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
16 extern const struct exception_table_entry __start___ex_table[];
17 extern const struct exception_table_entry __stop___ex_table[];
18
19 static inline unsigned long
search_one_table(const struct exception_table_entry * first,const struct exception_table_entry * last,unsigned long value)20 search_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
40 extern spinlock_t modlist_lock;
41
42 unsigned long
search_exception_table(unsigned long addr)43 search_exception_table(unsigned long addr)
44 {
45 unsigned long ret = 0;
46 unsigned long flags;
47
48 #ifndef CONFIG_MODULES
49 addr &= 0x7fffffff; /* remove amode bit from address */
50 /* There is only the kernel to search. */
51 ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
52 if (ret) ret = FIX_PSW(ret);
53 return ret;
54 #else
55 /* The kernel is the last "module" -- no need to treat it special. */
56 struct module *mp;
57 addr &= 0x7fffffff; /* remove amode bit from address */
58
59 spin_lock_irqsave(&modlist_lock, flags);
60 for (mp = module_list; mp != NULL; mp = mp->next) {
61 if (mp->ex_table_start == NULL || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
62 continue;
63 ret = search_one_table(mp->ex_table_start,
64 mp->ex_table_end - 1, addr);
65 if (ret) {
66 ret = FIX_PSW(ret);
67 break;
68 }
69 }
70 spin_unlock_irqrestore(&modlist_lock, flags);
71 return ret;
72 #endif
73 }
74