Re: fyi: gcc33-hammer crashes when compiling kvm emulate.c

From: H. Peter Anvin
Date: Tue Oct 26 2010 - 12:35:15 EST


On 10/26/2010 05:38 AM, Andi Kleen wrote:
> Hi,
>
> While doing a test run with the minimum supported compiler
> I found:
>
> An old gcc 3.3-hammer segfaults when compiling the current KVM
> emulate.c (or rather in x86_emulate_insns) on x86-64.
>
> The compiler goes into an endless recursion in validate_rtx and then
> eventually overflows the stack and dies.
>
> I minimized a test case, but didn't find a workaround
> (minimized test case http://halobates.de/emulate-min.i)
>
> My guess it's related to some of the inline assembler uses.
>
> This might be an excuse to bump the minimum compiler version again.
>

We have said 3.4 minimum for x86 for a long time now, and have an RFC
out to bump to 4.1. Unfortunately there isn't a good repo of
arch-specific version requirements in the kernel source code; in fact, I
just talked to Tony Luck yesterday about the need for that.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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