On Fri, 9 Feb 2024 at 05:06, Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
>
> From: Alexei Starovoitov <ast@xxxxxxxxxx>
>
> Recognize 'void *p__map' kfunc argument as 'struct bpf_map *p__map'.
> It allows kfunc to have 'void *' argument for maps, since bpf progs
> will call them as:
> struct {
> __uint(type, BPF_MAP_TYPE_ARENA);
> ...
> } arena SEC(".maps");
>
> bpf_kfunc_with_map(... &arena ...);
>
> Underneath libbpf will load CONST_PTR_TO_MAP into the register via ld_imm64 insn.
> If kfunc was defined with 'struct bpf_map *' it would pass
> the verifier, but bpf prog would need to use '(void *)&arena'.
> Which is not clean.
>
> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> ---
Acked-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> [...]
