6.11-stable review patch. If anyone has any objections, please let me know.
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From: Tony Ambardar tony.ambardar@gmail.com
[ Upstream commit da18bfa59d403040d8bcba1284285916fe9e4425 ]
New split BTF needs to preserve base's endianness. Similarly, when creating a distilled BTF, we need to preserve original endianness.
Fix by updating libbpf's btf__distill_base() and btf_new_empty() to retain the byte order of any source BTF objects when creating new ones.
Fixes: ba451366bf44 ("libbpf: Implement basic split BTF support") Fixes: 58e185a0dc35 ("libbpf: Add btf__distill_base() creating split BTF with distilled base BTF") Reported-by: Song Liu song@kernel.org Reported-by: Eduard Zingerman eddyz87@gmail.com Suggested-by: Eduard Zingerman eddyz87@gmail.com Signed-off-by: Tony Ambardar tony.ambardar@gmail.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Tested-by: Alan Maguire alan.maguire@oracle.com Acked-by: Eduard Zingerman eddyz87@gmail.com Link: https://lore.kernel.org/bpf/6358db36c5f68b07873a0a5be2d062b1af5ea5f8.camel@g... Link: https://lore.kernel.org/bpf/20240830095150.278881-1-tony.ambardar@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/btf.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 32c00db3b91b9..40aae244e35f7 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -996,6 +996,7 @@ static struct btf *btf_new_empty(struct btf *base_btf) btf->base_btf = base_btf; btf->start_id = btf__type_cnt(base_btf); btf->start_str_off = base_btf->hdr->str_len; + btf->swapped_endian = base_btf->swapped_endian; }
/* +1 for empty string at offset 0 */ @@ -5394,6 +5395,9 @@ int btf__distill_base(const struct btf *src_btf, struct btf **new_base_btf, new_base = btf__new_empty(); if (!new_base) return libbpf_err(-ENOMEM); + + btf__set_endianness(new_base, btf__endianness(src_btf)); + dist.id_map = calloc(n, sizeof(*dist.id_map)); if (!dist.id_map) { err = -ENOMEM;