Re: [PATCH 19/64] ip: Use struct_group() for memcpy() regions

On Wed, Jul 28, 2021 at 07:55:53AM +0200, Greg Kroah-Hartman wrote:

...

struct ethhdr {

• unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
• unsigned char h_source[ETH_ALEN]; /* source ether addr */

• union {

• struct {
  

• 	unsigned char h_dest[ETH_ALEN];	  /* destination eth addr */
  

• 	unsigned char h_source[ETH_ALEN]; /* source ether addr	  */
  

• };
  

• struct {
  

• 	unsigned char h_dest[ETH_ALEN];	  /* destination eth addr */
  

• 	unsigned char h_source[ETH_ALEN]; /* source ether addr	  */
  

• } addrs;
  

A union of the same fields in the same structure in the same way?

Ah, because struct_group() can not be used here? Still feels odd to see in a userspace-visible header.

Yeah, there is some inconsistency here. I will clean this up for v2.

Is there a place we can put kernel-specific macros for use in UAPI headers? (I need to figure out where things like __kernel_size_t get defined...)