[PATCH 3.10 075/268] s390/vmlogrdr: fix IUCV buffer allocation

Willy Tarreau
2017-06-19T18:35:10Z

From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

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: Willy Tarreau <w@1wt.eu>
---
drivers/s390/char/vmlogrdr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index 9b3a24e..5e41e84 100644
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -873,7 +873,7 @@ 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;
--
2.8.0.rc2.1.gbe9624a