From b1ae345d971664f70cfdc293029c40ccfb093591 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 21 Feb 2013 16:42:47 -0800 Subject: [PATCH] lockdep: make lockdep_assert_held() not have a return value I recently made the mistake of writing: foo = lockdep_dereference_protected(..., lockdep_assert_held(...)); which is clearly bogus. If lockdep is disabled in the config this would cause a compile failure, if it is enabled then it compiles and causes a puzzling warning about dereferencing without the correct protection. Wrap the macro in "do { ... } while (0)" to also fail compile for this when lockdep is enabled. Signed-off-by: Johannes Berg Cc: Peter Zijlstra Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/lockdep.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 2bca44b0893c..bfe88c4aa251 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -359,7 +359,9 @@ extern void lockdep_trace_alloc(gfp_t mask); #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) -#define lockdep_assert_held(l) WARN_ON(debug_locks && !lockdep_is_held(l)) +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held(l)); \ + } while (0) #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion)