From: Yonghong Song <yhs@fb.com> mainline inclusion from mainline-5.17-rc1 commit d52f5c639dd8605d2563b77b190e278f615a2b8a category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Add BTF_KIND_TYPE_TAG documentation in btf.rst. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211112012656.1509082-1-yhs@fb.com (cherry picked from commit d52f5c639dd8605d2563b77b190e278f615a2b8a) Signed-off-by: Wang Yufen <wangyufen@huawei.com> --- Documentation/bpf/btf.rst | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst index 672aa0abf49f..183f398c68d6 100644 --- a/Documentation/bpf/btf.rst +++ b/Documentation/bpf/btf.rst @@ -85,6 +85,7 @@ sequentially and type id is assigned to each recognized type starting from id #define BTF_KIND_VAR 14 /* Variable */ #define BTF_KIND_DATASEC 15 /* Section */ #define BTF_KIND_DECL_TAG 17 /* Decl Tag */ + #define BTF_KIND_TYPE_TAG 18 /* Type Tag */ Note that the type section encodes debug info, not just pure types. ``BTF_KIND_FUNC`` is not a type, and it represents a defined subprogram. @@ -106,7 +107,7 @@ Each type contains the following common data:: * "size" tells the size of the type it is describing. * * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT, - * FUNC, FUNC_PROTO and DECL_TAG. + * FUNC, FUNC_PROTO, DECL_TAG and TYPE_TAG. * "type" is a type_id referring to another type. */ union { @@ -479,6 +480,16 @@ the attribute is applied to a ``struct``/``union`` member or a ``func`` argument, and ``btf_decl_tag.component_idx`` should be a valid index (starting from 0) pointing to a member or an argument. +2.2.17 BTF_KIND_TYPE_TAG +~~~~~~~~~~~~~~~~~~~~~~~~ + +``struct btf_type`` encoding requirement: + * ``name_off``: offset to a non-empty string + * ``info.kind_flag``: 0 + * ``info.kind``: BTF_KIND_TYPE_TAG + * ``info.vlen``: 0 + * ``type``: the type with ``btf_type_tag`` attribute + 3. BTF Kernel API ***************** -- 2.20.1