linux-kernel - Re: Objtool segfault inside an VM, based on commit 24172e0d7990

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Message-ID: <2625850d-de30-42ae-bd0d-5f92f7f2f6e7@gmx.com>
Date: Tue, 18 Nov 2025 06:57:58 +1030
From: Qu Wenruo <quwenruo.btrfs@....com>
To: Nathan Chancellor <nathan@...nel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 linux-btrfs <linux-btrfs@...r.kernel.org>
Subject: Re: Objtool segfault inside an VM, based on commit 24172e0d7990



在 2025/11/18 04:20, Nathan Chancellor 写道:
> On Mon, Nov 17, 2025 at 03:40:35PM +1030, Qu Wenruo wrote:
>>
>>
>> 在 2025/11/17 13:33, Qu Wenruo 写道:
>>>
>>>
>>> 在 2025/11/17 13:10, Qu Wenruo 写道:
>>>> Hi,
>>>>
>>>> Recently I'm hitting pretty frequent objtool crashes, sometimes
>>>> during module linking (btrfs in my case) sometimes during the
>>>> vmlinux linking.
>>>>
>>>> Unfortunately I don't have a coredump for it.
>>>>
>>>> The only info so far is from dmesg (and obvious the compile failure):
>>>>
>>>> [  625.066787] traps: objtool[46220] general protection fault
>>>> ip:563ab54c6eb0 sp:7ffd9c2ba7c8 error:0 in
>>>> objtool[19eb0,563ab54b2000+1f000]
>>>>
>>>> The involved VM has the following spec:
>>>>
>>>> - Kernel branch
>>>>     Btrfs' development branch.
>>>>
>>>>     The base commit is 24172e0d79900908cf5ebf366600616d29c9b417, around
>>>>     v6.18-rc6.
>>
>> Furthermore, if just compiling on old kernels (in my case, 6.17.8), I
>> haven't yet hit a linking time segfault.
>>
>> So it's something in the v6.18 release cycle.
>>
>> Not sure if it's the recent Zen5 related hassles.
> 
> I had similar objtool crashes and David's fix [1] from another bug
> report thread [2] appears to resolve this for me.
> 
> [1]: https://github.com/davidhildenbrand/linux/commit/58e62699f77738188730d489accd01ad8e3cdeeb
> [2]: https://lore.kernel.org/20251117082023.90176-1-00107082@163.com/

Thanks a lot!

Indeed this thread explains why aarch64 doesn't crash and with the patch 
applied I haven't yet hit another kernel compiling crash.

Thanks,
Qu

> 
> Cheers,
> Nathan