[PATCH 12 of 33] IB/ipath - fix bad argument to clear_bit that trashed memory and/or crashed

["Bryan O'Sullivan" <bos@pathscale.com>]

# HG changeset patch
# User Bryan O'Sullivan <bos@pathscale.com>
# Date 1173994465 25200
# Node ID 84a9691cf7ff54ce76de402d2353a451ba9c555b
# Parent  c793dc8a526564b73018924a707bcb21052f8f36
IB/ipath - fix bad argument to clear_bit that trashed memory and/or crashed

Code was converted from a &= ~mask to clear_bit, but the bit was left shifted
instead of being used directly, so we were either trashing memory several
pages away, or sometimes taking a kernel page fault on an invalid page.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>

diff -r c793dc8a5265 -r 84a9691cf7ff drivers/infiniband/hw/ipath/ipath_intr.c
--- a/drivers/infiniband/hw/ipath/ipath_intr.c	Thu Mar 15 14:34:24 2007 -0700
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c	Thu Mar 15 14:34:25 2007 -0700
@@ -842,11 +842,10 @@ static void handle_urcv(struct ipath_dev
 		struct ipath_portdata *pd = dd->ipath_pd[i];
 		if (portr & (1 << i) && pd && pd->port_cnt &&
 			test_bit(IPATH_PORT_WAITING_RCV, &pd->port_flag)) {
-			int rcbit;
 			clear_bit(IPATH_PORT_WAITING_RCV,
 				  &pd->port_flag);
-			rcbit = i + INFINIPATH_R_INTRAVAIL_SHIFT;
-			clear_bit(1UL << rcbit, &dd->ipath_rcvctrl);
+			clear_bit(i + INFINIPATH_R_INTRAVAIL_SHIFT,
+				  &dd->ipath_rcvctrl);
 			wake_up_interruptible(&pd->port_wait);
 			rcvdint = 1;
 		}