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 */
263 * A specific tracer, represented by methods that operate on a trace array:
267 void (*init)(struct trace_array *tr);
268 void (*reset)(struct trace_array *tr);
269 void (*start)(struct trace_array *tr);
270 void (*stop)(struct trace_array *tr);
271 void (*open)(struct trace_iterator *iter);
272 void (*pipe_open)(struct trace_iterator *iter);
273 void (*close)(struct trace_iterator *iter);
274 ssize_t (*read)(struct trace_iterator *iter,
275 struct file *filp, char __user *ubuf,
276 size_t cnt, loff_t *ppos);
277 #ifdef CONFIG_FTRACE_STARTUP_TEST
278 int (*selftest)(struct tracer *trace,
279 struct trace_array *tr);
281 enum print_line_t (*print_line)(struct trace_iterator *iter);
287 unsigned char buffer[PAGE_SIZE];
289 unsigned int readpos;
293 * Trace iterator - used by printout routines who present trace
294 * results to users and which routines might sleep, etc:
296 struct trace_iterator {
297 struct trace_array *tr;
298 struct tracer *trace;
300 struct ring_buffer_iter *buffer_iter[NR_CPUS];
302 /* The below is zeroed out in pipe_read */
303 struct trace_seq seq;
304 struct trace_entry *ent;
308 unsigned long iter_flags;
315 int tracing_is_enabled(void);
316 void trace_wake_up(void);
317 void tracing_reset(struct trace_array *tr, int cpu);
318 int tracing_open_generic(struct inode *inode, struct file *filp);
319 struct dentry *tracing_init_dentry(void);
320 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
322 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
323 struct trace_array_cpu *data);
324 void tracing_generic_entry_update(struct trace_entry *entry,
328 void ftrace(struct trace_array *tr,
329 struct trace_array_cpu *data,
331 unsigned long parent_ip,
332 unsigned long flags, int pc);
333 void tracing_sched_switch_trace(struct trace_array *tr,
334 struct trace_array_cpu *data,
335 struct task_struct *prev,
336 struct task_struct *next,
337 unsigned long flags, int pc);
338 void tracing_record_cmdline(struct task_struct *tsk);
340 void tracing_sched_wakeup_trace(struct trace_array *tr,
341 struct trace_array_cpu *data,
342 struct task_struct *wakee,
343 struct task_struct *cur,
344 unsigned long flags, int pc);
345 void trace_special(struct trace_array *tr,
346 struct trace_array_cpu *data,
349 unsigned long arg3, int pc);
350 void trace_function(struct trace_array *tr,
351 struct trace_array_cpu *data,
353 unsigned long parent_ip,
354 unsigned long flags, int pc);
356 trace_function_return(struct ftrace_retfunc *trace);
358 void tracing_start_cmdline_record(void);
359 void tracing_stop_cmdline_record(void);
360 void tracing_sched_switch_assign_trace(struct trace_array *tr);
361 void tracing_stop_sched_switch_record(void);
362 void tracing_start_sched_switch_record(void);
363 int register_tracer(struct tracer *type);
364 void unregister_tracer(struct tracer *type);
366 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
368 extern unsigned long tracing_max_latency;
369 extern unsigned long tracing_thresh;
371 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
372 void update_max_tr_single(struct trace_array *tr,
373 struct task_struct *tsk, int cpu);
375 extern cycle_t ftrace_now(int cpu);
377 #ifdef CONFIG_FUNCTION_TRACER
378 void tracing_start_function_trace(void);
379 void tracing_stop_function_trace(void);
381 # define tracing_start_function_trace() do { } while (0)
382 # define tracing_stop_function_trace() do { } while (0)
385 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
387 (*tracer_switch_func_t)(void *private,
389 struct task_struct *prev,
390 struct task_struct *next);
392 struct tracer_switch_ops {
393 tracer_switch_func_t func;
395 struct tracer_switch_ops *next;
398 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
400 #ifdef CONFIG_DYNAMIC_FTRACE
401 extern unsigned long ftrace_update_tot_cnt;
402 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
403 extern int DYN_FTRACE_TEST_NAME(void);
406 #ifdef CONFIG_FTRACE_STARTUP_TEST
407 extern int trace_selftest_startup_function(struct tracer *trace,
408 struct trace_array *tr);
409 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
410 struct trace_array *tr);
411 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
412 struct trace_array *tr);
413 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
414 struct trace_array *tr);
415 extern int trace_selftest_startup_wakeup(struct tracer *trace,
416 struct trace_array *tr);
417 extern int trace_selftest_startup_nop(struct tracer *trace,
418 struct trace_array *tr);
419 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
420 struct trace_array *tr);
421 extern int trace_selftest_startup_sysprof(struct tracer *trace,
422 struct trace_array *tr);
423 extern int trace_selftest_startup_branch(struct tracer *trace,
424 struct trace_array *tr);
425 #endif /* CONFIG_FTRACE_STARTUP_TEST */
427 extern void *head_page(struct trace_array_cpu *data);
428 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
429 extern void trace_seq_print_cont(struct trace_seq *s,
430 struct trace_iterator *iter);
433 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
434 unsigned long sym_flags);
435 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
437 extern long ns2usecs(cycle_t nsec);
438 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
440 extern unsigned long trace_flags;
442 /* Standard output formatting function used for function return traces */
443 #ifdef CONFIG_FUNCTION_RET_TRACER
444 extern enum print_line_t print_return_function(struct trace_iterator *iter);
446 static inline enum print_line_t
447 print_return_function(struct trace_iterator *iter)
449 return TRACE_TYPE_UNHANDLED;
454 * trace_iterator_flags is an enumeration that defines bit
455 * positions into trace_flags that controls the output.
457 * NOTE: These bits must match the trace_options array in
460 enum trace_iterator_flags {
461 TRACE_ITER_PRINT_PARENT = 0x01,
462 TRACE_ITER_SYM_OFFSET = 0x02,
463 TRACE_ITER_SYM_ADDR = 0x04,
464 TRACE_ITER_VERBOSE = 0x08,
465 TRACE_ITER_RAW = 0x10,
466 TRACE_ITER_HEX = 0x20,
467 TRACE_ITER_BIN = 0x40,
468 TRACE_ITER_BLOCK = 0x80,
469 TRACE_ITER_STACKTRACE = 0x100,
470 TRACE_ITER_SCHED_TREE = 0x200,
471 TRACE_ITER_PRINTK = 0x400,
472 TRACE_ITER_PREEMPTONLY = 0x800,
473 TRACE_ITER_BRANCH = 0x1000,
474 TRACE_ITER_ANNOTATE = 0x2000,
478 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
479 * control the output of kernel symbols.
481 #define TRACE_ITER_SYM_MASK \
482 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
484 extern struct tracer nop_trace;
487 * ftrace_preempt_disable - disable preemption scheduler safe
489 * When tracing can happen inside the scheduler, there exists
490 * cases that the tracing might happen before the need_resched
491 * flag is checked. If this happens and the tracer calls
492 * preempt_enable (after a disable), a schedule might take place
493 * causing an infinite recursion.
495 * To prevent this, we read the need_recshed flag before
496 * disabling preemption. When we want to enable preemption we
497 * check the flag, if it is set, then we call preempt_enable_no_resched.
498 * Otherwise, we call preempt_enable.
500 * The rational for doing the above is that if need resched is set
501 * and we have yet to reschedule, we are either in an atomic location
502 * (where we do not need to check for scheduling) or we are inside
503 * the scheduler and do not want to resched.
505 static inline int ftrace_preempt_disable(void)
509 resched = need_resched();
510 preempt_disable_notrace();
516 * ftrace_preempt_enable - enable preemption scheduler safe
517 * @resched: the return value from ftrace_preempt_disable
519 * This is a scheduler safe way to enable preemption and not miss
520 * any preemption checks. The disabled saved the state of preemption.
521 * If resched is set, then we were either inside an atomic or
522 * are inside the scheduler (we would have already scheduled
523 * otherwise). In this case, we do not want to call normal
524 * preempt_enable, but preempt_enable_no_resched instead.
526 static inline void ftrace_preempt_enable(int resched)
529 preempt_enable_no_resched_notrace();
531 preempt_enable_notrace();
534 #ifdef CONFIG_BRANCH_TRACER
535 extern int enable_branch_tracing(struct trace_array *tr);
536 extern void disable_branch_tracing(void);
537 static inline int trace_branch_enable(struct trace_array *tr)
539 if (trace_flags & TRACE_ITER_BRANCH)
540 return enable_branch_tracing(tr);
543 static inline void trace_branch_disable(void)
545 /* due to races, always disable */
546 disable_branch_tracing();
549 static inline int trace_branch_enable(struct trace_array *tr)
553 static inline void trace_branch_disable(void)
556 #endif /* CONFIG_BRANCH_TRACER */
558 #endif /* _LINUX_KERNEL_TRACE_H */