powerpc/iseries: Initialise on-stack completion

get_viotape_info() declares a vio_waitevent on the stack, which
contains a completion, but never initialises the completion.

I have no idea how this ever worked, and on recent kernels it causes
an oops in handle_tape_event() when we access the non-initialised
completion.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/iseries/vio.c b/arch/powerpc/platforms/iseries/vio.c
index 657b72f68493..2aa8b5631beb 100644
--- a/arch/powerpc/platforms/iseries/vio.c
+++ b/arch/powerpc/platforms/iseries/vio.c
@@ -474,6 +474,8 @@ static void __init get_viotape_info(struct device_node *vio_root)
         struct vio_waitevent we;
         int ret;
 
+        init_completion(&we.com);
+
         ret = viopath_open(viopath_hostLp, viomajorsubtype_tape, 2);
         if (ret) {
                 printk(KERN_WARNING "get_viotape_info: "