Re: linux-5.10.11 build failure

[Chris Clayton <chris2553@googlemail.com>]

On 28/01/2021 14:41, Greg Kroah-Hartman wrote:
> On Thu, Jan 28, 2021 at 01:38:25PM +0000, Chris Clayton wrote:
>> Thanks, Thomas.
>>
>> On 28/01/2021 11:24, Thomas Backlund wrote:
>>> Den 28.1.2021 kl. 12:05, skrev Chris Clayton:
>>>>
>>>> On 28/01/2021 09:34, Greg Kroah-Hartman wrote:
>>>>> On Thu, Jan 28, 2021 at 09:17:10AM +0000, Chris Clayton wrote:
>>>>>> Hi,
>>>>>>
>>>>>> Building 5.10.11 fails on my (x86-64) laptop thusly:
>>>>>>
>>>>>> ..
>>>>>>
>>>>>>   AS      arch/x86/entry/thunk_64.o
>>>>>>    CC      arch/x86/entry/vsyscall/vsyscall_64.o
>>>>>>    AS      arch/x86/realmode/rm/header.o
>>>>>>    CC      arch/x86/mm/pat/set_memory.o
>>>>>>    CC      arch/x86/events/amd/core.o
>>>>>>    CC      arch/x86/kernel/fpu/init.o
>>>>>>    CC      arch/x86/entry/vdso/vma.o
>>>>>>    CC      kernel/sched/core.o
>>>>>> arch/x86/entry/thunk_64.o: warning: objtool: missing symbol for insn at offset 0x3e
>>>>>>
>>>>>>    AS      arch/x86/realmode/rm/trampoline_64.o
>>>>>> make[2]: *** [scripts/Makefile.build:360: arch/x86/entry/thunk_64.o] Error 255
>>>>>> make[2]: *** Deleting file 'arch/x86/entry/thunk_64.o'
>>>>>> make[2]: *** Waiting for unfinished jobs....
>>>>>>
>>>>>> ..
>>>>>>
>>>>>> Compiler is latest snapshot of gcc-10.
>>>>>>
>>>>>> Happy to test the fix but please cc me as I'm not subscribed
>>>>>
>>>>> Can you do 'git bisect' to track down the offending commit?
>>>>>
>>>>
>>>> Sure, but I'll hold that request for a while. I updated to binutils-2.36 on Monday and I'm pretty sure that is a feature
>>>> of this build fail. I've reverted binutils to 2.35.1, and the build succeeds. Updated to 2.36 again and, surprise,
>>>> surprise, the kernel build fails again.
>>>>
>>>> I've had a glance at the binutils ML and there are all sorts of issues being reported, but it's beyond my knowledge to
>>>> assess if this build error is related to any of them.
>>>>
>>>> I'll stick with binutils-2.35.1 for the time being.
>>>>
>>>>> And what exact gcc version are you using?
>>>>>
>>>>
>>>>   It's built from the 10-20210123 snapshot tarball.
>>>>
>>>> I can report this to the binutils folks, but might it be better if the objtool maintainer looks at it first? The
>>>> binutils change might just have opened the gate to a bug in objtool.
>>>>
>>>>> thanks,
>>>>>
>>>>> greg k-h
>>>>>
>>>>
>>>
>>>
>>> AFAIK you need this in stable trees:
>>>
>>>  From 1d489151e9f9d1647110277ff77282fe4d96d09b Mon Sep 17 00:00:00 2001
>>> From: Josh Poimboeuf <jpoimboe@redhat.com>
>>> Date: Thu, 14 Jan 2021 16:14:01 -0600
>>> Subject: [PATCH] objtool: Don't fail on missing symbol table
>>>
>>>
>>
>> That may be the caae, but it doesn't fix the build failure I've reported in this thread. However, as suggested by Tor,
>> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/patch/?id=5e6dca82bcaa49348f9e5fcb48df4881f6d6c4ae does fix it.
>>
>> That hasn't made Linus' tree yet and I don't see a pull request, but it is in linux-next so I guess it could make it in
>> -rc6.
> 
> Ok, thanks, so this is not a new regression for 5.10.y.
> 

That seems to be the case, Greg. Neither 5.10.10 nor 5.10.9 build either.

> greg k-h
>