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| author | Jiri Kosina <jkosina@suse.cz> | 2007-10-20 00:05:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-11-16 09:30:23 -0800 |
| commit | 70ad1f56fd045f830191956fbf25058733d40b96 (patch) | |
| tree | 47afe07068f521720b2c1b21d50517840d343a37 | |
| parent | 4b4257111c971458a73e21821d437bf130966cd9 (diff) | |
| download | lwn-70ad1f56fd045f830191956fbf25058733d40b96.tar.gz lwn-70ad1f56fd045f830191956fbf25058733d40b96.zip | |
USB: usbserial - fix potential deadlock between write() and IRQ
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>
| -rw-r--r-- | drivers/usb/serial/generic.c | 7 |
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; |