From: Kang Yang quic_kangyang@quicinc.com

commit 95c38953cb1ecf40399a676a1f85dfe2b5780a9a upstream.

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 Tested-by: David Ruth druth@chromium.org Reviewed-by: David Ruth druth@chromium.org Link: https://patch.msgid.link/20241008022246.1010-1-quic_kangyang@quicinc.com Signed-off-by: Jeff Johnson quic_jjohnson@quicinc.com Signed-off-by: Bin Lan lanbincn@qq.com --- drivers/net/wireless/ath/ath10k/sdio.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c index 79e09c7a82b3..886070b2a722 100644 --- a/drivers/net/wireless/ath/ath10k/sdio.c +++ b/drivers/net/wireless/ath/ath10k/sdio.c @@ -3,6 +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) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved. */

#include <linux/module.h> @@ -2647,9 +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[] = {