Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/arch/sparc/mm/extable.c | |
3 | */ | |
4 | ||
1da177e4 LT |
5 | #include <linux/module.h> |
6 | #include <asm/uaccess.h> | |
7 | ||
8 | void sort_extable(struct exception_table_entry *start, | |
9 | struct exception_table_entry *finish) | |
10 | { | |
11 | } | |
12 | ||
13 | /* Caller knows they are in a range if ret->fixup == 0 */ | |
14 | const struct exception_table_entry * | |
15 | search_extable(const struct exception_table_entry *start, | |
16 | const struct exception_table_entry *last, | |
17 | unsigned long value) | |
18 | { | |
19 | const struct exception_table_entry *walk; | |
20 | ||
21 | /* Single insn entries are encoded as: | |
22 | * word 1: insn address | |
23 | * word 2: fixup code address | |
24 | * | |
25 | * Range entries are encoded as: | |
26 | * word 1: first insn address | |
27 | * word 2: 0 | |
28 | * word 3: last insn address + 4 bytes | |
29 | * word 4: fixup code address | |
30 | * | |
ad6561df RR |
31 | * Deleted entries are encoded as: |
32 | * word 1: unused | |
33 | * word 2: -1 | |
34 | * | |
1da177e4 LT |
35 | * See asm/uaccess.h for more details. |
36 | */ | |
37 | ||
38 | /* 1. Try to find an exact match. */ | |
39 | for (walk = start; walk <= last; walk++) { | |
40 | if (walk->fixup == 0) { | |
41 | /* A range entry, skip both parts. */ | |
42 | walk++; | |
43 | continue; | |
44 | } | |
45 | ||
ad6561df RR |
46 | /* A deleted entry; see trim_init_extable */ |
47 | if (walk->fixup == -1) | |
48 | continue; | |
49 | ||
1da177e4 LT |
50 | if (walk->insn == value) |
51 | return walk; | |
52 | } | |
53 | ||
54 | /* 2. Try to find a range match. */ | |
55 | for (walk = start; walk <= (last - 1); walk++) { | |
56 | if (walk->fixup) | |
57 | continue; | |
58 | ||
59 | if (walk[0].insn <= value && walk[1].insn > value) | |
60 | return walk; | |
61 | ||
62 | walk++; | |
63 | } | |
64 | ||
65 | return NULL; | |
66 | } | |
67 | ||
ad6561df RR |
68 | #ifdef CONFIG_MODULES |
69 | /* We could memmove them around; easier to mark the trimmed ones. */ | |
70 | void trim_init_extable(struct module *m) | |
71 | { | |
72 | unsigned int i; | |
73 | bool range; | |
74 | ||
75 | for (i = 0; i < m->num_exentries; i += range ? 2 : 1) { | |
76 | range = m->extable[i].fixup == 0; | |
77 | ||
78 | if (within_module_init(m->extable[i].insn, m)) { | |
79 | m->extable[i].fixup = -1; | |
80 | if (range) | |
81 | m->extable[i+1].fixup = -1; | |
82 | } | |
83 | if (range) | |
84 | i++; | |
85 | } | |
86 | } | |
87 | #endif /* CONFIG_MODULES */ | |
88 | ||
1da177e4 LT |
89 | /* Special extable search, which handles ranges. Returns fixup */ |
90 | unsigned long search_extables_range(unsigned long addr, unsigned long *g2) | |
91 | { | |
92 | const struct exception_table_entry *entry; | |
93 | ||
94 | entry = search_exception_tables(addr); | |
95 | if (!entry) | |
96 | return 0; | |
97 | ||
98 | /* Inside range? Fix g2 and return correct fixup */ | |
99 | if (!entry->fixup) { | |
100 | *g2 = (addr - entry->insn) / 4; | |
101 | return (entry + 1)->fixup; | |
102 | } | |
103 | ||
104 | return entry->fixup; | |
105 | } |