1 // SPDX-License-Identifier: GPL-2.0
3 * self test for change_page_attr.
5 * Clears the a test pte bit on random pages in the direct mapping,
6 * then reverts and compares page tables forwards and afterwards.
8 #include <linux/memblock.h>
9 #include <linux/kthread.h>
10 #include <linux/random.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
14 #include <linux/vmalloc.h>
16 #include <asm/cacheflush.h>
17 #include <asm/pgtable.h>
18 #include <asm/kdebug.h>
21 * Only print the results of the first pass:
23 static __read_mostly int print = 1;
29 LPS = (1 << PMD_SHIFT),
30 #elif defined(CONFIG_X86_PAE)
31 LPS = (1 << PMD_SHIFT),
38 #define PAGE_CPA_TEST __pgprot(_PAGE_CPA_TEST)
40 static int pte_testbit(pte_t pte)
42 return pte_flags(pte) & _PAGE_SOFTW1;
46 long lpg, gpg, spg, exec;
47 long min_exec, max_exec;
50 static int print_split(struct split_state *s)
52 long i, expected, missed = 0;
55 s->lpg = s->gpg = s->spg = s->exec = 0;
58 for (i = 0; i < max_pfn_mapped; ) {
59 unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
63 pte = lookup_address(addr, &level);
70 if (level == PG_LEVEL_1G && sizeof(long) == 8) {
73 } else if (level == PG_LEVEL_2M) {
74 if ((pte_val(*pte) & _PAGE_PRESENT) && !(pte_val(*pte) & _PAGE_PSE)) {
76 "%lx level %d but not PSE %Lx\n",
77 addr, level, (u64)pte_val(*pte));
86 if (!(pte_val(*pte) & _PAGE_NX)) {
88 if (addr < s->min_exec)
90 if (addr > s->max_exec)
96 " 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,
102 expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
104 printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n",
105 max_pfn_mapped, expected);
111 static unsigned long addr[NTEST];
112 static unsigned int len[NTEST];
114 static struct page *pages[NPAGES];
115 static unsigned long addrs[NPAGES];
117 /* Change the global bit on random pages in the direct mapping */
118 static int pageattr_test(void)
120 struct split_state sa, sb, sc;
129 printk(KERN_INFO "CPA self-test:\n");
131 bm = vzalloc((max_pfn_mapped + 7) / 8);
133 printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
137 failed += print_split(&sa);
139 for (i = 0; i < NTEST; i++) {
140 unsigned long pfn = prandom_u32() % max_pfn_mapped;
142 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
143 len[i] = prandom_u32() % NPAGES;
144 len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
150 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
152 for (k = 0; k < len[i]; k++) {
153 pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
154 if (!pte || pgprot_val(pte_pgprot(*pte)) == 0 ||
155 !(pte_val(*pte) & _PAGE_PRESENT)) {
162 if (pgprot_val(pte_pgprot(*pte)) !=
163 pgprot_val(pte_pgprot(pte0))) {
168 if (test_bit(pfn + k, bm)) {
172 __set_bit(pfn + k, bm);
173 addrs[k] = addr[i] + k*PAGE_SIZE;
174 pages[k] = pfn_to_page(pfn + k);
176 if (!addr[i] || !pte || !k) {
183 err = change_page_attr_set(&addr[i], len[i], PAGE_CPA_TEST, 0);
187 err = change_page_attr_set(addrs, len[1], PAGE_CPA_TEST, 1);
191 err = cpa_set_pages_array(pages, len[i], PAGE_CPA_TEST);
197 printk(KERN_ERR "CPA %d failed %d\n", i, err);
201 pte = lookup_address(addr[i], &level);
202 if (!pte || !pte_testbit(*pte) || pte_huge(*pte)) {
203 printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
204 pte ? (u64)pte_val(*pte) : 0ULL);
207 if (level != PG_LEVEL_4K) {
208 printk(KERN_ERR "CPA %lx: unexpected level %d\n",
216 failed += print_split(&sb);
218 for (i = 0; i < NTEST; i++) {
221 pte = lookup_address(addr[i], &level);
223 printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
227 err = change_page_attr_clear(&addr[i], len[i], PAGE_CPA_TEST, 0);
229 printk(KERN_ERR "CPA reverting failed: %d\n", err);
232 pte = lookup_address(addr[i], &level);
233 if (!pte || pte_testbit(*pte)) {
234 printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
235 addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
241 failed += print_split(&sc);
244 WARN(1, KERN_ERR "NOT PASSED. Please report.\n");
248 printk(KERN_INFO "ok.\n");
254 static int do_pageattr_test(void *__unused)
256 while (!kthread_should_stop()) {
257 schedule_timeout_interruptible(HZ*30);
258 if (pageattr_test() < 0)
266 static int start_pageattr_test(void)
268 struct task_struct *p;
270 p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
278 device_initcall(start_pageattr_test);