2 * self test for change_page_attr.
4 * Clears the a test pte bit on random pages in the direct mapping,
5 * then reverts and compares page tables forwards and afterwards.
7 #include <linux/bootmem.h>
8 #include <linux/kthread.h>
9 #include <linux/random.h>
10 #include <linux/kernel.h>
13 #include <asm/cacheflush.h>
14 #include <asm/pgtable.h>
15 #include <asm/kdebug.h>
18 * Only print the results of the first pass:
20 static __read_mostly int print = 1;
25 LPS = (1 << PMD_SHIFT),
26 #elif defined(CONFIG_X86_PAE)
27 LPS = (1 << PMD_SHIFT),
34 #define PAGE_CPA_TEST __pgprot(_PAGE_CPA_TEST)
36 static int pte_testbit(pte_t pte)
38 return pte_flags(pte) & _PAGE_SOFTW1;
42 long lpg, gpg, spg, exec;
43 long min_exec, max_exec;
46 static int print_split(struct split_state *s)
48 long i, expected, missed = 0;
51 s->lpg = s->gpg = s->spg = s->exec = 0;
54 for (i = 0; i < max_pfn_mapped; ) {
55 unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
59 pte = lookup_address(addr, &level);
66 if (level == PG_LEVEL_1G && sizeof(long) == 8) {
69 } else if (level == PG_LEVEL_2M) {
70 if ((pte_val(*pte) & _PAGE_PRESENT) && !(pte_val(*pte) & _PAGE_PSE)) {
72 "%lx level %d but not PSE %Lx\n",
73 addr, level, (u64)pte_val(*pte));
82 if (!(pte_val(*pte) & _PAGE_NX)) {
84 if (addr < s->min_exec)
86 if (addr > s->max_exec)
92 " 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
93 s->spg, s->lpg, s->gpg, s->exec,
94 s->min_exec != ~0UL ? s->min_exec : 0,
98 expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
100 printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n",
101 max_pfn_mapped, expected);
107 static unsigned long addr[NTEST];
108 static unsigned int len[NTEST];
110 /* Change the global bit on random pages in the direct mapping */
111 static int pageattr_test(void)
113 struct split_state sa, sb, sc;
120 unsigned long test_addr;
123 printk(KERN_INFO "CPA self-test:\n");
125 bm = vzalloc((max_pfn_mapped + 7) / 8);
127 printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
131 failed += print_split(&sa);
133 for (i = 0; i < NTEST; i++) {
134 unsigned long pfn = prandom_u32() % max_pfn_mapped;
136 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
137 len[i] = prandom_u32() % 100;
138 len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
144 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
146 for (k = 0; k < len[i]; k++) {
147 pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
148 if (!pte || pgprot_val(pte_pgprot(*pte)) == 0 ||
149 !(pte_val(*pte) & _PAGE_PRESENT)) {
156 if (pgprot_val(pte_pgprot(*pte)) !=
157 pgprot_val(pte_pgprot(pte0))) {
162 if (test_bit(pfn + k, bm)) {
166 __set_bit(pfn + k, bm);
168 if (!addr[i] || !pte || !k) {
174 err = change_page_attr_set(&test_addr, len[i], PAGE_CPA_TEST, 0);
176 printk(KERN_ERR "CPA %d failed %d\n", i, err);
180 pte = lookup_address(addr[i], &level);
181 if (!pte || !pte_testbit(*pte) || pte_huge(*pte)) {
182 printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
183 pte ? (u64)pte_val(*pte) : 0ULL);
186 if (level != PG_LEVEL_4K) {
187 printk(KERN_ERR "CPA %lx: unexpected level %d\n",
195 failed += print_split(&sb);
197 for (i = 0; i < NTEST; i++) {
200 pte = lookup_address(addr[i], &level);
202 printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
207 err = change_page_attr_clear(&test_addr, len[i], PAGE_CPA_TEST, 0);
209 printk(KERN_ERR "CPA reverting failed: %d\n", err);
212 pte = lookup_address(addr[i], &level);
213 if (!pte || pte_testbit(*pte)) {
214 printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
215 addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
221 failed += print_split(&sc);
224 WARN(1, KERN_ERR "NOT PASSED. Please report.\n");
228 printk(KERN_INFO "ok.\n");
234 static int do_pageattr_test(void *__unused)
236 while (!kthread_should_stop()) {
237 schedule_timeout_interruptible(HZ*30);
238 if (pageattr_test() < 0)
246 static int start_pageattr_test(void)
248 struct task_struct *p;
250 p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
259 module_init(start_pageattr_test);