From: Ian Rogers <irogers@google.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Ian Rogers <irogers@google.com>,
Stanislav Fomichev <sdf@google.com>,
Petar Penkov <ppenkov@google.com>
Subject: [PATCH] libbpf: Add NULL check to add_dummy_ksym_var
Date: Tue, 4 May 2021 16:49:10 -0700 [thread overview]
Message-ID: <20210504234910.976501-1-irogers@google.com> (raw)
Avoids a segv if btf isn't present. Seen on the call path
__bpf_object__open calling bpf_object__collect_externs.
Fixes: 5bd022ec01f0 (libbpf: Support extern kernel function)
Suggested-by: Stanislav Fomichev <sdf@google.com>
Suggested-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/lib/bpf/libbpf.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index de9a5b0118fe..97d9a1c2d680 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3216,6 +3216,9 @@ static int add_dummy_ksym_var(struct btf *btf)
const struct btf_var_secinfo *vs;
const struct btf_type *sec;
+ if (!btf)
+ return 0;
+
sec_btf_id = btf__find_by_name_kind(btf, KSYMS_SEC,
BTF_KIND_DATASEC);
if (sec_btf_id < 0)
--
2.31.1.607.g51e8a6a459-goog
next reply other threads:[~2021-05-04 23:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-04 23:49 Ian Rogers [this message]
2021-05-05 18:40 ` [PATCH] libbpf: Add NULL check to add_dummy_ksym_var patchwork-bot+netdevbpf
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