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