Re: [PATCH 1/3] x86/entry: Fix idtentry unwind hint

Andrei Vagin
2017-10-26T16:42:48Z

On Thu, Oct 26, 2017 at 10:24:29AM -0500, Josh Poimboeuf wrote:
> On Wed, Oct 25, 2017 at 02:07:38PM -0700, Andrei Vagin wrote:
> > Hi Josh,
> >
> > Here is one more warning:
> > [ 5.852094] WARNING: can't dereference iret registers at ffffb6ce01b7ffe0 for ip entry_SYSCALL_64_fastpath+0xa/0xc2
>
> Thanks, I hadn't seen this one yet.
>
> I suspect this is in the middle of the ENABLE_INTERRUPTS() paravirt
> code, which would mean this is another issue that will be fixed by my
> "Make pv ops code generation more closely match reality" patches.
>
> If you can share either the entry_64.o file or the .config, and what
> virt platform it's running on (kvm, xen, native), I should be able to
> confirm the issue.

The config is attached to this e-mail. It is a travis-ci vm. I think
they are hosted in Google Cloud:

[ 0.000000] DMI: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 0.000000] Hypervisor detected: KVM

https://travis-ci.org/avagin/linux/jobs/292773933

>
> I'm in Prague this week but I should have a v2 of those patches in a
> week or two (will cc you).

Good!

>
> --
> Josh