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From: Andi Kleen <ak@suse.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Petr Vandrovec <petr@vandrovec.name>,
	discuss@x86-64.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Fix triplefault on x86-64 bootup
Date: Sun, 12 Aug 2007 12:01:48 +0200	[thread overview]
Message-ID: <200708121201.48383.ak@suse.de> (raw)
In-Reply-To: <alpine.LFD.0.999.0708120151150.30176@woody.linux-foundation.org>

On Sunday 12 August 2007 10:59, Linus Torvalds wrote:
> On Sun, 12 Aug 2007, Linus Torvalds wrote:
> > Hmm. Patch looks ok, I just wonder what started triggering this for you?
>
> Oh. It's the "Make patching more robust" commit.

No it should have been the earlier text_poke change which first
started using mempcy in that path.

> "Robust" my ass.
>
> We used to just copy the replacement in one go (works fine, since it just
> overwrote the two first bytes), and then "nop_out()" the rest (works fine,
> since it didn't matter for memcpy).
>
> That whole commit looks a bit dubious. It also adds a 254-byte stack
> usage (anything actually even close to that big?). Gaah.

The x86-64 copy_user copies the whole function as alternative
and it is over 200 bytes.
The original patch had a smaller buffer and cause x86-64 to BUG
at boot

-Andi



  reply	other threads:[~2007-08-12 10:03 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-08-12  8:12 [PATCH] Fix triplefault on x86-64 bootup Petr Vandrovec
2007-08-12  8:40 ` Linus Torvalds
2007-08-12  8:59   ` Linus Torvalds
2007-08-12 10:01     ` Andi Kleen [this message]
2007-08-12  9:59   ` Andi Kleen
2007-08-12 17:56     ` Linus Torvalds
2007-08-12  9:57 ` [discuss] " Andi Kleen
2007-08-12 10:09 ` Please remove ab144f5ec64c42218a555ec1dbde6b60cf2982d6 was " Andi Kleen
2007-08-12 10:42   ` Petr Vandrovec
2007-08-12 13:55     ` Andi Kleen
2007-08-12 13:46       ` Paolo Ornati
2007-08-12 17:57       ` Linus Torvalds
2007-08-12 10:46 ` Alexey Dobriyan
2007-08-12 13:53   ` Andi Kleen
2007-08-12 13:12     ` Alexey Dobriyan

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