Re: [PATCH bpf-next v4 15/18] bpf,x86: Implement JIT support for stack arguments

Yonghong Song
2026-04-13T20:32:57Z

On 4/13/26 12:59 PM, Alexei Starovoitov wrote:
> On Mon, Apr 13, 2026 at 10:26 AM Yonghong Song <yonghong.song@linux.dev> wrote:
>>
>> Yes, we can do something like below:
>>
>> case BPF_ST | BPF_MEM | BPF_DW:
>> - if (adjust_stack_arg_off && insn->off == -outgoing_stack_arg_depth) {
>> + if (dst_reg == BPF_REG_STACK_ARG_BASE && insn->off == -outgoing_stack_arg_depth) {
> Something like that, but use BPF_REG_ARG_PTR name ?
> here and in the verifier?

We have a bunch of ARG_PTR_* (e.g. ARG_PTR_TO_MAP_VALUE, ...).
So maybe BPF_REG_STACK_ARG_PTR to distinguish ARG_PTR_*?
BPF_REG_STACK_ARG_BASE_PTR seems a better name as it does represents
the base pointer for stack arguments of a particular function.
But BPF_REG_STACK_ARG_BASE_PTR seems too long so BPF_REG_STACK_ARG_PTR?