xref: /openbmc/linux/kernel/trace/trace.h (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef _LINUX_KERNEL_TRACE_H
4 #define _LINUX_KERNEL_TRACE_H
5 
6 #include <linux/fs.h>
7 #include <linux/atomic.h>
8 #include <linux/sched.h>
9 #include <linux/clocksource.h>
10 #include <linux/ring_buffer.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/tracepoint.h>
13 #include <linux/ftrace.h>
14 #include <linux/hw_breakpoint.h>
15 #include <linux/trace_seq.h>
16 #include <linux/trace_events.h>
17 #include <linux/compiler.h>
18 #include <linux/trace_seq.h>
19 #include <linux/glob.h>
20 
21 #ifdef CONFIG_FTRACE_SYSCALLS
22 #include <asm/unistd.h>		/* For NR_SYSCALLS	     */
23 #include <asm/syscall.h>	/* some archs define it here */
24 #endif
25 
26 enum trace_type {
27 	__TRACE_FIRST_TYPE = 0,
28 
29 	TRACE_FN,
30 	TRACE_CTX,
31 	TRACE_WAKE,
32 	TRACE_STACK,
33 	TRACE_PRINT,
34 	TRACE_BPRINT,
35 	TRACE_MMIO_RW,
36 	TRACE_MMIO_MAP,
37 	TRACE_BRANCH,
38 	TRACE_GRAPH_RET,
39 	TRACE_GRAPH_ENT,
40 	TRACE_USER_STACK,
41 	TRACE_BLK,
42 	TRACE_BPUTS,
43 	TRACE_HWLAT,
44 	TRACE_RAW_DATA,
45 
46 	__TRACE_LAST_TYPE,
47 };
48 
49 
50 #undef __field
51 #define __field(type, item)		type	item;
52 
53 #undef __field_struct
54 #define __field_struct(type, item)	__field(type, item)
55 
56 #undef __field_desc
57 #define __field_desc(type, container, item)
58 
59 #undef __array
60 #define __array(type, item, size)	type	item[size];
61 
62 #undef __array_desc
63 #define __array_desc(type, container, item, size)
64 
65 #undef __dynamic_array
66 #define __dynamic_array(type, item)	type	item[];
67 
68 #undef F_STRUCT
69 #define F_STRUCT(args...)		args
70 
71 #undef FTRACE_ENTRY
72 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
73 	struct struct_name {						\
74 		struct trace_entry	ent;				\
75 		tstruct							\
76 	}
77 
78 #undef FTRACE_ENTRY_DUP
79 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
80 
81 #undef FTRACE_ENTRY_REG
82 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print,	\
83 			 filter, regfn) \
84 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
85 		     filter)
86 
87 #undef FTRACE_ENTRY_PACKED
88 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,	\
89 			    filter)					\
90 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
91 		     filter) __packed
92 
93 #include "trace_entries.h"
94 
95 /*
96  * syscalls are special, and need special handling, this is why
97  * they are not included in trace_entries.h
98  */
99 struct syscall_trace_enter {
100 	struct trace_entry	ent;
101 	int			nr;
102 	unsigned long		args[];
103 };
104 
105 struct syscall_trace_exit {
106 	struct trace_entry	ent;
107 	int			nr;
108 	long			ret;
109 };
110 
111 struct kprobe_trace_entry_head {
112 	struct trace_entry	ent;
113 	unsigned long		ip;
114 };
115 
116 struct kretprobe_trace_entry_head {
117 	struct trace_entry	ent;
118 	unsigned long		func;
119 	unsigned long		ret_ip;
120 };
121 
122 /*
123  * trace_flag_type is an enumeration that holds different
124  * states when a trace occurs. These are:
125  *  IRQS_OFF		- interrupts were disabled
126  *  IRQS_NOSUPPORT	- arch does not support irqs_disabled_flags
127  *  NEED_RESCHED	- reschedule is requested
128  *  HARDIRQ		- inside an interrupt handler
129  *  SOFTIRQ		- inside a softirq handler
130  */
131 enum trace_flag_type {
132 	TRACE_FLAG_IRQS_OFF		= 0x01,
133 	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
134 	TRACE_FLAG_NEED_RESCHED		= 0x04,
135 	TRACE_FLAG_HARDIRQ		= 0x08,
136 	TRACE_FLAG_SOFTIRQ		= 0x10,
137 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
138 	TRACE_FLAG_NMI			= 0x40,
139 };
140 
141 #define TRACE_BUF_SIZE		1024
142 
143 struct trace_array;
144 
145 /*
146  * The CPU trace array - it consists of thousands of trace entries
147  * plus some other descriptor data: (for example which task started
148  * the trace, etc.)
149  */
150 struct trace_array_cpu {
151 	atomic_t		disabled;
152 	void			*buffer_page;	/* ring buffer spare */
153 
154 	unsigned long		entries;
155 	unsigned long		saved_latency;
156 	unsigned long		critical_start;
157 	unsigned long		critical_end;
158 	unsigned long		critical_sequence;
159 	unsigned long		nice;
160 	unsigned long		policy;
161 	unsigned long		rt_priority;
162 	unsigned long		skipped_entries;
163 	u64			preempt_timestamp;
164 	pid_t			pid;
165 	kuid_t			uid;
166 	char			comm[TASK_COMM_LEN];
167 
168 	bool			ignore_pid;
169 #ifdef CONFIG_FUNCTION_TRACER
170 	bool			ftrace_ignore_pid;
171 #endif
172 };
173 
174 struct tracer;
175 struct trace_option_dentry;
176 
177 struct trace_buffer {
178 	struct trace_array		*tr;
179 	struct ring_buffer		*buffer;
180 	struct trace_array_cpu __percpu	*data;
181 	u64				time_start;
182 	int				cpu;
183 };
184 
185 #define TRACE_FLAGS_MAX_SIZE		32
186 
187 struct trace_options {
188 	struct tracer			*tracer;
189 	struct trace_option_dentry	*topts;
190 };
191 
192 struct trace_pid_list {
193 	int				pid_max;
194 	unsigned long			*pids;
195 };
196 
197 /*
198  * The trace array - an array of per-CPU trace arrays. This is the
199  * highest level data structure that individual tracers deal with.
200  * They have on/off state as well:
201  */
202 struct trace_array {
203 	struct list_head	list;
204 	char			*name;
205 	struct trace_buffer	trace_buffer;
206 #ifdef CONFIG_TRACER_MAX_TRACE
207 	/*
208 	 * The max_buffer is used to snapshot the trace when a maximum
209 	 * latency is reached, or when the user initiates a snapshot.
210 	 * Some tracers will use this to store a maximum trace while
211 	 * it continues examining live traces.
212 	 *
213 	 * The buffers for the max_buffer are set up the same as the trace_buffer
214 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
215 	 * with the buffer of the trace_buffer and the buffers are reset for
216 	 * the trace_buffer so the tracing can continue.
217 	 */
218 	struct trace_buffer	max_buffer;
219 	bool			allocated_snapshot;
220 #endif
221 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
222 	unsigned long		max_latency;
223 #endif
224 	struct trace_pid_list	__rcu *filtered_pids;
225 	/*
226 	 * max_lock is used to protect the swapping of buffers
227 	 * when taking a max snapshot. The buffers themselves are
228 	 * protected by per_cpu spinlocks. But the action of the swap
229 	 * needs its own lock.
230 	 *
231 	 * This is defined as a arch_spinlock_t in order to help
232 	 * with performance when lockdep debugging is enabled.
233 	 *
234 	 * It is also used in other places outside the update_max_tr
235 	 * so it needs to be defined outside of the
236 	 * CONFIG_TRACER_MAX_TRACE.
237 	 */
238 	arch_spinlock_t		max_lock;
239 	int			buffer_disabled;
240 #ifdef CONFIG_FTRACE_SYSCALLS
241 	int			sys_refcount_enter;
242 	int			sys_refcount_exit;
243 	struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
244 	struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
245 #endif
246 	int			stop_count;
247 	int			clock_id;
248 	int			nr_topts;
249 	bool			clear_trace;
250 	struct tracer		*current_trace;
251 	unsigned int		trace_flags;
252 	unsigned char		trace_flags_index[TRACE_FLAGS_MAX_SIZE];
253 	unsigned int		flags;
254 	raw_spinlock_t		start_lock;
255 	struct dentry		*dir;
256 	struct dentry		*options;
257 	struct dentry		*percpu_dir;
258 	struct dentry		*event_dir;
259 	struct trace_options	*topts;
260 	struct list_head	systems;
261 	struct list_head	events;
262 	struct trace_event_file *trace_marker_file;
263 	cpumask_var_t		tracing_cpumask; /* only trace on set CPUs */
264 	int			ref;
265 #ifdef CONFIG_FUNCTION_TRACER
266 	struct ftrace_ops	*ops;
267 	struct trace_pid_list	__rcu *function_pids;
268 #ifdef CONFIG_DYNAMIC_FTRACE
269 	/* All of these are protected by the ftrace_lock */
270 	struct list_head	func_probes;
271 	struct list_head	mod_trace;
272 	struct list_head	mod_notrace;
273 #endif
274 	/* function tracing enabled */
275 	int			function_enabled;
276 #endif
277 	int			time_stamp_abs_ref;
278 	struct list_head	hist_vars;
279 };
280 
281 enum {
282 	TRACE_ARRAY_FL_GLOBAL	= (1 << 0)
283 };
284 
285 extern struct list_head ftrace_trace_arrays;
286 
287 extern struct mutex trace_types_lock;
288 
289 extern int trace_array_get(struct trace_array *tr);
290 extern void trace_array_put(struct trace_array *tr);
291 
292 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
293 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
294 
295 extern bool trace_clock_in_ns(struct trace_array *tr);
296 
297 /*
298  * The global tracer (top) should be the first trace array added,
299  * but we check the flag anyway.
300  */
301 static inline struct trace_array *top_trace_array(void)
302 {
303 	struct trace_array *tr;
304 
305 	if (list_empty(&ftrace_trace_arrays))
306 		return NULL;
307 
308 	tr = list_entry(ftrace_trace_arrays.prev,
309 			typeof(*tr), list);
310 	WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
311 	return tr;
312 }
313 
314 #define FTRACE_CMP_TYPE(var, type) \
315 	__builtin_types_compatible_p(typeof(var), type *)
316 
317 #undef IF_ASSIGN
318 #define IF_ASSIGN(var, entry, etype, id)		\
319 	if (FTRACE_CMP_TYPE(var, etype)) {		\
320 		var = (typeof(var))(entry);		\
321 		WARN_ON(id && (entry)->type != id);	\
322 		break;					\
323 	}
324 
325 /* Will cause compile errors if type is not found. */
326 extern void __ftrace_bad_type(void);
327 
328 /*
329  * The trace_assign_type is a verifier that the entry type is
330  * the same as the type being assigned. To add new types simply
331  * add a line with the following format:
332  *
333  * IF_ASSIGN(var, ent, type, id);
334  *
335  *  Where "type" is the trace type that includes the trace_entry
336  *  as the "ent" item. And "id" is the trace identifier that is
337  *  used in the trace_type enum.
338  *
339  *  If the type can have more than one id, then use zero.
340  */
341 #define trace_assign_type(var, ent)					\
342 	do {								\
343 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
344 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
345 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
346 		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
347 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
348 		IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT);	\
349 		IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);	\
350 		IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);	\
351 		IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
352 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
353 			  TRACE_MMIO_RW);				\
354 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
355 			  TRACE_MMIO_MAP);				\
356 		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
357 		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
358 			  TRACE_GRAPH_ENT);		\
359 		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
360 			  TRACE_GRAPH_RET);		\
361 		__ftrace_bad_type();					\
362 	} while (0)
363 
364 /*
365  * An option specific to a tracer. This is a boolean value.
366  * The bit is the bit index that sets its value on the
367  * flags value in struct tracer_flags.
368  */
369 struct tracer_opt {
370 	const char	*name; /* Will appear on the trace_options file */
371 	u32		bit; /* Mask assigned in val field in tracer_flags */
372 };
373 
374 /*
375  * The set of specific options for a tracer. Your tracer
376  * have to set the initial value of the flags val.
377  */
378 struct tracer_flags {
379 	u32			val;
380 	struct tracer_opt	*opts;
381 	struct tracer		*trace;
382 };
383 
384 /* Makes more easy to define a tracer opt */
385 #define TRACER_OPT(s, b)	.name = #s, .bit = b
386 
387 
388 struct trace_option_dentry {
389 	struct tracer_opt		*opt;
390 	struct tracer_flags		*flags;
391 	struct trace_array		*tr;
392 	struct dentry			*entry;
393 };
394 
395 /**
396  * struct tracer - a specific tracer and its callbacks to interact with tracefs
397  * @name: the name chosen to select it on the available_tracers file
398  * @init: called when one switches to this tracer (echo name > current_tracer)
399  * @reset: called when one switches to another tracer
400  * @start: called when tracing is unpaused (echo 1 > tracing_on)
401  * @stop: called when tracing is paused (echo 0 > tracing_on)
402  * @update_thresh: called when tracing_thresh is updated
403  * @open: called when the trace file is opened
404  * @pipe_open: called when the trace_pipe file is opened
405  * @close: called when the trace file is released
406  * @pipe_close: called when the trace_pipe file is released
407  * @read: override the default read callback on trace_pipe
408  * @splice_read: override the default splice_read callback on trace_pipe
409  * @selftest: selftest to run on boot (see trace_selftest.c)
410  * @print_headers: override the first lines that describe your columns
411  * @print_line: callback that prints a trace
412  * @set_flag: signals one of your private flags changed (trace_options file)
413  * @flags: your private flags
414  */
415 struct tracer {
416 	const char		*name;
417 	int			(*init)(struct trace_array *tr);
418 	void			(*reset)(struct trace_array *tr);
419 	void			(*start)(struct trace_array *tr);
420 	void			(*stop)(struct trace_array *tr);
421 	int			(*update_thresh)(struct trace_array *tr);
422 	void			(*open)(struct trace_iterator *iter);
423 	void			(*pipe_open)(struct trace_iterator *iter);
424 	void			(*close)(struct trace_iterator *iter);
425 	void			(*pipe_close)(struct trace_iterator *iter);
426 	ssize_t			(*read)(struct trace_iterator *iter,
427 					struct file *filp, char __user *ubuf,
428 					size_t cnt, loff_t *ppos);
429 	ssize_t			(*splice_read)(struct trace_iterator *iter,
430 					       struct file *filp,
431 					       loff_t *ppos,
432 					       struct pipe_inode_info *pipe,
433 					       size_t len,
434 					       unsigned int flags);
435 #ifdef CONFIG_FTRACE_STARTUP_TEST
436 	int			(*selftest)(struct tracer *trace,
437 					    struct trace_array *tr);
438 #endif
439 	void			(*print_header)(struct seq_file *m);
440 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
441 	/* If you handled the flag setting, return 0 */
442 	int			(*set_flag)(struct trace_array *tr,
443 					    u32 old_flags, u32 bit, int set);
444 	/* Return 0 if OK with change, else return non-zero */
445 	int			(*flag_changed)(struct trace_array *tr,
446 						u32 mask, int set);
447 	struct tracer		*next;
448 	struct tracer_flags	*flags;
449 	int			enabled;
450 	int			ref;
451 	bool			print_max;
452 	bool			allow_instances;
453 #ifdef CONFIG_TRACER_MAX_TRACE
454 	bool			use_max_tr;
455 #endif
456 	/* True if tracer cannot be enabled in kernel param */
457 	bool			noboot;
458 };
459 
460 
461 /* Only current can touch trace_recursion */
462 
463 /*
464  * For function tracing recursion:
465  *  The order of these bits are important.
466  *
467  *  When function tracing occurs, the following steps are made:
468  *   If arch does not support a ftrace feature:
469  *    call internal function (uses INTERNAL bits) which calls...
470  *   If callback is registered to the "global" list, the list
471  *    function is called and recursion checks the GLOBAL bits.
472  *    then this function calls...
473  *   The function callback, which can use the FTRACE bits to
474  *    check for recursion.
475  *
476  * Now if the arch does not suppport a feature, and it calls
477  * the global list function which calls the ftrace callback
478  * all three of these steps will do a recursion protection.
479  * There's no reason to do one if the previous caller already
480  * did. The recursion that we are protecting against will
481  * go through the same steps again.
482  *
483  * To prevent the multiple recursion checks, if a recursion
484  * bit is set that is higher than the MAX bit of the current
485  * check, then we know that the check was made by the previous
486  * caller, and we can skip the current check.
487  */
488 enum {
489 	TRACE_BUFFER_BIT,
490 	TRACE_BUFFER_NMI_BIT,
491 	TRACE_BUFFER_IRQ_BIT,
492 	TRACE_BUFFER_SIRQ_BIT,
493 
494 	/* Start of function recursion bits */
495 	TRACE_FTRACE_BIT,
496 	TRACE_FTRACE_NMI_BIT,
497 	TRACE_FTRACE_IRQ_BIT,
498 	TRACE_FTRACE_SIRQ_BIT,
499 
500 	/* INTERNAL_BITs must be greater than FTRACE_BITs */
501 	TRACE_INTERNAL_BIT,
502 	TRACE_INTERNAL_NMI_BIT,
503 	TRACE_INTERNAL_IRQ_BIT,
504 	TRACE_INTERNAL_SIRQ_BIT,
505 
506 	TRACE_BRANCH_BIT,
507 /*
508  * Abuse of the trace_recursion.
509  * As we need a way to maintain state if we are tracing the function
510  * graph in irq because we want to trace a particular function that
511  * was called in irq context but we have irq tracing off. Since this
512  * can only be modified by current, we can reuse trace_recursion.
513  */
514 	TRACE_IRQ_BIT,
515 
516 	/* Set if the function is in the set_graph_function file */
517 	TRACE_GRAPH_BIT,
518 
519 	/*
520 	 * In the very unlikely case that an interrupt came in
521 	 * at a start of graph tracing, and we want to trace
522 	 * the function in that interrupt, the depth can be greater
523 	 * than zero, because of the preempted start of a previous
524 	 * trace. In an even more unlikely case, depth could be 2
525 	 * if a softirq interrupted the start of graph tracing,
526 	 * followed by an interrupt preempting a start of graph
527 	 * tracing in the softirq, and depth can even be 3
528 	 * if an NMI came in at the start of an interrupt function
529 	 * that preempted a softirq start of a function that
530 	 * preempted normal context!!!! Luckily, it can't be
531 	 * greater than 3, so the next two bits are a mask
532 	 * of what the depth is when we set TRACE_GRAPH_BIT
533 	 */
534 
535 	TRACE_GRAPH_DEPTH_START_BIT,
536 	TRACE_GRAPH_DEPTH_END_BIT,
537 };
538 
539 #define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
540 #define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
541 #define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
542 
543 #define trace_recursion_depth() \
544 	(((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
545 #define trace_recursion_set_depth(depth) \
546 	do {								\
547 		current->trace_recursion &=				\
548 			~(3 << TRACE_GRAPH_DEPTH_START_BIT);		\
549 		current->trace_recursion |=				\
550 			((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT;	\
551 	} while (0)
552 
553 #define TRACE_CONTEXT_BITS	4
554 
555 #define TRACE_FTRACE_START	TRACE_FTRACE_BIT
556 #define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
557 
558 #define TRACE_LIST_START	TRACE_INTERNAL_BIT
559 #define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
560 
561 #define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
562 
563 static __always_inline int trace_get_context_bit(void)
564 {
565 	int bit;
566 
567 	if (in_interrupt()) {
568 		if (in_nmi())
569 			bit = 0;
570 
571 		else if (in_irq())
572 			bit = 1;
573 		else
574 			bit = 2;
575 	} else
576 		bit = 3;
577 
578 	return bit;
579 }
580 
581 static __always_inline int trace_test_and_set_recursion(int start, int max)
582 {
583 	unsigned int val = current->trace_recursion;
584 	int bit;
585 
586 	/* A previous recursion check was made */
587 	if ((val & TRACE_CONTEXT_MASK) > max)
588 		return 0;
589 
590 	bit = trace_get_context_bit() + start;
591 	if (unlikely(val & (1 << bit)))
592 		return -1;
593 
594 	val |= 1 << bit;
595 	current->trace_recursion = val;
596 	barrier();
597 
598 	return bit;
599 }
600 
601 static __always_inline void trace_clear_recursion(int bit)
602 {
603 	unsigned int val = current->trace_recursion;
604 
605 	if (!bit)
606 		return;
607 
608 	bit = 1 << bit;
609 	val &= ~bit;
610 
611 	barrier();
612 	current->trace_recursion = val;
613 }
614 
615 static inline struct ring_buffer_iter *
616 trace_buffer_iter(struct trace_iterator *iter, int cpu)
617 {
618 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
619 }
620 
621 int tracer_init(struct tracer *t, struct trace_array *tr);
622 int tracing_is_enabled(void);
623 void tracing_reset(struct trace_buffer *buf, int cpu);
624 void tracing_reset_online_cpus(struct trace_buffer *buf);
625 void tracing_reset_current(int cpu);
626 void tracing_reset_all_online_cpus(void);
627 int tracing_open_generic(struct inode *inode, struct file *filp);
628 bool tracing_is_disabled(void);
629 bool tracer_tracing_is_on(struct trace_array *tr);
630 void tracer_tracing_on(struct trace_array *tr);
631 void tracer_tracing_off(struct trace_array *tr);
632 struct dentry *trace_create_file(const char *name,
633 				 umode_t mode,
634 				 struct dentry *parent,
635 				 void *data,
636 				 const struct file_operations *fops);
637 
638 struct dentry *tracing_init_dentry(void);
639 
640 struct ring_buffer_event;
641 
642 struct ring_buffer_event *
643 trace_buffer_lock_reserve(struct ring_buffer *buffer,
644 			  int type,
645 			  unsigned long len,
646 			  unsigned long flags,
647 			  int pc);
648 
649 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
650 						struct trace_array_cpu *data);
651 
652 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
653 					  int *ent_cpu, u64 *ent_ts);
654 
655 void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
656 					struct ring_buffer_event *event);
657 
658 int trace_empty(struct trace_iterator *iter);
659 
660 void *trace_find_next_entry_inc(struct trace_iterator *iter);
661 
662 void trace_init_global_iter(struct trace_iterator *iter);
663 
664 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
665 
666 void trace_function(struct trace_array *tr,
667 		    unsigned long ip,
668 		    unsigned long parent_ip,
669 		    unsigned long flags, int pc);
670 void trace_graph_function(struct trace_array *tr,
671 		    unsigned long ip,
672 		    unsigned long parent_ip,
673 		    unsigned long flags, int pc);
674 void trace_latency_header(struct seq_file *m);
675 void trace_default_header(struct seq_file *m);
676 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
677 int trace_empty(struct trace_iterator *iter);
678 
679 void trace_graph_return(struct ftrace_graph_ret *trace);
680 int trace_graph_entry(struct ftrace_graph_ent *trace);
681 void set_graph_array(struct trace_array *tr);
682 
683 void tracing_start_cmdline_record(void);
684 void tracing_stop_cmdline_record(void);
685 void tracing_start_tgid_record(void);
686 void tracing_stop_tgid_record(void);
687 
688 int register_tracer(struct tracer *type);
689 int is_tracing_stopped(void);
690 
691 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
692 
693 extern cpumask_var_t __read_mostly tracing_buffer_mask;
694 
695 #define for_each_tracing_cpu(cpu)	\
696 	for_each_cpu(cpu, tracing_buffer_mask)
697 
698 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
699 
700 extern unsigned long tracing_thresh;
701 
702 /* PID filtering */
703 
704 extern int pid_max;
705 
706 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
707 			     pid_t search_pid);
708 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
709 			    struct task_struct *task);
710 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
711 				  struct task_struct *self,
712 				  struct task_struct *task);
713 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
714 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
715 int trace_pid_show(struct seq_file *m, void *v);
716 void trace_free_pid_list(struct trace_pid_list *pid_list);
717 int trace_pid_write(struct trace_pid_list *filtered_pids,
718 		    struct trace_pid_list **new_pid_list,
719 		    const char __user *ubuf, size_t cnt);
720 
721 #ifdef CONFIG_TRACER_MAX_TRACE
722 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
723 void update_max_tr_single(struct trace_array *tr,
724 			  struct task_struct *tsk, int cpu);
725 #endif /* CONFIG_TRACER_MAX_TRACE */
726 
727 #ifdef CONFIG_STACKTRACE
728 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
729 			    int pc);
730 
731 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
732 		   int pc);
733 #else
734 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
735 					  unsigned long flags, int pc)
736 {
737 }
738 
739 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
740 				 int skip, int pc)
741 {
742 }
743 #endif /* CONFIG_STACKTRACE */
744 
745 extern u64 ftrace_now(int cpu);
746 
747 extern void trace_find_cmdline(int pid, char comm[]);
748 extern int trace_find_tgid(int pid);
749 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
750 
751 #ifdef CONFIG_DYNAMIC_FTRACE
752 extern unsigned long ftrace_update_tot_cnt;
753 void ftrace_init_trace_array(struct trace_array *tr);
754 #else
755 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
756 #endif
757 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
758 extern int DYN_FTRACE_TEST_NAME(void);
759 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
760 extern int DYN_FTRACE_TEST_NAME2(void);
761 
762 extern bool ring_buffer_expanded;
763 extern bool tracing_selftest_disabled;
764 
765 #ifdef CONFIG_FTRACE_STARTUP_TEST
766 extern int trace_selftest_startup_function(struct tracer *trace,
767 					   struct trace_array *tr);
768 extern int trace_selftest_startup_function_graph(struct tracer *trace,
769 						 struct trace_array *tr);
770 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
771 					  struct trace_array *tr);
772 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
773 					     struct trace_array *tr);
774 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
775 						 struct trace_array *tr);
776 extern int trace_selftest_startup_wakeup(struct tracer *trace,
777 					 struct trace_array *tr);
778 extern int trace_selftest_startup_nop(struct tracer *trace,
779 					 struct trace_array *tr);
780 extern int trace_selftest_startup_branch(struct tracer *trace,
781 					 struct trace_array *tr);
782 /*
783  * Tracer data references selftest functions that only occur
784  * on boot up. These can be __init functions. Thus, when selftests
785  * are enabled, then the tracers need to reference __init functions.
786  */
787 #define __tracer_data		__refdata
788 #else
789 /* Tracers are seldom changed. Optimize when selftests are disabled. */
790 #define __tracer_data		__read_mostly
791 #endif /* CONFIG_FTRACE_STARTUP_TEST */
792 
793 extern void *head_page(struct trace_array_cpu *data);
794 extern unsigned long long ns2usecs(u64 nsec);
795 extern int
796 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
797 extern int
798 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
799 extern int
800 trace_array_vprintk(struct trace_array *tr,
801 		    unsigned long ip, const char *fmt, va_list args);
802 int trace_array_printk(struct trace_array *tr,
803 		       unsigned long ip, const char *fmt, ...);
804 int trace_array_printk_buf(struct ring_buffer *buffer,
805 			   unsigned long ip, const char *fmt, ...);
806 void trace_printk_seq(struct trace_seq *s);
807 enum print_line_t print_trace_line(struct trace_iterator *iter);
808 
809 extern char trace_find_mark(unsigned long long duration);
810 
811 struct ftrace_hash;
812 
813 struct ftrace_mod_load {
814 	struct list_head	list;
815 	char			*func;
816 	char			*module;
817 	int			 enable;
818 };
819 
820 enum {
821 	FTRACE_HASH_FL_MOD	= (1 << 0),
822 };
823 
824 struct ftrace_hash {
825 	unsigned long		size_bits;
826 	struct hlist_head	*buckets;
827 	unsigned long		count;
828 	unsigned long		flags;
829 	struct rcu_head		rcu;
830 };
831 
832 struct ftrace_func_entry *
833 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
834 
835 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
836 {
837 	return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
838 }
839 
840 /* Standard output formatting function used for function return traces */
841 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
842 
843 /* Flag options */
844 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
845 #define TRACE_GRAPH_PRINT_CPU           0x2
846 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
847 #define TRACE_GRAPH_PRINT_PROC          0x8
848 #define TRACE_GRAPH_PRINT_DURATION      0x10
849 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
850 #define TRACE_GRAPH_PRINT_IRQS          0x40
851 #define TRACE_GRAPH_PRINT_TAIL          0x80
852 #define TRACE_GRAPH_SLEEP_TIME		0x100
853 #define TRACE_GRAPH_GRAPH_TIME		0x200
854 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
855 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
856 
857 extern void ftrace_graph_sleep_time_control(bool enable);
858 extern void ftrace_graph_graph_time_control(bool enable);
859 
860 extern enum print_line_t
861 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
862 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
863 extern void
864 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
865 extern void graph_trace_open(struct trace_iterator *iter);
866 extern void graph_trace_close(struct trace_iterator *iter);
867 extern int __trace_graph_entry(struct trace_array *tr,
868 			       struct ftrace_graph_ent *trace,
869 			       unsigned long flags, int pc);
870 extern void __trace_graph_return(struct trace_array *tr,
871 				 struct ftrace_graph_ret *trace,
872 				 unsigned long flags, int pc);
873 
874 #ifdef CONFIG_DYNAMIC_FTRACE
875 extern struct ftrace_hash *ftrace_graph_hash;
876 extern struct ftrace_hash *ftrace_graph_notrace_hash;
877 
878 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
879 {
880 	unsigned long addr = trace->func;
881 	int ret = 0;
882 
883 	preempt_disable_notrace();
884 
885 	if (ftrace_hash_empty(ftrace_graph_hash)) {
886 		ret = 1;
887 		goto out;
888 	}
889 
890 	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
891 
892 		/*
893 		 * This needs to be cleared on the return functions
894 		 * when the depth is zero.
895 		 */
896 		trace_recursion_set(TRACE_GRAPH_BIT);
897 		trace_recursion_set_depth(trace->depth);
898 
899 		/*
900 		 * If no irqs are to be traced, but a set_graph_function
901 		 * is set, and called by an interrupt handler, we still
902 		 * want to trace it.
903 		 */
904 		if (in_irq())
905 			trace_recursion_set(TRACE_IRQ_BIT);
906 		else
907 			trace_recursion_clear(TRACE_IRQ_BIT);
908 		ret = 1;
909 	}
910 
911 out:
912 	preempt_enable_notrace();
913 	return ret;
914 }
915 
916 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
917 {
918 	if (trace_recursion_test(TRACE_GRAPH_BIT) &&
919 	    trace->depth == trace_recursion_depth())
920 		trace_recursion_clear(TRACE_GRAPH_BIT);
921 }
922 
923 static inline int ftrace_graph_notrace_addr(unsigned long addr)
924 {
925 	int ret = 0;
926 
927 	preempt_disable_notrace();
928 
929 	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
930 		ret = 1;
931 
932 	preempt_enable_notrace();
933 	return ret;
934 }
935 #else
936 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
937 {
938 	return 1;
939 }
940 
941 static inline int ftrace_graph_notrace_addr(unsigned long addr)
942 {
943 	return 0;
944 }
945 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
946 { }
947 #endif /* CONFIG_DYNAMIC_FTRACE */
948 
949 extern unsigned int fgraph_max_depth;
950 
951 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
952 {
953 	/* trace it when it is-nested-in or is a function enabled. */
954 	return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
955 		 ftrace_graph_addr(trace)) ||
956 		(trace->depth < 0) ||
957 		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
958 }
959 
960 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
961 static inline enum print_line_t
962 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
963 {
964 	return TRACE_TYPE_UNHANDLED;
965 }
966 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
967 
968 extern struct list_head ftrace_pids;
969 
970 #ifdef CONFIG_FUNCTION_TRACER
971 struct ftrace_func_command {
972 	struct list_head	list;
973 	char			*name;
974 	int			(*func)(struct trace_array *tr,
975 					struct ftrace_hash *hash,
976 					char *func, char *cmd,
977 					char *params, int enable);
978 };
979 extern bool ftrace_filter_param __initdata;
980 static inline int ftrace_trace_task(struct trace_array *tr)
981 {
982 	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
983 }
984 extern int ftrace_is_dead(void);
985 int ftrace_create_function_files(struct trace_array *tr,
986 				 struct dentry *parent);
987 void ftrace_destroy_function_files(struct trace_array *tr);
988 void ftrace_init_global_array_ops(struct trace_array *tr);
989 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
990 void ftrace_reset_array_ops(struct trace_array *tr);
991 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
992 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
993 				  struct dentry *d_tracer);
994 void ftrace_clear_pids(struct trace_array *tr);
995 int init_function_trace(void);
996 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
997 #else
998 static inline int ftrace_trace_task(struct trace_array *tr)
999 {
1000 	return 1;
1001 }
1002 static inline int ftrace_is_dead(void) { return 0; }
1003 static inline int
1004 ftrace_create_function_files(struct trace_array *tr,
1005 			     struct dentry *parent)
1006 {
1007 	return 0;
1008 }
1009 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
1010 static inline __init void
1011 ftrace_init_global_array_ops(struct trace_array *tr) { }
1012 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
1013 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
1014 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
1015 static inline void ftrace_clear_pids(struct trace_array *tr) { }
1016 static inline int init_function_trace(void) { return 0; }
1017 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
1018 /* ftace_func_t type is not defined, use macro instead of static inline */
1019 #define ftrace_init_array_ops(tr, func) do { } while (0)
1020 #endif /* CONFIG_FUNCTION_TRACER */
1021 
1022 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
1023 
1024 struct ftrace_probe_ops {
1025 	void			(*func)(unsigned long ip,
1026 					unsigned long parent_ip,
1027 					struct trace_array *tr,
1028 					struct ftrace_probe_ops *ops,
1029 					void *data);
1030 	int			(*init)(struct ftrace_probe_ops *ops,
1031 					struct trace_array *tr,
1032 					unsigned long ip, void *init_data,
1033 					void **data);
1034 	void			(*free)(struct ftrace_probe_ops *ops,
1035 					struct trace_array *tr,
1036 					unsigned long ip, void *data);
1037 	int			(*print)(struct seq_file *m,
1038 					 unsigned long ip,
1039 					 struct ftrace_probe_ops *ops,
1040 					 void *data);
1041 };
1042 
1043 struct ftrace_func_mapper;
1044 typedef int (*ftrace_mapper_func)(void *data);
1045 
1046 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
1047 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
1048 					   unsigned long ip);
1049 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1050 			       unsigned long ip, void *data);
1051 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1052 				   unsigned long ip);
1053 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1054 			     ftrace_mapper_func free_func);
1055 
1056 extern int
1057 register_ftrace_function_probe(char *glob, struct trace_array *tr,
1058 			       struct ftrace_probe_ops *ops, void *data);
1059 extern int
1060 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1061 				      struct ftrace_probe_ops *ops);
1062 extern void clear_ftrace_function_probes(struct trace_array *tr);
1063 
1064 int register_ftrace_command(struct ftrace_func_command *cmd);
1065 int unregister_ftrace_command(struct ftrace_func_command *cmd);
1066 
1067 void ftrace_create_filter_files(struct ftrace_ops *ops,
1068 				struct dentry *parent);
1069 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1070 #else
1071 struct ftrace_func_command;
1072 
1073 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1074 {
1075 	return -EINVAL;
1076 }
1077 static inline __init int unregister_ftrace_command(char *cmd_name)
1078 {
1079 	return -EINVAL;
1080 }
1081 static inline void clear_ftrace_function_probes(struct trace_array *tr)
1082 {
1083 }
1084 
1085 /*
1086  * The ops parameter passed in is usually undefined.
1087  * This must be a macro.
1088  */
1089 #define ftrace_create_filter_files(ops, parent) do { } while (0)
1090 #define ftrace_destroy_filter_files(ops) do { } while (0)
1091 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1092 
1093 bool ftrace_event_is_function(struct trace_event_call *call);
1094 
1095 /*
1096  * struct trace_parser - servers for reading the user input separated by spaces
1097  * @cont: set if the input is not complete - no final space char was found
1098  * @buffer: holds the parsed user input
1099  * @idx: user input length
1100  * @size: buffer size
1101  */
1102 struct trace_parser {
1103 	bool		cont;
1104 	char		*buffer;
1105 	unsigned	idx;
1106 	unsigned	size;
1107 };
1108 
1109 static inline bool trace_parser_loaded(struct trace_parser *parser)
1110 {
1111 	return (parser->idx != 0);
1112 }
1113 
1114 static inline bool trace_parser_cont(struct trace_parser *parser)
1115 {
1116 	return parser->cont;
1117 }
1118 
1119 static inline void trace_parser_clear(struct trace_parser *parser)
1120 {
1121 	parser->cont = false;
1122 	parser->idx = 0;
1123 }
1124 
1125 extern int trace_parser_get_init(struct trace_parser *parser, int size);
1126 extern void trace_parser_put(struct trace_parser *parser);
1127 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1128 	size_t cnt, loff_t *ppos);
1129 
1130 /*
1131  * Only create function graph options if function graph is configured.
1132  */
1133 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1134 # define FGRAPH_FLAGS						\
1135 		C(DISPLAY_GRAPH,	"display-graph"),
1136 #else
1137 # define FGRAPH_FLAGS
1138 #endif
1139 
1140 #ifdef CONFIG_BRANCH_TRACER
1141 # define BRANCH_FLAGS					\
1142 		C(BRANCH,		"branch"),
1143 #else
1144 # define BRANCH_FLAGS
1145 #endif
1146 
1147 #ifdef CONFIG_FUNCTION_TRACER
1148 # define FUNCTION_FLAGS						\
1149 		C(FUNCTION,		"function-trace"),	\
1150 		C(FUNC_FORK,		"function-fork"),
1151 # define FUNCTION_DEFAULT_FLAGS		TRACE_ITER_FUNCTION
1152 #else
1153 # define FUNCTION_FLAGS
1154 # define FUNCTION_DEFAULT_FLAGS		0UL
1155 # define TRACE_ITER_FUNC_FORK		0UL
1156 #endif
1157 
1158 #ifdef CONFIG_STACKTRACE
1159 # define STACK_FLAGS				\
1160 		C(STACKTRACE,		"stacktrace"),
1161 #else
1162 # define STACK_FLAGS
1163 #endif
1164 
1165 /*
1166  * trace_iterator_flags is an enumeration that defines bit
1167  * positions into trace_flags that controls the output.
1168  *
1169  * NOTE: These bits must match the trace_options array in
1170  *       trace.c (this macro guarantees it).
1171  */
1172 #define TRACE_FLAGS						\
1173 		C(PRINT_PARENT,		"print-parent"),	\
1174 		C(SYM_OFFSET,		"sym-offset"),		\
1175 		C(SYM_ADDR,		"sym-addr"),		\
1176 		C(VERBOSE,		"verbose"),		\
1177 		C(RAW,			"raw"),			\
1178 		C(HEX,			"hex"),			\
1179 		C(BIN,			"bin"),			\
1180 		C(BLOCK,		"block"),		\
1181 		C(PRINTK,		"trace_printk"),	\
1182 		C(ANNOTATE,		"annotate"),		\
1183 		C(USERSTACKTRACE,	"userstacktrace"),	\
1184 		C(SYM_USEROBJ,		"sym-userobj"),		\
1185 		C(PRINTK_MSGONLY,	"printk-msg-only"),	\
1186 		C(CONTEXT_INFO,		"context-info"),   /* Print pid/cpu/time */ \
1187 		C(LATENCY_FMT,		"latency-format"),	\
1188 		C(RECORD_CMD,		"record-cmd"),		\
1189 		C(RECORD_TGID,		"record-tgid"),		\
1190 		C(OVERWRITE,		"overwrite"),		\
1191 		C(STOP_ON_FREE,		"disable_on_free"),	\
1192 		C(IRQ_INFO,		"irq-info"),		\
1193 		C(MARKERS,		"markers"),		\
1194 		C(EVENT_FORK,		"event-fork"),		\
1195 		FUNCTION_FLAGS					\
1196 		FGRAPH_FLAGS					\
1197 		STACK_FLAGS					\
1198 		BRANCH_FLAGS
1199 
1200 /*
1201  * By defining C, we can make TRACE_FLAGS a list of bit names
1202  * that will define the bits for the flag masks.
1203  */
1204 #undef C
1205 #define C(a, b) TRACE_ITER_##a##_BIT
1206 
1207 enum trace_iterator_bits {
1208 	TRACE_FLAGS
1209 	/* Make sure we don't go more than we have bits for */
1210 	TRACE_ITER_LAST_BIT
1211 };
1212 
1213 /*
1214  * By redefining C, we can make TRACE_FLAGS a list of masks that
1215  * use the bits as defined above.
1216  */
1217 #undef C
1218 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1219 
1220 enum trace_iterator_flags { TRACE_FLAGS };
1221 
1222 /*
1223  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1224  * control the output of kernel symbols.
1225  */
1226 #define TRACE_ITER_SYM_MASK \
1227 	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1228 
1229 extern struct tracer nop_trace;
1230 
1231 #ifdef CONFIG_BRANCH_TRACER
1232 extern int enable_branch_tracing(struct trace_array *tr);
1233 extern void disable_branch_tracing(void);
1234 static inline int trace_branch_enable(struct trace_array *tr)
1235 {
1236 	if (tr->trace_flags & TRACE_ITER_BRANCH)
1237 		return enable_branch_tracing(tr);
1238 	return 0;
1239 }
1240 static inline void trace_branch_disable(void)
1241 {
1242 	/* due to races, always disable */
1243 	disable_branch_tracing();
1244 }
1245 #else
1246 static inline int trace_branch_enable(struct trace_array *tr)
1247 {
1248 	return 0;
1249 }
1250 static inline void trace_branch_disable(void)
1251 {
1252 }
1253 #endif /* CONFIG_BRANCH_TRACER */
1254 
1255 /* set ring buffers to default size if not already done so */
1256 int tracing_update_buffers(void);
1257 
1258 struct ftrace_event_field {
1259 	struct list_head	link;
1260 	const char		*name;
1261 	const char		*type;
1262 	int			filter_type;
1263 	int			offset;
1264 	int			size;
1265 	int			is_signed;
1266 };
1267 
1268 struct prog_entry;
1269 
1270 struct event_filter {
1271 	struct prog_entry __rcu	*prog;
1272 	char			*filter_string;
1273 };
1274 
1275 struct event_subsystem {
1276 	struct list_head	list;
1277 	const char		*name;
1278 	struct event_filter	*filter;
1279 	int			ref_count;
1280 };
1281 
1282 struct trace_subsystem_dir {
1283 	struct list_head		list;
1284 	struct event_subsystem		*subsystem;
1285 	struct trace_array		*tr;
1286 	struct dentry			*entry;
1287 	int				ref_count;
1288 	int				nr_events;
1289 };
1290 
1291 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1292 				     struct ring_buffer *buffer,
1293 				     struct ring_buffer_event *event);
1294 
1295 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1296 				     struct ring_buffer *buffer,
1297 				     struct ring_buffer_event *event,
1298 				     unsigned long flags, int pc,
1299 				     struct pt_regs *regs);
1300 
1301 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1302 					      struct ring_buffer *buffer,
1303 					      struct ring_buffer_event *event,
1304 					      unsigned long flags, int pc)
1305 {
1306 	trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1307 }
1308 
1309 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1310 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1311 void trace_buffered_event_disable(void);
1312 void trace_buffered_event_enable(void);
1313 
1314 static inline void
1315 __trace_event_discard_commit(struct ring_buffer *buffer,
1316 			     struct ring_buffer_event *event)
1317 {
1318 	if (this_cpu_read(trace_buffered_event) == event) {
1319 		/* Simply release the temp buffer */
1320 		this_cpu_dec(trace_buffered_event_cnt);
1321 		return;
1322 	}
1323 	ring_buffer_discard_commit(buffer, event);
1324 }
1325 
1326 /*
1327  * Helper function for event_trigger_unlock_commit{_regs}().
1328  * If there are event triggers attached to this event that requires
1329  * filtering against its fields, then they wil be called as the
1330  * entry already holds the field information of the current event.
1331  *
1332  * It also checks if the event should be discarded or not.
1333  * It is to be discarded if the event is soft disabled and the
1334  * event was only recorded to process triggers, or if the event
1335  * filter is active and this event did not match the filters.
1336  *
1337  * Returns true if the event is discarded, false otherwise.
1338  */
1339 static inline bool
1340 __event_trigger_test_discard(struct trace_event_file *file,
1341 			     struct ring_buffer *buffer,
1342 			     struct ring_buffer_event *event,
1343 			     void *entry,
1344 			     enum event_trigger_type *tt)
1345 {
1346 	unsigned long eflags = file->flags;
1347 
1348 	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1349 		*tt = event_triggers_call(file, entry, event);
1350 
1351 	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1352 	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1353 	     !filter_match_preds(file->filter, entry))) {
1354 		__trace_event_discard_commit(buffer, event);
1355 		return true;
1356 	}
1357 
1358 	return false;
1359 }
1360 
1361 /**
1362  * event_trigger_unlock_commit - handle triggers and finish event commit
1363  * @file: The file pointer assoctiated to the event
1364  * @buffer: The ring buffer that the event is being written to
1365  * @event: The event meta data in the ring buffer
1366  * @entry: The event itself
1367  * @irq_flags: The state of the interrupts at the start of the event
1368  * @pc: The state of the preempt count at the start of the event.
1369  *
1370  * This is a helper function to handle triggers that require data
1371  * from the event itself. It also tests the event against filters and
1372  * if the event is soft disabled and should be discarded.
1373  */
1374 static inline void
1375 event_trigger_unlock_commit(struct trace_event_file *file,
1376 			    struct ring_buffer *buffer,
1377 			    struct ring_buffer_event *event,
1378 			    void *entry, unsigned long irq_flags, int pc)
1379 {
1380 	enum event_trigger_type tt = ETT_NONE;
1381 
1382 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1383 		trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1384 
1385 	if (tt)
1386 		event_triggers_post_call(file, tt);
1387 }
1388 
1389 /**
1390  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1391  * @file: The file pointer assoctiated to the event
1392  * @buffer: The ring buffer that the event is being written to
1393  * @event: The event meta data in the ring buffer
1394  * @entry: The event itself
1395  * @irq_flags: The state of the interrupts at the start of the event
1396  * @pc: The state of the preempt count at the start of the event.
1397  *
1398  * This is a helper function to handle triggers that require data
1399  * from the event itself. It also tests the event against filters and
1400  * if the event is soft disabled and should be discarded.
1401  *
1402  * Same as event_trigger_unlock_commit() but calls
1403  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1404  */
1405 static inline void
1406 event_trigger_unlock_commit_regs(struct trace_event_file *file,
1407 				 struct ring_buffer *buffer,
1408 				 struct ring_buffer_event *event,
1409 				 void *entry, unsigned long irq_flags, int pc,
1410 				 struct pt_regs *regs)
1411 {
1412 	enum event_trigger_type tt = ETT_NONE;
1413 
1414 	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1415 		trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1416 						irq_flags, pc, regs);
1417 
1418 	if (tt)
1419 		event_triggers_post_call(file, tt);
1420 }
1421 
1422 #define FILTER_PRED_INVALID	((unsigned short)-1)
1423 #define FILTER_PRED_IS_RIGHT	(1 << 15)
1424 #define FILTER_PRED_FOLD	(1 << 15)
1425 
1426 /*
1427  * The max preds is the size of unsigned short with
1428  * two flags at the MSBs. One bit is used for both the IS_RIGHT
1429  * and FOLD flags. The other is reserved.
1430  *
1431  * 2^14 preds is way more than enough.
1432  */
1433 #define MAX_FILTER_PRED		16384
1434 
1435 struct filter_pred;
1436 struct regex;
1437 
1438 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1439 
1440 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1441 
1442 enum regex_type {
1443 	MATCH_FULL = 0,
1444 	MATCH_FRONT_ONLY,
1445 	MATCH_MIDDLE_ONLY,
1446 	MATCH_END_ONLY,
1447 	MATCH_GLOB,
1448 };
1449 
1450 struct regex {
1451 	char			pattern[MAX_FILTER_STR_VAL];
1452 	int			len;
1453 	int			field_len;
1454 	regex_match_func	match;
1455 };
1456 
1457 struct filter_pred {
1458 	filter_pred_fn_t 	fn;
1459 	u64 			val;
1460 	struct regex		regex;
1461 	unsigned short		*ops;
1462 	struct ftrace_event_field *field;
1463 	int 			offset;
1464 	int			not;
1465 	int 			op;
1466 };
1467 
1468 static inline bool is_string_field(struct ftrace_event_field *field)
1469 {
1470 	return field->filter_type == FILTER_DYN_STRING ||
1471 	       field->filter_type == FILTER_STATIC_STRING ||
1472 	       field->filter_type == FILTER_PTR_STRING ||
1473 	       field->filter_type == FILTER_COMM;
1474 }
1475 
1476 static inline bool is_function_field(struct ftrace_event_field *field)
1477 {
1478 	return field->filter_type == FILTER_TRACE_FN;
1479 }
1480 
1481 extern enum regex_type
1482 filter_parse_regex(char *buff, int len, char **search, int *not);
1483 extern void print_event_filter(struct trace_event_file *file,
1484 			       struct trace_seq *s);
1485 extern int apply_event_filter(struct trace_event_file *file,
1486 			      char *filter_string);
1487 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1488 					char *filter_string);
1489 extern void print_subsystem_event_filter(struct event_subsystem *system,
1490 					 struct trace_seq *s);
1491 extern int filter_assign_type(const char *type);
1492 extern int create_event_filter(struct trace_event_call *call,
1493 			       char *filter_str, bool set_str,
1494 			       struct event_filter **filterp);
1495 extern void free_event_filter(struct event_filter *filter);
1496 
1497 struct ftrace_event_field *
1498 trace_find_event_field(struct trace_event_call *call, char *name);
1499 
1500 extern void trace_event_enable_cmd_record(bool enable);
1501 extern void trace_event_enable_tgid_record(bool enable);
1502 
1503 extern int event_trace_init(void);
1504 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1505 extern int event_trace_del_tracer(struct trace_array *tr);
1506 
1507 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
1508 						  const char *system,
1509 						  const char *event);
1510 extern struct trace_event_file *find_event_file(struct trace_array *tr,
1511 						const char *system,
1512 						const char *event);
1513 
1514 static inline void *event_file_data(struct file *filp)
1515 {
1516 	return READ_ONCE(file_inode(filp)->i_private);
1517 }
1518 
1519 extern struct mutex event_mutex;
1520 extern struct list_head ftrace_events;
1521 
1522 extern const struct file_operations event_trigger_fops;
1523 extern const struct file_operations event_hist_fops;
1524 
1525 #ifdef CONFIG_HIST_TRIGGERS
1526 extern int register_trigger_hist_cmd(void);
1527 extern int register_trigger_hist_enable_disable_cmds(void);
1528 #else
1529 static inline int register_trigger_hist_cmd(void) { return 0; }
1530 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1531 #endif
1532 
1533 extern int register_trigger_cmds(void);
1534 extern void clear_event_triggers(struct trace_array *tr);
1535 
1536 struct event_trigger_data {
1537 	unsigned long			count;
1538 	int				ref;
1539 	struct event_trigger_ops	*ops;
1540 	struct event_command		*cmd_ops;
1541 	struct event_filter __rcu	*filter;
1542 	char				*filter_str;
1543 	void				*private_data;
1544 	bool				paused;
1545 	bool				paused_tmp;
1546 	struct list_head		list;
1547 	char				*name;
1548 	struct list_head		named_list;
1549 	struct event_trigger_data	*named_data;
1550 };
1551 
1552 /* Avoid typos */
1553 #define ENABLE_EVENT_STR	"enable_event"
1554 #define DISABLE_EVENT_STR	"disable_event"
1555 #define ENABLE_HIST_STR		"enable_hist"
1556 #define DISABLE_HIST_STR	"disable_hist"
1557 
1558 struct enable_trigger_data {
1559 	struct trace_event_file		*file;
1560 	bool				enable;
1561 	bool				hist;
1562 };
1563 
1564 extern int event_enable_trigger_print(struct seq_file *m,
1565 				      struct event_trigger_ops *ops,
1566 				      struct event_trigger_data *data);
1567 extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1568 				      struct event_trigger_data *data);
1569 extern int event_enable_trigger_func(struct event_command *cmd_ops,
1570 				     struct trace_event_file *file,
1571 				     char *glob, char *cmd, char *param);
1572 extern int event_enable_register_trigger(char *glob,
1573 					 struct event_trigger_ops *ops,
1574 					 struct event_trigger_data *data,
1575 					 struct trace_event_file *file);
1576 extern void event_enable_unregister_trigger(char *glob,
1577 					    struct event_trigger_ops *ops,
1578 					    struct event_trigger_data *test,
1579 					    struct trace_event_file *file);
1580 extern void trigger_data_free(struct event_trigger_data *data);
1581 extern int event_trigger_init(struct event_trigger_ops *ops,
1582 			      struct event_trigger_data *data);
1583 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1584 					      int trigger_enable);
1585 extern void update_cond_flag(struct trace_event_file *file);
1586 extern int set_trigger_filter(char *filter_str,
1587 			      struct event_trigger_data *trigger_data,
1588 			      struct trace_event_file *file);
1589 extern struct event_trigger_data *find_named_trigger(const char *name);
1590 extern bool is_named_trigger(struct event_trigger_data *test);
1591 extern int save_named_trigger(const char *name,
1592 			      struct event_trigger_data *data);
1593 extern void del_named_trigger(struct event_trigger_data *data);
1594 extern void pause_named_trigger(struct event_trigger_data *data);
1595 extern void unpause_named_trigger(struct event_trigger_data *data);
1596 extern void set_named_trigger_data(struct event_trigger_data *data,
1597 				   struct event_trigger_data *named_data);
1598 extern struct event_trigger_data *
1599 get_named_trigger_data(struct event_trigger_data *data);
1600 extern int register_event_command(struct event_command *cmd);
1601 extern int unregister_event_command(struct event_command *cmd);
1602 extern int register_trigger_hist_enable_disable_cmds(void);
1603 
1604 /**
1605  * struct event_trigger_ops - callbacks for trace event triggers
1606  *
1607  * The methods in this structure provide per-event trigger hooks for
1608  * various trigger operations.
1609  *
1610  * All the methods below, except for @init() and @free(), must be
1611  * implemented.
1612  *
1613  * @func: The trigger 'probe' function called when the triggering
1614  *	event occurs.  The data passed into this callback is the data
1615  *	that was supplied to the event_command @reg() function that
1616  *	registered the trigger (see struct event_command) along with
1617  *	the trace record, rec.
1618  *
1619  * @init: An optional initialization function called for the trigger
1620  *	when the trigger is registered (via the event_command reg()
1621  *	function).  This can be used to perform per-trigger
1622  *	initialization such as incrementing a per-trigger reference
1623  *	count, for instance.  This is usually implemented by the
1624  *	generic utility function @event_trigger_init() (see
1625  *	trace_event_triggers.c).
1626  *
1627  * @free: An optional de-initialization function called for the
1628  *	trigger when the trigger is unregistered (via the
1629  *	event_command @reg() function).  This can be used to perform
1630  *	per-trigger de-initialization such as decrementing a
1631  *	per-trigger reference count and freeing corresponding trigger
1632  *	data, for instance.  This is usually implemented by the
1633  *	generic utility function @event_trigger_free() (see
1634  *	trace_event_triggers.c).
1635  *
1636  * @print: The callback function invoked to have the trigger print
1637  *	itself.  This is usually implemented by a wrapper function
1638  *	that calls the generic utility function @event_trigger_print()
1639  *	(see trace_event_triggers.c).
1640  */
1641 struct event_trigger_ops {
1642 	void			(*func)(struct event_trigger_data *data,
1643 					void *rec,
1644 					struct ring_buffer_event *rbe);
1645 	int			(*init)(struct event_trigger_ops *ops,
1646 					struct event_trigger_data *data);
1647 	void			(*free)(struct event_trigger_ops *ops,
1648 					struct event_trigger_data *data);
1649 	int			(*print)(struct seq_file *m,
1650 					 struct event_trigger_ops *ops,
1651 					 struct event_trigger_data *data);
1652 };
1653 
1654 /**
1655  * struct event_command - callbacks and data members for event commands
1656  *
1657  * Event commands are invoked by users by writing the command name
1658  * into the 'trigger' file associated with a trace event.  The
1659  * parameters associated with a specific invocation of an event
1660  * command are used to create an event trigger instance, which is
1661  * added to the list of trigger instances associated with that trace
1662  * event.  When the event is hit, the set of triggers associated with
1663  * that event is invoked.
1664  *
1665  * The data members in this structure provide per-event command data
1666  * for various event commands.
1667  *
1668  * All the data members below, except for @post_trigger, must be set
1669  * for each event command.
1670  *
1671  * @name: The unique name that identifies the event command.  This is
1672  *	the name used when setting triggers via trigger files.
1673  *
1674  * @trigger_type: A unique id that identifies the event command
1675  *	'type'.  This value has two purposes, the first to ensure that
1676  *	only one trigger of the same type can be set at a given time
1677  *	for a particular event e.g. it doesn't make sense to have both
1678  *	a traceon and traceoff trigger attached to a single event at
1679  *	the same time, so traceon and traceoff have the same type
1680  *	though they have different names.  The @trigger_type value is
1681  *	also used as a bit value for deferring the actual trigger
1682  *	action until after the current event is finished.  Some
1683  *	commands need to do this if they themselves log to the trace
1684  *	buffer (see the @post_trigger() member below).  @trigger_type
1685  *	values are defined by adding new values to the trigger_type
1686  *	enum in include/linux/trace_events.h.
1687  *
1688  * @flags: See the enum event_command_flags below.
1689  *
1690  * All the methods below, except for @set_filter() and @unreg_all(),
1691  * must be implemented.
1692  *
1693  * @func: The callback function responsible for parsing and
1694  *	registering the trigger written to the 'trigger' file by the
1695  *	user.  It allocates the trigger instance and registers it with
1696  *	the appropriate trace event.  It makes use of the other
1697  *	event_command callback functions to orchestrate this, and is
1698  *	usually implemented by the generic utility function
1699  *	@event_trigger_callback() (see trace_event_triggers.c).
1700  *
1701  * @reg: Adds the trigger to the list of triggers associated with the
1702  *	event, and enables the event trigger itself, after
1703  *	initializing it (via the event_trigger_ops @init() function).
1704  *	This is also where commands can use the @trigger_type value to
1705  *	make the decision as to whether or not multiple instances of
1706  *	the trigger should be allowed.  This is usually implemented by
1707  *	the generic utility function @register_trigger() (see
1708  *	trace_event_triggers.c).
1709  *
1710  * @unreg: Removes the trigger from the list of triggers associated
1711  *	with the event, and disables the event trigger itself, after
1712  *	initializing it (via the event_trigger_ops @free() function).
1713  *	This is usually implemented by the generic utility function
1714  *	@unregister_trigger() (see trace_event_triggers.c).
1715  *
1716  * @unreg_all: An optional function called to remove all the triggers
1717  *	from the list of triggers associated with the event.  Called
1718  *	when a trigger file is opened in truncate mode.
1719  *
1720  * @set_filter: An optional function called to parse and set a filter
1721  *	for the trigger.  If no @set_filter() method is set for the
1722  *	event command, filters set by the user for the command will be
1723  *	ignored.  This is usually implemented by the generic utility
1724  *	function @set_trigger_filter() (see trace_event_triggers.c).
1725  *
1726  * @get_trigger_ops: The callback function invoked to retrieve the
1727  *	event_trigger_ops implementation associated with the command.
1728  */
1729 struct event_command {
1730 	struct list_head	list;
1731 	char			*name;
1732 	enum event_trigger_type	trigger_type;
1733 	int			flags;
1734 	int			(*func)(struct event_command *cmd_ops,
1735 					struct trace_event_file *file,
1736 					char *glob, char *cmd, char *params);
1737 	int			(*reg)(char *glob,
1738 				       struct event_trigger_ops *ops,
1739 				       struct event_trigger_data *data,
1740 				       struct trace_event_file *file);
1741 	void			(*unreg)(char *glob,
1742 					 struct event_trigger_ops *ops,
1743 					 struct event_trigger_data *data,
1744 					 struct trace_event_file *file);
1745 	void			(*unreg_all)(struct trace_event_file *file);
1746 	int			(*set_filter)(char *filter_str,
1747 					      struct event_trigger_data *data,
1748 					      struct trace_event_file *file);
1749 	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1750 };
1751 
1752 /**
1753  * enum event_command_flags - flags for struct event_command
1754  *
1755  * @POST_TRIGGER: A flag that says whether or not this command needs
1756  *	to have its action delayed until after the current event has
1757  *	been closed.  Some triggers need to avoid being invoked while
1758  *	an event is currently in the process of being logged, since
1759  *	the trigger may itself log data into the trace buffer.  Thus
1760  *	we make sure the current event is committed before invoking
1761  *	those triggers.  To do that, the trigger invocation is split
1762  *	in two - the first part checks the filter using the current
1763  *	trace record; if a command has the @post_trigger flag set, it
1764  *	sets a bit for itself in the return value, otherwise it
1765  *	directly invokes the trigger.  Once all commands have been
1766  *	either invoked or set their return flag, the current record is
1767  *	either committed or discarded.  At that point, if any commands
1768  *	have deferred their triggers, those commands are finally
1769  *	invoked following the close of the current event.  In other
1770  *	words, if the event_trigger_ops @func() probe implementation
1771  *	itself logs to the trace buffer, this flag should be set,
1772  *	otherwise it can be left unspecified.
1773  *
1774  * @NEEDS_REC: A flag that says whether or not this command needs
1775  *	access to the trace record in order to perform its function,
1776  *	regardless of whether or not it has a filter associated with
1777  *	it (filters make a trigger require access to the trace record
1778  *	but are not always present).
1779  */
1780 enum event_command_flags {
1781 	EVENT_CMD_FL_POST_TRIGGER	= 1,
1782 	EVENT_CMD_FL_NEEDS_REC		= 2,
1783 };
1784 
1785 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1786 {
1787 	return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1788 }
1789 
1790 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1791 {
1792 	return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1793 }
1794 
1795 extern int trace_event_enable_disable(struct trace_event_file *file,
1796 				      int enable, int soft_disable);
1797 extern int tracing_alloc_snapshot(void);
1798 
1799 extern const char *__start___trace_bprintk_fmt[];
1800 extern const char *__stop___trace_bprintk_fmt[];
1801 
1802 extern const char *__start___tracepoint_str[];
1803 extern const char *__stop___tracepoint_str[];
1804 
1805 void trace_printk_control(bool enabled);
1806 void trace_printk_init_buffers(void);
1807 void trace_printk_start_comm(void);
1808 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1809 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1810 
1811 #define MAX_EVENT_NAME_LEN	64
1812 
1813 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1814 extern ssize_t trace_parse_run_command(struct file *file,
1815 		const char __user *buffer, size_t count, loff_t *ppos,
1816 		int (*createfn)(int, char**));
1817 
1818 /*
1819  * Normal trace_printk() and friends allocates special buffers
1820  * to do the manipulation, as well as saves the print formats
1821  * into sections to display. But the trace infrastructure wants
1822  * to use these without the added overhead at the price of being
1823  * a bit slower (used mainly for warnings, where we don't care
1824  * about performance). The internal_trace_puts() is for such
1825  * a purpose.
1826  */
1827 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1828 
1829 #undef FTRACE_ENTRY
1830 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)	\
1831 	extern struct trace_event_call					\
1832 	__aligned(4) event_##call;
1833 #undef FTRACE_ENTRY_DUP
1834 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter)	\
1835 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1836 		     filter)
1837 #undef FTRACE_ENTRY_PACKED
1838 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1839 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1840 		     filter)
1841 
1842 #include "trace_entries.h"
1843 
1844 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1845 int perf_ftrace_event_register(struct trace_event_call *call,
1846 			       enum trace_reg type, void *data);
1847 #else
1848 #define perf_ftrace_event_register NULL
1849 #endif
1850 
1851 #ifdef CONFIG_FTRACE_SYSCALLS
1852 void init_ftrace_syscalls(void);
1853 const char *get_syscall_name(int syscall);
1854 #else
1855 static inline void init_ftrace_syscalls(void) { }
1856 static inline const char *get_syscall_name(int syscall)
1857 {
1858 	return NULL;
1859 }
1860 #endif
1861 
1862 #ifdef CONFIG_EVENT_TRACING
1863 void trace_event_init(void);
1864 void trace_event_eval_update(struct trace_eval_map **map, int len);
1865 #else
1866 static inline void __init trace_event_init(void) { }
1867 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1868 #endif
1869 
1870 #ifdef CONFIG_TRACER_SNAPSHOT
1871 void tracing_snapshot_instance(struct trace_array *tr);
1872 int tracing_alloc_snapshot_instance(struct trace_array *tr);
1873 #else
1874 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1875 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1876 {
1877 	return 0;
1878 }
1879 #endif
1880 
1881 #ifdef CONFIG_PREEMPT_TRACER
1882 void tracer_preempt_on(unsigned long a0, unsigned long a1);
1883 void tracer_preempt_off(unsigned long a0, unsigned long a1);
1884 #else
1885 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
1886 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
1887 #endif
1888 #ifdef CONFIG_IRQSOFF_TRACER
1889 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
1890 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
1891 #else
1892 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
1893 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
1894 #endif
1895 
1896 extern struct trace_iterator *tracepoint_print_iter;
1897 
1898 #endif /* _LINUX_KERNEL_TRACE_H */
1899