| From 95c38953cb1ecf40399a676a1f85dfe2b5780a9a Mon Sep 17 00:00:00 2001 |
| From: Kang Yang <quic_kangyang@quicinc.com> |
| Date: Tue, 8 Oct 2024 10:22:46 +0800 |
| Subject: wifi: ath10k: avoid NULL pointer error during sdio remove |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| 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: Alva Lan <alvalan9@foxmail.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/wireless/ath/ath10k/sdio.c | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| --- 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> |
| @@ -2648,9 +2649,9 @@ static void ath10k_sdio_remove(struct sd |
| |
| 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[] = { |
