linux-stable/include/linux/ftrace_event.h
Steven Rostedt 0429578016 tracing/events: Show real number in array fields
Currently we have in something like the sched_switch event:

  field:char prev_comm[TASK_COMM_LEN];	offset:12;	size:16;	signed:1;

When a userspace tool such as perf tries to parse this, the
TASK_COMM_LEN is meaningless. This is done because the TRACE_EVENT() macro
simply uses a #len to show the string of the length. When the length is
an enum, we get a string that means nothing for tools.

By adding a static buffer and a mutex to protect it, we can store the
string into that buffer with snprintf and show the actual number.
Now we get:

  field:char prev_comm[16];       offset:12;      size:16;        signed:1;

Something much more useful.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-19 10:18:47 -05:00

285 lines
7.9 KiB
C

#ifndef _LINUX_FTRACE_EVENT_H
#define _LINUX_FTRACE_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>
struct trace_array;
struct tracer;
struct dentry;
struct trace_print_flags {
unsigned long mask;
const char *name;
};
const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
unsigned long flags,
const struct trace_print_flags *flag_array);
const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
const struct trace_print_flags *symbol_array);
const char *ftrace_print_hex_seq(struct trace_seq *p,
const unsigned char *buf, int len);
/*
* 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;
int lock_depth;
};
#define FTRACE_MAX_EVENT \
((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;
void *private;
int cpu_file;
struct mutex mutex;
struct ring_buffer_iter *buffer_iter[NR_CPUS];
unsigned long iter_flags;
/* trace_seq for __print_flags() and __print_symbolic() etc. */
struct trace_seq tmp_seq;
/* The below is zeroed out in pipe_read */
struct trace_seq seq;
struct trace_entry *ent;
unsigned long lost_events;
int leftover;
int cpu;
u64 ts;
loff_t pos;
long idx;
cpumask_var_t started;
};
struct trace_event;
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_ftrace_event(struct trace_event *event);
extern int unregister_ftrace_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 */
};
void tracing_generic_entry_update(struct trace_entry *entry,
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_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc);
void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event);
void tracing_record_cmdline(struct task_struct *tsk);
struct event_filter;
enum trace_reg {
TRACE_REG_REGISTER,
TRACE_REG_UNREGISTER,
TRACE_REG_PERF_REGISTER,
TRACE_REG_PERF_UNREGISTER,
};
struct ftrace_event_call;
struct ftrace_event_class {
char *system;
void *probe;
#ifdef CONFIG_PERF_EVENTS
void *perf_probe;
#endif
int (*reg)(struct ftrace_event_call *event,
enum trace_reg type);
int (*define_fields)(struct ftrace_event_call *);
struct list_head *(*get_fields)(struct ftrace_event_call *);
struct list_head fields;
int (*raw_init)(struct ftrace_event_call *);
};
extern int ftrace_event_reg(struct ftrace_event_call *event,
enum trace_reg type);
enum {
TRACE_EVENT_FL_ENABLED_BIT,
TRACE_EVENT_FL_FILTERED_BIT,
TRACE_EVENT_FL_RECORDED_CMD_BIT,
TRACE_EVENT_FL_CAP_ANY_BIT,
};
enum {
TRACE_EVENT_FL_ENABLED = (1 << TRACE_EVENT_FL_ENABLED_BIT),
TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
TRACE_EVENT_FL_RECORDED_CMD = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
};
struct ftrace_event_call {
struct list_head list;
struct ftrace_event_class *class;
char *name;
struct dentry *dir;
struct trace_event event;
const char *print_fmt;
struct event_filter *filter;
void *mod;
void *data;
/*
* 32 bit flags:
* bit 1: enabled
* bit 2: filter_active
* bit 3: enabled cmd record
*
* Changes to flags must hold the event_mutex.
*
* Note: Reads of flags do not hold the event_mutex since
* they occur in critical sections. But the way flags
* is currently used, these changes do no 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.
*/
unsigned int flags;
#ifdef CONFIG_PERF_EVENTS
int perf_refcount;
struct hlist_head __percpu *perf_events;
#endif
};
#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 PERF_MAX_TRACE_SIZE 2048
#define MAX_FILTER_PRED 32
#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
extern void destroy_preds(struct ftrace_event_call *call);
extern int filter_match_preds(struct event_filter *filter, void *rec);
extern int filter_current_check_discard(struct ring_buffer *buffer,
struct ftrace_event_call *call,
void *rec,
struct ring_buffer_event *event);
enum {
FILTER_OTHER = 0,
FILTER_STATIC_STRING,
FILTER_DYN_STRING,
FILTER_PTR_STRING,
};
#define EVENT_STORAGE_SIZE 128
extern struct mutex event_storage_mutex;
extern char event_storage[EVENT_STORAGE_SIZE];
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 void trace_remove_event_call(struct ftrace_event_call *call);
#define is_signed_type(type) (((type)(-1)) < 0)
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)
{
perf_tp_event(addr, count, raw_data, size, regs, head, rctx);
}
#endif
#endif /* _LINUX_FTRACE_EVENT_H */