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| author | Orson Zhai <orson.zhai@unisoc.com> | 2020-06-07 21:40:14 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-08 11:05:56 -0700 |
| commit | ceabef7dd71720aef58bd182943352c9c307a3de (patch) | |
| tree | f5270f714445383a3ccd71774a2a96658b9c6f86 /lib | |
| parent | e1eb26fa62d04ec0955432be1aa8722a97cb52e7 (diff) | |
| download | lwn-ceabef7dd71720aef58bd182943352c9c307a3de.tar.gz lwn-ceabef7dd71720aef58bd182943352c9c307a3de.zip | |
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: 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>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 12 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/dynamic_debug.c | 9 |
3 files changed, 20 insertions, 3 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 9bd4eb7f5ec1..333e878d8af9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -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 diff --git a/lib/Makefile b/lib/Makefile index 32f19b4d1d2a..315516fa4ef4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -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 diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 8f199f403ab5..321437bbf87d 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -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; |