From: "H. Peter Anvin" <hpa@zytor.com>
To: Stephen Boyd <sboyd@codeaurora.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org,
Arjan van de Ven <arjan@linux.intel.com>,
Helge Deller <deller@gmx.de>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Chris Metcalf <cmetcalf@tilera.com>
Subject: Re: [PATCH] Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECK
Date: Wed, 27 Feb 2013 14:55:11 -0800 [thread overview]
Message-ID: <512E8ECF.1080307@zytor.com> (raw)
In-Reply-To: <512E8E48.8020007@codeaurora.org>
On 02/27/2013 02:52 PM, Stephen Boyd wrote:
> On 02/27/13 14:19, H. Peter Anvin wrote:
>> On 02/27/2013 12:42 PM, Stephen Boyd wrote:
>>>> It's fine to do your patch as a first step though, which would not
>>>> change the behavior.
>>> A lot of arches seem to not want to enable it because false positives
>>> are everywhere. It really depends on how good the compiler is at doing
>>> constant propagation and dead code removal.
>>>
>> Although some of the cases I have seen being flagged as "false
>> positives" have been real bugs.
>
> There were so many false-positives on x86_64 that Andrew eventually
> dropped my patch to add support for this option to the copy_from_user()
> function there.
>
I would probably have taken it, especially if it came with more x86-64
to i386 unification.
It's an option, though.
-hpa
next prev parent reply other threads:[~2013-02-27 22:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-27 3:00 [PATCH] Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS Stephen Boyd
2013-02-27 20:32 ` [PATCH] Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECK Arnd Bergmann
2013-02-27 20:42 ` Stephen Boyd
2013-02-27 21:33 ` Arnd Bergmann
2013-02-27 22:19 ` H. Peter Anvin
2013-02-27 22:45 ` Stephen Rothwell
2013-02-27 22:52 ` H. Peter Anvin
2013-02-27 22:56 ` Arjan van de Ven
2013-02-27 22:52 ` Stephen Boyd
2013-02-27 22:55 ` H. Peter Anvin [this message]
2013-02-27 23:19 ` Stephen Boyd
2013-02-27 23:21 ` H. Peter Anvin
2013-02-27 22:41 ` [PATCH] Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS Helge Deller
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