From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 9CC676B0007 for ; Mon, 19 Mar 2018 03:57:12 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id x8-v6so1404699pln.9 for ; Mon, 19 Mar 2018 00:57:12 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id x10-v6sor274508plo.143.2018.03.19.00.57.11 for (Google Transport Security); Mon, 19 Mar 2018 00:57:11 -0700 (PDT) From: Michal Hocko Subject: [PATCH] include/linux/mmdebug.h: make VM_WARN* non-rvals Date: Mon, 19 Mar 2018 08:57:02 +0100 Message-Id: <20180319075702.25645-1-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, LKML , Stephen Rothwell , Michal Hocko 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. Cc: Michal Hocko Cc: Stephen Rothwell [akpm@linux-foundation.org: changelog] Signed-off-by: Michal Hocko Signed-off-by: Andrew Morton --- include/linux/mmdebug.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h index 35d77b0dae3b..14baf1d9d65b 100644 --- a/include/linux/mmdebug.h +++ b/include/linux/mmdebug.h @@ -37,10 +37,10 @@ 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) -- 2.16.1