Re: [PATCH v15 bpf-next 17/18] net: xdp: introduce bpf_xdp_pointer utility routine

On Fri,  8 Oct 2021 14:49:55 +0200 Lorenzo Bianconi wrote:

quoted

+BPF_CALL_4(bpf_xdp_load_bytes, struct xdp_buff *, xdp, u32, offset,
+	   void *, buf, u32, len)
+{
+	void *ptr;
+
+	if (!buf)
+		return -EINVAL;

Can we make the verifier ensure it's not NULL?

I guess we can use ARG_PTR_TO_MEM instead of ARG_PTR_TO_UNINIT_MEM

quoted

+	ptr = bpf_xdp_pointer(xdp, offset, len, buf);
+	if (ptr != buf)
+		memcpy(buf, ptr, len);

Don't we need to return an error in case offset + length > frame size?

ack, I will fix it.

Regards,
Lorenzo

quoted

+	return 0;
+}