diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2021-02-26 21:22:56 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-03-04 18:31:53 -0800 |
| commit | 6be6a0baffc1357b6d2023155753f111624c4fec (patch) | |
| tree | 206f7fc16a8f368467e3a2e7c5ac716494ace314 /Documentation/bpf/btf.rst | |
| parent | 7999cf7df899caf244236dcc11cce844347dab4a (diff) | |
bpf: Document BTF_KIND_FLOAT in btf.rst
Also document the expansion of the kind bitfield.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210226202256.116518-11-iii@linux.ibm.com
Diffstat (limited to 'Documentation/bpf/btf.rst')
| -rw-r--r-- | Documentation/bpf/btf.rst | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst index 44dc789de2b4..846354cd2d69 100644 --- a/Documentation/bpf/btf.rst +++ b/Documentation/bpf/btf.rst @@ -84,6 +84,7 @@ sequentially and type id is assigned to each recognized type starting from id #define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ #define BTF_KIND_VAR 14 /* Variable */ #define BTF_KIND_DATASEC 15 /* Section */ + #define BTF_KIND_FLOAT 16 /* Floating point */ 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. @@ -95,8 +96,8 @@ Each type contains the following common data:: /* "info" bits arrangement * bits 0-15: vlen (e.g. # of struct's members) * bits 16-23: unused - * bits 24-27: kind (e.g. int, ptr, array...etc) - * bits 28-30: unused + * bits 24-28: kind (e.g. int, ptr, array...etc) + * bits 29-30: unused * bit 31: kind_flag, currently used by * struct, union and fwd */ @@ -452,6 +453,18 @@ map definition. * ``offset``: the in-section offset of the variable * ``size``: the size of the variable in bytes +2.2.16 BTF_KIND_FLOAT +~~~~~~~~~~~~~~~~~~~~~ + +``struct btf_type`` encoding requirement: + * ``name_off``: any valid offset + * ``info.kind_flag``: 0 + * ``info.kind``: BTF_KIND_FLOAT + * ``info.vlen``: 0 + * ``size``: the size of the float type in bytes: 2, 4, 8, 12 or 16. + +No additional type data follow ``btf_type``. + 3. BTF Kernel API ***************** |