Fwd: Fwd: X stopped working with 5.14 on iBook
Christophe Leroy
christophe.leroy at csgroup.eu
Fri Nov 5 03:40:08 AEDT 2021
Le 02/11/2021 à 03:20, Finn Thain a écrit :
> Hi Christopher,
>
> After many builds and tests, Stan and I were able to determine that this
> regression only affects builds with CONFIG_USER_NS=y. That is,
>
> d3ccc9781560 + CONFIG_USER_NS=y --> fail
> d3ccc9781560 + CONFIG_USER_NS=n --> okay
> d3ccc9781560~ + CONFIG_USER_NS=y --> okay
> d3ccc9781560~ + CONFIG_USER_NS=n --> okay
>
> Stan also tested a PowerMac G3 system and found that the regression is not
> present there. Thus far, only PowerMac G4 systems are known to be affected
> (Stan's Cube and Riccardo's PowerBook).
>
> I asked Stan to try v5.15-rc after reverting commit d3ccc9781560.
> Unexpectedly, this build had the same issue. So, it appears there are
> multiple bad commits that produce this Xorg failure, of which d3ccc9781560
> is just the first.
>
> But there's no easy way to identify the other bad commits using bisection.
> So I've addressed this message to you. Can you help fix this regression?
>
I'm wondering if this commit is really the cause of the problem.
Are you using GCC 11 ?
If yes, I think it could be a false positive, fixed by
https://github.com/linuxppc/linux/commit/7315e457d6bc
Can you try with GCC 10 or older ?
Can you cherry pick 7315e457d6bc ("powerpc/uaccess: Fix __get_user()
with CONFIG_CC_HAS_ASM_GOTO_OUTPUT") on top of d3ccc9781560 and see what
happens ?
Thanks
Christophe
More information about the Linuxppc-dev
mailing list