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[79.22.100.164]) by smtp.gmail.com with ESMTPSA id q14sm4102081ejc.93.2021.08.28.04.36.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 28 Aug 2021 04:37:00 -0700 (PDT) From: "Fabio M. De Francesco" To: Greg Kroah-Hartman , Larry Finger , Phillip Potter , Martin Kaiser , Michael Straube , Pavel Skripkin , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Aakash Hemadri Cc: "Fabio M. De Francesco" Subject: [PATCH v5] staging: r8188eu: Remove _enter/_exit_critical_mutex() Date: Sat, 28 Aug 2021 13:36:56 +0200 Message-Id: <20210828113656.6963-1-fmdefrancesco@gmail.com> X-Mailer: git-send-email 2.32.0 Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Remove _enter_critical_mutex() and _exit_critical_mutex(). They are unnecessary wrappers, respectively to mutex_lock_interruptible() and to mutex_unlock(). They also have an odd interface that takes an unused argument named pirqL of type unsigned long. The original code enters the critical section if the mutex API is interrupted while waiting to acquire the lock; therefore it could lead to a race condition. Use mutex_lock() because it is uninterruptible and so avoid that above-mentioned potential race condition. Tested-by: Pavel Skripkin Reviewed-by: Pavel Skripkin Signed-off-by: Fabio M. De Francesco --- v5: Fix a typo in the subject line. Reported by Aakash Hemadri. v4: Tested and reviewed by Pavel Skripkin. No changes to the code. v3: Assume that the original authors don't expect that mutex_lock_interruptible() can be really interrupted and then lead to a potential race condition. Furthermore, Greg Kroah-Hartman makes me notice that "[] one almost never needs interruptable locks in a driver". Therefore, replace the calls to mutex_lock_interruptible() with calls to mutex_lock() since the latter is uninterruptible and avoid race conditions without the necessity to handle -EINTR errors. v2: Ignore return values from Mutexes API because the original authors don't check and manage return errors from mutex_lock_interruptible(). drivers/staging/r8188eu/core/rtw_mlme_ext.c | 4 ++-- drivers/staging/r8188eu/hal/usb_ops_linux.c | 4 ++-- drivers/staging/r8188eu/include/osdep_service.h | 13 ------------- drivers/staging/r8188eu/os_dep/os_intfs.c | 4 ++-- 4 files changed, 6 insertions(+), 19 deletions(-) diff --git a/drivers/staging/r8188eu/core/rtw_mlme_ext.c b/drivers/staging/r8188eu/core/rtw_mlme_ext.c index 5a472a4954b0..3df02bd0db89 100644 --- a/drivers/staging/r8188eu/core/rtw_mlme_ext.c +++ b/drivers/staging/r8188eu/core/rtw_mlme_ext.c @@ -4359,7 +4359,7 @@ s32 dump_mgntframe_and_wait_ack(struct adapter *padapter, struct xmit_frame *pmg if (padapter->bSurpriseRemoved || padapter->bDriverStopped) return -1; - _enter_critical_mutex(&pxmitpriv->ack_tx_mutex, NULL); + mutex_lock(&pxmitpriv->ack_tx_mutex); pxmitpriv->ack_tx = true; pmgntframe->ack_report = 1; @@ -4368,7 +4368,7 @@ s32 dump_mgntframe_and_wait_ack(struct adapter *padapter, struct xmit_frame *pmg } pxmitpriv->ack_tx = false; - _exit_critical_mutex(&pxmitpriv->ack_tx_mutex, NULL); + mutex_unlock(&pxmitpriv->ack_tx_mutex); return ret; } diff --git a/drivers/staging/r8188eu/hal/usb_ops_linux.c b/drivers/staging/r8188eu/hal/usb_ops_linux.c index 0cf69033c529..065b0d8e030a 100644 --- a/drivers/staging/r8188eu/hal/usb_ops_linux.c +++ b/drivers/staging/r8188eu/hal/usb_ops_linux.c @@ -29,7 +29,7 @@ static int usbctrl_vendorreq(struct intf_hdl *pintfhdl, u16 value, void *pdata, goto exit; } - _enter_critical_mutex(&dvobjpriv->usb_vendor_req_mutex, NULL); + mutex_lock(&dvobjpriv->usb_vendor_req_mutex); /* Acquire IO memory for vendorreq */ pIo_buf = dvobjpriv->usb_vendor_req_buf; @@ -92,7 +92,7 @@ static int usbctrl_vendorreq(struct intf_hdl *pintfhdl, u16 value, void *pdata, break; } release_mutex: - _exit_critical_mutex(&dvobjpriv->usb_vendor_req_mutex, NULL); + mutex_unlock(&dvobjpriv->usb_vendor_req_mutex); exit: return status; } diff --git a/drivers/staging/r8188eu/include/osdep_service.h b/drivers/staging/r8188eu/include/osdep_service.h index 029aa4e92c9b..bb92b9d74bd7 100644 --- a/drivers/staging/r8188eu/include/osdep_service.h +++ b/drivers/staging/r8188eu/include/osdep_service.h @@ -56,19 +56,6 @@ static inline struct list_head *get_list_head(struct __queue *queue) return (&(queue->queue)); } -static inline int _enter_critical_mutex(struct mutex *pmutex, unsigned long *pirqL) -{ - int ret; - - ret = mutex_lock_interruptible(pmutex); - return ret; -} - -static inline void _exit_critical_mutex(struct mutex *pmutex, unsigned long *pirqL) -{ - mutex_unlock(pmutex); -} - static inline void rtw_list_delete(struct list_head *plist) { list_del_init(plist); diff --git a/drivers/staging/r8188eu/os_dep/os_intfs.c b/drivers/staging/r8188eu/os_dep/os_intfs.c index 8d0158f4a45d..6821dcdf1523 100644 --- a/drivers/staging/r8188eu/os_dep/os_intfs.c +++ b/drivers/staging/r8188eu/os_dep/os_intfs.c @@ -1062,9 +1062,9 @@ int netdev_open(struct net_device *pnetdev) int ret; struct adapter *padapter = (struct adapter *)rtw_netdev_priv(pnetdev); - _enter_critical_mutex(padapter->hw_init_mutex, NULL); + mutex_lock(padapter->hw_init_mutex); ret = _netdev_open(pnetdev); - _exit_critical_mutex(padapter->hw_init_mutex, NULL); + mutex_unlock(padapter->hw_init_mutex); return ret; } -- 2.32.0