Re: [PATCH] kexec_file: Drop pr_err in weak implementations of arch_kexec_apply_relocations[_add]

[Naveen N. Rao]

Baoquan He wrote:
> On 05/18/22 at 12:26pm, Michael Ellerman wrote:
> > It seems that recordmcount is not really maintained anymore now that x86
> > uses objtool?
> >
> > There've been several threads about fixing recordmcount, but none of
> > them seem to have lead to a solution.
> >
> > These weak symbol vs recordmcount problems have been worked around going
> > back as far as 2020:
>
> 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 
same and "unused" section symbols are being dropped.

For recordmcount, there were a few threads and approaches that have been 
tried:
- https://patchwork.ozlabs.org/project/linuxppc-dev/patch/cd0f6bdfdf1ee096fb2c07e7b38940921b8e9118.1637764848.git.christophe.leroy@xxxxxxxxxx/
- https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=297434&state=*

Objtool has picked up a more appropriate fix for this recently, and 
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/tools/objtool/elf.c?id=4abff6d48dbcea8200c7ea35ba70c242d128ebf3

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


- Naveen