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From: Song Liu <song@kernel.org>
To: KP Singh <kpsingh@kernel.org>
Cc: bpf <bpf@vger.kernel.org>, Andrii Nakryiko <andrii@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Florent Revest <revest@chromium.org>,
	Brendan Jackman <jackmanb@chromium.org>
Subject: Re: [PATCH bpf-next v2 1/2] bpf: Allow usage of BPF ringbuffer in sleepable programs
Date: Thu, 4 Feb 2021 12:57:06 -0800	[thread overview]
Message-ID: <CAPhsuW7faA0t+VjrzDcxv0mmvB7FVDVeKyfgU+P7N5Uz+S=98A@mail.gmail.com> (raw)
In-Reply-To: <20210204193622.3367275-2-kpsingh@kernel.org>

On Thu, Feb 4, 2021 at 11:39 AM KP Singh <kpsingh@kernel.org> wrote:
>
> The BPF ringbuffer map is pre-allocated and the implementation logic
> does not rely on disabling preemption or per-cpu data structures. Using
> the BPF ringbuffer sleepable LSM and tracing programs does not trigger
> any warnings with DEBUG_ATOMIC_SLEEP, DEBUG_PREEMPT,
> PROVE_RCU and PROVE_LOCKING and LOCKDEP enabled.
>
> This allows helpers like bpf_copy_from_user and bpf_ima_inode_hash to
> write to the BPF ring buffer from sleepable BPF programs.
>
> Acked-by: Andrii Nakryiko <andrii@kernel.org>
> Signed-off-by: KP Singh <kpsingh@kernel.org>
> ---
>  kernel/bpf/verifier.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 5e09632efddb..4c33b4840438 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -10024,6 +10024,8 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
>                                 return -EINVAL;
>                         }
>                         break;
> +               case BPF_MAP_TYPE_RINGBUF:
> +                       break;
>                 default:
>                         verbose(env,
>                                 "Sleepable programs can only use array and hash maps\n");

Shall we update this message?

Thanks,
Song

> --
> 2.30.0.365.g02bc693789-goog
>

  reply	other threads:[~2021-02-04 20:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-04 19:36 [PATCH bpf-next v2 0/2] BPF Ringbuffer + Sleepable Programs KP Singh
2021-02-04 19:36 ` [PATCH bpf-next v2 1/2] bpf: Allow usage of BPF ringbuffer in sleepable programs KP Singh
2021-02-04 20:57   ` Song Liu [this message]
2021-02-05  1:15     ` Andrii Nakryiko
2021-02-04 19:36 ` [PATCH bpf-next v2 2/2] bpf/selftests: Update the IMA test to use BPF ring buffer KP Singh
2021-02-05  7:06 ` [PATCH bpf-next v2 0/2] BPF Ringbuffer + Sleepable Programs Andrii Nakryiko

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