1 files changed, 71 insertions, 0 deletions
diff --git a/arch/sparc/lib/user_fixup.c b/arch/sparc/lib/user_fixup.c
new file mode 100644
index 00000000000..ac96ae23670
--- /dev/null
+++ b/arch/sparc/lib/user_fixup.c
@@ -0,0 +1,71 @@
+/* user_fixup.c: Fix up user copy faults.
+ *
+ * Copyright (C) 2004 David S. Miller <davem@redhat.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+
+#include <asm/uaccess.h>
+
+/* Calculating the exact fault address when using
+ * block loads and stores can be very complicated.
+ *
+ * Instead of trying to be clever and handling all
+ * of the cases, just fix things up simply here.
+ */
+
+static unsigned long compute_size(unsigned long start, unsigned long size, unsigned long *offset)
+{
+	unsigned long fault_addr = current_thread_info()->fault_address;
+	unsigned long end = start + size;
+
+	if (fault_addr < start || fault_addr >= end) {
+		*offset = 0;
+	} else {
+		*offset = fault_addr - start;
+		size = end - fault_addr;
+	}
+	return size;
+}
+
+unsigned long copy_from_user_fixup(void *to, const void __user *from, unsigned long size)
+{
+	unsigned long offset;
+
+	size = compute_size((unsigned long) from, size, &offset);
+	if (likely(size))
+		memset(to + offset, 0, size);
+
+	return size;
+}
+EXPORT_SYMBOL(copy_from_user_fixup);
+
+unsigned long copy_to_user_fixup(void __user *to, const void *from, unsigned long size)
+{
+	unsigned long offset;
+
+	return compute_size((unsigned long) to, size, &offset);
+}
+EXPORT_SYMBOL(copy_to_user_fixup);
+
+unsigned long copy_in_user_fixup(void __user *to, void __user *from, unsigned long size)
+{
+	unsigned long fault_addr = current_thread_info()->fault_address;
+	unsigned long start = (unsigned long) to;
+	unsigned long end = start + size;
+
+	if (fault_addr >= start && fault_addr < end)
+		return end - fault_addr;
+
+	start = (unsigned long) from;
+	end = start + size;
+	if (fault_addr >= start && fault_addr < end)
+		return end - fault_addr;
+
+	return size;
+}
+EXPORT_SYMBOL(copy_in_user_fixup);