um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held

since GFP_KERNEL with GFP_ATOMIC while spinlock is held,
as code while holding a spinlock should be atomic.
GFP_KERNEL may sleep and can cause deadlock,
where as GFP_ATOMIC may fail but certainly avoids deadlockdex f70dd54..d898f6c 100644

Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 9 insertions, 8 deletions

diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index f70dd540655d..9ef669d24bb2 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -388,7 +388,7 @@ static const struct net_device_ops uml_netdev_ops = {
 static int driver_registered;
 
 static void eth_configure(int n, void *init, char *mac,
-                          struct transport *transport)
+                          struct transport *transport, gfp_t gfp_mask)
 {
         struct uml_net *device;
         struct net_device *dev;
@@ -397,7 +397,7 @@ static void eth_configure(int n, void *init, char *mac,
 
         size = transport->private_size + sizeof(struct uml_net_private);
 
-        device = kzalloc(sizeof(*device), GFP_KERNEL);
+        device = kzalloc(sizeof(*device), gfp_mask);
         if (device == NULL) {
                 printk(KERN_ERR "eth_configure failed to allocate struct "
                        "uml_net\n");
@@ -568,7 +568,7 @@ static LIST_HEAD(transports);
 static LIST_HEAD(eth_cmd_line);
 
 static int check_transport(struct transport *transport, char *eth, int n,
-                           void **init_out, char **mac_out)
+                           void **init_out, char **mac_out, gfp_t gfp_mask)
 {
         int len;
 
@@ -582,7 +582,7 @@ static int check_transport(struct transport *transport, char *eth, int n,
         else if (*eth != '\0')
                 return 0;
 
-        *init_out = kmalloc(transport->setup_size, GFP_KERNEL);
+        *init_out = kmalloc(transport->setup_size, gfp_mask);
         if (*init_out == NULL)
                 return 1;
 
@@ -609,11 +609,11 @@ void register_transport(struct transport *new)
         list_for_each_safe(ele, next, &eth_cmd_line) {
                 eth = list_entry(ele, struct eth_init, list);
                 match = check_transport(new, eth->init, eth->index, &init,
-                                        &mac);
+                                        &mac, GFP_KERNEL);
                 if (!match)
                         continue;
                 else if (init != NULL) {
-                        eth_configure(eth->index, init, mac, new);
+                        eth_configure(eth->index, init, mac, new, GFP_KERNEL);
                         kfree(init);
                 }
                 list_del(&eth->list);
@@ -631,10 +631,11 @@ static int eth_setup_common(char *str, int index)
         spin_lock(&transports_lock);
         list_for_each(ele, &transports) {
                 transport = list_entry(ele, struct transport, list);
-                if (!check_transport(transport, str, index, &init, &mac))
+                if (!check_transport(transport, str, index, &init,
+                                        &mac, GFP_ATOMIC))
                         continue;
                 if (init != NULL) {
-                        eth_configure(index, init, mac, transport);
+                        eth_configure(index, init, mac, transport, GFP_ATOMIC);
                         kfree(init);
                 }
                 found = 1;