From: Andrii Nakryiko <andriin@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
<daniel@iogearbox.net>
Cc: <andrii.nakryiko@gmail.com>, <kernel-team@fb.com>,
Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH bpf-next 2/4] libbpf: ignore incompatible types with matching name during CO-RE relocation
Date: Fri, 13 Mar 2020 00:54:39 -0700 [thread overview]
Message-ID: <20200313075442.4071486-3-andriin@fb.com> (raw)
In-Reply-To: <20200313075442.4071486-1-andriin@fb.com>
When finding target type candidates, ignore forward declarations, functions,
and other named types of incompatible kind. Not doing this can cause false
errors. See [0] for one such case (due to struct pt_regs forward
declaration).
[0] https://github.com/iovisor/bcc/pull/2806#issuecomment-598543645
Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Wenbo Zhang <ethercflow@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/lib/bpf/libbpf.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 1a787a2faf58..085e41f9b68e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3873,6 +3873,10 @@ static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
if (str_is_empty(targ_name))
continue;
+ t = skip_mods_and_typedefs(targ_btf, i, NULL);
+ if (!btf_is_composite(t) && !btf_is_array(t))
+ continue;
+
targ_essent_len = bpf_core_essential_name_len(targ_name);
if (targ_essent_len != local_essent_len)
continue;
--
2.17.1
next prev parent reply other threads:[~2020-03-13 7:56 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-13 7:54 [PATCH bpf-next 0/4] CO-RE candidate matching fix and tracing test Andrii Nakryiko
2020-03-13 7:54 ` [PATCH bpf-next 1/4] selftests/bpf: ensure consistent test failure output Andrii Nakryiko
2020-03-13 7:54 ` Andrii Nakryiko [this message]
2020-03-13 7:54 ` [PATCH bpf-next 3/4] libbpf: provide CO-RE variants of PT_REGS macros Andrii Nakryiko
2020-03-13 7:54 ` [PATCH bpf-next 4/4] selftests/bpf: add vmlinux.h selftest exercising tracing of syscalls Andrii Nakryiko
2020-03-13 17:02 ` [Potential Spoof] " Martin KaFai Lau
2020-03-13 17:16 ` Andrii Nakryiko
2020-03-13 17:23 [PATCH bpf-next 0/4] CO-RE candidate matching fix and tracing test Andrii Nakryiko
2020-03-13 17:23 ` [PATCH bpf-next 2/4] libbpf: ignore incompatible types with matching name during CO-RE relocation Andrii Nakryiko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200313075442.4071486-3-andriin@fb.com \
--to=andriin@fb.com \
--cc=andrii.nakryiko@gmail.com \
--cc=ast@fb.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=kernel-team@fb.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).