xref: /linux/kernel/trace/trace.h (revision 93d546399c2b7d66a54d5fbd5eee17de19246bf6)
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3 
4 #include <linux/fs.h>
5 #include <asm/atomic.h>
6 #include <linux/sched.h>
7 #include <linux/clocksource.h>
8 #include <linux/ring_buffer.h>
9 #include <linux/mmiotrace.h>
10 #include <linux/ftrace.h>
11 
12 enum trace_type {
13 	__TRACE_FIRST_TYPE = 0,
14 
15 	TRACE_FN,
16 	TRACE_CTX,
17 	TRACE_WAKE,
18 	TRACE_CONT,
19 	TRACE_STACK,
20 	TRACE_PRINT,
21 	TRACE_SPECIAL,
22 	TRACE_MMIO_RW,
23 	TRACE_MMIO_MAP,
24 	TRACE_BOOT,
25 
26 	__TRACE_LAST_TYPE
27 };
28 
29 /*
30  * The trace entry - the most basic unit of tracing. This is what
31  * is printed in the end as a single line in the trace output, such as:
32  *
33  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
34  */
35 struct trace_entry {
36 	unsigned char		type;
37 	unsigned char		cpu;
38 	unsigned char		flags;
39 	unsigned char		preempt_count;
40 	int			pid;
41 };
42 
43 /*
44  * Function trace entry - function address and parent function addres:
45  */
46 struct ftrace_entry {
47 	struct trace_entry	ent;
48 	unsigned long		ip;
49 	unsigned long		parent_ip;
50 };
51 extern struct tracer boot_tracer;
52 
53 /*
54  * Context switch trace entry - which task (and prio) we switched from/to:
55  */
56 struct ctx_switch_entry {
57 	struct trace_entry	ent;
58 	unsigned int		prev_pid;
59 	unsigned char		prev_prio;
60 	unsigned char		prev_state;
61 	unsigned int		next_pid;
62 	unsigned char		next_prio;
63 	unsigned char		next_state;
64 	unsigned int		next_cpu;
65 };
66 
67 /*
68  * Special (free-form) trace entry:
69  */
70 struct special_entry {
71 	struct trace_entry	ent;
72 	unsigned long		arg1;
73 	unsigned long		arg2;
74 	unsigned long		arg3;
75 };
76 
77 /*
78  * Stack-trace entry:
79  */
80 
81 #define FTRACE_STACK_ENTRIES	8
82 
83 struct stack_entry {
84 	struct trace_entry	ent;
85 	unsigned long		caller[FTRACE_STACK_ENTRIES];
86 };
87 
88 /*
89  * ftrace_printk entry:
90  */
91 struct print_entry {
92 	struct trace_entry	ent;
93 	unsigned long		ip;
94 	char			buf[];
95 };
96 
97 #define TRACE_OLD_SIZE		88
98 
99 struct trace_field_cont {
100 	unsigned char		type;
101 	/* Temporary till we get rid of this completely */
102 	char			buf[TRACE_OLD_SIZE - 1];
103 };
104 
105 struct trace_mmiotrace_rw {
106 	struct trace_entry	ent;
107 	struct mmiotrace_rw	rw;
108 };
109 
110 struct trace_mmiotrace_map {
111 	struct trace_entry	ent;
112 	struct mmiotrace_map	map;
113 };
114 
115 struct trace_boot {
116 	struct trace_entry	ent;
117 	struct boot_trace	initcall;
118 };
119 
120 /*
121  * trace_flag_type is an enumeration that holds different
122  * states when a trace occurs. These are:
123  *  IRQS_OFF		- interrupts were disabled
124  *  IRQS_NOSUPPORT 	- arch does not support irqs_disabled_flags
125  *  NEED_RESCED		- reschedule is requested
126  *  HARDIRQ		- inside an interrupt handler
127  *  SOFTIRQ		- inside a softirq handler
128  *  CONT		- multiple entries hold the trace item
129  */
130 enum 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_CONT			= 0x20,
137 };
138 
139 #define TRACE_BUF_SIZE		1024
140 
141 /*
142  * The CPU trace array - it consists of thousands of trace entries
143  * plus some other descriptor data: (for example which task started
144  * the trace, etc.)
145  */
146 struct trace_array_cpu {
147 	atomic_t		disabled;
148 
149 	/* these fields get copied into max-trace: */
150 	unsigned long		trace_idx;
151 	unsigned long		overrun;
152 	unsigned long		saved_latency;
153 	unsigned long		critical_start;
154 	unsigned long		critical_end;
155 	unsigned long		critical_sequence;
156 	unsigned long		nice;
157 	unsigned long		policy;
158 	unsigned long		rt_priority;
159 	cycle_t			preempt_timestamp;
160 	pid_t			pid;
161 	uid_t			uid;
162 	char			comm[TASK_COMM_LEN];
163 };
164 
165 struct trace_iterator;
166 
167 /*
168  * The trace array - an array of per-CPU trace arrays. This is the
169  * highest level data structure that individual tracers deal with.
170  * They have on/off state as well:
171  */
172 struct trace_array {
173 	struct ring_buffer	*buffer;
174 	unsigned long		entries;
175 	long			ctrl;
176 	int			cpu;
177 	cycle_t			time_start;
178 	struct task_struct	*waiter;
179 	struct trace_array_cpu	*data[NR_CPUS];
180 };
181 
182 #define FTRACE_CMP_TYPE(var, type) \
183 	__builtin_types_compatible_p(typeof(var), type *)
184 
185 #undef IF_ASSIGN
186 #define IF_ASSIGN(var, entry, etype, id)		\
187 	if (FTRACE_CMP_TYPE(var, etype)) {		\
188 		var = (typeof(var))(entry);		\
189 		WARN_ON(id && (entry)->type != id);	\
190 		break;					\
191 	}
192 
193 /* Will cause compile errors if type is not found. */
194 extern void __ftrace_bad_type(void);
195 
196 /*
197  * The trace_assign_type is a verifier that the entry type is
198  * the same as the type being assigned. To add new types simply
199  * add a line with the following format:
200  *
201  * IF_ASSIGN(var, ent, type, id);
202  *
203  *  Where "type" is the trace type that includes the trace_entry
204  *  as the "ent" item. And "id" is the trace identifier that is
205  *  used in the trace_type enum.
206  *
207  *  If the type can have more than one id, then use zero.
208  */
209 #define trace_assign_type(var, ent)					\
210 	do {								\
211 		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
212 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
213 		IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
214 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
215 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
216 		IF_ASSIGN(var, ent, struct special_entry, 0);		\
217 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
218 			  TRACE_MMIO_RW);				\
219 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
220 			  TRACE_MMIO_MAP);				\
221 		IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT);	\
222 		__ftrace_bad_type();					\
223 	} while (0)
224 
225 /* Return values for print_line callback */
226 enum print_line_t {
227 	TRACE_TYPE_PARTIAL_LINE	= 0,	/* Retry after flushing the seq */
228 	TRACE_TYPE_HANDLED	= 1,
229 	TRACE_TYPE_UNHANDLED	= 2	/* Relay to other output functions */
230 };
231 
232 /*
233  * A specific tracer, represented by methods that operate on a trace array:
234  */
235 struct tracer {
236 	const char		*name;
237 	void			(*init)(struct trace_array *tr);
238 	void			(*reset)(struct trace_array *tr);
239 	void			(*open)(struct trace_iterator *iter);
240 	void			(*pipe_open)(struct trace_iterator *iter);
241 	void			(*close)(struct trace_iterator *iter);
242 	void			(*start)(struct trace_iterator *iter);
243 	void			(*stop)(struct trace_iterator *iter);
244 	ssize_t			(*read)(struct trace_iterator *iter,
245 					struct file *filp, char __user *ubuf,
246 					size_t cnt, loff_t *ppos);
247 	void			(*ctrl_update)(struct trace_array *tr);
248 #ifdef CONFIG_FTRACE_STARTUP_TEST
249 	int			(*selftest)(struct tracer *trace,
250 					    struct trace_array *tr);
251 #endif
252 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
253 	struct tracer		*next;
254 	int			print_max;
255 };
256 
257 struct trace_seq {
258 	unsigned char		buffer[PAGE_SIZE];
259 	unsigned int		len;
260 	unsigned int		readpos;
261 };
262 
263 /*
264  * Trace iterator - used by printout routines who present trace
265  * results to users and which routines might sleep, etc:
266  */
267 struct trace_iterator {
268 	struct trace_array	*tr;
269 	struct tracer		*trace;
270 	void			*private;
271 	struct ring_buffer_iter	*buffer_iter[NR_CPUS];
272 
273 	/* The below is zeroed out in pipe_read */
274 	struct trace_seq	seq;
275 	struct trace_entry	*ent;
276 	int			cpu;
277 	u64			ts;
278 
279 	unsigned long		iter_flags;
280 	loff_t			pos;
281 	long			idx;
282 };
283 
284 void trace_wake_up(void);
285 void tracing_reset(struct trace_array *tr, int cpu);
286 int tracing_open_generic(struct inode *inode, struct file *filp);
287 struct dentry *tracing_init_dentry(void);
288 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
289 
290 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
291 						struct trace_array_cpu *data);
292 void tracing_generic_entry_update(struct trace_entry *entry,
293 				  unsigned long flags,
294 				  int pc);
295 
296 void ftrace(struct trace_array *tr,
297 			    struct trace_array_cpu *data,
298 			    unsigned long ip,
299 			    unsigned long parent_ip,
300 			    unsigned long flags, int pc);
301 void tracing_sched_switch_trace(struct trace_array *tr,
302 				struct trace_array_cpu *data,
303 				struct task_struct *prev,
304 				struct task_struct *next,
305 				unsigned long flags, int pc);
306 void tracing_record_cmdline(struct task_struct *tsk);
307 
308 void tracing_sched_wakeup_trace(struct trace_array *tr,
309 				struct trace_array_cpu *data,
310 				struct task_struct *wakee,
311 				struct task_struct *cur,
312 				unsigned long flags, int pc);
313 void trace_special(struct trace_array *tr,
314 		   struct trace_array_cpu *data,
315 		   unsigned long arg1,
316 		   unsigned long arg2,
317 		   unsigned long arg3, int pc);
318 void trace_function(struct trace_array *tr,
319 		    struct trace_array_cpu *data,
320 		    unsigned long ip,
321 		    unsigned long parent_ip,
322 		    unsigned long flags, int pc);
323 
324 void tracing_start_cmdline_record(void);
325 void tracing_stop_cmdline_record(void);
326 int register_tracer(struct tracer *type);
327 void unregister_tracer(struct tracer *type);
328 
329 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
330 
331 extern unsigned long tracing_max_latency;
332 extern unsigned long tracing_thresh;
333 
334 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
335 void update_max_tr_single(struct trace_array *tr,
336 			  struct task_struct *tsk, int cpu);
337 
338 extern cycle_t ftrace_now(int cpu);
339 
340 #ifdef CONFIG_FUNCTION_TRACER
341 void tracing_start_function_trace(void);
342 void tracing_stop_function_trace(void);
343 #else
344 # define tracing_start_function_trace()		do { } while (0)
345 # define tracing_stop_function_trace()		do { } while (0)
346 #endif
347 
348 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
349 typedef void
350 (*tracer_switch_func_t)(void *private,
351 			void *__rq,
352 			struct task_struct *prev,
353 			struct task_struct *next);
354 
355 struct tracer_switch_ops {
356 	tracer_switch_func_t		func;
357 	void				*private;
358 	struct tracer_switch_ops	*next;
359 };
360 
361 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
362 
363 #ifdef CONFIG_DYNAMIC_FTRACE
364 extern unsigned long ftrace_update_tot_cnt;
365 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
366 extern int DYN_FTRACE_TEST_NAME(void);
367 #endif
368 
369 #ifdef CONFIG_FTRACE_STARTUP_TEST
370 extern int trace_selftest_startup_function(struct tracer *trace,
371 					   struct trace_array *tr);
372 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
373 					  struct trace_array *tr);
374 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
375 					     struct trace_array *tr);
376 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
377 						 struct trace_array *tr);
378 extern int trace_selftest_startup_wakeup(struct tracer *trace,
379 					 struct trace_array *tr);
380 extern int trace_selftest_startup_nop(struct tracer *trace,
381 					 struct trace_array *tr);
382 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
383 					       struct trace_array *tr);
384 extern int trace_selftest_startup_sysprof(struct tracer *trace,
385 					       struct trace_array *tr);
386 #endif /* CONFIG_FTRACE_STARTUP_TEST */
387 
388 extern void *head_page(struct trace_array_cpu *data);
389 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
390 extern void trace_seq_print_cont(struct trace_seq *s,
391 				 struct trace_iterator *iter);
392 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
393 				 size_t cnt);
394 extern long ns2usecs(cycle_t nsec);
395 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
396 
397 extern unsigned long trace_flags;
398 
399 /*
400  * trace_iterator_flags is an enumeration that defines bit
401  * positions into trace_flags that controls the output.
402  *
403  * NOTE: These bits must match the trace_options array in
404  *       trace.c.
405  */
406 enum trace_iterator_flags {
407 	TRACE_ITER_PRINT_PARENT		= 0x01,
408 	TRACE_ITER_SYM_OFFSET		= 0x02,
409 	TRACE_ITER_SYM_ADDR		= 0x04,
410 	TRACE_ITER_VERBOSE		= 0x08,
411 	TRACE_ITER_RAW			= 0x10,
412 	TRACE_ITER_HEX			= 0x20,
413 	TRACE_ITER_BIN			= 0x40,
414 	TRACE_ITER_BLOCK		= 0x80,
415 	TRACE_ITER_STACKTRACE		= 0x100,
416 	TRACE_ITER_SCHED_TREE		= 0x200,
417 	TRACE_ITER_PRINTK		= 0x400,
418 };
419 
420 extern struct tracer nop_trace;
421 
422 #endif /* _LINUX_KERNEL_TRACE_H */
423