From: Xu Kuohai Date: Tue, 1 Mar 2022 05:32:49 +0000 (-0500) Subject: libbpf: Skip forward declaration when counting duplicated type names X-Git-Tag: v5.18-rc1~136^2~185^2~5 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4226961b0019b2e1612029e8950a9e911affc995;p=thirdparty%2Flinux.git libbpf: Skip forward declaration when counting duplicated type names 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 Signed-off-by: Daniel Borkmann Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20220301053250.1464204-2-xukuohai@huawei.com --- diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 07ebe70d3a309..6b1bc1f43728c 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -1505,6 +1505,11 @@ 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;