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Date:   Wed, 18 May 2022 14:48:30 +0530
From:   "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Subject: Re: [PATCH] kexec_file: Drop pr_err in weak implementations of
 arch_kexec_apply_relocations[_add]
To:     Baoquan He <bhe@redhat.com>, Michael Ellerman <mpe@ellerman.id.au>
Cc:     "Eric W. Biederman" <ebiederm@xmission.com>,
        kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org
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Baoquan He wrote:
> On 05/18/22 at 12:26pm, Michael Ellerman wrote:
>>=20
>> It seems that recordmcount is not really maintained anymore now that x86
>> uses objtool?
>>=20
>> There've been several threads about fixing recordmcount, but none of
>> them seem to have lead to a solution.
>>=20
>> These weak symbol vs recordmcount problems have been worked around going
>> back as far as 2020:
>=20
> It gives me feeling that llvm or recordmcount should make adjustment,
> but not innocent kernel code, if there are a lot of places reported.
> I am curious how llvm or recordmcount dev respond to this.

As Michael stated, this is not just llvm - binutils has also adopted the=20
same and "unused" section symbols are being dropped.

For recordmcount, there were a few threads and approaches that have been=20
tried:
- https://patchwork.ozlabs.org/project/linuxppc-dev/patch/cd0f6bdfdf1ee096f=
b2c07e7b38940921b8e9118.1637764848.git.christophe.leroy@csgroup.eu/
- https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=3D297434&s=
tate=3D*

Objtool has picked up a more appropriate fix for this recently, and=20
long-term, we would like to move to using objtool for ftrace purposes:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/t=
ools/objtool/elf.c?id=3D4abff6d48dbcea8200c7ea35ba70c242d128ebf3

While that is being pursued, we want to unbreak some of the CI and users=20
who are hitting this.


- Naveen