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From: "drepper.fsp at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sources.redhat.com
Subject: [Bug libc/12518] memcpy acts randomly (and differently) with overlapping areas
Date: Fri, 25 Feb 2011 09:59:00 -0000	[thread overview]
Message-ID: <bug-12518-131-js24DYy9YB@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-12518-131@http.sourceware.org/bugzilla/>

http://sourceware.org/bugzilla/show_bug.cgi?id=12518

--- Comment #4 from Ulrich Drepper <drepper.fsp at gmail dot com> 2011-02-25 09:59:18 UTC ---
The existence of code written by people who should never have been allowed to
touch a keyboard cannot be allowed to prevent a correct implementation.  If
there is a large bod of code out there we can work around the issue for that.

We can have the existing memcpy@GLIBC_2.2.5 implementation work around the
issue by avoiding the backward copying code.  A new memcpy@GLIBC_2.14 could use
the code currently in use.

Whether the current, new memcpy is only slightly faster than one mimicking
memmove is really not that important.  There are going to be more and different
implementations in the future and they shouldn't be prevented from being used
because of buggy programs.  We should be happy to have this code here and now.

With this proposed implementation old code remains in working order until those
lousy programmers use a newer platform and then they will experience the
problems themselves and will fix them before releasing their code.

I'm happy to entertain a patch to this effect.

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  parent reply	other threads:[~2011-02-25  9:59 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 [this message]
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
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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