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Subject: Re: [PATCH bpf 1/2] bpf: support PTR_TO_MEM{,_OR_NULL} register
 spilling
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>,
        Gilad Reti <gilad.reti@gmail.com>
Cc:     bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Networking <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
References: <20210112091403.10458-1-gilad.reti@gmail.com>
 <CAEf4BzY2ezxxeUbhMy-kw-zRv974JG2NAQ+2g5_rtVSn8EmNcw@mail.gmail.com>
From:   Daniel Borkmann <daniel@iogearbox.net>
Message-ID: <c532894e-2934-b6ae-103d-ade0ed5b7792@iogearbox.net>
Date:   Tue, 12 Jan 2021 21:21:48 +0100
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On 1/12/21 8:46 PM, Andrii Nakryiko wrote:
> On Tue, Jan 12, 2021 at 1:14 AM Gilad Reti <gilad.reti@gmail.com> wrote:
>>
>> Add support for pointer to mem register spilling, to allow the verifier
>> to track pointer to valid memory addresses. Such pointers are returned
>> for example by a successful call of the bpf_ringbuf_reserve helper.
>>
>> This patch was suggested as a solution by Yonghong Song.
>>
>> The patch was partially contibuted by CyberArk Software, Inc.
>>
>> Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier
>> support for it")
> 
> Surprised no one mentioned this yet. Fixes tag should always be on a
> single unwrapped line, however long it is, please fix.

Especially for first-time contributors there is usually some luxury that we
would have fixed this up on the fly while applying. ;) But given a v2 is going
to be sent anyway it's good to point it out for future reference, agree.

Thanks,
Daniel