On Thu, 3 Jul 2025 at 00:43, Eduard Zingerman <eddyz87@xxxxxxxxx> wrote:
>
> Allow specifying __arg_untrusted for void */char */int */long *
> parameters. Treat such parameters as
> PTR_TO_MEM|MEM_RDONLY|PTR_UNTRUSTED of size zero.
> Intended usage is as follows:
>
> int memcmp(char *a __arg_untrusted, char *b __arg_untrusted, size_t n) {
> bpf_for(i, 0, n) {
> if (a[i] - b[i]) // load at any offset is allowed
> return a[i] - b[i];
> }
> return 0;
> }
>
> Allocate register id for ARG_PTR_TO_MEM parameters only when
> PTR_MAYBE_NULL is set. Register id for PTR_TO_MEM is used only to
> propagate non-null status after conditionals.
>
> Suggested-by: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
> Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
> ---
Acked-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> [...]
