633 lines
20 KiB
C
633 lines
20 KiB
C
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#ifndef _LINUX_FTRACE_EVENT_H
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#define _LINUX_FTRACE_EVENT_H
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#include <linux/ring_buffer.h>
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#include <linux/trace_seq.h>
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#include <linux/percpu.h>
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#include <linux/hardirq.h>
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#include <linux/perf_event.h>
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#include <linux/tracepoint.h>
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struct trace_array;
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struct trace_buffer;
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struct tracer;
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struct dentry;
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struct trace_print_flags {
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unsigned long mask;
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const char *name;
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};
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struct trace_print_flags_u64 {
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unsigned long long mask;
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const char *name;
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};
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const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
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unsigned long flags,
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const struct trace_print_flags *flag_array);
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const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
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const struct trace_print_flags *symbol_array);
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#if BITS_PER_LONG == 32
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const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
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unsigned long long val,
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const struct trace_print_flags_u64
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*symbol_array);
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#endif
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const char *ftrace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
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unsigned int bitmask_size);
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const char *ftrace_print_hex_seq(struct trace_seq *p,
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const unsigned char *buf, int len);
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struct trace_iterator;
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struct trace_event;
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int ftrace_raw_output_prep(struct trace_iterator *iter,
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struct trace_event *event);
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/*
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* The trace entry - the most basic unit of tracing. This is what
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* is printed in the end as a single line in the trace output, such as:
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*
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* bash-15816 [01] 235.197585: idle_cpu <- irq_enter
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*/
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struct trace_entry {
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unsigned short type;
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unsigned char flags;
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unsigned char preempt_count;
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int pid;
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};
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#define FTRACE_MAX_EVENT \
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((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
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/*
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* Trace iterator - used by printout routines who present trace
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* results to users and which routines might sleep, etc:
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*/
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struct trace_iterator {
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struct trace_array *tr;
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struct tracer *trace;
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struct trace_buffer *trace_buffer;
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void *private;
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int cpu_file;
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struct mutex mutex;
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struct ring_buffer_iter **buffer_iter;
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unsigned long iter_flags;
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/* trace_seq for __print_flags() and __print_symbolic() etc. */
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struct trace_seq tmp_seq;
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cpumask_var_t started;
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/* it's true when current open file is snapshot */
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bool snapshot;
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/* The below is zeroed out in pipe_read */
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struct trace_seq seq;
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struct trace_entry *ent;
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unsigned long lost_events;
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int leftover;
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int ent_size;
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int cpu;
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u64 ts;
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loff_t pos;
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long idx;
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/* All new field here will be zeroed out in pipe_read */
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};
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enum trace_iter_flags {
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TRACE_FILE_LAT_FMT = 1,
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TRACE_FILE_ANNOTATE = 2,
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TRACE_FILE_TIME_IN_NS = 4,
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};
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typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
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int flags, struct trace_event *event);
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struct trace_event_functions {
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trace_print_func trace;
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trace_print_func raw;
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trace_print_func hex;
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trace_print_func binary;
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};
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struct trace_event {
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struct hlist_node node;
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struct list_head list;
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int type;
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struct trace_event_functions *funcs;
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};
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extern int register_ftrace_event(struct trace_event *event);
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extern int unregister_ftrace_event(struct trace_event *event);
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/* Return values for print_line callback */
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enum print_line_t {
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TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
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TRACE_TYPE_HANDLED = 1,
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TRACE_TYPE_UNHANDLED = 2, /* Relay to other output functions */
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TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
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};
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void tracing_generic_entry_update(struct trace_entry *entry,
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unsigned long flags,
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int pc);
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struct ftrace_event_file;
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struct ring_buffer_event *
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trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
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struct ftrace_event_file *ftrace_file,
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int type, unsigned long len,
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unsigned long flags, int pc);
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struct ring_buffer_event *
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trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
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int type, unsigned long len,
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unsigned long flags, int pc);
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void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
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struct ring_buffer_event *event,
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unsigned long flags, int pc);
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void trace_buffer_unlock_commit(struct ring_buffer *buffer,
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struct ring_buffer_event *event,
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unsigned long flags, int pc);
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void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
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struct ring_buffer_event *event,
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unsigned long flags, int pc,
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struct pt_regs *regs);
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void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
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struct ring_buffer_event *event);
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void tracing_record_cmdline(struct task_struct *tsk);
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int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
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struct event_filter;
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enum trace_reg {
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TRACE_REG_REGISTER,
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TRACE_REG_UNREGISTER,
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#ifdef CONFIG_PERF_EVENTS
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TRACE_REG_PERF_REGISTER,
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TRACE_REG_PERF_UNREGISTER,
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TRACE_REG_PERF_OPEN,
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TRACE_REG_PERF_CLOSE,
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TRACE_REG_PERF_ADD,
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TRACE_REG_PERF_DEL,
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#endif
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};
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struct ftrace_event_call;
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struct ftrace_event_class {
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char *system;
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void *probe;
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#ifdef CONFIG_PERF_EVENTS
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void *perf_probe;
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#endif
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int (*reg)(struct ftrace_event_call *event,
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enum trace_reg type, void *data);
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int (*define_fields)(struct ftrace_event_call *);
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struct list_head *(*get_fields)(struct ftrace_event_call *);
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struct list_head fields;
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int (*raw_init)(struct ftrace_event_call *);
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};
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extern int ftrace_event_reg(struct ftrace_event_call *event,
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enum trace_reg type, void *data);
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int ftrace_output_event(struct trace_iterator *iter, struct ftrace_event_call *event,
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char *fmt, ...);
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int ftrace_event_define_field(struct ftrace_event_call *call,
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char *type, int len, char *item, int offset,
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int field_size, int sign, int filter);
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struct ftrace_event_buffer {
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struct ring_buffer *buffer;
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struct ring_buffer_event *event;
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struct ftrace_event_file *ftrace_file;
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void *entry;
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unsigned long flags;
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int pc;
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};
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void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
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struct ftrace_event_file *ftrace_file,
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unsigned long len);
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void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer);
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int ftrace_event_define_field(struct ftrace_event_call *call,
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char *type, int len, char *item, int offset,
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int field_size, int sign, int filter);
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enum {
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TRACE_EVENT_FL_FILTERED_BIT,
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TRACE_EVENT_FL_CAP_ANY_BIT,
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TRACE_EVENT_FL_NO_SET_FILTER_BIT,
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TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
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TRACE_EVENT_FL_WAS_ENABLED_BIT,
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TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
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TRACE_EVENT_FL_TRACEPOINT_BIT,
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};
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/*
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* Event flags:
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* FILTERED - The event has a filter attached
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* CAP_ANY - Any user can enable for perf
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* NO_SET_FILTER - Set when filter has error and is to be ignored
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* IGNORE_ENABLE - For ftrace internal events, do not enable with debugfs file
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* WAS_ENABLED - Set and stays set when an event was ever enabled
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* (used for module unloading, if a module event is enabled,
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* it is best to clear the buffers that used it).
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* USE_CALL_FILTER - For ftrace internal events, don't use file filter
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* TRACEPOINT - Event is a tracepoint
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*/
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enum {
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TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
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TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
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TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
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TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
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TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
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TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
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TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
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};
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struct ftrace_event_call {
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struct list_head list;
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struct ftrace_event_class *class;
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union {
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char *name;
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/* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
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struct tracepoint *tp;
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};
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struct trace_event event;
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const char *print_fmt;
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struct event_filter *filter;
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void *mod;
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void *data;
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/*
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* bit 0: filter_active
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* bit 1: allow trace by non root (cap any)
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* bit 2: failed to apply filter
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* bit 3: ftrace internal event (do not enable)
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* bit 4: Event was enabled by module
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* bit 5: use call filter rather than file filter
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* bit 6: Event is a tracepoint
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*/
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int flags; /* static flags of different events */
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#ifdef CONFIG_PERF_EVENTS
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int perf_refcount;
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struct hlist_head __percpu *perf_events;
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int (*perf_perm)(struct ftrace_event_call *,
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struct perf_event *);
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#endif
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};
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static inline const char *
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ftrace_event_name(struct ftrace_event_call *call)
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{
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if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
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return call->tp ? call->tp->name : NULL;
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else
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return call->name;
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}
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struct trace_array;
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struct ftrace_subsystem_dir;
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enum {
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FTRACE_EVENT_FL_ENABLED_BIT,
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FTRACE_EVENT_FL_RECORDED_CMD_BIT,
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FTRACE_EVENT_FL_FILTERED_BIT,
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FTRACE_EVENT_FL_NO_SET_FILTER_BIT,
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FTRACE_EVENT_FL_SOFT_MODE_BIT,
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FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
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FTRACE_EVENT_FL_TRIGGER_MODE_BIT,
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FTRACE_EVENT_FL_TRIGGER_COND_BIT,
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};
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/*
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* Ftrace event file flags:
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* ENABLED - The event is enabled
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* RECORDED_CMD - The comms should be recorded at sched_switch
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* FILTERED - The event has a filter attached
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* NO_SET_FILTER - Set when filter has error and is to be ignored
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* SOFT_MODE - The event is enabled/disabled by SOFT_DISABLED
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* SOFT_DISABLED - When set, do not trace the event (even though its
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* tracepoint may be enabled)
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* TRIGGER_MODE - When set, invoke the triggers associated with the event
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* TRIGGER_COND - When set, one or more triggers has an associated filter
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*/
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enum {
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FTRACE_EVENT_FL_ENABLED = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
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FTRACE_EVENT_FL_RECORDED_CMD = (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
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FTRACE_EVENT_FL_FILTERED = (1 << FTRACE_EVENT_FL_FILTERED_BIT),
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FTRACE_EVENT_FL_NO_SET_FILTER = (1 << FTRACE_EVENT_FL_NO_SET_FILTER_BIT),
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FTRACE_EVENT_FL_SOFT_MODE = (1 << FTRACE_EVENT_FL_SOFT_MODE_BIT),
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FTRACE_EVENT_FL_SOFT_DISABLED = (1 << FTRACE_EVENT_FL_SOFT_DISABLED_BIT),
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FTRACE_EVENT_FL_TRIGGER_MODE = (1 << FTRACE_EVENT_FL_TRIGGER_MODE_BIT),
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FTRACE_EVENT_FL_TRIGGER_COND = (1 << FTRACE_EVENT_FL_TRIGGER_COND_BIT),
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};
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struct ftrace_event_file {
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struct list_head list;
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struct ftrace_event_call *event_call;
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struct event_filter *filter;
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struct dentry *dir;
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struct trace_array *tr;
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struct ftrace_subsystem_dir *system;
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struct list_head triggers;
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/*
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* 32 bit flags:
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* bit 0: enabled
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* bit 1: enabled cmd record
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* bit 2: enable/disable with the soft disable bit
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* bit 3: soft disabled
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* bit 4: trigger enabled
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*
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* Note: The bits must be set atomically to prevent races
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* from other writers. Reads of flags do not need to be in
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* sync as they occur in critical sections. But the way flags
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* is currently used, these changes do not affect the code
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* except that when a change is made, it may have a slight
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* delay in propagating the changes to other CPUs due to
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* caching and such. Which is mostly OK ;-)
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*/
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unsigned long flags;
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atomic_t sm_ref; /* soft-mode reference counter */
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atomic_t tm_ref; /* trigger-mode reference counter */
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};
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#define __TRACE_EVENT_FLAGS(name, value) \
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static int __init trace_init_flags_##name(void) \
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{ \
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event_##name.flags |= value; \
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return 0; \
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} \
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early_initcall(trace_init_flags_##name);
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#define __TRACE_EVENT_PERF_PERM(name, expr...) \
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static int perf_perm_##name(struct ftrace_event_call *tp_event, \
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struct perf_event *p_event) \
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{ \
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return ({ expr; }); \
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} \
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static int __init trace_init_perf_perm_##name(void) \
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{ \
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event_##name.perf_perm = &perf_perm_##name; \
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return 0; \
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} \
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early_initcall(trace_init_perf_perm_##name);
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#define PERF_MAX_TRACE_SIZE 2048
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#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
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enum event_trigger_type {
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ETT_NONE = (0),
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ETT_TRACE_ONOFF = (1 << 0),
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ETT_SNAPSHOT = (1 << 1),
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ETT_STACKTRACE = (1 << 2),
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ETT_EVENT_ENABLE = (1 << 3),
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};
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extern int filter_match_preds(struct event_filter *filter, void *rec);
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extern int filter_check_discard(struct ftrace_event_file *file, void *rec,
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struct ring_buffer *buffer,
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struct ring_buffer_event *event);
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extern int call_filter_check_discard(struct ftrace_event_call *call, void *rec,
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struct ring_buffer *buffer,
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struct ring_buffer_event *event);
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extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *file,
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void *rec);
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extern void event_triggers_post_call(struct ftrace_event_file *file,
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enum event_trigger_type tt);
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/**
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* ftrace_trigger_soft_disabled - do triggers and test if soft disabled
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* @file: The file pointer of the event to test
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*
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* If any triggers without filters are attached to this event, they
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* will be called here. If the event is soft disabled and has no
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* triggers that require testing the fields, it will return true,
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* otherwise false.
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*/
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static inline bool
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ftrace_trigger_soft_disabled(struct ftrace_event_file *file)
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{
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unsigned long eflags = file->flags;
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if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
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if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
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event_triggers_call(file, NULL);
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if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
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return true;
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}
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return false;
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}
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/*
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* Helper function for event_trigger_unlock_commit{_regs}().
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* If there are event triggers attached to this event that requires
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* filtering against its fields, then they wil be called as the
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* entry already holds the field information of the current event.
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*
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* It also checks if the event should be discarded or not.
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* It is to be discarded if the event is soft disabled and the
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* event was only recorded to process triggers, or if the event
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* filter is active and this event did not match the filters.
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*
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* Returns true if the event is discarded, false otherwise.
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*/
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static inline bool
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__event_trigger_test_discard(struct ftrace_event_file *file,
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struct ring_buffer *buffer,
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struct ring_buffer_event *event,
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void *entry,
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enum event_trigger_type *tt)
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{
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unsigned long eflags = file->flags;
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if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
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*tt = event_triggers_call(file, entry);
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if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
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ring_buffer_discard_commit(buffer, event);
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else if (!filter_check_discard(file, entry, buffer, event))
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return false;
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return true;
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}
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/**
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* event_trigger_unlock_commit - handle triggers and finish event commit
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* @file: The file pointer assoctiated to the event
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* @buffer: The ring buffer that the event is being written to
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* @event: The event meta data in the ring buffer
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* @entry: The event itself
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* @irq_flags: The state of the interrupts at the start of the event
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* @pc: The state of the preempt count at the start of the event.
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*
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* This is a helper function to handle triggers that require data
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* from the event itself. It also tests the event against filters and
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* if the event is soft disabled and should be discarded.
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*/
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static inline void
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event_trigger_unlock_commit(struct ftrace_event_file *file,
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struct ring_buffer *buffer,
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struct ring_buffer_event *event,
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void *entry, unsigned long irq_flags, int pc)
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{
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enum event_trigger_type tt = ETT_NONE;
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if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
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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 ftrace_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);
|
|
}
|
|
|
|
enum {
|
|
FILTER_OTHER = 0,
|
|
FILTER_STATIC_STRING,
|
|
FILTER_DYN_STRING,
|
|
FILTER_PTR_STRING,
|
|
FILTER_TRACE_FN,
|
|
};
|
|
|
|
extern int trace_event_raw_init(struct ftrace_event_call *call);
|
|
extern int trace_define_field(struct ftrace_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 ftrace_event_call *call);
|
|
extern int trace_remove_event_call(struct ftrace_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)
|
|
|
|
/**
|
|
* tracepoint_string - register constant persistent string to trace system
|
|
* @str - a constant persistent string that will be referenced in tracepoints
|
|
*
|
|
* If constant strings are being used in tracepoints, it is faster and
|
|
* more efficient to just save the pointer to the string and reference
|
|
* that with a printf "%s" instead of saving the string in the ring buffer
|
|
* and wasting space and time.
|
|
*
|
|
* The problem with the above approach is that userspace tools that read
|
|
* the binary output of the trace buffers do not have access to the string.
|
|
* Instead they just show the address of the string which is not very
|
|
* useful to users.
|
|
*
|
|
* With tracepoint_string(), the string will be registered to the tracing
|
|
* system and exported to userspace via the debugfs/tracing/printk_formats
|
|
* file that maps the string address to the string text. This way userspace
|
|
* tools that read the binary buffers have a way to map the pointers to
|
|
* the ASCII strings they represent.
|
|
*
|
|
* The @str used must be a constant string and persistent as it would not
|
|
* make sense to show a string that no longer exists. But it is still fine
|
|
* to be used with modules, because when modules are unloaded, if they
|
|
* had tracepoints, the ring buffers are cleared too. As long as the string
|
|
* does not change during the life of the module, it is fine to use
|
|
* tracepoint_string() within a module.
|
|
*/
|
|
#define tracepoint_string(str) \
|
|
({ \
|
|
static const char *___tp_str __tracepoint_string = str; \
|
|
___tp_str; \
|
|
})
|
|
#define __tracepoint_string __attribute__((section("__tracepoint_str")))
|
|
|
|
#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_FTRACE_EVENT_H */
|