1 files changed, 84 insertions, 0 deletions
diff --git a/arch/sh/mm/extable_64.c b/arch/sh/mm/extable_64.c
new file mode 100644
index 000000000..7a3b4d33d
--- /dev/null
+++ b/arch/sh/mm/extable_64.c
@@ -0,0 +1,84 @@
+/*
+ * arch/sh/mm/extable_64.c
+ *
+ * Copyright (C) 2003 Richard Curnow
+ * Copyright (C) 2003, 2004  Paul Mundt
+ *
+ * Cloned from the 2.5 SH version..
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/bsearch.h>
+#include <linux/rwsem.h>
+#include <linux/extable.h>
+#include <linux/uaccess.h>
+
+extern unsigned long copy_user_memcpy, copy_user_memcpy_end;
+extern void __copy_user_fixup(void);
+
+static const struct exception_table_entry __copy_user_fixup_ex = {
+	.fixup = (unsigned long)&__copy_user_fixup,
+};
+
+/*
+ * Some functions that may trap due to a bad user-mode address have too
+ * many loads and stores in them to make it at all practical to label
+ * each one and put them all in the main exception table.
+ *
+ * In particular, the fast memcpy routine is like this.  It's fix-up is
+ * just to fall back to a slow byte-at-a-time copy, which is handled the
+ * conventional way.  So it's functionally OK to just handle any trap
+ * occurring in the fast memcpy with that fixup.
+ */
+static const struct exception_table_entry *check_exception_ranges(unsigned long addr)
+{
+	if ((addr >= (unsigned long)&copy_user_memcpy) &&
+	    (addr <= (unsigned long)&copy_user_memcpy_end))
+		return &__copy_user_fixup_ex;
+
+	return NULL;
+}
+
+static int cmp_ex_search(const void *key, const void *elt)
+{
+	const struct exception_table_entry *_elt = elt;
+	unsigned long _key = *(unsigned long *)key;
+
+	/* avoid overflow */
+	if (_key > _elt->insn)
+		return 1;
+	if (_key < _elt->insn)
+		return -1;
+	return 0;
+}
+
+/* Simple binary search */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *base,
+		 const size_t num,
+		 unsigned long value)
+{
+	const struct exception_table_entry *mid;
+
+	mid = check_exception_ranges(value);
+	if (mid)
+		return mid;
+
+	return bsearch(&value, base, num,
+		       sizeof(struct exception_table_entry), cmp_ex_search);
+}
+
+int fixup_exception(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+
+	fixup = search_exception_tables(regs->pc);
+	if (fixup) {
+		regs->pc = fixup->fixup;
+		return 1;
+	}
+
+	return 0;
+}