Re: [PATCH trival 1/2] bpf: clean up put_cpu_var usage

[Daniel Borkmann]

Shaohua,

On 09/27/2016 01:51 AM, Alexei Starovoitov wrote:
> On Mon, Sep 26, 2016 at 11:14:50AM -0700, Shaohua Li wrote:
> > put_cpu_var takes the percpu data, not the data returned from
> > get_cpu_var.
> >
> > This doesn't change the behavior.
> >
> > Cc: Tejun Heo <tj@xxxxxxxxxx>
> > Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Signed-off-by: Shaohua Li <shli@xxxxxx>
>
> Looks good. Nice catch.
> Please rebase to net-next tree and send it to netdev list.

+1

> Otherwise we'll have conflicts at the time of the merge window.

While you're at it, the same kind of cleanup can be done for
prandom_u32() and prandom_bytes(), so you could either squash
that into this patch as well or make it two patches. Both for
netdev.

Thanks,
Daniel

> > ---
> >   kernel/bpf/core.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> > index 03fd23d..b73913b 100644
> > --- a/kernel/bpf/core.c
> > +++ b/kernel/bpf/core.c
> > @@ -1031,7 +1031,7 @@ u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
> >
> >   	state = &get_cpu_var(bpf_user_rnd_state);
> >   	res = prandom_u32_state(state);
> > -	put_cpu_var(state);
> > +	put_cpu_var(bpf_user_rnd_state);
> >
> >   	return res;
> >   }
> > --
> > 2.9.3