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

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Message-ID: <2869131.K5Z6hvSGBl@blindfold>
Date:   Mon, 16 Oct 2017 21:22:42 +0200
From:   Richard Weinberger <richard@....at>
To:     Daniel Borkmann <daniel@...earbox.net>
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        ast@...nel.org
Subject: Re: [PATCH 2/3] bpf: Remove dead variable

Am Montag, 16. Oktober 2017, 21:11:47 CEST schrieb Daniel Borkmann: 
> > 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.

Why a compile error? It emits a warning.

> BPF_CALL_0(bpf_get_current_uid_gid)
> {
> 	struct task_struct *task = current;
> 	kuid_t uid;
> 	kgid_t gid;
> 
> 	if (unlikely(!task))
> 		return -EINVAL;

Well, this is the only "user". Okay.

> 	current_uid_gid(&uid, &gid);

Here we use current. So, task was always in vain.

So, I can happily squash 2/3 into 1/3 and resent.
The series just represented the way I've worked on the code... 

Thanks,
//richard