[linux-morello] Re: [PATCH 10/10] bpf: use user pointer types in uAPI structs

On 08/06/2023 10:42, Zachary Leaf wrote:

[...]

@@ -4241,20 +4251,20 @@ static int bpf_prog_get_info_by_fd(struct file *file, ulen = info.nr_prog_tags; info.nr_prog_tags = prog->aux->func_cnt ? : 1; if (ulen) {

• __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
  

• __u8 __user *user_prog_tags;
  

  u32 i;

• user_prog_tags = u64_to_user_ptr(info.prog_tags);
  

• user_prog_tags = (__u8 __user *)info.prog_tags;
  

  ulen = min_t(u32, info.nr_prog_tags, ulen); if (prog->aux->func_cnt) { for (i = 0; i < ulen; i++) {

• 		if (copy_to_user(user_prog_tags[i],
  

• 		if (copy_to_user(user_prog_tags+i,
  

Nit: &user_prog_tags[i] would be slightly more idiomatic (and closer to the original code). Similarly &user_prog_tags[0] could be used below.

Kevin

				 prog->aux->func[i]->tag,
				 BPF_TAG_SIZE))
			return -EFAULT;
	}
} else {

• 	if (copy_to_user(user_prog_tags[0],
  

• 	if (copy_to_user(user_prog_tags,
  		 prog->tag, BPF_TAG_SIZE))
  	return -EFAULT;
  

  }