diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /lib/extable.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'lib/extable.c')
-rw-r--r-- | lib/extable.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/extable.c b/lib/extable.c new file mode 100644 index 00000000000..3f677a8f0c3 --- /dev/null +++ b/lib/extable.c | |||
@@ -0,0 +1,79 @@ | |||
1 | /* | ||
2 | * lib/extable.c | ||
3 | * Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c. | ||
4 | * | ||
5 | * Copyright (C) 2004 Paul Mackerras, IBM Corp. | ||
6 | * | ||
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. | ||
11 | */ | ||
12 | |||
13 | #include <linux/config.h> | ||
14 | #include <linux/module.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/sort.h> | ||
17 | #include <asm/uaccess.h> | ||
18 | |||
19 | extern struct exception_table_entry __start___ex_table[]; | ||
20 | extern struct exception_table_entry __stop___ex_table[]; | ||
21 | |||
22 | #ifndef ARCH_HAS_SORT_EXTABLE | ||
23 | /* | ||
24 | * The exception table needs to be sorted so that the binary | ||
25 | * search that we use to find entries in it works properly. | ||
26 | * This is used both for the kernel exception table and for | ||
27 | * the exception tables of modules that get loaded. | ||
28 | */ | ||
29 | static int cmp_ex(const void *a, const void *b) | ||
30 | { | ||
31 | const struct exception_table_entry *x = a, *y = b; | ||
32 | |||
33 | /* avoid overflow */ | ||
34 | if (x->insn > y->insn) | ||
35 | return 1; | ||
36 | if (x->insn < y->insn) | ||
37 | return -1; | ||
38 | return 0; | ||
39 | } | ||
40 | |||
41 | void sort_extable(struct exception_table_entry *start, | ||
42 | struct exception_table_entry *finish) | ||
43 | { | ||
44 | sort(start, finish - start, sizeof(struct exception_table_entry), | ||
45 | cmp_ex, NULL); | ||
46 | } | ||
47 | #endif | ||
48 | |||
49 | #ifndef ARCH_HAS_SEARCH_EXTABLE | ||
50 | /* | ||
51 | * Search one exception table for an entry corresponding to the | ||
52 | * given instruction address, and return the address of the entry, | ||
53 | * or NULL if none is found. | ||
54 | * We use a binary search, and thus we assume that the table is | ||
55 | * already sorted. | ||
56 | */ | ||
57 | const struct exception_table_entry * | ||
58 | search_extable(const struct exception_table_entry *first, | ||
59 | const struct exception_table_entry *last, | ||
60 | unsigned long value) | ||
61 | { | ||
62 | while (first <= last) { | ||
63 | const struct exception_table_entry *mid; | ||
64 | |||
65 | mid = (last - first) / 2 + first; | ||
66 | /* | ||
67 | * careful, the distance between entries can be | ||
68 | * larger than 2GB: | ||
69 | */ | ||
70 | if (mid->insn < value) | ||
71 | first = mid + 1; | ||
72 | else if (mid->insn > value) | ||
73 | last = mid - 1; | ||
74 | else | ||
75 | return mid; | ||
76 | } | ||
77 | return NULL; | ||
78 | } | ||
79 | #endif | ||