1 files changed, 19 insertions, 0 deletions
diff --git a/arch/um/kernel/maccess.c b/arch/um/kernel/maccess.c
new file mode 100644
index 0000000000..8ccd56813f
--- /dev/null
+++ b/arch/um/kernel/maccess.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
+ */
+
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+#include <os.h>
+
+bool copy_from_kernel_nofault_allowed(const void *src, size_t size)
+{
+	void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
+
+	if ((unsigned long)src < PAGE_SIZE || size <= 0)
+		return false;
+	if (os_mincore(psrc, size + src - psrc) <= 0)
+		return false;
+	return true;
+}