Commit e5e23424 authored by Indu Bhagat's avatar Indu Bhagat Committed by Alexei Starovoitov
Browse files

docs/bpf: Update documentation for BTF_KIND_FUNC 



The vlen bits in the BTF type of kind BTF_KIND_FUNC are used to convey the
linkage information for functions. The Linux kernel only supports
linkage values of BTF_FUNC_STATIC and BTF_FUNC_GLOBAL at this time.

Signed-off-by: default avatarIndu Bhagat <indu.bhagat@oracle.com>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220714223310.1140097-1-indu.bhagat@oracle.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 3908fcdd

Documentation/bpf/btf.rst

+5 −1
Original line number Diff line number Diff line
@@ -369,7 +369,8 @@ No additional type data follow ``btf_type``. 
  * ``name_off``: offset to a valid C identifier

  * ``info.kind_flag``: 0

  * ``info.kind``: BTF_KIND_FUNC

  * ``info.vlen``: 0

  * ``info.vlen``: linkage information (BTF_FUNC_STATIC, BTF_FUNC_GLOBAL

                   or BTF_FUNC_EXTERN)

  * ``type``: a BTF_KIND_FUNC_PROTO type



No additional type data follow ``btf_type``.
@@ -380,6 +381,9 @@ type. The BTF_KIND_FUNC may in turn be referenced by a func_info in the 
:ref:`BTF_Ext_Section` (ELF) or in the arguments to :ref:`BPF_Prog_Load`

(ABI).



Currently, only linkage values of BTF_FUNC_STATIC and BTF_FUNC_GLOBAL are

supported in the kernel.



2.2.13 BTF_KIND_FUNC_PROTO

~~~~~~~~~~~~~~~~~~~~~~~~~~