s390/vmlogrdr: fix IUCV buffer allocation

commit 5457e03de918f7a3e294eb9d26a608ab8a579976 upstream.

The buffer for iucv_message_receive() needs to be below 2 GB. In
__iucv_message_receive(), the buffer address is casted to an u32, which
would result in either memory corruption or an addressing exception when
using addresses >= 2 GB.

Fix this by using GFP_DMA for the buffer allocation.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index 524d988..8d2a3c7 100644 (file)
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -876,7 +876,7 @@ static int __init vmlogrdr_init(void)
                goto cleanup;
 
        for (i=0; i < MAXMINOR; ++i ) {
-               sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL);
+               sys_ser[i].buffer = (char *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
                if (!sys_ser[i].buffer) {
                        rc = -ENOMEM;
                        break;