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From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
	<daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 10/17] libbpf: tighten BTF type ID rewriting with error checking
Date: Wed, 14 Apr 2021 13:01:39 -0700	[thread overview]
Message-ID: <20210414200146.2663044-11-andrii@kernel.org> (raw)
In-Reply-To: <20210414200146.2663044-1-andrii@kernel.org>

It should never fail, but if it does, it's better to know about this rather
than end up with nonsensical type IDs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 tools/lib/bpf/linker.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index dc202a5d8235..978756889de6 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -1425,6 +1425,15 @@ static int linker_fixup_btf(struct src_obj *obj)
 static int remap_type_id(__u32 *type_id, void *ctx)
 {
 	int *id_map = ctx;
+	int new_id = id_map[*type_id];
+
+	if (*type_id == 0)
+		return 0;
+
+	if (new_id == 0) {
+		pr_warn("failed to find new ID mapping for original BTF type ID %u\n", *type_id);
+		return -EINVAL;
+	}
 
 	*type_id = id_map[*type_id];
 
-- 
2.30.2


  parent reply	other threads:[~2021-04-14 20:04 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-14 20:01 [PATCH bpf-next 00/17] BPF static linker: support externs Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 01/17] bpftool: support dumping BTF VAR's "extern" linkage Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 02/17] bpftool: dump more info about DATASEC members Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 03/17] libbpf: suppress compiler warning when using SEC() macro with externs Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 04/17] libbpf: mark BPF subprogs with hidden visibility as static for BPF verifier Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 05/17] libbpf: allow gaps in BPF program sections to support overriden weak functions Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 06/17] libbpf: refactor BTF map definition parsing Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 07/17] libbpf: factor out symtab and relos sanity checks Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 08/17] libbpf: make few internal helpers available outside of libbpf.c Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 09/17] libbpf: extend sanity checking ELF symbols with externs validation Andrii Nakryiko
2021-04-14 20:01 ` Andrii Nakryiko [this message]
2021-04-14 20:01 ` [PATCH bpf-next 11/17] libbpf: add linker extern resolution support for functions and global variables Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 12/17] libbpf: support extern resolution for BTF-defined maps in .maps section Andrii Nakryiko
2021-04-14 22:00   ` Alexei Starovoitov
2021-04-14 23:48     ` Andrii Nakryiko
2021-04-15  2:01       ` Alexei Starovoitov
2021-04-15 20:35         ` Andrii Nakryiko
2021-04-15 20:57           ` Alexei Starovoitov
2021-04-14 20:01 ` [PATCH bpf-next 13/17] selftests/bpf: use -O0 instead of -Og in selftests builds Andrii Nakryiko
2021-04-14 22:02   ` Alexei Starovoitov
2021-04-14 22:15   ` David Laight
2021-04-15  0:03     ` Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 14/17] selftests/bpf: omit skeleton generation for multi-linked BPF object files Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 15/17] selftests/bpf: add function linking selftest Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 16/17] selftests/bpf: add global variables " Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 17/17] sleftests/bpf: add map " Andrii Nakryiko
2021-04-15  0:21 ` [PATCH bpf-next 00/17] BPF static linker: support externs Andrii Nakryiko

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