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;
63 unsigned long overrun;
65 extern struct tracer boot_tracer;
68 * Context switch trace entry - which task (and prio) we switched from/to:
70 struct ctx_switch_entry {
71 struct trace_entry ent;
72 unsigned int prev_pid;
73 unsigned char prev_prio;
74 unsigned char prev_state;
75 unsigned int next_pid;
76 unsigned char next_prio;
77 unsigned char next_state;
78 unsigned int next_cpu;
82 * Special (free-form) trace entry:
84 struct special_entry {
85 struct trace_entry ent;
95 #define FTRACE_STACK_ENTRIES 8
98 struct trace_entry ent;
99 unsigned long caller[FTRACE_STACK_ENTRIES];
103 * ftrace_printk entry:
106 struct trace_entry ent;
111 #define TRACE_OLD_SIZE 88
113 struct trace_field_cont {
115 /* Temporary till we get rid of this completely */
116 char buf[TRACE_OLD_SIZE - 1];
119 struct trace_mmiotrace_rw {
120 struct trace_entry ent;
121 struct mmiotrace_rw rw;
124 struct trace_mmiotrace_map {
125 struct trace_entry ent;
126 struct mmiotrace_map map;
129 struct trace_boot_call {
130 struct trace_entry ent;
131 struct boot_trace_call boot_call;
134 struct trace_boot_ret {
135 struct trace_entry ent;
136 struct boot_trace_ret boot_ret;
139 #define TRACE_FUNC_SIZE 30
140 #define TRACE_FILE_SIZE 20
141 struct trace_branch {
142 struct trace_entry ent;
144 char func[TRACE_FUNC_SIZE+1];
145 char file[TRACE_FILE_SIZE+1];
150 * trace_flag_type is an enumeration that holds different
151 * states when a trace occurs. These are:
152 * IRQS_OFF - interrupts were disabled
153 * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
154 * NEED_RESCED - reschedule is requested
155 * HARDIRQ - inside an interrupt handler
156 * SOFTIRQ - inside a softirq handler
157 * CONT - multiple entries hold the trace item
159 enum trace_flag_type {
160 TRACE_FLAG_IRQS_OFF = 0x01,
161 TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
162 TRACE_FLAG_NEED_RESCHED = 0x04,
163 TRACE_FLAG_HARDIRQ = 0x08,
164 TRACE_FLAG_SOFTIRQ = 0x10,
165 TRACE_FLAG_CONT = 0x20,
168 #define TRACE_BUF_SIZE 1024
171 * The CPU trace array - it consists of thousands of trace entries
172 * plus some other descriptor data: (for example which task started
175 struct trace_array_cpu {
178 /* these fields get copied into max-trace: */
179 unsigned long trace_idx;
180 unsigned long overrun;
181 unsigned long saved_latency;
182 unsigned long critical_start;
183 unsigned long critical_end;
184 unsigned long critical_sequence;
186 unsigned long policy;
187 unsigned long rt_priority;
188 cycle_t preempt_timestamp;
191 char comm[TASK_COMM_LEN];
194 struct trace_iterator;
197 * The trace array - an array of per-CPU trace arrays. This is the
198 * highest level data structure that individual tracers deal with.
199 * They have on/off state as well:
202 struct ring_buffer *buffer;
203 unsigned long entries;
206 struct task_struct *waiter;
207 struct trace_array_cpu *data[NR_CPUS];
210 #define FTRACE_CMP_TYPE(var, type) \
211 __builtin_types_compatible_p(typeof(var), type *)
214 #define IF_ASSIGN(var, entry, etype, id) \
215 if (FTRACE_CMP_TYPE(var, etype)) { \
216 var = (typeof(var))(entry); \
217 WARN_ON(id && (entry)->type != id); \
221 /* Will cause compile errors if type is not found. */
222 extern void __ftrace_bad_type(void);
225 * The trace_assign_type is a verifier that the entry type is
226 * the same as the type being assigned. To add new types simply
227 * add a line with the following format:
229 * IF_ASSIGN(var, ent, type, id);
231 * Where "type" is the trace type that includes the trace_entry
232 * as the "ent" item. And "id" is the trace identifier that is
233 * used in the trace_type enum.
235 * If the type can have more than one id, then use zero.
237 #define trace_assign_type(var, ent) \
239 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
240 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
241 IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
242 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
243 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
244 IF_ASSIGN(var, ent, struct special_entry, 0); \
245 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
247 IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
249 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
250 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
251 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
252 IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
253 __ftrace_bad_type(); \
256 /* Return values for print_line callback */
258 TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
259 TRACE_TYPE_HANDLED = 1,
260 TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
265 * An option specific to a tracer. This is a boolean value.
266 * The bit is the bit index that sets its value on the
267 * flags value in struct tracer_flags.
270 const char *name; /* Will appear on the trace_options file */
271 u32 bit; /* Mask assigned in val field in tracer_flags */
275 * The set of specific options for a tracer. Your tracer
276 * have to set the initial value of the flags val.
278 struct tracer_flags {
280 struct tracer_opt *opts;
283 /* Makes more easy to define a tracer opt */
284 #define TRACER_OPT(s, b) .name = #s, .bit = b
287 * A specific tracer, represented by methods that operate on a trace array:
291 /* Your tracer should raise a warning if init fails */
292 int (*init)(struct trace_array *tr);
293 void (*reset)(struct trace_array *tr);
294 void (*start)(struct trace_array *tr);
295 void (*stop)(struct trace_array *tr);
296 void (*open)(struct trace_iterator *iter);
297 void (*pipe_open)(struct trace_iterator *iter);
298 void (*close)(struct trace_iterator *iter);
299 ssize_t (*read)(struct trace_iterator *iter,
300 struct file *filp, char __user *ubuf,
301 size_t cnt, loff_t *ppos);
302 #ifdef CONFIG_FTRACE_STARTUP_TEST
303 int (*selftest)(struct tracer *trace,
304 struct trace_array *tr);
306 enum print_line_t (*print_line)(struct trace_iterator *iter);
307 /* If you handled the flag setting, return 0 */
308 int (*set_flag)(u32 old_flags, u32 bit, int set);
311 struct tracer_flags *flags;
315 unsigned char buffer[PAGE_SIZE];
317 unsigned int readpos;
321 * Trace iterator - used by printout routines who present trace
322 * results to users and which routines might sleep, etc:
324 struct trace_iterator {
325 struct trace_array *tr;
326 struct tracer *trace;
328 struct ring_buffer_iter *buffer_iter[NR_CPUS];
330 /* The below is zeroed out in pipe_read */
331 struct trace_seq seq;
332 struct trace_entry *ent;
336 unsigned long iter_flags;
343 int tracing_is_enabled(void);
344 void trace_wake_up(void);
345 void tracing_reset(struct trace_array *tr, int cpu);
346 int tracing_open_generic(struct inode *inode, struct file *filp);
347 struct dentry *tracing_init_dentry(void);
348 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
350 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
351 struct trace_array_cpu *data);
352 void tracing_generic_entry_update(struct trace_entry *entry,
356 void ftrace(struct trace_array *tr,
357 struct trace_array_cpu *data,
359 unsigned long parent_ip,
360 unsigned long flags, int pc);
361 void tracing_sched_switch_trace(struct trace_array *tr,
362 struct trace_array_cpu *data,
363 struct task_struct *prev,
364 struct task_struct *next,
365 unsigned long flags, int pc);
366 void tracing_record_cmdline(struct task_struct *tsk);
368 void tracing_sched_wakeup_trace(struct trace_array *tr,
369 struct trace_array_cpu *data,
370 struct task_struct *wakee,
371 struct task_struct *cur,
372 unsigned long flags, int pc);
373 void trace_special(struct trace_array *tr,
374 struct trace_array_cpu *data,
377 unsigned long arg3, int pc);
378 void trace_function(struct trace_array *tr,
379 struct trace_array_cpu *data,
381 unsigned long parent_ip,
382 unsigned long flags, int pc);
384 trace_function_return(struct ftrace_retfunc *trace);
386 void tracing_start_cmdline_record(void);
387 void tracing_stop_cmdline_record(void);
388 void tracing_sched_switch_assign_trace(struct trace_array *tr);
389 void tracing_stop_sched_switch_record(void);
390 void tracing_start_sched_switch_record(void);
391 int register_tracer(struct tracer *type);
392 void unregister_tracer(struct tracer *type);
394 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
396 extern unsigned long tracing_max_latency;
397 extern unsigned long tracing_thresh;
399 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
400 void update_max_tr_single(struct trace_array *tr,
401 struct task_struct *tsk, int cpu);
403 extern cycle_t ftrace_now(int cpu);
405 #ifdef CONFIG_FUNCTION_TRACER
406 void tracing_start_function_trace(void);
407 void tracing_stop_function_trace(void);
409 # define tracing_start_function_trace() do { } while (0)
410 # define tracing_stop_function_trace() do { } while (0)
413 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
415 (*tracer_switch_func_t)(void *private,
417 struct task_struct *prev,
418 struct task_struct *next);
420 struct tracer_switch_ops {
421 tracer_switch_func_t func;
423 struct tracer_switch_ops *next;
426 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
428 #ifdef CONFIG_DYNAMIC_FTRACE
429 extern unsigned long ftrace_update_tot_cnt;
430 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
431 extern int DYN_FTRACE_TEST_NAME(void);
434 #ifdef CONFIG_FTRACE_STARTUP_TEST
435 extern int trace_selftest_startup_function(struct tracer *trace,
436 struct trace_array *tr);
437 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
438 struct trace_array *tr);
439 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
440 struct trace_array *tr);
441 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
442 struct trace_array *tr);
443 extern int trace_selftest_startup_wakeup(struct tracer *trace,
444 struct trace_array *tr);
445 extern int trace_selftest_startup_nop(struct tracer *trace,
446 struct trace_array *tr);
447 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
448 struct trace_array *tr);
449 extern int trace_selftest_startup_sysprof(struct tracer *trace,
450 struct trace_array *tr);
451 extern int trace_selftest_startup_branch(struct tracer *trace,
452 struct trace_array *tr);
453 #endif /* CONFIG_FTRACE_STARTUP_TEST */
455 extern void *head_page(struct trace_array_cpu *data);
456 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
457 extern void trace_seq_print_cont(struct trace_seq *s,
458 struct trace_iterator *iter);
461 seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
462 unsigned long sym_flags);
463 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
465 extern long ns2usecs(cycle_t nsec);
466 extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
468 extern unsigned long trace_flags;
470 /* Standard output formatting function used for function return traces */
471 #ifdef CONFIG_FUNCTION_RET_TRACER
472 extern enum print_line_t print_return_function(struct trace_iterator *iter);
474 static inline enum print_line_t
475 print_return_function(struct trace_iterator *iter)
477 return TRACE_TYPE_UNHANDLED;
482 * trace_iterator_flags is an enumeration that defines bit
483 * positions into trace_flags that controls the output.
485 * NOTE: These bits must match the trace_options array in
488 enum trace_iterator_flags {
489 TRACE_ITER_PRINT_PARENT = 0x01,
490 TRACE_ITER_SYM_OFFSET = 0x02,
491 TRACE_ITER_SYM_ADDR = 0x04,
492 TRACE_ITER_VERBOSE = 0x08,
493 TRACE_ITER_RAW = 0x10,
494 TRACE_ITER_HEX = 0x20,
495 TRACE_ITER_BIN = 0x40,
496 TRACE_ITER_BLOCK = 0x80,
497 TRACE_ITER_STACKTRACE = 0x100,
498 TRACE_ITER_SCHED_TREE = 0x200,
499 TRACE_ITER_PRINTK = 0x400,
500 TRACE_ITER_PREEMPTONLY = 0x800,
501 TRACE_ITER_BRANCH = 0x1000,
502 TRACE_ITER_ANNOTATE = 0x2000,
506 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
507 * control the output of kernel symbols.
509 #define TRACE_ITER_SYM_MASK \
510 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
512 extern struct tracer nop_trace;
515 * ftrace_preempt_disable - disable preemption scheduler safe
517 * When tracing can happen inside the scheduler, there exists
518 * cases that the tracing might happen before the need_resched
519 * flag is checked. If this happens and the tracer calls
520 * preempt_enable (after a disable), a schedule might take place
521 * causing an infinite recursion.
523 * To prevent this, we read the need_recshed flag before
524 * disabling preemption. When we want to enable preemption we
525 * check the flag, if it is set, then we call preempt_enable_no_resched.
526 * Otherwise, we call preempt_enable.
528 * The rational for doing the above is that if need resched is set
529 * and we have yet to reschedule, we are either in an atomic location
530 * (where we do not need to check for scheduling) or we are inside
531 * the scheduler and do not want to resched.
533 static inline int ftrace_preempt_disable(void)
537 resched = need_resched();
538 preempt_disable_notrace();
544 * ftrace_preempt_enable - enable preemption scheduler safe
545 * @resched: the return value from ftrace_preempt_disable
547 * This is a scheduler safe way to enable preemption and not miss
548 * any preemption checks. The disabled saved the state of preemption.
549 * If resched is set, then we were either inside an atomic or
550 * are inside the scheduler (we would have already scheduled
551 * otherwise). In this case, we do not want to call normal
552 * preempt_enable, but preempt_enable_no_resched instead.
554 static inline void ftrace_preempt_enable(int resched)
557 preempt_enable_no_resched_notrace();
559 preempt_enable_notrace();
562 #ifdef CONFIG_BRANCH_TRACER
563 extern int enable_branch_tracing(struct trace_array *tr);
564 extern void disable_branch_tracing(void);
565 static inline int trace_branch_enable(struct trace_array *tr)
567 if (trace_flags & TRACE_ITER_BRANCH)
568 return enable_branch_tracing(tr);
571 static inline void trace_branch_disable(void)
573 /* due to races, always disable */
574 disable_branch_tracing();
577 static inline int trace_branch_enable(struct trace_array *tr)
581 static inline void trace_branch_disable(void)
584 #endif /* CONFIG_BRANCH_TRACER */
586 #endif /* _LINUX_KERNEL_TRACE_H */