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authorJiri Kosina <jkosina@suse.cz>2007-10-20 00:05:19 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2007-10-25 21:18:45 +0200
commitacd2a847e7fee7df11817f67dba75a2802793e5d (patch)
tree7eba6fe6c15f5f11ffdec779c9979f1ec6b4c6b9
parentusb: serial/pl2303: support for IO Data Device RSAQ5 (diff)
downloadlinux-acd2a847e7fee7df11817f67dba75a2802793e5d.tar.xz
linux-acd2a847e7fee7df11817f67dba75a2802793e5d.zip
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 <jkosina@suse.cz> Acked-by: Larry Finger <larry.finger@lwfinger.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/serial/generic.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 88a2c7dce335..9eb4a65ee4d9 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;