aboutsummaryrefslogtreecommitdiff
path: root/kernel/trace/trace.h
blob: e541a6b7e312db6e9a1b0af40519056893e62a03 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
#ifndef _LINUX_KERNEL_TRACE_H
#define _LINUX_KERNEL_TRACE_H

#include <linux/fs.h>
#include <asm/atomic.h>
#include <linux/sched.h>
#include <linux/clocksource.h>
#include <linux/ring_buffer.h>
#include <linux/mmiotrace.h>
#include <linux/ftrace.h>

enum trace_type {
	__TRACE_FIRST_TYPE = 0,

	TRACE_FN,
	TRACE_CTX,
	TRACE_WAKE,
	TRACE_CONT,
	TRACE_STACK,
	TRACE_PRINT,
	TRACE_SPECIAL,
	TRACE_MMIO_RW,
	TRACE_MMIO_MAP,
	TRACE_BOOT,

	__TRACE_LAST_TYPE
};

/*
 * The trace entry - the most basic unit of tracing. This is what
 * is printed in the end as a single line in the trace output, such as:
 *
 *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
 */
struct trace_entry {
	unsigned char		type;
	unsigned char		cpu;
	unsigned char		flags;
	unsigned char		preempt_count;
	int			pid;
};

/*
 * Function trace entry - function address and parent function addres:
 */
struct ftrace_entry {
	struct trace_entry	ent;
	unsigned long		ip;
	unsigned long		parent_ip;
};
extern struct tracer boot_tracer;

/*
 * Context switch trace entry - which task (and prio) we switched from/to:
 */
struct ctx_switch_entry {
	struct trace_entry	ent;
	unsigned int		prev_pid;
	unsigned char		prev_prio;
	unsigned char		prev_state;
	unsigned int		next_pid;
	unsigned char		next_prio;
	unsigned char		next_state;
	unsigned int		next_cpu;
};

/*
 * Special (free-form) trace entry:
 */
struct special_entry {
	struct trace_entry	ent;
	unsigned long		arg1;
	unsigned long		arg2;
	unsigned long		arg3;
};

/*
 * Stack-trace entry:
 */

#define FTRACE_STACK_ENTRIES	8

struct stack_entry {
	struct trace_entry	ent;
	unsigned long		caller[FTRACE_STACK_ENTRIES];
};

/*
 * ftrace_printk entry:
 */
struct print_entry {
	struct trace_entry	ent;
	unsigned long		ip;
	char			buf[];
};

#define TRACE_OLD_SIZE		88

struct trace_field_cont {
	unsigned char		type;
	/* Temporary till we get rid of this completely */
	char			buf[TRACE_OLD_SIZE - 1];
};

struct trace_mmiotrace_rw {
	struct trace_entry	ent;
	struct mmiotrace_rw	rw;
};

struct trace_mmiotrace_map {
	struct trace_entry	ent;
	struct mmiotrace_map	map;
};

struct trace_boot {
	struct trace_entry	ent;
	struct boot_trace	initcall;
};

/*
 * trace_flag_type is an enumeration that holds different
 * states when a trace occurs. These are:
 *  IRQS_OFF	- interrupts were disabled
 *  NEED_RESCED - reschedule is requested
 *  HARDIRQ	- inside an interrupt handler
 *  SOFTIRQ	- inside a softirq handler
 *  CONT	- multiple entries hold the trace item
 */
enum trace_flag_type {
	TRACE_FLAG_IRQS_OFF		= 0x01,
	TRACE_FLAG_NEED_RESCHED		= 0x02,
	TRACE_FLAG_HARDIRQ		= 0x04,
	TRACE_FLAG_SOFTIRQ		= 0x08,
	TRACE_FLAG_CONT			= 0x10,
};

#define TRACE_BUF_SIZE		1024

/*
 * The CPU trace array - it consists of thousands of trace entries
 * plus some other descriptor data: (for example which task started
 * the trace, etc.)
 */
struct trace_array_cpu {
	atomic_t		disabled;

	/* these fields get copied into max-trace: */
	unsigned long		trace_idx;
	unsigned long		overrun;
	unsigned long		saved_latency;
	unsigned long		critical_start;
	unsigned long		critical_end;
	unsigned long		critical_sequence;
	unsigned long		nice;
	unsigned long		policy;
	unsigned long		rt_priority;
	cycle_t			preempt_timestamp;
	pid_t			pid;
	uid_t			uid;
	char			comm[TASK_COMM_LEN];
};

struct trace_iterator;

/*
 * The trace array - an array of per-CPU trace arrays. This is the
 * highest level data structure that individual tracers deal with.
 * They have on/off state as well:
 */
struct trace_array {
	struct ring_buffer	*buffer;
	unsigned long		entries;
	long			ctrl;
	int			cpu;
	cycle_t			time_start;
	struct task_struct	*waiter;
	struct trace_array_cpu	*data[NR_CPUS];
};

/*
 * A specific tracer, represented by methods that operate on a trace array:
 */
struct tracer {
	const char		*name;
	void			(*init)(struct trace_array *tr);
	void			(*reset)(struct trace_array *tr);
	void			(*open)(struct trace_iterator *iter);
	void			(*pipe_open)(struct trace_iterator *iter);
	void			(*close)(struct trace_iterator *iter);
	void			(*start)(struct trace_iterator *iter);
	void			(*stop)(struct trace_iterator *iter);
	ssize_t			(*read)(struct trace_iterator *iter,
					struct file *filp, char __user *ubuf,
					size_t cnt, loff_t *ppos);
	void			(*ctrl_update)(struct trace_array *tr);
#ifdef CONFIG_FTRACE_STARTUP_TEST
	int			(*selftest)(struct tracer *trace,
					    struct trace_array *tr);
#endif
	int			(*print_line)(struct trace_iterator *iter);
	struct tracer		*next;
	int			print_max;
};

struct trace_seq {
	unsigned char		buffer[PAGE_SIZE];
	unsigned int		len;
	unsigned int		readpos;
};

/*
 * Trace iterator - used by printout routines who present trace
 * results to users and which routines might sleep, etc:
 */
struct trace_iterator {
	struct trace_array	*tr;
	struct tracer		*trace;
	void			*private;
	struct ring_buffer_iter	*buffer_iter[NR_CPUS];

	/* The below is zeroed out in pipe_read */
	struct trace_seq	seq;
	struct trace_entry	*ent;
	int			cpu;
	u64			ts;

	unsigned long		iter_flags;
	loff_t			pos;
	long			idx;
};

void trace_wake_up(void);
void tracing_reset(struct trace_array *tr, int cpu);
int tracing_open_generic(struct inode *inode, struct file *filp);
struct dentry *tracing_init_dentry(void);
void init_tracer_sysprof_debugfs(struct dentry *d_tracer);

struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
						struct trace_array_cpu *data);
void tracing_generic_entry_update(struct trace_entry *entry,
						unsigned long flags);

void ftrace(struct trace_array *tr,
			    struct trace_array_cpu *data,
			    unsigned long ip,
			    unsigned long parent_ip,
			    unsigned long flags);
void tracing_sched_switch_trace(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct task_struct *prev,
				struct task_struct *next,
				unsigned long flags);
void tracing_record_cmdline(struct task_struct *tsk);

void tracing_sched_wakeup_trace(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct task_struct *wakee,
				struct task_struct *cur,
				unsigned long flags);
void trace_special(struct trace_array *tr,
		   struct trace_array_cpu *data,
		   unsigned long arg1,
		   unsigned long arg2,
		   unsigned long arg3);
void trace_function(struct trace_array *tr,
		    struct trace_array_cpu *data,
		    unsigned long ip,
		    unsigned long parent_ip,
		    unsigned long flags);

void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
int register_tracer(struct tracer *type);
void unregister_tracer(struct tracer *type);

extern unsigned long nsecs_to_usecs(unsigned long nsecs);

extern unsigned long tracing_max_latency;
extern unsigned long tracing_thresh;

void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
void update_max_tr_single(struct trace_array *tr,
			  struct task_struct *tsk, int cpu);

extern cycle_t ftrace_now(int cpu);

#ifdef CONFIG_FTRACE
void tracing_start_function_trace(void);
void tracing_stop_function_trace(void);
#else
# define tracing_start_function_trace()		do { } while (0)
# define tracing_stop_function_trace()		do { } while (0)
#endif

#ifdef CONFIG_CONTEXT_SWITCH_TRACER
typedef void
(*tracer_switch_func_t)(void *private,
			void *__rq,
			struct task_struct *prev,
			struct task_struct *next);

struct tracer_switch_ops {
	tracer_switch_func_t		func;
	void				*private;
	struct tracer_switch_ops	*next;
};

#endif /* CONFIG_CONTEXT_SWITCH_TRACER */

#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
extern int DYN_FTRACE_TEST_NAME(void);
#endif

#ifdef CONFIG_FTRACE_STARTUP_TEST
extern int trace_selftest_startup_function(struct tracer *trace,
					   struct trace_array *tr);
extern int trace_selftest_startup_irqsoff(struct tracer *trace,
					  struct trace_array *tr);
extern int trace_selftest_startup_preemptoff(struct tracer *trace,
					     struct trace_array *tr);
extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
						 struct trace_array *tr);
extern int trace_selftest_startup_wakeup(struct tracer *trace,
					 struct trace_array *tr);
extern int trace_selftest_startup_nop(struct tracer *trace,
					 struct trace_array *tr);
extern int trace_selftest_startup_sched_switch(struct tracer *trace,
					       struct trace_array *tr);
extern int trace_selftest_startup_sysprof(struct tracer *trace,
					       struct trace_array *tr);
#endif /* CONFIG_FTRACE_STARTUP_TEST */

extern void *head_page(struct trace_array_cpu *data);
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
extern void trace_seq_print_cont(struct trace_seq *s,
				 struct trace_iterator *iter);
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
				 size_t cnt);
extern long ns2usecs(cycle_t nsec);
extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);

extern unsigned long trace_flags;

/*
 * trace_iterator_flags is an enumeration that defines bit
 * positions into trace_flags that controls the output.
 *
 * NOTE: These bits must match the trace_options array in
 *       trace.c.
 */
enum trace_iterator_flags {
	TRACE_ITER_PRINT_PARENT		= 0x01,
	TRACE_ITER_SYM_OFFSET		= 0x02,
	TRACE_ITER_SYM_ADDR		= 0x04,
	TRACE_ITER_VERBOSE		= 0x08,
	TRACE_ITER_RAW			= 0x10,
	TRACE_ITER_HEX			= 0x20,
	TRACE_ITER_BIN			= 0x40,
	TRACE_ITER_BLOCK		= 0x80,
	TRACE_ITER_STACKTRACE		= 0x100,
	TRACE_ITER_SCHED_TREE		= 0x200,
	TRACE_ITER_PRINTK		= 0x400,
};

extern struct tracer nop_trace;

#endif /* _LINUX_KERNEL_TRACE_H */