https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106263
Bug ID: 106263
Summary: BTF_KIND_FUNC type does not encode linkage
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: ibhagat at gcc dot gnu.org
Target Milestone: ---
GCC generates BTF_KIND_FUNC with vlen set to 0. libbpf expects the vlen field
to include the linkage information.
The issue was reported here:
https://lore.kernel.org/bpf/8735fbcv3x....@oracle.com/
Although GCC is currently generating the BTF_KIND_FUNC as per the BTF format
documentation (see excerpt below), this needs to be changed to allow the tools
to work well with each other.
[Source: https://www.kernel.org/doc/Documentation/bpf/btf.rst]
...
2.2.12 BTF_KIND_FUNC
~~~~~~~~~~~~~~~~~~~~
``struct btf_type`` encoding requirement:
* ``name_off``: offset to a valid C identifier
* ``info.kind_flag``: 0
* ``info.kind``: BTF_KIND_FUNC
* ``info.vlen``: 0
* ``type``: a BTF_KIND_FUNC_PROTO type
...
