Re: [PATCH 08/11] objtool/loongarch: Add unwind hints in prepare_frametrace()
From: Ingo Molnar
Date: Tue Apr 01 2025 - 04:11:05 EST
* Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
> On 04/01/2025 03:08 PM, Ingo Molnar wrote:
> >
> > * Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> >
> > > If 'regs' points to a local stack variable, prepare_frametrace() stores
> > > all registers to the stack. This confuses objtool as it expects them to
> > > be restored from the stack later.
> > >
> > > The stores don't affect stack tracing, so use unwind hints to hide them
> > > from objtool.
> > >
> > > Fixes the following warnings:
> > >
> > > arch/loongarch/kernel/traps.o: warning: objtool: show_stack+0xe0: stack state mismatch: reg1[22]=-1+0 reg2[22]=-2-160
> > > arch/loongarch/kernel/traps.o: warning: objtool: show_stack+0xe0: stack state mismatch: reg1[23]=-1+0 reg2[23]=-2-152
> > >
> > > Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
> > > Fixes: cb8a2ef0848c ("LoongArch: Add ORC stack unwinder support")
> > > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/202503280703.OARM8SrY-lkp@xxxxxxxxx/
> > > Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> >
> > Note, I skipped this fix from tip:objtool/urgent for the time being,
> > because Tiezhu Yang indicated that he'd be reviewing and testing this
> > patch.
>
> Tested-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Thank you! Is it fine with you if I send this fix with tonight's
objtool/urgent pull request to Linus?
Thanks,
Ingo