diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2025-05-13 07:28:12 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-05-13 18:47:54 -0700 |
| commit | bc049387b41f41bee61e8cc338a5e99ca9798a09 (patch) | |
| tree | 8bbcda454e67d13f94721909517957b22c98648e /Documentation/bpf | |
| parent | 3880cdbed1c4607e378f58fa924c5d6df900d1d3 (diff) | |
bpf: Add support for __prog argument suffix to pass in prog->aux
Instead of hardcoding the list of kfuncs that need prog->aux passed to
them with a combination of fixup_kfunc_call adjustment + __ign suffix,
combine both in __prog suffix, which ignores the argument passed in, and
fixes it up to the prog->aux. This allows kfuncs to have the prog->aux
passed into them without having to touch the verifier.
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250513142812.1021591-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'Documentation/bpf')
| -rw-r--r-- | Documentation/bpf/kfuncs.rst | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst index a8f5782bd833..ae468b781d31 100644 --- a/Documentation/bpf/kfuncs.rst +++ b/Documentation/bpf/kfuncs.rst @@ -160,6 +160,23 @@ Or:: ... } +2.2.6 __prog Annotation +--------------------------- +This annotation is used to indicate that the argument needs to be fixed up to +the bpf_prog_aux of the caller BPF program. Any value passed into this argument +is ignored, and rewritten by the verifier. + +An example is given below:: + + __bpf_kfunc int bpf_wq_set_callback_impl(struct bpf_wq *wq, + int (callback_fn)(void *map, int *key, void *value), + unsigned int flags, + void *aux__prog) + { + struct bpf_prog_aux *aux = aux__prog; + ... + } + .. _BPF_kfunc_nodef: 2.3 Using an existing kernel function |