x86: fix c_p_a() boot crash
[sfrench/cifs-2.6.git] / arch / x86 / mm / pageattr-test.c
1 /*
2  * self test for change_page_attr.
3  *
4  * Clears the global bit on random pages in the direct mapping, then reverts
5  * and compares page tables forwards and afterwards.
6  */
7 #include <linux/bootmem.h>
8 #include <linux/random.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/mm.h>
12
13 #include <asm/cacheflush.h>
14 #include <asm/pgtable.h>
15 #include <asm/kdebug.h>
16
17 enum {
18         NTEST                   = 400,
19 #ifdef CONFIG_X86_64
20         LOWEST_LEVEL            = 4,
21         LPS                     = (1 << PMD_SHIFT),
22 #elif defined(CONFIG_X86_PAE)
23         LOWEST_LEVEL            = 3,
24         LPS                     = (1 << PMD_SHIFT),
25 #else
26         LOWEST_LEVEL            = 3, /* lookup_address lies here */
27         LPS                     = (1 << 22),
28 #endif
29         GPS                     = (1<<30)
30 };
31
32 #ifdef CONFIG_X86_64
33 # include <asm/proto.h>
34 # define max_mapped             end_pfn_map
35 #else
36 # define max_mapped             max_low_pfn
37 #endif
38
39 struct split_state {
40         long lpg, gpg, spg, exec;
41         long min_exec, max_exec;
42 };
43
44 static __init int print_split(struct split_state *s)
45 {
46         long i, expected, missed = 0;
47         int printed = 0;
48         int err = 0;
49
50         s->lpg = s->gpg = s->spg = s->exec = 0;
51         s->min_exec = ~0UL;
52         s->max_exec = 0;
53         for (i = 0; i < max_mapped; ) {
54                 unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
55                 int level;
56                 pte_t *pte;
57
58                 pte = lookup_address(addr, &level);
59                 if (!pte) {
60                         if (!printed) {
61                                 dump_pagetable(addr);
62                                 printk(KERN_INFO "CPA %lx no pte level %d\n",
63                                         addr, level);
64                                 printed = 1;
65                         }
66                         missed++;
67                         i++;
68                         continue;
69                 }
70
71                 if (level == 2 && sizeof(long) == 8) {
72                         s->gpg++;
73                         i += GPS/PAGE_SIZE;
74                 } else if (level != LOWEST_LEVEL) {
75                         if (!(pte_val(*pte) & _PAGE_PSE)) {
76                                 printk(KERN_ERR
77                                         "%lx level %d but not PSE %Lx\n",
78                                         addr, level, (u64)pte_val(*pte));
79                                 err = 1;
80                         }
81                         s->lpg++;
82                         i += LPS/PAGE_SIZE;
83                 } else {
84                         s->spg++;
85                         i++;
86                 }
87                 if (!(pte_val(*pte) & _PAGE_NX)) {
88                         s->exec++;
89                         if (addr < s->min_exec)
90                                 s->min_exec = addr;
91                         if (addr > s->max_exec)
92                                 s->max_exec = addr;
93                 }
94         }
95         printk(KERN_INFO
96                 "CPA mapping 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
97                 s->spg, s->lpg, s->gpg, s->exec,
98                 s->min_exec != ~0UL ? s->min_exec : 0, s->max_exec, missed);
99
100         expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
101         if (expected != i) {
102                 printk(KERN_ERR "CPA max_mapped %lu but expected %lu\n",
103                         max_mapped, expected);
104                 return 1;
105         }
106         return err;
107 }
108
109 static __init int state_same(struct split_state *a, struct split_state *b)
110 {
111         return a->lpg == b->lpg && a->gpg == b->gpg && a->spg == b->spg &&
112                 a->exec == b->exec;
113 }
114
115 static unsigned long __initdata addr[NTEST];
116 static unsigned int __initdata len[NTEST];
117
118 /* Change the global bit on random pages in the direct mapping */
119 static __init int exercise_pageattr(void)
120 {
121         struct split_state sa, sb, sc;
122         unsigned long *bm;
123         pte_t *pte, pte0;
124         int failed = 0;
125         int level;
126         int i, k;
127         int err;
128
129         printk(KERN_INFO "CPA exercising pageattr\n");
130
131         bm = vmalloc((max_mapped + 7) / 8);
132         if (!bm) {
133                 printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
134                 return -ENOMEM;
135         }
136         memset(bm, 0, (max_mapped + 7) / 8);
137
138         failed += print_split(&sa);
139         srandom32(100);
140
141         for (i = 0; i < NTEST; i++) {
142                 unsigned long pfn = random32() % max_mapped;
143
144                 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
145                 len[i] = random32() % 100;
146                 len[i] = min_t(unsigned long, len[i], max_mapped - pfn - 1);
147
148                 if (len[i] == 0)
149                         len[i] = 1;
150
151                 pte = NULL;
152                 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
153
154                 for (k = 0; k < len[i]; k++) {
155                         pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
156                         if (!pte || pgprot_val(pte_pgprot(*pte)) == 0) {
157                                 addr[i] = 0;
158                                 break;
159                         }
160                         if (k == 0) {
161                                 pte0 = *pte;
162                         } else {
163                                 if (pgprot_val(pte_pgprot(*pte)) !=
164                                         pgprot_val(pte_pgprot(pte0))) {
165                                         len[i] = k;
166                                         break;
167                                 }
168                         }
169                         if (test_bit(pfn + k, bm)) {
170                                 len[i] = k;
171                                 break;
172                         }
173                         __set_bit(pfn + k, bm);
174                 }
175                 if (!addr[i] || !pte || !k) {
176                         addr[i] = 0;
177                         continue;
178                 }
179
180                 err = change_page_attr_addr(addr[i], len[i],
181                             pte_pgprot(pte_clrhuge(pte_clrglobal(pte0))));
182                 if (err < 0) {
183                         printk(KERN_ERR "CPA %d failed %d\n", i, err);
184                         failed++;
185                 }
186
187                 pte = lookup_address(addr[i], &level);
188                 if (!pte || pte_global(*pte) || pte_huge(*pte)) {
189                         printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
190                                 pte ? (u64)pte_val(*pte) : 0ULL);
191                         failed++;
192                 }
193                 if (level != LOWEST_LEVEL) {
194                         printk(KERN_ERR "CPA %lx: unexpected level %d\n",
195                                 addr[i], level);
196                         failed++;
197                 }
198
199         }
200         vfree(bm);
201         global_flush_tlb();
202
203         failed += print_split(&sb);
204
205         printk(KERN_INFO "CPA reverting everything\n");
206         for (i = 0; i < NTEST; i++) {
207                 if (!addr[i])
208                         continue;
209                 pte = lookup_address(addr[i], &level);
210                 if (!pte) {
211                         printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
212                         failed++;
213                         continue;
214                 }
215                 err = change_page_attr_addr(addr[i], len[i],
216                                           pte_pgprot(pte_mkglobal(*pte)));
217                 if (err < 0) {
218                         printk(KERN_ERR "CPA reverting failed: %d\n", err);
219                         failed++;
220                 }
221                 pte = lookup_address(addr[i], &level);
222                 if (!pte || !pte_global(*pte)) {
223                         printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
224                                 addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
225                         failed++;
226                 }
227
228         }
229         global_flush_tlb();
230
231         failed += print_split(&sc);
232         if (!state_same(&sa, &sc))
233                 failed++;
234
235         if (failed)
236                 printk(KERN_ERR "CPA selftests NOT PASSED. Please report.\n");
237         else
238                 printk(KERN_INFO "CPA selftests PASSED\n");
239
240         return 0;
241 }
242 module_init(exercise_pageattr);