From 3368ba25bf387109b24732c1e270c628f20e345d Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 5 Sep 2012 14:20:41 +0200 Subject: [PATCH] s390/cio: invalidate cdev pointer before deregistration Make sure that the cdev pointer for IO subchannels is set to NULL when we deregister the device (and release its last reference). This will fix a bug were another process operates on an already freed ccw device. Acked-by: Peter Oberparleiter Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index e8e1a108cdf..fc916f5d731 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -1521,11 +1521,14 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process) goto out; break; case IO_SCH_UNREG_ATTACH: + spin_lock_irqsave(sch->lock, flags); if (cdev->private->flags.resuming) { /* Device will be handled later. */ rc = 0; - goto out; + goto out_unlock; } + sch_set_cdev(sch, NULL); + spin_unlock_irqrestore(sch->lock, flags); /* Unregister ccw device. */ ccw_device_unregister(cdev); break;