linux-stable/include/linux/dynamic_debug.h
Yehuda Sadeh ff49d74ad3 module: initialize module dynamic debug later
We should initialize the module dynamic debug datastructures
only after determining that the module is not loaded yet. This
fixes a bug that introduced in 2.6.35-rc2, where when a trying
to load a module twice, we also load it's dynamic printing data
twice which causes all sorts of nasty issues. Also handle
the dynamic debug cleanup later on failure.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-04 20:17:22 -07:00

87 lines
2.7 KiB
C

#ifndef _DYNAMIC_DEBUG_H
#define _DYNAMIC_DEBUG_H
/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
* bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
* use independent hash functions, to reduce the chance of false positives.
*/
extern long long dynamic_debug_enabled;
extern long long dynamic_debug_enabled2;
/*
* An instance of this structure is created in a special
* ELF section at every dynamic debug callsite. At runtime,
* the special section is treated as an array of these.
*/
struct _ddebug {
/*
* These fields are used to drive the user interface
* for selecting and displaying debug callsites.
*/
const char *modname;
const char *function;
const char *filename;
const char *format;
char primary_hash;
char secondary_hash;
unsigned int lineno:24;
/*
* The flags field controls the behaviour at the callsite.
* The bits here are changed dynamically when the user
* writes commands to <debugfs>/dynamic_debug/control
*/
#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
#define _DPRINTK_FLAGS_DEFAULT 0
unsigned int flags:8;
} __attribute__((aligned(8)));
int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname);
#if defined(CONFIG_DYNAMIC_DEBUG)
extern int ddebug_remove_module(const char *mod_name);
#define __dynamic_dbg_enabled(dd) ({ \
int __ret = 0; \
if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \
(dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \
if (unlikely(dd.flags)) \
__ret = 1; \
__ret; })
#define dynamic_pr_debug(fmt, ...) do { \
static struct _ddebug descriptor \
__used \
__attribute__((section("__verbose"), aligned(8))) = \
{ KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
if (__dynamic_dbg_enabled(descriptor)) \
printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
} while (0)
#define dynamic_dev_dbg(dev, fmt, ...) do { \
static struct _ddebug descriptor \
__used \
__attribute__((section("__verbose"), aligned(8))) = \
{ KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \
DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \
if (__dynamic_dbg_enabled(descriptor)) \
dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \
} while (0)
#else
static inline int ddebug_remove_module(const char *mod)
{
return 0;
}
#define dynamic_pr_debug(fmt, ...) \
do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
#define dynamic_dev_dbg(dev, format, ...) \
do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
#endif
#endif