[PATCH 62/75] tty: Drop the lock_kernel in the private ioctl hook

Alan Cox
2009-01-02T13:48:42Z

From: Alan Cox <alan@redhat.com>

We don't need the BKL here any more so it can go. In a couple of spots the
driver requirements are not clear so push the lock down into the driver.

Signed-off-by: Alan Cox <alan@redhat.com>
---

drivers/usb/serial/ftdi_sio.c | 9 ++++++++-
drivers/usb/serial/kl5kusb105.c | 1 +
drivers/usb/serial/mct_u232.c | 2 +-
drivers/usb/serial/mos7840.c | 3 +++
drivers/usb/serial/usb-serial.c | 7 +------
5 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index fb6f293..ef6cfa5 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1054,6 +1054,8 @@ static int set_serial_info(struct tty_struct *tty,

if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
return -EFAULT;
+
+ lock_kernel();
old_priv = *priv;

/* Do error checking and permission checking */
@@ -1069,8 +1071,10 @@ static int set_serial_info(struct tty_struct *tty,
}

if ((new_serial.baud_base != priv->baud_base) &&
- (new_serial.baud_base < 9600))
+ (new_serial.baud_base < 9600)) {
+ unlock_kernel();
return -EINVAL;
+ }

/* Make the changes - these are privileged changes! */

@@ -1098,8 +1102,11 @@ check_and_exit:
(priv->flags & ASYNC_SPD_MASK)) ||
(((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
(old_priv.custom_divisor != priv->custom_divisor))) {
+ unlock_kernel();
change_speed(tty, port);
}
+ else
+ unlock_kernel();
return 0;

} /* set_serial_info */
diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index dc36a05..fcd9082 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -878,6 +878,7 @@ static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)

dbg("%sstate=%d", __func__, break_state);

+ /* LOCKING */
if (break_state)
lcr |= MCT_U232_SET_BREAK;

diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index 07710cf..82930a7 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -721,10 +721,10 @@ static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)

spin_lock_irqsave(&priv->lock, flags);
lcr = priv->last_lcr;
- spin_unlock_irqrestore(&priv->lock, flags);

if (break_state)
lcr |= MCT_U232_SET_BREAK;
+ spin_unlock_irqrestore(&priv->lock, flags);

mct_u232_set_line_ctrl(serial, lcr);
} /* mct_u232_break_ctl */
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index fda4a64..96a8c77 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1343,6 +1343,7 @@ static void mos7840_break(struct tty_struct *tty, int break_state)
else
data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;

+ /* FIXME: no locking on shadowLCR anywhere in driver */
mos7840_port->shadowLCR = data;
dbg("mcs7840_break mos7840_port->shadowLCR is %x\n",
mos7840_port->shadowLCR);
@@ -2214,10 +2215,12 @@ static int mos7840_set_modem_info(struct moschip_port *mos7840_port,
break;
}

+ lock_kernel();
mos7840_port->shadowMCR = mcr;

Data = mos7840_port->shadowMCR;
status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
+ unlock_kernel();
if (status < 0) {
dbg("setting MODEM_CONTROL_REGISTER Failed\n");
return -1;
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 8d51890..080ade2 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -382,9 +382,7 @@ static int serial_ioctl(struct tty_struct *tty, struct file *file,
/* pass on to the driver specific version of this function
if it is available */
if (port->serial->type->ioctl) {
- lock_kernel();
retval = port->serial->type->ioctl(tty, file, cmd, arg);
- unlock_kernel();
} else
retval = -ENOIOCTLCMD;
return retval;
@@ -413,11 +411,8 @@ static int serial_break(struct tty_struct *tty, int break_state)
WARN_ON(!port->port.count);
/* pass on to the driver specific version of this function
if it is available */
- if (port->serial->type->break_ctl) {
- lock_kernel();
+ if (port->serial->type->break_ctl)
port->serial->type->break_ctl(tty, break_state);
- unlock_kernel();
- }
return 0;
}