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| author | Yonghong Song <yhs@fb.com> | 2021-11-12 04:26:09 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-11-12 04:41:11 +0300 |
| commit | 8c42d2fa4eeab6c37a0b1b1aa7a2715248ef4f34 (patch) | |
| tree | c119fc05841e8bdd8667e34b4536e76d8253d727 /include/uapi | |
| parent | 2326ff8d5c6628e581c87f37a8f6db1db7dc00ee (diff) | |
| download | linux-8c42d2fa4eeab6c37a0b1b1aa7a2715248ef4f34.tar.xz | |
bpf: Support BTF_KIND_TYPE_TAG for btf_type_tag attributes
LLVM patches ([1] for clang, [2] and [3] for BPF backend)
added support for btf_type_tag attributes. This patch
added support for the kernel.
The main motivation for btf_type_tag is to bring kernel
annotations __user, __rcu etc. to btf. With such information
available in btf, bpf verifier can detect mis-usages
and reject the program. For example, for __user tagged pointer,
developers can then use proper helper like bpf_probe_read_user()
etc. to read the data.
BTF_KIND_TYPE_TAG may also useful for other tracing
facility where instead of to require user to specify
kernel/user address type, the kernel can detect it
by itself with btf.
[1] https://reviews.llvm.org/D111199
[2] https://reviews.llvm.org/D113222
[3] https://reviews.llvm.org/D113496
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/20211112012609.1505032-1-yhs@fb.com
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/btf.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/uapi/linux/btf.h b/include/uapi/linux/btf.h index deb12f755f0f..b0d8fea1951d 100644 --- a/include/uapi/linux/btf.h +++ b/include/uapi/linux/btf.h @@ -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 DECL_TAG. + * FUNC, FUNC_PROTO, VAR, DECL_TAG and TYPE_TAG. * "type" is a type_id referring to another type. */ union { @@ -75,6 +75,7 @@ enum { BTF_KIND_DATASEC = 15, /* Section */ BTF_KIND_FLOAT = 16, /* Floating point */ BTF_KIND_DECL_TAG = 17, /* Decl Tag */ + BTF_KIND_TYPE_TAG = 18, /* Type Tag */ NR_BTF_KINDS, BTF_KIND_MAX = NR_BTF_KINDS - 1, |