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