From: Xu Kuohai xukuohai@huawei.com
stable inclusion from stable-v5.10.110 commit 3e04a837dba71593dc3c21ecbe142bb465e48a16 bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 4226961b0019b2e1612029e8950a9e911affc995 ]
Currently if a declaration appears in the BTF before the definition, the definition is dumped as a conflicting name, e.g.:
$ bpftool btf dump file vmlinux format raw | grep "'unix_sock'" [81287] FWD 'unix_sock' fwd_kind=struct [89336] STRUCT 'unix_sock' size=1024 vlen=14
$ bpftool btf dump file vmlinux format c | grep "struct unix_sock" struct unix_sock; struct unix_sock___2 { <--- conflict, the "___2" is unexpected struct unix_sock___2 *unix_sk;
This causes a compilation error if the dump output is used as a header file.
Fix it by skipping declaration when counting duplicated type names.
Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Signed-off-by: Xu Kuohai xukuohai@huawei.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Song Liu songliubraving@fb.com Link: https://lore.kernel.org/bpf/20220301053250.1464204-2-xukuohai@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- tools/lib/bpf/btf_dump.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 0911aea4cdbe..bd22853be4a6 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1416,6 +1416,11 @@ static const char *btf_dump_resolve_name(struct btf_dump *d, __u32 id, if (s->name_resolved) return *cached_name ? *cached_name : orig_name;
+ if (btf_is_fwd(t) || (btf_is_enum(t) && btf_vlen(t) == 0)) { + s->name_resolved = 1; + return orig_name; + } + dup_cnt = btf_dump_name_dups(d, name_map, orig_name); if (dup_cnt > 1) { const size_t max_len = 256;