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/kdebug.h>
20 * Only print the results of the first pass:
22 static __read_mostly int print = 1;
28 LPS = (1 << PMD_SHIFT),
29 #elif defined(CONFIG_X86_PAE)
30 LPS = (1 << PMD_SHIFT),
37 #define PAGE_CPA_TEST __pgprot(_PAGE_CPA_TEST)
39 static int pte_testbit(pte_t pte)
41 return pte_flags(pte) & _PAGE_SOFTW1;
45 long lpg, gpg, spg, exec;
46 long min_exec, max_exec;
49 static int print_split(struct split_state *s)
51 long i, expected, missed = 0;
54 s->lpg = s->gpg = s->spg = s->exec = 0;
57 for (i = 0; i < max_pfn_mapped; ) {
58 unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT);
62 pte = lookup_address(addr, &level);
69 if (level == PG_LEVEL_1G && sizeof(long) == 8) {
72 } else if (level == PG_LEVEL_2M) {
73 if ((pte_val(*pte) & _PAGE_PRESENT) && !(pte_val(*pte) & _PAGE_PSE)) {
75 "%lx level %d but not PSE %Lx\n",
76 addr, level, (u64)pte_val(*pte));
85 if (!(pte_val(*pte) & _PAGE_NX)) {
87 if (addr < s->min_exec)
89 if (addr > s->max_exec)
95 " 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
96 s->spg, s->lpg, s->gpg, s->exec,
97 s->min_exec != ~0UL ? s->min_exec : 0,
101 expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
103 printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n",
104 max_pfn_mapped, expected);
110 static unsigned long addr[NTEST];
111 static unsigned int len[NTEST];
113 static struct page *pages[NPAGES];
114 static unsigned long addrs[NPAGES];
116 /* Change the global bit on random pages in the direct mapping */
117 static int pageattr_test(void)
119 struct split_state sa, sb, sc;
128 printk(KERN_INFO "CPA self-test:\n");
130 bm = vzalloc((max_pfn_mapped + 7) / 8);
132 printk(KERN_ERR "CPA Cannot vmalloc bitmap\n");
136 failed += print_split(&sa);
138 for (i = 0; i < NTEST; i++) {
139 unsigned long pfn = get_random_u32_below(max_pfn_mapped);
141 addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
142 len[i] = get_random_u32_below(NPAGES);
143 len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
149 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */
151 for (k = 0; k < len[i]; k++) {
152 pte = lookup_address(addr[i] + k*PAGE_SIZE, &level);
153 if (!pte || pgprot_val(pte_pgprot(*pte)) == 0 ||
154 !(pte_val(*pte) & _PAGE_PRESENT)) {
161 if (pgprot_val(pte_pgprot(*pte)) !=
162 pgprot_val(pte_pgprot(pte0))) {
167 if (test_bit(pfn + k, bm)) {
171 __set_bit(pfn + k, bm);
172 addrs[k] = addr[i] + k*PAGE_SIZE;
173 pages[k] = pfn_to_page(pfn + k);
175 if (!addr[i] || !pte || !k) {
182 err = change_page_attr_set(&addr[i], len[i], PAGE_CPA_TEST, 0);
186 err = change_page_attr_set(addrs, len[1], PAGE_CPA_TEST, 1);
190 err = cpa_set_pages_array(pages, len[i], PAGE_CPA_TEST);
196 printk(KERN_ERR "CPA %d failed %d\n", i, err);
200 pte = lookup_address(addr[i], &level);
201 if (!pte || !pte_testbit(*pte) || pte_huge(*pte)) {
202 printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
203 pte ? (u64)pte_val(*pte) : 0ULL);
206 if (level != PG_LEVEL_4K) {
207 printk(KERN_ERR "CPA %lx: unexpected level %d\n",
215 failed += print_split(&sb);
217 for (i = 0; i < NTEST; i++) {
220 pte = lookup_address(addr[i], &level);
222 printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]);
226 err = change_page_attr_clear(&addr[i], len[i], PAGE_CPA_TEST, 0);
228 printk(KERN_ERR "CPA reverting failed: %d\n", err);
231 pte = lookup_address(addr[i], &level);
232 if (!pte || pte_testbit(*pte)) {
233 printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
234 addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
240 failed += print_split(&sc);
243 WARN(1, KERN_ERR "NOT PASSED. Please report.\n");
247 printk(KERN_INFO "ok.\n");
253 static int do_pageattr_test(void *__unused)
255 while (!kthread_should_stop()) {
256 schedule_timeout_interruptible(HZ*30);
257 if (pageattr_test() < 0)
265 static int start_pageattr_test(void)
267 struct task_struct *p;
269 p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
277 device_initcall(start_pageattr_test);