2 * self test for change_page_attr.
4 * Clears the global bit on random pages in the direct mapping, then reverts
5 * and compares page tables forwards and afterwards.
9 #include <linux/random.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/bootmem.h>
13 #include <asm/cacheflush.h>
14 #include <asm/pgtable.h>
15 #include <asm/kdebug.h>
21 LPS = (1 << PMD_SHIFT),
22 #elif defined(CONFIG_X86_PAE)
24 LPS = (1 << PMD_SHIFT),
26 LOWEST_LEVEL = 3, /* lookup_address lies here */
33 #include <asm/proto.h>
34 #define max_mapped end_pfn_map
36 #define max_mapped max_low_pfn
40 long lpg, gpg, spg, exec;
41 long min_exec, max_exec;
44 static __init int print_split(struct split_state *s)
47 long i, expected, missed = 0;
50 s->lpg = s->gpg = s->spg = s->exec = 0;
53 for (i = 0; i < max_mapped; ) {
56 unsigned long adr = (unsigned long)__va(i << PAGE_SHIFT);
58 pte = lookup_address(adr, &level);
62 printk("CPA %lx no pte level %d\n", adr, level);
70 if (level == 2 && sizeof(long) == 8) {
73 } else if (level != LOWEST_LEVEL) {
74 if (!(pte_val(*pte) & _PAGE_PSE)) {
75 printk("%lx level %d but not PSE %Lx\n",
76 adr, level, (u64)pte_val(*pte));
85 if (!(pte_val(*pte) & _PAGE_NX)) {
87 if (adr < s->min_exec)
89 if (adr > s->max_exec)
93 printk("CPA mapping 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, s->max_exec, missed);
96 expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
98 printk("CPA max_mapped %lu but expected %lu\n",
99 max_mapped, expected);
105 static __init int state_same(struct split_state *a, struct split_state *b)
107 return a->lpg == b->lpg && a->gpg == b->gpg && a->spg == b->spg &&
111 static unsigned long addr[NTEST] __initdata;
112 static unsigned len[NTEST] __initdata;
114 /* Change the global bit on random pages in the direct mapping */
115 static __init int exercise_pageattr(void)
121 struct split_state sa, sb, sc;
125 printk("CPA exercising pageattr\n");
127 bm = vmalloc((max_mapped + 7) / 8);
129 printk("CPA Cannot vmalloc bitmap\n");
132 memset(bm, 0, (max_mapped + 7) / 8);
134 failed += print_split(&sa);
136 for (i = 0; i < NTEST; i++) {
137 unsigned long pfn = random32() % max_mapped;
138 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
139 len[i] = random32() % 100;
140 len[i] = min_t(unsigned long, len[i], max_mapped - pfn - 1);
145 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) {
154 else if (pgprot_val(pte_pgprot(*pte)) !=
155 pgprot_val(pte_pgprot(pte0))) {
159 if (test_bit(pfn + k, bm)) {
163 __set_bit(pfn + k, bm);
165 if (!addr[i] || !pte || !k) {
170 err = change_page_attr(virt_to_page(addr[i]), len[i],
171 pte_pgprot(pte_clrhuge(pte_clrglobal(pte0))));
173 printk("CPA %d failed %d\n", i, err);
177 pte = lookup_address(addr[i], &level);
178 if (!pte || pte_global(*pte) || pte_huge(*pte)) {
179 printk("CPA %lx: bad pte %Lx\n", addr[i],
180 pte ? (u64)pte_val(*pte) : 0ULL);
183 if (level != LOWEST_LEVEL) {
184 printk("CPA %lx: unexpected level %d\n", addr[i],
193 failed += print_split(&sb);
195 printk("CPA reverting everything\n");
196 for (i = 0; i < NTEST; i++) {
199 pte = lookup_address(addr[i], &level);
201 printk("CPA lookup of %lx failed\n", addr[i]);
205 err = change_page_attr(virt_to_page(addr[i]), len[i],
206 pte_pgprot(pte_mkglobal(*pte)));
208 printk("CPA reverting failed: %d\n", err);
211 pte = lookup_address(addr[i], &level);
212 if (!pte || !pte_global(*pte)) {
213 printk("CPA %lx: bad pte after revert %Lx\n", addr[i],
214 pte ? (u64)pte_val(*pte) : 0ULL);
221 failed += print_split(&sc);
222 if (!state_same(&sa, &sc))
226 printk("CPA selftests NOT PASSED. Please report.\n");
228 printk("CPA selftests PASSED\n");
233 module_init(exercise_pageattr);