Re: [PATCH v4 0/4] objtool: Fix INSN_CONTEXT_SWITCH

From: Ingo Molnar
Date: Tue Apr 08 2025 - 03:15:11 EST



* Ingo Molnar <mingo@xxxxxxxxxx> wrote:

>
> * Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
>
> > I decided to keep the "unsupported instruction in callable function"
> > warning, it's not hurting anything. As a result we now have
> > INSN_SYSCALL and INSN_SYSRET.
> >
> > v4:
> > - split up patches
> > - don't get rid of "unsupported instruction in callable function" warning
> > - split INSN_CONTEXT_SWITCH -> INSN_SYSCALL / INSN_SYSRET
> >
> > v3: https://lore.kernel.org/9b23e4413873bee38961e628b0c73f6d3a26d494.1743799705.git.jpoimboe@xxxxxxxxxx
> >
> > Josh Poimboeuf (4):
> > objtool: Fix INSN_CONTEXT_SWITCH handling in validate_unret()
> > objtool: Split INSN_CONTEXT_SWITCH into INSN_SYSCALL and INSN_SYSRET
> > objtool: Stop UNRET validation on UD2
> > objtool, xen: Fix INSN_SYSCALL / INSN_SYSRET semantics
> >
> > arch/x86/xen/xen-asm.S | 4 +---
> > tools/objtool/arch/x86/decode.c | 18 ++++++++++-------
> > tools/objtool/check.c | 29 +++++++++++++++++++++-------
> > tools/objtool/include/objtool/arch.h | 3 ++-
> > 4 files changed, 36 insertions(+), 18 deletions(-)
>
> I'm wondering about the timing: can this wait for v6.16, or does it
> trigger on some popular config/build-tools combination?

On a second look, I think these fixes should go upstream now, so I've
applied them to tip:objtool/urgent.

Thanks,

Ingo