On Sat, Feb 19, 2022 at 05:07:40PM +0530, Kumar Kartikeya Dwivedi wrote:
>
> +/* Caller ensures reg->type does not have PTR_MAYBE_NULL */
> +int check_func_arg_reg_off(struct bpf_verifier_env *env,
> + const struct bpf_reg_state *reg, int regno,
> + bool arg_alloc_mem)
> +{
> + enum bpf_reg_type type = reg->type;
> + int err;
> +
> + WARN_ON_ONCE(type & PTR_MAYBE_NULL);
So the warn was added and made things more difficult and check had to be moved
into check_mem_reg to clear that flag?
Why add that warn in the first place then?
The logic get convoluted because of that.
> + if (reg->off < 0) {
> + verbose(env, "negative offset %s ptr R%d off=%d disallowed\n",
> + reg_type_str(env, reg->type), regno, reg->off);
> + return -EACCES;
> + }
Out of the whole patch this part is useful. The rest seems to dealing
with self inflicted pain.
Just call check_ptr_off_reg() for kfunc ?
The patch seems to be doing several things at once. Please split.
