| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Sat, 19 Sep 2009 14:37:23 -0700
From: Greg Kroah-Hartman <gregkh@...e.de>
To: linux-kernel@...r.kernel.org
Cc: Alan Stern <stern@...land.harvard.edu>, stable <stable@...nel.org>,
Greg Kroah-Hartman <gregkh@...e.de>
Subject: [PATCH 78/79] usb-serial: straighten out serial_open
From: Alan Stern <stern@...land.harvard.edu>
This patch (as1291) removes a bunch of code from serial_open(), things
that were rendered unnecessary by earlier patches. A missing spinlock
is added to protect port->port.count, which needs to be incremented
even if the open fails but not if the tty has gotten a hangup. The
test for whether the hardware has been initialized, based on the use
count, is replaced by a more transparent test of the
ASYNCB_INITIALIZED bit in the port flags.
Signed-off-by: Alan Stern <stern@...land.harvard.edu>
Cc: stable <stable@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
---
drivers/usb/serial/usb-serial.c | 59 ++++++++++++++------------------------
1 files changed, 22 insertions(+), 37 deletions(-)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 9a32580..9d7ca48 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -245,55 +245,40 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
return retval;
}
-static int serial_open (struct tty_struct *tty, struct file *filp)
+static int serial_open(struct tty_struct *tty, struct file *filp)
{
- struct usb_serial *serial;
- struct usb_serial_port *port;
- int retval = 0;
- int first = 0;
-
- port = tty->driver_data;
- serial = port->serial;
+ struct usb_serial_port *port = tty->driver_data;
+ struct usb_serial *serial = port->serial;
+ int retval;
dbg("%s - port %d", __func__, port->number);
- if (mutex_lock_interruptible(&port->mutex))
- return -ERESTARTSYS;
-
- ++port->port.count;
+ spin_lock_irq(&port->port.lock);
+ if (!tty_hung_up_p(filp))
+ ++port->port.count;
+ spin_unlock_irq(&port->port.lock);
tty_port_tty_set(&port->port, tty);
- /* If the console is attached, the device is already open */
- if (port->port.count == 1 && !port->console) {
- first = 1;
+ /* Do the device-specific open only if the hardware isn't
+ * already initialized.
+ */
+ if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
+ if (mutex_lock_interruptible(&port->mutex))
+ return -ERESTARTSYS;
mutex_lock(&serial->disc_mutex);
-
- /* only call the device specific open if this
- * is the first time the port is opened */
- retval = serial->type->open(tty, port);
- if (retval)
- goto bailout_module_put;
+ if (serial->disconnected)
+ retval = -ENODEV;
+ else
+ retval = port->serial->type->open(tty, port);
mutex_unlock(&serial->disc_mutex);
+ mutex_unlock(&port->mutex);
+ if (retval)
+ return retval;
set_bit(ASYNCB_INITIALIZED, &port->port.flags);
}
- mutex_unlock(&port->mutex);
+
/* Now do the correct tty layer semantics */
retval = tty_port_block_til_ready(&port->port, tty, filp);
- if (retval == 0) {
- if (!first)
- usb_serial_put(serial);
- return 0;
- }
- mutex_lock(&port->mutex);
- if (first == 0)
- goto bailout_mutex_unlock;
- /* Undo the initial port actions */
- mutex_lock(&serial->disc_mutex);
-bailout_module_put:
- mutex_unlock(&serial->disc_mutex);
-bailout_mutex_unlock:
- port->port.count = 0;
- mutex_unlock(&port->mutex);
return retval;
}
--
1.6.4.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists