From 69ff304792709dcdc5c8918b236cf06fe7db448f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 25 Aug 2020 21:21:14 +0200 Subject: [PATCH] bpf: Add elem_id pointer as argument to __btf_resolve_size If the resolved type is array, make btf_resolve_size return also ID of the elem type. It will be needed in following changes. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200825192124.710397-5-jolsa@kernel.org --- kernel/bpf/btf.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 6ed4ecc60381..dbc70fedfb44 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1079,6 +1079,7 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) * *type_size: (x * y * sizeof(u32)). Hence, *type_size always * corresponds to the return type. * *elem_type: u32 + * *elem_id: id of u32 * *total_nelems: (x * y). Hence, individual elem size is * (*type_size / *total_nelems) * @@ -1086,15 +1087,16 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) * return type: type "struct X" * *type_size: sizeof(struct X) * *elem_type: same as return type ("struct X") + * *elem_id: 0 * *total_nelems: 1 */ static const struct btf_type * __btf_resolve_size(const struct btf *btf, const struct btf_type *type, u32 *type_size, const struct btf_type **elem_type, - u32 *total_nelems) + u32 *elem_id, u32 *total_nelems) { const struct btf_type *array_type = NULL; - const struct btf_array *array; + const struct btf_array *array = NULL; u32 i, size, nelems = 1; for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { @@ -1146,6 +1148,8 @@ resolved: *total_nelems = nelems; if (elem_type) *elem_type = type; + if (elem_id) + *elem_id = array ? array->type : 0; return array_type ? : type; } @@ -3984,7 +3988,7 @@ error: mname = __btf_name_by_offset(btf_vmlinux, member->name_off); mtype = __btf_resolve_size(btf_vmlinux, mtype, &msize, - &elem_type, &total_nelems); + &elem_type, NULL, &total_nelems); if (IS_ERR(mtype)) { bpf_log(log, "field %s doesn't have size\n", mname); return -EFAULT; -- 2.25.1