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bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG

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Patch set [1] introduced BTF_KIND_TAG to allow tagging
declarations for struct/union, struct/union field, var, func
and func arguments and these tags will be encoded into
dwarf. They are also encoded to btf by llvm for the bpf target.

After BTF_KIND_TAG is introduced, we intended to use it
for kernel __user attributes. But kernel __user is actually
a type attribute. Upstream and internal discussion showed
it is not a good idea to mix declaration attribute and
type attribute. So we proposed to introduce btf_type_tag
as a type attribute and existing btf_tag renamed to
btf_decl_tag ([2]).

This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some
other declarations with *_tag to *_decl_tag to make it clear
the tag is for declaration. In the future, BTF_KIND_TYPE_TAG
might be introduced per [3].

 [1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/
 [2] https://reviews.llvm.org/D111588
 [3] https://reviews.llvm.org/D111199

Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec003 ("bpftool: Add support for BTF_KIND_TAG")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
This commit is contained in:
Yonghong Song
2021-10-12 09:48:38 -07:00
committed by Andrii Nakryiko
parent ebf17ac628
commit 0f3ba10651
7 changed files with 46 additions and 46 deletions
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8
include/uapi/linux/btf.h
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@@ -43,7 +43,7 @@ struct btf_type {
* "size" tells the size of the type it is describing.
*
* "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
* FUNC, FUNC_PROTO, VAR and TAG.
* FUNC, FUNC_PROTO, VAR and DECL_TAG.
* "type" is a type_id referring to another type.
*/
union {
@@ -74,7 +74,7 @@ enum {
BTF_KIND_VAR = 14, /* Variable */
BTF_KIND_DATASEC = 15, /* Section */
BTF_KIND_FLOAT = 16, /* Floating point */
BTF_KIND_TAG = 17, /* Tag */
BTF_KIND_DECL_TAG = 17, /* Decl Tag */
NR_BTF_KINDS,
BTF_KIND_MAX = NR_BTF_KINDS - 1,
@@ -174,14 +174,14 @@ struct btf_var_secinfo {
__u32 size;
};
/* BTF_KIND_TAG is followed by a single "struct btf_tag" to describe
/* BTF_KIND_DECL_TAG is followed by a single "struct btf_decl_tag" to describe
* additional information related to the tag applied location.
* If component_idx == -1, the tag is applied to a struct, union,
* variable or function. Otherwise, it is applied to a struct/union
* member or a func argument, and component_idx indicates which member
* or argument (0 ... vlen-1).
*/
struct btf_tag {
struct btf_decl_tag {
__s32 component_idx;
};