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From: "vincent+libc at vinc17 dot org" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug libc/12518] memcpy acts randomly (and differently) with overlapping areas Date: Wed, 04 May 2011 13:32:00 -0000 [thread overview] Message-ID: <bug-12518-131-5NtzWO6GCg@http.sourceware.org/bugzilla/> (raw) In-Reply-To: <bug-12518-131@http.sourceware.org/bugzilla/> http://sourceware.org/bugzilla/show_bug.cgi?id=12518 Vincent Lefèvre <vincent+libc at vinc17 dot org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |vincent+libc at vinc17 dot | |org --- Comment #26 from Vincent Lefèvre <vincent+libc at vinc17 dot org> 2011-05-04 13:29:06 UTC --- (In reply to comment #18) > The problem we're facing just made this fact plain: there is no reason why > memcpy should not be memmove. If these two functions should behave in the same way, then why not all programmers use memmove (which has fewer requirements)? If memcpy is called while the objects overlap, the bug is not necessarily that memmove should have been used instead. The cause may be an incorrect size. So, with this point of view, it should be safer to abort than letting the program behave in an uncontrolled way. (In reply to comment #25) > So, again, I think we need at least a transition period so that people can > detect and fix the issues. But it may be difficult to detect the issues. For instance, zsh was affected by a similar problem (now fixed in CVS only) with the optimized strcpy, but to detect the problem, it involves keyboard input: http://www.zsh.org/mla/workers/2011/msg00533.html http://www.zsh.org/mla/workers/2011/msg00544.html For strcpy, this is even worse, as there is no strmove function, so that either programmers have to write non-portable code or they have to reimplement a naive version of strcpy or find some other workaround, such as memmove + strlen: http://www.zsh.org/mla/workers/2011/msg00542.html I suppose that if this has been done for memcpy, then strcpy should also be patched in some way... -- 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.
next prev parent reply other threads:[~2011-05-04 13:32 UTC|newest] Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-02-25 2:26 [Bug libc/12518] New: " torvalds@linux-foundation.org 2011-02-25 2:29 ` [Bug libc/12518] " torvalds@linux-foundation.org 2011-02-25 3:57 ` hjl.tools at gmail dot com 2011-02-25 4:15 ` torvalds@linux-foundation.org 2011-02-25 9:59 ` drepper.fsp at gmail dot com 2011-02-25 11:49 ` tolzmann at molgen dot mpg.de 2011-02-25 12:07 ` jakub at redhat dot com 2011-02-25 15:20 ` hjl.tools at gmail dot com 2011-02-26 1:56 ` drepper.fsp at gmail dot com 2011-03-02 4:03 ` alexander.hunt2005 at gmail dot com 2011-03-02 20:12 ` smconvey at gmail dot com 2011-03-03 23:28 ` felipe.contreras at gmail dot com 2011-03-04 3:02 ` jvillalo at redhat dot com 2011-03-04 9:28 ` thierry.vignaud at gmail dot com 2011-03-04 16:07 ` ml-bz-dale at riyescott dot com 2011-03-04 23:42 ` drepper.fsp at gmail dot com 2011-03-04 23:54 ` torvalds@linux-foundation.org 2011-03-05 0:28 ` felipe.contreras at gmail dot com 2011-03-05 13:28 ` oliver.henshaw at gmail dot com 2011-03-12 16:38 ` tmoody at ku dot edu 2011-03-24 21:04 ` bvasselle at gmail dot com 2011-03-25 4:37 ` hjl.tools at gmail dot com 2011-03-25 6:46 ` jakub at redhat dot com 2011-03-28 11:53 ` tmraz at redhat dot com 2011-03-28 11:54 ` felipe.contreras at gmail dot com 2011-03-29 14:43 ` felipe.contreras at gmail dot com 2011-03-29 22:28 ` bvasselle at gmail dot com 2011-03-30 5:14 ` felipe.contreras at gmail dot com 2011-03-30 7:21 ` felipe.contreras at gmail dot com 2011-03-30 10:20 ` y.pronenko at gmail dot com 2011-03-31 8:37 ` shaforostoff at gmail dot com 2011-04-01 23:42 ` drepper.fsp at gmail dot com 2011-04-02 2:57 ` hjl.tools at gmail dot com 2011-04-10 15:39 ` bvasselle at gmail dot com 2011-04-10 15:50 ` felipe.contreras at gmail dot com 2011-05-04 13:32 ` vincent+libc at vinc17 dot org [this message] 2011-05-04 15:02 ` felipe.contreras at gmail dot com 2011-06-07 3:07 ` kenyon at kenyonralph dot com 2013-08-12 17:20 ` tudorb at gmail dot com 2013-08-19 23:48 ` Ondřej Bílka 2013-08-19 23:48 ` neleai at seznam dot cz 2013-08-20 1:12 ` tudorb at gmail dot com 2014-02-16 19:41 ` jackie.rosen at hushmail dot com 2014-02-16 19:54 ` kenyon at kenyonralph dot com 2014-05-28 19:41 ` schwab at sourceware dot org 2014-06-27 13:49 ` fweimer at redhat dot com 2015-02-25 10:28 ` mwest@awek-microdata.de
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