Re: [PATCH v9 00/16] Add support for Clang LTO

Josh Poimboeuf
2021-01-09T15:38:42Z

On Sat, Jan 09, 2021 at 03:54:20PM +0100, Sedat Dilek wrote:
> I am interested in having Clang LTO (Clang-CFI) for x86-64 working and
> help with testing.
>
> I tried the Git tree mentioned in [3] <jpoimboe.git#objtool-vmlinux>
> (together with changes from <peterz.git#x86/urgent>).
>
> I only see in my build-log...
>
> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:
> eb_relocate_parse_slow()+0x3d0: stack state mismatch: cfa1=7+120
> cfa2=-1+0
> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:
> eb_copy_relocations()+0x229: stack state mismatch: cfa1=7+120
> cfa2=-1+0
>
> ...which was reported and worked on in [1].
>
> This is with Clang-IAS version 11.0.1.
>
> Unfortunately, the recent changes in <samitolvanen.github#clang-cfi>
> do not cleanly apply with Josh stuff.
> My intention/wish was to report this combination of patchsets "heals"
> a lot of objtool-warnings for vmlinux.o I observed with Clang-CFI.
>
> Is it possible to have a Git branch where Josh's objtool-vmlinux is
> working together with Clang-LTO?
> For testing purposes.

I updated my branch with my most recent work from before the holidays,
can you try it now? It still doesn't fix any of the crypto warnings,
but I'll do that in a separate set after posting these next week.

--
Josh