Documentation/bpf: make it clear that kfuncs should be non-static

Browse source

The kfunc documentation mentions how the macro __bpf_kfunc prevents
inlining for static functions. This makes it sound like static kfuncs are
acceptable. Although static kfuncs may happen to work, it is by chance that
the compiler chose not to rename these functions and BTF resolution still
succeeds.

Make it clear in the documentation why kfuncs should not be declared
static. First, remove wording that makes it sound like static is ok. Then
point out the external naming needed for BTF resolution. Finally point out
that sparse may warn on unreferenced kfuncs and that this warning can be
ignored.

Signed-off-by: JP Kobryn <jp.kobryn@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260626172026.7327-1-jp.kobryn@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

...

This commit is contained in:

JP Kobryn 2026-06-26 10:20:26 -07:00 • committed by Alexei Starovoitov

parent d262a25d8b

commit 0b58988cac

1 changed files with 15 additions and 8 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

23

Documentation/bpf/kfuncs.rst

View file