| Message ID | 20241008022246.1010-1-quic_kangyang@quicinc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Johnson |
| Headers | show |
| Series | wifi: ath10k: avoid NULL pointer error during sdio remove | expand |
Tested-by: David Ruth <druth@chromium.org> Reviewed-by: David Ruth <druth@chromium.org>
On Tue, 08 Oct 2024 10:22:46 +0800, Kang Yang wrote: > When running 'rmmod ath10k', ath10k_sdio_remove() will free sdio > workqueue by destroy_workqueue(). But if CONFIG_INIT_ON_FREE_DEFAULT_ON > is set to yes, kernel panic will happen: > Call trace: > destroy_workqueue+0x1c/0x258 > ath10k_sdio_remove+0x84/0x94 > sdio_bus_remove+0x50/0x16c > device_release_driver_internal+0x188/0x25c > device_driver_detach+0x20/0x2c > > [...] Applied, thanks! [1/1] wifi: ath10k: avoid NULL pointer error during sdio remove commit: 95c38953cb1ecf40399a676a1f85dfe2b5780a9a Best regards,
diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c index 08a6f36a6be9..6805357ee29e 100644 --- a/drivers/net/wireless/ath/ath10k/sdio.c +++ b/drivers/net/wireless/ath/ath10k/sdio.c @@ -3,7 +3,7 @@ * Copyright (c) 2004-2011 Atheros Communications Inc. * Copyright (c) 2011-2012,2017 Qualcomm Atheros, Inc. * Copyright (c) 2016-2017 Erik Stromdahl <erik.stromdahl@gmail.com> - * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. + * Copyright (c) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved. */ #include <linux/module.h> @@ -2648,9 +2648,9 @@ static void ath10k_sdio_remove(struct sdio_func *func) netif_napi_del(&ar->napi); - ath10k_core_destroy(ar); - destroy_workqueue(ar_sdio->workqueue); + + ath10k_core_destroy(ar); } static const struct sdio_device_id ath10k_sdio_devices[] = {
When running 'rmmod ath10k', ath10k_sdio_remove() will free sdio workqueue by destroy_workqueue(). But if CONFIG_INIT_ON_FREE_DEFAULT_ON is set to yes, kernel panic will happen: Call trace: destroy_workqueue+0x1c/0x258 ath10k_sdio_remove+0x84/0x94 sdio_bus_remove+0x50/0x16c device_release_driver_internal+0x188/0x25c device_driver_detach+0x20/0x2c This is because during 'rmmod ath10k', ath10k_sdio_remove() will call ath10k_core_destroy() before destroy_workqueue(). wiphy_dev_release() will finally be called in ath10k_core_destroy(). This function will free struct cfg80211_registered_device *rdev and all its members, including wiphy, dev and the pointer of sdio workqueue. Then the pointer of sdio workqueue will be set to NULL due to CONFIG_INIT_ON_FREE_DEFAULT_ON. After device release, destroy_workqueue() will use NULL pointer then the kernel panic happen. Call trace: ath10k_sdio_remove ->ath10k_core_unregister …… ->ath10k_core_stop ->ath10k_hif_stop ->ath10k_sdio_irq_disable ->ath10k_hif_power_down ->del_timer_sync(&ar_sdio->sleep_timer) ->ath10k_core_destroy ->ath10k_mac_destroy ->ieee80211_free_hw ->wiphy_free …… ->wiphy_dev_release ->destroy_workqueue Need to call destroy_workqueue() before ath10k_core_destroy(), free the work queue buffer first and then free pointer of work queue by ath10k_core_destroy(). This order matches the error path order in ath10k_sdio_probe(). No work will be queued on sdio workqueue between it is destroyed and ath10k_core_destroy() is called. Based on the call_stack above, the reason is: Only ath10k_sdio_sleep_timer_handler(), ath10k_sdio_hif_tx_sg() and ath10k_sdio_irq_disable() will queue work on sdio workqueue. Sleep timer will be deleted before ath10k_core_destroy() in ath10k_hif_power_down(). ath10k_sdio_irq_disable() only be called in ath10k_hif_stop(). ath10k_core_unregister() will call ath10k_hif_power_down() to stop hif bus, so ath10k_sdio_hif_tx_sg() won't be called anymore. Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00189 Signed-off-by: Kang Yang <quic_kangyang@quicinc.com> --- drivers/net/wireless/ath/ath10k/sdio.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)