Re: [PATCH 6.1 000/591] 6.1.39-rc1 review

[Guenter Roeck]

On 7/16/23 16:40, Daniel Díaz wrote:
> Hello!
>
> On Sun, 16 Jul 2023 at 14:31, Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > This is the start of the stable review cycle for the 6.1.39 release.
> > There are 591 patches in this series, all will be posted as a response
> > to this one.  If anyone has any issues with these being applied, please
> > let me know.
> >
> > Responses should be made by Tue, 18 Jul 2023 19:48:07 +0000.
> > Anything received after that time might be too late.
[ ... ]
> We're seeing build failures on i386 and x86 with Clang:
> -----8<-----
> /builds/linux/block/blk-cgroup.c:1238:6: error: variable 'ret' is used
> uninitialized whenever 'if' condition is true
> [-Werror,-Wsometimes-uninitialized]
>          if (init_blkcg_llists(blkcg))
>              ^~~~~~~~~~~~~~~~~~~~~~~~
> /builds/linux/block/blk-cgroup.c:1288:9: note: uninitialized use occurs here
>          return ret;
>                 ^~~
> /builds/linux/block/blk-cgroup.c:1238:2: note: remove the 'if' if its
> condition is always false
>          if (init_blkcg_llists(blkcg))
>          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /builds/linux/block/blk-cgroup.c:1223:33: note: initialize the
> variable 'ret' to silence this warning
>          struct cgroup_subsys_state *ret;
>                                         ^
>                                          = NULL
> 1 error generated.
> ----->8-----
>
> More info to follow soon.

Caused by 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()")
which is missing its prerequisite b5a9adcbd5dc ("blk-cgroup: Return
-ENOMEM directly in blkcg_css_alloc() error path"). With three Fixup:
patches following, it is one of those patches where I wonder if it
is worth the trouble.

Guenter