diff options
author | Jason Baron <jbaron@redhat.com> | 2008-08-12 16:46:19 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-16 12:24:47 -0400 |
commit | 346e15beb5343c2eb8216d820f2ed8f150822b08 (patch) | |
tree | 6433cf2980bbfbed4a9482c5edb156fc8371e071 /include/linux | |
parent | 33376c1c043c05077b4ac79c33804266f6c45e49 (diff) |
driver core: basic infrastructure for per-module dynamic debug messages
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>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/device.h | 6 | ||||
-rw-r--r-- | include/linux/dynamic_printk.h | 93 | ||||
-rw-r--r-- | include/linux/kernel.h | 7 | ||||
-rw-r--r-- | include/linux/module.h | 1 |
4 files changed, 104 insertions, 3 deletions
diff --git a/include/linux/device.h b/include/linux/device.h index 60f6456691a6..fb034461b395 100644 --- a/include/linux/device.h +++ b/include/linux/device.h | |||
@@ -550,7 +550,11 @@ extern const char *dev_driver_string(const struct device *dev); | |||
550 | #define dev_info(dev, format, arg...) \ | 550 | #define dev_info(dev, format, arg...) \ |
551 | dev_printk(KERN_INFO , dev , format , ## arg) | 551 | dev_printk(KERN_INFO , dev , format , ## arg) |
552 | 552 | ||
553 | #ifdef DEBUG | 553 | #if defined(CONFIG_DYNAMIC_PRINTK_DEBUG) |
554 | #define dev_dbg(dev, format, ...) do { \ | ||
555 | dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \ | ||
556 | } while (0) | ||
557 | #elif defined(DEBUG) | ||
554 | #define dev_dbg(dev, format, arg...) \ | 558 | #define dev_dbg(dev, format, arg...) \ |
555 | dev_printk(KERN_DEBUG , dev , format , ## arg) | 559 | dev_printk(KERN_DEBUG , dev , format , ## arg) |
556 | #else | 560 | #else |
diff --git a/include/linux/dynamic_printk.h b/include/linux/dynamic_printk.h new file mode 100644 index 000000000000..2d528d009074 --- /dev/null +++ b/include/linux/dynamic_printk.h | |||
@@ -0,0 +1,93 @@ | |||
1 | #ifndef _DYNAMIC_PRINTK_H | ||
2 | #define _DYNAMIC_PRINTK_H | ||
3 | |||
4 | #define DYNAMIC_DEBUG_HASH_BITS 6 | ||
5 | #define DEBUG_HASH_TABLE_SIZE (1 << DYNAMIC_DEBUG_HASH_BITS) | ||
6 | |||
7 | #define TYPE_BOOLEAN 1 | ||
8 | |||
9 | #define DYNAMIC_ENABLED_ALL 0 | ||
10 | #define DYNAMIC_ENABLED_NONE 1 | ||
11 | #define DYNAMIC_ENABLED_SOME 2 | ||
12 | |||
13 | extern int dynamic_enabled; | ||
14 | |||
15 | /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which | ||
16 | * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They | ||
17 | * use independent hash functions, to reduce the chance of false positives. | ||
18 | */ | ||
19 | extern long long dynamic_printk_enabled; | ||
20 | extern long long dynamic_printk_enabled2; | ||
21 | |||
22 | struct mod_debug { | ||
23 | char *modname; | ||
24 | char *logical_modname; | ||
25 | char *flag_names; | ||
26 | int type; | ||
27 | int hash; | ||
28 | int hash2; | ||
29 | } __attribute__((aligned(8))); | ||
30 | |||
31 | int register_dynamic_debug_module(char *mod_name, int type, char *share_name, | ||
32 | char *flags, int hash, int hash2); | ||
33 | |||
34 | #if defined(CONFIG_DYNAMIC_PRINTK_DEBUG) | ||
35 | extern int unregister_dynamic_debug_module(char *mod_name); | ||
36 | extern int __dynamic_dbg_enabled_helper(char *modname, int type, | ||
37 | int value, int hash); | ||
38 | |||
39 | #define __dynamic_dbg_enabled(module, type, value, level, hash) ({ \ | ||
40 | int __ret = 0; \ | ||
41 | if (unlikely((dynamic_printk_enabled & (1LL << DEBUG_HASH)) && \ | ||
42 | (dynamic_printk_enabled2 & (1LL << DEBUG_HASH2)))) \ | ||
43 | __ret = __dynamic_dbg_enabled_helper(module, type, \ | ||
44 | value, hash);\ | ||
45 | __ret; }) | ||
46 | |||
47 | #define dynamic_pr_debug(fmt, ...) do { \ | ||
48 | static char mod_name[] \ | ||
49 | __attribute__((section("__verbose_strings"))) \ | ||
50 | = KBUILD_MODNAME; \ | ||
51 | static struct mod_debug descriptor \ | ||
52 | __used \ | ||
53 | __attribute__((section("__verbose"), aligned(8))) = \ | ||
54 | { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\ | ||
55 | if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \ | ||
56 | 0, 0, DEBUG_HASH)) \ | ||
57 | printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \ | ||
58 | ##__VA_ARGS__); \ | ||
59 | } while (0) | ||
60 | |||
61 | #define dynamic_dev_dbg(dev, format, ...) do { \ | ||
62 | static char mod_name[] \ | ||
63 | __attribute__((section("__verbose_strings"))) \ | ||
64 | = KBUILD_MODNAME; \ | ||
65 | static struct mod_debug descriptor \ | ||
66 | __used \ | ||
67 | __attribute__((section("__verbose"), aligned(8))) = \ | ||
68 | { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\ | ||
69 | if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \ | ||
70 | 0, 0, DEBUG_HASH)) \ | ||
71 | dev_printk(KERN_DEBUG, dev, \ | ||
72 | KBUILD_MODNAME ": " format, \ | ||
73 | ##__VA_ARGS__); \ | ||
74 | } while (0) | ||
75 | |||
76 | #else | ||
77 | |||
78 | static inline int unregister_dynamic_debug_module(const char *mod_name) | ||
79 | { | ||
80 | return 0; | ||
81 | } | ||
82 | static inline int __dynamic_dbg_enabled_helper(char *modname, int type, | ||
83 | int value, int hash) | ||
84 | { | ||
85 | return 0; | ||
86 | } | ||
87 | |||
88 | #define __dynamic_dbg_enabled(module, type, value, level, hash) ({ 0; }) | ||
89 | #define dynamic_pr_debug(fmt, ...) do { } while (0) | ||
90 | #define dynamic_dev_dbg(dev, format, ...) do { } while (0) | ||
91 | #endif | ||
92 | |||
93 | #endif | ||
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 75d81f157d2e..ededb6e83b41 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h | |||
@@ -16,6 +16,7 @@ | |||
16 | #include <linux/log2.h> | 16 | #include <linux/log2.h> |
17 | #include <linux/typecheck.h> | 17 | #include <linux/typecheck.h> |
18 | #include <linux/ratelimit.h> | 18 | #include <linux/ratelimit.h> |
19 | #include <linux/dynamic_printk.h> | ||
19 | #include <asm/byteorder.h> | 20 | #include <asm/byteorder.h> |
20 | #include <asm/bug.h> | 21 | #include <asm/bug.h> |
21 | 22 | ||
@@ -303,8 +304,12 @@ static inline char *pack_hex_byte(char *buf, u8 byte) | |||
303 | #define pr_info(fmt, arg...) \ | 304 | #define pr_info(fmt, arg...) \ |
304 | printk(KERN_INFO fmt, ##arg) | 305 | printk(KERN_INFO fmt, ##arg) |
305 | 306 | ||
306 | #ifdef DEBUG | ||
307 | /* If you are writing a driver, please use dev_dbg instead */ | 307 | /* If you are writing a driver, please use dev_dbg instead */ |
308 | #if defined(CONFIG_DYNAMIC_PRINTK_DEBUG) | ||
309 | #define pr_debug(fmt, ...) do { \ | ||
310 | dynamic_pr_debug(fmt, ##__VA_ARGS__); \ | ||
311 | } while (0) | ||
312 | #elif defined(DEBUG) | ||
308 | #define pr_debug(fmt, arg...) \ | 313 | #define pr_debug(fmt, arg...) \ |
309 | printk(KERN_DEBUG fmt, ##arg) | 314 | printk(KERN_DEBUG fmt, ##arg) |
310 | #else | 315 | #else |
diff --git a/include/linux/module.h b/include/linux/module.h index 68e09557c951..a41555cbe00a 100644 --- a/include/linux/module.h +++ b/include/linux/module.h | |||
@@ -345,7 +345,6 @@ struct module | |||
345 | /* Reference counts */ | 345 | /* Reference counts */ |
346 | struct module_ref ref[NR_CPUS]; | 346 | struct module_ref ref[NR_CPUS]; |
347 | #endif | 347 | #endif |
348 | |||
349 | }; | 348 | }; |
350 | #ifndef MODULE_ARCH_INIT | 349 | #ifndef MODULE_ARCH_INIT |
351 | #define MODULE_ARCH_INIT {} | 350 | #define MODULE_ARCH_INIT {} |