From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1304 invoked by alias); 29 Mar 2011 14:43:40 -0000 Received: (qmail 1138 invoked by uid 22791); 29 Mar 2011 14:43:37 -0000 X-SWARE-Spam-Status: No, hits=-0.6 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_CP X-Spam-Check-By: sourceware.org Received: from localhost (HELO sourceware.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 29 Mar 2011 14:43:34 +0000 From: "felipe.contreras at gmail dot com" To: glibc-bugs@sources.redhat.com Subject: [Bug libc/12518] memcpy acts randomly (and differently) with overlapping areas X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: libc X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: felipe.contreras at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: drepper.fsp at gmail dot com X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Tue, 29 Mar 2011 14:43:00 -0000 Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org X-SW-Source: 2011-03/txt/msg00117.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=12518 --- Comment #17 from Felipe Contreras 2011-03-29 14:43:31 UTC --- Actually, why not have both? I think this plan would fit everyone: 1) Apply Linus' patch Both to 2.13 and 2.14, this would not introduce any issues and would restore back the previous behavior, so applications would still work. As I mentioned before, the disadvantages are minimal. 2) Apply H.J. Lu's patch This would go to 2.14, but not only to x86 but all architectures, and add an overlap check, and when triggered issue a crash. This would allow old binaries to keep working on 2.14, but newly compiled ones would crash if they are doing something wrong. This would allow all the users of glibc to fix their code for the impending changes. 3) Remove overlap checks On 2.15, after a transition period, the overlap checks can be removed, and thus save the few extra cycles. This has all the advantages of all the proposals, and makes it easy to fix the applications that are using memcpy wrong. -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.