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Commit | Line | Data |
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bc0c38d1 SR |
1 | /* |
2 | * ring buffer based function tracer | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally taken from the RT patch by: | |
8 | * Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code from the latency_tracer, that is: | |
11 | * Copyright (C) 2004-2006 Ingo Molnar | |
12 | * Copyright (C) 2004 William Lee Irwin III | |
13 | */ | |
2cadf913 | 14 | #include <linux/ring_buffer.h> |
bc0c38d1 | 15 | #include <linux/utsrelease.h> |
2cadf913 SR |
16 | #include <linux/stacktrace.h> |
17 | #include <linux/writeback.h> | |
bc0c38d1 SR |
18 | #include <linux/kallsyms.h> |
19 | #include <linux/seq_file.h> | |
3f5a54e3 | 20 | #include <linux/notifier.h> |
2cadf913 | 21 | #include <linux/irqflags.h> |
bc0c38d1 | 22 | #include <linux/debugfs.h> |
4c11d7ae | 23 | #include <linux/pagemap.h> |
bc0c38d1 SR |
24 | #include <linux/hardirq.h> |
25 | #include <linux/linkage.h> | |
26 | #include <linux/uaccess.h> | |
2cadf913 | 27 | #include <linux/kprobes.h> |
bc0c38d1 SR |
28 | #include <linux/ftrace.h> |
29 | #include <linux/module.h> | |
30 | #include <linux/percpu.h> | |
2cadf913 | 31 | #include <linux/splice.h> |
3f5a54e3 | 32 | #include <linux/kdebug.h> |
bc0c38d1 SR |
33 | #include <linux/ctype.h> |
34 | #include <linux/init.h> | |
2a2cc8f7 | 35 | #include <linux/poll.h> |
bc0c38d1 SR |
36 | #include <linux/gfp.h> |
37 | #include <linux/fs.h> | |
86387f7e | 38 | |
bc0c38d1 | 39 | #include "trace.h" |
f0868d1e | 40 | #include "trace_output.h" |
bc0c38d1 | 41 | |
3928a8a2 SR |
42 | #define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE) |
43 | ||
745b1626 | 44 | unsigned long __read_mostly tracing_max_latency; |
bc0c38d1 SR |
45 | unsigned long __read_mostly tracing_thresh; |
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 | */ | |
51 | static int ring_buffer_expanded; | |
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 | */ | |
65 | static bool __read_mostly tracing_selftest_disabled; | |
66 | ||
adf9f195 FW |
67 | /* For tracers that don't implement custom flags */ |
68 | static struct tracer_opt dummy_tracer_opt[] = { | |
69 | { } | |
70 | }; | |
71 | ||
72 | static struct tracer_flags dummy_tracer_flags = { | |
73 | .val = 0, | |
74 | .opts = dummy_tracer_opt | |
75 | }; | |
76 | ||
77 | static int dummy_set_flag(u32 old_flags, u32 bit, int set) | |
78 | { | |
79 | return 0; | |
80 | } | |
0f048701 SR |
81 | |
82 | /* | |
83 | * Kill all tracing for good (never come back). | |
84 | * It is initialized to 1 but will turn to zero if the initialization | |
85 | * of the tracer is successful. But that is the only place that sets | |
86 | * this back to zero. | |
87 | */ | |
4fd27358 | 88 | static int tracing_disabled = 1; |
0f048701 | 89 | |
d769041f SR |
90 | static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled); |
91 | ||
92 | static inline void ftrace_disable_cpu(void) | |
93 | { | |
94 | preempt_disable(); | |
95 | local_inc(&__get_cpu_var(ftrace_cpu_disabled)); | |
96 | } | |
97 | ||
98 | static inline void ftrace_enable_cpu(void) | |
99 | { | |
100 | local_dec(&__get_cpu_var(ftrace_cpu_disabled)); | |
101 | preempt_enable(); | |
102 | } | |
103 | ||
9e01c1b7 | 104 | static cpumask_var_t __read_mostly tracing_buffer_mask; |
ab46428c | 105 | |
b04cc6b1 FW |
106 | /* Define which cpu buffers are currently read in trace_pipe */ |
107 | static cpumask_var_t tracing_reader_cpumask; | |
108 | ||
ab46428c | 109 | #define for_each_tracing_cpu(cpu) \ |
9e01c1b7 | 110 | for_each_cpu(cpu, tracing_buffer_mask) |
ab46428c | 111 | |
944ac425 SR |
112 | /* |
113 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
114 | * | |
115 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
116 | * is set, then ftrace_dump is called. This will output the contents | |
117 | * of the ftrace buffers to the console. This is very useful for | |
118 | * capturing traces that lead to crashes and outputing it to a | |
119 | * serial console. | |
120 | * | |
121 | * It is default off, but you can enable it with either specifying | |
122 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
123 | * /proc/sys/kernel/ftrace_dump_on_oops to true. | |
124 | */ | |
125 | int ftrace_dump_on_oops; | |
126 | ||
b2821ae6 SR |
127 | static int tracing_set_tracer(const char *buf); |
128 | ||
129 | #define BOOTUP_TRACER_SIZE 100 | |
130 | static char bootup_tracer_buf[BOOTUP_TRACER_SIZE] __initdata; | |
131 | static char *default_bootup_tracer; | |
d9e54076 PZ |
132 | |
133 | static int __init set_ftrace(char *str) | |
134 | { | |
b2821ae6 SR |
135 | strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE); |
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 | } | |
b2821ae6 | 141 | __setup("ftrace=", set_ftrace); |
d9e54076 | 142 | |
944ac425 SR |
143 | static int __init set_ftrace_dump_on_oops(char *str) |
144 | { | |
145 | ftrace_dump_on_oops = 1; | |
146 | return 1; | |
147 | } | |
148 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
60a11774 | 149 | |
72829bc3 | 150 | long |
bc0c38d1 SR |
151 | ns2usecs(cycle_t nsec) |
152 | { | |
153 | nsec += 500; | |
154 | do_div(nsec, 1000); | |
155 | return nsec; | |
156 | } | |
157 | ||
4fcdae83 SR |
158 | /* |
159 | * The global_trace is the descriptor that holds the tracing | |
160 | * buffers for the live tracing. For each CPU, it contains | |
161 | * a link list of pages that will store trace entries. The | |
162 | * page descriptor of the pages in the memory is used to hold | |
163 | * the link list by linking the lru item in the page descriptor | |
164 | * to each of the pages in the buffer per CPU. | |
165 | * | |
166 | * For each active CPU there is a data field that holds the | |
167 | * pages for the buffer for that CPU. Each CPU has the same number | |
168 | * of pages allocated for its buffer. | |
169 | */ | |
bc0c38d1 SR |
170 | static struct trace_array global_trace; |
171 | ||
172 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
173 | ||
37886f6a SR |
174 | cycle_t ftrace_now(int cpu) |
175 | { | |
176 | u64 ts; | |
177 | ||
178 | /* Early boot up does not have a buffer yet */ | |
179 | if (!global_trace.buffer) | |
180 | return trace_clock_local(); | |
181 | ||
182 | ts = ring_buffer_time_stamp(global_trace.buffer, cpu); | |
183 | ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts); | |
184 | ||
185 | return ts; | |
186 | } | |
bc0c38d1 | 187 | |
4fcdae83 SR |
188 | /* |
189 | * The max_tr is used to snapshot the global_trace when a maximum | |
190 | * latency is reached. Some tracers will use this to store a maximum | |
191 | * trace while it continues examining live traces. | |
192 | * | |
193 | * The buffers for the max_tr are set up the same as the global_trace. | |
194 | * When a snapshot is taken, the link list of the max_tr is swapped | |
195 | * with the link list of the global_trace and the buffers are reset for | |
196 | * the global_trace so the tracing can continue. | |
197 | */ | |
bc0c38d1 SR |
198 | static struct trace_array max_tr; |
199 | ||
200 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); | |
201 | ||
4fcdae83 | 202 | /* tracer_enabled is used to toggle activation of a tracer */ |
26994ead | 203 | static int tracer_enabled = 1; |
4fcdae83 | 204 | |
9036990d SR |
205 | /** |
206 | * tracing_is_enabled - return tracer_enabled status | |
207 | * | |
208 | * This function is used by other tracers to know the status | |
209 | * of the tracer_enabled flag. Tracers may use this function | |
210 | * to know if it should enable their features when starting | |
211 | * up. See irqsoff tracer for an example (start_irqsoff_tracer). | |
212 | */ | |
213 | int tracing_is_enabled(void) | |
214 | { | |
215 | return tracer_enabled; | |
216 | } | |
217 | ||
4fcdae83 | 218 | /* |
3928a8a2 SR |
219 | * trace_buf_size is the size in bytes that is allocated |
220 | * for a buffer. Note, the number of bytes is always rounded | |
221 | * to page size. | |
3f5a54e3 SR |
222 | * |
223 | * This number is purposely set to a low number of 16384. | |
224 | * If the dump on oops happens, it will be much appreciated | |
225 | * to not have to wait for all that output. Anyway this can be | |
226 | * boot time and run time configurable. | |
4fcdae83 | 227 | */ |
3928a8a2 | 228 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
3f5a54e3 | 229 | |
3928a8a2 | 230 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
bc0c38d1 | 231 | |
4fcdae83 | 232 | /* trace_types holds a link list of available tracers. */ |
bc0c38d1 | 233 | static struct tracer *trace_types __read_mostly; |
4fcdae83 SR |
234 | |
235 | /* current_trace points to the tracer that is currently active */ | |
bc0c38d1 | 236 | static struct tracer *current_trace __read_mostly; |
4fcdae83 SR |
237 | |
238 | /* | |
239 | * max_tracer_type_len is used to simplify the allocating of | |
240 | * buffers to read userspace tracer names. We keep track of | |
241 | * the longest tracer name registered. | |
242 | */ | |
bc0c38d1 SR |
243 | static int max_tracer_type_len; |
244 | ||
4fcdae83 SR |
245 | /* |
246 | * trace_types_lock is used to protect the trace_types list. | |
247 | * This lock is also used to keep user access serialized. | |
248 | * Accesses from userspace will grab this lock while userspace | |
249 | * activities happen inside the kernel. | |
250 | */ | |
bc0c38d1 | 251 | static DEFINE_MUTEX(trace_types_lock); |
4fcdae83 SR |
252 | |
253 | /* trace_wait is a waitqueue for tasks blocked on trace_poll */ | |
4e655519 IM |
254 | static DECLARE_WAIT_QUEUE_HEAD(trace_wait); |
255 | ||
ee6bce52 | 256 | /* trace_flags holds trace_options default values */ |
12ef7d44 | 257 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | |
be6f164a | 258 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME; |
4e655519 | 259 | |
4fcdae83 SR |
260 | /** |
261 | * trace_wake_up - wake up tasks waiting for trace input | |
262 | * | |
263 | * Simply wakes up any task that is blocked on the trace_wait | |
264 | * queue. These is used with trace_poll for tasks polling the trace. | |
265 | */ | |
4e655519 IM |
266 | void trace_wake_up(void) |
267 | { | |
017730c1 IM |
268 | /* |
269 | * The runqueue_is_locked() can fail, but this is the best we | |
270 | * have for now: | |
271 | */ | |
272 | if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked()) | |
4e655519 IM |
273 | wake_up(&trace_wait); |
274 | } | |
bc0c38d1 | 275 | |
3928a8a2 | 276 | static int __init set_buf_size(char *str) |
bc0c38d1 | 277 | { |
3928a8a2 | 278 | unsigned long buf_size; |
c6caeeb1 SR |
279 | int ret; |
280 | ||
bc0c38d1 SR |
281 | if (!str) |
282 | return 0; | |
3928a8a2 | 283 | ret = strict_strtoul(str, 0, &buf_size); |
c6caeeb1 | 284 | /* nr_entries can not be zero */ |
3928a8a2 | 285 | if (ret < 0 || buf_size == 0) |
c6caeeb1 | 286 | return 0; |
3928a8a2 | 287 | trace_buf_size = buf_size; |
bc0c38d1 SR |
288 | return 1; |
289 | } | |
3928a8a2 | 290 | __setup("trace_buf_size=", set_buf_size); |
bc0c38d1 | 291 | |
57f50be1 SR |
292 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
293 | { | |
294 | return nsecs / 1000; | |
295 | } | |
296 | ||
4fcdae83 | 297 | /* These must match the bit postions in trace_iterator_flags */ |
bc0c38d1 SR |
298 | static const char *trace_options[] = { |
299 | "print-parent", | |
300 | "sym-offset", | |
301 | "sym-addr", | |
302 | "verbose", | |
f9896bf3 | 303 | "raw", |
5e3ca0ec | 304 | "hex", |
cb0f12aa | 305 | "bin", |
2a2cc8f7 | 306 | "block", |
86387f7e | 307 | "stacktrace", |
4ac3ba41 | 308 | "sched-tree", |
5e1607a0 | 309 | "trace_printk", |
b2a866f9 | 310 | "ftrace_preempt", |
9f029e83 | 311 | "branch", |
12ef7d44 | 312 | "annotate", |
02b67518 | 313 | "userstacktrace", |
b54d3de9 | 314 | "sym-userobj", |
66896a85 | 315 | "printk-msg-only", |
c4a8e8be | 316 | "context-info", |
c032ef64 | 317 | "latency-format", |
af4617bd | 318 | "global-clock", |
be6f164a | 319 | "sleep-time", |
bc0c38d1 SR |
320 | NULL |
321 | }; | |
322 | ||
4fcdae83 SR |
323 | /* |
324 | * ftrace_max_lock is used to protect the swapping of buffers | |
325 | * when taking a max snapshot. The buffers themselves are | |
326 | * protected by per_cpu spinlocks. But the action of the swap | |
327 | * needs its own lock. | |
328 | * | |
329 | * This is defined as a raw_spinlock_t in order to help | |
330 | * with performance when lockdep debugging is enabled. | |
331 | */ | |
92205c23 SR |
332 | static raw_spinlock_t ftrace_max_lock = |
333 | (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; | |
bc0c38d1 SR |
334 | |
335 | /* | |
336 | * Copy the new maximum trace into the separate maximum-trace | |
337 | * structure. (this way the maximum trace is permanently saved, | |
338 | * for later retrieval via /debugfs/tracing/latency_trace) | |
339 | */ | |
e309b41d | 340 | static void |
bc0c38d1 SR |
341 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
342 | { | |
343 | struct trace_array_cpu *data = tr->data[cpu]; | |
344 | ||
345 | max_tr.cpu = cpu; | |
346 | max_tr.time_start = data->preempt_timestamp; | |
347 | ||
348 | data = max_tr.data[cpu]; | |
349 | data->saved_latency = tracing_max_latency; | |
350 | ||
351 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
352 | data->pid = tsk->pid; | |
b6dff3ec | 353 | data->uid = task_uid(tsk); |
bc0c38d1 SR |
354 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; |
355 | data->policy = tsk->policy; | |
356 | data->rt_priority = tsk->rt_priority; | |
357 | ||
358 | /* record this tasks comm */ | |
af513098 | 359 | tracing_record_cmdline(tsk); |
bc0c38d1 SR |
360 | } |
361 | ||
6c6c2796 PP |
362 | ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) |
363 | { | |
364 | int len; | |
365 | int ret; | |
366 | ||
2dc5d12b SR |
367 | if (!cnt) |
368 | return 0; | |
369 | ||
6c6c2796 PP |
370 | if (s->len <= s->readpos) |
371 | return -EBUSY; | |
372 | ||
373 | len = s->len - s->readpos; | |
374 | if (cnt > len) | |
375 | cnt = len; | |
376 | ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); | |
2dc5d12b | 377 | if (ret == cnt) |
6c6c2796 PP |
378 | return -EFAULT; |
379 | ||
2dc5d12b SR |
380 | cnt -= ret; |
381 | ||
e74da523 | 382 | s->readpos += cnt; |
6c6c2796 | 383 | return cnt; |
214023c3 SR |
384 | } |
385 | ||
b8b94265 | 386 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
3c56819b EGM |
387 | { |
388 | int len; | |
389 | void *ret; | |
390 | ||
391 | if (s->len <= s->readpos) | |
392 | return -EBUSY; | |
393 | ||
394 | len = s->len - s->readpos; | |
395 | if (cnt > len) | |
396 | cnt = len; | |
397 | ret = memcpy(buf, s->buffer + s->readpos, cnt); | |
398 | if (!ret) | |
399 | return -EFAULT; | |
400 | ||
e74da523 | 401 | s->readpos += cnt; |
3c56819b EGM |
402 | return cnt; |
403 | } | |
404 | ||
e309b41d | 405 | static void |
214023c3 SR |
406 | trace_print_seq(struct seq_file *m, struct trace_seq *s) |
407 | { | |
408 | int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; | |
409 | ||
410 | s->buffer[len] = 0; | |
411 | seq_puts(m, s->buffer); | |
412 | ||
f9520750 | 413 | trace_seq_init(s); |
214023c3 SR |
414 | } |
415 | ||
4fcdae83 SR |
416 | /** |
417 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
418 | * @tr: tracer | |
419 | * @tsk: the task with the latency | |
420 | * @cpu: The cpu that initiated the trace. | |
421 | * | |
422 | * Flip the buffers between the @tr and the max_tr and record information | |
423 | * about which task was the cause of this latency. | |
424 | */ | |
e309b41d | 425 | void |
bc0c38d1 SR |
426 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
427 | { | |
3928a8a2 | 428 | struct ring_buffer *buf = tr->buffer; |
bc0c38d1 | 429 | |
4c11d7ae | 430 | WARN_ON_ONCE(!irqs_disabled()); |
92205c23 | 431 | __raw_spin_lock(&ftrace_max_lock); |
3928a8a2 SR |
432 | |
433 | tr->buffer = max_tr.buffer; | |
434 | max_tr.buffer = buf; | |
435 | ||
d769041f | 436 | ftrace_disable_cpu(); |
3928a8a2 | 437 | ring_buffer_reset(tr->buffer); |
d769041f | 438 | ftrace_enable_cpu(); |
bc0c38d1 SR |
439 | |
440 | __update_max_tr(tr, tsk, cpu); | |
92205c23 | 441 | __raw_spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
442 | } |
443 | ||
444 | /** | |
445 | * update_max_tr_single - only copy one trace over, and reset the rest | |
446 | * @tr - tracer | |
447 | * @tsk - task with the latency | |
448 | * @cpu - the cpu of the buffer to copy. | |
4fcdae83 SR |
449 | * |
450 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
bc0c38d1 | 451 | */ |
e309b41d | 452 | void |
bc0c38d1 SR |
453 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
454 | { | |
3928a8a2 | 455 | int ret; |
bc0c38d1 | 456 | |
4c11d7ae | 457 | WARN_ON_ONCE(!irqs_disabled()); |
92205c23 | 458 | __raw_spin_lock(&ftrace_max_lock); |
bc0c38d1 | 459 | |
d769041f SR |
460 | ftrace_disable_cpu(); |
461 | ||
3928a8a2 SR |
462 | ring_buffer_reset(max_tr.buffer); |
463 | ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); | |
464 | ||
d769041f SR |
465 | ftrace_enable_cpu(); |
466 | ||
97b17efe | 467 | WARN_ON_ONCE(ret && ret != -EAGAIN); |
bc0c38d1 SR |
468 | |
469 | __update_max_tr(tr, tsk, cpu); | |
92205c23 | 470 | __raw_spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
471 | } |
472 | ||
4fcdae83 SR |
473 | /** |
474 | * register_tracer - register a tracer with the ftrace system. | |
475 | * @type - the plugin for the tracer | |
476 | * | |
477 | * Register a new plugin tracer. | |
478 | */ | |
bc0c38d1 | 479 | int register_tracer(struct tracer *type) |
e7669b8e HE |
480 | __releases(kernel_lock) |
481 | __acquires(kernel_lock) | |
bc0c38d1 SR |
482 | { |
483 | struct tracer *t; | |
484 | int len; | |
485 | int ret = 0; | |
486 | ||
487 | if (!type->name) { | |
488 | pr_info("Tracer must have a name\n"); | |
489 | return -1; | |
490 | } | |
491 | ||
86fa2f60 IM |
492 | /* |
493 | * When this gets called we hold the BKL which means that | |
494 | * preemption is disabled. Various trace selftests however | |
495 | * need to disable and enable preemption for successful tests. | |
496 | * So we drop the BKL here and grab it after the tests again. | |
497 | */ | |
498 | unlock_kernel(); | |
bc0c38d1 | 499 | mutex_lock(&trace_types_lock); |
86fa2f60 | 500 | |
8e1b82e0 FW |
501 | tracing_selftest_running = true; |
502 | ||
bc0c38d1 SR |
503 | for (t = trace_types; t; t = t->next) { |
504 | if (strcmp(type->name, t->name) == 0) { | |
505 | /* already found */ | |
506 | pr_info("Trace %s already registered\n", | |
507 | type->name); | |
508 | ret = -1; | |
509 | goto out; | |
510 | } | |
511 | } | |
512 | ||
adf9f195 FW |
513 | if (!type->set_flag) |
514 | type->set_flag = &dummy_set_flag; | |
515 | if (!type->flags) | |
516 | type->flags = &dummy_tracer_flags; | |
517 | else | |
518 | if (!type->flags->opts) | |
519 | type->flags->opts = dummy_tracer_opt; | |
6eaaa5d5 FW |
520 | if (!type->wait_pipe) |
521 | type->wait_pipe = default_wait_pipe; | |
522 | ||
adf9f195 | 523 | |
60a11774 | 524 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
b2821ae6 | 525 | if (type->selftest && !tracing_selftest_disabled) { |
60a11774 | 526 | struct tracer *saved_tracer = current_trace; |
60a11774 | 527 | struct trace_array *tr = &global_trace; |
60a11774 | 528 | int i; |
ff32504f | 529 | |
60a11774 SR |
530 | /* |
531 | * Run a selftest on this tracer. | |
532 | * Here we reset the trace buffer, and set the current | |
533 | * tracer to be this tracer. The tracer can then run some | |
534 | * internal tracing to verify that everything is in order. | |
535 | * If we fail, we do not register this tracer. | |
536 | */ | |
86fa2f60 | 537 | for_each_tracing_cpu(i) |
3928a8a2 | 538 | tracing_reset(tr, i); |
86fa2f60 | 539 | |
60a11774 | 540 | current_trace = type; |
60a11774 SR |
541 | /* the test is responsible for initializing and enabling */ |
542 | pr_info("Testing tracer %s: ", type->name); | |
543 | ret = type->selftest(type, tr); | |
544 | /* the test is responsible for resetting too */ | |
545 | current_trace = saved_tracer; | |
60a11774 SR |
546 | if (ret) { |
547 | printk(KERN_CONT "FAILED!\n"); | |
548 | goto out; | |
549 | } | |
1d4db00a | 550 | /* Only reset on passing, to avoid touching corrupted buffers */ |
86fa2f60 | 551 | for_each_tracing_cpu(i) |
3928a8a2 | 552 | tracing_reset(tr, i); |
86fa2f60 | 553 | |
60a11774 SR |
554 | printk(KERN_CONT "PASSED\n"); |
555 | } | |
556 | #endif | |
557 | ||
bc0c38d1 SR |
558 | type->next = trace_types; |
559 | trace_types = type; | |
560 | len = strlen(type->name); | |
561 | if (len > max_tracer_type_len) | |
562 | max_tracer_type_len = len; | |
60a11774 | 563 | |
bc0c38d1 | 564 | out: |
8e1b82e0 | 565 | tracing_selftest_running = false; |
bc0c38d1 SR |
566 | mutex_unlock(&trace_types_lock); |
567 | ||
dac74940 SR |
568 | if (ret || !default_bootup_tracer) |
569 | goto out_unlock; | |
570 | ||
571 | if (strncmp(default_bootup_tracer, type->name, BOOTUP_TRACER_SIZE)) | |
572 | goto out_unlock; | |
573 | ||
574 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
575 | /* Do we want this tracer to start on bootup? */ | |
576 | tracing_set_tracer(type->name); | |
577 | default_bootup_tracer = NULL; | |
578 | /* disable other selftests, since this will break it. */ | |
579 | tracing_selftest_disabled = 1; | |
b2821ae6 | 580 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
dac74940 SR |
581 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", |
582 | type->name); | |
b2821ae6 | 583 | #endif |
b2821ae6 | 584 | |
dac74940 | 585 | out_unlock: |
b2821ae6 | 586 | lock_kernel(); |
bc0c38d1 SR |
587 | return ret; |
588 | } | |
589 | ||
590 | void unregister_tracer(struct tracer *type) | |
591 | { | |
592 | struct tracer **t; | |
593 | int len; | |
594 | ||
595 | mutex_lock(&trace_types_lock); | |
596 | for (t = &trace_types; *t; t = &(*t)->next) { | |
597 | if (*t == type) | |
598 | goto found; | |
599 | } | |
600 | pr_info("Trace %s not registered\n", type->name); | |
601 | goto out; | |
602 | ||
603 | found: | |
604 | *t = (*t)->next; | |
b5db03c4 ACM |
605 | |
606 | if (type == current_trace && tracer_enabled) { | |
607 | tracer_enabled = 0; | |
608 | tracing_stop(); | |
609 | if (current_trace->stop) | |
610 | current_trace->stop(&global_trace); | |
611 | current_trace = &nop_trace; | |
612 | } | |
613 | ||
bc0c38d1 SR |
614 | if (strlen(type->name) != max_tracer_type_len) |
615 | goto out; | |
616 | ||
617 | max_tracer_type_len = 0; | |
618 | for (t = &trace_types; *t; t = &(*t)->next) { | |
619 | len = strlen((*t)->name); | |
620 | if (len > max_tracer_type_len) | |
621 | max_tracer_type_len = len; | |
622 | } | |
623 | out: | |
624 | mutex_unlock(&trace_types_lock); | |
625 | } | |
626 | ||
3928a8a2 | 627 | void tracing_reset(struct trace_array *tr, int cpu) |
bc0c38d1 | 628 | { |
d769041f | 629 | ftrace_disable_cpu(); |
3928a8a2 | 630 | ring_buffer_reset_cpu(tr->buffer, cpu); |
d769041f | 631 | ftrace_enable_cpu(); |
bc0c38d1 SR |
632 | } |
633 | ||
213cc060 PE |
634 | void tracing_reset_online_cpus(struct trace_array *tr) |
635 | { | |
636 | int cpu; | |
637 | ||
638 | tr->time_start = ftrace_now(tr->cpu); | |
639 | ||
640 | for_each_online_cpu(cpu) | |
641 | tracing_reset(tr, cpu); | |
642 | } | |
643 | ||
bc0c38d1 | 644 | #define SAVED_CMDLINES 128 |
2c7eea4c | 645 | #define NO_CMDLINE_MAP UINT_MAX |
bc0c38d1 SR |
646 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; |
647 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
648 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
649 | static int cmdline_idx; | |
efed792d | 650 | static raw_spinlock_t trace_cmdline_lock = __RAW_SPIN_LOCK_UNLOCKED; |
25b0b44a | 651 | |
25b0b44a | 652 | /* temporary disable recording */ |
4fd27358 | 653 | static atomic_t trace_record_cmdline_disabled __read_mostly; |
bc0c38d1 SR |
654 | |
655 | static void trace_init_cmdlines(void) | |
656 | { | |
2c7eea4c TG |
657 | memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); |
658 | memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); | |
bc0c38d1 SR |
659 | cmdline_idx = 0; |
660 | } | |
661 | ||
0f048701 SR |
662 | static int trace_stop_count; |
663 | static DEFINE_SPINLOCK(tracing_start_lock); | |
664 | ||
69bb54ec SR |
665 | /** |
666 | * ftrace_off_permanent - disable all ftrace code permanently | |
667 | * | |
668 | * This should only be called when a serious anomally has | |
669 | * been detected. This will turn off the function tracing, | |
670 | * ring buffers, and other tracing utilites. It takes no | |
671 | * locks and can be called from any context. | |
672 | */ | |
673 | void ftrace_off_permanent(void) | |
674 | { | |
675 | tracing_disabled = 1; | |
676 | ftrace_stop(); | |
677 | tracing_off_permanent(); | |
678 | } | |
679 | ||
0f048701 SR |
680 | /** |
681 | * tracing_start - quick start of the tracer | |
682 | * | |
683 | * If tracing is enabled but was stopped by tracing_stop, | |
684 | * this will start the tracer back up. | |
685 | */ | |
686 | void tracing_start(void) | |
687 | { | |
688 | struct ring_buffer *buffer; | |
689 | unsigned long flags; | |
690 | ||
691 | if (tracing_disabled) | |
692 | return; | |
693 | ||
694 | spin_lock_irqsave(&tracing_start_lock, flags); | |
b06a8301 SR |
695 | if (--trace_stop_count) { |
696 | if (trace_stop_count < 0) { | |
697 | /* Someone screwed up their debugging */ | |
698 | WARN_ON_ONCE(1); | |
699 | trace_stop_count = 0; | |
700 | } | |
0f048701 SR |
701 | goto out; |
702 | } | |
703 | ||
704 | ||
705 | buffer = global_trace.buffer; | |
706 | if (buffer) | |
707 | ring_buffer_record_enable(buffer); | |
708 | ||
709 | buffer = max_tr.buffer; | |
710 | if (buffer) | |
711 | ring_buffer_record_enable(buffer); | |
712 | ||
713 | ftrace_start(); | |
714 | out: | |
715 | spin_unlock_irqrestore(&tracing_start_lock, flags); | |
716 | } | |
717 | ||
718 | /** | |
719 | * tracing_stop - quick stop of the tracer | |
720 | * | |
721 | * Light weight way to stop tracing. Use in conjunction with | |
722 | * tracing_start. | |
723 | */ | |
724 | void tracing_stop(void) | |
725 | { | |
726 | struct ring_buffer *buffer; | |
727 | unsigned long flags; | |
728 | ||
729 | ftrace_stop(); | |
730 | spin_lock_irqsave(&tracing_start_lock, flags); | |
731 | if (trace_stop_count++) | |
732 | goto out; | |
733 | ||
734 | buffer = global_trace.buffer; | |
735 | if (buffer) | |
736 | ring_buffer_record_disable(buffer); | |
737 | ||
738 | buffer = max_tr.buffer; | |
739 | if (buffer) | |
740 | ring_buffer_record_disable(buffer); | |
741 | ||
742 | out: | |
743 | spin_unlock_irqrestore(&tracing_start_lock, flags); | |
744 | } | |
745 | ||
e309b41d | 746 | void trace_stop_cmdline_recording(void); |
bc0c38d1 | 747 | |
e309b41d | 748 | static void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 | 749 | { |
a635cf04 | 750 | unsigned pid, idx; |
bc0c38d1 SR |
751 | |
752 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
753 | return; | |
754 | ||
755 | /* | |
756 | * It's not the end of the world if we don't get | |
757 | * the lock, but we also don't want to spin | |
758 | * nor do we want to disable interrupts, | |
759 | * so if we miss here, then better luck next time. | |
760 | */ | |
efed792d | 761 | if (!__raw_spin_trylock(&trace_cmdline_lock)) |
bc0c38d1 SR |
762 | return; |
763 | ||
764 | idx = map_pid_to_cmdline[tsk->pid]; | |
2c7eea4c | 765 | if (idx == NO_CMDLINE_MAP) { |
bc0c38d1 SR |
766 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; |
767 | ||
a635cf04 CE |
768 | /* |
769 | * Check whether the cmdline buffer at idx has a pid | |
770 | * mapped. We are going to overwrite that entry so we | |
771 | * need to clear the map_pid_to_cmdline. Otherwise we | |
772 | * would read the new comm for the old pid. | |
773 | */ | |
774 | pid = map_cmdline_to_pid[idx]; | |
775 | if (pid != NO_CMDLINE_MAP) | |
776 | map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; | |
bc0c38d1 | 777 | |
a635cf04 | 778 | map_cmdline_to_pid[idx] = tsk->pid; |
bc0c38d1 SR |
779 | map_pid_to_cmdline[tsk->pid] = idx; |
780 | ||
781 | cmdline_idx = idx; | |
782 | } | |
783 | ||
784 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
785 | ||
efed792d | 786 | __raw_spin_unlock(&trace_cmdline_lock); |
bc0c38d1 SR |
787 | } |
788 | ||
4ca53085 | 789 | void trace_find_cmdline(int pid, char comm[]) |
bc0c38d1 | 790 | { |
bc0c38d1 SR |
791 | unsigned map; |
792 | ||
4ca53085 SR |
793 | if (!pid) { |
794 | strcpy(comm, "<idle>"); | |
795 | return; | |
796 | } | |
bc0c38d1 | 797 | |
4ca53085 SR |
798 | if (pid > PID_MAX_DEFAULT) { |
799 | strcpy(comm, "<...>"); | |
800 | return; | |
801 | } | |
bc0c38d1 | 802 | |
4ca53085 | 803 | __raw_spin_lock(&trace_cmdline_lock); |
bc0c38d1 | 804 | map = map_pid_to_cmdline[pid]; |
50d88758 TG |
805 | if (map != NO_CMDLINE_MAP) |
806 | strcpy(comm, saved_cmdlines[map]); | |
807 | else | |
808 | strcpy(comm, "<...>"); | |
bc0c38d1 | 809 | |
4ca53085 | 810 | __raw_spin_unlock(&trace_cmdline_lock); |
bc0c38d1 SR |
811 | } |
812 | ||
e309b41d | 813 | void tracing_record_cmdline(struct task_struct *tsk) |
bc0c38d1 | 814 | { |
18aecd36 TG |
815 | if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled || |
816 | !tracing_is_on()) | |
bc0c38d1 SR |
817 | return; |
818 | ||
819 | trace_save_cmdline(tsk); | |
820 | } | |
821 | ||
45dcd8b8 | 822 | void |
38697053 SR |
823 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, |
824 | int pc) | |
bc0c38d1 SR |
825 | { |
826 | struct task_struct *tsk = current; | |
bc0c38d1 | 827 | |
777e208d SR |
828 | entry->preempt_count = pc & 0xff; |
829 | entry->pid = (tsk) ? tsk->pid : 0; | |
ef18012b | 830 | entry->tgid = (tsk) ? tsk->tgid : 0; |
777e208d | 831 | entry->flags = |
9244489a | 832 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT |
2e2ca155 | 833 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
9244489a SR |
834 | #else |
835 | TRACE_FLAG_IRQS_NOSUPPORT | | |
836 | #endif | |
bc0c38d1 SR |
837 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
838 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
839 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
840 | } | |
841 | ||
51a763dd ACM |
842 | struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr, |
843 | unsigned char type, | |
844 | unsigned long len, | |
845 | unsigned long flags, int pc) | |
846 | { | |
847 | struct ring_buffer_event *event; | |
848 | ||
849 | event = ring_buffer_lock_reserve(tr->buffer, len); | |
850 | if (event != NULL) { | |
851 | struct trace_entry *ent = ring_buffer_event_data(event); | |
852 | ||
853 | tracing_generic_entry_update(ent, flags, pc); | |
854 | ent->type = type; | |
855 | } | |
856 | ||
857 | return event; | |
858 | } | |
859 | static void ftrace_trace_stack(struct trace_array *tr, | |
860 | unsigned long flags, int skip, int pc); | |
861 | static void ftrace_trace_userstack(struct trace_array *tr, | |
862 | unsigned long flags, int pc); | |
863 | ||
864 | void trace_buffer_unlock_commit(struct trace_array *tr, | |
865 | struct ring_buffer_event *event, | |
866 | unsigned long flags, int pc) | |
867 | { | |
868 | ring_buffer_unlock_commit(tr->buffer, event); | |
869 | ||
870 | ftrace_trace_stack(tr, flags, 6, pc); | |
871 | ftrace_trace_userstack(tr, flags, pc); | |
872 | trace_wake_up(); | |
873 | } | |
874 | ||
ef5580d0 SR |
875 | struct ring_buffer_event * |
876 | trace_current_buffer_lock_reserve(unsigned char type, unsigned long len, | |
877 | unsigned long flags, int pc) | |
878 | { | |
879 | return trace_buffer_lock_reserve(&global_trace, | |
880 | type, len, flags, pc); | |
881 | } | |
882 | ||
883 | void trace_current_buffer_unlock_commit(struct ring_buffer_event *event, | |
884 | unsigned long flags, int pc) | |
885 | { | |
886 | return trace_buffer_unlock_commit(&global_trace, event, flags, pc); | |
887 | } | |
888 | ||
e309b41d | 889 | void |
7be42151 | 890 | trace_function(struct trace_array *tr, |
38697053 SR |
891 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
892 | int pc) | |
bc0c38d1 | 893 | { |
3928a8a2 | 894 | struct ring_buffer_event *event; |
777e208d | 895 | struct ftrace_entry *entry; |
bc0c38d1 | 896 | |
d769041f SR |
897 | /* If we are reading the ring buffer, don't trace */ |
898 | if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) | |
899 | return; | |
900 | ||
51a763dd ACM |
901 | event = trace_buffer_lock_reserve(tr, TRACE_FN, sizeof(*entry), |
902 | flags, pc); | |
3928a8a2 SR |
903 | if (!event) |
904 | return; | |
905 | entry = ring_buffer_event_data(event); | |
777e208d SR |
906 | entry->ip = ip; |
907 | entry->parent_ip = parent_ip; | |
0a987751 | 908 | ring_buffer_unlock_commit(tr->buffer, event); |
bc0c38d1 SR |
909 | } |
910 | ||
fb52607a | 911 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
287b6e68 | 912 | static void __trace_graph_entry(struct trace_array *tr, |
287b6e68 FW |
913 | struct ftrace_graph_ent *trace, |
914 | unsigned long flags, | |
915 | int pc) | |
916 | { | |
917 | struct ring_buffer_event *event; | |
918 | struct ftrace_graph_ent_entry *entry; | |
287b6e68 FW |
919 | |
920 | if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) | |
921 | return; | |
922 | ||
51a763dd ACM |
923 | event = trace_buffer_lock_reserve(&global_trace, TRACE_GRAPH_ENT, |
924 | sizeof(*entry), flags, pc); | |
287b6e68 FW |
925 | if (!event) |
926 | return; | |
927 | entry = ring_buffer_event_data(event); | |
287b6e68 | 928 | entry->graph_ent = *trace; |
0a987751 | 929 | ring_buffer_unlock_commit(global_trace.buffer, event); |
287b6e68 FW |
930 | } |
931 | ||
932 | static void __trace_graph_return(struct trace_array *tr, | |
fb52607a | 933 | struct ftrace_graph_ret *trace, |
15e6cb36 FW |
934 | unsigned long flags, |
935 | int pc) | |
936 | { | |
937 | struct ring_buffer_event *event; | |
287b6e68 | 938 | struct ftrace_graph_ret_entry *entry; |
15e6cb36 FW |
939 | |
940 | if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) | |
941 | return; | |
942 | ||
51a763dd ACM |
943 | event = trace_buffer_lock_reserve(&global_trace, TRACE_GRAPH_RET, |
944 | sizeof(*entry), flags, pc); | |
15e6cb36 FW |
945 | if (!event) |
946 | return; | |
947 | entry = ring_buffer_event_data(event); | |
287b6e68 | 948 | entry->ret = *trace; |
0a987751 | 949 | ring_buffer_unlock_commit(global_trace.buffer, event); |
15e6cb36 FW |
950 | } |
951 | #endif | |
952 | ||
e309b41d | 953 | void |
2e0f5761 | 954 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, |
38697053 SR |
955 | unsigned long ip, unsigned long parent_ip, unsigned long flags, |
956 | int pc) | |
2e0f5761 IM |
957 | { |
958 | if (likely(!atomic_read(&data->disabled))) | |
7be42151 | 959 | trace_function(tr, ip, parent_ip, flags, pc); |
2e0f5761 IM |
960 | } |
961 | ||
53614991 | 962 | static void __ftrace_trace_stack(struct trace_array *tr, |
53614991 SR |
963 | unsigned long flags, |
964 | int skip, int pc) | |
86387f7e | 965 | { |
c2c80529 | 966 | #ifdef CONFIG_STACKTRACE |
3928a8a2 | 967 | struct ring_buffer_event *event; |
777e208d | 968 | struct stack_entry *entry; |
86387f7e IM |
969 | struct stack_trace trace; |
970 | ||
51a763dd ACM |
971 | event = trace_buffer_lock_reserve(tr, TRACE_STACK, |
972 | sizeof(*entry), flags, pc); | |
3928a8a2 SR |
973 | if (!event) |
974 | return; | |
975 | entry = ring_buffer_event_data(event); | |
777e208d | 976 | memset(&entry->caller, 0, sizeof(entry->caller)); |
86387f7e IM |
977 | |
978 | trace.nr_entries = 0; | |
979 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
980 | trace.skip = skip; | |
777e208d | 981 | trace.entries = entry->caller; |
86387f7e IM |
982 | |
983 | save_stack_trace(&trace); | |
0a987751 | 984 | ring_buffer_unlock_commit(tr->buffer, event); |
c2c80529 | 985 | #endif |
f0a920d5 IM |
986 | } |
987 | ||
53614991 | 988 | static void ftrace_trace_stack(struct trace_array *tr, |
53614991 SR |
989 | unsigned long flags, |
990 | int skip, int pc) | |
991 | { | |
992 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
993 | return; | |
994 | ||
7be42151 | 995 | __ftrace_trace_stack(tr, flags, skip, pc); |
53614991 SR |
996 | } |
997 | ||
38697053 | 998 | void __trace_stack(struct trace_array *tr, |
38697053 | 999 | unsigned long flags, |
53614991 | 1000 | int skip, int pc) |
38697053 | 1001 | { |
7be42151 | 1002 | __ftrace_trace_stack(tr, flags, skip, pc); |
38697053 SR |
1003 | } |
1004 | ||
02b67518 | 1005 | static void ftrace_trace_userstack(struct trace_array *tr, |
7be42151 | 1006 | unsigned long flags, int pc) |
02b67518 | 1007 | { |
c7425acb | 1008 | #ifdef CONFIG_STACKTRACE |
8d7c6a96 | 1009 | struct ring_buffer_event *event; |
02b67518 TE |
1010 | struct userstack_entry *entry; |
1011 | struct stack_trace trace; | |
02b67518 TE |
1012 | |
1013 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1014 | return; | |
1015 | ||
51a763dd ACM |
1016 | event = trace_buffer_lock_reserve(tr, TRACE_USER_STACK, |
1017 | sizeof(*entry), flags, pc); | |
02b67518 TE |
1018 | if (!event) |
1019 | return; | |
1020 | entry = ring_buffer_event_data(event); | |
02b67518 TE |
1021 | |
1022 | memset(&entry->caller, 0, sizeof(entry->caller)); | |
1023 | ||
1024 | trace.nr_entries = 0; | |
1025 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1026 | trace.skip = 0; | |
1027 | trace.entries = entry->caller; | |
1028 | ||
1029 | save_stack_trace_user(&trace); | |
0a987751 | 1030 | ring_buffer_unlock_commit(tr->buffer, event); |
c7425acb | 1031 | #endif |
02b67518 TE |
1032 | } |
1033 | ||
4fd27358 HE |
1034 | #ifdef UNUSED |
1035 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
02b67518 | 1036 | { |
7be42151 | 1037 | ftrace_trace_userstack(tr, flags, preempt_count()); |
02b67518 | 1038 | } |
4fd27358 | 1039 | #endif /* UNUSED */ |
02b67518 | 1040 | |
38697053 | 1041 | static void |
7be42151 | 1042 | ftrace_trace_special(void *__tr, |
38697053 SR |
1043 | unsigned long arg1, unsigned long arg2, unsigned long arg3, |
1044 | int pc) | |
a4feb834 | 1045 | { |
3928a8a2 | 1046 | struct ring_buffer_event *event; |
a4feb834 | 1047 | struct trace_array *tr = __tr; |
777e208d | 1048 | struct special_entry *entry; |
a4feb834 | 1049 | |
51a763dd ACM |
1050 | event = trace_buffer_lock_reserve(tr, TRACE_SPECIAL, |
1051 | sizeof(*entry), 0, pc); | |
3928a8a2 SR |
1052 | if (!event) |
1053 | return; | |
1054 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1055 | entry->arg1 = arg1; |
1056 | entry->arg2 = arg2; | |
1057 | entry->arg3 = arg3; | |
51a763dd | 1058 | trace_buffer_unlock_commit(tr, event, 0, pc); |
a4feb834 IM |
1059 | } |
1060 | ||
38697053 SR |
1061 | void |
1062 | __trace_special(void *__tr, void *__data, | |
1063 | unsigned long arg1, unsigned long arg2, unsigned long arg3) | |
1064 | { | |
7be42151 | 1065 | ftrace_trace_special(__tr, arg1, arg2, arg3, preempt_count()); |
38697053 SR |
1066 | } |
1067 | ||
e309b41d | 1068 | void |
bc0c38d1 | 1069 | tracing_sched_switch_trace(struct trace_array *tr, |
86387f7e IM |
1070 | struct task_struct *prev, |
1071 | struct task_struct *next, | |
38697053 | 1072 | unsigned long flags, int pc) |
bc0c38d1 | 1073 | { |
3928a8a2 | 1074 | struct ring_buffer_event *event; |
777e208d | 1075 | struct ctx_switch_entry *entry; |
bc0c38d1 | 1076 | |
51a763dd ACM |
1077 | event = trace_buffer_lock_reserve(tr, TRACE_CTX, |
1078 | sizeof(*entry), flags, pc); | |
3928a8a2 SR |
1079 | if (!event) |
1080 | return; | |
1081 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1082 | entry->prev_pid = prev->pid; |
1083 | entry->prev_prio = prev->prio; | |
1084 | entry->prev_state = prev->state; | |
1085 | entry->next_pid = next->pid; | |
1086 | entry->next_prio = next->prio; | |
1087 | entry->next_state = next->state; | |
1088 | entry->next_cpu = task_cpu(next); | |
51a763dd | 1089 | trace_buffer_unlock_commit(tr, event, flags, pc); |
bc0c38d1 SR |
1090 | } |
1091 | ||
57422797 IM |
1092 | void |
1093 | tracing_sched_wakeup_trace(struct trace_array *tr, | |
86387f7e IM |
1094 | struct task_struct *wakee, |
1095 | struct task_struct *curr, | |
38697053 | 1096 | unsigned long flags, int pc) |
57422797 | 1097 | { |
3928a8a2 | 1098 | struct ring_buffer_event *event; |
777e208d | 1099 | struct ctx_switch_entry *entry; |
57422797 | 1100 | |
51a763dd ACM |
1101 | event = trace_buffer_lock_reserve(tr, TRACE_WAKE, |
1102 | sizeof(*entry), flags, pc); | |
3928a8a2 SR |
1103 | if (!event) |
1104 | return; | |
1105 | entry = ring_buffer_event_data(event); | |
777e208d SR |
1106 | entry->prev_pid = curr->pid; |
1107 | entry->prev_prio = curr->prio; | |
1108 | entry->prev_state = curr->state; | |
1109 | entry->next_pid = wakee->pid; | |
1110 | entry->next_prio = wakee->prio; | |
1111 | entry->next_state = wakee->state; | |
1112 | entry->next_cpu = task_cpu(wakee); | |
6eaaa5d5 FW |
1113 | |
1114 | ring_buffer_unlock_commit(tr->buffer, event); | |
1115 | ftrace_trace_stack(tr, flags, 6, pc); | |
1116 | ftrace_trace_userstack(tr, flags, pc); | |
57422797 IM |
1117 | } |
1118 | ||
4902f884 SR |
1119 | void |
1120 | ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) | |
1121 | { | |
1122 | struct trace_array *tr = &global_trace; | |
1123 | struct trace_array_cpu *data; | |
5aa1ba6a | 1124 | unsigned long flags; |
4902f884 | 1125 | int cpu; |
38697053 | 1126 | int pc; |
4902f884 | 1127 | |
c76f0694 | 1128 | if (tracing_disabled) |
4902f884 SR |
1129 | return; |
1130 | ||
38697053 | 1131 | pc = preempt_count(); |
5aa1ba6a | 1132 | local_irq_save(flags); |
4902f884 SR |
1133 | cpu = raw_smp_processor_id(); |
1134 | data = tr->data[cpu]; | |
4902f884 | 1135 | |
5aa1ba6a | 1136 | if (likely(atomic_inc_return(&data->disabled) == 1)) |
7be42151 | 1137 | ftrace_trace_special(tr, arg1, arg2, arg3, pc); |
4902f884 | 1138 | |
5aa1ba6a SR |
1139 | atomic_dec(&data->disabled); |
1140 | local_irq_restore(flags); | |
4902f884 SR |
1141 | } |
1142 | ||
fb52607a | 1143 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e49dc19c | 1144 | int trace_graph_entry(struct ftrace_graph_ent *trace) |
15e6cb36 FW |
1145 | { |
1146 | struct trace_array *tr = &global_trace; | |
1147 | struct trace_array_cpu *data; | |
1148 | unsigned long flags; | |
1149 | long disabled; | |
1150 | int cpu; | |
1151 | int pc; | |
1152 | ||
804a6851 SR |
1153 | if (!ftrace_trace_task(current)) |
1154 | return 0; | |
1155 | ||
ea4e2bc4 SR |
1156 | if (!ftrace_graph_addr(trace->func)) |
1157 | return 0; | |
1158 | ||
a5e25883 | 1159 | local_irq_save(flags); |
15e6cb36 FW |
1160 | cpu = raw_smp_processor_id(); |
1161 | data = tr->data[cpu]; | |
1162 | disabled = atomic_inc_return(&data->disabled); | |
1163 | if (likely(disabled == 1)) { | |
1164 | pc = preempt_count(); | |
7be42151 | 1165 | __trace_graph_entry(tr, trace, flags, pc); |
287b6e68 | 1166 | } |
ea4e2bc4 SR |
1167 | /* Only do the atomic if it is not already set */ |
1168 | if (!test_tsk_trace_graph(current)) | |
1169 | set_tsk_trace_graph(current); | |
287b6e68 | 1170 | atomic_dec(&data->disabled); |
a5e25883 | 1171 | local_irq_restore(flags); |
e49dc19c SR |
1172 | |
1173 | return 1; | |
287b6e68 FW |
1174 | } |
1175 | ||
1176 | void trace_graph_return(struct ftrace_graph_ret *trace) | |
1177 | { | |
1178 | struct trace_array *tr = &global_trace; | |
1179 | struct trace_array_cpu *data; | |
1180 | unsigned long flags; | |
1181 | long disabled; | |
1182 | int cpu; | |
1183 | int pc; | |
1184 | ||
a5e25883 | 1185 | local_irq_save(flags); |
287b6e68 FW |
1186 | cpu = raw_smp_processor_id(); |
1187 | data = tr->data[cpu]; | |
1188 | disabled = atomic_inc_return(&data->disabled); | |
1189 | if (likely(disabled == 1)) { | |
1190 | pc = preempt_count(); | |
7be42151 | 1191 | __trace_graph_return(tr, trace, flags, pc); |
15e6cb36 | 1192 | } |
ea4e2bc4 SR |
1193 | if (!trace->depth) |
1194 | clear_tsk_trace_graph(current); | |
15e6cb36 | 1195 | atomic_dec(&data->disabled); |
a5e25883 | 1196 | local_irq_restore(flags); |
15e6cb36 | 1197 | } |
fb52607a | 1198 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
15e6cb36 | 1199 | |
769b0441 FW |
1200 | |
1201 | /** | |
48ead020 | 1202 | * trace_vbprintk - write binary msg to tracing buffer |
769b0441 FW |
1203 | * |
1204 | */ | |
40ce74f1 | 1205 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
769b0441 | 1206 | { |
80370cb7 SR |
1207 | static raw_spinlock_t trace_buf_lock = |
1208 | (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; | |
769b0441 FW |
1209 | static u32 trace_buf[TRACE_BUF_SIZE]; |
1210 | ||
1211 | struct ring_buffer_event *event; | |
1212 | struct trace_array *tr = &global_trace; | |
1213 | struct trace_array_cpu *data; | |
48ead020 | 1214 | struct bprint_entry *entry; |
769b0441 FW |
1215 | unsigned long flags; |
1216 | int resched; | |
1217 | int cpu, len = 0, size, pc; | |
1218 | ||
1219 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
1220 | return 0; | |
1221 | ||
1222 | /* Don't pollute graph traces with trace_vprintk internals */ | |
1223 | pause_graph_tracing(); | |
1224 | ||
1225 | pc = preempt_count(); | |
1226 | resched = ftrace_preempt_disable(); | |
1227 | cpu = raw_smp_processor_id(); | |
1228 | data = tr->data[cpu]; | |
1229 | ||
1230 | if (unlikely(atomic_read(&data->disabled))) | |
1231 | goto out; | |
1232 | ||
80370cb7 SR |
1233 | /* Lockdep uses trace_printk for lock tracing */ |
1234 | local_irq_save(flags); | |
1235 | __raw_spin_lock(&trace_buf_lock); | |
769b0441 FW |
1236 | len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); |
1237 | ||
1238 | if (len > TRACE_BUF_SIZE || len < 0) | |
1239 | goto out_unlock; | |
1240 | ||
1241 | size = sizeof(*entry) + sizeof(u32) * len; | |
48ead020 | 1242 | event = trace_buffer_lock_reserve(tr, TRACE_BPRINT, size, flags, pc); |
769b0441 FW |
1243 | if (!event) |
1244 | goto out_unlock; | |
1245 | entry = ring_buffer_event_data(event); | |
1246 | entry->ip = ip; | |
769b0441 FW |
1247 | entry->fmt = fmt; |
1248 | ||
1249 | memcpy(entry->buf, trace_buf, sizeof(u32) * len); | |
1250 | ring_buffer_unlock_commit(tr->buffer, event); | |
1251 | ||
1252 | out_unlock: | |
80370cb7 SR |
1253 | __raw_spin_unlock(&trace_buf_lock); |
1254 | local_irq_restore(flags); | |
769b0441 FW |
1255 | |
1256 | out: | |
1257 | ftrace_preempt_enable(resched); | |
1258 | unpause_graph_tracing(); | |
1259 | ||
1260 | return len; | |
1261 | } | |
48ead020 FW |
1262 | EXPORT_SYMBOL_GPL(trace_vbprintk); |
1263 | ||
40ce74f1 | 1264 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) |
48ead020 FW |
1265 | { |
1266 | static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED; | |
1267 | static char trace_buf[TRACE_BUF_SIZE]; | |
1268 | ||
1269 | struct ring_buffer_event *event; | |
1270 | struct trace_array *tr = &global_trace; | |
1271 | struct trace_array_cpu *data; | |
1272 | int cpu, len = 0, size, pc; | |
1273 | struct print_entry *entry; | |
1274 | unsigned long irq_flags; | |
1275 | ||
1276 | if (tracing_disabled || tracing_selftest_running) | |
1277 | return 0; | |
1278 | ||
1279 | pc = preempt_count(); | |
1280 | preempt_disable_notrace(); | |
1281 | cpu = raw_smp_processor_id(); | |
1282 | data = tr->data[cpu]; | |
1283 | ||
1284 | if (unlikely(atomic_read(&data->disabled))) | |
1285 | goto out; | |
1286 | ||
1287 | pause_graph_tracing(); | |
1288 | raw_local_irq_save(irq_flags); | |
1289 | __raw_spin_lock(&trace_buf_lock); | |
1290 | len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); | |
1291 | ||
1292 | len = min(len, TRACE_BUF_SIZE-1); | |
1293 | trace_buf[len] = 0; | |
1294 | ||
1295 | size = sizeof(*entry) + len + 1; | |
1296 | event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, irq_flags, pc); | |
1297 | if (!event) | |
1298 | goto out_unlock; | |
1299 | entry = ring_buffer_event_data(event); | |
1300 | entry->ip = ip; | |
48ead020 FW |
1301 | |
1302 | memcpy(&entry->buf, trace_buf, len); | |
1303 | entry->buf[len] = 0; | |
1304 | ring_buffer_unlock_commit(tr->buffer, event); | |
1305 | ||
1306 | out_unlock: | |
1307 | __raw_spin_unlock(&trace_buf_lock); | |
1308 | raw_local_irq_restore(irq_flags); | |
1309 | unpause_graph_tracing(); | |
1310 | out: | |
1311 | preempt_enable_notrace(); | |
1312 | ||
1313 | return len; | |
1314 | } | |
769b0441 FW |
1315 | EXPORT_SYMBOL_GPL(trace_vprintk); |
1316 | ||
bc0c38d1 SR |
1317 | enum trace_file_type { |
1318 | TRACE_FILE_LAT_FMT = 1, | |
12ef7d44 | 1319 | TRACE_FILE_ANNOTATE = 2, |
bc0c38d1 SR |
1320 | }; |
1321 | ||
e2ac8ef5 | 1322 | static void trace_iterator_increment(struct trace_iterator *iter) |
5a90f577 | 1323 | { |
d769041f SR |
1324 | /* Don't allow ftrace to trace into the ring buffers */ |
1325 | ftrace_disable_cpu(); | |
1326 | ||
5a90f577 | 1327 | iter->idx++; |
d769041f SR |
1328 | if (iter->buffer_iter[iter->cpu]) |
1329 | ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); | |
1330 | ||
1331 | ftrace_enable_cpu(); | |
5a90f577 SR |
1332 | } |
1333 | ||
e309b41d | 1334 | static struct trace_entry * |
3928a8a2 | 1335 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) |
dd0e545f | 1336 | { |
3928a8a2 SR |
1337 | struct ring_buffer_event *event; |
1338 | struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; | |
dd0e545f | 1339 | |
d769041f SR |
1340 | /* Don't allow ftrace to trace into the ring buffers */ |
1341 | ftrace_disable_cpu(); | |
1342 | ||
1343 | if (buf_iter) | |
1344 | event = ring_buffer_iter_peek(buf_iter, ts); | |
1345 | else | |
1346 | event = ring_buffer_peek(iter->tr->buffer, cpu, ts); | |
1347 | ||
1348 | ftrace_enable_cpu(); | |
1349 | ||
3928a8a2 | 1350 | return event ? ring_buffer_event_data(event) : NULL; |
dd0e545f | 1351 | } |
d769041f | 1352 | |
dd0e545f | 1353 | static struct trace_entry * |
3928a8a2 | 1354 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) |
bc0c38d1 | 1355 | { |
3928a8a2 | 1356 | struct ring_buffer *buffer = iter->tr->buffer; |
bc0c38d1 | 1357 | struct trace_entry *ent, *next = NULL; |
b04cc6b1 | 1358 | int cpu_file = iter->cpu_file; |
3928a8a2 | 1359 | u64 next_ts = 0, ts; |
bc0c38d1 SR |
1360 | int next_cpu = -1; |
1361 | int cpu; | |
1362 | ||
b04cc6b1 FW |
1363 | /* |
1364 | * If we are in a per_cpu trace file, don't bother by iterating over | |
1365 | * all cpu and peek directly. | |
1366 | */ | |
1367 | if (cpu_file > TRACE_PIPE_ALL_CPU) { | |
1368 | if (ring_buffer_empty_cpu(buffer, cpu_file)) | |
1369 | return NULL; | |
1370 | ent = peek_next_entry(iter, cpu_file, ent_ts); | |
1371 | if (ent_cpu) | |
1372 | *ent_cpu = cpu_file; | |
1373 | ||
1374 | return ent; | |
1375 | } | |
1376 | ||
ab46428c | 1377 | for_each_tracing_cpu(cpu) { |
dd0e545f | 1378 | |
3928a8a2 SR |
1379 | if (ring_buffer_empty_cpu(buffer, cpu)) |
1380 | continue; | |
dd0e545f | 1381 | |
3928a8a2 | 1382 | ent = peek_next_entry(iter, cpu, &ts); |
dd0e545f | 1383 | |
cdd31cd2 IM |
1384 | /* |
1385 | * Pick the entry with the smallest timestamp: | |
1386 | */ | |
3928a8a2 | 1387 | if (ent && (!next || ts < next_ts)) { |
bc0c38d1 SR |
1388 | next = ent; |
1389 | next_cpu = cpu; | |
3928a8a2 | 1390 | next_ts = ts; |
bc0c38d1 SR |
1391 | } |
1392 | } | |
1393 | ||
1394 | if (ent_cpu) | |
1395 | *ent_cpu = next_cpu; | |
1396 | ||
3928a8a2 SR |
1397 | if (ent_ts) |
1398 | *ent_ts = next_ts; | |
1399 | ||
bc0c38d1 SR |
1400 | return next; |
1401 | } | |
1402 | ||
dd0e545f | 1403 | /* Find the next real entry, without updating the iterator itself */ |
c4a8e8be FW |
1404 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
1405 | int *ent_cpu, u64 *ent_ts) | |
bc0c38d1 | 1406 | { |
3928a8a2 | 1407 | return __find_next_entry(iter, ent_cpu, ent_ts); |
dd0e545f SR |
1408 | } |
1409 | ||
1410 | /* Find the next real entry, and increment the iterator to the next entry */ | |
1411 | static void *find_next_entry_inc(struct trace_iterator *iter) | |
1412 | { | |
3928a8a2 | 1413 | iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts); |
dd0e545f | 1414 | |
3928a8a2 | 1415 | if (iter->ent) |
e2ac8ef5 | 1416 | trace_iterator_increment(iter); |
dd0e545f | 1417 | |
3928a8a2 | 1418 | return iter->ent ? iter : NULL; |
b3806b43 | 1419 | } |
bc0c38d1 | 1420 | |
e309b41d | 1421 | static void trace_consume(struct trace_iterator *iter) |
b3806b43 | 1422 | { |
d769041f SR |
1423 | /* Don't allow ftrace to trace into the ring buffers */ |
1424 | ftrace_disable_cpu(); | |
3928a8a2 | 1425 | ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts); |
d769041f | 1426 | ftrace_enable_cpu(); |
bc0c38d1 SR |
1427 | } |
1428 | ||
e309b41d | 1429 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
1430 | { |
1431 | struct trace_iterator *iter = m->private; | |
bc0c38d1 | 1432 | int i = (int)*pos; |
4e3c3333 | 1433 | void *ent; |
bc0c38d1 SR |
1434 | |
1435 | (*pos)++; | |
1436 | ||
1437 | /* can't go backwards */ | |
1438 | if (iter->idx > i) | |
1439 | return NULL; | |
1440 | ||
1441 | if (iter->idx < 0) | |
1442 | ent = find_next_entry_inc(iter); | |
1443 | else | |
1444 | ent = iter; | |
1445 | ||
1446 | while (ent && iter->idx < i) | |
1447 | ent = find_next_entry_inc(iter); | |
1448 | ||
1449 | iter->pos = *pos; | |
1450 | ||
bc0c38d1 SR |
1451 | return ent; |
1452 | } | |
1453 | ||
d7350c3f FW |
1454 | /* |
1455 | * No necessary locking here. The worst thing which can | |
1456 | * happen is loosing events consumed at the same time | |
1457 | * by a trace_pipe reader. | |
1458 | * Other than that, we don't risk to crash the ring buffer | |
1459 | * because it serializes the readers. | |
1460 | * | |
1461 | * The current tracer is copied to avoid a global locking | |
1462 | * all around. | |
1463 | */ | |
bc0c38d1 SR |
1464 | static void *s_start(struct seq_file *m, loff_t *pos) |
1465 | { | |
1466 | struct trace_iterator *iter = m->private; | |
d7350c3f | 1467 | static struct tracer *old_tracer; |
b04cc6b1 | 1468 | int cpu_file = iter->cpu_file; |
bc0c38d1 SR |
1469 | void *p = NULL; |
1470 | loff_t l = 0; | |
3928a8a2 | 1471 | int cpu; |
bc0c38d1 | 1472 | |
d7350c3f | 1473 | /* copy the tracer to avoid using a global lock all around */ |
bc0c38d1 | 1474 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
1475 | if (unlikely(old_tracer != current_trace && current_trace)) { |
1476 | old_tracer = current_trace; | |
1477 | *iter->trace = *current_trace; | |
d15f57f2 | 1478 | } |
d7350c3f | 1479 | mutex_unlock(&trace_types_lock); |
bc0c38d1 SR |
1480 | |
1481 | atomic_inc(&trace_record_cmdline_disabled); | |
1482 | ||
bc0c38d1 SR |
1483 | if (*pos != iter->pos) { |
1484 | iter->ent = NULL; | |
1485 | iter->cpu = 0; | |
1486 | iter->idx = -1; | |
1487 | ||
d769041f SR |
1488 | ftrace_disable_cpu(); |
1489 | ||
b04cc6b1 FW |
1490 | if (cpu_file == TRACE_PIPE_ALL_CPU) { |
1491 | for_each_tracing_cpu(cpu) | |
1492 | ring_buffer_iter_reset(iter->buffer_iter[cpu]); | |
1493 | } else | |
1494 | ring_buffer_iter_reset(iter->buffer_iter[cpu_file]); | |
1495 | ||
bc0c38d1 | 1496 | |
d769041f SR |
1497 | ftrace_enable_cpu(); |
1498 | ||
bc0c38d1 SR |
1499 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
1500 | ; | |
1501 | ||
1502 | } else { | |
4c11d7ae | 1503 | l = *pos - 1; |
bc0c38d1 SR |
1504 | p = s_next(m, p, &l); |
1505 | } | |
1506 | ||
1507 | return p; | |
1508 | } | |
1509 | ||
1510 | static void s_stop(struct seq_file *m, void *p) | |
1511 | { | |
bc0c38d1 | 1512 | atomic_dec(&trace_record_cmdline_disabled); |
bc0c38d1 SR |
1513 | } |
1514 | ||
e309b41d | 1515 | static void print_lat_help_header(struct seq_file *m) |
bc0c38d1 | 1516 | { |
a6168353 ME |
1517 | seq_puts(m, "# _------=> CPU# \n"); |
1518 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
1519 | seq_puts(m, "# | / _----=> need-resched \n"); | |
1520 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
1521 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
1522 | seq_puts(m, "# |||| / \n"); | |
1523 | seq_puts(m, "# ||||| delay \n"); | |
1524 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
1525 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
bc0c38d1 SR |
1526 | } |
1527 | ||
e309b41d | 1528 | static void print_func_help_header(struct seq_file *m) |
bc0c38d1 | 1529 | { |
a6168353 ME |
1530 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); |
1531 | seq_puts(m, "# | | | | |\n"); | |
bc0c38d1 SR |
1532 | } |
1533 | ||
1534 | ||
e309b41d | 1535 | static void |
bc0c38d1 SR |
1536 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
1537 | { | |
1538 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
1539 | struct trace_array *tr = iter->tr; | |
1540 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
1541 | struct tracer *type = current_trace; | |
3928a8a2 SR |
1542 | unsigned long total; |
1543 | unsigned long entries; | |
bc0c38d1 SR |
1544 | const char *name = "preemption"; |
1545 | ||
1546 | if (type) | |
1547 | name = type->name; | |
1548 | ||
3928a8a2 SR |
1549 | entries = ring_buffer_entries(iter->tr->buffer); |
1550 | total = entries + | |
1551 | ring_buffer_overruns(iter->tr->buffer); | |
bc0c38d1 | 1552 | |
888b55dc | 1553 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
bc0c38d1 | 1554 | name, UTS_RELEASE); |
888b55dc | 1555 | seq_puts(m, "# -----------------------------------" |
bc0c38d1 | 1556 | "---------------------------------\n"); |
888b55dc | 1557 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
bc0c38d1 | 1558 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
57f50be1 | 1559 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 1560 | entries, |
4c11d7ae | 1561 | total, |
bc0c38d1 SR |
1562 | tr->cpu, |
1563 | #if defined(CONFIG_PREEMPT_NONE) | |
1564 | "server", | |
1565 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
1566 | "desktop", | |
b5c21b45 | 1567 | #elif defined(CONFIG_PREEMPT) |
bc0c38d1 SR |
1568 | "preempt", |
1569 | #else | |
1570 | "unknown", | |
1571 | #endif | |
1572 | /* These are reserved for later use */ | |
1573 | 0, 0, 0, 0); | |
1574 | #ifdef CONFIG_SMP | |
1575 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
1576 | #else | |
1577 | seq_puts(m, ")\n"); | |
1578 | #endif | |
888b55dc KM |
1579 | seq_puts(m, "# -----------------\n"); |
1580 | seq_printf(m, "# | task: %.16s-%d " | |
bc0c38d1 SR |
1581 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
1582 | data->comm, data->pid, data->uid, data->nice, | |
1583 | data->policy, data->rt_priority); | |
888b55dc | 1584 | seq_puts(m, "# -----------------\n"); |
bc0c38d1 SR |
1585 | |
1586 | if (data->critical_start) { | |
888b55dc | 1587 | seq_puts(m, "# => started at: "); |
214023c3 SR |
1588 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
1589 | trace_print_seq(m, &iter->seq); | |
888b55dc | 1590 | seq_puts(m, "\n# => ended at: "); |
214023c3 SR |
1591 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
1592 | trace_print_seq(m, &iter->seq); | |
888b55dc | 1593 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
1594 | } |
1595 | ||
888b55dc | 1596 | seq_puts(m, "#\n"); |
bc0c38d1 SR |
1597 | } |
1598 | ||
a309720c SR |
1599 | static void test_cpu_buff_start(struct trace_iterator *iter) |
1600 | { | |
1601 | struct trace_seq *s = &iter->seq; | |
1602 | ||
12ef7d44 SR |
1603 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) |
1604 | return; | |
1605 | ||
1606 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
1607 | return; | |
1608 | ||
4462344e | 1609 | if (cpumask_test_cpu(iter->cpu, iter->started)) |
a309720c SR |
1610 | return; |
1611 | ||
4462344e | 1612 | cpumask_set_cpu(iter->cpu, iter->started); |
a309720c SR |
1613 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu); |
1614 | } | |
1615 | ||
2c4f035f | 1616 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 1617 | { |
214023c3 | 1618 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 1619 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 1620 | struct trace_entry *entry; |
f633cef0 | 1621 | struct trace_event *event; |
bc0c38d1 | 1622 | |
4e3c3333 | 1623 | entry = iter->ent; |
dd0e545f | 1624 | |
a309720c SR |
1625 | test_cpu_buff_start(iter); |
1626 | ||
c4a8e8be | 1627 | event = ftrace_find_event(entry->type); |
bc0c38d1 | 1628 | |
c4a8e8be | 1629 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
27d48be8 SR |
1630 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
1631 | if (!trace_print_lat_context(iter)) | |
1632 | goto partial; | |
1633 | } else { | |
1634 | if (!trace_print_context(iter)) | |
1635 | goto partial; | |
1636 | } | |
c4a8e8be | 1637 | } |
bc0c38d1 | 1638 | |
268ccda0 | 1639 | if (event) |
d9793bd8 ACM |
1640 | return event->trace(iter, sym_flags); |
1641 | ||
1642 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
1643 | goto partial; | |
02b67518 | 1644 | |
2c4f035f | 1645 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
1646 | partial: |
1647 | return TRACE_TYPE_PARTIAL_LINE; | |
bc0c38d1 SR |
1648 | } |
1649 | ||
2c4f035f | 1650 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
f9896bf3 IM |
1651 | { |
1652 | struct trace_seq *s = &iter->seq; | |
1653 | struct trace_entry *entry; | |
f633cef0 | 1654 | struct trace_event *event; |
f9896bf3 IM |
1655 | |
1656 | entry = iter->ent; | |
dd0e545f | 1657 | |
c4a8e8be | 1658 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
d9793bd8 ACM |
1659 | if (!trace_seq_printf(s, "%d %d %llu ", |
1660 | entry->pid, iter->cpu, iter->ts)) | |
1661 | goto partial; | |
c4a8e8be | 1662 | } |
f9896bf3 | 1663 | |
f633cef0 | 1664 | event = ftrace_find_event(entry->type); |
268ccda0 | 1665 | if (event) |
d9793bd8 ACM |
1666 | return event->raw(iter, 0); |
1667 | ||
1668 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
1669 | goto partial; | |
777e208d | 1670 | |
2c4f035f | 1671 | return TRACE_TYPE_HANDLED; |
d9793bd8 ACM |
1672 | partial: |
1673 | return TRACE_TYPE_PARTIAL_LINE; | |
f9896bf3 IM |
1674 | } |
1675 | ||
2c4f035f | 1676 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
5e3ca0ec IM |
1677 | { |
1678 | struct trace_seq *s = &iter->seq; | |
1679 | unsigned char newline = '\n'; | |
1680 | struct trace_entry *entry; | |
f633cef0 | 1681 | struct trace_event *event; |
5e3ca0ec IM |
1682 | |
1683 | entry = iter->ent; | |
dd0e545f | 1684 | |
c4a8e8be FW |
1685 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
1686 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
1687 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
1688 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
1689 | } | |
5e3ca0ec | 1690 | |
f633cef0 | 1691 | event = ftrace_find_event(entry->type); |
268ccda0 | 1692 | if (event) { |
ae7462b4 | 1693 | enum print_line_t ret = event->hex(iter, 0); |
d9793bd8 ACM |
1694 | if (ret != TRACE_TYPE_HANDLED) |
1695 | return ret; | |
1696 | } | |
7104f300 | 1697 | |
5e3ca0ec IM |
1698 | SEQ_PUT_FIELD_RET(s, newline); |
1699 | ||
2c4f035f | 1700 | return TRACE_TYPE_HANDLED; |
5e3ca0ec IM |
1701 | } |
1702 | ||
2c4f035f | 1703 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
cb0f12aa IM |
1704 | { |
1705 | struct trace_seq *s = &iter->seq; | |
1706 | struct trace_entry *entry; | |
f633cef0 | 1707 | struct trace_event *event; |
cb0f12aa IM |
1708 | |
1709 | entry = iter->ent; | |
dd0e545f | 1710 | |
c4a8e8be FW |
1711 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
1712 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
1830b52d | 1713 | SEQ_PUT_FIELD_RET(s, iter->cpu); |
c4a8e8be FW |
1714 | SEQ_PUT_FIELD_RET(s, iter->ts); |
1715 | } | |
cb0f12aa | 1716 | |
f633cef0 | 1717 | event = ftrace_find_event(entry->type); |
268ccda0 | 1718 | return event ? event->binary(iter, 0) : TRACE_TYPE_HANDLED; |
cb0f12aa IM |
1719 | } |
1720 | ||
bc0c38d1 SR |
1721 | static int trace_empty(struct trace_iterator *iter) |
1722 | { | |
bc0c38d1 SR |
1723 | int cpu; |
1724 | ||
9aba60fe SR |
1725 | /* If we are looking at one CPU buffer, only check that one */ |
1726 | if (iter->cpu_file != TRACE_PIPE_ALL_CPU) { | |
1727 | cpu = iter->cpu_file; | |
1728 | if (iter->buffer_iter[cpu]) { | |
1729 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
1730 | return 0; | |
1731 | } else { | |
1732 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
1733 | return 0; | |
1734 | } | |
1735 | return 1; | |
1736 | } | |
1737 | ||
ab46428c | 1738 | for_each_tracing_cpu(cpu) { |
d769041f SR |
1739 | if (iter->buffer_iter[cpu]) { |
1740 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
1741 | return 0; | |
1742 | } else { | |
1743 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
1744 | return 0; | |
1745 | } | |
bc0c38d1 | 1746 | } |
d769041f | 1747 | |
797d3712 | 1748 | return 1; |
bc0c38d1 SR |
1749 | } |
1750 | ||
2c4f035f | 1751 | static enum print_line_t print_trace_line(struct trace_iterator *iter) |
f9896bf3 | 1752 | { |
2c4f035f FW |
1753 | enum print_line_t ret; |
1754 | ||
1755 | if (iter->trace && iter->trace->print_line) { | |
1756 | ret = iter->trace->print_line(iter); | |
1757 | if (ret != TRACE_TYPE_UNHANDLED) | |
1758 | return ret; | |
1759 | } | |
72829bc3 | 1760 | |
48ead020 FW |
1761 | if (iter->ent->type == TRACE_BPRINT && |
1762 | trace_flags & TRACE_ITER_PRINTK && | |
1763 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 1764 | return trace_print_bprintk_msg_only(iter); |
48ead020 | 1765 | |
66896a85 FW |
1766 | if (iter->ent->type == TRACE_PRINT && |
1767 | trace_flags & TRACE_ITER_PRINTK && | |
1768 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
5ef841f6 | 1769 | return trace_print_printk_msg_only(iter); |
66896a85 | 1770 | |
cb0f12aa IM |
1771 | if (trace_flags & TRACE_ITER_BIN) |
1772 | return print_bin_fmt(iter); | |
1773 | ||
5e3ca0ec IM |
1774 | if (trace_flags & TRACE_ITER_HEX) |
1775 | return print_hex_fmt(iter); | |
1776 | ||
f9896bf3 IM |
1777 | if (trace_flags & TRACE_ITER_RAW) |
1778 | return print_raw_fmt(iter); | |
1779 | ||
f9896bf3 IM |
1780 | return print_trace_fmt(iter); |
1781 | } | |
1782 | ||
bc0c38d1 SR |
1783 | static int s_show(struct seq_file *m, void *v) |
1784 | { | |
1785 | struct trace_iterator *iter = v; | |
1786 | ||
1787 | if (iter->ent == NULL) { | |
1788 | if (iter->tr) { | |
1789 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
1790 | seq_puts(m, "#\n"); | |
1791 | } | |
8bba1bf5 MM |
1792 | if (iter->trace && iter->trace->print_header) |
1793 | iter->trace->print_header(m); | |
1794 | else if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
bc0c38d1 SR |
1795 | /* print nothing if the buffers are empty */ |
1796 | if (trace_empty(iter)) | |
1797 | return 0; | |
1798 | print_trace_header(m, iter); | |
1799 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1800 | print_lat_help_header(m); | |
1801 | } else { | |
1802 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1803 | print_func_help_header(m); | |
1804 | } | |
1805 | } else { | |
f9896bf3 | 1806 | print_trace_line(iter); |
214023c3 | 1807 | trace_print_seq(m, &iter->seq); |
bc0c38d1 SR |
1808 | } |
1809 | ||
1810 | return 0; | |
1811 | } | |
1812 | ||
1813 | static struct seq_operations tracer_seq_ops = { | |
4bf39a94 IM |
1814 | .start = s_start, |
1815 | .next = s_next, | |
1816 | .stop = s_stop, | |
1817 | .show = s_show, | |
bc0c38d1 SR |
1818 | }; |
1819 | ||
e309b41d | 1820 | static struct trace_iterator * |
85a2f9b4 | 1821 | __tracing_open(struct inode *inode, struct file *file) |
bc0c38d1 | 1822 | { |
b04cc6b1 | 1823 | long cpu_file = (long) inode->i_private; |
85a2f9b4 | 1824 | void *fail_ret = ERR_PTR(-ENOMEM); |
bc0c38d1 | 1825 | struct trace_iterator *iter; |
3928a8a2 | 1826 | struct seq_file *m; |
85a2f9b4 | 1827 | int cpu, ret; |
bc0c38d1 | 1828 | |
85a2f9b4 SR |
1829 | if (tracing_disabled) |
1830 | return ERR_PTR(-ENODEV); | |
60a11774 | 1831 | |
bc0c38d1 | 1832 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
85a2f9b4 SR |
1833 | if (!iter) |
1834 | return ERR_PTR(-ENOMEM); | |
bc0c38d1 | 1835 | |
d7350c3f FW |
1836 | /* |
1837 | * We make a copy of the current tracer to avoid concurrent | |
1838 | * changes on it while we are reading. | |
1839 | */ | |
bc0c38d1 | 1840 | mutex_lock(&trace_types_lock); |
d7350c3f | 1841 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
85a2f9b4 | 1842 | if (!iter->trace) |
d7350c3f | 1843 | goto fail; |
85a2f9b4 | 1844 | |
d7350c3f FW |
1845 | if (current_trace) |
1846 | *iter->trace = *current_trace; | |
1847 | ||
bc0c38d1 SR |
1848 | if (current_trace && current_trace->print_max) |
1849 | iter->tr = &max_tr; | |
1850 | else | |
b04cc6b1 | 1851 | iter->tr = &global_trace; |
bc0c38d1 | 1852 | iter->pos = -1; |
d7350c3f | 1853 | mutex_init(&iter->mutex); |
b04cc6b1 | 1854 | iter->cpu_file = cpu_file; |
bc0c38d1 | 1855 | |
8bba1bf5 MM |
1856 | /* Notify the tracer early; before we stop tracing. */ |
1857 | if (iter->trace && iter->trace->open) | |
a93751ca | 1858 | iter->trace->open(iter); |
8bba1bf5 | 1859 | |
12ef7d44 SR |
1860 | /* Annotate start of buffers if we had overruns */ |
1861 | if (ring_buffer_overruns(iter->tr->buffer)) | |
1862 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
1863 | ||
b04cc6b1 FW |
1864 | if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { |
1865 | for_each_tracing_cpu(cpu) { | |
12ef7d44 | 1866 | |
b04cc6b1 FW |
1867 | iter->buffer_iter[cpu] = |
1868 | ring_buffer_read_start(iter->tr->buffer, cpu); | |
b04cc6b1 FW |
1869 | } |
1870 | } else { | |
1871 | cpu = iter->cpu_file; | |
3928a8a2 | 1872 | iter->buffer_iter[cpu] = |
b04cc6b1 | 1873 | ring_buffer_read_start(iter->tr->buffer, cpu); |
3928a8a2 SR |
1874 | } |
1875 | ||
bc0c38d1 | 1876 | /* TODO stop tracer */ |
85a2f9b4 SR |
1877 | ret = seq_open(file, &tracer_seq_ops); |
1878 | if (ret < 0) { | |
1879 | fail_ret = ERR_PTR(ret); | |
3928a8a2 | 1880 | goto fail_buffer; |
85a2f9b4 | 1881 | } |
bc0c38d1 | 1882 | |
3928a8a2 SR |
1883 | m = file->private_data; |
1884 | m->private = iter; | |
bc0c38d1 | 1885 | |
3928a8a2 | 1886 | /* stop the trace while dumping */ |
9036990d | 1887 | tracing_stop(); |
3928a8a2 | 1888 | |
bc0c38d1 SR |
1889 | mutex_unlock(&trace_types_lock); |
1890 | ||
bc0c38d1 | 1891 | return iter; |
3928a8a2 SR |
1892 | |
1893 | fail_buffer: | |
1894 | for_each_tracing_cpu(cpu) { | |
1895 | if (iter->buffer_iter[cpu]) | |
1896 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
1897 | } | |
d7350c3f | 1898 | fail: |
3928a8a2 | 1899 | mutex_unlock(&trace_types_lock); |
d7350c3f | 1900 | kfree(iter->trace); |
0bb943c7 | 1901 | kfree(iter); |
3928a8a2 | 1902 | |
85a2f9b4 | 1903 | return fail_ret; |
bc0c38d1 SR |
1904 | } |
1905 | ||
1906 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
1907 | { | |
60a11774 SR |
1908 | if (tracing_disabled) |
1909 | return -ENODEV; | |
1910 | ||
bc0c38d1 SR |
1911 | filp->private_data = inode->i_private; |
1912 | return 0; | |
1913 | } | |
1914 | ||
4fd27358 | 1915 | static int tracing_release(struct inode *inode, struct file *file) |
bc0c38d1 SR |
1916 | { |
1917 | struct seq_file *m = (struct seq_file *)file->private_data; | |
4acd4d00 | 1918 | struct trace_iterator *iter; |
3928a8a2 | 1919 | int cpu; |
bc0c38d1 | 1920 | |
4acd4d00 SR |
1921 | if (!(file->f_mode & FMODE_READ)) |
1922 | return 0; | |
1923 | ||
1924 | iter = m->private; | |
1925 | ||
bc0c38d1 | 1926 | mutex_lock(&trace_types_lock); |
3928a8a2 SR |
1927 | for_each_tracing_cpu(cpu) { |
1928 | if (iter->buffer_iter[cpu]) | |
1929 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
1930 | } | |
1931 | ||
bc0c38d1 SR |
1932 | if (iter->trace && iter->trace->close) |
1933 | iter->trace->close(iter); | |
1934 | ||
1935 | /* reenable tracing if it was previously enabled */ | |
9036990d | 1936 | tracing_start(); |
bc0c38d1 SR |
1937 | mutex_unlock(&trace_types_lock); |
1938 | ||
1939 | seq_release(inode, file); | |
d7350c3f FW |
1940 | mutex_destroy(&iter->mutex); |
1941 | kfree(iter->trace); | |
bc0c38d1 SR |
1942 | kfree(iter); |
1943 | return 0; | |
1944 | } | |
1945 | ||
1946 | static int tracing_open(struct inode *inode, struct file *file) | |
1947 | { | |
85a2f9b4 SR |
1948 | struct trace_iterator *iter; |
1949 | int ret = 0; | |
bc0c38d1 | 1950 | |
4acd4d00 SR |
1951 | /* If this file was open for write, then erase contents */ |
1952 | if ((file->f_mode & FMODE_WRITE) && | |
1953 | !(file->f_flags & O_APPEND)) { | |
1954 | long cpu = (long) inode->i_private; | |
bc0c38d1 | 1955 | |
4acd4d00 SR |
1956 | if (cpu == TRACE_PIPE_ALL_CPU) |
1957 | tracing_reset_online_cpus(&global_trace); | |
1958 | else | |
1959 | tracing_reset(&global_trace, cpu); | |
1960 | } | |
bc0c38d1 | 1961 | |
4acd4d00 SR |
1962 | if (file->f_mode & FMODE_READ) { |
1963 | iter = __tracing_open(inode, file); | |
1964 | if (IS_ERR(iter)) | |
1965 | ret = PTR_ERR(iter); | |
1966 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
1967 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
1968 | } | |
bc0c38d1 SR |
1969 | return ret; |
1970 | } | |
1971 | ||
e309b41d | 1972 | static void * |
bc0c38d1 SR |
1973 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1974 | { | |
1975 | struct tracer *t = m->private; | |
1976 | ||
1977 | (*pos)++; | |
1978 | ||
1979 | if (t) | |
1980 | t = t->next; | |
1981 | ||
1982 | m->private = t; | |
1983 | ||
1984 | return t; | |
1985 | } | |
1986 | ||
1987 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1988 | { | |
1989 | struct tracer *t = m->private; | |
1990 | loff_t l = 0; | |
1991 | ||
1992 | mutex_lock(&trace_types_lock); | |
1993 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
1994 | ; | |
1995 | ||
1996 | return t; | |
1997 | } | |
1998 | ||
1999 | static void t_stop(struct seq_file *m, void *p) | |
2000 | { | |
2001 | mutex_unlock(&trace_types_lock); | |
2002 | } | |
2003 | ||
2004 | static int t_show(struct seq_file *m, void *v) | |
2005 | { | |
2006 | struct tracer *t = v; | |
2007 | ||
2008 | if (!t) | |
2009 | return 0; | |
2010 | ||
2011 | seq_printf(m, "%s", t->name); | |
2012 | if (t->next) | |
2013 | seq_putc(m, ' '); | |
2014 | else | |
2015 | seq_putc(m, '\n'); | |
2016 | ||
2017 | return 0; | |
2018 | } | |
2019 | ||
2020 | static struct seq_operations show_traces_seq_ops = { | |
4bf39a94 IM |
2021 | .start = t_start, |
2022 | .next = t_next, | |
2023 | .stop = t_stop, | |
2024 | .show = t_show, | |
bc0c38d1 SR |
2025 | }; |
2026 | ||
2027 | static int show_traces_open(struct inode *inode, struct file *file) | |
2028 | { | |
2029 | int ret; | |
2030 | ||
60a11774 SR |
2031 | if (tracing_disabled) |
2032 | return -ENODEV; | |
2033 | ||
bc0c38d1 SR |
2034 | ret = seq_open(file, &show_traces_seq_ops); |
2035 | if (!ret) { | |
2036 | struct seq_file *m = file->private_data; | |
2037 | m->private = trace_types; | |
2038 | } | |
2039 | ||
2040 | return ret; | |
2041 | } | |
2042 | ||
4acd4d00 SR |
2043 | static ssize_t |
2044 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
2045 | size_t count, loff_t *ppos) | |
2046 | { | |
2047 | return count; | |
2048 | } | |
2049 | ||
5e2336a0 | 2050 | static const struct file_operations tracing_fops = { |
4bf39a94 IM |
2051 | .open = tracing_open, |
2052 | .read = seq_read, | |
4acd4d00 | 2053 | .write = tracing_write_stub, |
4bf39a94 IM |
2054 | .llseek = seq_lseek, |
2055 | .release = tracing_release, | |
bc0c38d1 SR |
2056 | }; |
2057 | ||
5e2336a0 | 2058 | static const struct file_operations show_traces_fops = { |
c7078de1 IM |
2059 | .open = show_traces_open, |
2060 | .read = seq_read, | |
2061 | .release = seq_release, | |
2062 | }; | |
2063 | ||
36dfe925 IM |
2064 | /* |
2065 | * Only trace on a CPU if the bitmask is set: | |
2066 | */ | |
9e01c1b7 | 2067 | static cpumask_var_t tracing_cpumask; |
36dfe925 IM |
2068 | |
2069 | /* | |
2070 | * The tracer itself will not take this lock, but still we want | |
2071 | * to provide a consistent cpumask to user-space: | |
2072 | */ | |
2073 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
2074 | ||
2075 | /* | |
2076 | * Temporary storage for the character representation of the | |
2077 | * CPU bitmask (and one more byte for the newline): | |
2078 | */ | |
2079 | static char mask_str[NR_CPUS + 1]; | |
2080 | ||
c7078de1 IM |
2081 | static ssize_t |
2082 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
2083 | size_t count, loff_t *ppos) | |
2084 | { | |
36dfe925 | 2085 | int len; |
c7078de1 IM |
2086 | |
2087 | mutex_lock(&tracing_cpumask_update_lock); | |
36dfe925 | 2088 | |
9e01c1b7 | 2089 | len = cpumask_scnprintf(mask_str, count, tracing_cpumask); |
36dfe925 IM |
2090 | if (count - len < 2) { |
2091 | count = -EINVAL; | |
2092 | goto out_err; | |
2093 | } | |
2094 | len += sprintf(mask_str + len, "\n"); | |
2095 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
2096 | ||
2097 | out_err: | |
c7078de1 IM |
2098 | mutex_unlock(&tracing_cpumask_update_lock); |
2099 | ||
2100 | return count; | |
2101 | } | |
2102 | ||
2103 | static ssize_t | |
2104 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
2105 | size_t count, loff_t *ppos) | |
2106 | { | |
36dfe925 | 2107 | int err, cpu; |
9e01c1b7 RR |
2108 | cpumask_var_t tracing_cpumask_new; |
2109 | ||
2110 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
2111 | return -ENOMEM; | |
c7078de1 IM |
2112 | |
2113 | mutex_lock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 2114 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
c7078de1 | 2115 | if (err) |
36dfe925 IM |
2116 | goto err_unlock; |
2117 | ||
a5e25883 | 2118 | local_irq_disable(); |
92205c23 | 2119 | __raw_spin_lock(&ftrace_max_lock); |
ab46428c | 2120 | for_each_tracing_cpu(cpu) { |
36dfe925 IM |
2121 | /* |
2122 | * Increase/decrease the disabled counter if we are | |
2123 | * about to flip a bit in the cpumask: | |
2124 | */ | |
9e01c1b7 RR |
2125 | if (cpumask_test_cpu(cpu, tracing_cpumask) && |
2126 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 IM |
2127 | atomic_inc(&global_trace.data[cpu]->disabled); |
2128 | } | |
9e01c1b7 RR |
2129 | if (!cpumask_test_cpu(cpu, tracing_cpumask) && |
2130 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
36dfe925 IM |
2131 | atomic_dec(&global_trace.data[cpu]->disabled); |
2132 | } | |
2133 | } | |
92205c23 | 2134 | __raw_spin_unlock(&ftrace_max_lock); |
a5e25883 | 2135 | local_irq_enable(); |
36dfe925 | 2136 | |
9e01c1b7 | 2137 | cpumask_copy(tracing_cpumask, tracing_cpumask_new); |
36dfe925 IM |
2138 | |
2139 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 2140 | free_cpumask_var(tracing_cpumask_new); |
c7078de1 IM |
2141 | |
2142 | return count; | |
36dfe925 IM |
2143 | |
2144 | err_unlock: | |
2145 | mutex_unlock(&tracing_cpumask_update_lock); | |
9e01c1b7 | 2146 | free_cpumask_var(tracing_cpumask); |
36dfe925 IM |
2147 | |
2148 | return err; | |
c7078de1 IM |
2149 | } |
2150 | ||
5e2336a0 | 2151 | static const struct file_operations tracing_cpumask_fops = { |
c7078de1 IM |
2152 | .open = tracing_open_generic, |
2153 | .read = tracing_cpumask_read, | |
2154 | .write = tracing_cpumask_write, | |
bc0c38d1 SR |
2155 | }; |
2156 | ||
2157 | static ssize_t | |
ee6bce52 | 2158 | tracing_trace_options_read(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
2159 | size_t cnt, loff_t *ppos) |
2160 | { | |
d8e83d26 SR |
2161 | struct tracer_opt *trace_opts; |
2162 | u32 tracer_flags; | |
2163 | int len = 0; | |
bc0c38d1 SR |
2164 | char *buf; |
2165 | int r = 0; | |
d8e83d26 | 2166 | int i; |
adf9f195 | 2167 | |
bc0c38d1 | 2168 | |
c3706f00 | 2169 | /* calculate max size */ |
bc0c38d1 SR |
2170 | for (i = 0; trace_options[i]; i++) { |
2171 | len += strlen(trace_options[i]); | |
5c6a3ae1 | 2172 | len += 3; /* "no" and newline */ |
bc0c38d1 SR |
2173 | } |
2174 | ||
d8e83d26 SR |
2175 | mutex_lock(&trace_types_lock); |
2176 | tracer_flags = current_trace->flags->val; | |
2177 | trace_opts = current_trace->flags->opts; | |
2178 | ||
adf9f195 FW |
2179 | /* |
2180 | * Increase the size with names of options specific | |
2181 | * of the current tracer. | |
2182 | */ | |
2183 | for (i = 0; trace_opts[i].name; i++) { | |
2184 | len += strlen(trace_opts[i].name); | |
5c6a3ae1 | 2185 | len += 3; /* "no" and newline */ |
adf9f195 FW |
2186 | } |
2187 | ||
bc0c38d1 SR |
2188 | /* +2 for \n and \0 */ |
2189 | buf = kmalloc(len + 2, GFP_KERNEL); | |
d8e83d26 SR |
2190 | if (!buf) { |
2191 | mutex_unlock(&trace_types_lock); | |
bc0c38d1 | 2192 | return -ENOMEM; |
d8e83d26 | 2193 | } |
bc0c38d1 SR |
2194 | |
2195 | for (i = 0; trace_options[i]; i++) { | |
2196 | if (trace_flags & (1 << i)) | |
5c6a3ae1 | 2197 | r += sprintf(buf + r, "%s\n", trace_options[i]); |
bc0c38d1 | 2198 | else |
5c6a3ae1 | 2199 | r += sprintf(buf + r, "no%s\n", trace_options[i]); |
bc0c38d1 SR |
2200 | } |
2201 | ||
adf9f195 FW |
2202 | for (i = 0; trace_opts[i].name; i++) { |
2203 | if (tracer_flags & trace_opts[i].bit) | |
5c6a3ae1 | 2204 | r += sprintf(buf + r, "%s\n", |
adf9f195 FW |
2205 | trace_opts[i].name); |
2206 | else | |
5c6a3ae1 | 2207 | r += sprintf(buf + r, "no%s\n", |
adf9f195 FW |
2208 | trace_opts[i].name); |
2209 | } | |
d8e83d26 | 2210 | mutex_unlock(&trace_types_lock); |
adf9f195 | 2211 | |
bc0c38d1 SR |
2212 | WARN_ON(r >= len + 2); |
2213 | ||
36dfe925 | 2214 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2215 | |
2216 | kfree(buf); | |
bc0c38d1 SR |
2217 | return r; |
2218 | } | |
2219 | ||
adf9f195 FW |
2220 | /* Try to assign a tracer specific option */ |
2221 | static int set_tracer_option(struct tracer *trace, char *cmp, int neg) | |
2222 | { | |
2223 | struct tracer_flags *trace_flags = trace->flags; | |
2224 | struct tracer_opt *opts = NULL; | |
2225 | int ret = 0, i = 0; | |
2226 | int len; | |
2227 | ||
2228 | for (i = 0; trace_flags->opts[i].name; i++) { | |
2229 | opts = &trace_flags->opts[i]; | |
2230 | len = strlen(opts->name); | |
2231 | ||
2232 | if (strncmp(cmp, opts->name, len) == 0) { | |
2233 | ret = trace->set_flag(trace_flags->val, | |
2234 | opts->bit, !neg); | |
2235 | break; | |
2236 | } | |
2237 | } | |
2238 | /* Not found */ | |
2239 | if (!trace_flags->opts[i].name) | |
2240 | return -EINVAL; | |
2241 | ||
2242 | /* Refused to handle */ | |
2243 | if (ret) | |
2244 | return ret; | |
2245 | ||
2246 | if (neg) | |
2247 | trace_flags->val &= ~opts->bit; | |
2248 | else | |
2249 | trace_flags->val |= opts->bit; | |
2250 | ||
2251 | return 0; | |
2252 | } | |
2253 | ||
af4617bd SR |
2254 | static void set_tracer_flags(unsigned int mask, int enabled) |
2255 | { | |
2256 | /* do nothing if flag is already set */ | |
2257 | if (!!(trace_flags & mask) == !!enabled) | |
2258 | return; | |
2259 | ||
2260 | if (enabled) | |
2261 | trace_flags |= mask; | |
2262 | else | |
2263 | trace_flags &= ~mask; | |
2264 | ||
2265 | if (mask == TRACE_ITER_GLOBAL_CLK) { | |
2266 | u64 (*func)(void); | |
2267 | ||
2268 | if (enabled) | |
2269 | func = trace_clock_global; | |
2270 | else | |
2271 | func = trace_clock_local; | |
2272 | ||
2273 | mutex_lock(&trace_types_lock); | |
2274 | ring_buffer_set_clock(global_trace.buffer, func); | |
2275 | ||
2276 | if (max_tr.buffer) | |
2277 | ring_buffer_set_clock(max_tr.buffer, func); | |
2278 | mutex_unlock(&trace_types_lock); | |
2279 | } | |
2280 | } | |
2281 | ||
bc0c38d1 | 2282 | static ssize_t |
ee6bce52 | 2283 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, |
bc0c38d1 SR |
2284 | size_t cnt, loff_t *ppos) |
2285 | { | |
2286 | char buf[64]; | |
2287 | char *cmp = buf; | |
2288 | int neg = 0; | |
adf9f195 | 2289 | int ret; |
bc0c38d1 SR |
2290 | int i; |
2291 | ||
cffae437 SR |
2292 | if (cnt >= sizeof(buf)) |
2293 | return -EINVAL; | |
bc0c38d1 SR |
2294 | |
2295 | if (copy_from_user(&buf, ubuf, cnt)) | |
2296 | return -EFAULT; | |
2297 | ||
2298 | buf[cnt] = 0; | |
2299 | ||
2300 | if (strncmp(buf, "no", 2) == 0) { | |
2301 | neg = 1; | |
2302 | cmp += 2; | |
2303 | } | |
2304 | ||
2305 | for (i = 0; trace_options[i]; i++) { | |
2306 | int len = strlen(trace_options[i]); | |
2307 | ||
2308 | if (strncmp(cmp, trace_options[i], len) == 0) { | |
af4617bd | 2309 | set_tracer_flags(1 << i, !neg); |
bc0c38d1 SR |
2310 | break; |
2311 | } | |
2312 | } | |
adf9f195 FW |
2313 | |
2314 | /* If no option could be set, test the specific tracer options */ | |
2315 | if (!trace_options[i]) { | |
d8e83d26 | 2316 | mutex_lock(&trace_types_lock); |
adf9f195 | 2317 | ret = set_tracer_option(current_trace, cmp, neg); |
d8e83d26 | 2318 | mutex_unlock(&trace_types_lock); |
adf9f195 FW |
2319 | if (ret) |
2320 | return ret; | |
2321 | } | |
bc0c38d1 SR |
2322 | |
2323 | filp->f_pos += cnt; | |
2324 | ||
2325 | return cnt; | |
2326 | } | |
2327 | ||
5e2336a0 | 2328 | static const struct file_operations tracing_iter_fops = { |
c7078de1 | 2329 | .open = tracing_open_generic, |
ee6bce52 SR |
2330 | .read = tracing_trace_options_read, |
2331 | .write = tracing_trace_options_write, | |
bc0c38d1 SR |
2332 | }; |
2333 | ||
7bd2f24c IM |
2334 | static const char readme_msg[] = |
2335 | "tracing mini-HOWTO:\n\n" | |
2336 | "# mkdir /debug\n" | |
2337 | "# mount -t debugfs nodev /debug\n\n" | |
2338 | "# cat /debug/tracing/available_tracers\n" | |
2339 | "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" | |
2340 | "# cat /debug/tracing/current_tracer\n" | |
2341 | "none\n" | |
2342 | "# echo sched_switch > /debug/tracing/current_tracer\n" | |
2343 | "# cat /debug/tracing/current_tracer\n" | |
2344 | "sched_switch\n" | |
ee6bce52 | 2345 | "# cat /debug/tracing/trace_options\n" |
7bd2f24c | 2346 | "noprint-parent nosym-offset nosym-addr noverbose\n" |
ee6bce52 | 2347 | "# echo print-parent > /debug/tracing/trace_options\n" |
7bd2f24c IM |
2348 | "# echo 1 > /debug/tracing/tracing_enabled\n" |
2349 | "# cat /debug/tracing/trace > /tmp/trace.txt\n" | |
2350 | "echo 0 > /debug/tracing/tracing_enabled\n" | |
2351 | ; | |
2352 | ||
2353 | static ssize_t | |
2354 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
2355 | size_t cnt, loff_t *ppos) | |
2356 | { | |
2357 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
2358 | readme_msg, strlen(readme_msg)); | |
2359 | } | |
2360 | ||
5e2336a0 | 2361 | static const struct file_operations tracing_readme_fops = { |
c7078de1 IM |
2362 | .open = tracing_open_generic, |
2363 | .read = tracing_readme_read, | |
7bd2f24c IM |
2364 | }; |
2365 | ||
bc0c38d1 SR |
2366 | static ssize_t |
2367 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
2368 | size_t cnt, loff_t *ppos) | |
2369 | { | |
bc0c38d1 SR |
2370 | char buf[64]; |
2371 | int r; | |
2372 | ||
9036990d | 2373 | r = sprintf(buf, "%u\n", tracer_enabled); |
4e3c3333 | 2374 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2375 | } |
2376 | ||
2377 | static ssize_t | |
2378 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
2379 | size_t cnt, loff_t *ppos) | |
2380 | { | |
2381 | struct trace_array *tr = filp->private_data; | |
bc0c38d1 | 2382 | char buf[64]; |
5e39841c | 2383 | unsigned long val; |
c6caeeb1 | 2384 | int ret; |
bc0c38d1 | 2385 | |
cffae437 SR |
2386 | if (cnt >= sizeof(buf)) |
2387 | return -EINVAL; | |
bc0c38d1 SR |
2388 | |
2389 | if (copy_from_user(&buf, ubuf, cnt)) | |
2390 | return -EFAULT; | |
2391 | ||
2392 | buf[cnt] = 0; | |
2393 | ||
c6caeeb1 SR |
2394 | ret = strict_strtoul(buf, 10, &val); |
2395 | if (ret < 0) | |
2396 | return ret; | |
bc0c38d1 SR |
2397 | |
2398 | val = !!val; | |
2399 | ||
2400 | mutex_lock(&trace_types_lock); | |
9036990d SR |
2401 | if (tracer_enabled ^ val) { |
2402 | if (val) { | |
bc0c38d1 | 2403 | tracer_enabled = 1; |
9036990d SR |
2404 | if (current_trace->start) |
2405 | current_trace->start(tr); | |
2406 | tracing_start(); | |
2407 | } else { | |
bc0c38d1 | 2408 | tracer_enabled = 0; |
9036990d SR |
2409 | tracing_stop(); |
2410 | if (current_trace->stop) | |
2411 | current_trace->stop(tr); | |
2412 | } | |
bc0c38d1 SR |
2413 | } |
2414 | mutex_unlock(&trace_types_lock); | |
2415 | ||
2416 | filp->f_pos += cnt; | |
2417 | ||
2418 | return cnt; | |
2419 | } | |
2420 | ||
2421 | static ssize_t | |
2422 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
2423 | size_t cnt, loff_t *ppos) | |
2424 | { | |
2425 | char buf[max_tracer_type_len+2]; | |
2426 | int r; | |
2427 | ||
2428 | mutex_lock(&trace_types_lock); | |
2429 | if (current_trace) | |
2430 | r = sprintf(buf, "%s\n", current_trace->name); | |
2431 | else | |
2432 | r = sprintf(buf, "\n"); | |
2433 | mutex_unlock(&trace_types_lock); | |
2434 | ||
4bf39a94 | 2435 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2436 | } |
2437 | ||
b6f11df2 ACM |
2438 | int tracer_init(struct tracer *t, struct trace_array *tr) |
2439 | { | |
2440 | tracing_reset_online_cpus(tr); | |
2441 | return t->init(tr); | |
2442 | } | |
2443 | ||
73c5162a SR |
2444 | static int tracing_resize_ring_buffer(unsigned long size) |
2445 | { | |
2446 | int ret; | |
2447 | ||
2448 | /* | |
2449 | * If kernel or user changes the size of the ring buffer | |
a123c52b SR |
2450 | * we use the size that was given, and we can forget about |
2451 | * expanding it later. | |
73c5162a SR |
2452 | */ |
2453 | ring_buffer_expanded = 1; | |
2454 | ||
2455 | ret = ring_buffer_resize(global_trace.buffer, size); | |
2456 | if (ret < 0) | |
2457 | return ret; | |
2458 | ||
2459 | ret = ring_buffer_resize(max_tr.buffer, size); | |
2460 | if (ret < 0) { | |
2461 | int r; | |
2462 | ||
2463 | r = ring_buffer_resize(global_trace.buffer, | |
2464 | global_trace.entries); | |
2465 | if (r < 0) { | |
a123c52b SR |
2466 | /* |
2467 | * AARGH! We are left with different | |
2468 | * size max buffer!!!! | |
2469 | * The max buffer is our "snapshot" buffer. | |
2470 | * When a tracer needs a snapshot (one of the | |
2471 | * latency tracers), it swaps the max buffer | |
2472 | * with the saved snap shot. We succeeded to | |
2473 | * update the size of the main buffer, but failed to | |
2474 | * update the size of the max buffer. But when we tried | |
2475 | * to reset the main buffer to the original size, we | |
2476 | * failed there too. This is very unlikely to | |
2477 | * happen, but if it does, warn and kill all | |
2478 | * tracing. | |
2479 | */ | |
73c5162a SR |
2480 | WARN_ON(1); |
2481 | tracing_disabled = 1; | |
2482 | } | |
2483 | return ret; | |
2484 | } | |
2485 | ||
2486 | global_trace.entries = size; | |
2487 | ||
2488 | return ret; | |
2489 | } | |
2490 | ||
1852fcce SR |
2491 | /** |
2492 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
2493 | * | |
2494 | * To save on memory when the tracing is never used on a system with it | |
2495 | * configured in. The ring buffers are set to a minimum size. But once | |
2496 | * a user starts to use the tracing facility, then they need to grow | |
2497 | * to their default size. | |
2498 | * | |
2499 | * This function is to be called when a tracer is about to be used. | |
2500 | */ | |
2501 | int tracing_update_buffers(void) | |
2502 | { | |
2503 | int ret = 0; | |
2504 | ||
1027fcb2 | 2505 | mutex_lock(&trace_types_lock); |
1852fcce SR |
2506 | if (!ring_buffer_expanded) |
2507 | ret = tracing_resize_ring_buffer(trace_buf_size); | |
1027fcb2 | 2508 | mutex_unlock(&trace_types_lock); |
1852fcce SR |
2509 | |
2510 | return ret; | |
2511 | } | |
2512 | ||
577b785f SR |
2513 | struct trace_option_dentry; |
2514 | ||
2515 | static struct trace_option_dentry * | |
2516 | create_trace_option_files(struct tracer *tracer); | |
2517 | ||
2518 | static void | |
2519 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
2520 | ||
b2821ae6 | 2521 | static int tracing_set_tracer(const char *buf) |
bc0c38d1 | 2522 | { |
577b785f | 2523 | static struct trace_option_dentry *topts; |
bc0c38d1 SR |
2524 | struct trace_array *tr = &global_trace; |
2525 | struct tracer *t; | |
d9e54076 | 2526 | int ret = 0; |
bc0c38d1 | 2527 | |
1027fcb2 SR |
2528 | mutex_lock(&trace_types_lock); |
2529 | ||
73c5162a SR |
2530 | if (!ring_buffer_expanded) { |
2531 | ret = tracing_resize_ring_buffer(trace_buf_size); | |
2532 | if (ret < 0) | |
59f586db | 2533 | goto out; |
73c5162a SR |
2534 | ret = 0; |
2535 | } | |
2536 | ||
bc0c38d1 SR |
2537 | for (t = trace_types; t; t = t->next) { |
2538 | if (strcmp(t->name, buf) == 0) | |
2539 | break; | |
2540 | } | |
c2931e05 FW |
2541 | if (!t) { |
2542 | ret = -EINVAL; | |
2543 | goto out; | |
2544 | } | |
2545 | if (t == current_trace) | |
bc0c38d1 SR |
2546 | goto out; |
2547 | ||
9f029e83 | 2548 | trace_branch_disable(); |
bc0c38d1 SR |
2549 | if (current_trace && current_trace->reset) |
2550 | current_trace->reset(tr); | |
2551 | ||
577b785f SR |
2552 | destroy_trace_option_files(topts); |
2553 | ||
bc0c38d1 | 2554 | current_trace = t; |
577b785f SR |
2555 | |
2556 | topts = create_trace_option_files(current_trace); | |
2557 | ||
1c80025a | 2558 | if (t->init) { |
b6f11df2 | 2559 | ret = tracer_init(t, tr); |
1c80025a FW |
2560 | if (ret) |
2561 | goto out; | |
2562 | } | |
bc0c38d1 | 2563 | |
9f029e83 | 2564 | trace_branch_enable(tr); |
bc0c38d1 SR |
2565 | out: |
2566 | mutex_unlock(&trace_types_lock); | |
2567 | ||
d9e54076 PZ |
2568 | return ret; |
2569 | } | |
2570 | ||
2571 | static ssize_t | |
2572 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
2573 | size_t cnt, loff_t *ppos) | |
2574 | { | |
2575 | char buf[max_tracer_type_len+1]; | |
2576 | int i; | |
2577 | size_t ret; | |
e6e7a65a FW |
2578 | int err; |
2579 | ||
2580 | ret = cnt; | |
d9e54076 PZ |
2581 | |
2582 | if (cnt > max_tracer_type_len) | |
2583 | cnt = max_tracer_type_len; | |
2584 | ||
2585 | if (copy_from_user(&buf, ubuf, cnt)) | |
2586 | return -EFAULT; | |
2587 | ||
2588 | buf[cnt] = 0; | |
2589 | ||
2590 | /* strip ending whitespace. */ | |
2591 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
2592 | buf[i] = 0; | |
2593 | ||
e6e7a65a FW |
2594 | err = tracing_set_tracer(buf); |
2595 | if (err) | |
2596 | return err; | |
d9e54076 | 2597 | |
e6e7a65a | 2598 | filp->f_pos += ret; |
bc0c38d1 | 2599 | |
c2931e05 | 2600 | return ret; |
bc0c38d1 SR |
2601 | } |
2602 | ||
2603 | static ssize_t | |
2604 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
2605 | size_t cnt, loff_t *ppos) | |
2606 | { | |
2607 | unsigned long *ptr = filp->private_data; | |
2608 | char buf[64]; | |
2609 | int r; | |
2610 | ||
cffae437 | 2611 | r = snprintf(buf, sizeof(buf), "%ld\n", |
bc0c38d1 | 2612 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
cffae437 SR |
2613 | if (r > sizeof(buf)) |
2614 | r = sizeof(buf); | |
4bf39a94 | 2615 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
2616 | } |
2617 | ||
2618 | static ssize_t | |
2619 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
2620 | size_t cnt, loff_t *ppos) | |
2621 | { | |
5e39841c | 2622 | unsigned long *ptr = filp->private_data; |
bc0c38d1 | 2623 | char buf[64]; |
5e39841c | 2624 | unsigned long val; |
c6caeeb1 | 2625 | int ret; |
bc0c38d1 | 2626 | |
cffae437 SR |
2627 | if (cnt >= sizeof(buf)) |
2628 | return -EINVAL; | |
bc0c38d1 SR |
2629 | |
2630 | if (copy_from_user(&buf, ubuf, cnt)) | |
2631 | return -EFAULT; | |
2632 | ||
2633 | buf[cnt] = 0; | |
2634 | ||
c6caeeb1 SR |
2635 | ret = strict_strtoul(buf, 10, &val); |
2636 | if (ret < 0) | |
2637 | return ret; | |
bc0c38d1 SR |
2638 | |
2639 | *ptr = val * 1000; | |
2640 | ||
2641 | return cnt; | |
2642 | } | |
2643 | ||
b3806b43 SR |
2644 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
2645 | { | |
b04cc6b1 | 2646 | long cpu_file = (long) inode->i_private; |
b3806b43 | 2647 | struct trace_iterator *iter; |
b04cc6b1 | 2648 | int ret = 0; |
b3806b43 SR |
2649 | |
2650 | if (tracing_disabled) | |
2651 | return -ENODEV; | |
2652 | ||
b04cc6b1 FW |
2653 | mutex_lock(&trace_types_lock); |
2654 | ||
2655 | /* We only allow one reader per cpu */ | |
2656 | if (cpu_file == TRACE_PIPE_ALL_CPU) { | |
2657 | if (!cpumask_empty(tracing_reader_cpumask)) { | |
2658 | ret = -EBUSY; | |
2659 | goto out; | |
2660 | } | |
2661 | cpumask_setall(tracing_reader_cpumask); | |
2662 | } else { | |
2663 | if (!cpumask_test_cpu(cpu_file, tracing_reader_cpumask)) | |
2664 | cpumask_set_cpu(cpu_file, tracing_reader_cpumask); | |
2665 | else { | |
2666 | ret = -EBUSY; | |
2667 | goto out; | |
2668 | } | |
b3806b43 SR |
2669 | } |
2670 | ||
2671 | /* create a buffer to store the information to pass to userspace */ | |
2672 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
b04cc6b1 FW |
2673 | if (!iter) { |
2674 | ret = -ENOMEM; | |
2675 | goto out; | |
2676 | } | |
b3806b43 | 2677 | |
d7350c3f FW |
2678 | /* |
2679 | * We make a copy of the current tracer to avoid concurrent | |
2680 | * changes on it while we are reading. | |
2681 | */ | |
2682 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
2683 | if (!iter->trace) { | |
2684 | ret = -ENOMEM; | |
2685 | goto fail; | |
2686 | } | |
2687 | if (current_trace) | |
2688 | *iter->trace = *current_trace; | |
2689 | ||
4462344e | 2690 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
b04cc6b1 | 2691 | ret = -ENOMEM; |
d7350c3f | 2692 | goto fail; |
4462344e RR |
2693 | } |
2694 | ||
a309720c | 2695 | /* trace pipe does not show start of buffer */ |
4462344e | 2696 | cpumask_setall(iter->started); |
a309720c | 2697 | |
b04cc6b1 | 2698 | iter->cpu_file = cpu_file; |
b3806b43 | 2699 | iter->tr = &global_trace; |
d7350c3f | 2700 | mutex_init(&iter->mutex); |
b3806b43 SR |
2701 | filp->private_data = iter; |
2702 | ||
107bad8b SR |
2703 | if (iter->trace->pipe_open) |
2704 | iter->trace->pipe_open(iter); | |
107bad8b | 2705 | |
b04cc6b1 FW |
2706 | out: |
2707 | mutex_unlock(&trace_types_lock); | |
2708 | return ret; | |
d7350c3f FW |
2709 | |
2710 | fail: | |
2711 | kfree(iter->trace); | |
2712 | kfree(iter); | |
2713 | mutex_unlock(&trace_types_lock); | |
2714 | return ret; | |
b3806b43 SR |
2715 | } |
2716 | ||
2717 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
2718 | { | |
2719 | struct trace_iterator *iter = file->private_data; | |
2720 | ||
b04cc6b1 FW |
2721 | mutex_lock(&trace_types_lock); |
2722 | ||
2723 | if (iter->cpu_file == TRACE_PIPE_ALL_CPU) | |
2724 | cpumask_clear(tracing_reader_cpumask); | |
2725 | else | |
2726 | cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask); | |
2727 | ||
2728 | mutex_unlock(&trace_types_lock); | |
2729 | ||
4462344e | 2730 | free_cpumask_var(iter->started); |
d7350c3f FW |
2731 | mutex_destroy(&iter->mutex); |
2732 | kfree(iter->trace); | |
b3806b43 | 2733 | kfree(iter); |
b3806b43 SR |
2734 | |
2735 | return 0; | |
2736 | } | |
2737 | ||
2a2cc8f7 SSP |
2738 | static unsigned int |
2739 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
2740 | { | |
2741 | struct trace_iterator *iter = filp->private_data; | |
2742 | ||
2743 | if (trace_flags & TRACE_ITER_BLOCK) { | |
2744 | /* | |
2745 | * Always select as readable when in blocking mode | |
2746 | */ | |
2747 | return POLLIN | POLLRDNORM; | |
afc2abc0 | 2748 | } else { |
2a2cc8f7 SSP |
2749 | if (!trace_empty(iter)) |
2750 | return POLLIN | POLLRDNORM; | |
2751 | poll_wait(filp, &trace_wait, poll_table); | |
2752 | if (!trace_empty(iter)) | |
2753 | return POLLIN | POLLRDNORM; | |
2754 | ||
2755 | return 0; | |
2756 | } | |
2757 | } | |
2758 | ||
6eaaa5d5 FW |
2759 | |
2760 | void default_wait_pipe(struct trace_iterator *iter) | |
2761 | { | |
2762 | DEFINE_WAIT(wait); | |
2763 | ||
2764 | prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE); | |
2765 | ||
2766 | if (trace_empty(iter)) | |
2767 | schedule(); | |
2768 | ||
2769 | finish_wait(&trace_wait, &wait); | |
2770 | } | |
2771 | ||
2772 | /* | |
2773 | * This is a make-shift waitqueue. | |
2774 | * A tracer might use this callback on some rare cases: | |
2775 | * | |
2776 | * 1) the current tracer might hold the runqueue lock when it wakes up | |
2777 | * a reader, hence a deadlock (sched, function, and function graph tracers) | |
2778 | * 2) the function tracers, trace all functions, we don't want | |
2779 | * the overhead of calling wake_up and friends | |
2780 | * (and tracing them too) | |
2781 | * | |
2782 | * Anyway, this is really very primitive wakeup. | |
2783 | */ | |
2784 | void poll_wait_pipe(struct trace_iterator *iter) | |
2785 | { | |
2786 | set_current_state(TASK_INTERRUPTIBLE); | |
2787 | /* sleep for 100 msecs, and try again. */ | |
2788 | schedule_timeout(HZ / 10); | |
2789 | } | |
2790 | ||
ff98781b EGM |
2791 | /* Must be called with trace_types_lock mutex held. */ |
2792 | static int tracing_wait_pipe(struct file *filp) | |
b3806b43 SR |
2793 | { |
2794 | struct trace_iterator *iter = filp->private_data; | |
b3806b43 | 2795 | |
b3806b43 | 2796 | while (trace_empty(iter)) { |
2dc8f095 | 2797 | |
107bad8b | 2798 | if ((filp->f_flags & O_NONBLOCK)) { |
ff98781b | 2799 | return -EAGAIN; |
107bad8b | 2800 | } |
2dc8f095 | 2801 | |
d7350c3f | 2802 | mutex_unlock(&iter->mutex); |
107bad8b | 2803 | |
6eaaa5d5 | 2804 | iter->trace->wait_pipe(iter); |
b3806b43 | 2805 | |
d7350c3f | 2806 | mutex_lock(&iter->mutex); |
107bad8b | 2807 | |
6eaaa5d5 | 2808 | if (signal_pending(current)) |
ff98781b | 2809 | return -EINTR; |
b3806b43 SR |
2810 | |
2811 | /* | |
2812 | * We block until we read something and tracing is disabled. | |
2813 | * We still block if tracing is disabled, but we have never | |
2814 | * read anything. This allows a user to cat this file, and | |
2815 | * then enable tracing. But after we have read something, | |
2816 | * we give an EOF when tracing is again disabled. | |
2817 | * | |
2818 | * iter->pos will be 0 if we haven't read anything. | |
2819 | */ | |
2820 | if (!tracer_enabled && iter->pos) | |
2821 | break; | |
b3806b43 SR |
2822 | } |
2823 | ||
ff98781b EGM |
2824 | return 1; |
2825 | } | |
2826 | ||
2827 | /* | |
2828 | * Consumer reader. | |
2829 | */ | |
2830 | static ssize_t | |
2831 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
2832 | size_t cnt, loff_t *ppos) | |
2833 | { | |
2834 | struct trace_iterator *iter = filp->private_data; | |
d7350c3f | 2835 | static struct tracer *old_tracer; |
ff98781b EGM |
2836 | ssize_t sret; |
2837 | ||
2838 | /* return any leftover data */ | |
2839 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
2840 | if (sret != -EBUSY) | |
2841 | return sret; | |
2842 | ||
f9520750 | 2843 | trace_seq_init(&iter->seq); |
ff98781b | 2844 | |
d7350c3f | 2845 | /* copy the tracer to avoid using a global lock all around */ |
ff98781b | 2846 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
2847 | if (unlikely(old_tracer != current_trace && current_trace)) { |
2848 | old_tracer = current_trace; | |
2849 | *iter->trace = *current_trace; | |
2850 | } | |
2851 | mutex_unlock(&trace_types_lock); | |
2852 | ||
2853 | /* | |
2854 | * Avoid more than one consumer on a single file descriptor | |
2855 | * This is just a matter of traces coherency, the ring buffer itself | |
2856 | * is protected. | |
2857 | */ | |
2858 | mutex_lock(&iter->mutex); | |
ff98781b EGM |
2859 | if (iter->trace->read) { |
2860 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
2861 | if (sret) | |
2862 | goto out; | |
2863 | } | |
2864 | ||
2865 | waitagain: | |
2866 | sret = tracing_wait_pipe(filp); | |
2867 | if (sret <= 0) | |
2868 | goto out; | |
2869 | ||
b3806b43 | 2870 | /* stop when tracing is finished */ |
ff98781b EGM |
2871 | if (trace_empty(iter)) { |
2872 | sret = 0; | |
107bad8b | 2873 | goto out; |
ff98781b | 2874 | } |
b3806b43 SR |
2875 | |
2876 | if (cnt >= PAGE_SIZE) | |
2877 | cnt = PAGE_SIZE - 1; | |
2878 | ||
53d0aa77 | 2879 | /* reset all but tr, trace, and overruns */ |
53d0aa77 SR |
2880 | memset(&iter->seq, 0, |
2881 | sizeof(struct trace_iterator) - | |
2882 | offsetof(struct trace_iterator, seq)); | |
4823ed7e | 2883 | iter->pos = -1; |
b3806b43 | 2884 | |
088b1e42 | 2885 | while (find_next_entry_inc(iter) != NULL) { |
2c4f035f | 2886 | enum print_line_t ret; |
088b1e42 SR |
2887 | int len = iter->seq.len; |
2888 | ||
f9896bf3 | 2889 | ret = print_trace_line(iter); |
2c4f035f | 2890 | if (ret == TRACE_TYPE_PARTIAL_LINE) { |
088b1e42 SR |
2891 | /* don't print partial lines */ |
2892 | iter->seq.len = len; | |
b3806b43 | 2893 | break; |
088b1e42 | 2894 | } |
b91facc3 FW |
2895 | if (ret != TRACE_TYPE_NO_CONSUME) |
2896 | trace_consume(iter); | |
b3806b43 SR |
2897 | |
2898 | if (iter->seq.len >= cnt) | |
2899 | break; | |
b3806b43 SR |
2900 | } |
2901 | ||
b3806b43 | 2902 | /* Now copy what we have to the user */ |
6c6c2796 PP |
2903 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
2904 | if (iter->seq.readpos >= iter->seq.len) | |
f9520750 | 2905 | trace_seq_init(&iter->seq); |
9ff4b974 PP |
2906 | |
2907 | /* | |
2908 | * If there was nothing to send to user, inspite of consuming trace | |
2909 | * entries, go back to wait for more entries. | |
2910 | */ | |
6c6c2796 | 2911 | if (sret == -EBUSY) |
9ff4b974 | 2912 | goto waitagain; |
b3806b43 | 2913 | |
107bad8b | 2914 | out: |
d7350c3f | 2915 | mutex_unlock(&iter->mutex); |
107bad8b | 2916 | |
6c6c2796 | 2917 | return sret; |
b3806b43 SR |
2918 | } |
2919 | ||
3c56819b EGM |
2920 | static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, |
2921 | struct pipe_buffer *buf) | |
2922 | { | |
2923 | __free_page(buf->page); | |
2924 | } | |
2925 | ||
2926 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, | |
2927 | unsigned int idx) | |
2928 | { | |
2929 | __free_page(spd->pages[idx]); | |
2930 | } | |
2931 | ||
2932 | static struct pipe_buf_operations tracing_pipe_buf_ops = { | |
34cd4998 SR |
2933 | .can_merge = 0, |
2934 | .map = generic_pipe_buf_map, | |
2935 | .unmap = generic_pipe_buf_unmap, | |
2936 | .confirm = generic_pipe_buf_confirm, | |
2937 | .release = tracing_pipe_buf_release, | |
2938 | .steal = generic_pipe_buf_steal, | |
2939 | .get = generic_pipe_buf_get, | |
3c56819b EGM |
2940 | }; |
2941 | ||
34cd4998 | 2942 | static size_t |
fa7c7f6e | 2943 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
34cd4998 SR |
2944 | { |
2945 | size_t count; | |
2946 | int ret; | |
2947 | ||
2948 | /* Seq buffer is page-sized, exactly what we need. */ | |
2949 | for (;;) { | |
2950 | count = iter->seq.len; | |
2951 | ret = print_trace_line(iter); | |
2952 | count = iter->seq.len - count; | |
2953 | if (rem < count) { | |
2954 | rem = 0; | |
2955 | iter->seq.len -= count; | |
2956 | break; | |
2957 | } | |
2958 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
2959 | iter->seq.len -= count; | |
2960 | break; | |
2961 | } | |
2962 | ||
2963 | trace_consume(iter); | |
2964 | rem -= count; | |
2965 | if (!find_next_entry_inc(iter)) { | |
2966 | rem = 0; | |
2967 | iter->ent = NULL; | |
2968 | break; | |
2969 | } | |
2970 | } | |
2971 | ||
2972 | return rem; | |
2973 | } | |
2974 | ||
3c56819b EGM |
2975 | static ssize_t tracing_splice_read_pipe(struct file *filp, |
2976 | loff_t *ppos, | |
2977 | struct pipe_inode_info *pipe, | |
2978 | size_t len, | |
2979 | unsigned int flags) | |
2980 | { | |
2981 | struct page *pages[PIPE_BUFFERS]; | |
2982 | struct partial_page partial[PIPE_BUFFERS]; | |
2983 | struct trace_iterator *iter = filp->private_data; | |
2984 | struct splice_pipe_desc spd = { | |
34cd4998 SR |
2985 | .pages = pages, |
2986 | .partial = partial, | |
2987 | .nr_pages = 0, /* This gets updated below. */ | |
2988 | .flags = flags, | |
2989 | .ops = &tracing_pipe_buf_ops, | |
2990 | .spd_release = tracing_spd_release_pipe, | |
3c56819b | 2991 | }; |
d7350c3f | 2992 | static struct tracer *old_tracer; |
3c56819b | 2993 | ssize_t ret; |
34cd4998 | 2994 | size_t rem; |
3c56819b EGM |
2995 | unsigned int i; |
2996 | ||
d7350c3f | 2997 | /* copy the tracer to avoid using a global lock all around */ |
3c56819b | 2998 | mutex_lock(&trace_types_lock); |
d7350c3f FW |
2999 | if (unlikely(old_tracer != current_trace && current_trace)) { |
3000 | old_tracer = current_trace; | |
3001 | *iter->trace = *current_trace; | |
3002 | } | |
3003 | mutex_unlock(&trace_types_lock); | |
3004 | ||
3005 | mutex_lock(&iter->mutex); | |
3c56819b EGM |
3006 | |
3007 | if (iter->trace->splice_read) { | |
3008 | ret = iter->trace->splice_read(iter, filp, | |
3009 | ppos, pipe, len, flags); | |
3010 | if (ret) | |
34cd4998 | 3011 | goto out_err; |
3c56819b EGM |
3012 | } |
3013 | ||
3014 | ret = tracing_wait_pipe(filp); | |
3015 | if (ret <= 0) | |
34cd4998 | 3016 | goto out_err; |
3c56819b EGM |
3017 | |
3018 | if (!iter->ent && !find_next_entry_inc(iter)) { | |
3019 | ret = -EFAULT; | |
34cd4998 | 3020 | goto out_err; |
3c56819b EGM |
3021 | } |
3022 | ||
3023 | /* Fill as many pages as possible. */ | |
3024 | for (i = 0, rem = len; i < PIPE_BUFFERS && rem; i++) { | |
3025 | pages[i] = alloc_page(GFP_KERNEL); | |
34cd4998 SR |
3026 | if (!pages[i]) |
3027 | break; | |
3c56819b | 3028 | |
fa7c7f6e | 3029 | rem = tracing_fill_pipe_page(rem, iter); |
3c56819b EGM |
3030 | |
3031 | /* Copy the data into the page, so we can start over. */ | |
3032 | ret = trace_seq_to_buffer(&iter->seq, | |
3033 | page_address(pages[i]), | |
3034 | iter->seq.len); | |
3035 | if (ret < 0) { | |
3036 | __free_page(pages[i]); | |
3037 | break; | |
3038 | } | |
3039 | partial[i].offset = 0; | |
3040 | partial[i].len = iter->seq.len; | |
3041 | ||
f9520750 | 3042 | trace_seq_init(&iter->seq); |
3c56819b EGM |
3043 | } |
3044 | ||
d7350c3f | 3045 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
3046 | |
3047 | spd.nr_pages = i; | |
3048 | ||
3049 | return splice_to_pipe(pipe, &spd); | |
3050 | ||
34cd4998 | 3051 | out_err: |
d7350c3f | 3052 | mutex_unlock(&iter->mutex); |
3c56819b EGM |
3053 | |
3054 | return ret; | |
3055 | } | |
3056 | ||
a98a3c3f SR |
3057 | static ssize_t |
3058 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
3059 | size_t cnt, loff_t *ppos) | |
3060 | { | |
3061 | struct trace_array *tr = filp->private_data; | |
db526ca3 | 3062 | char buf[96]; |
a98a3c3f SR |
3063 | int r; |
3064 | ||
db526ca3 SR |
3065 | mutex_lock(&trace_types_lock); |
3066 | if (!ring_buffer_expanded) | |
3067 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
3068 | tr->entries >> 10, | |
3069 | trace_buf_size >> 10); | |
3070 | else | |
3071 | r = sprintf(buf, "%lu\n", tr->entries >> 10); | |
3072 | mutex_unlock(&trace_types_lock); | |
3073 | ||
a98a3c3f SR |
3074 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
3075 | } | |
3076 | ||
3077 | static ssize_t | |
3078 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
3079 | size_t cnt, loff_t *ppos) | |
3080 | { | |
3081 | unsigned long val; | |
3082 | char buf[64]; | |
bf5e6519 | 3083 | int ret, cpu; |
a98a3c3f | 3084 | |
cffae437 SR |
3085 | if (cnt >= sizeof(buf)) |
3086 | return -EINVAL; | |
a98a3c3f SR |
3087 | |
3088 | if (copy_from_user(&buf, ubuf, cnt)) | |
3089 | return -EFAULT; | |
3090 | ||
3091 | buf[cnt] = 0; | |
3092 | ||
c6caeeb1 SR |
3093 | ret = strict_strtoul(buf, 10, &val); |
3094 | if (ret < 0) | |
3095 | return ret; | |
a98a3c3f SR |
3096 | |
3097 | /* must have at least 1 entry */ | |
3098 | if (!val) | |
3099 | return -EINVAL; | |
3100 | ||
3101 | mutex_lock(&trace_types_lock); | |
3102 | ||
c76f0694 | 3103 | tracing_stop(); |
a98a3c3f | 3104 | |
bf5e6519 SR |
3105 | /* disable all cpu buffers */ |
3106 | for_each_tracing_cpu(cpu) { | |
3107 | if (global_trace.data[cpu]) | |
3108 | atomic_inc(&global_trace.data[cpu]->disabled); | |
3109 | if (max_tr.data[cpu]) | |
3110 | atomic_inc(&max_tr.data[cpu]->disabled); | |
3111 | } | |
3112 | ||
1696b2b0 SR |
3113 | /* value is in KB */ |
3114 | val <<= 10; | |
3115 | ||
3928a8a2 | 3116 | if (val != global_trace.entries) { |
73c5162a | 3117 | ret = tracing_resize_ring_buffer(val); |
3928a8a2 SR |
3118 | if (ret < 0) { |
3119 | cnt = ret; | |
3eefae99 SR |
3120 | goto out; |
3121 | } | |
a98a3c3f SR |
3122 | } |
3123 | ||
3124 | filp->f_pos += cnt; | |
3125 | ||
19384c03 SR |
3126 | /* If check pages failed, return ENOMEM */ |
3127 | if (tracing_disabled) | |
3128 | cnt = -ENOMEM; | |
a98a3c3f | 3129 | out: |
bf5e6519 SR |
3130 | for_each_tracing_cpu(cpu) { |
3131 | if (global_trace.data[cpu]) | |
3132 | atomic_dec(&global_trace.data[cpu]->disabled); | |
3133 | if (max_tr.data[cpu]) | |
3134 | atomic_dec(&max_tr.data[cpu]->disabled); | |
3135 | } | |
3136 | ||
c76f0694 | 3137 | tracing_start(); |
a98a3c3f SR |
3138 | max_tr.entries = global_trace.entries; |
3139 | mutex_unlock(&trace_types_lock); | |
3140 | ||
3141 | return cnt; | |
3142 | } | |
3143 | ||
5bf9a1ee PP |
3144 | static int mark_printk(const char *fmt, ...) |
3145 | { | |
3146 | int ret; | |
3147 | va_list args; | |
3148 | va_start(args, fmt); | |
40ce74f1 | 3149 | ret = trace_vprintk(0, fmt, args); |
5bf9a1ee PP |
3150 | va_end(args); |
3151 | return ret; | |
3152 | } | |
3153 | ||
3154 | static ssize_t | |
3155 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
3156 | size_t cnt, loff_t *fpos) | |
3157 | { | |
3158 | char *buf; | |
3159 | char *end; | |
5bf9a1ee | 3160 | |
c76f0694 | 3161 | if (tracing_disabled) |
5bf9a1ee PP |
3162 | return -EINVAL; |
3163 | ||
3164 | if (cnt > TRACE_BUF_SIZE) | |
3165 | cnt = TRACE_BUF_SIZE; | |
3166 | ||
3167 | buf = kmalloc(cnt + 1, GFP_KERNEL); | |
3168 | if (buf == NULL) | |
3169 | return -ENOMEM; | |
3170 | ||
3171 | if (copy_from_user(buf, ubuf, cnt)) { | |
3172 | kfree(buf); | |
3173 | return -EFAULT; | |
3174 | } | |
3175 | ||
3176 | /* Cut from the first nil or newline. */ | |
3177 | buf[cnt] = '\0'; | |
3178 | end = strchr(buf, '\n'); | |
3179 | if (end) | |
3180 | *end = '\0'; | |
3181 | ||
3182 | cnt = mark_printk("%s\n", buf); | |
3183 | kfree(buf); | |
3184 | *fpos += cnt; | |
3185 | ||
3186 | return cnt; | |
3187 | } | |
3188 | ||
5e2336a0 | 3189 | static const struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
3190 | .open = tracing_open_generic, |
3191 | .read = tracing_max_lat_read, | |
3192 | .write = tracing_max_lat_write, | |
bc0c38d1 SR |
3193 | }; |
3194 | ||
5e2336a0 | 3195 | static const struct file_operations tracing_ctrl_fops = { |
4bf39a94 IM |
3196 | .open = tracing_open_generic, |
3197 | .read = tracing_ctrl_read, | |
3198 | .write = tracing_ctrl_write, | |
bc0c38d1 SR |
3199 | }; |
3200 | ||
5e2336a0 | 3201 | static const struct file_operations set_tracer_fops = { |
4bf39a94 IM |
3202 | .open = tracing_open_generic, |
3203 | .read = tracing_set_trace_read, | |
3204 | .write = tracing_set_trace_write, | |
bc0c38d1 SR |
3205 | }; |
3206 | ||
5e2336a0 | 3207 | static const struct file_operations tracing_pipe_fops = { |
4bf39a94 | 3208 | .open = tracing_open_pipe, |
2a2cc8f7 | 3209 | .poll = tracing_poll_pipe, |
4bf39a94 | 3210 | .read = tracing_read_pipe, |
3c56819b | 3211 | .splice_read = tracing_splice_read_pipe, |
4bf39a94 | 3212 | .release = tracing_release_pipe, |
b3806b43 SR |
3213 | }; |
3214 | ||
5e2336a0 | 3215 | static const struct file_operations tracing_entries_fops = { |
a98a3c3f SR |
3216 | .open = tracing_open_generic, |
3217 | .read = tracing_entries_read, | |
3218 | .write = tracing_entries_write, | |
3219 | }; | |
3220 | ||
5e2336a0 | 3221 | static const struct file_operations tracing_mark_fops = { |
43a15386 | 3222 | .open = tracing_open_generic, |
5bf9a1ee PP |
3223 | .write = tracing_mark_write, |
3224 | }; | |
3225 | ||
2cadf913 SR |
3226 | struct ftrace_buffer_info { |
3227 | struct trace_array *tr; | |
3228 | void *spare; | |
3229 | int cpu; | |
3230 | unsigned int read; | |
3231 | }; | |
3232 | ||
3233 | static int tracing_buffers_open(struct inode *inode, struct file *filp) | |
3234 | { | |
3235 | int cpu = (int)(long)inode->i_private; | |
3236 | struct ftrace_buffer_info *info; | |
3237 | ||
3238 | if (tracing_disabled) | |
3239 | return -ENODEV; | |
3240 | ||
3241 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
3242 | if (!info) | |
3243 | return -ENOMEM; | |
3244 | ||
3245 | info->tr = &global_trace; | |
3246 | info->cpu = cpu; | |
3247 | info->spare = ring_buffer_alloc_read_page(info->tr->buffer); | |
3248 | /* Force reading ring buffer for first read */ | |
3249 | info->read = (unsigned int)-1; | |
3250 | if (!info->spare) | |
3251 | goto out; | |
3252 | ||
3253 | filp->private_data = info; | |
3254 | ||
3255 | return 0; | |
3256 | ||
3257 | out: | |
3258 | kfree(info); | |
3259 | return -ENOMEM; | |
3260 | } | |
3261 | ||
3262 | static ssize_t | |
3263 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
3264 | size_t count, loff_t *ppos) | |
3265 | { | |
3266 | struct ftrace_buffer_info *info = filp->private_data; | |
3267 | unsigned int pos; | |
3268 | ssize_t ret; | |
3269 | size_t size; | |
3270 | ||
2dc5d12b SR |
3271 | if (!count) |
3272 | return 0; | |
3273 | ||
2cadf913 SR |
3274 | /* Do we have previous read data to read? */ |
3275 | if (info->read < PAGE_SIZE) | |
3276 | goto read; | |
3277 | ||
3278 | info->read = 0; | |
3279 | ||
3280 | ret = ring_buffer_read_page(info->tr->buffer, | |
3281 | &info->spare, | |
3282 | count, | |
3283 | info->cpu, 0); | |
3284 | if (ret < 0) | |
3285 | return 0; | |
3286 | ||
3287 | pos = ring_buffer_page_len(info->spare); | |
3288 | ||
3289 | if (pos < PAGE_SIZE) | |
3290 | memset(info->spare + pos, 0, PAGE_SIZE - pos); | |
3291 | ||
3292 | read: | |
3293 | size = PAGE_SIZE - info->read; | |
3294 | if (size > count) | |
3295 | size = count; | |
3296 | ||
3297 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
2dc5d12b | 3298 | if (ret == size) |
2cadf913 | 3299 | return -EFAULT; |
2dc5d12b SR |
3300 | size -= ret; |
3301 | ||
2cadf913 SR |
3302 | *ppos += size; |
3303 | info->read += size; | |
3304 | ||
3305 | return size; | |
3306 | } | |
3307 | ||
3308 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
3309 | { | |
3310 | struct ftrace_buffer_info *info = file->private_data; | |
3311 | ||
3312 | ring_buffer_free_read_page(info->tr->buffer, info->spare); | |
3313 | kfree(info); | |
3314 | ||
3315 | return 0; | |
3316 | } | |
3317 | ||
3318 | struct buffer_ref { | |
3319 | struct ring_buffer *buffer; | |
3320 | void *page; | |
3321 | int ref; | |
3322 | }; | |
3323 | ||
3324 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
3325 | struct pipe_buffer *buf) | |
3326 | { | |
3327 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
3328 | ||
3329 | if (--ref->ref) | |
3330 | return; | |
3331 | ||
3332 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
3333 | kfree(ref); | |
3334 | buf->private = 0; | |
3335 | } | |
3336 | ||
3337 | static int buffer_pipe_buf_steal(struct pipe_inode_info *pipe, | |
3338 | struct pipe_buffer *buf) | |
3339 | { | |
3340 | return 1; | |
3341 | } | |
3342 | ||
3343 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, | |
3344 | struct pipe_buffer *buf) | |
3345 | { | |
3346 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
3347 | ||
3348 | ref->ref++; | |
3349 | } | |
3350 | ||
3351 | /* Pipe buffer operations for a buffer. */ | |
3352 | static struct pipe_buf_operations buffer_pipe_buf_ops = { | |
3353 | .can_merge = 0, | |
3354 | .map = generic_pipe_buf_map, | |
3355 | .unmap = generic_pipe_buf_unmap, | |
3356 | .confirm = generic_pipe_buf_confirm, | |
3357 | .release = buffer_pipe_buf_release, | |
3358 | .steal = buffer_pipe_buf_steal, | |
3359 | .get = buffer_pipe_buf_get, | |
3360 | }; | |
3361 | ||
3362 | /* | |
3363 | * Callback from splice_to_pipe(), if we need to release some pages | |
3364 | * at the end of the spd in case we error'ed out in filling the pipe. | |
3365 | */ | |
3366 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
3367 | { | |
3368 | struct buffer_ref *ref = | |
3369 | (struct buffer_ref *)spd->partial[i].private; | |
3370 | ||
3371 | if (--ref->ref) | |
3372 | return; | |
3373 | ||
3374 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
3375 | kfree(ref); | |
3376 | spd->partial[i].private = 0; | |
3377 | } | |
3378 | ||
3379 | static ssize_t | |
3380 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
3381 | struct pipe_inode_info *pipe, size_t len, | |
3382 | unsigned int flags) | |
3383 | { | |
3384 | struct ftrace_buffer_info *info = file->private_data; | |
3385 | struct partial_page partial[PIPE_BUFFERS]; | |
3386 | struct page *pages[PIPE_BUFFERS]; | |
3387 | struct splice_pipe_desc spd = { | |
3388 | .pages = pages, | |
3389 | .partial = partial, | |
3390 | .flags = flags, | |
3391 | .ops = &buffer_pipe_buf_ops, | |
3392 | .spd_release = buffer_spd_release, | |
3393 | }; | |
3394 | struct buffer_ref *ref; | |
3395 | int size, i; | |
3396 | size_t ret; | |
3397 | ||
3398 | /* | |
3399 | * We can't seek on a buffer input | |
3400 | */ | |
3401 | if (unlikely(*ppos)) | |
3402 | return -ESPIPE; | |
3403 | ||
3404 | ||
3405 | for (i = 0; i < PIPE_BUFFERS && len; i++, len -= size) { | |
3406 | struct page *page; | |
3407 | int r; | |
3408 | ||
3409 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
3410 | if (!ref) | |
3411 | break; | |
3412 | ||
3413 | ref->buffer = info->tr->buffer; | |
3414 | ref->page = ring_buffer_alloc_read_page(ref->buffer); | |
3415 | if (!ref->page) { | |
3416 | kfree(ref); | |
3417 | break; | |
3418 | } | |
3419 | ||
3420 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
3421 | len, info->cpu, 0); | |
3422 | if (r < 0) { | |
3423 | ring_buffer_free_read_page(ref->buffer, | |
3424 | ref->page); | |
3425 | kfree(ref); | |
3426 | break; | |
3427 | } | |
3428 | ||
3429 | /* | |
3430 | * zero out any left over data, this is going to | |
3431 | * user land. | |
3432 | */ | |
3433 | size = ring_buffer_page_len(ref->page); | |
3434 | if (size < PAGE_SIZE) | |
3435 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
3436 | ||
3437 | page = virt_to_page(ref->page); | |
3438 | ||
3439 | spd.pages[i] = page; | |
3440 | spd.partial[i].len = PAGE_SIZE; | |
3441 | spd.partial[i].offset = 0; | |
3442 | spd.partial[i].private = (unsigned long)ref; | |
3443 | spd.nr_pages++; | |
3444 | } | |
3445 | ||
3446 | spd.nr_pages = i; | |
3447 | ||
3448 | /* did we read anything? */ | |
3449 | if (!spd.nr_pages) { | |
3450 | if (flags & SPLICE_F_NONBLOCK) | |
3451 | ret = -EAGAIN; | |
3452 | else | |
3453 | ret = 0; | |
3454 | /* TODO: block */ | |
3455 | return ret; | |
3456 | } | |
3457 | ||
3458 | ret = splice_to_pipe(pipe, &spd); | |
3459 | ||
3460 | return ret; | |
3461 | } | |
3462 | ||
3463 | static const struct file_operations tracing_buffers_fops = { | |
3464 | .open = tracing_buffers_open, | |
3465 | .read = tracing_buffers_read, | |
3466 | .release = tracing_buffers_release, | |
3467 | .splice_read = tracing_buffers_splice_read, | |
3468 | .llseek = no_llseek, | |
3469 | }; | |
3470 | ||
bc0c38d1 SR |
3471 | #ifdef CONFIG_DYNAMIC_FTRACE |
3472 | ||
b807c3d0 SR |
3473 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) |
3474 | { | |
3475 | return 0; | |
3476 | } | |
3477 | ||
bc0c38d1 | 3478 | static ssize_t |
b807c3d0 | 3479 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
bc0c38d1 SR |
3480 | size_t cnt, loff_t *ppos) |
3481 | { | |
a26a2a27 SR |
3482 | static char ftrace_dyn_info_buffer[1024]; |
3483 | static DEFINE_MUTEX(dyn_info_mutex); | |
bc0c38d1 | 3484 | unsigned long *p = filp->private_data; |
b807c3d0 | 3485 | char *buf = ftrace_dyn_info_buffer; |
a26a2a27 | 3486 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); |
bc0c38d1 SR |
3487 | int r; |
3488 | ||
b807c3d0 SR |
3489 | mutex_lock(&dyn_info_mutex); |
3490 | r = sprintf(buf, "%ld ", *p); | |
4bf39a94 | 3491 | |
a26a2a27 | 3492 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); |
b807c3d0 SR |
3493 | buf[r++] = '\n'; |
3494 | ||
3495 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3496 | ||
3497 | mutex_unlock(&dyn_info_mutex); | |
3498 | ||
3499 | return r; | |
bc0c38d1 SR |
3500 | } |
3501 | ||
5e2336a0 | 3502 | static const struct file_operations tracing_dyn_info_fops = { |
4bf39a94 | 3503 | .open = tracing_open_generic, |
b807c3d0 | 3504 | .read = tracing_read_dyn_info, |
bc0c38d1 SR |
3505 | }; |
3506 | #endif | |
3507 | ||
3508 | static struct dentry *d_tracer; | |
3509 | ||
3510 | struct dentry *tracing_init_dentry(void) | |
3511 | { | |
3512 | static int once; | |
3513 | ||
3514 | if (d_tracer) | |
3515 | return d_tracer; | |
3516 | ||
3e1f60b8 FW |
3517 | if (!debugfs_initialized()) |
3518 | return NULL; | |
3519 | ||
bc0c38d1 SR |
3520 | d_tracer = debugfs_create_dir("tracing", NULL); |
3521 | ||
3522 | if (!d_tracer && !once) { | |
3523 | once = 1; | |
3524 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
3525 | return NULL; | |
3526 | } | |
3527 | ||
3528 | return d_tracer; | |
3529 | } | |
3530 | ||
b04cc6b1 FW |
3531 | static struct dentry *d_percpu; |
3532 | ||
3533 | struct dentry *tracing_dentry_percpu(void) | |
3534 | { | |
3535 | static int once; | |
3536 | struct dentry *d_tracer; | |
3537 | ||
3538 | if (d_percpu) | |
3539 | return d_percpu; | |
3540 | ||
3541 | d_tracer = tracing_init_dentry(); | |
3542 | ||
3543 | if (!d_tracer) | |
3544 | return NULL; | |
3545 | ||
3546 | d_percpu = debugfs_create_dir("per_cpu", d_tracer); | |
3547 | ||
3548 | if (!d_percpu && !once) { | |
3549 | once = 1; | |
3550 | pr_warning("Could not create debugfs directory 'per_cpu'\n"); | |
3551 | return NULL; | |
3552 | } | |
3553 | ||
3554 | return d_percpu; | |
3555 | } | |
3556 | ||
3557 | static void tracing_init_debugfs_percpu(long cpu) | |
3558 | { | |
3559 | struct dentry *d_percpu = tracing_dentry_percpu(); | |
8656e7a2 FW |
3560 | struct dentry *entry, *d_cpu; |
3561 | /* strlen(cpu) + MAX(log10(cpu)) + '\0' */ | |
3562 | char cpu_dir[7]; | |
b04cc6b1 FW |
3563 | |
3564 | if (cpu > 999 || cpu < 0) | |
3565 | return; | |
3566 | ||
8656e7a2 FW |
3567 | sprintf(cpu_dir, "cpu%ld", cpu); |
3568 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); | |
3569 | if (!d_cpu) { | |
3570 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
3571 | return; | |
3572 | } | |
b04cc6b1 | 3573 | |
8656e7a2 FW |
3574 | /* per cpu trace_pipe */ |
3575 | entry = debugfs_create_file("trace_pipe", 0444, d_cpu, | |
b04cc6b1 FW |
3576 | (void *) cpu, &tracing_pipe_fops); |
3577 | if (!entry) | |
8656e7a2 | 3578 | pr_warning("Could not create debugfs 'trace_pipe' entry\n"); |
b04cc6b1 FW |
3579 | |
3580 | /* per cpu trace */ | |
4acd4d00 | 3581 | entry = debugfs_create_file("trace", 0644, d_cpu, |
b04cc6b1 FW |
3582 | (void *) cpu, &tracing_fops); |
3583 | if (!entry) | |
8656e7a2 | 3584 | pr_warning("Could not create debugfs 'trace' entry\n"); |
7f96f93f SR |
3585 | |
3586 | entry = debugfs_create_file("trace_pipe_raw", 0444, d_cpu, | |
3587 | (void *) cpu, &tracing_buffers_fops); | |
3588 | if (!entry) | |
3589 | pr_warning("Could not create debugfs 'trace_pipe_raw' entry\n"); | |
b04cc6b1 FW |
3590 | } |
3591 | ||
60a11774 SR |
3592 | #ifdef CONFIG_FTRACE_SELFTEST |
3593 | /* Let selftest have access to static functions in this file */ | |
3594 | #include "trace_selftest.c" | |
3595 | #endif | |
3596 | ||
577b785f SR |
3597 | struct trace_option_dentry { |
3598 | struct tracer_opt *opt; | |
3599 | struct tracer_flags *flags; | |
3600 | struct dentry *entry; | |
3601 | }; | |
3602 | ||
3603 | static ssize_t | |
3604 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
3605 | loff_t *ppos) | |
3606 | { | |
3607 | struct trace_option_dentry *topt = filp->private_data; | |
3608 | char *buf; | |
3609 | ||
3610 | if (topt->flags->val & topt->opt->bit) | |
3611 | buf = "1\n"; | |
3612 | else | |
3613 | buf = "0\n"; | |
3614 | ||
3615 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
3616 | } | |
3617 | ||
3618 | static ssize_t | |
3619 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
3620 | loff_t *ppos) | |
3621 | { | |
3622 | struct trace_option_dentry *topt = filp->private_data; | |
3623 | unsigned long val; | |
3624 | char buf[64]; | |
3625 | int ret; | |
3626 | ||
3627 | if (cnt >= sizeof(buf)) | |
3628 | return -EINVAL; | |
3629 | ||
3630 | if (copy_from_user(&buf, ubuf, cnt)) | |
3631 | return -EFAULT; | |
3632 | ||
3633 | buf[cnt] = 0; | |
3634 | ||
3635 | ret = strict_strtoul(buf, 10, &val); | |
3636 | if (ret < 0) | |
3637 | return ret; | |
3638 | ||
3639 | ret = 0; | |
3640 | switch (val) { | |
3641 | case 0: | |
3642 | /* do nothing if already cleared */ | |
3643 | if (!(topt->flags->val & topt->opt->bit)) | |
3644 | break; | |
3645 | ||
3646 | mutex_lock(&trace_types_lock); | |
3647 | if (current_trace->set_flag) | |
3648 | ret = current_trace->set_flag(topt->flags->val, | |
3649 | topt->opt->bit, 0); | |
3650 | mutex_unlock(&trace_types_lock); | |
3651 | if (ret) | |
3652 | return ret; | |
3653 | topt->flags->val &= ~topt->opt->bit; | |
3654 | break; | |
3655 | case 1: | |
3656 | /* do nothing if already set */ | |
3657 | if (topt->flags->val & topt->opt->bit) | |
3658 | break; | |
3659 | ||
3660 | mutex_lock(&trace_types_lock); | |
3661 | if (current_trace->set_flag) | |
3662 | ret = current_trace->set_flag(topt->flags->val, | |
3663 | topt->opt->bit, 1); | |
3664 | mutex_unlock(&trace_types_lock); | |
3665 | if (ret) | |
3666 | return ret; | |
3667 | topt->flags->val |= topt->opt->bit; | |
3668 | break; | |
3669 | ||
3670 | default: | |
3671 | return -EINVAL; | |
3672 | } | |
3673 | ||
3674 | *ppos += cnt; | |
3675 | ||
3676 | return cnt; | |
3677 | } | |
3678 | ||
3679 | ||
3680 | static const struct file_operations trace_options_fops = { | |
3681 | .open = tracing_open_generic, | |
3682 | .read = trace_options_read, | |
3683 | .write = trace_options_write, | |
3684 | }; | |
3685 | ||
a8259075 SR |
3686 | static ssize_t |
3687 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
3688 | loff_t *ppos) | |
3689 | { | |
3690 | long index = (long)filp->private_data; | |
3691 | char *buf; | |
3692 | ||
3693 | if (trace_flags & (1 << index)) | |
3694 | buf = "1\n"; | |
3695 | else | |
3696 | buf = "0\n"; | |
3697 | ||
3698 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
3699 | } | |
3700 | ||
3701 | static ssize_t | |
3702 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
3703 | loff_t *ppos) | |
3704 | { | |
3705 | long index = (long)filp->private_data; | |
3706 | char buf[64]; | |
3707 | unsigned long val; | |
3708 | int ret; | |
3709 | ||
3710 | if (cnt >= sizeof(buf)) | |
3711 | return -EINVAL; | |
3712 | ||
3713 | if (copy_from_user(&buf, ubuf, cnt)) | |
3714 | return -EFAULT; | |
3715 | ||
3716 | buf[cnt] = 0; | |
3717 | ||
3718 | ret = strict_strtoul(buf, 10, &val); | |
3719 | if (ret < 0) | |
3720 | return ret; | |
3721 | ||
3722 | switch (val) { | |
3723 | case 0: | |
3724 | trace_flags &= ~(1 << index); | |
3725 | break; | |
3726 | case 1: | |
3727 | trace_flags |= 1 << index; | |
3728 | break; | |
3729 | ||
3730 | default: | |
3731 | return -EINVAL; | |
3732 | } | |
3733 | ||
3734 | *ppos += cnt; | |
3735 | ||
3736 | return cnt; | |
3737 | } | |
3738 | ||
a8259075 SR |
3739 | static const struct file_operations trace_options_core_fops = { |
3740 | .open = tracing_open_generic, | |
3741 | .read = trace_options_core_read, | |
3742 | .write = trace_options_core_write, | |
3743 | }; | |
3744 | ||
3745 | static struct dentry *trace_options_init_dentry(void) | |
3746 | { | |
3747 | struct dentry *d_tracer; | |
3748 | static struct dentry *t_options; | |
3749 | ||
3750 | if (t_options) | |
3751 | return t_options; | |
3752 | ||
3753 | d_tracer = tracing_init_dentry(); | |
3754 | if (!d_tracer) | |
3755 | return NULL; | |
3756 | ||
3757 | t_options = debugfs_create_dir("options", d_tracer); | |
3758 | if (!t_options) { | |
3759 | pr_warning("Could not create debugfs directory 'options'\n"); | |
3760 | return NULL; | |
3761 | } | |
3762 | ||
3763 | return t_options; | |
3764 | } | |
3765 | ||
577b785f SR |
3766 | static void |
3767 | create_trace_option_file(struct trace_option_dentry *topt, | |
3768 | struct tracer_flags *flags, | |
3769 | struct tracer_opt *opt) | |
3770 | { | |
3771 | struct dentry *t_options; | |
3772 | struct dentry *entry; | |
3773 | ||
3774 | t_options = trace_options_init_dentry(); | |
3775 | if (!t_options) | |
3776 | return; | |
3777 | ||
3778 | topt->flags = flags; | |
3779 | topt->opt = opt; | |
3780 | ||
3781 | entry = debugfs_create_file(opt->name, 0644, t_options, topt, | |
3782 | &trace_options_fops); | |
3783 | ||
3784 | topt->entry = entry; | |
3785 | ||
3786 | } | |
3787 | ||
3788 | static struct trace_option_dentry * | |
3789 | create_trace_option_files(struct tracer *tracer) | |
3790 | { | |
3791 | struct trace_option_dentry *topts; | |
3792 | struct tracer_flags *flags; | |
3793 | struct tracer_opt *opts; | |
3794 | int cnt; | |
3795 | ||
3796 | if (!tracer) | |
3797 | return NULL; | |
3798 | ||
3799 | flags = tracer->flags; | |
3800 | ||
3801 | if (!flags || !flags->opts) | |
3802 | return NULL; | |
3803 | ||
3804 | opts = flags->opts; | |
3805 | ||
3806 | for (cnt = 0; opts[cnt].name; cnt++) | |
3807 | ; | |
3808 | ||
0cfe8245 | 3809 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
577b785f SR |
3810 | if (!topts) |
3811 | return NULL; | |
3812 | ||
3813 | for (cnt = 0; opts[cnt].name; cnt++) | |
3814 | create_trace_option_file(&topts[cnt], flags, | |
3815 | &opts[cnt]); | |
3816 | ||
3817 | return topts; | |
3818 | } | |
3819 | ||
3820 | static void | |
3821 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
3822 | { | |
3823 | int cnt; | |
3824 | ||
3825 | if (!topts) | |
3826 | return; | |
3827 | ||
3828 | for (cnt = 0; topts[cnt].opt; cnt++) { | |
3829 | if (topts[cnt].entry) | |
3830 | debugfs_remove(topts[cnt].entry); | |
3831 | } | |
3832 | ||
3833 | kfree(topts); | |
3834 | } | |
3835 | ||
a8259075 SR |
3836 | static struct dentry * |
3837 | create_trace_option_core_file(const char *option, long index) | |
3838 | { | |
3839 | struct dentry *t_options; | |
3840 | struct dentry *entry; | |
3841 | ||
3842 | t_options = trace_options_init_dentry(); | |
3843 | if (!t_options) | |
3844 | return NULL; | |
3845 | ||
3846 | entry = debugfs_create_file(option, 0644, t_options, (void *)index, | |
3847 | &trace_options_core_fops); | |
3848 | ||
3849 | return entry; | |
3850 | } | |
3851 | ||
3852 | static __init void create_trace_options_dir(void) | |
3853 | { | |
3854 | struct dentry *t_options; | |
3855 | struct dentry *entry; | |
3856 | int i; | |
3857 | ||
3858 | t_options = trace_options_init_dentry(); | |
3859 | if (!t_options) | |
3860 | return; | |
3861 | ||
3862 | for (i = 0; trace_options[i]; i++) { | |
3863 | entry = create_trace_option_core_file(trace_options[i], i); | |
3864 | if (!entry) | |
3865 | pr_warning("Could not create debugfs %s entry\n", | |
3866 | trace_options[i]); | |
3867 | } | |
3868 | } | |
3869 | ||
b5ad384e | 3870 | static __init int tracer_init_debugfs(void) |
bc0c38d1 SR |
3871 | { |
3872 | struct dentry *d_tracer; | |
3873 | struct dentry *entry; | |
b04cc6b1 | 3874 | int cpu; |
bc0c38d1 SR |
3875 | |
3876 | d_tracer = tracing_init_dentry(); | |
3877 | ||
3878 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, | |
3879 | &global_trace, &tracing_ctrl_fops); | |
3880 | if (!entry) | |
3881 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); | |
3882 | ||
ee6bce52 | 3883 | entry = debugfs_create_file("trace_options", 0644, d_tracer, |
bc0c38d1 SR |
3884 | NULL, &tracing_iter_fops); |
3885 | if (!entry) | |
ee6bce52 | 3886 | pr_warning("Could not create debugfs 'trace_options' entry\n"); |
bc0c38d1 | 3887 | |
a8259075 SR |
3888 | create_trace_options_dir(); |
3889 | ||
c7078de1 IM |
3890 | entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer, |
3891 | NULL, &tracing_cpumask_fops); | |
3892 | if (!entry) | |
3893 | pr_warning("Could not create debugfs 'tracing_cpumask' entry\n"); | |
3894 | ||
4acd4d00 | 3895 | entry = debugfs_create_file("trace", 0644, d_tracer, |
b04cc6b1 | 3896 | (void *) TRACE_PIPE_ALL_CPU, &tracing_fops); |
bc0c38d1 SR |
3897 | if (!entry) |
3898 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
3899 | ||
3900 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, | |
3901 | &global_trace, &show_traces_fops); | |
3902 | if (!entry) | |
98a983aa | 3903 | pr_warning("Could not create debugfs 'available_tracers' entry\n"); |
bc0c38d1 SR |
3904 | |
3905 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, | |
3906 | &global_trace, &set_tracer_fops); | |
3907 | if (!entry) | |
98a983aa | 3908 | pr_warning("Could not create debugfs 'current_tracer' entry\n"); |
bc0c38d1 SR |
3909 | |
3910 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, | |
3911 | &tracing_max_latency, | |
3912 | &tracing_max_lat_fops); | |
3913 | if (!entry) | |
3914 | pr_warning("Could not create debugfs " | |
3915 | "'tracing_max_latency' entry\n"); | |
3916 | ||
3917 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, | |
3918 | &tracing_thresh, &tracing_max_lat_fops); | |
3919 | if (!entry) | |
3920 | pr_warning("Could not create debugfs " | |
98a983aa | 3921 | "'tracing_thresh' entry\n"); |
7bd2f24c IM |
3922 | entry = debugfs_create_file("README", 0644, d_tracer, |
3923 | NULL, &tracing_readme_fops); | |
3924 | if (!entry) | |
3925 | pr_warning("Could not create debugfs 'README' entry\n"); | |
3926 | ||
b04cc6b1 FW |
3927 | entry = debugfs_create_file("trace_pipe", 0444, d_tracer, |
3928 | (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); | |
b3806b43 SR |
3929 | if (!entry) |
3930 | pr_warning("Could not create debugfs " | |
98a983aa | 3931 | "'trace_pipe' entry\n"); |
bc0c38d1 | 3932 | |
a94c80e7 | 3933 | entry = debugfs_create_file("buffer_size_kb", 0644, d_tracer, |
a98a3c3f SR |
3934 | &global_trace, &tracing_entries_fops); |
3935 | if (!entry) | |
3936 | pr_warning("Could not create debugfs " | |
a94c80e7 | 3937 | "'buffer_size_kb' entry\n"); |
a98a3c3f | 3938 | |
5bf9a1ee PP |
3939 | entry = debugfs_create_file("trace_marker", 0220, d_tracer, |
3940 | NULL, &tracing_mark_fops); | |
3941 | if (!entry) | |
3942 | pr_warning("Could not create debugfs " | |
3943 | "'trace_marker' entry\n"); | |
3944 | ||
bc0c38d1 SR |
3945 | #ifdef CONFIG_DYNAMIC_FTRACE |
3946 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
3947 | &ftrace_update_tot_cnt, | |
b807c3d0 | 3948 | &tracing_dyn_info_fops); |
bc0c38d1 SR |
3949 | if (!entry) |
3950 | pr_warning("Could not create debugfs " | |
3951 | "'dyn_ftrace_total_info' entry\n"); | |
3952 | #endif | |
d618b3e6 IM |
3953 | #ifdef CONFIG_SYSPROF_TRACER |
3954 | init_tracer_sysprof_debugfs(d_tracer); | |
3955 | #endif | |
b04cc6b1 FW |
3956 | |
3957 | for_each_tracing_cpu(cpu) | |
3958 | tracing_init_debugfs_percpu(cpu); | |
3959 | ||
b5ad384e | 3960 | return 0; |
bc0c38d1 SR |
3961 | } |
3962 | ||
3f5a54e3 SR |
3963 | static int trace_panic_handler(struct notifier_block *this, |
3964 | unsigned long event, void *unused) | |
3965 | { | |
944ac425 SR |
3966 | if (ftrace_dump_on_oops) |
3967 | ftrace_dump(); | |
3f5a54e3 SR |
3968 | return NOTIFY_OK; |
3969 | } | |
3970 | ||
3971 | static struct notifier_block trace_panic_notifier = { | |
3972 | .notifier_call = trace_panic_handler, | |
3973 | .next = NULL, | |
3974 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
3975 | }; | |
3976 | ||
3977 | static int trace_die_handler(struct notifier_block *self, | |
3978 | unsigned long val, | |
3979 | void *data) | |
3980 | { | |
3981 | switch (val) { | |
3982 | case DIE_OOPS: | |
944ac425 SR |
3983 | if (ftrace_dump_on_oops) |
3984 | ftrace_dump(); | |
3f5a54e3 SR |
3985 | break; |
3986 | default: | |
3987 | break; | |
3988 | } | |
3989 | return NOTIFY_OK; | |
3990 | } | |
3991 | ||
3992 | static struct notifier_block trace_die_notifier = { | |
3993 | .notifier_call = trace_die_handler, | |
3994 | .priority = 200 | |
3995 | }; | |
3996 | ||
3997 | /* | |
3998 | * printk is set to max of 1024, we really don't need it that big. | |
3999 | * Nothing should be printing 1000 characters anyway. | |
4000 | */ | |
4001 | #define TRACE_MAX_PRINT 1000 | |
4002 | ||
4003 | /* | |
4004 | * Define here KERN_TRACE so that we have one place to modify | |
4005 | * it if we decide to change what log level the ftrace dump | |
4006 | * should be at. | |
4007 | */ | |
428aee14 | 4008 | #define KERN_TRACE KERN_EMERG |
3f5a54e3 SR |
4009 | |
4010 | static void | |
4011 | trace_printk_seq(struct trace_seq *s) | |
4012 | { | |
4013 | /* Probably should print a warning here. */ | |
4014 | if (s->len >= 1000) | |
4015 | s->len = 1000; | |
4016 | ||
4017 | /* should be zero ended, but we are paranoid. */ | |
4018 | s->buffer[s->len] = 0; | |
4019 | ||
4020 | printk(KERN_TRACE "%s", s->buffer); | |
4021 | ||
f9520750 | 4022 | trace_seq_init(s); |
3f5a54e3 SR |
4023 | } |
4024 | ||
cf586b61 | 4025 | static void __ftrace_dump(bool disable_tracing) |
3f5a54e3 SR |
4026 | { |
4027 | static DEFINE_SPINLOCK(ftrace_dump_lock); | |
4028 | /* use static because iter can be a bit big for the stack */ | |
4029 | static struct trace_iterator iter; | |
cf586b61 | 4030 | unsigned int old_userobj; |
3f5a54e3 | 4031 | static int dump_ran; |
d769041f SR |
4032 | unsigned long flags; |
4033 | int cnt = 0, cpu; | |
3f5a54e3 SR |
4034 | |
4035 | /* only one dump */ | |
4036 | spin_lock_irqsave(&ftrace_dump_lock, flags); | |
4037 | if (dump_ran) | |
4038 | goto out; | |
4039 | ||
4040 | dump_ran = 1; | |
4041 | ||
0ee6b6cf | 4042 | tracing_off(); |
cf586b61 FW |
4043 | |
4044 | if (disable_tracing) | |
4045 | ftrace_kill(); | |
3f5a54e3 | 4046 | |
d769041f SR |
4047 | for_each_tracing_cpu(cpu) { |
4048 | atomic_inc(&global_trace.data[cpu]->disabled); | |
4049 | } | |
4050 | ||
cf586b61 FW |
4051 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; |
4052 | ||
b54d3de9 TE |
4053 | /* don't look at user memory in panic mode */ |
4054 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
4055 | ||
3f5a54e3 SR |
4056 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); |
4057 | ||
e543ad76 | 4058 | /* Simulate the iterator */ |
3f5a54e3 SR |
4059 | iter.tr = &global_trace; |
4060 | iter.trace = current_trace; | |
e543ad76 | 4061 | iter.cpu_file = TRACE_PIPE_ALL_CPU; |
3f5a54e3 SR |
4062 | |
4063 | /* | |
4064 | * We need to stop all tracing on all CPUS to read the | |
4065 | * the next buffer. This is a bit expensive, but is | |
4066 | * not done often. We fill all what we can read, | |
4067 | * and then release the locks again. | |
4068 | */ | |
4069 | ||
3f5a54e3 SR |
4070 | while (!trace_empty(&iter)) { |
4071 | ||
4072 | if (!cnt) | |
4073 | printk(KERN_TRACE "---------------------------------\n"); | |
4074 | ||
4075 | cnt++; | |
4076 | ||
4077 | /* reset all but tr, trace, and overruns */ | |
4078 | memset(&iter.seq, 0, | |
4079 | sizeof(struct trace_iterator) - | |
4080 | offsetof(struct trace_iterator, seq)); | |
4081 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
4082 | iter.pos = -1; | |
4083 | ||
4084 | if (find_next_entry_inc(&iter) != NULL) { | |
4085 | print_trace_line(&iter); | |
4086 | trace_consume(&iter); | |
4087 | } | |
4088 | ||
4089 | trace_printk_seq(&iter.seq); | |
4090 | } | |
4091 | ||
4092 | if (!cnt) | |
4093 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
4094 | else | |
4095 | printk(KERN_TRACE "---------------------------------\n"); | |
4096 | ||
cf586b61 FW |
4097 | /* Re-enable tracing if requested */ |
4098 | if (!disable_tracing) { | |
4099 | trace_flags |= old_userobj; | |
4100 | ||
4101 | for_each_tracing_cpu(cpu) { | |
4102 | atomic_dec(&global_trace.data[cpu]->disabled); | |
4103 | } | |
4104 | tracing_on(); | |
4105 | } | |
4106 | ||
3f5a54e3 SR |
4107 | out: |
4108 | spin_unlock_irqrestore(&ftrace_dump_lock, flags); | |
4109 | } | |
4110 | ||
cf586b61 FW |
4111 | /* By default: disable tracing after the dump */ |
4112 | void ftrace_dump(void) | |
4113 | { | |
4114 | __ftrace_dump(true); | |
4115 | } | |
4116 | ||
3928a8a2 | 4117 | __init static int tracer_alloc_buffers(void) |
bc0c38d1 | 4118 | { |
4c11d7ae | 4119 | struct trace_array_cpu *data; |
73c5162a | 4120 | int ring_buf_size; |
4c11d7ae | 4121 | int i; |
9e01c1b7 | 4122 | int ret = -ENOMEM; |
4c11d7ae | 4123 | |
9e01c1b7 RR |
4124 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
4125 | goto out; | |
4126 | ||
4127 | if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) | |
4128 | goto out_free_buffer_mask; | |
4c11d7ae | 4129 | |
b04cc6b1 FW |
4130 | if (!alloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL)) |
4131 | goto out_free_tracing_cpumask; | |
4132 | ||
73c5162a SR |
4133 | /* To save memory, keep the ring buffer size to its minimum */ |
4134 | if (ring_buffer_expanded) | |
4135 | ring_buf_size = trace_buf_size; | |
4136 | else | |
4137 | ring_buf_size = 1; | |
4138 | ||
9e01c1b7 RR |
4139 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
4140 | cpumask_copy(tracing_cpumask, cpu_all_mask); | |
b04cc6b1 | 4141 | cpumask_clear(tracing_reader_cpumask); |
9e01c1b7 RR |
4142 | |
4143 | /* TODO: make the number of buffers hot pluggable with CPUS */ | |
73c5162a | 4144 | global_trace.buffer = ring_buffer_alloc(ring_buf_size, |
3928a8a2 SR |
4145 | TRACE_BUFFER_FLAGS); |
4146 | if (!global_trace.buffer) { | |
4147 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); | |
4148 | WARN_ON(1); | |
9e01c1b7 | 4149 | goto out_free_cpumask; |
4c11d7ae | 4150 | } |
3928a8a2 | 4151 | global_trace.entries = ring_buffer_size(global_trace.buffer); |
4c11d7ae | 4152 | |
9e01c1b7 | 4153 | |
4c11d7ae | 4154 | #ifdef CONFIG_TRACER_MAX_TRACE |
73c5162a | 4155 | max_tr.buffer = ring_buffer_alloc(ring_buf_size, |
3928a8a2 SR |
4156 | TRACE_BUFFER_FLAGS); |
4157 | if (!max_tr.buffer) { | |
4158 | printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); | |
4159 | WARN_ON(1); | |
4160 | ring_buffer_free(global_trace.buffer); | |
9e01c1b7 | 4161 | goto out_free_cpumask; |
4c11d7ae | 4162 | } |
3928a8a2 SR |
4163 | max_tr.entries = ring_buffer_size(max_tr.buffer); |
4164 | WARN_ON(max_tr.entries != global_trace.entries); | |
a98a3c3f | 4165 | #endif |
ab46428c | 4166 | |
4c11d7ae | 4167 | /* Allocate the first page for all buffers */ |
ab46428c | 4168 | for_each_tracing_cpu(i) { |
4c11d7ae | 4169 | data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
bc0c38d1 | 4170 | max_tr.data[i] = &per_cpu(max_data, i); |
4c11d7ae | 4171 | } |
bc0c38d1 | 4172 | |
bc0c38d1 SR |
4173 | trace_init_cmdlines(); |
4174 | ||
43a15386 | 4175 | register_tracer(&nop_trace); |
79fb0768 | 4176 | current_trace = &nop_trace; |
b5ad384e FW |
4177 | #ifdef CONFIG_BOOT_TRACER |
4178 | register_tracer(&boot_tracer); | |
b5ad384e | 4179 | #endif |
60a11774 SR |
4180 | /* All seems OK, enable tracing */ |
4181 | tracing_disabled = 0; | |
3928a8a2 | 4182 | |
3f5a54e3 SR |
4183 | atomic_notifier_chain_register(&panic_notifier_list, |
4184 | &trace_panic_notifier); | |
4185 | ||
4186 | register_die_notifier(&trace_die_notifier); | |
2fc1dfbe FW |
4187 | |
4188 | return 0; | |
3f5a54e3 | 4189 | |
9e01c1b7 | 4190 | out_free_cpumask: |
b04cc6b1 FW |
4191 | free_cpumask_var(tracing_reader_cpumask); |
4192 | out_free_tracing_cpumask: | |
9e01c1b7 RR |
4193 | free_cpumask_var(tracing_cpumask); |
4194 | out_free_buffer_mask: | |
4195 | free_cpumask_var(tracing_buffer_mask); | |
4196 | out: | |
4197 | return ret; | |
bc0c38d1 | 4198 | } |
b2821ae6 SR |
4199 | |
4200 | __init static int clear_boot_tracer(void) | |
4201 | { | |
4202 | /* | |
4203 | * The default tracer at boot buffer is an init section. | |
4204 | * This function is called in lateinit. If we did not | |
4205 | * find the boot tracer, then clear it out, to prevent | |
4206 | * later registration from accessing the buffer that is | |
4207 | * about to be freed. | |
4208 | */ | |
4209 | if (!default_bootup_tracer) | |
4210 | return 0; | |
4211 | ||
4212 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
4213 | default_bootup_tracer); | |
4214 | default_bootup_tracer = NULL; | |
4215 | ||
4216 | return 0; | |
4217 | } | |
4218 | ||
b5ad384e FW |
4219 | early_initcall(tracer_alloc_buffers); |
4220 | fs_initcall(tracer_init_debugfs); | |
b2821ae6 | 4221 | late_initcall(clear_boot_tracer); |