projects/linux·blob v5.2 · 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/glob.h>
19
20#ifdef CONFIG_FTRACE_SYSCALLS
21#include <asm/unistd.h> /* For NR_SYSCALLS */
22#include <asm/syscall.h> /* some archs define it here */
23#endif
24
25enum trace_type {
26 __TRACE_FIRST_TYPE = 0,
27
28 TRACE_FN,
29 TRACE_CTX,
30 TRACE_WAKE,
31 TRACE_STACK,
32 TRACE_PRINT,
33 TRACE_BPRINT,
34 TRACE_MMIO_RW,
35 TRACE_MMIO_MAP,
36 TRACE_BRANCH,
37 TRACE_GRAPH_RET,
38 TRACE_GRAPH_ENT,
39 TRACE_USER_STACK,
40 TRACE_BLK,
41 TRACE_BPUTS,
42 TRACE_HWLAT,
43 TRACE_RAW_DATA,
44
45 __TRACE_LAST_TYPE,
46};
47
48
49#undef __field
50#define __field(type, item) type item;
51
52#undef __field_struct
53#define __field_struct(type, item) __field(type, item)
54
55#undef __field_desc
56#define __field_desc(type, container, item)
57
58#undef __array
59#define __array(type, item, size) type item[size];
60
61#undef __array_desc
62#define __array_desc(type, container, item, size)
63
64#undef __dynamic_array
65#define __dynamic_array(type, item) type item[];
66
67#undef F_STRUCT
68#define F_STRUCT(args...) args
69
70#undef FTRACE_ENTRY
71#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \
72 struct struct_name { \
73 struct trace_entry ent; \
74 tstruct \
75 }
76
77#undef FTRACE_ENTRY_DUP
78#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
79
80#undef FTRACE_ENTRY_REG
81#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
82 filter, regfn) \
83 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
84 filter)
85
86#undef FTRACE_ENTRY_PACKED
87#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print, \
88 filter) \
89 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
90 filter) __packed
91
92#include "trace_entries.h"
93
94/*
95 * syscalls are special, and need special handling, this is why
96 * they are not included in trace_entries.h
97 */
98struct syscall_trace_enter {
99 struct trace_entry ent;
100 int nr;
101 unsigned long args[];
102};
103
104struct syscall_trace_exit {
105 struct trace_entry ent;
106 int nr;
107 long ret;
108};
109
110struct kprobe_trace_entry_head {
111 struct trace_entry ent;
112 unsigned long ip;
113};
114
115struct kretprobe_trace_entry_head {
116 struct trace_entry ent;
117 unsigned long func;
118 unsigned long ret_ip;
119};
120
121/*
122 * trace_flag_type is an enumeration that holds different
123 * states when a trace occurs. These are:
124 * IRQS_OFF - interrupts were disabled
125 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
126 * NEED_RESCHED - reschedule is requested
127 * HARDIRQ - inside an interrupt handler
128 * SOFTIRQ - inside a softirq handler
129 */
130enum trace_flag_type {
131 TRACE_FLAG_IRQS_OFF = 0x01,
132 TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
133 TRACE_FLAG_NEED_RESCHED = 0x04,
134 TRACE_FLAG_HARDIRQ = 0x08,
135 TRACE_FLAG_SOFTIRQ = 0x10,
136 TRACE_FLAG_PREEMPT_RESCHED = 0x20,
137 TRACE_FLAG_NMI = 0x40,
138};
139
140#define TRACE_BUF_SIZE 1024
141
142struct trace_array;
143
144/*
145 * The CPU trace array - it consists of thousands of trace entries
146 * plus some other descriptor data: (for example which task started
147 * the trace, etc.)
148 */
149struct trace_array_cpu {
150 atomic_t disabled;
151 void *buffer_page; /* ring buffer spare */
152
153 unsigned long entries;
154 unsigned long saved_latency;
155 unsigned long critical_start;
156 unsigned long critical_end;
157 unsigned long critical_sequence;
158 unsigned long nice;
159 unsigned long policy;
160 unsigned long rt_priority;
161 unsigned long skipped_entries;
162 u64 preempt_timestamp;
163 pid_t pid;
164 kuid_t uid;
165 char comm[TASK_COMM_LEN];
166
167 bool ignore_pid;
168#ifdef CONFIG_FUNCTION_TRACER
169 bool ftrace_ignore_pid;
170#endif
171};
172
173struct tracer;
174struct trace_option_dentry;
175
176struct trace_buffer {
177 struct trace_array *tr;
178 struct ring_buffer *buffer;
179 struct trace_array_cpu __percpu *data;
180 u64 time_start;
181 int cpu;
182};
183
184#define TRACE_FLAGS_MAX_SIZE 32
185
186struct trace_options {
187 struct tracer *tracer;
188 struct trace_option_dentry *topts;
189};
190
191struct trace_pid_list {
192 int pid_max;
193 unsigned long *pids;
194};
195
196typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
197
198/**
199 * struct cond_snapshot - conditional snapshot data and callback
200 *
201 * The cond_snapshot structure encapsulates a callback function and
202 * data associated with the snapshot for a given tracing instance.
203 *
204 * When a snapshot is taken conditionally, by invoking
205 * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
206 * passed in turn to the cond_snapshot.update() function. That data
207 * can be compared by the update() implementation with the cond_data
208 * contained wihin the struct cond_snapshot instance associated with
209 * the trace_array. Because the tr->max_lock is held throughout the
210 * update() call, the update() function can directly retrieve the
211 * cond_snapshot and cond_data associated with the per-instance
212 * snapshot associated with the trace_array.
213 *
214 * The cond_snapshot.update() implementation can save data to be
215 * associated with the snapshot if it decides to, and returns 'true'
216 * in that case, or it returns 'false' if the conditional snapshot
217 * shouldn't be taken.
218 *
219 * The cond_snapshot instance is created and associated with the
220 * user-defined cond_data by tracing_cond_snapshot_enable().
221 * Likewise, the cond_snapshot instance is destroyed and is no longer
222 * associated with the trace instance by
223 * tracing_cond_snapshot_disable().
224 *
225 * The method below is required.
226 *
227 * @update: When a conditional snapshot is invoked, the update()
228 * callback function is invoked with the tr->max_lock held. The
229 * update() implementation signals whether or not to actually
230 * take the snapshot, by returning 'true' if so, 'false' if no
231 * snapshot should be taken. Because the max_lock is held for
232 * the duration of update(), the implementation is safe to
233 * directly retrieven and save any implementation data it needs
234 * to in association with the snapshot.
235 */
236struct cond_snapshot {
237 void *cond_data;
238 cond_update_fn_t update;
239};
240
241/*
242 * The trace array - an array of per-CPU trace arrays. This is the
243 * highest level data structure that individual tracers deal with.
244 * They have on/off state as well:
245 */
246struct trace_array {
247 struct list_head list;
248 char *name;
249 struct trace_buffer trace_buffer;
250#ifdef CONFIG_TRACER_MAX_TRACE
251 /*
252 * The max_buffer is used to snapshot the trace when a maximum
253 * latency is reached, or when the user initiates a snapshot.
254 * Some tracers will use this to store a maximum trace while
255 * it continues examining live traces.
256 *
257 * The buffers for the max_buffer are set up the same as the trace_buffer
258 * When a snapshot is taken, the buffer of the max_buffer is swapped
259 * with the buffer of the trace_buffer and the buffers are reset for
260 * the trace_buffer so the tracing can continue.
261 */
262 struct trace_buffer max_buffer;
263 bool allocated_snapshot;
264#endif
265#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
266 unsigned long max_latency;
267#endif
268 struct trace_pid_list __rcu *filtered_pids;
269 /*
270 * max_lock is used to protect the swapping of buffers
271 * when taking a max snapshot. The buffers themselves are
272 * protected by per_cpu spinlocks. But the action of the swap
273 * needs its own lock.
274 *
275 * This is defined as a arch_spinlock_t in order to help
276 * with performance when lockdep debugging is enabled.
277 *
278 * It is also used in other places outside the update_max_tr
279 * so it needs to be defined outside of the
280 * CONFIG_TRACER_MAX_TRACE.
281 */
282 arch_spinlock_t max_lock;
283 int buffer_disabled;
284#ifdef CONFIG_FTRACE_SYSCALLS
285 int sys_refcount_enter;
286 int sys_refcount_exit;
287 struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
288 struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
289#endif
290 int stop_count;
291 int clock_id;
292 int nr_topts;
293 bool clear_trace;
294 int buffer_percent;
295 unsigned int n_err_log_entries;
296 struct tracer *current_trace;
297 unsigned int trace_flags;
298 unsigned char trace_flags_index[TRACE_FLAGS_MAX_SIZE];
299 unsigned int flags;
300 raw_spinlock_t start_lock;
301 struct list_head err_log;
302 struct dentry *dir;
303 struct dentry *options;
304 struct dentry *percpu_dir;
305 struct dentry *event_dir;
306 struct trace_options *topts;
307 struct list_head systems;
308 struct list_head events;
309 struct trace_event_file *trace_marker_file;
310 cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
311 int ref;
312#ifdef CONFIG_FUNCTION_TRACER
313 struct ftrace_ops *ops;
314 struct trace_pid_list __rcu *function_pids;
315#ifdef CONFIG_DYNAMIC_FTRACE
316 /* All of these are protected by the ftrace_lock */
317 struct list_head func_probes;
318 struct list_head mod_trace;
319 struct list_head mod_notrace;
320#endif
321 /* function tracing enabled */
322 int function_enabled;
323#endif
324 int time_stamp_abs_ref;
325 struct list_head hist_vars;
326#ifdef CONFIG_TRACER_SNAPSHOT
327 struct cond_snapshot *cond_snapshot;
328#endif
329};
330
331enum {
332 TRACE_ARRAY_FL_GLOBAL = (1 << 0)
333};
334
335extern struct list_head ftrace_trace_arrays;
336
337extern struct mutex trace_types_lock;
338
339extern int trace_array_get(struct trace_array *tr);
340extern void trace_array_put(struct trace_array *tr);
341
342extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
343extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
344
345extern bool trace_clock_in_ns(struct trace_array *tr);
346
347/*
348 * The global tracer (top) should be the first trace array added,
349 * but we check the flag anyway.
350 */
351static inline struct trace_array *top_trace_array(void)
352{
353 struct trace_array *tr;
354
355 if (list_empty(&ftrace_trace_arrays))
356 return NULL;
357
358 tr = list_entry(ftrace_trace_arrays.prev,
359 typeof(*tr), list);
360 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
361 return tr;
362}
363
364#define FTRACE_CMP_TYPE(var, type) \
365 __builtin_types_compatible_p(typeof(var), type *)
366
367#undef IF_ASSIGN
368#define IF_ASSIGN(var, entry, etype, id) \
369 if (FTRACE_CMP_TYPE(var, etype)) { \
370 var = (typeof(var))(entry); \
371 WARN_ON(id && (entry)->type != id); \
372 break; \
373 }
374
375/* Will cause compile errors if type is not found. */
376extern void __ftrace_bad_type(void);
377
378/*
379 * The trace_assign_type is a verifier that the entry type is
380 * the same as the type being assigned. To add new types simply
381 * add a line with the following format:
382 *
383 * IF_ASSIGN(var, ent, type, id);
384 *
385 * Where "type" is the trace type that includes the trace_entry
386 * as the "ent" item. And "id" is the trace identifier that is
387 * used in the trace_type enum.
388 *
389 * If the type can have more than one id, then use zero.
390 */
391#define trace_assign_type(var, ent) \
392 do { \
393 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
394 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
395 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
396 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
397 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
398 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
399 IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \
400 IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT); \
401 IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
402 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
403 TRACE_MMIO_RW); \
404 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
405 TRACE_MMIO_MAP); \
406 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
407 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
408 TRACE_GRAPH_ENT); \
409 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
410 TRACE_GRAPH_RET); \
411 __ftrace_bad_type(); \
412 } while (0)
413
414/*
415 * An option specific to a tracer. This is a boolean value.
416 * The bit is the bit index that sets its value on the
417 * flags value in struct tracer_flags.
418 */
419struct tracer_opt {
420 const char *name; /* Will appear on the trace_options file */
421 u32 bit; /* Mask assigned in val field in tracer_flags */
422};
423
424/*
425 * The set of specific options for a tracer. Your tracer
426 * have to set the initial value of the flags val.
427 */
428struct tracer_flags {
429 u32 val;
430 struct tracer_opt *opts;
431 struct tracer *trace;
432};
433
434/* Makes more easy to define a tracer opt */
435#define TRACER_OPT(s, b) .name = #s, .bit = b
436
437
438struct trace_option_dentry {
439 struct tracer_opt *opt;
440 struct tracer_flags *flags;
441 struct trace_array *tr;
442 struct dentry *entry;
443};
444
445/**
446 * struct tracer - a specific tracer and its callbacks to interact with tracefs
447 * @name: the name chosen to select it on the available_tracers file
448 * @init: called when one switches to this tracer (echo name > current_tracer)
449 * @reset: called when one switches to another tracer
450 * @start: called when tracing is unpaused (echo 1 > tracing_on)
451 * @stop: called when tracing is paused (echo 0 > tracing_on)
452 * @update_thresh: called when tracing_thresh is updated
453 * @open: called when the trace file is opened
454 * @pipe_open: called when the trace_pipe file is opened
455 * @close: called when the trace file is released
456 * @pipe_close: called when the trace_pipe file is released
457 * @read: override the default read callback on trace_pipe
458 * @splice_read: override the default splice_read callback on trace_pipe
459 * @selftest: selftest to run on boot (see trace_selftest.c)
460 * @print_headers: override the first lines that describe your columns
461 * @print_line: callback that prints a trace
462 * @set_flag: signals one of your private flags changed (trace_options file)
463 * @flags: your private flags
464 */
465struct tracer {
466 const char *name;
467 int (*init)(struct trace_array *tr);
468 void (*reset)(struct trace_array *tr);
469 void (*start)(struct trace_array *tr);
470 void (*stop)(struct trace_array *tr);
471 int (*update_thresh)(struct trace_array *tr);
472 void (*open)(struct trace_iterator *iter);
473 void (*pipe_open)(struct trace_iterator *iter);
474 void (*close)(struct trace_iterator *iter);
475 void (*pipe_close)(struct trace_iterator *iter);
476 ssize_t (*read)(struct trace_iterator *iter,
477 struct file *filp, char __user *ubuf,
478 size_t cnt, loff_t *ppos);
479 ssize_t (*splice_read)(struct trace_iterator *iter,
480 struct file *filp,
481 loff_t *ppos,
482 struct pipe_inode_info *pipe,
483 size_t len,
484 unsigned int flags);
485#ifdef CONFIG_FTRACE_STARTUP_TEST
486 int (*selftest)(struct tracer *trace,
487 struct trace_array *tr);
488#endif
489 void (*print_header)(struct seq_file *m);
490 enum print_line_t (*print_line)(struct trace_iterator *iter);
491 /* If you handled the flag setting, return 0 */
492 int (*set_flag)(struct trace_array *tr,
493 u32 old_flags, u32 bit, int set);
494 /* Return 0 if OK with change, else return non-zero */
495 int (*flag_changed)(struct trace_array *tr,
496 u32 mask, int set);
497 struct tracer *next;
498 struct tracer_flags *flags;
499 int enabled;
500 int ref;
501 bool print_max;
502 bool allow_instances;
503#ifdef CONFIG_TRACER_MAX_TRACE
504 bool use_max_tr;
505#endif
506 /* True if tracer cannot be enabled in kernel param */
507 bool noboot;
508};
509
510
511/* Only current can touch trace_recursion */
512
513/*
514 * For function tracing recursion:
515 * The order of these bits are important.
516 *
517 * When function tracing occurs, the following steps are made:
518 * If arch does not support a ftrace feature:
519 * call internal function (uses INTERNAL bits) which calls...
520 * If callback is registered to the "global" list, the list
521 * function is called and recursion checks the GLOBAL bits.
522 * then this function calls...
523 * The function callback, which can use the FTRACE bits to
524 * check for recursion.
525 *
526 * Now if the arch does not suppport a feature, and it calls
527 * the global list function which calls the ftrace callback
528 * all three of these steps will do a recursion protection.
529 * There's no reason to do one if the previous caller already
530 * did. The recursion that we are protecting against will
531 * go through the same steps again.
532 *
533 * To prevent the multiple recursion checks, if a recursion
534 * bit is set that is higher than the MAX bit of the current
535 * check, then we know that the check was made by the previous
536 * caller, and we can skip the current check.
537 */
538enum {
539 TRACE_BUFFER_BIT,
540 TRACE_BUFFER_NMI_BIT,
541 TRACE_BUFFER_IRQ_BIT,
542 TRACE_BUFFER_SIRQ_BIT,
543
544 /* Start of function recursion bits */
545 TRACE_FTRACE_BIT,
546 TRACE_FTRACE_NMI_BIT,
547 TRACE_FTRACE_IRQ_BIT,
548 TRACE_FTRACE_SIRQ_BIT,
549
550 /* INTERNAL_BITs must be greater than FTRACE_BITs */
551 TRACE_INTERNAL_BIT,
552 TRACE_INTERNAL_NMI_BIT,
553 TRACE_INTERNAL_IRQ_BIT,
554 TRACE_INTERNAL_SIRQ_BIT,
555
556 TRACE_BRANCH_BIT,
557/*
558 * Abuse of the trace_recursion.
559 * As we need a way to maintain state if we are tracing the function
560 * graph in irq because we want to trace a particular function that
561 * was called in irq context but we have irq tracing off. Since this
562 * can only be modified by current, we can reuse trace_recursion.
563 */
564 TRACE_IRQ_BIT,
565
566 /* Set if the function is in the set_graph_function file */
567 TRACE_GRAPH_BIT,
568
569 /*
570 * In the very unlikely case that an interrupt came in
571 * at a start of graph tracing, and we want to trace
572 * the function in that interrupt, the depth can be greater
573 * than zero, because of the preempted start of a previous
574 * trace. In an even more unlikely case, depth could be 2
575 * if a softirq interrupted the start of graph tracing,
576 * followed by an interrupt preempting a start of graph
577 * tracing in the softirq, and depth can even be 3
578 * if an NMI came in at the start of an interrupt function
579 * that preempted a softirq start of a function that
580 * preempted normal context!!!! Luckily, it can't be
581 * greater than 3, so the next two bits are a mask
582 * of what the depth is when we set TRACE_GRAPH_BIT
583 */
584
585 TRACE_GRAPH_DEPTH_START_BIT,
586 TRACE_GRAPH_DEPTH_END_BIT,
587
588 /*
589 * To implement set_graph_notrace, if this bit is set, we ignore
590 * function graph tracing of called functions, until the return
591 * function is called to clear it.
592 */
593 TRACE_GRAPH_NOTRACE_BIT,
594};
595
596#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
597#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
598#define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
599
600#define trace_recursion_depth() \
601 (((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
602#define trace_recursion_set_depth(depth) \
603 do { \
604 current->trace_recursion &= \
605 ~(3 << TRACE_GRAPH_DEPTH_START_BIT); \
606 current->trace_recursion |= \
607 ((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT; \
608 } while (0)
609
610#define TRACE_CONTEXT_BITS 4
611
612#define TRACE_FTRACE_START TRACE_FTRACE_BIT
613#define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
614
615#define TRACE_LIST_START TRACE_INTERNAL_BIT
616#define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
617
618#define TRACE_CONTEXT_MASK TRACE_LIST_MAX
619
620static __always_inline int trace_get_context_bit(void)
621{
622 int bit;
623
624 if (in_interrupt()) {
625 if (in_nmi())
626 bit = 0;
627
628 else if (in_irq())
629 bit = 1;
630 else
631 bit = 2;
632 } else
633 bit = 3;
634
635 return bit;
636}
637
638static __always_inline int trace_test_and_set_recursion(int start, int max)
639{
640 unsigned int val = current->trace_recursion;
641 int bit;
642
643 /* A previous recursion check was made */
644 if ((val & TRACE_CONTEXT_MASK) > max)
645 return 0;
646
647 bit = trace_get_context_bit() + start;
648 if (unlikely(val & (1 << bit)))
649 return -1;
650
651 val |= 1 << bit;
652 current->trace_recursion = val;
653 barrier();
654
655 return bit;
656}
657
658static __always_inline void trace_clear_recursion(int bit)
659{
660 unsigned int val = current->trace_recursion;
661
662 if (!bit)
663 return;
664
665 bit = 1 << bit;
666 val &= ~bit;
667
668 barrier();
669 current->trace_recursion = val;
670}
671
672static inline struct ring_buffer_iter *
673trace_buffer_iter(struct trace_iterator *iter, int cpu)
674{
675 return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
676}
677
678int tracer_init(struct tracer *t, struct trace_array *tr);
679int tracing_is_enabled(void);
680void tracing_reset(struct trace_buffer *buf, int cpu);
681void tracing_reset_online_cpus(struct trace_buffer *buf);
682void tracing_reset_current(int cpu);
683void tracing_reset_all_online_cpus(void);
684int tracing_open_generic(struct inode *inode, struct file *filp);
685bool tracing_is_disabled(void);
686bool tracer_tracing_is_on(struct trace_array *tr);
687void tracer_tracing_on(struct trace_array *tr);
688void tracer_tracing_off(struct trace_array *tr);
689struct dentry *trace_create_file(const char *name,
690 umode_t mode,
691 struct dentry *parent,
692 void *data,
693 const struct file_operations *fops);
694
695struct dentry *tracing_init_dentry(void);
696
697struct ring_buffer_event;
698
699struct ring_buffer_event *
700trace_buffer_lock_reserve(struct ring_buffer *buffer,
701 int type,
702 unsigned long len,
703 unsigned long flags,
704 int pc);
705
706struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
707 struct trace_array_cpu *data);
708
709struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
710 int *ent_cpu, u64 *ent_ts);
711
712void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
713 struct ring_buffer_event *event);
714
715int trace_empty(struct trace_iterator *iter);
716
717void *trace_find_next_entry_inc(struct trace_iterator *iter);
718
719void trace_init_global_iter(struct trace_iterator *iter);
720
721void tracing_iter_reset(struct trace_iterator *iter, int cpu);
722
723unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
724unsigned long trace_total_entries(struct trace_array *tr);
725
726void trace_function(struct trace_array *tr,
727 unsigned long ip,
728 unsigned long parent_ip,
729 unsigned long flags, int pc);
730void trace_graph_function(struct trace_array *tr,
731 unsigned long ip,
732 unsigned long parent_ip,
733 unsigned long flags, int pc);
734void trace_latency_header(struct seq_file *m);
735void trace_default_header(struct seq_file *m);
736void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
737int trace_empty(struct trace_iterator *iter);
738
739void trace_graph_return(struct ftrace_graph_ret *trace);
740int trace_graph_entry(struct ftrace_graph_ent *trace);
741void set_graph_array(struct trace_array *tr);
742
743void tracing_start_cmdline_record(void);
744void tracing_stop_cmdline_record(void);
745void tracing_start_tgid_record(void);
746void tracing_stop_tgid_record(void);
747
748int register_tracer(struct tracer *type);
749int is_tracing_stopped(void);
750
751loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
752
753extern cpumask_var_t __read_mostly tracing_buffer_mask;
754
755#define for_each_tracing_cpu(cpu) \
756 for_each_cpu(cpu, tracing_buffer_mask)
757
758extern unsigned long nsecs_to_usecs(unsigned long nsecs);
759
760extern unsigned long tracing_thresh;
761
762/* PID filtering */
763
764extern int pid_max;
765
766bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
767 pid_t search_pid);
768bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
769 struct task_struct *task);
770void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
771 struct task_struct *self,
772 struct task_struct *task);
773void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
774void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
775int trace_pid_show(struct seq_file *m, void *v);
776void trace_free_pid_list(struct trace_pid_list *pid_list);
777int trace_pid_write(struct trace_pid_list *filtered_pids,
778 struct trace_pid_list **new_pid_list,
779 const char __user *ubuf, size_t cnt);
780
781#ifdef CONFIG_TRACER_MAX_TRACE
782void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
783 void *cond_data);
784void update_max_tr_single(struct trace_array *tr,
785 struct task_struct *tsk, int cpu);
786#endif /* CONFIG_TRACER_MAX_TRACE */
787
788#ifdef CONFIG_STACKTRACE
789void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
790 int pc);
791#else
792static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
793 int skip, int pc)
794{
795}
796#endif /* CONFIG_STACKTRACE */
797
798extern u64 ftrace_now(int cpu);
799
800extern void trace_find_cmdline(int pid, char comm[]);
801extern int trace_find_tgid(int pid);
802extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
803
804#ifdef CONFIG_DYNAMIC_FTRACE
805extern unsigned long ftrace_update_tot_cnt;
806void ftrace_init_trace_array(struct trace_array *tr);
807#else
808static inline void ftrace_init_trace_array(struct trace_array *tr) { }
809#endif
810#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
811extern int DYN_FTRACE_TEST_NAME(void);
812#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
813extern int DYN_FTRACE_TEST_NAME2(void);
814
815extern bool ring_buffer_expanded;
816extern bool tracing_selftest_disabled;
817
818#ifdef CONFIG_FTRACE_STARTUP_TEST
819extern int trace_selftest_startup_function(struct tracer *trace,
820 struct trace_array *tr);
821extern int trace_selftest_startup_function_graph(struct tracer *trace,
822 struct trace_array *tr);
823extern int trace_selftest_startup_irqsoff(struct tracer *trace,
824 struct trace_array *tr);
825extern int trace_selftest_startup_preemptoff(struct tracer *trace,
826 struct trace_array *tr);
827extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
828 struct trace_array *tr);
829extern int trace_selftest_startup_wakeup(struct tracer *trace,
830 struct trace_array *tr);
831extern int trace_selftest_startup_nop(struct tracer *trace,
832 struct trace_array *tr);
833extern int trace_selftest_startup_branch(struct tracer *trace,
834 struct trace_array *tr);
835/*
836 * Tracer data references selftest functions that only occur
837 * on boot up. These can be __init functions. Thus, when selftests
838 * are enabled, then the tracers need to reference __init functions.
839 */
840#define __tracer_data __refdata
841#else
842/* Tracers are seldom changed. Optimize when selftests are disabled. */
843#define __tracer_data __read_mostly
844#endif /* CONFIG_FTRACE_STARTUP_TEST */
845
846extern void *head_page(struct trace_array_cpu *data);
847extern unsigned long long ns2usecs(u64 nsec);
848extern int
849trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
850extern int
851trace_vprintk(unsigned long ip, const char *fmt, va_list args);
852extern int
853trace_array_vprintk(struct trace_array *tr,
854 unsigned long ip, const char *fmt, va_list args);
855int trace_array_printk(struct trace_array *tr,
856 unsigned long ip, const char *fmt, ...);
857int trace_array_printk_buf(struct ring_buffer *buffer,
858 unsigned long ip, const char *fmt, ...);
859void trace_printk_seq(struct trace_seq *s);
860enum print_line_t print_trace_line(struct trace_iterator *iter);
861
862extern char trace_find_mark(unsigned long long duration);
863
864struct ftrace_hash;
865
866struct ftrace_mod_load {
867 struct list_head list;
868 char *func;
869 char *module;
870 int enable;
871};
872
873enum {
874 FTRACE_HASH_FL_MOD = (1 << 0),
875};
876
877struct ftrace_hash {
878 unsigned long size_bits;
879 struct hlist_head *buckets;
880 unsigned long count;
881 unsigned long flags;
882 struct rcu_head rcu;
883};
884
885struct ftrace_func_entry *
886ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
887
888static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
889{
890 return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
891}
892
893/* Standard output formatting function used for function return traces */
894#ifdef CONFIG_FUNCTION_GRAPH_TRACER
895
896/* Flag options */
897#define TRACE_GRAPH_PRINT_OVERRUN 0x1
898#define TRACE_GRAPH_PRINT_CPU 0x2
899#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
900#define TRACE_GRAPH_PRINT_PROC 0x8
901#define TRACE_GRAPH_PRINT_DURATION 0x10
902#define TRACE_GRAPH_PRINT_ABS_TIME 0x20
903#define TRACE_GRAPH_PRINT_REL_TIME 0x40
904#define TRACE_GRAPH_PRINT_IRQS 0x80
905#define TRACE_GRAPH_PRINT_TAIL 0x100
906#define TRACE_GRAPH_SLEEP_TIME 0x200
907#define TRACE_GRAPH_GRAPH_TIME 0x400
908#define TRACE_GRAPH_PRINT_FILL_SHIFT 28
909#define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
910
911extern void ftrace_graph_sleep_time_control(bool enable);
912
913#ifdef CONFIG_FUNCTION_PROFILER
914extern void ftrace_graph_graph_time_control(bool enable);
915#else
916static inline void ftrace_graph_graph_time_control(bool enable) { }
917#endif
918
919extern enum print_line_t
920print_graph_function_flags(struct trace_iterator *iter, u32 flags);
921extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
922extern void
923trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
924extern void graph_trace_open(struct trace_iterator *iter);
925extern void graph_trace_close(struct trace_iterator *iter);
926extern int __trace_graph_entry(struct trace_array *tr,
927 struct ftrace_graph_ent *trace,
928 unsigned long flags, int pc);
929extern void __trace_graph_return(struct trace_array *tr,
930 struct ftrace_graph_ret *trace,
931 unsigned long flags, int pc);
932
933#ifdef CONFIG_DYNAMIC_FTRACE
934extern struct ftrace_hash *ftrace_graph_hash;
935extern struct ftrace_hash *ftrace_graph_notrace_hash;
936
937static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
938{
939 unsigned long addr = trace->func;
940 int ret = 0;
941
942 preempt_disable_notrace();
943
944 if (ftrace_hash_empty(ftrace_graph_hash)) {
945 ret = 1;
946 goto out;
947 }
948
949 if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
950
951 /*
952 * This needs to be cleared on the return functions
953 * when the depth is zero.
954 */
955 trace_recursion_set(TRACE_GRAPH_BIT);
956 trace_recursion_set_depth(trace->depth);
957
958 /*
959 * If no irqs are to be traced, but a set_graph_function
960 * is set, and called by an interrupt handler, we still
961 * want to trace it.
962 */
963 if (in_irq())
964 trace_recursion_set(TRACE_IRQ_BIT);
965 else
966 trace_recursion_clear(TRACE_IRQ_BIT);
967 ret = 1;
968 }
969
970out:
971 preempt_enable_notrace();
972 return ret;
973}
974
975static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
976{
977 if (trace_recursion_test(TRACE_GRAPH_BIT) &&
978 trace->depth == trace_recursion_depth())
979 trace_recursion_clear(TRACE_GRAPH_BIT);
980}
981
982static inline int ftrace_graph_notrace_addr(unsigned long addr)
983{
984 int ret = 0;
985
986 preempt_disable_notrace();
987
988 if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
989 ret = 1;
990
991 preempt_enable_notrace();
992 return ret;
993}
994#else
995static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
996{
997 return 1;
998}
999
1000static inline int ftrace_graph_notrace_addr(unsigned long addr)
1001{
1002 return 0;
1003}
1004static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
1005{ }
1006#endif /* CONFIG_DYNAMIC_FTRACE */
1007
1008extern unsigned int fgraph_max_depth;
1009
1010static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
1011{
1012 /* trace it when it is-nested-in or is a function enabled. */
1013 return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
1014 ftrace_graph_addr(trace)) ||
1015 (trace->depth < 0) ||
1016 (fgraph_max_depth && trace->depth >= fgraph_max_depth);
1017}
1018
1019#else /* CONFIG_FUNCTION_GRAPH_TRACER */
1020static inline enum print_line_t
1021print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1022{
1023 return TRACE_TYPE_UNHANDLED;
1024}
1025#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1026
1027extern struct list_head ftrace_pids;
1028
1029#ifdef CONFIG_FUNCTION_TRACER
1030struct ftrace_func_command {
1031 struct list_head list;
1032 char *name;
1033 int (*func)(struct trace_array *tr,
1034 struct ftrace_hash *hash,
1035 char *func, char *cmd,
1036 char *params, int enable);
1037};
1038extern bool ftrace_filter_param __initdata;
1039static inline int ftrace_trace_task(struct trace_array *tr)
1040{
1041 return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
1042}
1043extern int ftrace_is_dead(void);
1044int ftrace_create_function_files(struct trace_array *tr,
1045 struct dentry *parent);
1046void ftrace_destroy_function_files(struct trace_array *tr);
1047void ftrace_init_global_array_ops(struct trace_array *tr);
1048void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
1049void ftrace_reset_array_ops(struct trace_array *tr);
1050void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
1051void ftrace_init_tracefs_toplevel(struct trace_array *tr,
1052 struct dentry *d_tracer);
1053void ftrace_clear_pids(struct trace_array *tr);
1054int init_function_trace(void);
1055void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
1056#else
1057static inline int ftrace_trace_task(struct trace_array *tr)
1058{
1059 return 1;
1060}
1061static inline int ftrace_is_dead(void) { return 0; }
1062static inline int
1063ftrace_create_function_files(struct trace_array *tr,
1064 struct dentry *parent)
1065{
1066 return 0;
1067}
1068static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1069static inline __init void
1070ftrace_init_global_array_ops(struct trace_array *tr) { }
1071static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1072static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1073static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1074static inline void ftrace_clear_pids(struct trace_array *tr) { }
1075static inline int init_function_trace(void) { return 0; }
1076static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1077/* ftace_func_t type is not defined, use macro instead of static inline */
1078#define ftrace_init_array_ops(tr, func) do { } while (0)
1079#endif /* CONFIG_FUNCTION_TRACER */
1080
1081#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1082
1083struct ftrace_probe_ops {
1084 void (*func)(unsigned long ip,
1085 unsigned long parent_ip,
1086 struct trace_array *tr,
1087 struct ftrace_probe_ops *ops,
1088 void *data);
1089 int (*init)(struct ftrace_probe_ops *ops,
1090 struct trace_array *tr,
1091 unsigned long ip, void *init_data,
1092 void **data);
1093 void (*free)(struct ftrace_probe_ops *ops,
1094 struct trace_array *tr,
1095 unsigned long ip, void *data);
1096 int (*print)(struct seq_file *m,
1097 unsigned long ip,
1098 struct ftrace_probe_ops *ops,
1099 void *data);
1100};
1101
1102struct ftrace_func_mapper;
1103typedef int (*ftrace_mapper_func)(void *data);
1104
1105struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1106void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1107 unsigned long ip);
1108int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1109 unsigned long ip, void *data);
1110void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1111 unsigned long ip);
1112void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1113 ftrace_mapper_func free_func);
1114
1115extern int
1116register_ftrace_function_probe(char *glob, struct trace_array *tr,
1117 struct ftrace_probe_ops *ops, void *data);
1118extern int
1119unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1120 struct ftrace_probe_ops *ops);
1121extern void clear_ftrace_function_probes(struct trace_array *tr);
1122
1123int register_ftrace_command(struct ftrace_func_command *cmd);
1124int unregister_ftrace_command(struct ftrace_func_command *cmd);
1125
1126void ftrace_create_filter_files(struct ftrace_ops *ops,
1127 struct dentry *parent);
1128void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1129#else
1130struct ftrace_func_command;
1131
1132static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1133{
1134 return -EINVAL;
1135}
1136static inline __init int unregister_ftrace_command(char *cmd_name)
1137{
1138 return -EINVAL;
1139}
1140static inline void clear_ftrace_function_probes(struct trace_array *tr)
1141{
1142}
1143
1144/*
1145 * The ops parameter passed in is usually undefined.
1146 * This must be a macro.
1147 */
1148#define ftrace_create_filter_files(ops, parent) do { } while (0)
1149#define ftrace_destroy_filter_files(ops) do { } while (0)
1150#endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1151
1152bool ftrace_event_is_function(struct trace_event_call *call);
1153
1154/*
1155 * struct trace_parser - servers for reading the user input separated by spaces
1156 * @cont: set if the input is not complete - no final space char was found
1157 * @buffer: holds the parsed user input
1158 * @idx: user input length
1159 * @size: buffer size
1160 */
1161struct trace_parser {
1162 bool cont;
1163 char *buffer;
1164 unsigned idx;
1165 unsigned size;
1166};
1167
1168static inline bool trace_parser_loaded(struct trace_parser *parser)
1169{
1170 return (parser->idx != 0);
1171}
1172
1173static inline bool trace_parser_cont(struct trace_parser *parser)
1174{
1175 return parser->cont;
1176}
1177
1178static inline void trace_parser_clear(struct trace_parser *parser)
1179{
1180 parser->cont = false;
1181 parser->idx = 0;
1182}
1183
1184extern int trace_parser_get_init(struct trace_parser *parser, int size);
1185extern void trace_parser_put(struct trace_parser *parser);
1186extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1187 size_t cnt, loff_t *ppos);
1188
1189/*
1190 * Only create function graph options if function graph is configured.
1191 */
1192#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1193# define FGRAPH_FLAGS \
1194 C(DISPLAY_GRAPH, "display-graph"),
1195#else
1196# define FGRAPH_FLAGS
1197#endif
1198
1199#ifdef CONFIG_BRANCH_TRACER
1200# define BRANCH_FLAGS \
1201 C(BRANCH, "branch"),
1202#else
1203# define BRANCH_FLAGS
1204#endif
1205
1206#ifdef CONFIG_FUNCTION_TRACER
1207# define FUNCTION_FLAGS \
1208 C(FUNCTION, "function-trace"), \
1209 C(FUNC_FORK, "function-fork"),
1210# define FUNCTION_DEFAULT_FLAGS TRACE_ITER_FUNCTION
1211#else
1212# define FUNCTION_FLAGS
1213# define FUNCTION_DEFAULT_FLAGS 0UL
1214# define TRACE_ITER_FUNC_FORK 0UL
1215#endif
1216
1217#ifdef CONFIG_STACKTRACE
1218# define STACK_FLAGS \
1219 C(STACKTRACE, "stacktrace"),
1220#else
1221# define STACK_FLAGS
1222#endif
1223
1224/*
1225 * trace_iterator_flags is an enumeration that defines bit
1226 * positions into trace_flags that controls the output.
1227 *
1228 * NOTE: These bits must match the trace_options array in
1229 * trace.c (this macro guarantees it).
1230 */
1231#define TRACE_FLAGS \
1232 C(PRINT_PARENT, "print-parent"), \
1233 C(SYM_OFFSET, "sym-offset"), \
1234 C(SYM_ADDR, "sym-addr"), \
1235 C(VERBOSE, "verbose"), \
1236 C(RAW, "raw"), \
1237 C(HEX, "hex"), \
1238 C(BIN, "bin"), \
1239 C(BLOCK, "block"), \
1240 C(PRINTK, "trace_printk"), \
1241 C(ANNOTATE, "annotate"), \
1242 C(USERSTACKTRACE, "userstacktrace"), \
1243 C(SYM_USEROBJ, "sym-userobj"), \
1244 C(PRINTK_MSGONLY, "printk-msg-only"), \
1245 C(CONTEXT_INFO, "context-info"), /* Print pid/cpu/time */ \
1246 C(LATENCY_FMT, "latency-format"), \
1247 C(RECORD_CMD, "record-cmd"), \
1248 C(RECORD_TGID, "record-tgid"), \
1249 C(OVERWRITE, "overwrite"), \
1250 C(STOP_ON_FREE, "disable_on_free"), \
1251 C(IRQ_INFO, "irq-info"), \
1252 C(MARKERS, "markers"), \
1253 C(EVENT_FORK, "event-fork"), \
1254 FUNCTION_FLAGS \
1255 FGRAPH_FLAGS \
1256 STACK_FLAGS \
1257 BRANCH_FLAGS
1258
1259/*
1260 * By defining C, we can make TRACE_FLAGS a list of bit names
1261 * that will define the bits for the flag masks.
1262 */
1263#undef C
1264#define C(a, b) TRACE_ITER_##a##_BIT
1265
1266enum trace_iterator_bits {
1267 TRACE_FLAGS
1268 /* Make sure we don't go more than we have bits for */
1269 TRACE_ITER_LAST_BIT
1270};
1271
1272/*
1273 * By redefining C, we can make TRACE_FLAGS a list of masks that
1274 * use the bits as defined above.
1275 */
1276#undef C
1277#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1278
1279enum trace_iterator_flags { TRACE_FLAGS };
1280
1281/*
1282 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1283 * control the output of kernel symbols.
1284 */
1285#define TRACE_ITER_SYM_MASK \
1286 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1287
1288extern struct tracer nop_trace;
1289
1290#ifdef CONFIG_BRANCH_TRACER
1291extern int enable_branch_tracing(struct trace_array *tr);
1292extern void disable_branch_tracing(void);
1293static inline int trace_branch_enable(struct trace_array *tr)
1294{
1295 if (tr->trace_flags & TRACE_ITER_BRANCH)
1296 return enable_branch_tracing(tr);
1297 return 0;
1298}
1299static inline void trace_branch_disable(void)
1300{
1301 /* due to races, always disable */
1302 disable_branch_tracing();
1303}
1304#else
1305static inline int trace_branch_enable(struct trace_array *tr)
1306{
1307 return 0;
1308}
1309static inline void trace_branch_disable(void)
1310{
1311}
1312#endif /* CONFIG_BRANCH_TRACER */
1313
1314/* set ring buffers to default size if not already done so */
1315int tracing_update_buffers(void);
1316
1317struct ftrace_event_field {
1318 struct list_head link;
1319 const char *name;
1320 const char *type;
1321 int filter_type;
1322 int offset;
1323 int size;
1324 int is_signed;
1325};
1326
1327struct prog_entry;
1328
1329struct event_filter {
1330 struct prog_entry __rcu *prog;
1331 char *filter_string;
1332};
1333
1334struct event_subsystem {
1335 struct list_head list;
1336 const char *name;
1337 struct event_filter *filter;
1338 int ref_count;
1339};
1340
1341struct trace_subsystem_dir {
1342 struct list_head list;
1343 struct event_subsystem *subsystem;
1344 struct trace_array *tr;
1345 struct dentry *entry;
1346 int ref_count;
1347 int nr_events;
1348};
1349
1350extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1351 struct ring_buffer *buffer,
1352 struct ring_buffer_event *event);
1353
1354void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1355 struct ring_buffer *buffer,
1356 struct ring_buffer_event *event,
1357 unsigned long flags, int pc,
1358 struct pt_regs *regs);
1359
1360static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1361 struct ring_buffer *buffer,
1362 struct ring_buffer_event *event,
1363 unsigned long flags, int pc)
1364{
1365 trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1366}
1367
1368DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1369DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1370void trace_buffered_event_disable(void);
1371void trace_buffered_event_enable(void);
1372
1373static inline void
1374__trace_event_discard_commit(struct ring_buffer *buffer,
1375 struct ring_buffer_event *event)
1376{
1377 if (this_cpu_read(trace_buffered_event) == event) {
1378 /* Simply release the temp buffer */
1379 this_cpu_dec(trace_buffered_event_cnt);
1380 return;
1381 }
1382 ring_buffer_discard_commit(buffer, event);
1383}
1384
1385/*
1386 * Helper function for event_trigger_unlock_commit{_regs}().
1387 * If there are event triggers attached to this event that requires
1388 * filtering against its fields, then they wil be called as the
1389 * entry already holds the field information of the current event.
1390 *
1391 * It also checks if the event should be discarded or not.
1392 * It is to be discarded if the event is soft disabled and the
1393 * event was only recorded to process triggers, or if the event
1394 * filter is active and this event did not match the filters.
1395 *
1396 * Returns true if the event is discarded, false otherwise.
1397 */
1398static inline bool
1399__event_trigger_test_discard(struct trace_event_file *file,
1400 struct ring_buffer *buffer,
1401 struct ring_buffer_event *event,
1402 void *entry,
1403 enum event_trigger_type *tt)
1404{
1405 unsigned long eflags = file->flags;
1406
1407 if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1408 *tt = event_triggers_call(file, entry, event);
1409
1410 if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1411 (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1412 !filter_match_preds(file->filter, entry))) {
1413 __trace_event_discard_commit(buffer, event);
1414 return true;
1415 }
1416
1417 return false;
1418}
1419
1420/**
1421 * event_trigger_unlock_commit - handle triggers and finish event commit
1422 * @file: The file pointer assoctiated to the event
1423 * @buffer: The ring buffer that the event is being written to
1424 * @event: The event meta data in the ring buffer
1425 * @entry: The event itself
1426 * @irq_flags: The state of the interrupts at the start of the event
1427 * @pc: The state of the preempt count at the start of the event.
1428 *
1429 * This is a helper function to handle triggers that require data
1430 * from the event itself. It also tests the event against filters and
1431 * if the event is soft disabled and should be discarded.
1432 */
1433static inline void
1434event_trigger_unlock_commit(struct trace_event_file *file,
1435 struct ring_buffer *buffer,
1436 struct ring_buffer_event *event,
1437 void *entry, unsigned long irq_flags, int pc)
1438{
1439 enum event_trigger_type tt = ETT_NONE;
1440
1441 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1442 trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1443
1444 if (tt)
1445 event_triggers_post_call(file, tt);
1446}
1447
1448/**
1449 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1450 * @file: The file pointer assoctiated to the event
1451 * @buffer: The ring buffer that the event is being written to
1452 * @event: The event meta data in the ring buffer
1453 * @entry: The event itself
1454 * @irq_flags: The state of the interrupts at the start of the event
1455 * @pc: The state of the preempt count at the start of the event.
1456 *
1457 * This is a helper function to handle triggers that require data
1458 * from the event itself. It also tests the event against filters and
1459 * if the event is soft disabled and should be discarded.
1460 *
1461 * Same as event_trigger_unlock_commit() but calls
1462 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1463 */
1464static inline void
1465event_trigger_unlock_commit_regs(struct trace_event_file *file,
1466 struct ring_buffer *buffer,
1467 struct ring_buffer_event *event,
1468 void *entry, unsigned long irq_flags, int pc,
1469 struct pt_regs *regs)
1470{
1471 enum event_trigger_type tt = ETT_NONE;
1472
1473 if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1474 trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1475 irq_flags, pc, regs);
1476
1477 if (tt)
1478 event_triggers_post_call(file, tt);
1479}
1480
1481#define FILTER_PRED_INVALID ((unsigned short)-1)
1482#define FILTER_PRED_IS_RIGHT (1 << 15)
1483#define FILTER_PRED_FOLD (1 << 15)
1484
1485/*
1486 * The max preds is the size of unsigned short with
1487 * two flags at the MSBs. One bit is used for both the IS_RIGHT
1488 * and FOLD flags. The other is reserved.
1489 *
1490 * 2^14 preds is way more than enough.
1491 */
1492#define MAX_FILTER_PRED 16384
1493
1494struct filter_pred;
1495struct regex;
1496
1497typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1498
1499typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1500
1501enum regex_type {
1502 MATCH_FULL = 0,
1503 MATCH_FRONT_ONLY,
1504 MATCH_MIDDLE_ONLY,
1505 MATCH_END_ONLY,
1506 MATCH_GLOB,
1507 MATCH_INDEX,
1508};
1509
1510struct regex {
1511 char pattern[MAX_FILTER_STR_VAL];
1512 int len;
1513 int field_len;
1514 regex_match_func match;
1515};
1516
1517struct filter_pred {
1518 filter_pred_fn_t fn;
1519 u64 val;
1520 struct regex regex;
1521 unsigned short *ops;
1522 struct ftrace_event_field *field;
1523 int offset;
1524 int not;
1525 int op;
1526};
1527
1528static inline bool is_string_field(struct ftrace_event_field *field)
1529{
1530 return field->filter_type == FILTER_DYN_STRING ||
1531 field->filter_type == FILTER_STATIC_STRING ||
1532 field->filter_type == FILTER_PTR_STRING ||
1533 field->filter_type == FILTER_COMM;
1534}
1535
1536static inline bool is_function_field(struct ftrace_event_field *field)
1537{
1538 return field->filter_type == FILTER_TRACE_FN;
1539}
1540
1541extern enum regex_type
1542filter_parse_regex(char *buff, int len, char **search, int *not);
1543extern void print_event_filter(struct trace_event_file *file,
1544 struct trace_seq *s);
1545extern int apply_event_filter(struct trace_event_file *file,
1546 char *filter_string);
1547extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1548 char *filter_string);
1549extern void print_subsystem_event_filter(struct event_subsystem *system,
1550 struct trace_seq *s);
1551extern int filter_assign_type(const char *type);
1552extern int create_event_filter(struct trace_array *tr,
1553 struct trace_event_call *call,
1554 char *filter_str, bool set_str,
1555 struct event_filter **filterp);
1556extern void free_event_filter(struct event_filter *filter);
1557
1558struct ftrace_event_field *
1559trace_find_event_field(struct trace_event_call *call, char *name);
1560
1561extern void trace_event_enable_cmd_record(bool enable);
1562extern void trace_event_enable_tgid_record(bool enable);
1563
1564extern int event_trace_init(void);
1565extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1566extern int event_trace_del_tracer(struct trace_array *tr);
1567
1568extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1569 const char *system,
1570 const char *event);
1571extern struct trace_event_file *find_event_file(struct trace_array *tr,
1572 const char *system,
1573 const char *event);
1574
1575static inline void *event_file_data(struct file *filp)
1576{
1577 return READ_ONCE(file_inode(filp)->i_private);
1578}
1579
1580extern struct mutex event_mutex;
1581extern struct list_head ftrace_events;
1582
1583extern const struct file_operations event_trigger_fops;
1584extern const struct file_operations event_hist_fops;
1585
1586#ifdef CONFIG_HIST_TRIGGERS
1587extern int register_trigger_hist_cmd(void);
1588extern int register_trigger_hist_enable_disable_cmds(void);
1589#else
1590static inline int register_trigger_hist_cmd(void) { return 0; }
1591static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1592#endif
1593
1594extern int register_trigger_cmds(void);
1595extern void clear_event_triggers(struct trace_array *tr);
1596
1597struct event_trigger_data {
1598 unsigned long count;
1599 int ref;
1600 struct event_trigger_ops *ops;
1601 struct event_command *cmd_ops;
1602 struct event_filter __rcu *filter;
1603 char *filter_str;
1604 void *private_data;
1605 bool paused;
1606 bool paused_tmp;
1607 struct list_head list;
1608 char *name;
1609 struct list_head named_list;
1610 struct event_trigger_data *named_data;
1611};
1612
1613/* Avoid typos */
1614#define ENABLE_EVENT_STR "enable_event"
1615#define DISABLE_EVENT_STR "disable_event"
1616#define ENABLE_HIST_STR "enable_hist"
1617#define DISABLE_HIST_STR "disable_hist"
1618
1619struct enable_trigger_data {
1620 struct trace_event_file *file;
1621 bool enable;
1622 bool hist;
1623};
1624
1625extern int event_enable_trigger_print(struct seq_file *m,
1626 struct event_trigger_ops *ops,
1627 struct event_trigger_data *data);
1628extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1629 struct event_trigger_data *data);
1630extern int event_enable_trigger_func(struct event_command *cmd_ops,
1631 struct trace_event_file *file,
1632 char *glob, char *cmd, char *param);
1633extern int event_enable_register_trigger(char *glob,
1634 struct event_trigger_ops *ops,
1635 struct event_trigger_data *data,
1636 struct trace_event_file *file);
1637extern void event_enable_unregister_trigger(char *glob,
1638 struct event_trigger_ops *ops,
1639 struct event_trigger_data *test,
1640 struct trace_event_file *file);
1641extern void trigger_data_free(struct event_trigger_data *data);
1642extern int event_trigger_init(struct event_trigger_ops *ops,
1643 struct event_trigger_data *data);
1644extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1645 int trigger_enable);
1646extern void update_cond_flag(struct trace_event_file *file);
1647extern int set_trigger_filter(char *filter_str,
1648 struct event_trigger_data *trigger_data,
1649 struct trace_event_file *file);
1650extern struct event_trigger_data *find_named_trigger(const char *name);
1651extern bool is_named_trigger(struct event_trigger_data *test);
1652extern int save_named_trigger(const char *name,
1653 struct event_trigger_data *data);
1654extern void del_named_trigger(struct event_trigger_data *data);
1655extern void pause_named_trigger(struct event_trigger_data *data);
1656extern void unpause_named_trigger(struct event_trigger_data *data);
1657extern void set_named_trigger_data(struct event_trigger_data *data,
1658 struct event_trigger_data *named_data);
1659extern struct event_trigger_data *
1660get_named_trigger_data(struct event_trigger_data *data);
1661extern int register_event_command(struct event_command *cmd);
1662extern int unregister_event_command(struct event_command *cmd);
1663extern int register_trigger_hist_enable_disable_cmds(void);
1664
1665/**
1666 * struct event_trigger_ops - callbacks for trace event triggers
1667 *
1668 * The methods in this structure provide per-event trigger hooks for
1669 * various trigger operations.
1670 *
1671 * All the methods below, except for @init() and @free(), must be
1672 * implemented.
1673 *
1674 * @func: The trigger 'probe' function called when the triggering
1675 * event occurs. The data passed into this callback is the data
1676 * that was supplied to the event_command @reg() function that
1677 * registered the trigger (see struct event_command) along with
1678 * the trace record, rec.
1679 *
1680 * @init: An optional initialization function called for the trigger
1681 * when the trigger is registered (via the event_command reg()
1682 * function). This can be used to perform per-trigger
1683 * initialization such as incrementing a per-trigger reference
1684 * count, for instance. This is usually implemented by the
1685 * generic utility function @event_trigger_init() (see
1686 * trace_event_triggers.c).
1687 *
1688 * @free: An optional de-initialization function called for the
1689 * trigger when the trigger is unregistered (via the
1690 * event_command @reg() function). This can be used to perform
1691 * per-trigger de-initialization such as decrementing a
1692 * per-trigger reference count and freeing corresponding trigger
1693 * data, for instance. This is usually implemented by the
1694 * generic utility function @event_trigger_free() (see
1695 * trace_event_triggers.c).
1696 *
1697 * @print: The callback function invoked to have the trigger print
1698 * itself. This is usually implemented by a wrapper function
1699 * that calls the generic utility function @event_trigger_print()
1700 * (see trace_event_triggers.c).
1701 */
1702struct event_trigger_ops {
1703 void (*func)(struct event_trigger_data *data,
1704 void *rec,
1705 struct ring_buffer_event *rbe);
1706 int (*init)(struct event_trigger_ops *ops,
1707 struct event_trigger_data *data);
1708 void (*free)(struct event_trigger_ops *ops,
1709 struct event_trigger_data *data);
1710 int (*print)(struct seq_file *m,
1711 struct event_trigger_ops *ops,
1712 struct event_trigger_data *data);
1713};
1714
1715/**
1716 * struct event_command - callbacks and data members for event commands
1717 *
1718 * Event commands are invoked by users by writing the command name
1719 * into the 'trigger' file associated with a trace event. The
1720 * parameters associated with a specific invocation of an event
1721 * command are used to create an event trigger instance, which is
1722 * added to the list of trigger instances associated with that trace
1723 * event. When the event is hit, the set of triggers associated with
1724 * that event is invoked.
1725 *
1726 * The data members in this structure provide per-event command data
1727 * for various event commands.
1728 *
1729 * All the data members below, except for @post_trigger, must be set
1730 * for each event command.
1731 *
1732 * @name: The unique name that identifies the event command. This is
1733 * the name used when setting triggers via trigger files.
1734 *
1735 * @trigger_type: A unique id that identifies the event command
1736 * 'type'. This value has two purposes, the first to ensure that
1737 * only one trigger of the same type can be set at a given time
1738 * for a particular event e.g. it doesn't make sense to have both
1739 * a traceon and traceoff trigger attached to a single event at
1740 * the same time, so traceon and traceoff have the same type
1741 * though they have different names. The @trigger_type value is
1742 * also used as a bit value for deferring the actual trigger
1743 * action until after the current event is finished. Some
1744 * commands need to do this if they themselves log to the trace
1745 * buffer (see the @post_trigger() member below). @trigger_type
1746 * values are defined by adding new values to the trigger_type
1747 * enum in include/linux/trace_events.h.
1748 *
1749 * @flags: See the enum event_command_flags below.
1750 *
1751 * All the methods below, except for @set_filter() and @unreg_all(),
1752 * must be implemented.
1753 *
1754 * @func: The callback function responsible for parsing and
1755 * registering the trigger written to the 'trigger' file by the
1756 * user. It allocates the trigger instance and registers it with
1757 * the appropriate trace event. It makes use of the other
1758 * event_command callback functions to orchestrate this, and is
1759 * usually implemented by the generic utility function
1760 * @event_trigger_callback() (see trace_event_triggers.c).
1761 *
1762 * @reg: Adds the trigger to the list of triggers associated with the
1763 * event, and enables the event trigger itself, after
1764 * initializing it (via the event_trigger_ops @init() function).
1765 * This is also where commands can use the @trigger_type value to
1766 * make the decision as to whether or not multiple instances of
1767 * the trigger should be allowed. This is usually implemented by
1768 * the generic utility function @register_trigger() (see
1769 * trace_event_triggers.c).
1770 *
1771 * @unreg: Removes the trigger from the list of triggers associated
1772 * with the event, and disables the event trigger itself, after
1773 * initializing it (via the event_trigger_ops @free() function).
1774 * This is usually implemented by the generic utility function
1775 * @unregister_trigger() (see trace_event_triggers.c).
1776 *
1777 * @unreg_all: An optional function called to remove all the triggers
1778 * from the list of triggers associated with the event. Called
1779 * when a trigger file is opened in truncate mode.
1780 *
1781 * @set_filter: An optional function called to parse and set a filter
1782 * for the trigger. If no @set_filter() method is set for the
1783 * event command, filters set by the user for the command will be
1784 * ignored. This is usually implemented by the generic utility
1785 * function @set_trigger_filter() (see trace_event_triggers.c).
1786 *
1787 * @get_trigger_ops: The callback function invoked to retrieve the
1788 * event_trigger_ops implementation associated with the command.
1789 */
1790struct event_command {
1791 struct list_head list;
1792 char *name;
1793 enum event_trigger_type trigger_type;
1794 int flags;
1795 int (*func)(struct event_command *cmd_ops,
1796 struct trace_event_file *file,
1797 char *glob, char *cmd, char *params);
1798 int (*reg)(char *glob,
1799 struct event_trigger_ops *ops,
1800 struct event_trigger_data *data,
1801 struct trace_event_file *file);
1802 void (*unreg)(char *glob,
1803 struct event_trigger_ops *ops,
1804 struct event_trigger_data *data,
1805 struct trace_event_file *file);
1806 void (*unreg_all)(struct trace_event_file *file);
1807 int (*set_filter)(char *filter_str,
1808 struct event_trigger_data *data,
1809 struct trace_event_file *file);
1810 struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1811};
1812
1813/**
1814 * enum event_command_flags - flags for struct event_command
1815 *
1816 * @POST_TRIGGER: A flag that says whether or not this command needs
1817 * to have its action delayed until after the current event has
1818 * been closed. Some triggers need to avoid being invoked while
1819 * an event is currently in the process of being logged, since
1820 * the trigger may itself log data into the trace buffer. Thus
1821 * we make sure the current event is committed before invoking
1822 * those triggers. To do that, the trigger invocation is split
1823 * in two - the first part checks the filter using the current
1824 * trace record; if a command has the @post_trigger flag set, it
1825 * sets a bit for itself in the return value, otherwise it
1826 * directly invokes the trigger. Once all commands have been
1827 * either invoked or set their return flag, the current record is
1828 * either committed or discarded. At that point, if any commands
1829 * have deferred their triggers, those commands are finally
1830 * invoked following the close of the current event. In other
1831 * words, if the event_trigger_ops @func() probe implementation
1832 * itself logs to the trace buffer, this flag should be set,
1833 * otherwise it can be left unspecified.
1834 *
1835 * @NEEDS_REC: A flag that says whether or not this command needs
1836 * access to the trace record in order to perform its function,
1837 * regardless of whether or not it has a filter associated with
1838 * it (filters make a trigger require access to the trace record
1839 * but are not always present).
1840 */
1841enum event_command_flags {
1842 EVENT_CMD_FL_POST_TRIGGER = 1,
1843 EVENT_CMD_FL_NEEDS_REC = 2,
1844};
1845
1846static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1847{
1848 return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1849}
1850
1851static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1852{
1853 return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1854}
1855
1856extern int trace_event_enable_disable(struct trace_event_file *file,
1857 int enable, int soft_disable);
1858extern int tracing_alloc_snapshot(void);
1859extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
1860extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
1861
1862extern int tracing_snapshot_cond_disable(struct trace_array *tr);
1863extern void *tracing_cond_snapshot_data(struct trace_array *tr);
1864
1865extern const char *__start___trace_bprintk_fmt[];
1866extern const char *__stop___trace_bprintk_fmt[];
1867
1868extern const char *__start___tracepoint_str[];
1869extern const char *__stop___tracepoint_str[];
1870
1871void trace_printk_control(bool enabled);
1872void trace_printk_init_buffers(void);
1873void trace_printk_start_comm(void);
1874int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1875int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1876
1877#define MAX_EVENT_NAME_LEN 64
1878
1879extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1880extern ssize_t trace_parse_run_command(struct file *file,
1881 const char __user *buffer, size_t count, loff_t *ppos,
1882 int (*createfn)(int, char**));
1883
1884extern unsigned int err_pos(char *cmd, const char *str);
1885extern void tracing_log_err(struct trace_array *tr,
1886 const char *loc, const char *cmd,
1887 const char **errs, u8 type, u8 pos);
1888
1889/*
1890 * Normal trace_printk() and friends allocates special buffers
1891 * to do the manipulation, as well as saves the print formats
1892 * into sections to display. But the trace infrastructure wants
1893 * to use these without the added overhead at the price of being
1894 * a bit slower (used mainly for warnings, where we don't care
1895 * about performance). The internal_trace_puts() is for such
1896 * a purpose.
1897 */
1898#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1899
1900#undef FTRACE_ENTRY
1901#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \
1902 extern struct trace_event_call \
1903 __aligned(4) event_##call;
1904#undef FTRACE_ENTRY_DUP
1905#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
1906 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1907 filter)
1908#undef FTRACE_ENTRY_PACKED
1909#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1910 FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1911 filter)
1912
1913#include "trace_entries.h"
1914
1915#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1916int perf_ftrace_event_register(struct trace_event_call *call,
1917 enum trace_reg type, void *data);
1918#else
1919#define perf_ftrace_event_register NULL
1920#endif
1921
1922#ifdef CONFIG_FTRACE_SYSCALLS
1923void init_ftrace_syscalls(void);
1924const char *get_syscall_name(int syscall);
1925#else
1926static inline void init_ftrace_syscalls(void) { }
1927static inline const char *get_syscall_name(int syscall)
1928{
1929 return NULL;
1930}
1931#endif
1932
1933#ifdef CONFIG_EVENT_TRACING
1934void trace_event_init(void);
1935void trace_event_eval_update(struct trace_eval_map **map, int len);
1936#else
1937static inline void __init trace_event_init(void) { }
1938static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1939#endif
1940
1941#ifdef CONFIG_TRACER_SNAPSHOT
1942void tracing_snapshot_instance(struct trace_array *tr);
1943int tracing_alloc_snapshot_instance(struct trace_array *tr);
1944#else
1945static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1946static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1947{
1948 return 0;
1949}
1950#endif
1951
1952#ifdef CONFIG_PREEMPT_TRACER
1953void tracer_preempt_on(unsigned long a0, unsigned long a1);
1954void tracer_preempt_off(unsigned long a0, unsigned long a1);
1955#else
1956static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1957static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1958#endif
1959#ifdef CONFIG_IRQSOFF_TRACER
1960void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1961void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1962#else
1963static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1964static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1965#endif
1966
1967extern struct trace_iterator *tracepoint_print_iter;
1968
1969/*
1970 * Reset the state of the trace_iterator so that it can read consumed data.
1971 * Normally, the trace_iterator is used for reading the data when it is not
1972 * consumed, and must retain state.
1973 */
1974static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
1975{
1976 const size_t offset = offsetof(struct trace_iterator, seq);
1977
1978 /*
1979 * Keep gcc from complaining about overwriting more than just one
1980 * member in the structure.
1981 */
1982 memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
1983
1984 iter->pos = -1;
1985}
1986
1987#endif /* _LINUX_KERNEL_TRACE_H */