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![Masami Hiramatsu](/assets/img/avatar_default.png)
Modify soft-mode flag only if no other soft-mode referrer (currently only the ftrace triggers) by using a reference counter in each ftrace_event_file. Without this fix, adding and removing several different enable/disable_event triggers on the same event clear soft-mode bit from the ftrace_event_file. This also happens with a typo of glob on setting triggers. e.g. # echo vfs_symlink:enable_event:net:netif_rx > set_ftrace_filter # cat events/net/netif_rx/enable 0* # echo typo_func:enable_event:net:netif_rx > set_ftrace_filter # cat events/net/netif_rx/enable 0 # cat set_ftrace_filter #### all functions enabled #### vfs_symlink:enable_event:net:netif_rx:unlimited As above, we still have a trigger, but soft-mode is gone. Link: http://lkml.kernel.org/r/20130509054429.30398.7464.stgit@mhiramat-M0-7522 Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: David Sharp <dhsharp@google.com> Cc: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
384 lines
11 KiB
C
384 lines
11 KiB
C
#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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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_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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/* 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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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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};
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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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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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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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};
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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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*/
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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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};
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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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char *name;
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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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struct list_head *files;
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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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*/
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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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#endif
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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_SOFT_MODE_BIT,
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FTRACE_EVENT_FL_SOFT_DISABLED_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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* 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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*/
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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_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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};
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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 dentry *dir;
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struct trace_array *tr;
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struct ftrace_subsystem_dir *system;
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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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*
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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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};
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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 PERF_MAX_TRACE_SIZE 2048
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#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
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extern void destroy_preds(struct ftrace_event_call *call);
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extern int filter_match_preds(struct event_filter *filter, void *rec);
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extern int filter_current_check_discard(struct ring_buffer *buffer,
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struct ftrace_event_call *call,
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void *rec,
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struct ring_buffer_event *event);
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enum {
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FILTER_OTHER = 0,
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FILTER_STATIC_STRING,
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FILTER_DYN_STRING,
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FILTER_PTR_STRING,
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FILTER_TRACE_FN,
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};
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#define EVENT_STORAGE_SIZE 128
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extern struct mutex event_storage_mutex;
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extern char event_storage[EVENT_STORAGE_SIZE];
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extern int trace_event_raw_init(struct ftrace_event_call *call);
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extern int trace_define_field(struct ftrace_event_call *call, const char *type,
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const char *name, int offset, int size,
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int is_signed, int filter_type);
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extern int trace_add_event_call(struct ftrace_event_call *call);
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extern void trace_remove_event_call(struct ftrace_event_call *call);
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#define is_signed_type(type) (((type)(-1)) < (type)1)
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int trace_set_clr_event(const char *system, const char *event, int set);
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/*
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* The double __builtin_constant_p is because gcc will give us an error
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* if we try to allocate the static variable to fmt if it is not a
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* constant. Even with the outer if statement optimizing out.
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*/
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#define event_trace_printk(ip, fmt, args...) \
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do { \
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__trace_printk_check_format(fmt, ##args); \
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tracing_record_cmdline(current); \
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if (__builtin_constant_p(fmt)) { \
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static const char *trace_printk_fmt \
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__attribute__((section("__trace_printk_fmt"))) = \
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__builtin_constant_p(fmt) ? fmt : NULL; \
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\
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__trace_bprintk(ip, trace_printk_fmt, ##args); \
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} else \
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__trace_printk(ip, fmt, ##args); \
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} while (0)
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#ifdef CONFIG_PERF_EVENTS
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struct perf_event;
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DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
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extern int perf_trace_init(struct perf_event *event);
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extern void perf_trace_destroy(struct perf_event *event);
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extern int perf_trace_add(struct perf_event *event, int flags);
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extern void perf_trace_del(struct perf_event *event, int flags);
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extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
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char *filter_str);
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extern void ftrace_profile_free_filter(struct perf_event *event);
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extern void *perf_trace_buf_prepare(int size, unsigned short type,
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struct pt_regs *regs, int *rctxp);
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static inline void
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perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
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u64 count, struct pt_regs *regs, void *head,
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struct task_struct *task)
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{
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perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
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}
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#endif
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#endif /* _LINUX_FTRACE_EVENT_H */
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