[RFC PATCH 3/3] objtool/mcount: Add powerpc specific functions

[Christophe Leroy]

Le 21/03/2022 à 03:27, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy at csgroup.eu> writes:
>> Le 18/03/2022 à 13:26, Peter Zijlstra a écrit :
>>> On Fri, Mar 18, 2022 at 04:21:40PM +0530, Sathvika Vasireddy wrote:
>>>> This patch adds powerpc specific functions required for
>>>> 'objtool mcount' to work, and enables mcount for ppc.
>>>
>>> I would love to see more objtool enablement for Power :-)
>>
>> I have not received this series and I can't see it on powerpc patchwork
>> either (https://patchwork.ozlabs.org/project/linuxppc-dev/list/)
>>
>> Did you send it to linuxppc-dev list ? If not can you resend it there ?
> 
> It is there, might have been delayed?
> 
> http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=291129
> 
> There are some CI failures.
> 

On PPC64 we randomly get:

/bin/sh: 1: ./tools/objtool/objtool: not found
make[2]: *** [arch/powerpc/kernel/vdso/vgettimeofday-64.o] Error 127
/linux/arch/powerpc/kernel/vdso/Makefile:77: recipe for target 
'arch/powerpc/kernel/vdso/vgettimeofday-64.o' failed
make[2]: *** Deleting file 'arch/powerpc/kernel/vdso/vgettimeofday-64.o'
make[1]: *** [vdso_prepare] Error 2
make[1]: *** Waiting for unfinished jobs....
/linux/arch/powerpc/Makefile:423: recipe for target 'vdso_prepare' failed
make: *** [__sub-make] Error 2
Makefile:219: recipe for target '__sub-make' failed

This is linkely because prepare: target depends on vdso_prepare and 
prepare: target depends on objtool, but vdso_prepare: doesn't depend on 
objtool.

I'm not sure it is correct to run objtool mcount on VDSO as it is kind 
of useless. Only VDSO64 seems to call objtool, not VDSO32.

Christophe