From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756660AbZBEIrb (ORCPT ); Thu, 5 Feb 2009 03:47:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751049AbZBEIrV (ORCPT ); Thu, 5 Feb 2009 03:47:21 -0500 Received: from mail-fx0-f20.google.com ([209.85.220.20]:58645 "EHLO mail-fx0-f20.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750866AbZBEIrU (ORCPT ); Thu, 5 Feb 2009 03:47:20 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=nr19IYSRzPUM/v3XN/f4fx2YDMmp6PAQAAOC/SG2GZhmyzaM/qINeZvjXHyiIax6V+ M2Po2CklzG1DGXJAyQUjPNJxbyykMadUy2HlwSfTDDnNijt8zYW0JSA6i8joZSHp+UTd yUiHiO3sCwzBeqECHn2oKKK8faxqi5GmOjyso= MIME-Version: 1.0 Date: Thu, 5 Feb 2009 09:47:18 +0100 Message-ID: <56e1b5710902050047h2c58eec7l812a838491a0256a@mail.gmail.com> Subject: [PATCH] Kbuild: Enable the gcc flag -Wformat-security (was: Re: [PATCH] Kbuild: Disable the -Wformat-security gcc flag) From: Floris Kraak To: Sam Ravnborg Cc: Robert Hancock , Alan Cox , Linux Kernel Mailing List , Trivial Patch Monkey , Roland Dreier Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 5, 2009 at 9:26 AM, Floris Kraak wrote: > > As I noted applying a patch that does the reverse and enables the > check instead is perfectly acceptable to me. Long term somebody > probably needs to go through all of them and fix (most of) them > anyway. > Here goes: [PATCH] Kbuild: Enable the gcc flag -Wformat-security Some distributions have enabled the gcc flag -Wformat-security by default. This causes about 150 new warnings to show up in an allyesconfig kernel build that are never seen by the majority of the developers. However there is some value to having this warning. In some cases there are potential (security) bugs involved where malicious or simply malformed data from outside the kernel could trigger stack overflows or other nastyness. Instead of having a cleanup team running around in perpetuity going over all new format strings in code it's better to just emit the warning in all cases. Signed-off-by: Floris Kraak --- diff --git a/Makefile b/Makefile index 7715b2c..ed3b973 100644 --- a/Makefile +++ b/Makefile @@ -346,7 +346,8 @@ KBUILD_CPPFLAGS := -D__KERNEL__ KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common \ - -Werror-implicit-function-declaration + -Werror-implicit-function-declaration \ + -Wformat-security KBUILD_AFLAGS := -D__ASSEMBLY__ # Read KERNELRELEASE from include/config/kernel.release (if it exists) --- "They that give up essential liberty to obtain temporary safety, deserve neither liberty nor safety." -- Ben Franklin "The course of history shows that as a government grows, liberty decreases." -- Thomas Jefferson