[PATCH 2/3] Staging: most: fix doing DMA on stack
Christian Gromm
christian.gromm at microchip.com
Thu Jul 30 13:31:38 UTC 2015
This patch fixes error "doing DMA on the stack" by using kzalloc
for buffer allocation.
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Christian Gromm <christian.gromm at microchip.com>
---
drivers/staging/most/hdm-usb/hdm_usb.c | 39 +++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 13 deletions(-)
diff --git a/drivers/staging/most/hdm-usb/hdm_usb.c b/drivers/staging/most/hdm-usb/hdm_usb.c
index a4a3e26..9db31a2 100644
--- a/drivers/staging/most/hdm-usb/hdm_usb.c
+++ b/drivers/staging/most/hdm-usb/hdm_usb.c
@@ -45,6 +45,7 @@
#define USB_VENDOR_ID_SMSC 0x0424 /* VID: SMSC */
#define USB_DEV_ID_BRDG 0xC001 /* PID: USB Bridge */
#define USB_DEV_ID_INIC 0xCF18 /* PID: USB INIC */
+#define HW_RESYNC 0x0000
/* DRCI Addresses */
#define DRCI_REG_NI_STATE 0x0100
#define DRCI_REG_PACKET_BW 0x0101
@@ -139,21 +140,33 @@ static void wq_netinfo(struct work_struct *wq_obj);
* trigger_resync_vr - Vendor request to trigger HW re-sync mechanism
* @dev: usb device
*
+ * Since some architectures don't allow DMA to the stack, we use
+ * kzalloc for buffer allocation.
+ *
*/
-static inline void trigger_resync_vr(struct usb_device *dev)
+static void trigger_resync_vr(struct usb_device *dev)
{
- int data = 0;
-
- if (0 > usb_control_msg(dev,
- usb_sndctrlpipe(dev, 0),
- 0,
- USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT,
- 0,
- 0,
- &data,
- 0,
- 5 * HZ))
- pr_info("Vendor request \"stall\" failed\n");
+ int retval;
+ u8 request_type = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT;
+ int *data = kzalloc(sizeof(*data), GFP_KERNEL);
+
+ if (!data)
+ goto error;
+ *data = HW_RESYNC;
+ retval = usb_control_msg(dev,
+ usb_sndctrlpipe(dev, 0),
+ 0,
+ request_type,
+ 0,
+ 0,
+ data,
+ 0,
+ 5 * HZ);
+ kfree(data);
+ if (retval >= 0)
+ return;
+error:
+ pr_info("Vendor request \"stall\" failed\n");
}
/**
--
1.7.9.5
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