diff options
Diffstat (limited to 'include/linux/trace_events.h')
| -rw-r--r-- | include/linux/trace_events.h | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h new file mode 100644 index 000000000..1063c850d --- /dev/null +++ b/include/linux/trace_events.h @@ -0,0 +1,616 @@ + +#ifndef _LINUX_TRACE_EVENT_H +#define _LINUX_TRACE_EVENT_H + +#include <linux/ring_buffer.h> +#include <linux/trace_seq.h> +#include <linux/percpu.h> +#include <linux/hardirq.h> +#include <linux/perf_event.h> +#include <linux/tracepoint.h> + +struct trace_array; +struct trace_buffer; +struct tracer; +struct dentry; +struct bpf_prog; + +struct trace_print_flags { + unsigned long mask; + const char *name; +}; + +struct trace_print_flags_u64 { + unsigned long long mask; + const char *name; +}; + +const char *trace_print_flags_seq(struct trace_seq *p, const char *delim, + unsigned long flags, + const struct trace_print_flags *flag_array); + +const char *trace_print_symbols_seq(struct trace_seq *p, unsigned long val, + const struct trace_print_flags *symbol_array); + +#if BITS_PER_LONG == 32 +const char *trace_print_symbols_seq_u64(struct trace_seq *p, + unsigned long long val, + const struct trace_print_flags_u64 + *symbol_array); +#endif + +const char *trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr, + unsigned int bitmask_size); + +const char *trace_print_hex_seq(struct trace_seq *p, + const unsigned char *buf, int len); + +const char *trace_print_array_seq(struct trace_seq *p, + const void *buf, int count, + size_t el_size); + +struct trace_iterator; +struct trace_event; + +int trace_raw_output_prep(struct trace_iterator *iter, + struct trace_event *event); + +/* + * The trace entry - the most basic unit of tracing. This is what + * is printed in the end as a single line in the trace output, such as: + * + * bash-15816 [01] 235.197585: idle_cpu <- irq_enter + */ +struct trace_entry { + unsigned short type; + unsigned char flags; + unsigned char preempt_count; + int pid; +}; + +#define TRACE_EVENT_TYPE_MAX \ + ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1) + +/* + * Trace iterator - used by printout routines who present trace + * results to users and which routines might sleep, etc: + */ +struct trace_iterator { + struct trace_array *tr; + struct tracer *trace; + struct trace_buffer *trace_buffer; + void *private; + int cpu_file; + struct mutex mutex; + struct ring_buffer_iter **buffer_iter; + unsigned long iter_flags; + + /* trace_seq for __print_flags() and __print_symbolic() etc. */ + struct trace_seq tmp_seq; + + cpumask_var_t started; + + /* it's true when current open file is snapshot */ + bool snapshot; + + /* The below is zeroed out in pipe_read */ + struct trace_seq seq; + struct trace_entry *ent; + unsigned long lost_events; + int leftover; + int ent_size; + int cpu; + u64 ts; + + loff_t pos; + long idx; + + /* All new field here will be zeroed out in pipe_read */ +}; + +enum trace_iter_flags { + TRACE_FILE_LAT_FMT = 1, + TRACE_FILE_ANNOTATE = 2, + TRACE_FILE_TIME_IN_NS = 4, +}; + + +typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter, + int flags, struct trace_event *event); + +struct trace_event_functions { + trace_print_func trace; + trace_print_func raw; + trace_print_func hex; + trace_print_func binary; +}; + +struct trace_event { + struct hlist_node node; + struct list_head list; + int type; + struct trace_event_functions *funcs; +}; + +extern int register_trace_event(struct trace_event *event); +extern int unregister_trace_event(struct trace_event *event); + +/* Return values for print_line callback */ +enum print_line_t { + TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */ + TRACE_TYPE_HANDLED = 1, + TRACE_TYPE_UNHANDLED = 2, /* Relay to other output functions */ + TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */ +}; + +/* + * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq + * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function + * simplifies those functions and keeps them in sync. + */ +static inline enum print_line_t trace_handle_return(struct trace_seq *s) +{ + return trace_seq_has_overflowed(s) ? + TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED; +} + +void tracing_generic_entry_update(struct trace_entry *entry, + unsigned long flags, + int pc); +struct trace_event_file; + +struct ring_buffer_event * +trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer, + struct trace_event_file *trace_file, + int type, unsigned long len, + unsigned long flags, int pc); +struct ring_buffer_event * +trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer, + int type, unsigned long len, + unsigned long flags, int pc); +void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags, int pc); +void trace_buffer_unlock_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags, int pc); +void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags, int pc, + struct pt_regs *regs); +void trace_current_buffer_discard_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event); + +void tracing_record_cmdline(struct task_struct *tsk); + +int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...); + +struct event_filter; + +enum trace_reg { + TRACE_REG_REGISTER, + TRACE_REG_UNREGISTER, +#ifdef CONFIG_PERF_EVENTS + TRACE_REG_PERF_REGISTER, + TRACE_REG_PERF_UNREGISTER, + TRACE_REG_PERF_OPEN, + TRACE_REG_PERF_CLOSE, + TRACE_REG_PERF_ADD, + TRACE_REG_PERF_DEL, +#endif +}; + +struct trace_event_call; + +struct trace_event_class { + const char *system; + void *probe; +#ifdef CONFIG_PERF_EVENTS + void *perf_probe; +#endif + int (*reg)(struct trace_event_call *event, + enum trace_reg type, void *data); + int (*define_fields)(struct trace_event_call *); + struct list_head *(*get_fields)(struct trace_event_call *); + struct list_head fields; + int (*raw_init)(struct trace_event_call *); +}; + +extern int trace_event_reg(struct trace_event_call *event, + enum trace_reg type, void *data); + +struct trace_event_buffer { + struct ring_buffer *buffer; + struct ring_buffer_event *event; + struct trace_event_file *trace_file; + void *entry; + unsigned long flags; + int pc; +}; + +void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, + struct trace_event_file *trace_file, + unsigned long len); + +void trace_event_buffer_commit(struct trace_event_buffer *fbuffer); + +enum { + TRACE_EVENT_FL_FILTERED_BIT, + TRACE_EVENT_FL_CAP_ANY_BIT, + TRACE_EVENT_FL_NO_SET_FILTER_BIT, + TRACE_EVENT_FL_IGNORE_ENABLE_BIT, + TRACE_EVENT_FL_WAS_ENABLED_BIT, + TRACE_EVENT_FL_USE_CALL_FILTER_BIT, + TRACE_EVENT_FL_TRACEPOINT_BIT, + TRACE_EVENT_FL_KPROBE_BIT, +}; + +/* + * Event flags: + * FILTERED - The event has a filter attached + * CAP_ANY - Any user can enable for perf + * NO_SET_FILTER - Set when filter has error and is to be ignored + * IGNORE_ENABLE - For trace internal events, do not enable with debugfs file + * WAS_ENABLED - Set and stays set when an event was ever enabled + * (used for module unloading, if a module event is enabled, + * it is best to clear the buffers that used it). + * USE_CALL_FILTER - For trace internal events, don't use file filter + * TRACEPOINT - Event is a tracepoint + * KPROBE - Event is a kprobe + */ +enum { + TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT), + TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT), + TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT), + TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT), + TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT), + TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT), + TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT), + TRACE_EVENT_FL_KPROBE = (1 << TRACE_EVENT_FL_KPROBE_BIT), +}; + +struct trace_event_call { + struct list_head list; + struct trace_event_class *class; + union { + char *name; + /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */ + struct tracepoint *tp; + }; + struct trace_event event; + char *print_fmt; + struct event_filter *filter; + void *mod; + void *data; + /* + * bit 0: filter_active + * bit 1: allow trace by non root (cap any) + * bit 2: failed to apply filter + * bit 3: trace internal event (do not enable) + * bit 4: Event was enabled by module + * bit 5: use call filter rather than file filter + * bit 6: Event is a tracepoint + */ + int flags; /* static flags of different events */ + +#ifdef CONFIG_PERF_EVENTS + int perf_refcount; + struct hlist_head __percpu *perf_events; + struct bpf_prog *prog; + + int (*perf_perm)(struct trace_event_call *, + struct perf_event *); +#endif +}; + +static inline const char * +trace_event_name(struct trace_event_call *call) +{ + if (call->flags & TRACE_EVENT_FL_TRACEPOINT) + return call->tp ? call->tp->name : NULL; + else + return call->name; +} + +struct trace_array; +struct trace_subsystem_dir; + +enum { + EVENT_FILE_FL_ENABLED_BIT, + EVENT_FILE_FL_RECORDED_CMD_BIT, + EVENT_FILE_FL_FILTERED_BIT, + EVENT_FILE_FL_NO_SET_FILTER_BIT, + EVENT_FILE_FL_SOFT_MODE_BIT, + EVENT_FILE_FL_SOFT_DISABLED_BIT, + EVENT_FILE_FL_TRIGGER_MODE_BIT, + EVENT_FILE_FL_TRIGGER_COND_BIT, +}; + +/* + * Event file flags: + * ENABLED - The event is enabled + * RECORDED_CMD - The comms should be recorded at sched_switch + * FILTERED - The event has a filter attached + * NO_SET_FILTER - Set when filter has error and is to be ignored + * SOFT_MODE - The event is enabled/disabled by SOFT_DISABLED + * SOFT_DISABLED - When set, do not trace the event (even though its + * tracepoint may be enabled) + * TRIGGER_MODE - When set, invoke the triggers associated with the event + * TRIGGER_COND - When set, one or more triggers has an associated filter + */ +enum { + EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT), + EVENT_FILE_FL_RECORDED_CMD = (1 << EVENT_FILE_FL_RECORDED_CMD_BIT), + EVENT_FILE_FL_FILTERED = (1 << EVENT_FILE_FL_FILTERED_BIT), + EVENT_FILE_FL_NO_SET_FILTER = (1 << EVENT_FILE_FL_NO_SET_FILTER_BIT), + EVENT_FILE_FL_SOFT_MODE = (1 << EVENT_FILE_FL_SOFT_MODE_BIT), + EVENT_FILE_FL_SOFT_DISABLED = (1 << EVENT_FILE_FL_SOFT_DISABLED_BIT), + EVENT_FILE_FL_TRIGGER_MODE = (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT), + EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT), +}; + +struct trace_event_file { + struct list_head list; + struct trace_event_call *event_call; + struct event_filter *filter; + struct dentry *dir; + struct trace_array *tr; + struct trace_subsystem_dir *system; + struct list_head triggers; + + /* + * 32 bit flags: + * bit 0: enabled + * bit 1: enabled cmd record + * bit 2: enable/disable with the soft disable bit + * bit 3: soft disabled + * bit 4: trigger enabled + * + * Note: The bits must be set atomically to prevent races + * from other writers. Reads of flags do not need to be in + * sync as they occur in critical sections. But the way flags + * is currently used, these changes do not affect the code + * except that when a change is made, it may have a slight + * delay in propagating the changes to other CPUs due to + * caching and such. Which is mostly OK ;-) + */ + unsigned long flags; + atomic_t sm_ref; /* soft-mode reference counter */ + atomic_t tm_ref; /* trigger-mode reference counter */ +}; + +#define __TRACE_EVENT_FLAGS(name, value) \ + static int __init trace_init_flags_##name(void) \ + { \ + event_##name.flags |= value; \ + return 0; \ + } \ + early_initcall(trace_init_flags_##name); + +#define __TRACE_EVENT_PERF_PERM(name, expr...) \ + static int perf_perm_##name(struct trace_event_call *tp_event, \ + struct perf_event *p_event) \ + { \ + return ({ expr; }); \ + } \ + static int __init trace_init_perf_perm_##name(void) \ + { \ + event_##name.perf_perm = &perf_perm_##name; \ + return 0; \ + } \ + early_initcall(trace_init_perf_perm_##name); + +#define PERF_MAX_TRACE_SIZE 2048 + +#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */ + +enum event_trigger_type { + ETT_NONE = (0), + ETT_TRACE_ONOFF = (1 << 0), + ETT_SNAPSHOT = (1 << 1), + ETT_STACKTRACE = (1 << 2), + ETT_EVENT_ENABLE = (1 << 3), +}; + +extern int filter_match_preds(struct event_filter *filter, void *rec); + +extern int filter_check_discard(struct trace_event_file *file, void *rec, + struct ring_buffer *buffer, + struct ring_buffer_event *event); +extern int call_filter_check_discard(struct trace_event_call *call, void *rec, + struct ring_buffer *buffer, + struct ring_buffer_event *event); +extern enum event_trigger_type event_triggers_call(struct trace_event_file *file, + void *rec); +extern void event_triggers_post_call(struct trace_event_file *file, + enum event_trigger_type tt); + +/** + * trace_trigger_soft_disabled - do triggers and test if soft disabled + * @file: The file pointer of the event to test + * + * If any triggers without filters are attached to this event, they + * will be called here. If the event is soft disabled and has no + * triggers that require testing the fields, it will return true, + * otherwise false. + */ +static inline bool +trace_trigger_soft_disabled(struct trace_event_file *file) +{ + unsigned long eflags = file->flags; + + if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) { + if (eflags & EVENT_FILE_FL_TRIGGER_MODE) + event_triggers_call(file, NULL); + if (eflags & EVENT_FILE_FL_SOFT_DISABLED) + return true; + } + return false; +} + +/* + * Helper function for event_trigger_unlock_commit{_regs}(). + * If there are event triggers attached to this event that requires + * filtering against its fields, then they wil be called as the + * entry already holds the field information of the current event. + * + * It also checks if the event should be discarded or not. + * It is to be discarded if the event is soft disabled and the + * event was only recorded to process triggers, or if the event + * filter is active and this event did not match the filters. + * + * Returns true if the event is discarded, false otherwise. + */ +static inline bool +__event_trigger_test_discard(struct trace_event_file *file, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + void *entry, + enum event_trigger_type *tt) +{ + unsigned long eflags = file->flags; + + if (eflags & EVENT_FILE_FL_TRIGGER_COND) + *tt = event_triggers_call(file, entry); + + if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags)) + ring_buffer_discard_commit(buffer, event); + else if (!filter_check_discard(file, entry, buffer, event)) + return false; + + return true; +} + +/** + * event_trigger_unlock_commit - handle triggers and finish event commit + * @file: The file pointer assoctiated to the event + * @buffer: The ring buffer that the event is being written to + * @event: The event meta data in the ring buffer + * @entry: The event itself + * @irq_flags: The state of the interrupts at the start of the event + * @pc: The state of the preempt count at the start of the event. + * + * This is a helper function to handle triggers that require data + * from the event itself. It also tests the event against filters and + * if the event is soft disabled and should be discarded. + */ +static inline void +event_trigger_unlock_commit(struct trace_event_file *file, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + void *entry, unsigned long irq_flags, int pc) +{ + enum event_trigger_type tt = ETT_NONE; + + if (!__event_trigger_test_discard(file, buffer, event, entry, &tt)) + trace_buffer_unlock_commit(buffer, event, irq_flags, pc); + + if (tt) + event_triggers_post_call(file, tt); +} + +/** + * event_trigger_unlock_commit_regs - handle triggers and finish event commit + * @file: The file pointer assoctiated to the event + * @buffer: The ring buffer that the event is being written to + * @event: The event meta data in the ring buffer + * @entry: The event itself + * @irq_flags: The state of the interrupts at the start of the event + * @pc: The state of the preempt count at the start of the event. + * + * This is a helper function to handle triggers that require data + * from the event itself. It also tests the event against filters and + * if the event is soft disabled and should be discarded. + * + * Same as event_trigger_unlock_commit() but calls + * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit(). + */ +static inline void +event_trigger_unlock_commit_regs(struct trace_event_file *file, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + void *entry, unsigned long irq_flags, int pc, + struct pt_regs *regs) +{ + enum event_trigger_type tt = ETT_NONE; + + if (!__event_trigger_test_discard(file, buffer, event, entry, &tt)) + trace_buffer_unlock_commit_regs(buffer, event, + irq_flags, pc, regs); + + if (tt) + event_triggers_post_call(file, tt); +} + +#ifdef CONFIG_BPF_SYSCALL +unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx); +#else +static inline unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx) +{ + return 1; +} +#endif + +enum { + FILTER_OTHER = 0, + FILTER_STATIC_STRING, + FILTER_DYN_STRING, + FILTER_PTR_STRING, + FILTER_TRACE_FN, +}; + +extern int trace_event_raw_init(struct trace_event_call *call); +extern int trace_define_field(struct trace_event_call *call, const char *type, + const char *name, int offset, int size, + int is_signed, int filter_type); +extern int trace_add_event_call(struct trace_event_call *call); +extern int trace_remove_event_call(struct trace_event_call *call); + +#define is_signed_type(type) (((type)(-1)) < (type)1) + +int trace_set_clr_event(const char *system, const char *event, int set); + +/* + * The double __builtin_constant_p is because gcc will give us an error + * if we try to allocate the static variable to fmt if it is not a + * constant. Even with the outer if statement optimizing out. + */ +#define event_trace_printk(ip, fmt, args...) \ +do { \ + __trace_printk_check_format(fmt, ##args); \ + tracing_record_cmdline(current); \ + if (__builtin_constant_p(fmt)) { \ + static const char *trace_printk_fmt \ + __attribute__((section("__trace_printk_fmt"))) = \ + __builtin_constant_p(fmt) ? fmt : NULL; \ + \ + __trace_bprintk(ip, trace_printk_fmt, ##args); \ + } else \ + __trace_printk(ip, fmt, ##args); \ +} while (0) + +#ifdef CONFIG_PERF_EVENTS +struct perf_event; + +DECLARE_PER_CPU(struct pt_regs, perf_trace_regs); + +extern int perf_trace_init(struct perf_event *event); +extern void perf_trace_destroy(struct perf_event *event); +extern int perf_trace_add(struct perf_event *event, int flags); +extern void perf_trace_del(struct perf_event *event, int flags); +extern int ftrace_profile_set_filter(struct perf_event *event, int event_id, + char *filter_str); +extern void ftrace_profile_free_filter(struct perf_event *event); +extern void *perf_trace_buf_prepare(int size, unsigned short type, + struct pt_regs **regs, int *rctxp); + +static inline void +perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr, + u64 count, struct pt_regs *regs, void *head, + struct task_struct *task) +{ + perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task); +} +#endif + +#endif /* _LINUX_TRACE_EVENT_H */ |