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* [PATCH] staging: r8188eu: remove _rtw_mutex_{init,free}
@ 2021-09-03 19:33 Pavel Skripkin
  2021-09-04  7:34 ` Greg KH
  0 siblings, 1 reply; 3+ messages in thread
From: Pavel Skripkin @ 2021-09-03 19:33 UTC (permalink / raw)
  To: Larry.Finger, phil, gregkh, straube.linux
  Cc: linux-staging, linux-kernel, Pavel Skripkin, Fabio M . De Francesco

While testing Fabio's patch I hit lockdep warning about possible
deadlock:

[  252.063305] WARNING: possible recursive locking detected
[  252.063642] 5.14.0+ #9 Tainted: G         C
[  252.063946] --------------------------------------------
[  252.064282] ip/335 is trying to acquire lock:
[  252.064560] ffff888009ebad28 (pmutex){+.+.}-{4:4}, at: usbctrl_vendorreq+0xc5/0x4a0 [r8188eu]
[  252.065168]
[  252.065168] but task is already holding lock:
[  252.065536] ffffffffc021b3b8 (pmutex){+.+.}-{4:4}, at:  netdev_open+0x3a/0x5f [r8188eu]
[  252.066085]
[  252.066085] other info that might help us debug this:
[  252.066494]  Possible unsafe locking scenario:
[  252.066494]
[  252.066866]        CPU0
[  252.067025]        ----
[  252.067184]   lock(pmutex);
[  252.067367]   lock(pmutex);

There is one problem with this warning: there is no pmutex in this
driver, *BUT* all mutexes are initialized via private _rtw_mutex_init
API, which had struct mutex *pmutex argument.

So, all mutexes in this driver had same name in lockdep map. Of course,
lockdep will complain about any nested locking.

Fix it by open-coding _rtw_mutex_{init,free} wrappers, because we do not
need them at all.

Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Fixes: 15865124feed ("staging: r8188eu: introduce new core dir for RTL8188eu driver")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/staging/r8188eu/core/rtw_sreset.c       |  2 +-
 drivers/staging/r8188eu/core/rtw_xmit.c         |  4 ++--
 drivers/staging/r8188eu/include/osdep_service.h |  2 --
 drivers/staging/r8188eu/os_dep/osdep_service.c  | 10 ----------
 drivers/staging/r8188eu/os_dep/usb_intf.c       |  8 ++++----
 5 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_sreset.c b/drivers/staging/r8188eu/core/rtw_sreset.c
index c831033d20a9..1787c2d7ea5f 100644
--- a/drivers/staging/r8188eu/core/rtw_sreset.c
+++ b/drivers/staging/r8188eu/core/rtw_sreset.c
@@ -8,7 +8,7 @@ void sreset_init_value(struct adapter *padapter)
 	struct hal_data_8188e	*pHalData = GET_HAL_DATA(padapter);
 	struct sreset_priv *psrtpriv = &pHalData->srestpriv;
 
-	_rtw_mutex_init(&psrtpriv->silentreset_mutex);
+	mutex_init(&psrtpriv->silentreset_mutex);
 	psrtpriv->silent_reset_inprogress = false;
 	psrtpriv->wifi_error_status = WIFI_STATUS_SUCCESS;
 	psrtpriv->last_tx_time = 0;
diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
index bcc4d65cdcee..875d1bf1679c 100644
--- a/drivers/staging/r8188eu/core/rtw_xmit.c
+++ b/drivers/staging/r8188eu/core/rtw_xmit.c
@@ -196,7 +196,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 	pxmitpriv->voq_cnt = 0;
 
 	pxmitpriv->ack_tx = false;
-	_rtw_mutex_init(&pxmitpriv->ack_tx_mutex);
+	mutex_init(&pxmitpriv->ack_tx_mutex);
 	rtw_sctx_init(&pxmitpriv->ack_tx_ops, 0);
 
 	rtw_hal_init_xmit_priv(padapter);
@@ -243,7 +243,7 @@ void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv)
 
 	rtw_free_hwxmits(padapter);
 
-	_rtw_mutex_free(&pxmitpriv->ack_tx_mutex);
+	mutex_destroy(&pxmitpriv->ack_tx_mutex);
 }
 
 static void update_attrib_vcs_info(struct adapter *padapter, struct xmit_frame *pxmitframe)
diff --git a/drivers/staging/r8188eu/include/osdep_service.h b/drivers/staging/r8188eu/include/osdep_service.h
index 029aa4e92c9b..05bac61c3a19 100644
--- a/drivers/staging/r8188eu/include/osdep_service.h
+++ b/drivers/staging/r8188eu/include/osdep_service.h
@@ -155,8 +155,6 @@ extern unsigned char RSN_TKIP_CIPHER[4];
 void *rtw_malloc2d(int h, int w, int size);
 
 u32  _rtw_down_sema(struct semaphore *sema);
-void _rtw_mutex_init(struct mutex *pmutex);
-void _rtw_mutex_free(struct mutex *pmutex);
 
 void _rtw_init_queue(struct __queue *pqueue);
 
diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c
index 95ac6086370b..4328992907f2 100644
--- a/drivers/staging/r8188eu/os_dep/osdep_service.c
+++ b/drivers/staging/r8188eu/os_dep/osdep_service.c
@@ -67,16 +67,6 @@ u32 _rtw_down_sema(struct semaphore *sema)
 		return _SUCCESS;
 }
 
-void	_rtw_mutex_init(struct mutex *pmutex)
-{
-	mutex_init(pmutex);
-}
-
-void	_rtw_mutex_free(struct mutex *pmutex)
-{
-	mutex_destroy(pmutex);
-}
-
 void	_rtw_init_queue(struct __queue *pqueue)
 {
 	INIT_LIST_HEAD(&pqueue->queue);
diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c
index bb85ab77fd26..8a981a30ea1f 100644
--- a/drivers/staging/r8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/r8188eu/os_dep/usb_intf.c
@@ -116,7 +116,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
 {
 	u8 rst = _SUCCESS;
 
-	_rtw_mutex_init(&dvobj->usb_vendor_req_mutex);
+	mutex_init(&dvobj->usb_vendor_req_mutex);
 
 	dvobj->usb_alloc_vendor_req_buf = kzalloc(MAX_USB_IO_CTL_SIZE, GFP_KERNEL);
 	if (!dvobj->usb_alloc_vendor_req_buf) {
@@ -132,7 +132,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
 static void rtw_deinit_intf_priv(struct dvobj_priv *dvobj)
 {
 	kfree(dvobj->usb_alloc_vendor_req_buf);
-	_rtw_mutex_free(&dvobj->usb_vendor_req_mutex);
+	mutex_destroy(&dvobj->usb_vendor_req_mutex);
 }
 
 static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
@@ -760,7 +760,7 @@ static int __init rtw_drv_entry(void)
 {
 	DBG_88E(DRV_NAME " driver version=%s\n", DRIVERVERSION);
 
-	_rtw_mutex_init(&usb_drv->hw_init_mutex);
+	mutex_init(&usb_drv->hw_init_mutex);
 
 	usb_drv->drv_registered = true;
 	return usb_register(&usb_drv->usbdrv);
@@ -773,7 +773,7 @@ static void __exit rtw_drv_halt(void)
 	usb_drv->drv_registered = false;
 	usb_deregister(&usb_drv->usbdrv);
 
-	_rtw_mutex_free(&usb_drv->hw_init_mutex);
+	mutex_destroy(&usb_drv->hw_init_mutex);
 	DBG_88E("-rtw_drv_halt\n");
 }
 
-- 
2.33.0


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] staging: r8188eu: remove _rtw_mutex_{init,free}
  2021-09-03 19:33 [PATCH] staging: r8188eu: remove _rtw_mutex_{init,free} Pavel Skripkin
@ 2021-09-04  7:34 ` Greg KH
  2021-09-04 12:47   ` [PATCH v2] " Pavel Skripkin
  0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2021-09-04  7:34 UTC (permalink / raw)
  To: Pavel Skripkin
  Cc: Larry.Finger, phil, straube.linux, linux-staging, linux-kernel,
	Fabio M . De Francesco

On Fri, Sep 03, 2021 at 10:33:56PM +0300, Pavel Skripkin wrote:
> While testing Fabio's patch I hit lockdep warning about possible
> deadlock:
> 
> [  252.063305] WARNING: possible recursive locking detected
> [  252.063642] 5.14.0+ #9 Tainted: G         C
> [  252.063946] --------------------------------------------
> [  252.064282] ip/335 is trying to acquire lock:
> [  252.064560] ffff888009ebad28 (pmutex){+.+.}-{4:4}, at: usbctrl_vendorreq+0xc5/0x4a0 [r8188eu]
> [  252.065168]
> [  252.065168] but task is already holding lock:
> [  252.065536] ffffffffc021b3b8 (pmutex){+.+.}-{4:4}, at:  netdev_open+0x3a/0x5f [r8188eu]
> [  252.066085]
> [  252.066085] other info that might help us debug this:
> [  252.066494]  Possible unsafe locking scenario:
> [  252.066494]
> [  252.066866]        CPU0
> [  252.067025]        ----
> [  252.067184]   lock(pmutex);
> [  252.067367]   lock(pmutex);
> 
> There is one problem with this warning: there is no pmutex in this
> driver, *BUT* all mutexes are initialized via private _rtw_mutex_init
> API, which had struct mutex *pmutex argument.
> 
> So, all mutexes in this driver had same name in lockdep map. Of course,
> lockdep will complain about any nested locking.
> 
> Fix it by open-coding _rtw_mutex_{init,free} wrappers, because we do not
> need them at all.
> 
> Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> Fixes: 15865124feed ("staging: r8188eu: introduce new core dir for RTL8188eu driver")

No need for "Fixes:" on this, as it's not a bug, it's just a badly
designed implementation.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH v2] staging: r8188eu: remove _rtw_mutex_{init,free}
  2021-09-04  7:34 ` Greg KH
@ 2021-09-04 12:47   ` Pavel Skripkin
  0 siblings, 0 replies; 3+ messages in thread
From: Pavel Skripkin @ 2021-09-04 12:47 UTC (permalink / raw)
  To: Larry.Finger, phil, gregkh, straube.linux
  Cc: linux-staging, linux-kernel, Pavel Skripkin, Fabio M . De Francesco

While testing Fabio's patch I hit lockdep warning about possible
deadlock:

[  252.063305] WARNING: possible recursive locking detected
[  252.063642] 5.14.0+ #9 Tainted: G         C
[  252.063946] --------------------------------------------
[  252.064282] ip/335 is trying to acquire lock:
[  252.064560] ffff888009ebad28 (pmutex){+.+.}-{4:4}, at: usbctrl_vendorreq+0xc5/0x4a0 [r8188eu]
[  252.065168]
[  252.065168] but task is already holding lock:
[  252.065536] ffffffffc021b3b8 (pmutex){+.+.}-{4:4}, at:  netdev_open+0x3a/0x5f [r8188eu]
[  252.066085]
[  252.066085] other info that might help us debug this:
[  252.066494]  Possible unsafe locking scenario:
[  252.066494]
[  252.066866]        CPU0
[  252.067025]        ----
[  252.067184]   lock(pmutex);
[  252.067367]   lock(pmutex);

There is one problem with this warning: there is no pmutex in this
driver, *BUT* all mutexes are initialized via private _rtw_mutex_init
API, which had struct mutex *pmutex argument.

So, all mutexes in this driver had same name in lockdep map. Of course,
lockdep will complain about any nested locking.

Fix it by open-coding _rtw_mutex_{init,free} wrappers, because we do not
need them at all.

Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---

Changes in v2:
	Removed Fixes tag (suggested by Greg)

---
 drivers/staging/r8188eu/core/rtw_sreset.c       |  2 +-
 drivers/staging/r8188eu/core/rtw_xmit.c         |  4 ++--
 drivers/staging/r8188eu/include/osdep_service.h |  2 --
 drivers/staging/r8188eu/os_dep/osdep_service.c  | 10 ----------
 drivers/staging/r8188eu/os_dep/usb_intf.c       |  8 ++++----
 5 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_sreset.c b/drivers/staging/r8188eu/core/rtw_sreset.c
index c831033d20a9..1787c2d7ea5f 100644
--- a/drivers/staging/r8188eu/core/rtw_sreset.c
+++ b/drivers/staging/r8188eu/core/rtw_sreset.c
@@ -8,7 +8,7 @@ void sreset_init_value(struct adapter *padapter)
 	struct hal_data_8188e	*pHalData = GET_HAL_DATA(padapter);
 	struct sreset_priv *psrtpriv = &pHalData->srestpriv;
 
-	_rtw_mutex_init(&psrtpriv->silentreset_mutex);
+	mutex_init(&psrtpriv->silentreset_mutex);
 	psrtpriv->silent_reset_inprogress = false;
 	psrtpriv->wifi_error_status = WIFI_STATUS_SUCCESS;
 	psrtpriv->last_tx_time = 0;
diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
index 46fe62c7c32c..bbb9889c4b89 100644
--- a/drivers/staging/r8188eu/core/rtw_xmit.c
+++ b/drivers/staging/r8188eu/core/rtw_xmit.c
@@ -196,7 +196,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 	pxmitpriv->voq_cnt = 0;
 
 	pxmitpriv->ack_tx = false;
-	_rtw_mutex_init(&pxmitpriv->ack_tx_mutex);
+	mutex_init(&pxmitpriv->ack_tx_mutex);
 	rtw_sctx_init(&pxmitpriv->ack_tx_ops, 0);
 
 	rtw_hal_init_xmit_priv(padapter);
@@ -243,7 +243,7 @@ void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv)
 
 	rtw_free_hwxmits(padapter);
 
-	_rtw_mutex_free(&pxmitpriv->ack_tx_mutex);
+	mutex_destroy(&pxmitpriv->ack_tx_mutex);
 }
 
 static void update_attrib_vcs_info(struct adapter *padapter, struct xmit_frame *pxmitframe)
diff --git a/drivers/staging/r8188eu/include/osdep_service.h b/drivers/staging/r8188eu/include/osdep_service.h
index 029aa4e92c9b..05bac61c3a19 100644
--- a/drivers/staging/r8188eu/include/osdep_service.h
+++ b/drivers/staging/r8188eu/include/osdep_service.h
@@ -155,8 +155,6 @@ extern unsigned char RSN_TKIP_CIPHER[4];
 void *rtw_malloc2d(int h, int w, int size);
 
 u32  _rtw_down_sema(struct semaphore *sema);
-void _rtw_mutex_init(struct mutex *pmutex);
-void _rtw_mutex_free(struct mutex *pmutex);
 
 void _rtw_init_queue(struct __queue *pqueue);
 
diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c
index 95ac6086370b..4328992907f2 100644
--- a/drivers/staging/r8188eu/os_dep/osdep_service.c
+++ b/drivers/staging/r8188eu/os_dep/osdep_service.c
@@ -67,16 +67,6 @@ u32 _rtw_down_sema(struct semaphore *sema)
 		return _SUCCESS;
 }
 
-void	_rtw_mutex_init(struct mutex *pmutex)
-{
-	mutex_init(pmutex);
-}
-
-void	_rtw_mutex_free(struct mutex *pmutex)
-{
-	mutex_destroy(pmutex);
-}
-
 void	_rtw_init_queue(struct __queue *pqueue)
 {
 	INIT_LIST_HEAD(&pqueue->queue);
diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c
index bb85ab77fd26..8a981a30ea1f 100644
--- a/drivers/staging/r8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/r8188eu/os_dep/usb_intf.c
@@ -116,7 +116,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
 {
 	u8 rst = _SUCCESS;
 
-	_rtw_mutex_init(&dvobj->usb_vendor_req_mutex);
+	mutex_init(&dvobj->usb_vendor_req_mutex);
 
 	dvobj->usb_alloc_vendor_req_buf = kzalloc(MAX_USB_IO_CTL_SIZE, GFP_KERNEL);
 	if (!dvobj->usb_alloc_vendor_req_buf) {
@@ -132,7 +132,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
 static void rtw_deinit_intf_priv(struct dvobj_priv *dvobj)
 {
 	kfree(dvobj->usb_alloc_vendor_req_buf);
-	_rtw_mutex_free(&dvobj->usb_vendor_req_mutex);
+	mutex_destroy(&dvobj->usb_vendor_req_mutex);
 }
 
 static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
@@ -760,7 +760,7 @@ static int __init rtw_drv_entry(void)
 {
 	DBG_88E(DRV_NAME " driver version=%s\n", DRIVERVERSION);
 
-	_rtw_mutex_init(&usb_drv->hw_init_mutex);
+	mutex_init(&usb_drv->hw_init_mutex);
 
 	usb_drv->drv_registered = true;
 	return usb_register(&usb_drv->usbdrv);
@@ -773,7 +773,7 @@ static void __exit rtw_drv_halt(void)
 	usb_drv->drv_registered = false;
 	usb_deregister(&usb_drv->usbdrv);
 
-	_rtw_mutex_free(&usb_drv->hw_init_mutex);
+	mutex_destroy(&usb_drv->hw_init_mutex);
 	DBG_88E("-rtw_drv_halt\n");
 }
 
-- 
2.33.0


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-09-04 12:48 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-09-03 19:33 [PATCH] staging: r8188eu: remove _rtw_mutex_{init,free} Pavel Skripkin
2021-09-04  7:34 ` Greg KH
2021-09-04 12:47   ` [PATCH v2] " Pavel Skripkin

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