Re: [PATCH 5.18 000/231] 5.18.13-rc1 review

[Justin Forbes]

On Tue, Jul 19, 2022 at 12:32:48PM -0700, Linus Torvalds wrote:
> On Tue, Jul 19, 2022 at 10:57 AM Naresh Kamboju
> <naresh.kamboju@xxxxxxxxxx> wrote:
> >
> >
> > Details log:
> > ------------
> > 1. i386 build failures with clang-13 and clang-14
> > make --silent --keep-going --jobs=8
> > O=/home/tuxbuild/.cache/tuxmake/builds/1/build LLVM=1 LLVM_IAS=1
> > ARCH=i386 CROSS_COMPILE=i686-linux-gnu- 'HOSTCC=sccache clang'
> > 'CC=sccache clang'
> > ld.lld: error: undefined symbol: __udivdi3
> 
> Looks like the one introduced by aff1e0b09b54 ("drm/i915/ttm: fix
> sg_table construction"), and fixed by ced7866db39f ("drm/i915/ttm: fix
> 32b build").
> 
> > 2. Large number of build warnings on x86 with gcc-11,
> > I do not see these build warnings on mainline,
> ..
> > 'naked' return found in RETPOLINE build
> 
> Hmm. Does your cross-compiler support '-mfunction-return=thunk-extern'?
> 
> Your build does magic things with 'scripts/kconfig/merge_config.sh',
> and I'm wondering if you perhaps end up enabling CONFIG_RETHUNK with a
> compiler that doesn't actually support it, or something like that?

I am seeing these 'naked' return found in RETPOLINE build on the
standard fedora 36 toolchain as well. No cross compiling, nothing fancy.
These were not seen with mainline, or with the 5.18.12-rc1 retbleed
patches.

Justin