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 <tigran@veritas.com>, 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/rcupdate.h> 29 #include <linux/pfn.h> 30 #include <linux/kmemleak.h> 31 #include <linux/atomic.h> 32 #include <linux/compiler.h> 33 #include <linux/llist.h> 34 #include <linux/bitops.h> 35 #include <linux/rbtree_augmented.h> 36 #include <linux/overflow.h> 37 #include <linux/pgtable.h> 38 #include <linux/uaccess.h> 39 #include <asm/tlbflush.h> 40 #include <asm/shmparam.h> 41 42 #include "internal.h" 43 #include "pgalloc-track.h" 44 45 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC 46 static bool __ro_after_init vmap_allow_huge = true; 47 48 static int __init set_nohugevmalloc(char *str) 49 { 50 vmap_allow_huge = false; 51 return 0; 52 } 53 early_param("nohugevmalloc", set_nohugevmalloc); 54 #else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */ 55 static const bool vmap_allow_huge = false; 56 #endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */ 57 58 bool is_vmalloc_addr(const void *x) 59 { 60 unsigned long addr = (unsigned long)x; 61 62 return addr >= VMALLOC_START && addr < VMALLOC_END; 63 } 64 EXPORT_SYMBOL(is_vmalloc_addr); 65 66 struct vfree_deferred { 67 struct llist_head list; 68 struct work_struct wq; 69 }; 70 static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred); 71 72 static void __vunmap(const void *, int); 73 74 static void free_work(struct work_struct *w) 75 { 76 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq); 77 struct llist_node *t, *llnode; 78 79 llist_for_each_safe(llnode, t, llist_del_all(&p->list)) 80 __vunmap((void *)llnode, 1); 81 } 82 83 /*** Page table manipulation functions ***/ 84 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 85 phys_addr_t phys_addr, pgprot_t prot, 86 pgtbl_mod_mask *mask) 87 { 88 pte_t *pte; 89 u64 pfn; 90 91 pfn = phys_addr >> PAGE_SHIFT; 92 pte = pte_alloc_kernel_track(pmd, addr, mask); 93 if (!pte) 94 return -ENOMEM; 95 do { 96 BUG_ON(!pte_none(*pte)); 97 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); 98 pfn++; 99 } while (pte++, addr += PAGE_SIZE, addr != end); 100 *mask |= PGTBL_PTE_MODIFIED; 101 return 0; 102 } 103 104 static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end, 105 phys_addr_t phys_addr, pgprot_t prot, 106 unsigned int max_page_shift) 107 { 108 if (max_page_shift < PMD_SHIFT) 109 return 0; 110 111 if (!arch_vmap_pmd_supported(prot)) 112 return 0; 113 114 if ((end - addr) != PMD_SIZE) 115 return 0; 116 117 if (!IS_ALIGNED(addr, PMD_SIZE)) 118 return 0; 119 120 if (!IS_ALIGNED(phys_addr, PMD_SIZE)) 121 return 0; 122 123 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr)) 124 return 0; 125 126 return pmd_set_huge(pmd, phys_addr, prot); 127 } 128 129 static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, 130 phys_addr_t phys_addr, pgprot_t prot, 131 unsigned int max_page_shift, pgtbl_mod_mask *mask) 132 { 133 pmd_t *pmd; 134 unsigned long next; 135 136 pmd = pmd_alloc_track(&init_mm, pud, addr, mask); 137 if (!pmd) 138 return -ENOMEM; 139 do { 140 next = pmd_addr_end(addr, end); 141 142 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot, 143 max_page_shift)) { 144 *mask |= PGTBL_PMD_MODIFIED; 145 continue; 146 } 147 148 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, mask)) 149 return -ENOMEM; 150 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); 151 return 0; 152 } 153 154 static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end, 155 phys_addr_t phys_addr, pgprot_t prot, 156 unsigned int max_page_shift) 157 { 158 if (max_page_shift < PUD_SHIFT) 159 return 0; 160 161 if (!arch_vmap_pud_supported(prot)) 162 return 0; 163 164 if ((end - addr) != PUD_SIZE) 165 return 0; 166 167 if (!IS_ALIGNED(addr, PUD_SIZE)) 168 return 0; 169 170 if (!IS_ALIGNED(phys_addr, PUD_SIZE)) 171 return 0; 172 173 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr)) 174 return 0; 175 176 return pud_set_huge(pud, phys_addr, prot); 177 } 178 179 static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, 180 phys_addr_t phys_addr, pgprot_t prot, 181 unsigned int max_page_shift, pgtbl_mod_mask *mask) 182 { 183 pud_t *pud; 184 unsigned long next; 185 186 pud = pud_alloc_track(&init_mm, p4d, addr, mask); 187 if (!pud) 188 return -ENOMEM; 189 do { 190 next = pud_addr_end(addr, end); 191 192 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot, 193 max_page_shift)) { 194 *mask |= PGTBL_PUD_MODIFIED; 195 continue; 196 } 197 198 if (vmap_pmd_range(pud, addr, next, phys_addr, prot, 199 max_page_shift, mask)) 200 return -ENOMEM; 201 } while (pud++, phys_addr += (next - addr), addr = next, addr != end); 202 return 0; 203 } 204 205 static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end, 206 phys_addr_t phys_addr, pgprot_t prot, 207 unsigned int max_page_shift) 208 { 209 if (max_page_shift < P4D_SHIFT) 210 return 0; 211 212 if (!arch_vmap_p4d_supported(prot)) 213 return 0; 214 215 if ((end - addr) != P4D_SIZE) 216 return 0; 217 218 if (!IS_ALIGNED(addr, P4D_SIZE)) 219 return 0; 220 221 if (!IS_ALIGNED(phys_addr, P4D_SIZE)) 222 return 0; 223 224 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr)) 225 return 0; 226 227 return p4d_set_huge(p4d, phys_addr, prot); 228 } 229 230 static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, 231 phys_addr_t phys_addr, pgprot_t prot, 232 unsigned int max_page_shift, pgtbl_mod_mask *mask) 233 { 234 p4d_t *p4d; 235 unsigned long next; 236 237 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); 238 if (!p4d) 239 return -ENOMEM; 240 do { 241 next = p4d_addr_end(addr, end); 242 243 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot, 244 max_page_shift)) { 245 *mask |= PGTBL_P4D_MODIFIED; 246 continue; 247 } 248 249 if (vmap_pud_range(p4d, addr, next, phys_addr, prot, 250 max_page_shift, mask)) 251 return -ENOMEM; 252 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); 253 return 0; 254 } 255 256 static int vmap_range_noflush(unsigned long addr, unsigned long end, 257 phys_addr_t phys_addr, pgprot_t prot, 258 unsigned int max_page_shift) 259 { 260 pgd_t *pgd; 261 unsigned long start; 262 unsigned long next; 263 int err; 264 pgtbl_mod_mask mask = 0; 265 266 might_sleep(); 267 BUG_ON(addr >= end); 268 269 start = addr; 270 pgd = pgd_offset_k(addr); 271 do { 272 next = pgd_addr_end(addr, end); 273 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot, 274 max_page_shift, &mask); 275 if (err) 276 break; 277 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); 278 279 if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 280 arch_sync_kernel_mappings(start, end); 281 282 return err; 283 } 284 285 int vmap_range(unsigned long addr, unsigned long end, 286 phys_addr_t phys_addr, pgprot_t prot, 287 unsigned int max_page_shift) 288 { 289 int err; 290 291 err = vmap_range_noflush(addr, end, phys_addr, prot, max_page_shift); 292 flush_cache_vmap(addr, end); 293 294 return err; 295 } 296 297 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 298 pgtbl_mod_mask *mask) 299 { 300 pte_t *pte; 301 302 pte = pte_offset_kernel(pmd, addr); 303 do { 304 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); 305 WARN_ON(!pte_none(ptent) && !pte_present(ptent)); 306 } while (pte++, addr += PAGE_SIZE, addr != end); 307 *mask |= PGTBL_PTE_MODIFIED; 308 } 309 310 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, 311 pgtbl_mod_mask *mask) 312 { 313 pmd_t *pmd; 314 unsigned long next; 315 int cleared; 316 317 pmd = pmd_offset(pud, addr); 318 do { 319 next = pmd_addr_end(addr, end); 320 321 cleared = pmd_clear_huge(pmd); 322 if (cleared || pmd_bad(*pmd)) 323 *mask |= PGTBL_PMD_MODIFIED; 324 325 if (cleared) 326 continue; 327 if (pmd_none_or_clear_bad(pmd)) 328 continue; 329 vunmap_pte_range(pmd, addr, next, mask); 330 331 cond_resched(); 332 } while (pmd++, addr = next, addr != end); 333 } 334 335 static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, 336 pgtbl_mod_mask *mask) 337 { 338 pud_t *pud; 339 unsigned long next; 340 int cleared; 341 342 pud = pud_offset(p4d, addr); 343 do { 344 next = pud_addr_end(addr, end); 345 346 cleared = pud_clear_huge(pud); 347 if (cleared || pud_bad(*pud)) 348 *mask |= PGTBL_PUD_MODIFIED; 349 350 if (cleared) 351 continue; 352 if (pud_none_or_clear_bad(pud)) 353 continue; 354 vunmap_pmd_range(pud, addr, next, mask); 355 } while (pud++, addr = next, addr != end); 356 } 357 358 static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, 359 pgtbl_mod_mask *mask) 360 { 361 p4d_t *p4d; 362 unsigned long next; 363 int cleared; 364 365 p4d = p4d_offset(pgd, addr); 366 do { 367 next = p4d_addr_end(addr, end); 368 369 cleared = p4d_clear_huge(p4d); 370 if (cleared || p4d_bad(*p4d)) 371 *mask |= PGTBL_P4D_MODIFIED; 372 373 if (cleared) 374 continue; 375 if (p4d_none_or_clear_bad(p4d)) 376 continue; 377 vunmap_pud_range(p4d, addr, next, mask); 378 } while (p4d++, addr = next, addr != end); 379 } 380 381 /* 382 * vunmap_range_noflush is similar to vunmap_range, but does not 383 * flush caches or TLBs. 384 * 385 * The caller is responsible for calling flush_cache_vmap() before calling 386 * this function, and flush_tlb_kernel_range after it has returned 387 * successfully (and before the addresses are expected to cause a page fault 388 * or be re-mapped for something else, if TLB flushes are being delayed or 389 * coalesced). 390 * 391 * This is an internal function only. Do not use outside mm/. 392 */ 393 void vunmap_range_noflush(unsigned long start, unsigned long end) 394 { 395 unsigned long next; 396 pgd_t *pgd; 397 unsigned long addr = start; 398 pgtbl_mod_mask mask = 0; 399 400 BUG_ON(addr >= end); 401 pgd = pgd_offset_k(addr); 402 do { 403 next = pgd_addr_end(addr, end); 404 if (pgd_bad(*pgd)) 405 mask |= PGTBL_PGD_MODIFIED; 406 if (pgd_none_or_clear_bad(pgd)) 407 continue; 408 vunmap_p4d_range(pgd, addr, next, &mask); 409 } while (pgd++, addr = next, addr != end); 410 411 if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 412 arch_sync_kernel_mappings(start, end); 413 } 414 415 /** 416 * vunmap_range - unmap kernel virtual addresses 417 * @addr: start of the VM area to unmap 418 * @end: end of the VM area to unmap (non-inclusive) 419 * 420 * Clears any present PTEs in the virtual address range, flushes TLBs and 421 * caches. Any subsequent access to the address before it has been re-mapped 422 * is a kernel bug. 423 */ 424 void vunmap_range(unsigned long addr, unsigned long end) 425 { 426 flush_cache_vunmap(addr, end); 427 vunmap_range_noflush(addr, end); 428 flush_tlb_kernel_range(addr, end); 429 } 430 431 static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, 432 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 433 pgtbl_mod_mask *mask) 434 { 435 pte_t *pte; 436 437 /* 438 * nr is a running index into the array which helps higher level 439 * callers keep track of where we're up to. 440 */ 441 442 pte = pte_alloc_kernel_track(pmd, addr, mask); 443 if (!pte) 444 return -ENOMEM; 445 do { 446 struct page *page = pages[*nr]; 447 448 if (WARN_ON(!pte_none(*pte))) 449 return -EBUSY; 450 if (WARN_ON(!page)) 451 return -ENOMEM; 452 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); 453 (*nr)++; 454 } while (pte++, addr += PAGE_SIZE, addr != end); 455 *mask |= PGTBL_PTE_MODIFIED; 456 return 0; 457 } 458 459 static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr, 460 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 461 pgtbl_mod_mask *mask) 462 { 463 pmd_t *pmd; 464 unsigned long next; 465 466 pmd = pmd_alloc_track(&init_mm, pud, addr, mask); 467 if (!pmd) 468 return -ENOMEM; 469 do { 470 next = pmd_addr_end(addr, end); 471 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask)) 472 return -ENOMEM; 473 } while (pmd++, addr = next, addr != end); 474 return 0; 475 } 476 477 static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr, 478 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 479 pgtbl_mod_mask *mask) 480 { 481 pud_t *pud; 482 unsigned long next; 483 484 pud = pud_alloc_track(&init_mm, p4d, addr, mask); 485 if (!pud) 486 return -ENOMEM; 487 do { 488 next = pud_addr_end(addr, end); 489 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask)) 490 return -ENOMEM; 491 } while (pud++, addr = next, addr != end); 492 return 0; 493 } 494 495 static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr, 496 unsigned long end, pgprot_t prot, struct page **pages, int *nr, 497 pgtbl_mod_mask *mask) 498 { 499 p4d_t *p4d; 500 unsigned long next; 501 502 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); 503 if (!p4d) 504 return -ENOMEM; 505 do { 506 next = p4d_addr_end(addr, end); 507 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask)) 508 return -ENOMEM; 509 } while (p4d++, addr = next, addr != end); 510 return 0; 511 } 512 513 static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, 514 pgprot_t prot, struct page **pages) 515 { 516 unsigned long start = addr; 517 pgd_t *pgd; 518 unsigned long next; 519 int err = 0; 520 int nr = 0; 521 pgtbl_mod_mask mask = 0; 522 523 BUG_ON(addr >= end); 524 pgd = pgd_offset_k(addr); 525 do { 526 next = pgd_addr_end(addr, end); 527 if (pgd_bad(*pgd)) 528 mask |= PGTBL_PGD_MODIFIED; 529 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask); 530 if (err) 531 return err; 532 } while (pgd++, addr = next, addr != end); 533 534 if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 535 arch_sync_kernel_mappings(start, end); 536 537 return 0; 538 } 539 540 /* 541 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not 542 * flush caches. 543 * 544 * The caller is responsible for calling flush_cache_vmap() after this 545 * function returns successfully and before the addresses are accessed. 546 * 547 * This is an internal function only. Do not use outside mm/. 548 */ 549 int vmap_pages_range_noflush(unsigned long addr, unsigned long end, 550 pgprot_t prot, struct page **pages, unsigned int page_shift) 551 { 552 unsigned int i, nr = (end - addr) >> PAGE_SHIFT; 553 554 WARN_ON(page_shift < PAGE_SHIFT); 555 556 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || 557 page_shift == PAGE_SHIFT) 558 return vmap_small_pages_range_noflush(addr, end, prot, pages); 559 560 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) { 561 int err; 562 563 err = vmap_range_noflush(addr, addr + (1UL << page_shift), 564 __pa(page_address(pages[i])), prot, 565 page_shift); 566 if (err) 567 return err; 568 569 addr += 1UL << page_shift; 570 } 571 572 return 0; 573 } 574 575 /** 576 * vmap_pages_range - map pages to a kernel virtual address 577 * @addr: start of the VM area to map 578 * @end: end of the VM area to map (non-inclusive) 579 * @prot: page protection flags to use 580 * @pages: pages to map (always PAGE_SIZE pages) 581 * @page_shift: maximum shift that the pages may be mapped with, @pages must 582 * be aligned and contiguous up to at least this shift. 583 * 584 * RETURNS: 585 * 0 on success, -errno on failure. 586 */ 587 static int vmap_pages_range(unsigned long addr, unsigned long end, 588 pgprot_t prot, struct page **pages, unsigned int page_shift) 589 { 590 int err; 591 592 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift); 593 flush_cache_vmap(addr, end); 594 return err; 595 } 596 597 int is_vmalloc_or_module_addr(const void *x) 598 { 599 /* 600 * ARM, x86-64 and sparc64 put modules in a special place, 601 * and fall back on vmalloc() if that fails. Others 602 * just put it in the vmalloc space. 603 */ 604 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) 605 unsigned long addr = (unsigned long)x; 606 if (addr >= MODULES_VADDR && addr < MODULES_END) 607 return 1; 608 #endif 609 return is_vmalloc_addr(x); 610 } 611 612 /* 613 * Walk a vmap address to the struct page it maps. Huge vmap mappings will 614 * return the tail page that corresponds to the base page address, which 615 * matches small vmap mappings. 616 */ 617 struct page *vmalloc_to_page(const void *vmalloc_addr) 618 { 619 unsigned long addr = (unsigned long) vmalloc_addr; 620 struct page *page = NULL; 621 pgd_t *pgd = pgd_offset_k(addr); 622 p4d_t *p4d; 623 pud_t *pud; 624 pmd_t *pmd; 625 pte_t *ptep, pte; 626 627 /* 628 * XXX we might need to change this if we add VIRTUAL_BUG_ON for 629 * architectures that do not vmalloc module space 630 */ 631 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr)); 632 633 if (pgd_none(*pgd)) 634 return NULL; 635 if (WARN_ON_ONCE(pgd_leaf(*pgd))) 636 return NULL; /* XXX: no allowance for huge pgd */ 637 if (WARN_ON_ONCE(pgd_bad(*pgd))) 638 return NULL; 639 640 p4d = p4d_offset(pgd, addr); 641 if (p4d_none(*p4d)) 642 return NULL; 643 if (p4d_leaf(*p4d)) 644 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT); 645 if (WARN_ON_ONCE(p4d_bad(*p4d))) 646 return NULL; 647 648 pud = pud_offset(p4d, addr); 649 if (pud_none(*pud)) 650 return NULL; 651 if (pud_leaf(*pud)) 652 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); 653 if (WARN_ON_ONCE(pud_bad(*pud))) 654 return NULL; 655 656 pmd = pmd_offset(pud, addr); 657 if (pmd_none(*pmd)) 658 return NULL; 659 if (pmd_leaf(*pmd)) 660 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); 661 if (WARN_ON_ONCE(pmd_bad(*pmd))) 662 return NULL; 663 664 ptep = pte_offset_map(pmd, addr); 665 pte = *ptep; 666 if (pte_present(pte)) 667 page = pte_page(pte); 668 pte_unmap(ptep); 669 670 return page; 671 } 672 EXPORT_SYMBOL(vmalloc_to_page); 673 674 /* 675 * Map a vmalloc()-space virtual address to the physical page frame number. 676 */ 677 unsigned long vmalloc_to_pfn(const void *vmalloc_addr) 678 { 679 return page_to_pfn(vmalloc_to_page(vmalloc_addr)); 680 } 681 EXPORT_SYMBOL(vmalloc_to_pfn); 682 683 684 /*** Global kva allocator ***/ 685 686 #define DEBUG_AUGMENT_PROPAGATE_CHECK 0 687 #define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0 688 689 690 static DEFINE_SPINLOCK(vmap_area_lock); 691 static DEFINE_SPINLOCK(free_vmap_area_lock); 692 /* Export for kexec only */ 693 LIST_HEAD(vmap_area_list); 694 static struct rb_root vmap_area_root = RB_ROOT; 695 static bool vmap_initialized __read_mostly; 696 697 static struct rb_root purge_vmap_area_root = RB_ROOT; 698 static LIST_HEAD(purge_vmap_area_list); 699 static DEFINE_SPINLOCK(purge_vmap_area_lock); 700 701 /* 702 * This kmem_cache is used for vmap_area objects. Instead of 703 * allocating from slab we reuse an object from this cache to 704 * make things faster. Especially in "no edge" splitting of 705 * free block. 706 */ 707 static struct kmem_cache *vmap_area_cachep; 708 709 /* 710 * This linked list is used in pair with free_vmap_area_root. 711 * It gives O(1) access to prev/next to perform fast coalescing. 712 */ 713 static LIST_HEAD(free_vmap_area_list); 714 715 /* 716 * This augment red-black tree represents the free vmap space. 717 * All vmap_area objects in this tree are sorted by va->va_start 718 * address. It is used for allocation and merging when a vmap 719 * object is released. 720 * 721 * Each vmap_area node contains a maximum available free block 722 * of its sub-tree, right or left. Therefore it is possible to 723 * find a lowest match of free area. 724 */ 725 static struct rb_root free_vmap_area_root = RB_ROOT; 726 727 /* 728 * Preload a CPU with one object for "no edge" split case. The 729 * aim is to get rid of allocations from the atomic context, thus 730 * to use more permissive allocation masks. 731 */ 732 static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node); 733 734 static __always_inline unsigned long 735 va_size(struct vmap_area *va) 736 { 737 return (va->va_end - va->va_start); 738 } 739 740 static __always_inline unsigned long 741 get_subtree_max_size(struct rb_node *node) 742 { 743 struct vmap_area *va; 744 745 va = rb_entry_safe(node, struct vmap_area, rb_node); 746 return va ? va->subtree_max_size : 0; 747 } 748 749 /* 750 * Gets called when remove the node and rotate. 751 */ 752 static __always_inline unsigned long 753 compute_subtree_max_size(struct vmap_area *va) 754 { 755 return max3(va_size(va), 756 get_subtree_max_size(va->rb_node.rb_left), 757 get_subtree_max_size(va->rb_node.rb_right)); 758 } 759 760 RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb, 761 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size) 762 763 static void purge_vmap_area_lazy(void); 764 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); 765 static unsigned long lazy_max_pages(void); 766 767 static atomic_long_t nr_vmalloc_pages; 768 769 unsigned long vmalloc_nr_pages(void) 770 { 771 return atomic_long_read(&nr_vmalloc_pages); 772 } 773 774 static struct vmap_area *__find_vmap_area(unsigned long addr) 775 { 776 struct rb_node *n = vmap_area_root.rb_node; 777 778 while (n) { 779 struct vmap_area *va; 780 781 va = rb_entry(n, struct vmap_area, rb_node); 782 if (addr < va->va_start) 783 n = n->rb_left; 784 else if (addr >= va->va_end) 785 n = n->rb_right; 786 else 787 return va; 788 } 789 790 return NULL; 791 } 792 793 /* 794 * This function returns back addresses of parent node 795 * and its left or right link for further processing. 796 * 797 * Otherwise NULL is returned. In that case all further 798 * steps regarding inserting of conflicting overlap range 799 * have to be declined and actually considered as a bug. 800 */ 801 static __always_inline struct rb_node ** 802 find_va_links(struct vmap_area *va, 803 struct rb_root *root, struct rb_node *from, 804 struct rb_node **parent) 805 { 806 struct vmap_area *tmp_va; 807 struct rb_node **link; 808 809 if (root) { 810 link = &root->rb_node; 811 if (unlikely(!*link)) { 812 *parent = NULL; 813 return link; 814 } 815 } else { 816 link = &from; 817 } 818 819 /* 820 * Go to the bottom of the tree. When we hit the last point 821 * we end up with parent rb_node and correct direction, i name 822 * it link, where the new va->rb_node will be attached to. 823 */ 824 do { 825 tmp_va = rb_entry(*link, struct vmap_area, rb_node); 826 827 /* 828 * During the traversal we also do some sanity check. 829 * Trigger the BUG() if there are sides(left/right) 830 * or full overlaps. 831 */ 832 if (va->va_start < tmp_va->va_end && 833 va->va_end <= tmp_va->va_start) 834 link = &(*link)->rb_left; 835 else if (va->va_end > tmp_va->va_start && 836 va->va_start >= tmp_va->va_end) 837 link = &(*link)->rb_right; 838 else { 839 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n", 840 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end); 841 842 return NULL; 843 } 844 } while (*link); 845 846 *parent = &tmp_va->rb_node; 847 return link; 848 } 849 850 static __always_inline struct list_head * 851 get_va_next_sibling(struct rb_node *parent, struct rb_node **link) 852 { 853 struct list_head *list; 854 855 if (unlikely(!parent)) 856 /* 857 * The red-black tree where we try to find VA neighbors 858 * before merging or inserting is empty, i.e. it means 859 * there is no free vmap space. Normally it does not 860 * happen but we handle this case anyway. 861 */ 862 return NULL; 863 864 list = &rb_entry(parent, struct vmap_area, rb_node)->list; 865 return (&parent->rb_right == link ? list->next : list); 866 } 867 868 static __always_inline void 869 link_va(struct vmap_area *va, struct rb_root *root, 870 struct rb_node *parent, struct rb_node **link, struct list_head *head) 871 { 872 /* 873 * VA is still not in the list, but we can 874 * identify its future previous list_head node. 875 */ 876 if (likely(parent)) { 877 head = &rb_entry(parent, struct vmap_area, rb_node)->list; 878 if (&parent->rb_right != link) 879 head = head->prev; 880 } 881 882 /* Insert to the rb-tree */ 883 rb_link_node(&va->rb_node, parent, link); 884 if (root == &free_vmap_area_root) { 885 /* 886 * Some explanation here. Just perform simple insertion 887 * to the tree. We do not set va->subtree_max_size to 888 * its current size before calling rb_insert_augmented(). 889 * It is because of we populate the tree from the bottom 890 * to parent levels when the node _is_ in the tree. 891 * 892 * Therefore we set subtree_max_size to zero after insertion, 893 * to let __augment_tree_propagate_from() puts everything to 894 * the correct order later on. 895 */ 896 rb_insert_augmented(&va->rb_node, 897 root, &free_vmap_area_rb_augment_cb); 898 va->subtree_max_size = 0; 899 } else { 900 rb_insert_color(&va->rb_node, root); 901 } 902 903 /* Address-sort this list */ 904 list_add(&va->list, head); 905 } 906 907 static __always_inline void 908 unlink_va(struct vmap_area *va, struct rb_root *root) 909 { 910 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node))) 911 return; 912 913 if (root == &free_vmap_area_root) 914 rb_erase_augmented(&va->rb_node, 915 root, &free_vmap_area_rb_augment_cb); 916 else 917 rb_erase(&va->rb_node, root); 918 919 list_del(&va->list); 920 RB_CLEAR_NODE(&va->rb_node); 921 } 922 923 #if DEBUG_AUGMENT_PROPAGATE_CHECK 924 static void 925 augment_tree_propagate_check(void) 926 { 927 struct vmap_area *va; 928 unsigned long computed_size; 929 930 list_for_each_entry(va, &free_vmap_area_list, list) { 931 computed_size = compute_subtree_max_size(va); 932 if (computed_size != va->subtree_max_size) 933 pr_emerg("tree is corrupted: %lu, %lu\n", 934 va_size(va), va->subtree_max_size); 935 } 936 } 937 #endif 938 939 /* 940 * This function populates subtree_max_size from bottom to upper 941 * levels starting from VA point. The propagation must be done 942 * when VA size is modified by changing its va_start/va_end. Or 943 * in case of newly inserting of VA to the tree. 944 * 945 * It means that __augment_tree_propagate_from() must be called: 946 * - After VA has been inserted to the tree(free path); 947 * - After VA has been shrunk(allocation path); 948 * - After VA has been increased(merging path). 949 * 950 * Please note that, it does not mean that upper parent nodes 951 * and their subtree_max_size are recalculated all the time up 952 * to the root node. 953 * 954 * 4--8 955 * /\ 956 * / \ 957 * / \ 958 * 2--2 8--8 959 * 960 * For example if we modify the node 4, shrinking it to 2, then 961 * no any modification is required. If we shrink the node 2 to 1 962 * its subtree_max_size is updated only, and set to 1. If we shrink 963 * the node 8 to 6, then its subtree_max_size is set to 6 and parent 964 * node becomes 4--6. 965 */ 966 static __always_inline void 967 augment_tree_propagate_from(struct vmap_area *va) 968 { 969 /* 970 * Populate the tree from bottom towards the root until 971 * the calculated maximum available size of checked node 972 * is equal to its current one. 973 */ 974 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL); 975 976 #if DEBUG_AUGMENT_PROPAGATE_CHECK 977 augment_tree_propagate_check(); 978 #endif 979 } 980 981 static void 982 insert_vmap_area(struct vmap_area *va, 983 struct rb_root *root, struct list_head *head) 984 { 985 struct rb_node **link; 986 struct rb_node *parent; 987 988 link = find_va_links(va, root, NULL, &parent); 989 if (link) 990 link_va(va, root, parent, link, head); 991 } 992 993 static void 994 insert_vmap_area_augment(struct vmap_area *va, 995 struct rb_node *from, struct rb_root *root, 996 struct list_head *head) 997 { 998 struct rb_node **link; 999 struct rb_node *parent; 1000 1001 if (from) 1002 link = find_va_links(va, NULL, from, &parent); 1003 else 1004 link = find_va_links(va, root, NULL, &parent); 1005 1006 if (link) { 1007 link_va(va, root, parent, link, head); 1008 augment_tree_propagate_from(va); 1009 } 1010 } 1011 1012 /* 1013 * Merge de-allocated chunk of VA memory with previous 1014 * and next free blocks. If coalesce is not done a new 1015 * free area is inserted. If VA has been merged, it is 1016 * freed. 1017 * 1018 * Please note, it can return NULL in case of overlap 1019 * ranges, followed by WARN() report. Despite it is a 1020 * buggy behaviour, a system can be alive and keep 1021 * ongoing. 1022 */ 1023 static __always_inline struct vmap_area * 1024 merge_or_add_vmap_area(struct vmap_area *va, 1025 struct rb_root *root, struct list_head *head) 1026 { 1027 struct vmap_area *sibling; 1028 struct list_head *next; 1029 struct rb_node **link; 1030 struct rb_node *parent; 1031 bool merged = false; 1032 1033 /* 1034 * Find a place in the tree where VA potentially will be 1035 * inserted, unless it is merged with its sibling/siblings. 1036 */ 1037 link = find_va_links(va, root, NULL, &parent); 1038 if (!link) 1039 return NULL; 1040 1041 /* 1042 * Get next node of VA to check if merging can be done. 1043 */ 1044 next = get_va_next_sibling(parent, link); 1045 if (unlikely(next == NULL)) 1046 goto insert; 1047 1048 /* 1049 * start end 1050 * | | 1051 * |<------VA------>|<-----Next----->| 1052 * | | 1053 * start end 1054 */ 1055 if (next != head) { 1056 sibling = list_entry(next, struct vmap_area, list); 1057 if (sibling->va_start == va->va_end) { 1058 sibling->va_start = va->va_start; 1059 1060 /* Free vmap_area object. */ 1061 kmem_cache_free(vmap_area_cachep, va); 1062 1063 /* Point to the new merged area. */ 1064 va = sibling; 1065 merged = true; 1066 } 1067 } 1068 1069 /* 1070 * start end 1071 * | | 1072 * |<-----Prev----->|<------VA------>| 1073 * | | 1074 * start end 1075 */ 1076 if (next->prev != head) { 1077 sibling = list_entry(next->prev, struct vmap_area, list); 1078 if (sibling->va_end == va->va_start) { 1079 /* 1080 * If both neighbors are coalesced, it is important 1081 * to unlink the "next" node first, followed by merging 1082 * with "previous" one. Otherwise the tree might not be 1083 * fully populated if a sibling's augmented value is 1084 * "normalized" because of rotation operations. 1085 */ 1086 if (merged) 1087 unlink_va(va, root); 1088 1089 sibling->va_end = va->va_end; 1090 1091 /* Free vmap_area object. */ 1092 kmem_cache_free(vmap_area_cachep, va); 1093 1094 /* Point to the new merged area. */ 1095 va = sibling; 1096 merged = true; 1097 } 1098 } 1099 1100 insert: 1101 if (!merged) 1102 link_va(va, root, parent, link, head); 1103 1104 return va; 1105 } 1106 1107 static __always_inline struct vmap_area * 1108 merge_or_add_vmap_area_augment(struct vmap_area *va, 1109 struct rb_root *root, struct list_head *head) 1110 { 1111 va = merge_or_add_vmap_area(va, root, head); 1112 if (va) 1113 augment_tree_propagate_from(va); 1114 1115 return va; 1116 } 1117 1118 static __always_inline bool 1119 is_within_this_va(struct vmap_area *va, unsigned long size, 1120 unsigned long align, unsigned long vstart) 1121 { 1122 unsigned long nva_start_addr; 1123 1124 if (va->va_start > vstart) 1125 nva_start_addr = ALIGN(va->va_start, align); 1126 else 1127 nva_start_addr = ALIGN(vstart, align); 1128 1129 /* Can be overflowed due to big size or alignment. */ 1130 if (nva_start_addr + size < nva_start_addr || 1131 nva_start_addr < vstart) 1132 return false; 1133 1134 return (nva_start_addr + size <= va->va_end); 1135 } 1136 1137 /* 1138 * Find the first free block(lowest start address) in the tree, 1139 * that will accomplish the request corresponding to passing 1140 * parameters. 1141 */ 1142 static __always_inline struct vmap_area * 1143 find_vmap_lowest_match(unsigned long size, 1144 unsigned long align, unsigned long vstart) 1145 { 1146 struct vmap_area *va; 1147 struct rb_node *node; 1148 unsigned long length; 1149 1150 /* Start from the root. */ 1151 node = free_vmap_area_root.rb_node; 1152 1153 /* Adjust the search size for alignment overhead. */ 1154 length = size + align - 1; 1155 1156 while (node) { 1157 va = rb_entry(node, struct vmap_area, rb_node); 1158 1159 if (get_subtree_max_size(node->rb_left) >= length && 1160 vstart < va->va_start) { 1161 node = node->rb_left; 1162 } else { 1163 if (is_within_this_va(va, size, align, vstart)) 1164 return va; 1165 1166 /* 1167 * Does not make sense to go deeper towards the right 1168 * sub-tree if it does not have a free block that is 1169 * equal or bigger to the requested search length. 1170 */ 1171 if (get_subtree_max_size(node->rb_right) >= length) { 1172 node = node->rb_right; 1173 continue; 1174 } 1175 1176 /* 1177 * OK. We roll back and find the first right sub-tree, 1178 * that will satisfy the search criteria. It can happen 1179 * only once due to "vstart" restriction. 1180 */ 1181 while ((node = rb_parent(node))) { 1182 va = rb_entry(node, struct vmap_area, rb_node); 1183 if (is_within_this_va(va, size, align, vstart)) 1184 return va; 1185 1186 if (get_subtree_max_size(node->rb_right) >= length && 1187 vstart <= va->va_start) { 1188 node = node->rb_right; 1189 break; 1190 } 1191 } 1192 } 1193 } 1194 1195 return NULL; 1196 } 1197 1198 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK 1199 #include <linux/random.h> 1200 1201 static struct vmap_area * 1202 find_vmap_lowest_linear_match(unsigned long size, 1203 unsigned long align, unsigned long vstart) 1204 { 1205 struct vmap_area *va; 1206 1207 list_for_each_entry(va, &free_vmap_area_list, list) { 1208 if (!is_within_this_va(va, size, align, vstart)) 1209 continue; 1210 1211 return va; 1212 } 1213 1214 return NULL; 1215 } 1216 1217 static void 1218 find_vmap_lowest_match_check(unsigned long size) 1219 { 1220 struct vmap_area *va_1, *va_2; 1221 unsigned long vstart; 1222 unsigned int rnd; 1223 1224 get_random_bytes(&rnd, sizeof(rnd)); 1225 vstart = VMALLOC_START + rnd; 1226 1227 va_1 = find_vmap_lowest_match(size, 1, vstart); 1228 va_2 = find_vmap_lowest_linear_match(size, 1, vstart); 1229 1230 if (va_1 != va_2) 1231 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n", 1232 va_1, va_2, vstart); 1233 } 1234 #endif 1235 1236 enum fit_type { 1237 NOTHING_FIT = 0, 1238 FL_FIT_TYPE = 1, /* full fit */ 1239 LE_FIT_TYPE = 2, /* left edge fit */ 1240 RE_FIT_TYPE = 3, /* right edge fit */ 1241 NE_FIT_TYPE = 4 /* no edge fit */ 1242 }; 1243 1244 static __always_inline enum fit_type 1245 classify_va_fit_type(struct vmap_area *va, 1246 unsigned long nva_start_addr, unsigned long size) 1247 { 1248 enum fit_type type; 1249 1250 /* Check if it is within VA. */ 1251 if (nva_start_addr < va->va_start || 1252 nva_start_addr + size > va->va_end) 1253 return NOTHING_FIT; 1254 1255 /* Now classify. */ 1256 if (va->va_start == nva_start_addr) { 1257 if (va->va_end == nva_start_addr + size) 1258 type = FL_FIT_TYPE; 1259 else 1260 type = LE_FIT_TYPE; 1261 } else if (va->va_end == nva_start_addr + size) { 1262 type = RE_FIT_TYPE; 1263 } else { 1264 type = NE_FIT_TYPE; 1265 } 1266 1267 return type; 1268 } 1269 1270 static __always_inline int 1271 adjust_va_to_fit_type(struct vmap_area *va, 1272 unsigned long nva_start_addr, unsigned long size, 1273 enum fit_type type) 1274 { 1275 struct vmap_area *lva = NULL; 1276 1277 if (type == FL_FIT_TYPE) { 1278 /* 1279 * No need to split VA, it fully fits. 1280 * 1281 * | | 1282 * V NVA V 1283 * |---------------| 1284 */ 1285 unlink_va(va, &free_vmap_area_root); 1286 kmem_cache_free(vmap_area_cachep, va); 1287 } else if (type == LE_FIT_TYPE) { 1288 /* 1289 * Split left edge of fit VA. 1290 * 1291 * | | 1292 * V NVA V R 1293 * |-------|-------| 1294 */ 1295 va->va_start += size; 1296 } else if (type == RE_FIT_TYPE) { 1297 /* 1298 * Split right edge of fit VA. 1299 * 1300 * | | 1301 * L V NVA V 1302 * |-------|-------| 1303 */ 1304 va->va_end = nva_start_addr; 1305 } else if (type == NE_FIT_TYPE) { 1306 /* 1307 * Split no edge of fit VA. 1308 * 1309 * | | 1310 * L V NVA V R 1311 * |---|-------|---| 1312 */ 1313 lva = __this_cpu_xchg(ne_fit_preload_node, NULL); 1314 if (unlikely(!lva)) { 1315 /* 1316 * For percpu allocator we do not do any pre-allocation 1317 * and leave it as it is. The reason is it most likely 1318 * never ends up with NE_FIT_TYPE splitting. In case of 1319 * percpu allocations offsets and sizes are aligned to 1320 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE 1321 * are its main fitting cases. 1322 * 1323 * There are a few exceptions though, as an example it is 1324 * a first allocation (early boot up) when we have "one" 1325 * big free space that has to be split. 1326 * 1327 * Also we can hit this path in case of regular "vmap" 1328 * allocations, if "this" current CPU was not preloaded. 1329 * See the comment in alloc_vmap_area() why. If so, then 1330 * GFP_NOWAIT is used instead to get an extra object for 1331 * split purpose. That is rare and most time does not 1332 * occur. 1333 * 1334 * What happens if an allocation gets failed. Basically, 1335 * an "overflow" path is triggered to purge lazily freed 1336 * areas to free some memory, then, the "retry" path is 1337 * triggered to repeat one more time. See more details 1338 * in alloc_vmap_area() function. 1339 */ 1340 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT); 1341 if (!lva) 1342 return -1; 1343 } 1344 1345 /* 1346 * Build the remainder. 1347 */ 1348 lva->va_start = va->va_start; 1349 lva->va_end = nva_start_addr; 1350 1351 /* 1352 * Shrink this VA to remaining size. 1353 */ 1354 va->va_start = nva_start_addr + size; 1355 } else { 1356 return -1; 1357 } 1358 1359 if (type != FL_FIT_TYPE) { 1360 augment_tree_propagate_from(va); 1361 1362 if (lva) /* type == NE_FIT_TYPE */ 1363 insert_vmap_area_augment(lva, &va->rb_node, 1364 &free_vmap_area_root, &free_vmap_area_list); 1365 } 1366 1367 return 0; 1368 } 1369 1370 /* 1371 * Returns a start address of the newly allocated area, if success. 1372 * Otherwise a vend is returned that indicates failure. 1373 */ 1374 static __always_inline unsigned long 1375 __alloc_vmap_area(unsigned long size, unsigned long align, 1376 unsigned long vstart, unsigned long vend) 1377 { 1378 unsigned long nva_start_addr; 1379 struct vmap_area *va; 1380 enum fit_type type; 1381 int ret; 1382 1383 va = find_vmap_lowest_match(size, align, vstart); 1384 if (unlikely(!va)) 1385 return vend; 1386 1387 if (va->va_start > vstart) 1388 nva_start_addr = ALIGN(va->va_start, align); 1389 else 1390 nva_start_addr = ALIGN(vstart, align); 1391 1392 /* Check the "vend" restriction. */ 1393 if (nva_start_addr + size > vend) 1394 return vend; 1395 1396 /* Classify what we have found. */ 1397 type = classify_va_fit_type(va, nva_start_addr, size); 1398 if (WARN_ON_ONCE(type == NOTHING_FIT)) 1399 return vend; 1400 1401 /* Update the free vmap_area. */ 1402 ret = adjust_va_to_fit_type(va, nva_start_addr, size, type); 1403 if (ret) 1404 return vend; 1405 1406 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK 1407 find_vmap_lowest_match_check(size); 1408 #endif 1409 1410 return nva_start_addr; 1411 } 1412 1413 /* 1414 * Free a region of KVA allocated by alloc_vmap_area 1415 */ 1416 static void free_vmap_area(struct vmap_area *va) 1417 { 1418 /* 1419 * Remove from the busy tree/list. 1420 */ 1421 spin_lock(&vmap_area_lock); 1422 unlink_va(va, &vmap_area_root); 1423 spin_unlock(&vmap_area_lock); 1424 1425 /* 1426 * Insert/Merge it back to the free tree/list. 1427 */ 1428 spin_lock(&free_vmap_area_lock); 1429 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list); 1430 spin_unlock(&free_vmap_area_lock); 1431 } 1432 1433 static inline void 1434 preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node) 1435 { 1436 struct vmap_area *va = NULL; 1437 1438 /* 1439 * Preload this CPU with one extra vmap_area object. It is used 1440 * when fit type of free area is NE_FIT_TYPE. It guarantees that 1441 * a CPU that does an allocation is preloaded. 1442 * 1443 * We do it in non-atomic context, thus it allows us to use more 1444 * permissive allocation masks to be more stable under low memory 1445 * condition and high memory pressure. 1446 */ 1447 if (!this_cpu_read(ne_fit_preload_node)) 1448 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); 1449 1450 spin_lock(lock); 1451 1452 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va)) 1453 kmem_cache_free(vmap_area_cachep, va); 1454 } 1455 1456 /* 1457 * Allocate a region of KVA of the specified size and alignment, within the 1458 * vstart and vend. 1459 */ 1460 static struct vmap_area *alloc_vmap_area(unsigned long size, 1461 unsigned long align, 1462 unsigned long vstart, unsigned long vend, 1463 int node, gfp_t gfp_mask) 1464 { 1465 struct vmap_area *va; 1466 unsigned long addr; 1467 int purged = 0; 1468 int ret; 1469 1470 BUG_ON(!size); 1471 BUG_ON(offset_in_page(size)); 1472 BUG_ON(!is_power_of_2(align)); 1473 1474 if (unlikely(!vmap_initialized)) 1475 return ERR_PTR(-EBUSY); 1476 1477 might_sleep(); 1478 gfp_mask = gfp_mask & GFP_RECLAIM_MASK; 1479 1480 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); 1481 if (unlikely(!va)) 1482 return ERR_PTR(-ENOMEM); 1483 1484 /* 1485 * Only scan the relevant parts containing pointers to other objects 1486 * to avoid false negatives. 1487 */ 1488 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask); 1489 1490 retry: 1491 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node); 1492 addr = __alloc_vmap_area(size, align, vstart, vend); 1493 spin_unlock(&free_vmap_area_lock); 1494 1495 /* 1496 * If an allocation fails, the "vend" address is 1497 * returned. Therefore trigger the overflow path. 1498 */ 1499 if (unlikely(addr == vend)) 1500 goto overflow; 1501 1502 va->va_start = addr; 1503 va->va_end = addr + size; 1504 va->vm = NULL; 1505 1506 spin_lock(&vmap_area_lock); 1507 insert_vmap_area(va, &vmap_area_root, &vmap_area_list); 1508 spin_unlock(&vmap_area_lock); 1509 1510 BUG_ON(!IS_ALIGNED(va->va_start, align)); 1511 BUG_ON(va->va_start < vstart); 1512 BUG_ON(va->va_end > vend); 1513 1514 ret = kasan_populate_vmalloc(addr, size); 1515 if (ret) { 1516 free_vmap_area(va); 1517 return ERR_PTR(ret); 1518 } 1519 1520 return va; 1521 1522 overflow: 1523 if (!purged) { 1524 purge_vmap_area_lazy(); 1525 purged = 1; 1526 goto retry; 1527 } 1528 1529 if (gfpflags_allow_blocking(gfp_mask)) { 1530 unsigned long freed = 0; 1531 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed); 1532 if (freed > 0) { 1533 purged = 0; 1534 goto retry; 1535 } 1536 } 1537 1538 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) 1539 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", 1540 size); 1541 1542 kmem_cache_free(vmap_area_cachep, va); 1543 return ERR_PTR(-EBUSY); 1544 } 1545 1546 int register_vmap_purge_notifier(struct notifier_block *nb) 1547 { 1548 return blocking_notifier_chain_register(&vmap_notify_list, nb); 1549 } 1550 EXPORT_SYMBOL_GPL(register_vmap_purge_notifier); 1551 1552 int unregister_vmap_purge_notifier(struct notifier_block *nb) 1553 { 1554 return blocking_notifier_chain_unregister(&vmap_notify_list, nb); 1555 } 1556 EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier); 1557 1558 /* 1559 * lazy_max_pages is the maximum amount of virtual address space we gather up 1560 * before attempting to purge with a TLB flush. 1561 * 1562 * There is a tradeoff here: a larger number will cover more kernel page tables 1563 * and take slightly longer to purge, but it will linearly reduce the number of 1564 * global TLB flushes that must be performed. It would seem natural to scale 1565 * this number up linearly with the number of CPUs (because vmapping activity 1566 * could also scale linearly with the number of CPUs), however it is likely 1567 * that in practice, workloads might be constrained in other ways that mean 1568 * vmap activity will not scale linearly with CPUs. Also, I want to be 1569 * conservative and not introduce a big latency on huge systems, so go with 1570 * a less aggressive log scale. It will still be an improvement over the old 1571 * code, and it will be simple to change the scale factor if we find that it 1572 * becomes a problem on bigger systems. 1573 */ 1574 static unsigned long lazy_max_pages(void) 1575 { 1576 unsigned int log; 1577 1578 log = fls(num_online_cpus()); 1579 1580 return log * (32UL * 1024 * 1024 / PAGE_SIZE); 1581 } 1582 1583 static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0); 1584 1585 /* 1586 * Serialize vmap purging. There is no actual critical section protected 1587 * by this look, but we want to avoid concurrent calls for performance 1588 * reasons and to make the pcpu_get_vm_areas more deterministic. 1589 */ 1590 static DEFINE_MUTEX(vmap_purge_lock); 1591 1592 /* for per-CPU blocks */ 1593 static void purge_fragmented_blocks_allcpus(void); 1594 1595 /* 1596 * called before a call to iounmap() if the caller wants vm_area_struct's 1597 * immediately freed. 1598 */ 1599 void set_iounmap_nonlazy(void) 1600 { 1601 atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1); 1602 } 1603 1604 /* 1605 * Purges all lazily-freed vmap areas. 1606 */ 1607 static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) 1608 { 1609 unsigned long resched_threshold; 1610 struct list_head local_pure_list; 1611 struct vmap_area *va, *n_va; 1612 1613 lockdep_assert_held(&vmap_purge_lock); 1614 1615 spin_lock(&purge_vmap_area_lock); 1616 purge_vmap_area_root = RB_ROOT; 1617 list_replace_init(&purge_vmap_area_list, &local_pure_list); 1618 spin_unlock(&purge_vmap_area_lock); 1619 1620 if (unlikely(list_empty(&local_pure_list))) 1621 return false; 1622 1623 start = min(start, 1624 list_first_entry(&local_pure_list, 1625 struct vmap_area, list)->va_start); 1626 1627 end = max(end, 1628 list_last_entry(&local_pure_list, 1629 struct vmap_area, list)->va_end); 1630 1631 flush_tlb_kernel_range(start, end); 1632 resched_threshold = lazy_max_pages() << 1; 1633 1634 spin_lock(&free_vmap_area_lock); 1635 list_for_each_entry_safe(va, n_va, &local_pure_list, list) { 1636 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; 1637 unsigned long orig_start = va->va_start; 1638 unsigned long orig_end = va->va_end; 1639 1640 /* 1641 * Finally insert or merge lazily-freed area. It is 1642 * detached and there is no need to "unlink" it from 1643 * anything. 1644 */ 1645 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root, 1646 &free_vmap_area_list); 1647 1648 if (!va) 1649 continue; 1650 1651 if (is_vmalloc_or_module_addr((void *)orig_start)) 1652 kasan_release_vmalloc(orig_start, orig_end, 1653 va->va_start, va->va_end); 1654 1655 atomic_long_sub(nr, &vmap_lazy_nr); 1656 1657 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold) 1658 cond_resched_lock(&free_vmap_area_lock); 1659 } 1660 spin_unlock(&free_vmap_area_lock); 1661 return true; 1662 } 1663 1664 /* 1665 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody 1666 * is already purging. 1667 */ 1668 static void try_purge_vmap_area_lazy(void) 1669 { 1670 if (mutex_trylock(&vmap_purge_lock)) { 1671 __purge_vmap_area_lazy(ULONG_MAX, 0); 1672 mutex_unlock(&vmap_purge_lock); 1673 } 1674 } 1675 1676 /* 1677 * Kick off a purge of the outstanding lazy areas. 1678 */ 1679 static void purge_vmap_area_lazy(void) 1680 { 1681 mutex_lock(&vmap_purge_lock); 1682 purge_fragmented_blocks_allcpus(); 1683 __purge_vmap_area_lazy(ULONG_MAX, 0); 1684 mutex_unlock(&vmap_purge_lock); 1685 } 1686 1687 /* 1688 * Free a vmap area, caller ensuring that the area has been unmapped 1689 * and flush_cache_vunmap had been called for the correct range 1690 * previously. 1691 */ 1692 static void free_vmap_area_noflush(struct vmap_area *va) 1693 { 1694 unsigned long nr_lazy; 1695 1696 spin_lock(&vmap_area_lock); 1697 unlink_va(va, &vmap_area_root); 1698 spin_unlock(&vmap_area_lock); 1699 1700 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >> 1701 PAGE_SHIFT, &vmap_lazy_nr); 1702 1703 /* 1704 * Merge or place it to the purge tree/list. 1705 */ 1706 spin_lock(&purge_vmap_area_lock); 1707 merge_or_add_vmap_area(va, 1708 &purge_vmap_area_root, &purge_vmap_area_list); 1709 spin_unlock(&purge_vmap_area_lock); 1710 1711 /* After this point, we may free va at any time */ 1712 if (unlikely(nr_lazy > lazy_max_pages())) 1713 try_purge_vmap_area_lazy(); 1714 } 1715 1716 /* 1717 * Free and unmap a vmap area 1718 */ 1719 static void free_unmap_vmap_area(struct vmap_area *va) 1720 { 1721 flush_cache_vunmap(va->va_start, va->va_end); 1722 vunmap_range_noflush(va->va_start, va->va_end); 1723 if (debug_pagealloc_enabled_static()) 1724 flush_tlb_kernel_range(va->va_start, va->va_end); 1725 1726 free_vmap_area_noflush(va); 1727 } 1728 1729 static struct vmap_area *find_vmap_area(unsigned long addr) 1730 { 1731 struct vmap_area *va; 1732 1733 spin_lock(&vmap_area_lock); 1734 va = __find_vmap_area(addr); 1735 spin_unlock(&vmap_area_lock); 1736 1737 return va; 1738 } 1739 1740 /*** Per cpu kva allocator ***/ 1741 1742 /* 1743 * vmap space is limited especially on 32 bit architectures. Ensure there is 1744 * room for at least 16 percpu vmap blocks per CPU. 1745 */ 1746 /* 1747 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able 1748 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess 1749 * instead (we just need a rough idea) 1750 */ 1751 #if BITS_PER_LONG == 32 1752 #define VMALLOC_SPACE (128UL*1024*1024) 1753 #else 1754 #define VMALLOC_SPACE (128UL*1024*1024*1024) 1755 #endif 1756 1757 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE) 1758 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */ 1759 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */ 1760 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2) 1761 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */ 1762 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */ 1763 #define VMAP_BBMAP_BITS \ 1764 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \ 1765 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \ 1766 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16)) 1767 1768 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) 1769 1770 struct vmap_block_queue { 1771 spinlock_t lock; 1772 struct list_head free; 1773 }; 1774 1775 struct vmap_block { 1776 spinlock_t lock; 1777 struct vmap_area *va; 1778 unsigned long free, dirty; 1779 unsigned long dirty_min, dirty_max; /*< dirty range */ 1780 struct list_head free_list; 1781 struct rcu_head rcu_head; 1782 struct list_head purge; 1783 }; 1784 1785 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */ 1786 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue); 1787 1788 /* 1789 * XArray of vmap blocks, indexed by address, to quickly find a vmap block 1790 * in the free path. Could get rid of this if we change the API to return a 1791 * "cookie" from alloc, to be passed to free. But no big deal yet. 1792 */ 1793 static DEFINE_XARRAY(vmap_blocks); 1794 1795 /* 1796 * We should probably have a fallback mechanism to allocate virtual memory 1797 * out of partially filled vmap blocks. However vmap block sizing should be 1798 * fairly reasonable according to the vmalloc size, so it shouldn't be a 1799 * big problem. 1800 */ 1801 1802 static unsigned long addr_to_vb_idx(unsigned long addr) 1803 { 1804 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); 1805 addr /= VMAP_BLOCK_SIZE; 1806 return addr; 1807 } 1808 1809 static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) 1810 { 1811 unsigned long addr; 1812 1813 addr = va_start + (pages_off << PAGE_SHIFT); 1814 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start)); 1815 return (void *)addr; 1816 } 1817 1818 /** 1819 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this 1820 * block. Of course pages number can't exceed VMAP_BBMAP_BITS 1821 * @order: how many 2^order pages should be occupied in newly allocated block 1822 * @gfp_mask: flags for the page level allocator 1823 * 1824 * Return: virtual address in a newly allocated block or ERR_PTR(-errno) 1825 */ 1826 static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) 1827 { 1828 struct vmap_block_queue *vbq; 1829 struct vmap_block *vb; 1830 struct vmap_area *va; 1831 unsigned long vb_idx; 1832 int node, err; 1833 void *vaddr; 1834 1835 node = numa_node_id(); 1836 1837 vb = kmalloc_node(sizeof(struct vmap_block), 1838 gfp_mask & GFP_RECLAIM_MASK, node); 1839 if (unlikely(!vb)) 1840 return ERR_PTR(-ENOMEM); 1841 1842 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, 1843 VMALLOC_START, VMALLOC_END, 1844 node, gfp_mask); 1845 if (IS_ERR(va)) { 1846 kfree(vb); 1847 return ERR_CAST(va); 1848 } 1849 1850 vaddr = vmap_block_vaddr(va->va_start, 0); 1851 spin_lock_init(&vb->lock); 1852 vb->va = va; 1853 /* At least something should be left free */ 1854 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); 1855 vb->free = VMAP_BBMAP_BITS - (1UL << order); 1856 vb->dirty = 0; 1857 vb->dirty_min = VMAP_BBMAP_BITS; 1858 vb->dirty_max = 0; 1859 INIT_LIST_HEAD(&vb->free_list); 1860 1861 vb_idx = addr_to_vb_idx(va->va_start); 1862 err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask); 1863 if (err) { 1864 kfree(vb); 1865 free_vmap_area(va); 1866 return ERR_PTR(err); 1867 } 1868 1869 vbq = &get_cpu_var(vmap_block_queue); 1870 spin_lock(&vbq->lock); 1871 list_add_tail_rcu(&vb->free_list, &vbq->free); 1872 spin_unlock(&vbq->lock); 1873 put_cpu_var(vmap_block_queue); 1874 1875 return vaddr; 1876 } 1877 1878 static void free_vmap_block(struct vmap_block *vb) 1879 { 1880 struct vmap_block *tmp; 1881 1882 tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start)); 1883 BUG_ON(tmp != vb); 1884 1885 free_vmap_area_noflush(vb->va); 1886 kfree_rcu(vb, rcu_head); 1887 } 1888 1889 static void purge_fragmented_blocks(int cpu) 1890 { 1891 LIST_HEAD(purge); 1892 struct vmap_block *vb; 1893 struct vmap_block *n_vb; 1894 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); 1895 1896 rcu_read_lock(); 1897 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 1898 1899 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS)) 1900 continue; 1901 1902 spin_lock(&vb->lock); 1903 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) { 1904 vb->free = 0; /* prevent further allocs after releasing lock */ 1905 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */ 1906 vb->dirty_min = 0; 1907 vb->dirty_max = VMAP_BBMAP_BITS; 1908 spin_lock(&vbq->lock); 1909 list_del_rcu(&vb->free_list); 1910 spin_unlock(&vbq->lock); 1911 spin_unlock(&vb->lock); 1912 list_add_tail(&vb->purge, &purge); 1913 } else 1914 spin_unlock(&vb->lock); 1915 } 1916 rcu_read_unlock(); 1917 1918 list_for_each_entry_safe(vb, n_vb, &purge, purge) { 1919 list_del(&vb->purge); 1920 free_vmap_block(vb); 1921 } 1922 } 1923 1924 static void purge_fragmented_blocks_allcpus(void) 1925 { 1926 int cpu; 1927 1928 for_each_possible_cpu(cpu) 1929 purge_fragmented_blocks(cpu); 1930 } 1931 1932 static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 1933 { 1934 struct vmap_block_queue *vbq; 1935 struct vmap_block *vb; 1936 void *vaddr = NULL; 1937 unsigned int order; 1938 1939 BUG_ON(offset_in_page(size)); 1940 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); 1941 if (WARN_ON(size == 0)) { 1942 /* 1943 * Allocating 0 bytes isn't what caller wants since 1944 * get_order(0) returns funny result. Just warn and terminate 1945 * early. 1946 */ 1947 return NULL; 1948 } 1949 order = get_order(size); 1950 1951 rcu_read_lock(); 1952 vbq = &get_cpu_var(vmap_block_queue); 1953 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 1954 unsigned long pages_off; 1955 1956 spin_lock(&vb->lock); 1957 if (vb->free < (1UL << order)) { 1958 spin_unlock(&vb->lock); 1959 continue; 1960 } 1961 1962 pages_off = VMAP_BBMAP_BITS - vb->free; 1963 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); 1964 vb->free -= 1UL << order; 1965 if (vb->free == 0) { 1966 spin_lock(&vbq->lock); 1967 list_del_rcu(&vb->free_list); 1968 spin_unlock(&vbq->lock); 1969 } 1970 1971 spin_unlock(&vb->lock); 1972 break; 1973 } 1974 1975 put_cpu_var(vmap_block_queue); 1976 rcu_read_unlock(); 1977 1978 /* Allocate new block if nothing was found */ 1979 if (!vaddr) 1980 vaddr = new_vmap_block(order, gfp_mask); 1981 1982 return vaddr; 1983 } 1984 1985 static void vb_free(unsigned long addr, unsigned long size) 1986 { 1987 unsigned long offset; 1988 unsigned int order; 1989 struct vmap_block *vb; 1990 1991 BUG_ON(offset_in_page(size)); 1992 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); 1993 1994 flush_cache_vunmap(addr, addr + size); 1995 1996 order = get_order(size); 1997 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; 1998 vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr)); 1999 2000 vunmap_range_noflush(addr, addr + size); 2001 2002 if (debug_pagealloc_enabled_static()) 2003 flush_tlb_kernel_range(addr, addr + size); 2004 2005 spin_lock(&vb->lock); 2006 2007 /* Expand dirty range */ 2008 vb->dirty_min = min(vb->dirty_min, offset); 2009 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order)); 2010 2011 vb->dirty += 1UL << order; 2012 if (vb->dirty == VMAP_BBMAP_BITS) { 2013 BUG_ON(vb->free); 2014 spin_unlock(&vb->lock); 2015 free_vmap_block(vb); 2016 } else 2017 spin_unlock(&vb->lock); 2018 } 2019 2020 static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) 2021 { 2022 int cpu; 2023 2024 if (unlikely(!vmap_initialized)) 2025 return; 2026 2027 might_sleep(); 2028 2029 for_each_possible_cpu(cpu) { 2030 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); 2031 struct vmap_block *vb; 2032 2033 rcu_read_lock(); 2034 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 2035 spin_lock(&vb->lock); 2036 if (vb->dirty && vb->dirty != VMAP_BBMAP_BITS) { 2037 unsigned long va_start = vb->va->va_start; 2038 unsigned long s, e; 2039 2040 s = va_start + (vb->dirty_min << PAGE_SHIFT); 2041 e = va_start + (vb->dirty_max << PAGE_SHIFT); 2042 2043 start = min(s, start); 2044 end = max(e, end); 2045 2046 flush = 1; 2047 } 2048 spin_unlock(&vb->lock); 2049 } 2050 rcu_read_unlock(); 2051 } 2052 2053 mutex_lock(&vmap_purge_lock); 2054 purge_fragmented_blocks_allcpus(); 2055 if (!__purge_vmap_area_lazy(start, end) && flush) 2056 flush_tlb_kernel_range(start, end); 2057 mutex_unlock(&vmap_purge_lock); 2058 } 2059 2060 /** 2061 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer 2062 * 2063 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily 2064 * to amortize TLB flushing overheads. What this means is that any page you 2065 * have now, may, in a former life, have been mapped into kernel virtual 2066 * address by the vmap layer and so there might be some CPUs with TLB entries 2067 * still referencing that page (additional to the regular 1:1 kernel mapping). 2068 * 2069 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can 2070 * be sure that none of the pages we have control over will have any aliases 2071 * from the vmap layer. 2072 */ 2073 void vm_unmap_aliases(void) 2074 { 2075 unsigned long start = ULONG_MAX, end = 0; 2076 int flush = 0; 2077 2078 _vm_unmap_aliases(start, end, flush); 2079 } 2080 EXPORT_SYMBOL_GPL(vm_unmap_aliases); 2081 2082 /** 2083 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram 2084 * @mem: the pointer returned by vm_map_ram 2085 * @count: the count passed to that vm_map_ram call (cannot unmap partial) 2086 */ 2087 void vm_unmap_ram(const void *mem, unsigned int count) 2088 { 2089 unsigned long size = (unsigned long)count << PAGE_SHIFT; 2090 unsigned long addr = (unsigned long)mem; 2091 struct vmap_area *va; 2092 2093 might_sleep(); 2094 BUG_ON(!addr); 2095 BUG_ON(addr < VMALLOC_START); 2096 BUG_ON(addr > VMALLOC_END); 2097 BUG_ON(!PAGE_ALIGNED(addr)); 2098 2099 kasan_poison_vmalloc(mem, size); 2100 2101 if (likely(count <= VMAP_MAX_ALLOC)) { 2102 debug_check_no_locks_freed(mem, size); 2103 vb_free(addr, size); 2104 return; 2105 } 2106 2107 va = find_vmap_area(addr); 2108 BUG_ON(!va); 2109 debug_check_no_locks_freed((void *)va->va_start, 2110 (va->va_end - va->va_start)); 2111 free_unmap_vmap_area(va); 2112 } 2113 EXPORT_SYMBOL(vm_unmap_ram); 2114 2115 /** 2116 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) 2117 * @pages: an array of pointers to the pages to be mapped 2118 * @count: number of pages 2119 * @node: prefer to allocate data structures on this node 2120 * 2121 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be 2122 * faster than vmap so it's good. But if you mix long-life and short-life 2123 * objects with vm_map_ram(), it could consume lots of address space through 2124 * fragmentation (especially on a 32bit machine). You could see failures in 2125 * the end. Please use this function for short-lived objects. 2126 * 2127 * Returns: a pointer to the address that has been mapped, or %NULL on failure 2128 */ 2129 void *vm_map_ram(struct page **pages, unsigned int count, int node) 2130 { 2131 unsigned long size = (unsigned long)count << PAGE_SHIFT; 2132 unsigned long addr; 2133 void *mem; 2134 2135 if (likely(count <= VMAP_MAX_ALLOC)) { 2136 mem = vb_alloc(size, GFP_KERNEL); 2137 if (IS_ERR(mem)) 2138 return NULL; 2139 addr = (unsigned long)mem; 2140 } else { 2141 struct vmap_area *va; 2142 va = alloc_vmap_area(size, PAGE_SIZE, 2143 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL); 2144 if (IS_ERR(va)) 2145 return NULL; 2146 2147 addr = va->va_start; 2148 mem = (void *)addr; 2149 } 2150 2151 kasan_unpoison_vmalloc(mem, size); 2152 2153 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, 2154 pages, PAGE_SHIFT) < 0) { 2155 vm_unmap_ram(mem, count); 2156 return NULL; 2157 } 2158 2159 return mem; 2160 } 2161 EXPORT_SYMBOL(vm_map_ram); 2162 2163 static struct vm_struct *vmlist __initdata; 2164 2165 static inline unsigned int vm_area_page_order(struct vm_struct *vm) 2166 { 2167 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC 2168 return vm->page_order; 2169 #else 2170 return 0; 2171 #endif 2172 } 2173 2174 static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order) 2175 { 2176 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC 2177 vm->page_order = order; 2178 #else 2179 BUG_ON(order != 0); 2180 #endif 2181 } 2182 2183 /** 2184 * vm_area_add_early - add vmap area early during boot 2185 * @vm: vm_struct to add 2186 * 2187 * This function is used to add fixed kernel vm area to vmlist before 2188 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags 2189 * should contain proper values and the other fields should be zero. 2190 * 2191 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. 2192 */ 2193 void __init vm_area_add_early(struct vm_struct *vm) 2194 { 2195 struct vm_struct *tmp, **p; 2196 2197 BUG_ON(vmap_initialized); 2198 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { 2199 if (tmp->addr >= vm->addr) { 2200 BUG_ON(tmp->addr < vm->addr + vm->size); 2201 break; 2202 } else 2203 BUG_ON(tmp->addr + tmp->size > vm->addr); 2204 } 2205 vm->next = *p; 2206 *p = vm; 2207 } 2208 2209 /** 2210 * vm_area_register_early - register vmap area early during boot 2211 * @vm: vm_struct to register 2212 * @align: requested alignment 2213 * 2214 * This function is used to register kernel vm area before 2215 * vmalloc_init() is called. @vm->size and @vm->flags should contain 2216 * proper values on entry and other fields should be zero. On return, 2217 * vm->addr contains the allocated address. 2218 * 2219 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. 2220 */ 2221 void __init vm_area_register_early(struct vm_struct *vm, size_t align) 2222 { 2223 static size_t vm_init_off __initdata; 2224 unsigned long addr; 2225 2226 addr = ALIGN(VMALLOC_START + vm_init_off, align); 2227 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; 2228 2229 vm->addr = (void *)addr; 2230 2231 vm_area_add_early(vm); 2232 } 2233 2234 static void vmap_init_free_space(void) 2235 { 2236 unsigned long vmap_start = 1; 2237 const unsigned long vmap_end = ULONG_MAX; 2238 struct vmap_area *busy, *free; 2239 2240 /* 2241 * B F B B B F 2242 * -|-----|.....|-----|-----|-----|.....|- 2243 * | The KVA space | 2244 * |<--------------------------------->| 2245 */ 2246 list_for_each_entry(busy, &vmap_area_list, list) { 2247 if (busy->va_start - vmap_start > 0) { 2248 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); 2249 if (!WARN_ON_ONCE(!free)) { 2250 free->va_start = vmap_start; 2251 free->va_end = busy->va_start; 2252 2253 insert_vmap_area_augment(free, NULL, 2254 &free_vmap_area_root, 2255 &free_vmap_area_list); 2256 } 2257 } 2258 2259 vmap_start = busy->va_end; 2260 } 2261 2262 if (vmap_end - vmap_start > 0) { 2263 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); 2264 if (!WARN_ON_ONCE(!free)) { 2265 free->va_start = vmap_start; 2266 free->va_end = vmap_end; 2267 2268 insert_vmap_area_augment(free, NULL, 2269 &free_vmap_area_root, 2270 &free_vmap_area_list); 2271 } 2272 } 2273 } 2274 2275 void __init vmalloc_init(void) 2276 { 2277 struct vmap_area *va; 2278 struct vm_struct *tmp; 2279 int i; 2280 2281 /* 2282 * Create the cache for vmap_area objects. 2283 */ 2284 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC); 2285 2286 for_each_possible_cpu(i) { 2287 struct vmap_block_queue *vbq; 2288 struct vfree_deferred *p; 2289 2290 vbq = &per_cpu(vmap_block_queue, i); 2291 spin_lock_init(&vbq->lock); 2292 INIT_LIST_HEAD(&vbq->free); 2293 p = &per_cpu(vfree_deferred, i); 2294 init_llist_head(&p->list); 2295 INIT_WORK(&p->wq, free_work); 2296 } 2297 2298 /* Import existing vmlist entries. */ 2299 for (tmp = vmlist; tmp; tmp = tmp->next) { 2300 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); 2301 if (WARN_ON_ONCE(!va)) 2302 continue; 2303 2304 va->va_start = (unsigned long)tmp->addr; 2305 va->va_end = va->va_start + tmp->size; 2306 va->vm = tmp; 2307 insert_vmap_area(va, &vmap_area_root, &vmap_area_list); 2308 } 2309 2310 /* 2311 * Now we can initialize a free vmap space. 2312 */ 2313 vmap_init_free_space(); 2314 vmap_initialized = true; 2315 } 2316 2317 static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, 2318 struct vmap_area *va, unsigned long flags, const void *caller) 2319 { 2320 vm->flags = flags; 2321 vm->addr = (void *)va->va_start; 2322 vm->size = va->va_end - va->va_start; 2323 vm->caller = caller; 2324 va->vm = vm; 2325 } 2326 2327 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, 2328 unsigned long flags, const void *caller) 2329 { 2330 spin_lock(&vmap_area_lock); 2331 setup_vmalloc_vm_locked(vm, va, flags, caller); 2332 spin_unlock(&vmap_area_lock); 2333 } 2334 2335 static void clear_vm_uninitialized_flag(struct vm_struct *vm) 2336 { 2337 /* 2338 * Before removing VM_UNINITIALIZED, 2339 * we should make sure that vm has proper values. 2340 * Pair with smp_rmb() in show_numa_info(). 2341 */ 2342 smp_wmb(); 2343 vm->flags &= ~VM_UNINITIALIZED; 2344 } 2345 2346 static struct vm_struct *__get_vm_area_node(unsigned long size, 2347 unsigned long align, unsigned long shift, unsigned long flags, 2348 unsigned long start, unsigned long end, int node, 2349 gfp_t gfp_mask, const void *caller) 2350 { 2351 struct vmap_area *va; 2352 struct vm_struct *area; 2353 unsigned long requested_size = size; 2354 2355 BUG_ON(in_interrupt()); 2356 size = ALIGN(size, 1ul << shift); 2357 if (unlikely(!size)) 2358 return NULL; 2359 2360 if (flags & VM_IOREMAP) 2361 align = 1ul << clamp_t(int, get_count_order_long(size), 2362 PAGE_SHIFT, IOREMAP_MAX_ORDER); 2363 2364 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); 2365 if (unlikely(!area)) 2366 return NULL; 2367 2368 if (!(flags & VM_NO_GUARD)) 2369 size += PAGE_SIZE; 2370 2371 va = alloc_vmap_area(size, align, start, end, node, gfp_mask); 2372 if (IS_ERR(va)) { 2373 kfree(area); 2374 return NULL; 2375 } 2376 2377 kasan_unpoison_vmalloc((void *)va->va_start, requested_size); 2378 2379 setup_vmalloc_vm(area, va, flags, caller); 2380 2381 return area; 2382 } 2383 2384 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, 2385 unsigned long start, unsigned long end, 2386 const void *caller) 2387 { 2388 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end, 2389 NUMA_NO_NODE, GFP_KERNEL, caller); 2390 } 2391 2392 /** 2393 * get_vm_area - reserve a contiguous kernel virtual area 2394 * @size: size of the area 2395 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC 2396 * 2397 * Search an area of @size in the kernel virtual mapping area, 2398 * and reserved it for out purposes. Returns the area descriptor 2399 * on success or %NULL on failure. 2400 * 2401 * Return: the area descriptor on success or %NULL on failure. 2402 */ 2403 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) 2404 { 2405 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, 2406 VMALLOC_START, VMALLOC_END, 2407 NUMA_NO_NODE, GFP_KERNEL, 2408 __builtin_return_address(0)); 2409 } 2410 2411 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, 2412 const void *caller) 2413 { 2414 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, 2415 VMALLOC_START, VMALLOC_END, 2416 NUMA_NO_NODE, GFP_KERNEL, caller); 2417 } 2418 2419 /** 2420 * find_vm_area - find a continuous kernel virtual area 2421 * @addr: base address 2422 * 2423 * Search for the kernel VM area starting at @addr, and return it. 2424 * It is up to the caller to do all required locking to keep the returned 2425 * pointer valid. 2426 * 2427 * Return: the area descriptor on success or %NULL on failure. 2428 */ 2429 struct vm_struct *find_vm_area(const void *addr) 2430 { 2431 struct vmap_area *va; 2432 2433 va = find_vmap_area((unsigned long)addr); 2434 if (!va) 2435 return NULL; 2436 2437 return va->vm; 2438 } 2439 2440 /** 2441 * remove_vm_area - find and remove a continuous kernel virtual area 2442 * @addr: base address 2443 * 2444 * Search for the kernel VM area starting at @addr, and remove it. 2445 * This function returns the found VM area, but using it is NOT safe 2446 * on SMP machines, except for its size or flags. 2447 * 2448 * Return: the area descriptor on success or %NULL on failure. 2449 */ 2450 struct vm_struct *remove_vm_area(const void *addr) 2451 { 2452 struct vmap_area *va; 2453 2454 might_sleep(); 2455 2456 spin_lock(&vmap_area_lock); 2457 va = __find_vmap_area((unsigned long)addr); 2458 if (va && va->vm) { 2459 struct vm_struct *vm = va->vm; 2460 2461 va->vm = NULL; 2462 spin_unlock(&vmap_area_lock); 2463 2464 kasan_free_shadow(vm); 2465 free_unmap_vmap_area(va); 2466 2467 return vm; 2468 } 2469 2470 spin_unlock(&vmap_area_lock); 2471 return NULL; 2472 } 2473 2474 static inline void set_area_direct_map(const struct vm_struct *area, 2475 int (*set_direct_map)(struct page *page)) 2476 { 2477 int i; 2478 2479 /* HUGE_VMALLOC passes small pages to set_direct_map */ 2480 for (i = 0; i < area->nr_pages; i++) 2481 if (page_address(area->pages[i])) 2482 set_direct_map(area->pages[i]); 2483 } 2484 2485 /* Handle removing and resetting vm mappings related to the vm_struct. */ 2486 static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) 2487 { 2488 unsigned long start = ULONG_MAX, end = 0; 2489 unsigned int page_order = vm_area_page_order(area); 2490 int flush_reset = area->flags & VM_FLUSH_RESET_PERMS; 2491 int flush_dmap = 0; 2492 int i; 2493 2494 remove_vm_area(area->addr); 2495 2496 /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */ 2497 if (!flush_reset) 2498 return; 2499 2500 /* 2501 * If not deallocating pages, just do the flush of the VM area and 2502 * return. 2503 */ 2504 if (!deallocate_pages) { 2505 vm_unmap_aliases(); 2506 return; 2507 } 2508 2509 /* 2510 * If execution gets here, flush the vm mapping and reset the direct 2511 * map. Find the start and end range of the direct mappings to make sure 2512 * the vm_unmap_aliases() flush includes the direct map. 2513 */ 2514 for (i = 0; i < area->nr_pages; i += 1U << page_order) { 2515 unsigned long addr = (unsigned long)page_address(area->pages[i]); 2516 if (addr) { 2517 unsigned long page_size; 2518 2519 page_size = PAGE_SIZE << page_order; 2520 start = min(addr, start); 2521 end = max(addr + page_size, end); 2522 flush_dmap = 1; 2523 } 2524 } 2525 2526 /* 2527 * Set direct map to something invalid so that it won't be cached if 2528 * there are any accesses after the TLB flush, then flush the TLB and 2529 * reset the direct map permissions to the default. 2530 */ 2531 set_area_direct_map(area, set_direct_map_invalid_noflush); 2532 _vm_unmap_aliases(start, end, flush_dmap); 2533 set_area_direct_map(area, set_direct_map_default_noflush); 2534 } 2535 2536 static void __vunmap(const void *addr, int deallocate_pages) 2537 { 2538 struct vm_struct *area; 2539 2540 if (!addr) 2541 return; 2542 2543 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", 2544 addr)) 2545 return; 2546 2547 area = find_vm_area(addr); 2548 if (unlikely(!area)) { 2549 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", 2550 addr); 2551 return; 2552 } 2553 2554 debug_check_no_locks_freed(area->addr, get_vm_area_size(area)); 2555 debug_check_no_obj_freed(area->addr, get_vm_area_size(area)); 2556 2557 kasan_poison_vmalloc(area->addr, get_vm_area_size(area)); 2558 2559 vm_remove_mappings(area, deallocate_pages); 2560 2561 if (deallocate_pages) { 2562 unsigned int page_order = vm_area_page_order(area); 2563 int i; 2564 2565 for (i = 0; i < area->nr_pages; i += 1U << page_order) { 2566 struct page *page = area->pages[i]; 2567 2568 BUG_ON(!page); 2569 __free_pages(page, page_order); 2570 } 2571 atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); 2572 2573 kvfree(area->pages); 2574 } 2575 2576 kfree(area); 2577 } 2578 2579 static inline void __vfree_deferred(const void *addr) 2580 { 2581 /* 2582 * Use raw_cpu_ptr() because this can be called from preemptible 2583 * context. Preemption is absolutely fine here, because the llist_add() 2584 * implementation is lockless, so it works even if we are adding to 2585 * another cpu's list. schedule_work() should be fine with this too. 2586 */ 2587 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); 2588 2589 if (llist_add((struct llist_node *)addr, &p->list)) 2590 schedule_work(&p->wq); 2591 } 2592 2593 /** 2594 * vfree_atomic - release memory allocated by vmalloc() 2595 * @addr: memory base address 2596 * 2597 * This one is just like vfree() but can be called in any atomic context 2598 * except NMIs. 2599 */ 2600 void vfree_atomic(const void *addr) 2601 { 2602 BUG_ON(in_nmi()); 2603 2604 kmemleak_free(addr); 2605 2606 if (!addr) 2607 return; 2608 __vfree_deferred(addr); 2609 } 2610 2611 static void __vfree(const void *addr) 2612 { 2613 if (unlikely(in_interrupt())) 2614 __vfree_deferred(addr); 2615 else 2616 __vunmap(addr, 1); 2617 } 2618 2619 /** 2620 * vfree - Release memory allocated by vmalloc() 2621 * @addr: Memory base address 2622 * 2623 * Free the virtually continuous memory area starting at @addr, as obtained 2624 * from one of the vmalloc() family of APIs. This will usually also free the 2625 * physical memory underlying the virtual allocation, but that memory is 2626 * reference counted, so it will not be freed until the last user goes away. 2627 * 2628 * If @addr is NULL, no operation is performed. 2629 * 2630 * Context: 2631 * May sleep if called *not* from interrupt context. 2632 * Must not be called in NMI context (strictly speaking, it could be 2633 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling 2634 * conventions for vfree() arch-dependent would be a really bad idea). 2635 */ 2636 void vfree(const void *addr) 2637 { 2638 BUG_ON(in_nmi()); 2639 2640 kmemleak_free(addr); 2641 2642 might_sleep_if(!in_interrupt()); 2643 2644 if (!addr) 2645 return; 2646 2647 __vfree(addr); 2648 } 2649 EXPORT_SYMBOL(vfree); 2650 2651 /** 2652 * vunmap - release virtual mapping obtained by vmap() 2653 * @addr: memory base address 2654 * 2655 * Free the virtually contiguous memory area starting at @addr, 2656 * which was created from the page array passed to vmap(). 2657 * 2658 * Must not be called in interrupt context. 2659 */ 2660 void vunmap(const void *addr) 2661 { 2662 BUG_ON(in_interrupt()); 2663 might_sleep(); 2664 if (addr) 2665 __vunmap(addr, 0); 2666 } 2667 EXPORT_SYMBOL(vunmap); 2668 2669 /** 2670 * vmap - map an array of pages into virtually contiguous space 2671 * @pages: array of page pointers 2672 * @count: number of pages to map 2673 * @flags: vm_area->flags 2674 * @prot: page protection for the mapping 2675 * 2676 * Maps @count pages from @pages into contiguous kernel virtual space. 2677 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself 2678 * (which must be kmalloc or vmalloc memory) and one reference per pages in it 2679 * are transferred from the caller to vmap(), and will be freed / dropped when 2680 * vfree() is called on the return value. 2681 * 2682 * Return: the address of the area or %NULL on failure 2683 */ 2684 void *vmap(struct page **pages, unsigned int count, 2685 unsigned long flags, pgprot_t prot) 2686 { 2687 struct vm_struct *area; 2688 unsigned long addr; 2689 unsigned long size; /* In bytes */ 2690 2691 might_sleep(); 2692 2693 if (count > totalram_pages()) 2694 return NULL; 2695 2696 size = (unsigned long)count << PAGE_SHIFT; 2697 area = get_vm_area_caller(size, flags, __builtin_return_address(0)); 2698 if (!area) 2699 return NULL; 2700 2701 addr = (unsigned long)area->addr; 2702 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot), 2703 pages, PAGE_SHIFT) < 0) { 2704 vunmap(area->addr); 2705 return NULL; 2706 } 2707 2708 if (flags & VM_MAP_PUT_PAGES) { 2709 area->pages = pages; 2710 area->nr_pages = count; 2711 } 2712 return area->addr; 2713 } 2714 EXPORT_SYMBOL(vmap); 2715 2716 #ifdef CONFIG_VMAP_PFN 2717 struct vmap_pfn_data { 2718 unsigned long *pfns; 2719 pgprot_t prot; 2720 unsigned int idx; 2721 }; 2722 2723 static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) 2724 { 2725 struct vmap_pfn_data *data = private; 2726 2727 if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) 2728 return -EINVAL; 2729 *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); 2730 return 0; 2731 } 2732 2733 /** 2734 * vmap_pfn - map an array of PFNs into virtually contiguous space 2735 * @pfns: array of PFNs 2736 * @count: number of pages to map 2737 * @prot: page protection for the mapping 2738 * 2739 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns 2740 * the start address of the mapping. 2741 */ 2742 void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot) 2743 { 2744 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) }; 2745 struct vm_struct *area; 2746 2747 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP, 2748 __builtin_return_address(0)); 2749 if (!area) 2750 return NULL; 2751 if (apply_to_page_range(&init_mm, (unsigned long)area->addr, 2752 count * PAGE_SIZE, vmap_pfn_apply, &data)) { 2753 free_vm_area(area); 2754 return NULL; 2755 } 2756 return area->addr; 2757 } 2758 EXPORT_SYMBOL_GPL(vmap_pfn); 2759 #endif /* CONFIG_VMAP_PFN */ 2760 2761 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, 2762 pgprot_t prot, unsigned int page_shift, 2763 int node) 2764 { 2765 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; 2766 unsigned long addr = (unsigned long)area->addr; 2767 unsigned long size = get_vm_area_size(area); 2768 unsigned long array_size; 2769 unsigned int nr_small_pages = size >> PAGE_SHIFT; 2770 unsigned int page_order; 2771 struct page **pages; 2772 unsigned int i; 2773 2774 array_size = (unsigned long)nr_small_pages * sizeof(struct page *); 2775 gfp_mask |= __GFP_NOWARN; 2776 if (!(gfp_mask & (GFP_DMA | GFP_DMA32))) 2777 gfp_mask |= __GFP_HIGHMEM; 2778 2779 /* Please note that the recursion is strictly bounded. */ 2780 if (array_size > PAGE_SIZE) { 2781 pages = __vmalloc_node(array_size, 1, nested_gfp, node, 2782 area->caller); 2783 } else { 2784 pages = kmalloc_node(array_size, nested_gfp, node); 2785 } 2786 2787 if (!pages) { 2788 free_vm_area(area); 2789 warn_alloc(gfp_mask, NULL, 2790 "vmalloc size %lu allocation failure: " 2791 "page array size %lu allocation failed", 2792 nr_small_pages * PAGE_SIZE, array_size); 2793 return NULL; 2794 } 2795 2796 area->pages = pages; 2797 area->nr_pages = nr_small_pages; 2798 set_vm_area_page_order(area, page_shift - PAGE_SHIFT); 2799 2800 page_order = vm_area_page_order(area); 2801 2802 /* 2803 * Careful, we allocate and map page_order pages, but tracking is done 2804 * per PAGE_SIZE page so as to keep the vm_struct APIs independent of 2805 * the physical/mapped size. 2806 */ 2807 for (i = 0; i < area->nr_pages; i += 1U << page_order) { 2808 struct page *page; 2809 int p; 2810 2811 /* Compound pages required for remap_vmalloc_page */ 2812 page = alloc_pages_node(node, gfp_mask | __GFP_COMP, page_order); 2813 if (unlikely(!page)) { 2814 /* Successfully allocated i pages, free them in __vfree() */ 2815 area->nr_pages = i; 2816 atomic_long_add(area->nr_pages, &nr_vmalloc_pages); 2817 warn_alloc(gfp_mask, NULL, 2818 "vmalloc size %lu allocation failure: " 2819 "page order %u allocation failed", 2820 area->nr_pages * PAGE_SIZE, page_order); 2821 goto fail; 2822 } 2823 2824 for (p = 0; p < (1U << page_order); p++) 2825 area->pages[i + p] = page + p; 2826 2827 if (gfpflags_allow_blocking(gfp_mask)) 2828 cond_resched(); 2829 } 2830 atomic_long_add(area->nr_pages, &nr_vmalloc_pages); 2831 2832 if (vmap_pages_range(addr, addr + size, prot, pages, page_shift) < 0) { 2833 warn_alloc(gfp_mask, NULL, 2834 "vmalloc size %lu allocation failure: " 2835 "failed to map pages", 2836 area->nr_pages * PAGE_SIZE); 2837 goto fail; 2838 } 2839 2840 return area->addr; 2841 2842 fail: 2843 __vfree(area->addr); 2844 return NULL; 2845 } 2846 2847 /** 2848 * __vmalloc_node_range - allocate virtually contiguous memory 2849 * @size: allocation size 2850 * @align: desired alignment 2851 * @start: vm area range start 2852 * @end: vm area range end 2853 * @gfp_mask: flags for the page level allocator 2854 * @prot: protection mask for the allocated pages 2855 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) 2856 * @node: node to use for allocation or NUMA_NO_NODE 2857 * @caller: caller's return address 2858 * 2859 * Allocate enough pages to cover @size from the page level 2860 * allocator with @gfp_mask flags. Map them into contiguous 2861 * kernel virtual space, using a pagetable protection of @prot. 2862 * 2863 * Return: the address of the area or %NULL on failure 2864 */ 2865 void *__vmalloc_node_range(unsigned long size, unsigned long align, 2866 unsigned long start, unsigned long end, gfp_t gfp_mask, 2867 pgprot_t prot, unsigned long vm_flags, int node, 2868 const void *caller) 2869 { 2870 struct vm_struct *area; 2871 void *addr; 2872 unsigned long real_size = size; 2873 unsigned long real_align = align; 2874 unsigned int shift = PAGE_SHIFT; 2875 2876 if (WARN_ON_ONCE(!size)) 2877 return NULL; 2878 2879 if ((size >> PAGE_SHIFT) > totalram_pages()) { 2880 warn_alloc(gfp_mask, NULL, 2881 "vmalloc size %lu allocation failure: " 2882 "exceeds total pages", real_size); 2883 return NULL; 2884 } 2885 2886 if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP) && 2887 arch_vmap_pmd_supported(prot)) { 2888 unsigned long size_per_node; 2889 2890 /* 2891 * Try huge pages. Only try for PAGE_KERNEL allocations, 2892 * others like modules don't yet expect huge pages in 2893 * their allocations due to apply_to_page_range not 2894 * supporting them. 2895 */ 2896 2897 size_per_node = size; 2898 if (node == NUMA_NO_NODE) 2899 size_per_node /= num_online_nodes(); 2900 if (size_per_node >= PMD_SIZE) { 2901 shift = PMD_SHIFT; 2902 align = max(real_align, 1UL << shift); 2903 size = ALIGN(real_size, 1UL << shift); 2904 } 2905 } 2906 2907 again: 2908 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC | 2909 VM_UNINITIALIZED | vm_flags, start, end, node, 2910 gfp_mask, caller); 2911 if (!area) { 2912 warn_alloc(gfp_mask, NULL, 2913 "vmalloc size %lu allocation failure: " 2914 "vm_struct allocation failed", real_size); 2915 goto fail; 2916 } 2917 2918 addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node); 2919 if (!addr) 2920 goto fail; 2921 2922 /* 2923 * In this function, newly allocated vm_struct has VM_UNINITIALIZED 2924 * flag. It means that vm_struct is not fully initialized. 2925 * Now, it is fully initialized, so remove this flag here. 2926 */ 2927 clear_vm_uninitialized_flag(area); 2928 2929 size = PAGE_ALIGN(size); 2930 kmemleak_vmalloc(area, size, gfp_mask); 2931 2932 return addr; 2933 2934 fail: 2935 if (shift > PAGE_SHIFT) { 2936 shift = PAGE_SHIFT; 2937 align = real_align; 2938 size = real_size; 2939 goto again; 2940 } 2941 2942 return NULL; 2943 } 2944 2945 /** 2946 * __vmalloc_node - allocate virtually contiguous memory 2947 * @size: allocation size 2948 * @align: desired alignment 2949 * @gfp_mask: flags for the page level allocator 2950 * @node: node to use for allocation or NUMA_NO_NODE 2951 * @caller: caller's return address 2952 * 2953 * Allocate enough pages to cover @size from the page level allocator with 2954 * @gfp_mask flags. Map them into contiguous kernel virtual space. 2955 * 2956 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL 2957 * and __GFP_NOFAIL are not supported 2958 * 2959 * Any use of gfp flags outside of GFP_KERNEL should be consulted 2960 * with mm people. 2961 * 2962 * Return: pointer to the allocated memory or %NULL on error 2963 */ 2964 void *__vmalloc_node(unsigned long size, unsigned long align, 2965 gfp_t gfp_mask, int node, const void *caller) 2966 { 2967 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 2968 gfp_mask, PAGE_KERNEL, 0, node, caller); 2969 } 2970 /* 2971 * This is only for performance analysis of vmalloc and stress purpose. 2972 * It is required by vmalloc test module, therefore do not use it other 2973 * than that. 2974 */ 2975 #ifdef CONFIG_TEST_VMALLOC_MODULE 2976 EXPORT_SYMBOL_GPL(__vmalloc_node); 2977 #endif 2978 2979 void *__vmalloc(unsigned long size, gfp_t gfp_mask) 2980 { 2981 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE, 2982 __builtin_return_address(0)); 2983 } 2984 EXPORT_SYMBOL(__vmalloc); 2985 2986 /** 2987 * vmalloc - allocate virtually contiguous memory 2988 * @size: allocation size 2989 * 2990 * Allocate enough pages to cover @size from the page level 2991 * allocator and map them into contiguous kernel virtual space. 2992 * 2993 * For tight control over page level allocator and protection flags 2994 * use __vmalloc() instead. 2995 * 2996 * Return: pointer to the allocated memory or %NULL on error 2997 */ 2998 void *vmalloc(unsigned long size) 2999 { 3000 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE, 3001 __builtin_return_address(0)); 3002 } 3003 EXPORT_SYMBOL(vmalloc); 3004 3005 /** 3006 * vmalloc_no_huge - allocate virtually contiguous memory using small pages 3007 * @size: allocation size 3008 * 3009 * Allocate enough non-huge pages to cover @size from the page level 3010 * allocator and map them into contiguous kernel virtual space. 3011 * 3012 * Return: pointer to the allocated memory or %NULL on error 3013 */ 3014 void *vmalloc_no_huge(unsigned long size) 3015 { 3016 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, 3017 GFP_KERNEL, PAGE_KERNEL, VM_NO_HUGE_VMAP, 3018 NUMA_NO_NODE, __builtin_return_address(0)); 3019 } 3020 EXPORT_SYMBOL(vmalloc_no_huge); 3021 3022 /** 3023 * vzalloc - allocate virtually contiguous memory with zero fill 3024 * @size: allocation size 3025 * 3026 * Allocate enough pages to cover @size from the page level 3027 * allocator and map them into contiguous kernel virtual space. 3028 * The memory allocated is set to zero. 3029 * 3030 * For tight control over page level allocator and protection flags 3031 * use __vmalloc() instead. 3032 * 3033 * Return: pointer to the allocated memory or %NULL on error 3034 */ 3035 void *vzalloc(unsigned long size) 3036 { 3037 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, 3038 __builtin_return_address(0)); 3039 } 3040 EXPORT_SYMBOL(vzalloc); 3041 3042 /** 3043 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace 3044 * @size: allocation size 3045 * 3046 * The resulting memory area is zeroed so it can be mapped to userspace 3047 * without leaking data. 3048 * 3049 * Return: pointer to the allocated memory or %NULL on error 3050 */ 3051 void *vmalloc_user(unsigned long size) 3052 { 3053 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, 3054 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, 3055 VM_USERMAP, NUMA_NO_NODE, 3056 __builtin_return_address(0)); 3057 } 3058 EXPORT_SYMBOL(vmalloc_user); 3059 3060 /** 3061 * vmalloc_node - allocate memory on a specific node 3062 * @size: allocation size 3063 * @node: numa node 3064 * 3065 * Allocate enough pages to cover @size from the page level 3066 * allocator and map them into contiguous kernel virtual space. 3067 * 3068 * For tight control over page level allocator and protection flags 3069 * use __vmalloc() instead. 3070 * 3071 * Return: pointer to the allocated memory or %NULL on error 3072 */ 3073 void *vmalloc_node(unsigned long size, int node) 3074 { 3075 return __vmalloc_node(size, 1, GFP_KERNEL, node, 3076 __builtin_return_address(0)); 3077 } 3078 EXPORT_SYMBOL(vmalloc_node); 3079 3080 /** 3081 * vzalloc_node - allocate memory on a specific node with zero fill 3082 * @size: allocation size 3083 * @node: numa node 3084 * 3085 * Allocate enough pages to cover @size from the page level 3086 * allocator and map them into contiguous kernel virtual space. 3087 * The memory allocated is set to zero. 3088 * 3089 * Return: pointer to the allocated memory or %NULL on error 3090 */ 3091 void *vzalloc_node(unsigned long size, int node) 3092 { 3093 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node, 3094 __builtin_return_address(0)); 3095 } 3096 EXPORT_SYMBOL(vzalloc_node); 3097 3098 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) 3099 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) 3100 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) 3101 #define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL) 3102 #else 3103 /* 3104 * 64b systems should always have either DMA or DMA32 zones. For others 3105 * GFP_DMA32 should do the right thing and use the normal zone. 3106 */ 3107 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) 3108 #endif 3109 3110 /** 3111 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 3112 * @size: allocation size 3113 * 3114 * Allocate enough 32bit PA addressable pages to cover @size from the 3115 * page level allocator and map them into contiguous kernel virtual space. 3116 * 3117 * Return: pointer to the allocated memory or %NULL on error 3118 */ 3119 void *vmalloc_32(unsigned long size) 3120 { 3121 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE, 3122 __builtin_return_address(0)); 3123 } 3124 EXPORT_SYMBOL(vmalloc_32); 3125 3126 /** 3127 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 3128 * @size: allocation size 3129 * 3130 * The resulting memory area is 32bit addressable and zeroed so it can be 3131 * mapped to userspace without leaking data. 3132 * 3133 * Return: pointer to the allocated memory or %NULL on error 3134 */ 3135 void *vmalloc_32_user(unsigned long size) 3136 { 3137 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, 3138 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, 3139 VM_USERMAP, NUMA_NO_NODE, 3140 __builtin_return_address(0)); 3141 } 3142 EXPORT_SYMBOL(vmalloc_32_user); 3143 3144 /* 3145 * small helper routine , copy contents to buf from addr. 3146 * If the page is not present, fill zero. 3147 */ 3148 3149 static int aligned_vread(char *buf, char *addr, unsigned long count) 3150 { 3151 struct page *p; 3152 int copied = 0; 3153 3154 while (count) { 3155 unsigned long offset, length; 3156 3157 offset = offset_in_page(addr); 3158 length = PAGE_SIZE - offset; 3159 if (length > count) 3160 length = count; 3161 p = vmalloc_to_page(addr); 3162 /* 3163 * To do safe access to this _mapped_ area, we need 3164 * lock. But adding lock here means that we need to add 3165 * overhead of vmalloc()/vfree() calls for this _debug_ 3166 * interface, rarely used. Instead of that, we'll use 3167 * kmap() and get small overhead in this access function. 3168 */ 3169 if (p) { 3170 /* We can expect USER0 is not used -- see vread() */ 3171 void *map = kmap_atomic(p); 3172 memcpy(buf, map + offset, length); 3173 kunmap_atomic(map); 3174 } else 3175 memset(buf, 0, length); 3176 3177 addr += length; 3178 buf += length; 3179 copied += length; 3180 count -= length; 3181 } 3182 return copied; 3183 } 3184 3185 /** 3186 * vread() - read vmalloc area in a safe way. 3187 * @buf: buffer for reading data 3188 * @addr: vm address. 3189 * @count: number of bytes to be read. 3190 * 3191 * This function checks that addr is a valid vmalloc'ed area, and 3192 * copy data from that area to a given buffer. If the given memory range 3193 * of [addr...addr+count) includes some valid address, data is copied to 3194 * proper area of @buf. If there are memory holes, they'll be zero-filled. 3195 * IOREMAP area is treated as memory hole and no copy is done. 3196 * 3197 * If [addr...addr+count) doesn't includes any intersects with alive 3198 * vm_struct area, returns 0. @buf should be kernel's buffer. 3199 * 3200 * Note: In usual ops, vread() is never necessary because the caller 3201 * should know vmalloc() area is valid and can use memcpy(). 3202 * This is for routines which have to access vmalloc area without 3203 * any information, as /proc/kcore. 3204 * 3205 * Return: number of bytes for which addr and buf should be increased 3206 * (same number as @count) or %0 if [addr...addr+count) doesn't 3207 * include any intersection with valid vmalloc area 3208 */ 3209 long vread(char *buf, char *addr, unsigned long count) 3210 { 3211 struct vmap_area *va; 3212 struct vm_struct *vm; 3213 char *vaddr, *buf_start = buf; 3214 unsigned long buflen = count; 3215 unsigned long n; 3216 3217 /* Don't allow overflow */ 3218 if ((unsigned long) addr + count < count) 3219 count = -(unsigned long) addr; 3220 3221 spin_lock(&vmap_area_lock); 3222 va = __find_vmap_area((unsigned long)addr); 3223 if (!va) 3224 goto finished; 3225 list_for_each_entry_from(va, &vmap_area_list, list) { 3226 if (!count) 3227 break; 3228 3229 if (!va->vm) 3230 continue; 3231 3232 vm = va->vm; 3233 vaddr = (char *) vm->addr; 3234 if (addr >= vaddr + get_vm_area_size(vm)) 3235 continue; 3236 while (addr < vaddr) { 3237 if (count == 0) 3238 goto finished; 3239 *buf = '\0'; 3240 buf++; 3241 addr++; 3242 count--; 3243 } 3244 n = vaddr + get_vm_area_size(vm) - addr; 3245 if (n > count) 3246 n = count; 3247 if (!(vm->flags & VM_IOREMAP)) 3248 aligned_vread(buf, addr, n); 3249 else /* IOREMAP area is treated as memory hole */ 3250 memset(buf, 0, n); 3251 buf += n; 3252 addr += n; 3253 count -= n; 3254 } 3255 finished: 3256 spin_unlock(&vmap_area_lock); 3257 3258 if (buf == buf_start) 3259 return 0; 3260 /* zero-fill memory holes */ 3261 if (buf != buf_start + buflen) 3262 memset(buf, 0, buflen - (buf - buf_start)); 3263 3264 return buflen; 3265 } 3266 3267 /** 3268 * remap_vmalloc_range_partial - map vmalloc pages to userspace 3269 * @vma: vma to cover 3270 * @uaddr: target user address to start at 3271 * @kaddr: virtual address of vmalloc kernel memory 3272 * @pgoff: offset from @kaddr to start at 3273 * @size: size of map area 3274 * 3275 * Returns: 0 for success, -Exxx on failure 3276 * 3277 * This function checks that @kaddr is a valid vmalloc'ed area, 3278 * and that it is big enough to cover the range starting at 3279 * @uaddr in @vma. Will return failure if that criteria isn't 3280 * met. 3281 * 3282 * Similar to remap_pfn_range() (see mm/memory.c) 3283 */ 3284 int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, 3285 void *kaddr, unsigned long pgoff, 3286 unsigned long size) 3287 { 3288 struct vm_struct *area; 3289 unsigned long off; 3290 unsigned long end_index; 3291 3292 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off)) 3293 return -EINVAL; 3294 3295 size = PAGE_ALIGN(size); 3296 3297 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr)) 3298 return -EINVAL; 3299 3300 area = find_vm_area(kaddr); 3301 if (!area) 3302 return -EINVAL; 3303 3304 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT))) 3305 return -EINVAL; 3306 3307 if (check_add_overflow(size, off, &end_index) || 3308 end_index > get_vm_area_size(area)) 3309 return -EINVAL; 3310 kaddr += off; 3311 3312 do { 3313 struct page *page = vmalloc_to_page(kaddr); 3314 int ret; 3315 3316 ret = vm_insert_page(vma, uaddr, page); 3317 if (ret) 3318 return ret; 3319 3320 uaddr += PAGE_SIZE; 3321 kaddr += PAGE_SIZE; 3322 size -= PAGE_SIZE; 3323 } while (size > 0); 3324 3325 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 3326 3327 return 0; 3328 } 3329 3330 /** 3331 * remap_vmalloc_range - map vmalloc pages to userspace 3332 * @vma: vma to cover (map full range of vma) 3333 * @addr: vmalloc memory 3334 * @pgoff: number of pages into addr before first page to map 3335 * 3336 * Returns: 0 for success, -Exxx on failure 3337 * 3338 * This function checks that addr is a valid vmalloc'ed area, and 3339 * that it is big enough to cover the vma. Will return failure if 3340 * that criteria isn't met. 3341 * 3342 * Similar to remap_pfn_range() (see mm/memory.c) 3343 */ 3344 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 3345 unsigned long pgoff) 3346 { 3347 return remap_vmalloc_range_partial(vma, vma->vm_start, 3348 addr, pgoff, 3349 vma->vm_end - vma->vm_start); 3350 } 3351 EXPORT_SYMBOL(remap_vmalloc_range); 3352 3353 void free_vm_area(struct vm_struct *area) 3354 { 3355 struct vm_struct *ret; 3356 ret = remove_vm_area(area->addr); 3357 BUG_ON(ret != area); 3358 kfree(area); 3359 } 3360 EXPORT_SYMBOL_GPL(free_vm_area); 3361 3362 #ifdef CONFIG_SMP 3363 static struct vmap_area *node_to_va(struct rb_node *n) 3364 { 3365 return rb_entry_safe(n, struct vmap_area, rb_node); 3366 } 3367 3368 /** 3369 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to 3370 * @addr: target address 3371 * 3372 * Returns: vmap_area if it is found. If there is no such area 3373 * the first highest(reverse order) vmap_area is returned 3374 * i.e. va->va_start < addr && va->va_end < addr or NULL 3375 * if there are no any areas before @addr. 3376 */ 3377 static struct vmap_area * 3378 pvm_find_va_enclose_addr(unsigned long addr) 3379 { 3380 struct vmap_area *va, *tmp; 3381 struct rb_node *n; 3382 3383 n = free_vmap_area_root.rb_node; 3384 va = NULL; 3385 3386 while (n) { 3387 tmp = rb_entry(n, struct vmap_area, rb_node); 3388 if (tmp->va_start <= addr) { 3389 va = tmp; 3390 if (tmp->va_end >= addr) 3391 break; 3392 3393 n = n->rb_right; 3394 } else { 3395 n = n->rb_left; 3396 } 3397 } 3398 3399 return va; 3400 } 3401 3402 /** 3403 * pvm_determine_end_from_reverse - find the highest aligned address 3404 * of free block below VMALLOC_END 3405 * @va: 3406 * in - the VA we start the search(reverse order); 3407 * out - the VA with the highest aligned end address. 3408 * @align: alignment for required highest address 3409 * 3410 * Returns: determined end address within vmap_area 3411 */ 3412 static unsigned long 3413 pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align) 3414 { 3415 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); 3416 unsigned long addr; 3417 3418 if (likely(*va)) { 3419 list_for_each_entry_from_reverse((*va), 3420 &free_vmap_area_list, list) { 3421 addr = min((*va)->va_end & ~(align - 1), vmalloc_end); 3422 if ((*va)->va_start < addr) 3423 return addr; 3424 } 3425 } 3426 3427 return 0; 3428 } 3429 3430 /** 3431 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator 3432 * @offsets: array containing offset of each area 3433 * @sizes: array containing size of each area 3434 * @nr_vms: the number of areas to allocate 3435 * @align: alignment, all entries in @offsets and @sizes must be aligned to this 3436 * 3437 * Returns: kmalloc'd vm_struct pointer array pointing to allocated 3438 * vm_structs on success, %NULL on failure 3439 * 3440 * Percpu allocator wants to use congruent vm areas so that it can 3441 * maintain the offsets among percpu areas. This function allocates 3442 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to 3443 * be scattered pretty far, distance between two areas easily going up 3444 * to gigabytes. To avoid interacting with regular vmallocs, these 3445 * areas are allocated from top. 3446 * 3447 * Despite its complicated look, this allocator is rather simple. It 3448 * does everything top-down and scans free blocks from the end looking 3449 * for matching base. While scanning, if any of the areas do not fit the 3450 * base address is pulled down to fit the area. Scanning is repeated till 3451 * all the areas fit and then all necessary data structures are inserted 3452 * and the result is returned. 3453 */ 3454 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, 3455 const size_t *sizes, int nr_vms, 3456 size_t align) 3457 { 3458 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); 3459 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); 3460 struct vmap_area **vas, *va; 3461 struct vm_struct **vms; 3462 int area, area2, last_area, term_area; 3463 unsigned long base, start, size, end, last_end, orig_start, orig_end; 3464 bool purged = false; 3465 enum fit_type type; 3466 3467 /* verify parameters and allocate data structures */ 3468 BUG_ON(offset_in_page(align) || !is_power_of_2(align)); 3469 for (last_area = 0, area = 0; area < nr_vms; area++) { 3470 start = offsets[area]; 3471 end = start + sizes[area]; 3472 3473 /* is everything aligned properly? */ 3474 BUG_ON(!IS_ALIGNED(offsets[area], align)); 3475 BUG_ON(!IS_ALIGNED(sizes[area], align)); 3476 3477 /* detect the area with the highest address */ 3478 if (start > offsets[last_area]) 3479 last_area = area; 3480 3481 for (area2 = area + 1; area2 < nr_vms; area2++) { 3482 unsigned long start2 = offsets[area2]; 3483 unsigned long end2 = start2 + sizes[area2]; 3484 3485 BUG_ON(start2 < end && start < end2); 3486 } 3487 } 3488 last_end = offsets[last_area] + sizes[last_area]; 3489 3490 if (vmalloc_end - vmalloc_start < last_end) { 3491 WARN_ON(true); 3492 return NULL; 3493 } 3494 3495 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL); 3496 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL); 3497 if (!vas || !vms) 3498 goto err_free2; 3499 3500 for (area = 0; area < nr_vms; area++) { 3501 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL); 3502 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); 3503 if (!vas[area] || !vms[area]) 3504 goto err_free; 3505 } 3506 retry: 3507 spin_lock(&free_vmap_area_lock); 3508 3509 /* start scanning - we scan from the top, begin with the last area */ 3510 area = term_area = last_area; 3511 start = offsets[area]; 3512 end = start + sizes[area]; 3513 3514 va = pvm_find_va_enclose_addr(vmalloc_end); 3515 base = pvm_determine_end_from_reverse(&va, align) - end; 3516 3517 while (true) { 3518 /* 3519 * base might have underflowed, add last_end before 3520 * comparing. 3521 */ 3522 if (base + last_end < vmalloc_start + last_end) 3523 goto overflow; 3524 3525 /* 3526 * Fitting base has not been found. 3527 */ 3528 if (va == NULL) 3529 goto overflow; 3530 3531 /* 3532 * If required width exceeds current VA block, move 3533 * base downwards and then recheck. 3534 */ 3535 if (base + end > va->va_end) { 3536 base = pvm_determine_end_from_reverse(&va, align) - end; 3537 term_area = area; 3538 continue; 3539 } 3540 3541 /* 3542 * If this VA does not fit, move base downwards and recheck. 3543 */ 3544 if (base + start < va->va_start) { 3545 va = node_to_va(rb_prev(&va->rb_node)); 3546 base = pvm_determine_end_from_reverse(&va, align) - end; 3547 term_area = area; 3548 continue; 3549 } 3550 3551 /* 3552 * This area fits, move on to the previous one. If 3553 * the previous one is the terminal one, we're done. 3554 */ 3555 area = (area + nr_vms - 1) % nr_vms; 3556 if (area == term_area) 3557 break; 3558 3559 start = offsets[area]; 3560 end = start + sizes[area]; 3561 va = pvm_find_va_enclose_addr(base + end); 3562 } 3563 3564 /* we've found a fitting base, insert all va's */ 3565 for (area = 0; area < nr_vms; area++) { 3566 int ret; 3567 3568 start = base + offsets[area]; 3569 size = sizes[area]; 3570 3571 va = pvm_find_va_enclose_addr(start); 3572 if (WARN_ON_ONCE(va == NULL)) 3573 /* It is a BUG(), but trigger recovery instead. */ 3574 goto recovery; 3575 3576 type = classify_va_fit_type(va, start, size); 3577 if (WARN_ON_ONCE(type == NOTHING_FIT)) 3578 /* It is a BUG(), but trigger recovery instead. */ 3579 goto recovery; 3580 3581 ret = adjust_va_to_fit_type(va, start, size, type); 3582 if (unlikely(ret)) 3583 goto recovery; 3584 3585 /* Allocated area. */ 3586 va = vas[area]; 3587 va->va_start = start; 3588 va->va_end = start + size; 3589 } 3590 3591 spin_unlock(&free_vmap_area_lock); 3592 3593 /* populate the kasan shadow space */ 3594 for (area = 0; area < nr_vms; area++) { 3595 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) 3596 goto err_free_shadow; 3597 3598 kasan_unpoison_vmalloc((void *)vas[area]->va_start, 3599 sizes[area]); 3600 } 3601 3602 /* insert all vm's */ 3603 spin_lock(&vmap_area_lock); 3604 for (area = 0; area < nr_vms; area++) { 3605 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list); 3606 3607 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, 3608 pcpu_get_vm_areas); 3609 } 3610 spin_unlock(&vmap_area_lock); 3611 3612 kfree(vas); 3613 return vms; 3614 3615 recovery: 3616 /* 3617 * Remove previously allocated areas. There is no 3618 * need in removing these areas from the busy tree, 3619 * because they are inserted only on the final step 3620 * and when pcpu_get_vm_areas() is success. 3621 */ 3622 while (area--) { 3623 orig_start = vas[area]->va_start; 3624 orig_end = vas[area]->va_end; 3625 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, 3626 &free_vmap_area_list); 3627 if (va) 3628 kasan_release_vmalloc(orig_start, orig_end, 3629 va->va_start, va->va_end); 3630 vas[area] = NULL; 3631 } 3632 3633 overflow: 3634 spin_unlock(&free_vmap_area_lock); 3635 if (!purged) { 3636 purge_vmap_area_lazy(); 3637 purged = true; 3638 3639 /* Before "retry", check if we recover. */ 3640 for (area = 0; area < nr_vms; area++) { 3641 if (vas[area]) 3642 continue; 3643 3644 vas[area] = kmem_cache_zalloc( 3645 vmap_area_cachep, GFP_KERNEL); 3646 if (!vas[area]) 3647 goto err_free; 3648 } 3649 3650 goto retry; 3651 } 3652 3653 err_free: 3654 for (area = 0; area < nr_vms; area++) { 3655 if (vas[area]) 3656 kmem_cache_free(vmap_area_cachep, vas[area]); 3657 3658 kfree(vms[area]); 3659 } 3660 err_free2: 3661 kfree(vas); 3662 kfree(vms); 3663 return NULL; 3664 3665 err_free_shadow: 3666 spin_lock(&free_vmap_area_lock); 3667 /* 3668 * We release all the vmalloc shadows, even the ones for regions that 3669 * hadn't been successfully added. This relies on kasan_release_vmalloc 3670 * being able to tolerate this case. 3671 */ 3672 for (area = 0; area < nr_vms; area++) { 3673 orig_start = vas[area]->va_start; 3674 orig_end = vas[area]->va_end; 3675 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, 3676 &free_vmap_area_list); 3677 if (va) 3678 kasan_release_vmalloc(orig_start, orig_end, 3679 va->va_start, va->va_end); 3680 vas[area] = NULL; 3681 kfree(vms[area]); 3682 } 3683 spin_unlock(&free_vmap_area_lock); 3684 kfree(vas); 3685 kfree(vms); 3686 return NULL; 3687 } 3688 3689 /** 3690 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator 3691 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() 3692 * @nr_vms: the number of allocated areas 3693 * 3694 * Free vm_structs and the array allocated by pcpu_get_vm_areas(). 3695 */ 3696 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) 3697 { 3698 int i; 3699 3700 for (i = 0; i < nr_vms; i++) 3701 free_vm_area(vms[i]); 3702 kfree(vms); 3703 } 3704 #endif /* CONFIG_SMP */ 3705 3706 #ifdef CONFIG_PRINTK 3707 bool vmalloc_dump_obj(void *object) 3708 { 3709 struct vm_struct *vm; 3710 void *objp = (void *)PAGE_ALIGN((unsigned long)object); 3711 3712 vm = find_vm_area(objp); 3713 if (!vm) 3714 return false; 3715 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n", 3716 vm->nr_pages, (unsigned long)vm->addr, vm->caller); 3717 return true; 3718 } 3719 #endif 3720 3721 #ifdef CONFIG_PROC_FS 3722 static void *s_start(struct seq_file *m, loff_t *pos) 3723 __acquires(&vmap_purge_lock) 3724 __acquires(&vmap_area_lock) 3725 { 3726 mutex_lock(&vmap_purge_lock); 3727 spin_lock(&vmap_area_lock); 3728 3729 return seq_list_start(&vmap_area_list, *pos); 3730 } 3731 3732 static void *s_next(struct seq_file *m, void *p, loff_t *pos) 3733 { 3734 return seq_list_next(p, &vmap_area_list, pos); 3735 } 3736 3737 static void s_stop(struct seq_file *m, void *p) 3738 __releases(&vmap_area_lock) 3739 __releases(&vmap_purge_lock) 3740 { 3741 spin_unlock(&vmap_area_lock); 3742 mutex_unlock(&vmap_purge_lock); 3743 } 3744 3745 static void show_numa_info(struct seq_file *m, struct vm_struct *v) 3746 { 3747 if (IS_ENABLED(CONFIG_NUMA)) { 3748 unsigned int nr, *counters = m->private; 3749 3750 if (!counters) 3751 return; 3752 3753 if (v->flags & VM_UNINITIALIZED) 3754 return; 3755 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ 3756 smp_rmb(); 3757 3758 memset(counters, 0, nr_node_ids * sizeof(unsigned int)); 3759 3760 for (nr = 0; nr < v->nr_pages; nr++) 3761 counters[page_to_nid(v->pages[nr])]++; 3762 3763 for_each_node_state(nr, N_HIGH_MEMORY) 3764 if (counters[nr]) 3765 seq_printf(m, " N%u=%u", nr, counters[nr]); 3766 } 3767 } 3768 3769 static void show_purge_info(struct seq_file *m) 3770 { 3771 struct vmap_area *va; 3772 3773 spin_lock(&purge_vmap_area_lock); 3774 list_for_each_entry(va, &purge_vmap_area_list, list) { 3775 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", 3776 (void *)va->va_start, (void *)va->va_end, 3777 va->va_end - va->va_start); 3778 } 3779 spin_unlock(&purge_vmap_area_lock); 3780 } 3781 3782 static int s_show(struct seq_file *m, void *p) 3783 { 3784 struct vmap_area *va; 3785 struct vm_struct *v; 3786 3787 va = list_entry(p, struct vmap_area, list); 3788 3789 /* 3790 * s_show can encounter race with remove_vm_area, !vm on behalf 3791 * of vmap area is being tear down or vm_map_ram allocation. 3792 */ 3793 if (!va->vm) { 3794 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", 3795 (void *)va->va_start, (void *)va->va_end, 3796 va->va_end - va->va_start); 3797 3798 return 0; 3799 } 3800 3801 v = va->vm; 3802 3803 seq_printf(m, "0x%pK-0x%pK %7ld", 3804 v->addr, v->addr + v->size, v->size); 3805 3806 if (v->caller) 3807 seq_printf(m, " %pS", v->caller); 3808 3809 if (v->nr_pages) 3810 seq_printf(m, " pages=%d", v->nr_pages); 3811 3812 if (v->phys_addr) 3813 seq_printf(m, " phys=%pa", &v->phys_addr); 3814 3815 if (v->flags & VM_IOREMAP) 3816 seq_puts(m, " ioremap"); 3817 3818 if (v->flags & VM_ALLOC) 3819 seq_puts(m, " vmalloc"); 3820 3821 if (v->flags & VM_MAP) 3822 seq_puts(m, " vmap"); 3823 3824 if (v->flags & VM_USERMAP) 3825 seq_puts(m, " user"); 3826 3827 if (v->flags & VM_DMA_COHERENT) 3828 seq_puts(m, " dma-coherent"); 3829 3830 if (is_vmalloc_addr(v->pages)) 3831 seq_puts(m, " vpages"); 3832 3833 show_numa_info(m, v); 3834 seq_putc(m, '\n'); 3835 3836 /* 3837 * As a final step, dump "unpurged" areas. 3838 */ 3839 if (list_is_last(&va->list, &vmap_area_list)) 3840 show_purge_info(m); 3841 3842 return 0; 3843 } 3844 3845 static const struct seq_operations vmalloc_op = { 3846 .start = s_start, 3847 .next = s_next, 3848 .stop = s_stop, 3849 .show = s_show, 3850 }; 3851 3852 static int __init proc_vmalloc_init(void) 3853 { 3854 if (IS_ENABLED(CONFIG_NUMA)) 3855 proc_create_seq_private("vmallocinfo", 0400, NULL, 3856 &vmalloc_op, 3857 nr_node_ids * sizeof(unsigned int), NULL); 3858 else 3859 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op); 3860 return 0; 3861 } 3862 module_init(proc_vmalloc_init); 3863 3864 #endif 3865