1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * self test for change_page_attr. 4 * 5 * Clears the a test pte bit on random pages in the direct mapping, 6 * then reverts and compares page tables forwards and afterwards. 7 */ 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> 13 #include <linux/mm.h> 14 #include <linux/vmalloc.h> 15 16 #include <asm/cacheflush.h> 17 #include <asm/pgtable.h> 18 #include <asm/kdebug.h> 19 20 /* 21 * Only print the results of the first pass: 22 */ 23 static __read_mostly int print = 1; 24 25 enum { 26 NTEST = 3 * 100, 27 NPAGES = 100, 28 #ifdef CONFIG_X86_64 29 LPS = (1 << PMD_SHIFT), 30 #elif defined(CONFIG_X86_PAE) 31 LPS = (1 << PMD_SHIFT), 32 #else 33 LPS = (1 << 22), 34 #endif 35 GPS = (1<<30) 36 }; 37 38 #define PAGE_CPA_TEST __pgprot(_PAGE_CPA_TEST) 39 40 static int pte_testbit(pte_t pte) 41 { 42 return pte_flags(pte) & _PAGE_SOFTW1; 43 } 44 45 struct split_state { 46 long lpg, gpg, spg, exec; 47 long min_exec, max_exec; 48 }; 49 50 static int print_split(struct split_state *s) 51 { 52 long i, expected, missed = 0; 53 int err = 0; 54 55 s->lpg = s->gpg = s->spg = s->exec = 0; 56 s->min_exec = ~0UL; 57 s->max_exec = 0; 58 for (i = 0; i < max_pfn_mapped; ) { 59 unsigned long addr = (unsigned long)__va(i << PAGE_SHIFT); 60 unsigned int level; 61 pte_t *pte; 62 63 pte = lookup_address(addr, &level); 64 if (!pte) { 65 missed++; 66 i++; 67 continue; 68 } 69 70 if (level == PG_LEVEL_1G && sizeof(long) == 8) { 71 s->gpg++; 72 i += GPS/PAGE_SIZE; 73 } else if (level == PG_LEVEL_2M) { 74 if ((pte_val(*pte) & _PAGE_PRESENT) && !(pte_val(*pte) & _PAGE_PSE)) { 75 printk(KERN_ERR 76 "%lx level %d but not PSE %Lx\n", 77 addr, level, (u64)pte_val(*pte)); 78 err = 1; 79 } 80 s->lpg++; 81 i += LPS/PAGE_SIZE; 82 } else { 83 s->spg++; 84 i++; 85 } 86 if (!(pte_val(*pte) & _PAGE_NX)) { 87 s->exec++; 88 if (addr < s->min_exec) 89 s->min_exec = addr; 90 if (addr > s->max_exec) 91 s->max_exec = addr; 92 } 93 } 94 if (print) { 95 printk(KERN_INFO 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, 99 s->max_exec, missed); 100 } 101 102 expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed; 103 if (expected != i) { 104 printk(KERN_ERR "CPA max_pfn_mapped %lu but expected %lu\n", 105 max_pfn_mapped, expected); 106 return 1; 107 } 108 return err; 109 } 110 111 static unsigned long addr[NTEST]; 112 static unsigned int len[NTEST]; 113 114 static struct page *pages[NPAGES]; 115 static unsigned long addrs[NPAGES]; 116 117 /* Change the global bit on random pages in the direct mapping */ 118 static int pageattr_test(void) 119 { 120 struct split_state sa, sb, sc; 121 unsigned long *bm; 122 pte_t *pte, pte0; 123 int failed = 0; 124 unsigned int level; 125 int i, k; 126 int err; 127 128 if (print) 129 printk(KERN_INFO "CPA self-test:\n"); 130 131 bm = vzalloc((max_pfn_mapped + 7) / 8); 132 if (!bm) { 133 printk(KERN_ERR "CPA Cannot vmalloc bitmap\n"); 134 return -ENOMEM; 135 } 136 137 failed += print_split(&sa); 138 139 for (i = 0; i < NTEST; i++) { 140 unsigned long pfn = prandom_u32() % max_pfn_mapped; 141 142 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); 145 146 if (len[i] == 0) 147 len[i] = 1; 148 149 pte = NULL; 150 pte0 = pfn_pte(0, __pgprot(0)); /* shut gcc up */ 151 152 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)) { 156 addr[i] = 0; 157 break; 158 } 159 if (k == 0) { 160 pte0 = *pte; 161 } else { 162 if (pgprot_val(pte_pgprot(*pte)) != 163 pgprot_val(pte_pgprot(pte0))) { 164 len[i] = k; 165 break; 166 } 167 } 168 if (test_bit(pfn + k, bm)) { 169 len[i] = k; 170 break; 171 } 172 __set_bit(pfn + k, bm); 173 addrs[k] = addr[i] + k*PAGE_SIZE; 174 pages[k] = pfn_to_page(pfn + k); 175 } 176 if (!addr[i] || !pte || !k) { 177 addr[i] = 0; 178 continue; 179 } 180 181 switch (i % 3) { 182 case 0: 183 err = change_page_attr_set(&addr[i], len[i], PAGE_CPA_TEST, 0); 184 break; 185 186 case 1: 187 err = change_page_attr_set(addrs, len[1], PAGE_CPA_TEST, 1); 188 break; 189 190 case 2: 191 err = cpa_set_pages_array(pages, len[i], PAGE_CPA_TEST); 192 break; 193 } 194 195 196 if (err < 0) { 197 printk(KERN_ERR "CPA %d failed %d\n", i, err); 198 failed++; 199 } 200 201 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); 205 failed++; 206 } 207 if (level != PG_LEVEL_4K) { 208 printk(KERN_ERR "CPA %lx: unexpected level %d\n", 209 addr[i], level); 210 failed++; 211 } 212 213 } 214 vfree(bm); 215 216 failed += print_split(&sb); 217 218 for (i = 0; i < NTEST; i++) { 219 if (!addr[i]) 220 continue; 221 pte = lookup_address(addr[i], &level); 222 if (!pte) { 223 printk(KERN_ERR "CPA lookup of %lx failed\n", addr[i]); 224 failed++; 225 continue; 226 } 227 err = change_page_attr_clear(&addr[i], len[i], PAGE_CPA_TEST, 0); 228 if (err < 0) { 229 printk(KERN_ERR "CPA reverting failed: %d\n", err); 230 failed++; 231 } 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); 236 failed++; 237 } 238 239 } 240 241 failed += print_split(&sc); 242 243 if (failed) { 244 WARN(1, KERN_ERR "NOT PASSED. Please report.\n"); 245 return -EINVAL; 246 } else { 247 if (print) 248 printk(KERN_INFO "ok.\n"); 249 } 250 251 return 0; 252 } 253 254 static int do_pageattr_test(void *__unused) 255 { 256 while (!kthread_should_stop()) { 257 schedule_timeout_interruptible(HZ*30); 258 if (pageattr_test() < 0) 259 break; 260 if (print) 261 print--; 262 } 263 return 0; 264 } 265 266 static int start_pageattr_test(void) 267 { 268 struct task_struct *p; 269 270 p = kthread_create(do_pageattr_test, NULL, "pageattr-test"); 271 if (!IS_ERR(p)) 272 wake_up_process(p); 273 else 274 WARN_ON(1); 275 276 return 0; 277 } 278 device_initcall(start_pageattr_test); 279