err.no Git - linux-2.6/blob - 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(virt_to_page(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(virt_to_page(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);