diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 0dc2eb8e44e5fa56ad19cb1191f182090ee614f8..1012bd9305e905f9b75cc0539fae1f9fe0531f60 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -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)``.
diff --git a/include/linux/dev_printk.h b/include/linux/dev_printk.h
index 5aad06b4ca7bb1341d8991a212f1a4b8d7ec0b1b..3028b644b4fbde5dbfa3bdf298b042b669830a02 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_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 { \
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 4cf02ecd67de7f61c84ec7c8db22d48cd900fb85..abcd5fde30eb736e428fba8b27c8a096e32e8793 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/net.h b/include/linux/net.h
index e10f378194a59d22c6305f1737757852587b17d7..016a9c5faa3479b968443b1db07c1150e7e3a0f7 100644
--- a/include/linux/net.h
+++ b/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); \
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1a96e9c4ec36fce56d2b167298411277710eb84b..5b364a2e0006250e440a988b2a72da9a046bc70f 100644
--- a/include/linux/netdevice.h
+++ b/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)) \
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 3cc2f178bf06f03536df767e498a1e20162b2aec..fc8f03c545430292daa322b8dd941d88f951dc2f 100644
--- a/include/linux/printk.h
+++ b/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(const char *prefix_str, int prefix_type,
#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, \
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 033e7044f29c35b9fdee21c75614807d354e4bb4..ef2f3986c4933434d27b482e20747c2e8c491456 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -100,7 +100,8 @@ void ibdev_notice(const struct ib_device *ibdev, const char *format, ...);
__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 { \
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 9bd4eb7f5ec1952c97a6dddbb42eab37bbe9cdc7..333e878d8af95b2a27e034df0f5e033b7c72ca25 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 32f19b4d1d2a6209a55d19d0159ef19086b83a5b..315516fa4ef45b9a231fdb0a274b35482d25d346 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 8f199f403ab50656c4d91344932204bee6ac9d17..321437bbf87dd304a82d3452766b2102e60e7383 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;