6.12-stable review patch. If anyone has any objections, please let me know.
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From: Alan Maguire alan.maguire@oracle.com
[ Upstream commit 4e29128a9acec2a622734844bedee013e2901bdf ]
libbpf handling of split BTF has been written largely with the assumption that multiple splits are possible, i.e. split BTF on top of split BTF on top of base BTF. One area where this does not quite work is string handling in split BTF; the start string offset should be the base BTF string section length + the base BTF string offset. This worked in the past because for a single split BTF with base the start string offset was always 0.
Signed-off-by: Alan Maguire alan.maguire@oracle.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20250519165935.261614-2-alan.maguire@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 27e7bfae953bd..4a486798fe4c0 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -995,7 +995,7 @@ static struct btf *btf_new_empty(struct btf *base_btf) if (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->start_str_off = base_btf->hdr->str_len + base_btf->start_str_off; btf->swapped_endian = base_btf->swapped_endian; }