1/*
2 *  arch/s390/mm/extable.c
3 *
4 *  S390 version
5 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 *    Author(s): Hartmut Penner (hp@de.ibm.com)
7 *
8 *  Derived from "arch/i386/mm/extable.c"
9 */
10
11#include <linux/config.h>
12#include <linux/module.h>
13#include <linux/spinlock.h>
14#include <asm/uaccess.h>
15
16extern const struct exception_table_entry __start___ex_table[];
17extern const struct exception_table_entry __stop___ex_table[];
18
19static inline unsigned long
20search_one_table(const struct exception_table_entry *first,
21		 const struct exception_table_entry *last,
22		 unsigned long value)
23{
24        while (first <= last) {
25		const struct exception_table_entry *mid;
26		long diff;
27
28		mid = (last - first) / 2 + first;
29		diff = mid->insn - value;
30                if (diff == 0)
31                        return mid->fixup;
32                else if (diff < 0)
33                        first = mid+1;
34                else
35                        last = mid-1;
36        }
37        return 0;
38}
39
40extern spinlock_t modlist_lock;
41
42unsigned long
43search_exception_table(unsigned long addr)
44{
45	unsigned long ret = 0;
46	unsigned long flags;
47
48#ifndef CONFIG_MODULES
49	/* There is only the kernel to search.  */
50	ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
51	return ret;
52#else
53	/* The kernel is the last "module" -- no need to treat it special.  */
54	struct module *mp;
55
56	spin_lock_irqsave(&modlist_lock, flags);
57	for (mp = module_list; mp != NULL; mp = mp->next) {
58		if (mp->ex_table_start == NULL || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
59			continue;
60		ret = search_one_table(mp->ex_table_start,
61				       mp->ex_table_end - 1, addr);
62		if (ret)
63			break;
64	}
65	spin_unlock_irqrestore(&modlist_lock, flags);
66	return ret;
67#endif
68}
69