Re: [PATCH v9 1/3] vmlinux.lds.h: add DWARF v5 sections

From: Nick Desaulniers
Date: Fri Feb 05 2021 - 22:50:02 EST


On Fri, Feb 5, 2021 at 4:00 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, 5 Feb 2021 12:22:18 -0800 Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote:
>
> > We expect toolchains to produce these new debug info sections as part of
> > DWARF v5. Add explicit placements to prevent the linker warnings from
> > --orphan-section=warn.
> >
> > Compilers may produce such sections with explicit -gdwarf-5, or based on
> > the implicit default version of DWARF when -g is used via DEBUG_INFO.
> > This implicit default changes over time, and has changed to DWARF v5
> > with GCC 11.
> >
> > .debug_sup was mentioned in review, but without compilers producing it
> > today, let's wait to add it until it becomes necessary.
> >
>
> There isn't anything in this changelog which explains why a -stable
> backport was requested? Or is there? Irritating linker warnings?
> More than that?

Users adopting GCC 11 will start to see warnings from the linker due
to --orphan-section=warn when building the branches of the stable
tree. Stable has IME accepted patches for permitting newer toolchains
to continue to compile warning free.
--
Thanks,
~Nick Desaulniers