[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20210116185247.GA2491296@ubuntu-m3-large-x86>
Date: Sat, 16 Jan 2021 11:52:47 -0700
From: Nathan Chancellor <natechancellor@...il.com>
To: Segher Boessenkool <segher@...nel.crashing.org>
Cc: Michael Ellerman <mpe@...erman.id.au>,
Nick Desaulniers <ndesaulniers@...gle.com>,
linux-kernel@...r.kernel.org, stable@...r.kernel.org,
clang-built-linux@...glegroups.com,
Paul Mackerras <paulus@...ba.org>,
linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH v2] powerpc: Handle .text.{hot,unlikely}.* in linker
script
On Sat, Jan 16, 2021 at 12:44:38PM -0600, Segher Boessenkool wrote:
> Hi!
>
> Very late of course, and the patch is fine, but:
>
> On Mon, Jan 04, 2021 at 01:59:53PM -0700, Nathan Chancellor wrote:
> > Commit eff8728fe698 ("vmlinux.lds.h: Add PGO and AutoFDO input
> > sections") added ".text.unlikely.*" and ".text.hot.*" due to an LLVM
> > change [1].
> >
> > After another LLVM change [2], these sections are seen in some PowerPC
> > builds, where there is a orphan section warning then build failure:
> >
> > $ make -skj"$(nproc)" \
> > ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-gnu- LLVM=1 O=out \
> > distclean powernv_defconfig zImage.epapr
> > ld.lld: warning: kernel/built-in.a(panic.o):(.text.unlikely.) is being placed in '.text.unlikely.'
>
> Is the section really called ".text.unlikely.", i.e. the name ending in
> a dot? How very unusual, is there some bug elsewhere?
No, this was an intention change done by LLVM:
https://reviews.llvm.org/D79600
Cheers,
Nathan
Powered by blists - more mailing lists