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

From: Alexei Starovoitov
Date: Mon Sep 26 2016 - 19:52:20 EST


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

> ---
> 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
>