diff options
Diffstat (limited to 'tools/lib/bpf/btf_iter.c')
| -rw-r--r-- | tools/lib/bpf/btf_iter.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/tools/lib/bpf/btf_iter.c b/tools/lib/bpf/btf_iter.c new file mode 100644 index 000000000000..9a6c822c2294 --- /dev/null +++ b/tools/lib/bpf/btf_iter.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +/* Copyright (c) 2021 Facebook */ +/* Copyright (c) 2024, Oracle and/or its affiliates. */ + +#ifdef __KERNEL__ +#include <linux/bpf.h> +#include <linux/btf.h> + +#define btf_var_secinfos(t) (struct btf_var_secinfo *)btf_type_var_secinfo(t) + +#else +#include "btf.h" +#include "libbpf_internal.h" +#endif + +int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t, + enum btf_field_iter_kind iter_kind) +{ + it->p = NULL; + it->m_idx = -1; + it->off_idx = 0; + it->vlen = 0; + + switch (iter_kind) { + case BTF_FIELD_ITER_IDS: + switch (btf_kind(t)) { + case BTF_KIND_UNKN: + case BTF_KIND_INT: + case BTF_KIND_FLOAT: + case BTF_KIND_ENUM: + case BTF_KIND_ENUM64: + it->desc = (struct btf_field_desc) {}; + break; + case BTF_KIND_FWD: + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + case BTF_KIND_VAR: + case BTF_KIND_DECL_TAG: + case BTF_KIND_TYPE_TAG: + it->desc = (struct btf_field_desc) { 1, {offsetof(struct btf_type, type)} }; + break; + case BTF_KIND_ARRAY: + it->desc = (struct btf_field_desc) { + 2, {sizeof(struct btf_type) + offsetof(struct btf_array, type), + sizeof(struct btf_type) + offsetof(struct btf_array, index_type)} + }; + break; + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + it->desc = (struct btf_field_desc) { + 0, {}, + sizeof(struct btf_member), + 1, {offsetof(struct btf_member, type)} + }; + break; + case BTF_KIND_FUNC_PROTO: + it->desc = (struct btf_field_desc) { + 1, {offsetof(struct btf_type, type)}, + sizeof(struct btf_param), + 1, {offsetof(struct btf_param, type)} + }; + break; + case BTF_KIND_DATASEC: + it->desc = (struct btf_field_desc) { + 0, {}, + sizeof(struct btf_var_secinfo), + 1, {offsetof(struct btf_var_secinfo, type)} + }; + break; + default: + return -EINVAL; + } + break; + case BTF_FIELD_ITER_STRS: + switch (btf_kind(t)) { + case BTF_KIND_UNKN: + it->desc = (struct btf_field_desc) {}; + break; + case BTF_KIND_INT: + case BTF_KIND_FLOAT: + case BTF_KIND_FWD: + case BTF_KIND_ARRAY: + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + case BTF_KIND_VAR: + case BTF_KIND_DECL_TAG: + case BTF_KIND_TYPE_TAG: + case BTF_KIND_DATASEC: + it->desc = (struct btf_field_desc) { + 1, {offsetof(struct btf_type, name_off)} + }; + break; + case BTF_KIND_ENUM: + it->desc = (struct btf_field_desc) { + 1, {offsetof(struct btf_type, name_off)}, + sizeof(struct btf_enum), + 1, {offsetof(struct btf_enum, name_off)} + }; + break; + case BTF_KIND_ENUM64: + it->desc = (struct btf_field_desc) { + 1, {offsetof(struct btf_type, name_off)}, + sizeof(struct btf_enum64), + 1, {offsetof(struct btf_enum64, name_off)} + }; + break; + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + it->desc = (struct btf_field_desc) { + 1, {offsetof(struct btf_type, name_off)}, + sizeof(struct btf_member), + 1, {offsetof(struct btf_member, name_off)} + }; + break; + case BTF_KIND_FUNC_PROTO: + it->desc = (struct btf_field_desc) { + 1, {offsetof(struct btf_type, name_off)}, + sizeof(struct btf_param), + 1, {offsetof(struct btf_param, name_off)} + }; + break; + default: + return -EINVAL; + } + break; + default: + return -EINVAL; + } + + if (it->desc.m_sz) + it->vlen = btf_vlen(t); + + it->p = t; + return 0; +} + +__u32 *btf_field_iter_next(struct btf_field_iter *it) +{ + if (!it->p) + return NULL; + + if (it->m_idx < 0) { + if (it->off_idx < it->desc.t_off_cnt) + return it->p + it->desc.t_offs[it->off_idx++]; + /* move to per-member iteration */ + it->m_idx = 0; + it->p += sizeof(struct btf_type); + it->off_idx = 0; + } + + /* if type doesn't have members, stop */ + if (it->desc.m_sz == 0) { + it->p = NULL; + return NULL; + } + + if (it->off_idx >= it->desc.m_off_cnt) { + /* exhausted this member's fields, go to the next member */ + it->m_idx++; + it->p += it->desc.m_sz; + it->off_idx = 0; + } + + if (it->m_idx < it->vlen) + return it->p + it->desc.m_offs[it->off_idx++]; + + it->p = NULL; + return NULL; +} |