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
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include "pte.h"
#include "shadow.h"
/*
* Return the shadow address for the given address. Returns NULL if the
* address is not tracked.
*
* We need to be extremely careful not to follow any invalid pointers,
* because this function can be called for *any* possible address.
*/
void *kmemcheck_shadow_lookup(unsigned long address)
{
pte_t *pte;
struct page *page;
if (!virt_addr_valid(address))
return NULL;
pte = kmemcheck_pte_lookup(address);
if (!pte)
return NULL;
page = virt_to_page(address);
if (!page->shadow)
return NULL;
return page->shadow + (address & (PAGE_SIZE - 1));
}
static void mark_shadow(void *address, unsigned int n,
enum kmemcheck_shadow status)
{
void *shadow;
shadow = kmemcheck_shadow_lookup((unsigned long) address);
if (!shadow)
return;
__memset(shadow, status, n);
}
void kmemcheck_mark_unallocated(void *address, unsigned int n)
{
mark_shadow(address, n, KMEMCHECK_SHADOW_UNALLOCATED);
}
void kmemcheck_mark_uninitialized(void *address, unsigned int n)
{
mark_shadow(address, n, KMEMCHECK_SHADOW_UNINITIALIZED);
}
/*
* Fill the shadow memory of the given address such that the memory at that
* address is marked as being initialized.
*/
void kmemcheck_mark_initialized(void *address, unsigned int n)
{
mark_shadow(address, n, KMEMCHECK_SHADOW_INITIALIZED);
}
void kmemcheck_mark_freed(void *address, unsigned int n)
{
mark_shadow(address, n, KMEMCHECK_SHADOW_FREED);
}
void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n)
{
unsigned int i;
for (i = 0; i < n; ++i)
kmemcheck_mark_unallocated(page_address(&p[i]), PAGE_SIZE);
}
void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n)
{
unsigned int i;
for (i = 0; i < n; ++i)
kmemcheck_mark_uninitialized(page_address(&p[i]), PAGE_SIZE);
}
enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size)
{
uint8_t *x;
x = shadow;
#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
/*
* Make sure _some_ bytes are initialized. Gcc frequently generates
* code to access neighboring bytes.
*/
switch (size) {
#ifdef CONFIG_X86_64
case 64:
if (x[7] == KMEMCHECK_SHADOW_INITIALIZED)
return x[7];
if (x[6] == KMEMCHECK_SHADOW_INITIALIZED)
return x[6];
if (x[5] == KMEMCHECK_SHADOW_INITIALIZED)
return x[5];
if (x[4] == KMEMCHECK_SHADOW_INITIALIZED)
return x[4];
#endif
case 32:
if (x[3] == KMEMCHECK_SHADOW_INITIALIZED)
return x[3];
if (x[2] == KMEMCHECK_SHADOW_INITIALIZED)
return x[2];
case 16:
if (x[1] == KMEMCHECK_SHADOW_INITIALIZED)
return x[1];
case 8:
if (x[0] == KMEMCHECK_SHADOW_INITIALIZED)
return x[0];
}
#else
switch (size) {
#ifdef CONFIG_X86_64
case 64:
if (x[7] != KMEMCHECK_SHADOW_INITIALIZED)
return x[7];
if (x[6] != KMEMCHECK_SHADOW_INITIALIZED)
return x[6];
if (x[5] != KMEMCHECK_SHADOW_INITIALIZED)
return x[5];
if (x[4] != KMEMCHECK_SHADOW_INITIALIZED)
return x[4];
#endif
case 32:
if (x[3] != KMEMCHECK_SHADOW_INITIALIZED)
return x[3];
if (x[2] != KMEMCHECK_SHADOW_INITIALIZED)
return x[2];
case 16:
if (x[1] != KMEMCHECK_SHADOW_INITIALIZED)
return x[1];
case 8:
if (x[0] != KMEMCHECK_SHADOW_INITIALIZED)
return x[0];
}
#endif
return x[0];
}
void kmemcheck_shadow_set(void *shadow, unsigned int size)
{
uint8_t *x;
x = shadow;
switch (size) {
#ifdef CONFIG_X86_64
case 64:
x[7] = KMEMCHECK_SHADOW_INITIALIZED;
x[6] = KMEMCHECK_SHADOW_INITIALIZED;
x[5] = KMEMCHECK_SHADOW_INITIALIZED;
x[4] = KMEMCHECK_SHADOW_INITIALIZED;
#endif
case 32:
x[3] = KMEMCHECK_SHADOW_INITIALIZED;
x[2] = KMEMCHECK_SHADOW_INITIALIZED;
case 16:
x[1] = KMEMCHECK_SHADOW_INITIALIZED;
case 8:
x[0] = KMEMCHECK_SHADOW_INITIALIZED;
}
return;
}
|
