From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932283AbcI1JIH (ORCPT ); Wed, 28 Sep 2016 05:08:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57351 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932205AbcI1JHp (ORCPT ); Wed, 28 Sep 2016 05:07:45 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds Subject: [PATCH 4.4 21/73] Disable "maybe-uninitialized" warning globally Date: Wed, 28 Sep 2016 11:04:51 +0200 Message-Id: <20160928090436.048456912@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160928090434.509091655@linuxfoundation.org> References: <20160928090434.509091655@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Torvalds commit 6e8d666e925333c55378e8d5540a8a9ee0eea9c5 upstream. Several build configurations had already disabled this warning because it generates a lot of false positives. But some had not, and it was still enabled for "allmodconfig" builds, for example. Looking at the warnings produced, every single one I looked at was a false positive, and the warnings are frequent enough (and big enough) that they can easily hide real problems that you don't notice in the noise generated by -Wmaybe-uninitialized. The warning is good in theory, but this is a classic case of a warning that causes more problems than the warning can solve. If gcc gets better at avoiding false positives, we may be able to re-enable this warning. But as is, we're better off without it, and I want to be able to see the *real* warnings. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- Makefile | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/Makefile +++ b/Makefile @@ -368,7 +368,7 @@ AFLAGS_MODULE = LDFLAGS_MODULE = CFLAGS_KERNEL = AFLAGS_KERNEL = -CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im -Wno-maybe-uninitialized +CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im # Use USERINCLUDE when you must reference the UAPI directories only. @@ -616,12 +616,13 @@ ARCH_CFLAGS := include arch/$(SRCARCH)/Makefile KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) +KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,) ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE -KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,) +KBUILD_CFLAGS += -Os else ifdef CONFIG_PROFILE_ALL_BRANCHES -KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,) +KBUILD_CFLAGS += -O2 else KBUILD_CFLAGS += -O2 endif