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Commit 3368e547 authored by Cornelia Huck's avatar Cornelia Huck Committed by Martin Schwidefsky
Browse files

vfio: ccw: process ssch with interrupts disabled 



When we call ssch, an interrupt might already be pending once we
return from the START SUBCHANNEL instruction. Therefore we need to
make sure interrupts are disabled while holding the subchannel lock
until after we're done with our processing.

Cc: stable@vger.kernel.org #v4.12+
Reviewed-by: default avatarDong Jia Shi <bjsdjshi@linux.ibm.com>
Acked-by: default avatarHalil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 2317b07d

drivers/s390/cio/vfio_ccw_fsm.c

+12 −7
Original line number Diff line number Diff line
@@ -20,12 +20,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private) 
	int ccode;

	__u8 lpm;

	unsigned long flags;

	int ret;



	sch = private->sch;



	spin_lock_irqsave(sch->lock, flags);

	private->state = VFIO_CCW_STATE_BUSY;

	spin_unlock_irqrestore(sch->lock, flags);



	orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);
@@ -38,10 +38,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private) 
		 * Initialize device status information

		 */

		sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;

		return 0;

		ret = 0;

		break;

	case 1:		/* Status pending */

	case 2:		/* Busy */

		return -EBUSY;

		ret = -EBUSY;

		break;

	case 3:		/* Device/path not operational */

	{

		lpm = orb->cmd.lpm;
@@ -51,13 +53,16 @@ static int fsm_io_helper(struct vfio_ccw_private *private) 
			sch->lpm = 0;



		if (cio_update_schib(sch))

			return -ENODEV;



		return sch->lpm ? -EACCES : -ENODEV;

			ret = -ENODEV;

		else

			ret = sch->lpm ? -EACCES : -ENODEV;

		break;

	}

	default:

		return ccode;

		ret = ccode;

	}

	spin_unlock_irqrestore(sch->lock, flags);

	return ret;

}



static void fsm_notoper(struct vfio_ccw_private *private,