WARN_ON_SMP(): Allow use in if() statements on UP (2092e6be) · Commits · 戴 / test

Both WARN_ON() and WARN_ON_SMP() should be able to be used in an if statement. if (WARN_ON_SMP(foo)) { ... } Because WARN_ON_SMP() is defined as a do { } while (0) on UP, it can not be used this way. Convert it to the same form that WARN_ON() is, even when CONFIG_SMP is off. Signed-off-by:

Steven Rostedt <rostedt@goodmis.org> Acked-by:

Thomas Gleixner <tglx@linutronix.de> Acked-by:

Peter Zijlstra <peterz@infradead.org> Acked-by:

Darren Hart <dvhart@linux.intel.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20110317192208.444147791@goodmis.org> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

include/asm-generic/bug.h

+27 −1

Original line number	Diff line number	Diff line
		@@ -165,10 +165,36 @@ extern void warn_slowpath_null(const char *file, const int line);
		#define WARN_ON_RATELIMIT(condition, state) \
		WARN_ON((condition) && __ratelimit(state))

		/*
		* WARN_ON_SMP() is for cases that the warning is either
		* meaningless for !SMP or may even cause failures.
		* This is usually used for cases that we have
		* WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
		* returns 0 for uniprocessor settings.
		* It can also be used with values that are only defined
		* on SMP:
		*
		* struct foo {
		* [...]
		* #ifdef CONFIG_SMP
		* int bar;
		* #endif
		* };
		*
		* void func(struct foo *zoot)
		* {
		* WARN_ON_SMP(!zoot->bar);
		*
		* For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
		* and should be a nop and return false for uniprocessor.
		*
		* if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
		* and x is true.
		*/
		#ifdef CONFIG_SMP
		# define WARN_ON_SMP(x) WARN_ON(x)
		#else
		# define WARN_ON_SMP(x) do { } while (0)
		# define WARN_ON_SMP(x) ({0;})
		#endif

		#endif

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