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