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

From: Josh Poimboeuf
Date: Mon Nov 13 2017 - 17:59:53 EST


On Mon, Nov 13, 2017 at 02:06:35PM -0800, Andrei Vagin wrote:
> Hi Josh,
>
> On Thu, Oct 26, 2017 at 8:24 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> 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.
> >
> > I'm in Prague this week but I should have a v2 of those patches in a
> > week or two (will cc you).
>
> Do you have any news? We still see this warning in the kernel log. Thanks!

Sorry, a bunch of other work got in the way. I haven't forgotten about
it. It's now (almost) at the top of my TODO list.

--
Josh