ARM: 7326/2: PL330: fix null pointer dereference in pl330_chan_ctrl()

This fixes the thrd->req_running field being accessed before thrd
is checked for null. The error was introduced in

   abb959f: ARM: 7237/1: PL330: Fix driver freeze

Reference: <1326458191-23492-1-git-send-email-mans.rullgard@linaro.org>

Cc: stable@kernel.org
Signed-off-by: Mans Rullgard <mans.rullgard@linaro.org>
Acked-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/arm/common/pl330.c b/arch/arm/common/pl330.c
index d8e44a43047c..ff3ad2244824 100644
--- a/arch/arm/common/pl330.c
+++ b/arch/arm/common/pl330.c
@@ -1502,12 +1502,13 @@ int pl330_chan_ctrl(void *ch_id, enum pl330_chan_op op)
         struct pl330_thread *thrd = ch_id;
         struct pl330_dmac *pl330;
         unsigned long flags;
-        int ret = 0, active = thrd->req_running;
+        int ret = 0, active;
 
         if (!thrd || thrd->free || thrd->dmac->state == DYING)
                 return -EINVAL;
 
         pl330 = thrd->dmac;
+        active = thrd->req_running;
 
         spin_lock_irqsave(&pl330->lock, flags);