Re: [PATCH 2/3] bpf: Remove dead variable

[Daniel Borkmann]

On 10/16/2017 08:59 PM, Richard Weinberger wrote:
> Am Montag, 16. Oktober 2017, 20:54:36 CEST schrieb Daniel Borkmann:
> > On 10/16/2017 08:18 PM, Richard Weinberger wrote:
> > > task is never used in bpf_get_current_uid_gid(), kill it.
> > >
> > > Signed-off-by: Richard Weinberger <richard@xxxxxx>
> > > ---
> > >
> > >    kernel/bpf/helpers.c | 1 -
> > >    1 file changed, 1 deletion(-)
> > >
> > > diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> > > index e8845adcd15e..511c9d522cfc 100644
> > > --- a/kernel/bpf/helpers.c
> > > +++ b/kernel/bpf/helpers.c
> > > @@ -131,7 +131,6 @@ const struct bpf_func_proto
> > > bpf_get_current_pid_tgid_proto = {>
> > >    BPF_CALL_0(bpf_get_current_uid_gid)
> > >    {
> > >
> > > -	struct task_struct *task = current;
> > >
> > >    	kuid_t uid;
> > >    	kgid_t gid;
> >
> > Needs to be squashed into patch 1/3?
>
> I can squash it into 1/3, I kept it that way because
> even without 1/3 this variable is unused.

Hmm, the helper looks like the below. In patch 1/3 you removed
the 'if (unlikely(!task))' test where the variable was used before,
so 2/3 without the 1/3 would result in a compile error.

BPF_CALL_0(bpf_get_current_uid_gid)
{
	struct task_struct *task = current;
	kuid_t uid;
	kgid_t gid;

	if (unlikely(!task))
		return -EINVAL;

	current_uid_gid(&uid, &gid);
	return (u64) from_kgid(&init_user_ns, gid) << 32 |
		     from_kuid(&init_user_ns, uid);
}