Blame view

kernel/linux-imx6_3.14.28/arch/s390/mm/extable.c 2.12 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
  #include <linux/module.h>
  #include <linux/sort.h>
  #include <asm/uaccess.h>
  
  /*
   * Search one exception table for an entry corresponding to the
   * given instruction address, and return the address of the entry,
   * or NULL if none is found.
   * We use a binary search, and thus we assume that the table is
   * already sorted.
   */
  const struct exception_table_entry *
  search_extable(const struct exception_table_entry *first,
  	       const struct exception_table_entry *last,
  	       unsigned long value)
  {
  	const struct exception_table_entry *mid;
  	unsigned long addr;
  
  	while (first <= last) {
  		mid = ((last - first) >> 1) + first;
  		addr = extable_insn(mid);
  		if (addr < value)
  			first = mid + 1;
  		else if (addr > value)
  			last = mid - 1;
  		else
  			return mid;
  	}
  	return NULL;
  }
  
  /*
   * The exception table needs to be sorted so that the binary
   * search that we use to find entries in it works properly.
   * This is used both for the kernel exception table and for
   * the exception tables of modules that get loaded.
   *
   */
  static int cmp_ex(const void *a, const void *b)
  {
  	const struct exception_table_entry *x = a, *y = b;
  
  	/* This compare is only valid after normalization. */
  	return x->insn - y->insn;
  }
  
  void sort_extable(struct exception_table_entry *start,
  		  struct exception_table_entry *finish)
  {
  	struct exception_table_entry *p;
  	int i;
  
  	/* Normalize entries to being relative to the start of the section */
  	for (p = start, i = 0; p < finish; p++, i += 8)
  		p->insn += i;
  	sort(start, finish - start, sizeof(*start), cmp_ex, NULL);
  	/* Denormalize all entries */
  	for (p = start, i = 0; p < finish; p++, i += 8)
  		p->insn -= i;
  }
  
  #ifdef CONFIG_MODULES
  /*
   * If the exception table is sorted, any referring to the module init
   * will be at the beginning or the end.
   */
  void trim_init_extable(struct module *m)
  {
  	/* Trim the beginning */
  	while (m->num_exentries &&
  	       within_module_init(extable_insn(&m->extable[0]), m)) {
  		m->extable++;
  		m->num_exentries--;
  	}
  	/* Trim the end */
  	while (m->num_exentries &&
  	       within_module_init(extable_insn(&m->extable[m->num_exentries-1]), m))
  		m->num_exentries--;
  }
  #endif /* CONFIG_MODULES */