개념 설명 전체 · v6.6 / mm/vmalloc.c
1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 1993 Linus Torvalds 4 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 5 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <[email protected]>, May 2000 6 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 7 * Numa awareness, Christoph Lameter, SGI, June 2005 8 * Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019 9 */ 10 11 #include <linux/vmalloc.h> 12 #include <linux/mm.h> 13 #include <linux/module.h> 14 #include <linux/highmem.h> 15 #include <linux/sched/signal.h> 16 #include <linux/slab.h> 17 #include <linux/spinlock.h> 18 #include <linux/interrupt.h> 19 #include <linux/proc_fs.h> 20 #include <linux/seq_file.h> 21 #include <linux/set_memory.h> 22 #include <linux/debugobjects.h> 23 #include <linux/kallsyms.h> 24 #include <linux/list.h> 25 #include <linux/notifier.h> 26 #include <linux/rbtree.h> 27 #include <linux/xarray.h> 28 #include <linux/io.h> 29 #include <linux/rcupdate.h> 30 #include <linux/pfn.h> 31 #include <linux/kmemleak.h> 32 #include <linux/atomic.h> 33 #include <linux/compiler.h> 34 #include <linux/memcontrol.h> 35 #include <linux/llist.h> 36 #include <linux/uio.h> 37 #include <linux/bitops.h> 38 #include <linux/rbtree_augmented.h> 39 #include <linux/overflow.h> 40 #include <linux/pgtable.h> 41 #include <linux/hugetlb.h> 42 #include <linux/sched/mm.h> 43 #include <asm/tlbflush.h> 44 #include <asm/shmparam.h> 45 46 #define CREATE_TRACE_POINTS 47 #include <trace/events/vmalloc.h> 48 49 #include "internal.h" 50 #include "pgalloc-track.h" 51 52 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP 53 static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1; 54 55 static int __init set_nohugeiomap(char *str) 56 { 57 ioremap_max_page_shift = PAGE_SHIFT; 58 return 0; 59 } 60 early_param("nohugeiomap", set_nohugeiomap); 61 #else /* CONFIG_HAVE_ARCH_HUGE_VMAP */ 62 static const unsigned int ioremap_max_page_shift = PAGE_SHIFT; 63 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ 64 65 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC 66 static bool __ro_after_init vmap_allow_huge = true; 67 68 static int __init set_nohugevmalloc(char *str) 69 { 70 vmap_allow_huge = false; 71 return 0; 72 } 73 early_param("nohugevmalloc", set_nohugevmalloc); 74 #else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */ 75 static const bool vmap_allow_huge = false; 76 #endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */ 77 78 bool is_vmalloc_addr(const void *x) 79 { 80 unsigned long addr = (unsigned long)kasan_reset_tag(x); 81 82 return addr >= VMALLOC_START && addr < VMALLOC_END; 83 } 84 EXPORT_SYMBOL(is_vmalloc_addr); 85 86 struct vfree_deferred { 87 struct llist_head list; 88 struct work_struct wq; 89 }; 90 static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred); 91 92 /*** Page table manipulation functions ***/ 93 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 94 phys_addr_t phys_addr, pgprot_t prot, 95 unsigned int max_page_shift, pgtbl_mod_mask *mask) 96 { 97 pte_t *pte; 98 u64 pfn; 99 unsigned long size = PAGE_SIZE; 100 101 pfn = phys_addr >> PAGE_SHIFT; 102 pte = pte_alloc_kernel_track(pmd, addr, mask); 103 if (!pte) 104 return -ENOMEM; 105 do { 106 BUG_ON(!pte_none(ptep_get(pte))); 107 108 #ifdef CONFIG_HUGETLB_PAGE 109 size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift); 110 if (size != PAGE_SIZE) { 111 pte_t entry = pfn_pte(pfn, prot); 112 113 entry = arch_make_huge_pte(entry, ilog2(size), 0); 114 set_huge_pte_at(&init_mm, addr, pte, entry, size); 115 pfn += PFN_DOWN(size); 116 continue; 117 } 118 #endif 119 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); 120 pfn++; 121 } while (pte += PFN_DOWN(size), addr += size, addr != end); 122 *mask |= PGTBL_PTE_MODIFIED; 123 return 0; 124 } 125 126 static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end, 127 phys_addr_t phys_addr, pgprot_t prot, 128 unsigned int max_page_shift) 129 { 130 if (max_page_shift < PMD_SHIFT) 131 return 0; 132 133 if (!arch_vmap_pmd_supported(prot)) 134 return 0; 135 136 if ((end - addr) != PMD_SIZE) 137 return 0; 138 139 if (!IS_ALIGNED(addr, PMD_SIZE)) 140 return 0; 141 142 if (!IS_ALIGNED(phys_addr, PMD_SIZE)) 143 return 0; 144 145 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr)) 146 return 0; 147 148 return pmd_set_huge(pmd, phys_addr, prot); 149 } 150 151 static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, 152 phys_addr_t phys_addr, pgprot_t prot, 153 unsigned int max_page_shift, pgtbl_mod_mask *mask) 154 { 155 pmd_t *pmd; 156 unsigned long next; 157 158 pmd = pmd_alloc_track(&init_mm, pud, addr, mask); 159 if (!pmd) 160 return -ENOMEM; 161 do { 162 next = pmd_addr_end(addr, end); 163 164 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot, 165 max_page_shift)) { 166 *mask |= PGTBL_PMD_MODIFIED; 167 continue; 168 } 169 170 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask)) 171 return -ENOMEM; 172 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); 173 return 0; 174 } 175 176 static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end, 177 phys_addr_t phys_addr, pgprot_t prot, 178 unsigned int max_page_shift) 179 { 180 if (max_page_shift < PUD_SHIFT) 181 return 0; 182 183 if (!arch_vmap_pud_supported(prot)) 184 return 0; 185 186 if ((end - addr) != PUD_SIZE) 187 return 0; 188 189 if (!IS_ALIGNED(addr, PUD_SIZE)) 190 return 0; 191 192 if (!IS_ALIGNED(phys_addr, PUD_SIZE)) 193 return 0; 194 195 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr)) 196 return 0; 197 198 return pud_set_huge(pud, phys_addr, prot); 199 } 200 201 static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, 202 phys_addr_t phys_addr, pgprot_t prot, 203 unsigned int max_page_shift, pgtbl_mod_mask *mask) 204 { 205 pud_t *pud; 206 unsigned long next; 207 208 pud = pud_alloc_track(&init_mm, p4d, addr, mask); 209 if (!pud) 210 return -ENOMEM; 211 do { 212 next = pud_addr_end(addr, end); 213 214 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot, 215 max_page_shift)) { 216 *mask |= PGTBL_PUD_MODIFIED; 217 continue; 218 } 219 220 if (vmap_pmd_range(pud, addr, next, phys_addr, prot, 221 max_page_shift, mask)) 222 return -ENOMEM; 223 } while (pud++, phys_addr += (next - addr), addr = next, addr != end); 224 return 0; 225 } 226 227 static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end, 228 phys_addr_t phys_addr, pgprot_t prot, 229 unsigned int max_page_shift) 230 { 231 if (max_page_shift < P4D_SHIFT) 232 return 0; 233 234 if (!arch_vmap_p4d_supported(prot)) 235 return 0; 236 237 if ((end - addr) != P4D_SIZE) 238 return 0; 239 240 if (!IS_ALIGNED(addr, P4D_SIZE)) 241 return 0; 242 243 if (!IS_ALIGNED(phys_addr, P4D_SIZE)) 244 return 0; 245 246 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr)) 247 return 0; 248 249 return p4d_set_huge(p4d, phys_addr, prot); 250 } 251 252 static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, 253 phys_addr_t phys_addr, pgprot_t prot, 254 unsigned int max_page_shift, pgtbl_mod_mask *mask) 255 { 256 p4d_t *p4d; 257 unsigned long next; 258 259 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); 260 if (!p4d) 261 return -ENOMEM; 262 do { 263 next = p4d_addr_end(addr, end); 264 265 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot, 266 max_page_shift)) { 267 *mask |= PGTBL_P4D_MODIFIED; 268 continue; 269 } 270 271 if (vmap_pud_range(p4d, addr, next, phys_addr, prot, 272 max_page_shift, mask)) 273 return -ENOMEM; 274 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); 275 return 0; 276 } 277 278 static int vmap_range_noflush(unsigned long addr, unsigned long end, 279 phys_addr_t phys_addr, pgprot_t prot, 280 unsigned int max_page_shift) 281 { 282 pgd_t *pgd; 283 unsigned long start; 284 unsigned long next; 285 int err; 286 pgtbl_mod_mask mask = 0; 287 288 might_sleep(); 289 BUG_ON(addr >= end); 290 291 start = addr; 292 pgd = pgd_offset_k(addr); 293 do { 294 next = pgd_addr_end(addr, end); 295 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot, 296 max_page_shift, &mask); 297 if (err) 298 break; 299 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); 300 301 if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 302 arch_sync_kernel_mappings(start, end); 303 304 return err; 305 } 306 307 int ioremap_page_range(unsigned long addr, unsigned long end, 308 phys_addr_t phys_addr, pgprot_t prot) 309 { 310 int err; 311 312 err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), 313 ioremap_max_page_shift); 314 flush_cache_vmap(addr, end); 315 if (!err) 316 err = kmsan_ioremap_page_range(addr, end, phys_addr, prot, 317 ioremap_max_page_shift); 318 return err; 319 } 320 321 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 322 pgtbl_mod_mask *mask) 323 { 324 pte_t *pte; 325 326 pte = pte_offset_kernel(pmd, addr); 327 do { 328 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); 329 WARN_ON(!pte_none(ptent) && !pte_present(ptent)); 330 } while (pte++, addr += PAGE_SIZE, addr != end); 331 *mask |= PGTBL_PTE_MODIFIED; 332 } 333 334 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, 335 pgtbl_mod_mask *mask) 336 { 337 pmd_t *pmd; 338 unsigned long next; 339 int cleared; 340 341 pmd = pmd_offset(pud, addr); 342 do { 343 next = pmd_addr_end(addr, end); 344 345 cleared = pmd_clear_huge(pmd); 346 if (cleared || pmd_bad(*pmd)) 347 *mask |= PGTBL_PMD_MODIFIED; 348 349 if (cleared) 350 continue; 351 if (pmd_none_or_clear_bad(pmd)) 352 continue; 353 vunmap_pte_range(pmd, addr, next, mask); 354 355 cond_resched(); 356 } while (pmd++, addr = next, addr != end); 357 } 358 359 static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, 360 pgtbl_mod_mask *mask) 361 { 362 pud_t *pud; 363 unsigned long next; 364 int cleared; 365 366 pud = pud_offset(p4d, addr); 367 do { 368 next = pud_addr_end(addr, end); 369 370 cleared = pud_clear_huge(pud); 371 if (cleared || pud_bad(*pud)) 372 *mask |= PGTBL_PUD_MODIFIED; 373 374 if (cleared) 375 continue; 376 if (pud_none_or_clear_bad(pud)) 377 continue; 378 vunmap_pmd_range(pud, addr, next, mask); 379 } while (pud++, addr = next, addr != end); 380 } 381 382 static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, 383 pgtbl_mod_mask *mask) 384 { 385 p4d_t *p4d; 386 unsigned long next; 387 388 p4d = p4d_offset(pgd, addr); 389 do { 390 next = p4d_addr_end(addr, end); 391 392 p4d_clear_huge(p4d); 393 if (p4d_bad(*p4d)) 394 *mask |= PGTBL_P4D_MODIFIED; 395 396 if (p4d_none_or_clear_bad(p4d)) 397 continue; 398 vunmap_pud_range(p4d, addr, next, mask); 399 } while (p4d++, addr = next, addr != end); 400 } 401 402 /* 403 * vunmap_range_noflush is similar to vunmap_range, but does not 404 * flush caches or TLBs. 405 * 406 * The caller is responsible for calling flush_cache_vmap() before calling 407 * this function, and flush_tlb_kernel_range after it has returned 408 * successfully (and before the addresses are expected to cause a page fault 409 * or be re-mapped for something else, if TLB flushes are being delayed or 410 * coalesced). 411 * 412 * This is an internal function only. Do not use outside mm/. 413 */ 414 void __vunmap_range_noflush(unsigned long start, unsigned long end) 415 { 416 unsigned long next; 417 pgd_t *pgd; 418 unsigned long addr = start; 419 pgtbl_mod_mask mask = 0; 420 421 BUG_ON(addr >= end); 422 pgd = pgd_offset_k(addr); 423 do { 424 next = pgd_addr_end(addr, end); 425 if (pgd_bad(*pgd)) 426 mask |= PGTBL_PGD_MODIFIED; 427 if (pgd_none_or_clear_bad(pgd)) 428 continue; 429 vunmap_p4d_range(pgd, addr, next, &mask); 430 } while (pgd++, addr = next, addr != end); 431 432 if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 433 arch_sync_kernel_mappings(start, end); 434 } 435 436 void vunmap_range_noflush(unsigned long start, unsigned long end) 437 { 438 kmsan_vunmap_range_noflush(start, end); 439 __vunmap_range_noflush(start, end); 440 } 441 442 /** 443 * vunmap_range - unmap kernel virtual addresses 444 * @addr: start of the VM area to unmap 445 * @end: end of the VM area to unmap (non-inclusive) 446 * 447 * Clears any present PTEs in the virtual address range, flushes TLBs and 448 * caches. Any subsequent access to the address before it has been re-mapped 449 * is a kernel bug. 450 */ 451 void vunmap_range(unsigned long addr, unsigned long end) 452 { 453 flush_cache_vunmap(addr, end); 454 vunmap_range_noflush(addr, end); 455 flush_tlb_kernel_range(addr, end); 456 } 457 458 static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, 459 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 460 pgtbl_mod_mask *mask) 461 { 462 pte_t *pte; 463 464 /* 465 * nr is a running index into the array which helps higher level 466 * callers keep track of where we're up to. 467 */ 468 469 pte = pte_alloc_kernel_track(pmd, addr, mask); 470 if (!pte) 471 return -ENOMEM; 472 do { 473 struct page *page = pages[*nr]; 474 475 if (WARN_ON(!pte_none(ptep_get(pte)))) 476 return -EBUSY; 477 if (WARN_ON(!page)) 478 return -ENOMEM; 479 if (WARN_ON(!pfn_valid(page_to_pfn(page)))) 480 return -EINVAL; 481 482 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); 483 (*nr)++; 484 } while (pte++, addr += PAGE_SIZE, addr != end); 485 *mask |= PGTBL_PTE_MODIFIED; 486 return 0; 487 } 488 489 static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr, 490 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 491 pgtbl_mod_mask *mask) 492 { 493 pmd_t *pmd; 494 unsigned long next; 495 496 pmd = pmd_alloc_track(&init_mm, pud, addr, mask); 497 if (!pmd) 498 return -ENOMEM; 499 do { 500 next = pmd_addr_end(addr, end); 501 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask)) 502 return -ENOMEM; 503 } while (pmd++, addr = next, addr != end); 504 return 0; 505 } 506 507 static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr, 508 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 509 pgtbl_mod_mask *mask) 510 { 511 pud_t *pud; 512 unsigned long next; 513 514 pud = pud_alloc_track(&init_mm, p4d, addr, mask); 515 if (!pud) 516 return -ENOMEM; 517 do { 518 next = pud_addr_end(addr, end); 519 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask)) 520 return -ENOMEM; 521 } while (pud++, addr = next, addr != end); 522 return 0; 523 } 524 525 static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr, 526 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 527 pgtbl_mod_mask *mask) 528 { 529 p4d_t *p4d; 530 unsigned long next; 531 532 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); 533 if (!p4d) 534 return -ENOMEM; 535 do { 536 next = p4d_addr_end(addr, end); 537 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask)) 538 return -ENOMEM; 539 } while (p4d++, addr = next, addr != end); 540 return 0; 541 } 542 543 static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, 544 pgprot_t prot, struct page **pages) 545 { 546 unsigned long start = addr; 547 pgd_t *pgd; 548 unsigned long next; 549 int err = 0; 550 int nr = 0; 551 pgtbl_mod_mask mask = 0; 552 553 BUG_ON(addr >= end); 554 pgd = pgd_offset_k(addr); 555 do { 556 next = pgd_addr_end(addr, end); 557 if (pgd_bad(*pgd)) 558 mask |= PGTBL_PGD_MODIFIED; 559 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask); 560 if (err) 561 return err; 562 } while (pgd++, addr = next, addr != end); 563 564 if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 565 arch_sync_kernel_mappings(start, end); 566 567 return 0; 568 } 569 570 /* 571 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not 572 * flush caches. 573 * 574 * The caller is responsible for calling flush_cache_vmap() after this 575 * function returns successfully and before the addresses are accessed. 576 * 577 * This is an internal function only. Do not use outside mm/. 578 */ 579 int __vmap_pages_range_noflush(unsigned long addr, unsigned long end, 580 pgprot_t prot, struct page **pages, unsigned int page_shift) 581 { 582 unsigned int i, nr = (end - addr) >> PAGE_SHIFT; 583 584 WARN_ON(page_shift < PAGE_SHIFT); 585 586 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || 587 page_shift == PAGE_SHIFT) 588 return vmap_small_pages_range_noflush(addr, end, prot, pages); 589 590 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) { 591 int err; 592 593 err = vmap_range_noflush(addr, addr + (1UL << page_shift), 594 page_to_phys(pages[i]), prot, 595 page_shift); 596 if (err) 597 return err; 598 599 addr += 1UL << page_shift; 600 } 601 602 return 0; 603 } 604 605 int vmap_pages_range_noflush(unsigned long addr, unsigned long end, 606 pgprot_t prot, struct page **pages, unsigned int page_shift) 607 { 608 int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages, 609 page_shift); 610 611 if (ret) 612 return ret; 613 return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift); 614 } 615 616 /** 617 * vmap_pages_range - map pages to a kernel virtual address 618 * @addr: start of the VM area to map 619 * @end: end of the VM area to map (non-inclusive) 620 * @prot: page protection flags to use 621 * @pages: pages to map (always PAGE_SIZE pages) 622 * @page_shift: maximum shift that the pages may be mapped with, @pages must 623 * be aligned and contiguous up to at least this shift. 624 * 625 * RETURNS: 626 * 0 on success, -errno on failure. 627 */ 628 static int vmap_pages_range(unsigned long addr, unsigned long end, 629 pgprot_t prot, struct page **pages, unsigned int page_shift) 630 { 631 int err; 632 633 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift); 634 flush_cache_vmap(addr, end); 635 return err; 636 } 637 638 int is_vmalloc_or_module_addr(const void *x) 639 { 640 /* 641 * ARM, x86-64 and sparc64 put modules in a special place, 642 * and fall back on vmalloc() if that fails. Others 643 * just put it in the vmalloc space. 644 */ 645 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) 646 unsigned long addr = (unsigned long)kasan_reset_tag(x); 647 if (addr >= MODULES_VADDR && addr < MODULES_END) 648 return 1; 649 #endif 650 return is_vmalloc_addr(x); 651 } 652 EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr); 653 654 /* 655 * Walk a vmap address to the struct page it maps. Huge vmap mappings will 656 * return the tail page that corresponds to the base page address, which 657 * matches small vmap mappings. 658 */ 659 struct page *vmalloc_to_page(const void *vmalloc_addr) 660 { 661 unsigned long addr = (unsigned long) vmalloc_addr; 662 struct page *page = NULL; 663 pgd_t *pgd = pgd_offset_k(addr); 664 p4d_t *p4d; 665 pud_t *pud; 666 pmd_t *pmd; 667 pte_t *ptep, pte; 668 669 /* 670 * XXX we might need to change this if we add VIRTUAL_BUG_ON for 671 * architectures that do not vmalloc module space 672 */ 673 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr)); 674 675 if (pgd_none(*pgd)) 676 return NULL; 677 if (WARN_ON_ONCE(pgd_leaf(*pgd))) 678 return NULL; /* XXX: no allowance for huge pgd */ 679 if (WARN_ON_ONCE(pgd_bad(*pgd))) 680 return NULL; 681 682 p4d = p4d_offset(pgd, addr); 683 if (p4d_none(*p4d)) 684 return NULL; 685 if (p4d_leaf(*p4d)) 686 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT); 687 if (WARN_ON_ONCE(p4d_bad(*p4d))) 688 return NULL; 689 690 pud = pud_offset(p4d, addr); 691 if (pud_none(*pud)) 692 return NULL; 693 if (pud_leaf(*pud)) 694 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); 695 if (WARN_ON_ONCE(pud_bad(*pud))) 696 return NULL; 697 698 pmd = pmd_offset(pud, addr); 699 if (pmd_none(*pmd)) 700 return NULL; 701 if (pmd_leaf(*pmd)) 702 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); 703 if (WARN_ON_ONCE(pmd_bad(*pmd))) 704 return NULL; 705 706 ptep = pte_offset_kernel(pmd, addr); 707 pte = ptep_get(ptep); 708 if (pte_present(pte)) 709 page = pte_page(pte); 710 711 return page; 712 } 713 EXPORT_SYMBOL(vmalloc_to_page); 714 715 /* 716 * Map a vmalloc()-space virtual address to the physical page frame number. 717 */ 718 unsigned long vmalloc_to_pfn(const void *vmalloc_addr) 719 { 720 return page_to_pfn(vmalloc_to_page(vmalloc_addr)); 721 } 722 EXPORT_SYMBOL(vmalloc_to_pfn); 723 724 725 /*** Global kva allocator ***/ 726 727 #define DEBUG_AUGMENT_PROPAGATE_CHECK 0 728 #define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0 729 730 731 static DEFINE_SPINLOCK(vmap_area_lock); 732 static DEFINE_SPINLOCK(free_vmap_area_lock); 733 /* Export for kexec only */ 734 LIST_HEAD(vmap_area_list); 735 static struct rb_root vmap_area_root = RB_ROOT; 736 static bool vmap_initialized __read_mostly; 737 738 static struct rb_root purge_vmap_area_root = RB_ROOT; 739 static LIST_HEAD(purge_vmap_area_list); 740 static DEFINE_SPINLOCK(purge_vmap_area_lock); 741 742 /* 743 * This kmem_cache is used for vmap_area objects. Instead of 744 * allocating from slab we reuse an object from this cache to 745 * make things faster. Especially in "no edge" splitting of 746 * free block. 747 */ 748 static struct kmem_cache *vmap_area_cachep; 749 750 /* 751 * This linked list is used in pair with free_vmap_area_root. 752 * It gives O(1) access to prev/next to perform fast coalescing. 753 */ 754 static LIST_HEAD(free_vmap_area_list); 755 756 /* 757 * This augment red-black tree represents the free vmap space. 758 * All vmap_area objects in this tree are sorted by va->va_start 759 * address. It is used for allocation and merging when a vmap 760 * object is released. 761 * 762 * Each vmap_area node contains a maximum available free block 763 * of its sub-tree, right or left. Therefore it is possible to 764 * find a lowest match of free area. 765 */ 766 static struct rb_root free_vmap_area_root = RB_ROOT; 767 768 /* 769 * Preload a CPU with one object for "no edge" split case. The 770 * aim is to get rid of allocations from the atomic context, thus 771 * to use more permissive allocation masks. 772 */ 773 static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node); 774 775 static __always_inline unsigned long 776 va_size(struct vmap_area *va) 777 { 778 return (va->va_end - va->va_start); 779 } 780 781 static __always_inline unsigned long 782 get_subtree_max_size(struct rb_node *node) 783 { 784 struct vmap_area *va; 785 786 va = rb_entry_safe(node, struct vmap_area, rb_node); 787 return va ? va->subtree_max_size : 0; 788 } 789 790 RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb, 791 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size) 792 793 static void reclaim_and_purge_vmap_areas(void); 794 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); 795 static void drain_vmap_area_work(struct work_struct *work); 796 static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work); 797 798 static atomic_long_t nr_vmalloc_pages; 799 800 unsigned long vmalloc_nr_pages(void) 801 { 802 return atomic_long_read(&nr_vmalloc_pages); 803 } 804 805 /* Look up the first VA which satisfies addr < va_end, NULL if none. */ 806 static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr) 807 { 808 struct vmap_area *va = NULL; 809 struct rb_node *n = vmap_area_root.rb_node; 810 811 addr = (unsigned long)kasan_reset_tag((void *)addr); 812 813 while (n) { 814 struct vmap_area *tmp; 815 816 tmp = rb_entry(n, struct vmap_area, rb_node); 817 if (tmp->va_end > addr) { 818 va = tmp; 819 if (tmp->va_start <= addr) 820 break; 821 822 n = n->rb_left; 823 } else 824 n = n->rb_right; 825 } 826 827 return va; 828 } 829 830 static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root) 831 { 832 struct rb_node *n = root->rb_node; 833 834 addr = (unsigned long)kasan_reset_tag((void *)addr); 835 836 while (n) { 837 struct vmap_area *va; 838 839 va = rb_entry(n, struct vmap_area, rb_node); 840 if (addr < va->va_start) 841 n = n->rb_left; 842 else if (addr >= va->va_end) 843 n = n->rb_right; 844 else 845 return va; 846 } 847 848 return NULL; 849 } 850 851 /* 852 * This function returns back addresses of parent node 853 * and its left or right link for further processing. 854 * 855 * Otherwise NULL is returned. In that case all further 856 * steps regarding inserting of conflicting overlap range 857 * have to be declined and actually considered as a bug. 858 */ 859 static __always_inline struct rb_node ** 860 find_va_links(struct vmap_area *va, 861 struct rb_root *root, struct rb_node *from, 862 struct rb_node **parent) 863 { 864 struct vmap_area *tmp_va; 865 struct rb_node **link; 866 867 if (root) { 868 link = &root->rb_node; 869 if (unlikely(!*link)) { 870 *parent = NULL; 871 return link; 872 } 873 } else { 874 link = &from; 875 } 876 877 /* 878 * Go to the bottom of the tree. When we hit the last point 879 * we end up with parent rb_node and correct direction, i name 880 * it link, where the new va->rb_node will be attached to. 881 */ 882 do { 883 tmp_va = rb_entry(*link, struct vmap_area, rb_node); 884 885 /* 886 * During the traversal we also do some sanity check. 887 * Trigger the BUG() if there are sides(left/right) 888 * or full overlaps. 889 */ 890 if (va->va_end <= tmp_va->va_start) 891 link = &(*link)->rb_left; 892 else if (va->va_start >= tmp_va->va_end) 893 link = &(*link)->rb_right; 894 else { 895 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n", 896 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end); 897 898 return NULL; 899 } 900 } while (*link); 901 902 *parent = &tmp_va->rb_node; 903 return link; 904 } 905 906 static __always_inline struct list_head * 907 get_va_next_sibling(struct rb_node *parent, struct rb_node **link) 908 { 909 struct list_head *list; 910 911 if (unlikely(!parent)) 912 /* 913 * The red-black tree where we try to find VA neighbors 914 * before merging or inserting is empty, i.e. it means 915 * there is no free vmap space. Normally it does not 916 * happen but we handle this case anyway. 917 */ 918 return NULL; 919 920 list = &rb_entry(parent, struct vmap_area, rb_node)->list; 921 return (&parent->rb_right == link ? list->next : list); 922 } 923 924 static __always_inline void 925 __link_va(struct vmap_area *va, struct rb_root *root, 926 struct rb_node *parent, struct rb_node **link, 927 struct list_head *head, bool augment) 928 { 929 /* 930 * VA is still not in the list, but we can 931 * identify its future previous list_head node. 932 */ 933 if (likely(parent)) { 934 head = &rb_entry(parent, struct vmap_area, rb_node)->list; 935 if (&parent->rb_right != link) 936 head = head->prev; 937 } 938 939 /* Insert to the rb-tree */ 940 rb_link_node(&va->rb_node, parent, link); 941 if (augment) { 942 /* 943 * Some explanation here. Just perform simple insertion 944 * to the tree. We do not set va->subtree_max_size to 945 * its current size before calling rb_insert_augmented(). 946 * It is because we populate the tree from the bottom 947 * to parent levels when the node _is_ in the tree. 948 * 949 * Therefore we set subtree_max_size to zero after insertion, 950 * to let __augment_tree_propagate_from() puts everything to 951 * the correct order later on. 952 */ 953 rb_insert_augmented(&va->rb_node, 954 root, &free_vmap_area_rb_augment_cb); 955 va->subtree_max_size = 0; 956 } else { 957 rb_insert_color(&va->rb_node, root); 958 } 959 960 /* Address-sort this list */ 961 list_add(&va->list, head); 962 } 963 964 static __always_inline void 965 link_va(struct vmap_area *va, struct rb_root *root, 966 struct rb_node *parent, struct rb_node **link, 967 struct list_head *head) 968 { 969 __link_va(va, root, parent, link, head, false); 970 } 971 972 static __always_inline void 973 link_va_augment(struct vmap_area *va, struct rb_root *root, 974 struct rb_node *parent, struct rb_node **link, 975 struct list_head *head) 976 { 977 __link_va(va, root, parent, link, head, true); 978 } 979 980 static __always_inline void 981 __unlink_va(struct vmap_area *va, struct rb_root *root, bool augment) 982 { 983 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node))) 984 return; 985 986 if (augment) 987 rb_erase_augmented(&va->rb_node, 988 root, &free_vmap_area_rb_augment_cb); 989 else 990 rb_erase(&va->rb_node, root); 991 992 list_del_init(&va->list); 993 RB_CLEAR_NODE(&va->rb_node); 994 } 995 996 static __always_inline void 997 unlink_va(struct vmap_area *va, struct rb_root *root) 998 { 999 __unlink_va(va, root, false); 1000 } 1001 1002 static __always_inline void 1003 unlink_va_augment(struct vmap_area *va, struct rb_root *root) 1004 { 1005 __unlink_va(va, root, true); 1006 } 1007 1008 #if DEBUG_AUGMENT_PROPAGATE_CHECK 1009 /* 1010 * Gets called when remove the node and rotate. 1011 */ 1012 static __always_inline unsigned long 1013 compute_subtree_max_size(struct vmap_area *va) 1014 { 1015 return max3(va_size(va), 1016 get_subtree_max_size(va->rb_node.rb_left), 1017 get_subtree_max_size(va->rb_node.rb_right)); 1018 } 1019 1020 static void 1021 augment_tree_propagate_check(void) 1022 { 1023 struct vmap_area *va; 1024 unsigned long computed_size; 1025 1026 list_for_each_entry(va, &free_vmap_area_list, list) { 1027 computed_size = compute_subtree_max_size(va); 1028 if (computed_size != va->subtree_max_size) 1029 pr_emerg("tree is corrupted: %lu, %lu\n", 1030 va_size(va), va->subtree_max_size); 1031 } 1032 } 1033 #endif 1034 1035 /* 1036 * This function populates subtree_max_size from bottom to upper 1037 * levels starting from VA point. The propagation must be done 1038 * when VA size is modified by changing its va_start/va_end. Or 1039 * in case of newly inserting of VA to the tree. 1040 * 1041 * It means that __augment_tree_propagate_from() must be called: 1042 * - After VA has been inserted to the tree(free path); 1043 * - After VA has been shrunk(allocation path); 1044 * - After VA has been increased(merging path). 1045 * 1046 * Please note that, it does not mean that upper parent nodes 1047 * and their subtree_max_size are recalculated all the time up 1048 * to the root node. 1049 * 1050 * 4--8 1051 * /\ 1052 * / \ 1053 * / \ 1054 * 2--2 8--8 1055 * 1056 * For example if we modify the node 4, shrinking it to 2, then 1057 * no any modification is required. If we shrink the node 2 to 1 1058 * its subtree_max_size is updated only, and set to 1. If we shrink 1059 * the node 8 to 6, then its subtree_max_size is set to 6 and parent 1060 * node becomes 4--6. 1061 */ 1062 static __always_inline void 1063 augment_tree_propagate_from(struct vmap_area *va) 1064 { 1065 /* 1066 * Populate the tree from bottom towards the root until 1067 * the calculated maximum available size of checked node 1068 * is equal to its current one. 1069 */ 1070 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL); 1071 1072 #if DEBUG_AUGMENT_PROPAGATE_CHECK 1073 augment_tree_propagate_check(); 1074 #endif 1075 } 1076 1077 static void 1078 insert_vmap_area(struct vmap_area *va, 1079 struct rb_root *root, struct list_head *head) 1080 { 1081 struct rb_node **link; 1082 struct rb_node *parent; 1083 1084 link = find_va_links(va, root, NULL, &parent); 1085 if (link) 1086 link_va(va, root, parent, link, head); 1087 } 1088 1089 static void 1090 insert_vmap_area_augment(struct vmap_area *va, 1091 struct rb_node *from, struct rb_root *root, 1092 struct list_head *head) 1093 { 1094 struct rb_node **link; 1095 struct rb_node *parent; 1096 1097 if (from) 1098 link = find_va_links(va, NULL, from, &parent); 1099 else 1100 link = find_va_links(va, root, NULL, &parent); 1101 1102 if (link) { 1103 link_va_augment(va, root, parent, link, head); 1104 augment_tree_propagate_from(va); 1105 } 1106 } 1107 1108 /* 1109 * Merge de-allocated chunk of VA memory with previous 1110 * and next free blocks. If coalesce is not done a new 1111 * free area is inserted. If VA has been merged, it is 1112 * freed. 1113 * 1114 * Please note, it can return NULL in case of overlap 1115 * ranges, followed by WARN() report. Despite it is a 1116 * buggy behaviour, a system can be alive and keep 1117 * ongoing. 1118 */ 1119 static __always_inline struct vmap_area * 1120 __merge_or_add_vmap_area(struct vmap_area *va, 1121 struct rb_root *root, struct list_head *head, bool augment) 1122 { 1123 struct vmap_area *sibling; 1124 struct list_head *next; 1125 struct rb_node **link; 1126 struct rb_node *parent; 1127 bool merged = false; 1128 1129 /* 1130 * Find a place in the tree where VA potentially will be 1131 * inserted, unless it is merged with its sibling/siblings. 1132 */ 1133 link = find_va_links(va, root, NULL, &parent); 1134 if (!link) 1135 return NULL; 1136 1137 /* 1138 * Get next node of VA to check if merging can be done. 1139 */ 1140 next = get_va_next_sibling(parent, link); 1141 if (unlikely(next == NULL)) 1142 goto insert; 1143 1144 /* 1145 * start end 1146 * | | 1147 * |<------VA------>|<-----Next----->| 1148 * | | 1149 * start end 1150 */ 1151 if (next != head) { 1152 sibling = list_entry(next, struct vmap_area, list); 1153 if (sibling->va_start == va->va_end) { 1154 sibling->va_start = va->va_start; 1155 1156 /* Free vmap_area object. */ 1157 kmem_cache_free(vmap_area_cachep, va); 1158 1159 /* Point to the new merged area. */ 1160 va = sibling; 1161 merged = true; 1162 } 1163 } 1164 1165 /* 1166 * start end 1167 * | | 1168 * |<-----Prev----->|<------VA------>| 1169 * | | 1170 * start end 1171 */ 1172 if (next->prev != head) { 1173 sibling = list_entry(next->prev, struct vmap_area, list); 1174 if (sibling->va_end == va->va_start) { 1175 /* 1176 * If both neighbors are coalesced, it is important 1177 * to unlink the "next" node first, followed by merging 1178 * with "previous" one. Otherwise the tree might not be 1179 * fully populated if a sibling's augmented value is 1180 * "normalized" because of rotation operations. 1181 */ 1182 if (merged) 1183 __unlink_va(va, root, augment); 1184 1185 sibling->va_end = va->va_end; 1186 1187 /* Free vmap_area object. */ 1188 kmem_cache_free(vmap_area_cachep, va); 1189 1190 /* Point to the new merged area. */ 1191 va = sibling; 1192 merged = true; 1193 } 1194 } 1195 1196 insert: 1197 if (!merged) 1198 __link_va(va, root, parent, link, head, augment); 1199 1200 return va; 1201 } 1202 1203 static __always_inline struct vmap_area * 1204 merge_or_add_vmap_area(struct vmap_area *va, 1205 struct rb_root *root, struct list_head *head) 1206 { 1207 return __merge_or_add_vmap_area(va, root, head, false); 1208 } 1209 1210 static __always_inline struct vmap_area * 1211 merge_or_add_vmap_area_augment(struct vmap_area *va, 1212 struct rb_root *root, struct list_head *head) 1213 { 1214 va = __merge_or_add_vmap_area(va, root, head, true); 1215 if (va) 1216 augment_tree_propagate_from(va); 1217 1218 return va; 1219 } 1220 1221 static __always_inline bool 1222 is_within_this_va(struct vmap_area *va, unsigned long size, 1223 unsigned long align, unsigned long vstart) 1224 { 1225 unsigned long nva_start_addr; 1226 1227 if (va->va_start > vstart) 1228 nva_start_addr = ALIGN(va->va_start, align); 1229 else 1230 nva_start_addr = ALIGN(vstart, align); 1231 1232 /* Can be overflowed due to big size or alignment. */ 1233 if (nva_start_addr + size < nva_start_addr || 1234 nva_start_addr < vstart) 1235 return false; 1236 1237 return (nva_start_addr + size <= va->va_end); 1238 } 1239 1240 /* 1241 * Find the first free block(lowest start address) in the tree, 1242 * that will accomplish the request corresponding to passing 1243 * parameters. Please note, with an alignment bigger than PAGE_SIZE, 1244 * a search length is adjusted to account for worst case alignment 1245 * overhead. 1246 */ 1247 static __always_inline struct vmap_area * 1248 find_vmap_lowest_match(struct rb_root *root, unsigned long size, 1249 unsigned long align, unsigned long vstart, bool adjust_search_size) 1250 { 1251 struct vmap_area *va; 1252 struct rb_node *node; 1253 unsigned long length; 1254 1255 /* Start from the root. */ 1256 node = root->rb_node; 1257 1258 /* Adjust the search size for alignment overhead. */ 1259 length = adjust_search_size ? size + align - 1 : size; 1260 1261 while (node) { 1262 va = rb_entry(node, struct vmap_area, rb_node); 1263 1264 if (get_subtree_max_size(node->rb_left) >= length && 1265 vstart < va->va_start) { 1266 node = node->rb_left; 1267 } else { 1268 if (is_within_this_va(va, size, align, vstart)) 1269 return va; 1270 1271 /* 1272 * Does not make sense to go deeper towards the right 1273 * sub-tree if it does not have a free block that is 1274 * equal or bigger to the requested search length. 1275 */ 1276 if (get_subtree_max_size(node->rb_right) >= length) { 1277 node = node->rb_right; 1278 continue; 1279 } 1280 1281 /* 1282 * OK. We roll back and find the first right sub-tree, 1283 * that will satisfy the search criteria. It can happen 1284 * due to "vstart" restriction or an alignment overhead 1285 * that is bigger then PAGE_SIZE. 1286 */ 1287 while ((node = rb_parent(node))) { 1288 va = rb_entry(node, struct vmap_area, rb_node); 1289 if (is_within_this_va(va, size, align, vstart)) 1290 return va; 1291 1292 if (get_subtree_max_size(node->rb_right) >= length && 1293 vstart <= va->va_start) { 1294 /* 1295 * Shift the vstart forward. Please note, we update it with 1296 * parent's start address adding "1" because we do not want 1297 * to enter same sub-tree after it has already been checked 1298 * and no suitable free block found there. 1299 */ 1300 vstart = va->va_start + 1; 1301 node = node->rb_right; 1302 break; 1303 } 1304 } 1305 } 1306 } 1307 1308 return NULL; 1309 } 1310 1311 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK 1312 #include <linux/random.h> 1313 1314 static struct vmap_area * 1315 find_vmap_lowest_linear_match(struct list_head *head, unsigned long size, 1316 unsigned long align, unsigned long vstart) 1317 { 1318 struct vmap_area *va; 1319 1320 list_for_each_entry(va, head, list) { 1321 if (!is_within_this_va(va, size, align, vstart)) 1322 continue; 1323 1324 return va; 1325 } 1326 1327 return NULL; 1328 } 1329 1330 static void 1331 find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head, 1332 unsigned long size, unsigned long align) 1333 { 1334 struct vmap_area *va_1, *va_2; 1335 unsigned long vstart; 1336 unsigned int rnd; 1337 1338 get_random_bytes(&rnd, sizeof(rnd)); 1339 vstart = VMALLOC_START + rnd; 1340 1341 va_1 = find_vmap_lowest_match(root, size, align, vstart, false); 1342 va_2 = find_vmap_lowest_linear_match(head, size, align, vstart); 1343 1344 if (va_1 != va_2) 1345 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n", 1346 va_1, va_2, vstart); 1347 } 1348 #endif 1349 1350 enum fit_type { 1351 NOTHING_FIT = 0, 1352 FL_FIT_TYPE = 1, /* full fit */ 1353 LE_FIT_TYPE = 2, /* left edge fit */ 1354 RE_FIT_TYPE = 3, /* right edge fit */ 1355 NE_FIT_TYPE = 4 /* no edge fit */ 1356 }; 1357 1358 static __always_inline enum fit_type 1359 classify_va_fit_type(struct vmap_area *va, 1360 unsigned long nva_start_addr, unsigned long size) 1361 { 1362 enum fit_type type; 1363 1364 /* Check if it is within VA. */ 1365 if (nva_start_addr < va->va_start || 1366 nva_start_addr + size > va->va_end) 1367 return NOTHING_FIT; 1368 1369 /* Now classify. */ 1370 if (va->va_start == nva_start_addr) { 1371 if (va->va_end == nva_start_addr + size) 1372 type = FL_FIT_TYPE; 1373 else 1374 type = LE_FIT_TYPE; 1375 } else if (va->va_end == nva_start_addr + size) { 1376 type = RE_FIT_TYPE; 1377 } else { 1378 type = NE_FIT_TYPE; 1379 } 1380 1381 return type; 1382 } 1383 1384 static __always_inline int 1385 adjust_va_to_fit_type(struct rb_root *root, struct list_head *head, 1386 struct vmap_area *va, unsigned long nva_start_addr, 1387 unsigned long size) 1388 { 1389 struct vmap_area *lva = NULL; 1390 enum fit_type type = classify_va_fit_type(va, nva_start_addr, size); 1391 1392 if (type == FL_FIT_TYPE) { 1393 /* 1394 * No need to split VA, it fully fits. 1395 * 1396 * | | 1397 * V NVA V 1398 * |---------------| 1399 */ 1400 unlink_va_augment(va, root); 1401 kmem_cache_free(vmap_area_cachep, va); 1402 } else if (type == LE_FIT_TYPE) { 1403 /* 1404 * Split left edge of fit VA. 1405 * 1406 * | | 1407 * V NVA V R 1408 * |-------|-------| 1409 */ 1410 va->va_start += size; 1411 } else if (type == RE_FIT_TYPE) { 1412 /* 1413 * Split right edge of fit VA. 1414 * 1415 * | | 1416 * L V NVA V 1417 * |-------|-------| 1418 */ 1419 va->va_end = nva_start_addr; 1420 } else if (type == NE_FIT_TYPE) { 1421 /* 1422 * Split no edge of fit VA. 1423 * 1424 * | | 1425 * L V NVA V R 1426 * |---|-------|---| 1427 */ 1428 lva = __this_cpu_xchg(ne_fit_preload_node, NULL); 1429 if (unlikely(!lva)) { 1430 /* 1431 * For percpu allocator we do not do any pre-allocation 1432 * and leave it as it is. The reason is it most likely 1433 * never ends up with NE_FIT_TYPE splitting. In case of 1434 * percpu allocations offsets and sizes are aligned to 1435 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE 1436 * are its main fitting cases. 1437 * 1438 * There are a few exceptions though, as an example it is 1439 * a first allocation (early boot up) when we have "one" 1440 * big free space that has to be split. 1441 * 1442 * Also we can hit this path in case of regular "vmap" 1443 * allocations, if "this" current CPU was not preloaded. 1444 * See the comment in alloc_vmap_area() why. If so, then 1445 * GFP_NOWAIT is used instead to get an extra object for 1446 * split purpose. That is rare and most time does not 1447 * occur. 1448 * 1449 * What happens if an allocation gets failed. Basically, 1450 * an "overflow" path is triggered to purge lazily freed 1451 * areas to free some memory, then, the "retry" path is 1452 * triggered to repeat one more time. See more details 1453 * in alloc_vmap_area() function. 1454 */ 1455 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT); 1456 if (!lva) 1457 return -1; 1458 } 1459 1460 /* 1461 * Build the remainder. 1462 */ 1463 lva->va_start = va->va_start; 1464 lva->va_end = nva_start_addr; 1465 1466 /* 1467 * Shrink this VA to remaining size. 1468 */ 1469 va->va_start = nva_start_addr + size; 1470 } else { 1471 return -1; 1472 } 1473 1474 if (type != FL_FIT_TYPE) { 1475 augment_tree_propagate_from(va); 1476 1477 if (lva) /* type == NE_FIT_TYPE */ 1478 insert_vmap_area_augment(lva, &va->rb_node, root, head); 1479 } 1480 1481 return 0; 1482 } 1483 1484 /* 1485 * Returns a start address of the newly allocated area, if success. 1486 * Otherwise a vend is returned that indicates failure. 1487 */ 1488 static __always_inline unsigned long 1489 __alloc_vmap_area(struct rb_root *root, struct list_head *head, 1490 unsigned long size, unsigned long align, 1491 unsigned long vstart, unsigned long vend) 1492 { 1493 bool adjust_search_size = true; 1494 unsigned long nva_start_addr; 1495 struct vmap_area *va; 1496 int ret; 1497 1498 /* 1499 * Do not adjust when: 1500 * a) align <= PAGE_SIZE, because it does not make any sense. 1501 * All blocks(their start addresses) are at least PAGE_SIZE 1502 * aligned anyway; 1503 * b) a short range where a requested size corresponds to exactly 1504 * specified [vstart:vend] interval and an alignment > PAGE_SIZE. 1505 * With adjusted search length an allocation would not succeed. 1506 */ 1507 if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size)) 1508 adjust_search_size = false; 1509 1510 va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size); 1511 if (unlikely(!va)) 1512 return vend; 1513 1514 if (va->va_start > vstart) 1515 nva_start_addr = ALIGN(va->va_start, align); 1516 else 1517 nva_start_addr = ALIGN(vstart, align); 1518 1519 /* Check the "vend" restriction. */ 1520 if (nva_start_addr + size > vend) 1521 return vend; 1522 1523 /* Update the free vmap_area. */ 1524 ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size); 1525 if (WARN_ON_ONCE(ret)) 1526 return vend; 1527 1528 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK 1529 find_vmap_lowest_match_check(root, head, size, align); 1530 #endif 1531 1532 return nva_start_addr; 1533 } 1534 1535 /* 1536 * Free a region of KVA allocated by alloc_vmap_area 1537 */ 1538 static void free_vmap_area(struct vmap_area *va) 1539 { 1540 /* 1541 * Remove from the busy tree/list. 1542 */ 1543 spin_lock(&vmap_area_lock); 1544 unlink_va(va, &vmap_area_root); 1545 spin_unlock(&vmap_area_lock); 1546 1547 /* 1548 * Insert/Merge it back to the free tree/list. 1549 */ 1550 spin_lock(&free_vmap_area_lock); 1551 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list); 1552 spin_unlock(&free_vmap_area_lock); 1553 } 1554 1555 static inline void 1556 preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node) 1557 { 1558 struct vmap_area *va = NULL; 1559 1560 /* 1561 * Preload this CPU with one extra vmap_area object. It is used 1562 * when fit type of free area is NE_FIT_TYPE. It guarantees that 1563 * a CPU that does an allocation is preloaded. 1564 * 1565 * We do it in non-atomic context, thus it allows us to use more 1566 * permissive allocation masks to be more stable under low memory 1567 * condition and high memory pressure. 1568 */ 1569 if (!this_cpu_read(ne_fit_preload_node)) 1570 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); 1571 1572 spin_lock(lock); 1573 1574 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va)) 1575 kmem_cache_free(vmap_area_cachep, va); 1576 } 1577 1578 /* 1579 * Allocate a region of KVA of the specified size and alignment, within the 1580 * vstart and vend. 1581 */ 1582 static struct vmap_area *alloc_vmap_area(unsigned long size, 1583 unsigned long align, 1584 unsigned long vstart, unsigned long vend, 1585 int node, gfp_t gfp_mask, 1586 unsigned long va_flags) 1587 { 1588 struct vmap_area *va; 1589 unsigned long freed; 1590 unsigned long addr; 1591 int purged = 0; 1592 int ret; 1593 1594 if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align))) 1595 return ERR_PTR(-EINVAL); 1596 1597 if (unlikely(!vmap_initialized)) 1598 return ERR_PTR(-EBUSY); 1599 1600 might_sleep(); 1601 gfp_mask = gfp_mask & GFP_RECLAIM_MASK; 1602 1603 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); 1604 if (unlikely(!va)) 1605 return ERR_PTR(-ENOMEM); 1606 1607 /* 1608 * Only scan the relevant parts containing pointers to other objects 1609 * to avoid false negatives. 1610 */ 1611 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask); 1612 1613 retry: 1614 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node); 1615 addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list, 1616 size, align, vstart, vend); 1617 spin_unlock(&free_vmap_area_lock); 1618 1619 trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend); 1620 1621 /* 1622 * If an allocation fails, the "vend" address is 1623 * returned. Therefore trigger the overflow path. 1624 */ 1625 if (unlikely(addr == vend)) 1626 goto overflow; 1627 1628 va->va_start = addr; 1629 va->va_end = addr + size; 1630 va->vm = NULL; 1631 va->flags = va_flags; 1632 1633 spin_lock(&vmap_area_lock); 1634 insert_vmap_area(va, &vmap_area_root, &vmap_area_list); 1635 spin_unlock(&vmap_area_lock); 1636 1637 BUG_ON(!IS_ALIGNED(va->va_start, align)); 1638 BUG_ON(va->va_start < vstart); 1639 BUG_ON(va->va_end > vend); 1640 1641 ret = kasan_populate_vmalloc(addr, size); 1642 if (ret) { 1643 free_vmap_area(va); 1644 return ERR_PTR(ret); 1645 } 1646 1647 return va; 1648 1649 overflow: 1650 if (!purged) { 1651 reclaim_and_purge_vmap_areas(); 1652 purged = 1; 1653 goto retry; 1654 } 1655 1656 freed = 0; 1657 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed); 1658 1659 if (freed > 0) { 1660 purged = 0; 1661 goto retry; 1662 } 1663 1664 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) 1665 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", 1666 size); 1667 1668 kmem_cache_free(vmap_area_cachep, va); 1669 return ERR_PTR(-EBUSY); 1670 } 1671 1672 int register_vmap_purge_notifier(struct notifier_block *nb) 1673 { 1674 return blocking_notifier_chain_register(&vmap_notify_list, nb); 1675 } 1676 EXPORT_SYMBOL_GPL(register_vmap_purge_notifier); 1677 1678 int unregister_vmap_purge_notifier(struct notifier_block *nb) 1679 { 1680 return blocking_notifier_chain_unregister(&vmap_notify_list, nb); 1681 } 1682 EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier); 1683 1684 /* 1685 * lazy_max_pages is the maximum amount of virtual address space we gather up 1686 * before attempting to purge with a TLB flush. 1687 * 1688 * There is a tradeoff here: a larger number will cover more kernel page tables 1689 * and take slightly longer to purge, but it will linearly reduce the number of 1690 * global TLB flushes that must be performed. It would seem natural to scale 1691 * this number up linearly with the number of CPUs (because vmapping activity 1692 * could also scale linearly with the number of CPUs), however it is likely 1693 * that in practice, workloads might be constrained in other ways that mean 1694 * vmap activity will not scale linearly with CPUs. Also, I want to be 1695 * conservative and not introduce a big latency on huge systems, so go with 1696 * a less aggressive log scale. It will still be an improvement over the old 1697 * code, and it will be simple to change the scale factor if we find that it 1698 * becomes a problem on bigger systems. 1699 */ 1700 static unsigned long lazy_max_pages(void) 1701 { 1702 unsigned int log; 1703 1704 log = fls(num_online_cpus()); 1705 1706 return log * (32UL * 1024 * 1024 / PAGE_SIZE); 1707 } 1708 1709 static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0); 1710 1711 /* 1712 * Serialize vmap purging. There is no actual critical section protected 1713 * by this lock, but we want to avoid concurrent calls for performance 1714 * reasons and to make the pcpu_get_vm_areas more deterministic. 1715 */ 1716 static DEFINE_MUTEX(vmap_purge_lock); 1717 1718 /* for per-CPU blocks */ 1719 static void purge_fragmented_blocks_allcpus(void); 1720 1721 /* 1722 * Purges all lazily-freed vmap areas. 1723 */ 1724 static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) 1725 { 1726 unsigned long resched_threshold; 1727 unsigned int num_purged_areas = 0; 1728 struct list_head local_purge_list; 1729 struct vmap_area *va, *n_va; 1730 1731 lockdep_assert_held(&vmap_purge_lock); 1732 1733 spin_lock(&purge_vmap_area_lock); 1734 purge_vmap_area_root = RB_ROOT; 1735 list_replace_init(&purge_vmap_area_list, &local_purge_list); 1736 spin_unlock(&purge_vmap_area_lock); 1737 1738 if (unlikely(list_empty(&local_purge_list))) 1739 goto out; 1740 1741 start = min(start, 1742 list_first_entry(&local_purge_list, 1743 struct vmap_area, list)->va_start); 1744 1745 end = max(end, 1746 list_last_entry(&local_purge_list, 1747 struct vmap_area, list)->va_end); 1748 1749 flush_tlb_kernel_range(start, end); 1750 resched_threshold = lazy_max_pages() << 1; 1751 1752 spin_lock(&free_vmap_area_lock); 1753 list_for_each_entry_safe(va, n_va, &local_purge_list, list) { 1754 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; 1755 unsigned long orig_start = va->va_start; 1756 unsigned long orig_end = va->va_end; 1757 1758 /* 1759 * Finally insert or merge lazily-freed area. It is 1760 * detached and there is no need to "unlink" it from 1761 * anything. 1762 */ 1763 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root, 1764 &free_vmap_area_list); 1765 1766 if (!va) 1767 continue; 1768 1769 if (is_vmalloc_or_module_addr((void *)orig_start)) 1770 kasan_release_vmalloc(orig_start, orig_end, 1771 va->va_start, va->va_end); 1772 1773 atomic_long_sub(nr, &vmap_lazy_nr); 1774 num_purged_areas++; 1775 1776 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold) 1777 cond_resched_lock(&free_vmap_area_lock); 1778 } 1779 spin_unlock(&free_vmap_area_lock); 1780 1781 out: 1782 trace_purge_vmap_area_lazy(start, end, num_purged_areas); 1783 return num_purged_areas > 0; 1784 } 1785 1786 /* 1787 * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list. 1788 */ 1789 static void reclaim_and_purge_vmap_areas(void) 1790 1791 { 1792 mutex_lock(&vmap_purge_lock); 1793 purge_fragmented_blocks_allcpus(); 1794 __purge_vmap_area_lazy(ULONG_MAX, 0); 1795 mutex_unlock(&vmap_purge_lock); 1796 } 1797 1798 static void drain_vmap_area_work(struct work_struct *work) 1799 { 1800 unsigned long nr_lazy; 1801 1802 do { 1803 mutex_lock(&vmap_purge_lock); 1804 __purge_vmap_area_lazy(ULONG_MAX, 0); 1805 mutex_unlock(&vmap_purge_lock); 1806 1807 /* Recheck if further work is required. */ 1808 nr_lazy = atomic_long_read(&vmap_lazy_nr); 1809 } while (nr_lazy > lazy_max_pages()); 1810 } 1811 1812 /* 1813 * Free a vmap area, caller ensuring that the area has been unmapped, 1814 * unlinked and flush_cache_vunmap had been called for the correct 1815 * range previously. 1816 */ 1817 static void free_vmap_area_noflush(struct vmap_area *va) 1818 { 1819 unsigned long nr_lazy_max = lazy_max_pages(); 1820 unsigned long va_start = va->va_start; 1821 unsigned long nr_lazy; 1822 1823 if (WARN_ON_ONCE(!list_empty(&va->list))) 1824 return; 1825 1826 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >> 1827 PAGE_SHIFT, &vmap_lazy_nr); 1828 1829 /* 1830 * Merge or place it to the purge tree/list. 1831 */ 1832 spin_lock(&purge_vmap_area_lock); 1833 merge_or_add_vmap_area(va, 1834 &purge_vmap_area_root, &purge_vmap_area_list); 1835 spin_unlock(&purge_vmap_area_lock); 1836 1837 trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max); 1838 1839 /* After this point, we may free va at any time */ 1840 if (unlikely(nr_lazy > nr_lazy_max)) 1841 schedule_work(&drain_vmap_work); 1842 } 1843 1844 /* 1845 * Free and unmap a vmap area 1846 */ 1847 static void free_unmap_vmap_area(struct vmap_area *va) 1848 { 1849 flush_cache_vunmap(va->va_start, va->va_end); 1850 vunmap_range_noflush(va->va_start, va->va_end); 1851 if (debug_pagealloc_enabled_static()) 1852 flush_tlb_kernel_range(va->va_start, va->va_end); 1853 1854 free_vmap_area_noflush(va); 1855 } 1856 1857 struct vmap_area *find_vmap_area(unsigned long addr) 1858 { 1859 struct vmap_area *va; 1860 1861 spin_lock(&vmap_area_lock); 1862 va = __find_vmap_area(addr, &vmap_area_root); 1863 spin_unlock(&vmap_area_lock); 1864 1865 return va; 1866 } 1867 1868 static struct vmap_area *find_unlink_vmap_area(unsigned long addr) 1869 { 1870 struct vmap_area *va; 1871 1872 spin_lock(&vmap_area_lock); 1873 va = __find_vmap_area(addr, &vmap_area_root); 1874 if (va) 1875 unlink_va(va, &vmap_area_root); 1876 spin_unlock(&vmap_area_lock); 1877 1878 return va; 1879 } 1880 1881 /*** Per cpu kva allocator ***/ 1882 1883 /* 1884 * vmap space is limited especially on 32 bit architectures. Ensure there is 1885 * room for at least 16 percpu vmap blocks per CPU. 1886 */ 1887 /* 1888 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able 1889 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess 1890 * instead (we just need a rough idea) 1891 */ 1892 #if BITS_PER_LONG == 32 1893 #define VMALLOC_SPACE (128UL*1024*1024) 1894 #else 1895 #define VMALLOC_SPACE (128UL*1024*1024*1024) 1896 #endif 1897 1898 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE) 1899 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */ 1900 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */ 1901 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2) 1902 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */ 1903 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */ 1904 #define VMAP_BBMAP_BITS \ 1905 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \ 1906 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \ 1907 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16)) 1908 1909 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) 1910 1911 /* 1912 * Purge threshold to prevent overeager purging of fragmented blocks for 1913 * regular operations: Purge if vb->free is less than 1/4 of the capacity. 1914 */ 1915 #define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4) 1916 1917 #define VMAP_RAM 0x1 /* indicates vm_map_ram area*/ 1918 #define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/ 1919 #define VMAP_FLAGS_MASK 0x3 1920 1921 struct vmap_block_queue { 1922 spinlock_t lock; 1923 struct list_head free; 1924 1925 /* 1926 * An xarray requires an extra memory dynamically to 1927 * be allocated. If it is an issue, we can use rb-tree 1928 * instead. 1929 */ 1930 struct xarray vmap_blocks; 1931 }; 1932 1933 struct vmap_block { 1934 spinlock_t lock; 1935 struct vmap_area *va; 1936 unsigned long free, dirty; 1937 DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); 1938 unsigned long dirty_min, dirty_max; /*< dirty range */ 1939 struct list_head free_list; 1940 struct rcu_head rcu_head; 1941 struct list_head purge; 1942 }; 1943 1944 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */ 1945 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue); 1946 1947 /* 1948 * In order to fast access to any "vmap_block" associated with a 1949 * specific address, we use a hash. 1950 * 1951 * A per-cpu vmap_block_queue is used in both ways, to serialize 1952 * an access to free block chains among CPUs(alloc path) and it 1953 * also acts as a vmap_block hash(alloc/free paths). It means we 1954 * overload it, since we already have the per-cpu array which is 1955 * used as a hash table. When used as a hash a 'cpu' passed to 1956 * per_cpu() is not actually a CPU but rather a hash index. 1957 * 1958 * A hash function is addr_to_vb_xa() which hashes any address 1959 * to a specific index(in a hash) it belongs to. This then uses a 1960 * per_cpu() macro to access an array with generated index. 1961 * 1962 * An example: 1963 * 1964 * CPU_1 CPU_2 CPU_0 1965 * | | | 1966 * V V V 1967 * 0 10 20 30 40 50 60 1968 * |------|------|------|------|------|------|...<vmap address space> 1969 * CPU0 CPU1 CPU2 CPU0 CPU1 CPU2 1970 * 1971 * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus 1972 * it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock; 1973 * 1974 * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus 1975 * it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock; 1976 * 1977 * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus 1978 * it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock. 1979 * 1980 * This technique almost always avoids lock contention on insert/remove, 1981 * however xarray spinlocks protect against any contention that remains. 1982 */ 1983 static struct xarray * 1984 addr_to_vb_xa(unsigned long addr) 1985 { 1986 int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus(); 1987 1988 return &per_cpu(vmap_block_queue, index).vmap_blocks; 1989 } 1990 1991 /* 1992 * We should probably have a fallback mechanism to allocate virtual memory 1993 * out of partially filled vmap blocks. However vmap block sizing should be 1994 * fairly reasonable according to the vmalloc size, so it shouldn't be a 1995 * big problem. 1996 */ 1997 1998 static unsigned long addr_to_vb_idx(unsigned long addr) 1999 { 2000 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); 2001 addr /= VMAP_BLOCK_SIZE; 2002 return addr; 2003 } 2004 2005 static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) 2006 { 2007 unsigned long addr; 2008 2009 addr = va_start + (pages_off << PAGE_SHIFT); 2010 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start)); 2011 return (void *)addr; 2012 } 2013 2014 /** 2015 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this 2016 * block. Of course pages number can't exceed VMAP_BBMAP_BITS 2017 * @order: how many 2^order pages should be occupied in newly allocated block 2018 * @gfp_mask: flags for the page level allocator 2019 * 2020 * Return: virtual address in a newly allocated block or ERR_PTR(-errno) 2021 */ 2022 static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) 2023 { 2024 struct vmap_block_queue *vbq; 2025 struct vmap_block *vb; 2026 struct vmap_area *va; 2027 struct xarray *xa; 2028 unsigned long vb_idx; 2029 int node, err; 2030 void *vaddr; 2031 2032 node = numa_node_id(); 2033 2034 vb = kmalloc_node(sizeof(struct vmap_block), 2035 gfp_mask & GFP_RECLAIM_MASK, node); 2036 if (unlikely(!vb)) 2037 return ERR_PTR(-ENOMEM); 2038 2039 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, 2040 VMALLOC_START, VMALLOC_END, 2041 node, gfp_mask, 2042 VMAP_RAM|VMAP_BLOCK); 2043 if (IS_ERR(va)) { 2044 kfree(vb); 2045 return ERR_CAST(va); 2046 } 2047 2048 vaddr = vmap_block_vaddr(va->va_start, 0); 2049 spin_lock_init(&vb->lock); 2050 vb->va = va; 2051 /* At least something should be left free */ 2052 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); 2053 bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); 2054 vb->free = VMAP_BBMAP_BITS - (1UL << order); 2055 vb->dirty = 0; 2056 vb->dirty_min = VMAP_BBMAP_BITS; 2057 vb->dirty_max = 0; 2058 bitmap_set(vb->used_map, 0, (1UL << order)); 2059 INIT_LIST_HEAD(&vb->free_list); 2060 2061 xa = addr_to_vb_xa(va->va_start); 2062 vb_idx = addr_to_vb_idx(va->va_start); 2063 err = xa_insert(xa, vb_idx, vb, gfp_mask); 2064 if (err) { 2065 kfree(vb); 2066 free_vmap_area(va); 2067 return ERR_PTR(err); 2068 } 2069 2070 vbq = raw_cpu_ptr(&vmap_block_queue); 2071 spin_lock(&vbq->lock); 2072 list_add_tail_rcu(&vb->free_list, &vbq->free); 2073 spin_unlock(&vbq->lock); 2074 2075 return vaddr; 2076 } 2077 2078 static void free_vmap_block(struct vmap_block *vb) 2079 { 2080 struct vmap_block *tmp; 2081 struct xarray *xa; 2082 2083 xa = addr_to_vb_xa(vb->va->va_start); 2084 tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start)); 2085 BUG_ON(tmp != vb); 2086 2087 spin_lock(&vmap_area_lock); 2088 unlink_va(vb->va, &vmap_area_root); 2089 spin_unlock(&vmap_area_lock); 2090 2091 free_vmap_area_noflush(vb->va); 2092 kfree_rcu(vb, rcu_head); 2093 } 2094 2095 static bool purge_fragmented_block(struct vmap_block *vb, 2096 struct vmap_block_queue *vbq, struct list_head *purge_list, 2097 bool force_purge) 2098 { 2099 if (vb->free + vb->dirty != VMAP_BBMAP_BITS || 2100 vb->dirty == VMAP_BBMAP_BITS) 2101 return false; 2102 2103 /* Don't overeagerly purge usable blocks unless requested */ 2104 if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) 2105 return false; 2106 2107 /* prevent further allocs after releasing lock */ 2108 WRITE_ONCE(vb->free, 0); 2109 /* prevent purging it again */ 2110 WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS); 2111 vb->dirty_min = 0; 2112 vb->dirty_max = VMAP_BBMAP_BITS; 2113 spin_lock(&vbq->lock); 2114 list_del_rcu(&vb->free_list); 2115 spin_unlock(&vbq->lock); 2116 list_add_tail(&vb->purge, purge_list); 2117 return true; 2118 } 2119 2120 static void free_purged_blocks(struct list_head *purge_list) 2121 { 2122 struct vmap_block *vb, *n_vb; 2123 2124 list_for_each_entry_safe(vb, n_vb, purge_list, purge) { 2125 list_del(&vb->purge); 2126 free_vmap_block(vb); 2127 } 2128 } 2129 2130 static void purge_fragmented_blocks(int cpu) 2131 { 2132 LIST_HEAD(purge); 2133 struct vmap_block *vb; 2134 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); 2135 2136 rcu_read_lock(); 2137 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 2138 unsigned long free = READ_ONCE(vb->free); 2139 unsigned long dirty = READ_ONCE(vb->dirty); 2140 2141 if (free + dirty != VMAP_BBMAP_BITS || 2142 dirty == VMAP_BBMAP_BITS) 2143 continue; 2144 2145 spin_lock(&vb->lock); 2146 purge_fragmented_block(vb, vbq, &purge, true); 2147 spin_unlock(&vb->lock); 2148 } 2149 rcu_read_unlock(); 2150 free_purged_blocks(&purge); 2151 } 2152 2153 static void purge_fragmented_blocks_allcpus(void) 2154 { 2155 int cpu; 2156 2157 for_each_possible_cpu(cpu) 2158 purge_fragmented_blocks(cpu); 2159 } 2160 2161 static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 2162 { 2163 struct vmap_block_queue *vbq; 2164 struct vmap_block *vb; 2165 void *vaddr = NULL; 2166 unsigned int order; 2167 2168 BUG_ON(offset_in_page(size)); 2169 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); 2170 if (WARN_ON(size == 0)) { 2171 /* 2172 * Allocating 0 bytes isn't what caller wants since 2173 * get_order(0) returns funny result. Just warn and terminate 2174 * early. 2175 */ 2176 return NULL; 2177 } 2178 order = get_order(size); 2179 2180 rcu_read_lock(); 2181 vbq = raw_cpu_ptr(&vmap_block_queue); 2182 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 2183 unsigned long pages_off; 2184 2185 if (READ_ONCE(vb->free) < (1UL << order)) 2186 continue; 2187 2188 spin_lock(&vb->lock); 2189 if (vb->free < (1UL << order)) { 2190 spin_unlock(&vb->lock); 2191 continue; 2192 } 2193 2194 pages_off = VMAP_BBMAP_BITS - vb->free; 2195 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); 2196 WRITE_ONCE(vb->free, vb->free - (1UL << order)); 2197 bitmap_set(vb->used_map, pages_off, (1UL << order)); 2198 if (vb->free == 0) { 2199 spin_lock(&vbq->lock); 2200 list_del_rcu(&vb->free_list); 2201 spin_unlock(&vbq->lock); 2202 } 2203 2204 spin_unlock(&vb->lock); 2205 break; 2206 } 2207 2208 rcu_read_unlock(); 2209 2210 /* Allocate new block if nothing was found */ 2211 if (!vaddr) 2212 vaddr = new_vmap_block(order, gfp_mask); 2213 2214 return vaddr; 2215 } 2216 2217 static void vb_free(unsigned long addr, unsigned long size) 2218 { 2219 unsigned long offset; 2220 unsigned int order; 2221 struct vmap_block *vb; 2222 struct xarray *xa; 2223 2224 BUG_ON(offset_in_page(size)); 2225 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); 2226 2227 flush_cache_vunmap(addr, addr + size); 2228 2229 order = get_order(size); 2230 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; 2231 2232 xa = addr_to_vb_xa(addr); 2233 vb = xa_load(xa, addr_to_vb_idx(addr)); 2234 2235 spin_lock(&vb->lock); 2236 bitmap_clear(vb->used_map, offset, (1UL << order)); 2237 spin_unlock(&vb->lock); 2238 2239 vunmap_range_noflush(addr, addr + size); 2240 2241 if (debug_pagealloc_enabled_static()) 2242 flush_tlb_kernel_range(addr, addr + size); 2243 2244 spin_lock(&vb->lock); 2245 2246 /* Expand the not yet TLB flushed dirty range */ 2247 vb->dirty_min = min(vb->dirty_min, offset); 2248 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order)); 2249 2250 WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order)); 2251 if (vb->dirty == VMAP_BBMAP_BITS) { 2252 BUG_ON(vb->free); 2253 spin_unlock(&vb->lock); 2254 free_vmap_block(vb); 2255 } else 2256 spin_unlock(&vb->lock); 2257 } 2258 2259 static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) 2260 { 2261 LIST_HEAD(purge_list); 2262 int cpu; 2263 2264 if (unlikely(!vmap_initialized)) 2265 return; 2266 2267 mutex_lock(&vmap_purge_lock); 2268 2269 for_each_possible_cpu(cpu) { 2270 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); 2271 struct vmap_block *vb; 2272 unsigned long idx; 2273 2274 rcu_read_lock(); 2275 xa_for_each(&vbq->vmap_blocks, idx, vb) { 2276 spin_lock(&vb->lock); 2277 2278 /* 2279 * Try to purge a fragmented block first. If it's 2280 * not purgeable, check whether there is dirty 2281 * space to be flushed. 2282 */ 2283 if (!purge_fragmented_block(vb, vbq, &purge_list, false) && 2284 vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { 2285 unsigned long va_start = vb->va->va_start; 2286 unsigned long s, e; 2287 2288 s = va_start + (vb->dirty_min << PAGE_SHIFT); 2289 e = va_start + (vb->dirty_max << PAGE_SHIFT); 2290 2291 start = min(s, start); 2292 end = max(e, end); 2293 2294 /* Prevent that this is flushed again */ 2295 vb->dirty_min = VMAP_BBMAP_BITS; 2296 vb->dirty_max = 0; 2297 2298 flush = 1; 2299 } 2300 spin_unlock(&vb->lock); 2301 } 2302 rcu_read_unlock(); 2303 } 2304 free_purged_blocks(&purge_list); 2305 2306 if (!__purge_vmap_area_lazy(start, end) && flush) 2307 flush_tlb_kernel_range(start, end); 2308 mutex_unlock(&vmap_purge_lock); 2309 } 2310 2311 /** 2312 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer 2313 * 2314 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily 2315 * to amortize TLB flushing overheads. What this means is that any page you 2316 * have now, may, in a former life, have been mapped into kernel virtual 2317 * address by the vmap layer and so there might be some CPUs with TLB entries 2318 * still referencing that page (additional to the regular 1:1 kernel mapping). 2319 * 2320 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can 2321 * be sure that none of the pages we have control over will have any aliases 2322 * from the vmap layer. 2323 */ 2324 void vm_unmap_aliases(void) 2325 { 2326 unsigned long start = ULONG_MAX, end = 0; 2327 int flush = 0; 2328 2329 _vm_unmap_aliases(start, end, flush); 2330 } 2331 EXPORT_SYMBOL_GPL(vm_unmap_aliases); 2332 2333 /** 2334 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram 2335 * @mem: the pointer returned by vm_map_ram 2336 * @count: the count passed to that vm_map_ram call (cannot unmap partial) 2337 */ 2338 void vm_unmap_ram(const void *mem, unsigned int count) 2339 { 2340 unsigned long size = (unsigned long)count << PAGE_SHIFT; 2341 unsigned long addr = (unsigned long)kasan_reset_tag(mem); 2342 struct vmap_area *va; 2343 2344 might_sleep(); 2345 BUG_ON(!addr); 2346 BUG_ON(addr < VMALLOC_START); 2347 BUG_ON(addr > VMALLOC_END); 2348 BUG_ON(!PAGE_ALIGNED(addr)); 2349 2350 kasan_poison_vmalloc(mem, size); 2351 2352 if (likely(count <= VMAP_MAX_ALLOC)) { 2353 debug_check_no_locks_freed(mem, size); 2354 vb_free(addr, size); 2355 return; 2356 } 2357 2358 va = find_unlink_vmap_area(addr); 2359 if (WARN_ON_ONCE(!va)) 2360 return; 2361 2362 debug_check_no_locks_freed((void *)va->va_start, 2363 (va->va_end - va->va_start)); 2364 free_unmap_vmap_area(va); 2365 } 2366 EXPORT_SYMBOL(vm_unmap_ram); 2367 2368 /** 2369 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) 2370 * @pages: an array of pointers to the pages to be mapped 2371 * @count: number of pages 2372 * @node: prefer to allocate data structures on this node 2373 * 2374 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be 2375 * faster than vmap so it's good. But if you mix long-life and short-life 2376 * objects with vm_map_ram(), it could consume lots of address space through 2377 * fragmentation (especially on a 32bit machine). You could see failures in 2378 * the end. Please use this function for short-lived objects. 2379 * 2380 * Returns: a pointer to the address that has been mapped, or %NULL on failure 2381 */ 2382 void *vm_map_ram(struct page **pages, unsigned int count, int node) 2383 { 2384 unsigned long size = (unsigned long)count << PAGE_SHIFT; 2385 unsigned long addr; 2386 void *mem; 2387 2388 if (likely(count <= VMAP_MAX_ALLOC)) { 2389 mem = vb_alloc(size, GFP_KERNEL); 2390 if (IS_ERR(mem)) 2391 return NULL; 2392 addr = (unsigned long)mem; 2393 } else { 2394 struct vmap_area *va; 2395 va = alloc_vmap_area(size, PAGE_SIZE, 2396 VMALLOC_START, VMALLOC_END, 2397 node, GFP_KERNEL, VMAP_RAM); 2398 if (IS_ERR(va)) 2399 return NULL; 2400 2401 addr = va->va_start; 2402 mem = (void *)addr; 2403 } 2404 2405 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, 2406 pages, PAGE_SHIFT) < 0) { 2407 vm_unmap_ram(mem, count); 2408 return NULL; 2409 } 2410 2411 /* 2412 * Mark the pages as accessible, now that they are mapped. 2413 * With hardware tag-based KASAN, marking is skipped for 2414 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). 2415 */ 2416 mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL); 2417 2418 return mem; 2419 } 2420 EXPORT_SYMBOL(vm_map_ram); 2421 2422 static struct vm_struct *vmlist __initdata; 2423 2424 static inline unsigned int vm_area_page_order(struct vm_struct *vm) 2425 { 2426 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC 2427 return vm->page_order; 2428 #else 2429 return 0; 2430 #endif 2431 } 2432 2433 static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order) 2434 { 2435 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC 2436 vm->page_order = order; 2437 #else 2438 BUG_ON(order != 0); 2439 #endif 2440 } 2441 2442 /** 2443 * vm_area_add_early - add vmap area early during boot 2444 * @vm: vm_struct to add 2445 * 2446 * This function is used to add fixed kernel vm area to vmlist before 2447 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags 2448 * should contain proper values and the other fields should be zero. 2449 * 2450 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. 2451 */ 2452 void __init vm_area_add_early(struct vm_struct *vm) 2453 { 2454 struct vm_struct *tmp, **p; 2455 2456 BUG_ON(vmap_initialized); 2457 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { 2458 if (tmp->addr >= vm->addr) { 2459 BUG_ON(tmp->addr < vm->addr + vm->size); 2460 break; 2461 } else 2462 BUG_ON(tmp->addr + tmp->size > vm->addr); 2463 } 2464 vm->next = *p; 2465 *p = vm; 2466 } 2467 2468 /** 2469 * vm_area_register_early - register vmap area early during boot 2470 * @vm: vm_struct to register 2471 * @align: requested alignment 2472 * 2473 * This function is used to register kernel vm area before 2474 * vmalloc_init() is called. @vm->size and @vm->flags should contain 2475 * proper values on entry and other fields should be zero. On return, 2476 * vm->addr contains the allocated address. 2477 * 2478 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. 2479 */ 2480 void __init vm_area_register_early(struct vm_struct *vm, size_t align) 2481 { 2482 unsigned long addr = ALIGN(VMALLOC_START, align); 2483 struct vm_struct *cur, **p; 2484 2485 BUG_ON(vmap_initialized); 2486 2487 for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) { 2488 if ((unsigned long)cur->addr - addr >= vm->size) 2489 break; 2490 addr = ALIGN((unsigned long)cur->addr + cur->size, align); 2491 } 2492 2493 BUG_ON(addr > VMALLOC_END - vm->size); 2494 vm->addr = (void *)addr; 2495 vm->next = *p; 2496 *p = vm; 2497 kasan_populate_early_vm_area_shadow(vm->addr, vm->size); 2498 } 2499 2500 static void vmap_init_free_space(void) 2501 { 2502 unsigned long vmap_start = 1; 2503 const unsigned long vmap_end = ULONG_MAX; 2504 struct vmap_area *busy, *free; 2505 2506 /* 2507 * B F B B B F 2508 * -|-----|.....|-----|-----|-----|.....|- 2509 * | The KVA space | 2510 * |<--------------------------------->| 2511 */ 2512 list_for_each_entry(busy, &vmap_area_list, list) { 2513 if (busy->va_start - vmap_start > 0) { 2514 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); 2515 if (!WARN_ON_ONCE(!free)) { 2516 free->va_start = vmap_start; 2517 free->va_end = busy->va_start; 2518 2519 insert_vmap_area_augment(free, NULL, 2520 &free_vmap_area_root, 2521 &free_vmap_area_list); 2522 } 2523 } 2524 2525 vmap_start = busy->va_end; 2526 } 2527 2528 if (vmap_end - vmap_start > 0) { 2529 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); 2530 if (!WARN_ON_ONCE(!free)) { 2531 free->va_start = vmap_start; 2532 free->va_end = vmap_end; 2533 2534 insert_vmap_area_augment(free, NULL, 2535 &free_vmap_area_root, 2536 &free_vmap_area_list); 2537 } 2538 } 2539 } 2540 2541 static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, 2542 struct vmap_area *va, unsigned long flags, const void *caller) 2543 { 2544 vm->flags = flags; 2545 vm->addr = (void *)va->va_start; 2546 vm->size = va->va_end - va->va_start; 2547 vm->caller = caller; 2548 va->vm = vm; 2549 } 2550 2551 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, 2552 unsigned long flags, const void *caller) 2553 { 2554 spin_lock(&vmap_area_lock); 2555 setup_vmalloc_vm_locked(vm, va, flags, caller); 2556 spin_unlock(&vmap_area_lock); 2557 } 2558 2559 static void clear_vm_uninitialized_flag(struct vm_struct *vm) 2560 { 2561 /* 2562 * Before removing VM_UNINITIALIZED, 2563 * we should make sure that vm has proper values. 2564 * Pair with smp_rmb() in show_numa_info(). 2565 */ 2566 smp_wmb(); 2567 vm->flags &= ~VM_UNINITIALIZED; 2568 } 2569 2570 static struct vm_struct *__get_vm_area_node(unsigned long size, 2571 unsigned long align, unsigned long shift, unsigned long flags, 2572 unsigned long start, unsigned long end, int node, 2573 gfp_t gfp_mask, const void *caller) 2574 { 2575 struct vmap_area *va; 2576 struct vm_struct *area; 2577 unsigned long requested_size = size; 2578 2579 BUG_ON(in_interrupt()); 2580 size = ALIGN(size, 1ul << shift); 2581 if (unlikely(!size)) 2582 return NULL; 2583 2584 if (flags & VM_IOREMAP) 2585 align = 1ul << clamp_t(int, get_count_order_long(size), 2586 PAGE_SHIFT, IOREMAP_MAX_ORDER); 2587 2588 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); 2589 if (unlikely(!area)) 2590 return NULL; 2591 2592 if (!(flags & VM_NO_GUARD)) 2593 size += PAGE_SIZE; 2594 2595 va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0); 2596 if (IS_ERR(va)) { 2597 kfree(area); 2598 return NULL; 2599 } 2600 2601 setup_vmalloc_vm(area, va, flags, caller); 2602 2603 /* 2604 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a 2605 * best-effort approach, as they can be mapped outside of vmalloc code. 2606 * For VM_ALLOC mappings, the pages are marked as accessible after 2607 * getting mapped in __vmalloc_node_range(). 2608 * With hardware tag-based KASAN, marking is skipped for 2609 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). 2610 */ 2611 if (!(flags & VM_ALLOC)) 2612 area->addr = kasan_unpoison_vmalloc(area->addr, requested_size, 2613 KASAN_VMALLOC_PROT_NORMAL); 2614 2615 return area; 2616 } 2617 2618 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, 2619 unsigned long start, unsigned long end, 2620 const void *caller) 2621 { 2622 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end, 2623 NUMA_NO_NODE, GFP_KERNEL, caller); 2624 } 2625 2626 /** 2627 * get_vm_area - reserve a contiguous kernel virtual area 2628 * @size: size of the area 2629 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC 2630 * 2631 * Search an area of @size in the kernel virtual mapping area, 2632 * and reserved it for out purposes. Returns the area descriptor 2633 * on success or %NULL on failure. 2634 * 2635 * Return: the area descriptor on success or %NULL on failure. 2636 */ 2637 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) 2638 { 2639 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, 2640 VMALLOC_START, VMALLOC_END, 2641 NUMA_NO_NODE, GFP_KERNEL, 2642 __builtin_return_address(0)); 2643 } 2644 2645 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, 2646 const void *caller) 2647 { 2648 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, 2649 VMALLOC_START, VMALLOC_END, 2650 NUMA_NO_NODE, GFP_KERNEL, caller); 2651 } 2652 2653 /** 2654 * find_vm_area - find a continuous kernel virtual area 2655 * @addr: base address 2656 * 2657 * Search for the kernel VM area starting at @addr, and return it. 2658 * It is up to the caller to do all required locking to keep the returned 2659 * pointer valid. 2660 * 2661 * Return: the area descriptor on success or %NULL on failure. 2662 */ 2663 struct vm_struct *find_vm_area(const void *addr) 2664 { 2665 struct vmap_area *va; 2666 2667 va = find_vmap_area((unsigned long)addr); 2668 if (!va) 2669 return NULL; 2670 2671 return va->vm; 2672 } 2673 2674 /** 2675 * remove_vm_area - find and remove a continuous kernel virtual area 2676 * @addr: base address 2677 * 2678 * Search for the kernel VM area starting at @addr, and remove it. 2679 * This function returns the found VM area, but using it is NOT safe 2680 * on SMP machines, except for its size or flags. 2681 * 2682 * Return: the area descriptor on success or %NULL on failure. 2683 */ 2684 struct vm_struct *remove_vm_area(const void *addr) 2685 { 2686 struct vmap_area *va; 2687 struct vm_struct *vm; 2688 2689 might_sleep(); 2690 2691 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", 2692 addr)) 2693 return NULL; 2694 2695 va = find_unlink_vmap_area((unsigned long)addr); 2696 if (!va || !va->vm) 2697 return NULL; 2698 vm = va->vm; 2699 2700 debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm)); 2701 debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm)); 2702 kasan_free_module_shadow(vm); 2703 kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm)); 2704 2705 free_unmap_vmap_area(va); 2706 return vm; 2707 } 2708 2709 static inline void set_area_direct_map(const struct vm_struct *area, 2710 int (*set_direct_map)(struct page *page)) 2711 { 2712 int i; 2713 2714 /* HUGE_VMALLOC passes small pages to set_direct_map */ 2715 for (i = 0; i < area->nr_pages; i++) 2716 if (page_address(area->pages[i])) 2717 set_direct_map(area->pages[i]); 2718 } 2719 2720 /* 2721 * Flush the vm mapping and reset the direct map. 2722 */ 2723 static void vm_reset_perms(struct vm_struct *area) 2724 { 2725 unsigned long start = ULONG_MAX, end = 0; 2726 unsigned int page_order = vm_area_page_order(area); 2727 int flush_dmap = 0; 2728 int i; 2729 2730 /* 2731 * Find the start and end range of the direct mappings to make sure that 2732 * the vm_unmap_aliases() flush includes the direct map. 2733 */ 2734 for (i = 0; i < area->nr_pages; i += 1U << page_order) { 2735 unsigned long addr = (unsigned long)page_address(area->pages[i]); 2736 2737 if (addr) { 2738 unsigned long page_size; 2739 2740 page_size = PAGE_SIZE << page_order; 2741 start = min(addr, start); 2742 end = max(addr + page_size, end); 2743 flush_dmap = 1; 2744 } 2745 } 2746 2747 /* 2748 * Set direct map to something invalid so that it won't be cached if 2749 * there are any accesses after the TLB flush, then flush the TLB and 2750 * reset the direct map permissions to the default. 2751 */ 2752 set_area_direct_map(area, set_direct_map_invalid_noflush); 2753 _vm_unmap_aliases(start, end, flush_dmap); 2754 set_area_direct_map(area, set_direct_map_default_noflush); 2755 } 2756 2757 static void delayed_vfree_work(struct work_struct *w) 2758 { 2759 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq); 2760 struct llist_node *t, *llnode; 2761 2762 llist_for_each_safe(llnode, t, llist_del_all(&p->list)) 2763 vfree(llnode); 2764 } 2765 2766 /** 2767 * vfree_atomic - release memory allocated by vmalloc() 2768 * @addr: memory base address 2769 * 2770 * This one is just like vfree() but can be called in any atomic context 2771 * except NMIs. 2772 */ 2773 void vfree_atomic(const void *addr) 2774 { 2775 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); 2776 2777 BUG_ON(in_nmi()); 2778 kmemleak_free(addr); 2779 2780 /* 2781 * Use raw_cpu_ptr() because this can be called from preemptible 2782 * context. Preemption is absolutely fine here, because the llist_add() 2783 * implementation is lockless, so it works even if we are adding to 2784 * another cpu's list. schedule_work() should be fine with this too. 2785 */ 2786 if (addr && llist_add((struct llist_node *)addr, &p->list)) 2787 schedule_work(&p->wq); 2788 } 2789 2790 /** 2791 * vfree - Release memory allocated by vmalloc() 2792 * @addr: Memory base address 2793 * 2794 * Free the virtually continuous memory area starting at @addr, as obtained 2795 * from one of the vmalloc() family of APIs. This will usually also free the 2796 * physical memory underlying the virtual allocation, but that memory is 2797 * reference counted, so it will not be freed until the last user goes away. 2798 * 2799 * If @addr is NULL, no operation is performed. 2800 * 2801 * Context: 2802 * May sleep if called *not* from interrupt context. 2803 * Must not be called in NMI context (strictly speaking, it could be 2804 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling 2805 * conventions for vfree() arch-dependent would be a really bad idea). 2806 */ 2807 void vfree(const void *addr) 2808 { 2809 struct vm_struct *vm; 2810 int i; 2811 2812 if (unlikely(in_interrupt())) { 2813 vfree_atomic(addr); 2814 return; 2815 } 2816 2817 BUG_ON(in_nmi()); 2818 kmemleak_free(addr); 2819 might_sleep(); 2820 2821 if (!addr) 2822 return; 2823 2824 vm = remove_vm_area(addr); 2825 if (unlikely(!vm)) { 2826 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", 2827 addr); 2828 return; 2829 } 2830 2831 if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS)) 2832 vm_reset_perms(vm); 2833 for (i = 0; i < vm->nr_pages; i++) { 2834 struct page *page = vm->pages[i]; 2835 2836 BUG_ON(!page); 2837 mod_memcg_page_state(page, MEMCG_VMALLOC, -1); 2838 /* 2839 * High-order allocs for huge vmallocs are split, so 2840 * can be freed as an array of order-0 allocations 2841 */ 2842 __free_page(page); 2843 cond_resched(); 2844 } 2845 atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); 2846 kvfree(vm->pages); 2847 kfree(vm); 2848 } 2849 EXPORT_SYMBOL(vfree); 2850 2851 /** 2852 * vunmap - release virtual mapping obtained by vmap() 2853 * @addr: memory base address 2854 * 2855 * Free the virtually contiguous memory area starting at @addr, 2856 * which was created from the page array passed to vmap(). 2857 * 2858 * Must not be called in interrupt context. 2859 */ 2860 void vunmap(const void *addr) 2861 { 2862 struct vm_struct *vm; 2863 2864 BUG_ON(in_interrupt()); 2865 might_sleep(); 2866 2867 if (!addr) 2868 return; 2869 vm = remove_vm_area(addr); 2870 if (unlikely(!vm)) { 2871 WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n", 2872 addr); 2873 return; 2874 } 2875 kfree(vm); 2876 } 2877 EXPORT_SYMBOL(vunmap); 2878 2879 /** 2880 * vmap - map an array of pages into virtually contiguous space 2881 * @pages: array of page pointers 2882 * @count: number of pages to map 2883 * @flags: vm_area->flags 2884 * @prot: page protection for the mapping 2885 * 2886 * Maps @count pages from @pages into contiguous kernel virtual space. 2887 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself 2888 * (which must be kmalloc or vmalloc memory) and one reference per pages in it 2889 * are transferred from the caller to vmap(), and will be freed / dropped when 2890 * vfree() is called on the return value. 2891 * 2892 * Return: the address of the area or %NULL on failure 2893 */ 2894 void *vmap(struct page **pages, unsigned int count, 2895 unsigned long flags, pgprot_t prot) 2896 { 2897 struct vm_struct *area; 2898 unsigned long addr; 2899 unsigned long size; /* In bytes */ 2900 2901 might_sleep(); 2902 2903 if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS)) 2904 return NULL; 2905 2906 /* 2907 * Your top guard is someone else's bottom guard. Not having a top 2908 * guard compromises someone else's mappings too. 2909 */ 2910 if (WARN_ON_ONCE(flags & VM_NO_GUARD)) 2911 flags &= ~VM_NO_GUARD; 2912 2913 if (count > totalram_pages()) 2914 return NULL; 2915 2916 size = (unsigned long)count << PAGE_SHIFT; 2917 area = get_vm_area_caller(size, flags, __builtin_return_address(0)); 2918 if (!area) 2919 return NULL; 2920 2921 addr = (unsigned long)area->addr; 2922 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot), 2923 pages, PAGE_SHIFT) < 0) { 2924 vunmap(area->addr); 2925 return NULL; 2926 } 2927 2928 if (flags & VM_MAP_PUT_PAGES) { 2929 area->pages = pages; 2930 area->nr_pages = count; 2931 } 2932 return area->addr; 2933 } 2934 EXPORT_SYMBOL(vmap); 2935 2936 #ifdef CONFIG_VMAP_PFN 2937 struct vmap_pfn_data { 2938 unsigned long *pfns; 2939 pgprot_t prot; 2940 unsigned int idx; 2941 }; 2942 2943 static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) 2944 { 2945 struct vmap_pfn_data *data = private; 2946 unsigned long pfn = data->pfns[data->idx]; 2947 pte_t ptent; 2948 2949 if (WARN_ON_ONCE(pfn_valid(pfn))) 2950 return -EINVAL; 2951 2952 ptent = pte_mkspecial(pfn_pte(pfn, data->prot)); 2953 set_pte_at(&init_mm, addr, pte, ptent); 2954 2955 data->idx++; 2956 return 0; 2957 } 2958 2959 /** 2960 * vmap_pfn - map an array of PFNs into virtually contiguous space 2961 * @pfns: array of PFNs 2962 * @count: number of pages to map 2963 * @prot: page protection for the mapping 2964 * 2965 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns 2966 * the start address of the mapping. 2967 */ 2968 void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot) 2969 { 2970 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) }; 2971 struct vm_struct *area; 2972 2973 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP, 2974 __builtin_return_address(0)); 2975 if (!area) 2976 return NULL; 2977 if (apply_to_page_range(&init_mm, (unsigned long)area->addr, 2978 count * PAGE_SIZE, vmap_pfn_apply, &data)) { 2979 free_vm_area(area); 2980 return NULL; 2981 } 2982 2983 flush_cache_vmap((unsigned long)area->addr, 2984 (unsigned long)area->addr + count * PAGE_SIZE); 2985 2986 return area->addr; 2987 } 2988 EXPORT_SYMBOL_GPL(vmap_pfn); 2989 #endif /* CONFIG_VMAP_PFN */ 2990 2991 static inline unsigned int 2992 vm_area_alloc_pages(gfp_t gfp, int nid, 2993 unsigned int order, unsigned int nr_pages, struct page **pages) 2994 { 2995 unsigned int nr_allocated = 0; 2996 gfp_t alloc_gfp = gfp; 2997 bool nofail = false; 2998 struct page *page; 2999 int i; 3000 3001 /* 3002 * For order-0 pages we make use of bulk allocator, if 3003 * the page array is partly or not at all populated due 3004 * to fails, fallback to a single page allocator that is 3005 * more permissive. 3006 */ 3007 if (!order) { 3008 /* bulk allocator doesn't support nofail req. officially */ 3009 gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; 3010 3011 while (nr_allocated < nr_pages) { 3012 unsigned int nr, nr_pages_request; 3013 3014 /* 3015 * A maximum allowed request is hard-coded and is 100 3016 * pages per call. That is done in order to prevent a 3017 * long preemption off scenario in the bulk-allocator 3018 * so the range is [1:100]. 3019 */ 3020 nr_pages_request = min(100U, nr_pages - nr_allocated); 3021 3022 /* memory allocation should consider mempolicy, we can't 3023 * wrongly use nearest node when nid == NUMA_NO_NODE, 3024 * otherwise memory may be allocated in only one node, 3025 * but mempolicy wants to alloc memory by interleaving. 3026 */ 3027 if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) 3028 nr = alloc_pages_bulk_array_mempolicy(bulk_gfp, 3029 nr_pages_request, 3030 pages + nr_allocated); 3031 3032 else 3033 nr = alloc_pages_bulk_array_node(bulk_gfp, nid, 3034 nr_pages_request, 3035 pages + nr_allocated); 3036 3037 nr_allocated += nr; 3038 cond_resched(); 3039 3040 /* 3041 * If zero or pages were obtained partly, 3042 * fallback to a single page allocator. 3043 */ 3044 if (nr != nr_pages_request) 3045 break; 3046 } 3047 } else if (gfp & __GFP_NOFAIL) { 3048 /* 3049 * Higher order nofail allocations are really expensive and 3050 * potentially dangerous (pre-mature OOM, disruptive reclaim 3051 * and compaction etc. 3052 */ 3053 alloc_gfp &= ~__GFP_NOFAIL; 3054 nofail = true; 3055 } 3056 3057 /* High-order pages or fallback path if "bulk" fails. */ 3058 while (nr_allocated < nr_pages) { 3059 if (fatal_signal_pending(current)) 3060 break; 3061 3062 if (nid == NUMA_NO_NODE) 3063 page = alloc_pages(alloc_gfp, order); 3064 else 3065 page = alloc_pages_node(nid, alloc_gfp, order); 3066 if (unlikely(!page)) { 3067 if (!nofail) 3068 break; 3069 3070 /* fall back to the zero order allocations */ 3071 alloc_gfp |= __GFP_NOFAIL; 3072 order = 0; 3073 continue; 3074 } 3075 3076 /* 3077 * Higher order allocations must be able to be treated as 3078 * indepdenent small pages by callers (as they can with 3079 * small-page vmallocs). Some drivers do their own refcounting 3080 * on vmalloc_to_page() pages, some use page->mapping, 3081 * page->lru, etc. 3082 */ 3083 if (order) 3084 split_page(page, order); 3085 3086 /* 3087 * Careful, we allocate and map page-order pages, but 3088 * tracking is done per PAGE_SIZE page so as to keep the 3089 * vm_struct APIs independent of the physical/mapped size. 3090 */ 3091 for (i = 0; i < (1U << order); i++) 3092 pages[nr_allocated + i] = page + i; 3093 3094 cond_resched(); 3095 nr_allocated += 1U << order; 3096 } 3097 3098 return nr_allocated; 3099 } 3100 3101 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, 3102 pgprot_t prot, unsigned int page_shift, 3103 int node) 3104 { 3105 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; 3106 bool nofail = gfp_mask & __GFP_NOFAIL; 3107 unsigned long addr = (unsigned long)area->addr; 3108 unsigned long size = get_vm_area_size(area); 3109 unsigned long array_size; 3110 unsigned int nr_small_pages = size >> PAGE_SHIFT; 3111 unsigned int page_order; 3112 unsigned int flags; 3113 int ret; 3114 3115 array_size = (unsigned long)nr_small_pages * sizeof(struct page *); 3116 3117 if (!(gfp_mask & (GFP_DMA | GFP_DMA32))) 3118 gfp_mask |= __GFP_HIGHMEM; 3119 3120 /* Please note that the recursion is strictly bounded. */ 3121 if (array_size > PAGE_SIZE) { 3122 area->pages = __vmalloc_node(array_size, 1, nested_gfp, node, 3123 area->caller); 3124 } else { 3125 area->pages = kmalloc_node(array_size, nested_gfp, node); 3126 } 3127 3128 if (!area->pages) { 3129 warn_alloc(gfp_mask, NULL, 3130 "vmalloc error: size %lu, failed to allocated page array size %lu", 3131 nr_small_pages * PAGE_SIZE, array_size); 3132 free_vm_area(area); 3133 return NULL; 3134 } 3135 3136 set_vm_area_page_order(area, page_shift - PAGE_SHIFT); 3137 page_order = vm_area_page_order(area); 3138 3139 area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, 3140 node, page_order, nr_small_pages, area->pages); 3141 3142 atomic_long_add(area->nr_pages, &nr_vmalloc_pages); 3143 if (gfp_mask & __GFP_ACCOUNT) { 3144 int i; 3145 3146 for (i = 0; i < area->nr_pages; i++) 3147 mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1); 3148 } 3149 3150 /* 3151 * If not enough pages were obtained to accomplish an 3152 * allocation request, free them via vfree() if any. 3153 */ 3154 if (area->nr_pages != nr_small_pages) { 3155 /* 3156 * vm_area_alloc_pages() can fail due to insufficient memory but 3157 * also:- 3158 * 3159 * - a pending fatal signal 3160 * - insufficient huge page-order pages 3161 * 3162 * Since we always retry allocations at order-0 in the huge page 3163 * case a warning for either is spurious. 3164 */ 3165 if (!fatal_signal_pending(current) && page_order == 0) 3166 warn_alloc(gfp_mask, NULL, 3167 "vmalloc error: size %lu, failed to allocate pages", 3168 area->nr_pages * PAGE_SIZE); 3169 goto fail; 3170 } 3171 3172 /* 3173 * page tables allocations ignore external gfp mask, enforce it 3174 * by the scope API 3175 */ 3176 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) 3177 flags = memalloc_nofs_save(); 3178 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) 3179 flags = memalloc_noio_save(); 3180 3181 do { 3182 ret = vmap_pages_range(addr, addr + size, prot, area->pages, 3183 page_shift); 3184 if (nofail && (ret < 0)) 3185 schedule_timeout_uninterruptible(1); 3186 } while (nofail && (ret < 0)); 3187 3188 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) 3189 memalloc_nofs_restore(flags); 3190 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) 3191 memalloc_noio_restore(flags); 3192 3193 if (ret < 0) { 3194 warn_alloc(gfp_mask, NULL, 3195 "vmalloc error: size %lu, failed to map pages", 3196 area->nr_pages * PAGE_SIZE); 3197 goto fail; 3198 } 3199 3200 return area->addr; 3201 3202 fail: 3203 vfree(area->addr); 3204 return NULL; 3205 } 3206 3207 /** 3208 * __vmalloc_node_range - allocate virtually contiguous memory 3209 * @size: allocation size 3210 * @align: desired alignment 3211 * @start: vm area range start 3212 * @end: vm area range end 3213 * @gfp_mask: flags for the page level allocator 3214 * @prot: protection mask for the allocated pages 3215 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) 3216 * @node: node to use for allocation or NUMA_NO_NODE 3217 * @caller: caller's return address 3218 * 3219 * Allocate enough pages to cover @size from the page level 3220 * allocator with @gfp_mask flags. Please note that the full set of gfp 3221 * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all 3222 * supported. 3223 * Zone modifiers are not supported. From the reclaim modifiers 3224 * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported) 3225 * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and 3226 * __GFP_RETRY_MAYFAIL are not supported). 3227 * 3228 * __GFP_NOWARN can be used to suppress failures messages. 3229 * 3230 * Map them into contiguous kernel virtual space, using a pagetable 3231 * protection of @prot. 3232 * 3233 * Return: the address of the area or %NULL on failure 3234 */ 3235 void *__vmalloc_node_range(unsigned long size, unsigned long align, 3236 unsigned long start, unsigned long end, gfp_t gfp_mask, 3237 pgprot_t prot, unsigned long vm_flags, int node, 3238 const void *caller) 3239 { 3240 struct vm_struct *area; 3241 void *ret; 3242 kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE; 3243 unsigned long real_size = size; 3244 unsigned long real_align = align; 3245 unsigned int shift = PAGE_SHIFT; 3246 3247 if (WARN_ON_ONCE(!size)) 3248 return NULL; 3249 3250 if ((size >> PAGE_SHIFT) > totalram_pages()) { 3251 warn_alloc(gfp_mask, NULL, 3252 "vmalloc error: size %lu, exceeds total pages", 3253 real_size); 3254 return NULL; 3255 } 3256 3257 if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) { 3258 unsigned long size_per_node; 3259 3260 /* 3261 * Try huge pages. Only try for PAGE_KERNEL allocations, 3262 * others like modules don't yet expect huge pages in 3263 * their allocations due to apply_to_page_range not 3264 * supporting them. 3265 */ 3266 3267 size_per_node = size; 3268 if (node == NUMA_NO_NODE) 3269 size_per_node /= num_online_nodes(); 3270 if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE) 3271 shift = PMD_SHIFT; 3272 else 3273 shift = arch_vmap_pte_supported_shift(size_per_node); 3274 3275 align = max(real_align, 1UL << shift); 3276 size = ALIGN(real_size, 1UL << shift); 3277 } 3278 3279 again: 3280 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC | 3281 VM_UNINITIALIZED | vm_flags, start, end, node, 3282 gfp_mask, caller); 3283 if (!area) { 3284 bool nofail = gfp_mask & __GFP_NOFAIL; 3285 warn_alloc(gfp_mask, NULL, 3286 "vmalloc error: size %lu, vm_struct allocation failed%s", 3287 real_size, (nofail) ? ". Retrying." : ""); 3288 if (nofail) { 3289 schedule_timeout_uninterruptible(1); 3290 goto again; 3291 } 3292 goto fail; 3293 } 3294 3295 /* 3296 * Prepare arguments for __vmalloc_area_node() and 3297 * kasan_unpoison_vmalloc(). 3298 */ 3299 if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) { 3300 if (kasan_hw_tags_enabled()) { 3301 /* 3302 * Modify protection bits to allow tagging. 3303 * This must be done before mapping. 3304 */ 3305 prot = arch_vmap_pgprot_tagged(prot); 3306 3307 /* 3308 * Skip page_alloc poisoning and zeroing for physical 3309 * pages backing VM_ALLOC mapping. Memory is instead 3310 * poisoned and zeroed by kasan_unpoison_vmalloc(). 3311 */ 3312 gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO; 3313 } 3314 3315 /* Take note that the mapping is PAGE_KERNEL. */ 3316 kasan_flags |= KASAN_VMALLOC_PROT_NORMAL; 3317 } 3318 3319 /* Allocate physical pages and map them into vmalloc space. */ 3320 ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node); 3321 if (!ret) 3322 goto fail; 3323 3324 /* 3325 * Mark the pages as accessible, now that they are mapped. 3326 * The condition for setting KASAN_VMALLOC_INIT should complement the 3327 * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check 3328 * to make sure that memory is initialized under the same conditions. 3329 * Tag-based KASAN modes only assign tags to normal non-executable 3330 * allocations, see __kasan_unpoison_vmalloc(). 3331 */ 3332 kasan_flags |= KASAN_VMALLOC_VM_ALLOC; 3333 if (!want_init_on_free() && want_init_on_alloc(gfp_mask) && 3334 (gfp_mask & __GFP_SKIP_ZERO)) 3335 kasan_flags |= KASAN_VMALLOC_INIT; 3336 /* KASAN_VMALLOC_PROT_NORMAL already set if required. */ 3337 area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags); 3338 3339 /* 3340 * In this function, newly allocated vm_struct has VM_UNINITIALIZED 3341 * flag. It means that vm_struct is not fully initialized. 3342 * Now, it is fully initialized, so remove this flag here. 3343 */ 3344 clear_vm_uninitialized_flag(area); 3345 3346 size = PAGE_ALIGN(size); 3347 if (!(vm_flags & VM_DEFER_KMEMLEAK)) 3348 kmemleak_vmalloc(area, size, gfp_mask); 3349 3350 return area->addr; 3351 3352 fail: 3353 if (shift > PAGE_SHIFT) { 3354 shift = PAGE_SHIFT; 3355 align = real_align; 3356 size = real_size; 3357 goto again; 3358 } 3359 3360 return NULL; 3361 } 3362 3363 /** 3364 * __vmalloc_node - allocate virtually contiguous memory 3365 * @size: allocation size 3366 * @align: desired alignment 3367 * @gfp_mask: flags for the page level allocator 3368 * @node: node to use for allocation or NUMA_NO_NODE 3369 * @caller: caller's return address 3370 * 3371 * Allocate enough pages to cover @size from the page level allocator with 3372 * @gfp_mask flags. Map them into contiguous kernel virtual space. 3373 * 3374 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL 3375 * and __GFP_NOFAIL are not supported 3376 * 3377 * Any use of gfp flags outside of GFP_KERNEL should be consulted 3378 * with mm people. 3379 * 3380 * Return: pointer to the allocated memory or %NULL on error 3381 */ 3382 void *__vmalloc_node(unsigned long size, unsigned long align, 3383 gfp_t gfp_mask, int node, const void *caller) 3384 { 3385 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 3386 gfp_mask, PAGE_KERNEL, 0, node, caller); 3387 } 3388 /* 3389 * This is only for performance analysis of vmalloc and stress purpose. 3390 * It is required by vmalloc test module, therefore do not use it other 3391 * than that. 3392 */ 3393 #ifdef CONFIG_TEST_VMALLOC_MODULE 3394 EXPORT_SYMBOL_GPL(__vmalloc_node); 3395 #endif 3396 3397 void *__vmalloc(unsigned long size, gfp_t gfp_mask) 3398 { 3399 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE, 3400 __builtin_return_address(0)); 3401 } 3402 EXPORT_SYMBOL(__vmalloc); 3403 3404 /** 3405 * vmalloc - allocate virtually contiguous memory 3406 * @size: allocation size 3407 * 3408 * Allocate enough pages to cover @size from the page level 3409 * allocator and map them into contiguous kernel virtual space. 3410 * 3411 * For tight control over page level allocator and protection flags 3412 * use __vmalloc() instead. 3413 * 3414 * Return: pointer to the allocated memory or %NULL on error 3415 */ 3416 void *vmalloc(unsigned long size) 3417 { 3418 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE, 3419 __builtin_return_address(0)); 3420 } 3421 EXPORT_SYMBOL(vmalloc); 3422 3423 /** 3424 * vmalloc_huge - allocate virtually contiguous memory, allow huge pages 3425 * @size: allocation size 3426 * @gfp_mask: flags for the page level allocator 3427 * 3428 * Allocate enough pages to cover @size from the page level 3429 * allocator and map them into contiguous kernel virtual space. 3430 * If @size is greater than or equal to PMD_SIZE, allow using 3431 * huge pages for the memory 3432 * 3433 * Return: pointer to the allocated memory or %NULL on error 3434 */ 3435 void *vmalloc_huge(unsigned long size, gfp_t gfp_mask) 3436 { 3437 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, 3438 gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP, 3439 NUMA_NO_NODE, __builtin_return_address(0)); 3440 } 3441 EXPORT_SYMBOL_GPL(vmalloc_huge); 3442 3443 /** 3444 * vzalloc - allocate virtually contiguous memory with zero fill 3445 * @size: allocation size 3446 * 3447 * Allocate enough pages to cover @size from the page level 3448 * allocator and map them into contiguous kernel virtual space. 3449 * The memory allocated is set to zero. 3450 * 3451 * For tight control over page level allocator and protection flags 3452 * use __vmalloc() instead. 3453 * 3454 * Return: pointer to the allocated memory or %NULL on error 3455 */ 3456 void *vzalloc(unsigned long size) 3457 { 3458 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, 3459 __builtin_return_address(0)); 3460 } 3461 EXPORT_SYMBOL(vzalloc); 3462 3463 /** 3464 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace 3465 * @size: allocation size 3466 * 3467 * The resulting memory area is zeroed so it can be mapped to userspace 3468 * without leaking data. 3469 * 3470 * Return: pointer to the allocated memory or %NULL on error 3471 */ 3472 void *vmalloc_user(unsigned long size) 3473 { 3474 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, 3475 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, 3476 VM_USERMAP, NUMA_NO_NODE, 3477 __builtin_return_address(0)); 3478 } 3479 EXPORT_SYMBOL(vmalloc_user); 3480 3481 /** 3482 * vmalloc_node - allocate memory on a specific node 3483 * @size: allocation size 3484 * @node: numa node 3485 * 3486 * Allocate enough pages to cover @size from the page level 3487 * allocator and map them into contiguous kernel virtual space. 3488 * 3489 * For tight control over page level allocator and protection flags 3490 * use __vmalloc() instead. 3491 * 3492 * Return: pointer to the allocated memory or %NULL on error 3493 */ 3494 void *vmalloc_node(unsigned long size, int node) 3495 { 3496 return __vmalloc_node(size, 1, GFP_KERNEL, node, 3497 __builtin_return_address(0)); 3498 } 3499 EXPORT_SYMBOL(vmalloc_node); 3500 3501 /** 3502 * vzalloc_node - allocate memory on a specific node with zero fill 3503 * @size: allocation size 3504 * @node: numa node 3505 * 3506 * Allocate enough pages to cover @size from the page level 3507 * allocator and map them into contiguous kernel virtual space. 3508 * The memory allocated is set to zero. 3509 * 3510 * Return: pointer to the allocated memory or %NULL on error 3511 */ 3512 void *vzalloc_node(unsigned long size, int node) 3513 { 3514 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node, 3515 __builtin_return_address(0)); 3516 } 3517 EXPORT_SYMBOL(vzalloc_node); 3518 3519 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) 3520 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) 3521 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) 3522 #define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL) 3523 #else 3524 /* 3525 * 64b systems should always have either DMA or DMA32 zones. For others 3526 * GFP_DMA32 should do the right thing and use the normal zone. 3527 */ 3528 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) 3529 #endif 3530 3531 /** 3532 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 3533 * @size: allocation size 3534 * 3535 * Allocate enough 32bit PA addressable pages to cover @size from the 3536 * page level allocator and map them into contiguous kernel virtual space. 3537 * 3538 * Return: pointer to the allocated memory or %NULL on error 3539 */ 3540 void *vmalloc_32(unsigned long size) 3541 { 3542 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE, 3543 __builtin_return_address(0)); 3544 } 3545 EXPORT_SYMBOL(vmalloc_32); 3546 3547 /** 3548 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 3549 * @size: allocation size 3550 * 3551 * The resulting memory area is 32bit addressable and zeroed so it can be 3552 * mapped to userspace without leaking data. 3553 * 3554 * Return: pointer to the allocated memory or %NULL on error 3555 */ 3556 void *vmalloc_32_user(unsigned long size) 3557 { 3558 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, 3559 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, 3560 VM_USERMAP, NUMA_NO_NODE, 3561 __builtin_return_address(0)); 3562 } 3563 EXPORT_SYMBOL(vmalloc_32_user); 3564 3565 /* 3566 * Atomically zero bytes in the iterator. 3567 * 3568 * Returns the number of zeroed bytes. 3569 */ 3570 static size_t zero_iter(struct iov_iter *iter, size_t count) 3571 { 3572 size_t remains = count; 3573 3574 while (remains > 0) { 3575 size_t num, copied; 3576 3577 num = min_t(size_t, remains, PAGE_SIZE); 3578 copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter); 3579 remains -= copied; 3580 3581 if (copied < num) 3582 break; 3583 } 3584 3585 return count - remains; 3586 } 3587 3588 /* 3589 * small helper routine, copy contents to iter from addr. 3590 * If the page is not present, fill zero. 3591 * 3592 * Returns the number of copied bytes. 3593 */ 3594 static size_t aligned_vread_iter(struct iov_iter *iter, 3595 const char *addr, size_t count) 3596 { 3597 size_t remains = count; 3598 struct page *page; 3599 3600 while (remains > 0) { 3601 unsigned long offset, length; 3602 size_t copied = 0; 3603 3604 offset = offset_in_page(addr); 3605 length = PAGE_SIZE - offset; 3606 if (length > remains) 3607 length = remains; 3608 page = vmalloc_to_page(addr); 3609 /* 3610 * To do safe access to this _mapped_ area, we need lock. But 3611 * adding lock here means that we need to add overhead of 3612 * vmalloc()/vfree() calls for this _debug_ interface, rarely 3613 * used. Instead of that, we'll use an local mapping via 3614 * copy_page_to_iter_nofault() and accept a small overhead in 3615 * this access function. 3616 */ 3617 if (page) 3618 copied = copy_page_to_iter_nofault(page, offset, 3619 length, iter); 3620 else 3621 copied = zero_iter(iter, length); 3622 3623 addr += copied; 3624 remains -= copied; 3625 3626 if (copied != length) 3627 break; 3628 } 3629 3630 return count - remains; 3631 } 3632 3633 /* 3634 * Read from a vm_map_ram region of memory. 3635 * 3636 * Returns the number of copied bytes. 3637 */ 3638 static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr, 3639 size_t count, unsigned long flags) 3640 { 3641 char *start; 3642 struct vmap_block *vb; 3643 struct xarray *xa; 3644 unsigned long offset; 3645 unsigned int rs, re; 3646 size_t remains, n; 3647 3648 /* 3649 * If it's area created by vm_map_ram() interface directly, but 3650 * not further subdividing and delegating management to vmap_block, 3651 * handle it here. 3652 */ 3653 if (!(flags & VMAP_BLOCK)) 3654 return aligned_vread_iter(iter, addr, count); 3655 3656 remains = count; 3657 3658 /* 3659 * Area is split into regions and tracked with vmap_block, read out 3660 * each region and zero fill the hole between regions. 3661 */ 3662 xa = addr_to_vb_xa((unsigned long) addr); 3663 vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr)); 3664 if (!vb) 3665 goto finished_zero; 3666 3667 spin_lock(&vb->lock); 3668 if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) { 3669 spin_unlock(&vb->lock); 3670 goto finished_zero; 3671 } 3672 3673 for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) { 3674 size_t copied; 3675 3676 if (remains == 0) 3677 goto finished; 3678 3679 start = vmap_block_vaddr(vb->va->va_start, rs); 3680 3681 if (addr < start) { 3682 size_t to_zero = min_t(size_t, start - addr, remains); 3683 size_t zeroed = zero_iter(iter, to_zero); 3684 3685 addr += zeroed; 3686 remains -= zeroed; 3687 3688 if (remains == 0 || zeroed != to_zero) 3689 goto finished; 3690 } 3691 3692 /*it could start reading from the middle of used region*/ 3693 offset = offset_in_page(addr); 3694 n = ((re - rs + 1) << PAGE_SHIFT) - offset; 3695 if (n > remains) 3696 n = remains; 3697 3698 copied = aligned_vread_iter(iter, start + offset, n); 3699 3700 addr += copied; 3701 remains -= copied; 3702 3703 if (copied != n) 3704 goto finished; 3705 } 3706 3707 spin_unlock(&vb->lock); 3708 3709 finished_zero: 3710 /* zero-fill the left dirty or free regions */ 3711 return count - remains + zero_iter(iter, remains); 3712 finished: 3713 /* We couldn't copy/zero everything */ 3714 spin_unlock(&vb->lock); 3715 return count - remains; 3716 } 3717 3718 /** 3719 * vread_iter() - read vmalloc area in a safe way to an iterator. 3720 * @iter: the iterator to which data should be written. 3721 * @addr: vm address. 3722 * @count: number of bytes to be read. 3723 * 3724 * This function checks that addr is a valid vmalloc'ed area, and 3725 * copy data from that area to a given buffer. If the given memory range 3726 * of [addr...addr+count) includes some valid address, data is copied to 3727 * proper area of @buf. If there are memory holes, they'll be zero-filled. 3728 * IOREMAP area is treated as memory hole and no copy is done. 3729 * 3730 * If [addr...addr+count) doesn't includes any intersects with alive 3731 * vm_struct area, returns 0. @buf should be kernel's buffer. 3732 * 3733 * Note: In usual ops, vread() is never necessary because the caller 3734 * should know vmalloc() area is valid and can use memcpy(). 3735 * This is for routines which have to access vmalloc area without 3736 * any information, as /proc/kcore. 3737 * 3738 * Return: number of bytes for which addr and buf should be increased 3739 * (same number as @count) or %0 if [addr...addr+count) doesn't 3740 * include any intersection with valid vmalloc area 3741 */ 3742 long vread_iter(struct iov_iter *iter, const char *addr, size_t count) 3743 { 3744 struct vmap_area *va; 3745 struct vm_struct *vm; 3746 char *vaddr; 3747 size_t n, size, flags, remains; 3748 3749 addr = kasan_reset_tag(addr); 3750 3751 /* Don't allow overflow */ 3752 if ((unsigned long) addr + count < count) 3753 count = -(unsigned long) addr; 3754 3755 remains = count; 3756 3757 spin_lock(&vmap_area_lock); 3758 va = find_vmap_area_exceed_addr((unsigned long)addr); 3759 if (!va) 3760 goto finished_zero; 3761 3762 /* no intersects with alive vmap_area */ 3763 if ((unsigned long)addr + remains <= va->va_start) 3764 goto finished_zero; 3765 3766 list_for_each_entry_from(va, &vmap_area_list, list) { 3767 size_t copied; 3768 3769 if (remains == 0) 3770 goto finished; 3771 3772 vm = va->vm; 3773 flags = va->flags & VMAP_FLAGS_MASK; 3774 /* 3775 * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need 3776 * be set together with VMAP_RAM. 3777 */ 3778 WARN_ON(flags == VMAP_BLOCK); 3779 3780 if (!vm && !flags) 3781 continue; 3782 3783 if (vm && (vm->flags & VM_UNINITIALIZED)) 3784 continue; 3785 3786 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ 3787 smp_rmb(); 3788 3789 vaddr = (char *) va->va_start; 3790 size = vm ? get_vm_area_size(vm) : va_size(va); 3791 3792 if (addr >= vaddr + size) 3793 continue; 3794 3795 if (addr < vaddr) { 3796 size_t to_zero = min_t(size_t, vaddr - addr, remains); 3797 size_t zeroed = zero_iter(iter, to_zero); 3798 3799 addr += zeroed; 3800 remains -= zeroed; 3801 3802 if (remains == 0 || zeroed != to_zero) 3803 goto finished; 3804 } 3805 3806 n = vaddr + size - addr; 3807 if (n > remains) 3808 n = remains; 3809 3810 if (flags & VMAP_RAM) 3811 copied = vmap_ram_vread_iter(iter, addr, n, flags); 3812 else if (!(vm->flags & VM_IOREMAP)) 3813 copied = aligned_vread_iter(iter, addr, n); 3814 else /* IOREMAP area is treated as memory hole */ 3815 copied = zero_iter(iter, n); 3816 3817 addr += copied; 3818 remains -= copied; 3819 3820 if (copied != n) 3821 goto finished; 3822 } 3823 3824 finished_zero: 3825 spin_unlock(&vmap_area_lock); 3826 /* zero-fill memory holes */ 3827 return count - remains + zero_iter(iter, remains); 3828 finished: 3829 /* Nothing remains, or We couldn't copy/zero everything. */ 3830 spin_unlock(&vmap_area_lock); 3831 3832 return count - remains; 3833 } 3834 3835 /** 3836 * remap_vmalloc_range_partial - map vmalloc pages to userspace 3837 * @vma: vma to cover 3838 * @uaddr: target user address to start at 3839 * @kaddr: virtual address of vmalloc kernel memory 3840 * @pgoff: offset from @kaddr to start at 3841 * @size: size of map area 3842 * 3843 * Returns: 0 for success, -Exxx on failure 3844 * 3845 * This function checks that @kaddr is a valid vmalloc'ed area, 3846 * and that it is big enough to cover the range starting at 3847 * @uaddr in @vma. Will return failure if that criteria isn't 3848 * met. 3849 * 3850 * Similar to remap_pfn_range() (see mm/memory.c) 3851 */ 3852 int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, 3853 void *kaddr, unsigned long pgoff, 3854 unsigned long size) 3855 { 3856 struct vm_struct *area; 3857 unsigned long off; 3858 unsigned long end_index; 3859 3860 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off)) 3861 return -EINVAL; 3862 3863 size = PAGE_ALIGN(size); 3864 3865 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr)) 3866 return -EINVAL; 3867 3868 area = find_vm_area(kaddr); 3869 if (!area) 3870 return -EINVAL; 3871 3872 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT))) 3873 return -EINVAL; 3874 3875 if (check_add_overflow(size, off, &end_index) || 3876 end_index > get_vm_area_size(area)) 3877 return -EINVAL; 3878 kaddr += off; 3879 3880 do { 3881 struct page *page = vmalloc_to_page(kaddr); 3882 int ret; 3883 3884 ret = vm_insert_page(vma, uaddr, page); 3885 if (ret) 3886 return ret; 3887 3888 uaddr += PAGE_SIZE; 3889 kaddr += PAGE_SIZE; 3890 size -= PAGE_SIZE; 3891 } while (size > 0); 3892 3893 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); 3894 3895 return 0; 3896 } 3897 3898 /** 3899 * remap_vmalloc_range - map vmalloc pages to userspace 3900 * @vma: vma to cover (map full range of vma) 3901 * @addr: vmalloc memory 3902 * @pgoff: number of pages into addr before first page to map 3903 * 3904 * Returns: 0 for success, -Exxx on failure 3905 * 3906 * This function checks that addr is a valid vmalloc'ed area, and 3907 * that it is big enough to cover the vma. Will return failure if 3908 * that criteria isn't met. 3909 * 3910 * Similar to remap_pfn_range() (see mm/memory.c) 3911 */ 3912 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 3913 unsigned long pgoff) 3914 { 3915 return remap_vmalloc_range_partial(vma, vma->vm_start, 3916 addr, pgoff, 3917 vma->vm_end - vma->vm_start); 3918 } 3919 EXPORT_SYMBOL(remap_vmalloc_range); 3920 3921 void free_vm_area(struct vm_struct *area) 3922 { 3923 struct vm_struct *ret; 3924 ret = remove_vm_area(area->addr); 3925 BUG_ON(ret != area); 3926 kfree(area); 3927 } 3928 EXPORT_SYMBOL_GPL(free_vm_area); 3929 3930 #ifdef CONFIG_SMP 3931 static struct vmap_area *node_to_va(struct rb_node *n) 3932 { 3933 return rb_entry_safe(n, struct vmap_area, rb_node); 3934 } 3935 3936 /** 3937 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to 3938 * @addr: target address 3939 * 3940 * Returns: vmap_area if it is found. If there is no such area 3941 * the first highest(reverse order) vmap_area is returned 3942 * i.e. va->va_start < addr && va->va_end < addr or NULL 3943 * if there are no any areas before @addr. 3944 */ 3945 static struct vmap_area * 3946 pvm_find_va_enclose_addr(unsigned long addr) 3947 { 3948 struct vmap_area *va, *tmp; 3949 struct rb_node *n; 3950 3951 n = free_vmap_area_root.rb_node; 3952 va = NULL; 3953 3954 while (n) { 3955 tmp = rb_entry(n, struct vmap_area, rb_node); 3956 if (tmp->va_start <= addr) { 3957 va = tmp; 3958 if (tmp->va_end >= addr) 3959 break; 3960 3961 n = n->rb_right; 3962 } else { 3963 n = n->rb_left; 3964 } 3965 } 3966 3967 return va; 3968 } 3969 3970 /** 3971 * pvm_determine_end_from_reverse - find the highest aligned address 3972 * of free block below VMALLOC_END 3973 * @va: 3974 * in - the VA we start the search(reverse order); 3975 * out - the VA with the highest aligned end address. 3976 * @align: alignment for required highest address 3977 * 3978 * Returns: determined end address within vmap_area 3979 */ 3980 static unsigned long 3981 pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align) 3982 { 3983 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); 3984 unsigned long addr; 3985 3986 if (likely(*va)) { 3987 list_for_each_entry_from_reverse((*va), 3988 &free_vmap_area_list, list) { 3989 addr = min((*va)->va_end & ~(align - 1), vmalloc_end); 3990 if ((*va)->va_start < addr) 3991 return addr; 3992 } 3993 } 3994 3995 return 0; 3996 } 3997 3998 /** 3999 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator 4000 * @offsets: array containing offset of each area 4001 * @sizes: array containing size of each area 4002 * @nr_vms: the number of areas to allocate 4003 * @align: alignment, all entries in @offsets and @sizes must be aligned to this 4004 * 4005 * Returns: kmalloc'd vm_struct pointer array pointing to allocated 4006 * vm_structs on success, %NULL on failure 4007 * 4008 * Percpu allocator wants to use congruent vm areas so that it can 4009 * maintain the offsets among percpu areas. This function allocates 4010 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to 4011 * be scattered pretty far, distance between two areas easily going up 4012 * to gigabytes. To avoid interacting with regular vmallocs, these 4013 * areas are allocated from top. 4014 * 4015 * Despite its complicated look, this allocator is rather simple. It 4016 * does everything top-down and scans free blocks from the end looking 4017 * for matching base. While scanning, if any of the areas do not fit the 4018 * base address is pulled down to fit the area. Scanning is repeated till 4019 * all the areas fit and then all necessary data structures are inserted 4020 * and the result is returned. 4021 */ 4022 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, 4023 const size_t *sizes, int nr_vms, 4024 size_t align) 4025 { 4026 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); 4027 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); 4028 struct vmap_area **vas, *va; 4029 struct vm_struct **vms; 4030 int area, area2, last_area, term_area; 4031 unsigned long base, start, size, end, last_end, orig_start, orig_end; 4032 bool purged = false; 4033 4034 /* verify parameters and allocate data structures */ 4035 BUG_ON(offset_in_page(align) || !is_power_of_2(align)); 4036 for (last_area = 0, area = 0; area < nr_vms; area++) { 4037 start = offsets[area]; 4038 end = start + sizes[area]; 4039 4040 /* is everything aligned properly? */ 4041 BUG_ON(!IS_ALIGNED(offsets[area], align)); 4042 BUG_ON(!IS_ALIGNED(sizes[area], align)); 4043 4044 /* detect the area with the highest address */ 4045 if (start > offsets[last_area]) 4046 last_area = area; 4047 4048 for (area2 = area + 1; area2 < nr_vms; area2++) { 4049 unsigned long start2 = offsets[area2]; 4050 unsigned long end2 = start2 + sizes[area2]; 4051 4052 BUG_ON(start2 < end && start < end2); 4053 } 4054 } 4055 last_end = offsets[last_area] + sizes[last_area]; 4056 4057 if (vmalloc_end - vmalloc_start < last_end) { 4058 WARN_ON(true); 4059 return NULL; 4060 } 4061 4062 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL); 4063 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL); 4064 if (!vas || !vms) 4065 goto err_free2; 4066 4067 for (area = 0; area < nr_vms; area++) { 4068 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL); 4069 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); 4070 if (!vas[area] || !vms[area]) 4071 goto err_free; 4072 } 4073 retry: 4074 spin_lock(&free_vmap_area_lock); 4075 4076 /* start scanning - we scan from the top, begin with the last area */ 4077 area = term_area = last_area; 4078 start = offsets[area]; 4079 end = start + sizes[area]; 4080 4081 va = pvm_find_va_enclose_addr(vmalloc_end); 4082 base = pvm_determine_end_from_reverse(&va, align) - end; 4083 4084 while (true) { 4085 /* 4086 * base might have underflowed, add last_end before 4087 * comparing. 4088 */ 4089 if (base + last_end < vmalloc_start + last_end) 4090 goto overflow; 4091 4092 /* 4093 * Fitting base has not been found. 4094 */ 4095 if (va == NULL) 4096 goto overflow; 4097 4098 /* 4099 * If required width exceeds current VA block, move 4100 * base downwards and then recheck. 4101 */ 4102 if (base + end > va->va_end) { 4103 base = pvm_determine_end_from_reverse(&va, align) - end; 4104 term_area = area; 4105 continue; 4106 } 4107 4108 /* 4109 * If this VA does not fit, move base downwards and recheck. 4110 */ 4111 if (base + start < va->va_start) { 4112 va = node_to_va(rb_prev(&va->rb_node)); 4113 base = pvm_determine_end_from_reverse(&va, align) - end; 4114 term_area = area; 4115 continue; 4116 } 4117 4118 /* 4119 * This area fits, move on to the previous one. If 4120 * the previous one is the terminal one, we're done. 4121 */ 4122 area = (area + nr_vms - 1) % nr_vms; 4123 if (area == term_area) 4124 break; 4125 4126 start = offsets[area]; 4127 end = start + sizes[area]; 4128 va = pvm_find_va_enclose_addr(base + end); 4129 } 4130 4131 /* we've found a fitting base, insert all va's */ 4132 for (area = 0; area < nr_vms; area++) { 4133 int ret; 4134 4135 start = base + offsets[area]; 4136 size = sizes[area]; 4137 4138 va = pvm_find_va_enclose_addr(start); 4139 if (WARN_ON_ONCE(va == NULL)) 4140 /* It is a BUG(), but trigger recovery instead. */ 4141 goto recovery; 4142 4143 ret = adjust_va_to_fit_type(&free_vmap_area_root, 4144 &free_vmap_area_list, 4145 va, start, size); 4146 if (WARN_ON_ONCE(unlikely(ret))) 4147 /* It is a BUG(), but trigger recovery instead. */ 4148 goto recovery; 4149 4150 /* Allocated area. */ 4151 va = vas[area]; 4152 va->va_start = start; 4153 va->va_end = start + size; 4154 } 4155 4156 spin_unlock(&free_vmap_area_lock); 4157 4158 /* populate the kasan shadow space */ 4159 for (area = 0; area < nr_vms; area++) { 4160 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) 4161 goto err_free_shadow; 4162 } 4163 4164 /* insert all vm's */ 4165 spin_lock(&vmap_area_lock); 4166 for (area = 0; area < nr_vms; area++) { 4167 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list); 4168 4169 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, 4170 pcpu_get_vm_areas); 4171 } 4172 spin_unlock(&vmap_area_lock); 4173 4174 /* 4175 * Mark allocated areas as accessible. Do it now as a best-effort 4176 * approach, as they can be mapped outside of vmalloc code. 4177 * With hardware tag-based KASAN, marking is skipped for 4178 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). 4179 */ 4180 for (area = 0; area < nr_vms; area++) 4181 vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, 4182 vms[area]->size, KASAN_VMALLOC_PROT_NORMAL); 4183 4184 kfree(vas); 4185 return vms; 4186 4187 recovery: 4188 /* 4189 * Remove previously allocated areas. There is no 4190 * need in removing these areas from the busy tree, 4191 * because they are inserted only on the final step 4192 * and when pcpu_get_vm_areas() is success. 4193 */ 4194 while (area--) { 4195 orig_start = vas[area]->va_start; 4196 orig_end = vas[area]->va_end; 4197 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, 4198 &free_vmap_area_list); 4199 if (va) 4200 kasan_release_vmalloc(orig_start, orig_end, 4201 va->va_start, va->va_end); 4202 vas[area] = NULL; 4203 } 4204 4205 overflow: 4206 spin_unlock(&free_vmap_area_lock); 4207 if (!purged) { 4208 reclaim_and_purge_vmap_areas(); 4209 purged = true; 4210 4211 /* Before "retry", check if we recover. */ 4212 for (area = 0; area < nr_vms; area++) { 4213 if (vas[area]) 4214 continue; 4215 4216 vas[area] = kmem_cache_zalloc( 4217 vmap_area_cachep, GFP_KERNEL); 4218 if (!vas[area]) 4219 goto err_free; 4220 } 4221 4222 goto retry; 4223 } 4224 4225 err_free: 4226 for (area = 0; area < nr_vms; area++) { 4227 if (vas[area]) 4228 kmem_cache_free(vmap_area_cachep, vas[area]); 4229 4230 kfree(vms[area]); 4231 } 4232 err_free2: 4233 kfree(vas); 4234 kfree(vms); 4235 return NULL; 4236 4237 err_free_shadow: 4238 spin_lock(&free_vmap_area_lock); 4239 /* 4240 * We release all the vmalloc shadows, even the ones for regions that 4241 * hadn't been successfully added. This relies on kasan_release_vmalloc 4242 * being able to tolerate this case. 4243 */ 4244 for (area = 0; area < nr_vms; area++) { 4245 orig_start = vas[area]->va_start; 4246 orig_end = vas[area]->va_end; 4247 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, 4248 &free_vmap_area_list); 4249 if (va) 4250 kasan_release_vmalloc(orig_start, orig_end, 4251 va->va_start, va->va_end); 4252 vas[area] = NULL; 4253 kfree(vms[area]); 4254 } 4255 spin_unlock(&free_vmap_area_lock); 4256 kfree(vas); 4257 kfree(vms); 4258 return NULL; 4259 } 4260 4261 /** 4262 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator 4263 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() 4264 * @nr_vms: the number of allocated areas 4265 * 4266 * Free vm_structs and the array allocated by pcpu_get_vm_areas(). 4267 */ 4268 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) 4269 { 4270 int i; 4271 4272 for (i = 0; i < nr_vms; i++) 4273 free_vm_area(vms[i]); 4274 kfree(vms); 4275 } 4276 #endif /* CONFIG_SMP */ 4277 4278 #ifdef CONFIG_PRINTK 4279 bool vmalloc_dump_obj(void *object) 4280 { 4281 void *objp = (void *)PAGE_ALIGN((unsigned long)object); 4282 const void *caller; 4283 struct vm_struct *vm; 4284 struct vmap_area *va; 4285 unsigned long addr; 4286 unsigned int nr_pages; 4287 4288 if (!spin_trylock(&vmap_area_lock)) 4289 return false; 4290 va = __find_vmap_area((unsigned long)objp, &vmap_area_root); 4291 if (!va) { 4292 spin_unlock(&vmap_area_lock); 4293 return false; 4294 } 4295 4296 vm = va->vm; 4297 if (!vm) { 4298 spin_unlock(&vmap_area_lock); 4299 return false; 4300 } 4301 addr = (unsigned long)vm->addr; 4302 caller = vm->caller; 4303 nr_pages = vm->nr_pages; 4304 spin_unlock(&vmap_area_lock); 4305 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n", 4306 nr_pages, addr, caller); 4307 return true; 4308 } 4309 #endif 4310 4311 #ifdef CONFIG_PROC_FS 4312 static void *s_start(struct seq_file *m, loff_t *pos) 4313 __acquires(&vmap_purge_lock) 4314 __acquires(&vmap_area_lock) 4315 { 4316 mutex_lock(&vmap_purge_lock); 4317 spin_lock(&vmap_area_lock); 4318 4319 return seq_list_start(&vmap_area_list, *pos); 4320 } 4321 4322 static void *s_next(struct seq_file *m, void *p, loff_t *pos) 4323 { 4324 return seq_list_next(p, &vmap_area_list, pos); 4325 } 4326 4327 static void s_stop(struct seq_file *m, void *p) 4328 __releases(&vmap_area_lock) 4329 __releases(&vmap_purge_lock) 4330 { 4331 spin_unlock(&vmap_area_lock); 4332 mutex_unlock(&vmap_purge_lock); 4333 } 4334 4335 static void show_numa_info(struct seq_file *m, struct vm_struct *v) 4336 { 4337 if (IS_ENABLED(CONFIG_NUMA)) { 4338 unsigned int nr, *counters = m->private; 4339 unsigned int step = 1U << vm_area_page_order(v); 4340 4341 if (!counters) 4342 return; 4343 4344 if (v->flags & VM_UNINITIALIZED) 4345 return; 4346 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ 4347 smp_rmb(); 4348 4349 memset(counters, 0, nr_node_ids * sizeof(unsigned int)); 4350 4351 for (nr = 0; nr < v->nr_pages; nr += step) 4352 counters[page_to_nid(v->pages[nr])] += step; 4353 for_each_node_state(nr, N_HIGH_MEMORY) 4354 if (counters[nr]) 4355 seq_printf(m, " N%u=%u", nr, counters[nr]); 4356 } 4357 } 4358 4359 static void show_purge_info(struct seq_file *m) 4360 { 4361 struct vmap_area *va; 4362 4363 spin_lock(&purge_vmap_area_lock); 4364 list_for_each_entry(va, &purge_vmap_area_list, list) { 4365 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", 4366 (void *)va->va_start, (void *)va->va_end, 4367 va->va_end - va->va_start); 4368 } 4369 spin_unlock(&purge_vmap_area_lock); 4370 } 4371 4372 static int s_show(struct seq_file *m, void *p) 4373 { 4374 struct vmap_area *va; 4375 struct vm_struct *v; 4376 4377 va = list_entry(p, struct vmap_area, list); 4378 4379 if (!va->vm) { 4380 if (va->flags & VMAP_RAM) 4381 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", 4382 (void *)va->va_start, (void *)va->va_end, 4383 va->va_end - va->va_start); 4384 4385 goto final; 4386 } 4387 4388 v = va->vm; 4389 4390 seq_printf(m, "0x%pK-0x%pK %7ld", 4391 v->addr, v->addr + v->size, v->size); 4392 4393 if (v->caller) 4394 seq_printf(m, " %pS", v->caller); 4395 4396 if (v->nr_pages) 4397 seq_printf(m, " pages=%d", v->nr_pages); 4398 4399 if (v->phys_addr) 4400 seq_printf(m, " phys=%pa", &v->phys_addr); 4401 4402 if (v->flags & VM_IOREMAP) 4403 seq_puts(m, " ioremap"); 4404 4405 if (v->flags & VM_ALLOC) 4406 seq_puts(m, " vmalloc"); 4407 4408 if (v->flags & VM_MAP) 4409 seq_puts(m, " vmap"); 4410 4411 if (v->flags & VM_USERMAP) 4412 seq_puts(m, " user"); 4413 4414 if (v->flags & VM_DMA_COHERENT) 4415 seq_puts(m, " dma-coherent"); 4416 4417 if (is_vmalloc_addr(v->pages)) 4418 seq_puts(m, " vpages"); 4419 4420 show_numa_info(m, v); 4421 seq_putc(m, '\n'); 4422 4423 /* 4424 * As a final step, dump "unpurged" areas. 4425 */ 4426 final: 4427 if (list_is_last(&va->list, &vmap_area_list)) 4428 show_purge_info(m); 4429 4430 return 0; 4431 } 4432 4433 static const struct seq_operations vmalloc_op = { 4434 .start = s_start, 4435 .next = s_next, 4436 .stop = s_stop, 4437 .show = s_show, 4438 }; 4439 4440 static int __init proc_vmalloc_init(void) 4441 { 4442 if (IS_ENABLED(CONFIG_NUMA)) 4443 proc_create_seq_private("vmallocinfo", 0400, NULL, 4444 &vmalloc_op, 4445 nr_node_ids * sizeof(unsigned int), NULL); 4446 else 4447 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op); 4448 return 0; 4449 } 4450 module_init(proc_vmalloc_init); 4451 4452 #endif 4453 4454 void __init vmalloc_init(void) 4455 { 4456 struct vmap_area *va; 4457 struct vm_struct *tmp; 4458 int i; 4459 4460 /* 4461 * Create the cache for vmap_area objects. 4462 */ 4463 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC); 4464 4465 for_each_possible_cpu(i) { 4466 struct vmap_block_queue *vbq; 4467 struct vfree_deferred *p; 4468 4469 vbq = &per_cpu(vmap_block_queue, i); 4470 spin_lock_init(&vbq->lock); 4471 INIT_LIST_HEAD(&vbq->free); 4472 p = &per_cpu(vfree_deferred, i); 4473 init_llist_head(&p->list); 4474 INIT_WORK(&p->wq, delayed_vfree_work); 4475 xa_init(&vbq->vmap_blocks); 4476 } 4477 4478 /* Import existing vmlist entries. */ 4479 for (tmp = vmlist; tmp; tmp = tmp->next) { 4480 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); 4481 if (WARN_ON_ONCE(!va)) 4482 continue; 4483 4484 va->va_start = (unsigned long)tmp->addr; 4485 va->va_end = va->va_start + tmp->size; 4486 va->vm = tmp; 4487 insert_vmap_area(va, &vmap_area_root, &vmap_area_list); 4488 } 4489 4490 /* 4491 * Now we can initialize a free vmap space. 4492 */ 4493 vmap_init_free_space(); 4494 vmap_initialized = true; 4495 }