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From:   Martin Lau <kafai@fb.com>
To:     =?iso-8859-1?Q?Toke_H=F8iland-J=F8rgensen?= <toke@redhat.com>
CC:     Daniel Borkmann <daniel@iogearbox.net>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        lkml <linux-kernel@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "bpf@vger.kernel.org" <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf v2] bpftool: Don't crash on missing jited insns or
 ksyms
Thread-Topic: [PATCH bpf v2] bpftool: Don't crash on missing jited insns or
 ksyms
Thread-Index: AQHVr4XTlNJlrcw9ukGEe5p86G241aezrksA
Date:   Tue, 10 Dec 2019 18:21:45 +0000
Message-ID: <20191210182141.eibshhthezq6d6zd@kafai-mbp>
References: <20191210181412.151226-1-toke@redhat.com>
In-Reply-To: <20191210181412.151226-1-toke@redhat.com>
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On Tue, Dec 10, 2019 at 07:14:12PM +0100, Toke H=F8iland-J=F8rgensen wrote:
> 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 tryi=
ng
> 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.
Acked-by: Martin KaFai Lau <kafai@fb.com>