From: Michal Hocko Date: Thu, 5 Apr 2018 23:25:30 +0000 (-0700) Subject: include/linux/mmdebug.h: make VM_WARN* non-rvals X-Git-Tag: v4.9.275~9 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=88a899fa2032b34ef3ac5dae3c70c8394fa5287c;p=thirdparty%2Fkernel%2Fstable.git include/linux/mmdebug.h: make VM_WARN* non-rvals [ Upstream commit 91241681c62a5a690c88eb2aca027f094125eaac ] At present the construct if (VM_WARN(...)) will compile OK with CONFIG_DEBUG_VM=y and will fail with CONFIG_DEBUG_VM=n. The reason is that VM_{WARN,BUG}* have always been special wrt. {WARN/BUG}* and never generate any code when DEBUG_VM is disabled. So we cannot really use it in conditionals. We considered changing things so that this construct works in both cases but that might cause unwanted code generation with CONFIG_DEBUG_VM=n. It is safer and simpler to make the build fail in both cases. [akpm@linux-foundation.org: changelog] Signed-off-by: Michal Hocko Reviewed-by: Andrew Morton Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h index 451a811f48f26..deaba1cc3cfcc 100644 --- a/include/linux/mmdebug.h +++ b/include/linux/mmdebug.h @@ -36,10 +36,10 @@ void dump_mm(const struct mm_struct *mm); BUG(); \ } \ } while (0) -#define VM_WARN_ON(cond) WARN_ON(cond) -#define VM_WARN_ON_ONCE(cond) WARN_ON_ONCE(cond) -#define VM_WARN_ONCE(cond, format...) WARN_ONCE(cond, format) -#define VM_WARN(cond, format...) WARN(cond, format) +#define VM_WARN_ON(cond) (void)WARN_ON(cond) +#define VM_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond) +#define VM_WARN_ONCE(cond, format...) (void)WARN_ONCE(cond, format) +#define VM_WARN(cond, format...) (void)WARN(cond, format) #else #define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond) #define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond)