qcacld-3.0: Fix RX data, peer unmap race condition
During peer unmap handler, while the peer is being deleted, there is a
possible race condition if the OL Rx thread is processing RX packets
and accesses the peer structure after its contents have been nulled.
Remove race condition by -
* Flush all RX packets in ol_txrx_peer_detach function which happens
before peer unmap event is received from firmware
* Avoid use of peer data structures (for example peer->local_id)
outside of peer->info_lock in ol_rx_data_cb function. Use cached
local copies of peer data structures instead
Crash signature due to the race condition:
wlan: [0:E :CDF] TXRX: Deleting peer ffffffc012fd13c0
(02:a0:c6:81:f8:c0)
Unable to handle kernel paging request at virtual address 400000001
pgd = ffffffc0018b4000
[400000001] *pgd=0000000000000000, *pud=0000000000000000
Internal error: Oops: 96000005 [#1] PREEMPT SMP
Modules linked in: wlan(O) [last unloaded: wlan]
CPU: 1 PID: 29506 Comm: cds_ol_rx_threa Tainted: G W O
3.18.20-g5222edf-13780-g2219ed2 #1
Hardware name: Qualcomm Technologies, Inc. MSM 8996 v3 + PMI8996 CD (DT)
task: ffffffc09350d400 ti: ffffffc0556a4000 task.ti: ffffffc0556a4000
PC is at hdd_rx_packet_cbk+0x84/0x224 [wlan]
LR is at hdd_rx_packet_cbk+0x48/0x224 [wlan]
pc : [<ffffffbffdd55b5c>] lr : [<ffffffbffdd55b20>] pstate: 80000145
Change-Id: I4b32313024ec214f33dcdcfc401aadfa8af9d692
CRs-Fixed: 1002081
2 files changed