Messages in this thread Patch in this message | | | Date | Wed, 14 Nov 2007 22:45:13 -0800 | From | Greg Kroah-Hartman <> | Subject | [patch 24/40] USB: usbserial - fix potential deadlock between write() and IRQ |
| |
-stable review patch. If anyone has any objections, please let us know.
------------------ From: Jiri Kosina <jkosina@suse.cz>
patch acd2a847e7fee7df11817f67dba75a2802793e5d in mainline.
USB: usbserial - fix potential deadlock between write() and IRQ
usb_serial_generic_write() doesn't disable interrupts when taking port->lock, and could therefore deadlock with usb_serial_generic_read_bulk_callback() being called from interrupt, taking the same lock. Fix it.
Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Larry Finger <larry.finger@lwfinger.net> Cc: Marcin Slusarz <marcin.slusarz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/usb/serial/generic.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -208,14 +208,15 @@ int usb_serial_generic_write(struct usb_ /* only do something if we have a bulk out endpoint */ if (serial->num_bulk_out) { - spin_lock_bh(&port->lock); + unsigned long flags; + spin_lock_irqsave(&port->lock, flags); if (port->write_urb_busy) { - spin_unlock_bh(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); dbg("%s - already writing", __FUNCTION__); return 0; } port->write_urb_busy = 1; - spin_unlock_bh(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); count = (count > port->bulk_out_size) ? port->bulk_out_size : count; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |