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dynamic_debug: add an option to enable dynamic debug for modules only

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Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic
debug.  With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic
debug will be tied to them.

This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.

[orson.zhai@unisoc.com: v2]
  Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@gmail.com

Signed-off-by: Orson Zhai <orson.zhai@unisoc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Orson Zhai 2020-06-07 21:40:14 -07:00 committed by Linus Torvalds
parent e1eb26fa62
commit ceabef7dd7
10 changed files with 46 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
Documentation/admin-guide/dynamic-debug-howto.rst
View File

@ -13,6 +13,11 @@ kernel code to obtain additional kernel information. Currently, if
``print_hex_dump_debug()``/``print_hex_dump_bytes()`` calls can be dynamically
enabled per-callsite.
If you do not want to enable dynamic debug globally (i.e. in some embedded
system), you may set ``CONFIG_DYNAMIC_DEBUG_CORE`` as basic support of dynamic
debug and add ``ccflags := -DDYNAMIC_DEBUG_MODULE`` into the Makefile of any
modules which you'd like to dynamically debug later.
If ``CONFIG_DYNAMIC_DEBUG`` is not set, ``print_hex_dump_debug()`` is just
shortcut for ``print_hex_dump(KERN_DEBUG)``.

6
include/linux/dev_printk.h
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@ -109,7 +109,8 @@ void _dev_info(const struct device *dev, const char *fmt, ...)
#define dev_info(dev, fmt, ...) \
_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#define dev_dbg(dev, fmt, ...) \
dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
#elif defined(DEBUG)
@ -181,7 +182,8 @@ do { \
dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
#define dev_info_ratelimited(dev, fmt, ...) \
dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
/* descriptor check is first to prevent flooding with "callbacks suppressed" */
#define dev_dbg_ratelimited(dev, fmt, ...) \
do { \

2
include/linux/dynamic_debug.h
View File

@ -48,7 +48,7 @@ struct _ddebug {
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG_CORE)
int ddebug_add_module(struct _ddebug *tab, unsigned int n,
const char *modname);
extern int ddebug_remove_module(const char *mod_name);

3
include/linux/net.h
View File

@ -264,7 +264,8 @@ do { \
net_ratelimited_function(pr_warn, fmt, ##__VA_ARGS__)
#define net_info_ratelimited(fmt, ...) \
net_ratelimited_function(pr_info, fmt, ##__VA_ARGS__)
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#define net_dbg_ratelimited(fmt, ...) \
do { \
DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \

6
include/linux/netdevice.h
View File

@ -4942,7 +4942,8 @@ do { \
#define MODULE_ALIAS_NETDEV(device) \
MODULE_ALIAS("netdev-" device)
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#define netdev_dbg(__dev, format, args...) \
do { \
dynamic_netdev_dbg(__dev, format, ##args); \
@ -5012,7 +5013,8 @@ do { \
#define netif_info(priv, type, dev, fmt, args...) \
netif_level(info, priv, type, dev, fmt, ##args)
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#define netif_dbg(priv, type, netdev, format, args...) \
do { \
if (netif_msg_##type(priv)) \

9
include/linux/printk.h
View File

@ -399,7 +399,8 @@ extern int kptr_restrict;
/* If you are writing a driver, please use dev_dbg instead */
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#include <linux/dynamic_debug.h>
/**
@ -535,7 +536,8 @@ extern int kptr_restrict;
#endif
/* If you are writing a driver, please use dev_dbg instead */
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
/* descriptor check is first to prevent flooding with "callbacks suppressed" */
#define pr_debug_ratelimited(fmt, ...) \
do { \
@ -582,7 +584,8 @@ static inline void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
#endif
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii) \
dynamic_hex_dump(prefix_str, prefix_type, rowsize, \

6
include/rdma/ib_verbs.h
View File

@ -100,7 +100,8 @@ void ibdev_notice(const struct ib_device *ibdev, const char *format, ...);
__printf(2, 3) __cold
void ibdev_info(const struct ib_device *ibdev, const char *format, ...);
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
#define ibdev_dbg(__dev, format, args...) \
dynamic_ibdev_dbg(__dev, format, ##args)
#else
@ -133,7 +134,8 @@ do { \
#define ibdev_info_ratelimited(ibdev, fmt, ...) \
ibdev_level_ratelimited(ibdev_info, ibdev, fmt, ##__VA_ARGS__)
#if defined(CONFIG_DYNAMIC_DEBUG)
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
/* descriptor check is first to prevent flooding with "callbacks suppressed" */
#define ibdev_dbg_ratelimited(ibdev, fmt, ...) \
do { \

12
lib/Kconfig.debug
View File

@ -99,6 +99,7 @@ config DYNAMIC_DEBUG
default n
depends on PRINTK
depends on (DEBUG_FS || PROC_FS)
select DYNAMIC_DEBUG_CORE
help
Compiles debug level messages into the kernel, which would not
@ -165,6 +166,17 @@ config DYNAMIC_DEBUG
See Documentation/admin-guide/dynamic-debug-howto.rst for additional
information.
config DYNAMIC_DEBUG_CORE
bool "Enable core function of dynamic debug support"
depends on PRINTK
depends on (DEBUG_FS || PROC_FS)
help
Enable core functional support of dynamic debug. It is useful
when you want to tie dynamic debug to your kernel modules with
DYNAMIC_DEBUG_MODULE defined for each of them, especially for
the case of embedded system where the kernel image size is
sensitive for people.
config SYMBOLIC_ERRNAME
bool "Support symbolic error names in printf"
default y if PRINTK

2
lib/Makefile
View File

@ -190,7 +190,7 @@ lib-$(CONFIG_GENERIC_BUG) += bug.o
obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o
obj-$(CONFIG_DYNAMIC_DEBUG_CORE) += dynamic_debug.o
obj-$(CONFIG_SYMBOLIC_ERRNAME) += errname.o
obj-$(CONFIG_NLATTR) += nlattr.o

9
lib/dynamic_debug.c
View File

@ -1032,8 +1032,13 @@ static int __init dynamic_debug_init(void)
int verbose_bytes = 0;
if (&__start___verbose == &__stop___verbose) {
pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
return 1;
if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
return 1;
}
pr_info("Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build\n");
ddebug_init_success = 1;
return 0;
}
iter = __start___verbose;
modname = iter->modname;