[PATCH 3/5] USB: ftdi_sio: fix DMA buffers on stack
From: Johan Hovold
Date: Thu Dec 24 2009 - 06:44:22 EST
Also remove unnecessary buffer allocations for zero-length transfers.
Reported-by: Matti Aarnio <matti.aarnio@xxxxxxxxxxx>
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
drivers/usb/serial/ftdi_sio.c | 69 ++++++++++++++++-------------------------
1 files changed, 27 insertions(+), 42 deletions(-)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 6d191fb..4b3f115 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -916,7 +916,6 @@ static int update_mctrl(struct usb_serial_port *port, unsigned int set,
unsigned int clear)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
- char *buf;
unsigned urb_value;
int rv;
@@ -925,10 +924,6 @@ static int update_mctrl(struct usb_serial_port *port, unsigned int set,
return 0; /* no change */
}
- buf = kmalloc(1, GFP_NOIO);
- if (!buf)
- return -ENOMEM;
-
clear &= ~set; /* 'set' takes precedence over 'clear' */
urb_value = 0;
if (clear & TIOCM_DTR)
@@ -944,9 +939,7 @@ static int update_mctrl(struct usb_serial_port *port, unsigned int set,
FTDI_SIO_SET_MODEM_CTRL_REQUEST,
FTDI_SIO_SET_MODEM_CTRL_REQUEST_TYPE,
urb_value, priv->interface,
- buf, 0, WDR_TIMEOUT);
-
- kfree(buf);
+ NULL, 0, WDR_TIMEOUT);
if (rv < 0) {
dbg("%s Error from MODEM_CTRL urb: DTR %s, RTS %s",
__func__,
@@ -1105,16 +1098,11 @@ static __u32 get_ftdi_divisor(struct tty_struct *tty,
static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
- char *buf;
__u16 urb_value;
__u16 urb_index;
__u32 urb_index_value;
int rv;
- buf = kmalloc(1, GFP_NOIO);
- if (!buf)
- return -ENOMEM;
-
urb_index_value = get_ftdi_divisor(tty, port);
urb_value = (__u16)urb_index_value;
urb_index = (__u16)(urb_index_value >> 16);
@@ -1127,9 +1115,7 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
FTDI_SIO_SET_BAUDRATE_REQUEST,
FTDI_SIO_SET_BAUDRATE_REQUEST_TYPE,
urb_value, urb_index,
- buf, 0, WDR_SHORT_TIMEOUT);
-
- kfree(buf);
+ NULL, 0, WDR_SHORT_TIMEOUT);
return rv;
}
@@ -1137,7 +1123,6 @@ static int write_latency_timer(struct usb_serial_port *port)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
struct usb_device *udev = port->serial->dev;
- char buf[1];
int rv = 0;
int l = priv->latency;
@@ -1151,8 +1136,7 @@ static int write_latency_timer(struct usb_serial_port *port)
FTDI_SIO_SET_LATENCY_TIMER_REQUEST,
FTDI_SIO_SET_LATENCY_TIMER_REQUEST_TYPE,
l, priv->interface,
- buf, 0, WDR_TIMEOUT);
-
+ NULL, 0, WDR_TIMEOUT);
if (rv < 0)
dev_err(&port->dev, "Unable to write latency timer: %i\n", rv);
return rv;
@@ -1426,7 +1410,6 @@ static ssize_t store_event_char(struct device *dev,
struct usb_serial_port *port = to_usb_serial_port(dev);
struct ftdi_private *priv = usb_get_serial_port_data(port);
struct usb_device *udev = port->serial->dev;
- char buf[1];
int v = simple_strtoul(valbuf, NULL, 10);
int rv = 0;
@@ -1437,8 +1420,7 @@ static ssize_t store_event_char(struct device *dev,
FTDI_SIO_SET_EVENT_CHAR_REQUEST,
FTDI_SIO_SET_EVENT_CHAR_REQUEST_TYPE,
v, priv->interface,
- buf, 0, WDR_TIMEOUT);
-
+ NULL, 0, WDR_TIMEOUT);
if (rv < 0) {
dbg("Unable to write event character: %i", rv);
return -EIO;
@@ -1617,7 +1599,6 @@ static int ftdi_NDI_device_setup(struct usb_serial *serial)
struct usb_device *udev = serial->dev;
int latency = ndi_latency_timer;
int rv = 0;
- char buf[1];
if (latency == 0)
latency = 1;
@@ -1630,7 +1611,7 @@ static int ftdi_NDI_device_setup(struct usb_serial *serial)
rv = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
FTDI_SIO_SET_LATENCY_TIMER_REQUEST,
FTDI_SIO_SET_LATENCY_TIMER_REQUEST_TYPE,
- latency, 0, buf, 0, WDR_TIMEOUT);
+ latency, 0, NULL, 0, WDR_TIMEOUT);
return 0;
}
@@ -1718,9 +1699,7 @@ static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
struct usb_device *dev = port->serial->dev;
struct ftdi_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
-
int result = 0;
- char buf[1]; /* Needed for the usb_control_msg I think */
dbg("%s", __func__);
@@ -1735,7 +1714,7 @@ static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
FTDI_SIO_RESET_REQUEST, FTDI_SIO_RESET_REQUEST_TYPE,
FTDI_SIO_RESET_SIO,
- priv->interface, buf, 0, WDR_TIMEOUT);
+ priv->interface, NULL, 0, WDR_TIMEOUT);
/* Termios defaults are set by usb_serial_init. We don't change
port->tty->termios - this would lose speed settings, etc.
@@ -1763,7 +1742,6 @@ static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
static void ftdi_dtr_rts(struct usb_serial_port *port, int on)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
- char buf[1];
mutex_lock(&port->serial->disc_mutex);
if (!port->serial->disconnected) {
@@ -1772,7 +1750,7 @@ static void ftdi_dtr_rts(struct usb_serial_port *port, int on)
usb_sndctrlpipe(port->serial->dev, 0),
FTDI_SIO_SET_FLOW_CTRL_REQUEST,
FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
- 0, priv->interface, buf, 0,
+ 0, priv->interface, NULL, 0,
WDR_TIMEOUT) < 0) {
dev_err(&port->dev, "error from flowcontrol urb\n");
}
@@ -2141,7 +2119,6 @@ static void ftdi_break_ctl(struct tty_struct *tty, int break_state)
struct usb_serial_port *port = tty->driver_data;
struct ftdi_private *priv = usb_get_serial_port_data(port);
__u16 urb_value = 0;
- char buf[1];
/* break_state = -1 to turn on break, and 0 to turn off break */
/* see drivers/char/tty_io.c to see it used */
@@ -2157,7 +2134,7 @@ static void ftdi_break_ctl(struct tty_struct *tty, int break_state)
FTDI_SIO_SET_DATA_REQUEST,
FTDI_SIO_SET_DATA_REQUEST_TYPE,
urb_value , priv->interface,
- buf, 0, WDR_TIMEOUT) < 0) {
+ NULL, 0, WDR_TIMEOUT) < 0) {
dev_err(&port->dev, "%s FAILED to enable/disable break state "
"(state was %d)\n", __func__, break_state);
}
@@ -2181,7 +2158,6 @@ static void ftdi_set_termios(struct tty_struct *tty,
struct ktermios *termios = tty->termios;
unsigned int cflag = termios->c_cflag;
__u16 urb_value; /* will hold the new flags */
- char buf[1]; /* Perhaps I should dynamically alloc this? */
/* Added for xon/xoff support */
unsigned int iflag = termios->c_iflag;
@@ -2247,7 +2223,7 @@ static void ftdi_set_termios(struct tty_struct *tty,
FTDI_SIO_SET_DATA_REQUEST,
FTDI_SIO_SET_DATA_REQUEST_TYPE,
urb_value , priv->interface,
- buf, 0, WDR_SHORT_TIMEOUT) < 0) {
+ NULL, 0, WDR_SHORT_TIMEOUT) < 0) {
dev_err(&port->dev, "%s FAILED to set "
"databits/stopbits/parity\n", __func__);
}
@@ -2259,7 +2235,7 @@ static void ftdi_set_termios(struct tty_struct *tty,
FTDI_SIO_SET_FLOW_CTRL_REQUEST,
FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
0, priv->interface,
- buf, 0, WDR_TIMEOUT) < 0) {
+ NULL, 0, WDR_TIMEOUT) < 0) {
dev_err(&port->dev,
"%s error from disable flowcontrol urb\n",
__func__);
@@ -2285,7 +2261,7 @@ static void ftdi_set_termios(struct tty_struct *tty,
FTDI_SIO_SET_FLOW_CTRL_REQUEST,
FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
0 , (FTDI_SIO_RTS_CTS_HS | priv->interface),
- buf, 0, WDR_TIMEOUT) < 0) {
+ NULL, 0, WDR_TIMEOUT) < 0) {
dev_err(&port->dev,
"urb failed to set to rts/cts flow control\n");
}
@@ -2317,7 +2293,7 @@ static void ftdi_set_termios(struct tty_struct *tty,
FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
urb_value , (FTDI_SIO_XON_XOFF_HS
| priv->interface),
- buf, 0, WDR_TIMEOUT) < 0) {
+ NULL, 0, WDR_TIMEOUT) < 0) {
dev_err(&port->dev, "urb failed to set to "
"xon/xoff flow control\n");
}
@@ -2331,7 +2307,7 @@ static void ftdi_set_termios(struct tty_struct *tty,
FTDI_SIO_SET_FLOW_CTRL_REQUEST,
FTDI_SIO_SET_FLOW_CTRL_REQUEST_TYPE,
0, priv->interface,
- buf, 0, WDR_TIMEOUT) < 0) {
+ NULL, 0, WDR_TIMEOUT) < 0) {
dev_err(&port->dev,
"urb failed to clear flow control\n");
}
@@ -2345,10 +2321,15 @@ static int ftdi_tiocmget(struct tty_struct *tty, struct file *file)
{
struct usb_serial_port *port = tty->driver_data;
struct ftdi_private *priv = usb_get_serial_port_data(port);
- unsigned char buf[2];
+ unsigned char *buf;
int ret;
dbg("%s TIOCMGET", __func__);
+
+ buf = kmalloc(2, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
switch (priv->chip_type) {
case SIO:
/* Request the status from the device */
@@ -2359,7 +2340,7 @@ static int ftdi_tiocmget(struct tty_struct *tty, struct file *file)
0, 0,
buf, 1, WDR_TIMEOUT);
if (ret < 0)
- return ret;
+ goto out;
break;
case FT8U232AM:
case FT232BM:
@@ -2377,17 +2358,21 @@ static int ftdi_tiocmget(struct tty_struct *tty, struct file *file)
0, priv->interface,
buf, 2, WDR_TIMEOUT);
if (ret < 0)
- return ret;
+ goto out;
break;
default:
- return -EFAULT;
+ ret = -EFAULT;
+ goto out;
}
- return (buf[0] & FTDI_SIO_DSR_MASK ? TIOCM_DSR : 0) |
+ ret = (buf[0] & FTDI_SIO_DSR_MASK ? TIOCM_DSR : 0) |
(buf[0] & FTDI_SIO_CTS_MASK ? TIOCM_CTS : 0) |
(buf[0] & FTDI_SIO_RI_MASK ? TIOCM_RI : 0) |
(buf[0] & FTDI_SIO_RLSD_MASK ? TIOCM_CD : 0) |
priv->last_dtr_rts;
+out:
+ kfree(buf);
+ return ret;
}
static int ftdi_tiocmset(struct tty_struct *tty, struct file *file,
--
1.6.6.rc4
--
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