From: Alexei Starovoitov <ast@kernel.org>
To: <davem@davemloft.net>
Cc: <daniel@iogearbox.net>, <netdev@vger.kernel.org>,
<bpf@vger.kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next] bpf: Enforce 'return 0' in BTF-enabled raw_tp programs
Date: Mon, 28 Oct 2019 20:24:26 -0700 [thread overview]
Message-ID: <20191029032426.1206762-1-ast@kernel.org> (raw)
The return value of raw_tp programs is ignored by __bpf_trace_run()
that calls them. The verifier also allows any value to be returned.
For BTF-enabled raw_tp lets enforce 'return 0', so that return value
can be used for something in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
kernel/bpf/verifier.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c59778c0fc4d..6b0de04f8b91 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6279,6 +6279,11 @@ static int check_return_code(struct bpf_verifier_env *env)
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
break;
+ case BPF_PROG_TYPE_RAW_TRACEPOINT:
+ if (!env->prog->aux->attach_btf_id)
+ return 0;
+ range = tnum_const(0);
+ break;
default:
return 0;
}
--
2.17.1
next reply other threads:[~2019-10-29 3:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-29 3:24 Alexei Starovoitov [this message]
2019-10-29 4:32 ` [PATCH bpf-next] bpf: Enforce 'return 0' in BTF-enabled raw_tp programs Andrii Nakryiko
2019-10-30 15:53 ` Daniel Borkmann
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