watchdog: pcwd_usb: Use allocated buffer for usb_control_msg
usb_control_msg() must use a dma-capable buffer.
This fixes the following error reported by smatch:
drivers/watchdog/pcwd_usb.c:257 usb_pcwd_send_command() error: doing dma on the
stack (buf)
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c
index 7b14d184..115a0eb 100644
--- a/drivers/watchdog/pcwd_usb.c
+++ b/drivers/watchdog/pcwd_usb.c
@@ -235,13 +235,17 @@
unsigned char cmd, unsigned char *msb, unsigned char *lsb)
{
int got_response, count;
- unsigned char buf[6];
+ unsigned char *buf;
/* We will not send any commands if the USB PCWD device does
* not exist */
if ((!usb_pcwd) || (!usb_pcwd->exists))
return -1;
+ buf = kmalloc(6, GFP_KERNEL);
+ if (buf == NULL)
+ return 0;
+
/* The USB PC Watchdog uses a 6 byte report format.
* The board currently uses only 3 of the six bytes of the report. */
buf[0] = cmd; /* Byte 0 = CMD */
@@ -277,6 +281,8 @@
*lsb = usb_pcwd->cmd_data_lsb;
}
+ kfree(buf);
+
return got_response;
}