kernel-ark/include/linux/marker.h
Mathieu Desnoyers acc4988bcf markers: add an if(0) to __mark_check_format()
Wrap __mark_check_format() into an if(0) to make sure that parameters such as

trace_mark(mm_page_alloc, "order %u pfn %lu", order, page?page_to_pfn(page):0);

(where page_to_pfn() has side-effects) won't generate code because of the
__mark_check_format().

Thanks to Jan Kiszka for reporting this.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:14 -08:00

146 lines
4.3 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
* @probe_private: probe private data
* @call_private: call site private data
* @fmt: format string
* @args: variable argument list pointer. Use a pointer to overcome C's
* inability to pass this around as a pointer in a portable manner in
* the callee otherwise.
*
* 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(void *probe_private, void *call_private,
const char *fmt, va_list *args);
struct marker_probe_closure {
marker_probe_func *func; /* Callback */
void *probe_private; /* Private probe data */
};
struct marker {
const char *name; /* Marker name */
const char *format; /* Marker format string, describing the
* variable argument list.
*/
char state; /* Marker state. */
char ptype; /* probe type : 0 : single, 1 : multi */
void (*call)(const struct marker *mdata, /* Probe wrapper */
void *call_private, const char *fmt, ...);
struct marker_probe_closure single;
struct marker_probe_closure *multi;
} __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_private, format, args...) \
do { \
static const char __mstrtab_##name[] \
__attribute__((section("__markers_strings"))) \
= #name "\0" format; \
static struct marker __mark_##name \
__attribute__((section("__markers"), aligned(8))) = \
{ __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
0, 0, marker_probe_cb, \
{ __mark_empty_function, NULL}, NULL }; \
__mark_check_format(format, ## args); \
if (unlikely(__mark_##name.state)) { \
(*__mark_##name.call) \
(&__mark_##name, call_private, \
format, ## args); \
} \
} while (0)
extern void marker_update_probe_range(struct marker *begin,
struct marker *end);
#else /* !CONFIG_MARKERS */
#define __trace_mark(name, call_private, format, args...) \
__mark_check_format(format, ## args)
static inline void marker_update_probe_range(struct marker *begin,
struct marker *end)
{ }
#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)
/**
* 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, ...)
{
}
#define __mark_check_format(format, args...) \
do { \
if (0) \
___mark_check_format(format, ## args); \
} while (0)
extern marker_probe_func __mark_empty_function;
extern void marker_probe_cb(const struct marker *mdata,
void *call_private, const char *fmt, ...);
extern void marker_probe_cb_noarg(const struct marker *mdata,
void *call_private, const char *fmt, ...);
/*
* 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 *probe_private);
/*
* Returns the private data given to marker_probe_register.
*/
extern int marker_probe_unregister(const char *name,
marker_probe_func *probe, void *probe_private);
/*
* Unregister a marker by providing the registered private data.
*/
extern int marker_probe_unregister_private_data(marker_probe_func *probe,
void *probe_private);
extern void *marker_get_private_data(const char *name, marker_probe_func *probe,
int num);
#endif