Re: [BUG] missing return thunk: __ret+0x5/0x7e-__ret+0x0/0x7e: e9 f6 ff ff ff

Paul E. McKenney
2023-08-17T21:29:43Z

On Thu, Aug 17, 2023 at 11:49:52PM +0300, Nikolay Borisov wrote:
>
>
> On 16.08.23 г. 20:54 ч., Paul E. McKenney wrote:
> > Hello!
> >
> > I hit the splat at the end of this message in recent mainline, and has
> > appeared some time since v6.5-rc1. Should I be worried?
> >
> > Reproducer on a two-socket hyperthreaded 20-core-per-socket x86 system:
> >
> > tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 5m --torture refscale --kcsan --kconfig "CONFIG_NR_CPUS=40" --kmake-args "CC=clang" --bootargs "refscale.scale_type=typesafe_seqlock refscale.nreaders=40 refscale.loops=10000 refscale.holdoff=20 torture.disable_onoff_at_boot refscale.verbose_batched=5 torture.verbose_sleep_frequency=8 torture.verbose_sleep_duration=5"
> >
> > This is from overnight testing that hit this only in the KCSAN runs.
> > The KASAN and non-debug runs had no trouble.
> >
> > This commit added the warning long ago:
> >
> > 65cdf0d623be ("x86/alternative: Report missing return thunk details")
> >
> > Thoughts?
> >
> > Thanx, Paul
>
> Likely fixed by the following commit in tip/urgen :
> 4ae68b26c3ab5a82aa271e6e9fc9b1a06e1d6b40 [tip: x86/urgent] objtool/x86: Fix
> SRSO mess

Thank you! Given the "urgent", I am guessing that this is going
upstream soon?

Thanx, Paul