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

Nikolay Borisov
2023-08-17T20:50:50Z

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