linux-stable/include/linux/marker.h
Mathieu Desnoyers 31155bc03e Linux Kernel Markers - Samples
Module example showing how to use the Linux Kernel Markers.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:55 -07:00

129 lines
3.8 KiB
C

#ifndef _LINUX_MARKER_H
#define _LINUX_MARKER_H
/*
* Code markup for dynamic and static tracing.
*
* See Documentation/marker.txt.
*
* (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
*
* This file is released under the GPLv2.
* See the file COPYING for more details.
*/
#include <linux/types.h>
struct module;
struct marker;
/**
* marker_probe_func - Type of a marker probe function
* @mdata: pointer of type struct marker
* @private_data: caller site private data
* @fmt: format string
* @...: variable argument list
*
* Type of marker probe functions. They receive the mdata and need to parse the
* format string to recover the variable argument list.
*/
typedef void marker_probe_func(const struct marker *mdata,
void *private_data, const char *fmt, ...);
struct marker {
const char *name; /* Marker name */
const char *format; /* Marker format string, describing the
* variable argument list.
*/
char state; /* Marker state. */
marker_probe_func *call;/* Probe handler function pointer */
void *private; /* Private probe data */
} __attribute__((aligned(8)));
#ifdef CONFIG_MARKERS
/*
* Note : the empty asm volatile with read constraint is used here instead of a
* "used" attribute to fix a gcc 4.1.x bug.
* Make sure the alignment of the structure in the __markers section will
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
*/
#define __trace_mark(name, call_data, format, args...) \
do { \
static const char __mstrtab_name_##name[] \
__attribute__((section("__markers_strings"))) \
= #name; \
static const char __mstrtab_format_##name[] \
__attribute__((section("__markers_strings"))) \
= format; \
static struct marker __mark_##name \
__attribute__((section("__markers"), aligned(8))) = \
{ __mstrtab_name_##name, __mstrtab_format_##name, \
0, __mark_empty_function, NULL }; \
__mark_check_format(format, ## args); \
if (unlikely(__mark_##name.state)) { \
preempt_disable(); \
(*__mark_##name.call) \
(&__mark_##name, call_data, \
format, ## args); \
preempt_enable(); \
} \
} while (0)
extern void marker_update_probe_range(struct marker *begin,
struct marker *end, struct module *probe_module, int *refcount);
#else /* !CONFIG_MARKERS */
#define __trace_mark(name, call_data, format, args...) \
__mark_check_format(format, ## args)
static inline void marker_update_probe_range(struct marker *begin,
struct marker *end, struct module *probe_module, int *refcount)
{ }
#endif /* CONFIG_MARKERS */
/**
* trace_mark - Marker
* @name: marker name, not quoted.
* @format: format string
* @args...: variable argument list
*
* Places a marker.
*/
#define trace_mark(name, format, args...) \
__trace_mark(name, NULL, format, ## args)
#define MARK_MAX_FORMAT_LEN 1024
/**
* MARK_NOARGS - Format string for a marker with no argument.
*/
#define MARK_NOARGS " "
/* To be used for string format validity checking with gcc */
static inline void __printf(1, 2) __mark_check_format(const char *fmt, ...)
{
}
extern marker_probe_func __mark_empty_function;
/*
* Connect a probe to a marker.
* private data pointer must be a valid allocated memory address, or NULL.
*/
extern int marker_probe_register(const char *name, const char *format,
marker_probe_func *probe, void *private);
/*
* Returns the private data given to marker_probe_register.
*/
extern void *marker_probe_unregister(const char *name);
/*
* Unregister a marker by providing the registered private data.
*/
extern void *marker_probe_unregister_private_data(void *private);
extern int marker_arm(const char *name);
extern int marker_disarm(const char *name);
extern void *marker_get_private_data(const char *name);
#endif