From 9ec71c1cdbdd6c4ac0150a51d64e06c5d1bd207e Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 26 Mar 2019 22:00:06 -0700 Subject: [PATCH] libbpf: fix btf_dedup equivalence check handling of different kinds btf_dedup_is_equiv() used to compare btf_type->info fields, before doing kind-specific equivalence check. This comparsion implicitly verified that candidate and canonical types are of the same kind. With enum fwd resolution logic this check couldn't be done generically anymore, as for enums info contains vlen, which differs between enum fwd and fully-defined enum, so this check was subsumed by kind-specific equivalence checks. This change caused btf_dedup_is_equiv() to let through VOID vs other types check to reach switch, which was never meant to be handing VOID kind, as VOID kind is always pre-resolved to itself and is only equivalent to itself, which is checked early in btf_dedup_is_equiv(). This change adds back BTF kind equality check in place of more generic btf_type->info check, still defering further kind-specific checks to a per-kind switch. Fixes: 9768095ba97c ("btf: resolve enum fwds in btf_dedup") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/btf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 87e3020ac1bc..cf119c9b6f27 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -2107,6 +2107,9 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, return fwd_kind == real_kind; } + if (cand_kind != canon_kind) + return 0; + switch (cand_kind) { case BTF_KIND_INT: return btf_equal_int(cand_type, canon_type); -- 2.30.2