Messages in this thread | | | From | Thomas Garnier <> | Date | Thu, 5 Dec 2019 09:01:50 -0800 | Subject | Re: [PATCH v10 04/11] x86/entry/64: Adapt assembly for PIE support |
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On Thu, Dec 5, 2019 at 1:04 AM Peter Zijlstra <peterz@infradead.org> wrote: > > On Wed, Dec 04, 2019 at 04:09:41PM -0800, Thomas Garnier wrote: > > > @@ -1625,7 +1627,11 @@ first_nmi: > > addq $8, (%rsp) /* Fix up RSP */ > > pushfq /* RFLAGS */ > > pushq $__KERNEL_CS /* CS */ > > - pushq $1f /* RIP */ > > + pushq $0 /* Future return address */ > > We're building an IRET frame, the IRET frame does not have a 'future > return address' field.
I assumed that's the target RIP after iretq.
> > > + pushq %rdx /* Save RAX */ > > fail..
Yes, sorry. I was asked to switch from RAX to RDX and missed the comment.
> > > + leaq 1f(%rip), %rdx /* RIP */ > > nonsensical comment
That was the same comment from the push $1f that I changed.
> > > + movq %rdx, 8(%rsp) /* Put 1f on return address */ > > + popq %rdx /* Restore RAX */ > > fail..
I will change in next iteration.
> > > iretq /* continues at repeat_nmi below */ > > UNWIND_HINT_IRET_REGS > > 1: > > -- > > 2.24.0.393.g34dc348eaf-goog > >
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