1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_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 #include <trace/boot.h>
14 __TRACE_FIRST_TYPE = 0,
34 * The trace entry - the most basic unit of tracing. This is what
35 * is printed in the end as a single line in the trace output, such as:
37 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
43 unsigned char preempt_count;
48 * Function trace entry - function address and parent function addres:
51 struct trace_entry ent;
53 unsigned long parent_ip;
56 /* Function return entry */
57 struct ftrace_ret_entry {
58 struct trace_entry ent;
60 unsigned long parent_ip;
61 unsigned long long calltime;
62 unsigned long long rettime;
64 extern struct tracer boot_tracer;
67 * Context switch trace entry - which task (and prio) we switched from/to:
69 struct ctx_switch_entry {
70 struct trace_entry ent;
71 unsigned int prev_pid;
72 unsigned char prev_prio;
73 unsigned char prev_state;
74 unsigned int next_pid;
75 unsigned char next_prio;
76 unsigned char next_state;
77 unsigned int next_cpu;
81 * Special (free-form) trace entry:
83 struct special_entry {
84 struct trace_entry ent;
94 #define FTRACE_STACK_ENTRIES 8
97 struct trace_entry ent;
98 unsigned long caller[FTRACE_STACK_ENTRIES];
102 * ftrace_printk entry:
105 struct trace_entry ent;
110 #define TRACE_OLD_SIZE 88
112 struct trace_field_cont {
114 /* Temporary till we get rid of this completely */
115 char buf[TRACE_OLD_SIZE - 1];
118 struct trace_mmiotrace_rw {
119 struct trace_entry ent;
120 struct mmiotrace_rw rw;
123 struct trace_mmiotrace_map {
124 struct trace_entry ent;
125 struct mmiotrace_map map;
128 struct trace_boot_call {
129 struct trace_entry ent;
130 struct boot_trace_call boot_call;
133 struct trace_boot_ret {
134 struct trace_entry ent;
135 struct boot_trace_ret boot_ret;
138 #define TRACE_FUNC_SIZE 30
139 #define TRACE_FILE_SIZE 20
140 struct trace_branch {
141 struct trace_entry ent;
143 char func[TRACE_FUNC_SIZE+1];
144 char file[TRACE_FILE_SIZE+1];
149 * trace_flag_type is an enumeration that holds different
150 * states when a trace occurs. These are:
151 * IRQS_OFF - interrupts were disabled
152 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
153 * NEED_RESCED - reschedule is requested
154 * HARDIRQ - inside an interrupt handler
155 * SOFTIRQ - inside a softirq handler
156 * CONT - multiple entries hold the trace item
158 enum trace_flag_type {
159 TRACE_FLAG_IRQS_OFF = 0x01,
160 TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
161 TRACE_FLAG_NEED_RESCHED = 0x04,
162 TRACE_FLAG_HARDIRQ = 0x08,
163 TRACE_FLAG_SOFTIRQ = 0x10,
164 TRACE_FLAG_CONT = 0x20,
167 #define TRACE_BUF_SIZE 1024
170 * The CPU trace array - it consists of thousands of trace entries
171 * plus some other descriptor data: (for example which task started
174 struct trace_array_cpu {
177 /* these fields get copied into max-trace: */
178 unsigned long trace_idx;
179 unsigned long overrun;
180 unsigned long saved_latency;
181 unsigned long critical_start;
182 unsigned long critical_end;
183 unsigned long critical_sequence;
185 unsigned long policy;
186 unsigned long rt_priority;
187 cycle_t preempt_timestamp;
190 char comm[TASK_COMM_LEN];
193 struct trace_iterator;
196 * The trace array - an array of per-CPU trace arrays. This is the
197 * highest level data structure that individual tracers deal with.
198 * They have on/off state as well:
201 struct ring_buffer *buffer;
202 unsigned long entries;
205 struct task_struct *waiter;
206 struct trace_array_cpu *data[NR_CPUS];
209 #define FTRACE_CMP_TYPE(var, type) \
210 __builtin_types_compatible_p(typeof(var), type *)
213 #define IF_ASSIGN(var, entry, etype, id) \
214 if (FTRACE_CMP_TYPE(var, etype)) { \
215 var = (typeof(var))(entry); \
216 WARN_ON(id && (entry)->type != id); \
220 /* Will cause compile errors if type is not found. */
221 extern void __ftrace_bad_type(void);
224 * The trace_assign_type is a verifier that the entry type is
225 * the same as the type being assigned. To add new types simply
226 * add a line with the following format:
228 * IF_ASSIGN(var, ent, type, id);
230 * Where "type" is the trace type that includes the trace_entry
231 * as the "ent" item. And "id" is the trace identifier that is
232 * used in the trace_type enum.
234 * If the type can have more than one id, then use zero.
236 #define trace_assign_type(var, ent) \
238 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
239 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
240 IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
241 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
242 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
243 IF_ASSIGN(var, ent, struct special_entry, 0); \
244 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
246 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
248 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
249 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
250 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
251 IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
252 __ftrace_bad_type(); \
255 /* Return values for print_line callback */
257 TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
258 TRACE_TYPE_HANDLED = 1,
259 TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
264 * An option specific to a tracer. This is a boolean value.
265 * The bit is the bit index that sets its value on the
266 * flags value in struct tracer_flags.
269 const char *name; /* Will appear on the trace_options file */
270 u32 bit; /* Mask assigned in val field in tracer_flags */
274 * The set of specific options for a tracer. Your tracer
275 * have to set the initial value of the flags val.
277 struct tracer_flags {
279 struct tracer_opt *opts;
282 /* Makes more easy to define a tracer opt */
283 #define TRACER_OPT(s, b) .name = #s, .bit = b
286 * A specific tracer, represented by methods that operate on a trace array:
290 /* Your tracer should raise a warning if init fails */
291 int (*init)(struct trace_array *tr);
292 void (*reset)(struct trace_array *tr);
293 void (*start)(struct trace_array *tr);
294 void (*stop)(struct trace_array *tr);
295 void (*open)(struct trace_iterator *iter);
296 void (*pipe_open)(struct trace_iterator *iter);
297 void (*close)(struct trace_iterator *iter);
298 ssize_t (*read)(struct trace_iterator *iter,
299 struct file *filp, char __user *ubuf,
300 size_t cnt, loff_t *ppos);
301 #ifdef CONFIG_FTRACE_STARTUP_TEST
302 int (*selftest)(struct tracer *trace,
303 struct trace_array *tr);
305 enum print_line_t (*print_line)(struct trace_iterator *iter);
306 /* If you handled the flag setting, return 0 */
307 int (*set_flag)(u32 old_flags, u32 bit, int set);
310 struct tracer_flags *flags;
314 unsigned char buffer[PAGE_SIZE];
316 unsigned int readpos;
320 * Trace iterator - used by printout routines who present trace
321 * results to users and which routines might sleep, etc:
323 struct trace_iterator {
324 struct trace_array *tr;
325 struct tracer *trace;
327 struct ring_buffer_iter *buffer_iter[NR_CPUS];
329 /* The below is zeroed out in pipe_read */
330 struct trace_seq seq;
331 struct trace_entry *ent;
335 unsigned long iter_flags;
342 int tracing_is_enabled(void);
343 void trace_wake_up(void);
344 void tracing_reset(struct trace_array *tr, int cpu);
345 int tracing_open_generic(struct inode *inode, struct file *filp);
346 struct dentry *tracing_init_dentry(void);
347 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
349 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
350 struct trace_array_cpu *data);
351 void tracing_generic_entry_update(struct trace_entry *entry,
355 void ftrace(struct trace_array *tr,
356 struct trace_array_cpu *data,
358 unsigned long parent_ip,
359 unsigned long flags, int pc);
360 void tracing_sched_switch_trace(struct trace_array *tr,
361 struct trace_array_cpu *data,
362 struct task_struct *prev,
363 struct task_struct *next,
364 unsigned long flags, int pc);
365 void tracing_record_cmdline(struct task_struct *tsk);
367 void tracing_sched_wakeup_trace(struct trace_array *tr,
368 struct trace_array_cpu *data,
369 struct task_struct *wakee,
370 struct task_struct *cur,
371 unsigned long flags, int pc);
372 void trace_special(struct trace_array *tr,
373 struct trace_array_cpu *data,
376 unsigned long arg3, int pc);
377 void trace_function(struct trace_array *tr,
378 struct trace_array_cpu *data,
380 unsigned long parent_ip,
381 unsigned long flags, int pc);
383 trace_function_return(struct ftrace_retfunc *trace);
385 void tracing_start_cmdline_record(void);
386 void tracing_stop_cmdline_record(void);
387 void tracing_sched_switch_assign_trace(struct trace_array *tr);
388 void tracing_stop_sched_switch_record(void);
389 void tracing_start_sched_switch_record(void);
390 int register_tracer(struct tracer *type);
391 void unregister_tracer(struct tracer *type);
393 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
395 extern unsigned long tracing_max_latency;
396 extern unsigned long tracing_thresh;
398 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
399 void update_max_tr_single(struct trace_array *tr,
400 struct task_struct *tsk, int cpu);
402 extern cycle_t ftrace_now(int cpu);
404 #ifdef CONFIG_FUNCTION_TRACER
405 void tracing_start_function_trace(void);
406 void tracing_stop_function_trace(void);
408 # define tracing_start_function_trace() do { } while (0)
409 # define tracing_stop_function_trace() do { } while (0)
412 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
414 (*tracer_switch_func_t)(void *private,
416 struct task_struct *prev,
417 struct task_struct *next);
419 struct tracer_switch_ops {
420 tracer_switch_func_t func;
422 struct tracer_switch_ops *next;
425 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
427 #ifdef CONFIG_DYNAMIC_FTRACE
428 extern unsigned long ftrace_update_tot_cnt;
429 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
430 extern int DYN_FTRACE_TEST_NAME(void);
433 #ifdef CONFIG_FTRACE_STARTUP_TEST
434 extern int trace_selftest_startup_function(struct tracer *trace,
435 struct trace_array *tr);
436 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
437 struct trace_array *tr);
438 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
439 struct trace_array *tr);
440 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
441 struct trace_array *tr);
442 extern int trace_selftest_startup_wakeup(struct tracer *trace,
443 struct trace_array *tr);
444 extern int trace_selftest_startup_nop(struct tracer *trace,
445 struct trace_array *tr);
446 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
447 struct trace_array *tr);
448 extern int trace_selftest_startup_sysprof(struct tracer *trace,
449 struct trace_array *tr);
450 extern int trace_selftest_startup_branch(struct tracer *trace,
451 struct trace_array *tr);
452 #endif /* CONFIG_FTRACE_STARTUP_TEST */
454 extern void *head_page(struct trace_array_cpu *data);
455 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
456 extern void trace_seq_print_cont(struct trace_seq *s,
457 struct trace_iterator *iter);
460 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
461 unsigned long sym_flags);
462 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
464 extern long ns2usecs(cycle_t nsec);
465 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
467 extern unsigned long trace_flags;
469 /* Standard output formatting function used for function return traces */
470 #ifdef CONFIG_FUNCTION_RET_TRACER
471 extern enum print_line_t print_return_function(struct trace_iterator *iter);
473 static inline enum print_line_t
474 print_return_function(struct trace_iterator *iter)
476 return TRACE_TYPE_UNHANDLED;
481 * trace_iterator_flags is an enumeration that defines bit
482 * positions into trace_flags that controls the output.
484 * NOTE: These bits must match the trace_options array in
487 enum trace_iterator_flags {
488 TRACE_ITER_PRINT_PARENT = 0x01,
489 TRACE_ITER_SYM_OFFSET = 0x02,
490 TRACE_ITER_SYM_ADDR = 0x04,
491 TRACE_ITER_VERBOSE = 0x08,
492 TRACE_ITER_RAW = 0x10,
493 TRACE_ITER_HEX = 0x20,
494 TRACE_ITER_BIN = 0x40,
495 TRACE_ITER_BLOCK = 0x80,
496 TRACE_ITER_STACKTRACE = 0x100,
497 TRACE_ITER_SCHED_TREE = 0x200,
498 TRACE_ITER_PRINTK = 0x400,
499 TRACE_ITER_PREEMPTONLY = 0x800,
500 TRACE_ITER_BRANCH = 0x1000,
501 TRACE_ITER_ANNOTATE = 0x2000,
505 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
506 * control the output of kernel symbols.
508 #define TRACE_ITER_SYM_MASK \
509 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
511 extern struct tracer nop_trace;
514 * ftrace_preempt_disable - disable preemption scheduler safe
516 * When tracing can happen inside the scheduler, there exists
517 * cases that the tracing might happen before the need_resched
518 * flag is checked. If this happens and the tracer calls
519 * preempt_enable (after a disable), a schedule might take place
520 * causing an infinite recursion.
522 * To prevent this, we read the need_recshed flag before
523 * disabling preemption. When we want to enable preemption we
524 * check the flag, if it is set, then we call preempt_enable_no_resched.
525 * Otherwise, we call preempt_enable.
527 * The rational for doing the above is that if need resched is set
528 * and we have yet to reschedule, we are either in an atomic location
529 * (where we do not need to check for scheduling) or we are inside
530 * the scheduler and do not want to resched.
532 static inline int ftrace_preempt_disable(void)
536 resched = need_resched();
537 preempt_disable_notrace();
543 * ftrace_preempt_enable - enable preemption scheduler safe
544 * @resched: the return value from ftrace_preempt_disable
546 * This is a scheduler safe way to enable preemption and not miss
547 * any preemption checks. The disabled saved the state of preemption.
548 * If resched is set, then we were either inside an atomic or
549 * are inside the scheduler (we would have already scheduled
550 * otherwise). In this case, we do not want to call normal
551 * preempt_enable, but preempt_enable_no_resched instead.
553 static inline void ftrace_preempt_enable(int resched)
556 preempt_enable_no_resched_notrace();
558 preempt_enable_notrace();
561 #ifdef CONFIG_BRANCH_TRACER
562 extern int enable_branch_tracing(struct trace_array *tr);
563 extern void disable_branch_tracing(void);
564 static inline int trace_branch_enable(struct trace_array *tr)
566 if (trace_flags & TRACE_ITER_BRANCH)
567 return enable_branch_tracing(tr);
570 static inline void trace_branch_disable(void)
572 /* due to races, always disable */
573 disable_branch_tracing();
576 static inline int trace_branch_enable(struct trace_array *tr)
580 static inline void trace_branch_disable(void)
583 #endif /* CONFIG_BRANCH_TRACER */
585 #endif /* _LINUX_KERNEL_TRACE_H */