This is a note to let you know that I've just added the patch titled
USB: mos7840: fix race in led handling
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-mos7840-fix-race-in-led-handling.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 05cf0dec5ccc696a7636c84b265b477173498156 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@xxxxxxxxx>
Date: Fri, 26 Jul 2013 11:55:19 +0200
Subject: USB: mos7840: fix race in led handling
From: Johan Hovold <jhovold@xxxxxxxxx>
commit 05cf0dec5ccc696a7636c84b265b477173498156 upstream.
Fix race in LED handling introduced by commit 0eafe4de ("USB: serial:
mos7840: add support for MCS7810 devices") which reused the port control
urb for manipulating the LED without making sure that the urb is not
already in use. This could lead to the control urb being manipulated
while in flight.
Fix by adding a dedicated LED urb and ctrlrequest along with a LED-busy
flag to handle concurrency.
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/serial/mos7840.c | 59 ++++++++++++++++++++++++++-----------------
1 file changed, 37 insertions(+), 22 deletions(-)
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -185,6 +185,7 @@
enum mos7840_flag {
MOS7840_FLAG_CTRL_BUSY,
+ MOS7840_FLAG_LED_BUSY,
};
static const struct usb_device_id id_table[] = {
@@ -240,9 +241,10 @@ struct moschip_port {
/* For device(s) with LED indicator */
bool has_led;
- bool led_flag;
struct timer_list led_timer1; /* Timer for LED on */
struct timer_list led_timer2; /* Timer for LED off */
+ struct urb *led_urb;
+ struct usb_ctrlrequest *led_dr;
unsigned long flags;
};
@@ -542,7 +544,7 @@ static void mos7840_set_led_async(struct
__u16 reg)
{
struct usb_device *dev = mcs->port->serial->dev;
- struct usb_ctrlrequest *dr = mcs->dr;
+ struct usb_ctrlrequest *dr = mcs->led_dr;
dr->bRequestType = MCS_WR_RTYPE;
dr->bRequest = MCS_WRREQ;
@@ -550,10 +552,10 @@ static void mos7840_set_led_async(struct
dr->wIndex = cpu_to_le16(reg);
dr->wLength = cpu_to_le16(0);
- usb_fill_control_urb(mcs->control_urb, dev, usb_sndctrlpipe(dev, 0),
+ usb_fill_control_urb(mcs->led_urb, dev, usb_sndctrlpipe(dev, 0),
(unsigned char *)dr, NULL, 0, mos7840_set_led_callback, NULL);
- usb_submit_urb(mcs->control_urb, GFP_ATOMIC);
+ usb_submit_urb(mcs->led_urb, GFP_ATOMIC);
}
static void mos7840_set_led_sync(struct usb_serial_port *port, __u16 reg,
@@ -579,7 +581,19 @@ static void mos7840_led_flag_off(unsigne
{
struct moschip_port *mcs = (struct moschip_port *) arg;
- mcs->led_flag = false;
+ clear_bit_unlock(MOS7840_FLAG_LED_BUSY, &mcs->flags);
+}
+
+static void mos7840_led_activity(struct usb_serial_port *port)
+{
+ struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
+
+ if (test_and_set_bit_lock(MOS7840_FLAG_LED_BUSY, &mos7840_port->flags))
+ return;
+
+ mos7840_set_led_async(mos7840_port, 0x0301, MODEM_CONTROL_REGISTER);
+ mod_timer(&mos7840_port->led_timer1,
+ jiffies + msecs_to_jiffies(LED_ON_MS));
}
/*****************************************************************************
@@ -779,14 +793,8 @@ static void mos7840_bulk_in_callback(str
return;
}
- /* Turn on LED */
- if (mos7840_port->has_led && !mos7840_port->led_flag) {
- mos7840_port->led_flag = true;
- mos7840_set_led_async(mos7840_port, 0x0301,
- MODEM_CONTROL_REGISTER);
- mod_timer(&mos7840_port->led_timer1,
- jiffies + msecs_to_jiffies(LED_ON_MS));
- }
+ if (mos7840_port->has_led)
+ mos7840_led_activity(port);
mos7840_port->read_urb_busy = true;
retval = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
@@ -1467,13 +1475,8 @@ static int mos7840_write(struct tty_stru
data1 = urb->transfer_buffer;
dev_dbg(&port->dev, "bulkout endpoint is %d\n", port->bulk_out_endpointAddress);
- /* Turn on LED */
- if (mos7840_port->has_led && !mos7840_port->led_flag) {
- mos7840_port->led_flag = true;
- mos7840_set_led_sync(port, MODEM_CONTROL_REGISTER, 0x0301);
- mod_timer(&mos7840_port->led_timer1,
- jiffies + msecs_to_jiffies(LED_ON_MS));
- }
+ if (mos7840_port->has_led)
+ mos7840_led_activity(port);
/* send it down the pipe */
status = usb_submit_urb(urb, GFP_ATOMIC);
@@ -2429,6 +2432,14 @@ static int mos7840_port_probe(struct usb
if (device_type == MOSCHIP_DEVICE_ID_7810) {
mos7840_port->has_led = true;
+ mos7840_port->led_urb = usb_alloc_urb(0, GFP_KERNEL);
+ mos7840_port->led_dr = kmalloc(sizeof(*mos7840_port->led_dr),
+ GFP_KERNEL);
+ if (!mos7840_port->led_urb || !mos7840_port->led_dr) {
+ status = -ENOMEM;
+ goto error;
+ }
+
init_timer(&mos7840_port->led_timer1);
mos7840_port->led_timer1.function = mos7840_led_off;
mos7840_port->led_timer1.expires =
@@ -2441,8 +2452,6 @@ static int mos7840_port_probe(struct usb
jiffies + msecs_to_jiffies(LED_OFF_MS);
mos7840_port->led_timer2.data = (unsigned long)mos7840_port;
- mos7840_port->led_flag = false;
-
/* Turn off LED */
mos7840_set_led_sync(port, MODEM_CONTROL_REGISTER, 0x0300);
}
@@ -2464,6 +2473,8 @@ out:
}
return 0;
error:
+ kfree(mos7840_port->led_dr);
+ usb_free_urb(mos7840_port->led_urb);
kfree(mos7840_port->dr);
kfree(mos7840_port->ctrl_buf);
usb_free_urb(mos7840_port->control_urb);
@@ -2484,6 +2495,10 @@ static int mos7840_port_remove(struct us
del_timer_sync(&mos7840_port->led_timer1);
del_timer_sync(&mos7840_port->led_timer2);
+
+ usb_kill_urb(mos7840_port->led_urb);
+ usb_free_urb(mos7840_port->led_urb);
+ kfree(mos7840_port->led_dr);
}
usb_kill_urb(mos7840_port->control_urb);
usb_free_urb(mos7840_port->control_urb);
Patches currently in stable-queue which might be from jhovold@xxxxxxxxx are
queue-3.10/usb-mos7840-fix-device-type-detection.patch
queue-3.10/usb-mos7840-fix-pointer-casts.patch
queue-3.10/usb-mos7840-fix-race-in-register-handling.patch
queue-3.10/usb-mos7840-fix-race-in-led-handling.patch
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