1 // SPDX-License-Identifier: GPL-2.0-only
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
11 #include <linux/vmalloc.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>
29 #include <linux/rcupdate.h>
30 #include <linux/pfn.h>
31 #include <linux/kmemleak.h>
32 #include <linux/atomic.h>
33 #include <linux/compiler.h>
34 #include <linux/memcontrol.h>
35 #include <linux/llist.h>
36 #include <linux/uio.h>
37 #include <linux/bitops.h>
38 #include <linux/rbtree_augmented.h>
39 #include <linux/overflow.h>
40 #include <linux/pgtable.h>
41 #include <linux/hugetlb.h>
42 #include <linux/sched/mm.h>
43 #include <asm/tlbflush.h>
44 #include <asm/shmparam.h>
46 #define CREATE_TRACE_POINTS
47 #include <trace/events/vmalloc.h>
50 #include "pgalloc-track.h"
52 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
53 static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1;
55 static int __init set_nohugeiomap(char *str)
57 ioremap_max_page_shift = PAGE_SHIFT;
60 early_param("nohugeiomap", set_nohugeiomap);
61 #else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
62 static const unsigned int ioremap_max_page_shift = PAGE_SHIFT;
63 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
65 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
66 static bool __ro_after_init vmap_allow_huge = true;
68 static int __init set_nohugevmalloc(char *str)
70 vmap_allow_huge = false;
73 early_param("nohugevmalloc", set_nohugevmalloc);
74 #else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
75 static const bool vmap_allow_huge = false;
76 #endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
78 bool is_vmalloc_addr(const void *x)
80 unsigned long addr = (unsigned long)kasan_reset_tag(x);
82 return addr >= VMALLOC_START && addr < VMALLOC_END;
84 EXPORT_SYMBOL(is_vmalloc_addr);
86 struct vfree_deferred {
87 struct llist_head list;
88 struct work_struct wq;
90 static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
92 /*** Page table manipulation functions ***/
93 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
94 phys_addr_t phys_addr, pgprot_t prot,
95 unsigned int max_page_shift, pgtbl_mod_mask *mask)
99 unsigned long size = PAGE_SIZE;
101 pfn = phys_addr >> PAGE_SHIFT;
102 pte = pte_alloc_kernel_track(pmd, addr, mask);
106 BUG_ON(!pte_none(ptep_get(pte)));
108 #ifdef CONFIG_HUGETLB_PAGE
109 size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
110 if (size != PAGE_SIZE) {
111 pte_t entry = pfn_pte(pfn, prot);
113 entry = arch_make_huge_pte(entry, ilog2(size), 0);
114 set_huge_pte_at(&init_mm, addr, pte, entry, size);
115 pfn += PFN_DOWN(size);
119 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
121 } while (pte += PFN_DOWN(size), addr += size, addr != end);
122 *mask |= PGTBL_PTE_MODIFIED;
126 static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
127 phys_addr_t phys_addr, pgprot_t prot,
128 unsigned int max_page_shift)
130 if (max_page_shift < PMD_SHIFT)
133 if (!arch_vmap_pmd_supported(prot))
136 if ((end - addr) != PMD_SIZE)
139 if (!IS_ALIGNED(addr, PMD_SIZE))
142 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
145 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
148 return pmd_set_huge(pmd, phys_addr, prot);
151 static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
152 phys_addr_t phys_addr, pgprot_t prot,
153 unsigned int max_page_shift, pgtbl_mod_mask *mask)
158 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
162 next = pmd_addr_end(addr, end);
164 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
166 *mask |= PGTBL_PMD_MODIFIED;
170 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
172 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
176 static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
177 phys_addr_t phys_addr, pgprot_t prot,
178 unsigned int max_page_shift)
180 if (max_page_shift < PUD_SHIFT)
183 if (!arch_vmap_pud_supported(prot))
186 if ((end - addr) != PUD_SIZE)
189 if (!IS_ALIGNED(addr, PUD_SIZE))
192 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
195 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
198 return pud_set_huge(pud, phys_addr, prot);
201 static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
202 phys_addr_t phys_addr, pgprot_t prot,
203 unsigned int max_page_shift, pgtbl_mod_mask *mask)
208 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
212 next = pud_addr_end(addr, end);
214 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
216 *mask |= PGTBL_PUD_MODIFIED;
220 if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
221 max_page_shift, mask))
223 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
227 static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
228 phys_addr_t phys_addr, pgprot_t prot,
229 unsigned int max_page_shift)
231 if (max_page_shift < P4D_SHIFT)
234 if (!arch_vmap_p4d_supported(prot))
237 if ((end - addr) != P4D_SIZE)
240 if (!IS_ALIGNED(addr, P4D_SIZE))
243 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
246 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
249 return p4d_set_huge(p4d, phys_addr, prot);
252 static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
253 phys_addr_t phys_addr, pgprot_t prot,
254 unsigned int max_page_shift, pgtbl_mod_mask *mask)
259 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
263 next = p4d_addr_end(addr, end);
265 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
267 *mask |= PGTBL_P4D_MODIFIED;
271 if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
272 max_page_shift, mask))
274 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
278 static int vmap_range_noflush(unsigned long addr, unsigned long end,
279 phys_addr_t phys_addr, pgprot_t prot,
280 unsigned int max_page_shift)
286 pgtbl_mod_mask mask = 0;
292 pgd = pgd_offset_k(addr);
294 next = pgd_addr_end(addr, end);
295 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
296 max_page_shift, &mask);
299 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
301 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
302 arch_sync_kernel_mappings(start, end);
307 int vmap_page_range(unsigned long addr, unsigned long end,
308 phys_addr_t phys_addr, pgprot_t prot)
312 err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot),
313 ioremap_max_page_shift);
314 flush_cache_vmap(addr, end);
316 err = kmsan_ioremap_page_range(addr, end, phys_addr, prot,
317 ioremap_max_page_shift);
321 int ioremap_page_range(unsigned long addr, unsigned long end,
322 phys_addr_t phys_addr, pgprot_t prot)
324 struct vm_struct *area;
326 area = find_vm_area((void *)addr);
327 if (!area || !(area->flags & VM_IOREMAP)) {
328 WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr);
331 if (addr != (unsigned long)area->addr ||
332 (void *)end != area->addr + get_vm_area_size(area)) {
333 WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n",
334 addr, end, (long)area->addr,
335 (long)area->addr + get_vm_area_size(area));
338 return vmap_page_range(addr, end, phys_addr, prot);
341 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
342 pgtbl_mod_mask *mask)
346 pte = pte_offset_kernel(pmd, addr);
348 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
349 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
350 } while (pte++, addr += PAGE_SIZE, addr != end);
351 *mask |= PGTBL_PTE_MODIFIED;
354 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
355 pgtbl_mod_mask *mask)
361 pmd = pmd_offset(pud, addr);
363 next = pmd_addr_end(addr, end);
365 cleared = pmd_clear_huge(pmd);
366 if (cleared || pmd_bad(*pmd))
367 *mask |= PGTBL_PMD_MODIFIED;
371 if (pmd_none_or_clear_bad(pmd))
373 vunmap_pte_range(pmd, addr, next, mask);
376 } while (pmd++, addr = next, addr != end);
379 static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
380 pgtbl_mod_mask *mask)
386 pud = pud_offset(p4d, addr);
388 next = pud_addr_end(addr, end);
390 cleared = pud_clear_huge(pud);
391 if (cleared || pud_bad(*pud))
392 *mask |= PGTBL_PUD_MODIFIED;
396 if (pud_none_or_clear_bad(pud))
398 vunmap_pmd_range(pud, addr, next, mask);
399 } while (pud++, addr = next, addr != end);
402 static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
403 pgtbl_mod_mask *mask)
408 p4d = p4d_offset(pgd, addr);
410 next = p4d_addr_end(addr, end);
414 *mask |= PGTBL_P4D_MODIFIED;
416 if (p4d_none_or_clear_bad(p4d))
418 vunmap_pud_range(p4d, addr, next, mask);
419 } while (p4d++, addr = next, addr != end);
423 * vunmap_range_noflush is similar to vunmap_range, but does not
424 * flush caches or TLBs.
426 * The caller is responsible for calling flush_cache_vmap() before calling
427 * this function, and flush_tlb_kernel_range after it has returned
428 * successfully (and before the addresses are expected to cause a page fault
429 * or be re-mapped for something else, if TLB flushes are being delayed or
432 * This is an internal function only. Do not use outside mm/.
434 void __vunmap_range_noflush(unsigned long start, unsigned long end)
438 unsigned long addr = start;
439 pgtbl_mod_mask mask = 0;
442 pgd = pgd_offset_k(addr);
444 next = pgd_addr_end(addr, end);
446 mask |= PGTBL_PGD_MODIFIED;
447 if (pgd_none_or_clear_bad(pgd))
449 vunmap_p4d_range(pgd, addr, next, &mask);
450 } while (pgd++, addr = next, addr != end);
452 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
453 arch_sync_kernel_mappings(start, end);
456 void vunmap_range_noflush(unsigned long start, unsigned long end)
458 kmsan_vunmap_range_noflush(start, end);
459 __vunmap_range_noflush(start, end);
463 * vunmap_range - unmap kernel virtual addresses
464 * @addr: start of the VM area to unmap
465 * @end: end of the VM area to unmap (non-inclusive)
467 * Clears any present PTEs in the virtual address range, flushes TLBs and
468 * caches. Any subsequent access to the address before it has been re-mapped
471 void vunmap_range(unsigned long addr, unsigned long end)
473 flush_cache_vunmap(addr, end);
474 vunmap_range_noflush(addr, end);
475 flush_tlb_kernel_range(addr, end);
478 static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
479 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
480 pgtbl_mod_mask *mask)
485 * nr is a running index into the array which helps higher level
486 * callers keep track of where we're up to.
489 pte = pte_alloc_kernel_track(pmd, addr, mask);
493 struct page *page = pages[*nr];
495 if (WARN_ON(!pte_none(ptep_get(pte))))
499 if (WARN_ON(!pfn_valid(page_to_pfn(page))))
502 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
504 } while (pte++, addr += PAGE_SIZE, addr != end);
505 *mask |= PGTBL_PTE_MODIFIED;
509 static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
510 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
511 pgtbl_mod_mask *mask)
516 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
520 next = pmd_addr_end(addr, end);
521 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
523 } while (pmd++, addr = next, addr != end);
527 static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
528 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
529 pgtbl_mod_mask *mask)
534 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
538 next = pud_addr_end(addr, end);
539 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
541 } while (pud++, addr = next, addr != end);
545 static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
546 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
547 pgtbl_mod_mask *mask)
552 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
556 next = p4d_addr_end(addr, end);
557 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
559 } while (p4d++, addr = next, addr != end);
563 static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
564 pgprot_t prot, struct page **pages)
566 unsigned long start = addr;
571 pgtbl_mod_mask mask = 0;
574 pgd = pgd_offset_k(addr);
576 next = pgd_addr_end(addr, end);
578 mask |= PGTBL_PGD_MODIFIED;
579 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
582 } while (pgd++, addr = next, addr != end);
584 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
585 arch_sync_kernel_mappings(start, end);
591 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
594 * The caller is responsible for calling flush_cache_vmap() after this
595 * function returns successfully and before the addresses are accessed.
597 * This is an internal function only. Do not use outside mm/.
599 int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
600 pgprot_t prot, struct page **pages, unsigned int page_shift)
602 unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
604 WARN_ON(page_shift < PAGE_SHIFT);
606 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
607 page_shift == PAGE_SHIFT)
608 return vmap_small_pages_range_noflush(addr, end, prot, pages);
610 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
613 err = vmap_range_noflush(addr, addr + (1UL << page_shift),
614 page_to_phys(pages[i]), prot,
619 addr += 1UL << page_shift;
625 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
626 pgprot_t prot, struct page **pages, unsigned int page_shift)
628 int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages,
633 return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
637 * vmap_pages_range - map pages to a kernel virtual address
638 * @addr: start of the VM area to map
639 * @end: end of the VM area to map (non-inclusive)
640 * @prot: page protection flags to use
641 * @pages: pages to map (always PAGE_SIZE pages)
642 * @page_shift: maximum shift that the pages may be mapped with, @pages must
643 * be aligned and contiguous up to at least this shift.
646 * 0 on success, -errno on failure.
648 static int vmap_pages_range(unsigned long addr, unsigned long end,
649 pgprot_t prot, struct page **pages, unsigned int page_shift)
653 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
654 flush_cache_vmap(addr, end);
658 static int check_sparse_vm_area(struct vm_struct *area, unsigned long start,
662 if (WARN_ON_ONCE(area->flags & VM_FLUSH_RESET_PERMS))
664 if (WARN_ON_ONCE(area->flags & VM_NO_GUARD))
666 if (WARN_ON_ONCE(!(area->flags & VM_SPARSE)))
668 if ((end - start) >> PAGE_SHIFT > totalram_pages())
670 if (start < (unsigned long)area->addr ||
671 (void *)end > area->addr + get_vm_area_size(area))
677 * vm_area_map_pages - map pages inside given sparse vm_area
679 * @start: start address inside vm_area
680 * @end: end address inside vm_area
681 * @pages: pages to map (always PAGE_SIZE pages)
683 int vm_area_map_pages(struct vm_struct *area, unsigned long start,
684 unsigned long end, struct page **pages)
688 err = check_sparse_vm_area(area, start, end);
692 return vmap_pages_range(start, end, PAGE_KERNEL, pages, PAGE_SHIFT);
696 * vm_area_unmap_pages - unmap pages inside given sparse vm_area
698 * @start: start address inside vm_area
699 * @end: end address inside vm_area
701 void vm_area_unmap_pages(struct vm_struct *area, unsigned long start,
704 if (check_sparse_vm_area(area, start, end))
707 vunmap_range(start, end);
710 int is_vmalloc_or_module_addr(const void *x)
713 * ARM, x86-64 and sparc64 put modules in a special place,
714 * and fall back on vmalloc() if that fails. Others
715 * just put it in the vmalloc space.
717 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
718 unsigned long addr = (unsigned long)kasan_reset_tag(x);
719 if (addr >= MODULES_VADDR && addr < MODULES_END)
722 return is_vmalloc_addr(x);
724 EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr);
727 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
728 * return the tail page that corresponds to the base page address, which
729 * matches small vmap mappings.
731 struct page *vmalloc_to_page(const void *vmalloc_addr)
733 unsigned long addr = (unsigned long) vmalloc_addr;
734 struct page *page = NULL;
735 pgd_t *pgd = pgd_offset_k(addr);
742 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
743 * architectures that do not vmalloc module space
745 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
749 if (WARN_ON_ONCE(pgd_leaf(*pgd)))
750 return NULL; /* XXX: no allowance for huge pgd */
751 if (WARN_ON_ONCE(pgd_bad(*pgd)))
754 p4d = p4d_offset(pgd, addr);
758 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
759 if (WARN_ON_ONCE(p4d_bad(*p4d)))
762 pud = pud_offset(p4d, addr);
766 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
767 if (WARN_ON_ONCE(pud_bad(*pud)))
770 pmd = pmd_offset(pud, addr);
774 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
775 if (WARN_ON_ONCE(pmd_bad(*pmd)))
778 ptep = pte_offset_kernel(pmd, addr);
779 pte = ptep_get(ptep);
780 if (pte_present(pte))
781 page = pte_page(pte);
785 EXPORT_SYMBOL(vmalloc_to_page);
788 * Map a vmalloc()-space virtual address to the physical page frame number.
790 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
792 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
794 EXPORT_SYMBOL(vmalloc_to_pfn);
797 /*** Global kva allocator ***/
799 #define DEBUG_AUGMENT_PROPAGATE_CHECK 0
800 #define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
803 static DEFINE_SPINLOCK(vmap_area_lock);
804 static DEFINE_SPINLOCK(free_vmap_area_lock);
805 /* Export for kexec only */
806 LIST_HEAD(vmap_area_list);
807 static struct rb_root vmap_area_root = RB_ROOT;
808 static bool vmap_initialized __read_mostly;
810 static struct rb_root purge_vmap_area_root = RB_ROOT;
811 static LIST_HEAD(purge_vmap_area_list);
812 static DEFINE_SPINLOCK(purge_vmap_area_lock);
815 * This kmem_cache is used for vmap_area objects. Instead of
816 * allocating from slab we reuse an object from this cache to
817 * make things faster. Especially in "no edge" splitting of
820 static struct kmem_cache *vmap_area_cachep;
823 * This linked list is used in pair with free_vmap_area_root.
824 * It gives O(1) access to prev/next to perform fast coalescing.
826 static LIST_HEAD(free_vmap_area_list);
829 * This augment red-black tree represents the free vmap space.
830 * All vmap_area objects in this tree are sorted by va->va_start
831 * address. It is used for allocation and merging when a vmap
832 * object is released.
834 * Each vmap_area node contains a maximum available free block
835 * of its sub-tree, right or left. Therefore it is possible to
836 * find a lowest match of free area.
838 static struct rb_root free_vmap_area_root = RB_ROOT;
841 * Preload a CPU with one object for "no edge" split case. The
842 * aim is to get rid of allocations from the atomic context, thus
843 * to use more permissive allocation masks.
845 static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
847 static __always_inline unsigned long
848 va_size(struct vmap_area *va)
850 return (va->va_end - va->va_start);
853 static __always_inline unsigned long
854 get_subtree_max_size(struct rb_node *node)
856 struct vmap_area *va;
858 va = rb_entry_safe(node, struct vmap_area, rb_node);
859 return va ? va->subtree_max_size : 0;
862 RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
863 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
865 static void reclaim_and_purge_vmap_areas(void);
866 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
867 static void drain_vmap_area_work(struct work_struct *work);
868 static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work);
870 static atomic_long_t nr_vmalloc_pages;
872 unsigned long vmalloc_nr_pages(void)
874 return atomic_long_read(&nr_vmalloc_pages);
877 /* Look up the first VA which satisfies addr < va_end, NULL if none. */
878 static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
880 struct vmap_area *va = NULL;
881 struct rb_node *n = vmap_area_root.rb_node;
883 addr = (unsigned long)kasan_reset_tag((void *)addr);
886 struct vmap_area *tmp;
888 tmp = rb_entry(n, struct vmap_area, rb_node);
889 if (tmp->va_end > addr) {
891 if (tmp->va_start <= addr)
902 static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root)
904 struct rb_node *n = root->rb_node;
906 addr = (unsigned long)kasan_reset_tag((void *)addr);
909 struct vmap_area *va;
911 va = rb_entry(n, struct vmap_area, rb_node);
912 if (addr < va->va_start)
914 else if (addr >= va->va_end)
924 * This function returns back addresses of parent node
925 * and its left or right link for further processing.
927 * Otherwise NULL is returned. In that case all further
928 * steps regarding inserting of conflicting overlap range
929 * have to be declined and actually considered as a bug.
931 static __always_inline struct rb_node **
932 find_va_links(struct vmap_area *va,
933 struct rb_root *root, struct rb_node *from,
934 struct rb_node **parent)
936 struct vmap_area *tmp_va;
937 struct rb_node **link;
940 link = &root->rb_node;
941 if (unlikely(!*link)) {
950 * Go to the bottom of the tree. When we hit the last point
951 * we end up with parent rb_node and correct direction, i name
952 * it link, where the new va->rb_node will be attached to.
955 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
958 * During the traversal we also do some sanity check.
959 * Trigger the BUG() if there are sides(left/right)
962 if (va->va_end <= tmp_va->va_start)
963 link = &(*link)->rb_left;
964 else if (va->va_start >= tmp_va->va_end)
965 link = &(*link)->rb_right;
967 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
968 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
974 *parent = &tmp_va->rb_node;
978 static __always_inline struct list_head *
979 get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
981 struct list_head *list;
983 if (unlikely(!parent))
985 * The red-black tree where we try to find VA neighbors
986 * before merging or inserting is empty, i.e. it means
987 * there is no free vmap space. Normally it does not
988 * happen but we handle this case anyway.
992 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
993 return (&parent->rb_right == link ? list->next : list);
996 static __always_inline void
997 __link_va(struct vmap_area *va, struct rb_root *root,
998 struct rb_node *parent, struct rb_node **link,
999 struct list_head *head, bool augment)
1002 * VA is still not in the list, but we can
1003 * identify its future previous list_head node.
1005 if (likely(parent)) {
1006 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
1007 if (&parent->rb_right != link)
1011 /* Insert to the rb-tree */
1012 rb_link_node(&va->rb_node, parent, link);
1015 * Some explanation here. Just perform simple insertion
1016 * to the tree. We do not set va->subtree_max_size to
1017 * its current size before calling rb_insert_augmented().
1018 * It is because we populate the tree from the bottom
1019 * to parent levels when the node _is_ in the tree.
1021 * Therefore we set subtree_max_size to zero after insertion,
1022 * to let __augment_tree_propagate_from() puts everything to
1023 * the correct order later on.
1025 rb_insert_augmented(&va->rb_node,
1026 root, &free_vmap_area_rb_augment_cb);
1027 va->subtree_max_size = 0;
1029 rb_insert_color(&va->rb_node, root);
1032 /* Address-sort this list */
1033 list_add(&va->list, head);
1036 static __always_inline void
1037 link_va(struct vmap_area *va, struct rb_root *root,
1038 struct rb_node *parent, struct rb_node **link,
1039 struct list_head *head)
1041 __link_va(va, root, parent, link, head, false);
1044 static __always_inline void
1045 link_va_augment(struct vmap_area *va, struct rb_root *root,
1046 struct rb_node *parent, struct rb_node **link,
1047 struct list_head *head)
1049 __link_va(va, root, parent, link, head, true);
1052 static __always_inline void
1053 __unlink_va(struct vmap_area *va, struct rb_root *root, bool augment)
1055 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
1059 rb_erase_augmented(&va->rb_node,
1060 root, &free_vmap_area_rb_augment_cb);
1062 rb_erase(&va->rb_node, root);
1064 list_del_init(&va->list);
1065 RB_CLEAR_NODE(&va->rb_node);
1068 static __always_inline void
1069 unlink_va(struct vmap_area *va, struct rb_root *root)
1071 __unlink_va(va, root, false);
1074 static __always_inline void
1075 unlink_va_augment(struct vmap_area *va, struct rb_root *root)
1077 __unlink_va(va, root, true);
1080 #if DEBUG_AUGMENT_PROPAGATE_CHECK
1082 * Gets called when remove the node and rotate.
1084 static __always_inline unsigned long
1085 compute_subtree_max_size(struct vmap_area *va)
1087 return max3(va_size(va),
1088 get_subtree_max_size(va->rb_node.rb_left),
1089 get_subtree_max_size(va->rb_node.rb_right));
1093 augment_tree_propagate_check(void)
1095 struct vmap_area *va;
1096 unsigned long computed_size;
1098 list_for_each_entry(va, &free_vmap_area_list, list) {
1099 computed_size = compute_subtree_max_size(va);
1100 if (computed_size != va->subtree_max_size)
1101 pr_emerg("tree is corrupted: %lu, %lu\n",
1102 va_size(va), va->subtree_max_size);
1108 * This function populates subtree_max_size from bottom to upper
1109 * levels starting from VA point. The propagation must be done
1110 * when VA size is modified by changing its va_start/va_end. Or
1111 * in case of newly inserting of VA to the tree.
1113 * It means that __augment_tree_propagate_from() must be called:
1114 * - After VA has been inserted to the tree(free path);
1115 * - After VA has been shrunk(allocation path);
1116 * - After VA has been increased(merging path).
1118 * Please note that, it does not mean that upper parent nodes
1119 * and their subtree_max_size are recalculated all the time up
1128 * For example if we modify the node 4, shrinking it to 2, then
1129 * no any modification is required. If we shrink the node 2 to 1
1130 * its subtree_max_size is updated only, and set to 1. If we shrink
1131 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
1132 * node becomes 4--6.
1134 static __always_inline void
1135 augment_tree_propagate_from(struct vmap_area *va)
1138 * Populate the tree from bottom towards the root until
1139 * the calculated maximum available size of checked node
1140 * is equal to its current one.
1142 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
1144 #if DEBUG_AUGMENT_PROPAGATE_CHECK
1145 augment_tree_propagate_check();
1150 insert_vmap_area(struct vmap_area *va,
1151 struct rb_root *root, struct list_head *head)
1153 struct rb_node **link;
1154 struct rb_node *parent;
1156 link = find_va_links(va, root, NULL, &parent);
1158 link_va(va, root, parent, link, head);
1162 insert_vmap_area_augment(struct vmap_area *va,
1163 struct rb_node *from, struct rb_root *root,
1164 struct list_head *head)
1166 struct rb_node **link;
1167 struct rb_node *parent;
1170 link = find_va_links(va, NULL, from, &parent);
1172 link = find_va_links(va, root, NULL, &parent);
1175 link_va_augment(va, root, parent, link, head);
1176 augment_tree_propagate_from(va);
1181 * Merge de-allocated chunk of VA memory with previous
1182 * and next free blocks. If coalesce is not done a new
1183 * free area is inserted. If VA has been merged, it is
1186 * Please note, it can return NULL in case of overlap
1187 * ranges, followed by WARN() report. Despite it is a
1188 * buggy behaviour, a system can be alive and keep
1191 static __always_inline struct vmap_area *
1192 __merge_or_add_vmap_area(struct vmap_area *va,
1193 struct rb_root *root, struct list_head *head, bool augment)
1195 struct vmap_area *sibling;
1196 struct list_head *next;
1197 struct rb_node **link;
1198 struct rb_node *parent;
1199 bool merged = false;
1202 * Find a place in the tree where VA potentially will be
1203 * inserted, unless it is merged with its sibling/siblings.
1205 link = find_va_links(va, root, NULL, &parent);
1210 * Get next node of VA to check if merging can be done.
1212 next = get_va_next_sibling(parent, link);
1213 if (unlikely(next == NULL))
1219 * |<------VA------>|<-----Next----->|
1224 sibling = list_entry(next, struct vmap_area, list);
1225 if (sibling->va_start == va->va_end) {
1226 sibling->va_start = va->va_start;
1228 /* Free vmap_area object. */
1229 kmem_cache_free(vmap_area_cachep, va);
1231 /* Point to the new merged area. */
1240 * |<-----Prev----->|<------VA------>|
1244 if (next->prev != head) {
1245 sibling = list_entry(next->prev, struct vmap_area, list);
1246 if (sibling->va_end == va->va_start) {
1248 * If both neighbors are coalesced, it is important
1249 * to unlink the "next" node first, followed by merging
1250 * with "previous" one. Otherwise the tree might not be
1251 * fully populated if a sibling's augmented value is
1252 * "normalized" because of rotation operations.
1255 __unlink_va(va, root, augment);
1257 sibling->va_end = va->va_end;
1259 /* Free vmap_area object. */
1260 kmem_cache_free(vmap_area_cachep, va);
1262 /* Point to the new merged area. */
1270 __link_va(va, root, parent, link, head, augment);
1275 static __always_inline struct vmap_area *
1276 merge_or_add_vmap_area(struct vmap_area *va,
1277 struct rb_root *root, struct list_head *head)
1279 return __merge_or_add_vmap_area(va, root, head, false);
1282 static __always_inline struct vmap_area *
1283 merge_or_add_vmap_area_augment(struct vmap_area *va,
1284 struct rb_root *root, struct list_head *head)
1286 va = __merge_or_add_vmap_area(va, root, head, true);
1288 augment_tree_propagate_from(va);
1293 static __always_inline bool
1294 is_within_this_va(struct vmap_area *va, unsigned long size,
1295 unsigned long align, unsigned long vstart)
1297 unsigned long nva_start_addr;
1299 if (va->va_start > vstart)
1300 nva_start_addr = ALIGN(va->va_start, align);
1302 nva_start_addr = ALIGN(vstart, align);
1304 /* Can be overflowed due to big size or alignment. */
1305 if (nva_start_addr + size < nva_start_addr ||
1306 nva_start_addr < vstart)
1309 return (nva_start_addr + size <= va->va_end);
1313 * Find the first free block(lowest start address) in the tree,
1314 * that will accomplish the request corresponding to passing
1315 * parameters. Please note, with an alignment bigger than PAGE_SIZE,
1316 * a search length is adjusted to account for worst case alignment
1319 static __always_inline struct vmap_area *
1320 find_vmap_lowest_match(struct rb_root *root, unsigned long size,
1321 unsigned long align, unsigned long vstart, bool adjust_search_size)
1323 struct vmap_area *va;
1324 struct rb_node *node;
1325 unsigned long length;
1327 /* Start from the root. */
1328 node = root->rb_node;
1330 /* Adjust the search size for alignment overhead. */
1331 length = adjust_search_size ? size + align - 1 : size;
1334 va = rb_entry(node, struct vmap_area, rb_node);
1336 if (get_subtree_max_size(node->rb_left) >= length &&
1337 vstart < va->va_start) {
1338 node = node->rb_left;
1340 if (is_within_this_va(va, size, align, vstart))
1344 * Does not make sense to go deeper towards the right
1345 * sub-tree if it does not have a free block that is
1346 * equal or bigger to the requested search length.
1348 if (get_subtree_max_size(node->rb_right) >= length) {
1349 node = node->rb_right;
1354 * OK. We roll back and find the first right sub-tree,
1355 * that will satisfy the search criteria. It can happen
1356 * due to "vstart" restriction or an alignment overhead
1357 * that is bigger then PAGE_SIZE.
1359 while ((node = rb_parent(node))) {
1360 va = rb_entry(node, struct vmap_area, rb_node);
1361 if (is_within_this_va(va, size, align, vstart))
1364 if (get_subtree_max_size(node->rb_right) >= length &&
1365 vstart <= va->va_start) {
1367 * Shift the vstart forward. Please note, we update it with
1368 * parent's start address adding "1" because we do not want
1369 * to enter same sub-tree after it has already been checked
1370 * and no suitable free block found there.
1372 vstart = va->va_start + 1;
1373 node = node->rb_right;
1383 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1384 #include <linux/random.h>
1386 static struct vmap_area *
1387 find_vmap_lowest_linear_match(struct list_head *head, unsigned long size,
1388 unsigned long align, unsigned long vstart)
1390 struct vmap_area *va;
1392 list_for_each_entry(va, head, list) {
1393 if (!is_within_this_va(va, size, align, vstart))
1403 find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head,
1404 unsigned long size, unsigned long align)
1406 struct vmap_area *va_1, *va_2;
1407 unsigned long vstart;
1410 get_random_bytes(&rnd, sizeof(rnd));
1411 vstart = VMALLOC_START + rnd;
1413 va_1 = find_vmap_lowest_match(root, size, align, vstart, false);
1414 va_2 = find_vmap_lowest_linear_match(head, size, align, vstart);
1417 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1418 va_1, va_2, vstart);
1424 FL_FIT_TYPE = 1, /* full fit */
1425 LE_FIT_TYPE = 2, /* left edge fit */
1426 RE_FIT_TYPE = 3, /* right edge fit */
1427 NE_FIT_TYPE = 4 /* no edge fit */
1430 static __always_inline enum fit_type
1431 classify_va_fit_type(struct vmap_area *va,
1432 unsigned long nva_start_addr, unsigned long size)
1436 /* Check if it is within VA. */
1437 if (nva_start_addr < va->va_start ||
1438 nva_start_addr + size > va->va_end)
1442 if (va->va_start == nva_start_addr) {
1443 if (va->va_end == nva_start_addr + size)
1447 } else if (va->va_end == nva_start_addr + size) {
1456 static __always_inline int
1457 adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
1458 struct vmap_area *va, unsigned long nva_start_addr,
1461 struct vmap_area *lva = NULL;
1462 enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
1464 if (type == FL_FIT_TYPE) {
1466 * No need to split VA, it fully fits.
1472 unlink_va_augment(va, root);
1473 kmem_cache_free(vmap_area_cachep, va);
1474 } else if (type == LE_FIT_TYPE) {
1476 * Split left edge of fit VA.
1482 va->va_start += size;
1483 } else if (type == RE_FIT_TYPE) {
1485 * Split right edge of fit VA.
1491 va->va_end = nva_start_addr;
1492 } else if (type == NE_FIT_TYPE) {
1494 * Split no edge of fit VA.
1500 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
1501 if (unlikely(!lva)) {
1503 * For percpu allocator we do not do any pre-allocation
1504 * and leave it as it is. The reason is it most likely
1505 * never ends up with NE_FIT_TYPE splitting. In case of
1506 * percpu allocations offsets and sizes are aligned to
1507 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1508 * are its main fitting cases.
1510 * There are a few exceptions though, as an example it is
1511 * a first allocation (early boot up) when we have "one"
1512 * big free space that has to be split.
1514 * Also we can hit this path in case of regular "vmap"
1515 * allocations, if "this" current CPU was not preloaded.
1516 * See the comment in alloc_vmap_area() why. If so, then
1517 * GFP_NOWAIT is used instead to get an extra object for
1518 * split purpose. That is rare and most time does not
1521 * What happens if an allocation gets failed. Basically,
1522 * an "overflow" path is triggered to purge lazily freed
1523 * areas to free some memory, then, the "retry" path is
1524 * triggered to repeat one more time. See more details
1525 * in alloc_vmap_area() function.
1527 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
1533 * Build the remainder.
1535 lva->va_start = va->va_start;
1536 lva->va_end = nva_start_addr;
1539 * Shrink this VA to remaining size.
1541 va->va_start = nva_start_addr + size;
1546 if (type != FL_FIT_TYPE) {
1547 augment_tree_propagate_from(va);
1549 if (lva) /* type == NE_FIT_TYPE */
1550 insert_vmap_area_augment(lva, &va->rb_node, root, head);
1557 * Returns a start address of the newly allocated area, if success.
1558 * Otherwise a vend is returned that indicates failure.
1560 static __always_inline unsigned long
1561 __alloc_vmap_area(struct rb_root *root, struct list_head *head,
1562 unsigned long size, unsigned long align,
1563 unsigned long vstart, unsigned long vend)
1565 bool adjust_search_size = true;
1566 unsigned long nva_start_addr;
1567 struct vmap_area *va;
1571 * Do not adjust when:
1572 * a) align <= PAGE_SIZE, because it does not make any sense.
1573 * All blocks(their start addresses) are at least PAGE_SIZE
1575 * b) a short range where a requested size corresponds to exactly
1576 * specified [vstart:vend] interval and an alignment > PAGE_SIZE.
1577 * With adjusted search length an allocation would not succeed.
1579 if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size))
1580 adjust_search_size = false;
1582 va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size);
1586 if (va->va_start > vstart)
1587 nva_start_addr = ALIGN(va->va_start, align);
1589 nva_start_addr = ALIGN(vstart, align);
1591 /* Check the "vend" restriction. */
1592 if (nva_start_addr + size > vend)
1595 /* Update the free vmap_area. */
1596 ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
1597 if (WARN_ON_ONCE(ret))
1600 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1601 find_vmap_lowest_match_check(root, head, size, align);
1604 return nva_start_addr;
1608 * Free a region of KVA allocated by alloc_vmap_area
1610 static void free_vmap_area(struct vmap_area *va)
1613 * Remove from the busy tree/list.
1615 spin_lock(&vmap_area_lock);
1616 unlink_va(va, &vmap_area_root);
1617 spin_unlock(&vmap_area_lock);
1620 * Insert/Merge it back to the free tree/list.
1622 spin_lock(&free_vmap_area_lock);
1623 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
1624 spin_unlock(&free_vmap_area_lock);
1628 preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
1630 struct vmap_area *va = NULL;
1633 * Preload this CPU with one extra vmap_area object. It is used
1634 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1635 * a CPU that does an allocation is preloaded.
1637 * We do it in non-atomic context, thus it allows us to use more
1638 * permissive allocation masks to be more stable under low memory
1639 * condition and high memory pressure.
1641 if (!this_cpu_read(ne_fit_preload_node))
1642 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1646 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va))
1647 kmem_cache_free(vmap_area_cachep, va);
1651 * Allocate a region of KVA of the specified size and alignment, within the
1654 static struct vmap_area *alloc_vmap_area(unsigned long size,
1655 unsigned long align,
1656 unsigned long vstart, unsigned long vend,
1657 int node, gfp_t gfp_mask,
1658 unsigned long va_flags)
1660 struct vmap_area *va;
1661 unsigned long freed;
1666 if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
1667 return ERR_PTR(-EINVAL);
1669 if (unlikely(!vmap_initialized))
1670 return ERR_PTR(-EBUSY);
1673 gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
1675 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1677 return ERR_PTR(-ENOMEM);
1680 * Only scan the relevant parts containing pointers to other objects
1681 * to avoid false negatives.
1683 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
1686 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
1687 addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list,
1688 size, align, vstart, vend);
1689 spin_unlock(&free_vmap_area_lock);
1691 trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend);
1694 * If an allocation fails, the "vend" address is
1695 * returned. Therefore trigger the overflow path.
1697 if (unlikely(addr == vend))
1700 va->va_start = addr;
1701 va->va_end = addr + size;
1703 va->flags = va_flags;
1705 spin_lock(&vmap_area_lock);
1706 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1707 spin_unlock(&vmap_area_lock);
1709 BUG_ON(!IS_ALIGNED(va->va_start, align));
1710 BUG_ON(va->va_start < vstart);
1711 BUG_ON(va->va_end > vend);
1713 ret = kasan_populate_vmalloc(addr, size);
1716 return ERR_PTR(ret);
1723 reclaim_and_purge_vmap_areas();
1729 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
1736 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
1737 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1740 kmem_cache_free(vmap_area_cachep, va);
1741 return ERR_PTR(-EBUSY);
1744 int register_vmap_purge_notifier(struct notifier_block *nb)
1746 return blocking_notifier_chain_register(&vmap_notify_list, nb);
1748 EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
1750 int unregister_vmap_purge_notifier(struct notifier_block *nb)
1752 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
1754 EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
1757 * lazy_max_pages is the maximum amount of virtual address space we gather up
1758 * before attempting to purge with a TLB flush.
1760 * There is a tradeoff here: a larger number will cover more kernel page tables
1761 * and take slightly longer to purge, but it will linearly reduce the number of
1762 * global TLB flushes that must be performed. It would seem natural to scale
1763 * this number up linearly with the number of CPUs (because vmapping activity
1764 * could also scale linearly with the number of CPUs), however it is likely
1765 * that in practice, workloads might be constrained in other ways that mean
1766 * vmap activity will not scale linearly with CPUs. Also, I want to be
1767 * conservative and not introduce a big latency on huge systems, so go with
1768 * a less aggressive log scale. It will still be an improvement over the old
1769 * code, and it will be simple to change the scale factor if we find that it
1770 * becomes a problem on bigger systems.
1772 static unsigned long lazy_max_pages(void)
1776 log = fls(num_online_cpus());
1778 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
1781 static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
1784 * Serialize vmap purging. There is no actual critical section protected
1785 * by this lock, but we want to avoid concurrent calls for performance
1786 * reasons and to make the pcpu_get_vm_areas more deterministic.
1788 static DEFINE_MUTEX(vmap_purge_lock);
1790 /* for per-CPU blocks */
1791 static void purge_fragmented_blocks_allcpus(void);
1794 * Purges all lazily-freed vmap areas.
1796 static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
1798 unsigned long resched_threshold;
1799 unsigned int num_purged_areas = 0;
1800 struct list_head local_purge_list;
1801 struct vmap_area *va, *n_va;
1803 lockdep_assert_held(&vmap_purge_lock);
1805 spin_lock(&purge_vmap_area_lock);
1806 purge_vmap_area_root = RB_ROOT;
1807 list_replace_init(&purge_vmap_area_list, &local_purge_list);
1808 spin_unlock(&purge_vmap_area_lock);
1810 if (unlikely(list_empty(&local_purge_list)))
1814 list_first_entry(&local_purge_list,
1815 struct vmap_area, list)->va_start);
1818 list_last_entry(&local_purge_list,
1819 struct vmap_area, list)->va_end);
1821 flush_tlb_kernel_range(start, end);
1822 resched_threshold = lazy_max_pages() << 1;
1824 spin_lock(&free_vmap_area_lock);
1825 list_for_each_entry_safe(va, n_va, &local_purge_list, list) {
1826 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
1827 unsigned long orig_start = va->va_start;
1828 unsigned long orig_end = va->va_end;
1831 * Finally insert or merge lazily-freed area. It is
1832 * detached and there is no need to "unlink" it from
1835 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root,
1836 &free_vmap_area_list);
1841 if (is_vmalloc_or_module_addr((void *)orig_start))
1842 kasan_release_vmalloc(orig_start, orig_end,
1843 va->va_start, va->va_end);
1845 atomic_long_sub(nr, &vmap_lazy_nr);
1848 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
1849 cond_resched_lock(&free_vmap_area_lock);
1851 spin_unlock(&free_vmap_area_lock);
1854 trace_purge_vmap_area_lazy(start, end, num_purged_areas);
1855 return num_purged_areas > 0;
1859 * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list.
1861 static void reclaim_and_purge_vmap_areas(void)
1864 mutex_lock(&vmap_purge_lock);
1865 purge_fragmented_blocks_allcpus();
1866 __purge_vmap_area_lazy(ULONG_MAX, 0);
1867 mutex_unlock(&vmap_purge_lock);
1870 static void drain_vmap_area_work(struct work_struct *work)
1872 unsigned long nr_lazy;
1875 mutex_lock(&vmap_purge_lock);
1876 __purge_vmap_area_lazy(ULONG_MAX, 0);
1877 mutex_unlock(&vmap_purge_lock);
1879 /* Recheck if further work is required. */
1880 nr_lazy = atomic_long_read(&vmap_lazy_nr);
1881 } while (nr_lazy > lazy_max_pages());
1885 * Free a vmap area, caller ensuring that the area has been unmapped,
1886 * unlinked and flush_cache_vunmap had been called for the correct
1889 static void free_vmap_area_noflush(struct vmap_area *va)
1891 unsigned long nr_lazy_max = lazy_max_pages();
1892 unsigned long va_start = va->va_start;
1893 unsigned long nr_lazy;
1895 if (WARN_ON_ONCE(!list_empty(&va->list)))
1898 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
1899 PAGE_SHIFT, &vmap_lazy_nr);
1902 * Merge or place it to the purge tree/list.
1904 spin_lock(&purge_vmap_area_lock);
1905 merge_or_add_vmap_area(va,
1906 &purge_vmap_area_root, &purge_vmap_area_list);
1907 spin_unlock(&purge_vmap_area_lock);
1909 trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max);
1911 /* After this point, we may free va at any time */
1912 if (unlikely(nr_lazy > nr_lazy_max))
1913 schedule_work(&drain_vmap_work);
1917 * Free and unmap a vmap area
1919 static void free_unmap_vmap_area(struct vmap_area *va)
1921 flush_cache_vunmap(va->va_start, va->va_end);
1922 vunmap_range_noflush(va->va_start, va->va_end);
1923 if (debug_pagealloc_enabled_static())
1924 flush_tlb_kernel_range(va->va_start, va->va_end);
1926 free_vmap_area_noflush(va);
1929 struct vmap_area *find_vmap_area(unsigned long addr)
1931 struct vmap_area *va;
1933 spin_lock(&vmap_area_lock);
1934 va = __find_vmap_area(addr, &vmap_area_root);
1935 spin_unlock(&vmap_area_lock);
1940 static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
1942 struct vmap_area *va;
1944 spin_lock(&vmap_area_lock);
1945 va = __find_vmap_area(addr, &vmap_area_root);
1947 unlink_va(va, &vmap_area_root);
1948 spin_unlock(&vmap_area_lock);
1953 /*** Per cpu kva allocator ***/
1956 * vmap space is limited especially on 32 bit architectures. Ensure there is
1957 * room for at least 16 percpu vmap blocks per CPU.
1960 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1961 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1962 * instead (we just need a rough idea)
1964 #if BITS_PER_LONG == 32
1965 #define VMALLOC_SPACE (128UL*1024*1024)
1967 #define VMALLOC_SPACE (128UL*1024*1024*1024)
1970 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1971 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1972 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1973 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1974 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1975 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1976 #define VMAP_BBMAP_BITS \
1977 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1978 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1979 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1981 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1984 * Purge threshold to prevent overeager purging of fragmented blocks for
1985 * regular operations: Purge if vb->free is less than 1/4 of the capacity.
1987 #define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4)
1989 #define VMAP_RAM 0x1 /* indicates vm_map_ram area*/
1990 #define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/
1991 #define VMAP_FLAGS_MASK 0x3
1993 struct vmap_block_queue {
1995 struct list_head free;
1998 * An xarray requires an extra memory dynamically to
1999 * be allocated. If it is an issue, we can use rb-tree
2002 struct xarray vmap_blocks;
2007 struct vmap_area *va;
2008 unsigned long free, dirty;
2009 DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS);
2010 unsigned long dirty_min, dirty_max; /*< dirty range */
2011 struct list_head free_list;
2012 struct rcu_head rcu_head;
2013 struct list_head purge;
2016 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
2017 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
2020 * In order to fast access to any "vmap_block" associated with a
2021 * specific address, we use a hash.
2023 * A per-cpu vmap_block_queue is used in both ways, to serialize
2024 * an access to free block chains among CPUs(alloc path) and it
2025 * also acts as a vmap_block hash(alloc/free paths). It means we
2026 * overload it, since we already have the per-cpu array which is
2027 * used as a hash table. When used as a hash a 'cpu' passed to
2028 * per_cpu() is not actually a CPU but rather a hash index.
2030 * A hash function is addr_to_vb_xa() which hashes any address
2031 * to a specific index(in a hash) it belongs to. This then uses a
2032 * per_cpu() macro to access an array with generated index.
2039 * 0 10 20 30 40 50 60
2040 * |------|------|------|------|------|------|...<vmap address space>
2041 * CPU0 CPU1 CPU2 CPU0 CPU1 CPU2
2043 * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus
2044 * it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock;
2046 * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus
2047 * it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock;
2049 * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus
2050 * it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock.
2052 * This technique almost always avoids lock contention on insert/remove,
2053 * however xarray spinlocks protect against any contention that remains.
2055 static struct xarray *
2056 addr_to_vb_xa(unsigned long addr)
2058 int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus();
2060 return &per_cpu(vmap_block_queue, index).vmap_blocks;
2064 * We should probably have a fallback mechanism to allocate virtual memory
2065 * out of partially filled vmap blocks. However vmap block sizing should be
2066 * fairly reasonable according to the vmalloc size, so it shouldn't be a
2070 static unsigned long addr_to_vb_idx(unsigned long addr)
2072 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
2073 addr /= VMAP_BLOCK_SIZE;
2077 static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
2081 addr = va_start + (pages_off << PAGE_SHIFT);
2082 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
2083 return (void *)addr;
2087 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
2088 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
2089 * @order: how many 2^order pages should be occupied in newly allocated block
2090 * @gfp_mask: flags for the page level allocator
2092 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
2094 static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
2096 struct vmap_block_queue *vbq;
2097 struct vmap_block *vb;
2098 struct vmap_area *va;
2100 unsigned long vb_idx;
2104 node = numa_node_id();
2106 vb = kmalloc_node(sizeof(struct vmap_block),
2107 gfp_mask & GFP_RECLAIM_MASK, node);
2109 return ERR_PTR(-ENOMEM);
2111 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
2112 VMALLOC_START, VMALLOC_END,
2114 VMAP_RAM|VMAP_BLOCK);
2117 return ERR_CAST(va);
2120 vaddr = vmap_block_vaddr(va->va_start, 0);
2121 spin_lock_init(&vb->lock);
2123 /* At least something should be left free */
2124 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
2125 bitmap_zero(vb->used_map, VMAP_BBMAP_BITS);
2126 vb->free = VMAP_BBMAP_BITS - (1UL << order);
2128 vb->dirty_min = VMAP_BBMAP_BITS;
2130 bitmap_set(vb->used_map, 0, (1UL << order));
2131 INIT_LIST_HEAD(&vb->free_list);
2133 xa = addr_to_vb_xa(va->va_start);
2134 vb_idx = addr_to_vb_idx(va->va_start);
2135 err = xa_insert(xa, vb_idx, vb, gfp_mask);
2139 return ERR_PTR(err);
2142 vbq = raw_cpu_ptr(&vmap_block_queue);
2143 spin_lock(&vbq->lock);
2144 list_add_tail_rcu(&vb->free_list, &vbq->free);
2145 spin_unlock(&vbq->lock);
2150 static void free_vmap_block(struct vmap_block *vb)
2152 struct vmap_block *tmp;
2155 xa = addr_to_vb_xa(vb->va->va_start);
2156 tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start));
2159 spin_lock(&vmap_area_lock);
2160 unlink_va(vb->va, &vmap_area_root);
2161 spin_unlock(&vmap_area_lock);
2163 free_vmap_area_noflush(vb->va);
2164 kfree_rcu(vb, rcu_head);
2167 static bool purge_fragmented_block(struct vmap_block *vb,
2168 struct vmap_block_queue *vbq, struct list_head *purge_list,
2171 if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
2172 vb->dirty == VMAP_BBMAP_BITS)
2175 /* Don't overeagerly purge usable blocks unless requested */
2176 if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD))
2179 /* prevent further allocs after releasing lock */
2180 WRITE_ONCE(vb->free, 0);
2181 /* prevent purging it again */
2182 WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS);
2184 vb->dirty_max = VMAP_BBMAP_BITS;
2185 spin_lock(&vbq->lock);
2186 list_del_rcu(&vb->free_list);
2187 spin_unlock(&vbq->lock);
2188 list_add_tail(&vb->purge, purge_list);
2192 static void free_purged_blocks(struct list_head *purge_list)
2194 struct vmap_block *vb, *n_vb;
2196 list_for_each_entry_safe(vb, n_vb, purge_list, purge) {
2197 list_del(&vb->purge);
2198 free_vmap_block(vb);
2202 static void purge_fragmented_blocks(int cpu)
2205 struct vmap_block *vb;
2206 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2209 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2210 unsigned long free = READ_ONCE(vb->free);
2211 unsigned long dirty = READ_ONCE(vb->dirty);
2213 if (free + dirty != VMAP_BBMAP_BITS ||
2214 dirty == VMAP_BBMAP_BITS)
2217 spin_lock(&vb->lock);
2218 purge_fragmented_block(vb, vbq, &purge, true);
2219 spin_unlock(&vb->lock);
2222 free_purged_blocks(&purge);
2225 static void purge_fragmented_blocks_allcpus(void)
2229 for_each_possible_cpu(cpu)
2230 purge_fragmented_blocks(cpu);
2233 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
2235 struct vmap_block_queue *vbq;
2236 struct vmap_block *vb;
2240 BUG_ON(offset_in_page(size));
2241 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2242 if (WARN_ON(size == 0)) {
2244 * Allocating 0 bytes isn't what caller wants since
2245 * get_order(0) returns funny result. Just warn and terminate
2250 order = get_order(size);
2253 vbq = raw_cpu_ptr(&vmap_block_queue);
2254 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2255 unsigned long pages_off;
2257 if (READ_ONCE(vb->free) < (1UL << order))
2260 spin_lock(&vb->lock);
2261 if (vb->free < (1UL << order)) {
2262 spin_unlock(&vb->lock);
2266 pages_off = VMAP_BBMAP_BITS - vb->free;
2267 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
2268 WRITE_ONCE(vb->free, vb->free - (1UL << order));
2269 bitmap_set(vb->used_map, pages_off, (1UL << order));
2270 if (vb->free == 0) {
2271 spin_lock(&vbq->lock);
2272 list_del_rcu(&vb->free_list);
2273 spin_unlock(&vbq->lock);
2276 spin_unlock(&vb->lock);
2282 /* Allocate new block if nothing was found */
2284 vaddr = new_vmap_block(order, gfp_mask);
2289 static void vb_free(unsigned long addr, unsigned long size)
2291 unsigned long offset;
2293 struct vmap_block *vb;
2296 BUG_ON(offset_in_page(size));
2297 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2299 flush_cache_vunmap(addr, addr + size);
2301 order = get_order(size);
2302 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
2304 xa = addr_to_vb_xa(addr);
2305 vb = xa_load(xa, addr_to_vb_idx(addr));
2307 spin_lock(&vb->lock);
2308 bitmap_clear(vb->used_map, offset, (1UL << order));
2309 spin_unlock(&vb->lock);
2311 vunmap_range_noflush(addr, addr + size);
2313 if (debug_pagealloc_enabled_static())
2314 flush_tlb_kernel_range(addr, addr + size);
2316 spin_lock(&vb->lock);
2318 /* Expand the not yet TLB flushed dirty range */
2319 vb->dirty_min = min(vb->dirty_min, offset);
2320 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
2322 WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order));
2323 if (vb->dirty == VMAP_BBMAP_BITS) {
2325 spin_unlock(&vb->lock);
2326 free_vmap_block(vb);
2328 spin_unlock(&vb->lock);
2331 static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
2333 LIST_HEAD(purge_list);
2336 if (unlikely(!vmap_initialized))
2339 mutex_lock(&vmap_purge_lock);
2341 for_each_possible_cpu(cpu) {
2342 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2343 struct vmap_block *vb;
2347 xa_for_each(&vbq->vmap_blocks, idx, vb) {
2348 spin_lock(&vb->lock);
2351 * Try to purge a fragmented block first. If it's
2352 * not purgeable, check whether there is dirty
2353 * space to be flushed.
2355 if (!purge_fragmented_block(vb, vbq, &purge_list, false) &&
2356 vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
2357 unsigned long va_start = vb->va->va_start;
2360 s = va_start + (vb->dirty_min << PAGE_SHIFT);
2361 e = va_start + (vb->dirty_max << PAGE_SHIFT);
2363 start = min(s, start);
2366 /* Prevent that this is flushed again */
2367 vb->dirty_min = VMAP_BBMAP_BITS;
2372 spin_unlock(&vb->lock);
2376 free_purged_blocks(&purge_list);
2378 if (!__purge_vmap_area_lazy(start, end) && flush)
2379 flush_tlb_kernel_range(start, end);
2380 mutex_unlock(&vmap_purge_lock);
2384 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2386 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2387 * to amortize TLB flushing overheads. What this means is that any page you
2388 * have now, may, in a former life, have been mapped into kernel virtual
2389 * address by the vmap layer and so there might be some CPUs with TLB entries
2390 * still referencing that page (additional to the regular 1:1 kernel mapping).
2392 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2393 * be sure that none of the pages we have control over will have any aliases
2394 * from the vmap layer.
2396 void vm_unmap_aliases(void)
2398 unsigned long start = ULONG_MAX, end = 0;
2401 _vm_unmap_aliases(start, end, flush);
2403 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
2406 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2407 * @mem: the pointer returned by vm_map_ram
2408 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2410 void vm_unmap_ram(const void *mem, unsigned int count)
2412 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2413 unsigned long addr = (unsigned long)kasan_reset_tag(mem);
2414 struct vmap_area *va;
2418 BUG_ON(addr < VMALLOC_START);
2419 BUG_ON(addr > VMALLOC_END);
2420 BUG_ON(!PAGE_ALIGNED(addr));
2422 kasan_poison_vmalloc(mem, size);
2424 if (likely(count <= VMAP_MAX_ALLOC)) {
2425 debug_check_no_locks_freed(mem, size);
2426 vb_free(addr, size);
2430 va = find_unlink_vmap_area(addr);
2431 if (WARN_ON_ONCE(!va))
2434 debug_check_no_locks_freed((void *)va->va_start,
2435 (va->va_end - va->va_start));
2436 free_unmap_vmap_area(va);
2438 EXPORT_SYMBOL(vm_unmap_ram);
2441 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2442 * @pages: an array of pointers to the pages to be mapped
2443 * @count: number of pages
2444 * @node: prefer to allocate data structures on this node
2446 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2447 * faster than vmap so it's good. But if you mix long-life and short-life
2448 * objects with vm_map_ram(), it could consume lots of address space through
2449 * fragmentation (especially on a 32bit machine). You could see failures in
2450 * the end. Please use this function for short-lived objects.
2452 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2454 void *vm_map_ram(struct page **pages, unsigned int count, int node)
2456 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2460 if (likely(count <= VMAP_MAX_ALLOC)) {
2461 mem = vb_alloc(size, GFP_KERNEL);
2464 addr = (unsigned long)mem;
2466 struct vmap_area *va;
2467 va = alloc_vmap_area(size, PAGE_SIZE,
2468 VMALLOC_START, VMALLOC_END,
2469 node, GFP_KERNEL, VMAP_RAM);
2473 addr = va->va_start;
2477 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
2478 pages, PAGE_SHIFT) < 0) {
2479 vm_unmap_ram(mem, count);
2484 * Mark the pages as accessible, now that they are mapped.
2485 * With hardware tag-based KASAN, marking is skipped for
2486 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
2488 mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL);
2492 EXPORT_SYMBOL(vm_map_ram);
2494 static struct vm_struct *vmlist __initdata;
2496 static inline unsigned int vm_area_page_order(struct vm_struct *vm)
2498 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2499 return vm->page_order;
2505 static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
2507 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2508 vm->page_order = order;
2515 * vm_area_add_early - add vmap area early during boot
2516 * @vm: vm_struct to add
2518 * This function is used to add fixed kernel vm area to vmlist before
2519 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
2520 * should contain proper values and the other fields should be zero.
2522 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2524 void __init vm_area_add_early(struct vm_struct *vm)
2526 struct vm_struct *tmp, **p;
2528 BUG_ON(vmap_initialized);
2529 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
2530 if (tmp->addr >= vm->addr) {
2531 BUG_ON(tmp->addr < vm->addr + vm->size);
2534 BUG_ON(tmp->addr + tmp->size > vm->addr);
2541 * vm_area_register_early - register vmap area early during boot
2542 * @vm: vm_struct to register
2543 * @align: requested alignment
2545 * This function is used to register kernel vm area before
2546 * vmalloc_init() is called. @vm->size and @vm->flags should contain
2547 * proper values on entry and other fields should be zero. On return,
2548 * vm->addr contains the allocated address.
2550 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2552 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
2554 unsigned long addr = ALIGN(VMALLOC_START, align);
2555 struct vm_struct *cur, **p;
2557 BUG_ON(vmap_initialized);
2559 for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) {
2560 if ((unsigned long)cur->addr - addr >= vm->size)
2562 addr = ALIGN((unsigned long)cur->addr + cur->size, align);
2565 BUG_ON(addr > VMALLOC_END - vm->size);
2566 vm->addr = (void *)addr;
2569 kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
2572 static void vmap_init_free_space(void)
2574 unsigned long vmap_start = 1;
2575 const unsigned long vmap_end = ULONG_MAX;
2576 struct vmap_area *busy, *free;
2580 * -|-----|.....|-----|-----|-----|.....|-
2582 * |<--------------------------------->|
2584 list_for_each_entry(busy, &vmap_area_list, list) {
2585 if (busy->va_start - vmap_start > 0) {
2586 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2587 if (!WARN_ON_ONCE(!free)) {
2588 free->va_start = vmap_start;
2589 free->va_end = busy->va_start;
2591 insert_vmap_area_augment(free, NULL,
2592 &free_vmap_area_root,
2593 &free_vmap_area_list);
2597 vmap_start = busy->va_end;
2600 if (vmap_end - vmap_start > 0) {
2601 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2602 if (!WARN_ON_ONCE(!free)) {
2603 free->va_start = vmap_start;
2604 free->va_end = vmap_end;
2606 insert_vmap_area_augment(free, NULL,
2607 &free_vmap_area_root,
2608 &free_vmap_area_list);
2613 static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
2614 struct vmap_area *va, unsigned long flags, const void *caller)
2617 vm->addr = (void *)va->va_start;
2618 vm->size = va->va_end - va->va_start;
2619 vm->caller = caller;
2623 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
2624 unsigned long flags, const void *caller)
2626 spin_lock(&vmap_area_lock);
2627 setup_vmalloc_vm_locked(vm, va, flags, caller);
2628 spin_unlock(&vmap_area_lock);
2631 static void clear_vm_uninitialized_flag(struct vm_struct *vm)
2634 * Before removing VM_UNINITIALIZED,
2635 * we should make sure that vm has proper values.
2636 * Pair with smp_rmb() in show_numa_info().
2639 vm->flags &= ~VM_UNINITIALIZED;
2642 static struct vm_struct *__get_vm_area_node(unsigned long size,
2643 unsigned long align, unsigned long shift, unsigned long flags,
2644 unsigned long start, unsigned long end, int node,
2645 gfp_t gfp_mask, const void *caller)
2647 struct vmap_area *va;
2648 struct vm_struct *area;
2649 unsigned long requested_size = size;
2651 BUG_ON(in_interrupt());
2652 size = ALIGN(size, 1ul << shift);
2653 if (unlikely(!size))
2656 if (flags & VM_IOREMAP)
2657 align = 1ul << clamp_t(int, get_count_order_long(size),
2658 PAGE_SHIFT, IOREMAP_MAX_ORDER);
2660 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
2661 if (unlikely(!area))
2664 if (!(flags & VM_NO_GUARD))
2667 va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0);
2673 setup_vmalloc_vm(area, va, flags, caller);
2676 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a
2677 * best-effort approach, as they can be mapped outside of vmalloc code.
2678 * For VM_ALLOC mappings, the pages are marked as accessible after
2679 * getting mapped in __vmalloc_node_range().
2680 * With hardware tag-based KASAN, marking is skipped for
2681 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
2683 if (!(flags & VM_ALLOC))
2684 area->addr = kasan_unpoison_vmalloc(area->addr, requested_size,
2685 KASAN_VMALLOC_PROT_NORMAL);
2690 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
2691 unsigned long start, unsigned long end,
2694 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
2695 NUMA_NO_NODE, GFP_KERNEL, caller);
2699 * get_vm_area - reserve a contiguous kernel virtual area
2700 * @size: size of the area
2701 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2703 * Search an area of @size in the kernel virtual mapping area,
2704 * and reserved it for out purposes. Returns the area descriptor
2705 * on success or %NULL on failure.
2707 * Return: the area descriptor on success or %NULL on failure.
2709 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
2711 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2712 VMALLOC_START, VMALLOC_END,
2713 NUMA_NO_NODE, GFP_KERNEL,
2714 __builtin_return_address(0));
2717 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
2720 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2721 VMALLOC_START, VMALLOC_END,
2722 NUMA_NO_NODE, GFP_KERNEL, caller);
2726 * find_vm_area - find a continuous kernel virtual area
2727 * @addr: base address
2729 * Search for the kernel VM area starting at @addr, and return it.
2730 * It is up to the caller to do all required locking to keep the returned
2733 * Return: the area descriptor on success or %NULL on failure.
2735 struct vm_struct *find_vm_area(const void *addr)
2737 struct vmap_area *va;
2739 va = find_vmap_area((unsigned long)addr);
2747 * remove_vm_area - find and remove a continuous kernel virtual area
2748 * @addr: base address
2750 * Search for the kernel VM area starting at @addr, and remove it.
2751 * This function returns the found VM area, but using it is NOT safe
2752 * on SMP machines, except for its size or flags.
2754 * Return: the area descriptor on success or %NULL on failure.
2756 struct vm_struct *remove_vm_area(const void *addr)
2758 struct vmap_area *va;
2759 struct vm_struct *vm;
2763 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
2767 va = find_unlink_vmap_area((unsigned long)addr);
2772 debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm));
2773 debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm));
2774 kasan_free_module_shadow(vm);
2775 kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm));
2777 free_unmap_vmap_area(va);
2781 static inline void set_area_direct_map(const struct vm_struct *area,
2782 int (*set_direct_map)(struct page *page))
2786 /* HUGE_VMALLOC passes small pages to set_direct_map */
2787 for (i = 0; i < area->nr_pages; i++)
2788 if (page_address(area->pages[i]))
2789 set_direct_map(area->pages[i]);
2793 * Flush the vm mapping and reset the direct map.
2795 static void vm_reset_perms(struct vm_struct *area)
2797 unsigned long start = ULONG_MAX, end = 0;
2798 unsigned int page_order = vm_area_page_order(area);
2803 * Find the start and end range of the direct mappings to make sure that
2804 * the vm_unmap_aliases() flush includes the direct map.
2806 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2807 unsigned long addr = (unsigned long)page_address(area->pages[i]);
2810 unsigned long page_size;
2812 page_size = PAGE_SIZE << page_order;
2813 start = min(addr, start);
2814 end = max(addr + page_size, end);
2820 * Set direct map to something invalid so that it won't be cached if
2821 * there are any accesses after the TLB flush, then flush the TLB and
2822 * reset the direct map permissions to the default.
2824 set_area_direct_map(area, set_direct_map_invalid_noflush);
2825 _vm_unmap_aliases(start, end, flush_dmap);
2826 set_area_direct_map(area, set_direct_map_default_noflush);
2829 static void delayed_vfree_work(struct work_struct *w)
2831 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
2832 struct llist_node *t, *llnode;
2834 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
2839 * vfree_atomic - release memory allocated by vmalloc()
2840 * @addr: memory base address
2842 * This one is just like vfree() but can be called in any atomic context
2845 void vfree_atomic(const void *addr)
2847 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
2850 kmemleak_free(addr);
2853 * Use raw_cpu_ptr() because this can be called from preemptible
2854 * context. Preemption is absolutely fine here, because the llist_add()
2855 * implementation is lockless, so it works even if we are adding to
2856 * another cpu's list. schedule_work() should be fine with this too.
2858 if (addr && llist_add((struct llist_node *)addr, &p->list))
2859 schedule_work(&p->wq);
2863 * vfree - Release memory allocated by vmalloc()
2864 * @addr: Memory base address
2866 * Free the virtually continuous memory area starting at @addr, as obtained
2867 * from one of the vmalloc() family of APIs. This will usually also free the
2868 * physical memory underlying the virtual allocation, but that memory is
2869 * reference counted, so it will not be freed until the last user goes away.
2871 * If @addr is NULL, no operation is performed.
2874 * May sleep if called *not* from interrupt context.
2875 * Must not be called in NMI context (strictly speaking, it could be
2876 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2877 * conventions for vfree() arch-dependent would be a really bad idea).
2879 void vfree(const void *addr)
2881 struct vm_struct *vm;
2884 if (unlikely(in_interrupt())) {
2890 kmemleak_free(addr);
2896 vm = remove_vm_area(addr);
2897 if (unlikely(!vm)) {
2898 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
2903 if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
2905 for (i = 0; i < vm->nr_pages; i++) {
2906 struct page *page = vm->pages[i];
2909 mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
2911 * High-order allocs for huge vmallocs are split, so
2912 * can be freed as an array of order-0 allocations
2917 atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages);
2921 EXPORT_SYMBOL(vfree);
2924 * vunmap - release virtual mapping obtained by vmap()
2925 * @addr: memory base address
2927 * Free the virtually contiguous memory area starting at @addr,
2928 * which was created from the page array passed to vmap().
2930 * Must not be called in interrupt context.
2932 void vunmap(const void *addr)
2934 struct vm_struct *vm;
2936 BUG_ON(in_interrupt());
2941 vm = remove_vm_area(addr);
2942 if (unlikely(!vm)) {
2943 WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n",
2949 EXPORT_SYMBOL(vunmap);
2952 * vmap - map an array of pages into virtually contiguous space
2953 * @pages: array of page pointers
2954 * @count: number of pages to map
2955 * @flags: vm_area->flags
2956 * @prot: page protection for the mapping
2958 * Maps @count pages from @pages into contiguous kernel virtual space.
2959 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
2960 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
2961 * are transferred from the caller to vmap(), and will be freed / dropped when
2962 * vfree() is called on the return value.
2964 * Return: the address of the area or %NULL on failure
2966 void *vmap(struct page **pages, unsigned int count,
2967 unsigned long flags, pgprot_t prot)
2969 struct vm_struct *area;
2971 unsigned long size; /* In bytes */
2975 if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS))
2979 * Your top guard is someone else's bottom guard. Not having a top
2980 * guard compromises someone else's mappings too.
2982 if (WARN_ON_ONCE(flags & VM_NO_GUARD))
2983 flags &= ~VM_NO_GUARD;
2985 if (count > totalram_pages())
2988 size = (unsigned long)count << PAGE_SHIFT;
2989 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
2993 addr = (unsigned long)area->addr;
2994 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
2995 pages, PAGE_SHIFT) < 0) {
3000 if (flags & VM_MAP_PUT_PAGES) {
3001 area->pages = pages;
3002 area->nr_pages = count;
3006 EXPORT_SYMBOL(vmap);
3008 #ifdef CONFIG_VMAP_PFN
3009 struct vmap_pfn_data {
3010 unsigned long *pfns;
3015 static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
3017 struct vmap_pfn_data *data = private;
3018 unsigned long pfn = data->pfns[data->idx];
3021 if (WARN_ON_ONCE(pfn_valid(pfn)))
3024 ptent = pte_mkspecial(pfn_pte(pfn, data->prot));
3025 set_pte_at(&init_mm, addr, pte, ptent);
3032 * vmap_pfn - map an array of PFNs into virtually contiguous space
3033 * @pfns: array of PFNs
3034 * @count: number of pages to map
3035 * @prot: page protection for the mapping
3037 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
3038 * the start address of the mapping.
3040 void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
3042 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
3043 struct vm_struct *area;
3045 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
3046 __builtin_return_address(0));
3049 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
3050 count * PAGE_SIZE, vmap_pfn_apply, &data)) {
3055 flush_cache_vmap((unsigned long)area->addr,
3056 (unsigned long)area->addr + count * PAGE_SIZE);
3060 EXPORT_SYMBOL_GPL(vmap_pfn);
3061 #endif /* CONFIG_VMAP_PFN */
3063 static inline unsigned int
3064 vm_area_alloc_pages(gfp_t gfp, int nid,
3065 unsigned int order, unsigned int nr_pages, struct page **pages)
3067 unsigned int nr_allocated = 0;
3068 gfp_t alloc_gfp = gfp;
3069 bool nofail = false;
3074 * For order-0 pages we make use of bulk allocator, if
3075 * the page array is partly or not at all populated due
3076 * to fails, fallback to a single page allocator that is
3080 /* bulk allocator doesn't support nofail req. officially */
3081 gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL;
3083 while (nr_allocated < nr_pages) {
3084 unsigned int nr, nr_pages_request;
3087 * A maximum allowed request is hard-coded and is 100
3088 * pages per call. That is done in order to prevent a
3089 * long preemption off scenario in the bulk-allocator
3090 * so the range is [1:100].
3092 nr_pages_request = min(100U, nr_pages - nr_allocated);
3094 /* memory allocation should consider mempolicy, we can't
3095 * wrongly use nearest node when nid == NUMA_NO_NODE,
3096 * otherwise memory may be allocated in only one node,
3097 * but mempolicy wants to alloc memory by interleaving.
3099 if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
3100 nr = alloc_pages_bulk_array_mempolicy(bulk_gfp,
3102 pages + nr_allocated);
3105 nr = alloc_pages_bulk_array_node(bulk_gfp, nid,
3107 pages + nr_allocated);
3113 * If zero or pages were obtained partly,
3114 * fallback to a single page allocator.
3116 if (nr != nr_pages_request)
3119 } else if (gfp & __GFP_NOFAIL) {
3121 * Higher order nofail allocations are really expensive and
3122 * potentially dangerous (pre-mature OOM, disruptive reclaim
3123 * and compaction etc.
3125 alloc_gfp &= ~__GFP_NOFAIL;
3129 /* High-order pages or fallback path if "bulk" fails. */
3130 while (nr_allocated < nr_pages) {
3131 if (fatal_signal_pending(current))
3134 if (nid == NUMA_NO_NODE)
3135 page = alloc_pages(alloc_gfp, order);
3137 page = alloc_pages_node(nid, alloc_gfp, order);
3138 if (unlikely(!page)) {
3142 /* fall back to the zero order allocations */
3143 alloc_gfp |= __GFP_NOFAIL;
3149 * Higher order allocations must be able to be treated as
3150 * indepdenent small pages by callers (as they can with
3151 * small-page vmallocs). Some drivers do their own refcounting
3152 * on vmalloc_to_page() pages, some use page->mapping,
3156 split_page(page, order);
3159 * Careful, we allocate and map page-order pages, but
3160 * tracking is done per PAGE_SIZE page so as to keep the
3161 * vm_struct APIs independent of the physical/mapped size.
3163 for (i = 0; i < (1U << order); i++)
3164 pages[nr_allocated + i] = page + i;
3167 nr_allocated += 1U << order;
3170 return nr_allocated;
3173 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
3174 pgprot_t prot, unsigned int page_shift,
3177 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
3178 bool nofail = gfp_mask & __GFP_NOFAIL;
3179 unsigned long addr = (unsigned long)area->addr;
3180 unsigned long size = get_vm_area_size(area);
3181 unsigned long array_size;
3182 unsigned int nr_small_pages = size >> PAGE_SHIFT;
3183 unsigned int page_order;
3187 array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
3189 if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
3190 gfp_mask |= __GFP_HIGHMEM;
3192 /* Please note that the recursion is strictly bounded. */
3193 if (array_size > PAGE_SIZE) {
3194 area->pages = __vmalloc_node(array_size, 1, nested_gfp, node,
3197 area->pages = kmalloc_node(array_size, nested_gfp, node);
3201 warn_alloc(gfp_mask, NULL,
3202 "vmalloc error: size %lu, failed to allocated page array size %lu",
3203 nr_small_pages * PAGE_SIZE, array_size);
3208 set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
3209 page_order = vm_area_page_order(area);
3211 area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN,
3212 node, page_order, nr_small_pages, area->pages);
3214 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
3215 if (gfp_mask & __GFP_ACCOUNT) {
3218 for (i = 0; i < area->nr_pages; i++)
3219 mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1);
3223 * If not enough pages were obtained to accomplish an
3224 * allocation request, free them via vfree() if any.
3226 if (area->nr_pages != nr_small_pages) {
3228 * vm_area_alloc_pages() can fail due to insufficient memory but
3231 * - a pending fatal signal
3232 * - insufficient huge page-order pages
3234 * Since we always retry allocations at order-0 in the huge page
3235 * case a warning for either is spurious.
3237 if (!fatal_signal_pending(current) && page_order == 0)
3238 warn_alloc(gfp_mask, NULL,
3239 "vmalloc error: size %lu, failed to allocate pages",
3240 area->nr_pages * PAGE_SIZE);
3245 * page tables allocations ignore external gfp mask, enforce it
3248 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3249 flags = memalloc_nofs_save();
3250 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3251 flags = memalloc_noio_save();
3254 ret = vmap_pages_range(addr, addr + size, prot, area->pages,
3256 if (nofail && (ret < 0))
3257 schedule_timeout_uninterruptible(1);
3258 } while (nofail && (ret < 0));
3260 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3261 memalloc_nofs_restore(flags);
3262 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3263 memalloc_noio_restore(flags);
3266 warn_alloc(gfp_mask, NULL,
3267 "vmalloc error: size %lu, failed to map pages",
3268 area->nr_pages * PAGE_SIZE);
3280 * __vmalloc_node_range - allocate virtually contiguous memory
3281 * @size: allocation size
3282 * @align: desired alignment
3283 * @start: vm area range start
3284 * @end: vm area range end
3285 * @gfp_mask: flags for the page level allocator
3286 * @prot: protection mask for the allocated pages
3287 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
3288 * @node: node to use for allocation or NUMA_NO_NODE
3289 * @caller: caller's return address
3291 * Allocate enough pages to cover @size from the page level
3292 * allocator with @gfp_mask flags. Please note that the full set of gfp
3293 * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all
3295 * Zone modifiers are not supported. From the reclaim modifiers
3296 * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported)
3297 * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and
3298 * __GFP_RETRY_MAYFAIL are not supported).
3300 * __GFP_NOWARN can be used to suppress failures messages.
3302 * Map them into contiguous kernel virtual space, using a pagetable
3303 * protection of @prot.
3305 * Return: the address of the area or %NULL on failure
3307 void *__vmalloc_node_range(unsigned long size, unsigned long align,
3308 unsigned long start, unsigned long end, gfp_t gfp_mask,
3309 pgprot_t prot, unsigned long vm_flags, int node,
3312 struct vm_struct *area;
3314 kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE;
3315 unsigned long real_size = size;
3316 unsigned long real_align = align;
3317 unsigned int shift = PAGE_SHIFT;
3319 if (WARN_ON_ONCE(!size))
3322 if ((size >> PAGE_SHIFT) > totalram_pages()) {
3323 warn_alloc(gfp_mask, NULL,
3324 "vmalloc error: size %lu, exceeds total pages",
3329 if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) {
3330 unsigned long size_per_node;
3333 * Try huge pages. Only try for PAGE_KERNEL allocations,
3334 * others like modules don't yet expect huge pages in
3335 * their allocations due to apply_to_page_range not
3339 size_per_node = size;
3340 if (node == NUMA_NO_NODE)
3341 size_per_node /= num_online_nodes();
3342 if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
3345 shift = arch_vmap_pte_supported_shift(size_per_node);
3347 align = max(real_align, 1UL << shift);
3348 size = ALIGN(real_size, 1UL << shift);
3352 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
3353 VM_UNINITIALIZED | vm_flags, start, end, node,
3356 bool nofail = gfp_mask & __GFP_NOFAIL;
3357 warn_alloc(gfp_mask, NULL,
3358 "vmalloc error: size %lu, vm_struct allocation failed%s",
3359 real_size, (nofail) ? ". Retrying." : "");
3361 schedule_timeout_uninterruptible(1);
3368 * Prepare arguments for __vmalloc_area_node() and
3369 * kasan_unpoison_vmalloc().
3371 if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) {
3372 if (kasan_hw_tags_enabled()) {
3374 * Modify protection bits to allow tagging.
3375 * This must be done before mapping.
3377 prot = arch_vmap_pgprot_tagged(prot);
3380 * Skip page_alloc poisoning and zeroing for physical
3381 * pages backing VM_ALLOC mapping. Memory is instead
3382 * poisoned and zeroed by kasan_unpoison_vmalloc().
3384 gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO;
3387 /* Take note that the mapping is PAGE_KERNEL. */
3388 kasan_flags |= KASAN_VMALLOC_PROT_NORMAL;
3391 /* Allocate physical pages and map them into vmalloc space. */
3392 ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
3397 * Mark the pages as accessible, now that they are mapped.
3398 * The condition for setting KASAN_VMALLOC_INIT should complement the
3399 * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check
3400 * to make sure that memory is initialized under the same conditions.
3401 * Tag-based KASAN modes only assign tags to normal non-executable
3402 * allocations, see __kasan_unpoison_vmalloc().
3404 kasan_flags |= KASAN_VMALLOC_VM_ALLOC;
3405 if (!want_init_on_free() && want_init_on_alloc(gfp_mask) &&
3406 (gfp_mask & __GFP_SKIP_ZERO))
3407 kasan_flags |= KASAN_VMALLOC_INIT;
3408 /* KASAN_VMALLOC_PROT_NORMAL already set if required. */
3409 area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags);
3412 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
3413 * flag. It means that vm_struct is not fully initialized.
3414 * Now, it is fully initialized, so remove this flag here.
3416 clear_vm_uninitialized_flag(area);
3418 size = PAGE_ALIGN(size);
3419 if (!(vm_flags & VM_DEFER_KMEMLEAK))
3420 kmemleak_vmalloc(area, size, gfp_mask);
3425 if (shift > PAGE_SHIFT) {
3436 * __vmalloc_node - allocate virtually contiguous memory
3437 * @size: allocation size
3438 * @align: desired alignment
3439 * @gfp_mask: flags for the page level allocator
3440 * @node: node to use for allocation or NUMA_NO_NODE
3441 * @caller: caller's return address
3443 * Allocate enough pages to cover @size from the page level allocator with
3444 * @gfp_mask flags. Map them into contiguous kernel virtual space.
3446 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
3447 * and __GFP_NOFAIL are not supported
3449 * Any use of gfp flags outside of GFP_KERNEL should be consulted
3452 * Return: pointer to the allocated memory or %NULL on error
3454 void *__vmalloc_node(unsigned long size, unsigned long align,
3455 gfp_t gfp_mask, int node, const void *caller)
3457 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
3458 gfp_mask, PAGE_KERNEL, 0, node, caller);
3461 * This is only for performance analysis of vmalloc and stress purpose.
3462 * It is required by vmalloc test module, therefore do not use it other
3465 #ifdef CONFIG_TEST_VMALLOC_MODULE
3466 EXPORT_SYMBOL_GPL(__vmalloc_node);
3469 void *__vmalloc(unsigned long size, gfp_t gfp_mask)
3471 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE,
3472 __builtin_return_address(0));
3474 EXPORT_SYMBOL(__vmalloc);
3477 * vmalloc - allocate virtually contiguous memory
3478 * @size: allocation size
3480 * Allocate enough pages to cover @size from the page level
3481 * allocator and map them into contiguous kernel virtual space.
3483 * For tight control over page level allocator and protection flags
3484 * use __vmalloc() instead.
3486 * Return: pointer to the allocated memory or %NULL on error
3488 void *vmalloc(unsigned long size)
3490 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE,
3491 __builtin_return_address(0));
3493 EXPORT_SYMBOL(vmalloc);
3496 * vmalloc_huge - allocate virtually contiguous memory, allow huge pages
3497 * @size: allocation size
3498 * @gfp_mask: flags for the page level allocator
3500 * Allocate enough pages to cover @size from the page level
3501 * allocator and map them into contiguous kernel virtual space.
3502 * If @size is greater than or equal to PMD_SIZE, allow using
3503 * huge pages for the memory
3505 * Return: pointer to the allocated memory or %NULL on error
3507 void *vmalloc_huge(unsigned long size, gfp_t gfp_mask)
3509 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
3510 gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
3511 NUMA_NO_NODE, __builtin_return_address(0));
3513 EXPORT_SYMBOL_GPL(vmalloc_huge);
3516 * vzalloc - allocate virtually contiguous memory with zero fill
3517 * @size: allocation size
3519 * Allocate enough pages to cover @size from the page level
3520 * allocator and map them into contiguous kernel virtual space.
3521 * The memory allocated is set to zero.
3523 * For tight control over page level allocator and protection flags
3524 * use __vmalloc() instead.
3526 * Return: pointer to the allocated memory or %NULL on error
3528 void *vzalloc(unsigned long size)
3530 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
3531 __builtin_return_address(0));
3533 EXPORT_SYMBOL(vzalloc);
3536 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3537 * @size: allocation size
3539 * The resulting memory area is zeroed so it can be mapped to userspace
3540 * without leaking data.
3542 * Return: pointer to the allocated memory or %NULL on error
3544 void *vmalloc_user(unsigned long size)
3546 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3547 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
3548 VM_USERMAP, NUMA_NO_NODE,
3549 __builtin_return_address(0));
3551 EXPORT_SYMBOL(vmalloc_user);
3554 * vmalloc_node - allocate memory on a specific node
3555 * @size: allocation size
3558 * Allocate enough pages to cover @size from the page level
3559 * allocator and map them into contiguous kernel virtual space.
3561 * For tight control over page level allocator and protection flags
3562 * use __vmalloc() instead.
3564 * Return: pointer to the allocated memory or %NULL on error
3566 void *vmalloc_node(unsigned long size, int node)
3568 return __vmalloc_node(size, 1, GFP_KERNEL, node,
3569 __builtin_return_address(0));
3571 EXPORT_SYMBOL(vmalloc_node);
3574 * vzalloc_node - allocate memory on a specific node with zero fill
3575 * @size: allocation size
3578 * Allocate enough pages to cover @size from the page level
3579 * allocator and map them into contiguous kernel virtual space.
3580 * The memory allocated is set to zero.
3582 * Return: pointer to the allocated memory or %NULL on error
3584 void *vzalloc_node(unsigned long size, int node)
3586 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node,
3587 __builtin_return_address(0));
3589 EXPORT_SYMBOL(vzalloc_node);
3591 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
3592 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3593 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
3594 #define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
3597 * 64b systems should always have either DMA or DMA32 zones. For others
3598 * GFP_DMA32 should do the right thing and use the normal zone.
3600 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3604 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
3605 * @size: allocation size
3607 * Allocate enough 32bit PA addressable pages to cover @size from the
3608 * page level allocator and map them into contiguous kernel virtual space.
3610 * Return: pointer to the allocated memory or %NULL on error
3612 void *vmalloc_32(unsigned long size)
3614 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
3615 __builtin_return_address(0));
3617 EXPORT_SYMBOL(vmalloc_32);
3620 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
3621 * @size: allocation size
3623 * The resulting memory area is 32bit addressable and zeroed so it can be
3624 * mapped to userspace without leaking data.
3626 * Return: pointer to the allocated memory or %NULL on error
3628 void *vmalloc_32_user(unsigned long size)
3630 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3631 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
3632 VM_USERMAP, NUMA_NO_NODE,
3633 __builtin_return_address(0));
3635 EXPORT_SYMBOL(vmalloc_32_user);
3638 * Atomically zero bytes in the iterator.
3640 * Returns the number of zeroed bytes.
3642 static size_t zero_iter(struct iov_iter *iter, size_t count)
3644 size_t remains = count;
3646 while (remains > 0) {
3649 num = min_t(size_t, remains, PAGE_SIZE);
3650 copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter);
3657 return count - remains;
3661 * small helper routine, copy contents to iter from addr.
3662 * If the page is not present, fill zero.
3664 * Returns the number of copied bytes.
3666 static size_t aligned_vread_iter(struct iov_iter *iter,
3667 const char *addr, size_t count)
3669 size_t remains = count;
3672 while (remains > 0) {
3673 unsigned long offset, length;
3676 offset = offset_in_page(addr);
3677 length = PAGE_SIZE - offset;
3678 if (length > remains)
3680 page = vmalloc_to_page(addr);
3682 * To do safe access to this _mapped_ area, we need lock. But
3683 * adding lock here means that we need to add overhead of
3684 * vmalloc()/vfree() calls for this _debug_ interface, rarely
3685 * used. Instead of that, we'll use an local mapping via
3686 * copy_page_to_iter_nofault() and accept a small overhead in
3687 * this access function.
3690 copied = copy_page_to_iter_nofault(page, offset,
3693 copied = zero_iter(iter, length);
3698 if (copied != length)
3702 return count - remains;
3706 * Read from a vm_map_ram region of memory.
3708 * Returns the number of copied bytes.
3710 static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr,
3711 size_t count, unsigned long flags)
3714 struct vmap_block *vb;
3716 unsigned long offset;
3717 unsigned int rs, re;
3721 * If it's area created by vm_map_ram() interface directly, but
3722 * not further subdividing and delegating management to vmap_block,
3725 if (!(flags & VMAP_BLOCK))
3726 return aligned_vread_iter(iter, addr, count);
3731 * Area is split into regions and tracked with vmap_block, read out
3732 * each region and zero fill the hole between regions.
3734 xa = addr_to_vb_xa((unsigned long) addr);
3735 vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr));
3739 spin_lock(&vb->lock);
3740 if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
3741 spin_unlock(&vb->lock);
3745 for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) {
3751 start = vmap_block_vaddr(vb->va->va_start, rs);
3754 size_t to_zero = min_t(size_t, start - addr, remains);
3755 size_t zeroed = zero_iter(iter, to_zero);
3760 if (remains == 0 || zeroed != to_zero)
3764 /*it could start reading from the middle of used region*/
3765 offset = offset_in_page(addr);
3766 n = ((re - rs + 1) << PAGE_SHIFT) - offset;
3770 copied = aligned_vread_iter(iter, start + offset, n);
3779 spin_unlock(&vb->lock);
3782 /* zero-fill the left dirty or free regions */
3783 return count - remains + zero_iter(iter, remains);
3785 /* We couldn't copy/zero everything */
3786 spin_unlock(&vb->lock);
3787 return count - remains;
3791 * vread_iter() - read vmalloc area in a safe way to an iterator.
3792 * @iter: the iterator to which data should be written.
3793 * @addr: vm address.
3794 * @count: number of bytes to be read.
3796 * This function checks that addr is a valid vmalloc'ed area, and
3797 * copy data from that area to a given buffer. If the given memory range
3798 * of [addr...addr+count) includes some valid address, data is copied to
3799 * proper area of @buf. If there are memory holes, they'll be zero-filled.
3800 * IOREMAP area is treated as memory hole and no copy is done.
3802 * If [addr...addr+count) doesn't includes any intersects with alive
3803 * vm_struct area, returns 0. @buf should be kernel's buffer.
3805 * Note: In usual ops, vread() is never necessary because the caller
3806 * should know vmalloc() area is valid and can use memcpy().
3807 * This is for routines which have to access vmalloc area without
3808 * any information, as /proc/kcore.
3810 * Return: number of bytes for which addr and buf should be increased
3811 * (same number as @count) or %0 if [addr...addr+count) doesn't
3812 * include any intersection with valid vmalloc area
3814 long vread_iter(struct iov_iter *iter, const char *addr, size_t count)
3816 struct vmap_area *va;
3817 struct vm_struct *vm;
3819 size_t n, size, flags, remains;
3821 addr = kasan_reset_tag(addr);
3823 /* Don't allow overflow */
3824 if ((unsigned long) addr + count < count)
3825 count = -(unsigned long) addr;
3829 spin_lock(&vmap_area_lock);
3830 va = find_vmap_area_exceed_addr((unsigned long)addr);
3834 /* no intersects with alive vmap_area */
3835 if ((unsigned long)addr + remains <= va->va_start)
3838 list_for_each_entry_from(va, &vmap_area_list, list) {
3845 flags = va->flags & VMAP_FLAGS_MASK;
3847 * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need
3848 * be set together with VMAP_RAM.
3850 WARN_ON(flags == VMAP_BLOCK);
3855 if (vm && (vm->flags & VM_UNINITIALIZED))
3858 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
3861 vaddr = (char *) va->va_start;
3862 size = vm ? get_vm_area_size(vm) : va_size(va);
3864 if (addr >= vaddr + size)
3868 size_t to_zero = min_t(size_t, vaddr - addr, remains);
3869 size_t zeroed = zero_iter(iter, to_zero);
3874 if (remains == 0 || zeroed != to_zero)
3878 n = vaddr + size - addr;
3882 if (flags & VMAP_RAM)
3883 copied = vmap_ram_vread_iter(iter, addr, n, flags);
3884 else if (!(vm && (vm->flags & (VM_IOREMAP | VM_SPARSE))))
3885 copied = aligned_vread_iter(iter, addr, n);
3886 else /* IOREMAP | SPARSE area is treated as memory hole */
3887 copied = zero_iter(iter, n);
3897 spin_unlock(&vmap_area_lock);
3898 /* zero-fill memory holes */
3899 return count - remains + zero_iter(iter, remains);
3901 /* Nothing remains, or We couldn't copy/zero everything. */
3902 spin_unlock(&vmap_area_lock);
3904 return count - remains;
3908 * remap_vmalloc_range_partial - map vmalloc pages to userspace
3909 * @vma: vma to cover
3910 * @uaddr: target user address to start at
3911 * @kaddr: virtual address of vmalloc kernel memory
3912 * @pgoff: offset from @kaddr to start at
3913 * @size: size of map area
3915 * Returns: 0 for success, -Exxx on failure
3917 * This function checks that @kaddr is a valid vmalloc'ed area,
3918 * and that it is big enough to cover the range starting at
3919 * @uaddr in @vma. Will return failure if that criteria isn't
3922 * Similar to remap_pfn_range() (see mm/memory.c)
3924 int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
3925 void *kaddr, unsigned long pgoff,
3928 struct vm_struct *area;
3930 unsigned long end_index;
3932 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
3935 size = PAGE_ALIGN(size);
3937 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
3940 area = find_vm_area(kaddr);
3944 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
3947 if (check_add_overflow(size, off, &end_index) ||
3948 end_index > get_vm_area_size(area))
3953 struct page *page = vmalloc_to_page(kaddr);
3956 ret = vm_insert_page(vma, uaddr, page);
3965 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
3971 * remap_vmalloc_range - map vmalloc pages to userspace
3972 * @vma: vma to cover (map full range of vma)
3973 * @addr: vmalloc memory
3974 * @pgoff: number of pages into addr before first page to map
3976 * Returns: 0 for success, -Exxx on failure
3978 * This function checks that addr is a valid vmalloc'ed area, and
3979 * that it is big enough to cover the vma. Will return failure if
3980 * that criteria isn't met.
3982 * Similar to remap_pfn_range() (see mm/memory.c)
3984 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
3985 unsigned long pgoff)
3987 return remap_vmalloc_range_partial(vma, vma->vm_start,
3989 vma->vm_end - vma->vm_start);
3991 EXPORT_SYMBOL(remap_vmalloc_range);
3993 void free_vm_area(struct vm_struct *area)
3995 struct vm_struct *ret;
3996 ret = remove_vm_area(area->addr);
3997 BUG_ON(ret != area);
4000 EXPORT_SYMBOL_GPL(free_vm_area);
4003 static struct vmap_area *node_to_va(struct rb_node *n)
4005 return rb_entry_safe(n, struct vmap_area, rb_node);
4009 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
4010 * @addr: target address
4012 * Returns: vmap_area if it is found. If there is no such area
4013 * the first highest(reverse order) vmap_area is returned
4014 * i.e. va->va_start < addr && va->va_end < addr or NULL
4015 * if there are no any areas before @addr.
4017 static struct vmap_area *
4018 pvm_find_va_enclose_addr(unsigned long addr)
4020 struct vmap_area *va, *tmp;
4023 n = free_vmap_area_root.rb_node;
4027 tmp = rb_entry(n, struct vmap_area, rb_node);
4028 if (tmp->va_start <= addr) {
4030 if (tmp->va_end >= addr)
4043 * pvm_determine_end_from_reverse - find the highest aligned address
4044 * of free block below VMALLOC_END
4046 * in - the VA we start the search(reverse order);
4047 * out - the VA with the highest aligned end address.
4048 * @align: alignment for required highest address
4050 * Returns: determined end address within vmap_area
4052 static unsigned long
4053 pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
4055 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
4059 list_for_each_entry_from_reverse((*va),
4060 &free_vmap_area_list, list) {
4061 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
4062 if ((*va)->va_start < addr)
4071 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
4072 * @offsets: array containing offset of each area
4073 * @sizes: array containing size of each area
4074 * @nr_vms: the number of areas to allocate
4075 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
4077 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
4078 * vm_structs on success, %NULL on failure
4080 * Percpu allocator wants to use congruent vm areas so that it can
4081 * maintain the offsets among percpu areas. This function allocates
4082 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
4083 * be scattered pretty far, distance between two areas easily going up
4084 * to gigabytes. To avoid interacting with regular vmallocs, these
4085 * areas are allocated from top.
4087 * Despite its complicated look, this allocator is rather simple. It
4088 * does everything top-down and scans free blocks from the end looking
4089 * for matching base. While scanning, if any of the areas do not fit the
4090 * base address is pulled down to fit the area. Scanning is repeated till
4091 * all the areas fit and then all necessary data structures are inserted
4092 * and the result is returned.
4094 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
4095 const size_t *sizes, int nr_vms,
4098 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
4099 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
4100 struct vmap_area **vas, *va;
4101 struct vm_struct **vms;
4102 int area, area2, last_area, term_area;
4103 unsigned long base, start, size, end, last_end, orig_start, orig_end;
4104 bool purged = false;
4106 /* verify parameters and allocate data structures */
4107 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
4108 for (last_area = 0, area = 0; area < nr_vms; area++) {
4109 start = offsets[area];
4110 end = start + sizes[area];
4112 /* is everything aligned properly? */
4113 BUG_ON(!IS_ALIGNED(offsets[area], align));
4114 BUG_ON(!IS_ALIGNED(sizes[area], align));
4116 /* detect the area with the highest address */
4117 if (start > offsets[last_area])
4120 for (area2 = area + 1; area2 < nr_vms; area2++) {
4121 unsigned long start2 = offsets[area2];
4122 unsigned long end2 = start2 + sizes[area2];
4124 BUG_ON(start2 < end && start < end2);
4127 last_end = offsets[last_area] + sizes[last_area];
4129 if (vmalloc_end - vmalloc_start < last_end) {
4134 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
4135 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
4139 for (area = 0; area < nr_vms; area++) {
4140 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
4141 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
4142 if (!vas[area] || !vms[area])
4146 spin_lock(&free_vmap_area_lock);
4148 /* start scanning - we scan from the top, begin with the last area */
4149 area = term_area = last_area;
4150 start = offsets[area];
4151 end = start + sizes[area];
4153 va = pvm_find_va_enclose_addr(vmalloc_end);
4154 base = pvm_determine_end_from_reverse(&va, align) - end;
4158 * base might have underflowed, add last_end before
4161 if (base + last_end < vmalloc_start + last_end)
4165 * Fitting base has not been found.
4171 * If required width exceeds current VA block, move
4172 * base downwards and then recheck.
4174 if (base + end > va->va_end) {
4175 base = pvm_determine_end_from_reverse(&va, align) - end;
4181 * If this VA does not fit, move base downwards and recheck.
4183 if (base + start < va->va_start) {
4184 va = node_to_va(rb_prev(&va->rb_node));
4185 base = pvm_determine_end_from_reverse(&va, align) - end;
4191 * This area fits, move on to the previous one. If
4192 * the previous one is the terminal one, we're done.
4194 area = (area + nr_vms - 1) % nr_vms;
4195 if (area == term_area)
4198 start = offsets[area];
4199 end = start + sizes[area];
4200 va = pvm_find_va_enclose_addr(base + end);
4203 /* we've found a fitting base, insert all va's */
4204 for (area = 0; area < nr_vms; area++) {
4207 start = base + offsets[area];
4210 va = pvm_find_va_enclose_addr(start);
4211 if (WARN_ON_ONCE(va == NULL))
4212 /* It is a BUG(), but trigger recovery instead. */
4215 ret = adjust_va_to_fit_type(&free_vmap_area_root,
4216 &free_vmap_area_list,
4218 if (WARN_ON_ONCE(unlikely(ret)))
4219 /* It is a BUG(), but trigger recovery instead. */
4222 /* Allocated area. */
4224 va->va_start = start;
4225 va->va_end = start + size;
4228 spin_unlock(&free_vmap_area_lock);
4230 /* populate the kasan shadow space */
4231 for (area = 0; area < nr_vms; area++) {
4232 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
4233 goto err_free_shadow;
4236 /* insert all vm's */
4237 spin_lock(&vmap_area_lock);
4238 for (area = 0; area < nr_vms; area++) {
4239 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
4241 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
4244 spin_unlock(&vmap_area_lock);
4247 * Mark allocated areas as accessible. Do it now as a best-effort
4248 * approach, as they can be mapped outside of vmalloc code.
4249 * With hardware tag-based KASAN, marking is skipped for
4250 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
4252 for (area = 0; area < nr_vms; area++)
4253 vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr,
4254 vms[area]->size, KASAN_VMALLOC_PROT_NORMAL);
4261 * Remove previously allocated areas. There is no
4262 * need in removing these areas from the busy tree,
4263 * because they are inserted only on the final step
4264 * and when pcpu_get_vm_areas() is success.
4267 orig_start = vas[area]->va_start;
4268 orig_end = vas[area]->va_end;
4269 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4270 &free_vmap_area_list);
4272 kasan_release_vmalloc(orig_start, orig_end,
4273 va->va_start, va->va_end);
4278 spin_unlock(&free_vmap_area_lock);
4280 reclaim_and_purge_vmap_areas();
4283 /* Before "retry", check if we recover. */
4284 for (area = 0; area < nr_vms; area++) {
4288 vas[area] = kmem_cache_zalloc(
4289 vmap_area_cachep, GFP_KERNEL);
4298 for (area = 0; area < nr_vms; area++) {
4300 kmem_cache_free(vmap_area_cachep, vas[area]);
4310 spin_lock(&free_vmap_area_lock);
4312 * We release all the vmalloc shadows, even the ones for regions that
4313 * hadn't been successfully added. This relies on kasan_release_vmalloc
4314 * being able to tolerate this case.
4316 for (area = 0; area < nr_vms; area++) {
4317 orig_start = vas[area]->va_start;
4318 orig_end = vas[area]->va_end;
4319 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4320 &free_vmap_area_list);
4322 kasan_release_vmalloc(orig_start, orig_end,
4323 va->va_start, va->va_end);
4327 spin_unlock(&free_vmap_area_lock);
4334 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
4335 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
4336 * @nr_vms: the number of allocated areas
4338 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
4340 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
4344 for (i = 0; i < nr_vms; i++)
4345 free_vm_area(vms[i]);
4348 #endif /* CONFIG_SMP */
4350 #ifdef CONFIG_PRINTK
4351 bool vmalloc_dump_obj(void *object)
4353 void *objp = (void *)PAGE_ALIGN((unsigned long)object);
4355 struct vm_struct *vm;
4356 struct vmap_area *va;
4358 unsigned int nr_pages;
4360 if (!spin_trylock(&vmap_area_lock))
4362 va = __find_vmap_area((unsigned long)objp, &vmap_area_root);
4364 spin_unlock(&vmap_area_lock);
4370 spin_unlock(&vmap_area_lock);
4373 addr = (unsigned long)vm->addr;
4374 caller = vm->caller;
4375 nr_pages = vm->nr_pages;
4376 spin_unlock(&vmap_area_lock);
4377 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
4378 nr_pages, addr, caller);
4383 #ifdef CONFIG_PROC_FS
4384 static void *s_start(struct seq_file *m, loff_t *pos)
4385 __acquires(&vmap_purge_lock)
4386 __acquires(&vmap_area_lock)
4388 mutex_lock(&vmap_purge_lock);
4389 spin_lock(&vmap_area_lock);
4391 return seq_list_start(&vmap_area_list, *pos);
4394 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4396 return seq_list_next(p, &vmap_area_list, pos);
4399 static void s_stop(struct seq_file *m, void *p)
4400 __releases(&vmap_area_lock)
4401 __releases(&vmap_purge_lock)
4403 spin_unlock(&vmap_area_lock);
4404 mutex_unlock(&vmap_purge_lock);
4407 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
4409 if (IS_ENABLED(CONFIG_NUMA)) {
4410 unsigned int nr, *counters = m->private;
4411 unsigned int step = 1U << vm_area_page_order(v);
4416 if (v->flags & VM_UNINITIALIZED)
4418 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
4421 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
4423 for (nr = 0; nr < v->nr_pages; nr += step)
4424 counters[page_to_nid(v->pages[nr])] += step;
4425 for_each_node_state(nr, N_HIGH_MEMORY)
4427 seq_printf(m, " N%u=%u", nr, counters[nr]);
4431 static void show_purge_info(struct seq_file *m)
4433 struct vmap_area *va;
4435 spin_lock(&purge_vmap_area_lock);
4436 list_for_each_entry(va, &purge_vmap_area_list, list) {
4437 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
4438 (void *)va->va_start, (void *)va->va_end,
4439 va->va_end - va->va_start);
4441 spin_unlock(&purge_vmap_area_lock);
4444 static int s_show(struct seq_file *m, void *p)
4446 struct vmap_area *va;
4447 struct vm_struct *v;
4449 va = list_entry(p, struct vmap_area, list);
4452 if (va->flags & VMAP_RAM)
4453 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
4454 (void *)va->va_start, (void *)va->va_end,
4455 va->va_end - va->va_start);
4462 seq_printf(m, "0x%pK-0x%pK %7ld",
4463 v->addr, v->addr + v->size, v->size);
4466 seq_printf(m, " %pS", v->caller);
4469 seq_printf(m, " pages=%d", v->nr_pages);
4472 seq_printf(m, " phys=%pa", &v->phys_addr);
4474 if (v->flags & VM_IOREMAP)
4475 seq_puts(m, " ioremap");
4477 if (v->flags & VM_SPARSE)
4478 seq_puts(m, " sparse");
4480 if (v->flags & VM_ALLOC)
4481 seq_puts(m, " vmalloc");
4483 if (v->flags & VM_MAP)
4484 seq_puts(m, " vmap");
4486 if (v->flags & VM_USERMAP)
4487 seq_puts(m, " user");
4489 if (v->flags & VM_DMA_COHERENT)
4490 seq_puts(m, " dma-coherent");
4492 if (is_vmalloc_addr(v->pages))
4493 seq_puts(m, " vpages");
4495 show_numa_info(m, v);
4499 * As a final step, dump "unpurged" areas.
4502 if (list_is_last(&va->list, &vmap_area_list))
4508 static const struct seq_operations vmalloc_op = {
4515 static int __init proc_vmalloc_init(void)
4517 if (IS_ENABLED(CONFIG_NUMA))
4518 proc_create_seq_private("vmallocinfo", 0400, NULL,
4520 nr_node_ids * sizeof(unsigned int), NULL);
4522 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
4525 module_init(proc_vmalloc_init);
4529 void __init vmalloc_init(void)
4531 struct vmap_area *va;
4532 struct vm_struct *tmp;
4536 * Create the cache for vmap_area objects.
4538 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
4540 for_each_possible_cpu(i) {
4541 struct vmap_block_queue *vbq;
4542 struct vfree_deferred *p;
4544 vbq = &per_cpu(vmap_block_queue, i);
4545 spin_lock_init(&vbq->lock);
4546 INIT_LIST_HEAD(&vbq->free);
4547 p = &per_cpu(vfree_deferred, i);
4548 init_llist_head(&p->list);
4549 INIT_WORK(&p->wq, delayed_vfree_work);
4550 xa_init(&vbq->vmap_blocks);
4553 /* Import existing vmlist entries. */
4554 for (tmp = vmlist; tmp; tmp = tmp->next) {
4555 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
4556 if (WARN_ON_ONCE(!va))
4559 va->va_start = (unsigned long)tmp->addr;
4560 va->va_end = va->va_start + tmp->size;
4562 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
4566 * Now we can initialize a free vmap space.
4568 vmap_init_free_space();
4569 vmap_initialized = true;