On Mon, May 12, 2025 at 2:02 PM Kumar Kartikeya Dwivedi
<memxor@xxxxxxxxx> wrote:
>
> 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 __aux 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@xxxxxxxxxx>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> ---
> include/linux/bpf_verifier.h | 1 +
> kernel/bpf/helpers.c | 4 ++--
> kernel/bpf/verifier.c | 33 +++++++++++++++++++++++++++------
> 3 files changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
> index 9734544b6957..1d90e44a1d04 100644
> --- a/include/linux/bpf_verifier.h
> +++ b/include/linux/bpf_verifier.h
> @@ -606,6 +606,7 @@ struct bpf_insn_aux_data {
> bool calls_callback;
> /* registers alive before this instruction. */
> u16 live_regs_before;
> + u16 arg_prog_aux;
> };
>
> #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index fed53da75025..2b6bac4bf6e3 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -3012,9 +3012,9 @@ __bpf_kfunc int bpf_wq_start(struct bpf_wq *wq, unsigned int flags)
> __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__ign)
> + void *aux__aux)
aux__aux is an odd name.
"__aux" as a suffix also looks strange.
How about "__prog" suffix ?
It will be similar to the existing "__map" suffix.
We can also standardize the argument name as
__bpf_kfunc int bpf_wq_set_callback_impl(.. , void *aux__prog)
then the name is more or less explanatory.
> {
> - struct bpf_prog_aux *aux = (struct bpf_prog_aux *)aux__ign;
> + struct bpf_prog_aux *aux = (struct bpf_prog_aux *)aux__aux;
and here it will be:
+ struct bpf_prog_aux *aux = (struct bpf_prog_aux *)aux__prog;
which looks ok to me.
pw-bot: cr
