From: "H. Peter Anvin" <hpa@zytor.com>
To: Wolfgang Walter <wolfgang.walter@stwm.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
Suresh Siddha <suresh.b.siddha@intel.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>,
"viro@ZenIV.linux.org.uk" <viro@zeniv.linux.org.uk>,
"vegard.nossum@gmail.com" <vegard.nossum@gmail.com>
Subject: Re: Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes
Date: Sat, 09 Aug 2008 09:10:05 -0700 [thread overview]
Message-ID: <489DC15D.9070308@zytor.com> (raw)
In-Reply-To: <200808091757.32999.wolfgang.walter@stwm.de>
Wolfgang Walter wrote:
> How could any kernel code use MMX/SSE/FPU when the interrupt case isn't
> handled?
I don't think we have ever allowed MMX/SSE/FPU code in interrupt
handlers. kernel_fpu_begin()..end() lock out preemption, and so could
only be interrupted, not preempted.
> Or is your argument that its lazy allocation itself is the problem: this
> nesting could always happen and was a bug but only with lazy allocation it is
> dangerous (as it may cause a spurious math fault in the race window).
>
> If this were right than any kernel code executing SSE may trigger now a oops
> in __switch_to() under some special circumstances.
If lazy allocation can cause the RAID code, for example (which executes
SSE instructions in the kernel, but not at interrupt time) to start
randomly oopsing, then lazy allocations have to be pulled.
-hpa
next prev parent reply other threads:[~2008-08-09 16:16 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-17 14:53 Kernel oops with 2.6.26 and ipsec (Was: Re: IPSEC in 2.6.25 causes stalled connections) Wolfgang Walter
2008-07-17 20:42 ` Kernel oops with 2.6.26 and ipsec Wolfgang Walter
[not found] ` <200807301411.01622.wolfgang.walter@stwm.de>
[not found] ` <20080806103354.GA31623@gondor.apana.org.au>
2008-08-06 17:33 ` Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes Wolfgang Walter
2008-08-06 20:14 ` Suresh Siddha
2008-08-06 21:21 ` Suresh Siddha
2008-08-07 0:38 ` Wolfgang Walter
2008-08-08 8:44 ` Wolfgang Walter
2008-08-08 18:31 ` Vegard Nossum
2008-08-07 16:23 ` Wolfgang Walter
2008-08-08 10:36 ` Wolfgang Walter
2008-08-08 18:53 ` Suresh Siddha
2008-08-08 19:01 ` H. Peter Anvin
2008-08-08 19:19 ` Wolfgang Walter
2008-08-08 23:11 ` Suresh Siddha
2008-08-09 0:38 ` Herbert Xu
2008-08-09 1:23 ` Herbert Xu
2008-08-09 1:54 ` Wolfgang Walter
2008-08-09 2:16 ` Herbert Xu
2008-08-09 3:09 ` Wolfgang Walter
2008-08-09 3:20 ` Herbert Xu
2008-08-09 14:29 ` Herbert Xu
2008-08-09 14:32 ` Herbert Xu
2008-08-09 17:52 ` Suresh Siddha
2008-08-10 5:30 ` Herbert Xu
2008-08-10 5:41 ` H. Peter Anvin
2008-08-11 22:57 ` Suresh Siddha
2008-08-09 17:48 ` Suresh Siddha
2008-08-09 1:28 ` Wolfgang Walter
2008-08-09 13:31 ` Herbert Xu
2008-08-09 14:37 ` Herbert Xu
2008-08-09 15:14 ` Wolfgang Walter
2008-08-09 15:57 ` Wolfgang Walter
2008-08-09 16:10 ` H. Peter Anvin [this message]
2008-08-09 17:02 ` Wolfgang Walter
2008-08-09 18:52 ` Suresh Siddha
2008-08-09 19:37 ` Suresh Siddha
2008-08-09 22:59 ` Wolfgang Walter
2008-08-10 3:05 ` Herbert Xu
2008-08-11 19:01 ` Suresh Siddha
2008-08-11 19:22 ` Ingo Molnar
2008-08-11 19:24 ` H. Peter Anvin
2008-08-11 20:19 ` Suresh Siddha
2008-08-12 0:39 ` Herbert Xu
2008-08-12 0:42 ` H. Peter Anvin
2008-08-12 0:46 ` Herbert Xu
2008-08-12 0:48 ` H. Peter Anvin
2008-08-12 0:52 ` Herbert Xu
2008-08-12 0:38 ` Wolfgang Walter
2008-08-12 11:43 ` Wolfgang Walter
2008-08-12 12:02 ` Herbert Xu
2008-08-12 18:28 ` Suresh Siddha
2008-08-12 23:40 ` Herbert Xu
2008-08-09 18:12 ` Suresh Siddha
2008-08-09 18:54 ` Suresh Siddha
2008-08-09 16:05 ` H. Peter Anvin
2008-08-09 18:14 ` Suresh Siddha
2008-08-10 0:29 ` Herbert Xu
2008-08-10 1:56 ` Wolfgang Walter
2008-08-10 1:59 ` Herbert Xu
2008-08-09 17:59 ` Suresh Siddha
2008-08-10 1:40 ` Herbert Xu
2008-08-09 1:49 ` Herbert Xu
2008-08-09 1:59 ` H. Peter Anvin
2008-08-09 2:43 ` Wolfgang Walter
2008-08-09 3:30 ` H. Peter Anvin
2008-08-09 10:50 ` Wolfgang Walter
2008-08-08 19:09 ` Wolfgang Walter
2008-08-08 19:32 ` Suresh Siddha
2008-08-08 23:10 ` Wolfgang Walter
2008-08-08 23:15 ` Suresh Siddha
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