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/arch/sparc64/mm/extable.c

https://bitbucket.org/evzijst/gittest
C | 80 lines | 44 code | 15 blank | 21 comment | 11 complexity | d5faa1514bd4da3c65cb946ce81a08fd MD5 | raw file
 1/*
 2 * linux/arch/sparc64/mm/extable.c
 3 */
 4
 5#include <linux/config.h>
 6#include <linux/module.h>
 7#include <asm/uaccess.h>
 8
 9extern const struct exception_table_entry __start___ex_table[];
10extern const struct exception_table_entry __stop___ex_table[];
11
12void sort_extable(struct exception_table_entry *start,
13		  struct exception_table_entry *finish)
14{
15}
16
17/* Caller knows they are in a range if ret->fixup == 0 */
18const struct exception_table_entry *
19search_extable(const struct exception_table_entry *start,
20	       const struct exception_table_entry *last,
21	       unsigned long value)
22{
23	const struct exception_table_entry *walk;
24
25	/* Single insn entries are encoded as:
26	 *	word 1:	insn address
27	 *	word 2:	fixup code address
28	 *
29	 * Range entries are encoded as:
30	 *	word 1: first insn address
31	 *	word 2: 0
32	 *	word 3: last insn address + 4 bytes
33	 *	word 4: fixup code address
34	 *
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
46		if (walk->insn == value)
47			return walk;
48	}
49
50	/* 2. Try to find a range match. */
51	for (walk = start; walk <= (last - 1); walk++) {
52		if (walk->fixup)
53			continue;
54
55		if (walk[0].insn <= value && walk[1].insn > value)
56			return walk;
57
58		walk++;
59	}
60
61        return NULL;
62}
63
64/* Special extable search, which handles ranges.  Returns fixup */
65unsigned long search_extables_range(unsigned long addr, unsigned long *g2)
66{
67	const struct exception_table_entry *entry;
68
69	entry = search_exception_tables(addr);
70	if (!entry)
71		return 0;
72
73	/* Inside range?  Fix g2 and return correct fixup */
74	if (!entry->fixup) {
75		*g2 = (addr - entry->insn) / 4;
76		return (entry + 1)->fixup;
77	}
78
79	return entry->fixup;
80}