diff mbox series

[8/8] usb_pcwd: remove superfluous usb_device pointer

Message ID 20230427133350.31064-9-oneukum@suse.com (mailing list archive)
State Rejected
Headers show
Series [1/8] pwcd_usb: fix error handling in probe | expand

Commit Message

Oliver Neukum April 27, 2023, 1:33 p.m. UTC
Retrieve the device from the interface

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/watchdog/pcwd_usb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Dan Carpenter May 13, 2023, 8:52 a.m. UTC | #1
Hi Oliver,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Oliver-Neukum/pcwd_usb-stop-open-race-disconnect/20230427-223413
base:   linus/master
patch link:    https://lore.kernel.org/r/20230427133350.31064-9-oneukum%40suse.com
patch subject: [PATCH 8/8] usb_pcwd: remove superfluous usb_device pointer
config: parisc-randconfig-m041-20230509 (https://download.01.org/0day-ci/archive/20230512/202305122231.n8RlGMhT-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Link: https://lore.kernel.org/r/202305122231.n8RlGMhT-lkp@intel.com/

smatch warnings:
drivers/watchdog/pcwd_usb.c:215 usb_pcwd_send_command() warn: variable dereferenced before check 'usb_pcwd' (see line 211)

vim +/usb_pcwd +215 drivers/watchdog/pcwd_usb.c

143a2e54bf5321 drivers/watchdog/pcwd_usb.c      Wim Van Sebroeck   2009-03-18  206  static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
143a2e54bf5321 drivers/watchdog/pcwd_usb.c      Wim Van Sebroeck   2009-03-18  207  		unsigned char cmd, unsigned char *msb, unsigned char *lsb)
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  208  {
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  209  	int got_response, count;
5412df0bda90a2 drivers/watchdog/pcwd_usb.c      Guenter Roeck      2013-10-14  210  	unsigned char *buf;
41b4f0869562d7 drivers/watchdog/pcwd_usb.c      Oliver Neukum      2023-04-27 @211  	struct usb_device *udev = interface_to_usbdev(usb_pcwd->interface);
                                                                                                                                      ^^^^^^^^^^
Dereference.

^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  212  
143a2e54bf5321 drivers/watchdog/pcwd_usb.c      Wim Van Sebroeck   2009-03-18  213  	/* We will not send any commands if the USB PCWD device does
143a2e54bf5321 drivers/watchdog/pcwd_usb.c      Wim Van Sebroeck   2009-03-18  214  	 * not exist */
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16 @215  	if ((!usb_pcwd) || (!usb_pcwd->exists))
                                                                                            ^^^^^^^^^^^
Checked too late.

^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  216  		return -1;
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  217  
5412df0bda90a2 drivers/watchdog/pcwd_usb.c      Guenter Roeck      2013-10-14  218  	buf = kmalloc(6, GFP_KERNEL);
5412df0bda90a2 drivers/watchdog/pcwd_usb.c      Guenter Roeck      2013-10-14  219  	if (buf == NULL)
5412df0bda90a2 drivers/watchdog/pcwd_usb.c      Guenter Roeck      2013-10-14  220  		return 0;
5412df0bda90a2 drivers/watchdog/pcwd_usb.c      Guenter Roeck      2013-10-14  221  
143a2e54bf5321 drivers/watchdog/pcwd_usb.c      Wim Van Sebroeck   2009-03-18  222  	/* The USB PC Watchdog uses a 6 byte report format.
143a2e54bf5321 drivers/watchdog/pcwd_usb.c      Wim Van Sebroeck   2009-03-18  223  	 * The board currently uses only 3 of the six bytes of the report. */
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  224  	buf[0] = cmd;			/* Byte 0 = CMD */
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  225  	buf[1] = *msb;			/* Byte 1 = Data MSB */
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  226  	buf[2] = *lsb;			/* Byte 2 = Data LSB */
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  227  	buf[3] = buf[4] = buf[5] = 0;	/* All other bytes not used */
^1da177e4c3f41 drivers/char/watchdog/pcwd_usb.c Linus Torvalds     2005-04-16  228  
d7e92f7f768477 drivers/watchdog/pcwd_usb.c      Greg Kroah-Hartman 2013-12-19  229  	dev_dbg(&usb_pcwd->interface->dev,
diff mbox series

Patch

diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c
index 09cae7a6ad07..055acc191af9 100644
--- a/drivers/watchdog/pcwd_usb.c
+++ b/drivers/watchdog/pcwd_usb.c
@@ -112,8 +112,6 @@  static char expect_release;
 
 /* Structure to hold all of our device specific stuff */
 struct usb_pcwd_private {
-	/* save off the usb device pointer */
-	struct usb_device	*udev;
 	/* the interface for this device */
 	struct usb_interface	*interface;
 
@@ -210,6 +208,7 @@  static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 {
 	int got_response, count;
 	unsigned char *buf;
+	struct usb_device *udev = interface_to_usbdev(usb_pcwd->interface);
 
 	/* We will not send any commands if the USB PCWD device does
 	 * not exist */
@@ -233,7 +232,7 @@  static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
 
 	atomic_set(&usb_pcwd->cmd_received, 0);
 
-	if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
+	if (usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 			HID_REQ_SET_REPORT, HID_DT_REPORT,
 			0x0200, usb_pcwd->interface_number, buf, 6,
 			USB_COMMAND_TIMEOUT) != 6) {
@@ -625,8 +624,10 @@  static struct notifier_block usb_pcwd_notifier = {
  */
 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 {
+	struct usb_device *udev = interface_to_usbdev(usb_pcwd->interface);
+
 	usb_free_urb(usb_pcwd->intr_urb);
-	usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
+	usb_free_coherent(udev, usb_pcwd->intr_size,
 			  usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 	kfree(usb_pcwd);
 }
@@ -691,7 +692,6 @@  static int usb_pcwd_probe(struct usb_interface *interface,
 	usb_pcwd_device = usb_pcwd;
 
 	mutex_init(&usb_pcwd->mtx);
-	usb_pcwd->udev = udev;
 	usb_pcwd->interface = interface;
 	usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
 	usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?