Merge branch 'do_once_lite'

Tanner Love says:

====================
net: update netdev_rx_csum_fault() print dump only once

First patch implements DO_ONCE_LITE to abstract uses of the ".data.once"
trick. It is defined in its own, new header file  -- rather than
alongside the existing DO_ONCE in include/linux/once.h -- because
include/linux/once.h includes include/linux/jump_label.h, and this
causes the build to break for some architectures if
include/linux/once.h is included in include/linux/printk.h or
include/asm-generic/bug.h.

Second patch uses DO_ONCE_LITE in netdev_rx_csum_fault to print dump
only once.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 34 insertions, 50 deletions

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index b402494883b6..bafc51f483c4 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -4,6 +4,7 @@
 
 #include <linux/compiler.h>
 #include <linux/instrumentation.h>
+#include <linux/once_lite.h>
 
 #define CUT_HERE		"------------[ cut here ]------------\n"
 
@@ -140,39 +141,15 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 })
 
 #ifndef WARN_ON_ONCE
-#define WARN_ON_ONCE(condition)	({				\
-	static bool __section(".data.once") __warned;		\
-	int __ret_warn_once = !!(condition);			\
-								\
-	if (unlikely(__ret_warn_once && !__warned)) {		\
-		__warned = true;				\
-		WARN_ON(1);					\
-	}							\
-	unlikely(__ret_warn_once);				\
-})
+#define WARN_ON_ONCE(condition)					\
+	DO_ONCE_LITE_IF(condition, WARN_ON, 1)
 #endif
 
-#define WARN_ONCE(condition, format...)	({			\
-	static bool __section(".data.once") __warned;		\
-	int __ret_warn_once = !!(condition);			\
-								\
-	if (unlikely(__ret_warn_once && !__warned)) {		\
-		__warned = true;				\
-		WARN(1, format);				\
-	}							\
-	unlikely(__ret_warn_once);				\
-})
+#define WARN_ONCE(condition, format...)				\
+	DO_ONCE_LITE_IF(condition, WARN, 1, format)
 
-#define WARN_TAINT_ONCE(condition, taint, format...)	({	\
-	static bool __section(".data.once") __warned;		\
-	int __ret_warn_once = !!(condition);			\
-								\
-	if (unlikely(__ret_warn_once && !__warned)) {		\
-		__warned = true;				\
-		WARN_TAINT(1, taint, format);			\
-	}							\
-	unlikely(__ret_warn_once);				\
-})
+#define WARN_TAINT_ONCE(condition, taint, format...)		\
+	DO_ONCE_LITE_IF(condition, WARN_TAINT, 1, taint, format)
 
 #else /* !CONFIG_BUG */
 #ifndef HAVE_ARCH_BUG
diff --git a/include/linux/once_lite.h b/include/linux/once_lite.h
new file mode 100644
index 000000000000..861e606b820f
--- /dev/null
+++ b/include/linux/once_lite.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_ONCE_LITE_H
+#define _LINUX_ONCE_LITE_H
+
+#include <linux/types.h>
+
+/* Call a function once. Similar to DO_ONCE(), but does not use jump label
+ * patching via static keys.
+ */
+#define DO_ONCE_LITE(func, ...)						\
+	DO_ONCE_LITE_IF(true, func, ##__VA_ARGS__)
+#define DO_ONCE_LITE_IF(condition, func, ...)				\
+	({								\
+		static bool __section(".data.once") __already_done;	\
+		bool __ret_do_once = !!(condition);			\
+									\
+		if (unlikely(__ret_do_once && !__already_done)) {	\
+			__already_done = true;				\
+			func(__VA_ARGS__);				\
+		}							\
+		unlikely(__ret_do_once);				\
+	})
+
+#endif /* _LINUX_ONCE_LITE_H */
diff --git a/include/linux/printk.h b/include/linux/printk.h
index fe7eb2351610..885379a1c9a1 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -8,6 +8,7 @@
 #include <linux/linkage.h>
 #include <linux/cache.h>
 #include <linux/ratelimit_types.h>
+#include <linux/once_lite.h>
 
 extern const char linux_banner[];
 extern const char linux_proc_banner[];
@@ -436,27 +437,9 @@ extern int kptr_restrict;
 
 #ifdef CONFIG_PRINTK
 #define printk_once(fmt, ...)					\
-({								\
-	static bool __section(".data.once") __print_once;	\
-	bool __ret_print_once = !__print_once;			\
-								\
-	if (!__print_once) {					\
-		__print_once = true;				\
-		printk(fmt, ##__VA_ARGS__);			\
-	}							\
-	unlikely(__ret_print_once);				\
-})
+	DO_ONCE_LITE(printk, fmt, ##__VA_ARGS__)
 #define printk_deferred_once(fmt, ...)				\
-({								\
-	static bool __section(".data.once") __print_once;	\
-	bool __ret_print_once = !__print_once;			\
-								\
-	if (!__print_once) {					\
-		__print_once = true;				\
-		printk_deferred(fmt, ##__VA_ARGS__);		\
-	}							\
-	unlikely(__ret_print_once);				\
-})
+	DO_ONCE_LITE(printk_deferred, fmt, ##__VA_ARGS__)
 #else
 #define printk_once(fmt, ...)					\
 	no_printk(fmt, ##__VA_ARGS__)