forked from luck/tmp_suning_uos_patched
346e15beb5
Base infrastructure to enable per-module debug messages. I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes control of debugging statements on a per-module basis in one /proc file, currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG, is not set, debugging statements can still be enabled as before, often by defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set. The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls can be dynamically enabled/disabled on a per-module basis. Future plans include extending this functionality to subsystems, that define their own debug levels and flags. Usage: Dynamic debugging is controlled by the debugfs file, <debugfs>/dynamic_printk/modules. This file contains a list of the modules that can be enabled. The format of the file is as follows: <module_name> <enabled=0/1> . . . <module_name> : Name of the module in which the debug call resides <enabled=0/1> : whether the messages are enabled or not For example: snd_hda_intel enabled=0 fixup enabled=1 driver enabled=0 Enable a module: $echo "set enabled=1 <module_name>" > dynamic_printk/modules Disable a module: $echo "set enabled=0 <module_name>" > dynamic_printk/modules Enable all modules: $echo "set enabled=1 all" > dynamic_printk/modules Disable all modules: $echo "set enabled=0 all" > dynamic_printk/modules Finally, passing "dynamic_printk" at the command line enables debugging for all modules. This mode can be turned off via the above disable command. [gkh: minor cleanups and tweaks to make the build work quietly] Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
94 lines
2.9 KiB
C
94 lines
2.9 KiB
C
#ifndef _DYNAMIC_PRINTK_H
|
|
#define _DYNAMIC_PRINTK_H
|
|
|
|
#define DYNAMIC_DEBUG_HASH_BITS 6
|
|
#define DEBUG_HASH_TABLE_SIZE (1 << DYNAMIC_DEBUG_HASH_BITS)
|
|
|
|
#define TYPE_BOOLEAN 1
|
|
|
|
#define DYNAMIC_ENABLED_ALL 0
|
|
#define DYNAMIC_ENABLED_NONE 1
|
|
#define DYNAMIC_ENABLED_SOME 2
|
|
|
|
extern int dynamic_enabled;
|
|
|
|
/* 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_printk_enabled;
|
|
extern long long dynamic_printk_enabled2;
|
|
|
|
struct mod_debug {
|
|
char *modname;
|
|
char *logical_modname;
|
|
char *flag_names;
|
|
int type;
|
|
int hash;
|
|
int hash2;
|
|
} __attribute__((aligned(8)));
|
|
|
|
int register_dynamic_debug_module(char *mod_name, int type, char *share_name,
|
|
char *flags, int hash, int hash2);
|
|
|
|
#if defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
|
|
extern int unregister_dynamic_debug_module(char *mod_name);
|
|
extern int __dynamic_dbg_enabled_helper(char *modname, int type,
|
|
int value, int hash);
|
|
|
|
#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ \
|
|
int __ret = 0; \
|
|
if (unlikely((dynamic_printk_enabled & (1LL << DEBUG_HASH)) && \
|
|
(dynamic_printk_enabled2 & (1LL << DEBUG_HASH2)))) \
|
|
__ret = __dynamic_dbg_enabled_helper(module, type, \
|
|
value, hash);\
|
|
__ret; })
|
|
|
|
#define dynamic_pr_debug(fmt, ...) do { \
|
|
static char mod_name[] \
|
|
__attribute__((section("__verbose_strings"))) \
|
|
= KBUILD_MODNAME; \
|
|
static struct mod_debug descriptor \
|
|
__used \
|
|
__attribute__((section("__verbose"), aligned(8))) = \
|
|
{ mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\
|
|
if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \
|
|
0, 0, DEBUG_HASH)) \
|
|
printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \
|
|
##__VA_ARGS__); \
|
|
} while (0)
|
|
|
|
#define dynamic_dev_dbg(dev, format, ...) do { \
|
|
static char mod_name[] \
|
|
__attribute__((section("__verbose_strings"))) \
|
|
= KBUILD_MODNAME; \
|
|
static struct mod_debug descriptor \
|
|
__used \
|
|
__attribute__((section("__verbose"), aligned(8))) = \
|
|
{ mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\
|
|
if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \
|
|
0, 0, DEBUG_HASH)) \
|
|
dev_printk(KERN_DEBUG, dev, \
|
|
KBUILD_MODNAME ": " format, \
|
|
##__VA_ARGS__); \
|
|
} while (0)
|
|
|
|
#else
|
|
|
|
static inline int unregister_dynamic_debug_module(const char *mod_name)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int __dynamic_dbg_enabled_helper(char *modname, int type,
|
|
int value, int hash)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ 0; })
|
|
#define dynamic_pr_debug(fmt, ...) do { } while (0)
|
|
#define dynamic_dev_dbg(dev, format, ...) do { } while (0)
|
|
#endif
|
|
|
|
#endif
|