?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ftrace: use kretprobe trampoline name to test in output
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / trace / trace.c
blob9f3b478f91716bdd1cc48ac6872c2a3c1412dbb8
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 */
14 #include <linux/utsrelease.h>
15 #include <linux/kallsyms.h>
16 #include <linux/seq_file.h>
17 #include <linux/notifier.h>
18 #include <linux/debugfs.h>
19 #include <linux/pagemap.h>
20 #include <linux/hardirq.h>
21 #include <linux/linkage.h>
22 #include <linux/uaccess.h>
23 #include <linux/ftrace.h>
24 #include <linux/module.h>
25 #include <linux/percpu.h>
26 #include <linux/kdebug.h>
27 #include <linux/ctype.h>
28 #include <linux/init.h>
29 #include <linux/poll.h>
30 #include <linux/gfp.h>
31 #include <linux/fs.h>
32 #include <linux/kprobes.h>
33 #include <linux/writeback.h>
34
35 #include <linux/stacktrace.h>
36 #include <linux/ring_buffer.h>
37 #include <linux/irqflags.h>
38
39 #include "trace.h"
40
41 #define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
42
43 unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
44 unsigned long __read_mostly tracing_thresh;
45
46 static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
47
48 static inline void ftrace_disable_cpu(void)
49 {
50 preempt_disable();
51 local_inc(&__get_cpu_var(ftrace_cpu_disabled));
52 }
53
54 static inline void ftrace_enable_cpu(void)
55 {
56 local_dec(&__get_cpu_var(ftrace_cpu_disabled));
57 preempt_enable();
58 }
59
60 static cpumask_t __read_mostly tracing_buffer_mask;
61
62 #define for_each_tracing_cpu(cpu) \
63 for_each_cpu_mask(cpu, tracing_buffer_mask)
64
65 static int tracing_disabled = 1;
66
67 long
68 ns2usecs(cycle_t nsec)
69 {
70 nsec += 500;
71 do_div(nsec, 1000);
72 return nsec;
73 }
74
75 cycle_t ftrace_now(int cpu)
76 {
77 u64 ts = ring_buffer_time_stamp(cpu);
78 ring_buffer_normalize_time_stamp(cpu, &ts);
79 return ts;
80 }
81
82 /*
83 * The global_trace is the descriptor that holds the tracing
84 * buffers for the live tracing. For each CPU, it contains
85 * a link list of pages that will store trace entries. The
86 * page descriptor of the pages in the memory is used to hold
87 * the link list by linking the lru item in the page descriptor
88 * to each of the pages in the buffer per CPU.
89 *
90 * For each active CPU there is a data field that holds the
91 * pages for the buffer for that CPU. Each CPU has the same number
92 * of pages allocated for its buffer.
93 */
94 static struct trace_array global_trace;
95
96 static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
97
98 /*
99 * The max_tr is used to snapshot the global_trace when a maximum
100 * latency is reached. Some tracers will use this to store a maximum
101 * trace while it continues examining live traces.
102 *
103 * The buffers for the max_tr are set up the same as the global_trace.
104 * When a snapshot is taken, the link list of the max_tr is swapped
105 * with the link list of the global_trace and the buffers are reset for
106 * the global_trace so the tracing can continue.
107 */
108 static struct trace_array max_tr;
109
110 static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
111
112 /* tracer_enabled is used to toggle activation of a tracer */
113 static int tracer_enabled = 1;
114
115 /* function tracing enabled */
116 int ftrace_function_enabled;
117
118 /*
119 * trace_buf_size is the size in bytes that is allocated
120 * for a buffer. Note, the number of bytes is always rounded
121 * to page size.
122 *
123 * This number is purposely set to a low number of 16384.
124 * If the dump on oops happens, it will be much appreciated
125 * to not have to wait for all that output. Anyway this can be
126 * boot time and run time configurable.
127 */
128 #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
129
130 static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
131
132 /* trace_types holds a link list of available tracers. */
133 static struct tracer *trace_types __read_mostly;
134
135 /* current_trace points to the tracer that is currently active */
136 static struct tracer *current_trace __read_mostly;
137
138 /*
139 * max_tracer_type_len is used to simplify the allocating of
140 * buffers to read userspace tracer names. We keep track of
141 * the longest tracer name registered.
142 */
143 static int max_tracer_type_len;
144
145 /*
146 * trace_types_lock is used to protect the trace_types list.
147 * This lock is also used to keep user access serialized.
148 * Accesses from userspace will grab this lock while userspace
149 * activities happen inside the kernel.
150 */
151 static DEFINE_MUTEX(trace_types_lock);
152
153 /* trace_wait is a waitqueue for tasks blocked on trace_poll */
154 static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
155
156 /* trace_flags holds iter_ctrl options */
157 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
158
159 /**
160 * trace_wake_up - wake up tasks waiting for trace input
161 *
162 * Simply wakes up any task that is blocked on the trace_wait
163 * queue. These is used with trace_poll for tasks polling the trace.
164 */
165 void trace_wake_up(void)
166 {
167 /*
168 * The runqueue_is_locked() can fail, but this is the best we
169 * have for now:
170 */
171 if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
172 wake_up(&trace_wait);
173 }
174
175 static int __init set_buf_size(char *str)
176 {
177 unsigned long buf_size;
178 int ret;
179
180 if (!str)
181 return 0;
182 ret = strict_strtoul(str, 0, &buf_size);
183 /* nr_entries can not be zero */
184 if (ret < 0 || buf_size == 0)
185 return 0;
186 trace_buf_size = buf_size;
187 return 1;
188 }
189 __setup("trace_buf_size=", set_buf_size);
190
191 unsigned long nsecs_to_usecs(unsigned long nsecs)
192 {
193 return nsecs / 1000;
194 }
195
196 /*
197 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
198 * control the output of kernel symbols.
199 */
200 #define TRACE_ITER_SYM_MASK \
201 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
202
203 /* These must match the bit postions in trace_iterator_flags */
204 static const char *trace_options[] = {
205 "print-parent",
206 "sym-offset",
207 "sym-addr",
208 "verbose",
209 "raw",
210 "hex",
211 "bin",
212 "block",
213 "stacktrace",
214 "sched-tree",
215 "ftrace_printk",
216 NULL
217 };
218
219 /*
220 * ftrace_max_lock is used to protect the swapping of buffers
221 * when taking a max snapshot. The buffers themselves are
222 * protected by per_cpu spinlocks. But the action of the swap
223 * needs its own lock.
224 *
225 * This is defined as a raw_spinlock_t in order to help
226 * with performance when lockdep debugging is enabled.
227 */
228 static raw_spinlock_t ftrace_max_lock =
229 (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
230
231 /*
232 * Copy the new maximum trace into the separate maximum-trace
233 * structure. (this way the maximum trace is permanently saved,
234 * for later retrieval via /debugfs/tracing/latency_trace)
235 */
236 static void
237 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
238 {
239 struct trace_array_cpu *data = tr->data[cpu];
240
241 max_tr.cpu = cpu;
242 max_tr.time_start = data->preempt_timestamp;
243
244 data = max_tr.data[cpu];
245 data->saved_latency = tracing_max_latency;
246
247 memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
248 data->pid = tsk->pid;
249 data->uid = tsk->uid;
250 data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
251 data->policy = tsk->policy;
252 data->rt_priority = tsk->rt_priority;
253
254 /* record this tasks comm */
255 tracing_record_cmdline(current);
256 }
257
258 /**
259 * trace_seq_printf - sequence printing of trace information
260 * @s: trace sequence descriptor
261 * @fmt: printf format string
262 *
263 * The tracer may use either sequence operations or its own
264 * copy to user routines. To simplify formating of a trace
265 * trace_seq_printf is used to store strings into a special
266 * buffer (@s). Then the output may be either used by
267 * the sequencer or pulled into another buffer.
268 */
269 int
270 trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
271 {
272 int len = (PAGE_SIZE - 1) - s->len;
273 va_list ap;
274 int ret;
275
276 if (!len)
277 return 0;
278
279 va_start(ap, fmt);
280 ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
281 va_end(ap);
282
283 /* If we can't write it all, don't bother writing anything */
284 if (ret >= len)
285 return 0;
286
287 s->len += ret;
288
289 return len;
290 }
291
292 /**
293 * trace_seq_puts - trace sequence printing of simple string
294 * @s: trace sequence descriptor
295 * @str: simple string to record
296 *
297 * The tracer may use either the sequence operations or its own
298 * copy to user routines. This function records a simple string
299 * into a special buffer (@s) for later retrieval by a sequencer
300 * or other mechanism.
301 */
302 static int
303 trace_seq_puts(struct trace_seq *s, const char *str)
304 {
305 int len = strlen(str);
306
307 if (len > ((PAGE_SIZE - 1) - s->len))
308 return 0;
309
310 memcpy(s->buffer + s->len, str, len);
311 s->len += len;
312
313 return len;
314 }
315
316 static int
317 trace_seq_putc(struct trace_seq *s, unsigned char c)
318 {
319 if (s->len >= (PAGE_SIZE - 1))
320 return 0;
321
322 s->buffer[s->len++] = c;
323
324 return 1;
325 }
326
327 static int
328 trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
329 {
330 if (len > ((PAGE_SIZE - 1) - s->len))
331 return 0;
332
333 memcpy(s->buffer + s->len, mem, len);
334 s->len += len;
335
336 return len;
337 }
338
339 #define MAX_MEMHEX_BYTES 8
340 #define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
341
342 static int
343 trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
344 {
345 unsigned char hex[HEX_CHARS];
346 unsigned char *data = mem;
347 int i, j;
348
349 #ifdef __BIG_ENDIAN
350 for (i = 0, j = 0; i < len; i++) {
351 #else
352 for (i = len-1, j = 0; i >= 0; i--) {
353 #endif
354 hex[j++] = hex_asc_hi(data[i]);
355 hex[j++] = hex_asc_lo(data[i]);
356 }
357 hex[j++] = ' ';
358
359 return trace_seq_putmem(s, hex, j);
360 }
361
362 static void
363 trace_seq_reset(struct trace_seq *s)
364 {
365 s->len = 0;
366 s->readpos = 0;
367 }
368
369 ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
370 {
371 int len;
372 int ret;
373
374 if (s->len <= s->readpos)
375 return -EBUSY;
376
377 len = s->len - s->readpos;
378 if (cnt > len)
379 cnt = len;
380 ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
381 if (ret)
382 return -EFAULT;
383
384 s->readpos += len;
385 return cnt;
386 }
387
388 static void
389 trace_print_seq(struct seq_file *m, struct trace_seq *s)
390 {
391 int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
392
393 s->buffer[len] = 0;
394 seq_puts(m, s->buffer);
395
396 trace_seq_reset(s);
397 }
398
399 /**
400 * update_max_tr - snapshot all trace buffers from global_trace to max_tr
401 * @tr: tracer
402 * @tsk: the task with the latency
403 * @cpu: The cpu that initiated the trace.
404 *
405 * Flip the buffers between the @tr and the max_tr and record information
406 * about which task was the cause of this latency.
407 */
408 void
409 update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
410 {
411 struct ring_buffer *buf = tr->buffer;
412
413 WARN_ON_ONCE(!irqs_disabled());
414 __raw_spin_lock(&ftrace_max_lock);
415
416 tr->buffer = max_tr.buffer;
417 max_tr.buffer = buf;
418
419 ftrace_disable_cpu();
420 ring_buffer_reset(tr->buffer);
421 ftrace_enable_cpu();
422
423 __update_max_tr(tr, tsk, cpu);
424 __raw_spin_unlock(&ftrace_max_lock);
425 }
426
427 /**
428 * update_max_tr_single - only copy one trace over, and reset the rest
429 * @tr - tracer
430 * @tsk - task with the latency
431 * @cpu - the cpu of the buffer to copy.
432 *
433 * Flip the trace of a single CPU buffer between the @tr and the max_tr.
434 */
435 void
436 update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
437 {
438 int ret;
439
440 WARN_ON_ONCE(!irqs_disabled());
441 __raw_spin_lock(&ftrace_max_lock);
442
443 ftrace_disable_cpu();
444
445 ring_buffer_reset(max_tr.buffer);
446 ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
447
448 ftrace_enable_cpu();
449
450 WARN_ON_ONCE(ret);
451
452 __update_max_tr(tr, tsk, cpu);
453 __raw_spin_unlock(&ftrace_max_lock);
454 }
455
456 /**
457 * register_tracer - register a tracer with the ftrace system.
458 * @type - the plugin for the tracer
459 *
460 * Register a new plugin tracer.
461 */
462 int register_tracer(struct tracer *type)
463 {
464 struct tracer *t;
465 int len;
466 int ret = 0;
467
468 if (!type->name) {
469 pr_info("Tracer must have a name\n");
470 return -1;
471 }
472
473 mutex_lock(&trace_types_lock);
474 for (t = trace_types; t; t = t->next) {
475 if (strcmp(type->name, t->name) == 0) {
476 /* already found */
477 pr_info("Trace %s already registered\n",
478 type->name);
479 ret = -1;
480 goto out;
481 }
482 }
483
484 #ifdef CONFIG_FTRACE_STARTUP_TEST
485 if (type->selftest) {
486 struct tracer *saved_tracer = current_trace;
487 struct trace_array *tr = &global_trace;
488 int saved_ctrl = tr->ctrl;
489 int i;
490 /*
491 * Run a selftest on this tracer.
492 * Here we reset the trace buffer, and set the current
493 * tracer to be this tracer. The tracer can then run some
494 * internal tracing to verify that everything is in order.
495 * If we fail, we do not register this tracer.
496 */
497 for_each_tracing_cpu(i) {
498 tracing_reset(tr, i);
499 }
500 current_trace = type;
501 tr->ctrl = 0;
502 /* the test is responsible for initializing and enabling */
503 pr_info("Testing tracer %s: ", type->name);
504 ret = type->selftest(type, tr);
505 /* the test is responsible for resetting too */
506 current_trace = saved_tracer;
507 tr->ctrl = saved_ctrl;
508 if (ret) {
509 printk(KERN_CONT "FAILED!\n");
510 goto out;
511 }
512 /* Only reset on passing, to avoid touching corrupted buffers */
513 for_each_tracing_cpu(i) {
514 tracing_reset(tr, i);
515 }
516 printk(KERN_CONT "PASSED\n");
517 }
518 #endif
519
520 type->next = trace_types;
521 trace_types = type;
522 len = strlen(type->name);
523 if (len > max_tracer_type_len)
524 max_tracer_type_len = len;
525
526 out:
527 mutex_unlock(&trace_types_lock);
528
529 return ret;
530 }
531
532 void unregister_tracer(struct tracer *type)
533 {
534 struct tracer **t;
535 int len;
536
537 mutex_lock(&trace_types_lock);
538 for (t = &trace_types; *t; t = &(*t)->next) {
539 if (*t == type)
540 goto found;
541 }
542 pr_info("Trace %s not registered\n", type->name);
543 goto out;
544
545 found:
546 *t = (*t)->next;
547 if (strlen(type->name) != max_tracer_type_len)
548 goto out;
549
550 max_tracer_type_len = 0;
551 for (t = &trace_types; *t; t = &(*t)->next) {
552 len = strlen((*t)->name);
553 if (len > max_tracer_type_len)
554 max_tracer_type_len = len;
555 }
556 out:
557 mutex_unlock(&trace_types_lock);
558 }
559
560 void tracing_reset(struct trace_array *tr, int cpu)
561 {
562 ftrace_disable_cpu();
563 ring_buffer_reset_cpu(tr->buffer, cpu);
564 ftrace_enable_cpu();
565 }
566
567 #define SAVED_CMDLINES 128
568 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
569 static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
570 static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
571 static int cmdline_idx;
572 static DEFINE_SPINLOCK(trace_cmdline_lock);
573
574 /* temporary disable recording */
575 atomic_t trace_record_cmdline_disabled __read_mostly;
576
577 static void trace_init_cmdlines(void)
578 {
579 memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline));
580 memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid));
581 cmdline_idx = 0;
582 }
583
584 void trace_stop_cmdline_recording(void);
585
586 static void trace_save_cmdline(struct task_struct *tsk)
587 {
588 unsigned map;
589 unsigned idx;
590
591 if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
592 return;
593
594 /*
595 * It's not the end of the world if we don't get
596 * the lock, but we also don't want to spin
597 * nor do we want to disable interrupts,
598 * so if we miss here, then better luck next time.
599 */
600 if (!spin_trylock(&trace_cmdline_lock))
601 return;
602
603 idx = map_pid_to_cmdline[tsk->pid];
604 if (idx >= SAVED_CMDLINES) {
605 idx = (cmdline_idx + 1) % SAVED_CMDLINES;
606
607 map = map_cmdline_to_pid[idx];
608 if (map <= PID_MAX_DEFAULT)
609 map_pid_to_cmdline[map] = (unsigned)-1;
610
611 map_pid_to_cmdline[tsk->pid] = idx;
612
613 cmdline_idx = idx;
614 }
615
616 memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
617
618 spin_unlock(&trace_cmdline_lock);
619 }
620
621 static char *trace_find_cmdline(int pid)
622 {
623 char *cmdline = "<...>";
624 unsigned map;
625
626 if (!pid)
627 return "<idle>";
628
629 if (pid > PID_MAX_DEFAULT)
630 goto out;
631
632 map = map_pid_to_cmdline[pid];
633 if (map >= SAVED_CMDLINES)
634 goto out;
635
636 cmdline = saved_cmdlines[map];
637
638 out:
639 return cmdline;
640 }
641
642 void tracing_record_cmdline(struct task_struct *tsk)
643 {
644 if (atomic_read(&trace_record_cmdline_disabled))
645 return;
646
647 trace_save_cmdline(tsk);
648 }
649
650 void
651 tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
652 int pc)
653 {
654 struct task_struct *tsk = current;
655
656 entry->preempt_count = pc & 0xff;
657 entry->pid = (tsk) ? tsk->pid : 0;
658 entry->flags =
659 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
660 (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
661 #else
662 TRACE_FLAG_IRQS_NOSUPPORT |
663 #endif
664 ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
665 ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
666 (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
667 }
668
669 void
670 trace_function(struct trace_array *tr, struct trace_array_cpu *data,
671 unsigned long ip, unsigned long parent_ip, unsigned long flags,
672 int pc)
673 {
674 struct ring_buffer_event *event;
675 struct ftrace_entry *entry;
676 unsigned long irq_flags;
677
678 /* If we are reading the ring buffer, don't trace */
679 if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
680 return;
681
682 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
683 &irq_flags);
684 if (!event)
685 return;
686 entry = ring_buffer_event_data(event);
687 tracing_generic_entry_update(&entry->ent, flags, pc);
688 entry->ent.type = TRACE_FN;
689 entry->ip = ip;
690 entry->parent_ip = parent_ip;
691 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
692 }
693
694 void
695 ftrace(struct trace_array *tr, struct trace_array_cpu *data,
696 unsigned long ip, unsigned long parent_ip, unsigned long flags,
697 int pc)
698 {
699 if (likely(!atomic_read(&data->disabled)))
700 trace_function(tr, data, ip, parent_ip, flags, pc);
701 }
702
703 static void ftrace_trace_stack(struct trace_array *tr,
704 struct trace_array_cpu *data,
705 unsigned long flags,
706 int skip, int pc)
707 {
708 #ifdef CONFIG_STACKTRACE
709 struct ring_buffer_event *event;
710 struct stack_entry *entry;
711 struct stack_trace trace;
712 unsigned long irq_flags;
713
714 if (!(trace_flags & TRACE_ITER_STACKTRACE))
715 return;
716
717 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
718 &irq_flags);
719 if (!event)
720 return;
721 entry = ring_buffer_event_data(event);
722 tracing_generic_entry_update(&entry->ent, flags, pc);
723 entry->ent.type = TRACE_STACK;
724
725 memset(&entry->caller, 0, sizeof(entry->caller));
726
727 trace.nr_entries = 0;
728 trace.max_entries = FTRACE_STACK_ENTRIES;
729 trace.skip = skip;
730 trace.entries = entry->caller;
731
732 save_stack_trace(&trace);
733 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
734 #endif
735 }
736
737 void __trace_stack(struct trace_array *tr,
738 struct trace_array_cpu *data,
739 unsigned long flags,
740 int skip)
741 {
742 ftrace_trace_stack(tr, data, flags, skip, preempt_count());
743 }
744
745 static void
746 ftrace_trace_special(void *__tr, void *__data,
747 unsigned long arg1, unsigned long arg2, unsigned long arg3,
748 int pc)
749 {
750 struct ring_buffer_event *event;
751 struct trace_array_cpu *data = __data;
752 struct trace_array *tr = __tr;
753 struct special_entry *entry;
754 unsigned long irq_flags;
755
756 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
757 &irq_flags);
758 if (!event)
759 return;
760 entry = ring_buffer_event_data(event);
761 tracing_generic_entry_update(&entry->ent, 0, pc);
762 entry->ent.type = TRACE_SPECIAL;
763 entry->arg1 = arg1;
764 entry->arg2 = arg2;
765 entry->arg3 = arg3;
766 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
767 ftrace_trace_stack(tr, data, irq_flags, 4, pc);
768
769 trace_wake_up();
770 }
771
772 void
773 __trace_special(void *__tr, void *__data,
774 unsigned long arg1, unsigned long arg2, unsigned long arg3)
775 {
776 ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
777 }
778
779 void
780 tracing_sched_switch_trace(struct trace_array *tr,
781 struct trace_array_cpu *data,
782 struct task_struct *prev,
783 struct task_struct *next,
784 unsigned long flags, int pc)
785 {
786 struct ring_buffer_event *event;
787 struct ctx_switch_entry *entry;
788 unsigned long irq_flags;
789
790 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
791 &irq_flags);
792 if (!event)
793 return;
794 entry = ring_buffer_event_data(event);
795 tracing_generic_entry_update(&entry->ent, flags, pc);
796 entry->ent.type = TRACE_CTX;
797 entry->prev_pid = prev->pid;
798 entry->prev_prio = prev->prio;
799 entry->prev_state = prev->state;
800 entry->next_pid = next->pid;
801 entry->next_prio = next->prio;
802 entry->next_state = next->state;
803 entry->next_cpu = task_cpu(next);
804 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
805 ftrace_trace_stack(tr, data, flags, 5, pc);
806 }
807
808 void
809 tracing_sched_wakeup_trace(struct trace_array *tr,
810 struct trace_array_cpu *data,
811 struct task_struct *wakee,
812 struct task_struct *curr,
813 unsigned long flags, int pc)
814 {
815 struct ring_buffer_event *event;
816 struct ctx_switch_entry *entry;
817 unsigned long irq_flags;
818
819 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
820 &irq_flags);
821 if (!event)
822 return;
823 entry = ring_buffer_event_data(event);
824 tracing_generic_entry_update(&entry->ent, flags, pc);
825 entry->ent.type = TRACE_WAKE;
826 entry->prev_pid = curr->pid;
827 entry->prev_prio = curr->prio;
828 entry->prev_state = curr->state;
829 entry->next_pid = wakee->pid;
830 entry->next_prio = wakee->prio;
831 entry->next_state = wakee->state;
832 entry->next_cpu = task_cpu(wakee);
833 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
834 ftrace_trace_stack(tr, data, flags, 6, pc);
835
836 trace_wake_up();
837 }
838
839 void
840 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
841 {
842 struct trace_array *tr = &global_trace;
843 struct trace_array_cpu *data;
844 int cpu;
845 int pc;
846
847 if (tracing_disabled || !tr->ctrl)
848 return;
849
850 pc = preempt_count();
851 preempt_disable_notrace();
852 cpu = raw_smp_processor_id();
853 data = tr->data[cpu];
854
855 if (likely(!atomic_read(&data->disabled)))
856 ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
857
858 preempt_enable_notrace();
859 }
860
861 #ifdef CONFIG_FUNCTION_TRACER
862 static void
863 function_trace_call(unsigned long ip, unsigned long parent_ip)
864 {
865 struct trace_array *tr = &global_trace;
866 struct trace_array_cpu *data;
867 unsigned long flags;
868 long disabled;
869 int cpu, resched;
870 int pc;
871
872 if (unlikely(!ftrace_function_enabled))
873 return;
874
875 pc = preempt_count();
876 resched = need_resched();
877 preempt_disable_notrace();
878 local_save_flags(flags);
879 cpu = raw_smp_processor_id();
880 data = tr->data[cpu];
881 disabled = atomic_inc_return(&data->disabled);
882
883 if (likely(disabled == 1))
884 trace_function(tr, data, ip, parent_ip, flags, pc);
885
886 atomic_dec(&data->disabled);
887 if (resched)
888 preempt_enable_no_resched_notrace();
889 else
890 preempt_enable_notrace();
891 }
892
893 static struct ftrace_ops trace_ops __read_mostly =
894 {
895 .func = function_trace_call,
896 };
897
898 void tracing_start_function_trace(void)
899 {
900 ftrace_function_enabled = 0;
901 register_ftrace_function(&trace_ops);
902 if (tracer_enabled)
903 ftrace_function_enabled = 1;
904 }
905
906 void tracing_stop_function_trace(void)
907 {
908 ftrace_function_enabled = 0;
909 unregister_ftrace_function(&trace_ops);
910 }
911 #endif
912
913 enum trace_file_type {
914 TRACE_FILE_LAT_FMT = 1,
915 };
916
917 static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
918 {
919 /* Don't allow ftrace to trace into the ring buffers */
920 ftrace_disable_cpu();
921
922 iter->idx++;
923 if (iter->buffer_iter[iter->cpu])
924 ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
925
926 ftrace_enable_cpu();
927 }
928
929 static struct trace_entry *
930 peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
931 {
932 struct ring_buffer_event *event;
933 struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
934
935 /* Don't allow ftrace to trace into the ring buffers */
936 ftrace_disable_cpu();
937
938 if (buf_iter)
939 event = ring_buffer_iter_peek(buf_iter, ts);
940 else
941 event = ring_buffer_peek(iter->tr->buffer, cpu, ts);
942
943 ftrace_enable_cpu();
944
945 return event ? ring_buffer_event_data(event) : NULL;
946 }
947
948 static struct trace_entry *
949 __find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
950 {
951 struct ring_buffer *buffer = iter->tr->buffer;
952 struct trace_entry *ent, *next = NULL;
953 u64 next_ts = 0, ts;
954 int next_cpu = -1;
955 int cpu;
956
957 for_each_tracing_cpu(cpu) {
958
959 if (ring_buffer_empty_cpu(buffer, cpu))
960 continue;
961
962 ent = peek_next_entry(iter, cpu, &ts);
963
964 /*
965 * Pick the entry with the smallest timestamp:
966 */
967 if (ent && (!next || ts < next_ts)) {
968 next = ent;
969 next_cpu = cpu;
970 next_ts = ts;
971 }
972 }
973
974 if (ent_cpu)
975 *ent_cpu = next_cpu;
976
977 if (ent_ts)
978 *ent_ts = next_ts;
979
980 return next;
981 }
982
983 /* Find the next real entry, without updating the iterator itself */
984 static struct trace_entry *
985 find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
986 {
987 return __find_next_entry(iter, ent_cpu, ent_ts);
988 }
989
990 /* Find the next real entry, and increment the iterator to the next entry */
991 static void *find_next_entry_inc(struct trace_iterator *iter)
992 {
993 iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
994
995 if (iter->ent)
996 trace_iterator_increment(iter, iter->cpu);
997
998 return iter->ent ? iter : NULL;
999 }
1000
1001 static void trace_consume(struct trace_iterator *iter)
1002 {
1003 /* Don't allow ftrace to trace into the ring buffers */
1004 ftrace_disable_cpu();
1005 ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
1006 ftrace_enable_cpu();
1007 }
1008
1009 static void *s_next(struct seq_file *m, void *v, loff_t *pos)
1010 {
1011 struct trace_iterator *iter = m->private;
1012 int i = (int)*pos;
1013 void *ent;
1014
1015 (*pos)++;
1016
1017 /* can't go backwards */
1018 if (iter->idx > i)
1019 return NULL;
1020
1021 if (iter->idx < 0)
1022 ent = find_next_entry_inc(iter);
1023 else
1024 ent = iter;
1025
1026 while (ent && iter->idx < i)
1027 ent = find_next_entry_inc(iter);
1028
1029 iter->pos = *pos;
1030
1031 return ent;
1032 }
1033
1034 static void *s_start(struct seq_file *m, loff_t *pos)
1035 {
1036 struct trace_iterator *iter = m->private;
1037 void *p = NULL;
1038 loff_t l = 0;
1039 int cpu;
1040
1041 mutex_lock(&trace_types_lock);
1042
1043 if (!current_trace || current_trace != iter->trace) {
1044 mutex_unlock(&trace_types_lock);
1045 return NULL;
1046 }
1047
1048 atomic_inc(&trace_record_cmdline_disabled);
1049
1050 /* let the tracer grab locks here if needed */
1051 if (current_trace->start)
1052 current_trace->start(iter);
1053
1054 if (*pos != iter->pos) {
1055 iter->ent = NULL;
1056 iter->cpu = 0;
1057 iter->idx = -1;
1058
1059 ftrace_disable_cpu();
1060
1061 for_each_tracing_cpu(cpu) {
1062 ring_buffer_iter_reset(iter->buffer_iter[cpu]);
1063 }
1064
1065 ftrace_enable_cpu();
1066
1067 for (p = iter; p && l < *pos; p = s_next(m, p, &l))
1068 ;
1069
1070 } else {
1071 l = *pos - 1;
1072 p = s_next(m, p, &l);
1073 }
1074
1075 return p;
1076 }
1077
1078 static void s_stop(struct seq_file *m, void *p)
1079 {
1080 struct trace_iterator *iter = m->private;
1081
1082 atomic_dec(&trace_record_cmdline_disabled);
1083
1084 /* let the tracer release locks here if needed */
1085 if (current_trace && current_trace == iter->trace && iter->trace->stop)
1086 iter->trace->stop(iter);
1087
1088 mutex_unlock(&trace_types_lock);
1089 }
1090
1091 #ifdef CONFIG_KRETPROBES
1092 static inline const char *kretprobed(const char *name)
1093 {
1094 static const char tramp_name[] = "kretprobe_trampoline";
1095 int size = sizeof(tramp_name);
1096
1097 if (strncmp(tramp_name, name, size) == 0)
1098 return "[unknown/kretprobe'd]";
1099 return name;
1100 }
1101 #else
1102 static inline const char *kretprobed(const char *name)
1103 {
1104 return name;
1105 }
1106 #endif /* CONFIG_KRETPROBES */
1107
1108 static int
1109 seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
1110 {
1111 #ifdef CONFIG_KALLSYMS
1112 char str[KSYM_SYMBOL_LEN];
1113 const char *name;
1114
1115 kallsyms_lookup(address, NULL, NULL, NULL, str);
1116
1117 name = kretprobed(str);
1118
1119 return trace_seq_printf(s, fmt, name);
1120 #endif
1121 return 1;
1122 }
1123
1124 static int
1125 seq_print_sym_offset(struct trace_seq *s, const char *fmt,
1126 unsigned long address)
1127 {
1128 #ifdef CONFIG_KALLSYMS
1129 char str[KSYM_SYMBOL_LEN];
1130 const char *name;
1131
1132 sprint_symbol(str, address);
1133 name = kretprobed(str);
1134
1135 return trace_seq_printf(s, fmt, name);
1136 #endif
1137 return 1;
1138 }
1139
1140 #ifndef CONFIG_64BIT
1141 # define IP_FMT "%08lx"
1142 #else
1143 # define IP_FMT "%016lx"
1144 #endif
1145
1146 static int
1147 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
1148 {
1149 int ret;
1150
1151 if (!ip)
1152 return trace_seq_printf(s, "0");
1153
1154 if (sym_flags & TRACE_ITER_SYM_OFFSET)
1155 ret = seq_print_sym_offset(s, "%s", ip);
1156 else
1157 ret = seq_print_sym_short(s, "%s", ip);
1158
1159 if (!ret)
1160 return 0;
1161
1162 if (sym_flags & TRACE_ITER_SYM_ADDR)
1163 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
1164 return ret;
1165 }
1166
1167 static void print_lat_help_header(struct seq_file *m)
1168 {
1169 seq_puts(m, "# _------=> CPU# \n");
1170 seq_puts(m, "# / _-----=> irqs-off \n");
1171 seq_puts(m, "# | / _----=> need-resched \n");
1172 seq_puts(m, "# || / _---=> hardirq/softirq \n");
1173 seq_puts(m, "# ||| / _--=> preempt-depth \n");
1174 seq_puts(m, "# |||| / \n");
1175 seq_puts(m, "# ||||| delay \n");
1176 seq_puts(m, "# cmd pid ||||| time | caller \n");
1177 seq_puts(m, "# \\ / ||||| \\ | / \n");
1178 }
1179
1180 static void print_func_help_header(struct seq_file *m)
1181 {
1182 seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
1183 seq_puts(m, "# | | | | |\n");
1184 }
1185
1186
1187 static void
1188 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
1189 {
1190 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1191 struct trace_array *tr = iter->tr;
1192 struct trace_array_cpu *data = tr->data[tr->cpu];
1193 struct tracer *type = current_trace;
1194 unsigned long total;
1195 unsigned long entries;
1196 const char *name = "preemption";
1197
1198 if (type)
1199 name = type->name;
1200
1201 entries = ring_buffer_entries(iter->tr->buffer);
1202 total = entries +
1203 ring_buffer_overruns(iter->tr->buffer);
1204
1205 seq_printf(m, "%s latency trace v1.1.5 on %s\n",
1206 name, UTS_RELEASE);
1207 seq_puts(m, "-----------------------------------"
1208 "---------------------------------\n");
1209 seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
1210 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
1211 nsecs_to_usecs(data->saved_latency),
1212 entries,
1213 total,
1214 tr->cpu,
1215 #if defined(CONFIG_PREEMPT_NONE)
1216 "server",
1217 #elif defined(CONFIG_PREEMPT_VOLUNTARY)
1218 "desktop",
1219 #elif defined(CONFIG_PREEMPT)
1220 "preempt",
1221 #else
1222 "unknown",
1223 #endif
1224 /* These are reserved for later use */
1225 0, 0, 0, 0);
1226 #ifdef CONFIG_SMP
1227 seq_printf(m, " #P:%d)\n", num_online_cpus());
1228 #else
1229 seq_puts(m, ")\n");
1230 #endif
1231 seq_puts(m, " -----------------\n");
1232 seq_printf(m, " | task: %.16s-%d "
1233 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
1234 data->comm, data->pid, data->uid, data->nice,
1235 data->policy, data->rt_priority);
1236 seq_puts(m, " -----------------\n");
1237
1238 if (data->critical_start) {
1239 seq_puts(m, " => started at: ");
1240 seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
1241 trace_print_seq(m, &iter->seq);
1242 seq_puts(m, "\n => ended at: ");
1243 seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
1244 trace_print_seq(m, &iter->seq);
1245 seq_puts(m, "\n");
1246 }
1247
1248 seq_puts(m, "\n");
1249 }
1250
1251 static void
1252 lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
1253 {
1254 int hardirq, softirq;
1255 char *comm;
1256
1257 comm = trace_find_cmdline(entry->pid);
1258
1259 trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
1260 trace_seq_printf(s, "%3d", cpu);
1261 trace_seq_printf(s, "%c%c",
1262 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
1263 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.',
1264 ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
1265
1266 hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
1267 softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
1268 if (hardirq && softirq) {
1269 trace_seq_putc(s, 'H');
1270 } else {
1271 if (hardirq) {
1272 trace_seq_putc(s, 'h');
1273 } else {
1274 if (softirq)
1275 trace_seq_putc(s, 's');
1276 else
1277 trace_seq_putc(s, '.');
1278 }
1279 }
1280
1281 if (entry->preempt_count)
1282 trace_seq_printf(s, "%x", entry->preempt_count);
1283 else
1284 trace_seq_puts(s, ".");
1285 }
1286
1287 unsigned long preempt_mark_thresh = 100;
1288
1289 static void
1290 lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
1291 unsigned long rel_usecs)
1292 {
1293 trace_seq_printf(s, " %4lldus", abs_usecs);
1294 if (rel_usecs > preempt_mark_thresh)
1295 trace_seq_puts(s, "!: ");
1296 else if (rel_usecs > 1)
1297 trace_seq_puts(s, "+: ");
1298 else
1299 trace_seq_puts(s, " : ");
1300 }
1301
1302 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
1303
1304 /*
1305 * The message is supposed to contain an ending newline.
1306 * If the printing stops prematurely, try to add a newline of our own.
1307 */
1308 void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
1309 {
1310 struct trace_entry *ent;
1311 struct trace_field_cont *cont;
1312 bool ok = true;
1313
1314 ent = peek_next_entry(iter, iter->cpu, NULL);
1315 if (!ent || ent->type != TRACE_CONT) {
1316 trace_seq_putc(s, '\n');
1317 return;
1318 }
1319
1320 do {
1321 cont = (struct trace_field_cont *)ent;
1322 if (ok)
1323 ok = (trace_seq_printf(s, "%s", cont->buf) > 0);
1324
1325 ftrace_disable_cpu();
1326
1327 if (iter->buffer_iter[iter->cpu])
1328 ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
1329 else
1330 ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
1331
1332 ftrace_enable_cpu();
1333
1334 ent = peek_next_entry(iter, iter->cpu, NULL);
1335 } while (ent && ent->type == TRACE_CONT);
1336
1337 if (!ok)
1338 trace_seq_putc(s, '\n');
1339 }
1340
1341 static enum print_line_t
1342 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
1343 {
1344 struct trace_seq *s = &iter->seq;
1345 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1346 struct trace_entry *next_entry;
1347 unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
1348 struct trace_entry *entry = iter->ent;
1349 unsigned long abs_usecs;
1350 unsigned long rel_usecs;
1351 u64 next_ts;
1352 char *comm;
1353 int S, T;
1354 int i;
1355 unsigned state;
1356
1357 if (entry->type == TRACE_CONT)
1358 return TRACE_TYPE_HANDLED;
1359
1360 next_entry = find_next_entry(iter, NULL, &next_ts);
1361 if (!next_entry)
1362 next_ts = iter->ts;
1363 rel_usecs = ns2usecs(next_ts - iter->ts);
1364 abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
1365
1366 if (verbose) {
1367 comm = trace_find_cmdline(entry->pid);
1368 trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]"
1369 " %ld.%03ldms (+%ld.%03ldms): ",
1370 comm,
1371 entry->pid, cpu, entry->flags,
1372 entry->preempt_count, trace_idx,
1373 ns2usecs(iter->ts),
1374 abs_usecs/1000,
1375 abs_usecs % 1000, rel_usecs/1000,
1376 rel_usecs % 1000);
1377 } else {
1378 lat_print_generic(s, entry, cpu);
1379 lat_print_timestamp(s, abs_usecs, rel_usecs);
1380 }
1381 switch (entry->type) {
1382 case TRACE_FN: {
1383 struct ftrace_entry *field;
1384
1385 trace_assign_type(field, entry);
1386
1387 seq_print_ip_sym(s, field->ip, sym_flags);
1388 trace_seq_puts(s, " (");
1389 seq_print_ip_sym(s, field->parent_ip, sym_flags);
1390 trace_seq_puts(s, ")\n");
1391 break;
1392 }
1393 case TRACE_CTX:
1394 case TRACE_WAKE: {
1395 struct ctx_switch_entry *field;
1396
1397 trace_assign_type(field, entry);
1398
1399 T = field->next_state < sizeof(state_to_char) ?
1400 state_to_char[field->next_state] : 'X';
1401
1402 state = field->prev_state ?
1403 __ffs(field->prev_state) + 1 : 0;
1404 S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
1405 comm = trace_find_cmdline(field->next_pid);
1406 trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1407 field->prev_pid,
1408 field->prev_prio,
1409 S, entry->type == TRACE_CTX ? "==>" : " +",
1410 field->next_cpu,
1411 field->next_pid,
1412 field->next_prio,
1413 T, comm);
1414 break;
1415 }
1416 case TRACE_SPECIAL: {
1417 struct special_entry *field;
1418
1419 trace_assign_type(field, entry);
1420
1421 trace_seq_printf(s, "# %ld %ld %ld\n",
1422 field->arg1,
1423 field->arg2,
1424 field->arg3);
1425 break;
1426 }
1427 case TRACE_STACK: {
1428 struct stack_entry *field;
1429
1430 trace_assign_type(field, entry);
1431
1432 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1433 if (i)
1434 trace_seq_puts(s, " <= ");
1435 seq_print_ip_sym(s, field->caller[i], sym_flags);
1436 }
1437 trace_seq_puts(s, "\n");
1438 break;
1439 }
1440 case TRACE_PRINT: {
1441 struct print_entry *field;
1442
1443 trace_assign_type(field, entry);
1444
1445 seq_print_ip_sym(s, field->ip, sym_flags);
1446 trace_seq_printf(s, ": %s", field->buf);
1447 if (entry->flags & TRACE_FLAG_CONT)
1448 trace_seq_print_cont(s, iter);
1449 break;
1450 }
1451 default:
1452 trace_seq_printf(s, "Unknown type %d\n", entry->type);
1453 }
1454 return TRACE_TYPE_HANDLED;
1455 }
1456
1457 static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
1458 {
1459 struct trace_seq *s = &iter->seq;
1460 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1461 struct trace_entry *entry;
1462 unsigned long usec_rem;
1463 unsigned long long t;
1464 unsigned long secs;
1465 char *comm;
1466 int ret;
1467 int S, T;
1468 int i;
1469
1470 entry = iter->ent;
1471
1472 if (entry->type == TRACE_CONT)
1473 return TRACE_TYPE_HANDLED;
1474
1475 comm = trace_find_cmdline(iter->ent->pid);
1476
1477 t = ns2usecs(iter->ts);
1478 usec_rem = do_div(t, 1000000ULL);
1479 secs = (unsigned long)t;
1480
1481 ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
1482 if (!ret)
1483 return TRACE_TYPE_PARTIAL_LINE;
1484 ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
1485 if (!ret)
1486 return TRACE_TYPE_PARTIAL_LINE;
1487 ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
1488 if (!ret)
1489 return TRACE_TYPE_PARTIAL_LINE;
1490
1491 switch (entry->type) {
1492 case TRACE_FN: {
1493 struct ftrace_entry *field;
1494
1495 trace_assign_type(field, entry);
1496
1497 ret = seq_print_ip_sym(s, field->ip, sym_flags);
1498 if (!ret)
1499 return TRACE_TYPE_PARTIAL_LINE;
1500 if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
1501 field->parent_ip) {
1502 ret = trace_seq_printf(s, " <-");
1503 if (!ret)
1504 return TRACE_TYPE_PARTIAL_LINE;
1505 ret = seq_print_ip_sym(s,
1506 field->parent_ip,
1507 sym_flags);
1508 if (!ret)
1509 return TRACE_TYPE_PARTIAL_LINE;
1510 }
1511 ret = trace_seq_printf(s, "\n");
1512 if (!ret)
1513 return TRACE_TYPE_PARTIAL_LINE;
1514 break;
1515 }
1516 case TRACE_CTX:
1517 case TRACE_WAKE: {
1518 struct ctx_switch_entry *field;
1519
1520 trace_assign_type(field, entry);
1521
1522 S = field->prev_state < sizeof(state_to_char) ?
1523 state_to_char[field->prev_state] : 'X';
1524 T = field->next_state < sizeof(state_to_char) ?
1525 state_to_char[field->next_state] : 'X';
1526 ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
1527 field->prev_pid,
1528 field->prev_prio,
1529 S,
1530 entry->type == TRACE_CTX ? "==>" : " +",
1531 field->next_cpu,
1532 field->next_pid,
1533 field->next_prio,
1534 T);
1535 if (!ret)
1536 return TRACE_TYPE_PARTIAL_LINE;
1537 break;
1538 }
1539 case TRACE_SPECIAL: {
1540 struct special_entry *field;
1541
1542 trace_assign_type(field, entry);
1543
1544 ret = trace_seq_printf(s, "# %ld %ld %ld\n",
1545 field->arg1,
1546 field->arg2,
1547 field->arg3);
1548 if (!ret)
1549 return TRACE_TYPE_PARTIAL_LINE;
1550 break;
1551 }
1552 case TRACE_STACK: {
1553 struct stack_entry *field;
1554
1555 trace_assign_type(field, entry);
1556
1557 for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
1558 if (i) {
1559 ret = trace_seq_puts(s, " <= ");
1560 if (!ret)
1561 return TRACE_TYPE_PARTIAL_LINE;
1562 }
1563 ret = seq_print_ip_sym(s, field->caller[i],
1564 sym_flags);
1565 if (!ret)
1566 return TRACE_TYPE_PARTIAL_LINE;
1567 }
1568 ret = trace_seq_puts(s, "\n");
1569 if (!ret)
1570 return TRACE_TYPE_PARTIAL_LINE;
1571 break;
1572 }
1573 case TRACE_PRINT: {
1574 struct print_entry *field;
1575
1576 trace_assign_type(field, entry);
1577
1578 seq_print_ip_sym(s, field->ip, sym_flags);
1579 trace_seq_printf(s, ": %s", field->buf);
1580 if (entry->flags & TRACE_FLAG_CONT)
1581 trace_seq_print_cont(s, iter);
1582 break;
1583 }
1584 }
1585 return TRACE_TYPE_HANDLED;
1586 }
1587
1588 static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
1589 {
1590 struct trace_seq *s = &iter->seq;
1591 struct trace_entry *entry;
1592 int ret;
1593 int S, T;
1594
1595 entry = iter->ent;
1596
1597 if (entry->type == TRACE_CONT)
1598 return TRACE_TYPE_HANDLED;
1599
1600 ret = trace_seq_printf(s, "%d %d %llu ",
1601 entry->pid, iter->cpu, iter->ts);
1602 if (!ret)
1603 return TRACE_TYPE_PARTIAL_LINE;
1604
1605 switch (entry->type) {
1606 case TRACE_FN: {
1607 struct ftrace_entry *field;
1608
1609 trace_assign_type(field, entry);
1610
1611 ret = trace_seq_printf(s, "%x %x\n",
1612 field->ip,
1613 field->parent_ip);
1614 if (!ret)
1615 return TRACE_TYPE_PARTIAL_LINE;
1616 break;
1617 }
1618 case TRACE_CTX:
1619 case TRACE_WAKE: {
1620 struct ctx_switch_entry *field;
1621
1622 trace_assign_type(field, entry);
1623
1624 S = field->prev_state < sizeof(state_to_char) ?
1625 state_to_char[field->prev_state] : 'X';
1626 T = field->next_state < sizeof(state_to_char) ?
1627 state_to_char[field->next_state] : 'X';
1628 if (entry->type == TRACE_WAKE)
1629 S = '+';
1630 ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
1631 field->prev_pid,
1632 field->prev_prio,
1633 S,
1634 field->next_cpu,
1635 field->next_pid,
1636 field->next_prio,
1637 T);
1638 if (!ret)
1639 return TRACE_TYPE_PARTIAL_LINE;
1640 break;
1641 }
1642 case TRACE_SPECIAL:
1643 case TRACE_STACK: {
1644 struct special_entry *field;
1645
1646 trace_assign_type(field, entry);
1647
1648 ret = trace_seq_printf(s, "# %ld %ld %ld\n",
1649 field->arg1,
1650 field->arg2,
1651 field->arg3);
1652 if (!ret)
1653 return TRACE_TYPE_PARTIAL_LINE;
1654 break;
1655 }
1656 case TRACE_PRINT: {
1657 struct print_entry *field;
1658
1659 trace_assign_type(field, entry);
1660
1661 trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
1662 if (entry->flags & TRACE_FLAG_CONT)
1663 trace_seq_print_cont(s, iter);
1664 break;
1665 }
1666 }
1667 return TRACE_TYPE_HANDLED;
1668 }
1669
1670 #define SEQ_PUT_FIELD_RET(s, x) \
1671 do { \
1672 if (!trace_seq_putmem(s, &(x), sizeof(x))) \
1673 return 0; \
1674 } while (0)
1675
1676 #define SEQ_PUT_HEX_FIELD_RET(s, x) \
1677 do { \
1678 BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \
1679 if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
1680 return 0; \
1681 } while (0)
1682
1683 static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
1684 {
1685 struct trace_seq *s = &iter->seq;
1686 unsigned char newline = '\n';
1687 struct trace_entry *entry;
1688 int S, T;
1689
1690 entry = iter->ent;
1691
1692 if (entry->type == TRACE_CONT)
1693 return TRACE_TYPE_HANDLED;
1694
1695 SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
1696 SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
1697 SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
1698
1699 switch (entry->type) {
1700 case TRACE_FN: {
1701 struct ftrace_entry *field;
1702
1703 trace_assign_type(field, entry);
1704
1705 SEQ_PUT_HEX_FIELD_RET(s, field->ip);
1706 SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
1707 break;
1708 }
1709 case TRACE_CTX:
1710 case TRACE_WAKE: {
1711 struct ctx_switch_entry *field;
1712
1713 trace_assign_type(field, entry);
1714
1715 S = field->prev_state < sizeof(state_to_char) ?
1716 state_to_char[field->prev_state] : 'X';
1717 T = field->next_state < sizeof(state_to_char) ?
1718 state_to_char[field->next_state] : 'X';
1719 if (entry->type == TRACE_WAKE)
1720 S = '+';
1721 SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
1722 SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
1723 SEQ_PUT_HEX_FIELD_RET(s, S);
1724 SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
1725 SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
1726 SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
1727 SEQ_PUT_HEX_FIELD_RET(s, T);
1728 break;
1729 }
1730 case TRACE_SPECIAL:
1731 case TRACE_STACK: {
1732 struct special_entry *field;
1733
1734 trace_assign_type(field, entry);
1735
1736 SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
1737 SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
1738 SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
1739 break;
1740 }
1741 }
1742 SEQ_PUT_FIELD_RET(s, newline);
1743
1744 return TRACE_TYPE_HANDLED;
1745 }
1746
1747 static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
1748 {
1749 struct trace_seq *s = &iter->seq;
1750 struct trace_entry *entry;
1751
1752 entry = iter->ent;
1753
1754 if (entry->type == TRACE_CONT)
1755 return TRACE_TYPE_HANDLED;
1756
1757 SEQ_PUT_FIELD_RET(s, entry->pid);
1758 SEQ_PUT_FIELD_RET(s, iter->cpu);
1759 SEQ_PUT_FIELD_RET(s, iter->ts);
1760
1761 switch (entry->type) {
1762 case TRACE_FN: {
1763 struct ftrace_entry *field;
1764
1765 trace_assign_type(field, entry);
1766
1767 SEQ_PUT_FIELD_RET(s, field->ip);
1768 SEQ_PUT_FIELD_RET(s, field->parent_ip);
1769 break;
1770 }
1771 case TRACE_CTX: {
1772 struct ctx_switch_entry *field;
1773
1774 trace_assign_type(field, entry);
1775
1776 SEQ_PUT_FIELD_RET(s, field->prev_pid);
1777 SEQ_PUT_FIELD_RET(s, field->prev_prio);
1778 SEQ_PUT_FIELD_RET(s, field->prev_state);
1779 SEQ_PUT_FIELD_RET(s, field->next_pid);
1780 SEQ_PUT_FIELD_RET(s, field->next_prio);
1781 SEQ_PUT_FIELD_RET(s, field->next_state);
1782 break;
1783 }
1784 case TRACE_SPECIAL:
1785 case TRACE_STACK: {
1786 struct special_entry *field;
1787
1788 trace_assign_type(field, entry);
1789
1790 SEQ_PUT_FIELD_RET(s, field->arg1);
1791 SEQ_PUT_FIELD_RET(s, field->arg2);
1792 SEQ_PUT_FIELD_RET(s, field->arg3);
1793 break;
1794 }
1795 }
1796 return 1;
1797 }
1798
1799 static int trace_empty(struct trace_iterator *iter)
1800 {
1801 int cpu;
1802
1803 for_each_tracing_cpu(cpu) {
1804 if (iter->buffer_iter[cpu]) {
1805 if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
1806 return 0;
1807 } else {
1808 if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
1809 return 0;
1810 }
1811 }
1812
1813 return 1;
1814 }
1815
1816 static enum print_line_t print_trace_line(struct trace_iterator *iter)
1817 {
1818 enum print_line_t ret;
1819
1820 if (iter->trace && iter->trace->print_line) {
1821 ret = iter->trace->print_line(iter);
1822 if (ret != TRACE_TYPE_UNHANDLED)
1823 return ret;
1824 }
1825
1826 if (trace_flags & TRACE_ITER_BIN)
1827 return print_bin_fmt(iter);
1828
1829 if (trace_flags & TRACE_ITER_HEX)
1830 return print_hex_fmt(iter);
1831
1832 if (trace_flags & TRACE_ITER_RAW)
1833 return print_raw_fmt(iter);
1834
1835 if (iter->iter_flags & TRACE_FILE_LAT_FMT)
1836 return print_lat_fmt(iter, iter->idx, iter->cpu);
1837
1838 return print_trace_fmt(iter);
1839 }
1840
1841 static int s_show(struct seq_file *m, void *v)
1842 {
1843 struct trace_iterator *iter = v;
1844
1845 if (iter->ent == NULL) {
1846 if (iter->tr) {
1847 seq_printf(m, "# tracer: %s\n", iter->trace->name);
1848 seq_puts(m, "#\n");
1849 }
1850 if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
1851 /* print nothing if the buffers are empty */
1852 if (trace_empty(iter))
1853 return 0;
1854 print_trace_header(m, iter);
1855 if (!(trace_flags & TRACE_ITER_VERBOSE))
1856 print_lat_help_header(m);
1857 } else {
1858 if (!(trace_flags & TRACE_ITER_VERBOSE))
1859 print_func_help_header(m);
1860 }
1861 } else {
1862 print_trace_line(iter);
1863 trace_print_seq(m, &iter->seq);
1864 }
1865
1866 return 0;
1867 }
1868
1869 static struct seq_operations tracer_seq_ops = {
1870 .start = s_start,
1871 .next = s_next,
1872 .stop = s_stop,
1873 .show = s_show,
1874 };
1875
1876 static struct trace_iterator *
1877 __tracing_open(struct inode *inode, struct file *file, int *ret)
1878 {
1879 struct trace_iterator *iter;
1880 struct seq_file *m;
1881 int cpu;
1882
1883 if (tracing_disabled) {
1884 *ret = -ENODEV;
1885 return NULL;
1886 }
1887
1888 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
1889 if (!iter) {
1890 *ret = -ENOMEM;
1891 goto out;
1892 }
1893
1894 mutex_lock(&trace_types_lock);
1895 if (current_trace && current_trace->print_max)
1896 iter->tr = &max_tr;
1897 else
1898 iter->tr = inode->i_private;
1899 iter->trace = current_trace;
1900 iter->pos = -1;
1901
1902 for_each_tracing_cpu(cpu) {
1903
1904 iter->buffer_iter[cpu] =
1905 ring_buffer_read_start(iter->tr->buffer, cpu);
1906
1907 if (!iter->buffer_iter[cpu])
1908 goto fail_buffer;
1909 }
1910
1911 /* TODO stop tracer */
1912 *ret = seq_open(file, &tracer_seq_ops);
1913 if (*ret)
1914 goto fail_buffer;
1915
1916 m = file->private_data;
1917 m->private = iter;
1918
1919 /* stop the trace while dumping */
1920 if (iter->tr->ctrl) {
1921 tracer_enabled = 0;
1922 ftrace_function_enabled = 0;
1923 }
1924
1925 if (iter->trace && iter->trace->open)
1926 iter->trace->open(iter);
1927
1928 mutex_unlock(&trace_types_lock);
1929
1930 out:
1931 return iter;
1932
1933 fail_buffer:
1934 for_each_tracing_cpu(cpu) {
1935 if (iter->buffer_iter[cpu])
1936 ring_buffer_read_finish(iter->buffer_iter[cpu]);
1937 }
1938 mutex_unlock(&trace_types_lock);
1939
1940 return ERR_PTR(-ENOMEM);
1941 }
1942
1943 int tracing_open_generic(struct inode *inode, struct file *filp)
1944 {
1945 if (tracing_disabled)
1946 return -ENODEV;
1947
1948 filp->private_data = inode->i_private;
1949 return 0;
1950 }
1951
1952 int tracing_release(struct inode *inode, struct file *file)
1953 {
1954 struct seq_file *m = (struct seq_file *)file->private_data;
1955 struct trace_iterator *iter = m->private;
1956 int cpu;
1957
1958 mutex_lock(&trace_types_lock);
1959 for_each_tracing_cpu(cpu) {
1960 if (iter->buffer_iter[cpu])
1961 ring_buffer_read_finish(iter->buffer_iter[cpu]);
1962 }
1963
1964 if (iter->trace && iter->trace->close)
1965 iter->trace->close(iter);
1966
1967 /* reenable tracing if it was previously enabled */
1968 if (iter->tr->ctrl) {
1969 tracer_enabled = 1;
1970 /*
1971 * It is safe to enable function tracing even if it
1972 * isn't used
1973 */
1974 ftrace_function_enabled = 1;
1975 }
1976 mutex_unlock(&trace_types_lock);
1977
1978 seq_release(inode, file);
1979 kfree(iter);
1980 return 0;
1981 }
1982
1983 static int tracing_open(struct inode *inode, struct file *file)
1984 {
1985 int ret;
1986
1987 __tracing_open(inode, file, &ret);
1988
1989 return ret;
1990 }
1991
1992 static int tracing_lt_open(struct inode *inode, struct file *file)
1993 {
1994 struct trace_iterator *iter;
1995 int ret;
1996
1997 iter = __tracing_open(inode, file, &ret);
1998
1999 if (!ret)
2000 iter->iter_flags |= TRACE_FILE_LAT_FMT;
2001
2002 return ret;
2003 }
2004
2005
2006 static void *
2007 t_next(struct seq_file *m, void *v, loff_t *pos)
2008 {
2009 struct tracer *t = m->private;
2010
2011 (*pos)++;
2012
2013 if (t)
2014 t = t->next;
2015
2016 m->private = t;
2017
2018 return t;
2019 }
2020
2021 static void *t_start(struct seq_file *m, loff_t *pos)
2022 {
2023 struct tracer *t = m->private;
2024 loff_t l = 0;
2025
2026 mutex_lock(&trace_types_lock);
2027 for (; t && l < *pos; t = t_next(m, t, &l))
2028 ;
2029
2030 return t;
2031 }
2032
2033 static void t_stop(struct seq_file *m, void *p)
2034 {
2035 mutex_unlock(&trace_types_lock);
2036 }
2037
2038 static int t_show(struct seq_file *m, void *v)
2039 {
2040 struct tracer *t = v;
2041
2042 if (!t)
2043 return 0;
2044
2045 seq_printf(m, "%s", t->name);
2046 if (t->next)
2047 seq_putc(m, ' ');
2048 else
2049 seq_putc(m, '\n');
2050
2051 return 0;
2052 }
2053
2054 static struct seq_operations show_traces_seq_ops = {
2055 .start = t_start,
2056 .next = t_next,
2057 .stop = t_stop,
2058 .show = t_show,
2059 };
2060
2061 static int show_traces_open(struct inode *inode, struct file *file)
2062 {
2063 int ret;
2064
2065 if (tracing_disabled)
2066 return -ENODEV;
2067
2068 ret = seq_open(file, &show_traces_seq_ops);
2069 if (!ret) {
2070 struct seq_file *m = file->private_data;
2071 m->private = trace_types;
2072 }
2073
2074 return ret;
2075 }
2076
2077 static struct file_operations tracing_fops = {
2078 .open = tracing_open,
2079 .read = seq_read,
2080 .llseek = seq_lseek,
2081 .release = tracing_release,
2082 };
2083
2084 static struct file_operations tracing_lt_fops = {
2085 .open = tracing_lt_open,
2086 .read = seq_read,
2087 .llseek = seq_lseek,
2088 .release = tracing_release,
2089 };
2090
2091 static struct file_operations show_traces_fops = {
2092 .open = show_traces_open,
2093 .read = seq_read,
2094 .release = seq_release,
2095 };
2096
2097 /*
2098 * Only trace on a CPU if the bitmask is set:
2099 */
2100 static cpumask_t tracing_cpumask = CPU_MASK_ALL;
2101
2102 /*
2103 * When tracing/tracing_cpu_mask is modified then this holds
2104 * the new bitmask we are about to install:
2105 */
2106 static cpumask_t tracing_cpumask_new;
2107
2108 /*
2109 * The tracer itself will not take this lock, but still we want
2110 * to provide a consistent cpumask to user-space:
2111 */
2112 static DEFINE_MUTEX(tracing_cpumask_update_lock);
2113
2114 /*
2115 * Temporary storage for the character representation of the
2116 * CPU bitmask (and one more byte for the newline):
2117 */
2118 static char mask_str[NR_CPUS + 1];
2119
2120 static ssize_t
2121 tracing_cpumask_read(struct file *filp, char __user *ubuf,
2122 size_t count, loff_t *ppos)
2123 {
2124 int len;
2125
2126 mutex_lock(&tracing_cpumask_update_lock);
2127
2128 len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
2129 if (count - len < 2) {
2130 count = -EINVAL;
2131 goto out_err;
2132 }
2133 len += sprintf(mask_str + len, "\n");
2134 count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
2135
2136 out_err:
2137 mutex_unlock(&tracing_cpumask_update_lock);
2138
2139 return count;
2140 }
2141
2142 static ssize_t
2143 tracing_cpumask_write(struct file *filp, const char __user *ubuf,
2144 size_t count, loff_t *ppos)
2145 {
2146 int err, cpu;
2147
2148 mutex_lock(&tracing_cpumask_update_lock);
2149 err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
2150 if (err)
2151 goto err_unlock;
2152
2153 raw_local_irq_disable();
2154 __raw_spin_lock(&ftrace_max_lock);
2155 for_each_tracing_cpu(cpu) {
2156 /*
2157 * Increase/decrease the disabled counter if we are
2158 * about to flip a bit in the cpumask:
2159 */
2160 if (cpu_isset(cpu, tracing_cpumask) &&
2161 !cpu_isset(cpu, tracing_cpumask_new)) {
2162 atomic_inc(&global_trace.data[cpu]->disabled);
2163 }
2164 if (!cpu_isset(cpu, tracing_cpumask) &&
2165 cpu_isset(cpu, tracing_cpumask_new)) {
2166 atomic_dec(&global_trace.data[cpu]->disabled);
2167 }
2168 }
2169 __raw_spin_unlock(&ftrace_max_lock);
2170 raw_local_irq_enable();
2171
2172 tracing_cpumask = tracing_cpumask_new;
2173
2174 mutex_unlock(&tracing_cpumask_update_lock);
2175
2176 return count;
2177
2178 err_unlock:
2179 mutex_unlock(&tracing_cpumask_update_lock);
2180
2181 return err;
2182 }
2183
2184 static struct file_operations tracing_cpumask_fops = {
2185 .open = tracing_open_generic,
2186 .read = tracing_cpumask_read,
2187 .write = tracing_cpumask_write,
2188 };
2189
2190 static ssize_t
2191 tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
2192 size_t cnt, loff_t *ppos)
2193 {
2194 char *buf;
2195 int r = 0;
2196 int len = 0;
2197 int i;
2198
2199 /* calulate max size */
2200 for (i = 0; trace_options[i]; i++) {
2201 len += strlen(trace_options[i]);
2202 len += 3; /* "no" and space */
2203 }
2204
2205 /* +2 for \n and \0 */
2206 buf = kmalloc(len + 2, GFP_KERNEL);
2207 if (!buf)
2208 return -ENOMEM;
2209
2210 for (i = 0; trace_options[i]; i++) {
2211 if (trace_flags & (1 << i))
2212 r += sprintf(buf + r, "%s ", trace_options[i]);
2213 else
2214 r += sprintf(buf + r, "no%s ", trace_options[i]);
2215 }
2216
2217 r += sprintf(buf + r, "\n");
2218 WARN_ON(r >= len + 2);
2219
2220 r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2221
2222 kfree(buf);
2223
2224 return r;
2225 }
2226
2227 static ssize_t
2228 tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
2229 size_t cnt, loff_t *ppos)
2230 {
2231 char buf[64];
2232 char *cmp = buf;
2233 int neg = 0;
2234 int i;
2235
2236 if (cnt >= sizeof(buf))
2237 return -EINVAL;
2238
2239 if (copy_from_user(&buf, ubuf, cnt))
2240 return -EFAULT;
2241
2242 buf[cnt] = 0;
2243
2244 if (strncmp(buf, "no", 2) == 0) {
2245 neg = 1;
2246 cmp += 2;
2247 }
2248
2249 for (i = 0; trace_options[i]; i++) {
2250 int len = strlen(trace_options[i]);
2251
2252 if (strncmp(cmp, trace_options[i], len) == 0) {
2253 if (neg)
2254 trace_flags &= ~(1 << i);
2255 else
2256 trace_flags |= (1 << i);
2257 break;
2258 }
2259 }
2260 /*
2261 * If no option could be set, return an error:
2262 */
2263 if (!trace_options[i])
2264 return -EINVAL;
2265
2266 filp->f_pos += cnt;
2267
2268 return cnt;
2269 }
2270
2271 static struct file_operations tracing_iter_fops = {
2272 .open = tracing_open_generic,
2273 .read = tracing_iter_ctrl_read,
2274 .write = tracing_iter_ctrl_write,
2275 };
2276
2277 static const char readme_msg[] =
2278 "tracing mini-HOWTO:\n\n"
2279 "# mkdir /debug\n"
2280 "# mount -t debugfs nodev /debug\n\n"
2281 "# cat /debug/tracing/available_tracers\n"
2282 "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
2283 "# cat /debug/tracing/current_tracer\n"
2284 "none\n"
2285 "# echo sched_switch > /debug/tracing/current_tracer\n"
2286 "# cat /debug/tracing/current_tracer\n"
2287 "sched_switch\n"
2288 "# cat /debug/tracing/iter_ctrl\n"
2289 "noprint-parent nosym-offset nosym-addr noverbose\n"
2290 "# echo print-parent > /debug/tracing/iter_ctrl\n"
2291 "# echo 1 > /debug/tracing/tracing_enabled\n"
2292 "# cat /debug/tracing/trace > /tmp/trace.txt\n"
2293 "echo 0 > /debug/tracing/tracing_enabled\n"
2294 ;
2295
2296 static ssize_t
2297 tracing_readme_read(struct file *filp, char __user *ubuf,
2298 size_t cnt, loff_t *ppos)
2299 {
2300 return simple_read_from_buffer(ubuf, cnt, ppos,
2301 readme_msg, strlen(readme_msg));
2302 }
2303
2304 static struct file_operations tracing_readme_fops = {
2305 .open = tracing_open_generic,
2306 .read = tracing_readme_read,
2307 };
2308
2309 static ssize_t
2310 tracing_ctrl_read(struct file *filp, char __user *ubuf,
2311 size_t cnt, loff_t *ppos)
2312 {
2313 struct trace_array *tr = filp->private_data;
2314 char buf[64];
2315 int r;
2316
2317 r = sprintf(buf, "%ld\n", tr->ctrl);
2318 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2319 }
2320
2321 static ssize_t
2322 tracing_ctrl_write(struct file *filp, const char __user *ubuf,
2323 size_t cnt, loff_t *ppos)
2324 {
2325 struct trace_array *tr = filp->private_data;
2326 char buf[64];
2327 long val;
2328 int ret;
2329
2330 if (cnt >= sizeof(buf))
2331 return -EINVAL;
2332
2333 if (copy_from_user(&buf, ubuf, cnt))
2334 return -EFAULT;
2335
2336 buf[cnt] = 0;
2337
2338 ret = strict_strtoul(buf, 10, &val);
2339 if (ret < 0)
2340 return ret;
2341
2342 val = !!val;
2343
2344 mutex_lock(&trace_types_lock);
2345 if (tr->ctrl ^ val) {
2346 if (val)
2347 tracer_enabled = 1;
2348 else
2349 tracer_enabled = 0;
2350
2351 tr->ctrl = val;
2352
2353 if (current_trace && current_trace->ctrl_update)
2354 current_trace->ctrl_update(tr);
2355 }
2356 mutex_unlock(&trace_types_lock);
2357
2358 filp->f_pos += cnt;
2359
2360 return cnt;
2361 }
2362
2363 static ssize_t
2364 tracing_set_trace_read(struct file *filp, char __user *ubuf,
2365 size_t cnt, loff_t *ppos)
2366 {
2367 char buf[max_tracer_type_len+2];
2368 int r;
2369
2370 mutex_lock(&trace_types_lock);
2371 if (current_trace)
2372 r = sprintf(buf, "%s\n", current_trace->name);
2373 else
2374 r = sprintf(buf, "\n");
2375 mutex_unlock(&trace_types_lock);
2376
2377 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2378 }
2379
2380 static ssize_t
2381 tracing_set_trace_write(struct file *filp, const char __user *ubuf,
2382 size_t cnt, loff_t *ppos)
2383 {
2384 struct trace_array *tr = &global_trace;
2385 struct tracer *t;
2386 char buf[max_tracer_type_len+1];
2387 int i;
2388 size_t ret;
2389
2390 ret = cnt;
2391
2392 if (cnt > max_tracer_type_len)
2393 cnt = max_tracer_type_len;
2394
2395 if (copy_from_user(&buf, ubuf, cnt))
2396 return -EFAULT;
2397
2398 buf[cnt] = 0;
2399
2400 /* strip ending whitespace. */
2401 for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
2402 buf[i] = 0;
2403
2404 mutex_lock(&trace_types_lock);
2405 for (t = trace_types; t; t = t->next) {
2406 if (strcmp(t->name, buf) == 0)
2407 break;
2408 }
2409 if (!t) {
2410 ret = -EINVAL;
2411 goto out;
2412 }
2413 if (t == current_trace)
2414 goto out;
2415
2416 if (current_trace && current_trace->reset)
2417 current_trace->reset(tr);
2418
2419 current_trace = t;
2420 if (t->init)
2421 t->init(tr);
2422
2423 out:
2424 mutex_unlock(&trace_types_lock);
2425
2426 if (ret > 0)
2427 filp->f_pos += ret;
2428
2429 return ret;
2430 }
2431
2432 static ssize_t
2433 tracing_max_lat_read(struct file *filp, char __user *ubuf,
2434 size_t cnt, loff_t *ppos)
2435 {
2436 unsigned long *ptr = filp->private_data;
2437 char buf[64];
2438 int r;
2439
2440 r = snprintf(buf, sizeof(buf), "%ld\n",
2441 *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
2442 if (r > sizeof(buf))
2443 r = sizeof(buf);
2444 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2445 }
2446
2447 static ssize_t
2448 tracing_max_lat_write(struct file *filp, const char __user *ubuf,
2449 size_t cnt, loff_t *ppos)
2450 {
2451 long *ptr = filp->private_data;
2452 char buf[64];
2453 long val;
2454 int ret;
2455
2456 if (cnt >= sizeof(buf))
2457 return -EINVAL;
2458
2459 if (copy_from_user(&buf, ubuf, cnt))
2460 return -EFAULT;
2461
2462 buf[cnt] = 0;
2463
2464 ret = strict_strtoul(buf, 10, &val);
2465 if (ret < 0)
2466 return ret;
2467
2468 *ptr = val * 1000;
2469
2470 return cnt;
2471 }
2472
2473 static atomic_t tracing_reader;
2474
2475 static int tracing_open_pipe(struct inode *inode, struct file *filp)
2476 {
2477 struct trace_iterator *iter;
2478
2479 if (tracing_disabled)
2480 return -ENODEV;
2481
2482 /* We only allow for reader of the pipe */
2483 if (atomic_inc_return(&tracing_reader) != 1) {
2484 atomic_dec(&tracing_reader);
2485 return -EBUSY;
2486 }
2487
2488 /* create a buffer to store the information to pass to userspace */
2489 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2490 if (!iter)
2491 return -ENOMEM;
2492
2493 mutex_lock(&trace_types_lock);
2494 iter->tr = &global_trace;
2495 iter->trace = current_trace;
2496 filp->private_data = iter;
2497
2498 if (iter->trace->pipe_open)
2499 iter->trace->pipe_open(iter);
2500 mutex_unlock(&trace_types_lock);
2501
2502 return 0;
2503 }
2504
2505 static int tracing_release_pipe(struct inode *inode, struct file *file)
2506 {
2507 struct trace_iterator *iter = file->private_data;
2508
2509 kfree(iter);
2510 atomic_dec(&tracing_reader);
2511
2512 return 0;
2513 }
2514
2515 static unsigned int
2516 tracing_poll_pipe(struct file *filp, poll_table *poll_table)
2517 {
2518 struct trace_iterator *iter = filp->private_data;
2519
2520 if (trace_flags & TRACE_ITER_BLOCK) {
2521 /*
2522 * Always select as readable when in blocking mode
2523 */
2524 return POLLIN | POLLRDNORM;
2525 } else {
2526 if (!trace_empty(iter))
2527 return POLLIN | POLLRDNORM;
2528 poll_wait(filp, &trace_wait, poll_table);
2529 if (!trace_empty(iter))
2530 return POLLIN | POLLRDNORM;
2531
2532 return 0;
2533 }
2534 }
2535
2536 /*
2537 * Consumer reader.
2538 */
2539 static ssize_t
2540 tracing_read_pipe(struct file *filp, char __user *ubuf,
2541 size_t cnt, loff_t *ppos)
2542 {
2543 struct trace_iterator *iter = filp->private_data;
2544 ssize_t sret;
2545
2546 /* return any leftover data */
2547 sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
2548 if (sret != -EBUSY)
2549 return sret;
2550
2551 trace_seq_reset(&iter->seq);
2552
2553 mutex_lock(&trace_types_lock);
2554 if (iter->trace->read) {
2555 sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
2556 if (sret)
2557 goto out;
2558 }
2559
2560 waitagain:
2561 sret = 0;
2562 while (trace_empty(iter)) {
2563
2564 if ((filp->f_flags & O_NONBLOCK)) {
2565 sret = -EAGAIN;
2566 goto out;
2567 }
2568
2569 /*
2570 * This is a make-shift waitqueue. The reason we don't use
2571 * an actual wait queue is because:
2572 * 1) we only ever have one waiter
2573 * 2) the tracing, traces all functions, we don't want
2574 * the overhead of calling wake_up and friends
2575 * (and tracing them too)
2576 * Anyway, this is really very primitive wakeup.
2577 */
2578 set_current_state(TASK_INTERRUPTIBLE);
2579 iter->tr->waiter = current;
2580
2581 mutex_unlock(&trace_types_lock);
2582
2583 /* sleep for 100 msecs, and try again. */
2584 schedule_timeout(HZ/10);
2585
2586 mutex_lock(&trace_types_lock);
2587
2588 iter->tr->waiter = NULL;
2589
2590 if (signal_pending(current)) {
2591 sret = -EINTR;
2592 goto out;
2593 }
2594
2595 if (iter->trace != current_trace)
2596 goto out;
2597
2598 /*
2599 * We block until we read something and tracing is disabled.
2600 * We still block if tracing is disabled, but we have never
2601 * read anything. This allows a user to cat this file, and
2602 * then enable tracing. But after we have read something,
2603 * we give an EOF when tracing is again disabled.
2604 *
2605 * iter->pos will be 0 if we haven't read anything.
2606 */
2607 if (!tracer_enabled && iter->pos)
2608 break;
2609
2610 continue;
2611 }
2612
2613 /* stop when tracing is finished */
2614 if (trace_empty(iter))
2615 goto out;
2616
2617 if (cnt >= PAGE_SIZE)
2618 cnt = PAGE_SIZE - 1;
2619
2620 /* reset all but tr, trace, and overruns */
2621 memset(&iter->seq, 0,
2622 sizeof(struct trace_iterator) -
2623 offsetof(struct trace_iterator, seq));
2624 iter->pos = -1;
2625
2626 while (find_next_entry_inc(iter) != NULL) {
2627 enum print_line_t ret;
2628 int len = iter->seq.len;
2629
2630 ret = print_trace_line(iter);
2631 if (ret == TRACE_TYPE_PARTIAL_LINE) {
2632 /* don't print partial lines */
2633 iter->seq.len = len;
2634 break;
2635 }
2636
2637 trace_consume(iter);
2638
2639 if (iter->seq.len >= cnt)
2640 break;
2641 }
2642
2643 /* Now copy what we have to the user */
2644 sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
2645 if (iter->seq.readpos >= iter->seq.len)
2646 trace_seq_reset(&iter->seq);
2647
2648 /*
2649 * If there was nothing to send to user, inspite of consuming trace
2650 * entries, go back to wait for more entries.
2651 */
2652 if (sret == -EBUSY)
2653 goto waitagain;
2654
2655 out:
2656 mutex_unlock(&trace_types_lock);
2657
2658 return sret;
2659 }
2660
2661 static ssize_t
2662 tracing_entries_read(struct file *filp, char __user *ubuf,
2663 size_t cnt, loff_t *ppos)
2664 {
2665 struct trace_array *tr = filp->private_data;
2666 char buf[64];
2667 int r;
2668
2669 r = sprintf(buf, "%lu\n", tr->entries);
2670 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2671 }
2672
2673 static ssize_t
2674 tracing_entries_write(struct file *filp, const char __user *ubuf,
2675 size_t cnt, loff_t *ppos)
2676 {
2677 unsigned long val;
2678 char buf[64];
2679 int ret;
2680 struct trace_array *tr = filp->private_data;
2681
2682 if (cnt >= sizeof(buf))
2683 return -EINVAL;
2684
2685 if (copy_from_user(&buf, ubuf, cnt))
2686 return -EFAULT;
2687
2688 buf[cnt] = 0;
2689
2690 ret = strict_strtoul(buf, 10, &val);
2691 if (ret < 0)
2692 return ret;
2693
2694 /* must have at least 1 entry */
2695 if (!val)
2696 return -EINVAL;
2697
2698 mutex_lock(&trace_types_lock);
2699
2700 if (tr->ctrl) {
2701 cnt = -EBUSY;
2702 pr_info("ftrace: please disable tracing"
2703 " before modifying buffer size\n");
2704 goto out;
2705 }
2706
2707 if (val != global_trace.entries) {
2708 ret = ring_buffer_resize(global_trace.buffer, val);
2709 if (ret < 0) {
2710 cnt = ret;
2711 goto out;
2712 }
2713
2714 ret = ring_buffer_resize(max_tr.buffer, val);
2715 if (ret < 0) {
2716 int r;
2717 cnt = ret;
2718 r = ring_buffer_resize(global_trace.buffer,
2719 global_trace.entries);
2720 if (r < 0) {
2721 /* AARGH! We are left with different
2722 * size max buffer!!!! */
2723 WARN_ON(1);
2724 tracing_disabled = 1;
2725 }
2726 goto out;
2727 }
2728
2729 global_trace.entries = val;
2730 }
2731
2732 filp->f_pos += cnt;
2733
2734 /* If check pages failed, return ENOMEM */
2735 if (tracing_disabled)
2736 cnt = -ENOMEM;
2737 out:
2738 max_tr.entries = global_trace.entries;
2739 mutex_unlock(&trace_types_lock);
2740
2741 return cnt;
2742 }
2743
2744 static int mark_printk(const char *fmt, ...)
2745 {
2746 int ret;
2747 va_list args;
2748 va_start(args, fmt);
2749 ret = trace_vprintk(0, fmt, args);
2750 va_end(args);
2751 return ret;
2752 }
2753
2754 static ssize_t
2755 tracing_mark_write(struct file *filp, const char __user *ubuf,
2756 size_t cnt, loff_t *fpos)
2757 {
2758 char *buf;
2759 char *end;
2760 struct trace_array *tr = &global_trace;
2761
2762 if (!tr->ctrl || tracing_disabled)
2763 return -EINVAL;
2764
2765 if (cnt > TRACE_BUF_SIZE)
2766 cnt = TRACE_BUF_SIZE;
2767
2768 buf = kmalloc(cnt + 1, GFP_KERNEL);
2769 if (buf == NULL)
2770 return -ENOMEM;
2771
2772 if (copy_from_user(buf, ubuf, cnt)) {
2773 kfree(buf);
2774 return -EFAULT;
2775 }
2776
2777 /* Cut from the first nil or newline. */
2778 buf[cnt] = '\0';
2779 end = strchr(buf, '\n');
2780 if (end)
2781 *end = '\0';
2782
2783 cnt = mark_printk("%s\n", buf);
2784 kfree(buf);
2785 *fpos += cnt;
2786
2787 return cnt;
2788 }
2789
2790 static struct file_operations tracing_max_lat_fops = {
2791 .open = tracing_open_generic,
2792 .read = tracing_max_lat_read,
2793 .write = tracing_max_lat_write,
2794 };
2795
2796 static struct file_operations tracing_ctrl_fops = {
2797 .open = tracing_open_generic,
2798 .read = tracing_ctrl_read,
2799 .write = tracing_ctrl_write,
2800 };
2801
2802 static struct file_operations set_tracer_fops = {
2803 .open = tracing_open_generic,
2804 .read = tracing_set_trace_read,
2805 .write = tracing_set_trace_write,
2806 };
2807
2808 static struct file_operations tracing_pipe_fops = {
2809 .open = tracing_open_pipe,
2810 .poll = tracing_poll_pipe,
2811 .read = tracing_read_pipe,
2812 .release = tracing_release_pipe,
2813 };
2814
2815 static struct file_operations tracing_entries_fops = {
2816 .open = tracing_open_generic,
2817 .read = tracing_entries_read,
2818 .write = tracing_entries_write,
2819 };
2820
2821 static struct file_operations tracing_mark_fops = {
2822 .open = tracing_open_generic,
2823 .write = tracing_mark_write,
2824 };
2825
2826 #ifdef CONFIG_DYNAMIC_FTRACE
2827
2828 static ssize_t
2829 tracing_read_long(struct file *filp, char __user *ubuf,
2830 size_t cnt, loff_t *ppos)
2831 {
2832 unsigned long *p = filp->private_data;
2833 char buf[64];
2834 int r;
2835
2836 r = sprintf(buf, "%ld\n", *p);
2837
2838 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2839 }
2840
2841 static struct file_operations tracing_read_long_fops = {
2842 .open = tracing_open_generic,
2843 .read = tracing_read_long,
2844 };
2845 #endif
2846
2847 static struct dentry *d_tracer;
2848
2849 struct dentry *tracing_init_dentry(void)
2850 {
2851 static int once;
2852
2853 if (d_tracer)
2854 return d_tracer;
2855
2856 d_tracer = debugfs_create_dir("tracing", NULL);
2857
2858 if (!d_tracer && !once) {
2859 once = 1;
2860 pr_warning("Could not create debugfs directory 'tracing'\n");
2861 return NULL;
2862 }
2863
2864 return d_tracer;
2865 }
2866
2867 #ifdef CONFIG_FTRACE_SELFTEST
2868 /* Let selftest have access to static functions in this file */
2869 #include "trace_selftest.c"
2870 #endif
2871
2872 static __init int tracer_init_debugfs(void)
2873 {
2874 struct dentry *d_tracer;
2875 struct dentry *entry;
2876
2877 d_tracer = tracing_init_dentry();
2878
2879 entry = debugfs_create_file("tracing_enabled", 0644, d_tracer,
2880 &global_trace, &tracing_ctrl_fops);
2881 if (!entry)
2882 pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
2883
2884 entry = debugfs_create_file("iter_ctrl", 0644, d_tracer,
2885 NULL, &tracing_iter_fops);
2886 if (!entry)
2887 pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
2888
2889 entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
2890 NULL, &tracing_cpumask_fops);
2891 if (!entry)
2892 pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
2893
2894 entry = debugfs_create_file("latency_trace", 0444, d_tracer,
2895 &global_trace, &tracing_lt_fops);
2896 if (!entry)
2897 pr_warning("Could not create debugfs 'latency_trace' entry\n");
2898
2899 entry = debugfs_create_file("trace", 0444, d_tracer,
2900 &global_trace, &tracing_fops);
2901 if (!entry)
2902 pr_warning("Could not create debugfs 'trace' entry\n");
2903
2904 entry = debugfs_create_file("available_tracers", 0444, d_tracer,
2905 &global_trace, &show_traces_fops);
2906 if (!entry)
2907 pr_warning("Could not create debugfs 'available_tracers' entry\n");
2908
2909 entry = debugfs_create_file("current_tracer", 0444, d_tracer,
2910 &global_trace, &set_tracer_fops);
2911 if (!entry)
2912 pr_warning("Could not create debugfs 'current_tracer' entry\n");
2913
2914 entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
2915 &tracing_max_latency,
2916 &tracing_max_lat_fops);
2917 if (!entry)
2918 pr_warning("Could not create debugfs "
2919 "'tracing_max_latency' entry\n");
2920
2921 entry = debugfs_create_file("tracing_thresh", 0644, d_tracer,
2922 &tracing_thresh, &tracing_max_lat_fops);
2923 if (!entry)
2924 pr_warning("Could not create debugfs "
2925 "'tracing_thresh' entry\n");
2926 entry = debugfs_create_file("README", 0644, d_tracer,
2927 NULL, &tracing_readme_fops);
2928 if (!entry)
2929 pr_warning("Could not create debugfs 'README' entry\n");
2930
2931 entry = debugfs_create_file("trace_pipe", 0644, d_tracer,
2932 NULL, &tracing_pipe_fops);
2933 if (!entry)
2934 pr_warning("Could not create debugfs "
2935 "'trace_pipe' entry\n");
2936
2937 entry = debugfs_create_file("trace_entries", 0644, d_tracer,
2938 &global_trace, &tracing_entries_fops);
2939 if (!entry)
2940 pr_warning("Could not create debugfs "
2941 "'trace_entries' entry\n");
2942
2943 entry = debugfs_create_file("trace_marker", 0220, d_tracer,
2944 NULL, &tracing_mark_fops);
2945 if (!entry)
2946 pr_warning("Could not create debugfs "
2947 "'trace_marker' entry\n");
2948
2949 #ifdef CONFIG_DYNAMIC_FTRACE
2950 entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
2951 &ftrace_update_tot_cnt,
2952 &tracing_read_long_fops);
2953 if (!entry)
2954 pr_warning("Could not create debugfs "
2955 "'dyn_ftrace_total_info' entry\n");
2956 #endif
2957 #ifdef CONFIG_SYSPROF_TRACER
2958 init_tracer_sysprof_debugfs(d_tracer);
2959 #endif
2960 return 0;
2961 }
2962
2963 int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
2964 {
2965 static DEFINE_SPINLOCK(trace_buf_lock);
2966 static char trace_buf[TRACE_BUF_SIZE];
2967
2968 struct ring_buffer_event *event;
2969 struct trace_array *tr = &global_trace;
2970 struct trace_array_cpu *data;
2971 struct print_entry *entry;
2972 unsigned long flags, irq_flags;
2973 int cpu, len = 0, size, pc;
2974
2975 if (!tr->ctrl || tracing_disabled)
2976 return 0;
2977
2978 pc = preempt_count();
2979 preempt_disable_notrace();
2980 cpu = raw_smp_processor_id();
2981 data = tr->data[cpu];
2982
2983 if (unlikely(atomic_read(&data->disabled)))
2984 goto out;
2985
2986 spin_lock_irqsave(&trace_buf_lock, flags);
2987 len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
2988
2989 len = min(len, TRACE_BUF_SIZE-1);
2990 trace_buf[len] = 0;
2991
2992 size = sizeof(*entry) + len + 1;
2993 event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags);
2994 if (!event)
2995 goto out_unlock;
2996 entry = ring_buffer_event_data(event);
2997 tracing_generic_entry_update(&entry->ent, flags, pc);
2998 entry->ent.type = TRACE_PRINT;
2999 entry->ip = ip;
3000
3001 memcpy(&entry->buf, trace_buf, len);
3002 entry->buf[len] = 0;
3003 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
3004
3005 out_unlock:
3006 spin_unlock_irqrestore(&trace_buf_lock, flags);
3007
3008 out:
3009 preempt_enable_notrace();
3010
3011 return len;
3012 }
3013 EXPORT_SYMBOL_GPL(trace_vprintk);
3014
3015 int __ftrace_printk(unsigned long ip, const char *fmt, ...)
3016 {
3017 int ret;
3018 va_list ap;
3019
3020 if (!(trace_flags & TRACE_ITER_PRINTK))
3021 return 0;
3022
3023 va_start(ap, fmt);
3024 ret = trace_vprintk(ip, fmt, ap);
3025 va_end(ap);
3026 return ret;
3027 }
3028 EXPORT_SYMBOL_GPL(__ftrace_printk);
3029
3030 static int trace_panic_handler(struct notifier_block *this,
3031 unsigned long event, void *unused)
3032 {
3033 ftrace_dump();
3034 return NOTIFY_OK;
3035 }
3036
3037 static struct notifier_block trace_panic_notifier = {
3038 .notifier_call = trace_panic_handler,
3039 .next = NULL,
3040 .priority = 150 /* priority: INT_MAX >= x >= 0 */
3041 };
3042
3043 static int trace_die_handler(struct notifier_block *self,
3044 unsigned long val,
3045 void *data)
3046 {
3047 switch (val) {
3048 case DIE_OOPS:
3049 ftrace_dump();
3050 break;
3051 default:
3052 break;
3053 }
3054 return NOTIFY_OK;
3055 }
3056
3057 static struct notifier_block trace_die_notifier = {
3058 .notifier_call = trace_die_handler,
3059 .priority = 200
3060 };
3061
3062 /*
3063 * printk is set to max of 1024, we really don't need it that big.
3064 * Nothing should be printing 1000 characters anyway.
3065 */
3066 #define TRACE_MAX_PRINT 1000
3067
3068 /*
3069 * Define here KERN_TRACE so that we have one place to modify
3070 * it if we decide to change what log level the ftrace dump
3071 * should be at.
3072 */
3073 #define KERN_TRACE KERN_INFO
3074
3075 static void
3076 trace_printk_seq(struct trace_seq *s)
3077 {
3078 /* Probably should print a warning here. */
3079 if (s->len >= 1000)
3080 s->len = 1000;
3081
3082 /* should be zero ended, but we are paranoid. */
3083 s->buffer[s->len] = 0;
3084
3085 printk(KERN_TRACE "%s", s->buffer);
3086
3087 trace_seq_reset(s);
3088 }
3089
3090
3091 void ftrace_dump(void)
3092 {
3093 static DEFINE_SPINLOCK(ftrace_dump_lock);
3094 /* use static because iter can be a bit big for the stack */
3095 static struct trace_iterator iter;
3096 static cpumask_t mask;
3097 static int dump_ran;
3098 unsigned long flags;
3099 int cnt = 0, cpu;
3100
3101 /* only one dump */
3102 spin_lock_irqsave(&ftrace_dump_lock, flags);
3103 if (dump_ran)
3104 goto out;
3105
3106 dump_ran = 1;
3107
3108 /* No turning back! */
3109 ftrace_kill();
3110
3111 for_each_tracing_cpu(cpu) {
3112 atomic_inc(&global_trace.data[cpu]->disabled);
3113 }
3114
3115 printk(KERN_TRACE "Dumping ftrace buffer:\n");
3116
3117 iter.tr = &global_trace;
3118 iter.trace = current_trace;
3119
3120 /*
3121 * We need to stop all tracing on all CPUS to read the
3122 * the next buffer. This is a bit expensive, but is
3123 * not done often. We fill all what we can read,
3124 * and then release the locks again.
3125 */
3126
3127 cpus_clear(mask);
3128
3129 while (!trace_empty(&iter)) {
3130
3131 if (!cnt)
3132 printk(KERN_TRACE "---------------------------------\n");
3133
3134 cnt++;
3135
3136 /* reset all but tr, trace, and overruns */
3137 memset(&iter.seq, 0,
3138 sizeof(struct trace_iterator) -
3139 offsetof(struct trace_iterator, seq));
3140 iter.iter_flags |= TRACE_FILE_LAT_FMT;
3141 iter.pos = -1;
3142
3143 if (find_next_entry_inc(&iter) != NULL) {
3144 print_trace_line(&iter);
3145 trace_consume(&iter);
3146 }
3147
3148 trace_printk_seq(&iter.seq);
3149 }
3150
3151 if (!cnt)
3152 printk(KERN_TRACE " (ftrace buffer empty)\n");
3153 else
3154 printk(KERN_TRACE "---------------------------------\n");
3155
3156 out:
3157 spin_unlock_irqrestore(&ftrace_dump_lock, flags);
3158 }
3159
3160 __init static int tracer_alloc_buffers(void)
3161 {
3162 struct trace_array_cpu *data;
3163 int i;
3164
3165 /* TODO: make the number of buffers hot pluggable with CPUS */
3166 tracing_buffer_mask = cpu_possible_map;
3167
3168 global_trace.buffer = ring_buffer_alloc(trace_buf_size,
3169 TRACE_BUFFER_FLAGS);
3170 if (!global_trace.buffer) {
3171 printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
3172 WARN_ON(1);
3173 return 0;
3174 }
3175 global_trace.entries = ring_buffer_size(global_trace.buffer);
3176
3177 #ifdef CONFIG_TRACER_MAX_TRACE
3178 max_tr.buffer = ring_buffer_alloc(trace_buf_size,
3179 TRACE_BUFFER_FLAGS);
3180 if (!max_tr.buffer) {
3181 printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
3182 WARN_ON(1);
3183 ring_buffer_free(global_trace.buffer);
3184 return 0;
3185 }
3186 max_tr.entries = ring_buffer_size(max_tr.buffer);
3187 WARN_ON(max_tr.entries != global_trace.entries);
3188 #endif
3189
3190 /* Allocate the first page for all buffers */
3191 for_each_tracing_cpu(i) {
3192 data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
3193 max_tr.data[i] = &per_cpu(max_data, i);
3194 }
3195
3196 trace_init_cmdlines();
3197
3198 register_tracer(&nop_trace);
3199 #ifdef CONFIG_BOOT_TRACER
3200 register_tracer(&boot_tracer);
3201 current_trace = &boot_tracer;
3202 current_trace->init(&global_trace);
3203 #else
3204 current_trace = &nop_trace;
3205 #endif
3206
3207 /* All seems OK, enable tracing */
3208 global_trace.ctrl = tracer_enabled;
3209 tracing_disabled = 0;
3210
3211 atomic_notifier_chain_register(&panic_notifier_list,
3212 &trace_panic_notifier);
3213
3214 register_die_notifier(&trace_die_notifier);
3215
3216 return 0;
3217 }
3218 early_initcall(tracer_alloc_buffers);
3219 fs_initcall(tracer_init_debugfs);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree