Re: [RFC PATCH 2/2] objtool/LoongArch: Fix unreachable instruction warnings about head.S

[Tiezhu Yang]

On 2025/8/27 上午7:43, Josh Poimboeuf wrote:
> On Tue, Aug 26, 2025 at 08:30:23PM +0800, Tiezhu Yang wrote:
> > On 2025/8/26 下午4:26, Huacai Chen wrote:
> > > On Tue, Aug 26, 2025 at 2:46 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
> > > > When compiling with LLVM and CONFIG_LTO_CLANG is set, there exist the
> > > > following objtool warnings after silencing all of the other warnings:
> >
> > ...
> >
> > > >    arch/loongarch/kernel/head.S | 8 ++++----
> > > >    1 file changed, 4 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
> > > > index e3865e92a917..566a1dbf5fa0 100644
> > > > --- a/arch/loongarch/kernel/head.S
> > > > +++ b/arch/loongarch/kernel/head.S
> > > > @@ -20,6 +20,7 @@
> > > >           __HEAD
> > > >
> > > >    _head:
> > > > +       UNWIND_HINT_UNDEFINED
> > > >           .word   IMAGE_DOS_SIGNATURE     /* "MZ", MS-DOS header */
> > > >           .org    0x8
> > > >           .dword  _kernel_entry           /* Kernel entry point (physical address) */
> > > > @@ -30,6 +31,7 @@ _head:
> > > >           .long   pe_header - _head       /* Offset to the PE header */
> > > >
> > > >    pe_header:
> > > > +       UNWIND_HINT_UNDEFINED
> > > >           __EFI_PE_HEADER
> > > The efi header is completely not code, the annotations are very strange.
> >
> > Yes, I think so too, but the aim is only to not checking for objtool,
> > it seems no other better way.
>
> Objtool is only getting confused because there's data in a text section.
> Why not put that in a data section?

Thank you very much, that is to say, these EFISTUB instructions can be
ignored by objtool, I will do it.

Thanks,
Tiezhu