Messages in this thread | | | From | Orson Zhai <> | Date | Sat, 28 Mar 2020 14:17:43 +0800 | Subject | Re: [RFC PATCH V2] dynamic_debug: Add config option of DYNAMIC_DEBUG_CORE |
| |
Hi Jason,
On Thu, Mar 26, 2020 at 1:13 AM Orson Zhai <orson.unisoc@gmail.com> wrote: > > Instead of enabling whole kernel with CONFIG_DYNAMIC_DEBUG, CONFIG_ > DYNAMIC_DEBUG_CORE will only make the basic function definition and > exported symbols to be built without replacing pr_debug or dev_dbg > to dynamic version unless DEBUG is defined for any desired modules
How do you think about this idea? Optionally enable dynamic debug of modules by the DEBUG macro.
Best Regards, -Orson
> together by users. > > This is useful for people who only want to enable dynamic debug for some > specific kernel modules without worrying about whole kernel image size will > be significantly increased and more memory consumption caused by CONFIG_ > DYNAMIC_DEBUG. > > Signed-off-by: Orson Zhai <orson.unisoc@gmail.com> > --- > Changes from V1: > - Rewrite commit message for more generic usage. > - Add combination use of CONFIG_DYNAMIC_DEBUG_CORE and DEBUG to enable > dynamic debug seperately. > - Ignore empty _ddtable and return success when only the core is enabled. > - Fix all typoes. > > include/linux/dev_printk.h | 6 ++++-- > include/linux/dynamic_debug.h | 2 +- > include/linux/printk.h | 12 ++++++++---- > lib/Kconfig.debug | 18 ++++++++++++++++++ > lib/Makefile | 2 +- > lib/dynamic_debug.c | 9 +++++++-- > 6 files changed, 39 insertions(+), 10 deletions(-) > > diff --git a/include/linux/dev_printk.h b/include/linux/dev_printk.h > index 5aad06b..ed40030 100644 > --- a/include/linux/dev_printk.h > +++ b/include/linux/dev_printk.h > @@ -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_CORE) && defined(DEBUG)) > #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_CORE) && defined(DEBUG)) > /* descriptor check is first to prevent flooding with "callbacks suppressed" */ > #define dev_dbg_ratelimited(dev, fmt, ...) \ > do { \ > diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h > index 4cf02ec..abcd5fd 100644 > --- a/include/linux/dynamic_debug.h > +++ b/include/linux/dynamic_debug.h > @@ -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); > diff --git a/include/linux/printk.h b/include/linux/printk.h > index 1e6108b..44d5378 100644 > --- a/include/linux/printk.h > +++ b/include/linux/printk.h > @@ -292,7 +292,8 @@ extern int kptr_restrict; > * These can be used to print at the various log levels. > * All of these will print unconditionally, although note that pr_debug() > * and other debug macros are compiled out unless either DEBUG is defined > - * or CONFIG_DYNAMIC_DEBUG is set. > + * or CONFIG_DYNAMIC_DEBUG is set, or both CONFIG_DYNAMIC_DEBUG_CORE and > + * DEBUG is defined. > */ > #define pr_emerg(fmt, ...) \ > printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__) > @@ -327,7 +328,8 @@ 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_CORE) && defined(DEBUG)) > #include <linux/dynamic_debug.h> > > /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */ > @@ -453,7 +455,8 @@ 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_CORE) && defined(DEBUG)) > /* descriptor check is first to prevent flooding with "callbacks suppressed" */ > #define pr_debug_ratelimited(fmt, ...) \ > do { \ > @@ -500,7 +503,8 @@ 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_CORE) && defined(DEBUG)) > #define print_hex_dump_debug(prefix_str, prefix_type, rowsize, \ > groupsize, buf, len, ascii) \ > dynamic_hex_dump(prefix_str, prefix_type, rowsize, \ > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 69def4a..8381b19 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 > + select DYNAMIC_DEBUG_CORE > help > > Compiles debug level messages into the kernel, which would not > @@ -164,6 +165,23 @@ config DYNAMIC_DEBUG > See Documentation/admin-guide/dynamic-debug-howto.rst for additional > information. > > +config DYNAMIC_DEBUG_CORE > + bool "Enable core functions of dynamic debug support" > + depends on PRINTK > + depends on DEBUG_FS > + help > + Enable this option to build ddebug_* and __dynamic_* routines > + into kernel. If you want enable whole dynamic debug features, > + select CONFIG_DYNAMIC_DEBUG directly and this option will be > + automatically selected as well. > + > + This option can be selected with DEBUG together which could be > + defined for desired kernel modules to enable dynamic debug > + features instead for whole kernel. Especially being used in > + the case that kernel modules are built out of kernel tree to > + have dynamic debug capabilities without affecting the kernel > + base. > + > config SYMBOLIC_ERRNAME > bool "Support symbolic error names in printf" > default y if PRINTK > diff --git a/lib/Makefile b/lib/Makefile > index 611872c..2096d83 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -183,7 +183,7 @@ 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 c604091..34f303a 100644 > --- a/lib/dynamic_debug.c > +++ b/lib/dynamic_debug.c > @@ -1014,8 +1014,13 @@ 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 core only build\n"); > + ddebug_init_success = 1; > + return 0; > } > iter = __start___verbose; > modname = iter->modname; > -- > 2.7.4 >
| |