 | p = s_next(m, p, &l); | |
2006 | } | |
bc0c38d1 SR |
2007 | } |
2008 | ||
4f535968 | 2009 | trace_event_read_lock(); |
7e53bd42 | 2010 | trace_access_lock(cpu_file); |
bc0c38d1 SR |
2011 | return p; |
2012 | } | |
2013 | ||
2014 | static void s_stop(struct seq_file *m, void *p) | |
2015 | { | |
7e53bd42 LJ |
2016 | struct trace_iterator *iter = m->private; |
2017 | ||
debdd57f HT |
2018 | if (iter->snapshot && iter->trace->use_max_tr) |
2019 | return; | |
2020 | ||
2021 | if (!iter->snapshot) | |
2022 | atomic_dec(&trace_record_cmdline_disabled); | |
7e53bd42 | 2023 | trace_access_unlock(iter->cpu_file); |
4f535968 | 2024 | trace_event_read_unlock(); |
bc0c38d1 SR |
2025 | } |
2026 | ||
39eaf7ef SR |
2027 | static void |
2028 | get_total_entries(struct trace_array *tr, unsigned long *total, unsigned long *entries) | |
2029 | { | |
2030 | unsigned long count; | |
2031 | int cpu; | |
2032 | ||
2033 | *total = 0; | |
2034 | *entries = 0; | |
2035 | ||
2036 | for_each_tracing_cpu(cpu) { | |
2037 | count = ring_buffer_entries_cpu(tr->buffer, cpu); | |
2038 | /* | |
2039 | * If this buffer has skipped entries, then we hold all | |
2040 | * entries for the trace and we need to ignore the | |
2041 | * ones before the time stamp. | |
2042 | */ | |
2043 | if (tr->data[cpu]->skipped_entries) { | |
2044 | count -= tr->data[cpu]->skipped_entries; | |
2045 | /* total is the same as the entries */ | |
2046 | *total += count; | |
2047 | } else | |
2048 | *total += count + | |
2049 | ring_buffer_overrun_cpu(tr->buffer, cpu); | |
2050 | *entries += count; | |
2051 | } | |
2052 | } | |
2053 | ||
e309b41d | 2054 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 2055 | { |
a6168353 ME |
2056 | seq_puts(m, "# _------=> CPU# \n"); |
2057 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
2058 | seq_puts(m, "# | / _----=> need-resched \n"); | |
2059 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
2060 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
e6e1e259 SR |
2061 | seq_puts(m, "# |||| / delay \n"); |
2062 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
2063 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
bc0c38d1 SR |
2064 | } |
2065 | ||
39eaf7ef | 2066 | static void print_event_info(struct trace_array *tr, struct seq_file *m) |
bc0c38d1 | 2067 | { |
39eaf7ef SR |
2068 | unsigned long total; |
2069 | unsigned long entries; | |
2070 | ||
2071 | get_total_entries(tr, &total, &entries); | |
2072 | seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", | |
2073 | entries, total, num_online_cpus()); | |
2074 | seq_puts(m, "#\n"); | |
2075 | } | |
2076 | ||
2077 | static void print_func_help_header(struct trace_array *tr, struct seq_file *m) | |
2078 | { | |
2079 | print_event_info(tr, m); | |
77271ce4 | 2080 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); |
a6168353 | 2081 | seq_puts(m, "# | | | | |\n"); |
bc0c38d1 SR |
2082 | } |
2083 | ||
39eaf7ef | 2084 | static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *m) |
77271ce4 | 2085 | { |
39eaf7ef | 2086 | print_event_info(tr, m); |
77271ce4 SR |
2087 | seq_puts(m, "# _-----=> irqs-off\n"); |
2088 | seq_puts(m, "# / _----=> need-resched\n"); | |
2089 | seq_puts(m, "# | / _---=> hardirq/softirq\n"); | |
2090 | seq_puts(m, "# || / _--=> preempt-depth\n"); | |
2091 | seq_puts(m, "# ||| / delay\n"); | |
2092 | seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"); | |
2093 | seq_puts(m, "# | | | |||| | |\n"); | |
2094 | } | |
bc0c38d1 | 2095 | |
62b915f1 | 2096 | void |
bc0c38d1 SR |
2097 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
2098 | { | |
2099 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
2100 | struct trace_array *tr = iter->tr; | |
2101 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
2102 | struct tracer *type = current_trace; | |
39eaf7ef SR |
2103 | unsigned long entries; |
2104 | unsigned long total; | |
bc0c38d1 SR |
2105 | const char *name = "preemption"; |
2106 | ||
d840f718 | 2107 | name = type->name; |
bc0c38d1 | 2108 | |
39eaf7ef | 2109 | get_total_entries(tr, &total, &entries); |
bc0c38d1 | 2110 | |
888b55dc | 2111 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 2112 | name, UTS_RELEASE); |
888b55dc | 2113 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 2114 | "---------------------------------\n"); |
888b55dc | 2115 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 2116 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 2117 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 2118 | entries, |
4c11d7ae | 2119 | total, |
bc0c38d1 SR |
2120 | tr->cpu, |
2121 | #if defined(CONFIG_PREEMPT_NONE) | |
2122 | "server", | |
2123 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
2124 | "desktop", | |
b5c21b45 | 2125 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
2126 | "preempt", |
2127 | #else | |
2128 | "unknown", | |
2129 | #endif | |
2130 | /* These are reserved for later use */ | |
2131 | 0, 0, 0, 0); | |
2132 | #ifdef CONFIG_SMP | |
2133 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
2134 | #else | |
2135 | seq_puts(m, ")\n"); | |
2136 | #endif | |
888b55dc KM |
2137 | seq_puts(m, "# -----------------\n"); |
2138 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 | 2139 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
d20b92ab EB |
2140 | data->comm, data->pid, |
2141 | from_kuid_munged(seq_user_ns(m), data->uid), data->nice, | |
bc0c38d1 | 2142 | data->policy, data->rt_priority); |
888b55dc | 2143 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
2144 | |
2145 | if (data->critical_start) { | |
888b55dc | 2146 | seq_puts(m, "# => started at: "); |
214023c3 SR |
2147 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
2148 | trace_print_seq(m, &iter->seq); | |
888b55dc | 2149 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
2150 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
2151 | trace_print_seq(m, &iter->seq); | |
8248ac05 | 2152 | seq_puts(m, "\n#\n"); |
bc0c38d1 SR |
2153 | } |
2154 | ||
888b55dc | 2155 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
2156 | } |
2157 | ||
a309720c SR |
2158 | static void test_cpu_buff_start(struct trace_iterator *iter) |
2159 | { | |
2160 | struct trace_seq *s = &iter->seq; | |
2161 | ||
12ef7d44 SR |
2162 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) |
2163 | return; | |
2164 | ||
2165 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
2166 | return; | |
2167 | ||
4462344e | 2168 | if (cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
2169 | return; |
2170 | ||
2f26ebd5 SR |
2171 | if (iter->tr->data[iter->cpu]->skipped_entries) |
2172 | return; | |
2173 | ||
4462344e | 2174 | cpumask_set_cpu(iter->cpu, iter->started); |
b0dfa978 FW |
2175 | |
2176 | /* Don't print started cpu buffer for the first entry of the trace */ | |
2177 | if (iter->idx > 1) | |
2178 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
2179 | iter->cpu); | |
a309720c SR |
2180 | } |
2181 | ||
2c4f035f | 2182 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 2183 | { |
214023c3 | 2184 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 2185 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 2186 | struct trace_entry *entry; |
f633cef0 | 2187 | struct trace_event *event; |
bc0c38d1 | 2188 | |
4e3c3333 | 2189 | entry = iter->ent; |
dd0e545f | 2190 | |
a309720c SR |
2191 | test_cpu_buff_start(iter); |
2192 | ||
c4a8e8be | 2193 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 2194 | |
c4a8e8be | 2195 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
27d48be8 SR |
2196 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2197 | if (!trace_print_lat_context(iter)) | |
2198 | goto partial; | |
2199 | } else { | |
2200 | if (!trace_print_context(iter)) | |
2201 | goto partial; | |
2202 | } | |
c4a8e8be | 2203 | } |
bc0c38d1 | 2204 | |
268ccda0 | 2205 | if (event) |
a9a57763 | 2206 | return event->funcs->trace(iter, sym_flags, event); |
d9793bd8 ACM |
2207 | |
2208 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
2209 | goto partial; | |
02b67518 | 2210 | |
2c4f035f | 2211 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
2212 | partial: |
2213 | return TRACE_TYPE_PARTIAL_LINE; | |
bc0c38d1 SR |
2214 | } |
2215 | ||
2c4f035f | 2216 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 IM |
2217 | { |
2218 | struct trace_seq *s = &iter->seq; | |
2219 | struct trace_entry *entry; | |
f633cef0 | 2220 | struct trace_event *event; |
f9896bf3 IM |
2221 | |
2222 | entry = iter->ent; | |
dd0e545f | 2223 | |
c4a8e8be | 2224 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
d9793bd8 ACM |
2225 | if (!trace_seq_printf(s, "%d %d %llu ", |
2226 | entry->pid, iter->cpu, iter->ts)) | |
2227 | goto partial; | |
c4a8e8be | 2228 | } |
f9896bf3 | 2229 | |
f633cef0 | 2230 | event = ftrace_find_event(entry->type); |
268ccda0 | 2231 | if (event) |
a9a57763 | 2232 | return event->funcs->raw(iter, 0, event); |
d9793bd8 ACM |
2233 | |
2234 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
2235 | goto partial; | |
777e208d | 2236 | |
2c4f035f | 2237 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
2238 | partial: |
2239 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 IM |
2240 | } |
2241 | ||
2c4f035f | 2242 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec IM |
2243 | { |
2244 | struct trace_seq *s = &iter->seq; | |
2245 | unsigned char newline = '\n'; | |
2246 | struct trace_entry *entry; | |
f633cef0 | 2247 | struct trace_event *event; |
5e3ca0ec IM |
2248 | |
2249 | entry = iter->ent; | |
dd0e545f | 2250 | |
c4a8e8be FW |
2251 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
2252 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
2253 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
2254 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
2255 | } | |
5e3ca0ec | 2256 | |
f633cef0 | 2257 | event = ftrace_find_event(entry->type); |
268ccda0 | 2258 | if (event) { |
a9a57763 | 2259 | enum print_line_t ret = event->funcs->hex(iter, 0, event); |
d9793bd8 ACM |
2260 | if (ret != TRACE_TYPE_HANDLED) |
2261 | return ret; | |
2262 | } | |
7104f300 | 2263 | |
5e3ca0ec IM |
2264 | SEQ_PUT_FIELD_RET(s, newline); |
2265 | ||
2c4f035f | 2266 | return TRACE_TYPE_HANDLED; |
5e3ca0ec IM |
2267 | } |
2268 | ||
2c4f035f | 2269 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa IM |
2270 | { |
2271 | struct trace_seq *s = &iter->seq; | |
2272 | struct trace_entry *entry; | |
f633cef0 | 2273 | struct trace_event *event; |
cb0f12aa IM |
2274 | |
2275 | entry = iter->ent; | |
dd0e545f | 2276 | |
c4a8e8be FW |
2277 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
2278 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
1830b52d | 2279 | SEQ_PUT_FIELD_RET(s, iter->cpu); |
c4a8e8be FW |
2280 | SEQ_PUT_FIELD_RET(s, iter->ts); |
2281 | } | |
cb0f12aa | 2282 | |
f633cef0 | 2283 | event = ftrace_find_event(entry->type); |
a9a57763 SR |
2284 | return event ? event->funcs->binary(iter, 0, event) : |
2285 | TRACE_TYPE_HANDLED; | |
cb0f12aa IM |
2286 | } |
2287 | ||
62b915f1 | 2288 | int trace_empty(struct trace_iterator *iter) |
bc0c38d1 | 2289 | { |
6d158a81 | 2290 | struct ring_buffer_iter *buf_iter; |
bc0c38d1 SR |
2291 | int cpu; |
2292 | ||
9aba60fe SR |
2293 | /* If we are looking at one CPU buffer, only check that one */ |
2294 | if (iter->cpu_file != TRACE_PIPE_ALL_CPU) { | |
2295 | cpu = iter->cpu_file; | |
6d158a81 SR |
2296 | buf_iter = trace_buffer_iter(iter, cpu); |
2297 | if (buf_iter) { | |
2298 | if (!ring_buffer_iter_empty(buf_iter)) | |
9aba60fe SR |
2299 | return 0; |
2300 | } else { | |
2301 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
2302 | return 0; | |
2303 | } | |
2304 | return 1; | |
2305 | } | |
2306 | ||
ab46428c | 2307 | for_each_tracing_cpu(cpu) { |
6d158a81 SR |
2308 | buf_iter = trace_buffer_iter(iter, cpu); |
2309 | if (buf_iter) { | |
2310 | if (!ring_buffer_iter_empty(buf_iter)) | |
d769041f SR |
2311 | return 0; |
2312 | } else { | |
2313 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
2314 | return 0; | |
2315 | } | |
bc0c38d1 | 2316 | } |
d769041f | 2317 | |
797d3712 | 2318 | return 1; |
bc0c38d1 SR |
2319 | } |
2320 | ||
4f535968 | 2321 | /* Called with trace_event_read_lock() held. */ |
955b61e5 | 2322 | enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 2323 | { |
2c4f035f FW |
2324 | enum print_line_t ret; |
2325 | ||
ee5e51f5 JO |
2326 | if (iter->lost_events && |
2327 | !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2328 | iter->cpu, iter->lost_events)) | |
2329 | return TRACE_TYPE_PARTIAL_LINE; | |
bc21b478 | 2330 | |
2c4f035f FW |
2331 | if (iter->trace && iter->trace->print_line) { |
2332 | ret = iter->trace->print_line(iter); | |
2333 | if (ret != TRACE_TYPE_UNHANDLED) | |
2334 | return ret; | |
2335 | } | |
72829bc3 | 2336 | |
48ead020 FW |
2337 | if (iter->ent->type == TRACE_BPRINT && |
2338 | trace_flags & TRACE_ITER_PRINTK && | |
2339 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2340 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 2341 | |
66896a85 FW |
2342 | if (iter->ent->type == TRACE_PRINT && |
2343 | trace_flags & TRACE_ITER_PRINTK && | |
2344 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 2345 | return trace_print_printk_msg_only(iter); |
66896a85 | 2346 | |
cb0f12aa IM |
2347 | if (trace_flags & TRACE_ITER_BIN) |
2348 | return print_bin_fmt(iter); | |
2349 | ||
5e3ca0ec IM |
2350 | if (trace_flags & TRACE_ITER_HEX) |
2351 | return print_hex_fmt(iter); | |
2352 | ||
f9896bf3 IM |
2353 | if (trace_flags & TRACE_ITER_RAW) |
2354 | return print_raw_fmt(iter); | |
2355 | ||
f9896bf3 IM |
2356 | return print_trace_fmt(iter); |
2357 | } | |
2358 | ||
7e9a49ef JO |
2359 | void trace_latency_header(struct seq_file *m) |
2360 | { | |
2361 | struct trace_iterator *iter = m->private; | |
2362 | ||
2363 | /* print nothing if the buffers are empty */ | |
2364 | if (trace_empty(iter)) | |
2365 | return; | |
2366 | ||
2367 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
2368 | print_trace_header(m, iter); | |
2369 | ||
2370 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2371 | print_lat_help_header(m); | |
2372 | } | |
2373 | ||
62b915f1 JO |
2374 | void trace_default_header(struct seq_file *m) |
2375 | { | |
2376 | struct trace_iterator *iter = m->private; | |
2377 | ||
f56e7f8e JO |
2378 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
2379 | return; | |
2380 | ||
62b915f1 JO |
2381 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
2382 | /* print nothing if the buffers are empty */ | |
2383 | if (trace_empty(iter)) | |
2384 | return; | |
2385 | print_trace_header(m, iter); | |
2386 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2387 | print_lat_help_header(m); | |
2388 | } else { | |
77271ce4 SR |
2389 | if (!(trace_flags & TRACE_ITER_VERBOSE)) { |
2390 | if (trace_flags & TRACE_ITER_IRQ_INFO) | |
39eaf7ef | 2391 | print_func_help_header_irq(iter->tr, m); |
77271ce4 | 2392 | else |
39eaf7ef | 2393 | print_func_help_header(iter->tr, m); |
77271ce4 | 2394 | } |
62b915f1 JO |
2395 | } |
2396 | } | |
2397 | ||
e0a413f6 SR |
2398 | static void test_ftrace_alive(struct seq_file *m) |
2399 | { | |
2400 | if (!ftrace_is_dead()) | |
2401 | return; | |
2402 | seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
2403 | seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n"); | |
2404 | } | |
2405 | ||
d8741e2e SRRH |
2406 | #ifdef CONFIG_TRACER_MAX_TRACE |
2407 | static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) | |
2408 | { | |
2409 | if (iter->trace->allocated_snapshot) | |
2410 | seq_printf(m, "#\n# * Snapshot is allocated *\n#\n"); | |
2411 | else | |
2412 | seq_printf(m, "#\n# * Snapshot is freed *\n#\n"); | |
2413 | ||
2414 | seq_printf(m, "# Snapshot commands:\n"); | |
2415 | seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"); | |
2416 | seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); | |
2417 | seq_printf(m, "# Takes a snapshot of the main buffer.\n"); | |
2418 | seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate)\n"); | |
2419 | seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); | |
2420 | seq_printf(m, "# is not a '0' or '1')\n"); | |
2421 | } | |
2422 | #else | |
2423 | /* Should never be called */ | |
2424 | static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } | |
2425 | #endif | |
2426 | ||
bc0c38d1 SR |
2427 | static int s_show(struct seq_file *m, void *v) |
2428 | { | |
2429 | struct trace_iterator *iter = v; | |
a63ce5b3 | 2430 | int ret; |
bc0c38d1 SR |
2431 | |
2432 | if (iter->ent == NULL) { | |
2433 | if (iter->tr) { | |
2434 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2435 | seq_puts(m, "#\n"); | |
e0a413f6 | 2436 | test_ftrace_alive(m); |
bc0c38d1 | 2437 | } |
d8741e2e SRRH |
2438 | if (iter->snapshot && trace_empty(iter)) |
2439 | print_snapshot_help(m, iter); | |
2440 | else if (iter->trace && iter->trace->print_header) | |
8bba1bf5 | 2441 | iter->trace->print_header(m); |
62b915f1 JO |
2442 | else |
2443 | trace_default_header(m); | |
2444 | ||
a63ce5b3 SR |
2445 | } else if (iter->leftover) { |
2446 | /* | |
2447 | * If we filled the seq_file buffer earlier, we | |
2448 | * want to just show it now. | |
2449 | */ | |
2450 | ret = trace_print_seq(m, &iter->seq); | |
2451 | ||
2452 | /* ret should this time be zero, but you never know */ | |
2453 | iter->leftover = ret; | |
2454 | ||
bc0c38d1 | 2455 | } else { |
f9896bf3 | 2456 | print_trace_line(iter); |
a63ce5b3 SR |
2457 | ret = trace_print_seq(m, &iter->seq); |
2458 | /* | |
2459 | * If we overflow the seq_file buffer, then it will | |
2460 | * ask us for this data again at start up. | |
2461 | * Use that instead. | |
2462 | * ret is 0 if seq_file write succeeded. | |
2463 | * -1 otherwise. | |
2464 | */ | |
2465 | iter->leftover = ret; | |
bc0c38d1 SR |
2466 | } |
2467 | ||
2468 | return 0; | |
2469 | } | |
2470 | ||
88e9d34c | 2471 | static const struct seq_operations tracer_seq_ops = { |
4bf39a94 IM |
2472 | .start = s_start, |
2473 | .next = s_next, | |
2474 | .stop = s_stop, | |
2475 | .show = s_show, | |
bc0c38d1 SR |
2476 | }; |
2477 | ||
e309b41d | 2478 | static struct trace_iterator * |
debdd57f | 2479 | __tracing_open(struct inode *inode, struct file *file, bool snapshot) |
bc0c38d1 | 2480 | { |
b04cc6b1 | 2481 | long cpu_file = (long) inode->i_private; |
bc0c38d1 | 2482 | struct trace_iterator *iter; |
50e18b94 | 2483 | int cpu; |
bc0c38d1 | 2484 | |
85a2f9b4 SR |
2485 | if (tracing_disabled) |
2486 | return ERR_PTR(-ENODEV); | |
60a11774 | 2487 | |
50e18b94 | 2488 | iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); |
85a2f9b4 SR |
2489 | if (!iter) |
2490 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 2491 | |
6d158a81 SR |
2492 | iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(), |
2493 | GFP_KERNEL); | |
93574fcc DC |
2494 | if (!iter->buffer_iter) |
2495 | goto release; | |
2496 | ||
d7350c3f FW |
2497 | /* |
2498 | * We make a copy of the current tracer to avoid concurrent | |
2499 | * changes on it while we are reading. | |
2500 | */ | |
bc0c38d1 | 2501 | mutex_lock(&trace_types_lock); |
d7350c3f | 2502 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 2503 | if (!iter->trace) |
d7350c3f | 2504 | goto fail; |
85a2f9b4 | 2505 | |
d840f718 | 2506 | *iter->trace = *current_trace; |
d7350c3f | 2507 | |
79f55997 | 2508 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
b0dfa978 FW |
2509 | goto fail; |
2510 | ||
d840f718 | 2511 | if (current_trace->print_max || snapshot) |
bc0c38d1 SR |
2512 | iter->tr = &max_tr; |
2513 | else | |
b04cc6b1 | 2514 | iter->tr = &global_trace; |
debdd57f | 2515 | iter->snapshot = snapshot; |
bc0c38d1 | 2516 | iter->pos = -1; |
d7350c3f | 2517 | mutex_init(&iter->mutex); |
b04cc6b1 | 2518 | iter->cpu_file = cpu_file; |
bc0c38d1 | 2519 | |
8bba1bf5 MM |
2520 | /* Notify the tracer early; before we stop tracing. */ |
2521 | if (iter->trace && iter->trace->open) | |
a93751ca | 2522 | iter->trace->open(iter); |
8bba1bf5 | 2523 | |
12ef7d44 SR |
2524 | /* Annotate start of buffers if we had overruns */ |
2525 | if (ring_buffer_overruns(iter->tr->buffer)) | |
2526 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
2527 | ||
8be0709f DS |
2528 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
2529 | if (trace_clocks[trace_clock_id].in_ns) | |
2530 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
2531 | ||
debdd57f HT |
2532 | /* stop the trace while dumping if we are not opening "snapshot" */ |
2533 | if (!iter->snapshot) | |
2534 | tracing_stop(); | |
2f26ebd5 | 2535 | |
b04cc6b1 FW |
2536 | if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { |
2537 | for_each_tracing_cpu(cpu) { | |
b04cc6b1 | 2538 | iter->buffer_iter[cpu] = |
72c9ddfd DM |
2539 | ring_buffer_read_prepare(iter->tr->buffer, cpu); |
2540 | } | |
2541 | ring_buffer_read_prepare_sync(); | |
2542 | for_each_tracing_cpu(cpu) { | |
2543 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 2544 | tracing_iter_reset(iter, cpu); |
b04cc6b1 FW |
2545 | } |
2546 | } else { | |
2547 | cpu = iter->cpu_file; | |
3928a8a2 | 2548 | iter->buffer_iter[cpu] = |
72c9ddfd DM |
2549 | ring_buffer_read_prepare(iter->tr->buffer, cpu); |
2550 | ring_buffer_read_prepare_sync(); | |
2551 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2f26ebd5 | 2552 | tracing_iter_reset(iter, cpu); |
3928a8a2 SR |
2553 | } |
2554 | ||
bc0c38d1 SR |
2555 | mutex_unlock(&trace_types_lock); |
2556 | ||
bc0c38d1 | 2557 | return iter; |
3928a8a2 | 2558 | |
d7350c3f | 2559 | fail: |
3928a8a2 | 2560 | mutex_unlock(&trace_types_lock); |
d7350c3f | 2561 | kfree(iter->trace); |
6d158a81 | 2562 | kfree(iter->buffer_iter); |
93574fcc | 2563 | release: |
50e18b94 JO |
2564 | seq_release_private(inode, file); |
2565 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 SR |
2566 | } |
2567 | ||
2568 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
2569 | { | |
60a11774 SR |
2570 | if (tracing_disabled) |
2571 | return -ENODEV; | |
2572 | ||
bc0c38d1 SR |
2573 | filp->private_data = inode->i_private; |
2574 | return 0; | |
2575 | } | |
2576 | ||
4fd27358 | 2577 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 | 2578 | { |
907f2784 | 2579 | struct seq_file *m = file->private_data; |
4acd4d00 | 2580 | struct trace_iterator *iter; |
3928a8a2 | 2581 | int cpu; |
bc0c38d1 | 2582 | |
4acd4d00 SR |
2583 | if (!(file->f_mode & FMODE_READ)) |
2584 | return 0; | |
2585 | ||
2586 | iter = m->private; | |
2587 | ||
bc0c38d1 | 2588 | mutex_lock(&trace_types_lock); |
3928a8a2 SR |
2589 | for_each_tracing_cpu(cpu) { |
2590 | if (iter->buffer_iter[cpu]) | |
2591 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2592 | } | |
2593 | ||
bc0c38d1 SR |
2594 | if (iter->trace && iter->trace->close) |
2595 | iter->trace->close(iter); | |
2596 | ||
debdd57f HT |
2597 | if (!iter->snapshot) |
2598 | /* reenable tracing if it was previously enabled */ | |
2599 | tracing_start(); | |
bc0c38d1 SR |
2600 | mutex_unlock(&trace_types_lock); |
2601 | ||
d7350c3f | 2602 | mutex_destroy(&iter->mutex); |
b0dfa978 | 2603 | free_cpumask_var(iter->started); |
d7350c3f | 2604 | kfree(iter->trace); |
6d158a81 | 2605 | kfree(iter->buffer_iter); |
50e18b94 | 2606 | seq_release_private(inode, file); |
bc0c38d1 SR |
2607 | return 0; |
2608 | } | |
2609 | ||
2610 | static int tracing_open(struct inode *inode, struct file *file) | |
2611 | { | |
85a2f9b4 SR |
2612 | struct trace_iterator *iter; |
2613 | int ret = 0; | |
bc0c38d1 | 2614 | |
4acd4d00 SR |
2615 | /* If this file was open for write, then erase contents */ |
2616 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 2617 | (file->f_flags & O_TRUNC)) { |
4acd4d00 | 2618 | long cpu = (long) inode->i_private; |
bc0c38d1 | 2619 | |
4acd4d00 SR |
2620 | if (cpu == TRACE_PIPE_ALL_CPU) |
2621 | tracing_reset_online_cpus(&global_trace); | |
2622 | else | |
2623 | tracing_reset(&global_trace, cpu); | |
2624 | } | |
bc0c38d1 | 2625 | |
4acd4d00 | 2626 | if (file->f_mode & FMODE_READ) { |
debdd57f | 2627 | iter = __tracing_open(inode, file, false); |
4acd4d00 SR |
2628 | if (IS_ERR(iter)) |
2629 | ret = PTR_ERR(iter); | |
2630 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
2631 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
2632 | } | |
bc0c38d1 SR |
2633 | return ret; |
2634 | } | |
2635 | ||
e309b41d | 2636 | static void * |
bc0c38d1 SR |
2637 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2638 | { | |
f129e965 | 2639 | struct tracer *t = v; |
bc0c38d1 SR |
2640 | |
2641 | (*pos)++; | |
2642 | ||
2643 | if (t) | |
2644 | t = t->next; | |
2645 | ||
bc0c38d1 SR |
2646 | return t; |
2647 | } | |
2648 | ||
2649 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2650 | { | |
f129e965 | 2651 | struct tracer *t; |
bc0c38d1 SR |
2652 | loff_t l = 0; |
2653 | ||
2654 | mutex_lock(&trace_types_lock); | |
f129e965 | 2655 | for (t = trace_types; t && l < *pos; t = t_next(m, t, &l)) |
bc0c38d1 SR |
2656 | ; |
2657 | ||
2658 | return t; | |
2659 | } | |
2660 | ||
2661 | static void t_stop(struct seq_file *m, void *p) | |
2662 | { | |
2663 | mutex_unlock(&trace_types_lock); | |
2664 | } | |
2665 | ||
2666 | static int t_show(struct seq_file *m, void *v) | |
2667 | { | |
2668 | struct tracer *t = v; | |
2669 | ||
2670 | if (!t) | |
2671 | return 0; | |
2672 | ||
2673 | seq_printf(m, "%s", t->name); | |
2674 | if (t->next) | |
2675 | seq_putc(m, ' '); | |
2676 | else | |
2677 | seq_putc(m, '\n'); | |
2678 | ||
2679 | return 0; | |
2680 | } | |
2681 | ||
88e9d34c | 2682 | static const struct seq_operations show_traces_seq_ops = { |
4bf39a94 IM |
2683 | .start = t_start, |
2684 | .next = t_next, | |
2685 | .stop = t_stop, | |
2686 | .show = t_show, | |
bc0c38d1 SR |
2687 | }; |
2688 | ||
2689 | static int show_traces_open(struct inode *inode, struct file *file) | |
2690 | { | |
60a11774 SR |
2691 | if (tracing_disabled) |
2692 | return -ENODEV; | |
2693 | ||
f129e965 | 2694 | return seq_open(file, &show_traces_seq_ops); |
bc0c38d1 SR |
2695 | } |
2696 | ||
4acd4d00 SR |
2697 | static ssize_t |
2698 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
2699 | size_t count, loff_t *ppos) | |
2700 | { | |
2701 | return count; | |
2702 | } | |
2703 | ||
364829b1 SP |
2704 | static loff_t tracing_seek(struct file *file, loff_t offset, int origin) |
2705 | { | |
2706 | if (file->f_mode & FMODE_READ) | |
2707 | return seq_lseek(file, offset, origin); | |
2708 | else | |
2709 | return 0; | |
2710 | } | |
2711 | ||
5e2336a0 | 2712 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
2713 | .open = tracing_open, |
2714 | .read = seq_read, | |
4acd4d00 | 2715 | .write = tracing_write_stub, |
364829b1 | 2716 | .llseek = tracing_seek, |
4bf39a94 | 2717 | .release = tracing_release, |
bc0c38d1 SR |
2718 | }; |
2719 | ||
5e2336a0 | 2720 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
2721 | .open = show_traces_open, |
2722 | .read = seq_read, | |
2723 | .release = seq_release, | |
b444786f | 2724 | .llseek = seq_lseek, |
c7078de1 IM |
2725 | }; |
2726 | ||
36dfe925 IM |
2727 | /* |
2728 | * Only trace on a CPU if the bitmask is set: | |
2729 | */ | |
9e01c1b7 | 2730 | static cpumask_var_t tracing_cpumask; |
36dfe925 IM |
2731 | |
2732 | /* | |
2733 | * The tracer itself will not take this lock, but still we want | |
2734 | * to provide a consistent cpumask to user-space: | |
2735 | */ | |
2736 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
2737 | ||
2738 | /* | |
2739 | * Temporary storage for the character representation of the | |
2740 | * CPU bitmask (and one more byte for the newline): | |
2741 | */ | |
2742 | static char mask_str[NR_CPUS + 1]; | |
2743 | ||
c7078de1 IM |
2744 | static ssize_t |
2745 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
2746 | size_t count, loff_t *ppos) | |
2747 | { | |
36dfe925 | 2748 | int len; |
c7078de1 IM |
2749 | |
2750 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 2751 | |
9e01c1b7 | 2752 | len = cpumask_scnprintf(mask_str, count, tracing_cpumask); |
36dfe925 IM |
2753 | if (count - len < 2) { |
2754 | count = -EINVAL; | |
2755 | goto out_err; | |
2756 | } | |
2757 | len += sprintf(mask_str + len, "\n"); | |
2758 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
2759 | ||
2760 | out_err: | |
c7078de1 IM |
2761 | mutex_unlock(&tracing_cpumask_update_lock); |
2762 | ||
2763 | return count; | |
2764 | } | |
2765 | ||
2766 | static ssize_t | |
2767 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
2768 | size_t count, loff_t *ppos) | |
2769 | { | |
36dfe925 | 2770 | int err, cpu; |
9e01c1b7 RR |
2771 | cpumask_var_t tracing_cpumask_new; |
2772 | ||
2773 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
2774 | return -ENOMEM; | |
c7078de1 | 2775 | |
9e01c1b7 | 2776 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 2777 | if (err) |
36dfe925 IM |
2778 | goto err_unlock; |
2779 | ||
215368e8 LZ |
2780 | mutex_lock(&tracing_cpumask_update_lock); |
2781 | ||
a5e25883 | 2782 | local_irq_disable(); |
0199c4e6 | 2783 | arch_spin_lock(&ftrace_max_lock); |
ab46428c | 2784 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
2785 | /* |
2786 | * Increase/decrease the disabled counter if we are | |
2787 | * about to flip a bit in the cpumask: | |
2788 | */ | |
9e01c1b7 RR |
2789 | if (cpumask_test_cpu(cpu, tracing_cpumask) && |
2790 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 | 2791 | atomic_inc(&global_trace.data[cpu]->disabled); |
71babb27 | 2792 | ring_buffer_record_disable_cpu(global_trace.buffer, cpu); |
36dfe925 | 2793 | } |
9e01c1b7 RR |
2794 | if (!cpumask_test_cpu(cpu, tracing_cpumask) && |
2795 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 | 2796 | atomic_dec(&global_trace.data[cpu]->disabled); |
71babb27 | 2797 | ring_buffer_record_enable_cpu(global_trace.buffer, cpu); |
36dfe925 IM |
2798 | } |
2799 | } | |
0199c4e6 | 2800 | arch_spin_unlock(&ftrace_max_lock); |
a5e25883 | 2801 | local_irq_enable(); |
36dfe925 | 2802 | |
9e01c1b7 | 2803 | cpumask_copy(tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
2804 | |
2805 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 2806 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
2807 | |
2808 | return count; | |
36dfe925 IM |
2809 | |
2810 | err_unlock: | |
215368e8 | 2811 | free_cpumask_var(tracing_cpumask_new); |
36dfe925 IM |
2812 | |
2813 | return err; | |
c7078de1 IM |
2814 | } |
2815 | ||
5e2336a0 | 2816 | static const struct file_operations tracing_cpumask_fops = { |
c7078de1 IM |
2817 | .open = tracing_open_generic, |
2818 | .read = tracing_cpumask_read, | |
2819 | .write = tracing_cpumask_write, | |
b444786f | 2820 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
2821 | }; |
2822 | ||
fdb372ed | 2823 | static int tracing_trace_options_show(struct seq_file *m, void *v) |
bc0c38d1 | 2824 | { |
d8e83d26 SR |
2825 | struct tracer_opt *trace_opts; |
2826 | u32 tracer_flags; | |
d8e83d26 | 2827 | int i; |
adf9f195 | 2828 | |
d8e83d26 SR |
2829 | mutex_lock(&trace_types_lock); |
2830 | tracer_flags = current_trace->flags->val; | |
2831 | trace_opts = current_trace->flags->opts; | |
2832 | ||
bc0c38d1 SR |
2833 | for (i = 0; trace_options[i]; i++) { |
2834 | if (trace_flags & (1 << i)) | |
fdb372ed | 2835 | seq_printf(m, "%s\n", trace_options[i]); |
bc0c38d1 | 2836 | else |
fdb372ed | 2837 | seq_printf(m, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
2838 | } |
2839 | ||
adf9f195 FW |
2840 | for (i = 0; trace_opts[i].name; i++) { |
2841 | if (tracer_flags & trace_opts[i].bit) | |
fdb372ed | 2842 | seq_printf(m, "%s\n", trace_opts[i].name); |
adf9f195 | 2843 | else |
fdb372ed | 2844 | seq_printf(m, "no%s\n", trace_opts[i].name); |
adf9f195 | 2845 | } |
d8e83d26 | 2846 | mutex_unlock(&trace_types_lock); |
adf9f195 | 2847 | |
fdb372ed | 2848 | return 0; |
bc0c38d1 | 2849 | } |
bc0c38d1 | 2850 | |
8d18eaaf LZ |
2851 | static int __set_tracer_option(struct tracer *trace, |
2852 | struct tracer_flags *tracer_flags, | |
2853 | struct tracer_opt *opts, int neg) | |
2854 | { | |
2855 | int ret; | |
bc0c38d1 | 2856 | |
8d18eaaf LZ |
2857 | ret = trace->set_flag(tracer_flags->val, opts->bit, !neg); |
2858 | if (ret) | |
2859 | return ret; | |
2860 | ||
2861 | if (neg) | |
2862 | tracer_flags->val &= ~opts->bit; | |
2863 | else | |
2864 | tracer_flags->val |= opts->bit; | |
2865 | return 0; | |
bc0c38d1 SR |
2866 | } |
2867 | ||
adf9f195 FW |
2868 | /* Try to assign a tracer specific option */ |
2869 | static int set_tracer_option(struct tracer *trace, char *cmp, int neg) | |
2870 | { | |
7770841e | 2871 | struct tracer_flags *tracer_flags = trace->flags; |
adf9f195 | 2872 | struct tracer_opt *opts = NULL; |
8d18eaaf | 2873 | int i; |
adf9f195 | 2874 | |
7770841e Z |
2875 | for (i = 0; tracer_flags->opts[i].name; i++) { |
2876 | opts = &tracer_flags->opts[i]; | |
adf9f195 | 2877 | |
8d18eaaf LZ |
2878 | if (strcmp(cmp, opts->name) == 0) |
2879 | return __set_tracer_option(trace, trace->flags, | |
2880 | opts, neg); | |
adf9f195 | 2881 | } |
adf9f195 | 2882 | |
8d18eaaf | 2883 | return -EINVAL; |
adf9f195 FW |
2884 | } |
2885 | ||
613f04a0 SRRH |
2886 | /* Some tracers require overwrite to stay enabled */ |
2887 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) | |
2888 | { | |
2889 | if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) | |
2890 | return -1; | |
2891 | ||
2892 | return 0; | |
2893 | } | |
2894 | ||
2895 | int set_tracer_flag(unsigned int mask, int enabled) | |
af4617bd SR |
2896 | { |
2897 | /* do nothing if flag is already set */ | |
2898 | if (!!(trace_flags & mask) == !!enabled) | |
613f04a0 SRRH |
2899 | return 0; |
2900 | ||
2901 | /* Give the tracer a chance to approve the change */ | |
2902 | if (current_trace->flag_changed) | |
2903 | if (current_trace->flag_changed(current_trace, mask, !!enabled)) | |
2904 | return -EINVAL; | |
af4617bd SR |
2905 | |
2906 | if (enabled) | |
2907 | trace_flags |= mask; | |
2908 | else | |
2909 | trace_flags &= ~mask; | |
e870e9a1 LZ |
2910 | |
2911 | if (mask == TRACE_ITER_RECORD_CMD) | |
2912 | trace_event_enable_cmd_record(enabled); | |
750912fa | 2913 | |
80902822 | 2914 | if (mask == TRACE_ITER_OVERWRITE) { |
750912fa | 2915 | ring_buffer_change_overwrite(global_trace.buffer, enabled); |
80902822 SRRH |
2916 | #ifdef CONFIG_TRACER_MAX_TRACE |
2917 | ring_buffer_change_overwrite(max_tr.buffer, enabled); | |
2918 | #endif | |
2919 | } | |
81698831 SR |
2920 | |
2921 | if (mask == TRACE_ITER_PRINTK) | |
2922 | trace_printk_start_stop_comm(enabled); | |
613f04a0 SRRH |
2923 | |
2924 | return 0; | |
af4617bd SR |
2925 | } |
2926 | ||
7bcfaf54 | 2927 | static int trace_set_options(char *option) |
bc0c38d1 | 2928 | { |
8d18eaaf | 2929 | char *cmp; |
bc0c38d1 | 2930 | int neg = 0; |
613f04a0 | 2931 | int ret = -ENODEV; |
bc0c38d1 SR |
2932 | int i; |
2933 | ||
7bcfaf54 | 2934 | cmp = strstrip(option); |
bc0c38d1 | 2935 | |
8d18eaaf | 2936 | if (strncmp(cmp, "no", 2) == 0) { |
bc0c38d1 SR |
2937 | neg = 1; |
2938 | cmp += 2; | |
2939 | } | |
2940 | ||
69d34da2 SRRH |
2941 | mutex_lock(&trace_types_lock); |
2942 | ||
bc0c38d1 | 2943 | for (i = 0; trace_options[i]; i++) { |
8d18eaaf | 2944 | if (strcmp(cmp, trace_options[i]) == 0) { |
613f04a0 | 2945 | ret = set_tracer_flag(1 << i, !neg); |
bc0c38d1 SR |
2946 | break; |
2947 | } | |
2948 | } | |
adf9f195 FW |
2949 | |
2950 | /* If no option could be set, test the specific tracer options */ | |
69d34da2 | 2951 | if (!trace_options[i]) |
adf9f195 | 2952 | ret = set_tracer_option(current_trace, cmp, neg); |
69d34da2 SRRH |
2953 | |
2954 | mutex_unlock(&trace_types_lock); | |
bc0c38d1 | 2955 | |
7bcfaf54 SR |
2956 | return ret; |
2957 | } | |
2958 | ||
2959 | static ssize_t | |
2960 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, | |
2961 | size_t cnt, loff_t *ppos) | |
2962 | { | |
2963 | char buf[64]; | |
613f04a0 | 2964 | int ret; |
7bcfaf54 SR |
2965 | |
2966 | if (cnt >= sizeof(buf)) | |
2967 | return -EINVAL; | |
2968 | ||
2969 | if (copy_from_user(&buf, ubuf, cnt)) | |
2970 | return -EFAULT; | |
2971 | ||
a8dd2176 SR |
2972 | buf[cnt] = 0; |
2973 | ||
613f04a0 SRRH |
2974 | ret = trace_set_options(buf); |
2975 | if (ret < 0) | |
2976 | return ret; | |
7bcfaf54 | 2977 | |
cf8517cf | 2978 | *ppos += cnt; |
bc0c38d1 SR |
2979 | |
2980 | return cnt; | |
2981 | } | |
2982 | ||
fdb372ed LZ |
2983 | static int tracing_trace_options_open(struct inode *inode, struct file *file) |
2984 | { | |
2985 | if (tracing_disabled) | |
2986 | return -ENODEV; | |
2987 | return single_open(file, tracing_trace_options_show, NULL); | |
2988 | } | |
2989 | ||
5e2336a0 | 2990 | static const struct file_operations tracing_iter_fops = { |
fdb372ed LZ |
2991 | .open = tracing_trace_options_open, |
2992 | .read = seq_read, | |
2993 | .llseek = seq_lseek, | |
2994 | .release = single_release, | |
ee6bce52 | 2995 | .write = tracing_trace_options_write, |
bc0c38d1 SR |
2996 | }; |
2997 | ||
7bd2f24c IM |
2998 | static const char readme_msg[] = |
2999 | "tracing mini-HOWTO:\n\n" | |
156f5a78 GL |
3000 | "# mount -t debugfs nodev /sys/kernel/debug\n\n" |
3001 | "# cat /sys/kernel/debug/tracing/available_tracers\n" | |
1e42e83f | 3002 | "wakeup wakeup_rt preemptirqsoff preemptoff irqsoff function nop\n\n" |
156f5a78 | 3003 | "# cat /sys/kernel/debug/tracing/current_tracer\n" |
bc2b6871 | 3004 | "nop\n" |
1e42e83f | 3005 | "# echo wakeup > /sys/kernel/debug/tracing/current_tracer\n" |
156f5a78 | 3006 | "# cat /sys/kernel/debug/tracing/current_tracer\n" |
1e42e83f | 3007 | "wakeup\n" |
156f5a78 | 3008 | "# cat /sys/kernel/debug/tracing/trace_options\n" |
7bd2f24c | 3009 | "noprint-parent nosym-offset nosym-addr noverbose\n" |
156f5a78 | 3010 | "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n" |
9b5f8b31 | 3011 | "# echo 1 > /sys/kernel/debug/tracing/tracing_on\n" |
156f5a78 | 3012 | "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n" |
9b5f8b31 | 3013 | "# echo 0 > /sys/kernel/debug/tracing/tracing_on\n" |
7bd2f24c IM |
3014 | ; |
3015 | ||
3016 | static ssize_t | |
3017 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
3018 | size_t cnt, loff_t *ppos) | |
3019 | { | |
3020 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
3021 | readme_msg, strlen(readme_msg)); | |
3022 | } | |
3023 | ||
5e2336a0 | 3024 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
3025 | .open = tracing_open_generic, |
3026 | .read = tracing_readme_read, | |
b444786f | 3027 | .llseek = generic_file_llseek, |
7bd2f24c IM |
3028 | }; |
3029 | ||
69abe6a5 AP |
3030 | static ssize_t |
3031 | tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, | |
3032 | size_t cnt, loff_t *ppos) | |
3033 | { | |
3034 | char *buf_comm; | |
3035 | char *file_buf; | |
3036 | char *buf; | |
3037 | int len = 0; | |
3038 | int pid; | |
3039 | int i; | |
3040 | ||
3041 | file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL); | |
3042 | if (!file_buf) | |
3043 | return -ENOMEM; | |
3044 | ||
3045 | buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL); | |
3046 | if (!buf_comm) { | |
3047 | kfree(file_buf); | |
3048 | return -ENOMEM; | |
3049 | } | |
3050 | ||
3051 | buf = file_buf; | |
3052 | ||
3053 | for (i = 0; i < SAVED_CMDLINES; i++) { | |
3054 | int r; | |
3055 | ||
3056 | pid = map_cmdline_to_pid[i]; | |
3057 | if (pid == -1 || pid == NO_CMDLINE_MAP) | |
3058 | continue; | |
3059 | ||
3060 | trace_find_cmdline(pid, buf_comm); | |
3061 | r = sprintf(buf, "%d %s\n", pid, buf_comm); | |
3062 | buf += r; | |
3063 | len += r; | |
3064 | } | |
3065 | ||
3066 | len = simple_read_from_buffer(ubuf, cnt, ppos, | |
3067 | file_buf, len); | |
3068 | ||
3069 | kfree(file_buf); | |
3070 | kfree(buf_comm); | |
3071 | ||
3072 | return len; | |
3073 | } | |
3074 | ||
3075 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
3076 | .open = tracing_open_generic, | |
3077 | .read = tracing_saved_cmdlines_read, | |
b444786f | 3078 | .llseek = generic_file_llseek, |
69abe6a5 AP |
3079 | }; |
3080 | ||
bc0c38d1 SR |
3081 | static ssize_t |
3082 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
3083 | size_t cnt, loff_t *ppos) | |
3084 | { | |
ee6c2c1b | 3085 | char buf[MAX_TRACER_SIZE+2]; |
bc0c38d1 SR |
3086 | int r; |
3087 | ||
3088 | mutex_lock(&trace_types_lock); | |
d840f718 | 3089 | r = sprintf(buf, "%s\n", current_trace->name); |
bc0c38d1 SR |
3090 | mutex_unlock(&trace_types_lock); |
3091 | ||
4bf39a94 | 3092 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
3093 | } |
3094 | ||
b6f11df2 ACM |
3095 | int tracer_init(struct tracer *t, struct trace_array *tr) |
3096 | { | |
3097 | tracing_reset_online_cpus(tr); | |
3098 | return t->init(tr); | |
3099 | } | |
3100 | ||
438ced17 VN |
3101 | static void set_buffer_entries(struct trace_array *tr, unsigned long val) |
3102 | { | |
3103 | int cpu; | |
3104 | for_each_tracing_cpu(cpu) | |
3105 | tr->data[cpu]->entries = val; | |
3106 | } | |
3107 | ||
d60da506 HT |
3108 | /* resize @tr's buffer to the size of @size_tr's entries */ |
3109 | static int resize_buffer_duplicate_size(struct trace_array *tr, | |
3110 | struct trace_array *size_tr, int cpu_id) | |
3111 | { | |
3112 | int cpu, ret = 0; | |
3113 | ||
3114 | if (cpu_id == RING_BUFFER_ALL_CPUS) { | |
3115 | for_each_tracing_cpu(cpu) { | |
3116 | ret = ring_buffer_resize(tr->buffer, | |
3117 | size_tr->data[cpu]->entries, cpu); | |
3118 | if (ret < 0) | |
3119 | break; | |
3120 | tr->data[cpu]->entries = size_tr->data[cpu]->entries; | |
3121 | } | |
3122 | } else { | |
3123 | ret = ring_buffer_resize(tr->buffer, | |
3124 | size_tr->data[cpu_id]->entries, cpu_id); | |
3125 | if (ret == 0) | |
3126 | tr->data[cpu_id]->entries = | |
3127 | size_tr->data[cpu_id]->entries; | |
3128 | } | |
3129 | ||
3130 | return ret; | |
3131 | } | |
3132 | ||
438ced17 | 3133 | static int __tracing_resize_ring_buffer(unsigned long size, int cpu) |
73c5162a SR |
3134 | { |
3135 | int ret; | |
3136 | ||
3137 | /* | |
3138 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
3139 | * we use the size that was given, and we can forget about |
3140 | * expanding it later. | |
73c5162a SR |
3141 | */ |
3142 | ring_buffer_expanded = 1; | |
3143 | ||
b382ede6 SR |
3144 | /* May be called before buffers are initialized */ |
3145 | if (!global_trace.buffer) | |
3146 | return 0; | |
3147 | ||
438ced17 | 3148 | ret = ring_buffer_resize(global_trace.buffer, size, cpu); |
73c5162a SR |
3149 | if (ret < 0) |
3150 | return ret; | |
3151 | ||
ef710e10 KM |
3152 | if (!current_trace->use_max_tr) |
3153 | goto out; | |
3154 | ||
438ced17 | 3155 | ret = ring_buffer_resize(max_tr.buffer, size, cpu); |
73c5162a | 3156 | if (ret < 0) { |
d60da506 HT |
3157 | int r = resize_buffer_duplicate_size(&global_trace, |
3158 | &global_trace, cpu); | |
73c5162a | 3159 | if (r < 0) { |
a123c52b SR |
3160 | /* |
3161 | * AARGH! We are left with different | |
3162 | * size max buffer!!!! | |
3163 | * The max buffer is our "snapshot" buffer. | |
3164 | * When a tracer needs a snapshot (one of the | |
3165 | * latency tracers), it swaps the max buffer | |
3166 | * with the saved snap shot. We succeeded to | |
3167 | * update the size of the main buffer, but failed to | |
3168 | * update the size of the max buffer. But when we tried | |
3169 | * to reset the main buffer to the original size, we | |
3170 | * failed there too. This is very unlikely to | |
3171 | * happen, but if it does, warn and kill all | |
3172 | * tracing. | |
3173 | */ | |
73c5162a SR |
3174 | WARN_ON(1); |
3175 | tracing_disabled = 1; | |
3176 | } | |
3177 | return ret; | |
3178 | } | |
3179 | ||
438ced17 VN |
3180 | if (cpu == RING_BUFFER_ALL_CPUS) |
3181 | set_buffer_entries(&max_tr, size); | |
3182 | else | |
3183 | max_tr.data[cpu]->entries = size; | |
3184 | ||
ef710e10 | 3185 | out: |
438ced17 VN |
3186 | if (cpu == RING_BUFFER_ALL_CPUS) |
3187 | set_buffer_entries(&global_trace, size); | |
3188 | else | |
3189 | global_trace.data[cpu]->entries = size; | |
73c5162a SR |
3190 | |
3191 | return ret; | |
3192 | } | |
3193 | ||
438ced17 | 3194 | static ssize_t tracing_resize_ring_buffer(unsigned long size, int cpu_id) |
4f271a2a | 3195 | { |
83f40318 | 3196 | int ret = size; |
4f271a2a VN |
3197 | |
3198 | mutex_lock(&trace_types_lock); | |
3199 | ||
438ced17 VN |
3200 | if (cpu_id != RING_BUFFER_ALL_CPUS) { |
3201 | /* make sure, this cpu is enabled in the mask */ | |
3202 | if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { | |
3203 | ret = -EINVAL; | |
3204 | goto out; | |
3205 | } | |
3206 | } | |
4f271a2a | 3207 | |
438ced17 | 3208 | ret = __tracing_resize_ring_buffer(size, cpu_id); |
4f271a2a VN |
3209 | if (ret < 0) |
3210 | ret = -ENOMEM; | |
3211 | ||
438ced17 | 3212 | out: |
4f271a2a VN |
3213 | mutex_unlock(&trace_types_lock); |
3214 | ||
3215 | return ret; | |
3216 | } | |
3217 | ||
ef710e10 | 3218 | |
1852fcce SR |
3219 | /** |
3220 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
3221 | * | |
3222 | * To save on memory when the tracing is never used on a system with it | |
3223 | * configured in. The ring buffers are set to a minimum size. But once | |
3224 | * a user starts to use the tracing facility, then they need to grow | |
3225 | * to their default size. | |
3226 | * | |
3227 | * This function is to be called when a tracer is about to be used. | |
3228 | */ | |
3229 | int tracing_update_buffers(void) | |
3230 | { | |
3231 | int ret = 0; | |
3232 | ||
1027fcb2 | 3233 | mutex_lock(&trace_types_lock); |
1852fcce | 3234 | if (!ring_buffer_expanded) |
438ced17 VN |
3235 | ret = __tracing_resize_ring_buffer(trace_buf_size, |
3236 | RING_BUFFER_ALL_CPUS); | |
1027fcb2 | 3237 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
3238 | |
3239 | return ret; | |
3240 | } | |
3241 | ||
577b785f SR |
3242 | struct trace_option_dentry; |
3243 | ||
3244 | static struct trace_option_dentry * | |
3245 | create_trace_option_files(struct tracer *tracer); | |
3246 | ||
3247 | static void | |
3248 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
3249 | ||
b2821ae6 | 3250 | static int tracing_set_tracer(const char *buf) |
bc0c38d1 | 3251 | { |
577b785f | 3252 | static struct trace_option_dentry *topts; |
bc0c38d1 SR |
3253 | struct trace_array *tr = &global_trace; |
3254 | struct tracer *t; | |
34600f0e | 3255 | bool had_max_tr; |
d9e54076 | 3256 | int ret = 0; |
bc0c38d1 | 3257 | |
1027fcb2 SR |
3258 | mutex_lock(&trace_types_lock); |
3259 | ||
73c5162a | 3260 | if (!ring_buffer_expanded) { |
438ced17 VN |
3261 | ret = __tracing_resize_ring_buffer(trace_buf_size, |
3262 | RING_BUFFER_ALL_CPUS); | |
73c5162a | 3263 | if (ret < 0) |
59f586db | 3264 | goto out; |
73c5162a SR |
3265 | ret = 0; |
3266 | } | |
3267 | ||
bc0c38d1 SR |
3268 | for (t = trace_types; t; t = t->next) { |
3269 | if (strcmp(t->name, buf) == 0) | |
3270 | break; | |
3271 | } | |
c2931e05 FW |
3272 | if (!t) { |
3273 | ret = -EINVAL; | |
3274 | goto out; | |
3275 | } | |
3276 | if (t == current_trace) | |
bc0c38d1 SR |
3277 | goto out; |
3278 | ||
9f029e83 | 3279 | trace_branch_disable(); |
613f04a0 SRRH |
3280 | |
3281 | current_trace->enabled = false; | |
3282 | ||
d840f718 | 3283 | if (current_trace->reset) |
bc0c38d1 | 3284 | current_trace->reset(tr); |
34600f0e | 3285 | |
d840f718 | 3286 | had_max_tr = current_trace->allocated_snapshot; |
34600f0e SR |
3287 | current_trace = &nop_trace; |
3288 | ||
3289 | if (had_max_tr && !t->use_max_tr) { | |
3290 | /* | |
3291 | * We need to make sure that the update_max_tr sees that | |
3292 | * current_trace changed to nop_trace to keep it from | |
3293 | * swapping the buffers after we resize it. | |
3294 | * The update_max_tr is called from interrupts disabled | |
3295 | * so a synchronized_sched() is sufficient. | |
3296 | */ | |
3297 | synchronize_sched(); | |
ef710e10 KM |
3298 | /* |
3299 | * We don't free the ring buffer. instead, resize it because | |
3300 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
3301 | * we want preserve it. | |
3302 | */ | |
438ced17 VN |
3303 | ring_buffer_resize(max_tr.buffer, 1, RING_BUFFER_ALL_CPUS); |
3304 | set_buffer_entries(&max_tr, 1); | |
debdd57f HT |
3305 | tracing_reset_online_cpus(&max_tr); |
3306 | current_trace->allocated_snapshot = false; | |
ef710e10 | 3307 | } |
577b785f SR |
3308 | destroy_trace_option_files(topts); |
3309 | ||
b2ad368b | 3310 | topts = create_trace_option_files(t); |
34600f0e | 3311 | if (t->use_max_tr && !had_max_tr) { |
438ced17 | 3312 | /* we need to make per cpu buffer sizes equivalent */ |
d60da506 HT |
3313 | ret = resize_buffer_duplicate_size(&max_tr, &global_trace, |
3314 | RING_BUFFER_ALL_CPUS); | |
3315 | if (ret < 0) | |
3316 | goto out; | |
debdd57f | 3317 | t->allocated_snapshot = true; |
ef710e10 | 3318 | } |
577b785f | 3319 | |
1c80025a | 3320 | if (t->init) { |
b6f11df2 | 3321 | ret = tracer_init(t, tr); |
1c80025a FW |
3322 | if (ret) |
3323 | goto out; | |
3324 | } | |
bc0c38d1 | 3325 | |
b2ad368b | 3326 | current_trace = t; |
613f04a0 | 3327 | current_trace->enabled = true; |
9f029e83 | 3328 | trace_branch_enable(tr); |
bc0c38d1 SR |
3329 | out: |
3330 | mutex_unlock(&trace_types_lock); | |
3331 | ||
d9e54076 PZ |
3332 | return ret; |
3333 | } | |
3334 | ||
3335 | static ssize_t | |
3336 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
3337 | size_t cnt, loff_t *ppos) | |
3338 | { | |
ee6c2c1b | 3339 | char buf[MAX_TRACER_SIZE+1]; |
d9e54076 PZ |
3340 | int i; |
3341 | size_t ret; | |
e6e7a65a FW |
3342 | int err; |
3343 | ||
3344 | ret = cnt; | |
d9e54076 | 3345 | |
ee6c2c1b LZ |
3346 | if (cnt > MAX_TRACER_SIZE) |
3347 | cnt = MAX_TRACER_SIZE; | |
d9e54076 PZ |
3348 | |
3349 | if (copy_from_user(&buf, ubuf, cnt)) | |
3350 | return -EFAULT; | |
3351 | ||
3352 | buf[cnt] = 0; | |
3353 | ||
3354 | /* strip ending whitespace. */ | |
3355 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
3356 | buf[i] = 0; | |
3357 | ||
e6e7a65a FW |
3358 | err = tracing_set_tracer(buf); |
3359 | if (err) | |
3360 | return err; | |
d9e54076 | 3361 | |
cf8517cf | 3362 | *ppos += ret; |
bc0c38d1 | 3363 | |
c2931e05 | 3364 | return ret; |
bc0c38d1 SR |
3365 | } |
3366 | ||
3367 | static ssize_t | |
3368 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
3369 | size_t cnt, loff_t *ppos) | |
3370 | { | |
3371 | unsigned long *ptr = filp->private_data; | |
3372 | char buf[64]; | |
3373 | int r; | |
3374 | ||
cffae437 | 3375 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 3376 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
3377 | if (r > sizeof(buf)) |
3378 | r = sizeof(buf); | |
4bf39a94 | 3379 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
3380 | } |
3381 | ||
3382 | static ssize_t | |
3383 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
3384 | size_t cnt, loff_t *ppos) | |
3385 | { | |
5e39841c | 3386 | unsigned long *ptr = filp->private_data; |
5e39841c | 3387 | unsigned long val; |
c6caeeb1 | 3388 | int ret; |
bc0c38d1 | 3389 | |
22fe9b54 PH |
3390 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
3391 | if (ret) | |
c6caeeb1 | 3392 | return ret; |
bc0c38d1 SR |
3393 | |
3394 | *ptr = val * 1000; | |
3395 | ||
3396 | return cnt; | |
3397 | } | |
3398 | ||
b3806b43 SR |
3399 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
3400 | { | |
b04cc6b1 | 3401 | long cpu_file = (long) inode->i_private; |
b3806b43 | 3402 | struct trace_iterator *iter; |
b04cc6b1 | 3403 | int ret = 0; |
b3806b43 SR |
3404 | |
3405 | if (tracing_disabled) | |
3406 | return -ENODEV; | |
3407 | ||
b04cc6b1 FW |
3408 | mutex_lock(&trace_types_lock); |
3409 | ||
b3806b43 SR |
3410 | /* create a buffer to store the information to pass to userspace */ |
3411 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
3412 | if (!iter) { |
3413 | ret = -ENOMEM; | |
3414 | goto out; | |
3415 | } | |
b3806b43 | 3416 | |
d7350c3f FW |
3417 | /* |
3418 | * We make a copy of the current tracer to avoid concurrent | |
3419 | * changes on it while we are reading. | |
3420 | */ | |
3421 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
3422 | if (!iter->trace) { | |
3423 | ret = -ENOMEM; | |
3424 | goto fail; | |
3425 | } | |
d840f718 | 3426 | *iter->trace = *current_trace; |
d7350c3f | 3427 | |
4462344e | 3428 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 3429 | ret = -ENOMEM; |
d7350c3f | 3430 | goto fail; |
4462344e RR |
3431 | } |
3432 | ||
a309720c | 3433 | /* trace pipe does not show start of buffer */ |
4462344e | 3434 | cpumask_setall(iter->started); |
a309720c | 3435 | |
112f38a7 SR |
3436 | if (trace_flags & TRACE_ITER_LATENCY_FMT) |
3437 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
3438 | ||
8be0709f DS |
3439 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
3440 | if (trace_clocks[trace_clock_id].in_ns) | |
3441 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
3442 | ||
b04cc6b1 | 3443 | iter->cpu_file = cpu_file; |
b3806b43 | 3444 | iter->tr = &global_trace; |
d7350c3f | 3445 | mutex_init(&iter->mutex); |
b3806b43 SR |
3446 | filp->private_data = iter; |
3447 | ||
107bad8b SR |
3448 | if (iter->trace->pipe_open) |
3449 | iter->trace->pipe_open(iter); | |
107bad8b | 3450 | |
b444786f | 3451 | nonseekable_open(inode, filp); |
b04cc6b1 FW |
3452 | out: |
3453 | mutex_unlock(&trace_types_lock); | |
3454 | return ret; | |
d7350c3f FW |
3455 | |
3456 | fail: | |
3457 | kfree(iter->trace); | |
3458 | kfree(iter); | |
3459 | mutex_unlock(&trace_types_lock); | |
3460 | return ret; | |
b3806b43 SR |
3461 | } |
3462 | ||
3463 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
3464 | { | |
3465 | struct trace_iterator *iter = file->private_data; | |
3466 | ||
b04cc6b1 FW |
3467 | mutex_lock(&trace_types_lock); |
3468 | ||
29bf4a5e | 3469 | if (iter->trace->pipe_close) |
c521efd1 SR |
3470 | iter->trace->pipe_close(iter); |
3471 | ||
b04cc6b1 FW |
3472 | mutex_unlock(&trace_types_lock); |
3473 | ||
4462344e | 3474 | free_cpumask_var(iter->started); |
d7350c3f FW |
3475 | mutex_destroy(&iter->mutex); |
3476 | kfree(iter->trace); | |
b3806b43 | 3477 | kfree(iter); |
b3806b43 SR |
3478 | |
3479 | return 0; | |
3480 | } | |
3481 | ||
2a2cc8f7 SSP |
3482 | static unsigned int |
3483 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
3484 | { | |
3485 | struct trace_iterator *iter = filp->private_data; | |
3486 | ||
3487 | if (trace_flags & TRACE_ITER_BLOCK) { | |
3488 | /* | |
3489 | * Always select as readable when in blocking mode | |
3490 | */ | |
3491 | return POLLIN | POLLRDNORM; | |
afc2abc0 | 3492 | } else { |
2a2cc8f7 SSP |
3493 | if (!trace_empty(iter)) |
3494 | return POLLIN | POLLRDNORM; | |
3495 | poll_wait(filp, &trace_wait, poll_table); | |
3496 | if (!trace_empty(iter)) | |
3497 | return POLLIN | POLLRDNORM; | |
3498 | ||
3499 | return 0; | |
3500 | } | |
3501 | } | |
3502 | ||
6eaaa5d5 FW |
3503 | /* |
3504 | * This is a make-shift waitqueue. | |
3505 | * A tracer might use this callback on some rare cases: | |
3506 | * | |
3507 | * 1) the current tracer might hold the runqueue lock when it wakes up | |
3508 | * a reader, hence a deadlock (sched, function, and function graph tracers) | |
3509 | * 2) the function tracers, trace all functions, we don't want | |
3510 | * the overhead of calling wake_up and friends | |
3511 | * (and tracing them too) | |
3512 | * | |
3513 | * Anyway, this is really very primitive wakeup. | |
3514 | */ | |
3515 | void poll_wait_pipe(struct trace_iterator *iter) | |
3516 | { | |
3517 | set_current_state(TASK_INTERRUPTIBLE); | |
3518 | /* sleep for 100 msecs, and try again. */ | |
3519 | schedule_timeout(HZ / 10); | |
3520 | } | |
3521 | ||
ff98781b EGM |
3522 | /* Must be called with trace_types_lock mutex held. */ |
3523 | static int tracing_wait_pipe(struct file *filp) | |
b3806b43 SR |
3524 | { |
3525 | struct trace_iterator *iter = filp->private_data; | |
b3806b43 | 3526 | |
b3806b43 | 3527 | while (trace_empty(iter)) { |
2dc8f095 | 3528 | |
107bad8b | 3529 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 3530 | return -EAGAIN; |
107bad8b | 3531 | } |
2dc8f095 | 3532 | |
d7350c3f | 3533 | mutex_unlock(&iter->mutex); |
107bad8b | 3534 | |
6eaaa5d5 | 3535 | iter->trace->wait_pipe(iter); |
b3806b43 | 3536 | |
d7350c3f | 3537 | mutex_lock(&iter->mutex); |
107bad8b | 3538 | |
6eaaa5d5 | 3539 | if (signal_pending(current)) |
ff98781b | 3540 | return -EINTR; |
b3806b43 SR |
3541 | |
3542 | /* | |
250bfd3d | 3543 | * We block until we read something and tracing is disabled. |
b3806b43 SR |
3544 | * We still block if tracing is disabled, but we have never |
3545 | * read anything. This allows a user to cat this file, and | |
3546 | * then enable tracing. But after we have read something, | |
3547 | * we give an EOF when tracing is again disabled. | |
3548 | * | |
3549 | * iter->pos will be 0 if we haven't read anything. | |
3550 | */ | |
250bfd3d | 3551 | if (!tracing_is_enabled() && iter->pos) |
b3806b43 | 3552 | break; |
b3806b43 SR |
3553 | } |
3554 | ||
ff98781b EGM |
3555 | return 1; |
3556 | } | |
3557 | ||
3558 | /* | |
3559 | * Consumer reader. | |
3560 | */ | |
3561 | static ssize_t | |
3562 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
3563 | size_t cnt, loff_t *ppos) | |
3564 | { | |
3565 | struct trace_iterator *iter = filp->private_data; | |
3566 | ssize_t sret; | |
3567 | ||
3568 | /* return any leftover data */ | |
3569 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
3570 | if (sret != -EBUSY) | |
3571 | return sret; | |
3572 | ||
f9520750 | 3573 | trace_seq_init(&iter->seq); |
ff98781b | 3574 | |
d7350c3f | 3575 | /* copy the tracer to avoid using a global lock all around */ |
ff98781b | 3576 | mutex_lock(&trace_types_lock); |
d840f718 | 3577 | if (unlikely(iter->trace->name != current_trace->name)) |
d7350c3f | 3578 | *iter->trace = *current_trace; |
d7350c3f FW |
3579 | mutex_unlock(&trace_types_lock); |
3580 | ||
3581 | /* | |
3582 | * Avoid more than one consumer on a single file descriptor | |
3583 | * This is just a matter of traces coherency, the ring buffer itself | |
3584 | * is protected. | |
3585 | */ | |
3586 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
3587 | if (iter->trace->read) { |
3588 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
3589 | if (sret) | |
3590 | goto out; | |
3591 | } | |
3592 | ||
3593 | waitagain: | |
3594 | sret = tracing_wait_pipe(filp); | |
3595 | if (sret <= 0) | |
3596 | goto out; | |
3597 | ||
b3806b43 | 3598 | /* stop when tracing is finished */ |
ff98781b EGM |
3599 | if (trace_empty(iter)) { |
3600 | sret = 0; | |
107bad8b | 3601 | goto out; |
ff98781b | 3602 | } |
b3806b43 SR |
3603 | |
3604 | if (cnt >= PAGE_SIZE) | |
3605 | cnt = PAGE_SIZE - 1; | |
3606 | ||
53d0aa77 | 3607 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
3608 | memset(&iter->seq, 0, |
3609 | sizeof(struct trace_iterator) - | |
3610 | offsetof(struct trace_iterator, seq)); | |
4823ed7e | 3611 | iter->pos = -1; |
b3806b43 | 3612 | |
4f535968 | 3613 | trace_event_read_lock(); |
7e53bd42 | 3614 | trace_access_lock(iter->cpu_file); |
955b61e5 | 3615 | while (trace_find_next_entry_inc(iter) != NULL) { |
2c4f035f | 3616 | enum print_line_t ret; |
088b1e42 SR |
3617 | int len = iter->seq.len; |
3618 | ||
f9896bf3 | 3619 | ret = print_trace_line(iter); |
2c4f035f | 3620 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 SR |
3621 | /* don't print partial lines */ |
3622 | iter->seq.len = len; | |
b3806b43 | 3623 | break; |
088b1e42 | 3624 | } |
b91facc3 FW |
3625 | if (ret != TRACE_TYPE_NO_CONSUME) |
3626 | trace_consume(iter); | |
b3806b43 SR |
3627 | |
3628 | if (iter->seq.len >= cnt) | |
3629 | break; | |
ee5e51f5 JO |
3630 | |
3631 | /* | |
3632 | * Setting the full flag means we reached the trace_seq buffer | |
3633 | * size and we should leave by partial output condition above. | |
3634 | * One of the trace_seq_* functions is not used properly. | |
3635 | */ | |
3636 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
3637 | iter->ent->type); | |
b3806b43 | 3638 | } |
7e53bd42 | 3639 | trace_access_unlock(iter->cpu_file); |
4f535968 | 3640 | trace_event_read_unlock(); |
b3806b43 | 3641 | |
b3806b43 | 3642 | /* Now copy what we have to the user */ |
6c6c2796 PP |
3643 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
3644 | if (iter->seq.readpos >= iter->seq.len) | |
f9520750 | 3645 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
3646 | |
3647 | /* | |
25985edc | 3648 | * If there was nothing to send to user, in spite of consuming trace |
9ff4b974 PP |
3649 | * entries, go back to wait for more entries. |
3650 | */ | |
6c6c2796 | 3651 | if (sret == -EBUSY) |
9ff4b974 | 3652 | goto waitagain; |
b3806b43 | 3653 | |
107bad8b | 3654 | out: |
d7350c3f | 3655 | mutex_unlock(&iter->mutex); |
107bad8b | 3656 | |
6c6c2796 | 3657 | return sret; |
b3806b43 SR |
3658 | } |
3659 | ||
3c56819b EGM |
3660 | static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, |
3661 | struct pipe_buffer *buf) | |
3662 | { | |
3663 | __free_page(buf->page); | |
3664 | } | |
3665 | ||
3666 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, | |
3667 | unsigned int idx) | |
3668 | { | |
3669 | __free_page(spd->pages[idx]); | |
3670 | } | |
3671 | ||
28dfef8f | 3672 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { |
34cd4998 SR |
3673 | .can_merge = 0, |
3674 | .map = generic_pipe_buf_map, | |
3675 | .unmap = generic_pipe_buf_unmap, | |
3676 | .confirm = generic_pipe_buf_confirm, | |
3677 | .release = tracing_pipe_buf_release, | |
3678 | .steal = generic_pipe_buf_steal, | |
3679 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
3680 | }; |
3681 | ||
34cd4998 | 3682 | static size_t |
fa7c7f6e | 3683 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
3684 | { |
3685 | size_t count; | |
3686 | int ret; | |
3687 | ||
3688 | /* Seq buffer is page-sized, exactly what we need. */ | |
3689 | for (;;) { | |
3690 | count = iter->seq.len; | |
3691 | ret = print_trace_line(iter); | |
3692 | count = iter->seq.len - count; | |
3693 | if (rem < count) { | |
3694 | rem = 0; | |
3695 | iter->seq.len -= count; | |
3696 | break; | |
3697 | } | |
3698 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
3699 | iter->seq.len -= count; | |
3700 | break; | |
3701 | } | |
3702 | ||
74e7ff8c LJ |
3703 | if (ret != TRACE_TYPE_NO_CONSUME) |
3704 | trace_consume(iter); | |
34cd4998 | 3705 | rem -= count; |
955b61e5 | 3706 | if (!trace_find_next_entry_inc(iter)) { |
34cd4998 SR |
3707 | rem = 0; |
3708 | iter->ent = NULL; | |
3709 | break; | |
3710 | } | |
3711 | } | |
3712 | ||
3713 | return rem; | |
3714 | } | |
3715 | ||
3c56819b EGM |
3716 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
3717 | loff_t *ppos, | |
3718 | struct pipe_inode_info *pipe, | |
3719 | size_t len, | |
3720 | unsigned int flags) | |
3721 | { | |
35f3d14d JA |
3722 | struct page *pages_def[PIPE_DEF_BUFFERS]; |
3723 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3c56819b EGM |
3724 | struct trace_iterator *iter = filp->private_data; |
3725 | struct splice_pipe_desc spd = { | |
35f3d14d JA |
3726 | .pages = pages_def, |
3727 | .partial = partial_def, | |
34cd4998 | 3728 | .nr_pages = 0, /* This gets updated below. */ |
047fe360 | 3729 | .nr_pages_max = PIPE_DEF_BUFFERS, |
34cd4998 SR |
3730 | .flags = flags, |
3731 | .ops = &tracing_pipe_buf_ops, | |
3732 | .spd_release = tracing_spd_release_pipe, | |
3c56819b EGM |
3733 | }; |
3734 | ssize_t ret; | |
34cd4998 | 3735 | size_t rem; |
3c56819b EGM |
3736 | unsigned int i; |
3737 | ||
35f3d14d JA |
3738 | if (splice_grow_spd(pipe, &spd)) |
3739 | return -ENOMEM; | |
3740 | ||
d7350c3f | 3741 | /* copy the tracer to avoid using a global lock all around */ |
3c56819b | 3742 | mutex_lock(&trace_types_lock); |
d840f718 | 3743 | if (unlikely(iter->trace->name != current_trace->name)) |
d7350c3f | 3744 | *iter->trace = *current_trace; |
d7350c3f FW |
3745 | mutex_unlock(&trace_types_lock); |
3746 | ||
3747 | mutex_lock(&iter->mutex); | |
3c56819b EGM |
3748 | |
3749 | if (iter->trace->splice_read) { | |
3750 | ret = iter->trace->splice_read(iter, filp, | |
3751 | ppos, pipe, len, flags); | |
3752 | if (ret) | |
34cd4998 | 3753 | goto out_err; |
3c56819b EGM |
3754 | } |
3755 | ||
3756 | ret = tracing_wait_pipe(filp); | |
3757 | if (ret <= 0) | |
34cd4998 | 3758 | goto out_err; |
3c56819b | 3759 | |
955b61e5 | 3760 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { |
3c56819b | 3761 | ret = -EFAULT; |
34cd4998 | 3762 | goto out_err; |
3c56819b EGM |
3763 | } |
3764 | ||
4f535968 | 3765 | trace_event_read_lock(); |
7e53bd42 | 3766 | trace_access_lock(iter->cpu_file); |
4f535968 | 3767 | |
3c56819b | 3768 | /* Fill as many pages as possible. */ |
35f3d14d JA |
3769 | for (i = 0, rem = len; i < pipe->buffers && rem; i++) { |
3770 | spd.pages[i] = alloc_page(GFP_KERNEL); | |
3771 | if (!spd.pages[i]) | |
34cd4998 | 3772 | break; |
3c56819b | 3773 | |
fa7c7f6e | 3774 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
3775 | |
3776 | /* Copy the data into the page, so we can start over. */ | |
3777 | ret = trace_seq_to_buffer(&iter->seq, | |
35f3d14d | 3778 | page_address(spd.pages[i]), |
3c56819b EGM |
3779 | iter->seq.len); |
3780 | if (ret < 0) { | |
35f3d14d | 3781 | __free_page(spd.pages[i]); |
3c56819b EGM |
3782 | break; |
3783 | } | |
35f3d14d JA |
3784 | spd.partial[i].offset = 0; |
3785 | spd.partial[i].len = iter->seq.len; | |
3c56819b | 3786 | |
f9520750 | 3787 | trace_seq_init(&iter->seq); |
3c56819b EGM |
3788 | } |
3789 | ||
7e53bd42 | 3790 | trace_access_unlock(iter->cpu_file); |
4f535968 | 3791 | trace_event_read_unlock(); |
d7350c3f | 3792 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
3793 | |
3794 | spd.nr_pages = i; | |
3795 | ||
35f3d14d JA |
3796 | ret = splice_to_pipe(pipe, &spd); |
3797 | out: | |
047fe360 | 3798 | splice_shrink_spd(&spd); |
35f3d14d | 3799 | return ret; |
3c56819b | 3800 | |
34cd4998 | 3801 | out_err: |
d7350c3f | 3802 | mutex_unlock(&iter->mutex); |
35f3d14d | 3803 | goto out; |
3c56819b EGM |
3804 | } |
3805 | ||
438ced17 VN |
3806 | struct ftrace_entries_info { |
3807 | struct trace_array *tr; | |
3808 | int cpu; | |
3809 | }; | |
3810 | ||
3811 | static int tracing_entries_open(struct inode *inode, struct file *filp) | |
3812 | { | |
3813 | struct ftrace_entries_info *info; | |
3814 | ||
3815 | if (tracing_disabled) | |
3816 | return -ENODEV; | |
3817 | ||
3818 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
3819 | if (!info) | |
3820 | return -ENOMEM; | |
3821 | ||
3822 | info->tr = &global_trace; | |
3823 | info->cpu = (unsigned long)inode->i_private; | |
3824 | ||
3825 | filp->private_data = info; | |
3826 | ||
3827 | return 0; | |
3828 | } | |
3829 | ||
a98a3c3f SR |
3830 | static ssize_t |
3831 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
3832 | size_t cnt, loff_t *ppos) | |
3833 | { | |
438ced17 VN |
3834 | struct ftrace_entries_info *info = filp->private_data; |
3835 | struct trace_array *tr = info->tr; | |
3836 | char buf[64]; | |
3837 | int r = 0; | |
3838 | ssize_t ret; | |
a98a3c3f | 3839 | |
db526ca3 | 3840 | mutex_lock(&trace_types_lock); |
438ced17 VN |
3841 | |
3842 | if (info->cpu == RING_BUFFER_ALL_CPUS) { | |
3843 | int cpu, buf_size_same; | |
3844 | unsigned long size; | |
3845 | ||
3846 | size = 0; | |
3847 | buf_size_same = 1; | |
3848 | /* check if all cpu sizes are same */ | |
3849 | for_each_tracing_cpu(cpu) { | |
3850 | /* fill in the size from first enabled cpu */ | |
3851 | if (size == 0) | |
3852 | size = tr->data[cpu]->entries; | |
3853 | if (size != tr->data[cpu]->entries) { | |
3854 | buf_size_same = 0; | |
3855 | break; | |
3856 | } | |
3857 | } | |
3858 | ||
3859 | if (buf_size_same) { | |
3860 | if (!ring_buffer_expanded) | |
3861 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
3862 | size >> 10, | |
3863 | trace_buf_size >> 10); | |
3864 | else | |
3865 | r = sprintf(buf, "%lu\n", size >> 10); | |
3866 | } else | |
3867 | r = sprintf(buf, "X\n"); | |
3868 | } else | |
3869 | r = sprintf(buf, "%lu\n", tr->data[info->cpu]->entries >> 10); | |
3870 | ||
db526ca3 SR |
3871 | mutex_unlock(&trace_types_lock); |
3872 | ||
438ced17 VN |
3873 | ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
3874 | return ret; | |
a98a3c3f SR |
3875 | } |
3876 | ||
3877 | static ssize_t | |
3878 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
3879 | size_t cnt, loff_t *ppos) | |
3880 | { | |
438ced17 | 3881 | struct ftrace_entries_info *info = filp->private_data; |
a98a3c3f | 3882 | unsigned long val; |
4f271a2a | 3883 | int ret; |
a98a3c3f | 3884 | |
22fe9b54 PH |
3885 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
3886 | if (ret) | |
c6caeeb1 | 3887 | return ret; |
a98a3c3f SR |
3888 | |
3889 | /* must have at least 1 entry */ | |
3890 | if (!val) | |
3891 | return -EINVAL; | |
3892 | ||
1696b2b0 SR |
3893 | /* value is in KB */ |
3894 | val <<= 10; | |
3895 | ||
438ced17 | 3896 | ret = tracing_resize_ring_buffer(val, info->cpu); |
4f271a2a VN |
3897 | if (ret < 0) |
3898 | return ret; | |
a98a3c3f | 3899 | |
cf8517cf | 3900 | *ppos += cnt; |
a98a3c3f | 3901 | |
4f271a2a VN |
3902 | return cnt; |
3903 | } | |
bf5e6519 | 3904 | |
438ced17 VN |
3905 | static int |
3906 | tracing_entries_release(struct inode *inode, struct file *filp) | |
3907 | { | |
3908 | struct ftrace_entries_info *info = filp->private_data; | |
3909 | ||
3910 | kfree(info); | |
3911 | ||
3912 | return 0; | |
3913 | } | |
3914 | ||
f81ab074 VN |
3915 | static ssize_t |
3916 | tracing_total_entries_read(struct file *filp, char __user *ubuf, | |
3917 | size_t cnt, loff_t *ppos) | |
3918 | { | |
3919 | struct trace_array *tr = filp->private_data; | |
3920 | char buf[64]; | |
3921 | int r, cpu; | |
3922 | unsigned long size = 0, expanded_size = 0; | |
3923 | ||
3924 | mutex_lock(&trace_types_lock); | |
3925 | for_each_tracing_cpu(cpu) { | |
438ced17 | 3926 | size += tr->data[cpu]->entries >> 10; |
f81ab074 VN |
3927 | if (!ring_buffer_expanded) |
3928 | expanded_size += trace_buf_size >> 10; | |
3929 | } | |
3930 | if (ring_buffer_expanded) | |
3931 | r = sprintf(buf, "%lu\n", size); | |
3932 | else | |
3933 | r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); | |
3934 | mutex_unlock(&trace_types_lock); | |
3935 | ||
3936 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3937 | } | |
3938 | ||
4f271a2a VN |
3939 | static ssize_t |
3940 | tracing_free_buffer_write(struct file *filp, const char __user *ubuf, | |
3941 | size_t cnt, loff_t *ppos) | |
3942 | { | |
3943 | /* | |
3944 | * There is no need to read what the user has written, this function | |
3945 | * is just to make sure that there is no error when "echo" is used | |
3946 | */ | |
3947 | ||
3948 | *ppos += cnt; | |
a98a3c3f SR |
3949 | |
3950 | return cnt; | |
3951 | } | |
3952 | ||
4f271a2a VN |
3953 | static int |
3954 | tracing_free_buffer_release(struct inode *inode, struct file *filp) | |
3955 | { | |
cf30cf67 SR |
3956 | /* disable tracing ? */ |
3957 | if (trace_flags & TRACE_ITER_STOP_ON_FREE) | |
3958 | tracing_off(); | |
4f271a2a | 3959 | /* resize the ring buffer to 0 */ |
438ced17 | 3960 | tracing_resize_ring_buffer(0, RING_BUFFER_ALL_CPUS); |
4f271a2a VN |
3961 | |
3962 | return 0; | |
3963 | } | |
3964 | ||
5bf9a1ee PP |
3965 | static ssize_t |
3966 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
3967 | size_t cnt, loff_t *fpos) | |
3968 | { | |
d696b58c SR |
3969 | unsigned long addr = (unsigned long)ubuf; |
3970 | struct ring_buffer_event *event; | |
3971 | struct ring_buffer *buffer; | |
3972 | struct print_entry *entry; | |
3973 | unsigned long irq_flags; | |
3974 | struct page *pages[2]; | |
6edb2a8a | 3975 | void *map_page[2]; |
d696b58c SR |
3976 | int nr_pages = 1; |
3977 | ssize_t written; | |
d696b58c SR |
3978 | int offset; |
3979 | int size; | |
3980 | int len; | |
3981 | int ret; | |
6edb2a8a | 3982 | int i; |
5bf9a1ee | 3983 | |
c76f0694 | 3984 | if (tracing_disabled) |
5bf9a1ee PP |
3985 | return -EINVAL; |
3986 | ||
5224c3a3 MSB |
3987 | if (!(trace_flags & TRACE_ITER_MARKERS)) |
3988 | return -EINVAL; | |
3989 | ||
5bf9a1ee PP |
3990 | if (cnt > TRACE_BUF_SIZE) |
3991 | cnt = TRACE_BUF_SIZE; | |
3992 | ||
d696b58c SR |
3993 | /* |
3994 | * Userspace is injecting traces into the kernel trace buffer. | |
3995 | * We want to be as non intrusive as possible. | |
3996 | * To do so, we do not want to allocate any special buffers | |
3997 | * or take any locks, but instead write the userspace data | |
3998 | * straight into the ring buffer. | |
3999 | * | |
4000 | * First we need to pin the userspace buffer into memory, | |
4001 | * which, most likely it is, because it just referenced it. | |
4002 | * But there's no guarantee that it is. By using get_user_pages_fast() | |
4003 | * and kmap_atomic/kunmap_atomic() we can get access to the | |
4004 | * pages directly. We then write the data directly into the | |
4005 | * ring buffer. | |
4006 | */ | |
4007 | BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); | |
5bf9a1ee | 4008 | |
d696b58c SR |
4009 | /* check if we cross pages */ |
4010 | if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) | |
4011 | nr_pages = 2; | |
4012 | ||
4013 | offset = addr & (PAGE_SIZE - 1); | |
4014 | addr &= PAGE_MASK; | |
4015 | ||
4016 | ret = get_user_pages_fast(addr, nr_pages, 0, pages); | |
4017 | if (ret < nr_pages) { | |
4018 | while (--ret >= 0) | |
4019 | put_page(pages[ret]); | |
4020 | written = -EFAULT; | |
4021 | goto out; | |
5bf9a1ee | 4022 | } |
d696b58c | 4023 | |
6edb2a8a SR |
4024 | for (i = 0; i < nr_pages; i++) |
4025 | map_page[i] = kmap_atomic(pages[i]); | |
d696b58c SR |
4026 | |
4027 | local_save_flags(irq_flags); | |
4028 | size = sizeof(*entry) + cnt + 2; /* possible \n added */ | |
4029 | buffer = global_trace.buffer; | |
4030 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
4031 | irq_flags, preempt_count()); | |
4032 | if (!event) { | |
4033 | /* Ring buffer disabled, return as if not open for write */ | |
4034 | written = -EBADF; | |
4035 | goto out_unlock; | |
5bf9a1ee | 4036 | } |
d696b58c SR |
4037 | |
4038 | entry = ring_buffer_event_data(event); | |
4039 | entry->ip = _THIS_IP_; | |
4040 | ||
4041 | if (nr_pages == 2) { | |
4042 | len = PAGE_SIZE - offset; | |
6edb2a8a SR |
4043 | memcpy(&entry->buf, map_page[0] + offset, len); |
4044 | memcpy(&entry->buf[len], map_page[1], cnt - len); | |
c13d2f7c | 4045 | } else |
6edb2a8a | 4046 | memcpy(&entry->buf, map_page[0] + offset, cnt); |
5bf9a1ee | 4047 | |
d696b58c SR |
4048 | if (entry->buf[cnt - 1] != '\n') { |
4049 | entry->buf[cnt] = '\n'; | |
4050 | entry->buf[cnt + 1] = '\0'; | |
4051 | } else | |
4052 | entry->buf[cnt] = '\0'; | |
4053 | ||
7ffbd48d | 4054 | __buffer_unlock_commit(buffer, event); |
5bf9a1ee | 4055 | |
d696b58c | 4056 | written = cnt; |
5bf9a1ee | 4057 | |
d696b58c | 4058 | *fpos += written; |
1aa54bca | 4059 | |
d696b58c | 4060 | out_unlock: |
6edb2a8a SR |
4061 | for (i = 0; i < nr_pages; i++){ |
4062 | kunmap_atomic(map_page[i]); | |
4063 | put_page(pages[i]); | |
4064 | } | |
d696b58c | 4065 | out: |
1aa54bca | 4066 | return written; |
5bf9a1ee PP |
4067 | } |
4068 | ||
13f16d20 | 4069 | static int tracing_clock_show(struct seq_file *m, void *v) |
5079f326 | 4070 | { |
5079f326 Z |
4071 | int i; |
4072 | ||
4073 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
13f16d20 | 4074 | seq_printf(m, |
5079f326 Z |
4075 | "%s%s%s%s", i ? " " : "", |
4076 | i == trace_clock_id ? "[" : "", trace_clocks[i].name, | |
4077 | i == trace_clock_id ? "]" : ""); | |
13f16d20 | 4078 | seq_putc(m, '\n'); |
5079f326 | 4079 | |
13f16d20 | 4080 | return 0; |
5079f326 Z |
4081 | } |
4082 | ||
4083 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
4084 | size_t cnt, loff_t *fpos) | |
4085 | { | |
4086 | char buf[64]; | |
4087 | const char *clockstr; | |
4088 | int i; | |
4089 | ||
4090 | if (cnt >= sizeof(buf)) | |
4091 | return -EINVAL; | |
4092 | ||
4093 | if (copy_from_user(&buf, ubuf, cnt)) | |
4094 | return -EFAULT; | |
4095 | ||
4096 | buf[cnt] = 0; | |
4097 | ||
4098 | clockstr = strstrip(buf); | |
4099 | ||
4100 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { | |
4101 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
4102 | break; | |
4103 | } | |
4104 | if (i == ARRAY_SIZE(trace_clocks)) | |
4105 | return -EINVAL; | |
4106 | ||
4107 | trace_clock_id = i; | |
4108 | ||
4109 | mutex_lock(&trace_types_lock); | |
4110 | ||
4111 | ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func); | |
4112 | if (max_tr.buffer) | |
4113 | ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); | |
4114 | ||
60303ed3 DS |
4115 | /* |
4116 | * New clock may not be consistent with the previous clock. | |
4117 | * Reset the buffer so that it doesn't have incomparable timestamps. | |
4118 | */ | |
4119 | tracing_reset_online_cpus(&global_trace); | |
84c6cf0d | 4120 | tracing_reset_online_cpus(&max_tr); |
60303ed3 | 4121 | |
5079f326 Z |
4122 | mutex_unlock(&trace_types_lock); |
4123 | ||
4124 | *fpos += cnt; | |
4125 | ||
4126 | return cnt; | |
4127 | } | |
4128 | ||
13f16d20 LZ |
4129 | static int tracing_clock_open(struct inode *inode, struct file *file) |
4130 | { | |
4131 | if (tracing_disabled) | |
4132 | return -ENODEV; | |
4133 | return single_open(file, tracing_clock_show, NULL); | |
4134 | } | |
4135 | ||
debdd57f HT |
4136 | #ifdef CONFIG_TRACER_SNAPSHOT |
4137 | static int tracing_snapshot_open(struct inode *inode, struct file *file) | |
4138 | { | |
4139 | struct trace_iterator *iter; | |
4140 | int ret = 0; | |
4141 | ||
4142 | if (file->f_mode & FMODE_READ) { | |
4143 | iter = __tracing_open(inode, file, true); | |
4144 | if (IS_ERR(iter)) | |
4145 | ret = PTR_ERR(iter); | |
4146 | } | |
4147 | return ret; | |
4148 | } | |
4149 | ||
4150 | static ssize_t | |
4151 | tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4152 | loff_t *ppos) | |
4153 | { | |
4154 | unsigned long val; | |
4155 | int ret; | |
4156 | ||
4157 | ret = tracing_update_buffers(); | |
4158 | if (ret < 0) | |
4159 | return ret; | |
4160 | ||
4161 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
4162 | if (ret) | |
4163 | return ret; | |
4164 | ||
4165 | mutex_lock(&trace_types_lock); | |
4166 | ||
d840f718 | 4167 | if (current_trace->use_max_tr) { |
debdd57f HT |
4168 | ret = -EBUSY; |
4169 | goto out; | |
4170 | } | |
4171 | ||
4172 | switch (val) { | |
4173 | case 0: | |
4174 | if (current_trace->allocated_snapshot) { | |
4175 | /* free spare buffer */ | |
4176 | ring_buffer_resize(max_tr.buffer, 1, | |
4177 | RING_BUFFER_ALL_CPUS); | |
4178 | set_buffer_entries(&max_tr, 1); | |
4179 | tracing_reset_online_cpus(&max_tr); | |
4180 | current_trace->allocated_snapshot = false; | |
4181 | } | |
4182 | break; | |
4183 | case 1: | |
4184 | if (!current_trace->allocated_snapshot) { | |
4185 | /* allocate spare buffer */ | |
4186 | ret = resize_buffer_duplicate_size(&max_tr, | |
4187 | &global_trace, RING_BUFFER_ALL_CPUS); | |
4188 | if (ret < 0) | |
4189 | break; | |
4190 | current_trace->allocated_snapshot = true; | |
4191 | } | |
4192 | ||
4193 | local_irq_disable(); | |
4194 | /* Now, we're going to swap */ | |
4195 | update_max_tr(&global_trace, current, smp_processor_id()); | |
4196 | local_irq_enable(); | |
4197 | break; | |
4198 | default: | |
4199 | if (current_trace->allocated_snapshot) | |
4200 | tracing_reset_online_cpus(&max_tr); | |
debdd57f HT |
4201 | break; |
4202 | } | |
4203 | ||
4204 | if (ret >= 0) { | |
4205 | *ppos += cnt; | |
4206 | ret = cnt; | |
4207 | } | |
4208 | out: | |
4209 | mutex_unlock(&trace_types_lock); | |
4210 | return ret; | |
4211 | } | |
4212 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
4213 | ||
4214 | ||
5e2336a0 | 4215 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
4216 | .open = tracing_open_generic, |
4217 | .read = tracing_max_lat_read, | |
4218 | .write = tracing_max_lat_write, | |
b444786f | 4219 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
4220 | }; |
4221 | ||
5e2336a0 | 4222 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
4223 | .open = tracing_open_generic, |
4224 | .read = tracing_set_trace_read, | |
4225 | .write = tracing_set_trace_write, | |
b444786f | 4226 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
4227 | }; |
4228 | ||
5e2336a0 | 4229 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 4230 | .open = tracing_open_pipe, |
2a2cc8f7 | 4231 | .poll = tracing_poll_pipe, |
4bf39a94 | 4232 | .read = tracing_read_pipe, |
3c56819b | 4233 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 4234 | .release = tracing_release_pipe, |
b444786f | 4235 | .llseek = no_llseek, |
b3806b43 SR |
4236 | }; |
4237 | ||
5e2336a0 | 4238 | static const struct file_operations tracing_entries_fops = { |
438ced17 | 4239 | .open = tracing_entries_open, |
a98a3c3f SR |
4240 | .read = tracing_entries_read, |
4241 | .write = tracing_entries_write, | |
438ced17 | 4242 | .release = tracing_entries_release, |
b444786f | 4243 | .llseek = generic_file_llseek, |
a98a3c3f SR |
4244 | }; |
4245 | ||
f81ab074 VN |
4246 | static const struct file_operations tracing_total_entries_fops = { |
4247 | .open = tracing_open_generic, | |
4248 | .read = tracing_total_entries_read, | |
4249 | .llseek = generic_file_llseek, | |
4250 | }; | |
4251 | ||
4f271a2a VN |
4252 | static const struct file_operations tracing_free_buffer_fops = { |
4253 | .write = tracing_free_buffer_write, | |
4254 | .release = tracing_free_buffer_release, | |
4255 | }; | |
4256 | ||
5e2336a0 | 4257 | static const struct file_operations tracing_mark_fops = { |
43a15386 | 4258 | .open = tracing_open_generic, |
5bf9a1ee | 4259 | .write = tracing_mark_write, |
b444786f | 4260 | .llseek = generic_file_llseek, |
5bf9a1ee PP |
4261 | }; |
4262 | ||
5079f326 | 4263 | static const struct file_operations trace_clock_fops = { |
13f16d20 LZ |
4264 | .open = tracing_clock_open, |
4265 | .read = seq_read, | |
4266 | .llseek = seq_lseek, | |
4267 | .release = single_release, | |
5079f326 Z |
4268 | .write = tracing_clock_write, |
4269 | }; | |
4270 | ||
debdd57f HT |
4271 | #ifdef CONFIG_TRACER_SNAPSHOT |
4272 | static const struct file_operations snapshot_fops = { | |
4273 | .open = tracing_snapshot_open, | |
4274 | .read = seq_read, | |
4275 | .write = tracing_snapshot_write, | |
4276 | .llseek = tracing_seek, | |
4277 | .release = tracing_release, | |
4278 | }; | |
4279 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
4280 | ||
2cadf913 SR |
4281 | struct ftrace_buffer_info { |
4282 | struct trace_array *tr; | |
4283 | void *spare; | |
4284 | int cpu; | |
4285 | unsigned int read; | |
4286 | }; | |
4287 | ||
4288 | static int tracing_buffers_open(struct inode *inode, struct file *filp) | |
4289 | { | |
4290 | int cpu = (int)(long)inode->i_private; | |
4291 | struct ftrace_buffer_info *info; | |
4292 | ||
4293 | if (tracing_disabled) | |
4294 | return -ENODEV; | |
4295 | ||
4296 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
4297 | if (!info) | |
4298 | return -ENOMEM; | |
4299 | ||
4300 | info->tr = &global_trace; | |
4301 | info->cpu = cpu; | |
ddd538f3 | 4302 | info->spare = NULL; |
2cadf913 SR |
4303 | /* Force reading ring buffer for first read */ |
4304 | info->read = (unsigned int)-1; | |
2cadf913 SR |
4305 | |
4306 | filp->private_data = info; | |
4307 | ||
d1e7e02f | 4308 | return nonseekable_open(inode, filp); |
2cadf913 SR |
4309 | } |
4310 | ||
4311 | static ssize_t | |
4312 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
4313 | size_t count, loff_t *ppos) | |
4314 | { | |
4315 | struct ftrace_buffer_info *info = filp->private_data; | |
2cadf913 SR |
4316 | ssize_t ret; |
4317 | size_t size; | |
4318 | ||
2dc5d12b SR |
4319 | if (!count) |
4320 | return 0; | |
4321 | ||
ddd538f3 | 4322 | if (!info->spare) |
7ea59064 | 4323 | info->spare = ring_buffer_alloc_read_page(info->tr->buffer, info->cpu); |
ddd538f3 LJ |
4324 | if (!info->spare) |
4325 | return -ENOMEM; | |
4326 | ||
2cadf913 SR |
4327 | /* Do we have previous read data to read? */ |
4328 | if (info->read < PAGE_SIZE) | |
4329 | goto read; | |
4330 | ||
7e53bd42 | 4331 | trace_access_lock(info->cpu); |
2cadf913 SR |
4332 | ret = ring_buffer_read_page(info->tr->buffer, |
4333 | &info->spare, | |
4334 | count, | |
4335 | info->cpu, 0); | |
7e53bd42 | 4336 | trace_access_unlock(info->cpu); |
2cadf913 SR |
4337 | if (ret < 0) |
4338 | return 0; | |
4339 | ||
436fc280 SR |
4340 | info->read = 0; |
4341 | ||
2cadf913 SR |
4342 | read: |
4343 | size = PAGE_SIZE - info->read; | |
4344 | if (size > count) | |
4345 | size = count; | |
4346 | ||
4347 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
2dc5d12b | 4348 | if (ret == size) |
2cadf913 | 4349 | return -EFAULT; |
2dc5d12b SR |
4350 | size -= ret; |
4351 | ||
2cadf913 SR |
4352 | *ppos += size; |
4353 | info->read += size; | |
4354 | ||
4355 | return size; | |
4356 | } | |
4357 | ||
4358 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
4359 | { | |
4360 | struct ftrace_buffer_info *info = file->private_data; | |
4361 | ||
ddd538f3 LJ |
4362 | if (info->spare) |
4363 | ring_buffer_free_read_page(info->tr->buffer, info->spare); | |
2cadf913 SR |
4364 | kfree(info); |
4365 | ||
4366 | return 0; | |
4367 | } | |
4368 | ||
4369 | struct buffer_ref { | |
4370 | struct ring_buffer *buffer; | |
4371 | void *page; | |
4372 | int ref; | |
4373 | }; | |
4374 | ||
4375 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
4376 | struct pipe_buffer *buf) | |
4377 | { | |
4378 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
4379 | ||
4380 | if (--ref->ref) | |
4381 | return; | |
4382 | ||
4383 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
4384 | kfree(ref); | |
4385 | buf->private = 0; | |
4386 | } | |
4387 | ||
2cadf913 SR |
4388 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, |
4389 | struct pipe_buffer *buf) | |
4390 | { | |
4391 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
4392 | ||
4393 | ref->ref++; | |
4394 | } | |
4395 | ||
4396 | /* Pipe buffer operations for a buffer. */ | |
28dfef8f | 4397 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
2cadf913 SR |
4398 | .can_merge = 0, |
4399 | .map = generic_pipe_buf_map, | |
4400 | .unmap = generic_pipe_buf_unmap, | |
4401 | .confirm = generic_pipe_buf_confirm, | |
4402 | .release = buffer_pipe_buf_release, | |
d55cb6cf | 4403 | .steal = generic_pipe_buf_steal, |
2cadf913 SR |
4404 | .get = buffer_pipe_buf_get, |
4405 | }; | |
4406 | ||
4407 | /* | |
4408 | * Callback from splice_to_pipe(), if we need to release some pages | |
4409 | * at the end of the spd in case we error'ed out in filling the pipe. | |
4410 | */ | |
4411 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
4412 | { | |
4413 | struct buffer_ref *ref = | |
4414 | (struct buffer_ref *)spd->partial[i].private; | |
4415 | ||
4416 | if (--ref->ref) | |
4417 | return; | |
4418 | ||
4419 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
4420 | kfree(ref); | |
4421 | spd->partial[i].private = 0; | |
4422 | } | |
4423 | ||
4424 | static ssize_t | |
4425 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
4426 | struct pipe_inode_info *pipe, size_t len, | |
4427 | unsigned int flags) | |
4428 | { | |
4429 | struct ftrace_buffer_info *info = file->private_data; | |
35f3d14d JA |
4430 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
4431 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
2cadf913 | 4432 | struct splice_pipe_desc spd = { |
35f3d14d JA |
4433 | .pages = pages_def, |
4434 | .partial = partial_def, | |
047fe360 | 4435 | .nr_pages_max = PIPE_DEF_BUFFERS, |
2cadf913 SR |
4436 | .flags = flags, |
4437 | .ops = &buffer_pipe_buf_ops, | |
4438 | .spd_release = buffer_spd_release, | |
4439 | }; | |
4440 | struct buffer_ref *ref; | |
93459c6c | 4441 | int entries, size, i; |
2cadf913 SR |
4442 | size_t ret; |
4443 | ||
35f3d14d JA |
4444 | if (splice_grow_spd(pipe, &spd)) |
4445 | return -ENOMEM; | |
4446 | ||
93cfb3c9 | 4447 | if (*ppos & (PAGE_SIZE - 1)) { |
35f3d14d JA |
4448 | ret = -EINVAL; |
4449 | goto out; | |
93cfb3c9 LJ |
4450 | } |
4451 | ||
4452 | if (len & (PAGE_SIZE - 1)) { | |
35f3d14d JA |
4453 | if (len < PAGE_SIZE) { |
4454 | ret = -EINVAL; | |
4455 | goto out; | |
4456 | } | |
93cfb3c9 LJ |
4457 | len &= PAGE_MASK; |
4458 | } | |
4459 | ||
7e53bd42 | 4460 | trace_access_lock(info->cpu); |
93459c6c SR |
4461 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); |
4462 | ||
35f3d14d | 4463 | for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { |
2cadf913 SR |
4464 | struct page *page; |
4465 | int r; | |
4466 | ||
4467 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
4468 | if (!ref) | |
4469 | break; | |
4470 | ||
7267fa68 | 4471 | ref->ref = 1; |
2cadf913 | 4472 | ref->buffer = info->tr->buffer; |
7ea59064 | 4473 | ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu); |
2cadf913 SR |
4474 | if (!ref->page) { |
4475 | kfree(ref); | |
4476 | break; | |
4477 | } | |
4478 | ||
4479 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
f2957f1f | 4480 | len, info->cpu, 1); |
2cadf913 | 4481 | if (r < 0) { |
7ea59064 | 4482 | ring_buffer_free_read_page(ref->buffer, ref->page); |
2cadf913 SR |
4483 | kfree(ref); |
4484 | break; | |
4485 | } | |
4486 | ||
4487 | /* | |
4488 | * zero out any left over data, this is going to | |
4489 | * user land. | |
4490 | */ | |
4491 | size = ring_buffer_page_len(ref->page); | |
4492 | if (size < PAGE_SIZE) | |
4493 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
4494 | ||
4495 | page = virt_to_page(ref->page); | |
4496 | ||
4497 | spd.pages[i] = page; | |
4498 | spd.partial[i].len = PAGE_SIZE; | |
4499 | spd.partial[i].offset = 0; | |
4500 | spd.partial[i].private = (unsigned long)ref; | |
4501 | spd.nr_pages++; | |
93cfb3c9 | 4502 | *ppos += PAGE_SIZE; |
93459c6c SR |
4503 | |
4504 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); | |
2cadf913 SR |
4505 | } |
4506 | ||
7e53bd42 | 4507 | trace_access_unlock(info->cpu); |
2cadf913 SR |
4508 | spd.nr_pages = i; |
4509 | ||
4510 | /* did we read anything? */ | |
4511 | if (!spd.nr_pages) { | |
4512 | if (flags & SPLICE_F_NONBLOCK) | |
4513 | ret = -EAGAIN; | |
4514 | else | |
4515 | ret = 0; | |
4516 | /* TODO: block */ | |
35f3d14d | 4517 | goto out; |
2cadf913 SR |
4518 | } |
4519 | ||
4520 | ret = splice_to_pipe(pipe, &spd); | |
047fe360 | 4521 | splice_shrink_spd(&spd); |
35f3d14d | 4522 | out: |
2cadf913 SR |
4523 | return ret; |
4524 | } | |
4525 | ||
4526 | static const struct file_operations tracing_buffers_fops = { | |
4527 | .open = tracing_buffers_open, | |
4528 | .read = tracing_buffers_read, | |
4529 | .release = tracing_buffers_release, | |
4530 | .splice_read = tracing_buffers_splice_read, | |
4531 | .llseek = no_llseek, | |
4532 | }; | |
4533 | ||
c8d77183 SR |
4534 | static ssize_t |
4535 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
4536 | size_t count, loff_t *ppos) | |
4537 | { | |
4538 | unsigned long cpu = (unsigned long)filp->private_data; | |
4539 | struct trace_array *tr = &global_trace; | |
4540 | struct trace_seq *s; | |
4541 | unsigned long cnt; | |
c64e148a VN |
4542 | unsigned long long t; |
4543 | unsigned long usec_rem; | |
c8d77183 | 4544 | |
e4f2d10f | 4545 | s = kmalloc(sizeof(*s), GFP_KERNEL); |
c8d77183 | 4546 | if (!s) |
a646365c | 4547 | return -ENOMEM; |
c8d77183 SR |
4548 | |
4549 | trace_seq_init(s); | |
4550 | ||
4551 | cnt = ring_buffer_entries_cpu(tr->buffer, cpu); | |
4552 | trace_seq_printf(s, "entries: %ld\n", cnt); | |
4553 | ||
4554 | cnt = ring_buffer_overrun_cpu(tr->buffer, cpu); | |
4555 | trace_seq_printf(s, "overrun: %ld\n", cnt); | |
4556 | ||
4557 | cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); | |
4558 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); | |
4559 | ||
c64e148a VN |
4560 | cnt = ring_buffer_bytes_cpu(tr->buffer, cpu); |
4561 | trace_seq_printf(s, "bytes: %ld\n", cnt); | |
4562 | ||
11043d8b YY |
4563 | if (trace_clocks[trace_clock_id].in_ns) { |
4564 | /* local or global for trace_clock */ | |
4565 | t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu)); | |
4566 | usec_rem = do_div(t, USEC_PER_SEC); | |
4567 | trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", | |
4568 | t, usec_rem); | |
4569 | ||
4570 | t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu)); | |
4571 | usec_rem = do_div(t, USEC_PER_SEC); | |
4572 | trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); | |
4573 | } else { | |
4574 | /* counter or tsc mode for trace_clock */ | |
4575 | trace_seq_printf(s, "oldest event ts: %llu\n", | |
4576 | ring_buffer_oldest_event_ts(tr->buffer, cpu)); | |
c64e148a | 4577 | |
11043d8b YY |
4578 | trace_seq_printf(s, "now ts: %llu\n", |
4579 | ring_buffer_time_stamp(tr->buffer, cpu)); | |
4580 | } | |
c64e148a | 4581 | |
884bfe89 SP |
4582 | cnt = ring_buffer_dropped_events_cpu(tr->buffer, cpu); |
4583 | trace_seq_printf(s, "dropped events: %ld\n", cnt); | |
4584 | ||
ad964704 SRRH |
4585 | cnt = ring_buffer_read_events_cpu(tr->buffer, cpu); |
4586 | trace_seq_printf(s, "read events: %ld\n", cnt); | |
4587 | ||
c8d77183 SR |
4588 | count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); |
4589 | ||
4590 | kfree(s); | |
4591 | ||
4592 | return count; | |
4593 | } | |
4594 | ||
4595 | static const struct file_operations tracing_stats_fops = { | |
4596 | .open = tracing_open_generic, | |
4597 | .read = tracing_stats_read, | |
b444786f | 4598 | .llseek = generic_file_llseek, |
c8d77183 SR |
4599 | }; |
4600 | ||
bc0c38d1 SR |
4601 | #ifdef CONFIG_DYNAMIC_FTRACE |
4602 | ||
b807c3d0 SR |
4603 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
4604 | { | |
4605 | return 0; | |
4606 | } | |
4607 | ||
bc0c38d1 | 4608 | static ssize_t |
b807c3d0 | 4609 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
4610 | size_t cnt, loff_t *ppos) |
4611 | { | |
a26a2a27 SR |
4612 | static char ftrace_dyn_info_buffer[1024]; |
4613 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 4614 | unsigned long *p = filp->private_data; |
b807c3d0 | 4615 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 4616 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
4617 | int r; |
4618 | ||
b807c3d0 SR |
4619 | mutex_lock(&dyn_info_mutex); |
4620 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 4621 | |
a26a2a27 | 4622 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
4623 | buf[r++] = '\n'; |
4624 | ||
4625 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4626 | ||
4627 | mutex_unlock(&dyn_info_mutex); | |
4628 | ||
4629 | return r; | |
bc0c38d1 SR |
4630 | } |
4631 | ||
5e2336a0 | 4632 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 4633 | .open = tracing_open_generic, |
b807c3d0 | 4634 | .read = tracing_read_dyn_info, |
b444786f | 4635 | .llseek = generic_file_llseek, |
bc0c38d1 SR |
4636 | }; |
4637 | #endif | |
4638 | ||
4639 | static struct dentry *d_tracer; | |
4640 | ||
4641 | struct dentry *tracing_init_dentry(void) | |
4642 | { | |
4643 | static int once; | |
4644 | ||
4645 | if (d_tracer) | |
4646 | return d_tracer; | |
4647 | ||
3e1f60b8 FW |
4648 | if (!debugfs_initialized()) |
4649 | return NULL; | |
4650 | ||
bc0c38d1 SR |
4651 | d_tracer = debugfs_create_dir("tracing", NULL); |
4652 | ||
4653 | if (!d_tracer && !once) { | |
4654 | once = 1; | |
4655 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
4656 | return NULL; | |
4657 | } | |
4658 | ||
4659 | return d_tracer; | |
4660 | } | |
4661 | ||
b04cc6b1 FW |
4662 | static struct dentry *d_percpu; |
4663 | ||
b736f48b | 4664 | static struct dentry *tracing_dentry_percpu(void) |
b04cc6b1 FW |
4665 | { |
4666 | static int once; | |
4667 | struct dentry *d_tracer; | |
4668 | ||
4669 | if (d_percpu) | |
4670 | return d_percpu; | |
4671 | ||
4672 | d_tracer = tracing_init_dentry(); | |
4673 | ||
4674 | if (!d_tracer) | |
4675 | return NULL; | |
4676 | ||
4677 | d_percpu = debugfs_create_dir("per_cpu", d_tracer); | |
4678 | ||
4679 | if (!d_percpu && !once) { | |
4680 | once = 1; | |
4681 | pr_warning("Could not create debugfs directory 'per_cpu'\n"); | |
4682 | return NULL; | |
4683 | } | |
4684 | ||
4685 | return d_percpu; | |
4686 | } | |
4687 | ||
4688 | static void tracing_init_debugfs_percpu(long cpu) | |
4689 | { | |
4690 | struct dentry *d_percpu = tracing_dentry_percpu(); | |
5452af66 | 4691 | struct dentry *d_cpu; |
dd49a38c | 4692 | char cpu_dir[30]; /* 30 characters should be more than enough */ |
b04cc6b1 | 4693 | |
0a3d7ce7 NK |
4694 | if (!d_percpu) |
4695 | return; | |
4696 | ||
dd49a38c | 4697 | snprintf(cpu_dir, 30, "cpu%ld", cpu); |
8656e7a2 FW |
4698 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); |
4699 | if (!d_cpu) { | |
4700 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
4701 | return; | |
4702 | } | |
b04cc6b1 | 4703 | |
8656e7a2 | 4704 | /* per cpu trace_pipe */ |
5452af66 FW |
4705 | trace_create_file("trace_pipe", 0444, d_cpu, |
4706 | (void *) cpu, &tracing_pipe_fops); | |
b04cc6b1 FW |
4707 | |
4708 | /* per cpu trace */ | |
5452af66 FW |
4709 | trace_create_file("trace", 0644, d_cpu, |
4710 | (void *) cpu, &tracing_fops); | |
7f96f93f | 4711 | |
5452af66 FW |
4712 | trace_create_file("trace_pipe_raw", 0444, d_cpu, |
4713 | (void *) cpu, &tracing_buffers_fops); | |
7f96f93f | 4714 | |
c8d77183 SR |
4715 | trace_create_file("stats", 0444, d_cpu, |
4716 | (void *) cpu, &tracing_stats_fops); | |
438ced17 VN |
4717 | |
4718 | trace_create_file("buffer_size_kb", 0444, d_cpu, | |
4719 | (void *) cpu, &tracing_entries_fops); | |
b04cc6b1 FW |
4720 | } |
4721 | ||
60a11774 SR |
4722 | #ifdef CONFIG_FTRACE_SELFTEST |
4723 | /* Let selftest have access to static functions in this file */ | |
4724 | #include "trace_selftest.c" | |
4725 | #endif | |
4726 | ||
577b785f SR |
4727 | struct trace_option_dentry { |
4728 | struct tracer_opt *opt; | |
4729 | struct tracer_flags *flags; | |
4730 | struct dentry *entry; | |
4731 | }; | |
4732 | ||
4733 | static ssize_t | |
4734 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4735 | loff_t *ppos) | |
4736 | { | |
4737 | struct trace_option_dentry *topt = filp->private_data; | |
4738 | char *buf; | |
4739 | ||
4740 | if (topt->flags->val & topt->opt->bit) | |
4741 | buf = "1\n"; | |
4742 | else | |
4743 | buf = "0\n"; | |
4744 | ||
4745 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4746 | } | |
4747 | ||
4748 | static ssize_t | |
4749 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4750 | loff_t *ppos) | |
4751 | { | |
4752 | struct trace_option_dentry *topt = filp->private_data; | |
4753 | unsigned long val; | |
577b785f SR |
4754 | int ret; |
4755 | ||
22fe9b54 PH |
4756 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4757 | if (ret) | |
577b785f SR |
4758 | return ret; |
4759 | ||
8d18eaaf LZ |
4760 | if (val != 0 && val != 1) |
4761 | return -EINVAL; | |
577b785f | 4762 | |
8d18eaaf | 4763 | if (!!(topt->flags->val & topt->opt->bit) != val) { |
577b785f | 4764 | mutex_lock(&trace_types_lock); |
8d18eaaf | 4765 | ret = __set_tracer_option(current_trace, topt->flags, |
c757bea9 | 4766 | topt->opt, !val); |
577b785f SR |
4767 | mutex_unlock(&trace_types_lock); |
4768 | if (ret) | |
4769 | return ret; | |
577b785f SR |
4770 | } |
4771 | ||
4772 | *ppos += cnt; | |
4773 | ||
4774 | return cnt; | |
4775 | } | |
4776 | ||
4777 | ||
4778 | static const struct file_operations trace_options_fops = { | |
4779 | .open = tracing_open_generic, | |
4780 | .read = trace_options_read, | |
4781 | .write = trace_options_write, | |
b444786f | 4782 | .llseek = generic_file_llseek, |
577b785f SR |
4783 | }; |
4784 | ||
a8259075 SR |
4785 | static ssize_t |
4786 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4787 | loff_t *ppos) | |
4788 | { | |
4789 | long index = (long)filp->private_data; | |
4790 | char *buf; | |
4791 | ||
4792 | if (trace_flags & (1 << index)) | |
4793 | buf = "1\n"; | |
4794 | else | |
4795 | buf = "0\n"; | |
4796 | ||
4797 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4798 | } | |
4799 | ||
4800 | static ssize_t | |
4801 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4802 | loff_t *ppos) | |
4803 | { | |
4804 | long index = (long)filp->private_data; | |
a8259075 SR |
4805 | unsigned long val; |
4806 | int ret; | |
4807 | ||
22fe9b54 PH |
4808 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
4809 | if (ret) | |
a8259075 SR |
4810 | return ret; |
4811 | ||
f2d84b65 | 4812 | if (val != 0 && val != 1) |
a8259075 | 4813 | return -EINVAL; |
69d34da2 SRRH |
4814 | |
4815 | mutex_lock(&trace_types_lock); | |
613f04a0 | 4816 | ret = set_tracer_flag(1 << index, val); |
69d34da2 | 4817 | mutex_unlock(&trace_types_lock); |
a8259075 | 4818 | |
613f04a0 SRRH |
4819 | if (ret < 0) |
4820 | return ret; | |
4821 | ||
a8259075 SR |
4822 | *ppos += cnt; |
4823 | ||
4824 | return cnt; | |
4825 | } | |
4826 | ||
a8259075 SR |
4827 | static const struct file_operations trace_options_core_fops = { |
4828 | .open = tracing_open_generic, | |
4829 | .read = trace_options_core_read, | |
4830 | .write = trace_options_core_write, | |
b444786f | 4831 | .llseek = generic_file_llseek, |
a8259075 SR |
4832 | }; |
4833 | ||
5452af66 | 4834 | struct dentry *trace_create_file(const char *name, |
f4ae40a6 | 4835 | umode_t mode, |
5452af66 FW |
4836 | struct dentry *parent, |
4837 | void *data, | |
4838 | const struct file_operations *fops) | |
4839 | { | |
4840 | struct dentry *ret; | |
4841 | ||
4842 | ret = debugfs_create_file(name, mode, parent, data, fops); | |
4843 | if (!ret) | |
4844 | pr_warning("Could not create debugfs '%s' entry\n", name); | |
4845 | ||
4846 | return ret; | |
4847 | } | |
4848 | ||
4849 | ||
a8259075 SR |
4850 | static struct dentry *trace_options_init_dentry(void) |
4851 | { | |
4852 | struct dentry *d_tracer; | |
4853 | static struct dentry *t_options; | |
4854 | ||
4855 | if (t_options) | |
4856 | return t_options; | |
4857 | ||
4858 | d_tracer = tracing_init_dentry(); | |
4859 | if (!d_tracer) | |
4860 | return NULL; | |
4861 | ||
4862 | t_options = debugfs_create_dir("options", d_tracer); | |
4863 | if (!t_options) { | |
4864 | pr_warning("Could not create debugfs directory 'options'\n"); | |
4865 | return NULL; | |
4866 | } | |
4867 | ||
4868 | return t_options; | |
4869 | } | |
4870 | ||
577b785f SR |
4871 | static void |
4872 | create_trace_option_file(struct trace_option_dentry *topt, | |
4873 | struct tracer_flags *flags, | |
4874 | struct tracer_opt *opt) | |
4875 | { | |
4876 | struct dentry *t_options; | |
577b785f SR |
4877 | |
4878 | t_options = trace_options_init_dentry(); | |
4879 | if (!t_options) | |
4880 | return; | |
4881 | ||
4882 | topt->flags = flags; | |
4883 | topt->opt = opt; | |
4884 | ||
5452af66 | 4885 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
577b785f SR |
4886 | &trace_options_fops); |
4887 | ||
577b785f SR |
4888 | } |
4889 | ||
4890 | static struct trace_option_dentry * | |
4891 | create_trace_option_files(struct tracer *tracer) | |
4892 | { | |
4893 | struct trace_option_dentry *topts; | |
4894 | struct tracer_flags *flags; | |
4895 | struct tracer_opt *opts; | |
4896 | int cnt; | |
4897 | ||
4898 | if (!tracer) | |
4899 | return NULL; | |
4900 | ||
4901 | flags = tracer->flags; | |
4902 | ||
4903 | if (!flags || !flags->opts) | |
4904 | return NULL; | |
4905 | ||
4906 | opts = flags->opts; | |
4907 | ||
4908 | for (cnt = 0; opts[cnt].name; cnt++) | |
4909 | ; | |
4910 | ||
0cfe8245 | 4911 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f SR |
4912 | if (!topts) |
4913 | return NULL; | |
4914 | ||
4915 | for (cnt = 0; opts[cnt].name; cnt++) | |
4916 | create_trace_option_file(&topts[cnt], flags, | |
4917 | &opts[cnt]); | |
4918 | ||
4919 | return topts; | |
4920 | } | |
4921 | ||
4922 | static void | |
4923 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
4924 | { | |
4925 | int cnt; | |
4926 | ||
4927 | if (!topts) | |
4928 | return; | |
4929 | ||
4930 | for (cnt = 0; topts[cnt].opt; cnt++) { | |
4931 | if (topts[cnt].entry) | |
4932 | debugfs_remove(topts[cnt].entry); | |
4933 | } | |
4934 | ||
4935 | kfree(topts); | |
4936 | } | |
4937 | ||
a8259075 SR |
4938 | static struct dentry * |
4939 | create_trace_option_core_file(const char *option, long index) | |
4940 | { | |
4941 | struct dentry *t_options; | |
a8259075 SR |
4942 | |
4943 | t_options = trace_options_init_dentry(); | |
4944 | if (!t_options) | |
4945 | return NULL; | |
4946 | ||
5452af66 | 4947 | return trace_create_file(option, 0644, t_options, (void *)index, |
a8259075 | 4948 | &trace_options_core_fops); |
a8259075 SR |
4949 | } |
4950 | ||
4951 | static __init void create_trace_options_dir(void) | |
4952 | { | |
4953 | struct dentry *t_options; | |
a8259075 SR |
4954 | int i; |
4955 | ||
4956 | t_options = trace_options_init_dentry(); | |
4957 | if (!t_options) | |
4958 | return; | |
4959 | ||
5452af66 FW |
4960 | for (i = 0; trace_options[i]; i++) |
4961 | create_trace_option_core_file(trace_options[i], i); | |
a8259075 SR |
4962 | } |
4963 | ||
499e5470 SR |
4964 | static ssize_t |
4965 | rb_simple_read(struct file *filp, char __user *ubuf, | |
4966 | size_t cnt, loff_t *ppos) | |
4967 | { | |
348f0fc2 SR |
4968 | struct trace_array *tr = filp->private_data; |
4969 | struct ring_buffer *buffer = tr->buffer; | |
499e5470 SR |
4970 | char buf[64]; |
4971 | int r; | |
4972 | ||
4973 | if (buffer) | |
4974 | r = ring_buffer_record_is_on(buffer); | |
4975 | else | |
4976 | r = 0; | |
4977 | ||
4978 | r = sprintf(buf, "%d\n", r); | |
4979 | ||
4980 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4981 | } | |
4982 | ||
4983 | static ssize_t | |
4984 | rb_simple_write(struct file *filp, const char __user *ubuf, | |
4985 | size_t cnt, loff_t *ppos) | |
4986 | { | |
348f0fc2 SR |
4987 | struct trace_array *tr = filp->private_data; |
4988 | struct ring_buffer *buffer = tr->buffer; | |
499e5470 SR |
4989 | unsigned long val; |
4990 | int ret; | |
4991 | ||
4992 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
4993 | if (ret) | |
4994 | return ret; | |
4995 | ||
4996 | if (buffer) { | |
2df8f8a6 SR |
4997 | mutex_lock(&trace_types_lock); |
4998 | if (val) { | |
499e5470 | 4999 | ring_buffer_record_on(buffer); |
2df8f8a6 SR |
5000 | if (current_trace->start) |
5001 | current_trace->start(tr); | |
5002 | } else { | |
499e5470 | 5003 | ring_buffer_record_off(buffer); |
2df8f8a6 SR |
5004 | if (current_trace->stop) |
5005 | current_trace->stop(tr); | |
5006 | } | |
5007 | mutex_unlock(&trace_types_lock); | |
499e5470 SR |
5008 | } |
5009 | ||
5010 | (*ppos)++; | |
5011 | ||
5012 | return cnt; | |
5013 | } | |
5014 | ||
5015 | static const struct file_operations rb_simple_fops = { | |
5016 | .open = tracing_open_generic, | |
5017 | .read = rb_simple_read, | |
5018 | .write = rb_simple_write, | |
5019 | .llseek = default_llseek, | |
5020 | }; | |
5021 | ||
b5ad384e | 5022 | static __init int tracer_init_debugfs(void) |
bc0c38d1 SR |
5023 | { |
5024 | struct dentry *d_tracer; | |
b04cc6b1 | 5025 | int cpu; |
bc0c38d1 | 5026 | |
7e53bd42 LJ |
5027 | trace_access_lock_init(); |
5028 | ||
bc0c38d1 SR |
5029 | d_tracer = tracing_init_dentry(); |
5030 | ||
5452af66 FW |
5031 | trace_create_file("trace_options", 0644, d_tracer, |
5032 | NULL, &tracing_iter_fops); | |
bc0c38d1 | 5033 | |
5452af66 FW |
5034 | trace_create_file("tracing_cpumask", 0644, d_tracer, |
5035 | NULL, &tracing_cpumask_fops); | |
5036 | ||
5037 | trace_create_file("trace", 0644, d_tracer, | |
5038 | (void *) TRACE_PIPE_ALL_CPU, &tracing_fops); | |
a8259075 | 5039 | |
5452af66 FW |
5040 | trace_create_file("available_tracers", 0444, d_tracer, |
5041 | &global_trace, &show_traces_fops); | |
5042 | ||
339ae5d3 | 5043 | trace_create_file("current_tracer", 0644, d_tracer, |
5452af66 FW |
5044 | &global_trace, &set_tracer_fops); |
5045 | ||
5d4a9dba | 5046 | #ifdef CONFIG_TRACER_MAX_TRACE |
5452af66 FW |
5047 | trace_create_file("tracing_max_latency", 0644, d_tracer, |
5048 | &tracing_max_latency, &tracing_max_lat_fops); | |
0e950173 | 5049 | #endif |
5452af66 FW |
5050 | |
5051 | trace_create_file("tracing_thresh", 0644, d_tracer, | |
5052 | &tracing_thresh, &tracing_max_lat_fops); | |
a8259075 | 5053 | |
339ae5d3 | 5054 | trace_create_file("README", 0444, d_tracer, |
5452af66 FW |
5055 | NULL, &tracing_readme_fops); |
5056 | ||
5057 | trace_create_file("trace_pipe", 0444, d_tracer, | |
b04cc6b1 | 5058 | (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); |
5452af66 FW |
5059 | |
5060 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
438ced17 | 5061 | (void *) RING_BUFFER_ALL_CPUS, &tracing_entries_fops); |
5452af66 | 5062 | |
f81ab074 VN |
5063 | trace_create_file("buffer_total_size_kb", 0444, d_tracer, |
5064 | &global_trace, &tracing_total_entries_fops); | |
5065 | ||
4f271a2a VN |
5066 | trace_create_file("free_buffer", 0644, d_tracer, |
5067 | &global_trace, &tracing_free_buffer_fops); | |
5068 | ||
5452af66 FW |
5069 | trace_create_file("trace_marker", 0220, d_tracer, |
5070 | NULL, &tracing_mark_fops); | |
5bf9a1ee | 5071 | |
69abe6a5 AP |
5072 | trace_create_file("saved_cmdlines", 0444, d_tracer, |
5073 | NULL, &tracing_saved_cmdlines_fops); | |
5bf9a1ee | 5074 | |
5079f326 Z |
5075 | trace_create_file("trace_clock", 0644, d_tracer, NULL, |
5076 | &trace_clock_fops); | |
5077 | ||
499e5470 | 5078 | trace_create_file("tracing_on", 0644, d_tracer, |
348f0fc2 | 5079 | &global_trace, &rb_simple_fops); |
499e5470 | 5080 | |
bc0c38d1 | 5081 | #ifdef CONFIG_DYNAMIC_FTRACE |
5452af66 FW |
5082 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
5083 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
bc0c38d1 | 5084 | #endif |
b04cc6b1 | 5085 | |
debdd57f HT |
5086 | #ifdef CONFIG_TRACER_SNAPSHOT |
5087 | trace_create_file("snapshot", 0644, d_tracer, | |
5088 | (void *) TRACE_PIPE_ALL_CPU, &snapshot_fops); | |
5089 | #endif | |
5090 | ||
5452af66 FW |
5091 | create_trace_options_dir(); |
5092 | ||
b04cc6b1 FW |
5093 | for_each_tracing_cpu(cpu) |
5094 | tracing_init_debugfs_percpu(cpu); | |
5095 | ||
b5ad384e | 5096 | return 0; |
bc0c38d1 SR |
5097 | } |
5098 | ||
3f5a54e3 SR |
5099 | static int trace_panic_handler(struct notifier_block *this, |
5100 | unsigned long event, void *unused) | |
5101 | { | |
944ac425 | 5102 | if (ftrace_dump_on_oops) |
cecbca96 | 5103 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
5104 | return NOTIFY_OK; |
5105 | } | |
5106 | ||
5107 | static struct notifier_block trace_panic_notifier = { | |
5108 | .notifier_call = trace_panic_handler, | |
5109 | .next = NULL, | |
5110 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
5111 | }; | |
5112 | ||
5113 | static int trace_die_handler(struct notifier_block *self, | |
5114 | unsigned long val, | |
5115 | void *data) | |
5116 | { | |
5117 | switch (val) { | |
5118 | case DIE_OOPS: | |
944ac425 | 5119 | if (ftrace_dump_on_oops) |
cecbca96 | 5120 | ftrace_dump(ftrace_dump_on_oops); |
3f5a54e3 SR |
5121 | break; |
5122 | default: | |
5123 | break; | |
5124 | } | |
5125 | return NOTIFY_OK; | |
5126 | } | |
5127 | ||
5128 | static struct notifier_block trace_die_notifier = { | |
5129 | .notifier_call = trace_die_handler, | |
5130 | .priority = 200 | |
5131 | }; | |
5132 | ||
5133 | /* | |
5134 | * printk is set to max of 1024, we really don't need it that big. | |
5135 | * Nothing should be printing 1000 characters anyway. | |
5136 | */ | |
5137 | #define TRACE_MAX_PRINT 1000 | |
5138 | ||
5139 | /* | |
5140 | * Define here KERN_TRACE so that we have one place to modify | |
5141 | * it if we decide to change what log level the ftrace dump | |
5142 | * should be at. | |
5143 | */ | |
428aee14 | 5144 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 | 5145 | |
955b61e5 | 5146 | void |
3f5a54e3 SR |
5147 | trace_printk_seq(struct trace_seq *s) |
5148 | { | |
5149 | /* Probably should print a warning here. */ | |
5150 | if (s->len >= 1000) | |
5151 | s->len = 1000; | |
5152 | ||
5153 | /* should be zero ended, but we are paranoid. */ | |
5154 | s->buffer[s->len] = 0; | |
5155 | ||
5156 | printk(KERN_TRACE "%s", s->buffer); | |
5157 | ||
f9520750 | 5158 | trace_seq_init(s); |
3f5a54e3 SR |
5159 | } |
5160 | ||
955b61e5 JW |
5161 | void trace_init_global_iter(struct trace_iterator *iter) |
5162 | { | |
5163 | iter->tr = &global_trace; | |
5164 | iter->trace = current_trace; | |
5165 | iter->cpu_file = TRACE_PIPE_ALL_CPU; | |
5166 | } | |
5167 | ||
cecbca96 FW |
5168 | static void |
5169 | __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) | |
3f5a54e3 | 5170 | { |
445c8951 | 5171 | static arch_spinlock_t ftrace_dump_lock = |
edc35bd7 | 5172 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
3f5a54e3 SR |
5173 | /* use static because iter can be a bit big for the stack */ |
5174 | static struct trace_iterator iter; | |
cf586b61 | 5175 | unsigned int old_userobj; |
3f5a54e3 | 5176 | static int dump_ran; |
d769041f SR |
5177 | unsigned long flags; |
5178 | int cnt = 0, cpu; | |
3f5a54e3 SR |
5179 | |
5180 | /* only one dump */ | |
cd891ae0 | 5181 | local_irq_save(flags); |
0199c4e6 | 5182 | arch_spin_lock(&ftrace_dump_lock); |
3f5a54e3 SR |
5183 | if (dump_ran) |
5184 | goto out; | |
5185 | ||
5186 | dump_ran = 1; | |
5187 | ||
0ee6b6cf | 5188 | tracing_off(); |
cf586b61 | 5189 | |
e0a413f6 SR |
5190 | /* Did function tracer already get disabled? */ |
5191 | if (ftrace_is_dead()) { | |
5192 | printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
5193 | printk("# MAY BE MISSING FUNCTION EVENTS\n"); | |
5194 | } | |
5195 | ||
cf586b61 FW |
5196 | if (disable_tracing) |
5197 | ftrace_kill(); | |
3f5a54e3 | 5198 | |
38dbe0b1 | 5199 | /* Simulate the iterator */ |
955b61e5 JW |
5200 | trace_init_global_iter(&iter); |
5201 | ||
d769041f | 5202 | for_each_tracing_cpu(cpu) { |
955b61e5 | 5203 | atomic_inc(&iter.tr->data[cpu]->disabled); |
d769041f SR |
5204 | } |
5205 | ||
cf586b61 FW |
5206 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; |
5207 | ||
b54d3de9 TE |
5208 | /* don't look at user memory in panic mode */ |
5209 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
5210 | ||
cecbca96 FW |
5211 | switch (oops_dump_mode) { |
5212 | case DUMP_ALL: | |
5213 | iter.cpu_file = TRACE_PIPE_ALL_CPU; | |
5214 | break; | |
5215 | case DUMP_ORIG: | |
5216 | iter.cpu_file = raw_smp_processor_id(); | |
5217 | break; | |
5218 | case DUMP_NONE: | |
5219 | goto out_enable; | |
5220 | default: | |
5221 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
5222 | iter.cpu_file = TRACE_PIPE_ALL_CPU; | |
5223 | } | |
5224 | ||
5225 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
3f5a54e3 SR |
5226 | |
5227 | /* | |
5228 | * We need to stop all tracing on all CPUS to read the | |
5229 | * the next buffer. This is a bit expensive, but is | |
5230 | * not done often. We fill all what we can read, | |
5231 | * and then release the locks again. | |
5232 | */ | |
5233 | ||
3f5a54e3 SR |
5234 | while (!trace_empty(&iter)) { |
5235 | ||
5236 | if (!cnt) | |
5237 | printk(KERN_TRACE "---------------------------------\n"); | |
5238 | ||
5239 | cnt++; | |
5240 | ||
5241 | /* reset all but tr, trace, and overruns */ | |
5242 | memset(&iter.seq, 0, | |
5243 | sizeof(struct trace_iterator) - | |
5244 | offsetof(struct trace_iterator, seq)); | |
5245 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
5246 | iter.pos = -1; | |
5247 | ||
955b61e5 | 5248 | if (trace_find_next_entry_inc(&iter) != NULL) { |
74e7ff8c LJ |
5249 | int ret; |
5250 | ||
5251 | ret = print_trace_line(&iter); | |
5252 | if (ret != TRACE_TYPE_NO_CONSUME) | |
5253 | trace_consume(&iter); | |
3f5a54e3 | 5254 | } |
b892e5c8 | 5255 | touch_nmi_watchdog(); |
3f5a54e3 SR |
5256 | |
5257 | trace_printk_seq(&iter.seq); | |
5258 | } | |
5259 | ||
5260 | if (!cnt) | |
5261 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
5262 | else | |
5263 | printk(KERN_TRACE "---------------------------------\n"); | |
5264 | ||
cecbca96 | 5265 | out_enable: |
cf586b61 FW |
5266 | /* Re-enable tracing if requested */ |
5267 | if (!disable_tracing) { | |
5268 | trace_flags |= old_userobj; | |
5269 | ||
5270 | for_each_tracing_cpu(cpu) { | |
955b61e5 | 5271 | atomic_dec(&iter.tr->data[cpu]->disabled); |
cf586b61 FW |
5272 | } |
5273 | tracing_on(); | |
5274 | } | |
5275 | ||
3f5a54e3 | 5276 | out: |
0199c4e6 | 5277 | arch_spin_unlock(&ftrace_dump_lock); |
cd891ae0 | 5278 | local_irq_restore(flags); |
3f5a54e3 SR |
5279 | } |
5280 | ||
cf586b61 | 5281 | /* By default: disable tracing after the dump */ |
cecbca96 | 5282 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) |
cf586b61 | 5283 | { |
cecbca96 | 5284 | __ftrace_dump(true, oops_dump_mode); |
cf586b61 | 5285 | } |
a8eecf22 | 5286 | EXPORT_SYMBOL_GPL(ftrace_dump); |
cf586b61 | 5287 | |
3928a8a2 | 5288 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 5289 | { |
73c5162a | 5290 | int ring_buf_size; |
750912fa | 5291 | enum ring_buffer_flags rb_flags; |
4c11d7ae | 5292 | int i; |
9e01c1b7 | 5293 | int ret = -ENOMEM; |
4c11d7ae | 5294 | |
750912fa | 5295 | |
9e01c1b7 RR |
5296 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
5297 | goto out; | |
5298 | ||
5299 | if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) | |
5300 | goto out_free_buffer_mask; | |
4c11d7ae | 5301 | |
07d777fe SR |
5302 | /* Only allocate trace_printk buffers if a trace_printk exists */ |
5303 | if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) | |
81698831 | 5304 | /* Must be called before global_trace.buffer is allocated */ |
07d777fe SR |
5305 | trace_printk_init_buffers(); |
5306 | ||
73c5162a SR |
5307 | /* To save memory, keep the ring buffer size to its minimum */ |
5308 | if (ring_buffer_expanded) | |
5309 | ring_buf_size = trace_buf_size; | |
5310 | else | |
5311 | ring_buf_size = 1; | |
5312 | ||
750912fa DS |
5313 | rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; |
5314 | ||
9e01c1b7 RR |
5315 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
5316 | cpumask_copy(tracing_cpumask, cpu_all_mask); | |
5317 | ||
5318 | /* TODO: make the number of buffers hot pluggable with CPUS */ | |
750912fa | 5319 | global_trace.buffer = ring_buffer_alloc(ring_buf_size, rb_flags); |
3928a8a2 SR |
5320 | if (!global_trace.buffer) { |
5321 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); | |
5322 | WARN_ON(1); | |
9e01c1b7 | 5323 | goto out_free_cpumask; |
4c11d7ae | 5324 | } |
499e5470 SR |
5325 | if (global_trace.buffer_disabled) |
5326 | tracing_off(); | |
4c11d7ae | 5327 | |
9e01c1b7 | 5328 | |
4c11d7ae | 5329 | #ifdef CONFIG_TRACER_MAX_TRACE |
750912fa | 5330 | max_tr.buffer = ring_buffer_alloc(1, rb_flags); |
3928a8a2 SR |
5331 | if (!max_tr.buffer) { |
5332 | printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); | |
5333 | WARN_ON(1); | |
5334 | ring_buffer_free(global_trace.buffer); | |
9e01c1b7 | 5335 | goto out_free_cpumask; |
4c11d7ae | 5336 | } |
a98a3c3f | 5337 | #endif |
ab46428c | 5338 | |
4c11d7ae | 5339 | /* Allocate the first page for all buffers */ |
ab46428c | 5340 | for_each_tracing_cpu(i) { |
566b0aaf | 5341 | global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
9705f69e | 5342 | max_tr.data[i] = &per_cpu(max_tr_data, i); |
4c11d7ae | 5343 | } |
438ced17 | 5344 | |
a591c73f VN |
5345 | set_buffer_entries(&global_trace, |
5346 | ring_buffer_size(global_trace.buffer, 0)); | |
438ced17 VN |
5347 | #ifdef CONFIG_TRACER_MAX_TRACE |
5348 | set_buffer_entries(&max_tr, 1); | |
5349 | #endif | |
bc0c38d1 | 5350 | |
bc0c38d1 | 5351 | trace_init_cmdlines(); |
0d5c6e1c | 5352 | init_irq_work(&trace_work_wakeup, trace_wake_up); |
bc0c38d1 | 5353 | |
43a15386 | 5354 | register_tracer(&nop_trace); |
d840f718 | 5355 | |
60a11774 SR |
5356 | /* All seems OK, enable tracing */ |
5357 | tracing_disabled = 0; | |
3928a8a2 | 5358 | |
3f5a54e3 SR |
5359 | atomic_notifier_chain_register(&panic_notifier_list, |
5360 | &trace_panic_notifier); | |
5361 | ||
5362 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe | 5363 | |
ae63b31e SR |
5364 | global_trace.flags = TRACE_ARRAY_FL_GLOBAL; |
5365 | ||
5366 | INIT_LIST_HEAD(&global_trace.systems); | |
5367 | INIT_LIST_HEAD(&global_trace.events); | |
5368 | list_add(&global_trace.list, &ftrace_trace_arrays); | |
5369 | ||
7bcfaf54 SR |
5370 | while (trace_boot_options) { |
5371 | char *option; | |
5372 | ||
5373 | option = strsep(&trace_boot_options, ","); | |
5374 | trace_set_options(option); | |
5375 | } | |
5376 | ||
2fc1dfbe | 5377 | return 0; |
3f5a54e3 | 5378 | |
9e01c1b7 RR |
5379 | out_free_cpumask: |
5380 | free_cpumask_var(tracing_cpumask); | |
5381 | out_free_buffer_mask: | |
5382 | free_cpumask_var(tracing_buffer_mask); | |
5383 | out: | |
5384 | return ret; | |
bc0c38d1 | 5385 | } |
b2821ae6 SR |
5386 | |
5387 | __init static int clear_boot_tracer(void) | |
5388 | { | |
5389 | /* | |
5390 | * The default tracer at boot buffer is an init section. | |
5391 | * This function is called in lateinit. If we did not | |
5392 | * find the boot tracer, then clear it out, to prevent | |
5393 | * later registration from accessing the buffer that is | |
5394 | * about to be freed. | |
5395 | */ | |
5396 | if (!default_bootup_tracer) | |
5397 | return 0; | |
5398 | ||
5399 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
5400 | default_bootup_tracer); | |
5401 | default_bootup_tracer = NULL; | |
5402 | ||
5403 | return 0; | |
5404 | } | |
5405 | ||
b5ad384e FW |
5406 | early_initcall(tracer_alloc_buffers); |
5407 | fs_initcall(tracer_init_debugfs); | |
b2821ae6 | 5408 | late_initcall(clear_boot_tracer); |