Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending

Ingo Molnar
2008-03-03T17:49:38Z

* Klaus S. Madsen <ksm@hjernemadsen.org> wrote:

> The following patch solves the segfault, by changing the mmap flags of
> the video memory area, to allow execution. The patch is against
> libx86-0.99 available from http://www.codon.org.uk/~mjg59/libx86/
>
> --- libx86-0.99/x86-common.c 2006-09-08 00:44:27.000000000 +0200
> +++ libx86-0.99.new/x86-common.c 2008-03-01 10:08:25.000000000 +0100
> @@ -232,7 +232,7 @@
> }
>
> m = mmap((void *)0xa0000, 0x100000 - 0xa0000,
> - PROT_READ | PROT_WRITE,
> + PROT_READ | PROT_WRITE | PROT_EXEC,

are you sure you ID-ed the right commit that broke things?

while requiring PROT_EXEC is fine, breaking existing user-space apps
over that is not fine. So are you absolutely sure that by reverting that
PWT|PCD commit, s2ram again starts to work? That's utmost weird...

perhaps there's some CPU bug that causes NX to _NOT_ work if only PCD is
used (not PCD|PWT). Seems like a pretty unlikely scenario though.

Ingo