答复: [patch 04/54] dynamic_debug: add an option to enable dynamic debug for modules only
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  • 答复: [patch 04/54] dynamic_debug: add an option to enable dynamic debug for modules only
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翟京 (Orson Zhai) June 8, 2020, 4:58 a.m. UTC
Hi Andrew and Linus,

Could you please also add "Acked-by: Petr Mladek <pmladek@suse.com>" into this patch according to his mailing list replies at [1].

Thanks,
Orson

[1] https://lore.kernel.org/lkml/20200518095026.GL7340@linux-b0ei/

Patch
diff mbox series

--- 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