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From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 03/10] libbpf: fix logic for finding matching program for CO-RE relocation
Date: Mon, 25 Apr 2022 17:45:04 -0700	[thread overview]
Message-ID: <20220426004511.2691730-4-andrii@kernel.org> (raw)
In-Reply-To: <20220426004511.2691730-1-andrii@kernel.org>

Fix the bug in bpf_object__relocate_core() which can lead to finding
invalid matching BPF program when processing CO-RE relocation. IF
matching program is not found, last encountered program will be assumed
to be correct program and thus error detection won't detect the problem.

Fixes: 9c82a63cf370 ("libbpf: Fix CO-RE relocs against .text section")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/lib/bpf/libbpf.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5f2750af0e27..840a26428937 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5677,9 +5677,10 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
 		 */
 		prog = NULL;
 		for (i = 0; i < obj->nr_programs; i++) {
-			prog = &obj->programs[i];
-			if (strcmp(prog->sec_name, sec_name) == 0)
+			if (strcmp(obj->programs[i].sec_name, sec_name) == 0) {
+				prog = &obj->programs[i];
 				break;
+			}
 		}
 		if (!prog) {
 			pr_warn("sec '%s': failed to find a BPF program\n", sec_name);
-- 
2.30.2


  parent reply	other threads:[~2022-04-26  0:45 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-26  0:45 [PATCH bpf-next 00/10] Teach libbpf to "fix up" BPF verifier log Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 01/10] libbpf: fix anonymous type check in CO-RE logic Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 02/10] libbpf: drop unhelpful "program too large" guess Andrii Nakryiko
2022-04-26  0:45 ` Andrii Nakryiko [this message]
2022-04-26  0:45 ` [PATCH bpf-next 04/10] libbpf: avoid joining .BTF.ext data with BPF programs by section name Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 05/10] selftests/bpf: add CO-RE relos and SEC("?...") to linked_funcs selftests Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 06/10] libbpf: record subprog-resolved CO-RE relocations unconditionally Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 07/10] libbpf: refactor CO-RE relo human description formatting routine Andrii Nakryiko
2022-04-26 18:52   ` Alexei Starovoitov
2022-04-26 22:20     ` Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 08/10] libbpf: simplify bpf_core_parse_spec() signature Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 09/10] libbpf: fix up verifier log for unguarded failed CO-RE relos Andrii Nakryiko
2022-04-26 18:59   ` Alexei Starovoitov
2022-04-26 22:16     ` Andrii Nakryiko
2022-04-26  0:45 ` [PATCH bpf-next 10/10] selftests/bpf: add libbpf's log fixup logic selftests Andrii Nakryiko
2022-04-26 22:50 ` [PATCH bpf-next 00/10] Teach libbpf to "fix up" BPF verifier log patchwork-bot+netdevbpf

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