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Date:   Thu, 11 Aug 2022 19:01:38 -0500
From:   David Vernet <void@manifault.com>
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
        andrii@kernel.org, john.fastabend@gmail.com, martin.lau@linux.dev,
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        haoluo@google.com, jolsa@kernel.org, tj@kernel.org,
        joannelkoong@gmail.com, linux-kernel@vger.kernel.org,
        Kernel-team@fb.com
Subject: Re: [PATCH 3/5] bpf: Add bpf_user_ringbuf_drain() helper
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 <20220808155341.2479054-3-void@manifault.com>
 <CAEf4BzZ-m-AUX+1+CGr7nMxMDnT=fjkn8DP9nP21Uts1y7fMyg@mail.gmail.com>
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On Thu, Aug 11, 2022 at 04:22:43PM -0700, Andrii Nakryiko wrote:
> On Mon, Aug 8, 2022 at 8:54 AM David Vernet <void@manifault.com> wrote:
> >
> > Now that we have a BPF_MAP_TYPE_USER_RINGBUF map type, we need to add a
> > helper function that allows BPF programs to drain samples from the ring
> > buffer, and invoke a callback for each. This patch adds a new
> > bpf_user_ringbuf_drain() helper that provides this abstraction.
> >
> > In order to support this, we needed to also add a new PTR_TO_DYNPTR
> > register type to reflect a dynptr that was allocated by a helper function
> > and passed to a BPF program. The verifier currently only supports
> > PTR_TO_DYNPTR registers that are also DYNPTR_TYPE_LOCAL and MEM_ALLOC.
> 
> This commit message is a bit too laconic. There is a lot of
> implications of various parts of this patch, it would be great to
> highlight most important ones. Please consider elaborating a bit more.

Not a problem, I'll do this in v3.