[LTP] [PATCH] lib: switch cgroup bit-fields from signed to unsigned int

[Li Wang]

On Fri, Jan 24, 2025 at 7:20 PM Cyril Hrubis <chrubis@suse.cz> wrote:

> Hi!
> > There is a problem in cgroup lib that the declearation int
> > can lead to -1 during the | operation.
> >
> > Becasue if the field contains uninitialized garbage data,
> > a bit-field declared as int could interpret 0b1 as -1 due
> > to signed arithmetic.
>
> Uff, so we have a number that can be either -1 or 0. Where did it break?
>

It doesn't break anything so far, I found that issue while reviewing
Guojie's patch-v2, when that memory_recursiveprot declared as int,
the test result is always wrong.

However, the root->nsdelegate avoids this problem by negating value twice:

static int cgroup_v2_nsdelegate(void)
{
    return !!roots[0].nsdelegate;
}

But I think we should fix this from the root.



> I suppose that things are okay as long as we do if (s->bar | s->bar).
>
>
> Anyways:
>
> Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
>
> --
> Cyril Hrubis
> chrubis@suse.cz
>
>

-- 
Regards,
Li Wang