Hi Andrew and Linus, Could you please also add "Acked-by: Petr Mladek <pmladek@xxxxxxxx>" into this patch according to his mailing list replies at [1]. Thanks, Orson [1] https://lore.kernel.org/lkml/20200518095026.GL7340@linux-b0ei/ ________________________________________ 发件人: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> 发送时间: 2020年6月8日 12:40 收件人: akpm@xxxxxxxxxxxxxxxxxxxx; corbet@xxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; jbaron@xxxxxxxxxx; linux-mm@xxxxxxxxx; mm-commits@xxxxxxxxxxxxxxx; 翟京 (Orson Zhai); pmladek@xxxxxxxx; rdunlap@xxxxxxxxxxxxx; rostedt@xxxxxxxxxxx; sergey.senozhatsky@xxxxxxxxx; torvalds@xxxxxxxxxxxxxxxxxxxx 主题: [patch 04/54] dynamic_debug: add an option to enable dynamic debug for modules only From: Orson Zhai <orson.zhai@xxxxxxxxxx> Subject: 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@xxxxxxxxxx: v2] Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@xxxxxxxxx Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@xxxxxxxxx Signed-off-by: Orson Zhai <orson.zhai@xxxxxxxxxx> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Jason Baron <jbaron@xxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/admin-guide/dynamic-debug-howto.rst | 5 +++++ include/linux/dev_printk.h | 6 ++++-- include/linux/dynamic_debug.h | 2 +- include/linux/net.h | 3 ++- include/linux/netdevice.h | 6 ++++-- include/linux/printk.h | 9 ++++++--- include/rdma/ib_verbs.h | 6 ++++-- lib/Kconfig.debug | 12 ++++++++++++ lib/Makefile | 2 +- lib/dynamic_debug.c | 9 +++++++-- 10 files changed, 46 insertions(+), 14 deletions(-) --- a/Documentation/admin-guide/dynamic-debug-howto.rst~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/Documentation/admin-guide/dynamic-debug-howto.rst @@ -13,6 +13,11 @@ kernel code to obtain additional kernel ``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)``. --- a/include/linux/dev_printk.h~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/include/linux/dev_printk.h @@ -109,7 +109,8 @@ void _dev_info(const struct device *dev, #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 { \ --- a/include/linux/dynamic_debug.h~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/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); --- a/include/linux/netdevice.h~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/include/linux/netdevice.h @@ -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)) \ --- a/include/linux/net.h~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/include/linux/net.h @@ -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); \ --- a/include/linux/printk.h~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/include/linux/printk.h @@ -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( #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, \ --- a/include/rdma/ib_verbs.h~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/include/rdma/ib_verbs.h @@ -100,7 +100,8 @@ void ibdev_notice(const struct ib_device __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 { \ --- a/lib/dynamic_debug.c~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/lib/dynamic_debug.c @@ -1032,8 +1032,13 @@ static int __init dynamic_debug_init(voi 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; --- a/lib/Kconfig.debug~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/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 --- a/lib/Makefile~dynamic_debug-add-an-option-to-enable-dynamic-debug-for-modules-only +++ a/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 _ ________________________________ This email (including its attachments) is intended only for the person or entity to which it is addressed and may contain information that is privileged, confidential or otherwise protected from disclosure. Unauthorized use, dissemination, distribution or copying of this email or the information herein or taking any action in reliance on the contents of this email or the information herein, by anyone other than the intended recipient, or an employee or agent responsible for delivering the message to the intended recipient, is strictly prohibited. If you are not the intended recipient, please do not read, copy, use or disclose any part of this e-mail to others. Please notify the sender immediately and permanently delete this e-mail and any attachments if you received it in error. Internet communications cannot be guaranteed to be timely, secure, error-free or virus-free. The sender does not accept liability for any errors or omissions. 本邮件及其附件具有保密性质，受法律保护不得泄露，仅发送给本邮件所指特定收件人。严禁非经授权使用、宣传、发布或复制本邮件或其内容。若非该特定收件人，请勿阅读、复制、 使用或披露本邮件的任何内容。若误收本邮件，请从系统中永久性删除本邮件及所有附件，并以回复邮件的方式即刻告知发件人。无法保证互联网通信及时、安全、无误或防毒。发件人对任何错漏均不承担责任。
