Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To:     Jakub Kicinski <jakub.kicinski@netronome.com>
Cc:     Daniel Borkmann <daniel@iogearbox.net>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        lkml <linux-kernel@vger.kernel.org>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, Martin Lau <kafai@fb.com>
Subject: Re: [PATCH bpf v2] bpftool: Don't crash on missing jited insns or ksyms
In-Reply-To: <20191210125457.13f7821a@cakuba.netronome.com>
References: <20191210181412.151226-1-toke@redhat.com> <20191210125457.13f7821a@cakuba.netronome.com>
Date:   Tue, 10 Dec 2019 22:09:55 +0100
Message-ID: <87eexbhopo.fsf@toke.dk>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Jakub Kicinski <jakub.kicinski@netronome.com> writes:

> On Tue, 10 Dec 2019 19:14:12 +0100, Toke H=C3=B8iland-J=C3=B8rgensen wrot=
e:
>> When the kptr_restrict sysctl is set, the kernel can fail to return
>> jited_ksyms or jited_prog_insns, but still have positive values in
>> nr_jited_ksyms and jited_prog_len. This causes bpftool to crash when try=
ing
>> to dump the program because it only checks the len fields not the actual
>> pointers to the instructions and ksyms.
>>=20
>> Fix this by adding the missing checks.
>>=20
>> Signed-off-by: Toke H=C3=B8iland-J=C3=B8rgensen <toke@redhat.com>
>
> Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool")
>
> and
>
> Fixes: f84192ee00b7 ("tools: bpftool: resolve calls without using imm fie=
ld")
>
> ?

Yeah, guess so? Although I must admit it's not quite clear to me whether
bpftool gets stable backports, or if it follows the "only moving
forward" credo of libbpf?

Anyhow, I don't suppose it'll hurt to have the Fixes: tag(s) in there;
does Patchwork pick these up (or can you guys do that when you apply
this?), or should I resend?

-Toke