Kang Yang <quic_kangyang@xxxxxxxxxxx> wrote:
> Warning will appear when running P2P GO:
>
> WARNING: suspicious RCU usage
> drivers/net/wireless/ath/ath12k/mac.c:583 suspicious rcu_dereference_check() usage!
> other info that might help us debug this:
> rcu_scheduler_active = 2, debug_locks = 1
> no locks held by swapper/0/0.
> stack backtrace:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.8.0-rc4-wt-ath+ #4
> Call Trace:
> <IRQ>
> dump_stack_lvl+0x82/0xa0
> dump_stack+0x14/0x20
> lockdep_rcu_suspicious+0x214/0x3b0
> ath12k_mac_get_ar_by_vdev_id+0x192/0x220 [ath12k]
> ath12k_wmi_op_rx+0x2d7/0x1b40 [ath12k]
>
> ath12k_mac_get_ar_by_vdev_id() requires its callers to have called
> rcu_read_lock(), but in ath12k_wmi_p2p_noa_event() it is called without
> doing so, and hence the warning was triggered.
>
> Add rcu_read_lock() and rcu_read_unlock() to avoid warning.
>
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
>
> Fixes: 9411eecb60cb ("wifi: ath12k: implement handling of P2P NoA event")
> Reported-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-wireless/87o7cusyvw.fsf@xxxxxxxxxx/
> Signed-off-by: Kang Yang <quic_kangyang@xxxxxxxxxxx>
> Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
> Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
Patch applied to ath-next branch of ath.git, thanks.
ee3b63586b30 wifi: ath12k: add rcu lock for ath12k_wmi_p2p_noa_event()
--
https://patchwork.kernel.org/project/linux-wireless/patch/20240223054505.438839-1-quic_kangyang@xxxxxxxxxxx/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
