Re: [git pull] core, x86: make LIST_POISON less deadly

From: Linus Torvalds
Date: Mon Jul 14 2008 - 12:27:06 EST




On Mon, 14 Jul 2008, Avi Kivity wrote:
>
> We could add a printk to the #GP handler that alerts the reader that a
> poisoned list is suspected, if we find the address pattern in one of the
> registers.

I wouldn't worry too much - it's going to be pretty visible anyway.

The only thing I _would_ worry about is the AMD prefetch bug - some AMD
cores raise a spurious page fault for prefetch instructions, and we ignore
it.

I _think_ that bug is a pure TLB issue and would never trigger for an
address that doesn't do page fault handling at all because it gets caught
in the "is the address valid" code, but it does make me go "Hmm".

See

http://lkml.org/lkml/2003/9/10/397

from Rich Brunner. The AMD errata listing does say just page fault, and
does talk about speculative TLB reloads, so I think we're all good.

Linus
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