iommu/vt-d: Fix QI_DEV_IOTLB_PFSID and QI_DEV_EIOTLB_PFSID macros

[linux-2.6-microblaze.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index bcdf531..55af693 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2561,7 +2561,35 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
        return 0;
 }
 
-static bool clone3_args_valid(const struct kernel_clone_args *kargs)
+/**
+ * clone3_stack_valid - check and prepare stack
+ * @kargs: kernel clone args
+ *
+ * Verify that the stack arguments userspace gave us are sane.
+ * In addition, set the stack direction for userspace since it's easy for us to
+ * determine.
+ */
+static inline bool clone3_stack_valid(struct kernel_clone_args *kargs)
+{
+       if (kargs->stack == 0) {
+               if (kargs->stack_size > 0)
+                       return false;
+       } else {
+               if (kargs->stack_size == 0)
+                       return false;
+
+               if (!access_ok((void __user *)kargs->stack, kargs->stack_size))
+                       return false;
+
+#if !defined(CONFIG_STACK_GROWSUP) && !defined(CONFIG_IA64)
+               kargs->stack += kargs->stack_size;
+#endif
+       }
+
+       return true;
+}
+
+static bool clone3_args_valid(struct kernel_clone_args *kargs)
 {
        /*
         * All lower bits of the flag word are taken.
@@ -2581,6 +2609,9 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
            kargs->exit_signal)
                return false;
 
+       if (!clone3_stack_valid(kargs))
+               return false;
+
        return true;
 }