Re: Resume Issues :Exec of NX page, Synaptics Botchup

From: Rafael J. Wysocki
Date: Sun May 22 2011 - 18:41:30 EST


On Monday, May 23, 2011, Parag Warudkar wrote:
>
> On Sun, 22 May 2011, Linus Torvalds wrote:
>
> >
> > Hmm. The "Code: " line is just full of complete garbage, so I think
> > the real issue is that you really are trying to execute data.
> >
> > And that in turn seems to be because "setup_disablecpuid()" has
> > actually been free'd, because it is marked as __init.
> >
> > Which is fine at the initial bootup, but not so fine at resume time,
> > since it was free'd long long ago by then.
> >
> > And it definitely shouldn' t be called at resume time. There's
> > something wrong there. That call trace is odd:
> >
> > Call Trace:
> > [<ffffffff8148a119>] ? identify_cpu+0xd8/0x2d8
> > [<ffffffff8148a32d>] identify_secondary_cpu+0x14/0x1b
> > [<ffffffff8148bf0f>] smp_store_cpu_info+0x3c/0x3e
> > [<ffffffff8148c2ef>] start_secondary+0xf7/0x1d2
> >
> > because none of those should be calling "setup_disablecpuid()" at all.
> >
> > Hmm. In fact, RIP is "setup_disablecpuid+0x40/0x40", ie it is one past
> > the _end_ of setup_disablecpuid.
> >
> > I suspect that is actually "setup_smep()" that got called, an dthat
> > there was some garbage data in there that caused it to jump back a
> > bit.
> >
> > Does the attached patch fix it?
> >
>
> Now I get a different call trace for the same NX error. (And Synaptics is
> completely dead this time - not attributable to the patch, it was dumb
> luck perhaps that it wored last time.)

Any chance to try with commit de5397ad5b9ad22e2401c4dacdf1bb3b19c05679
(x86, cpu: Enable/disable Supervisor Mode Execution Protection) reverted?

Rafael
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