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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
/*
* self test for change_page_attr.
*
* Clears the global bit on random pages in the direct mapping, then reverts
* and compares page tables forwards and afterwards.
*/
#include <linux/bootmem.h>
#include <linux/kthread.h>
#include <linux/random.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/kdebug.h>
/*
* Only print the results of the first pass:
*/
static __read_mostly int print = 1;
enum {
NTEST = 400,
#ifdef CONFIG_X86_64
LPS = (1 << PMD_SHIFT),
#elif defined(CONFIG_X86_PAE)
LPS = (1 << PMD_SHIFT),
#else
LPS = (1 << 22),
#endif
GPS = (1<<30)
};
struct split_state {
long lpg, gpg, spg, exec;
long min_exec, max_exec;
};
static int print_split(struct split_state *s)
{
long i, expected, missed = 0;
int err = 0;
s->lpg = s->gpg = s->spg = s->exec = 0;
s->min_exec = ~0UL;
s->max_exec = 0;
for (i = 0; i < max_pfn_mapped; ) {
unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
unsigned int level;
pte_t *pte;
pte = lookup_address(addr, &level);
if (!pte) {
missed++;
i++;
continue;
}
if (level == PG_LEVEL_1G && sizeof(long) == 8) {
s->gpg++;
i += GPS/PAGE_SIZE;
} else if (level == PG_LEVEL_2M) {
if (!(pte_val(*pte) & _PAGE_PSE)) {
printk(KERN_ERR
"%lx level %d but not PSE %Lx\n",
addr, level, (u64)pte_val(*pte));
err = 1;
}
s->lpg++;
i += LPS/PAGE_SIZE;
} else {
s->spg++;
i++;
}
if (!(pte_val(*pte) & _PAGE_NX)) {
s->exec++;
if (addr < s->min_exec)
s->min_exec = addr;
if (addr > s->max_exec)
s->max_exec = addr;
}
}
if (print) {
printk(KERN_INFO
" 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
s->spg, s->lpg, s->gpg, s->exec,
s->min_exec != ~0UL ? s->min_exec : 0,
s->max_exec, missed);
}
expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
if (expected != i) {
printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n",
max_pfn_mapped, expected);
return 1;
}
return err;
}
static unsigned long addr[NTEST];
static unsigned int len[NTEST];
/* Change the global bit on random pages in the direct mapping */
static int pageattr_test(void)
{
struct split_state sa, sb, sc;
unsigned long *bm;
pte_t *pte, pte0;
int failed = 0;
unsigned int level;
int i, k;
int err;
if (print)
printk(KERN_INFO "CPA self-test:\n");
bm = vmalloc((max_pfn_mapped + 7) / 8);
if (!bm) {
printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
return -ENOMEM;
}
memset(bm, 0, (max_pfn_mapped + 7) / 8);
failed += print_split(&sa);
srandom32(100);
for (i = 0; i < NTEST; i++) {
unsigned long pfn = random32() % max_pfn_mapped;
addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
len[i] = random32() % 100;
len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
if (len[i] == 0)
len[i] = 1;
pte = NULL;
pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
for (k = 0; k < len[i]; k++) {
pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
if (!pte || pgprot_val(pte_pgprot(*pte)) == 0 ||
!(pte_val(*pte) & _PAGE_PRESENT)) {
addr[i] = 0;
break;
}
if (k == 0) {
pte0 = *pte;
} else {
if (pgprot_val(pte_pgprot(*pte)) !=
pgprot_val(pte_pgprot(pte0))) {
len[i] = k;
break;
}
}
if (test_bit(pfn + k, bm)) {
len[i] = k;
break;
}
__set_bit(pfn + k, bm);
}
if (!addr[i] || !pte || !k) {
addr[i] = 0;
continue;
}
err = change_page_attr_clear(addr[i], len[i],
__pgprot(_PAGE_GLOBAL));
if (err < 0) {
printk(KERN_ERR "CPA %d failed %d\n", i, err);
failed++;
}
pte = lookup_address(addr[i], &level);
if (!pte || pte_global(*pte) || pte_huge(*pte)) {
printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
pte ? (u64)pte_val(*pte) : 0ULL);
failed++;
}
if (level != PG_LEVEL_4K) {
printk(KERN_ERR "CPA %lx: unexpected level %d\n",
addr[i], level);
failed++;
}
}
vfree(bm);
failed += print_split(&sb);
for (i = 0; i < NTEST; i++) {
if (!addr[i])
continue;
pte = lookup_address(addr[i], &level);
if (!pte) {
printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
failed++;
continue;
}
err = change_page_attr_set(addr[i], len[i],
__pgprot(_PAGE_GLOBAL));
if (err < 0) {
printk(KERN_ERR "CPA reverting failed: %d\n", err);
failed++;
}
pte = lookup_address(addr[i], &level);
if (!pte || !pte_global(*pte)) {
printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
failed++;
}
}
failed += print_split(&sc);
if (failed) {
printk(KERN_ERR "NOT PASSED. Please report.\n");
WARN_ON(1);
return -EINVAL;
} else {
if (print)
printk(KERN_INFO "ok.\n");
}
return 0;
}
static int do_pageattr_test(void *__unused)
{
while (!kthread_should_stop()) {
schedule_timeout_interruptible(HZ*30);
if (pageattr_test() < 0)
break;
if (print)
print--;
}
return 0;
}
static int start_pageattr_test(void)
{
struct task_struct *p;
p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
if (!IS_ERR(p))
wake_up_process(p);
else
WARN_ON(1);
return 0;
}
module_init(start_pageattr_test);
|
