Subject: Re: [PATCH] net: sched: Fix warnings from xchg() on RCU'd cookie pointer.

From: Marcelo Ricardo Leitner <[email-masked]>
Date: Mon, 9 Jul 2018 12:30:12 -0300

On Sun, Jul 08, 2018 at 05:03:58PM +0900, David Miller wrote:
> 
> The kbuild test robot reports:
> 
> >> net/sched/act_api.c:71:15: sparse: incorrect type in initializer (different address spaces) @@    expected struct tc_cookie [noderef] <asn:4>*__ret @@    got [noderef] <asn:4>*__ret @@
>    net/sched/act_api.c:71:15:    expected struct tc_cookie [noderef] <asn:4>*__ret
>    net/sched/act_api.c:71:15:    got struct tc_cookie *new_cookie
> >> net/sched/act_api.c:71:13: sparse: incorrect type in assignment (different address spaces) @@    expected struct tc_cookie *old @@    got struct tc_cookie [noderef] <struct tc_cookie *old @@
>    net/sched/act_api.c:71:13:    expected struct tc_cookie *old
>    net/sched/act_api.c:71:13:    got struct tc_cookie [noderef] <asn:4>*[assigned] __ret

This one:

> >> net/sched/act_api.c:132:48: sparse: dereference of noderef expression

Actually belongs to a different issue, that was reported in the same
email, but which wasn't handled in this patch.

  Marcelo