[PATCH 4.6 043/121] ath10k: fix kernel panic, move arvifs list head init before htt init

Greg Kroah-Hartman
2016-06-05T22:14:25Z

From: Anilkumar Kolli <akolli@qti.qualcomm.com>

commit 4ad24a9d83bd4bf0a85e95bf144e18d3fda4fbf1 upstream.

It is observed that while loading and unloading ath10k modules
in an infinite loop, before ath10k_core_start() completion HTT
rx frames are received, while processing these frames,
dereferencing the arvifs list code is getting hit before
initilizing the arvifs list, causing a kernel panic.

This patch initilizes the arvifs list before initilizing htt.

Fixes the below issue:
[<bf88b058>] (ath10k_htt_rx_pktlog_completion_handler+0x278/0xd08 [ath10k_core])
[<bf88b058>] (ath10k_htt_rx_pktlog_completion_handler [ath10k_core])
[<bf88c0dc>] (ath10k_htt_txrx_compl_task+0x5f4/0xeb0 [ath10k_core])
[<bf88c0dc>] (ath10k_htt_txrx_compl_task [ath10k_core])
[<c0234100>] (tasklet_action+0x8c/0xec)
[<c0234100>] (tasklet_action)
[<c02337c0>] (__do_softirq+0xf8/0x228)
[<c02337c0>] (__do_softirq) [<c0233920>] (run_ksoftirqd+0x30/0x90)
Code: e5954ad8 e2899008 e1540009 0a00000d (e5943008)
---[ end trace 71de5c2e011dbf56 ]---
Kernel panic - not syncing: Fatal exception in interrupt

Fixes: 500ff9f9389d ("ath10k: implement chanctx API")
Signed-off-by: Anilkumar Kolli <akolli@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/ath/ath10k/core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -1723,6 +1723,10 @@ int ath10k_core_start(struct ath10k *ar,
goto err_hif_stop;
}

+ ar->free_vdev_map = (1LL << ar->max_num_vdevs) - 1;
+
+ INIT_LIST_HEAD(&ar->arvifs);
+
/* we don't care about HTT in UTF mode */
if (mode == ATH10K_FIRMWARE_MODE_NORMAL) {
status = ath10k_htt_setup(&ar->htt);
@@ -1736,10 +1740,6 @@ int ath10k_core_start(struct ath10k *ar,
if (status)
goto err_hif_stop;

- ar->free_vdev_map = (1LL << ar->max_num_vdevs) - 1;
-
- INIT_LIST_HEAD(&ar->arvifs);
-
return 0;