956b620fcf
There is a common use-case when ELF object contains multiple BPF programs and every program has its own section name. If it's cgroup-bpf then programs have to be 1) loaded and 2) attached to a cgroup. It's convenient to have information necessary to load BPF program together with program itself. This is where section name works fine in conjunction with libbpf_prog_type_by_name that identifies prog_type and expected_attach_type and these can be used with BPF_PROG_LOAD. But there is currently no way to identify attach_type by section name and it leads to messy code in user space that reinvents guessing logic every time it has to identify attach type to use with BPF_PROG_ATTACH. The patch introduces libbpf_attach_type_by_name that guesses attach type by section name if a program can be attached. The difference between expected_attach_type provided by libbpf_prog_type_by_name and attach_type provided by libbpf_attach_type_by_name is the former is used at BPF_PROG_LOAD time and can be zero if a program of prog_type X has only one corresponding attach type Y whether the latter provides specific attach type to use with BPF_PROG_ATTACH. No new section names were added to section_names array. Only existing ones were reorganized and attach_type was added where appropriate. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.