Re: WARNING: modpost: "cmpxchg8b_emu" [lib/test_lockup.ko] has no CRC!

From: Arnd Bergmann
Date: Mon Mar 18 2024 - 10:25:54 EST


On Mon, Mar 18, 2024, at 14:27, kernel test robot wrote:
> tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> master
> head: f6cef5f8c37f58a3bc95b3754c3ae98e086631ca
> commit: 88a2b4edda3d0709727be53f4423b0b832d91de3 x86/Kconfig: Rework
> CONFIG_X86_PAE dependency
> date: 3 months ago
> config: um-randconfig-r035-20230726

> WARNING: modpost: EXPORT symbol "cmpxchg8b_emu" [vmlinux] version
> generation failed, symbol will not be versioned.
> Is "cmpxchg8b_emu" prototyped in <asm/asm-prototypes.h>?
> WARNING: modpost: EXPORT symbol "csum_partial" [vmlinux] version
> generation failed, symbol will not be versioned.
> Is "csum_partial" prototyped in <asm/asm-prototypes.h>?
> WARNING: modpost: EXPORT symbol "csum_partial_copy_generic" [vmlinux]
> version generation failed, symbol will not be versioned.
> Is "csum_partial_copy_generic" prototyped in <asm/asm-prototypes.h>?
>>> WARNING: modpost: "cmpxchg8b_emu" [lib/test_lockup.ko] has no CRC!
>>> WARNING: modpost: "cmpxchg8b_emu" [lib/atomic64_test.ko] has no CRC!

I have not tested arch/um randconfig builds, but my guess is that
this was not actually introduced by my patch but rather lkp bisected
this into my commit because that changed the config in a way that
hides the preexisting bug on older kernels.

Arnd