From: Jiri Kosina Date: Fri, 19 Oct 2007 22:05:19 +0000 (+0200) Subject: USB: usbserial - fix potential deadlock between write() and IRQ X-Git-Tag: v2.6.24-rc2~136^2~8 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=acd2a847e7fee7df11817f67dba75a2802793e5d;p=linux-2.6 USB: usbserial - fix potential deadlock between write() and IRQ 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 Acked-by: Larry Finger Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 88a2c7dce3..9eb4a65ee4 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -208,14 +208,15 @@ int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char * /* 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;