1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2019 Andes Technology Corporation 3 4 #include <linux/pfn.h> 5 #include <linux/init_task.h> 6 #include <linux/kasan.h> 7 #include <linux/kernel.h> 8 #include <linux/memblock.h> 9 #include <linux/pgtable.h> 10 #include <asm/tlbflush.h> 11 #include <asm/fixmap.h> 12 #include <asm/pgalloc.h> 13 14 /* 15 * Kasan shadow region must lie at a fixed address across sv39, sv48 and sv57 16 * which is right before the kernel. 17 * 18 * For sv39, the region is aligned on PGDIR_SIZE so we only need to populate 19 * the page global directory with kasan_early_shadow_pmd. 20 * 21 * For sv48 and sv57, the region start is aligned on PGDIR_SIZE whereas the end 22 * region is not and then we have to go down to the PUD level. 23 */ 24 25 extern pgd_t early_pg_dir[PTRS_PER_PGD]; 26 pgd_t tmp_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 27 p4d_t tmp_p4d[PTRS_PER_P4D] __page_aligned_bss; 28 pud_t tmp_pud[PTRS_PER_PUD] __page_aligned_bss; 29 30 static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end) 31 { 32 phys_addr_t phys_addr; 33 pte_t *ptep, *p; 34 35 if (pmd_none(*pmd)) { 36 p = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE); 37 set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(p)), PAGE_TABLE)); 38 } 39 40 ptep = pte_offset_kernel(pmd, vaddr); 41 42 do { 43 if (pte_none(*ptep)) { 44 phys_addr = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 45 set_pte(ptep, pfn_pte(PFN_DOWN(phys_addr), PAGE_KERNEL)); 46 memset(__va(phys_addr), KASAN_SHADOW_INIT, PAGE_SIZE); 47 } 48 } while (ptep++, vaddr += PAGE_SIZE, vaddr != end); 49 } 50 51 static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end) 52 { 53 phys_addr_t phys_addr; 54 pmd_t *pmdp, *p; 55 unsigned long next; 56 57 if (pud_none(*pud)) { 58 p = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); 59 set_pud(pud, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE)); 60 } 61 62 pmdp = pmd_offset(pud, vaddr); 63 64 do { 65 next = pmd_addr_end(vaddr, end); 66 67 if (pmd_none(*pmdp) && IS_ALIGNED(vaddr, PMD_SIZE) && (next - vaddr) >= PMD_SIZE) { 68 phys_addr = memblock_phys_alloc(PMD_SIZE, PMD_SIZE); 69 if (phys_addr) { 70 set_pmd(pmdp, pfn_pmd(PFN_DOWN(phys_addr), PAGE_KERNEL)); 71 memset(__va(phys_addr), KASAN_SHADOW_INIT, PMD_SIZE); 72 continue; 73 } 74 } 75 76 kasan_populate_pte(pmdp, vaddr, next); 77 } while (pmdp++, vaddr = next, vaddr != end); 78 } 79 80 static void __init kasan_populate_pud(p4d_t *p4d, 81 unsigned long vaddr, unsigned long end) 82 { 83 phys_addr_t phys_addr; 84 pud_t *pudp, *p; 85 unsigned long next; 86 87 if (p4d_none(*p4d)) { 88 p = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE); 89 set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE)); 90 } 91 92 pudp = pud_offset(p4d, vaddr); 93 94 do { 95 next = pud_addr_end(vaddr, end); 96 97 if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) { 98 phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE); 99 if (phys_addr) { 100 set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL)); 101 memset(__va(phys_addr), KASAN_SHADOW_INIT, PUD_SIZE); 102 continue; 103 } 104 } 105 106 kasan_populate_pmd(pudp, vaddr, next); 107 } while (pudp++, vaddr = next, vaddr != end); 108 } 109 110 static void __init kasan_populate_p4d(pgd_t *pgd, 111 unsigned long vaddr, unsigned long end) 112 { 113 phys_addr_t phys_addr; 114 p4d_t *p4dp, *p; 115 unsigned long next; 116 117 if (pgd_none(*pgd)) { 118 p = memblock_alloc(PTRS_PER_P4D * sizeof(p4d_t), PAGE_SIZE); 119 set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE)); 120 } 121 122 p4dp = p4d_offset(pgd, vaddr); 123 124 do { 125 next = p4d_addr_end(vaddr, end); 126 127 if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) { 128 phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE); 129 if (phys_addr) { 130 set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL)); 131 memset(__va(phys_addr), KASAN_SHADOW_INIT, P4D_SIZE); 132 continue; 133 } 134 } 135 136 kasan_populate_pud(p4dp, vaddr, next); 137 } while (p4dp++, vaddr = next, vaddr != end); 138 } 139 140 static void __init kasan_populate_pgd(pgd_t *pgdp, 141 unsigned long vaddr, unsigned long end) 142 { 143 phys_addr_t phys_addr; 144 unsigned long next; 145 146 do { 147 next = pgd_addr_end(vaddr, end); 148 149 if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) && 150 (next - vaddr) >= PGDIR_SIZE) { 151 phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE); 152 if (phys_addr) { 153 set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL)); 154 memset(__va(phys_addr), KASAN_SHADOW_INIT, PGDIR_SIZE); 155 continue; 156 } 157 } 158 159 kasan_populate_p4d(pgdp, vaddr, next); 160 } while (pgdp++, vaddr = next, vaddr != end); 161 } 162 163 static void __init kasan_early_clear_pud(p4d_t *p4dp, 164 unsigned long vaddr, unsigned long end) 165 { 166 pud_t *pudp, *base_pud; 167 unsigned long next; 168 169 if (!pgtable_l4_enabled) { 170 pudp = (pud_t *)p4dp; 171 } else { 172 base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp))); 173 pudp = base_pud + pud_index(vaddr); 174 } 175 176 do { 177 next = pud_addr_end(vaddr, end); 178 179 if (IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) { 180 pud_clear(pudp); 181 continue; 182 } 183 184 BUG(); 185 } while (pudp++, vaddr = next, vaddr != end); 186 } 187 188 static void __init kasan_early_clear_p4d(pgd_t *pgdp, 189 unsigned long vaddr, unsigned long end) 190 { 191 p4d_t *p4dp, *base_p4d; 192 unsigned long next; 193 194 if (!pgtable_l5_enabled) { 195 p4dp = (p4d_t *)pgdp; 196 } else { 197 base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp))); 198 p4dp = base_p4d + p4d_index(vaddr); 199 } 200 201 do { 202 next = p4d_addr_end(vaddr, end); 203 204 if (pgtable_l4_enabled && IS_ALIGNED(vaddr, P4D_SIZE) && 205 (next - vaddr) >= P4D_SIZE) { 206 p4d_clear(p4dp); 207 continue; 208 } 209 210 kasan_early_clear_pud(p4dp, vaddr, next); 211 } while (p4dp++, vaddr = next, vaddr != end); 212 } 213 214 static void __init kasan_early_clear_pgd(pgd_t *pgdp, 215 unsigned long vaddr, unsigned long end) 216 { 217 unsigned long next; 218 219 do { 220 next = pgd_addr_end(vaddr, end); 221 222 if (pgtable_l5_enabled && IS_ALIGNED(vaddr, PGDIR_SIZE) && 223 (next - vaddr) >= PGDIR_SIZE) { 224 pgd_clear(pgdp); 225 continue; 226 } 227 228 kasan_early_clear_p4d(pgdp, vaddr, next); 229 } while (pgdp++, vaddr = next, vaddr != end); 230 } 231 232 static void __init kasan_early_populate_pud(p4d_t *p4dp, 233 unsigned long vaddr, 234 unsigned long end) 235 { 236 pud_t *pudp, *base_pud; 237 phys_addr_t phys_addr; 238 unsigned long next; 239 240 if (!pgtable_l4_enabled) { 241 pudp = (pud_t *)p4dp; 242 } else { 243 base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp))); 244 pudp = base_pud + pud_index(vaddr); 245 } 246 247 do { 248 next = pud_addr_end(vaddr, end); 249 250 if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && 251 (next - vaddr) >= PUD_SIZE) { 252 phys_addr = __pa((uintptr_t)kasan_early_shadow_pmd); 253 set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE)); 254 continue; 255 } 256 257 BUG(); 258 } while (pudp++, vaddr = next, vaddr != end); 259 } 260 261 static void __init kasan_early_populate_p4d(pgd_t *pgdp, 262 unsigned long vaddr, 263 unsigned long end) 264 { 265 p4d_t *p4dp, *base_p4d; 266 phys_addr_t phys_addr; 267 unsigned long next; 268 269 /* 270 * We can't use pgd_page_vaddr here as it would return a linear 271 * mapping address but it is not mapped yet, but when populating 272 * early_pg_dir, we need the physical address and when populating 273 * swapper_pg_dir, we need the kernel virtual address so use 274 * pt_ops facility. 275 * Note that this test is then completely equivalent to 276 * p4dp = p4d_offset(pgdp, vaddr) 277 */ 278 if (!pgtable_l5_enabled) { 279 p4dp = (p4d_t *)pgdp; 280 } else { 281 base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp))); 282 p4dp = base_p4d + p4d_index(vaddr); 283 } 284 285 do { 286 next = p4d_addr_end(vaddr, end); 287 288 if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && 289 (next - vaddr) >= P4D_SIZE) { 290 phys_addr = __pa((uintptr_t)kasan_early_shadow_pud); 291 set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE)); 292 continue; 293 } 294 295 kasan_early_populate_pud(p4dp, vaddr, next); 296 } while (p4dp++, vaddr = next, vaddr != end); 297 } 298 299 static void __init kasan_early_populate_pgd(pgd_t *pgdp, 300 unsigned long vaddr, 301 unsigned long end) 302 { 303 phys_addr_t phys_addr; 304 unsigned long next; 305 306 do { 307 next = pgd_addr_end(vaddr, end); 308 309 if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) && 310 (next - vaddr) >= PGDIR_SIZE) { 311 phys_addr = __pa((uintptr_t)kasan_early_shadow_p4d); 312 set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE)); 313 continue; 314 } 315 316 kasan_early_populate_p4d(pgdp, vaddr, next); 317 } while (pgdp++, vaddr = next, vaddr != end); 318 } 319 320 asmlinkage void __init kasan_early_init(void) 321 { 322 uintptr_t i; 323 324 BUILD_BUG_ON(KASAN_SHADOW_OFFSET != 325 KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT))); 326 327 for (i = 0; i < PTRS_PER_PTE; ++i) 328 set_pte(kasan_early_shadow_pte + i, 329 pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL)); 330 331 for (i = 0; i < PTRS_PER_PMD; ++i) 332 set_pmd(kasan_early_shadow_pmd + i, 333 pfn_pmd(PFN_DOWN 334 (__pa((uintptr_t)kasan_early_shadow_pte)), 335 PAGE_TABLE)); 336 337 if (pgtable_l4_enabled) { 338 for (i = 0; i < PTRS_PER_PUD; ++i) 339 set_pud(kasan_early_shadow_pud + i, 340 pfn_pud(PFN_DOWN 341 (__pa(((uintptr_t)kasan_early_shadow_pmd))), 342 PAGE_TABLE)); 343 } 344 345 if (pgtable_l5_enabled) { 346 for (i = 0; i < PTRS_PER_P4D; ++i) 347 set_p4d(kasan_early_shadow_p4d + i, 348 pfn_p4d(PFN_DOWN 349 (__pa(((uintptr_t)kasan_early_shadow_pud))), 350 PAGE_TABLE)); 351 } 352 353 kasan_early_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START), 354 KASAN_SHADOW_START, KASAN_SHADOW_END); 355 356 local_flush_tlb_all(); 357 } 358 359 void __init kasan_swapper_init(void) 360 { 361 kasan_early_populate_pgd(pgd_offset_k(KASAN_SHADOW_START), 362 KASAN_SHADOW_START, KASAN_SHADOW_END); 363 364 local_flush_tlb_all(); 365 } 366 367 static void __init kasan_populate(void *start, void *end) 368 { 369 unsigned long vaddr = (unsigned long)start & PAGE_MASK; 370 unsigned long vend = PAGE_ALIGN((unsigned long)end); 371 372 kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend); 373 } 374 375 static void __init kasan_shallow_populate_pud(p4d_t *p4d, 376 unsigned long vaddr, unsigned long end) 377 { 378 unsigned long next; 379 void *p; 380 pud_t *pud_k = pud_offset(p4d, vaddr); 381 382 do { 383 next = pud_addr_end(vaddr, end); 384 385 if (pud_none(*pud_k)) { 386 p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 387 set_pud(pud_k, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE)); 388 continue; 389 } 390 391 BUG(); 392 } while (pud_k++, vaddr = next, vaddr != end); 393 } 394 395 static void __init kasan_shallow_populate_p4d(pgd_t *pgd, 396 unsigned long vaddr, unsigned long end) 397 { 398 unsigned long next; 399 void *p; 400 p4d_t *p4d_k = p4d_offset(pgd, vaddr); 401 402 do { 403 next = p4d_addr_end(vaddr, end); 404 405 if (p4d_none(*p4d_k)) { 406 p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 407 set_p4d(p4d_k, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE)); 408 continue; 409 } 410 411 kasan_shallow_populate_pud(p4d_k, vaddr, end); 412 } while (p4d_k++, vaddr = next, vaddr != end); 413 } 414 415 static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end) 416 { 417 unsigned long next; 418 void *p; 419 pgd_t *pgd_k = pgd_offset_k(vaddr); 420 421 do { 422 next = pgd_addr_end(vaddr, end); 423 424 if (pgd_none(*pgd_k)) { 425 p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 426 set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE)); 427 continue; 428 } 429 430 kasan_shallow_populate_p4d(pgd_k, vaddr, next); 431 } while (pgd_k++, vaddr = next, vaddr != end); 432 } 433 434 static void __init kasan_shallow_populate(void *start, void *end) 435 { 436 unsigned long vaddr = (unsigned long)start & PAGE_MASK; 437 unsigned long vend = PAGE_ALIGN((unsigned long)end); 438 439 kasan_shallow_populate_pgd(vaddr, vend); 440 } 441 442 static void create_tmp_mapping(void) 443 { 444 void *ptr; 445 p4d_t *base_p4d; 446 447 /* 448 * We need to clean the early mapping: this is hard to achieve "in-place", 449 * so install a temporary mapping like arm64 and x86 do. 450 */ 451 memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(pgd_t) * PTRS_PER_PGD); 452 453 /* Copy the last p4d since it is shared with the kernel mapping. */ 454 if (pgtable_l5_enabled) { 455 ptr = (p4d_t *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END)); 456 memcpy(tmp_p4d, ptr, sizeof(p4d_t) * PTRS_PER_P4D); 457 set_pgd(&tmp_pg_dir[pgd_index(KASAN_SHADOW_END)], 458 pfn_pgd(PFN_DOWN(__pa(tmp_p4d)), PAGE_TABLE)); 459 base_p4d = tmp_p4d; 460 } else { 461 base_p4d = (p4d_t *)tmp_pg_dir; 462 } 463 464 /* Copy the last pud since it is shared with the kernel mapping. */ 465 if (pgtable_l4_enabled) { 466 ptr = (pud_t *)p4d_page_vaddr(*(base_p4d + p4d_index(KASAN_SHADOW_END))); 467 memcpy(tmp_pud, ptr, sizeof(pud_t) * PTRS_PER_PUD); 468 set_p4d(&base_p4d[p4d_index(KASAN_SHADOW_END)], 469 pfn_p4d(PFN_DOWN(__pa(tmp_pud)), PAGE_TABLE)); 470 } 471 } 472 473 void __init kasan_init(void) 474 { 475 phys_addr_t p_start, p_end; 476 u64 i; 477 478 create_tmp_mapping(); 479 csr_write(CSR_SATP, PFN_DOWN(__pa(tmp_pg_dir)) | satp_mode); 480 481 kasan_early_clear_pgd(pgd_offset_k(KASAN_SHADOW_START), 482 KASAN_SHADOW_START, KASAN_SHADOW_END); 483 484 kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)FIXADDR_START), 485 (void *)kasan_mem_to_shadow((void *)VMALLOC_START)); 486 487 if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { 488 kasan_shallow_populate( 489 (void *)kasan_mem_to_shadow((void *)VMALLOC_START), 490 (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); 491 /* Shallow populate modules and BPF which are vmalloc-allocated */ 492 kasan_shallow_populate( 493 (void *)kasan_mem_to_shadow((void *)MODULES_VADDR), 494 (void *)kasan_mem_to_shadow((void *)MODULES_END)); 495 } else { 496 kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)VMALLOC_START), 497 (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); 498 } 499 500 /* Populate the linear mapping */ 501 for_each_mem_range(i, &p_start, &p_end) { 502 void *start = (void *)__va(p_start); 503 void *end = (void *)__va(p_end); 504 505 if (start >= end) 506 break; 507 508 kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end)); 509 } 510 511 /* Populate kernel */ 512 kasan_populate(kasan_mem_to_shadow((const void *)MODULES_END), 513 kasan_mem_to_shadow((const void *)MODULES_VADDR + SZ_2G)); 514 515 for (i = 0; i < PTRS_PER_PTE; i++) 516 set_pte(&kasan_early_shadow_pte[i], 517 mk_pte(virt_to_page(kasan_early_shadow_page), 518 __pgprot(_PAGE_PRESENT | _PAGE_READ | 519 _PAGE_ACCESSED))); 520 521 memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE); 522 init_task.kasan_depth = 0; 523 524 csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | satp_mode); 525 local_flush_tlb_all(); 526 } 527