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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc/mm/extable.c
Linux-2.6.12-rc2v2.6.12-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 'arch/sparc/mm/extable.c')
-rw-r--r--arch/sparc/mm/extable.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/sparc/mm/extable.c b/arch/sparc/mm/extable.c
new file mode 100644
index 000000000000..c9845c71f426
--- /dev/null
+++ b/arch/sparc/mm/extable.c
@@ -0,0 +1,77 @@
1/*
2 * linux/arch/sparc/mm/extable.c
3 */
4
5#include <linux/config.h>
6#include <linux/module.h>
7#include <asm/uaccess.h>
8
9void sort_extable(struct exception_table_entry *start,
10 struct exception_table_entry *finish)
11{
12}
13
14/* Caller knows they are in a range if ret->fixup == 0 */
15const struct exception_table_entry *
16search_extable(const struct exception_table_entry *start,
17 const struct exception_table_entry *last,
18 unsigned long value)
19{
20 const struct exception_table_entry *walk;
21
22 /* Single insn entries are encoded as:
23 * word 1: insn address
24 * word 2: fixup code address
25 *
26 * Range entries are encoded as:
27 * word 1: first insn address
28 * word 2: 0
29 * word 3: last insn address + 4 bytes
30 * word 4: fixup code address
31 *
32 * See asm/uaccess.h for more details.
33 */
34
35 /* 1. Try to find an exact match. */
36 for (walk = start; walk <= last; walk++) {
37 if (walk->fixup == 0) {
38 /* A range entry, skip both parts. */
39 walk++;
40 continue;
41 }
42
43 if (walk->insn == value)
44 return walk;
45 }
46
47 /* 2. Try to find a range match. */
48 for (walk = start; walk <= (last - 1); walk++) {
49 if (walk->fixup)
50 continue;
51
52 if (walk[0].insn <= value && walk[1].insn > value)
53 return walk;
54
55 walk++;
56 }
57
58 return NULL;
59}
60
61/* Special extable search, which handles ranges. Returns fixup */
62unsigned long search_extables_range(unsigned long addr, unsigned long *g2)
63{
64 const struct exception_table_entry *entry;
65
66 entry = search_exception_tables(addr);
67 if (!entry)
68 return 0;
69
70 /* Inside range? Fix g2 and return correct fixup */
71 if (!entry->fixup) {
72 *g2 = (addr - entry->insn) / 4;
73 return (entry + 1)->fixup;
74 }
75
76 return entry->fixup;
77}