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Date:   Mon, 11 Jul 2022 13:48:51 +0200
From:   Artem Savkov <asavkov@redhat.com>
To:     Jiri Olsa <olsajiri@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>, bpf@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC PATCH bpf-next 2/4] bpf: add BPF_F_DESTRUCTIVE flag for
 BPF_PROG_LOAD
Message-ID: <YswOIzI7urHs4XBi@samus.usersys.redhat.com>
Mail-Followup-To: Jiri Olsa <olsajiri@gmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>, bpf@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andrea Arcangeli <aarcange@redhat.com>
References: <20220711083220.2175036-1-asavkov@redhat.com>
 <20220711083220.2175036-3-asavkov@redhat.com>
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On Mon, Jul 11, 2022 at 12:56:28PM +0200, Jiri Olsa wrote:
> On Mon, Jul 11, 2022 at 10:32:18AM +0200, Artem Savkov wrote:
> > Add a BPF_F_DESTRUCTIVE will be required to be supplied to
> > BPF_PROG_LOAD for programs to utilize destructive helpers such as
> > bpf_panic().
> 
> I'd think that having kernel.destructive_bpf_enabled sysctl knob enabled
> would be enough to enable that helper from any program, not sure having
> extra load flag adds more security

I agree it doesn't add more security. The idea was to have a way for a
developer to explicitly state he understand this will be dangerous. This
flag can also translate well into something like a --destructive option
for bpftrace without needing to keep a list of destructive helpers on
their side.

-- 
 Artem