projects/linux·blob v5.12 · 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/trace.h>
15#include <linux/hw_breakpoint.h>
16#include <linux/trace_seq.h>
17#include <linux/trace_events.h>
18#include <linux/compiler.h>
19#include <linux/glob.h>
20#include <linux/irq_work.h>
21#include <linux/workqueue.h>
22#include <linux/ctype.h>
23
24#ifdef CONFIG_FTRACE_SYSCALLS
25#include <asm/unistd.h> /* For NR_SYSCALLS */
26#include <asm/syscall.h> /* some archs define it here */
27#endif
28
29enum trace_type {
30 __TRACE_FIRST_TYPE = 0,
31
32 TRACE_FN,
33 TRACE_CTX,
34 TRACE_WAKE,
35 TRACE_STACK,
36 TRACE_PRINT,
37 TRACE_BPRINT,
38 TRACE_MMIO_RW,
39 TRACE_MMIO_MAP,
40 TRACE_BRANCH,
41 TRACE_GRAPH_RET,
42 TRACE_GRAPH_ENT,
43 TRACE_USER_STACK,
44 TRACE_BLK,
45 TRACE_BPUTS,
46 TRACE_HWLAT,
47 TRACE_RAW_DATA,
48
49 __TRACE_LAST_TYPE,
50};
51
52
53#undef __field
54#define __field(type, item) type item;
55
56#undef __field_fn
57#define __field_fn(type, item) type item;
58
59#undef __field_struct
60#define __field_struct(type, item) __field(type, item)
61
62#undef __field_desc
63#define __field_desc(type, container, item)
64
65#undef __field_packed
66#define __field_packed(type, container, item)
67
68#undef __array
69#define __array(type, item, size) type item[size];
70
71#undef __array_desc
72#define __array_desc(type, container, item, size)
73
74#undef __dynamic_array
75#define __dynamic_array(type, item) type item[];
76
77#undef F_STRUCT
78#define F_STRUCT(args...) args
79
80#undef FTRACE_ENTRY
81#define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \
82 struct struct_name { \
83 struct trace_entry ent; \
84 tstruct \
85 }
86
87#undef FTRACE_ENTRY_DUP
88#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
89
90#undef FTRACE_ENTRY_REG
91#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, regfn) \
92 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
93
94#undef FTRACE_ENTRY_PACKED
95#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print) \
96 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
97
98#include "trace_entries.h"
99
100/* Use this for memory failure errors */
101#define MEM_FAIL(condition, fmt, ...) ({ \
102 static bool __section(".data.once") __warned; \
103 int __ret_warn_once = !!(condition); \
104 \
105 if (unlikely(__ret_warn_once && !__warned)) { \
106 __warned = true; \
107 pr_err("ERROR: " fmt, ##__VA_ARGS__); \
108 } \
109 unlikely(__ret_warn_once); \
110})
111
112/*
113 * syscalls are special, and need special handling, this is why
114 * they are not included in trace_entries.h
115 */
116struct syscall_trace_enter {
117 struct trace_entry ent;
118 int nr;
119 unsigned long args[];
120};
121
122struct syscall_trace_exit {
123 struct trace_entry ent;
124 int nr;
125 long ret;
126};
127
128struct kprobe_trace_entry_head {
129 struct trace_entry ent;
130 unsigned long ip;
131};
132
133struct kretprobe_trace_entry_head {
134 struct trace_entry ent;
135 unsigned long func;
136 unsigned long ret_ip;
137};
138
139#define TRACE_BUF_SIZE 1024
140
141struct trace_array;
142
143/*
144 * The CPU trace array - it consists of thousands of trace entries
145 * plus some other descriptor data: (for example which task started
146 * the trace, etc.)
147 */
148struct trace_array_cpu {
149 atomic_t disabled;
150 void *buffer_page; /* ring buffer spare */
151
152 unsigned long entries;
153 unsigned long saved_latency;
154 unsigned long critical_start;
155 unsigned long critical_end;
156 unsigned long critical_sequence;
157 unsigned long nice;
158 unsigned long policy;
159 unsigned long rt_priority;
160 unsigned long skipped_entries;
161 u64 preempt_timestamp;
162 pid_t pid;
163 kuid_t uid;
164 char comm[TASK_COMM_LEN];
165
166#ifdef CONFIG_FUNCTION_TRACER
167 int ftrace_ignore_pid;
168#endif
169 bool ignore_pid;
170};
171
172struct tracer;
173struct trace_option_dentry;
174
175struct array_buffer {
176 struct trace_array *tr;
177 struct trace_buffer *buffer;
178 struct trace_array_cpu __percpu *data;
179 u64 time_start;
180 int cpu;
181};
182
183#define TRACE_FLAGS_MAX_SIZE 32
184
185struct trace_options {
186 struct tracer *tracer;
187 struct trace_option_dentry *topts;
188};
189
190struct trace_pid_list {
191 int pid_max;
192 unsigned long *pids;
193};
194
195enum {
196 TRACE_PIDS = BIT(0),
197 TRACE_NO_PIDS = BIT(1),
198};
199
200static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
201 struct trace_pid_list *no_pid_list)
202{
203 /* Return true if the pid list in type has pids */
204 return ((type & TRACE_PIDS) && pid_list) ||
205 ((type & TRACE_NO_PIDS) && no_pid_list);
206}
207
208static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
209 struct trace_pid_list *no_pid_list)
210{
211 /*
212 * Turning off what is in @type, return true if the "other"
213 * pid list, still has pids in it.
214 */
215 return (!(type & TRACE_PIDS) && pid_list) ||
216 (!(type & TRACE_NO_PIDS) && no_pid_list);
217}
218
219typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
220
221/**
222 * struct cond_snapshot - conditional snapshot data and callback
223 *
224 * The cond_snapshot structure encapsulates a callback function and
225 * data associated with the snapshot for a given tracing instance.
226 *
227 * When a snapshot is taken conditionally, by invoking
228 * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
229 * passed in turn to the cond_snapshot.update() function. That data
230 * can be compared by the update() implementation with the cond_data
231 * contained within the struct cond_snapshot instance associated with
232 * the trace_array. Because the tr->max_lock is held throughout the
233 * update() call, the update() function can directly retrieve the
234 * cond_snapshot and cond_data associated with the per-instance
235 * snapshot associated with the trace_array.
236 *
237 * The cond_snapshot.update() implementation can save data to be
238 * associated with the snapshot if it decides to, and returns 'true'
239 * in that case, or it returns 'false' if the conditional snapshot
240 * shouldn't be taken.
241 *
242 * The cond_snapshot instance is created and associated with the
243 * user-defined cond_data by tracing_cond_snapshot_enable().
244 * Likewise, the cond_snapshot instance is destroyed and is no longer
245 * associated with the trace instance by
246 * tracing_cond_snapshot_disable().
247 *
248 * The method below is required.
249 *
250 * @update: When a conditional snapshot is invoked, the update()
251 * callback function is invoked with the tr->max_lock held. The
252 * update() implementation signals whether or not to actually
253 * take the snapshot, by returning 'true' if so, 'false' if no
254 * snapshot should be taken. Because the max_lock is held for
255 * the duration of update(), the implementation is safe to
256 * directly retrieved and save any implementation data it needs
257 * to in association with the snapshot.
258 */
259struct cond_snapshot {
260 void *cond_data;
261 cond_update_fn_t update;
262};
263
264/*
265 * The trace array - an array of per-CPU trace arrays. This is the
266 * highest level data structure that individual tracers deal with.
267 * They have on/off state as well:
268 */
269struct trace_array {
270 struct list_head list;
271 char *name;
272 struct array_buffer array_buffer;
273#ifdef CONFIG_TRACER_MAX_TRACE
274 /*
275 * The max_buffer is used to snapshot the trace when a maximum
276 * latency is reached, or when the user initiates a snapshot.
277 * Some tracers will use this to store a maximum trace while
278 * it continues examining live traces.
279 *
280 * The buffers for the max_buffer are set up the same as the array_buffer
281 * When a snapshot is taken, the buffer of the max_buffer is swapped
282 * with the buffer of the array_buffer and the buffers are reset for
283 * the array_buffer so the tracing can continue.
284 */
285 struct array_buffer max_buffer;
286 bool allocated_snapshot;
287#endif
288#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
289 unsigned long max_latency;
290#ifdef CONFIG_FSNOTIFY
291 struct dentry *d_max_latency;
292 struct work_struct fsnotify_work;
293 struct irq_work fsnotify_irqwork;
294#endif
295#endif
296 struct trace_pid_list __rcu *filtered_pids;
297 struct trace_pid_list __rcu *filtered_no_pids;
298 /*
299 * max_lock is used to protect the swapping of buffers
300 * when taking a max snapshot. The buffers themselves are
301 * protected by per_cpu spinlocks. But the action of the swap
302 * needs its own lock.
303 *
304 * This is defined as a arch_spinlock_t in order to help
305 * with performance when lockdep debugging is enabled.
306 *
307 * It is also used in other places outside the update_max_tr
308 * so it needs to be defined outside of the
309 * CONFIG_TRACER_MAX_TRACE.
310 */
311 arch_spinlock_t max_lock;
312 int buffer_disabled;
313#ifdef CONFIG_FTRACE_SYSCALLS
314 int sys_refcount_enter;
315 int sys_refcount_exit;
316 struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
317 struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
318#endif
319 int stop_count;
320 int clock_id;
321 int nr_topts;
322 bool clear_trace;
323 int buffer_percent;
324 unsigned int n_err_log_entries;
325 struct tracer *current_trace;
326 unsigned int trace_flags;
327 unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE];
328 unsigned int flags;
329 raw_spinlock_t start_lock;
330 struct list_head err_log;
331 struct dentry *dir;
332 struct dentry *options;
333 struct dentry *percpu_dir;
334 struct dentry *event_dir;
335 struct trace_options *topts;
336 struct list_head systems;
337 struct list_head events;
338 struct trace_event_file *trace_marker_file;
339 cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
340 int ref;
341 int trace_ref;
342#ifdef CONFIG_FUNCTION_TRACER
343 struct ftrace_ops *ops;
344 struct trace_pid_list __rcu *function_pids;
345 struct trace_pid_list __rcu *function_no_pids;
346#ifdef CONFIG_DYNAMIC_FTRACE
347 /* All of these are protected by the ftrace_lock */
348 struct list_head func_probes;
349 struct list_head mod_trace;
350 struct list_head mod_notrace;
351#endif
352 /* function tracing enabled */
353 int function_enabled;
354#endif
355 int time_stamp_abs_ref;
356 struct list_head hist_vars;
357#ifdef CONFIG_TRACER_SNAPSHOT
358 struct cond_snapshot *cond_snapshot;
359#endif
360};
361
362enum {
363 TRACE_ARRAY_FL_GLOBAL = (1 << 0)
364};
365
366extern struct list_head ftrace_trace_arrays;
367
368extern struct mutex trace_types_lock;
369
370extern int trace_array_get(struct trace_array *tr);
371extern int tracing_check_open_get_tr(struct trace_array *tr);
372extern struct trace_array *trace_array_find(const char *instance);
373extern struct trace_array *trace_array_find_get(const char *instance);
374
375extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
376extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
377
378extern bool trace_clock_in_ns(struct trace_array *tr);
379
380/*
381 * The global tracer (top) should be the first trace array added,
382 * but we check the flag anyway.
383 */
384static inline struct trace_array *top_trace_array(void)
385{
386 struct trace_array *tr;
387
388 if (list_empty(&ftrace_trace_arrays))
389 return NULL;
390
391 tr = list_entry(ftrace_trace_arrays.prev,
392 typeof(*tr), list);
393 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
394 return tr;
395}
396
397#define FTRACE_CMP_TYPE(var, type) \
398 __builtin_types_compatible_p(typeof(var), type *)
399
400#undef IF_ASSIGN
401#define IF_ASSIGN(var, entry, etype, id) \
402 if (FTRACE_CMP_TYPE(var, etype)) { \
403 var = (typeof(var))(entry); \
404 WARN_ON(id != 0 && (entry)->type != id); \
405 break; \
406 }
407
408/* Will cause compile errors if type is not found. */
409extern void __ftrace_bad_type(void);
410
411/*
412 * The trace_assign_type is a verifier that the entry type is
413 * the same as the type being assigned. To add new types simply
414 * add a line with the following format:
415 *
416 * IF_ASSIGN(var, ent, type, id);
417 *
418 * Where "type" is the trace type that includes the trace_entry
419 * as the "ent" item. And "id" is the trace identifier that is
420 * used in the trace_type enum.
421 *
422 * If the type can have more than one id, then use zero.
423 */
424#define trace_assign_type(var, ent) \
425 do { \
426 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
427 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
428 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
429 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
430 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
431 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
432 IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \
433 IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT); \
434 IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
435 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
436 TRACE_MMIO_RW); \
437 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
438 TRACE_MMIO_MAP); \
439 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
440 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
441 TRACE_GRAPH_ENT); \
442 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
443 TRACE_GRAPH_RET); \
444 __ftrace_bad_type(); \
445 } while (0)
446
447/*
448 * An option specific to a tracer. This is a boolean value.
449 * The bit is the bit index that sets its value on the
450 * flags value in struct tracer_flags.
451 */
452struct tracer_opt {
453 const char *name; /* Will appear on the trace_options file */
454 u32 bit; /* Mask assigned in val field in tracer_flags */
455};
456
457/*
458 * The set of specific options for a tracer. Your tracer
459 * have to set the initial value of the flags val.
460 */
461struct tracer_flags {
462 u32 val;
463 struct tracer_opt *opts;
464 struct tracer *trace;
465};
466
467/* Makes more easy to define a tracer opt */
468#define TRACER_OPT(s, b) .name = #s, .bit = b
469
470
471struct trace_option_dentry {
472 struct tracer_opt *opt;
473 struct tracer_flags *flags;
474 struct trace_array *tr;
475 struct dentry *entry;
476};
477
478/**
479 * struct tracer - a specific tracer and its callbacks to interact with tracefs
480 * @name: the name chosen to select it on the available_tracers file
481 * @init: called when one switches to this tracer (echo name > current_tracer)
482 * @reset: called when one switches to another tracer
483 * @start: called when tracing is unpaused (echo 1 > tracing_on)
484 * @stop: called when tracing is paused (echo 0 > tracing_on)
485 * @update_thresh: called when tracing_thresh is updated
486 * @open: called when the trace file is opened
487 * @pipe_open: called when the trace_pipe file is opened
488 * @close: called when the trace file is released
489 * @pipe_close: called when the trace_pipe file is released
490 * @read: override the default read callback on trace_pipe
491 * @splice_read: override the default splice_read callback on trace_pipe
492 * @selftest: selftest to run on boot (see trace_selftest.c)
493 * @print_headers: override the first lines that describe your columns
494 * @print_line: callback that prints a trace
495 * @set_flag: signals one of your private flags changed (trace_options file)
496 * @flags: your private flags
497 */
498struct tracer {
499 const char *name;
500 int (*init)(struct trace_array *tr);
501 void (*reset)(struct trace_array *tr);
502 void (*start)(struct trace_array *tr);
503 void (*stop)(struct trace_array *tr);
504 int (*update_thresh)(struct trace_array *tr);
505 void (*open)(struct trace_iterator *iter);
506 void (*pipe_open)(struct trace_iterator *iter);
507 void (*close)(struct trace_iterator *iter);
508 void (*pipe_close)(struct trace_iterator *iter);
509 ssize_t (*read)(struct trace_iterator *iter,
510 struct file *filp, char __user *ubuf,
511 size_t cnt, loff_t *ppos);
512 ssize_t (*splice_read)(struct trace_iterator *iter,
513 struct file *filp,
514 loff_t *ppos,
515 struct pipe_inode_info *pipe,
516 size_t len,
517 unsigned int flags);
518#ifdef CONFIG_FTRACE_STARTUP_TEST
519 int (*selftest)(struct tracer *trace,
520 struct trace_array *tr);
521#endif
522 void (*print_header)(struct seq_file *m);
523 enum print_line_t (*print_line)(struct trace_iterator *iter);
524 /* If you handled the flag setting, return 0 */
525 int (*set_flag)(struct trace_array *tr,
526 u32 old_flags, u32 bit, int set);
527 /* Return 0 if OK with change, else return non-zero */
528 int (*flag_changed)(struct trace_array *tr,
529 u32 mask, int set);
530 struct tracer *next;
531 struct tracer_flags *flags;
532 int enabled;
533 bool print_max;
534 bool allow_instances;
535#ifdef CONFIG_TRACER_MAX_TRACE
536 bool use_max_tr;
537#endif
538 /* True if tracer cannot be enabled in kernel param */
539 bool noboot;
540};
541
542static inline struct ring_buffer_iter *
543trace_buffer_iter(struct trace_iterator *iter, int cpu)
544{
545 return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
546}
547
548int tracer_init(struct tracer *t, struct trace_array *tr);
549int tracing_is_enabled(void);
550void tracing_reset_online_cpus(struct array_buffer *buf);
551void tracing_reset_current(int cpu);
552void tracing_reset_all_online_cpus(void);
553int tracing_open_generic(struct inode *inode, struct file *filp);
554int tracing_open_generic_tr(struct inode *inode, struct file *filp);
555bool tracing_is_disabled(void);
556bool tracer_tracing_is_on(struct trace_array *tr);
557void tracer_tracing_on(struct trace_array *tr);
558void tracer_tracing_off(struct trace_array *tr);
559struct dentry *trace_create_file(const char *name,
560 umode_t mode,
561 struct dentry *parent,
562 void *data,
563 const struct file_operations *fops);
564
565int tracing_init_dentry(void);
566
567struct ring_buffer_event;
568
569struct ring_buffer_event *
570trace_buffer_lock_reserve(struct trace_buffer *buffer,
571 int type,
572 unsigned long len,
573 unsigned int trace_ctx);
574
575struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
576 struct trace_array_cpu *data);
577
578struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
579 int *ent_cpu, u64 *ent_ts);
580
581void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
582 struct ring_buffer_event *event);
583
584const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
585
586int trace_empty(struct trace_iterator *iter);
587
588void *trace_find_next_entry_inc(struct trace_iterator *iter);
589
590void trace_init_global_iter(struct trace_iterator *iter);
591
592void tracing_iter_reset(struct trace_iterator *iter, int cpu);
593
594unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
595unsigned long trace_total_entries(struct trace_array *tr);
596
597void trace_function(struct trace_array *tr,
598 unsigned long ip,
599 unsigned long parent_ip,
600 unsigned int trace_ctx);
601void trace_graph_function(struct trace_array *tr,
602 unsigned long ip,
603 unsigned long parent_ip,
604 unsigned int trace_ctx);
605void trace_latency_header(struct seq_file *m);
606void trace_default_header(struct seq_file *m);
607void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
608
609void trace_graph_return(struct ftrace_graph_ret *trace);
610int trace_graph_entry(struct ftrace_graph_ent *trace);
611void set_graph_array(struct trace_array *tr);
612
613void tracing_start_cmdline_record(void);
614void tracing_stop_cmdline_record(void);
615void tracing_start_tgid_record(void);
616void tracing_stop_tgid_record(void);
617
618int register_tracer(struct tracer *type);
619int is_tracing_stopped(void);
620
621loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
622
623extern cpumask_var_t __read_mostly tracing_buffer_mask;
624
625#define for_each_tracing_cpu(cpu) \
626 for_each_cpu(cpu, tracing_buffer_mask)
627
628extern unsigned long nsecs_to_usecs(unsigned long nsecs);
629
630extern unsigned long tracing_thresh;
631
632/* PID filtering */
633
634extern int pid_max;
635
636bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
637 pid_t search_pid);
638bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
639 struct trace_pid_list *filtered_no_pids,
640 struct task_struct *task);
641void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
642 struct task_struct *self,
643 struct task_struct *task);
644void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
645void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
646int trace_pid_show(struct seq_file *m, void *v);
647void trace_free_pid_list(struct trace_pid_list *pid_list);
648int trace_pid_write(struct trace_pid_list *filtered_pids,
649 struct trace_pid_list **new_pid_list,
650 const char __user *ubuf, size_t cnt);
651
652#ifdef CONFIG_TRACER_MAX_TRACE
653void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
654 void *cond_data);
655void update_max_tr_single(struct trace_array *tr,
656 struct task_struct *tsk, int cpu);
657#endif /* CONFIG_TRACER_MAX_TRACE */
658
659#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
660 defined(CONFIG_FSNOTIFY)
661
662void latency_fsnotify(struct trace_array *tr);
663
664#else
665
666static inline void latency_fsnotify(struct trace_array *tr) { }
667
668#endif
669
670#ifdef CONFIG_STACKTRACE
671void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
672#else
673static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
674 int skip)
675{
676}
677#endif /* CONFIG_STACKTRACE */
678
679extern u64 ftrace_now(int cpu);
680
681extern void trace_find_cmdline(int pid, char comm[]);
682extern int trace_find_tgid(int pid);
683extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
684
685#ifdef CONFIG_DYNAMIC_FTRACE
686extern unsigned long ftrace_update_tot_cnt;
687extern unsigned long ftrace_number_of_pages;
688extern unsigned long ftrace_number_of_groups;
689void ftrace_init_trace_array(struct trace_array *tr);
690#else
691static inline void ftrace_init_trace_array(struct trace_array *tr) { }
692#endif
693#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
694extern int DYN_FTRACE_TEST_NAME(void);
695#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
696extern int DYN_FTRACE_TEST_NAME2(void);
697
698extern bool ring_buffer_expanded;
699extern bool tracing_selftest_disabled;
700
701#ifdef CONFIG_FTRACE_STARTUP_TEST
702extern void __init disable_tracing_selftest(const char *reason);
703
704extern int trace_selftest_startup_function(struct tracer *trace,
705 struct trace_array *tr);
706extern int trace_selftest_startup_function_graph(struct tracer *trace,
707 struct trace_array *tr);
708extern int trace_selftest_startup_irqsoff(struct tracer *trace,
709 struct trace_array *tr);
710extern int trace_selftest_startup_preemptoff(struct tracer *trace,
711 struct trace_array *tr);
712extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
713 struct trace_array *tr);
714extern int trace_selftest_startup_wakeup(struct tracer *trace,
715 struct trace_array *tr);
716extern int trace_selftest_startup_nop(struct tracer *trace,
717 struct trace_array *tr);
718extern int trace_selftest_startup_branch(struct tracer *trace,
719 struct trace_array *tr);
720/*
721 * Tracer data references selftest functions that only occur
722 * on boot up. These can be __init functions. Thus, when selftests
723 * are enabled, then the tracers need to reference __init functions.
724 */
725#define __tracer_data __refdata
726#else
727static inline void __init disable_tracing_selftest(const char *reason)
728{
729}
730/* Tracers are seldom changed. Optimize when selftests are disabled. */
731#define __tracer_data __read_mostly
732#endif /* CONFIG_FTRACE_STARTUP_TEST */
733
734extern void *head_page(struct trace_array_cpu *data);
735extern unsigned long long ns2usecs(u64 nsec);
736extern int
737trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
738extern int
739trace_vprintk(unsigned long ip, const char *fmt, va_list args);
740extern int
741trace_array_vprintk(struct trace_array *tr,
742 unsigned long ip, const char *fmt, va_list args);
743int trace_array_printk_buf(struct trace_buffer *buffer,
744 unsigned long ip, const char *fmt, ...);
745void trace_printk_seq(struct trace_seq *s);
746enum print_line_t print_trace_line(struct trace_iterator *iter);
747
748extern char trace_find_mark(unsigned long long duration);
749
750struct ftrace_hash;
751
752struct ftrace_mod_load {
753 struct list_head list;
754 char *func;
755 char *module;
756 int enable;
757};
758
759enum {
760 FTRACE_HASH_FL_MOD = (1 << 0),
761};
762
763struct ftrace_hash {
764 unsigned long size_bits;
765 struct hlist_head *buckets;
766 unsigned long count;
767 unsigned long flags;
768 struct rcu_head rcu;
769};
770
771struct ftrace_func_entry *
772ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
773
774static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
775{
776 return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
777}
778
779/* Standard output formatting function used for function return traces */
780#ifdef CONFIG_FUNCTION_GRAPH_TRACER
781
782/* Flag options */
783#define TRACE_GRAPH_PRINT_OVERRUN 0x1
784#define TRACE_GRAPH_PRINT_CPU 0x2
785#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
786#define TRACE_GRAPH_PRINT_PROC 0x8
787#define TRACE_GRAPH_PRINT_DURATION 0x10
788#define TRACE_GRAPH_PRINT_ABS_TIME 0x20
789#define TRACE_GRAPH_PRINT_REL_TIME 0x40
790#define TRACE_GRAPH_PRINT_IRQS 0x80
791#define TRACE_GRAPH_PRINT_TAIL 0x100
792#define TRACE_GRAPH_SLEEP_TIME 0x200
793#define TRACE_GRAPH_GRAPH_TIME 0x400
794#define TRACE_GRAPH_PRINT_FILL_SHIFT 28
795#define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
796
797extern void ftrace_graph_sleep_time_control(bool enable);
798
799#ifdef CONFIG_FUNCTION_PROFILER
800extern void ftrace_graph_graph_time_control(bool enable);
801#else
802static inline void ftrace_graph_graph_time_control(bool enable) { }
803#endif
804
805extern enum print_line_t
806print_graph_function_flags(struct trace_iterator *iter, u32 flags);
807extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
808extern void
809trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
810extern void graph_trace_open(struct trace_iterator *iter);
811extern void graph_trace_close(struct trace_iterator *iter);
812extern int __trace_graph_entry(struct trace_array *tr,
813 struct ftrace_graph_ent *trace,
814 unsigned int trace_ctx);
815extern void __trace_graph_return(struct trace_array *tr,
816 struct ftrace_graph_ret *trace,
817 unsigned int trace_ctx);
818
819#ifdef CONFIG_DYNAMIC_FTRACE
820extern struct ftrace_hash __rcu *ftrace_graph_hash;
821extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
822
823static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
824{
825 unsigned long addr = trace->func;
826 int ret = 0;
827 struct ftrace_hash *hash;
828
829 preempt_disable_notrace();
830
831 /*
832 * Have to open code "rcu_dereference_sched()" because the
833 * function graph tracer can be called when RCU is not
834 * "watching".
835 * Protected with schedule_on_each_cpu(ftrace_sync)
836 */
837 hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
838
839 if (ftrace_hash_empty(hash)) {
840 ret = 1;
841 goto out;
842 }
843
844 if (ftrace_lookup_ip(hash, addr)) {
845
846 /*
847 * This needs to be cleared on the return functions
848 * when the depth is zero.
849 */
850 trace_recursion_set(TRACE_GRAPH_BIT);
851 trace_recursion_set_depth(trace->depth);
852
853 /*
854 * If no irqs are to be traced, but a set_graph_function
855 * is set, and called by an interrupt handler, we still
856 * want to trace it.
857 */
858 if (in_irq())
859 trace_recursion_set(TRACE_IRQ_BIT);
860 else
861 trace_recursion_clear(TRACE_IRQ_BIT);
862 ret = 1;
863 }
864
865out:
866 preempt_enable_notrace();
867 return ret;
868}
869
870static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
871{
872 if (trace_recursion_test(TRACE_GRAPH_BIT) &&
873 trace->depth == trace_recursion_depth())
874 trace_recursion_clear(TRACE_GRAPH_BIT);
875}
876
877static inline int ftrace_graph_notrace_addr(unsigned long addr)
878{
879 int ret = 0;
880 struct ftrace_hash *notrace_hash;
881
882 preempt_disable_notrace();
883
884 /*
885 * Have to open code "rcu_dereference_sched()" because the
886 * function graph tracer can be called when RCU is not
887 * "watching".
888 * Protected with schedule_on_each_cpu(ftrace_sync)
889 */
890 notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
891 !preemptible());
892
893 if (ftrace_lookup_ip(notrace_hash, addr))
894 ret = 1;
895
896 preempt_enable_notrace();
897 return ret;
898}
899#else
900static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
901{
902 return 1;
903}
904
905static inline int ftrace_graph_notrace_addr(unsigned long addr)
906{
907 return 0;
908}
909static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
910{ }
911#endif /* CONFIG_DYNAMIC_FTRACE */
912
913extern unsigned int fgraph_max_depth;
914
915static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
916{
917 /* trace it when it is-nested-in or is a function enabled. */
918 return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
919 ftrace_graph_addr(trace)) ||
920 (trace->depth < 0) ||
921 (fgraph_max_depth && trace->depth >= fgraph_max_depth);
922}
923
924#else /* CONFIG_FUNCTION_GRAPH_TRACER */
925static inline enum print_line_t
926print_graph_function_flags(struct trace_iterator *iter, u32 flags)
927{
928 return TRACE_TYPE_UNHANDLED;
929}
930#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
931
932extern struct list_head ftrace_pids;
933
934#ifdef CONFIG_FUNCTION_TRACER
935
936#define FTRACE_PID_IGNORE -1
937#define FTRACE_PID_TRACE -2
938
939struct ftrace_func_command {
940 struct list_head list;
941 char *name;
942 int (*func)(struct trace_array *tr,
943 struct ftrace_hash *hash,
944 char *func, char *cmd,
945 char *params, int enable);
946};
947extern bool ftrace_filter_param __initdata;
948static inline int ftrace_trace_task(struct trace_array *tr)
949{
950 return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
951 FTRACE_PID_IGNORE;
952}
953extern int ftrace_is_dead(void);
954int ftrace_create_function_files(struct trace_array *tr,
955 struct dentry *parent);
956void ftrace_destroy_function_files(struct trace_array *tr);
957int ftrace_allocate_ftrace_ops(struct trace_array *tr);
958void ftrace_free_ftrace_ops(struct trace_array *tr);
959void ftrace_init_global_array_ops(struct trace_array *tr);
960void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
961void ftrace_reset_array_ops(struct trace_array *tr);
962void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
963void ftrace_init_tracefs_toplevel(struct trace_array *tr,
964 struct dentry *d_tracer);
965void ftrace_clear_pids(struct trace_array *tr);
966int init_function_trace(void);
967void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
968#else
969static inline int ftrace_trace_task(struct trace_array *tr)
970{
971 return 1;
972}
973static inline int ftrace_is_dead(void) { return 0; }
974static inline int
975ftrace_create_function_files(struct trace_array *tr,
976 struct dentry *parent)
977{
978 return 0;
979}
980static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
981{
982 return 0;
983}
984static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
985static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
986static inline __init void
987ftrace_init_global_array_ops(struct trace_array *tr) { }
988static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
989static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
990static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
991static inline void ftrace_clear_pids(struct trace_array *tr) { }
992static inline int init_function_trace(void) { return 0; }
993static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
994/* ftace_func_t type is not defined, use macro instead of static inline */
995#define ftrace_init_array_ops(tr, func) do { } while (0)
996#endif /* CONFIG_FUNCTION_TRACER */
997
998#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
999
1000struct ftrace_probe_ops {
1001 void (*func)(unsigned long ip,
1002 unsigned long parent_ip,
1003 struct trace_array *tr,
1004 struct ftrace_probe_ops *ops,
1005 void *data);
1006 int (*init)(struct ftrace_probe_ops *ops,
1007 struct trace_array *tr,
1008 unsigned long ip, void *init_data,
1009 void **data);
1010 void (*free)(struct ftrace_probe_ops *ops,
1011 struct trace_array *tr,
1012 unsigned long ip, void *data);
1013 int (*print)(struct seq_file *m,
1014 unsigned long ip,
1015 struct ftrace_probe_ops *ops,
1016 void *data);
1017};
1018
1019struct ftrace_func_mapper;
1020typedef int (*ftrace_mapper_func)(void *data);
1021
1022struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1023void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1024 unsigned long ip);
1025int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1026 unsigned long ip, void *data);
1027void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1028 unsigned long ip);
1029void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1030 ftrace_mapper_func free_func);
1031
1032extern int
1033register_ftrace_function_probe(char *glob, struct trace_array *tr,
1034 struct ftrace_probe_ops *ops, void *data);
1035extern int
1036unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1037 struct ftrace_probe_ops *ops);
1038extern void clear_ftrace_function_probes(struct trace_array *tr);
1039
1040int register_ftrace_command(struct ftrace_func_command *cmd);
1041int unregister_ftrace_command(struct ftrace_func_command *cmd);
1042
1043void ftrace_create_filter_files(struct ftrace_ops *ops,
1044 struct dentry *parent);
1045void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1046
1047extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
1048 int len, int reset);
1049extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
1050 int len, int reset);
1051#else
1052struct ftrace_func_command;
1053
1054static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1055{
1056 return -EINVAL;
1057}
1058static inline __init int unregister_ftrace_command(char *cmd_name)
1059{
1060 return -EINVAL;
1061}
1062static inline void clear_ftrace_function_probes(struct trace_array *tr)
1063{
1064}
1065
1066/*
1067 * The ops parameter passed in is usually undefined.
1068 * This must be a macro.
1069 */
1070#define ftrace_create_filter_files(ops, parent) do { } while (0)
1071#define ftrace_destroy_filter_files(ops) do { } while (0)
1072#endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1073
1074bool ftrace_event_is_function(struct trace_event_call *call);
1075
1076/*
1077 * struct trace_parser - servers for reading the user input separated by spaces
1078 * @cont: set if the input is not complete - no final space char was found
1079 * @buffer: holds the parsed user input
1080 * @idx: user input length
1081 * @size: buffer size
1082 */
1083struct trace_parser {
1084 bool cont;
1085 char *buffer;
1086 unsigned idx;
1087 unsigned size;
1088};
1089
1090static inline bool trace_parser_loaded(struct trace_parser *parser)
1091{
1092 return (parser->idx != 0);
1093}
1094
1095static inline bool trace_parser_cont(struct trace_parser *parser)
1096{
1097 return parser->cont;
1098}
1099
1100static inline void trace_parser_clear(struct trace_parser *parser)
1101{
1102 parser->cont = false;
1103 parser->idx = 0;
1104}
1105
1106extern int trace_parser_get_init(struct trace_parser *parser, int size);
1107extern void trace_parser_put(struct trace_parser *parser);
1108extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1109 size_t cnt, loff_t *ppos);
1110
1111/*
1112 * Only create function graph options if function graph is configured.
1113 */
1114#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1115# define FGRAPH_FLAGS \
1116 C(DISPLAY_GRAPH, "display-graph"),
1117#else
1118# define FGRAPH_FLAGS
1119#endif
1120
1121#ifdef CONFIG_BRANCH_TRACER
1122# define BRANCH_FLAGS \
1123 C(BRANCH, "branch"),
1124#else
1125# define BRANCH_FLAGS
1126#endif
1127
1128#ifdef CONFIG_FUNCTION_TRACER
1129# define FUNCTION_FLAGS \
1130 C(FUNCTION, "function-trace"), \
1131 C(FUNC_FORK, "function-fork"),
1132# define FUNCTION_DEFAULT_FLAGS TRACE_ITER_FUNCTION
1133#else
1134# define FUNCTION_FLAGS
1135# define FUNCTION_DEFAULT_FLAGS 0UL
1136# define TRACE_ITER_FUNC_FORK 0UL
1137#endif
1138
1139#ifdef CONFIG_STACKTRACE
1140# define STACK_FLAGS \
1141 C(STACKTRACE, "stacktrace"),
1142#else
1143# define STACK_FLAGS
1144#endif
1145
1146/*
1147 * trace_iterator_flags is an enumeration that defines bit
1148 * positions into trace_flags that controls the output.
1149 *
1150 * NOTE: These bits must match the trace_options array in
1151 * trace.c (this macro guarantees it).
1152 */
1153#define TRACE_FLAGS \
1154 C(PRINT_PARENT, "print-parent"), \
1155 C(SYM_OFFSET, "sym-offset"), \
1156 C(SYM_ADDR, "sym-addr"), \
1157 C(VERBOSE, "verbose"), \
1158 C(RAW, "raw"), \
1159 C(HEX, "hex"), \
1160 C(BIN, "bin"), \
1161 C(BLOCK, "block"), \
1162 C(PRINTK, "trace_printk"), \
1163 C(ANNOTATE, "annotate"), \
1164 C(USERSTACKTRACE, "userstacktrace"), \
1165 C(SYM_USEROBJ, "sym-userobj"), \
1166 C(PRINTK_MSGONLY, "printk-msg-only"), \
1167 C(CONTEXT_INFO, "context-info"), /* Print pid/cpu/time */ \
1168 C(LATENCY_FMT, "latency-format"), \
1169 C(RECORD_CMD, "record-cmd"), \
1170 C(RECORD_TGID, "record-tgid"), \
1171 C(OVERWRITE, "overwrite"), \
1172 C(STOP_ON_FREE, "disable_on_free"), \
1173 C(IRQ_INFO, "irq-info"), \
1174 C(MARKERS, "markers"), \
1175 C(EVENT_FORK, "event-fork"), \
1176 C(PAUSE_ON_TRACE, "pause-on-trace"), \
1177 C(HASH_PTR, "hash-ptr"), /* Print hashed pointer */ \
1178 FUNCTION_FLAGS \
1179 FGRAPH_FLAGS \
1180 STACK_FLAGS \
1181 BRANCH_FLAGS
1182
1183/*
1184 * By defining C, we can make TRACE_FLAGS a list of bit names
1185 * that will define the bits for the flag masks.
1186 */
1187#undef C
1188#define C(a, b) TRACE_ITER_##a##_BIT
1189
1190enum trace_iterator_bits {
1191 TRACE_FLAGS
1192 /* Make sure we don't go more than we have bits for */
1193 TRACE_ITER_LAST_BIT
1194};
1195
1196/*
1197 * By redefining C, we can make TRACE_FLAGS a list of masks that
1198 * use the bits as defined above.
1199 */
1200#undef C
1201#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1202
1203enum trace_iterator_flags { TRACE_FLAGS };
1204
1205/*
1206 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1207 * control the output of kernel symbols.
1208 */
1209#define TRACE_ITER_SYM_MASK \
1210 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1211
1212extern struct tracer nop_trace;
1213
1214#ifdef CONFIG_BRANCH_TRACER
1215extern int enable_branch_tracing(struct trace_array *tr);
1216extern void disable_branch_tracing(void);
1217static inline int trace_branch_enable(struct trace_array *tr)
1218{
1219 if (tr->trace_flags & TRACE_ITER_BRANCH)
1220 return enable_branch_tracing(tr);
1221 return 0;
1222}
1223static inline void trace_branch_disable(void)
1224{
1225 /* due to races, always disable */
1226 disable_branch_tracing();
1227}
1228#else
1229static inline int trace_branch_enable(struct trace_array *tr)
1230{
1231 return 0;
1232}
1233static inline void trace_branch_disable(void)
1234{
1235}
1236#endif /* CONFIG_BRANCH_TRACER */
1237
1238/* set ring buffers to default size if not already done so */
1239int tracing_update_buffers(void);
1240
1241struct ftrace_event_field {
1242 struct list_head link;
1243 const char *name;
1244 const char *type;
1245 int filter_type;
1246 int offset;
1247 int size;
1248 int is_signed;
1249};
1250
1251struct prog_entry;
1252
1253struct event_filter {
1254 struct prog_entry __rcu *prog;
1255 char *filter_string;
1256};
1257
1258struct event_subsystem {
1259 struct list_head list;
1260 const char *name;
1261 struct event_filter *filter;
1262 int ref_count;
1263};
1264
1265struct trace_subsystem_dir {
1266 struct list_head list;
1267 struct event_subsystem *subsystem;
1268 struct trace_array *tr;
1269 struct dentry *entry;
1270 int ref_count;
1271 int nr_events;
1272};
1273
1274extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1275 struct trace_buffer *buffer,
1276 struct ring_buffer_event *event);
1277
1278void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1279 struct trace_buffer *buffer,
1280 struct ring_buffer_event *event,
1281 unsigned int trcace_ctx,
1282 struct pt_regs *regs);
1283
1284static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1285 struct trace_buffer *buffer,
1286 struct ring_buffer_event *event,
1287 unsigned int trace_ctx)
1288{
1289 trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
1290}
1291
1292DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1293DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1294void trace_buffered_event_disable(void);
1295void trace_buffered_event_enable(void);
1296
1297static inline void
1298__trace_event_discard_commit(struct trace_buffer *buffer,
1299 struct ring_buffer_event *event)
1300{
1301 if (this_cpu_read(trace_buffered_event) == event) {
1302 /* Simply release the temp buffer */
1303 this_cpu_dec(trace_buffered_event_cnt);
1304 return;
1305 }
1306 ring_buffer_discard_commit(buffer, event);
1307}
1308
1309/*
1310 * Helper function for event_trigger_unlock_commit{_regs}().
1311 * If there are event triggers attached to this event that requires
1312 * filtering against its fields, then they will be called as the
1313 * entry already holds the field information of the current event.
1314 *
1315 * It also checks if the event should be discarded or not.
1316 * It is to be discarded if the event is soft disabled and the
1317 * event was only recorded to process triggers, or if the event
1318 * filter is active and this event did not match the filters.
1319 *
1320 * Returns true if the event is discarded, false otherwise.
1321 */
1322static inline bool
1323__event_trigger_test_discard(struct trace_event_file *file,
1324 struct trace_buffer *buffer,
1325 struct ring_buffer_event *event,
1326 void *entry,
1327 enum event_trigger_type *tt)
1328{
1329 unsigned long eflags = file->flags;
1330
1331 if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1332 *tt = event_triggers_call(file, entry, event);
1333
1334 if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1335 (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1336 !filter_match_preds(file->filter, entry))) {
1337 __trace_event_discard_commit(buffer, event);
1338 return true;
1339 }
1340
1341 return false;
1342}
1343
1344/**
1345 * event_trigger_unlock_commit - handle triggers and finish event commit
1346 * @file: The file pointer assoctiated to the event
1347 * @buffer: The ring buffer that the event is being written to
1348 * @event: The event meta data in the ring buffer
1349 * @entry: The event itself
1350 * @trace_ctx: The tracing context flags.
1351 *
1352 * This is a helper function to handle triggers that require data
1353 * from the event itself. It also tests the event against filters and
1354 * if the event is soft disabled and should be discarded.
1355 */
1356static inline void
1357event_trigger_unlock_commit(struct trace_event_file *file,
1358 struct trace_buffer *buffer,
1359 struct ring_buffer_event *event,
1360 void *entry, unsigned int trace_ctx)
1361{
1362 enum event_trigger_type tt = ETT_NONE;
1363
1364 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1365 trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
1366
1367 if (tt)
1368 event_triggers_post_call(file, tt);
1369}
1370
1371/**
1372 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1373 * @file: The file pointer assoctiated to the event
1374 * @buffer: The ring buffer that the event is being written to
1375 * @event: The event meta data in the ring buffer
1376 * @entry: The event itself
1377 * @trace_ctx: The tracing context flags.
1378 *
1379 * This is a helper function to handle triggers that require data
1380 * from the event itself. It also tests the event against filters and
1381 * if the event is soft disabled and should be discarded.
1382 *
1383 * Same as event_trigger_unlock_commit() but calls
1384 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1385 */
1386static inline void
1387event_trigger_unlock_commit_regs(struct trace_event_file *file,
1388 struct trace_buffer *buffer,
1389 struct ring_buffer_event *event,
1390 void *entry, unsigned int trace_ctx,
1391 struct pt_regs *regs)
1392{
1393 enum event_trigger_type tt = ETT_NONE;
1394
1395 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1396 trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1397 trace_ctx, regs);
1398
1399 if (tt)
1400 event_triggers_post_call(file, tt);
1401}
1402
1403#define FILTER_PRED_INVALID ((unsigned short)-1)
1404#define FILTER_PRED_IS_RIGHT (1 << 15)
1405#define FILTER_PRED_FOLD (1 << 15)
1406
1407/*
1408 * The max preds is the size of unsigned short with
1409 * two flags at the MSBs. One bit is used for both the IS_RIGHT
1410 * and FOLD flags. The other is reserved.
1411 *
1412 * 2^14 preds is way more than enough.
1413 */
1414#define MAX_FILTER_PRED 16384
1415
1416struct filter_pred;
1417struct regex;
1418
1419typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1420
1421typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1422
1423enum regex_type {
1424 MATCH_FULL = 0,
1425 MATCH_FRONT_ONLY,
1426 MATCH_MIDDLE_ONLY,
1427 MATCH_END_ONLY,
1428 MATCH_GLOB,
1429 MATCH_INDEX,
1430};
1431
1432struct regex {
1433 char pattern[MAX_FILTER_STR_VAL];
1434 int len;
1435 int field_len;
1436 regex_match_func match;
1437};
1438
1439struct filter_pred {
1440 filter_pred_fn_t fn;
1441 u64 val;
1442 struct regex regex;
1443 unsigned short *ops;
1444 struct ftrace_event_field *field;
1445 int offset;
1446 int not;
1447 int op;
1448};
1449
1450static inline bool is_string_field(struct ftrace_event_field *field)
1451{
1452 return field->filter_type == FILTER_DYN_STRING ||
1453 field->filter_type == FILTER_STATIC_STRING ||
1454 field->filter_type == FILTER_PTR_STRING ||
1455 field->filter_type == FILTER_COMM;
1456}
1457
1458static inline bool is_function_field(struct ftrace_event_field *field)
1459{
1460 return field->filter_type == FILTER_TRACE_FN;
1461}
1462
1463extern enum regex_type
1464filter_parse_regex(char *buff, int len, char **search, int *not);
1465extern void print_event_filter(struct trace_event_file *file,
1466 struct trace_seq *s);
1467extern int apply_event_filter(struct trace_event_file *file,
1468 char *filter_string);
1469extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1470 char *filter_string);
1471extern void print_subsystem_event_filter(struct event_subsystem *system,
1472 struct trace_seq *s);
1473extern int filter_assign_type(const char *type);
1474extern int create_event_filter(struct trace_array *tr,
1475 struct trace_event_call *call,
1476 char *filter_str, bool set_str,
1477 struct event_filter **filterp);
1478extern void free_event_filter(struct event_filter *filter);
1479
1480struct ftrace_event_field *
1481trace_find_event_field(struct trace_event_call *call, char *name);
1482
1483extern void trace_event_enable_cmd_record(bool enable);
1484extern void trace_event_enable_tgid_record(bool enable);
1485
1486extern int event_trace_init(void);
1487extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1488extern int event_trace_del_tracer(struct trace_array *tr);
1489extern void __trace_early_add_events(struct trace_array *tr);
1490
1491extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1492 const char *system,
1493 const char *event);
1494extern struct trace_event_file *find_event_file(struct trace_array *tr,
1495 const char *system,
1496 const char *event);
1497
1498static inline void *event_file_data(struct file *filp)
1499{
1500 return READ_ONCE(file_inode(filp)->i_private);
1501}
1502
1503extern struct mutex event_mutex;
1504extern struct list_head ftrace_events;
1505
1506extern const struct file_operations event_trigger_fops;
1507extern const struct file_operations event_hist_fops;
1508extern const struct file_operations event_hist_debug_fops;
1509extern const struct file_operations event_inject_fops;
1510
1511#ifdef CONFIG_HIST_TRIGGERS
1512extern int register_trigger_hist_cmd(void);
1513extern int register_trigger_hist_enable_disable_cmds(void);
1514#else
1515static inline int register_trigger_hist_cmd(void) { return 0; }
1516static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1517#endif
1518
1519extern int register_trigger_cmds(void);
1520extern void clear_event_triggers(struct trace_array *tr);
1521
1522struct event_trigger_data {
1523 unsigned long count;
1524 int ref;
1525 struct event_trigger_ops *ops;
1526 struct event_command *cmd_ops;
1527 struct event_filter __rcu *filter;
1528 char *filter_str;
1529 void *private_data;
1530 bool paused;
1531 bool paused_tmp;
1532 struct list_head list;
1533 char *name;
1534 struct list_head named_list;
1535 struct event_trigger_data *named_data;
1536};
1537
1538/* Avoid typos */
1539#define ENABLE_EVENT_STR "enable_event"
1540#define DISABLE_EVENT_STR "disable_event"
1541#define ENABLE_HIST_STR "enable_hist"
1542#define DISABLE_HIST_STR "disable_hist"
1543
1544struct enable_trigger_data {
1545 struct trace_event_file *file;
1546 bool enable;
1547 bool hist;
1548};
1549
1550extern int event_enable_trigger_print(struct seq_file *m,
1551 struct event_trigger_ops *ops,
1552 struct event_trigger_data *data);
1553extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1554 struct event_trigger_data *data);
1555extern int event_enable_trigger_func(struct event_command *cmd_ops,
1556 struct trace_event_file *file,
1557 char *glob, char *cmd, char *param);
1558extern int event_enable_register_trigger(char *glob,
1559 struct event_trigger_ops *ops,
1560 struct event_trigger_data *data,
1561 struct trace_event_file *file);
1562extern void event_enable_unregister_trigger(char *glob,
1563 struct event_trigger_ops *ops,
1564 struct event_trigger_data *test,
1565 struct trace_event_file *file);
1566extern void trigger_data_free(struct event_trigger_data *data);
1567extern int event_trigger_init(struct event_trigger_ops *ops,
1568 struct event_trigger_data *data);
1569extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1570 int trigger_enable);
1571extern void update_cond_flag(struct trace_event_file *file);
1572extern int set_trigger_filter(char *filter_str,
1573 struct event_trigger_data *trigger_data,
1574 struct trace_event_file *file);
1575extern struct event_trigger_data *find_named_trigger(const char *name);
1576extern bool is_named_trigger(struct event_trigger_data *test);
1577extern int save_named_trigger(const char *name,
1578 struct event_trigger_data *data);
1579extern void del_named_trigger(struct event_trigger_data *data);
1580extern void pause_named_trigger(struct event_trigger_data *data);
1581extern void unpause_named_trigger(struct event_trigger_data *data);
1582extern void set_named_trigger_data(struct event_trigger_data *data,
1583 struct event_trigger_data *named_data);
1584extern struct event_trigger_data *
1585get_named_trigger_data(struct event_trigger_data *data);
1586extern int register_event_command(struct event_command *cmd);
1587extern int unregister_event_command(struct event_command *cmd);
1588extern int register_trigger_hist_enable_disable_cmds(void);
1589
1590/**
1591 * struct event_trigger_ops - callbacks for trace event triggers
1592 *
1593 * The methods in this structure provide per-event trigger hooks for
1594 * various trigger operations.
1595 *
1596 * All the methods below, except for @init() and @free(), must be
1597 * implemented.
1598 *
1599 * @func: The trigger 'probe' function called when the triggering
1600 * event occurs. The data passed into this callback is the data
1601 * that was supplied to the event_command @reg() function that
1602 * registered the trigger (see struct event_command) along with
1603 * the trace record, rec.
1604 *
1605 * @init: An optional initialization function called for the trigger
1606 * when the trigger is registered (via the event_command reg()
1607 * function). This can be used to perform per-trigger
1608 * initialization such as incrementing a per-trigger reference
1609 * count, for instance. This is usually implemented by the
1610 * generic utility function @event_trigger_init() (see
1611 * trace_event_triggers.c).
1612 *
1613 * @free: An optional de-initialization function called for the
1614 * trigger when the trigger is unregistered (via the
1615 * event_command @reg() function). This can be used to perform
1616 * per-trigger de-initialization such as decrementing a
1617 * per-trigger reference count and freeing corresponding trigger
1618 * data, for instance. This is usually implemented by the
1619 * generic utility function @event_trigger_free() (see
1620 * trace_event_triggers.c).
1621 *
1622 * @print: The callback function invoked to have the trigger print
1623 * itself. This is usually implemented by a wrapper function
1624 * that calls the generic utility function @event_trigger_print()
1625 * (see trace_event_triggers.c).
1626 */
1627struct event_trigger_ops {
1628 void (*func)(struct event_trigger_data *data,
1629 void *rec,
1630 struct ring_buffer_event *rbe);
1631 int (*init)(struct event_trigger_ops *ops,
1632 struct event_trigger_data *data);
1633 void (*free)(struct event_trigger_ops *ops,
1634 struct event_trigger_data *data);
1635 int (*print)(struct seq_file *m,
1636 struct event_trigger_ops *ops,
1637 struct event_trigger_data *data);
1638};
1639
1640/**
1641 * struct event_command - callbacks and data members for event commands
1642 *
1643 * Event commands are invoked by users by writing the command name
1644 * into the 'trigger' file associated with a trace event. The
1645 * parameters associated with a specific invocation of an event
1646 * command are used to create an event trigger instance, which is
1647 * added to the list of trigger instances associated with that trace
1648 * event. When the event is hit, the set of triggers associated with
1649 * that event is invoked.
1650 *
1651 * The data members in this structure provide per-event command data
1652 * for various event commands.
1653 *
1654 * All the data members below, except for @post_trigger, must be set
1655 * for each event command.
1656 *
1657 * @name: The unique name that identifies the event command. This is
1658 * the name used when setting triggers via trigger files.
1659 *
1660 * @trigger_type: A unique id that identifies the event command
1661 * 'type'. This value has two purposes, the first to ensure that
1662 * only one trigger of the same type can be set at a given time
1663 * for a particular event e.g. it doesn't make sense to have both
1664 * a traceon and traceoff trigger attached to a single event at
1665 * the same time, so traceon and traceoff have the same type
1666 * though they have different names. The @trigger_type value is
1667 * also used as a bit value for deferring the actual trigger
1668 * action until after the current event is finished. Some
1669 * commands need to do this if they themselves log to the trace
1670 * buffer (see the @post_trigger() member below). @trigger_type
1671 * values are defined by adding new values to the trigger_type
1672 * enum in include/linux/trace_events.h.
1673 *
1674 * @flags: See the enum event_command_flags below.
1675 *
1676 * All the methods below, except for @set_filter() and @unreg_all(),
1677 * must be implemented.
1678 *
1679 * @func: The callback function responsible for parsing and
1680 * registering the trigger written to the 'trigger' file by the
1681 * user. It allocates the trigger instance and registers it with
1682 * the appropriate trace event. It makes use of the other
1683 * event_command callback functions to orchestrate this, and is
1684 * usually implemented by the generic utility function
1685 * @event_trigger_callback() (see trace_event_triggers.c).
1686 *
1687 * @reg: Adds the trigger to the list of triggers associated with the
1688 * event, and enables the event trigger itself, after
1689 * initializing it (via the event_trigger_ops @init() function).
1690 * This is also where commands can use the @trigger_type value to
1691 * make the decision as to whether or not multiple instances of
1692 * the trigger should be allowed. This is usually implemented by
1693 * the generic utility function @register_trigger() (see
1694 * trace_event_triggers.c).
1695 *
1696 * @unreg: Removes the trigger from the list of triggers associated
1697 * with the event, and disables the event trigger itself, after
1698 * initializing it (via the event_trigger_ops @free() function).
1699 * This is usually implemented by the generic utility function
1700 * @unregister_trigger() (see trace_event_triggers.c).
1701 *
1702 * @unreg_all: An optional function called to remove all the triggers
1703 * from the list of triggers associated with the event. Called
1704 * when a trigger file is opened in truncate mode.
1705 *
1706 * @set_filter: An optional function called to parse and set a filter
1707 * for the trigger. If no @set_filter() method is set for the
1708 * event command, filters set by the user for the command will be
1709 * ignored. This is usually implemented by the generic utility
1710 * function @set_trigger_filter() (see trace_event_triggers.c).
1711 *
1712 * @get_trigger_ops: The callback function invoked to retrieve the
1713 * event_trigger_ops implementation associated with the command.
1714 */
1715struct event_command {
1716 struct list_head list;
1717 char *name;
1718 enum event_trigger_type trigger_type;
1719 int flags;
1720 int (*func)(struct event_command *cmd_ops,
1721 struct trace_event_file *file,
1722 char *glob, char *cmd, char *params);
1723 int (*reg)(char *glob,
1724 struct event_trigger_ops *ops,
1725 struct event_trigger_data *data,
1726 struct trace_event_file *file);
1727 void (*unreg)(char *glob,
1728 struct event_trigger_ops *ops,
1729 struct event_trigger_data *data,
1730 struct trace_event_file *file);
1731 void (*unreg_all)(struct trace_event_file *file);
1732 int (*set_filter)(char *filter_str,
1733 struct event_trigger_data *data,
1734 struct trace_event_file *file);
1735 struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1736};
1737
1738/**
1739 * enum event_command_flags - flags for struct event_command
1740 *
1741 * @POST_TRIGGER: A flag that says whether or not this command needs
1742 * to have its action delayed until after the current event has
1743 * been closed. Some triggers need to avoid being invoked while
1744 * an event is currently in the process of being logged, since
1745 * the trigger may itself log data into the trace buffer. Thus
1746 * we make sure the current event is committed before invoking
1747 * those triggers. To do that, the trigger invocation is split
1748 * in two - the first part checks the filter using the current
1749 * trace record; if a command has the @post_trigger flag set, it
1750 * sets a bit for itself in the return value, otherwise it
1751 * directly invokes the trigger. Once all commands have been
1752 * either invoked or set their return flag, the current record is
1753 * either committed or discarded. At that point, if any commands
1754 * have deferred their triggers, those commands are finally
1755 * invoked following the close of the current event. In other
1756 * words, if the event_trigger_ops @func() probe implementation
1757 * itself logs to the trace buffer, this flag should be set,
1758 * otherwise it can be left unspecified.
1759 *
1760 * @NEEDS_REC: A flag that says whether or not this command needs
1761 * access to the trace record in order to perform its function,
1762 * regardless of whether or not it has a filter associated with
1763 * it (filters make a trigger require access to the trace record
1764 * but are not always present).
1765 */
1766enum event_command_flags {
1767 EVENT_CMD_FL_POST_TRIGGER = 1,
1768 EVENT_CMD_FL_NEEDS_REC = 2,
1769};
1770
1771static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1772{
1773 return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1774}
1775
1776static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1777{
1778 return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1779}
1780
1781extern int trace_event_enable_disable(struct trace_event_file *file,
1782 int enable, int soft_disable);
1783extern int tracing_alloc_snapshot(void);
1784extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1785extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1786
1787extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1788extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1789
1790extern const char *__start___trace_bprintk_fmt[];
1791extern const char *__stop___trace_bprintk_fmt[];
1792
1793extern const char *__start___tracepoint_str[];
1794extern const char *__stop___tracepoint_str[];
1795
1796void trace_printk_control(bool enabled);
1797void trace_printk_start_comm(void);
1798int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1799int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1800
1801/* Used from boot time tracer */
1802extern int trace_set_options(struct trace_array *tr, char *option);
1803extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
1804extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
1805 unsigned long size, int cpu_id);
1806extern int tracing_set_cpumask(struct trace_array *tr,
1807 cpumask_var_t tracing_cpumask_new);
1808
1809
1810#define MAX_EVENT_NAME_LEN 64
1811
1812extern ssize_t trace_parse_run_command(struct file *file,
1813 const char __user *buffer, size_t count, loff_t *ppos,
1814 int (*createfn)(const char *));
1815
1816extern unsigned int err_pos(char *cmd, const char *str);
1817extern void tracing_log_err(struct trace_array *tr,
1818 const char *loc, const char *cmd,
1819 const char **errs, u8 type, u8 pos);
1820
1821/*
1822 * Normal trace_printk() and friends allocates special buffers
1823 * to do the manipulation, as well as saves the print formats
1824 * into sections to display. But the trace infrastructure wants
1825 * to use these without the added overhead at the price of being
1826 * a bit slower (used mainly for warnings, where we don't care
1827 * about performance). The internal_trace_puts() is for such
1828 * a purpose.
1829 */
1830#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1831
1832#undef FTRACE_ENTRY
1833#define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \
1834 extern struct trace_event_call \
1835 __aligned(4) event_##call;
1836#undef FTRACE_ENTRY_DUP
1837#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print) \
1838 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1839#undef FTRACE_ENTRY_PACKED
1840#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
1841 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
1842
1843#include "trace_entries.h"
1844
1845#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1846int perf_ftrace_event_register(struct trace_event_call *call,
1847 enum trace_reg type, void *data);
1848#else
1849#define perf_ftrace_event_register NULL
1850#endif
1851
1852#ifdef CONFIG_FTRACE_SYSCALLS
1853void init_ftrace_syscalls(void);
1854const char *get_syscall_name(int syscall);
1855#else
1856static inline void init_ftrace_syscalls(void) { }
1857static inline const char *get_syscall_name(int syscall)
1858{
1859 return NULL;
1860}
1861#endif
1862
1863#ifdef CONFIG_EVENT_TRACING
1864void trace_event_init(void);
1865void trace_event_eval_update(struct trace_eval_map **map, int len);
1866/* Used from boot time tracer */
1867extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
1868extern int trigger_process_regex(struct trace_event_file *file, char *buff);
1869#else
1870static inline void __init trace_event_init(void) { }
1871static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1872#endif
1873
1874#ifdef CONFIG_TRACER_SNAPSHOT
1875void tracing_snapshot_instance(struct trace_array *tr);
1876int tracing_alloc_snapshot_instance(struct trace_array *tr);
1877#else
1878static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1879static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1880{
1881 return 0;
1882}
1883#endif
1884
1885#ifdef CONFIG_PREEMPT_TRACER
1886void tracer_preempt_on(unsigned long a0, unsigned long a1);
1887void tracer_preempt_off(unsigned long a0, unsigned long a1);
1888#else
1889static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1890static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1891#endif
1892#ifdef CONFIG_IRQSOFF_TRACER
1893void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1894void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1895#else
1896static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1897static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1898#endif
1899
1900extern struct trace_iterator *tracepoint_print_iter;
1901
1902/*
1903 * Reset the state of the trace_iterator so that it can read consumed data.
1904 * Normally, the trace_iterator is used for reading the data when it is not
1905 * consumed, and must retain state.
1906 */
1907static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1908{
1909 const size_t offset = offsetof(struct trace_iterator, seq);
1910
1911 /*
1912 * Keep gcc from complaining about overwriting more than just one
1913 * member in the structure.
1914 */
1915 memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
1916
1917 iter->pos = -1;
1918}
1919
1920/* Check the name is good for event/group/fields */
1921static inline bool is_good_name(const char *name)
1922{
1923 if (!isalpha(*name) && *name != '_')
1924 return false;
1925 while (*++name != '\0') {
1926 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
1927 return false;
1928 }
1929 return true;
1930}
1931
1932#endif /* _LINUX_KERNEL_TRACE_H */