summaryrefslogtreecommitdiff
path: root/kernel/trace/trace.h
blob: 7bdfef35c05ab7455d4d8cdab173cd00980a267f (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
#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>

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

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

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

/*
 * 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 {
	char			type;
	char			cpu;
	char			flags;
	char			preempt_count;
	int			pid;
	cycle_t			t;
	union {
		struct ftrace_entry		fn;
		struct ctx_switch_entry		ctx;
		struct special_entry		special;
	};
};

#define TRACE_ENTRY_SIZE	sizeof(struct trace_entry)

/*
 * 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 {
	struct list_head	trace_pages;
	atomic_t		disabled;
	spinlock_t		lock;
	struct lock_class_key	lock_key;

	/* these fields get copied into max-trace: */
	unsigned		trace_head_idx;
	unsigned		trace_tail_idx;
	void			*trace_head; /* producer */
	void			*trace_tail; /* consumer */
	unsigned long		trace_idx;
	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 {
	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			(*close)(struct trace_iterator *iter);
	void			(*start)(struct trace_iterator *iter);
	void			(*stop)(struct trace_iterator *iter);
	void			(*ctrl_update)(struct trace_array *tr);
#ifdef CONFIG_FTRACE_STARTUP_TEST
	int			(*selftest)(struct tracer *trace,
					    struct trace_array *tr);
#endif
	struct tracer		*next;
	int			print_max;
};

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

/*
 * Trace iterator - used by printout routines who present trace
 * results to users and which routines might sleep, etc:
 */
struct trace_iterator {
	struct trace_seq	seq;
	struct trace_array	*tr;
	struct tracer		*trace;

	struct trace_entry	*ent;
	int			cpu;

	struct trace_entry	*prev_ent;
	int			prev_cpu;

	unsigned long		iter_flags;
	loff_t			pos;
	unsigned long		next_idx[NR_CPUS];
	struct list_head	*next_page[NR_CPUS];
	unsigned		next_page_idx[NR_CPUS];
	long			idx;
};

void notrace tracing_reset(struct trace_array_cpu *data);
int tracing_open_generic(struct inode *inode, struct file *filp);
struct dentry *tracing_init_dentry(void);
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 trace_special(struct trace_array *tr,
		   struct trace_array_cpu *data,
		   unsigned long arg1,
		   unsigned long arg2,
		   unsigned long arg3);

void tracing_start_function_trace(void);
void tracing_stop_function_trace(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 notrace cycle_t ftrace_now(int cpu);

#ifdef CONFIG_SCHED_TRACER
extern void notrace
wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
#else
static inline void
wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
{
}
#endif

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

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

extern int register_tracer_switch(struct tracer_switch_ops *ops);
extern int unregister_tracer_switch(struct tracer_switch_ops *ops);

#endif /* CONFIG_CONTEXT_SWITCH_TRACER */

#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
#endif

#ifdef CONFIG_FTRACE_STARTUP_TEST
#ifdef CONFIG_FTRACE
extern int trace_selftest_startup_function(struct tracer *trace,
					   struct trace_array *tr);
#endif
#ifdef CONFIG_IRQSOFF_TRACER
extern int trace_selftest_startup_irqsoff(struct tracer *trace,
					  struct trace_array *tr);
#endif
#ifdef CONFIG_PREEMPT_TRACER
extern int trace_selftest_startup_preemptoff(struct tracer *trace,
					     struct trace_array *tr);
#endif
#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
						 struct trace_array *tr);
#endif
#ifdef CONFIG_SCHED_TRACER
extern int trace_selftest_startup_wakeup(struct tracer *trace,
					 struct trace_array *tr);
#endif
#ifdef CONFIG_CONTEXT_SWITCH_TRACER
extern int trace_selftest_startup_sched_switch(struct tracer *trace,
					       struct trace_array *tr);
#endif
#endif /* CONFIG_FTRACE_STARTUP_TEST */

extern void *head_page(struct trace_array_cpu *data);

#endif /* _LINUX_KERNEL_TRACE_H */