--- /dev/null
+/*
+ * Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c.
+ *
+ * Copyright (C) 2004 Paul Mackerras, IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <lwk/init.h>
+#include <lwk/sort.h>
+#include <lwk/extable.h>
+
+#ifndef ARCH_HAS_SORT_EXTABLE
+/*
+ * The exception table needs to be sorted so that the binary
+ * search that we use to find entries in it works properly.
+ * This is used both for the kernel exception table and for
+ * the exception tables of modules that get loaded.
+ */
+static int cmp_ex(const void *a, const void *b)
+{
+ const struct exception_table_entry *x = a, *y = b;
+
+ /* avoid overflow */
+ if (x->insn > y->insn)
+ return 1;
+ if (x->insn < y->insn)
+ return -1;
+ return 0;
+}
+
+void sort_extable(struct exception_table_entry *start,
+ struct exception_table_entry *finish)
+{
+ sort(start, finish - start, sizeof(struct exception_table_entry),
+ cmp_ex, NULL);
+}
+#endif
+
+#ifndef ARCH_HAS_SEARCH_EXTABLE
+/*
+ * Search one exception table for an entry corresponding to the
+ * given instruction address, and return the address of the entry,
+ * or NULL if none is found.
+ * We use a binary search, and thus we assume that the table is
+ * already sorted.
+ */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *first,
+ const struct exception_table_entry *last,
+ unsigned long value)
+{
+ while (first <= last) {
+ const struct exception_table_entry *mid;
+
+ mid = (last - first) / 2 + first;
+ /*
+ * careful, the distance between entries can be
+ * larger than 2GB:
+ */
+ if (mid->insn < value)
+ first = mid + 1;
+ else if (mid->insn > value)
+ last = mid - 1;
+ else
+ return mid;
+ }
+ return NULL;
+}
+#endif
