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,
35 * The trace entry - the most basic unit of tracing. This is what
36 * is printed in the end as a single line in the trace output, such as:
38 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
44 unsigned char preempt_count;
50 * Function trace entry - function address and parent function addres:
53 struct trace_entry ent;
55 unsigned long parent_ip;
58 /* Function return entry */
59 struct ftrace_ret_entry {
60 struct trace_entry ent;
62 unsigned long parent_ip;
63 unsigned long long calltime;
64 unsigned long long rettime;
65 unsigned long overrun;
67 extern struct tracer boot_tracer;
70 * Context switch trace entry - which task (and prio) we switched from/to:
72 struct ctx_switch_entry {
73 struct trace_entry ent;
74 unsigned int prev_pid;
75 unsigned char prev_prio;
76 unsigned char prev_state;
77 unsigned int next_pid;
78 unsigned char next_prio;
79 unsigned char next_state;
80 unsigned int next_cpu;
84 * Special (free-form) trace entry:
86 struct special_entry {
87 struct trace_entry ent;
97 #define FTRACE_STACK_ENTRIES 8
100 struct trace_entry ent;
101 unsigned long caller[FTRACE_STACK_ENTRIES];
104 struct userstack_entry {
105 struct trace_entry ent;
106 unsigned long caller[FTRACE_STACK_ENTRIES];
110 * ftrace_printk entry:
113 struct trace_entry ent;
118 #define TRACE_OLD_SIZE 88
120 struct trace_field_cont {
122 /* Temporary till we get rid of this completely */
123 char buf[TRACE_OLD_SIZE - 1];
126 struct trace_mmiotrace_rw {
127 struct trace_entry ent;
128 struct mmiotrace_rw rw;
131 struct trace_mmiotrace_map {
132 struct trace_entry ent;
133 struct mmiotrace_map map;
136 struct trace_boot_call {
137 struct trace_entry ent;
138 struct boot_trace_call boot_call;
141 struct trace_boot_ret {
142 struct trace_entry ent;
143 struct boot_trace_ret boot_ret;
146 #define TRACE_FUNC_SIZE 30
147 #define TRACE_FILE_SIZE 20
148 struct trace_branch {
149 struct trace_entry ent;
151 char func[TRACE_FUNC_SIZE+1];
152 char file[TRACE_FILE_SIZE+1];
157 * trace_flag_type is an enumeration that holds different
158 * states when a trace occurs. These are:
159 * IRQS_OFF - interrupts were disabled
160 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
161 * NEED_RESCED - reschedule is requested
162 * HARDIRQ - inside an interrupt handler
163 * SOFTIRQ - inside a softirq handler
164 * CONT - multiple entries hold the trace item
166 enum trace_flag_type {
167 TRACE_FLAG_IRQS_OFF = 0x01,
168 TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
169 TRACE_FLAG_NEED_RESCHED = 0x04,
170 TRACE_FLAG_HARDIRQ = 0x08,
171 TRACE_FLAG_SOFTIRQ = 0x10,
172 TRACE_FLAG_CONT = 0x20,
175 #define TRACE_BUF_SIZE 1024
178 * The CPU trace array - it consists of thousands of trace entries
179 * plus some other descriptor data: (for example which task started
182 struct trace_array_cpu {
185 /* these fields get copied into max-trace: */
186 unsigned long trace_idx;
187 unsigned long overrun;
188 unsigned long saved_latency;
189 unsigned long critical_start;
190 unsigned long critical_end;
191 unsigned long critical_sequence;
193 unsigned long policy;
194 unsigned long rt_priority;
195 cycle_t preempt_timestamp;
198 char comm[TASK_COMM_LEN];
201 struct trace_iterator;
204 * The trace array - an array of per-CPU trace arrays. This is the
205 * highest level data structure that individual tracers deal with.
206 * They have on/off state as well:
209 struct ring_buffer *buffer;
210 unsigned long entries;
213 struct task_struct *waiter;
214 struct trace_array_cpu *data[NR_CPUS];
217 #define FTRACE_CMP_TYPE(var, type) \
218 __builtin_types_compatible_p(typeof(var), type *)
221 #define IF_ASSIGN(var, entry, etype, id) \
222 if (FTRACE_CMP_TYPE(var, etype)) { \
223 var = (typeof(var))(entry); \
224 WARN_ON(id && (entry)->type != id); \
228 /* Will cause compile errors if type is not found. */
229 extern void __ftrace_bad_type(void);
232 * The trace_assign_type is a verifier that the entry type is
233 * the same as the type being assigned. To add new types simply
234 * add a line with the following format:
236 * IF_ASSIGN(var, ent, type, id);
238 * Where "type" is the trace type that includes the trace_entry
239 * as the "ent" item. And "id" is the trace identifier that is
240 * used in the trace_type enum.
242 * If the type can have more than one id, then use zero.
244 #define trace_assign_type(var, ent) \
246 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
247 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
248 IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
249 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
250 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
251 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
252 IF_ASSIGN(var, ent, struct special_entry, 0); \
253 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
255 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
257 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
258 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
259 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
260 IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
261 __ftrace_bad_type(); \
264 /* Return values for print_line callback */
266 TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
267 TRACE_TYPE_HANDLED = 1,
268 TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
273 * An option specific to a tracer. This is a boolean value.
274 * The bit is the bit index that sets its value on the
275 * flags value in struct tracer_flags.
278 const char *name; /* Will appear on the trace_options file */
279 u32 bit; /* Mask assigned in val field in tracer_flags */
283 * The set of specific options for a tracer. Your tracer
284 * have to set the initial value of the flags val.
286 struct tracer_flags {
288 struct tracer_opt *opts;
291 /* Makes more easy to define a tracer opt */
292 #define TRACER_OPT(s, b) .name = #s, .bit = b
295 * A specific tracer, represented by methods that operate on a trace array:
299 /* Your tracer should raise a warning if init fails */
300 int (*init)(struct trace_array *tr);
301 void (*reset)(struct trace_array *tr);
302 void (*start)(struct trace_array *tr);
303 void (*stop)(struct trace_array *tr);
304 void (*open)(struct trace_iterator *iter);
305 void (*pipe_open)(struct trace_iterator *iter);
306 void (*close)(struct trace_iterator *iter);
307 ssize_t (*read)(struct trace_iterator *iter,
308 struct file *filp, char __user *ubuf,
309 size_t cnt, loff_t *ppos);
310 #ifdef CONFIG_FTRACE_STARTUP_TEST
311 int (*selftest)(struct tracer *trace,
312 struct trace_array *tr);
314 enum print_line_t (*print_line)(struct trace_iterator *iter);
315 /* If you handled the flag setting, return 0 */
316 int (*set_flag)(u32 old_flags, u32 bit, int set);
319 struct tracer_flags *flags;
323 unsigned char buffer[PAGE_SIZE];
325 unsigned int readpos;
329 * Trace iterator - used by printout routines who present trace
330 * results to users and which routines might sleep, etc:
332 struct trace_iterator {
333 struct trace_array *tr;
334 struct tracer *trace;
336 struct ring_buffer_iter *buffer_iter[NR_CPUS];
338 /* The below is zeroed out in pipe_read */
339 struct trace_seq seq;
340 struct trace_entry *ent;
344 unsigned long iter_flags;
351 int tracing_is_enabled(void);
352 void trace_wake_up(void);
353 void tracing_reset(struct trace_array *tr, int cpu);
354 int tracing_open_generic(struct inode *inode, struct file *filp);
355 struct dentry *tracing_init_dentry(void);
356 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
358 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
359 struct trace_array_cpu *data);
360 void tracing_generic_entry_update(struct trace_entry *entry,
364 void ftrace(struct trace_array *tr,
365 struct trace_array_cpu *data,
367 unsigned long parent_ip,
368 unsigned long flags, int pc);
369 void tracing_sched_switch_trace(struct trace_array *tr,
370 struct trace_array_cpu *data,
371 struct task_struct *prev,
372 struct task_struct *next,
373 unsigned long flags, int pc);
374 void tracing_record_cmdline(struct task_struct *tsk);
376 void tracing_sched_wakeup_trace(struct trace_array *tr,
377 struct trace_array_cpu *data,
378 struct task_struct *wakee,
379 struct task_struct *cur,
380 unsigned long flags, int pc);
381 void trace_special(struct trace_array *tr,
382 struct trace_array_cpu *data,
385 unsigned long arg3, int pc);
386 void trace_function(struct trace_array *tr,
387 struct trace_array_cpu *data,
389 unsigned long parent_ip,
390 unsigned long flags, int pc);
392 trace_function_return(struct ftrace_retfunc *trace);
394 void tracing_start_cmdline_record(void);
395 void tracing_stop_cmdline_record(void);
396 void tracing_sched_switch_assign_trace(struct trace_array *tr);
397 void tracing_stop_sched_switch_record(void);
398 void tracing_start_sched_switch_record(void);
399 int register_tracer(struct tracer *type);
400 void unregister_tracer(struct tracer *type);
402 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
404 extern unsigned long tracing_max_latency;
405 extern unsigned long tracing_thresh;
407 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
408 void update_max_tr_single(struct trace_array *tr,
409 struct task_struct *tsk, int cpu);
411 extern cycle_t ftrace_now(int cpu);
413 #ifdef CONFIG_FUNCTION_TRACER
414 void tracing_start_function_trace(void);
415 void tracing_stop_function_trace(void);
417 # define tracing_start_function_trace() do { } while (0)
418 # define tracing_stop_function_trace() do { } while (0)
421 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
423 (*tracer_switch_func_t)(void *private,
425 struct task_struct *prev,
426 struct task_struct *next);
428 struct tracer_switch_ops {
429 tracer_switch_func_t func;
431 struct tracer_switch_ops *next;
434 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
436 #ifdef CONFIG_DYNAMIC_FTRACE
437 extern unsigned long ftrace_update_tot_cnt;
438 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
439 extern int DYN_FTRACE_TEST_NAME(void);
442 #ifdef CONFIG_FTRACE_STARTUP_TEST
443 extern int trace_selftest_startup_function(struct tracer *trace,
444 struct trace_array *tr);
445 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
446 struct trace_array *tr);
447 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
448 struct trace_array *tr);
449 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
450 struct trace_array *tr);
451 extern int trace_selftest_startup_wakeup(struct tracer *trace,
452 struct trace_array *tr);
453 extern int trace_selftest_startup_nop(struct tracer *trace,
454 struct trace_array *tr);
455 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
456 struct trace_array *tr);
457 extern int trace_selftest_startup_sysprof(struct tracer *trace,
458 struct trace_array *tr);
459 extern int trace_selftest_startup_branch(struct tracer *trace,
460 struct trace_array *tr);
461 #endif /* CONFIG_FTRACE_STARTUP_TEST */
463 extern void *head_page(struct trace_array_cpu *data);
464 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
465 extern void trace_seq_print_cont(struct trace_seq *s,
466 struct trace_iterator *iter);
469 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
470 unsigned long sym_flags);
471 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
473 extern long ns2usecs(cycle_t nsec);
474 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
476 extern unsigned long trace_flags;
478 /* Standard output formatting function used for function return traces */
479 #ifdef CONFIG_FUNCTION_RET_TRACER
480 extern enum print_line_t print_return_function(struct trace_iterator *iter);
482 static inline enum print_line_t
483 print_return_function(struct trace_iterator *iter)
485 return TRACE_TYPE_UNHANDLED;
490 * trace_iterator_flags is an enumeration that defines bit
491 * positions into trace_flags that controls the output.
493 * NOTE: These bits must match the trace_options array in
496 enum trace_iterator_flags {
497 TRACE_ITER_PRINT_PARENT = 0x01,
498 TRACE_ITER_SYM_OFFSET = 0x02,
499 TRACE_ITER_SYM_ADDR = 0x04,
500 TRACE_ITER_VERBOSE = 0x08,
501 TRACE_ITER_RAW = 0x10,
502 TRACE_ITER_HEX = 0x20,
503 TRACE_ITER_BIN = 0x40,
504 TRACE_ITER_BLOCK = 0x80,
505 TRACE_ITER_STACKTRACE = 0x100,
506 TRACE_ITER_SCHED_TREE = 0x200,
507 TRACE_ITER_PRINTK = 0x400,
508 TRACE_ITER_PREEMPTONLY = 0x800,
509 TRACE_ITER_BRANCH = 0x1000,
510 TRACE_ITER_ANNOTATE = 0x2000,
511 TRACE_ITER_USERSTACKTRACE = 0x4000,
512 TRACE_ITER_SYM_USEROBJ = 0x8000
516 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
517 * control the output of kernel symbols.
519 #define TRACE_ITER_SYM_MASK \
520 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
522 extern struct tracer nop_trace;
525 * ftrace_preempt_disable - disable preemption scheduler safe
527 * When tracing can happen inside the scheduler, there exists
528 * cases that the tracing might happen before the need_resched
529 * flag is checked. If this happens and the tracer calls
530 * preempt_enable (after a disable), a schedule might take place
531 * causing an infinite recursion.
533 * To prevent this, we read the need_recshed flag before
534 * disabling preemption. When we want to enable preemption we
535 * check the flag, if it is set, then we call preempt_enable_no_resched.
536 * Otherwise, we call preempt_enable.
538 * The rational for doing the above is that if need resched is set
539 * and we have yet to reschedule, we are either in an atomic location
540 * (where we do not need to check for scheduling) or we are inside
541 * the scheduler and do not want to resched.
543 static inline int ftrace_preempt_disable(void)
547 resched = need_resched();
548 preempt_disable_notrace();
554 * ftrace_preempt_enable - enable preemption scheduler safe
555 * @resched: the return value from ftrace_preempt_disable
557 * This is a scheduler safe way to enable preemption and not miss
558 * any preemption checks. The disabled saved the state of preemption.
559 * If resched is set, then we were either inside an atomic or
560 * are inside the scheduler (we would have already scheduled
561 * otherwise). In this case, we do not want to call normal
562 * preempt_enable, but preempt_enable_no_resched instead.
564 static inline void ftrace_preempt_enable(int resched)
567 preempt_enable_no_resched_notrace();
569 preempt_enable_notrace();
572 #ifdef CONFIG_BRANCH_TRACER
573 extern int enable_branch_tracing(struct trace_array *tr);
574 extern void disable_branch_tracing(void);
575 static inline int trace_branch_enable(struct trace_array *tr)
577 if (trace_flags & TRACE_ITER_BRANCH)
578 return enable_branch_tracing(tr);
581 static inline void trace_branch_disable(void)
583 /* due to races, always disable */
584 disable_branch_tracing();
587 static inline int trace_branch_enable(struct trace_array *tr)
591 static inline void trace_branch_disable(void)
594 #endif /* CONFIG_BRANCH_TRACER */
596 #endif /* _LINUX_KERNEL_TRACE_H */