s390/qeth: use vzalloc for QUERY OAT buffer

qeth_query_oat_command() currently allocates the kernel buffer for
the SIOC_QETH_QUERY_OAT ioctl with kzalloc. So on systems with
fragmented memory, large allocations may fail (eg. the qethqoat tool by
default uses 132KB).

Solve this issue by using vzalloc, backing the allocation with
non-contiguous memory.

Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index b60055e9cb1a64bd3fcb1f50fbb5028b2a447f09..de8282420f966f0d0f984c72868d9ebddcf11207 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -25,6 +25,7 @@
 #include <linux/netdevice.h>
 #include <linux/netdev_features.h>
 #include <linux/skbuff.h>
+#include <linux/vmalloc.h>
 
 #include <net/iucv/af_iucv.h>
 #include <net/dsfield.h>
@@ -4699,7 +4700,7 @@ static int qeth_query_oat_command(struct qeth_card *card, char __user *udata)
 
        priv.buffer_len = oat_data.buffer_len;
        priv.response_len = 0;
-       priv.buffer =  kzalloc(oat_data.buffer_len, GFP_KERNEL);
+       priv.buffer = vzalloc(oat_data.buffer_len);
        if (!priv.buffer) {
                rc = -ENOMEM;
                goto out;
@@ -4740,7 +4741,7 @@ static int qeth_query_oat_command(struct qeth_card *card, char __user *udata)
                        rc = -EFAULT;
 
 out_free:
-       kfree(priv.buffer);
+       vfree(priv.buffer);
 out:
        return rc;
 }