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 void (*print_header)(struct seq_file *m);
315 enum print_line_t (*print_line)(struct trace_iterator *iter);
316 /* If you handled the flag setting, return 0 */
317 int (*set_flag)(u32 old_flags, u32 bit, int set);
320 struct tracer_flags *flags;
324 unsigned char buffer[PAGE_SIZE];
326 unsigned int readpos;
330 * Trace iterator - used by printout routines who present trace
331 * results to users and which routines might sleep, etc:
333 struct trace_iterator {
334 struct trace_array *tr;
335 struct tracer *trace;
337 struct ring_buffer_iter *buffer_iter[NR_CPUS];
339 /* The below is zeroed out in pipe_read */
340 struct trace_seq seq;
341 struct trace_entry *ent;
345 unsigned long iter_flags;
352 int tracing_is_enabled(void);
353 void trace_wake_up(void);
354 void tracing_reset(struct trace_array *tr, int cpu);
355 int tracing_open_generic(struct inode *inode, struct file *filp);
356 struct dentry *tracing_init_dentry(void);
357 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
359 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
360 struct trace_array_cpu *data);
361 void tracing_generic_entry_update(struct trace_entry *entry,
365 void ftrace(struct trace_array *tr,
366 struct trace_array_cpu *data,
368 unsigned long parent_ip,
369 unsigned long flags, int pc);
370 void tracing_sched_switch_trace(struct trace_array *tr,
371 struct trace_array_cpu *data,
372 struct task_struct *prev,
373 struct task_struct *next,
374 unsigned long flags, int pc);
375 void tracing_record_cmdline(struct task_struct *tsk);
377 void tracing_sched_wakeup_trace(struct trace_array *tr,
378 struct trace_array_cpu *data,
379 struct task_struct *wakee,
380 struct task_struct *cur,
381 unsigned long flags, int pc);
382 void trace_special(struct trace_array *tr,
383 struct trace_array_cpu *data,
386 unsigned long arg3, int pc);
387 void trace_function(struct trace_array *tr,
388 struct trace_array_cpu *data,
390 unsigned long parent_ip,
391 unsigned long flags, int pc);
393 trace_function_return(struct ftrace_retfunc *trace);
395 void tracing_start_cmdline_record(void);
396 void tracing_stop_cmdline_record(void);
397 void tracing_sched_switch_assign_trace(struct trace_array *tr);
398 void tracing_stop_sched_switch_record(void);
399 void tracing_start_sched_switch_record(void);
400 int register_tracer(struct tracer *type);
401 void unregister_tracer(struct tracer *type);
403 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
405 extern unsigned long tracing_max_latency;
406 extern unsigned long tracing_thresh;
408 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
409 void update_max_tr_single(struct trace_array *tr,
410 struct task_struct *tsk, int cpu);
412 extern cycle_t ftrace_now(int cpu);
414 #ifdef CONFIG_FUNCTION_TRACER
415 void tracing_start_function_trace(void);
416 void tracing_stop_function_trace(void);
418 # define tracing_start_function_trace() do { } while (0)
419 # define tracing_stop_function_trace() do { } while (0)
422 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
424 (*tracer_switch_func_t)(void *private,
426 struct task_struct *prev,
427 struct task_struct *next);
429 struct tracer_switch_ops {
430 tracer_switch_func_t func;
432 struct tracer_switch_ops *next;
435 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
437 #ifdef CONFIG_DYNAMIC_FTRACE
438 extern unsigned long ftrace_update_tot_cnt;
439 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
440 extern int DYN_FTRACE_TEST_NAME(void);
443 #ifdef CONFIG_FTRACE_STARTUP_TEST
444 extern int trace_selftest_startup_function(struct tracer *trace,
445 struct trace_array *tr);
446 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
447 struct trace_array *tr);
448 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
449 struct trace_array *tr);
450 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
451 struct trace_array *tr);
452 extern int trace_selftest_startup_wakeup(struct tracer *trace,
453 struct trace_array *tr);
454 extern int trace_selftest_startup_nop(struct tracer *trace,
455 struct trace_array *tr);
456 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
457 struct trace_array *tr);
458 extern int trace_selftest_startup_sysprof(struct tracer *trace,
459 struct trace_array *tr);
460 extern int trace_selftest_startup_branch(struct tracer *trace,
461 struct trace_array *tr);
462 #endif /* CONFIG_FTRACE_STARTUP_TEST */
464 extern void *head_page(struct trace_array_cpu *data);
465 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
466 extern void trace_seq_print_cont(struct trace_seq *s,
467 struct trace_iterator *iter);
470 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
471 unsigned long sym_flags);
472 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
474 extern long ns2usecs(cycle_t nsec);
475 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
477 extern unsigned long trace_flags;
479 /* Standard output formatting function used for function return traces */
480 #ifdef CONFIG_FUNCTION_RET_TRACER
481 extern enum print_line_t print_return_function(struct trace_iterator *iter);
483 static inline enum print_line_t
484 print_return_function(struct trace_iterator *iter)
486 return TRACE_TYPE_UNHANDLED;
491 * trace_iterator_flags is an enumeration that defines bit
492 * positions into trace_flags that controls the output.
494 * NOTE: These bits must match the trace_options array in
497 enum trace_iterator_flags {
498 TRACE_ITER_PRINT_PARENT = 0x01,
499 TRACE_ITER_SYM_OFFSET = 0x02,
500 TRACE_ITER_SYM_ADDR = 0x04,
501 TRACE_ITER_VERBOSE = 0x08,
502 TRACE_ITER_RAW = 0x10,
503 TRACE_ITER_HEX = 0x20,
504 TRACE_ITER_BIN = 0x40,
505 TRACE_ITER_BLOCK = 0x80,
506 TRACE_ITER_STACKTRACE = 0x100,
507 TRACE_ITER_SCHED_TREE = 0x200,
508 TRACE_ITER_PRINTK = 0x400,
509 TRACE_ITER_PREEMPTONLY = 0x800,
510 TRACE_ITER_BRANCH = 0x1000,
511 TRACE_ITER_ANNOTATE = 0x2000,
512 TRACE_ITER_USERSTACKTRACE = 0x4000,
513 TRACE_ITER_SYM_USEROBJ = 0x8000
517 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
518 * control the output of kernel symbols.
520 #define TRACE_ITER_SYM_MASK \
521 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
523 extern struct tracer nop_trace;
526 * ftrace_preempt_disable - disable preemption scheduler safe
528 * When tracing can happen inside the scheduler, there exists
529 * cases that the tracing might happen before the need_resched
530 * flag is checked. If this happens and the tracer calls
531 * preempt_enable (after a disable), a schedule might take place
532 * causing an infinite recursion.
534 * To prevent this, we read the need_recshed flag before
535 * disabling preemption. When we want to enable preemption we
536 * check the flag, if it is set, then we call preempt_enable_no_resched.
537 * Otherwise, we call preempt_enable.
539 * The rational for doing the above is that if need resched is set
540 * and we have yet to reschedule, we are either in an atomic location
541 * (where we do not need to check for scheduling) or we are inside
542 * the scheduler and do not want to resched.
544 static inline int ftrace_preempt_disable(void)
548 resched = need_resched();
549 preempt_disable_notrace();
555 * ftrace_preempt_enable - enable preemption scheduler safe
556 * @resched: the return value from ftrace_preempt_disable
558 * This is a scheduler safe way to enable preemption and not miss
559 * any preemption checks. The disabled saved the state of preemption.
560 * If resched is set, then we were either inside an atomic or
561 * are inside the scheduler (we would have already scheduled
562 * otherwise). In this case, we do not want to call normal
563 * preempt_enable, but preempt_enable_no_resched instead.
565 static inline void ftrace_preempt_enable(int resched)
568 preempt_enable_no_resched_notrace();
570 preempt_enable_notrace();
573 #ifdef CONFIG_BRANCH_TRACER
574 extern int enable_branch_tracing(struct trace_array *tr);
575 extern void disable_branch_tracing(void);
576 static inline int trace_branch_enable(struct trace_array *tr)
578 if (trace_flags & TRACE_ITER_BRANCH)
579 return enable_branch_tracing(tr);
582 static inline void trace_branch_disable(void)
584 /* due to races, always disable */
585 disable_branch_tracing();
588 static inline int trace_branch_enable(struct trace_array *tr)
592 static inline void trace_branch_disable(void)
595 #endif /* CONFIG_BRANCH_TRACER */
597 #endif /* _LINUX_KERNEL_TRACE_H */