3 * Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c.
5 * Copyright (C) 2004 Paul Mackerras, IBM Corp.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <linux/config.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <asm/uaccess.h>
18 extern struct exception_table_entry __start___ex_table[];
19 extern struct exception_table_entry __stop___ex_table[];
21 #ifndef ARCH_HAS_SORT_EXTABLE
23 * The exception table needs to be sorted so that the binary
24 * search that we use to find entries in it works properly.
25 * This is used both for the kernel exception table and for
26 * the exception tables of modules that get loaded.
28 void sort_extable(struct exception_table_entry *start,
29 struct exception_table_entry *finish)
31 struct exception_table_entry el, *p, *q;
34 for (p = start + 1; p < finish; ++p) {
35 /* start .. p-1 is sorted */
36 if (p[0].insn < p[-1].insn) {
37 /* move element p down to its right place */
41 /* el comes before q[-1], move q[-1] up one */
44 } while (q > start && el.insn < q[-1].insn);
51 #ifndef ARCH_HAS_SEARCH_EXTABLE
53 * Search one exception table for an entry corresponding to the
54 * given instruction address, and return the address of the entry,
55 * or NULL if none is found.
56 * We use a binary search, and thus we assume that the table is
59 const struct exception_table_entry *
60 search_extable(const struct exception_table_entry *first,
61 const struct exception_table_entry *last,
64 while (first <= last) {
65 const struct exception_table_entry *mid;
67 mid = (last - first) / 2 + first;
69 * careful, the distance between entries can be
72 if (mid->insn < value)
74 else if (mid->insn > value)