[PATCH 1/2] wifi: ath11k: use RCU when accessing struct inet6_dev::ac_list

[Jeff Johnson]

On 4/11/2024 9:55 AM, Kalle Valo wrote:
> From: Kalle Valo <quic_kvalo at quicinc.com>
> 
> Commit c3718936ec47 ("ipv6: anycast: complete RCU handling of struct
> ifacaddr6") converted struct inet6_dev::ac_list to use RCU but missed that
> ath11k also accesses this list. Now sparse warns:
> 
> drivers/net/wireless/ath/ath11k/mac.c:9145:21: warning: incorrect type in assignment (different address spaces)
> drivers/net/wireless/ath/ath11k/mac.c:9145:21:    expected struct ifacaddr6 *ifaca6
> drivers/net/wireless/ath/ath11k/mac.c:9145:21:    got struct ifacaddr6 [noderef] __rcu *ac_list
> drivers/net/wireless/ath/ath11k/mac.c:9145:53: warning: incorrect type in assignment (different address spaces)
> drivers/net/wireless/ath/ath11k/mac.c:9145:53:    expected struct ifacaddr6 *ifaca6
> drivers/net/wireless/ath/ath11k/mac.c:9145:53:    got struct ifacaddr6 [noderef] __rcu *aca_next
> 
> Fix it by using rtnl_dereference(). Also add a note that read_lock_bh() calls
> rcu_read_lock() which I was not aware of.
> 
> Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37
> 
> Fixes: c3718936ec47 ("ipv6: anycast: complete RCU handling of struct ifacaddr6")
> Signed-off-by: Kalle Valo <quic_kvalo at quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson at quicinc.com>