Commit ceabef7d authored by Orson Zhai's avatar Orson Zhai Committed by Linus Torvalds
Browse files

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

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: default avatarOrson Zhai <orson.zhai@unisoc.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: default avatarPetr 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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e1eb26fa

Documentation/admin-guide/dynamic-debug-howto.rst

+5 −0
Original line number Diff line number Diff line
@@ -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)``.

include/linux/dev_printk.h

+4 −2
Original line number Diff line number Diff line
@@ -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 {									\

include/linux/dynamic_debug.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

include/linux/net.h

+2 −1
Original line number Diff line number Diff line
@@ -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);			\

include/linux/netdevice.h

+4 −2
Original line number Diff line number Diff line
@@ -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))				\

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