c7dcb6c9aa
Mark dynptr kfuncs as __weak to allow
verifier_global_subprogs/arg_ctx_{perf,kprobe,raw_tp} subtests to be
loadable on old kernels. Because bpf_dynptr_from_xdp() kfunc is used
from arg_tag_dynptr BPF program in progs/verifier_global_subprogs.c
*and* is not marked as __weak, loading any subtest from
verifier_global_subprogs fails on old kernels that don't have
bpf_dynptr_from_xdp() kfunc defined. Even if arg_tag_dynptr program
itself is not loaded, libbpf bails out on non-weak reference to
bpf_dynptr_from_xdp (that can't be resolved), which shared across all
programs in progs/verifier_global_subprogs.c.
So mark all dynptr-related kfuncs as __weak to unblock libbpf CI ([0]).
In the upcoming "kfunc in vmlinux.h" work we should make sure that
kfuncs are always declared __weak as well.
[0] https://github.com/libbpf/libbpf/actions/runs/7792673215/job/21251250831?pr=776#step:4:7961
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240206004008.1541513-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@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.