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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/mm.h>
static asmlinkage void no_lcall7(struct pt_regs * regs);
static unsigned long ident_map[32] = {
0, 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
};
struct exec_domain default_exec_domain = {
"Linux", /* name */
no_lcall7, /* lcall7 causes a seg fault. */
0, 0xff, /* All personalities. */
ident_map, /* Identity map signals. */
ident_map, /* - both ways. */
NULL, /* No usage counter. */
NULL /* Nothing after this in the list. */
};
static struct exec_domain *exec_domains = &default_exec_domain;
static asmlinkage void no_lcall7(struct pt_regs * regs)
{
/*
* This may have been a static linked SVr4 binary, so we would have the
* personality set incorrectly. Check to see whether SVr4 is available,
* and use it, otherwise give the user a SEGV.
*/
if (current->exec_domain && current->exec_domain->use_count)
(*current->exec_domain->use_count)--;
current->personality = PER_SVR4;
current->exec_domain = lookup_exec_domain(current->personality);
if (current->exec_domain && current->exec_domain->use_count)
(*current->exec_domain->use_count)++;
if (current->exec_domain && current->exec_domain->handler
&& current->exec_domain->handler != no_lcall7) {
current->exec_domain->handler(regs);
return;
}
send_sig(SIGSEGV, current, 1);
}
struct exec_domain *lookup_exec_domain(unsigned long personality)
{
unsigned long pers = personality & PER_MASK;
struct exec_domain *it;
for (it=exec_domains; it; it=it->next)
if (pers >= it->pers_low
&& pers <= it->pers_high)
return it;
/* Should never get this far. */
printk(KERN_ERR "No execution domain for personality 0x%02lx\n", pers);
return NULL;
}
int register_exec_domain(struct exec_domain *it)
{
struct exec_domain *tmp;
if (!it)
return -EINVAL;
if (it->next)
return -EBUSY;
for (tmp=exec_domains; tmp; tmp=tmp->next)
if (tmp == it)
return -EBUSY;
it->next = exec_domains;
exec_domains = it;
return 0;
}
int unregister_exec_domain(struct exec_domain *it)
{
struct exec_domain ** tmp;
tmp = &exec_domains;
while (*tmp) {
if (it == *tmp) {
*tmp = it->next;
it->next = NULL;
return 0;
}
tmp = &(*tmp)->next;
}
return -EINVAL;
}
asmlinkage int sys_personality(unsigned long personality)
{
struct exec_domain *it;
unsigned long old_personality;
if (personality == 0xffffffff)
return current->personality;
it = lookup_exec_domain(personality);
if (!it)
return -EINVAL;
old_personality = current->personality;
if (current->exec_domain && current->exec_domain->use_count)
(*current->exec_domain->use_count)--;
current->personality = personality;
current->exec_domain = it;
if (current->exec_domain->use_count)
(*current->exec_domain->use_count)++;
return old_personality;
}
|
