2 * ring buffer based function tracer
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
7 * Originally taken from the RT patch by:
8 * Arnaldo Carvalho de Melo <acme@redhat.com>
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
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>
32 #include <linux/kprobes.h>
33 #include <linux/seq_file.h>
34 #include <linux/writeback.h>
36 #include <linux/stacktrace.h>
37 #include <linux/ring_buffer.h>
38 #include <linux/irqflags.h>
42 #define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
44 unsigned long __read_mostly tracing_max_latency
= (cycle_t
)ULONG_MAX
;
45 unsigned long __read_mostly tracing_thresh
;
48 * We need to change this state when a selftest is running.
49 * A selftest will lurk into the ring-buffer to count the
50 * entries inserted during the selftest although some concurrent
51 * insertions into the ring-buffer such as ftrace_printk could occurred
52 * at the same time, giving false positive or negative results.
54 static bool __read_mostly tracing_selftest_running
;
56 /* For tracers that don't implement custom flags */
57 static struct tracer_opt dummy_tracer_opt
[] = {
61 static struct tracer_flags dummy_tracer_flags
= {
63 .opts
= dummy_tracer_opt
66 static int dummy_set_flag(u32 old_flags
, u32 bit
, int set
)
72 * Kill all tracing for good (never come back).
73 * It is initialized to 1 but will turn to zero if the initialization
74 * of the tracer is successful. But that is the only place that sets
77 int tracing_disabled
= 1;
79 static DEFINE_PER_CPU(local_t
, ftrace_cpu_disabled
);
81 static inline void ftrace_disable_cpu(void)
84 local_inc(&__get_cpu_var(ftrace_cpu_disabled
));
87 static inline void ftrace_enable_cpu(void)
89 local_dec(&__get_cpu_var(ftrace_cpu_disabled
));
93 static cpumask_t __read_mostly tracing_buffer_mask
;
95 #define for_each_tracing_cpu(cpu) \
96 for_each_cpu_mask(cpu, tracing_buffer_mask)
99 * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
101 * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
102 * is set, then ftrace_dump is called. This will output the contents
103 * of the ftrace buffers to the console. This is very useful for
104 * capturing traces that lead to crashes and outputing it to a
107 * It is default off, but you can enable it with either specifying
108 * "ftrace_dump_on_oops" in the kernel command line, or setting
109 * /proc/sys/kernel/ftrace_dump_on_oops to true.
111 int ftrace_dump_on_oops
;
113 static int tracing_set_tracer(char *buf
);
115 static int __init
set_ftrace(char *str
)
117 tracing_set_tracer(str
);
120 __setup("ftrace", set_ftrace
);
122 static int __init
set_ftrace_dump_on_oops(char *str
)
124 ftrace_dump_on_oops
= 1;
127 __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops
);
130 ns2usecs(cycle_t nsec
)
137 cycle_t
ftrace_now(int cpu
)
139 u64 ts
= ring_buffer_time_stamp(cpu
);
140 ring_buffer_normalize_time_stamp(cpu
, &ts
);
145 * The global_trace is the descriptor that holds the tracing
146 * buffers for the live tracing. For each CPU, it contains
147 * a link list of pages that will store trace entries. The
148 * page descriptor of the pages in the memory is used to hold
149 * the link list by linking the lru item in the page descriptor
150 * to each of the pages in the buffer per CPU.
152 * For each active CPU there is a data field that holds the
153 * pages for the buffer for that CPU. Each CPU has the same number
154 * of pages allocated for its buffer.
156 static struct trace_array global_trace
;
158 static DEFINE_PER_CPU(struct trace_array_cpu
, global_trace_cpu
);
161 * The max_tr is used to snapshot the global_trace when a maximum
162 * latency is reached. Some tracers will use this to store a maximum
163 * trace while it continues examining live traces.
165 * The buffers for the max_tr are set up the same as the global_trace.
166 * When a snapshot is taken, the link list of the max_tr is swapped
167 * with the link list of the global_trace and the buffers are reset for
168 * the global_trace so the tracing can continue.
170 static struct trace_array max_tr
;
172 static DEFINE_PER_CPU(struct trace_array_cpu
, max_data
);
174 /* tracer_enabled is used to toggle activation of a tracer */
175 static int tracer_enabled
= 1;
178 * tracing_is_enabled - return tracer_enabled status
180 * This function is used by other tracers to know the status
181 * of the tracer_enabled flag. Tracers may use this function
182 * to know if it should enable their features when starting
183 * up. See irqsoff tracer for an example (start_irqsoff_tracer).
185 int tracing_is_enabled(void)
187 return tracer_enabled
;
190 /* function tracing enabled */
191 int ftrace_function_enabled
;
194 * trace_buf_size is the size in bytes that is allocated
195 * for a buffer. Note, the number of bytes is always rounded
198 * This number is purposely set to a low number of 16384.
199 * If the dump on oops happens, it will be much appreciated
200 * to not have to wait for all that output. Anyway this can be
201 * boot time and run time configurable.
203 #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
205 static unsigned long trace_buf_size
= TRACE_BUF_SIZE_DEFAULT
;
207 /* trace_types holds a link list of available tracers. */
208 static struct tracer
*trace_types __read_mostly
;
210 /* current_trace points to the tracer that is currently active */
211 static struct tracer
*current_trace __read_mostly
;
214 * max_tracer_type_len is used to simplify the allocating of
215 * buffers to read userspace tracer names. We keep track of
216 * the longest tracer name registered.
218 static int max_tracer_type_len
;
221 * trace_types_lock is used to protect the trace_types list.
222 * This lock is also used to keep user access serialized.
223 * Accesses from userspace will grab this lock while userspace
224 * activities happen inside the kernel.
226 static DEFINE_MUTEX(trace_types_lock
);
228 /* trace_wait is a waitqueue for tasks blocked on trace_poll */
229 static DECLARE_WAIT_QUEUE_HEAD(trace_wait
);
231 /* trace_flags holds trace_options default values */
232 unsigned long trace_flags
= TRACE_ITER_PRINT_PARENT
| TRACE_ITER_PRINTK
|
236 * trace_wake_up - wake up tasks waiting for trace input
238 * Simply wakes up any task that is blocked on the trace_wait
239 * queue. These is used with trace_poll for tasks polling the trace.
241 void trace_wake_up(void)
244 * The runqueue_is_locked() can fail, but this is the best we
247 if (!(trace_flags
& TRACE_ITER_BLOCK
) && !runqueue_is_locked())
248 wake_up(&trace_wait
);
251 static int __init
set_buf_size(char *str
)
253 unsigned long buf_size
;
258 ret
= strict_strtoul(str
, 0, &buf_size
);
259 /* nr_entries can not be zero */
260 if (ret
< 0 || buf_size
== 0)
262 trace_buf_size
= buf_size
;
265 __setup("trace_buf_size=", set_buf_size
);
267 unsigned long nsecs_to_usecs(unsigned long nsecs
)
272 /* These must match the bit postions in trace_iterator_flags */
273 static const char *trace_options
[] = {
294 * ftrace_max_lock is used to protect the swapping of buffers
295 * when taking a max snapshot. The buffers themselves are
296 * protected by per_cpu spinlocks. But the action of the swap
297 * needs its own lock.
299 * This is defined as a raw_spinlock_t in order to help
300 * with performance when lockdep debugging is enabled.
302 static raw_spinlock_t ftrace_max_lock
=
303 (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
306 * Copy the new maximum trace into the separate maximum-trace
307 * structure. (this way the maximum trace is permanently saved,
308 * for later retrieval via /debugfs/tracing/latency_trace)
311 __update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
313 struct trace_array_cpu
*data
= tr
->data
[cpu
];
316 max_tr
.time_start
= data
->preempt_timestamp
;
318 data
= max_tr
.data
[cpu
];
319 data
->saved_latency
= tracing_max_latency
;
321 memcpy(data
->comm
, tsk
->comm
, TASK_COMM_LEN
);
322 data
->pid
= tsk
->pid
;
323 data
->uid
= tsk
->uid
;
324 data
->nice
= tsk
->static_prio
- 20 - MAX_RT_PRIO
;
325 data
->policy
= tsk
->policy
;
326 data
->rt_priority
= tsk
->rt_priority
;
328 /* record this tasks comm */
329 tracing_record_cmdline(current
);
333 * trace_seq_printf - sequence printing of trace information
334 * @s: trace sequence descriptor
335 * @fmt: printf format string
337 * The tracer may use either sequence operations or its own
338 * copy to user routines. To simplify formating of a trace
339 * trace_seq_printf is used to store strings into a special
340 * buffer (@s). Then the output may be either used by
341 * the sequencer or pulled into another buffer.
344 trace_seq_printf(struct trace_seq
*s
, const char *fmt
, ...)
346 int len
= (PAGE_SIZE
- 1) - s
->len
;
354 ret
= vsnprintf(s
->buffer
+ s
->len
, len
, fmt
, ap
);
357 /* If we can't write it all, don't bother writing anything */
367 * trace_seq_puts - trace sequence printing of simple string
368 * @s: trace sequence descriptor
369 * @str: simple string to record
371 * The tracer may use either the sequence operations or its own
372 * copy to user routines. This function records a simple string
373 * into a special buffer (@s) for later retrieval by a sequencer
374 * or other mechanism.
377 trace_seq_puts(struct trace_seq
*s
, const char *str
)
379 int len
= strlen(str
);
381 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
384 memcpy(s
->buffer
+ s
->len
, str
, len
);
391 trace_seq_putc(struct trace_seq
*s
, unsigned char c
)
393 if (s
->len
>= (PAGE_SIZE
- 1))
396 s
->buffer
[s
->len
++] = c
;
402 trace_seq_putmem(struct trace_seq
*s
, void *mem
, size_t len
)
404 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
407 memcpy(s
->buffer
+ s
->len
, mem
, len
);
413 #define MAX_MEMHEX_BYTES 8
414 #define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
417 trace_seq_putmem_hex(struct trace_seq
*s
, void *mem
, size_t len
)
419 unsigned char hex
[HEX_CHARS
];
420 unsigned char *data
= mem
;
424 for (i
= 0, j
= 0; i
< len
; i
++) {
426 for (i
= len
-1, j
= 0; i
>= 0; i
--) {
428 hex
[j
++] = hex_asc_hi(data
[i
]);
429 hex
[j
++] = hex_asc_lo(data
[i
]);
433 return trace_seq_putmem(s
, hex
, j
);
437 trace_seq_path(struct trace_seq
*s
, struct path
*path
)
441 if (s
->len
>= (PAGE_SIZE
- 1))
443 p
= d_path(path
, s
->buffer
+ s
->len
, PAGE_SIZE
- s
->len
);
445 p
= mangle_path(s
->buffer
+ s
->len
, p
, "\n");
447 s
->len
= p
- s
->buffer
;
451 s
->buffer
[s
->len
++] = '?';
459 trace_seq_reset(struct trace_seq
*s
)
465 ssize_t
trace_seq_to_user(struct trace_seq
*s
, char __user
*ubuf
, size_t cnt
)
470 if (s
->len
<= s
->readpos
)
473 len
= s
->len
- s
->readpos
;
476 ret
= copy_to_user(ubuf
, s
->buffer
+ s
->readpos
, cnt
);
485 trace_print_seq(struct seq_file
*m
, struct trace_seq
*s
)
487 int len
= s
->len
>= PAGE_SIZE
? PAGE_SIZE
- 1 : s
->len
;
490 seq_puts(m
, s
->buffer
);
496 * update_max_tr - snapshot all trace buffers from global_trace to max_tr
498 * @tsk: the task with the latency
499 * @cpu: The cpu that initiated the trace.
501 * Flip the buffers between the @tr and the max_tr and record information
502 * about which task was the cause of this latency.
505 update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
507 struct ring_buffer
*buf
= tr
->buffer
;
509 WARN_ON_ONCE(!irqs_disabled());
510 __raw_spin_lock(&ftrace_max_lock
);
512 tr
->buffer
= max_tr
.buffer
;
515 ftrace_disable_cpu();
516 ring_buffer_reset(tr
->buffer
);
519 __update_max_tr(tr
, tsk
, cpu
);
520 __raw_spin_unlock(&ftrace_max_lock
);
524 * update_max_tr_single - only copy one trace over, and reset the rest
526 * @tsk - task with the latency
527 * @cpu - the cpu of the buffer to copy.
529 * Flip the trace of a single CPU buffer between the @tr and the max_tr.
532 update_max_tr_single(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
536 WARN_ON_ONCE(!irqs_disabled());
537 __raw_spin_lock(&ftrace_max_lock
);
539 ftrace_disable_cpu();
541 ring_buffer_reset(max_tr
.buffer
);
542 ret
= ring_buffer_swap_cpu(max_tr
.buffer
, tr
->buffer
, cpu
);
548 __update_max_tr(tr
, tsk
, cpu
);
549 __raw_spin_unlock(&ftrace_max_lock
);
553 * register_tracer - register a tracer with the ftrace system.
554 * @type - the plugin for the tracer
556 * Register a new plugin tracer.
558 int register_tracer(struct tracer
*type
)
565 pr_info("Tracer must have a name\n");
570 * When this gets called we hold the BKL which means that
571 * preemption is disabled. Various trace selftests however
572 * need to disable and enable preemption for successful tests.
573 * So we drop the BKL here and grab it after the tests again.
576 mutex_lock(&trace_types_lock
);
578 tracing_selftest_running
= true;
580 for (t
= trace_types
; t
; t
= t
->next
) {
581 if (strcmp(type
->name
, t
->name
) == 0) {
583 pr_info("Trace %s already registered\n",
591 type
->set_flag
= &dummy_set_flag
;
593 type
->flags
= &dummy_tracer_flags
;
595 if (!type
->flags
->opts
)
596 type
->flags
->opts
= dummy_tracer_opt
;
598 #ifdef CONFIG_FTRACE_STARTUP_TEST
599 if (type
->selftest
) {
600 struct tracer
*saved_tracer
= current_trace
;
601 struct trace_array
*tr
= &global_trace
;
605 * Run a selftest on this tracer.
606 * Here we reset the trace buffer, and set the current
607 * tracer to be this tracer. The tracer can then run some
608 * internal tracing to verify that everything is in order.
609 * If we fail, we do not register this tracer.
611 for_each_tracing_cpu(i
)
612 tracing_reset(tr
, i
);
614 current_trace
= type
;
615 /* the test is responsible for initializing and enabling */
616 pr_info("Testing tracer %s: ", type
->name
);
617 ret
= type
->selftest(type
, tr
);
618 /* the test is responsible for resetting too */
619 current_trace
= saved_tracer
;
621 printk(KERN_CONT
"FAILED!\n");
624 /* Only reset on passing, to avoid touching corrupted buffers */
625 for_each_tracing_cpu(i
)
626 tracing_reset(tr
, i
);
628 printk(KERN_CONT
"PASSED\n");
632 type
->next
= trace_types
;
634 len
= strlen(type
->name
);
635 if (len
> max_tracer_type_len
)
636 max_tracer_type_len
= len
;
639 tracing_selftest_running
= false;
640 mutex_unlock(&trace_types_lock
);
646 void unregister_tracer(struct tracer
*type
)
651 mutex_lock(&trace_types_lock
);
652 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
656 pr_info("Trace %s not registered\n", type
->name
);
661 if (strlen(type
->name
) != max_tracer_type_len
)
664 max_tracer_type_len
= 0;
665 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
666 len
= strlen((*t
)->name
);
667 if (len
> max_tracer_type_len
)
668 max_tracer_type_len
= len
;
671 mutex_unlock(&trace_types_lock
);
674 void tracing_reset(struct trace_array
*tr
, int cpu
)
676 ftrace_disable_cpu();
677 ring_buffer_reset_cpu(tr
->buffer
, cpu
);
681 #define SAVED_CMDLINES 128
682 static unsigned map_pid_to_cmdline
[PID_MAX_DEFAULT
+1];
683 static unsigned map_cmdline_to_pid
[SAVED_CMDLINES
];
684 static char saved_cmdlines
[SAVED_CMDLINES
][TASK_COMM_LEN
];
685 static int cmdline_idx
;
686 static DEFINE_SPINLOCK(trace_cmdline_lock
);
688 /* temporary disable recording */
689 atomic_t trace_record_cmdline_disabled __read_mostly
;
691 static void trace_init_cmdlines(void)
693 memset(&map_pid_to_cmdline
, -1, sizeof(map_pid_to_cmdline
));
694 memset(&map_cmdline_to_pid
, -1, sizeof(map_cmdline_to_pid
));
698 static int trace_stop_count
;
699 static DEFINE_SPINLOCK(tracing_start_lock
);
702 * ftrace_off_permanent - disable all ftrace code permanently
704 * This should only be called when a serious anomally has
705 * been detected. This will turn off the function tracing,
706 * ring buffers, and other tracing utilites. It takes no
707 * locks and can be called from any context.
709 void ftrace_off_permanent(void)
711 tracing_disabled
= 1;
713 tracing_off_permanent();
717 * tracing_start - quick start of the tracer
719 * If tracing is enabled but was stopped by tracing_stop,
720 * this will start the tracer back up.
722 void tracing_start(void)
724 struct ring_buffer
*buffer
;
727 if (tracing_disabled
)
730 spin_lock_irqsave(&tracing_start_lock
, flags
);
731 if (--trace_stop_count
)
734 if (trace_stop_count
< 0) {
735 /* Someone screwed up their debugging */
737 trace_stop_count
= 0;
742 buffer
= global_trace
.buffer
;
744 ring_buffer_record_enable(buffer
);
746 buffer
= max_tr
.buffer
;
748 ring_buffer_record_enable(buffer
);
752 spin_unlock_irqrestore(&tracing_start_lock
, flags
);
756 * tracing_stop - quick stop of the tracer
758 * Light weight way to stop tracing. Use in conjunction with
761 void tracing_stop(void)
763 struct ring_buffer
*buffer
;
767 spin_lock_irqsave(&tracing_start_lock
, flags
);
768 if (trace_stop_count
++)
771 buffer
= global_trace
.buffer
;
773 ring_buffer_record_disable(buffer
);
775 buffer
= max_tr
.buffer
;
777 ring_buffer_record_disable(buffer
);
780 spin_unlock_irqrestore(&tracing_start_lock
, flags
);
783 void trace_stop_cmdline_recording(void);
785 static void trace_save_cmdline(struct task_struct
*tsk
)
790 if (!tsk
->pid
|| unlikely(tsk
->pid
> PID_MAX_DEFAULT
))
794 * It's not the end of the world if we don't get
795 * the lock, but we also don't want to spin
796 * nor do we want to disable interrupts,
797 * so if we miss here, then better luck next time.
799 if (!spin_trylock(&trace_cmdline_lock
))
802 idx
= map_pid_to_cmdline
[tsk
->pid
];
803 if (idx
>= SAVED_CMDLINES
) {
804 idx
= (cmdline_idx
+ 1) % SAVED_CMDLINES
;
806 map
= map_cmdline_to_pid
[idx
];
807 if (map
<= PID_MAX_DEFAULT
)
808 map_pid_to_cmdline
[map
] = (unsigned)-1;
810 map_pid_to_cmdline
[tsk
->pid
] = idx
;
815 memcpy(&saved_cmdlines
[idx
], tsk
->comm
, TASK_COMM_LEN
);
817 spin_unlock(&trace_cmdline_lock
);
820 char *trace_find_cmdline(int pid
)
822 char *cmdline
= "<...>";
828 if (pid
> PID_MAX_DEFAULT
)
831 map
= map_pid_to_cmdline
[pid
];
832 if (map
>= SAVED_CMDLINES
)
835 cmdline
= saved_cmdlines
[map
];
841 void tracing_record_cmdline(struct task_struct
*tsk
)
843 if (atomic_read(&trace_record_cmdline_disabled
))
846 trace_save_cmdline(tsk
);
850 tracing_generic_entry_update(struct trace_entry
*entry
, unsigned long flags
,
853 struct task_struct
*tsk
= current
;
855 entry
->preempt_count
= pc
& 0xff;
856 entry
->pid
= (tsk
) ? tsk
->pid
: 0;
857 entry
->tgid
= (tsk
) ? tsk
->tgid
: 0;
859 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
860 (irqs_disabled_flags(flags
) ? TRACE_FLAG_IRQS_OFF
: 0) |
862 TRACE_FLAG_IRQS_NOSUPPORT
|
864 ((pc
& HARDIRQ_MASK
) ? TRACE_FLAG_HARDIRQ
: 0) |
865 ((pc
& SOFTIRQ_MASK
) ? TRACE_FLAG_SOFTIRQ
: 0) |
866 (need_resched() ? TRACE_FLAG_NEED_RESCHED
: 0);
870 trace_function(struct trace_array
*tr
, struct trace_array_cpu
*data
,
871 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
,
874 struct ring_buffer_event
*event
;
875 struct ftrace_entry
*entry
;
876 unsigned long irq_flags
;
878 /* If we are reading the ring buffer, don't trace */
879 if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled
))))
882 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
886 entry
= ring_buffer_event_data(event
);
887 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
888 entry
->ent
.type
= TRACE_FN
;
890 entry
->parent_ip
= parent_ip
;
891 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
894 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
895 static void __trace_graph_entry(struct trace_array
*tr
,
896 struct trace_array_cpu
*data
,
897 struct ftrace_graph_ent
*trace
,
901 struct ring_buffer_event
*event
;
902 struct ftrace_graph_ent_entry
*entry
;
903 unsigned long irq_flags
;
905 if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled
))))
908 event
= ring_buffer_lock_reserve(global_trace
.buffer
, sizeof(*entry
),
912 entry
= ring_buffer_event_data(event
);
913 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
914 entry
->ent
.type
= TRACE_GRAPH_ENT
;
915 entry
->graph_ent
= *trace
;
916 ring_buffer_unlock_commit(global_trace
.buffer
, event
, irq_flags
);
919 static void __trace_graph_return(struct trace_array
*tr
,
920 struct trace_array_cpu
*data
,
921 struct ftrace_graph_ret
*trace
,
925 struct ring_buffer_event
*event
;
926 struct ftrace_graph_ret_entry
*entry
;
927 unsigned long irq_flags
;
929 if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled
))))
932 event
= ring_buffer_lock_reserve(global_trace
.buffer
, sizeof(*entry
),
936 entry
= ring_buffer_event_data(event
);
937 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
938 entry
->ent
.type
= TRACE_GRAPH_RET
;
940 ring_buffer_unlock_commit(global_trace
.buffer
, event
, irq_flags
);
945 ftrace(struct trace_array
*tr
, struct trace_array_cpu
*data
,
946 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
,
949 if (likely(!atomic_read(&data
->disabled
)))
950 trace_function(tr
, data
, ip
, parent_ip
, flags
, pc
);
953 static void ftrace_trace_stack(struct trace_array
*tr
,
954 struct trace_array_cpu
*data
,
958 #ifdef CONFIG_STACKTRACE
959 struct ring_buffer_event
*event
;
960 struct stack_entry
*entry
;
961 struct stack_trace trace
;
962 unsigned long irq_flags
;
964 if (!(trace_flags
& TRACE_ITER_STACKTRACE
))
967 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
971 entry
= ring_buffer_event_data(event
);
972 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
973 entry
->ent
.type
= TRACE_STACK
;
975 memset(&entry
->caller
, 0, sizeof(entry
->caller
));
977 trace
.nr_entries
= 0;
978 trace
.max_entries
= FTRACE_STACK_ENTRIES
;
980 trace
.entries
= entry
->caller
;
982 save_stack_trace(&trace
);
983 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
987 void __trace_stack(struct trace_array
*tr
,
988 struct trace_array_cpu
*data
,
992 ftrace_trace_stack(tr
, data
, flags
, skip
, preempt_count());
995 static void ftrace_trace_userstack(struct trace_array
*tr
,
996 struct trace_array_cpu
*data
,
997 unsigned long flags
, int pc
)
999 #ifdef CONFIG_STACKTRACE
1000 struct ring_buffer_event
*event
;
1001 struct userstack_entry
*entry
;
1002 struct stack_trace trace
;
1003 unsigned long irq_flags
;
1005 if (!(trace_flags
& TRACE_ITER_USERSTACKTRACE
))
1008 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
1012 entry
= ring_buffer_event_data(event
);
1013 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
1014 entry
->ent
.type
= TRACE_USER_STACK
;
1016 memset(&entry
->caller
, 0, sizeof(entry
->caller
));
1018 trace
.nr_entries
= 0;
1019 trace
.max_entries
= FTRACE_STACK_ENTRIES
;
1021 trace
.entries
= entry
->caller
;
1023 save_stack_trace_user(&trace
);
1024 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
1028 void __trace_userstack(struct trace_array
*tr
,
1029 struct trace_array_cpu
*data
,
1030 unsigned long flags
)
1032 ftrace_trace_userstack(tr
, data
, flags
, preempt_count());
1036 ftrace_trace_special(void *__tr
, void *__data
,
1037 unsigned long arg1
, unsigned long arg2
, unsigned long arg3
,
1040 struct ring_buffer_event
*event
;
1041 struct trace_array_cpu
*data
= __data
;
1042 struct trace_array
*tr
= __tr
;
1043 struct special_entry
*entry
;
1044 unsigned long irq_flags
;
1046 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
1050 entry
= ring_buffer_event_data(event
);
1051 tracing_generic_entry_update(&entry
->ent
, 0, pc
);
1052 entry
->ent
.type
= TRACE_SPECIAL
;
1056 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
1057 ftrace_trace_stack(tr
, data
, irq_flags
, 4, pc
);
1058 ftrace_trace_userstack(tr
, data
, irq_flags
, pc
);
1064 __trace_special(void *__tr
, void *__data
,
1065 unsigned long arg1
, unsigned long arg2
, unsigned long arg3
)
1067 ftrace_trace_special(__tr
, __data
, arg1
, arg2
, arg3
, preempt_count());
1071 tracing_sched_switch_trace(struct trace_array
*tr
,
1072 struct trace_array_cpu
*data
,
1073 struct task_struct
*prev
,
1074 struct task_struct
*next
,
1075 unsigned long flags
, int pc
)
1077 struct ring_buffer_event
*event
;
1078 struct ctx_switch_entry
*entry
;
1079 unsigned long irq_flags
;
1081 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
1085 entry
= ring_buffer_event_data(event
);
1086 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
1087 entry
->ent
.type
= TRACE_CTX
;
1088 entry
->prev_pid
= prev
->pid
;
1089 entry
->prev_prio
= prev
->prio
;
1090 entry
->prev_state
= prev
->state
;
1091 entry
->next_pid
= next
->pid
;
1092 entry
->next_prio
= next
->prio
;
1093 entry
->next_state
= next
->state
;
1094 entry
->next_cpu
= task_cpu(next
);
1095 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
1096 ftrace_trace_stack(tr
, data
, flags
, 5, pc
);
1097 ftrace_trace_userstack(tr
, data
, flags
, pc
);
1101 tracing_sched_wakeup_trace(struct trace_array
*tr
,
1102 struct trace_array_cpu
*data
,
1103 struct task_struct
*wakee
,
1104 struct task_struct
*curr
,
1105 unsigned long flags
, int pc
)
1107 struct ring_buffer_event
*event
;
1108 struct ctx_switch_entry
*entry
;
1109 unsigned long irq_flags
;
1111 event
= ring_buffer_lock_reserve(tr
->buffer
, sizeof(*entry
),
1115 entry
= ring_buffer_event_data(event
);
1116 tracing_generic_entry_update(&entry
->ent
, flags
, pc
);
1117 entry
->ent
.type
= TRACE_WAKE
;
1118 entry
->prev_pid
= curr
->pid
;
1119 entry
->prev_prio
= curr
->prio
;
1120 entry
->prev_state
= curr
->state
;
1121 entry
->next_pid
= wakee
->pid
;
1122 entry
->next_prio
= wakee
->prio
;
1123 entry
->next_state
= wakee
->state
;
1124 entry
->next_cpu
= task_cpu(wakee
);
1125 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
1126 ftrace_trace_stack(tr
, data
, flags
, 6, pc
);
1127 ftrace_trace_userstack(tr
, data
, flags
, pc
);
1133 ftrace_special(unsigned long arg1
, unsigned long arg2
, unsigned long arg3
)
1135 struct trace_array
*tr
= &global_trace
;
1136 struct trace_array_cpu
*data
;
1137 unsigned long flags
;
1141 if (tracing_disabled
)
1144 pc
= preempt_count();
1145 local_irq_save(flags
);
1146 cpu
= raw_smp_processor_id();
1147 data
= tr
->data
[cpu
];
1149 if (likely(atomic_inc_return(&data
->disabled
) == 1))
1150 ftrace_trace_special(tr
, data
, arg1
, arg2
, arg3
, pc
);
1152 atomic_dec(&data
->disabled
);
1153 local_irq_restore(flags
);
1156 #ifdef CONFIG_FUNCTION_TRACER
1158 function_trace_call_preempt_only(unsigned long ip
, unsigned long parent_ip
)
1160 struct trace_array
*tr
= &global_trace
;
1161 struct trace_array_cpu
*data
;
1162 unsigned long flags
;
1167 if (unlikely(!ftrace_function_enabled
))
1170 pc
= preempt_count();
1171 resched
= ftrace_preempt_disable();
1172 local_save_flags(flags
);
1173 cpu
= raw_smp_processor_id();
1174 data
= tr
->data
[cpu
];
1175 disabled
= atomic_inc_return(&data
->disabled
);
1177 if (likely(disabled
== 1))
1178 trace_function(tr
, data
, ip
, parent_ip
, flags
, pc
);
1180 atomic_dec(&data
->disabled
);
1181 ftrace_preempt_enable(resched
);
1185 function_trace_call(unsigned long ip
, unsigned long parent_ip
)
1187 struct trace_array
*tr
= &global_trace
;
1188 struct trace_array_cpu
*data
;
1189 unsigned long flags
;
1194 if (unlikely(!ftrace_function_enabled
))
1198 * Need to use raw, since this must be called before the
1199 * recursive protection is performed.
1201 local_irq_save(flags
);
1202 cpu
= raw_smp_processor_id();
1203 data
= tr
->data
[cpu
];
1204 disabled
= atomic_inc_return(&data
->disabled
);
1206 if (likely(disabled
== 1)) {
1207 pc
= preempt_count();
1208 trace_function(tr
, data
, ip
, parent_ip
, flags
, pc
);
1211 atomic_dec(&data
->disabled
);
1212 local_irq_restore(flags
);
1215 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1216 int trace_graph_entry(struct ftrace_graph_ent
*trace
)
1218 struct trace_array
*tr
= &global_trace
;
1219 struct trace_array_cpu
*data
;
1220 unsigned long flags
;
1225 if (!ftrace_trace_task(current
))
1228 if (!ftrace_graph_addr(trace
->func
))
1231 local_irq_save(flags
);
1232 cpu
= raw_smp_processor_id();
1233 data
= tr
->data
[cpu
];
1234 disabled
= atomic_inc_return(&data
->disabled
);
1235 if (likely(disabled
== 1)) {
1236 pc
= preempt_count();
1237 __trace_graph_entry(tr
, data
, trace
, flags
, pc
);
1239 /* Only do the atomic if it is not already set */
1240 if (!test_tsk_trace_graph(current
))
1241 set_tsk_trace_graph(current
);
1242 atomic_dec(&data
->disabled
);
1243 local_irq_restore(flags
);
1248 void trace_graph_return(struct ftrace_graph_ret
*trace
)
1250 struct trace_array
*tr
= &global_trace
;
1251 struct trace_array_cpu
*data
;
1252 unsigned long flags
;
1257 local_irq_save(flags
);
1258 cpu
= raw_smp_processor_id();
1259 data
= tr
->data
[cpu
];
1260 disabled
= atomic_inc_return(&data
->disabled
);
1261 if (likely(disabled
== 1)) {
1262 pc
= preempt_count();
1263 __trace_graph_return(tr
, data
, trace
, flags
, pc
);
1266 clear_tsk_trace_graph(current
);
1267 atomic_dec(&data
->disabled
);
1268 local_irq_restore(flags
);
1270 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1272 static struct ftrace_ops trace_ops __read_mostly
=
1274 .func
= function_trace_call
,
1277 void tracing_start_function_trace(void)
1279 ftrace_function_enabled
= 0;
1281 if (trace_flags
& TRACE_ITER_PREEMPTONLY
)
1282 trace_ops
.func
= function_trace_call_preempt_only
;
1284 trace_ops
.func
= function_trace_call
;
1286 register_ftrace_function(&trace_ops
);
1287 ftrace_function_enabled
= 1;
1290 void tracing_stop_function_trace(void)
1292 ftrace_function_enabled
= 0;
1293 unregister_ftrace_function(&trace_ops
);
1297 enum trace_file_type
{
1298 TRACE_FILE_LAT_FMT
= 1,
1299 TRACE_FILE_ANNOTATE
= 2,
1302 static void trace_iterator_increment(struct trace_iterator
*iter
, int cpu
)
1304 /* Don't allow ftrace to trace into the ring buffers */
1305 ftrace_disable_cpu();
1308 if (iter
->buffer_iter
[iter
->cpu
])
1309 ring_buffer_read(iter
->buffer_iter
[iter
->cpu
], NULL
);
1311 ftrace_enable_cpu();
1314 static struct trace_entry
*
1315 peek_next_entry(struct trace_iterator
*iter
, int cpu
, u64
*ts
)
1317 struct ring_buffer_event
*event
;
1318 struct ring_buffer_iter
*buf_iter
= iter
->buffer_iter
[cpu
];
1320 /* Don't allow ftrace to trace into the ring buffers */
1321 ftrace_disable_cpu();
1324 event
= ring_buffer_iter_peek(buf_iter
, ts
);
1326 event
= ring_buffer_peek(iter
->tr
->buffer
, cpu
, ts
);
1328 ftrace_enable_cpu();
1330 return event
? ring_buffer_event_data(event
) : NULL
;
1333 static struct trace_entry
*
1334 __find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
, u64
*ent_ts
)
1336 struct ring_buffer
*buffer
= iter
->tr
->buffer
;
1337 struct trace_entry
*ent
, *next
= NULL
;
1338 u64 next_ts
= 0, ts
;
1342 for_each_tracing_cpu(cpu
) {
1344 if (ring_buffer_empty_cpu(buffer
, cpu
))
1347 ent
= peek_next_entry(iter
, cpu
, &ts
);
1350 * Pick the entry with the smallest timestamp:
1352 if (ent
&& (!next
|| ts
< next_ts
)) {
1360 *ent_cpu
= next_cpu
;
1368 /* Find the next real entry, without updating the iterator itself */
1369 static struct trace_entry
*
1370 find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
, u64
*ent_ts
)
1372 return __find_next_entry(iter
, ent_cpu
, ent_ts
);
1375 /* Find the next real entry, and increment the iterator to the next entry */
1376 static void *find_next_entry_inc(struct trace_iterator
*iter
)
1378 iter
->ent
= __find_next_entry(iter
, &iter
->cpu
, &iter
->ts
);
1381 trace_iterator_increment(iter
, iter
->cpu
);
1383 return iter
->ent
? iter
: NULL
;
1386 static void trace_consume(struct trace_iterator
*iter
)
1388 /* Don't allow ftrace to trace into the ring buffers */
1389 ftrace_disable_cpu();
1390 ring_buffer_consume(iter
->tr
->buffer
, iter
->cpu
, &iter
->ts
);
1391 ftrace_enable_cpu();
1394 static void *s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1396 struct trace_iterator
*iter
= m
->private;
1402 /* can't go backwards */
1407 ent
= find_next_entry_inc(iter
);
1411 while (ent
&& iter
->idx
< i
)
1412 ent
= find_next_entry_inc(iter
);
1419 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
1421 struct trace_iterator
*iter
= m
->private;
1426 mutex_lock(&trace_types_lock
);
1428 if (!current_trace
|| current_trace
!= iter
->trace
) {
1429 mutex_unlock(&trace_types_lock
);
1433 atomic_inc(&trace_record_cmdline_disabled
);
1435 if (*pos
!= iter
->pos
) {
1440 ftrace_disable_cpu();
1442 for_each_tracing_cpu(cpu
) {
1443 ring_buffer_iter_reset(iter
->buffer_iter
[cpu
]);
1446 ftrace_enable_cpu();
1448 for (p
= iter
; p
&& l
< *pos
; p
= s_next(m
, p
, &l
))
1453 p
= s_next(m
, p
, &l
);
1459 static void s_stop(struct seq_file
*m
, void *p
)
1461 atomic_dec(&trace_record_cmdline_disabled
);
1462 mutex_unlock(&trace_types_lock
);
1465 #ifdef CONFIG_KRETPROBES
1466 static inline const char *kretprobed(const char *name
)
1468 static const char tramp_name
[] = "kretprobe_trampoline";
1469 int size
= sizeof(tramp_name
);
1471 if (strncmp(tramp_name
, name
, size
) == 0)
1472 return "[unknown/kretprobe'd]";
1476 static inline const char *kretprobed(const char *name
)
1480 #endif /* CONFIG_KRETPROBES */
1483 seq_print_sym_short(struct trace_seq
*s
, const char *fmt
, unsigned long address
)
1485 #ifdef CONFIG_KALLSYMS
1486 char str
[KSYM_SYMBOL_LEN
];
1489 kallsyms_lookup(address
, NULL
, NULL
, NULL
, str
);
1491 name
= kretprobed(str
);
1493 return trace_seq_printf(s
, fmt
, name
);
1499 seq_print_sym_offset(struct trace_seq
*s
, const char *fmt
,
1500 unsigned long address
)
1502 #ifdef CONFIG_KALLSYMS
1503 char str
[KSYM_SYMBOL_LEN
];
1506 sprint_symbol(str
, address
);
1507 name
= kretprobed(str
);
1509 return trace_seq_printf(s
, fmt
, name
);
1514 #ifndef CONFIG_64BIT
1515 # define IP_FMT "%08lx"
1517 # define IP_FMT "%016lx"
1521 seq_print_ip_sym(struct trace_seq
*s
, unsigned long ip
, unsigned long sym_flags
)
1526 return trace_seq_printf(s
, "0");
1528 if (sym_flags
& TRACE_ITER_SYM_OFFSET
)
1529 ret
= seq_print_sym_offset(s
, "%s", ip
);
1531 ret
= seq_print_sym_short(s
, "%s", ip
);
1536 if (sym_flags
& TRACE_ITER_SYM_ADDR
)
1537 ret
= trace_seq_printf(s
, " <" IP_FMT
">", ip
);
1541 static inline int seq_print_user_ip(struct trace_seq
*s
, struct mm_struct
*mm
,
1542 unsigned long ip
, unsigned long sym_flags
)
1544 struct file
*file
= NULL
;
1545 unsigned long vmstart
= 0;
1549 const struct vm_area_struct
*vma
;
1551 down_read(&mm
->mmap_sem
);
1552 vma
= find_vma(mm
, ip
);
1554 file
= vma
->vm_file
;
1555 vmstart
= vma
->vm_start
;
1558 ret
= trace_seq_path(s
, &file
->f_path
);
1560 ret
= trace_seq_printf(s
, "[+0x%lx]", ip
- vmstart
);
1562 up_read(&mm
->mmap_sem
);
1564 if (ret
&& ((sym_flags
& TRACE_ITER_SYM_ADDR
) || !file
))
1565 ret
= trace_seq_printf(s
, " <" IP_FMT
">", ip
);
1570 seq_print_userip_objs(const struct userstack_entry
*entry
, struct trace_seq
*s
,
1571 unsigned long sym_flags
)
1573 struct mm_struct
*mm
= NULL
;
1577 if (trace_flags
& TRACE_ITER_SYM_USEROBJ
) {
1578 struct task_struct
*task
;
1580 * we do the lookup on the thread group leader,
1581 * since individual threads might have already quit!
1584 task
= find_task_by_vpid(entry
->ent
.tgid
);
1586 mm
= get_task_mm(task
);
1590 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
1591 unsigned long ip
= entry
->caller
[i
];
1593 if (ip
== ULONG_MAX
|| !ret
)
1596 ret
= trace_seq_puts(s
, " <- ");
1599 ret
= trace_seq_puts(s
, "??");
1605 ret
= seq_print_user_ip(s
, mm
, ip
, sym_flags
);
1613 static void print_lat_help_header(struct seq_file
*m
)
1615 seq_puts(m
, "# _------=> CPU# \n");
1616 seq_puts(m
, "# / _-----=> irqs-off \n");
1617 seq_puts(m
, "# | / _----=> need-resched \n");
1618 seq_puts(m
, "# || / _---=> hardirq/softirq \n");
1619 seq_puts(m
, "# ||| / _--=> preempt-depth \n");
1620 seq_puts(m
, "# |||| / \n");
1621 seq_puts(m
, "# ||||| delay \n");
1622 seq_puts(m
, "# cmd pid ||||| time | caller \n");
1623 seq_puts(m
, "# \\ / ||||| \\ | / \n");
1626 static void print_func_help_header(struct seq_file
*m
)
1628 seq_puts(m
, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
1629 seq_puts(m
, "# | | | | |\n");
1634 print_trace_header(struct seq_file
*m
, struct trace_iterator
*iter
)
1636 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1637 struct trace_array
*tr
= iter
->tr
;
1638 struct trace_array_cpu
*data
= tr
->data
[tr
->cpu
];
1639 struct tracer
*type
= current_trace
;
1640 unsigned long total
;
1641 unsigned long entries
;
1642 const char *name
= "preemption";
1647 entries
= ring_buffer_entries(iter
->tr
->buffer
);
1649 ring_buffer_overruns(iter
->tr
->buffer
);
1651 seq_printf(m
, "%s latency trace v1.1.5 on %s\n",
1653 seq_puts(m
, "-----------------------------------"
1654 "---------------------------------\n");
1655 seq_printf(m
, " latency: %lu us, #%lu/%lu, CPU#%d |"
1656 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
1657 nsecs_to_usecs(data
->saved_latency
),
1661 #if defined(CONFIG_PREEMPT_NONE)
1663 #elif defined(CONFIG_PREEMPT_VOLUNTARY)
1665 #elif defined(CONFIG_PREEMPT)
1670 /* These are reserved for later use */
1673 seq_printf(m
, " #P:%d)\n", num_online_cpus());
1677 seq_puts(m
, " -----------------\n");
1678 seq_printf(m
, " | task: %.16s-%d "
1679 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
1680 data
->comm
, data
->pid
, data
->uid
, data
->nice
,
1681 data
->policy
, data
->rt_priority
);
1682 seq_puts(m
, " -----------------\n");
1684 if (data
->critical_start
) {
1685 seq_puts(m
, " => started at: ");
1686 seq_print_ip_sym(&iter
->seq
, data
->critical_start
, sym_flags
);
1687 trace_print_seq(m
, &iter
->seq
);
1688 seq_puts(m
, "\n => ended at: ");
1689 seq_print_ip_sym(&iter
->seq
, data
->critical_end
, sym_flags
);
1690 trace_print_seq(m
, &iter
->seq
);
1698 lat_print_generic(struct trace_seq
*s
, struct trace_entry
*entry
, int cpu
)
1700 int hardirq
, softirq
;
1703 comm
= trace_find_cmdline(entry
->pid
);
1705 trace_seq_printf(s
, "%8.8s-%-5d ", comm
, entry
->pid
);
1706 trace_seq_printf(s
, "%3d", cpu
);
1707 trace_seq_printf(s
, "%c%c",
1708 (entry
->flags
& TRACE_FLAG_IRQS_OFF
) ? 'd' :
1709 (entry
->flags
& TRACE_FLAG_IRQS_NOSUPPORT
) ? 'X' : '.',
1710 ((entry
->flags
& TRACE_FLAG_NEED_RESCHED
) ? 'N' : '.'));
1712 hardirq
= entry
->flags
& TRACE_FLAG_HARDIRQ
;
1713 softirq
= entry
->flags
& TRACE_FLAG_SOFTIRQ
;
1714 if (hardirq
&& softirq
) {
1715 trace_seq_putc(s
, 'H');
1718 trace_seq_putc(s
, 'h');
1721 trace_seq_putc(s
, 's');
1723 trace_seq_putc(s
, '.');
1727 if (entry
->preempt_count
)
1728 trace_seq_printf(s
, "%x", entry
->preempt_count
);
1730 trace_seq_puts(s
, ".");
1733 unsigned long preempt_mark_thresh
= 100;
1736 lat_print_timestamp(struct trace_seq
*s
, u64 abs_usecs
,
1737 unsigned long rel_usecs
)
1739 trace_seq_printf(s
, " %4lldus", abs_usecs
);
1740 if (rel_usecs
> preempt_mark_thresh
)
1741 trace_seq_puts(s
, "!: ");
1742 else if (rel_usecs
> 1)
1743 trace_seq_puts(s
, "+: ");
1745 trace_seq_puts(s
, " : ");
1748 static const char state_to_char
[] = TASK_STATE_TO_CHAR_STR
;
1751 * The message is supposed to contain an ending newline.
1752 * If the printing stops prematurely, try to add a newline of our own.
1754 void trace_seq_print_cont(struct trace_seq
*s
, struct trace_iterator
*iter
)
1756 struct trace_entry
*ent
;
1757 struct trace_field_cont
*cont
;
1760 ent
= peek_next_entry(iter
, iter
->cpu
, NULL
);
1761 if (!ent
|| ent
->type
!= TRACE_CONT
) {
1762 trace_seq_putc(s
, '\n');
1767 cont
= (struct trace_field_cont
*)ent
;
1769 ok
= (trace_seq_printf(s
, "%s", cont
->buf
) > 0);
1771 ftrace_disable_cpu();
1773 if (iter
->buffer_iter
[iter
->cpu
])
1774 ring_buffer_read(iter
->buffer_iter
[iter
->cpu
], NULL
);
1776 ring_buffer_consume(iter
->tr
->buffer
, iter
->cpu
, NULL
);
1778 ftrace_enable_cpu();
1780 ent
= peek_next_entry(iter
, iter
->cpu
, NULL
);
1781 } while (ent
&& ent
->type
== TRACE_CONT
);
1784 trace_seq_putc(s
, '\n');
1787 static void test_cpu_buff_start(struct trace_iterator
*iter
)
1789 struct trace_seq
*s
= &iter
->seq
;
1791 if (!(trace_flags
& TRACE_ITER_ANNOTATE
))
1794 if (!(iter
->iter_flags
& TRACE_FILE_ANNOTATE
))
1797 if (cpu_isset(iter
->cpu
, iter
->started
))
1800 cpu_set(iter
->cpu
, iter
->started
);
1801 trace_seq_printf(s
, "##### CPU %u buffer started ####\n", iter
->cpu
);
1804 static enum print_line_t
1805 print_lat_fmt(struct trace_iterator
*iter
, unsigned int trace_idx
, int cpu
)
1807 struct trace_seq
*s
= &iter
->seq
;
1808 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1809 struct trace_entry
*next_entry
;
1810 unsigned long verbose
= (trace_flags
& TRACE_ITER_VERBOSE
);
1811 struct trace_entry
*entry
= iter
->ent
;
1812 unsigned long abs_usecs
;
1813 unsigned long rel_usecs
;
1820 if (entry
->type
== TRACE_CONT
)
1821 return TRACE_TYPE_HANDLED
;
1823 test_cpu_buff_start(iter
);
1825 next_entry
= find_next_entry(iter
, NULL
, &next_ts
);
1828 rel_usecs
= ns2usecs(next_ts
- iter
->ts
);
1829 abs_usecs
= ns2usecs(iter
->ts
- iter
->tr
->time_start
);
1832 comm
= trace_find_cmdline(entry
->pid
);
1833 trace_seq_printf(s
, "%16s %5d %3d %d %08x %08x [%08lx]"
1834 " %ld.%03ldms (+%ld.%03ldms): ",
1836 entry
->pid
, cpu
, entry
->flags
,
1837 entry
->preempt_count
, trace_idx
,
1840 abs_usecs
% 1000, rel_usecs
/1000,
1843 lat_print_generic(s
, entry
, cpu
);
1844 lat_print_timestamp(s
, abs_usecs
, rel_usecs
);
1846 switch (entry
->type
) {
1848 struct ftrace_entry
*field
;
1850 trace_assign_type(field
, entry
);
1852 seq_print_ip_sym(s
, field
->ip
, sym_flags
);
1853 trace_seq_puts(s
, " (");
1854 seq_print_ip_sym(s
, field
->parent_ip
, sym_flags
);
1855 trace_seq_puts(s
, ")\n");
1860 struct ctx_switch_entry
*field
;
1862 trace_assign_type(field
, entry
);
1864 T
= field
->next_state
< sizeof(state_to_char
) ?
1865 state_to_char
[field
->next_state
] : 'X';
1867 state
= field
->prev_state
?
1868 __ffs(field
->prev_state
) + 1 : 0;
1869 S
= state
< sizeof(state_to_char
) - 1 ? state_to_char
[state
] : 'X';
1870 comm
= trace_find_cmdline(field
->next_pid
);
1871 trace_seq_printf(s
, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1874 S
, entry
->type
== TRACE_CTX
? "==>" : " +",
1881 case TRACE_SPECIAL
: {
1882 struct special_entry
*field
;
1884 trace_assign_type(field
, entry
);
1886 trace_seq_printf(s
, "# %ld %ld %ld\n",
1893 struct stack_entry
*field
;
1895 trace_assign_type(field
, entry
);
1897 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
1899 trace_seq_puts(s
, " <= ");
1900 seq_print_ip_sym(s
, field
->caller
[i
], sym_flags
);
1902 trace_seq_puts(s
, "\n");
1906 struct print_entry
*field
;
1908 trace_assign_type(field
, entry
);
1910 seq_print_ip_sym(s
, field
->ip
, sym_flags
);
1911 trace_seq_printf(s
, ": %s", field
->buf
);
1912 if (entry
->flags
& TRACE_FLAG_CONT
)
1913 trace_seq_print_cont(s
, iter
);
1916 case TRACE_BRANCH
: {
1917 struct trace_branch
*field
;
1919 trace_assign_type(field
, entry
);
1921 trace_seq_printf(s
, "[%s] %s:%s:%d\n",
1922 field
->correct
? " ok " : " MISS ",
1928 case TRACE_USER_STACK
: {
1929 struct userstack_entry
*field
;
1931 trace_assign_type(field
, entry
);
1933 seq_print_userip_objs(field
, s
, sym_flags
);
1934 trace_seq_putc(s
, '\n');
1938 trace_seq_printf(s
, "Unknown type %d\n", entry
->type
);
1940 return TRACE_TYPE_HANDLED
;
1943 static enum print_line_t
print_trace_fmt(struct trace_iterator
*iter
)
1945 struct trace_seq
*s
= &iter
->seq
;
1946 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1947 struct trace_entry
*entry
;
1948 unsigned long usec_rem
;
1949 unsigned long long t
;
1958 if (entry
->type
== TRACE_CONT
)
1959 return TRACE_TYPE_HANDLED
;
1961 test_cpu_buff_start(iter
);
1963 comm
= trace_find_cmdline(iter
->ent
->pid
);
1965 t
= ns2usecs(iter
->ts
);
1966 usec_rem
= do_div(t
, 1000000ULL);
1967 secs
= (unsigned long)t
;
1969 ret
= trace_seq_printf(s
, "%16s-%-5d ", comm
, entry
->pid
);
1971 return TRACE_TYPE_PARTIAL_LINE
;
1972 ret
= trace_seq_printf(s
, "[%03d] ", iter
->cpu
);
1974 return TRACE_TYPE_PARTIAL_LINE
;
1975 ret
= trace_seq_printf(s
, "%5lu.%06lu: ", secs
, usec_rem
);
1977 return TRACE_TYPE_PARTIAL_LINE
;
1979 switch (entry
->type
) {
1981 struct ftrace_entry
*field
;
1983 trace_assign_type(field
, entry
);
1985 ret
= seq_print_ip_sym(s
, field
->ip
, sym_flags
);
1987 return TRACE_TYPE_PARTIAL_LINE
;
1988 if ((sym_flags
& TRACE_ITER_PRINT_PARENT
) &&
1990 ret
= trace_seq_printf(s
, " <-");
1992 return TRACE_TYPE_PARTIAL_LINE
;
1993 ret
= seq_print_ip_sym(s
,
1997 return TRACE_TYPE_PARTIAL_LINE
;
1999 ret
= trace_seq_printf(s
, "\n");
2001 return TRACE_TYPE_PARTIAL_LINE
;
2006 struct ctx_switch_entry
*field
;
2008 trace_assign_type(field
, entry
);
2010 S
= field
->prev_state
< sizeof(state_to_char
) ?
2011 state_to_char
[field
->prev_state
] : 'X';
2012 T
= field
->next_state
< sizeof(state_to_char
) ?
2013 state_to_char
[field
->next_state
] : 'X';
2014 ret
= trace_seq_printf(s
, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
2018 entry
->type
== TRACE_CTX
? "==>" : " +",
2024 return TRACE_TYPE_PARTIAL_LINE
;
2027 case TRACE_SPECIAL
: {
2028 struct special_entry
*field
;
2030 trace_assign_type(field
, entry
);
2032 ret
= trace_seq_printf(s
, "# %ld %ld %ld\n",
2037 return TRACE_TYPE_PARTIAL_LINE
;
2041 struct stack_entry
*field
;
2043 trace_assign_type(field
, entry
);
2045 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
2047 ret
= trace_seq_puts(s
, " <= ");
2049 return TRACE_TYPE_PARTIAL_LINE
;
2051 ret
= seq_print_ip_sym(s
, field
->caller
[i
],
2054 return TRACE_TYPE_PARTIAL_LINE
;
2056 ret
= trace_seq_puts(s
, "\n");
2058 return TRACE_TYPE_PARTIAL_LINE
;
2062 struct print_entry
*field
;
2064 trace_assign_type(field
, entry
);
2066 seq_print_ip_sym(s
, field
->ip
, sym_flags
);
2067 trace_seq_printf(s
, ": %s", field
->buf
);
2068 if (entry
->flags
& TRACE_FLAG_CONT
)
2069 trace_seq_print_cont(s
, iter
);
2072 case TRACE_GRAPH_RET
: {
2073 return print_graph_function(iter
);
2075 case TRACE_GRAPH_ENT
: {
2076 return print_graph_function(iter
);
2078 case TRACE_BRANCH
: {
2079 struct trace_branch
*field
;
2081 trace_assign_type(field
, entry
);
2083 trace_seq_printf(s
, "[%s] %s:%s:%d\n",
2084 field
->correct
? " ok " : " MISS ",
2090 case TRACE_USER_STACK
: {
2091 struct userstack_entry
*field
;
2093 trace_assign_type(field
, entry
);
2095 ret
= seq_print_userip_objs(field
, s
, sym_flags
);
2097 return TRACE_TYPE_PARTIAL_LINE
;
2098 ret
= trace_seq_putc(s
, '\n');
2100 return TRACE_TYPE_PARTIAL_LINE
;
2104 return TRACE_TYPE_HANDLED
;
2107 static enum print_line_t
print_raw_fmt(struct trace_iterator
*iter
)
2109 struct trace_seq
*s
= &iter
->seq
;
2110 struct trace_entry
*entry
;
2116 if (entry
->type
== TRACE_CONT
)
2117 return TRACE_TYPE_HANDLED
;
2119 ret
= trace_seq_printf(s
, "%d %d %llu ",
2120 entry
->pid
, iter
->cpu
, iter
->ts
);
2122 return TRACE_TYPE_PARTIAL_LINE
;
2124 switch (entry
->type
) {
2126 struct ftrace_entry
*field
;
2128 trace_assign_type(field
, entry
);
2130 ret
= trace_seq_printf(s
, "%x %x\n",
2134 return TRACE_TYPE_PARTIAL_LINE
;
2139 struct ctx_switch_entry
*field
;
2141 trace_assign_type(field
, entry
);
2143 S
= field
->prev_state
< sizeof(state_to_char
) ?
2144 state_to_char
[field
->prev_state
] : 'X';
2145 T
= field
->next_state
< sizeof(state_to_char
) ?
2146 state_to_char
[field
->next_state
] : 'X';
2147 if (entry
->type
== TRACE_WAKE
)
2149 ret
= trace_seq_printf(s
, "%d %d %c %d %d %d %c\n",
2158 return TRACE_TYPE_PARTIAL_LINE
;
2162 case TRACE_USER_STACK
:
2164 struct special_entry
*field
;
2166 trace_assign_type(field
, entry
);
2168 ret
= trace_seq_printf(s
, "# %ld %ld %ld\n",
2173 return TRACE_TYPE_PARTIAL_LINE
;
2177 struct print_entry
*field
;
2179 trace_assign_type(field
, entry
);
2181 trace_seq_printf(s
, "# %lx %s", field
->ip
, field
->buf
);
2182 if (entry
->flags
& TRACE_FLAG_CONT
)
2183 trace_seq_print_cont(s
, iter
);
2187 return TRACE_TYPE_HANDLED
;
2190 #define SEQ_PUT_FIELD_RET(s, x) \
2192 if (!trace_seq_putmem(s, &(x), sizeof(x))) \
2196 #define SEQ_PUT_HEX_FIELD_RET(s, x) \
2198 BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \
2199 if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
2203 static enum print_line_t
print_hex_fmt(struct trace_iterator
*iter
)
2205 struct trace_seq
*s
= &iter
->seq
;
2206 unsigned char newline
= '\n';
2207 struct trace_entry
*entry
;
2212 if (entry
->type
== TRACE_CONT
)
2213 return TRACE_TYPE_HANDLED
;
2215 SEQ_PUT_HEX_FIELD_RET(s
, entry
->pid
);
2216 SEQ_PUT_HEX_FIELD_RET(s
, iter
->cpu
);
2217 SEQ_PUT_HEX_FIELD_RET(s
, iter
->ts
);
2219 switch (entry
->type
) {
2221 struct ftrace_entry
*field
;
2223 trace_assign_type(field
, entry
);
2225 SEQ_PUT_HEX_FIELD_RET(s
, field
->ip
);
2226 SEQ_PUT_HEX_FIELD_RET(s
, field
->parent_ip
);
2231 struct ctx_switch_entry
*field
;
2233 trace_assign_type(field
, entry
);
2235 S
= field
->prev_state
< sizeof(state_to_char
) ?
2236 state_to_char
[field
->prev_state
] : 'X';
2237 T
= field
->next_state
< sizeof(state_to_char
) ?
2238 state_to_char
[field
->next_state
] : 'X';
2239 if (entry
->type
== TRACE_WAKE
)
2241 SEQ_PUT_HEX_FIELD_RET(s
, field
->prev_pid
);
2242 SEQ_PUT_HEX_FIELD_RET(s
, field
->prev_prio
);
2243 SEQ_PUT_HEX_FIELD_RET(s
, S
);
2244 SEQ_PUT_HEX_FIELD_RET(s
, field
->next_cpu
);
2245 SEQ_PUT_HEX_FIELD_RET(s
, field
->next_pid
);
2246 SEQ_PUT_HEX_FIELD_RET(s
, field
->next_prio
);
2247 SEQ_PUT_HEX_FIELD_RET(s
, T
);
2251 case TRACE_USER_STACK
:
2253 struct special_entry
*field
;
2255 trace_assign_type(field
, entry
);
2257 SEQ_PUT_HEX_FIELD_RET(s
, field
->arg1
);
2258 SEQ_PUT_HEX_FIELD_RET(s
, field
->arg2
);
2259 SEQ_PUT_HEX_FIELD_RET(s
, field
->arg3
);
2263 SEQ_PUT_FIELD_RET(s
, newline
);
2265 return TRACE_TYPE_HANDLED
;
2268 static enum print_line_t
print_bin_fmt(struct trace_iterator
*iter
)
2270 struct trace_seq
*s
= &iter
->seq
;
2271 struct trace_entry
*entry
;
2275 if (entry
->type
== TRACE_CONT
)
2276 return TRACE_TYPE_HANDLED
;
2278 SEQ_PUT_FIELD_RET(s
, entry
->pid
);
2279 SEQ_PUT_FIELD_RET(s
, entry
->cpu
);
2280 SEQ_PUT_FIELD_RET(s
, iter
->ts
);
2282 switch (entry
->type
) {
2284 struct ftrace_entry
*field
;
2286 trace_assign_type(field
, entry
);
2288 SEQ_PUT_FIELD_RET(s
, field
->ip
);
2289 SEQ_PUT_FIELD_RET(s
, field
->parent_ip
);
2293 struct ctx_switch_entry
*field
;
2295 trace_assign_type(field
, entry
);
2297 SEQ_PUT_FIELD_RET(s
, field
->prev_pid
);
2298 SEQ_PUT_FIELD_RET(s
, field
->prev_prio
);
2299 SEQ_PUT_FIELD_RET(s
, field
->prev_state
);
2300 SEQ_PUT_FIELD_RET(s
, field
->next_pid
);
2301 SEQ_PUT_FIELD_RET(s
, field
->next_prio
);
2302 SEQ_PUT_FIELD_RET(s
, field
->next_state
);
2306 case TRACE_USER_STACK
:
2308 struct special_entry
*field
;
2310 trace_assign_type(field
, entry
);
2312 SEQ_PUT_FIELD_RET(s
, field
->arg1
);
2313 SEQ_PUT_FIELD_RET(s
, field
->arg2
);
2314 SEQ_PUT_FIELD_RET(s
, field
->arg3
);
2321 static int trace_empty(struct trace_iterator
*iter
)
2325 for_each_tracing_cpu(cpu
) {
2326 if (iter
->buffer_iter
[cpu
]) {
2327 if (!ring_buffer_iter_empty(iter
->buffer_iter
[cpu
]))
2330 if (!ring_buffer_empty_cpu(iter
->tr
->buffer
, cpu
))
2338 static enum print_line_t
print_trace_line(struct trace_iterator
*iter
)
2340 enum print_line_t ret
;
2342 if (iter
->trace
&& iter
->trace
->print_line
) {
2343 ret
= iter
->trace
->print_line(iter
);
2344 if (ret
!= TRACE_TYPE_UNHANDLED
)
2348 if (trace_flags
& TRACE_ITER_BIN
)
2349 return print_bin_fmt(iter
);
2351 if (trace_flags
& TRACE_ITER_HEX
)
2352 return print_hex_fmt(iter
);
2354 if (trace_flags
& TRACE_ITER_RAW
)
2355 return print_raw_fmt(iter
);
2357 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
)
2358 return print_lat_fmt(iter
, iter
->idx
, iter
->cpu
);
2360 return print_trace_fmt(iter
);
2363 static int s_show(struct seq_file
*m
, void *v
)
2365 struct trace_iterator
*iter
= v
;
2367 if (iter
->ent
== NULL
) {
2369 seq_printf(m
, "# tracer: %s\n", iter
->trace
->name
);
2372 if (iter
->trace
&& iter
->trace
->print_header
)
2373 iter
->trace
->print_header(m
);
2374 else if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
) {
2375 /* print nothing if the buffers are empty */
2376 if (trace_empty(iter
))
2378 print_trace_header(m
, iter
);
2379 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
2380 print_lat_help_header(m
);
2382 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
2383 print_func_help_header(m
);
2386 print_trace_line(iter
);
2387 trace_print_seq(m
, &iter
->seq
);
2393 static struct seq_operations tracer_seq_ops
= {
2400 static struct trace_iterator
*
2401 __tracing_open(struct inode
*inode
, struct file
*file
, int *ret
)
2403 struct trace_iterator
*iter
;
2407 if (tracing_disabled
) {
2412 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2418 mutex_lock(&trace_types_lock
);
2419 if (current_trace
&& current_trace
->print_max
)
2422 iter
->tr
= inode
->i_private
;
2423 iter
->trace
= current_trace
;
2426 /* Notify the tracer early; before we stop tracing. */
2427 if (iter
->trace
&& iter
->trace
->open
)
2428 iter
->trace
->open(iter
);
2430 /* Annotate start of buffers if we had overruns */
2431 if (ring_buffer_overruns(iter
->tr
->buffer
))
2432 iter
->iter_flags
|= TRACE_FILE_ANNOTATE
;
2435 for_each_tracing_cpu(cpu
) {
2437 iter
->buffer_iter
[cpu
] =
2438 ring_buffer_read_start(iter
->tr
->buffer
, cpu
);
2440 if (!iter
->buffer_iter
[cpu
])
2444 /* TODO stop tracer */
2445 *ret
= seq_open(file
, &tracer_seq_ops
);
2449 m
= file
->private_data
;
2452 /* stop the trace while dumping */
2455 mutex_unlock(&trace_types_lock
);
2461 for_each_tracing_cpu(cpu
) {
2462 if (iter
->buffer_iter
[cpu
])
2463 ring_buffer_read_finish(iter
->buffer_iter
[cpu
]);
2465 mutex_unlock(&trace_types_lock
);
2468 return ERR_PTR(-ENOMEM
);
2471 int tracing_open_generic(struct inode
*inode
, struct file
*filp
)
2473 if (tracing_disabled
)
2476 filp
->private_data
= inode
->i_private
;
2480 int tracing_release(struct inode
*inode
, struct file
*file
)
2482 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2483 struct trace_iterator
*iter
= m
->private;
2486 mutex_lock(&trace_types_lock
);
2487 for_each_tracing_cpu(cpu
) {
2488 if (iter
->buffer_iter
[cpu
])
2489 ring_buffer_read_finish(iter
->buffer_iter
[cpu
]);
2492 if (iter
->trace
&& iter
->trace
->close
)
2493 iter
->trace
->close(iter
);
2495 /* reenable tracing if it was previously enabled */
2497 mutex_unlock(&trace_types_lock
);
2499 seq_release(inode
, file
);
2504 static int tracing_open(struct inode
*inode
, struct file
*file
)
2508 __tracing_open(inode
, file
, &ret
);
2513 static int tracing_lt_open(struct inode
*inode
, struct file
*file
)
2515 struct trace_iterator
*iter
;
2518 iter
= __tracing_open(inode
, file
, &ret
);
2521 iter
->iter_flags
|= TRACE_FILE_LAT_FMT
;
2528 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2530 struct tracer
*t
= m
->private;
2542 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2544 struct tracer
*t
= m
->private;
2547 mutex_lock(&trace_types_lock
);
2548 for (; t
&& l
< *pos
; t
= t_next(m
, t
, &l
))
2554 static void t_stop(struct seq_file
*m
, void *p
)
2556 mutex_unlock(&trace_types_lock
);
2559 static int t_show(struct seq_file
*m
, void *v
)
2561 struct tracer
*t
= v
;
2566 seq_printf(m
, "%s", t
->name
);
2575 static struct seq_operations show_traces_seq_ops
= {
2582 static int show_traces_open(struct inode
*inode
, struct file
*file
)
2586 if (tracing_disabled
)
2589 ret
= seq_open(file
, &show_traces_seq_ops
);
2591 struct seq_file
*m
= file
->private_data
;
2592 m
->private = trace_types
;
2598 static struct file_operations tracing_fops
= {
2599 .open
= tracing_open
,
2601 .llseek
= seq_lseek
,
2602 .release
= tracing_release
,
2605 static struct file_operations tracing_lt_fops
= {
2606 .open
= tracing_lt_open
,
2608 .llseek
= seq_lseek
,
2609 .release
= tracing_release
,
2612 static struct file_operations show_traces_fops
= {
2613 .open
= show_traces_open
,
2615 .release
= seq_release
,
2619 * Only trace on a CPU if the bitmask is set:
2621 static cpumask_t tracing_cpumask
= CPU_MASK_ALL
;
2624 * When tracing/tracing_cpu_mask is modified then this holds
2625 * the new bitmask we are about to install:
2627 static cpumask_t tracing_cpumask_new
;
2630 * The tracer itself will not take this lock, but still we want
2631 * to provide a consistent cpumask to user-space:
2633 static DEFINE_MUTEX(tracing_cpumask_update_lock
);
2636 * Temporary storage for the character representation of the
2637 * CPU bitmask (and one more byte for the newline):
2639 static char mask_str
[NR_CPUS
+ 1];
2642 tracing_cpumask_read(struct file
*filp
, char __user
*ubuf
,
2643 size_t count
, loff_t
*ppos
)
2647 mutex_lock(&tracing_cpumask_update_lock
);
2649 len
= cpumask_scnprintf(mask_str
, count
, &tracing_cpumask
);
2650 if (count
- len
< 2) {
2654 len
+= sprintf(mask_str
+ len
, "\n");
2655 count
= simple_read_from_buffer(ubuf
, count
, ppos
, mask_str
, NR_CPUS
+1);
2658 mutex_unlock(&tracing_cpumask_update_lock
);
2664 tracing_cpumask_write(struct file
*filp
, const char __user
*ubuf
,
2665 size_t count
, loff_t
*ppos
)
2669 mutex_lock(&tracing_cpumask_update_lock
);
2670 err
= cpumask_parse_user(ubuf
, count
, &tracing_cpumask_new
);
2674 local_irq_disable();
2675 __raw_spin_lock(&ftrace_max_lock
);
2676 for_each_tracing_cpu(cpu
) {
2678 * Increase/decrease the disabled counter if we are
2679 * about to flip a bit in the cpumask:
2681 if (cpu_isset(cpu
, tracing_cpumask
) &&
2682 !cpu_isset(cpu
, tracing_cpumask_new
)) {
2683 atomic_inc(&global_trace
.data
[cpu
]->disabled
);
2685 if (!cpu_isset(cpu
, tracing_cpumask
) &&
2686 cpu_isset(cpu
, tracing_cpumask_new
)) {
2687 atomic_dec(&global_trace
.data
[cpu
]->disabled
);
2690 __raw_spin_unlock(&ftrace_max_lock
);
2693 tracing_cpumask
= tracing_cpumask_new
;
2695 mutex_unlock(&tracing_cpumask_update_lock
);
2700 mutex_unlock(&tracing_cpumask_update_lock
);
2705 static struct file_operations tracing_cpumask_fops
= {
2706 .open
= tracing_open_generic
,
2707 .read
= tracing_cpumask_read
,
2708 .write
= tracing_cpumask_write
,
2712 tracing_trace_options_read(struct file
*filp
, char __user
*ubuf
,
2713 size_t cnt
, loff_t
*ppos
)
2719 u32 tracer_flags
= current_trace
->flags
->val
;
2720 struct tracer_opt
*trace_opts
= current_trace
->flags
->opts
;
2723 /* calulate max size */
2724 for (i
= 0; trace_options
[i
]; i
++) {
2725 len
+= strlen(trace_options
[i
]);
2726 len
+= 3; /* "no" and space */
2730 * Increase the size with names of options specific
2731 * of the current tracer.
2733 for (i
= 0; trace_opts
[i
].name
; i
++) {
2734 len
+= strlen(trace_opts
[i
].name
);
2735 len
+= 3; /* "no" and space */
2738 /* +2 for \n and \0 */
2739 buf
= kmalloc(len
+ 2, GFP_KERNEL
);
2743 for (i
= 0; trace_options
[i
]; i
++) {
2744 if (trace_flags
& (1 << i
))
2745 r
+= sprintf(buf
+ r
, "%s ", trace_options
[i
]);
2747 r
+= sprintf(buf
+ r
, "no%s ", trace_options
[i
]);
2750 for (i
= 0; trace_opts
[i
].name
; i
++) {
2751 if (tracer_flags
& trace_opts
[i
].bit
)
2752 r
+= sprintf(buf
+ r
, "%s ",
2753 trace_opts
[i
].name
);
2755 r
+= sprintf(buf
+ r
, "no%s ",
2756 trace_opts
[i
].name
);
2759 r
+= sprintf(buf
+ r
, "\n");
2760 WARN_ON(r
>= len
+ 2);
2762 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2769 /* Try to assign a tracer specific option */
2770 static int set_tracer_option(struct tracer
*trace
, char *cmp
, int neg
)
2772 struct tracer_flags
*trace_flags
= trace
->flags
;
2773 struct tracer_opt
*opts
= NULL
;
2777 for (i
= 0; trace_flags
->opts
[i
].name
; i
++) {
2778 opts
= &trace_flags
->opts
[i
];
2779 len
= strlen(opts
->name
);
2781 if (strncmp(cmp
, opts
->name
, len
) == 0) {
2782 ret
= trace
->set_flag(trace_flags
->val
,
2788 if (!trace_flags
->opts
[i
].name
)
2791 /* Refused to handle */
2796 trace_flags
->val
&= ~opts
->bit
;
2798 trace_flags
->val
|= opts
->bit
;
2804 tracing_trace_options_write(struct file
*filp
, const char __user
*ubuf
,
2805 size_t cnt
, loff_t
*ppos
)
2813 if (cnt
>= sizeof(buf
))
2816 if (copy_from_user(&buf
, ubuf
, cnt
))
2821 if (strncmp(buf
, "no", 2) == 0) {
2826 for (i
= 0; trace_options
[i
]; i
++) {
2827 int len
= strlen(trace_options
[i
]);
2829 if (strncmp(cmp
, trace_options
[i
], len
) == 0) {
2831 trace_flags
&= ~(1 << i
);
2833 trace_flags
|= (1 << i
);
2838 /* If no option could be set, test the specific tracer options */
2839 if (!trace_options
[i
]) {
2840 ret
= set_tracer_option(current_trace
, cmp
, neg
);
2850 static struct file_operations tracing_iter_fops
= {
2851 .open
= tracing_open_generic
,
2852 .read
= tracing_trace_options_read
,
2853 .write
= tracing_trace_options_write
,
2856 static const char readme_msg
[] =
2857 "tracing mini-HOWTO:\n\n"
2859 "# mount -t debugfs nodev /debug\n\n"
2860 "# cat /debug/tracing/available_tracers\n"
2861 "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
2862 "# cat /debug/tracing/current_tracer\n"
2864 "# echo sched_switch > /debug/tracing/current_tracer\n"
2865 "# cat /debug/tracing/current_tracer\n"
2867 "# cat /debug/tracing/trace_options\n"
2868 "noprint-parent nosym-offset nosym-addr noverbose\n"
2869 "# echo print-parent > /debug/tracing/trace_options\n"
2870 "# echo 1 > /debug/tracing/tracing_enabled\n"
2871 "# cat /debug/tracing/trace > /tmp/trace.txt\n"
2872 "echo 0 > /debug/tracing/tracing_enabled\n"
2876 tracing_readme_read(struct file
*filp
, char __user
*ubuf
,
2877 size_t cnt
, loff_t
*ppos
)
2879 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
2880 readme_msg
, strlen(readme_msg
));
2883 static struct file_operations tracing_readme_fops
= {
2884 .open
= tracing_open_generic
,
2885 .read
= tracing_readme_read
,
2889 tracing_ctrl_read(struct file
*filp
, char __user
*ubuf
,
2890 size_t cnt
, loff_t
*ppos
)
2895 r
= sprintf(buf
, "%u\n", tracer_enabled
);
2896 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2900 tracing_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
2901 size_t cnt
, loff_t
*ppos
)
2903 struct trace_array
*tr
= filp
->private_data
;
2908 if (cnt
>= sizeof(buf
))
2911 if (copy_from_user(&buf
, ubuf
, cnt
))
2916 ret
= strict_strtoul(buf
, 10, &val
);
2922 mutex_lock(&trace_types_lock
);
2923 if (tracer_enabled
^ val
) {
2926 if (current_trace
->start
)
2927 current_trace
->start(tr
);
2932 if (current_trace
->stop
)
2933 current_trace
->stop(tr
);
2936 mutex_unlock(&trace_types_lock
);
2944 tracing_set_trace_read(struct file
*filp
, char __user
*ubuf
,
2945 size_t cnt
, loff_t
*ppos
)
2947 char buf
[max_tracer_type_len
+2];
2950 mutex_lock(&trace_types_lock
);
2952 r
= sprintf(buf
, "%s\n", current_trace
->name
);
2954 r
= sprintf(buf
, "\n");
2955 mutex_unlock(&trace_types_lock
);
2957 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2960 static int tracing_set_tracer(char *buf
)
2962 struct trace_array
*tr
= &global_trace
;
2966 mutex_lock(&trace_types_lock
);
2967 for (t
= trace_types
; t
; t
= t
->next
) {
2968 if (strcmp(t
->name
, buf
) == 0)
2975 if (t
== current_trace
)
2978 trace_branch_disable();
2979 if (current_trace
&& current_trace
->reset
)
2980 current_trace
->reset(tr
);
2989 trace_branch_enable(tr
);
2991 mutex_unlock(&trace_types_lock
);
2997 tracing_set_trace_write(struct file
*filp
, const char __user
*ubuf
,
2998 size_t cnt
, loff_t
*ppos
)
3000 char buf
[max_tracer_type_len
+1];
3007 if (cnt
> max_tracer_type_len
)
3008 cnt
= max_tracer_type_len
;
3010 if (copy_from_user(&buf
, ubuf
, cnt
))
3015 /* strip ending whitespace. */
3016 for (i
= cnt
- 1; i
> 0 && isspace(buf
[i
]); i
--)
3019 err
= tracing_set_tracer(buf
);
3029 tracing_max_lat_read(struct file
*filp
, char __user
*ubuf
,
3030 size_t cnt
, loff_t
*ppos
)
3032 unsigned long *ptr
= filp
->private_data
;
3036 r
= snprintf(buf
, sizeof(buf
), "%ld\n",
3037 *ptr
== (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr
));
3038 if (r
> sizeof(buf
))
3040 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
3044 tracing_max_lat_write(struct file
*filp
, const char __user
*ubuf
,
3045 size_t cnt
, loff_t
*ppos
)
3047 long *ptr
= filp
->private_data
;
3052 if (cnt
>= sizeof(buf
))
3055 if (copy_from_user(&buf
, ubuf
, cnt
))
3060 ret
= strict_strtoul(buf
, 10, &val
);
3069 static atomic_t tracing_reader
;
3071 static int tracing_open_pipe(struct inode
*inode
, struct file
*filp
)
3073 struct trace_iterator
*iter
;
3075 if (tracing_disabled
)
3078 /* We only allow for reader of the pipe */
3079 if (atomic_inc_return(&tracing_reader
) != 1) {
3080 atomic_dec(&tracing_reader
);
3084 /* create a buffer to store the information to pass to userspace */
3085 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3089 mutex_lock(&trace_types_lock
);
3091 /* trace pipe does not show start of buffer */
3092 cpus_setall(iter
->started
);
3094 iter
->tr
= &global_trace
;
3095 iter
->trace
= current_trace
;
3096 filp
->private_data
= iter
;
3098 if (iter
->trace
->pipe_open
)
3099 iter
->trace
->pipe_open(iter
);
3100 mutex_unlock(&trace_types_lock
);
3105 static int tracing_release_pipe(struct inode
*inode
, struct file
*file
)
3107 struct trace_iterator
*iter
= file
->private_data
;
3110 atomic_dec(&tracing_reader
);
3116 tracing_poll_pipe(struct file
*filp
, poll_table
*poll_table
)
3118 struct trace_iterator
*iter
= filp
->private_data
;
3120 if (trace_flags
& TRACE_ITER_BLOCK
) {
3122 * Always select as readable when in blocking mode
3124 return POLLIN
| POLLRDNORM
;
3126 if (!trace_empty(iter
))
3127 return POLLIN
| POLLRDNORM
;
3128 poll_wait(filp
, &trace_wait
, poll_table
);
3129 if (!trace_empty(iter
))
3130 return POLLIN
| POLLRDNORM
;
3140 tracing_read_pipe(struct file
*filp
, char __user
*ubuf
,
3141 size_t cnt
, loff_t
*ppos
)
3143 struct trace_iterator
*iter
= filp
->private_data
;
3146 /* return any leftover data */
3147 sret
= trace_seq_to_user(&iter
->seq
, ubuf
, cnt
);
3151 trace_seq_reset(&iter
->seq
);
3153 mutex_lock(&trace_types_lock
);
3154 if (iter
->trace
->read
) {
3155 sret
= iter
->trace
->read(iter
, filp
, ubuf
, cnt
, ppos
);
3162 while (trace_empty(iter
)) {
3164 if ((filp
->f_flags
& O_NONBLOCK
)) {
3170 * This is a make-shift waitqueue. The reason we don't use
3171 * an actual wait queue is because:
3172 * 1) we only ever have one waiter
3173 * 2) the tracing, traces all functions, we don't want
3174 * the overhead of calling wake_up and friends
3175 * (and tracing them too)
3176 * Anyway, this is really very primitive wakeup.
3178 set_current_state(TASK_INTERRUPTIBLE
);
3179 iter
->tr
->waiter
= current
;
3181 mutex_unlock(&trace_types_lock
);
3183 /* sleep for 100 msecs, and try again. */
3184 schedule_timeout(HZ
/10);
3186 mutex_lock(&trace_types_lock
);
3188 iter
->tr
->waiter
= NULL
;
3190 if (signal_pending(current
)) {
3195 if (iter
->trace
!= current_trace
)
3199 * We block until we read something and tracing is disabled.
3200 * We still block if tracing is disabled, but we have never
3201 * read anything. This allows a user to cat this file, and
3202 * then enable tracing. But after we have read something,
3203 * we give an EOF when tracing is again disabled.
3205 * iter->pos will be 0 if we haven't read anything.
3207 if (!tracer_enabled
&& iter
->pos
)
3213 /* stop when tracing is finished */
3214 if (trace_empty(iter
))
3217 if (cnt
>= PAGE_SIZE
)
3218 cnt
= PAGE_SIZE
- 1;
3220 /* reset all but tr, trace, and overruns */
3221 memset(&iter
->seq
, 0,
3222 sizeof(struct trace_iterator
) -
3223 offsetof(struct trace_iterator
, seq
));
3226 while (find_next_entry_inc(iter
) != NULL
) {
3227 enum print_line_t ret
;
3228 int len
= iter
->seq
.len
;
3230 ret
= print_trace_line(iter
);
3231 if (ret
== TRACE_TYPE_PARTIAL_LINE
) {
3232 /* don't print partial lines */
3233 iter
->seq
.len
= len
;
3237 trace_consume(iter
);
3239 if (iter
->seq
.len
>= cnt
)
3243 /* Now copy what we have to the user */
3244 sret
= trace_seq_to_user(&iter
->seq
, ubuf
, cnt
);
3245 if (iter
->seq
.readpos
>= iter
->seq
.len
)
3246 trace_seq_reset(&iter
->seq
);
3249 * If there was nothing to send to user, inspite of consuming trace
3250 * entries, go back to wait for more entries.
3256 mutex_unlock(&trace_types_lock
);
3262 tracing_entries_read(struct file
*filp
, char __user
*ubuf
,
3263 size_t cnt
, loff_t
*ppos
)
3265 struct trace_array
*tr
= filp
->private_data
;
3269 r
= sprintf(buf
, "%lu\n", tr
->entries
>> 10);
3270 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
3274 tracing_entries_write(struct file
*filp
, const char __user
*ubuf
,
3275 size_t cnt
, loff_t
*ppos
)
3281 if (cnt
>= sizeof(buf
))
3284 if (copy_from_user(&buf
, ubuf
, cnt
))
3289 ret
= strict_strtoul(buf
, 10, &val
);
3293 /* must have at least 1 entry */
3297 mutex_lock(&trace_types_lock
);
3301 /* disable all cpu buffers */
3302 for_each_tracing_cpu(cpu
) {
3303 if (global_trace
.data
[cpu
])
3304 atomic_inc(&global_trace
.data
[cpu
]->disabled
);
3305 if (max_tr
.data
[cpu
])
3306 atomic_inc(&max_tr
.data
[cpu
]->disabled
);
3309 /* value is in KB */
3312 if (val
!= global_trace
.entries
) {
3313 ret
= ring_buffer_resize(global_trace
.buffer
, val
);
3319 ret
= ring_buffer_resize(max_tr
.buffer
, val
);
3323 r
= ring_buffer_resize(global_trace
.buffer
,
3324 global_trace
.entries
);
3326 /* AARGH! We are left with different
3327 * size max buffer!!!! */
3329 tracing_disabled
= 1;
3334 global_trace
.entries
= val
;
3339 /* If check pages failed, return ENOMEM */
3340 if (tracing_disabled
)
3343 for_each_tracing_cpu(cpu
) {
3344 if (global_trace
.data
[cpu
])
3345 atomic_dec(&global_trace
.data
[cpu
]->disabled
);
3346 if (max_tr
.data
[cpu
])
3347 atomic_dec(&max_tr
.data
[cpu
]->disabled
);
3351 max_tr
.entries
= global_trace
.entries
;
3352 mutex_unlock(&trace_types_lock
);
3357 static int mark_printk(const char *fmt
, ...)
3361 va_start(args
, fmt
);
3362 ret
= trace_vprintk(0, -1, fmt
, args
);
3368 tracing_mark_write(struct file
*filp
, const char __user
*ubuf
,
3369 size_t cnt
, loff_t
*fpos
)
3374 if (tracing_disabled
)
3377 if (cnt
> TRACE_BUF_SIZE
)
3378 cnt
= TRACE_BUF_SIZE
;
3380 buf
= kmalloc(cnt
+ 1, GFP_KERNEL
);
3384 if (copy_from_user(buf
, ubuf
, cnt
)) {
3389 /* Cut from the first nil or newline. */
3391 end
= strchr(buf
, '\n');
3395 cnt
= mark_printk("%s\n", buf
);
3402 static struct file_operations tracing_max_lat_fops
= {
3403 .open
= tracing_open_generic
,
3404 .read
= tracing_max_lat_read
,
3405 .write
= tracing_max_lat_write
,
3408 static struct file_operations tracing_ctrl_fops
= {
3409 .open
= tracing_open_generic
,
3410 .read
= tracing_ctrl_read
,
3411 .write
= tracing_ctrl_write
,
3414 static struct file_operations set_tracer_fops
= {
3415 .open
= tracing_open_generic
,
3416 .read
= tracing_set_trace_read
,
3417 .write
= tracing_set_trace_write
,
3420 static struct file_operations tracing_pipe_fops
= {
3421 .open
= tracing_open_pipe
,
3422 .poll
= tracing_poll_pipe
,
3423 .read
= tracing_read_pipe
,
3424 .release
= tracing_release_pipe
,
3427 static struct file_operations tracing_entries_fops
= {
3428 .open
= tracing_open_generic
,
3429 .read
= tracing_entries_read
,
3430 .write
= tracing_entries_write
,
3433 static struct file_operations tracing_mark_fops
= {
3434 .open
= tracing_open_generic
,
3435 .write
= tracing_mark_write
,
3438 #ifdef CONFIG_DYNAMIC_FTRACE
3440 int __weak
ftrace_arch_read_dyn_info(char *buf
, int size
)
3446 tracing_read_dyn_info(struct file
*filp
, char __user
*ubuf
,
3447 size_t cnt
, loff_t
*ppos
)
3449 static char ftrace_dyn_info_buffer
[1024];
3450 static DEFINE_MUTEX(dyn_info_mutex
);
3451 unsigned long *p
= filp
->private_data
;
3452 char *buf
= ftrace_dyn_info_buffer
;
3453 int size
= ARRAY_SIZE(ftrace_dyn_info_buffer
);
3456 mutex_lock(&dyn_info_mutex
);
3457 r
= sprintf(buf
, "%ld ", *p
);
3459 r
+= ftrace_arch_read_dyn_info(buf
+r
, (size
-1)-r
);
3462 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
3464 mutex_unlock(&dyn_info_mutex
);
3469 static struct file_operations tracing_dyn_info_fops
= {
3470 .open
= tracing_open_generic
,
3471 .read
= tracing_read_dyn_info
,
3475 static struct dentry
*d_tracer
;
3477 struct dentry
*tracing_init_dentry(void)
3484 d_tracer
= debugfs_create_dir("tracing", NULL
);
3486 if (!d_tracer
&& !once
) {
3488 pr_warning("Could not create debugfs directory 'tracing'\n");
3495 #ifdef CONFIG_FTRACE_SELFTEST
3496 /* Let selftest have access to static functions in this file */
3497 #include "trace_selftest.c"
3500 static __init
int tracer_init_debugfs(void)
3502 struct dentry
*d_tracer
;
3503 struct dentry
*entry
;
3505 d_tracer
= tracing_init_dentry();
3507 entry
= debugfs_create_file("tracing_enabled", 0644, d_tracer
,
3508 &global_trace
, &tracing_ctrl_fops
);
3510 pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
3512 entry
= debugfs_create_file("trace_options", 0644, d_tracer
,
3513 NULL
, &tracing_iter_fops
);
3515 pr_warning("Could not create debugfs 'trace_options' entry\n");
3517 entry
= debugfs_create_file("tracing_cpumask", 0644, d_tracer
,
3518 NULL
, &tracing_cpumask_fops
);
3520 pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
3522 entry
= debugfs_create_file("latency_trace", 0444, d_tracer
,
3523 &global_trace
, &tracing_lt_fops
);
3525 pr_warning("Could not create debugfs 'latency_trace' entry\n");
3527 entry
= debugfs_create_file("trace", 0444, d_tracer
,
3528 &global_trace
, &tracing_fops
);
3530 pr_warning("Could not create debugfs 'trace' entry\n");
3532 entry
= debugfs_create_file("available_tracers", 0444, d_tracer
,
3533 &global_trace
, &show_traces_fops
);
3535 pr_warning("Could not create debugfs 'available_tracers' entry\n");
3537 entry
= debugfs_create_file("current_tracer", 0444, d_tracer
,
3538 &global_trace
, &set_tracer_fops
);
3540 pr_warning("Could not create debugfs 'current_tracer' entry\n");
3542 entry
= debugfs_create_file("tracing_max_latency", 0644, d_tracer
,
3543 &tracing_max_latency
,
3544 &tracing_max_lat_fops
);
3546 pr_warning("Could not create debugfs "
3547 "'tracing_max_latency' entry\n");
3549 entry
= debugfs_create_file("tracing_thresh", 0644, d_tracer
,
3550 &tracing_thresh
, &tracing_max_lat_fops
);
3552 pr_warning("Could not create debugfs "
3553 "'tracing_thresh' entry\n");
3554 entry
= debugfs_create_file("README", 0644, d_tracer
,
3555 NULL
, &tracing_readme_fops
);
3557 pr_warning("Could not create debugfs 'README' entry\n");
3559 entry
= debugfs_create_file("trace_pipe", 0644, d_tracer
,
3560 NULL
, &tracing_pipe_fops
);
3562 pr_warning("Could not create debugfs "
3563 "'trace_pipe' entry\n");
3565 entry
= debugfs_create_file("buffer_size_kb", 0644, d_tracer
,
3566 &global_trace
, &tracing_entries_fops
);
3568 pr_warning("Could not create debugfs "
3569 "'buffer_size_kb' entry\n");
3571 entry
= debugfs_create_file("trace_marker", 0220, d_tracer
,
3572 NULL
, &tracing_mark_fops
);
3574 pr_warning("Could not create debugfs "
3575 "'trace_marker' entry\n");
3577 #ifdef CONFIG_DYNAMIC_FTRACE
3578 entry
= debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer
,
3579 &ftrace_update_tot_cnt
,
3580 &tracing_dyn_info_fops
);
3582 pr_warning("Could not create debugfs "
3583 "'dyn_ftrace_total_info' entry\n");
3585 #ifdef CONFIG_SYSPROF_TRACER
3586 init_tracer_sysprof_debugfs(d_tracer
);
3591 int trace_vprintk(unsigned long ip
, int depth
, const char *fmt
, va_list args
)
3593 static DEFINE_SPINLOCK(trace_buf_lock
);
3594 static char trace_buf
[TRACE_BUF_SIZE
];
3596 struct ring_buffer_event
*event
;
3597 struct trace_array
*tr
= &global_trace
;
3598 struct trace_array_cpu
*data
;
3599 int cpu
, len
= 0, size
, pc
;
3600 struct print_entry
*entry
;
3601 unsigned long irq_flags
;
3603 if (tracing_disabled
|| tracing_selftest_running
)
3606 pc
= preempt_count();
3607 preempt_disable_notrace();
3608 cpu
= raw_smp_processor_id();
3609 data
= tr
->data
[cpu
];
3611 if (unlikely(atomic_read(&data
->disabled
)))
3614 pause_graph_tracing();
3615 spin_lock_irqsave(&trace_buf_lock
, irq_flags
);
3616 len
= vsnprintf(trace_buf
, TRACE_BUF_SIZE
, fmt
, args
);
3618 len
= min(len
, TRACE_BUF_SIZE
-1);
3621 size
= sizeof(*entry
) + len
+ 1;
3622 event
= ring_buffer_lock_reserve(tr
->buffer
, size
, &irq_flags
);
3625 entry
= ring_buffer_event_data(event
);
3626 tracing_generic_entry_update(&entry
->ent
, irq_flags
, pc
);
3627 entry
->ent
.type
= TRACE_PRINT
;
3629 entry
->depth
= depth
;
3631 memcpy(&entry
->buf
, trace_buf
, len
);
3632 entry
->buf
[len
] = 0;
3633 ring_buffer_unlock_commit(tr
->buffer
, event
, irq_flags
);
3636 spin_unlock_irqrestore(&trace_buf_lock
, irq_flags
);
3637 unpause_graph_tracing();
3639 preempt_enable_notrace();
3643 EXPORT_SYMBOL_GPL(trace_vprintk
);
3645 int __ftrace_printk(unsigned long ip
, const char *fmt
, ...)
3650 if (!(trace_flags
& TRACE_ITER_PRINTK
))
3654 ret
= trace_vprintk(ip
, task_curr_ret_stack(current
), fmt
, ap
);
3658 EXPORT_SYMBOL_GPL(__ftrace_printk
);
3660 static int trace_panic_handler(struct notifier_block
*this,
3661 unsigned long event
, void *unused
)
3663 if (ftrace_dump_on_oops
)
3668 static struct notifier_block trace_panic_notifier
= {
3669 .notifier_call
= trace_panic_handler
,
3671 .priority
= 150 /* priority: INT_MAX >= x >= 0 */
3674 static int trace_die_handler(struct notifier_block
*self
,
3680 if (ftrace_dump_on_oops
)
3689 static struct notifier_block trace_die_notifier
= {
3690 .notifier_call
= trace_die_handler
,
3695 * printk is set to max of 1024, we really don't need it that big.
3696 * Nothing should be printing 1000 characters anyway.
3698 #define TRACE_MAX_PRINT 1000
3701 * Define here KERN_TRACE so that we have one place to modify
3702 * it if we decide to change what log level the ftrace dump
3705 #define KERN_TRACE KERN_INFO
3708 trace_printk_seq(struct trace_seq
*s
)
3710 /* Probably should print a warning here. */
3714 /* should be zero ended, but we are paranoid. */
3715 s
->buffer
[s
->len
] = 0;
3717 printk(KERN_TRACE
"%s", s
->buffer
);
3722 void ftrace_dump(void)
3724 static DEFINE_SPINLOCK(ftrace_dump_lock
);
3725 /* use static because iter can be a bit big for the stack */
3726 static struct trace_iterator iter
;
3727 static cpumask_t mask
;
3728 static int dump_ran
;
3729 unsigned long flags
;
3733 spin_lock_irqsave(&ftrace_dump_lock
, flags
);
3739 /* No turning back! */
3742 for_each_tracing_cpu(cpu
) {
3743 atomic_inc(&global_trace
.data
[cpu
]->disabled
);
3746 /* don't look at user memory in panic mode */
3747 trace_flags
&= ~TRACE_ITER_SYM_USEROBJ
;
3749 printk(KERN_TRACE
"Dumping ftrace buffer:\n");
3751 iter
.tr
= &global_trace
;
3752 iter
.trace
= current_trace
;
3755 * We need to stop all tracing on all CPUS to read the
3756 * the next buffer. This is a bit expensive, but is
3757 * not done often. We fill all what we can read,
3758 * and then release the locks again.
3763 while (!trace_empty(&iter
)) {
3766 printk(KERN_TRACE
"---------------------------------\n");
3770 /* reset all but tr, trace, and overruns */
3771 memset(&iter
.seq
, 0,
3772 sizeof(struct trace_iterator
) -
3773 offsetof(struct trace_iterator
, seq
));
3774 iter
.iter_flags
|= TRACE_FILE_LAT_FMT
;
3777 if (find_next_entry_inc(&iter
) != NULL
) {
3778 print_trace_line(&iter
);
3779 trace_consume(&iter
);
3782 trace_printk_seq(&iter
.seq
);
3786 printk(KERN_TRACE
" (ftrace buffer empty)\n");
3788 printk(KERN_TRACE
"---------------------------------\n");
3791 spin_unlock_irqrestore(&ftrace_dump_lock
, flags
);
3794 __init
static int tracer_alloc_buffers(void)
3796 struct trace_array_cpu
*data
;
3799 /* TODO: make the number of buffers hot pluggable with CPUS */
3800 tracing_buffer_mask
= cpu_possible_map
;
3802 global_trace
.buffer
= ring_buffer_alloc(trace_buf_size
,
3803 TRACE_BUFFER_FLAGS
);
3804 if (!global_trace
.buffer
) {
3805 printk(KERN_ERR
"tracer: failed to allocate ring buffer!\n");
3809 global_trace
.entries
= ring_buffer_size(global_trace
.buffer
);
3811 #ifdef CONFIG_TRACER_MAX_TRACE
3812 max_tr
.buffer
= ring_buffer_alloc(trace_buf_size
,
3813 TRACE_BUFFER_FLAGS
);
3814 if (!max_tr
.buffer
) {
3815 printk(KERN_ERR
"tracer: failed to allocate max ring buffer!\n");
3817 ring_buffer_free(global_trace
.buffer
);
3820 max_tr
.entries
= ring_buffer_size(max_tr
.buffer
);
3821 WARN_ON(max_tr
.entries
!= global_trace
.entries
);
3824 /* Allocate the first page for all buffers */
3825 for_each_tracing_cpu(i
) {
3826 data
= global_trace
.data
[i
] = &per_cpu(global_trace_cpu
, i
);
3827 max_tr
.data
[i
] = &per_cpu(max_data
, i
);
3830 trace_init_cmdlines();
3832 register_tracer(&nop_trace
);
3833 #ifdef CONFIG_BOOT_TRACER
3834 register_tracer(&boot_tracer
);
3835 current_trace
= &boot_tracer
;
3836 current_trace
->init(&global_trace
);
3838 current_trace
= &nop_trace
;
3841 /* All seems OK, enable tracing */
3842 tracing_disabled
= 0;
3844 atomic_notifier_chain_register(&panic_notifier_list
,
3845 &trace_panic_notifier
);
3847 register_die_notifier(&trace_die_notifier
);
3851 early_initcall(tracer_alloc_buffers
);
3852 fs_initcall(tracer_init_debugfs
);