Merge branch 'x86/urgent' into x86/pat
[linux-2.6.git] / arch / x86 / mm / pageattr-test.c
1 /*
2  * self test for change_page_attr.
3  *
4  * Clears the a test pte bit on random pages in the direct mapping,
5  * then reverts and compares page tables forwards and afterwards.
6  */
7 #include <linux/bootmem.h>
8 #include <linux/kthread.h>
9 #include <linux/random.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/mm.h>
13
14 #include <asm/cacheflush.h>
15 #include <asm/pgtable.h>
16 #include <asm/kdebug.h>
17
18 /*
19  * Only print the results of the first pass:
20  */
21 static __read_mostly int print = 1;
22
23 enum {
24         NTEST                   = 400,
25 #ifdef CONFIG_X86_64
26         LPS                     = (1 << PMD_SHIFT),
27 #elif defined(CONFIG_X86_PAE)
28         LPS                     = (1 << PMD_SHIFT),
29 #else
30         LPS                     = (1 << 22),
31 #endif
32         GPS                     = (1<<30)
33 };
34
35 #define PAGE_TESTBIT    __pgprot(_PAGE_UNUSED1)
36
37 static int pte_testbit(pte_t pte)
38 {
39         return pte_flags(pte) & _PAGE_UNUSED1;
40 }
41
42 struct split_state {
43         long lpg, gpg, spg, exec;
44         long min_exec, max_exec;
45 };
46
47 static int print_split(struct split_state *s)
48 {
49         long i, expected, missed = 0;
50         int err = 0;
51
52         s->lpg = s->gpg = s->spg = s->exec = 0;
53         s->min_exec = ~0UL;
54         s->max_exec = 0;
55         for (i = 0; i < max_pfn_mapped; ) {
56                 unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
57                 unsigned int level;
58                 pte_t *pte;
59
60                 pte = lookup_address(addr, &level);
61                 if (!pte) {
62                         missed++;
63                         i++;
64                         continue;
65                 }
66
67                 if (level == PG_LEVEL_1G && sizeof(long) == 8) {
68                         s->gpg++;
69                         i += GPS/PAGE_SIZE;
70                 } else if (level == PG_LEVEL_2M) {
71                         if (!(pte_val(*pte) & _PAGE_PSE)) {
72                                 printk(KERN_ERR
73                                         "%lx level %d but not PSE %Lx\n",
74                                         addr, level, (u64)pte_val(*pte));
75                                 err = 1;
76                         }
77                         s->lpg++;
78                         i += LPS/PAGE_SIZE;
79                 } else {
80                         s->spg++;
81                         i++;
82                 }
83                 if (!(pte_val(*pte) & _PAGE_NX)) {
84                         s->exec++;
85                         if (addr < s->min_exec)
86                                 s->min_exec = addr;
87                         if (addr > s->max_exec)
88                                 s->max_exec = addr;
89                 }
90         }
91         if (print) {
92                 printk(KERN_INFO
93                         " 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
94                         s->spg, s->lpg, s->gpg, s->exec,
95                         s->min_exec != ~0UL ? s->min_exec : 0,
96                         s->max_exec, missed);
97         }
98
99         expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
100         if (expected != i) {
101                 printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n",
102                         max_pfn_mapped, expected);
103                 return 1;
104         }
105         return err;
106 }
107
108 static unsigned long addr[NTEST];
109 static unsigned int len[NTEST];
110
111 /* Change the global bit on random pages in the direct mapping */
112 static int pageattr_test(void)
113 {
114         struct split_state sa, sb, sc;
115         unsigned long *bm;
116         pte_t *pte, pte0;
117         int failed = 0;
118         unsigned int level;
119         int i, k;
120         int err;
121         unsigned long test_addr;
122
123         if (print)
124                 printk(KERN_INFO "CPA self-test:\n");
125
126         bm = vmalloc((max_pfn_mapped + 7) / 8);
127         if (!bm) {
128                 printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
129                 return -ENOMEM;
130         }
131         memset(bm, 0, (max_pfn_mapped + 7) / 8);
132
133         failed += print_split(&sa);
134         srandom32(100);
135
136         for (i = 0; i < NTEST; i++) {
137                 unsigned long pfn = random32() % max_pfn_mapped;
138
139                 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
140                 len[i] = random32() % 100;
141                 len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
142
143                 if (len[i] == 0)
144                         len[i] = 1;
145
146                 pte = NULL;
147                 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
148
149                 for (k = 0; k < len[i]; k++) {
150                         pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
151                         if (!pte || pgprot_val(pte_pgprot(*pte)) == 0 ||
152                             !(pte_val(*pte) & _PAGE_PRESENT)) {
153                                 addr[i] = 0;
154                                 break;
155                         }
156                         if (k == 0) {
157                                 pte0 = *pte;
158                         } else {
159                                 if (pgprot_val(pte_pgprot(*pte)) !=
160                                         pgprot_val(pte_pgprot(pte0))) {
161                                         len[i] = k;
162                                         break;
163                                 }
164                         }
165                         if (test_bit(pfn + k, bm)) {
166                                 len[i] = k;
167                                 break;
168                         }
169                         __set_bit(pfn + k, bm);
170                 }
171                 if (!addr[i] || !pte || !k) {
172                         addr[i] = 0;
173                         continue;
174                 }
175
176                 test_addr = addr[i];
177                 err = change_page_attr_set(&test_addr, len[i], PAGE_TESTBIT, 0);
178                 if (err < 0) {
179                         printk(KERN_ERR "CPA %d failed %d\n", i, err);
180                         failed++;
181                 }
182
183                 pte = lookup_address(addr[i], &level);
184                 if (!pte || !pte_testbit(*pte) || pte_huge(*pte)) {
185                         printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
186                                 pte ? (u64)pte_val(*pte) : 0ULL);
187                         failed++;
188                 }
189                 if (level != PG_LEVEL_4K) {
190                         printk(KERN_ERR "CPA %lx: unexpected level %d\n",
191                                 addr[i], level);
192                         failed++;
193                 }
194
195         }
196         vfree(bm);
197
198         failed += print_split(&sb);
199
200         for (i = 0; i < NTEST; i++) {
201                 if (!addr[i])
202                         continue;
203                 pte = lookup_address(addr[i], &level);
204                 if (!pte) {
205                         printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
206                         failed++;
207                         continue;
208                 }
209                 test_addr = addr[i];
210                 err = change_page_attr_clear(&test_addr, len[i], PAGE_TESTBIT, 0);
211                 if (err < 0) {
212                         printk(KERN_ERR "CPA reverting failed: %d\n", err);
213                         failed++;
214                 }
215                 pte = lookup_address(addr[i], &level);
216                 if (!pte || pte_testbit(*pte)) {
217                         printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
218                                 addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
219                         failed++;
220                 }
221
222         }
223
224         failed += print_split(&sc);
225
226         if (failed) {
227                 WARN(1, KERN_ERR "NOT PASSED. Please report.\n");
228                 return -EINVAL;
229         } else {
230                 if (print)
231                         printk(KERN_INFO "ok.\n");
232         }
233
234         return 0;
235 }
236
237 static int do_pageattr_test(void *__unused)
238 {
239         while (!kthread_should_stop()) {
240                 schedule_timeout_interruptible(HZ*30);
241                 if (pageattr_test() < 0)
242                         break;
243                 if (print)
244                         print--;
245         }
246         return 0;
247 }
248
249 static int start_pageattr_test(void)
250 {
251         struct task_struct *p;
252
253         p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
254         if (!IS_ERR(p))
255                 wake_up_process(p);
256         else
257                 WARN_ON(1);
258
259         return 0;
260 }
261
262 module_init(start_pageattr_test);