Andrii Nakryiko
87dbdc230d
libbpf: Don't require full struct enum64 in UAPI headers
Drop the requirement for system-wide kernel UAPI headers to provide full struct btf_enum64 definition. This is an unexpected requirement that slipped in libbpf 1.0 and put unnecessary pressure ([0]) on users to have a bleeding-edge kernel UAPI header from unreleased Linux 6.0. To achieve this, we forward declare struct btf_enum64. But that's not enough as there is btf_enum64_value() helper that expects to know the layout of struct btf_enum64. So we get a bit creative with reinterpreting memory layout as array of __u32 and accesing lo32/hi32 fields as array elements. Alternative way would be to have a local pointer variable for anonymous struct with exactly the same layout as struct btf_enum64, but that gets us into C++ compiler errors complaining about invalid type casts. So play it safe, if ugly. [0] Closes: https://github.com/libbpf/libbpf/issues/562 Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump") Reported-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://lore.kernel.org/bpf/20220927042940.147185-1-andrii@kernel.org
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
Description
Languages
C
97.6%
Assembly
1%
Shell
0.5%
Python
0.3%
Makefile
0.3%