projects/linux·blob v4.19 · refs

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1// SPDX-License-Identifier: GPL-2.0
2
3#ifndef _LINUX_KERNEL_TRACE_H
4#define _LINUX_KERNEL_TRACE_H
5
6#include <linux/fs.h>
7#include <linux/atomic.h>
8#include <linux/sched.h>
9#include <linux/clocksource.h>
10#include <linux/ring_buffer.h>
11#include <linux/mmiotrace.h>
12#include <linux/tracepoint.h>
13#include <linux/ftrace.h>
14#include <linux/hw_breakpoint.h>
15#include <linux/trace_seq.h>
16#include <linux/trace_events.h>
17#include <linux/compiler.h>
18#include <linux/trace_seq.h>
19#include <linux/glob.h>
20
21#ifdef CONFIG_FTRACE_SYSCALLS
22#include <asm/unistd.h> /* For NR_SYSCALLS */
23#include <asm/syscall.h> /* some archs define it here */
24#endif
25
26enum trace_type {
27 __TRACE_FIRST_TYPE = 0,
28
29 TRACE_FN,
30 TRACE_CTX,
31 TRACE_WAKE,
32 TRACE_STACK,
33 TRACE_PRINT,
34 TRACE_BPRINT,
35 TRACE_MMIO_RW,
36 TRACE_MMIO_MAP,
37 TRACE_BRANCH,
38 TRACE_GRAPH_RET,
39 TRACE_GRAPH_ENT,
40 TRACE_USER_STACK,
41 TRACE_BLK,
42 TRACE_BPUTS,
43 TRACE_HWLAT,
44 TRACE_RAW_DATA,
45
46 __TRACE_LAST_TYPE,
47};
48
49
50#undef __field
51#define __field(type, item) type item;
52
53#undef __field_struct
54#define __field_struct(type, item) __field(type, item)
55
56#undef __field_desc
57#define __field_desc(type, container, item)
58
59#undef __array
60#define __array(type, item, size) type item[size];
61
62#undef __array_desc
63#define __array_desc(type, container, item, size)
64
65#undef __dynamic_array
66#define __dynamic_array(type, item) type item[];
67
68#undef F_STRUCT
69#define F_STRUCT(args...) args
70
71#undef FTRACE_ENTRY
72#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \
73 struct struct_name { \
74 struct trace_entry ent; \
75 tstruct \
76 }
77
78#undef FTRACE_ENTRY_DUP
79#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
80
81#undef FTRACE_ENTRY_REG
82#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
83 filter, regfn) \
84 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
85 filter)
86
87#undef FTRACE_ENTRY_PACKED
88#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print, \
89 filter) \
90 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
91 filter) __packed
92
93#include "trace_entries.h"
94
95/*
96 * syscalls are special, and need special handling, this is why
97 * they are not included in trace_entries.h
98 */
99struct syscall_trace_enter {
100 struct trace_entry ent;
101 int nr;
102 unsigned long args[];
103};
104
105struct syscall_trace_exit {
106 struct trace_entry ent;
107 int nr;
108 long ret;
109};
110
111struct kprobe_trace_entry_head {
112 struct trace_entry ent;
113 unsigned long ip;
114};
115
116struct kretprobe_trace_entry_head {
117 struct trace_entry ent;
118 unsigned long func;
119 unsigned long ret_ip;
120};
121
122/*
123 * trace_flag_type is an enumeration that holds different
124 * states when a trace occurs. These are:
125 * IRQS_OFF - interrupts were disabled
126 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
127 * NEED_RESCHED - reschedule is requested
128 * HARDIRQ - inside an interrupt handler
129 * SOFTIRQ - inside a softirq handler
130 */
131enum trace_flag_type {
132 TRACE_FLAG_IRQS_OFF = 0x01,
133 TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
134 TRACE_FLAG_NEED_RESCHED = 0x04,
135 TRACE_FLAG_HARDIRQ = 0x08,
136 TRACE_FLAG_SOFTIRQ = 0x10,
137 TRACE_FLAG_PREEMPT_RESCHED = 0x20,
138 TRACE_FLAG_NMI = 0x40,
139};
140
141#define TRACE_BUF_SIZE 1024
142
143struct trace_array;
144
145/*
146 * The CPU trace array - it consists of thousands of trace entries
147 * plus some other descriptor data: (for example which task started
148 * the trace, etc.)
149 */
150struct trace_array_cpu {
151 atomic_t disabled;
152 void *buffer_page; /* ring buffer spare */
153
154 unsigned long entries;
155 unsigned long saved_latency;
156 unsigned long critical_start;
157 unsigned long critical_end;
158 unsigned long critical_sequence;
159 unsigned long nice;
160 unsigned long policy;
161 unsigned long rt_priority;
162 unsigned long skipped_entries;
163 u64 preempt_timestamp;
164 pid_t pid;
165 kuid_t uid;
166 char comm[TASK_COMM_LEN];
167
168 bool ignore_pid;
169#ifdef CONFIG_FUNCTION_TRACER
170 bool ftrace_ignore_pid;
171#endif
172};
173
174struct tracer;
175struct trace_option_dentry;
176
177struct trace_buffer {
178 struct trace_array *tr;
179 struct ring_buffer *buffer;
180 struct trace_array_cpu __percpu *data;
181 u64 time_start;
182 int cpu;
183};
184
185#define TRACE_FLAGS_MAX_SIZE 32
186
187struct trace_options {
188 struct tracer *tracer;
189 struct trace_option_dentry *topts;
190};
191
192struct trace_pid_list {
193 int pid_max;
194 unsigned long *pids;
195};
196
197/*
198 * The trace array - an array of per-CPU trace arrays. This is the
199 * highest level data structure that individual tracers deal with.
200 * They have on/off state as well:
201 */
202struct trace_array {
203 struct list_head list;
204 char *name;
205 struct trace_buffer trace_buffer;
206#ifdef CONFIG_TRACER_MAX_TRACE
207 /*
208 * The max_buffer is used to snapshot the trace when a maximum
209 * latency is reached, or when the user initiates a snapshot.
210 * Some tracers will use this to store a maximum trace while
211 * it continues examining live traces.
212 *
213 * The buffers for the max_buffer are set up the same as the trace_buffer
214 * When a snapshot is taken, the buffer of the max_buffer is swapped
215 * with the buffer of the trace_buffer and the buffers are reset for
216 * the trace_buffer so the tracing can continue.
217 */
218 struct trace_buffer max_buffer;
219 bool allocated_snapshot;
220#endif
221#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
222 unsigned long max_latency;
223#endif
224 struct trace_pid_list __rcu *filtered_pids;
225 /*
226 * max_lock is used to protect the swapping of buffers
227 * when taking a max snapshot. The buffers themselves are
228 * protected by per_cpu spinlocks. But the action of the swap
229 * needs its own lock.
230 *
231 * This is defined as a arch_spinlock_t in order to help
232 * with performance when lockdep debugging is enabled.
233 *
234 * It is also used in other places outside the update_max_tr
235 * so it needs to be defined outside of the
236 * CONFIG_TRACER_MAX_TRACE.
237 */
238 arch_spinlock_t max_lock;
239 int buffer_disabled;
240#ifdef CONFIG_FTRACE_SYSCALLS
241 int sys_refcount_enter;
242 int sys_refcount_exit;
243 struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
244 struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
245#endif
246 int stop_count;
247 int clock_id;
248 int nr_topts;
249 bool clear_trace;
250 struct tracer *current_trace;
251 unsigned int trace_flags;
252 unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE];
253 unsigned int flags;
254 raw_spinlock_t start_lock;
255 struct dentry *dir;
256 struct dentry *options;
257 struct dentry *percpu_dir;
258 struct dentry *event_dir;
259 struct trace_options *topts;
260 struct list_head systems;
261 struct list_head events;
262 struct trace_event_file *trace_marker_file;
263 cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
264 int ref;
265#ifdef CONFIG_FUNCTION_TRACER
266 struct ftrace_ops *ops;
267 struct trace_pid_list __rcu *function_pids;
268#ifdef CONFIG_DYNAMIC_FTRACE
269 /* All of these are protected by the ftrace_lock */
270 struct list_head func_probes;
271 struct list_head mod_trace;
272 struct list_head mod_notrace;
273#endif
274 /* function tracing enabled */
275 int function_enabled;
276#endif
277 int time_stamp_abs_ref;
278 struct list_head hist_vars;
279};
280
281enum {
282 TRACE_ARRAY_FL_GLOBAL = (1 << 0)
283};
284
285extern struct list_head ftrace_trace_arrays;
286
287extern struct mutex trace_types_lock;
288
289extern int trace_array_get(struct trace_array *tr);
290extern void trace_array_put(struct trace_array *tr);
291
292extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
293extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
294
295extern bool trace_clock_in_ns(struct trace_array *tr);
296
297/*
298 * The global tracer (top) should be the first trace array added,
299 * but we check the flag anyway.
300 */
301static inline struct trace_array *top_trace_array(void)
302{
303 struct trace_array *tr;
304
305 if (list_empty(&ftrace_trace_arrays))
306 return NULL;
307
308 tr = list_entry(ftrace_trace_arrays.prev,
309 typeof(*tr), list);
310 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
311 return tr;
312}
313
314#define FTRACE_CMP_TYPE(var, type) \
315 __builtin_types_compatible_p(typeof(var), type *)
316
317#undef IF_ASSIGN
318#define IF_ASSIGN(var, entry, etype, id) \
319 if (FTRACE_CMP_TYPE(var, etype)) { \
320 var = (typeof(var))(entry); \
321 WARN_ON(id && (entry)->type != id); \
322 break; \
323 }
324
325/* Will cause compile errors if type is not found. */
326extern void __ftrace_bad_type(void);
327
328/*
329 * The trace_assign_type is a verifier that the entry type is
330 * the same as the type being assigned. To add new types simply
331 * add a line with the following format:
332 *
333 * IF_ASSIGN(var, ent, type, id);
334 *
335 * Where "type" is the trace type that includes the trace_entry
336 * as the "ent" item. And "id" is the trace identifier that is
337 * used in the trace_type enum.
338 *
339 * If the type can have more than one id, then use zero.
340 */
341#define trace_assign_type(var, ent) \
342 do { \
343 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
344 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
345 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
346 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
347 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
348 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
349 IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \
350 IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT); \
351 IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
352 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
353 TRACE_MMIO_RW); \
354 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
355 TRACE_MMIO_MAP); \
356 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
357 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
358 TRACE_GRAPH_ENT); \
359 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
360 TRACE_GRAPH_RET); \
361 __ftrace_bad_type(); \
362 } while (0)
363
364/*
365 * An option specific to a tracer. This is a boolean value.
366 * The bit is the bit index that sets its value on the
367 * flags value in struct tracer_flags.
368 */
369struct tracer_opt {
370 const char *name; /* Will appear on the trace_options file */
371 u32 bit; /* Mask assigned in val field in tracer_flags */
372};
373
374/*
375 * The set of specific options for a tracer. Your tracer
376 * have to set the initial value of the flags val.
377 */
378struct tracer_flags {
379 u32 val;
380 struct tracer_opt *opts;
381 struct tracer *trace;
382};
383
384/* Makes more easy to define a tracer opt */
385#define TRACER_OPT(s, b) .name = #s, .bit = b
386
387
388struct trace_option_dentry {
389 struct tracer_opt *opt;
390 struct tracer_flags *flags;
391 struct trace_array *tr;
392 struct dentry *entry;
393};
394
395/**
396 * struct tracer - a specific tracer and its callbacks to interact with tracefs
397 * @name: the name chosen to select it on the available_tracers file
398 * @init: called when one switches to this tracer (echo name > current_tracer)
399 * @reset: called when one switches to another tracer
400 * @start: called when tracing is unpaused (echo 1 > tracing_on)
401 * @stop: called when tracing is paused (echo 0 > tracing_on)
402 * @update_thresh: called when tracing_thresh is updated
403 * @open: called when the trace file is opened
404 * @pipe_open: called when the trace_pipe file is opened
405 * @close: called when the trace file is released
406 * @pipe_close: called when the trace_pipe file is released
407 * @read: override the default read callback on trace_pipe
408 * @splice_read: override the default splice_read callback on trace_pipe
409 * @selftest: selftest to run on boot (see trace_selftest.c)
410 * @print_headers: override the first lines that describe your columns
411 * @print_line: callback that prints a trace
412 * @set_flag: signals one of your private flags changed (trace_options file)
413 * @flags: your private flags
414 */
415struct tracer {
416 const char *name;
417 int (*init)(struct trace_array *tr);
418 void (*reset)(struct trace_array *tr);
419 void (*start)(struct trace_array *tr);
420 void (*stop)(struct trace_array *tr);
421 int (*update_thresh)(struct trace_array *tr);
422 void (*open)(struct trace_iterator *iter);
423 void (*pipe_open)(struct trace_iterator *iter);
424 void (*close)(struct trace_iterator *iter);
425 void (*pipe_close)(struct trace_iterator *iter);
426 ssize_t (*read)(struct trace_iterator *iter,
427 struct file *filp, char __user *ubuf,
428 size_t cnt, loff_t *ppos);
429 ssize_t (*splice_read)(struct trace_iterator *iter,
430 struct file *filp,
431 loff_t *ppos,
432 struct pipe_inode_info *pipe,
433 size_t len,
434 unsigned int flags);
435#ifdef CONFIG_FTRACE_STARTUP_TEST
436 int (*selftest)(struct tracer *trace,
437 struct trace_array *tr);
438#endif
439 void (*print_header)(struct seq_file *m);
440 enum print_line_t (*print_line)(struct trace_iterator *iter);
441 /* If you handled the flag setting, return 0 */
442 int (*set_flag)(struct trace_array *tr,
443 u32 old_flags, u32 bit, int set);
444 /* Return 0 if OK with change, else return non-zero */
445 int (*flag_changed)(struct trace_array *tr,
446 u32 mask, int set);
447 struct tracer *next;
448 struct tracer_flags *flags;
449 int enabled;
450 int ref;
451 bool print_max;
452 bool allow_instances;
453#ifdef CONFIG_TRACER_MAX_TRACE
454 bool use_max_tr;
455#endif
456 /* True if tracer cannot be enabled in kernel param */
457 bool noboot;
458};
459
460
461/* Only current can touch trace_recursion */
462
463/*
464 * For function tracing recursion:
465 * The order of these bits are important.
466 *
467 * When function tracing occurs, the following steps are made:
468 * If arch does not support a ftrace feature:
469 * call internal function (uses INTERNAL bits) which calls...
470 * If callback is registered to the "global" list, the list
471 * function is called and recursion checks the GLOBAL bits.
472 * then this function calls...
473 * The function callback, which can use the FTRACE bits to
474 * check for recursion.
475 *
476 * Now if the arch does not suppport a feature, and it calls
477 * the global list function which calls the ftrace callback
478 * all three of these steps will do a recursion protection.
479 * There's no reason to do one if the previous caller already
480 * did. The recursion that we are protecting against will
481 * go through the same steps again.
482 *
483 * To prevent the multiple recursion checks, if a recursion
484 * bit is set that is higher than the MAX bit of the current
485 * check, then we know that the check was made by the previous
486 * caller, and we can skip the current check.
487 */
488enum {
489 TRACE_BUFFER_BIT,
490 TRACE_BUFFER_NMI_BIT,
491 TRACE_BUFFER_IRQ_BIT,
492 TRACE_BUFFER_SIRQ_BIT,
493
494 /* Start of function recursion bits */
495 TRACE_FTRACE_BIT,
496 TRACE_FTRACE_NMI_BIT,
497 TRACE_FTRACE_IRQ_BIT,
498 TRACE_FTRACE_SIRQ_BIT,
499
500 /* INTERNAL_BITs must be greater than FTRACE_BITs */
501 TRACE_INTERNAL_BIT,
502 TRACE_INTERNAL_NMI_BIT,
503 TRACE_INTERNAL_IRQ_BIT,
504 TRACE_INTERNAL_SIRQ_BIT,
505
506 TRACE_BRANCH_BIT,
507/*
508 * Abuse of the trace_recursion.
509 * As we need a way to maintain state if we are tracing the function
510 * graph in irq because we want to trace a particular function that
511 * was called in irq context but we have irq tracing off. Since this
512 * can only be modified by current, we can reuse trace_recursion.
513 */
514 TRACE_IRQ_BIT,
515};
516
517#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
518#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
519#define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
520
521#define TRACE_CONTEXT_BITS 4
522
523#define TRACE_FTRACE_START TRACE_FTRACE_BIT
524#define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
525
526#define TRACE_LIST_START TRACE_INTERNAL_BIT
527#define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
528
529#define TRACE_CONTEXT_MASK TRACE_LIST_MAX
530
531static __always_inline int trace_get_context_bit(void)
532{
533 int bit;
534
535 if (in_interrupt()) {
536 if (in_nmi())
537 bit = 0;
538
539 else if (in_irq())
540 bit = 1;
541 else
542 bit = 2;
543 } else
544 bit = 3;
545
546 return bit;
547}
548
549static __always_inline int trace_test_and_set_recursion(int start, int max)
550{
551 unsigned int val = current->trace_recursion;
552 int bit;
553
554 /* A previous recursion check was made */
555 if ((val & TRACE_CONTEXT_MASK) > max)
556 return 0;
557
558 bit = trace_get_context_bit() + start;
559 if (unlikely(val & (1 << bit)))
560 return -1;
561
562 val |= 1 << bit;
563 current->trace_recursion = val;
564 barrier();
565
566 return bit;
567}
568
569static __always_inline void trace_clear_recursion(int bit)
570{
571 unsigned int val = current->trace_recursion;
572
573 if (!bit)
574 return;
575
576 bit = 1 << bit;
577 val &= ~bit;
578
579 barrier();
580 current->trace_recursion = val;
581}
582
583static inline struct ring_buffer_iter *
584trace_buffer_iter(struct trace_iterator *iter, int cpu)
585{
586 return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
587}
588
589int tracer_init(struct tracer *t, struct trace_array *tr);
590int tracing_is_enabled(void);
591void tracing_reset(struct trace_buffer *buf, int cpu);
592void tracing_reset_online_cpus(struct trace_buffer *buf);
593void tracing_reset_current(int cpu);
594void tracing_reset_all_online_cpus(void);
595int tracing_open_generic(struct inode *inode, struct file *filp);
596bool tracing_is_disabled(void);
597bool tracer_tracing_is_on(struct trace_array *tr);
598void tracer_tracing_on(struct trace_array *tr);
599void tracer_tracing_off(struct trace_array *tr);
600struct dentry *trace_create_file(const char *name,
601 umode_t mode,
602 struct dentry *parent,
603 void *data,
604 const struct file_operations *fops);
605
606struct dentry *tracing_init_dentry(void);
607
608struct ring_buffer_event;
609
610struct ring_buffer_event *
611trace_buffer_lock_reserve(struct ring_buffer *buffer,
612 int type,
613 unsigned long len,
614 unsigned long flags,
615 int pc);
616
617struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
618 struct trace_array_cpu *data);
619
620struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
621 int *ent_cpu, u64 *ent_ts);
622
623void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
624 struct ring_buffer_event *event);
625
626int trace_empty(struct trace_iterator *iter);
627
628void *trace_find_next_entry_inc(struct trace_iterator *iter);
629
630void trace_init_global_iter(struct trace_iterator *iter);
631
632void tracing_iter_reset(struct trace_iterator *iter, int cpu);
633
634void trace_function(struct trace_array *tr,
635 unsigned long ip,
636 unsigned long parent_ip,
637 unsigned long flags, int pc);
638void trace_graph_function(struct trace_array *tr,
639 unsigned long ip,
640 unsigned long parent_ip,
641 unsigned long flags, int pc);
642void trace_latency_header(struct seq_file *m);
643void trace_default_header(struct seq_file *m);
644void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
645int trace_empty(struct trace_iterator *iter);
646
647void trace_graph_return(struct ftrace_graph_ret *trace);
648int trace_graph_entry(struct ftrace_graph_ent *trace);
649void set_graph_array(struct trace_array *tr);
650
651void tracing_start_cmdline_record(void);
652void tracing_stop_cmdline_record(void);
653void tracing_start_tgid_record(void);
654void tracing_stop_tgid_record(void);
655
656int register_tracer(struct tracer *type);
657int is_tracing_stopped(void);
658
659loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
660
661extern cpumask_var_t __read_mostly tracing_buffer_mask;
662
663#define for_each_tracing_cpu(cpu) \
664 for_each_cpu(cpu, tracing_buffer_mask)
665
666extern unsigned long nsecs_to_usecs(unsigned long nsecs);
667
668extern unsigned long tracing_thresh;
669
670/* PID filtering */
671
672extern int pid_max;
673
674bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
675 pid_t search_pid);
676bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
677 struct task_struct *task);
678void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
679 struct task_struct *self,
680 struct task_struct *task);
681void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
682void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
683int trace_pid_show(struct seq_file *m, void *v);
684void trace_free_pid_list(struct trace_pid_list *pid_list);
685int trace_pid_write(struct trace_pid_list *filtered_pids,
686 struct trace_pid_list **new_pid_list,
687 const char __user *ubuf, size_t cnt);
688
689#ifdef CONFIG_TRACER_MAX_TRACE
690void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
691void update_max_tr_single(struct trace_array *tr,
692 struct task_struct *tsk, int cpu);
693#endif /* CONFIG_TRACER_MAX_TRACE */
694
695#ifdef CONFIG_STACKTRACE
696void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
697 int pc);
698
699void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
700 int pc);
701#else
702static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
703 unsigned long flags, int pc)
704{
705}
706
707static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
708 int skip, int pc)
709{
710}
711#endif /* CONFIG_STACKTRACE */
712
713extern u64 ftrace_now(int cpu);
714
715extern void trace_find_cmdline(int pid, char comm[]);
716extern int trace_find_tgid(int pid);
717extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
718
719#ifdef CONFIG_DYNAMIC_FTRACE
720extern unsigned long ftrace_update_tot_cnt;
721void ftrace_init_trace_array(struct trace_array *tr);
722#else
723static inline void ftrace_init_trace_array(struct trace_array *tr) { }
724#endif
725#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
726extern int DYN_FTRACE_TEST_NAME(void);
727#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
728extern int DYN_FTRACE_TEST_NAME2(void);
729
730extern bool ring_buffer_expanded;
731extern bool tracing_selftest_disabled;
732
733#ifdef CONFIG_FTRACE_STARTUP_TEST
734extern int trace_selftest_startup_function(struct tracer *trace,
735 struct trace_array *tr);
736extern int trace_selftest_startup_function_graph(struct tracer *trace,
737 struct trace_array *tr);
738extern int trace_selftest_startup_irqsoff(struct tracer *trace,
739 struct trace_array *tr);
740extern int trace_selftest_startup_preemptoff(struct tracer *trace,
741 struct trace_array *tr);
742extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
743 struct trace_array *tr);
744extern int trace_selftest_startup_wakeup(struct tracer *trace,
745 struct trace_array *tr);
746extern int trace_selftest_startup_nop(struct tracer *trace,
747 struct trace_array *tr);
748extern int trace_selftest_startup_branch(struct tracer *trace,
749 struct trace_array *tr);
750/*
751 * Tracer data references selftest functions that only occur
752 * on boot up. These can be __init functions. Thus, when selftests
753 * are enabled, then the tracers need to reference __init functions.
754 */
755#define __tracer_data __refdata
756#else
757/* Tracers are seldom changed. Optimize when selftests are disabled. */
758#define __tracer_data __read_mostly
759#endif /* CONFIG_FTRACE_STARTUP_TEST */
760
761extern void *head_page(struct trace_array_cpu *data);
762extern unsigned long long ns2usecs(u64 nsec);
763extern int
764trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
765extern int
766trace_vprintk(unsigned long ip, const char *fmt, va_list args);
767extern int
768trace_array_vprintk(struct trace_array *tr,
769 unsigned long ip, const char *fmt, va_list args);
770int trace_array_printk(struct trace_array *tr,
771 unsigned long ip, const char *fmt, ...);
772int trace_array_printk_buf(struct ring_buffer *buffer,
773 unsigned long ip, const char *fmt, ...);
774void trace_printk_seq(struct trace_seq *s);
775enum print_line_t print_trace_line(struct trace_iterator *iter);
776
777extern char trace_find_mark(unsigned long long duration);
778
779struct ftrace_hash;
780
781struct ftrace_mod_load {
782 struct list_head list;
783 char *func;
784 char *module;
785 int enable;
786};
787
788enum {
789 FTRACE_HASH_FL_MOD = (1 << 0),
790};
791
792struct ftrace_hash {
793 unsigned long size_bits;
794 struct hlist_head *buckets;
795 unsigned long count;
796 unsigned long flags;
797 struct rcu_head rcu;
798};
799
800struct ftrace_func_entry *
801ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
802
803static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
804{
805 return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
806}
807
808/* Standard output formatting function used for function return traces */
809#ifdef CONFIG_FUNCTION_GRAPH_TRACER
810
811/* Flag options */
812#define TRACE_GRAPH_PRINT_OVERRUN 0x1
813#define TRACE_GRAPH_PRINT_CPU 0x2
814#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
815#define TRACE_GRAPH_PRINT_PROC 0x8
816#define TRACE_GRAPH_PRINT_DURATION 0x10
817#define TRACE_GRAPH_PRINT_ABS_TIME 0x20
818#define TRACE_GRAPH_PRINT_IRQS 0x40
819#define TRACE_GRAPH_PRINT_TAIL 0x80
820#define TRACE_GRAPH_SLEEP_TIME 0x100
821#define TRACE_GRAPH_GRAPH_TIME 0x200
822#define TRACE_GRAPH_PRINT_FILL_SHIFT 28
823#define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
824
825extern void ftrace_graph_sleep_time_control(bool enable);
826extern void ftrace_graph_graph_time_control(bool enable);
827
828extern enum print_line_t
829print_graph_function_flags(struct trace_iterator *iter, u32 flags);
830extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
831extern void
832trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
833extern void graph_trace_open(struct trace_iterator *iter);
834extern void graph_trace_close(struct trace_iterator *iter);
835extern int __trace_graph_entry(struct trace_array *tr,
836 struct ftrace_graph_ent *trace,
837 unsigned long flags, int pc);
838extern void __trace_graph_return(struct trace_array *tr,
839 struct ftrace_graph_ret *trace,
840 unsigned long flags, int pc);
841
842#ifdef CONFIG_DYNAMIC_FTRACE
843extern struct ftrace_hash *ftrace_graph_hash;
844extern struct ftrace_hash *ftrace_graph_notrace_hash;
845
846static inline int ftrace_graph_addr(unsigned long addr)
847{
848 int ret = 0;
849
850 preempt_disable_notrace();
851
852 if (ftrace_hash_empty(ftrace_graph_hash)) {
853 ret = 1;
854 goto out;
855 }
856
857 if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
858 /*
859 * If no irqs are to be traced, but a set_graph_function
860 * is set, and called by an interrupt handler, we still
861 * want to trace it.
862 */
863 if (in_irq())
864 trace_recursion_set(TRACE_IRQ_BIT);
865 else
866 trace_recursion_clear(TRACE_IRQ_BIT);
867 ret = 1;
868 }
869
870out:
871 preempt_enable_notrace();
872 return ret;
873}
874
875static inline int ftrace_graph_notrace_addr(unsigned long addr)
876{
877 int ret = 0;
878
879 preempt_disable_notrace();
880
881 if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
882 ret = 1;
883
884 preempt_enable_notrace();
885 return ret;
886}
887#else
888static inline int ftrace_graph_addr(unsigned long addr)
889{
890 return 1;
891}
892
893static inline int ftrace_graph_notrace_addr(unsigned long addr)
894{
895 return 0;
896}
897#endif /* CONFIG_DYNAMIC_FTRACE */
898
899extern unsigned int fgraph_max_depth;
900
901static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
902{
903 /* trace it when it is-nested-in or is a function enabled. */
904 return !(trace->depth || ftrace_graph_addr(trace->func)) ||
905 (trace->depth < 0) ||
906 (fgraph_max_depth && trace->depth >= fgraph_max_depth);
907}
908
909#else /* CONFIG_FUNCTION_GRAPH_TRACER */
910static inline enum print_line_t
911print_graph_function_flags(struct trace_iterator *iter, u32 flags)
912{
913 return TRACE_TYPE_UNHANDLED;
914}
915#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
916
917extern struct list_head ftrace_pids;
918
919#ifdef CONFIG_FUNCTION_TRACER
920struct ftrace_func_command {
921 struct list_head list;
922 char *name;
923 int (*func)(struct trace_array *tr,
924 struct ftrace_hash *hash,
925 char *func, char *cmd,
926 char *params, int enable);
927};
928extern bool ftrace_filter_param __initdata;
929static inline int ftrace_trace_task(struct trace_array *tr)
930{
931 return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
932}
933extern int ftrace_is_dead(void);
934int ftrace_create_function_files(struct trace_array *tr,
935 struct dentry *parent);
936void ftrace_destroy_function_files(struct trace_array *tr);
937void ftrace_init_global_array_ops(struct trace_array *tr);
938void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
939void ftrace_reset_array_ops(struct trace_array *tr);
940void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
941void ftrace_init_tracefs_toplevel(struct trace_array *tr,
942 struct dentry *d_tracer);
943void ftrace_clear_pids(struct trace_array *tr);
944int init_function_trace(void);
945void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
946#else
947static inline int ftrace_trace_task(struct trace_array *tr)
948{
949 return 1;
950}
951static inline int ftrace_is_dead(void) { return 0; }
952static inline int
953ftrace_create_function_files(struct trace_array *tr,
954 struct dentry *parent)
955{
956 return 0;
957}
958static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
959static inline __init void
960ftrace_init_global_array_ops(struct trace_array *tr) { }
961static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
962static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
963static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
964static inline void ftrace_clear_pids(struct trace_array *tr) { }
965static inline int init_function_trace(void) { return 0; }
966static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
967/* ftace_func_t type is not defined, use macro instead of static inline */
968#define ftrace_init_array_ops(tr, func) do { } while (0)
969#endif /* CONFIG_FUNCTION_TRACER */
970
971#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
972
973struct ftrace_probe_ops {
974 void (*func)(unsigned long ip,
975 unsigned long parent_ip,
976 struct trace_array *tr,
977 struct ftrace_probe_ops *ops,
978 void *data);
979 int (*init)(struct ftrace_probe_ops *ops,
980 struct trace_array *tr,
981 unsigned long ip, void *init_data,
982 void **data);
983 void (*free)(struct ftrace_probe_ops *ops,
984 struct trace_array *tr,
985 unsigned long ip, void *data);
986 int (*print)(struct seq_file *m,
987 unsigned long ip,
988 struct ftrace_probe_ops *ops,
989 void *data);
990};
991
992struct ftrace_func_mapper;
993typedef int (*ftrace_mapper_func)(void *data);
994
995struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
996void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
997 unsigned long ip);
998int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
999 unsigned long ip, void *data);
1000void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1001 unsigned long ip);
1002void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1003 ftrace_mapper_func free_func);
1004
1005extern int
1006register_ftrace_function_probe(char *glob, struct trace_array *tr,
1007 struct ftrace_probe_ops *ops, void *data);
1008extern int
1009unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1010 struct ftrace_probe_ops *ops);
1011extern void clear_ftrace_function_probes(struct trace_array *tr);
1012
1013int register_ftrace_command(struct ftrace_func_command *cmd);
1014int unregister_ftrace_command(struct ftrace_func_command *cmd);
1015
1016void ftrace_create_filter_files(struct ftrace_ops *ops,
1017 struct dentry *parent);
1018void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1019#else
1020struct ftrace_func_command;
1021
1022static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1023{
1024 return -EINVAL;
1025}
1026static inline __init int unregister_ftrace_command(char *cmd_name)
1027{
1028 return -EINVAL;
1029}
1030static inline void clear_ftrace_function_probes(struct trace_array *tr)
1031{
1032}
1033
1034/*
1035 * The ops parameter passed in is usually undefined.
1036 * This must be a macro.
1037 */
1038#define ftrace_create_filter_files(ops, parent) do { } while (0)
1039#define ftrace_destroy_filter_files(ops) do { } while (0)
1040#endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1041
1042bool ftrace_event_is_function(struct trace_event_call *call);
1043
1044/*
1045 * struct trace_parser - servers for reading the user input separated by spaces
1046 * @cont: set if the input is not complete - no final space char was found
1047 * @buffer: holds the parsed user input
1048 * @idx: user input length
1049 * @size: buffer size
1050 */
1051struct trace_parser {
1052 bool cont;
1053 char *buffer;
1054 unsigned idx;
1055 unsigned size;
1056};
1057
1058static inline bool trace_parser_loaded(struct trace_parser *parser)
1059{
1060 return (parser->idx != 0);
1061}
1062
1063static inline bool trace_parser_cont(struct trace_parser *parser)
1064{
1065 return parser->cont;
1066}
1067
1068static inline void trace_parser_clear(struct trace_parser *parser)
1069{
1070 parser->cont = false;
1071 parser->idx = 0;
1072}
1073
1074extern int trace_parser_get_init(struct trace_parser *parser, int size);
1075extern void trace_parser_put(struct trace_parser *parser);
1076extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1077 size_t cnt, loff_t *ppos);
1078
1079/*
1080 * Only create function graph options if function graph is configured.
1081 */
1082#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1083# define FGRAPH_FLAGS \
1084 C(DISPLAY_GRAPH, "display-graph"),
1085#else
1086# define FGRAPH_FLAGS
1087#endif
1088
1089#ifdef CONFIG_BRANCH_TRACER
1090# define BRANCH_FLAGS \
1091 C(BRANCH, "branch"),
1092#else
1093# define BRANCH_FLAGS
1094#endif
1095
1096#ifdef CONFIG_FUNCTION_TRACER
1097# define FUNCTION_FLAGS \
1098 C(FUNCTION, "function-trace"), \
1099 C(FUNC_FORK, "function-fork"),
1100# define FUNCTION_DEFAULT_FLAGS TRACE_ITER_FUNCTION
1101#else
1102# define FUNCTION_FLAGS
1103# define FUNCTION_DEFAULT_FLAGS 0UL
1104# define TRACE_ITER_FUNC_FORK 0UL
1105#endif
1106
1107#ifdef CONFIG_STACKTRACE
1108# define STACK_FLAGS \
1109 C(STACKTRACE, "stacktrace"),
1110#else
1111# define STACK_FLAGS
1112#endif
1113
1114/*
1115 * trace_iterator_flags is an enumeration that defines bit
1116 * positions into trace_flags that controls the output.
1117 *
1118 * NOTE: These bits must match the trace_options array in
1119 * trace.c (this macro guarantees it).
1120 */
1121#define TRACE_FLAGS \
1122 C(PRINT_PARENT, "print-parent"), \
1123 C(SYM_OFFSET, "sym-offset"), \
1124 C(SYM_ADDR, "sym-addr"), \
1125 C(VERBOSE, "verbose"), \
1126 C(RAW, "raw"), \
1127 C(HEX, "hex"), \
1128 C(BIN, "bin"), \
1129 C(BLOCK, "block"), \
1130 C(PRINTK, "trace_printk"), \
1131 C(ANNOTATE, "annotate"), \
1132 C(USERSTACKTRACE, "userstacktrace"), \
1133 C(SYM_USEROBJ, "sym-userobj"), \
1134 C(PRINTK_MSGONLY, "printk-msg-only"), \
1135 C(CONTEXT_INFO, "context-info"), /* Print pid/cpu/time */ \
1136 C(LATENCY_FMT, "latency-format"), \
1137 C(RECORD_CMD, "record-cmd"), \
1138 C(RECORD_TGID, "record-tgid"), \
1139 C(OVERWRITE, "overwrite"), \
1140 C(STOP_ON_FREE, "disable_on_free"), \
1141 C(IRQ_INFO, "irq-info"), \
1142 C(MARKERS, "markers"), \
1143 C(EVENT_FORK, "event-fork"), \
1144 FUNCTION_FLAGS \
1145 FGRAPH_FLAGS \
1146 STACK_FLAGS \
1147 BRANCH_FLAGS
1148
1149/*
1150 * By defining C, we can make TRACE_FLAGS a list of bit names
1151 * that will define the bits for the flag masks.
1152 */
1153#undef C
1154#define C(a, b) TRACE_ITER_##a##_BIT
1155
1156enum trace_iterator_bits {
1157 TRACE_FLAGS
1158 /* Make sure we don't go more than we have bits for */
1159 TRACE_ITER_LAST_BIT
1160};
1161
1162/*
1163 * By redefining C, we can make TRACE_FLAGS a list of masks that
1164 * use the bits as defined above.
1165 */
1166#undef C
1167#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1168
1169enum trace_iterator_flags { TRACE_FLAGS };
1170
1171/*
1172 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1173 * control the output of kernel symbols.
1174 */
1175#define TRACE_ITER_SYM_MASK \
1176 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1177
1178extern struct tracer nop_trace;
1179
1180#ifdef CONFIG_BRANCH_TRACER
1181extern int enable_branch_tracing(struct trace_array *tr);
1182extern void disable_branch_tracing(void);
1183static inline int trace_branch_enable(struct trace_array *tr)
1184{
1185 if (tr->trace_flags & TRACE_ITER_BRANCH)
1186 return enable_branch_tracing(tr);
1187 return 0;
1188}
1189static inline void trace_branch_disable(void)
1190{
1191 /* due to races, always disable */
1192 disable_branch_tracing();
1193}
1194#else
1195static inline int trace_branch_enable(struct trace_array *tr)
1196{
1197 return 0;
1198}
1199static inline void trace_branch_disable(void)
1200{
1201}
1202#endif /* CONFIG_BRANCH_TRACER */
1203
1204/* set ring buffers to default size if not already done so */
1205int tracing_update_buffers(void);
1206
1207struct ftrace_event_field {
1208 struct list_head link;
1209 const char *name;
1210 const char *type;
1211 int filter_type;
1212 int offset;
1213 int size;
1214 int is_signed;
1215};
1216
1217struct prog_entry;
1218
1219struct event_filter {
1220 struct prog_entry __rcu *prog;
1221 char *filter_string;
1222};
1223
1224struct event_subsystem {
1225 struct list_head list;
1226 const char *name;
1227 struct event_filter *filter;
1228 int ref_count;
1229};
1230
1231struct trace_subsystem_dir {
1232 struct list_head list;
1233 struct event_subsystem *subsystem;
1234 struct trace_array *tr;
1235 struct dentry *entry;
1236 int ref_count;
1237 int nr_events;
1238};
1239
1240extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1241 struct ring_buffer *buffer,
1242 struct ring_buffer_event *event);
1243
1244void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1245 struct ring_buffer *buffer,
1246 struct ring_buffer_event *event,
1247 unsigned long flags, int pc,
1248 struct pt_regs *regs);
1249
1250static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1251 struct ring_buffer *buffer,
1252 struct ring_buffer_event *event,
1253 unsigned long flags, int pc)
1254{
1255 trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1256}
1257
1258DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1259DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1260void trace_buffered_event_disable(void);
1261void trace_buffered_event_enable(void);
1262
1263static inline void
1264__trace_event_discard_commit(struct ring_buffer *buffer,
1265 struct ring_buffer_event *event)
1266{
1267 if (this_cpu_read(trace_buffered_event) == event) {
1268 /* Simply release the temp buffer */
1269 this_cpu_dec(trace_buffered_event_cnt);
1270 return;
1271 }
1272 ring_buffer_discard_commit(buffer, event);
1273}
1274
1275/*
1276 * Helper function for event_trigger_unlock_commit{_regs}().
1277 * If there are event triggers attached to this event that requires
1278 * filtering against its fields, then they wil be called as the
1279 * entry already holds the field information of the current event.
1280 *
1281 * It also checks if the event should be discarded or not.
1282 * It is to be discarded if the event is soft disabled and the
1283 * event was only recorded to process triggers, or if the event
1284 * filter is active and this event did not match the filters.
1285 *
1286 * Returns true if the event is discarded, false otherwise.
1287 */
1288static inline bool
1289__event_trigger_test_discard(struct trace_event_file *file,
1290 struct ring_buffer *buffer,
1291 struct ring_buffer_event *event,
1292 void *entry,
1293 enum event_trigger_type *tt)
1294{
1295 unsigned long eflags = file->flags;
1296
1297 if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1298 *tt = event_triggers_call(file, entry, event);
1299
1300 if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1301 (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1302 !filter_match_preds(file->filter, entry))) {
1303 __trace_event_discard_commit(buffer, event);
1304 return true;
1305 }
1306
1307 return false;
1308}
1309
1310/**
1311 * event_trigger_unlock_commit - handle triggers and finish event commit
1312 * @file: The file pointer assoctiated to the event
1313 * @buffer: The ring buffer that the event is being written to
1314 * @event: The event meta data in the ring buffer
1315 * @entry: The event itself
1316 * @irq_flags: The state of the interrupts at the start of the event
1317 * @pc: The state of the preempt count at the start of the event.
1318 *
1319 * This is a helper function to handle triggers that require data
1320 * from the event itself. It also tests the event against filters and
1321 * if the event is soft disabled and should be discarded.
1322 */
1323static inline void
1324event_trigger_unlock_commit(struct trace_event_file *file,
1325 struct ring_buffer *buffer,
1326 struct ring_buffer_event *event,
1327 void *entry, unsigned long irq_flags, int pc)
1328{
1329 enum event_trigger_type tt = ETT_NONE;
1330
1331 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1332 trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1333
1334 if (tt)
1335 event_triggers_post_call(file, tt);
1336}
1337
1338/**
1339 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1340 * @file: The file pointer assoctiated to the event
1341 * @buffer: The ring buffer that the event is being written to
1342 * @event: The event meta data in the ring buffer
1343 * @entry: The event itself
1344 * @irq_flags: The state of the interrupts at the start of the event
1345 * @pc: The state of the preempt count at the start of the event.
1346 *
1347 * This is a helper function to handle triggers that require data
1348 * from the event itself. It also tests the event against filters and
1349 * if the event is soft disabled and should be discarded.
1350 *
1351 * Same as event_trigger_unlock_commit() but calls
1352 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1353 */
1354static inline void
1355event_trigger_unlock_commit_regs(struct trace_event_file *file,
1356 struct ring_buffer *buffer,
1357 struct ring_buffer_event *event,
1358 void *entry, unsigned long irq_flags, int pc,
1359 struct pt_regs *regs)
1360{
1361 enum event_trigger_type tt = ETT_NONE;
1362
1363 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1364 trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1365 irq_flags, pc, regs);
1366
1367 if (tt)
1368 event_triggers_post_call(file, tt);
1369}
1370
1371#define FILTER_PRED_INVALID ((unsigned short)-1)
1372#define FILTER_PRED_IS_RIGHT (1 << 15)
1373#define FILTER_PRED_FOLD (1 << 15)
1374
1375/*
1376 * The max preds is the size of unsigned short with
1377 * two flags at the MSBs. One bit is used for both the IS_RIGHT
1378 * and FOLD flags. The other is reserved.
1379 *
1380 * 2^14 preds is way more than enough.
1381 */
1382#define MAX_FILTER_PRED 16384
1383
1384struct filter_pred;
1385struct regex;
1386
1387typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1388
1389typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1390
1391enum regex_type {
1392 MATCH_FULL = 0,
1393 MATCH_FRONT_ONLY,
1394 MATCH_MIDDLE_ONLY,
1395 MATCH_END_ONLY,
1396 MATCH_GLOB,
1397};
1398
1399struct regex {
1400 char pattern[MAX_FILTER_STR_VAL];
1401 int len;
1402 int field_len;
1403 regex_match_func match;
1404};
1405
1406struct filter_pred {
1407 filter_pred_fn_t fn;
1408 u64 val;
1409 struct regex regex;
1410 unsigned short *ops;
1411 struct ftrace_event_field *field;
1412 int offset;
1413 int not;
1414 int op;
1415};
1416
1417static inline bool is_string_field(struct ftrace_event_field *field)
1418{
1419 return field->filter_type == FILTER_DYN_STRING ||
1420 field->filter_type == FILTER_STATIC_STRING ||
1421 field->filter_type == FILTER_PTR_STRING ||
1422 field->filter_type == FILTER_COMM;
1423}
1424
1425static inline bool is_function_field(struct ftrace_event_field *field)
1426{
1427 return field->filter_type == FILTER_TRACE_FN;
1428}
1429
1430extern enum regex_type
1431filter_parse_regex(char *buff, int len, char **search, int *not);
1432extern void print_event_filter(struct trace_event_file *file,
1433 struct trace_seq *s);
1434extern int apply_event_filter(struct trace_event_file *file,
1435 char *filter_string);
1436extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1437 char *filter_string);
1438extern void print_subsystem_event_filter(struct event_subsystem *system,
1439 struct trace_seq *s);
1440extern int filter_assign_type(const char *type);
1441extern int create_event_filter(struct trace_event_call *call,
1442 char *filter_str, bool set_str,
1443 struct event_filter **filterp);
1444extern void free_event_filter(struct event_filter *filter);
1445
1446struct ftrace_event_field *
1447trace_find_event_field(struct trace_event_call *call, char *name);
1448
1449extern void trace_event_enable_cmd_record(bool enable);
1450extern void trace_event_enable_tgid_record(bool enable);
1451
1452extern int event_trace_init(void);
1453extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1454extern int event_trace_del_tracer(struct trace_array *tr);
1455
1456extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1457 const char *system,
1458 const char *event);
1459extern struct trace_event_file *find_event_file(struct trace_array *tr,
1460 const char *system,
1461 const char *event);
1462
1463static inline void *event_file_data(struct file *filp)
1464{
1465 return READ_ONCE(file_inode(filp)->i_private);
1466}
1467
1468extern struct mutex event_mutex;
1469extern struct list_head ftrace_events;
1470
1471extern const struct file_operations event_trigger_fops;
1472extern const struct file_operations event_hist_fops;
1473
1474#ifdef CONFIG_HIST_TRIGGERS
1475extern int register_trigger_hist_cmd(void);
1476extern int register_trigger_hist_enable_disable_cmds(void);
1477#else
1478static inline int register_trigger_hist_cmd(void) { return 0; }
1479static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1480#endif
1481
1482extern int register_trigger_cmds(void);
1483extern void clear_event_triggers(struct trace_array *tr);
1484
1485struct event_trigger_data {
1486 unsigned long count;
1487 int ref;
1488 struct event_trigger_ops *ops;
1489 struct event_command *cmd_ops;
1490 struct event_filter __rcu *filter;
1491 char *filter_str;
1492 void *private_data;
1493 bool paused;
1494 bool paused_tmp;
1495 struct list_head list;
1496 char *name;
1497 struct list_head named_list;
1498 struct event_trigger_data *named_data;
1499};
1500
1501/* Avoid typos */
1502#define ENABLE_EVENT_STR "enable_event"
1503#define DISABLE_EVENT_STR "disable_event"
1504#define ENABLE_HIST_STR "enable_hist"
1505#define DISABLE_HIST_STR "disable_hist"
1506
1507struct enable_trigger_data {
1508 struct trace_event_file *file;
1509 bool enable;
1510 bool hist;
1511};
1512
1513extern int event_enable_trigger_print(struct seq_file *m,
1514 struct event_trigger_ops *ops,
1515 struct event_trigger_data *data);
1516extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1517 struct event_trigger_data *data);
1518extern int event_enable_trigger_func(struct event_command *cmd_ops,
1519 struct trace_event_file *file,
1520 char *glob, char *cmd, char *param);
1521extern int event_enable_register_trigger(char *glob,
1522 struct event_trigger_ops *ops,
1523 struct event_trigger_data *data,
1524 struct trace_event_file *file);
1525extern void event_enable_unregister_trigger(char *glob,
1526 struct event_trigger_ops *ops,
1527 struct event_trigger_data *test,
1528 struct trace_event_file *file);
1529extern void trigger_data_free(struct event_trigger_data *data);
1530extern int event_trigger_init(struct event_trigger_ops *ops,
1531 struct event_trigger_data *data);
1532extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1533 int trigger_enable);
1534extern void update_cond_flag(struct trace_event_file *file);
1535extern int set_trigger_filter(char *filter_str,
1536 struct event_trigger_data *trigger_data,
1537 struct trace_event_file *file);
1538extern struct event_trigger_data *find_named_trigger(const char *name);
1539extern bool is_named_trigger(struct event_trigger_data *test);
1540extern int save_named_trigger(const char *name,
1541 struct event_trigger_data *data);
1542extern void del_named_trigger(struct event_trigger_data *data);
1543extern void pause_named_trigger(struct event_trigger_data *data);
1544extern void unpause_named_trigger(struct event_trigger_data *data);
1545extern void set_named_trigger_data(struct event_trigger_data *data,
1546 struct event_trigger_data *named_data);
1547extern struct event_trigger_data *
1548get_named_trigger_data(struct event_trigger_data *data);
1549extern int register_event_command(struct event_command *cmd);
1550extern int unregister_event_command(struct event_command *cmd);
1551extern int register_trigger_hist_enable_disable_cmds(void);
1552
1553/**
1554 * struct event_trigger_ops - callbacks for trace event triggers
1555 *
1556 * The methods in this structure provide per-event trigger hooks for
1557 * various trigger operations.
1558 *
1559 * All the methods below, except for @init() and @free(), must be
1560 * implemented.
1561 *
1562 * @func: The trigger 'probe' function called when the triggering
1563 * event occurs. The data passed into this callback is the data
1564 * that was supplied to the event_command @reg() function that
1565 * registered the trigger (see struct event_command) along with
1566 * the trace record, rec.
1567 *
1568 * @init: An optional initialization function called for the trigger
1569 * when the trigger is registered (via the event_command reg()
1570 * function). This can be used to perform per-trigger
1571 * initialization such as incrementing a per-trigger reference
1572 * count, for instance. This is usually implemented by the
1573 * generic utility function @event_trigger_init() (see
1574 * trace_event_triggers.c).
1575 *
1576 * @free: An optional de-initialization function called for the
1577 * trigger when the trigger is unregistered (via the
1578 * event_command @reg() function). This can be used to perform
1579 * per-trigger de-initialization such as decrementing a
1580 * per-trigger reference count and freeing corresponding trigger
1581 * data, for instance. This is usually implemented by the
1582 * generic utility function @event_trigger_free() (see
1583 * trace_event_triggers.c).
1584 *
1585 * @print: The callback function invoked to have the trigger print
1586 * itself. This is usually implemented by a wrapper function
1587 * that calls the generic utility function @event_trigger_print()
1588 * (see trace_event_triggers.c).
1589 */
1590struct event_trigger_ops {
1591 void (*func)(struct event_trigger_data *data,
1592 void *rec,
1593 struct ring_buffer_event *rbe);
1594 int (*init)(struct event_trigger_ops *ops,
1595 struct event_trigger_data *data);
1596 void (*free)(struct event_trigger_ops *ops,
1597 struct event_trigger_data *data);
1598 int (*print)(struct seq_file *m,
1599 struct event_trigger_ops *ops,
1600 struct event_trigger_data *data);
1601};
1602
1603/**
1604 * struct event_command - callbacks and data members for event commands
1605 *
1606 * Event commands are invoked by users by writing the command name
1607 * into the 'trigger' file associated with a trace event. The
1608 * parameters associated with a specific invocation of an event
1609 * command are used to create an event trigger instance, which is
1610 * added to the list of trigger instances associated with that trace
1611 * event. When the event is hit, the set of triggers associated with
1612 * that event is invoked.
1613 *
1614 * The data members in this structure provide per-event command data
1615 * for various event commands.
1616 *
1617 * All the data members below, except for @post_trigger, must be set
1618 * for each event command.
1619 *
1620 * @name: The unique name that identifies the event command. This is
1621 * the name used when setting triggers via trigger files.
1622 *
1623 * @trigger_type: A unique id that identifies the event command
1624 * 'type'. This value has two purposes, the first to ensure that
1625 * only one trigger of the same type can be set at a given time
1626 * for a particular event e.g. it doesn't make sense to have both
1627 * a traceon and traceoff trigger attached to a single event at
1628 * the same time, so traceon and traceoff have the same type
1629 * though they have different names. The @trigger_type value is
1630 * also used as a bit value for deferring the actual trigger
1631 * action until after the current event is finished. Some
1632 * commands need to do this if they themselves log to the trace
1633 * buffer (see the @post_trigger() member below). @trigger_type
1634 * values are defined by adding new values to the trigger_type
1635 * enum in include/linux/trace_events.h.
1636 *
1637 * @flags: See the enum event_command_flags below.
1638 *
1639 * All the methods below, except for @set_filter() and @unreg_all(),
1640 * must be implemented.
1641 *
1642 * @func: The callback function responsible for parsing and
1643 * registering the trigger written to the 'trigger' file by the
1644 * user. It allocates the trigger instance and registers it with
1645 * the appropriate trace event. It makes use of the other
1646 * event_command callback functions to orchestrate this, and is
1647 * usually implemented by the generic utility function
1648 * @event_trigger_callback() (see trace_event_triggers.c).
1649 *
1650 * @reg: Adds the trigger to the list of triggers associated with the
1651 * event, and enables the event trigger itself, after
1652 * initializing it (via the event_trigger_ops @init() function).
1653 * This is also where commands can use the @trigger_type value to
1654 * make the decision as to whether or not multiple instances of
1655 * the trigger should be allowed. This is usually implemented by
1656 * the generic utility function @register_trigger() (see
1657 * trace_event_triggers.c).
1658 *
1659 * @unreg: Removes the trigger from the list of triggers associated
1660 * with the event, and disables the event trigger itself, after
1661 * initializing it (via the event_trigger_ops @free() function).
1662 * This is usually implemented by the generic utility function
1663 * @unregister_trigger() (see trace_event_triggers.c).
1664 *
1665 * @unreg_all: An optional function called to remove all the triggers
1666 * from the list of triggers associated with the event. Called
1667 * when a trigger file is opened in truncate mode.
1668 *
1669 * @set_filter: An optional function called to parse and set a filter
1670 * for the trigger. If no @set_filter() method is set for the
1671 * event command, filters set by the user for the command will be
1672 * ignored. This is usually implemented by the generic utility
1673 * function @set_trigger_filter() (see trace_event_triggers.c).
1674 *
1675 * @get_trigger_ops: The callback function invoked to retrieve the
1676 * event_trigger_ops implementation associated with the command.
1677 */
1678struct event_command {
1679 struct list_head list;
1680 char *name;
1681 enum event_trigger_type trigger_type;
1682 int flags;
1683 int (*func)(struct event_command *cmd_ops,
1684 struct trace_event_file *file,
1685 char *glob, char *cmd, char *params);
1686 int (*reg)(char *glob,
1687 struct event_trigger_ops *ops,
1688 struct event_trigger_data *data,
1689 struct trace_event_file *file);
1690 void (*unreg)(char *glob,
1691 struct event_trigger_ops *ops,
1692 struct event_trigger_data *data,
1693 struct trace_event_file *file);
1694 void (*unreg_all)(struct trace_event_file *file);
1695 int (*set_filter)(char *filter_str,
1696 struct event_trigger_data *data,
1697 struct trace_event_file *file);
1698 struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1699};
1700
1701/**
1702 * enum event_command_flags - flags for struct event_command
1703 *
1704 * @POST_TRIGGER: A flag that says whether or not this command needs
1705 * to have its action delayed until after the current event has
1706 * been closed. Some triggers need to avoid being invoked while
1707 * an event is currently in the process of being logged, since
1708 * the trigger may itself log data into the trace buffer. Thus
1709 * we make sure the current event is committed before invoking
1710 * those triggers. To do that, the trigger invocation is split
1711 * in two - the first part checks the filter using the current
1712 * trace record; if a command has the @post_trigger flag set, it
1713 * sets a bit for itself in the return value, otherwise it
1714 * directly invokes the trigger. Once all commands have been
1715 * either invoked or set their return flag, the current record is
1716 * either committed or discarded. At that point, if any commands
1717 * have deferred their triggers, those commands are finally
1718 * invoked following the close of the current event. In other
1719 * words, if the event_trigger_ops @func() probe implementation
1720 * itself logs to the trace buffer, this flag should be set,
1721 * otherwise it can be left unspecified.
1722 *
1723 * @NEEDS_REC: A flag that says whether or not this command needs
1724 * access to the trace record in order to perform its function,
1725 * regardless of whether or not it has a filter associated with
1726 * it (filters make a trigger require access to the trace record
1727 * but are not always present).
1728 */
1729enum event_command_flags {
1730 EVENT_CMD_FL_POST_TRIGGER = 1,
1731 EVENT_CMD_FL_NEEDS_REC = 2,
1732};
1733
1734static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1735{
1736 return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1737}
1738
1739static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1740{
1741 return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1742}
1743
1744extern int trace_event_enable_disable(struct trace_event_file *file,
1745 int enable, int soft_disable);
1746extern int tracing_alloc_snapshot(void);
1747
1748extern const char *__start___trace_bprintk_fmt[];
1749extern const char *__stop___trace_bprintk_fmt[];
1750
1751extern const char *__start___tracepoint_str[];
1752extern const char *__stop___tracepoint_str[];
1753
1754void trace_printk_control(bool enabled);
1755void trace_printk_init_buffers(void);
1756void trace_printk_start_comm(void);
1757int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1758int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1759
1760#define MAX_EVENT_NAME_LEN 64
1761
1762extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1763extern ssize_t trace_parse_run_command(struct file *file,
1764 const char __user *buffer, size_t count, loff_t *ppos,
1765 int (*createfn)(int, char**));
1766
1767/*
1768 * Normal trace_printk() and friends allocates special buffers
1769 * to do the manipulation, as well as saves the print formats
1770 * into sections to display. But the trace infrastructure wants
1771 * to use these without the added overhead at the price of being
1772 * a bit slower (used mainly for warnings, where we don't care
1773 * about performance). The internal_trace_puts() is for such
1774 * a purpose.
1775 */
1776#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1777
1778#undef FTRACE_ENTRY
1779#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \
1780 extern struct trace_event_call \
1781 __aligned(4) event_##call;
1782#undef FTRACE_ENTRY_DUP
1783#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
1784 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1785 filter)
1786#undef FTRACE_ENTRY_PACKED
1787#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1788 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1789 filter)
1790
1791#include "trace_entries.h"
1792
1793#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1794int perf_ftrace_event_register(struct trace_event_call *call,
1795 enum trace_reg type, void *data);
1796#else
1797#define perf_ftrace_event_register NULL
1798#endif
1799
1800#ifdef CONFIG_FTRACE_SYSCALLS
1801void init_ftrace_syscalls(void);
1802const char *get_syscall_name(int syscall);
1803#else
1804static inline void init_ftrace_syscalls(void) { }
1805static inline const char *get_syscall_name(int syscall)
1806{
1807 return NULL;
1808}
1809#endif
1810
1811#ifdef CONFIG_EVENT_TRACING
1812void trace_event_init(void);
1813void trace_event_eval_update(struct trace_eval_map **map, int len);
1814#else
1815static inline void __init trace_event_init(void) { }
1816static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1817#endif
1818
1819#ifdef CONFIG_TRACER_SNAPSHOT
1820void tracing_snapshot_instance(struct trace_array *tr);
1821int tracing_alloc_snapshot_instance(struct trace_array *tr);
1822#else
1823static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1824static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1825{
1826 return 0;
1827}
1828#endif
1829
1830#ifdef CONFIG_PREEMPT_TRACER
1831void tracer_preempt_on(unsigned long a0, unsigned long a1);
1832void tracer_preempt_off(unsigned long a0, unsigned long a1);
1833#else
1834static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1835static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1836#endif
1837#ifdef CONFIG_IRQSOFF_TRACER
1838void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1839void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1840#else
1841static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1842static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1843#endif
1844
1845extern struct trace_iterator *tracepoint_print_iter;
1846
1847#endif /* _LINUX_KERNEL_TRACE_H */