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[PATCH] LoongArch: Set defaults to exec stack 0.

Huacai Chen chenhuacai@kernel.org
Mon Jul 25 09:18:55 GMT 2022 
Hi, all,

On Mon, Jul 25, 2022 at 5:17 PM WANG Xuerui <i.swmail@xen0n.name> wrote:
>
> On 2022/7/25 16:35, Andreas Schwab via Binutils wrote:
> > On Jul 25 2022, Xi Ruoyao wrote:
> >
> >> The doc of elf_backend_default_execstack says:
> >>
> >>    /* True if an object file lacking a .note.GNU-stack section
> >>       should be assumed to be requesting exec stack.  At least one
> >>       other file in the link needs to have a .note.GNU-stack section
> >>       for a PT_GNU_STACK segment to be created.  */
> >>
> >> So I think it only controls the default behavior of bfd library and is
> >> not related to the kernel?
> > The kernel always controls the ultimate decision.
> >
> > It also means that if no input file has a GNU-stack note, no
> > PT_GNU_STACK segment is created for the output, in which case the kernel
> > default (which is PF_X for loongarch) applies.
> >
> > The value of DEFAULT_STACK_PERMS in glibc must also agree with the
> > kernel.
> >
> Well, actually the kernel behavior seems to be overlooked during the
> upstreaming process. No sane architecture in 2022 should have executable
> stacks in the beginning.
>
> We'll fix this before Linux 5.19 is released, fortunately there's the
> rc8 giving us the chance. Compatibility should not be a problem, as no
> modern program should rely on the incorrect behavior, and the new-world
> is still not widely adopted (read: <50 installations worldwide) so any
> breakage can be chased down and fixed.
>
> Thanks very much for spotting this.
Thank you very much, I will fix this in kernel side.

Huacai
>
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