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>
28 #include <linux/rcupdate.h>
29 #include <linux/pfn.h>
30 #include <linux/kmemleak.h>
31 #include <linux/atomic.h>
32 #include <linux/compiler.h>
33 #include <linux/llist.h>
34 #include <linux/bitops.h>
35 #include <linux/rbtree_augmented.h>
36 #include <linux/overflow.h>
37 #include <linux/pgtable.h>
38 #include <linux/uaccess.h>
39 #include <asm/tlbflush.h>
40 #include <asm/shmparam.h>
43 #include "pgalloc-track.h"
45 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
46 static bool __ro_after_init vmap_allow_huge
= true;
48 static int __init
set_nohugevmalloc(char *str
)
50 vmap_allow_huge
= false;
53 early_param("nohugevmalloc", set_nohugevmalloc
);
54 #else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
55 static const bool vmap_allow_huge
= false;
56 #endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
58 bool is_vmalloc_addr(const void *x
)
60 unsigned long addr
= (unsigned long)x
;
62 return addr
>= VMALLOC_START
&& addr
< VMALLOC_END
;
64 EXPORT_SYMBOL(is_vmalloc_addr
);
66 struct vfree_deferred
{
67 struct llist_head list
;
68 struct work_struct wq
;
70 static DEFINE_PER_CPU(struct vfree_deferred
, vfree_deferred
);
72 static void __vunmap(const void *, int);
74 static void free_work(struct work_struct
*w
)
76 struct vfree_deferred
*p
= container_of(w
, struct vfree_deferred
, wq
);
77 struct llist_node
*t
, *llnode
;
79 llist_for_each_safe(llnode
, t
, llist_del_all(&p
->list
))
80 __vunmap((void *)llnode
, 1);
83 /*** Page table manipulation functions ***/
84 static int vmap_pte_range(pmd_t
*pmd
, unsigned long addr
, unsigned long end
,
85 phys_addr_t phys_addr
, pgprot_t prot
,
91 pfn
= phys_addr
>> PAGE_SHIFT
;
92 pte
= pte_alloc_kernel_track(pmd
, addr
, mask
);
96 BUG_ON(!pte_none(*pte
));
97 set_pte_at(&init_mm
, addr
, pte
, pfn_pte(pfn
, prot
));
99 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
100 *mask
|= PGTBL_PTE_MODIFIED
;
104 static int vmap_try_huge_pmd(pmd_t
*pmd
, unsigned long addr
, unsigned long end
,
105 phys_addr_t phys_addr
, pgprot_t prot
,
106 unsigned int max_page_shift
)
108 if (max_page_shift
< PMD_SHIFT
)
111 if (!arch_vmap_pmd_supported(prot
))
114 if ((end
- addr
) != PMD_SIZE
)
117 if (!IS_ALIGNED(addr
, PMD_SIZE
))
120 if (!IS_ALIGNED(phys_addr
, PMD_SIZE
))
123 if (pmd_present(*pmd
) && !pmd_free_pte_page(pmd
, addr
))
126 return pmd_set_huge(pmd
, phys_addr
, prot
);
129 static int vmap_pmd_range(pud_t
*pud
, unsigned long addr
, unsigned long end
,
130 phys_addr_t phys_addr
, pgprot_t prot
,
131 unsigned int max_page_shift
, pgtbl_mod_mask
*mask
)
136 pmd
= pmd_alloc_track(&init_mm
, pud
, addr
, mask
);
140 next
= pmd_addr_end(addr
, end
);
142 if (vmap_try_huge_pmd(pmd
, addr
, next
, phys_addr
, prot
,
144 *mask
|= PGTBL_PMD_MODIFIED
;
148 if (vmap_pte_range(pmd
, addr
, next
, phys_addr
, prot
, mask
))
150 } while (pmd
++, phys_addr
+= (next
- addr
), addr
= next
, addr
!= end
);
154 static int vmap_try_huge_pud(pud_t
*pud
, unsigned long addr
, unsigned long end
,
155 phys_addr_t phys_addr
, pgprot_t prot
,
156 unsigned int max_page_shift
)
158 if (max_page_shift
< PUD_SHIFT
)
161 if (!arch_vmap_pud_supported(prot
))
164 if ((end
- addr
) != PUD_SIZE
)
167 if (!IS_ALIGNED(addr
, PUD_SIZE
))
170 if (!IS_ALIGNED(phys_addr
, PUD_SIZE
))
173 if (pud_present(*pud
) && !pud_free_pmd_page(pud
, addr
))
176 return pud_set_huge(pud
, phys_addr
, prot
);
179 static int vmap_pud_range(p4d_t
*p4d
, unsigned long addr
, unsigned long end
,
180 phys_addr_t phys_addr
, pgprot_t prot
,
181 unsigned int max_page_shift
, pgtbl_mod_mask
*mask
)
186 pud
= pud_alloc_track(&init_mm
, p4d
, addr
, mask
);
190 next
= pud_addr_end(addr
, end
);
192 if (vmap_try_huge_pud(pud
, addr
, next
, phys_addr
, prot
,
194 *mask
|= PGTBL_PUD_MODIFIED
;
198 if (vmap_pmd_range(pud
, addr
, next
, phys_addr
, prot
,
199 max_page_shift
, mask
))
201 } while (pud
++, phys_addr
+= (next
- addr
), addr
= next
, addr
!= end
);
205 static int vmap_try_huge_p4d(p4d_t
*p4d
, unsigned long addr
, unsigned long end
,
206 phys_addr_t phys_addr
, pgprot_t prot
,
207 unsigned int max_page_shift
)
209 if (max_page_shift
< P4D_SHIFT
)
212 if (!arch_vmap_p4d_supported(prot
))
215 if ((end
- addr
) != P4D_SIZE
)
218 if (!IS_ALIGNED(addr
, P4D_SIZE
))
221 if (!IS_ALIGNED(phys_addr
, P4D_SIZE
))
224 if (p4d_present(*p4d
) && !p4d_free_pud_page(p4d
, addr
))
227 return p4d_set_huge(p4d
, phys_addr
, prot
);
230 static int vmap_p4d_range(pgd_t
*pgd
, unsigned long addr
, unsigned long end
,
231 phys_addr_t phys_addr
, pgprot_t prot
,
232 unsigned int max_page_shift
, pgtbl_mod_mask
*mask
)
237 p4d
= p4d_alloc_track(&init_mm
, pgd
, addr
, mask
);
241 next
= p4d_addr_end(addr
, end
);
243 if (vmap_try_huge_p4d(p4d
, addr
, next
, phys_addr
, prot
,
245 *mask
|= PGTBL_P4D_MODIFIED
;
249 if (vmap_pud_range(p4d
, addr
, next
, phys_addr
, prot
,
250 max_page_shift
, mask
))
252 } while (p4d
++, phys_addr
+= (next
- addr
), addr
= next
, addr
!= end
);
256 static int vmap_range_noflush(unsigned long addr
, unsigned long end
,
257 phys_addr_t phys_addr
, pgprot_t prot
,
258 unsigned int max_page_shift
)
264 pgtbl_mod_mask mask
= 0;
270 pgd
= pgd_offset_k(addr
);
272 next
= pgd_addr_end(addr
, end
);
273 err
= vmap_p4d_range(pgd
, addr
, next
, phys_addr
, prot
,
274 max_page_shift
, &mask
);
277 } while (pgd
++, phys_addr
+= (next
- addr
), addr
= next
, addr
!= end
);
279 if (mask
& ARCH_PAGE_TABLE_SYNC_MASK
)
280 arch_sync_kernel_mappings(start
, end
);
285 int vmap_range(unsigned long addr
, unsigned long end
,
286 phys_addr_t phys_addr
, pgprot_t prot
,
287 unsigned int max_page_shift
)
291 err
= vmap_range_noflush(addr
, end
, phys_addr
, prot
, max_page_shift
);
292 flush_cache_vmap(addr
, end
);
297 static void vunmap_pte_range(pmd_t
*pmd
, unsigned long addr
, unsigned long end
,
298 pgtbl_mod_mask
*mask
)
302 pte
= pte_offset_kernel(pmd
, addr
);
304 pte_t ptent
= ptep_get_and_clear(&init_mm
, addr
, pte
);
305 WARN_ON(!pte_none(ptent
) && !pte_present(ptent
));
306 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
307 *mask
|= PGTBL_PTE_MODIFIED
;
310 static void vunmap_pmd_range(pud_t
*pud
, unsigned long addr
, unsigned long end
,
311 pgtbl_mod_mask
*mask
)
317 pmd
= pmd_offset(pud
, addr
);
319 next
= pmd_addr_end(addr
, end
);
321 cleared
= pmd_clear_huge(pmd
);
322 if (cleared
|| pmd_bad(*pmd
))
323 *mask
|= PGTBL_PMD_MODIFIED
;
327 if (pmd_none_or_clear_bad(pmd
))
329 vunmap_pte_range(pmd
, addr
, next
, mask
);
332 } while (pmd
++, addr
= next
, addr
!= end
);
335 static void vunmap_pud_range(p4d_t
*p4d
, unsigned long addr
, unsigned long end
,
336 pgtbl_mod_mask
*mask
)
342 pud
= pud_offset(p4d
, addr
);
344 next
= pud_addr_end(addr
, end
);
346 cleared
= pud_clear_huge(pud
);
347 if (cleared
|| pud_bad(*pud
))
348 *mask
|= PGTBL_PUD_MODIFIED
;
352 if (pud_none_or_clear_bad(pud
))
354 vunmap_pmd_range(pud
, addr
, next
, mask
);
355 } while (pud
++, addr
= next
, addr
!= end
);
358 static void vunmap_p4d_range(pgd_t
*pgd
, unsigned long addr
, unsigned long end
,
359 pgtbl_mod_mask
*mask
)
365 p4d
= p4d_offset(pgd
, addr
);
367 next
= p4d_addr_end(addr
, end
);
369 cleared
= p4d_clear_huge(p4d
);
370 if (cleared
|| p4d_bad(*p4d
))
371 *mask
|= PGTBL_P4D_MODIFIED
;
375 if (p4d_none_or_clear_bad(p4d
))
377 vunmap_pud_range(p4d
, addr
, next
, mask
);
378 } while (p4d
++, addr
= next
, addr
!= end
);
382 * vunmap_range_noflush is similar to vunmap_range, but does not
383 * flush caches or TLBs.
385 * The caller is responsible for calling flush_cache_vmap() before calling
386 * this function, and flush_tlb_kernel_range after it has returned
387 * successfully (and before the addresses are expected to cause a page fault
388 * or be re-mapped for something else, if TLB flushes are being delayed or
391 * This is an internal function only. Do not use outside mm/.
393 void vunmap_range_noflush(unsigned long start
, unsigned long end
)
397 unsigned long addr
= start
;
398 pgtbl_mod_mask mask
= 0;
401 pgd
= pgd_offset_k(addr
);
403 next
= pgd_addr_end(addr
, end
);
405 mask
|= PGTBL_PGD_MODIFIED
;
406 if (pgd_none_or_clear_bad(pgd
))
408 vunmap_p4d_range(pgd
, addr
, next
, &mask
);
409 } while (pgd
++, addr
= next
, addr
!= end
);
411 if (mask
& ARCH_PAGE_TABLE_SYNC_MASK
)
412 arch_sync_kernel_mappings(start
, end
);
416 * vunmap_range - unmap kernel virtual addresses
417 * @addr: start of the VM area to unmap
418 * @end: end of the VM area to unmap (non-inclusive)
420 * Clears any present PTEs in the virtual address range, flushes TLBs and
421 * caches. Any subsequent access to the address before it has been re-mapped
424 void vunmap_range(unsigned long addr
, unsigned long end
)
426 flush_cache_vunmap(addr
, end
);
427 vunmap_range_noflush(addr
, end
);
428 flush_tlb_kernel_range(addr
, end
);
431 static int vmap_pages_pte_range(pmd_t
*pmd
, unsigned long addr
,
432 unsigned long end
, pgprot_t prot
, struct page
**pages
, int *nr
,
433 pgtbl_mod_mask
*mask
)
438 * nr is a running index into the array which helps higher level
439 * callers keep track of where we're up to.
442 pte
= pte_alloc_kernel_track(pmd
, addr
, mask
);
446 struct page
*page
= pages
[*nr
];
448 if (WARN_ON(!pte_none(*pte
)))
452 set_pte_at(&init_mm
, addr
, pte
, mk_pte(page
, prot
));
454 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
455 *mask
|= PGTBL_PTE_MODIFIED
;
459 static int vmap_pages_pmd_range(pud_t
*pud
, unsigned long addr
,
460 unsigned long end
, pgprot_t prot
, struct page
**pages
, int *nr
,
461 pgtbl_mod_mask
*mask
)
466 pmd
= pmd_alloc_track(&init_mm
, pud
, addr
, mask
);
470 next
= pmd_addr_end(addr
, end
);
471 if (vmap_pages_pte_range(pmd
, addr
, next
, prot
, pages
, nr
, mask
))
473 } while (pmd
++, addr
= next
, addr
!= end
);
477 static int vmap_pages_pud_range(p4d_t
*p4d
, unsigned long addr
,
478 unsigned long end
, pgprot_t prot
, struct page
**pages
, int *nr
,
479 pgtbl_mod_mask
*mask
)
484 pud
= pud_alloc_track(&init_mm
, p4d
, addr
, mask
);
488 next
= pud_addr_end(addr
, end
);
489 if (vmap_pages_pmd_range(pud
, addr
, next
, prot
, pages
, nr
, mask
))
491 } while (pud
++, addr
= next
, addr
!= end
);
495 static int vmap_pages_p4d_range(pgd_t
*pgd
, unsigned long addr
,
496 unsigned long end
, pgprot_t prot
, struct page
**pages
, int *nr
,
497 pgtbl_mod_mask
*mask
)
502 p4d
= p4d_alloc_track(&init_mm
, pgd
, addr
, mask
);
506 next
= p4d_addr_end(addr
, end
);
507 if (vmap_pages_pud_range(p4d
, addr
, next
, prot
, pages
, nr
, mask
))
509 } while (p4d
++, addr
= next
, addr
!= end
);
513 static int vmap_small_pages_range_noflush(unsigned long addr
, unsigned long end
,
514 pgprot_t prot
, struct page
**pages
)
516 unsigned long start
= addr
;
521 pgtbl_mod_mask mask
= 0;
524 pgd
= pgd_offset_k(addr
);
526 next
= pgd_addr_end(addr
, end
);
528 mask
|= PGTBL_PGD_MODIFIED
;
529 err
= vmap_pages_p4d_range(pgd
, addr
, next
, prot
, pages
, &nr
, &mask
);
532 } while (pgd
++, addr
= next
, addr
!= end
);
534 if (mask
& ARCH_PAGE_TABLE_SYNC_MASK
)
535 arch_sync_kernel_mappings(start
, end
);
541 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
544 * The caller is responsible for calling flush_cache_vmap() after this
545 * function returns successfully and before the addresses are accessed.
547 * This is an internal function only. Do not use outside mm/.
549 int vmap_pages_range_noflush(unsigned long addr
, unsigned long end
,
550 pgprot_t prot
, struct page
**pages
, unsigned int page_shift
)
552 unsigned int i
, nr
= (end
- addr
) >> PAGE_SHIFT
;
554 WARN_ON(page_shift
< PAGE_SHIFT
);
556 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC
) ||
557 page_shift
== PAGE_SHIFT
)
558 return vmap_small_pages_range_noflush(addr
, end
, prot
, pages
);
560 for (i
= 0; i
< nr
; i
+= 1U << (page_shift
- PAGE_SHIFT
)) {
563 err
= vmap_range_noflush(addr
, addr
+ (1UL << page_shift
),
564 __pa(page_address(pages
[i
])), prot
,
569 addr
+= 1UL << page_shift
;
576 * vmap_pages_range - map pages to a kernel virtual address
577 * @addr: start of the VM area to map
578 * @end: end of the VM area to map (non-inclusive)
579 * @prot: page protection flags to use
580 * @pages: pages to map (always PAGE_SIZE pages)
581 * @page_shift: maximum shift that the pages may be mapped with, @pages must
582 * be aligned and contiguous up to at least this shift.
585 * 0 on success, -errno on failure.
587 static int vmap_pages_range(unsigned long addr
, unsigned long end
,
588 pgprot_t prot
, struct page
**pages
, unsigned int page_shift
)
592 err
= vmap_pages_range_noflush(addr
, end
, prot
, pages
, page_shift
);
593 flush_cache_vmap(addr
, end
);
597 int is_vmalloc_or_module_addr(const void *x
)
600 * ARM, x86-64 and sparc64 put modules in a special place,
601 * and fall back on vmalloc() if that fails. Others
602 * just put it in the vmalloc space.
604 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
605 unsigned long addr
= (unsigned long)x
;
606 if (addr
>= MODULES_VADDR
&& addr
< MODULES_END
)
609 return is_vmalloc_addr(x
);
613 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
614 * return the tail page that corresponds to the base page address, which
615 * matches small vmap mappings.
617 struct page
*vmalloc_to_page(const void *vmalloc_addr
)
619 unsigned long addr
= (unsigned long) vmalloc_addr
;
620 struct page
*page
= NULL
;
621 pgd_t
*pgd
= pgd_offset_k(addr
);
628 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
629 * architectures that do not vmalloc module space
631 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr
));
635 if (WARN_ON_ONCE(pgd_leaf(*pgd
)))
636 return NULL
; /* XXX: no allowance for huge pgd */
637 if (WARN_ON_ONCE(pgd_bad(*pgd
)))
640 p4d
= p4d_offset(pgd
, addr
);
644 return p4d_page(*p4d
) + ((addr
& ~P4D_MASK
) >> PAGE_SHIFT
);
645 if (WARN_ON_ONCE(p4d_bad(*p4d
)))
648 pud
= pud_offset(p4d
, addr
);
652 return pud_page(*pud
) + ((addr
& ~PUD_MASK
) >> PAGE_SHIFT
);
653 if (WARN_ON_ONCE(pud_bad(*pud
)))
656 pmd
= pmd_offset(pud
, addr
);
660 return pmd_page(*pmd
) + ((addr
& ~PMD_MASK
) >> PAGE_SHIFT
);
661 if (WARN_ON_ONCE(pmd_bad(*pmd
)))
664 ptep
= pte_offset_map(pmd
, addr
);
666 if (pte_present(pte
))
667 page
= pte_page(pte
);
672 EXPORT_SYMBOL(vmalloc_to_page
);
675 * Map a vmalloc()-space virtual address to the physical page frame number.
677 unsigned long vmalloc_to_pfn(const void *vmalloc_addr
)
679 return page_to_pfn(vmalloc_to_page(vmalloc_addr
));
681 EXPORT_SYMBOL(vmalloc_to_pfn
);
684 /*** Global kva allocator ***/
686 #define DEBUG_AUGMENT_PROPAGATE_CHECK 0
687 #define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
690 static DEFINE_SPINLOCK(vmap_area_lock
);
691 static DEFINE_SPINLOCK(free_vmap_area_lock
);
692 /* Export for kexec only */
693 LIST_HEAD(vmap_area_list
);
694 static struct rb_root vmap_area_root
= RB_ROOT
;
695 static bool vmap_initialized __read_mostly
;
697 static struct rb_root purge_vmap_area_root
= RB_ROOT
;
698 static LIST_HEAD(purge_vmap_area_list
);
699 static DEFINE_SPINLOCK(purge_vmap_area_lock
);
702 * This kmem_cache is used for vmap_area objects. Instead of
703 * allocating from slab we reuse an object from this cache to
704 * make things faster. Especially in "no edge" splitting of
707 static struct kmem_cache
*vmap_area_cachep
;
710 * This linked list is used in pair with free_vmap_area_root.
711 * It gives O(1) access to prev/next to perform fast coalescing.
713 static LIST_HEAD(free_vmap_area_list
);
716 * This augment red-black tree represents the free vmap space.
717 * All vmap_area objects in this tree are sorted by va->va_start
718 * address. It is used for allocation and merging when a vmap
719 * object is released.
721 * Each vmap_area node contains a maximum available free block
722 * of its sub-tree, right or left. Therefore it is possible to
723 * find a lowest match of free area.
725 static struct rb_root free_vmap_area_root
= RB_ROOT
;
728 * Preload a CPU with one object for "no edge" split case. The
729 * aim is to get rid of allocations from the atomic context, thus
730 * to use more permissive allocation masks.
732 static DEFINE_PER_CPU(struct vmap_area
*, ne_fit_preload_node
);
734 static __always_inline
unsigned long
735 va_size(struct vmap_area
*va
)
737 return (va
->va_end
- va
->va_start
);
740 static __always_inline
unsigned long
741 get_subtree_max_size(struct rb_node
*node
)
743 struct vmap_area
*va
;
745 va
= rb_entry_safe(node
, struct vmap_area
, rb_node
);
746 return va
? va
->subtree_max_size
: 0;
750 * Gets called when remove the node and rotate.
752 static __always_inline
unsigned long
753 compute_subtree_max_size(struct vmap_area
*va
)
755 return max3(va_size(va
),
756 get_subtree_max_size(va
->rb_node
.rb_left
),
757 get_subtree_max_size(va
->rb_node
.rb_right
));
760 RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb
,
761 struct vmap_area
, rb_node
, unsigned long, subtree_max_size
, va_size
)
763 static void purge_vmap_area_lazy(void);
764 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list
);
765 static unsigned long lazy_max_pages(void);
767 static atomic_long_t nr_vmalloc_pages
;
769 unsigned long vmalloc_nr_pages(void)
771 return atomic_long_read(&nr_vmalloc_pages
);
774 static struct vmap_area
*__find_vmap_area(unsigned long addr
)
776 struct rb_node
*n
= vmap_area_root
.rb_node
;
779 struct vmap_area
*va
;
781 va
= rb_entry(n
, struct vmap_area
, rb_node
);
782 if (addr
< va
->va_start
)
784 else if (addr
>= va
->va_end
)
794 * This function returns back addresses of parent node
795 * and its left or right link for further processing.
797 * Otherwise NULL is returned. In that case all further
798 * steps regarding inserting of conflicting overlap range
799 * have to be declined and actually considered as a bug.
801 static __always_inline
struct rb_node
**
802 find_va_links(struct vmap_area
*va
,
803 struct rb_root
*root
, struct rb_node
*from
,
804 struct rb_node
**parent
)
806 struct vmap_area
*tmp_va
;
807 struct rb_node
**link
;
810 link
= &root
->rb_node
;
811 if (unlikely(!*link
)) {
820 * Go to the bottom of the tree. When we hit the last point
821 * we end up with parent rb_node and correct direction, i name
822 * it link, where the new va->rb_node will be attached to.
825 tmp_va
= rb_entry(*link
, struct vmap_area
, rb_node
);
828 * During the traversal we also do some sanity check.
829 * Trigger the BUG() if there are sides(left/right)
832 if (va
->va_start
< tmp_va
->va_end
&&
833 va
->va_end
<= tmp_va
->va_start
)
834 link
= &(*link
)->rb_left
;
835 else if (va
->va_end
> tmp_va
->va_start
&&
836 va
->va_start
>= tmp_va
->va_end
)
837 link
= &(*link
)->rb_right
;
839 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
840 va
->va_start
, va
->va_end
, tmp_va
->va_start
, tmp_va
->va_end
);
846 *parent
= &tmp_va
->rb_node
;
850 static __always_inline
struct list_head
*
851 get_va_next_sibling(struct rb_node
*parent
, struct rb_node
**link
)
853 struct list_head
*list
;
855 if (unlikely(!parent
))
857 * The red-black tree where we try to find VA neighbors
858 * before merging or inserting is empty, i.e. it means
859 * there is no free vmap space. Normally it does not
860 * happen but we handle this case anyway.
864 list
= &rb_entry(parent
, struct vmap_area
, rb_node
)->list
;
865 return (&parent
->rb_right
== link
? list
->next
: list
);
868 static __always_inline
void
869 link_va(struct vmap_area
*va
, struct rb_root
*root
,
870 struct rb_node
*parent
, struct rb_node
**link
, struct list_head
*head
)
873 * VA is still not in the list, but we can
874 * identify its future previous list_head node.
876 if (likely(parent
)) {
877 head
= &rb_entry(parent
, struct vmap_area
, rb_node
)->list
;
878 if (&parent
->rb_right
!= link
)
882 /* Insert to the rb-tree */
883 rb_link_node(&va
->rb_node
, parent
, link
);
884 if (root
== &free_vmap_area_root
) {
886 * Some explanation here. Just perform simple insertion
887 * to the tree. We do not set va->subtree_max_size to
888 * its current size before calling rb_insert_augmented().
889 * It is because of we populate the tree from the bottom
890 * to parent levels when the node _is_ in the tree.
892 * Therefore we set subtree_max_size to zero after insertion,
893 * to let __augment_tree_propagate_from() puts everything to
894 * the correct order later on.
896 rb_insert_augmented(&va
->rb_node
,
897 root
, &free_vmap_area_rb_augment_cb
);
898 va
->subtree_max_size
= 0;
900 rb_insert_color(&va
->rb_node
, root
);
903 /* Address-sort this list */
904 list_add(&va
->list
, head
);
907 static __always_inline
void
908 unlink_va(struct vmap_area
*va
, struct rb_root
*root
)
910 if (WARN_ON(RB_EMPTY_NODE(&va
->rb_node
)))
913 if (root
== &free_vmap_area_root
)
914 rb_erase_augmented(&va
->rb_node
,
915 root
, &free_vmap_area_rb_augment_cb
);
917 rb_erase(&va
->rb_node
, root
);
920 RB_CLEAR_NODE(&va
->rb_node
);
923 #if DEBUG_AUGMENT_PROPAGATE_CHECK
925 augment_tree_propagate_check(void)
927 struct vmap_area
*va
;
928 unsigned long computed_size
;
930 list_for_each_entry(va
, &free_vmap_area_list
, list
) {
931 computed_size
= compute_subtree_max_size(va
);
932 if (computed_size
!= va
->subtree_max_size
)
933 pr_emerg("tree is corrupted: %lu, %lu\n",
934 va_size(va
), va
->subtree_max_size
);
940 * This function populates subtree_max_size from bottom to upper
941 * levels starting from VA point. The propagation must be done
942 * when VA size is modified by changing its va_start/va_end. Or
943 * in case of newly inserting of VA to the tree.
945 * It means that __augment_tree_propagate_from() must be called:
946 * - After VA has been inserted to the tree(free path);
947 * - After VA has been shrunk(allocation path);
948 * - After VA has been increased(merging path).
950 * Please note that, it does not mean that upper parent nodes
951 * and their subtree_max_size are recalculated all the time up
960 * For example if we modify the node 4, shrinking it to 2, then
961 * no any modification is required. If we shrink the node 2 to 1
962 * its subtree_max_size is updated only, and set to 1. If we shrink
963 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
966 static __always_inline
void
967 augment_tree_propagate_from(struct vmap_area
*va
)
970 * Populate the tree from bottom towards the root until
971 * the calculated maximum available size of checked node
972 * is equal to its current one.
974 free_vmap_area_rb_augment_cb_propagate(&va
->rb_node
, NULL
);
976 #if DEBUG_AUGMENT_PROPAGATE_CHECK
977 augment_tree_propagate_check();
982 insert_vmap_area(struct vmap_area
*va
,
983 struct rb_root
*root
, struct list_head
*head
)
985 struct rb_node
**link
;
986 struct rb_node
*parent
;
988 link
= find_va_links(va
, root
, NULL
, &parent
);
990 link_va(va
, root
, parent
, link
, head
);
994 insert_vmap_area_augment(struct vmap_area
*va
,
995 struct rb_node
*from
, struct rb_root
*root
,
996 struct list_head
*head
)
998 struct rb_node
**link
;
999 struct rb_node
*parent
;
1002 link
= find_va_links(va
, NULL
, from
, &parent
);
1004 link
= find_va_links(va
, root
, NULL
, &parent
);
1007 link_va(va
, root
, parent
, link
, head
);
1008 augment_tree_propagate_from(va
);
1013 * Merge de-allocated chunk of VA memory with previous
1014 * and next free blocks. If coalesce is not done a new
1015 * free area is inserted. If VA has been merged, it is
1018 * Please note, it can return NULL in case of overlap
1019 * ranges, followed by WARN() report. Despite it is a
1020 * buggy behaviour, a system can be alive and keep
1023 static __always_inline
struct vmap_area
*
1024 merge_or_add_vmap_area(struct vmap_area
*va
,
1025 struct rb_root
*root
, struct list_head
*head
)
1027 struct vmap_area
*sibling
;
1028 struct list_head
*next
;
1029 struct rb_node
**link
;
1030 struct rb_node
*parent
;
1031 bool merged
= false;
1034 * Find a place in the tree where VA potentially will be
1035 * inserted, unless it is merged with its sibling/siblings.
1037 link
= find_va_links(va
, root
, NULL
, &parent
);
1042 * Get next node of VA to check if merging can be done.
1044 next
= get_va_next_sibling(parent
, link
);
1045 if (unlikely(next
== NULL
))
1051 * |<------VA------>|<-----Next----->|
1056 sibling
= list_entry(next
, struct vmap_area
, list
);
1057 if (sibling
->va_start
== va
->va_end
) {
1058 sibling
->va_start
= va
->va_start
;
1060 /* Free vmap_area object. */
1061 kmem_cache_free(vmap_area_cachep
, va
);
1063 /* Point to the new merged area. */
1072 * |<-----Prev----->|<------VA------>|
1076 if (next
->prev
!= head
) {
1077 sibling
= list_entry(next
->prev
, struct vmap_area
, list
);
1078 if (sibling
->va_end
== va
->va_start
) {
1080 * If both neighbors are coalesced, it is important
1081 * to unlink the "next" node first, followed by merging
1082 * with "previous" one. Otherwise the tree might not be
1083 * fully populated if a sibling's augmented value is
1084 * "normalized" because of rotation operations.
1087 unlink_va(va
, root
);
1089 sibling
->va_end
= va
->va_end
;
1091 /* Free vmap_area object. */
1092 kmem_cache_free(vmap_area_cachep
, va
);
1094 /* Point to the new merged area. */
1102 link_va(va
, root
, parent
, link
, head
);
1107 static __always_inline
struct vmap_area
*
1108 merge_or_add_vmap_area_augment(struct vmap_area
*va
,
1109 struct rb_root
*root
, struct list_head
*head
)
1111 va
= merge_or_add_vmap_area(va
, root
, head
);
1113 augment_tree_propagate_from(va
);
1118 static __always_inline
bool
1119 is_within_this_va(struct vmap_area
*va
, unsigned long size
,
1120 unsigned long align
, unsigned long vstart
)
1122 unsigned long nva_start_addr
;
1124 if (va
->va_start
> vstart
)
1125 nva_start_addr
= ALIGN(va
->va_start
, align
);
1127 nva_start_addr
= ALIGN(vstart
, align
);
1129 /* Can be overflowed due to big size or alignment. */
1130 if (nva_start_addr
+ size
< nva_start_addr
||
1131 nva_start_addr
< vstart
)
1134 return (nva_start_addr
+ size
<= va
->va_end
);
1138 * Find the first free block(lowest start address) in the tree,
1139 * that will accomplish the request corresponding to passing
1142 static __always_inline
struct vmap_area
*
1143 find_vmap_lowest_match(unsigned long size
,
1144 unsigned long align
, unsigned long vstart
)
1146 struct vmap_area
*va
;
1147 struct rb_node
*node
;
1148 unsigned long length
;
1150 /* Start from the root. */
1151 node
= free_vmap_area_root
.rb_node
;
1153 /* Adjust the search size for alignment overhead. */
1154 length
= size
+ align
- 1;
1157 va
= rb_entry(node
, struct vmap_area
, rb_node
);
1159 if (get_subtree_max_size(node
->rb_left
) >= length
&&
1160 vstart
< va
->va_start
) {
1161 node
= node
->rb_left
;
1163 if (is_within_this_va(va
, size
, align
, vstart
))
1167 * Does not make sense to go deeper towards the right
1168 * sub-tree if it does not have a free block that is
1169 * equal or bigger to the requested search length.
1171 if (get_subtree_max_size(node
->rb_right
) >= length
) {
1172 node
= node
->rb_right
;
1177 * OK. We roll back and find the first right sub-tree,
1178 * that will satisfy the search criteria. It can happen
1179 * only once due to "vstart" restriction.
1181 while ((node
= rb_parent(node
))) {
1182 va
= rb_entry(node
, struct vmap_area
, rb_node
);
1183 if (is_within_this_va(va
, size
, align
, vstart
))
1186 if (get_subtree_max_size(node
->rb_right
) >= length
&&
1187 vstart
<= va
->va_start
) {
1188 node
= node
->rb_right
;
1198 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1199 #include <linux/random.h>
1201 static struct vmap_area
*
1202 find_vmap_lowest_linear_match(unsigned long size
,
1203 unsigned long align
, unsigned long vstart
)
1205 struct vmap_area
*va
;
1207 list_for_each_entry(va
, &free_vmap_area_list
, list
) {
1208 if (!is_within_this_va(va
, size
, align
, vstart
))
1218 find_vmap_lowest_match_check(unsigned long size
)
1220 struct vmap_area
*va_1
, *va_2
;
1221 unsigned long vstart
;
1224 get_random_bytes(&rnd
, sizeof(rnd
));
1225 vstart
= VMALLOC_START
+ rnd
;
1227 va_1
= find_vmap_lowest_match(size
, 1, vstart
);
1228 va_2
= find_vmap_lowest_linear_match(size
, 1, vstart
);
1231 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1232 va_1
, va_2
, vstart
);
1238 FL_FIT_TYPE
= 1, /* full fit */
1239 LE_FIT_TYPE
= 2, /* left edge fit */
1240 RE_FIT_TYPE
= 3, /* right edge fit */
1241 NE_FIT_TYPE
= 4 /* no edge fit */
1244 static __always_inline
enum fit_type
1245 classify_va_fit_type(struct vmap_area
*va
,
1246 unsigned long nva_start_addr
, unsigned long size
)
1250 /* Check if it is within VA. */
1251 if (nva_start_addr
< va
->va_start
||
1252 nva_start_addr
+ size
> va
->va_end
)
1256 if (va
->va_start
== nva_start_addr
) {
1257 if (va
->va_end
== nva_start_addr
+ size
)
1261 } else if (va
->va_end
== nva_start_addr
+ size
) {
1270 static __always_inline
int
1271 adjust_va_to_fit_type(struct vmap_area
*va
,
1272 unsigned long nva_start_addr
, unsigned long size
,
1275 struct vmap_area
*lva
= NULL
;
1277 if (type
== FL_FIT_TYPE
) {
1279 * No need to split VA, it fully fits.
1285 unlink_va(va
, &free_vmap_area_root
);
1286 kmem_cache_free(vmap_area_cachep
, va
);
1287 } else if (type
== LE_FIT_TYPE
) {
1289 * Split left edge of fit VA.
1295 va
->va_start
+= size
;
1296 } else if (type
== RE_FIT_TYPE
) {
1298 * Split right edge of fit VA.
1304 va
->va_end
= nva_start_addr
;
1305 } else if (type
== NE_FIT_TYPE
) {
1307 * Split no edge of fit VA.
1313 lva
= __this_cpu_xchg(ne_fit_preload_node
, NULL
);
1314 if (unlikely(!lva
)) {
1316 * For percpu allocator we do not do any pre-allocation
1317 * and leave it as it is. The reason is it most likely
1318 * never ends up with NE_FIT_TYPE splitting. In case of
1319 * percpu allocations offsets and sizes are aligned to
1320 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1321 * are its main fitting cases.
1323 * There are a few exceptions though, as an example it is
1324 * a first allocation (early boot up) when we have "one"
1325 * big free space that has to be split.
1327 * Also we can hit this path in case of regular "vmap"
1328 * allocations, if "this" current CPU was not preloaded.
1329 * See the comment in alloc_vmap_area() why. If so, then
1330 * GFP_NOWAIT is used instead to get an extra object for
1331 * split purpose. That is rare and most time does not
1334 * What happens if an allocation gets failed. Basically,
1335 * an "overflow" path is triggered to purge lazily freed
1336 * areas to free some memory, then, the "retry" path is
1337 * triggered to repeat one more time. See more details
1338 * in alloc_vmap_area() function.
1340 lva
= kmem_cache_alloc(vmap_area_cachep
, GFP_NOWAIT
);
1346 * Build the remainder.
1348 lva
->va_start
= va
->va_start
;
1349 lva
->va_end
= nva_start_addr
;
1352 * Shrink this VA to remaining size.
1354 va
->va_start
= nva_start_addr
+ size
;
1359 if (type
!= FL_FIT_TYPE
) {
1360 augment_tree_propagate_from(va
);
1362 if (lva
) /* type == NE_FIT_TYPE */
1363 insert_vmap_area_augment(lva
, &va
->rb_node
,
1364 &free_vmap_area_root
, &free_vmap_area_list
);
1371 * Returns a start address of the newly allocated area, if success.
1372 * Otherwise a vend is returned that indicates failure.
1374 static __always_inline
unsigned long
1375 __alloc_vmap_area(unsigned long size
, unsigned long align
,
1376 unsigned long vstart
, unsigned long vend
)
1378 unsigned long nva_start_addr
;
1379 struct vmap_area
*va
;
1383 va
= find_vmap_lowest_match(size
, align
, vstart
);
1387 if (va
->va_start
> vstart
)
1388 nva_start_addr
= ALIGN(va
->va_start
, align
);
1390 nva_start_addr
= ALIGN(vstart
, align
);
1392 /* Check the "vend" restriction. */
1393 if (nva_start_addr
+ size
> vend
)
1396 /* Classify what we have found. */
1397 type
= classify_va_fit_type(va
, nva_start_addr
, size
);
1398 if (WARN_ON_ONCE(type
== NOTHING_FIT
))
1401 /* Update the free vmap_area. */
1402 ret
= adjust_va_to_fit_type(va
, nva_start_addr
, size
, type
);
1406 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1407 find_vmap_lowest_match_check(size
);
1410 return nva_start_addr
;
1414 * Free a region of KVA allocated by alloc_vmap_area
1416 static void free_vmap_area(struct vmap_area
*va
)
1419 * Remove from the busy tree/list.
1421 spin_lock(&vmap_area_lock
);
1422 unlink_va(va
, &vmap_area_root
);
1423 spin_unlock(&vmap_area_lock
);
1426 * Insert/Merge it back to the free tree/list.
1428 spin_lock(&free_vmap_area_lock
);
1429 merge_or_add_vmap_area_augment(va
, &free_vmap_area_root
, &free_vmap_area_list
);
1430 spin_unlock(&free_vmap_area_lock
);
1434 preload_this_cpu_lock(spinlock_t
*lock
, gfp_t gfp_mask
, int node
)
1436 struct vmap_area
*va
= NULL
;
1439 * Preload this CPU with one extra vmap_area object. It is used
1440 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1441 * a CPU that does an allocation is preloaded.
1443 * We do it in non-atomic context, thus it allows us to use more
1444 * permissive allocation masks to be more stable under low memory
1445 * condition and high memory pressure.
1447 if (!this_cpu_read(ne_fit_preload_node
))
1448 va
= kmem_cache_alloc_node(vmap_area_cachep
, gfp_mask
, node
);
1452 if (va
&& __this_cpu_cmpxchg(ne_fit_preload_node
, NULL
, va
))
1453 kmem_cache_free(vmap_area_cachep
, va
);
1457 * Allocate a region of KVA of the specified size and alignment, within the
1460 static struct vmap_area
*alloc_vmap_area(unsigned long size
,
1461 unsigned long align
,
1462 unsigned long vstart
, unsigned long vend
,
1463 int node
, gfp_t gfp_mask
)
1465 struct vmap_area
*va
;
1471 BUG_ON(offset_in_page(size
));
1472 BUG_ON(!is_power_of_2(align
));
1474 if (unlikely(!vmap_initialized
))
1475 return ERR_PTR(-EBUSY
);
1478 gfp_mask
= gfp_mask
& GFP_RECLAIM_MASK
;
1480 va
= kmem_cache_alloc_node(vmap_area_cachep
, gfp_mask
, node
);
1482 return ERR_PTR(-ENOMEM
);
1485 * Only scan the relevant parts containing pointers to other objects
1486 * to avoid false negatives.
1488 kmemleak_scan_area(&va
->rb_node
, SIZE_MAX
, gfp_mask
);
1491 preload_this_cpu_lock(&free_vmap_area_lock
, gfp_mask
, node
);
1492 addr
= __alloc_vmap_area(size
, align
, vstart
, vend
);
1493 spin_unlock(&free_vmap_area_lock
);
1496 * If an allocation fails, the "vend" address is
1497 * returned. Therefore trigger the overflow path.
1499 if (unlikely(addr
== vend
))
1502 va
->va_start
= addr
;
1503 va
->va_end
= addr
+ size
;
1506 spin_lock(&vmap_area_lock
);
1507 insert_vmap_area(va
, &vmap_area_root
, &vmap_area_list
);
1508 spin_unlock(&vmap_area_lock
);
1510 BUG_ON(!IS_ALIGNED(va
->va_start
, align
));
1511 BUG_ON(va
->va_start
< vstart
);
1512 BUG_ON(va
->va_end
> vend
);
1514 ret
= kasan_populate_vmalloc(addr
, size
);
1517 return ERR_PTR(ret
);
1524 purge_vmap_area_lazy();
1529 if (gfpflags_allow_blocking(gfp_mask
)) {
1530 unsigned long freed
= 0;
1531 blocking_notifier_call_chain(&vmap_notify_list
, 0, &freed
);
1538 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit())
1539 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1542 kmem_cache_free(vmap_area_cachep
, va
);
1543 return ERR_PTR(-EBUSY
);
1546 int register_vmap_purge_notifier(struct notifier_block
*nb
)
1548 return blocking_notifier_chain_register(&vmap_notify_list
, nb
);
1550 EXPORT_SYMBOL_GPL(register_vmap_purge_notifier
);
1552 int unregister_vmap_purge_notifier(struct notifier_block
*nb
)
1554 return blocking_notifier_chain_unregister(&vmap_notify_list
, nb
);
1556 EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier
);
1559 * lazy_max_pages is the maximum amount of virtual address space we gather up
1560 * before attempting to purge with a TLB flush.
1562 * There is a tradeoff here: a larger number will cover more kernel page tables
1563 * and take slightly longer to purge, but it will linearly reduce the number of
1564 * global TLB flushes that must be performed. It would seem natural to scale
1565 * this number up linearly with the number of CPUs (because vmapping activity
1566 * could also scale linearly with the number of CPUs), however it is likely
1567 * that in practice, workloads might be constrained in other ways that mean
1568 * vmap activity will not scale linearly with CPUs. Also, I want to be
1569 * conservative and not introduce a big latency on huge systems, so go with
1570 * a less aggressive log scale. It will still be an improvement over the old
1571 * code, and it will be simple to change the scale factor if we find that it
1572 * becomes a problem on bigger systems.
1574 static unsigned long lazy_max_pages(void)
1578 log
= fls(num_online_cpus());
1580 return log
* (32UL * 1024 * 1024 / PAGE_SIZE
);
1583 static atomic_long_t vmap_lazy_nr
= ATOMIC_LONG_INIT(0);
1586 * Serialize vmap purging. There is no actual critical section protected
1587 * by this look, but we want to avoid concurrent calls for performance
1588 * reasons and to make the pcpu_get_vm_areas more deterministic.
1590 static DEFINE_MUTEX(vmap_purge_lock
);
1592 /* for per-CPU blocks */
1593 static void purge_fragmented_blocks_allcpus(void);
1596 * called before a call to iounmap() if the caller wants vm_area_struct's
1597 * immediately freed.
1599 void set_iounmap_nonlazy(void)
1601 atomic_long_set(&vmap_lazy_nr
, lazy_max_pages()+1);
1605 * Purges all lazily-freed vmap areas.
1607 static bool __purge_vmap_area_lazy(unsigned long start
, unsigned long end
)
1609 unsigned long resched_threshold
;
1610 struct list_head local_pure_list
;
1611 struct vmap_area
*va
, *n_va
;
1613 lockdep_assert_held(&vmap_purge_lock
);
1615 spin_lock(&purge_vmap_area_lock
);
1616 purge_vmap_area_root
= RB_ROOT
;
1617 list_replace_init(&purge_vmap_area_list
, &local_pure_list
);
1618 spin_unlock(&purge_vmap_area_lock
);
1620 if (unlikely(list_empty(&local_pure_list
)))
1624 list_first_entry(&local_pure_list
,
1625 struct vmap_area
, list
)->va_start
);
1628 list_last_entry(&local_pure_list
,
1629 struct vmap_area
, list
)->va_end
);
1631 flush_tlb_kernel_range(start
, end
);
1632 resched_threshold
= lazy_max_pages() << 1;
1634 spin_lock(&free_vmap_area_lock
);
1635 list_for_each_entry_safe(va
, n_va
, &local_pure_list
, list
) {
1636 unsigned long nr
= (va
->va_end
- va
->va_start
) >> PAGE_SHIFT
;
1637 unsigned long orig_start
= va
->va_start
;
1638 unsigned long orig_end
= va
->va_end
;
1641 * Finally insert or merge lazily-freed area. It is
1642 * detached and there is no need to "unlink" it from
1645 va
= merge_or_add_vmap_area_augment(va
, &free_vmap_area_root
,
1646 &free_vmap_area_list
);
1651 if (is_vmalloc_or_module_addr((void *)orig_start
))
1652 kasan_release_vmalloc(orig_start
, orig_end
,
1653 va
->va_start
, va
->va_end
);
1655 atomic_long_sub(nr
, &vmap_lazy_nr
);
1657 if (atomic_long_read(&vmap_lazy_nr
) < resched_threshold
)
1658 cond_resched_lock(&free_vmap_area_lock
);
1660 spin_unlock(&free_vmap_area_lock
);
1665 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
1666 * is already purging.
1668 static void try_purge_vmap_area_lazy(void)
1670 if (mutex_trylock(&vmap_purge_lock
)) {
1671 __purge_vmap_area_lazy(ULONG_MAX
, 0);
1672 mutex_unlock(&vmap_purge_lock
);
1677 * Kick off a purge of the outstanding lazy areas.
1679 static void purge_vmap_area_lazy(void)
1681 mutex_lock(&vmap_purge_lock
);
1682 purge_fragmented_blocks_allcpus();
1683 __purge_vmap_area_lazy(ULONG_MAX
, 0);
1684 mutex_unlock(&vmap_purge_lock
);
1688 * Free a vmap area, caller ensuring that the area has been unmapped
1689 * and flush_cache_vunmap had been called for the correct range
1692 static void free_vmap_area_noflush(struct vmap_area
*va
)
1694 unsigned long nr_lazy
;
1696 spin_lock(&vmap_area_lock
);
1697 unlink_va(va
, &vmap_area_root
);
1698 spin_unlock(&vmap_area_lock
);
1700 nr_lazy
= atomic_long_add_return((va
->va_end
- va
->va_start
) >>
1701 PAGE_SHIFT
, &vmap_lazy_nr
);
1704 * Merge or place it to the purge tree/list.
1706 spin_lock(&purge_vmap_area_lock
);
1707 merge_or_add_vmap_area(va
,
1708 &purge_vmap_area_root
, &purge_vmap_area_list
);
1709 spin_unlock(&purge_vmap_area_lock
);
1711 /* After this point, we may free va at any time */
1712 if (unlikely(nr_lazy
> lazy_max_pages()))
1713 try_purge_vmap_area_lazy();
1717 * Free and unmap a vmap area
1719 static void free_unmap_vmap_area(struct vmap_area
*va
)
1721 flush_cache_vunmap(va
->va_start
, va
->va_end
);
1722 vunmap_range_noflush(va
->va_start
, va
->va_end
);
1723 if (debug_pagealloc_enabled_static())
1724 flush_tlb_kernel_range(va
->va_start
, va
->va_end
);
1726 free_vmap_area_noflush(va
);
1729 static struct vmap_area
*find_vmap_area(unsigned long addr
)
1731 struct vmap_area
*va
;
1733 spin_lock(&vmap_area_lock
);
1734 va
= __find_vmap_area(addr
);
1735 spin_unlock(&vmap_area_lock
);
1740 /*** Per cpu kva allocator ***/
1743 * vmap space is limited especially on 32 bit architectures. Ensure there is
1744 * room for at least 16 percpu vmap blocks per CPU.
1747 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1748 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1749 * instead (we just need a rough idea)
1751 #if BITS_PER_LONG == 32
1752 #define VMALLOC_SPACE (128UL*1024*1024)
1754 #define VMALLOC_SPACE (128UL*1024*1024*1024)
1757 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1758 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1759 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1760 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1761 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1762 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1763 #define VMAP_BBMAP_BITS \
1764 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1765 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1766 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1768 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1770 struct vmap_block_queue
{
1772 struct list_head free
;
1777 struct vmap_area
*va
;
1778 unsigned long free
, dirty
;
1779 unsigned long dirty_min
, dirty_max
; /*< dirty range */
1780 struct list_head free_list
;
1781 struct rcu_head rcu_head
;
1782 struct list_head purge
;
1785 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
1786 static DEFINE_PER_CPU(struct vmap_block_queue
, vmap_block_queue
);
1789 * XArray of vmap blocks, indexed by address, to quickly find a vmap block
1790 * in the free path. Could get rid of this if we change the API to return a
1791 * "cookie" from alloc, to be passed to free. But no big deal yet.
1793 static DEFINE_XARRAY(vmap_blocks
);
1796 * We should probably have a fallback mechanism to allocate virtual memory
1797 * out of partially filled vmap blocks. However vmap block sizing should be
1798 * fairly reasonable according to the vmalloc size, so it shouldn't be a
1802 static unsigned long addr_to_vb_idx(unsigned long addr
)
1804 addr
-= VMALLOC_START
& ~(VMAP_BLOCK_SIZE
-1);
1805 addr
/= VMAP_BLOCK_SIZE
;
1809 static void *vmap_block_vaddr(unsigned long va_start
, unsigned long pages_off
)
1813 addr
= va_start
+ (pages_off
<< PAGE_SHIFT
);
1814 BUG_ON(addr_to_vb_idx(addr
) != addr_to_vb_idx(va_start
));
1815 return (void *)addr
;
1819 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
1820 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
1821 * @order: how many 2^order pages should be occupied in newly allocated block
1822 * @gfp_mask: flags for the page level allocator
1824 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
1826 static void *new_vmap_block(unsigned int order
, gfp_t gfp_mask
)
1828 struct vmap_block_queue
*vbq
;
1829 struct vmap_block
*vb
;
1830 struct vmap_area
*va
;
1831 unsigned long vb_idx
;
1835 node
= numa_node_id();
1837 vb
= kmalloc_node(sizeof(struct vmap_block
),
1838 gfp_mask
& GFP_RECLAIM_MASK
, node
);
1840 return ERR_PTR(-ENOMEM
);
1842 va
= alloc_vmap_area(VMAP_BLOCK_SIZE
, VMAP_BLOCK_SIZE
,
1843 VMALLOC_START
, VMALLOC_END
,
1847 return ERR_CAST(va
);
1850 vaddr
= vmap_block_vaddr(va
->va_start
, 0);
1851 spin_lock_init(&vb
->lock
);
1853 /* At least something should be left free */
1854 BUG_ON(VMAP_BBMAP_BITS
<= (1UL << order
));
1855 vb
->free
= VMAP_BBMAP_BITS
- (1UL << order
);
1857 vb
->dirty_min
= VMAP_BBMAP_BITS
;
1859 INIT_LIST_HEAD(&vb
->free_list
);
1861 vb_idx
= addr_to_vb_idx(va
->va_start
);
1862 err
= xa_insert(&vmap_blocks
, vb_idx
, vb
, gfp_mask
);
1866 return ERR_PTR(err
);
1869 vbq
= &get_cpu_var(vmap_block_queue
);
1870 spin_lock(&vbq
->lock
);
1871 list_add_tail_rcu(&vb
->free_list
, &vbq
->free
);
1872 spin_unlock(&vbq
->lock
);
1873 put_cpu_var(vmap_block_queue
);
1878 static void free_vmap_block(struct vmap_block
*vb
)
1880 struct vmap_block
*tmp
;
1882 tmp
= xa_erase(&vmap_blocks
, addr_to_vb_idx(vb
->va
->va_start
));
1885 free_vmap_area_noflush(vb
->va
);
1886 kfree_rcu(vb
, rcu_head
);
1889 static void purge_fragmented_blocks(int cpu
)
1892 struct vmap_block
*vb
;
1893 struct vmap_block
*n_vb
;
1894 struct vmap_block_queue
*vbq
= &per_cpu(vmap_block_queue
, cpu
);
1897 list_for_each_entry_rcu(vb
, &vbq
->free
, free_list
) {
1899 if (!(vb
->free
+ vb
->dirty
== VMAP_BBMAP_BITS
&& vb
->dirty
!= VMAP_BBMAP_BITS
))
1902 spin_lock(&vb
->lock
);
1903 if (vb
->free
+ vb
->dirty
== VMAP_BBMAP_BITS
&& vb
->dirty
!= VMAP_BBMAP_BITS
) {
1904 vb
->free
= 0; /* prevent further allocs after releasing lock */
1905 vb
->dirty
= VMAP_BBMAP_BITS
; /* prevent purging it again */
1907 vb
->dirty_max
= VMAP_BBMAP_BITS
;
1908 spin_lock(&vbq
->lock
);
1909 list_del_rcu(&vb
->free_list
);
1910 spin_unlock(&vbq
->lock
);
1911 spin_unlock(&vb
->lock
);
1912 list_add_tail(&vb
->purge
, &purge
);
1914 spin_unlock(&vb
->lock
);
1918 list_for_each_entry_safe(vb
, n_vb
, &purge
, purge
) {
1919 list_del(&vb
->purge
);
1920 free_vmap_block(vb
);
1924 static void purge_fragmented_blocks_allcpus(void)
1928 for_each_possible_cpu(cpu
)
1929 purge_fragmented_blocks(cpu
);
1932 static void *vb_alloc(unsigned long size
, gfp_t gfp_mask
)
1934 struct vmap_block_queue
*vbq
;
1935 struct vmap_block
*vb
;
1939 BUG_ON(offset_in_page(size
));
1940 BUG_ON(size
> PAGE_SIZE
*VMAP_MAX_ALLOC
);
1941 if (WARN_ON(size
== 0)) {
1943 * Allocating 0 bytes isn't what caller wants since
1944 * get_order(0) returns funny result. Just warn and terminate
1949 order
= get_order(size
);
1952 vbq
= &get_cpu_var(vmap_block_queue
);
1953 list_for_each_entry_rcu(vb
, &vbq
->free
, free_list
) {
1954 unsigned long pages_off
;
1956 spin_lock(&vb
->lock
);
1957 if (vb
->free
< (1UL << order
)) {
1958 spin_unlock(&vb
->lock
);
1962 pages_off
= VMAP_BBMAP_BITS
- vb
->free
;
1963 vaddr
= vmap_block_vaddr(vb
->va
->va_start
, pages_off
);
1964 vb
->free
-= 1UL << order
;
1965 if (vb
->free
== 0) {
1966 spin_lock(&vbq
->lock
);
1967 list_del_rcu(&vb
->free_list
);
1968 spin_unlock(&vbq
->lock
);
1971 spin_unlock(&vb
->lock
);
1975 put_cpu_var(vmap_block_queue
);
1978 /* Allocate new block if nothing was found */
1980 vaddr
= new_vmap_block(order
, gfp_mask
);
1985 static void vb_free(unsigned long addr
, unsigned long size
)
1987 unsigned long offset
;
1989 struct vmap_block
*vb
;
1991 BUG_ON(offset_in_page(size
));
1992 BUG_ON(size
> PAGE_SIZE
*VMAP_MAX_ALLOC
);
1994 flush_cache_vunmap(addr
, addr
+ size
);
1996 order
= get_order(size
);
1997 offset
= (addr
& (VMAP_BLOCK_SIZE
- 1)) >> PAGE_SHIFT
;
1998 vb
= xa_load(&vmap_blocks
, addr_to_vb_idx(addr
));
2000 vunmap_range_noflush(addr
, addr
+ size
);
2002 if (debug_pagealloc_enabled_static())
2003 flush_tlb_kernel_range(addr
, addr
+ size
);
2005 spin_lock(&vb
->lock
);
2007 /* Expand dirty range */
2008 vb
->dirty_min
= min(vb
->dirty_min
, offset
);
2009 vb
->dirty_max
= max(vb
->dirty_max
, offset
+ (1UL << order
));
2011 vb
->dirty
+= 1UL << order
;
2012 if (vb
->dirty
== VMAP_BBMAP_BITS
) {
2014 spin_unlock(&vb
->lock
);
2015 free_vmap_block(vb
);
2017 spin_unlock(&vb
->lock
);
2020 static void _vm_unmap_aliases(unsigned long start
, unsigned long end
, int flush
)
2024 if (unlikely(!vmap_initialized
))
2029 for_each_possible_cpu(cpu
) {
2030 struct vmap_block_queue
*vbq
= &per_cpu(vmap_block_queue
, cpu
);
2031 struct vmap_block
*vb
;
2034 list_for_each_entry_rcu(vb
, &vbq
->free
, free_list
) {
2035 spin_lock(&vb
->lock
);
2036 if (vb
->dirty
&& vb
->dirty
!= VMAP_BBMAP_BITS
) {
2037 unsigned long va_start
= vb
->va
->va_start
;
2040 s
= va_start
+ (vb
->dirty_min
<< PAGE_SHIFT
);
2041 e
= va_start
+ (vb
->dirty_max
<< PAGE_SHIFT
);
2043 start
= min(s
, start
);
2048 spin_unlock(&vb
->lock
);
2053 mutex_lock(&vmap_purge_lock
);
2054 purge_fragmented_blocks_allcpus();
2055 if (!__purge_vmap_area_lazy(start
, end
) && flush
)
2056 flush_tlb_kernel_range(start
, end
);
2057 mutex_unlock(&vmap_purge_lock
);
2061 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2063 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2064 * to amortize TLB flushing overheads. What this means is that any page you
2065 * have now, may, in a former life, have been mapped into kernel virtual
2066 * address by the vmap layer and so there might be some CPUs with TLB entries
2067 * still referencing that page (additional to the regular 1:1 kernel mapping).
2069 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2070 * be sure that none of the pages we have control over will have any aliases
2071 * from the vmap layer.
2073 void vm_unmap_aliases(void)
2075 unsigned long start
= ULONG_MAX
, end
= 0;
2078 _vm_unmap_aliases(start
, end
, flush
);
2080 EXPORT_SYMBOL_GPL(vm_unmap_aliases
);
2083 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2084 * @mem: the pointer returned by vm_map_ram
2085 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2087 void vm_unmap_ram(const void *mem
, unsigned int count
)
2089 unsigned long size
= (unsigned long)count
<< PAGE_SHIFT
;
2090 unsigned long addr
= (unsigned long)mem
;
2091 struct vmap_area
*va
;
2095 BUG_ON(addr
< VMALLOC_START
);
2096 BUG_ON(addr
> VMALLOC_END
);
2097 BUG_ON(!PAGE_ALIGNED(addr
));
2099 kasan_poison_vmalloc(mem
, size
);
2101 if (likely(count
<= VMAP_MAX_ALLOC
)) {
2102 debug_check_no_locks_freed(mem
, size
);
2103 vb_free(addr
, size
);
2107 va
= find_vmap_area(addr
);
2109 debug_check_no_locks_freed((void *)va
->va_start
,
2110 (va
->va_end
- va
->va_start
));
2111 free_unmap_vmap_area(va
);
2113 EXPORT_SYMBOL(vm_unmap_ram
);
2116 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2117 * @pages: an array of pointers to the pages to be mapped
2118 * @count: number of pages
2119 * @node: prefer to allocate data structures on this node
2121 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2122 * faster than vmap so it's good. But if you mix long-life and short-life
2123 * objects with vm_map_ram(), it could consume lots of address space through
2124 * fragmentation (especially on a 32bit machine). You could see failures in
2125 * the end. Please use this function for short-lived objects.
2127 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2129 void *vm_map_ram(struct page
**pages
, unsigned int count
, int node
)
2131 unsigned long size
= (unsigned long)count
<< PAGE_SHIFT
;
2135 if (likely(count
<= VMAP_MAX_ALLOC
)) {
2136 mem
= vb_alloc(size
, GFP_KERNEL
);
2139 addr
= (unsigned long)mem
;
2141 struct vmap_area
*va
;
2142 va
= alloc_vmap_area(size
, PAGE_SIZE
,
2143 VMALLOC_START
, VMALLOC_END
, node
, GFP_KERNEL
);
2147 addr
= va
->va_start
;
2151 kasan_unpoison_vmalloc(mem
, size
);
2153 if (vmap_pages_range(addr
, addr
+ size
, PAGE_KERNEL
,
2154 pages
, PAGE_SHIFT
) < 0) {
2155 vm_unmap_ram(mem
, count
);
2161 EXPORT_SYMBOL(vm_map_ram
);
2163 static struct vm_struct
*vmlist __initdata
;
2165 static inline unsigned int vm_area_page_order(struct vm_struct
*vm
)
2167 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2168 return vm
->page_order
;
2174 static inline void set_vm_area_page_order(struct vm_struct
*vm
, unsigned int order
)
2176 #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2177 vm
->page_order
= order
;
2184 * vm_area_add_early - add vmap area early during boot
2185 * @vm: vm_struct to add
2187 * This function is used to add fixed kernel vm area to vmlist before
2188 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
2189 * should contain proper values and the other fields should be zero.
2191 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2193 void __init
vm_area_add_early(struct vm_struct
*vm
)
2195 struct vm_struct
*tmp
, **p
;
2197 BUG_ON(vmap_initialized
);
2198 for (p
= &vmlist
; (tmp
= *p
) != NULL
; p
= &tmp
->next
) {
2199 if (tmp
->addr
>= vm
->addr
) {
2200 BUG_ON(tmp
->addr
< vm
->addr
+ vm
->size
);
2203 BUG_ON(tmp
->addr
+ tmp
->size
> vm
->addr
);
2210 * vm_area_register_early - register vmap area early during boot
2211 * @vm: vm_struct to register
2212 * @align: requested alignment
2214 * This function is used to register kernel vm area before
2215 * vmalloc_init() is called. @vm->size and @vm->flags should contain
2216 * proper values on entry and other fields should be zero. On return,
2217 * vm->addr contains the allocated address.
2219 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2221 void __init
vm_area_register_early(struct vm_struct
*vm
, size_t align
)
2223 static size_t vm_init_off __initdata
;
2226 addr
= ALIGN(VMALLOC_START
+ vm_init_off
, align
);
2227 vm_init_off
= PFN_ALIGN(addr
+ vm
->size
) - VMALLOC_START
;
2229 vm
->addr
= (void *)addr
;
2231 vm_area_add_early(vm
);
2234 static void vmap_init_free_space(void)
2236 unsigned long vmap_start
= 1;
2237 const unsigned long vmap_end
= ULONG_MAX
;
2238 struct vmap_area
*busy
, *free
;
2242 * -|-----|.....|-----|-----|-----|.....|-
2244 * |<--------------------------------->|
2246 list_for_each_entry(busy
, &vmap_area_list
, list
) {
2247 if (busy
->va_start
- vmap_start
> 0) {
2248 free
= kmem_cache_zalloc(vmap_area_cachep
, GFP_NOWAIT
);
2249 if (!WARN_ON_ONCE(!free
)) {
2250 free
->va_start
= vmap_start
;
2251 free
->va_end
= busy
->va_start
;
2253 insert_vmap_area_augment(free
, NULL
,
2254 &free_vmap_area_root
,
2255 &free_vmap_area_list
);
2259 vmap_start
= busy
->va_end
;
2262 if (vmap_end
- vmap_start
> 0) {
2263 free
= kmem_cache_zalloc(vmap_area_cachep
, GFP_NOWAIT
);
2264 if (!WARN_ON_ONCE(!free
)) {
2265 free
->va_start
= vmap_start
;
2266 free
->va_end
= vmap_end
;
2268 insert_vmap_area_augment(free
, NULL
,
2269 &free_vmap_area_root
,
2270 &free_vmap_area_list
);
2275 void __init
vmalloc_init(void)
2277 struct vmap_area
*va
;
2278 struct vm_struct
*tmp
;
2282 * Create the cache for vmap_area objects.
2284 vmap_area_cachep
= KMEM_CACHE(vmap_area
, SLAB_PANIC
);
2286 for_each_possible_cpu(i
) {
2287 struct vmap_block_queue
*vbq
;
2288 struct vfree_deferred
*p
;
2290 vbq
= &per_cpu(vmap_block_queue
, i
);
2291 spin_lock_init(&vbq
->lock
);
2292 INIT_LIST_HEAD(&vbq
->free
);
2293 p
= &per_cpu(vfree_deferred
, i
);
2294 init_llist_head(&p
->list
);
2295 INIT_WORK(&p
->wq
, free_work
);
2298 /* Import existing vmlist entries. */
2299 for (tmp
= vmlist
; tmp
; tmp
= tmp
->next
) {
2300 va
= kmem_cache_zalloc(vmap_area_cachep
, GFP_NOWAIT
);
2301 if (WARN_ON_ONCE(!va
))
2304 va
->va_start
= (unsigned long)tmp
->addr
;
2305 va
->va_end
= va
->va_start
+ tmp
->size
;
2307 insert_vmap_area(va
, &vmap_area_root
, &vmap_area_list
);
2311 * Now we can initialize a free vmap space.
2313 vmap_init_free_space();
2314 vmap_initialized
= true;
2317 static inline void setup_vmalloc_vm_locked(struct vm_struct
*vm
,
2318 struct vmap_area
*va
, unsigned long flags
, const void *caller
)
2321 vm
->addr
= (void *)va
->va_start
;
2322 vm
->size
= va
->va_end
- va
->va_start
;
2323 vm
->caller
= caller
;
2327 static void setup_vmalloc_vm(struct vm_struct
*vm
, struct vmap_area
*va
,
2328 unsigned long flags
, const void *caller
)
2330 spin_lock(&vmap_area_lock
);
2331 setup_vmalloc_vm_locked(vm
, va
, flags
, caller
);
2332 spin_unlock(&vmap_area_lock
);
2335 static void clear_vm_uninitialized_flag(struct vm_struct
*vm
)
2338 * Before removing VM_UNINITIALIZED,
2339 * we should make sure that vm has proper values.
2340 * Pair with smp_rmb() in show_numa_info().
2343 vm
->flags
&= ~VM_UNINITIALIZED
;
2346 static struct vm_struct
*__get_vm_area_node(unsigned long size
,
2347 unsigned long align
, unsigned long flags
, unsigned long start
,
2348 unsigned long end
, int node
, gfp_t gfp_mask
, const void *caller
)
2350 struct vmap_area
*va
;
2351 struct vm_struct
*area
;
2352 unsigned long requested_size
= size
;
2354 BUG_ON(in_interrupt());
2355 size
= PAGE_ALIGN(size
);
2356 if (unlikely(!size
))
2359 if (flags
& VM_IOREMAP
)
2360 align
= 1ul << clamp_t(int, get_count_order_long(size
),
2361 PAGE_SHIFT
, IOREMAP_MAX_ORDER
);
2363 area
= kzalloc_node(sizeof(*area
), gfp_mask
& GFP_RECLAIM_MASK
, node
);
2364 if (unlikely(!area
))
2367 if (!(flags
& VM_NO_GUARD
))
2370 va
= alloc_vmap_area(size
, align
, start
, end
, node
, gfp_mask
);
2376 kasan_unpoison_vmalloc((void *)va
->va_start
, requested_size
);
2378 setup_vmalloc_vm(area
, va
, flags
, caller
);
2383 struct vm_struct
*__get_vm_area_caller(unsigned long size
, unsigned long flags
,
2384 unsigned long start
, unsigned long end
,
2387 return __get_vm_area_node(size
, 1, flags
, start
, end
, NUMA_NO_NODE
,
2388 GFP_KERNEL
, caller
);
2392 * get_vm_area - reserve a contiguous kernel virtual area
2393 * @size: size of the area
2394 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2396 * Search an area of @size in the kernel virtual mapping area,
2397 * and reserved it for out purposes. Returns the area descriptor
2398 * on success or %NULL on failure.
2400 * Return: the area descriptor on success or %NULL on failure.
2402 struct vm_struct
*get_vm_area(unsigned long size
, unsigned long flags
)
2404 return __get_vm_area_node(size
, 1, flags
, VMALLOC_START
, VMALLOC_END
,
2405 NUMA_NO_NODE
, GFP_KERNEL
,
2406 __builtin_return_address(0));
2409 struct vm_struct
*get_vm_area_caller(unsigned long size
, unsigned long flags
,
2412 return __get_vm_area_node(size
, 1, flags
, VMALLOC_START
, VMALLOC_END
,
2413 NUMA_NO_NODE
, GFP_KERNEL
, caller
);
2417 * find_vm_area - find a continuous kernel virtual area
2418 * @addr: base address
2420 * Search for the kernel VM area starting at @addr, and return it.
2421 * It is up to the caller to do all required locking to keep the returned
2424 * Return: the area descriptor on success or %NULL on failure.
2426 struct vm_struct
*find_vm_area(const void *addr
)
2428 struct vmap_area
*va
;
2430 va
= find_vmap_area((unsigned long)addr
);
2438 * remove_vm_area - find and remove a continuous kernel virtual area
2439 * @addr: base address
2441 * Search for the kernel VM area starting at @addr, and remove it.
2442 * This function returns the found VM area, but using it is NOT safe
2443 * on SMP machines, except for its size or flags.
2445 * Return: the area descriptor on success or %NULL on failure.
2447 struct vm_struct
*remove_vm_area(const void *addr
)
2449 struct vmap_area
*va
;
2453 spin_lock(&vmap_area_lock
);
2454 va
= __find_vmap_area((unsigned long)addr
);
2456 struct vm_struct
*vm
= va
->vm
;
2459 spin_unlock(&vmap_area_lock
);
2461 kasan_free_shadow(vm
);
2462 free_unmap_vmap_area(va
);
2467 spin_unlock(&vmap_area_lock
);
2471 static inline void set_area_direct_map(const struct vm_struct
*area
,
2472 int (*set_direct_map
)(struct page
*page
))
2476 /* HUGE_VMALLOC passes small pages to set_direct_map */
2477 for (i
= 0; i
< area
->nr_pages
; i
++)
2478 if (page_address(area
->pages
[i
]))
2479 set_direct_map(area
->pages
[i
]);
2482 /* Handle removing and resetting vm mappings related to the vm_struct. */
2483 static void vm_remove_mappings(struct vm_struct
*area
, int deallocate_pages
)
2485 unsigned long start
= ULONG_MAX
, end
= 0;
2486 unsigned int page_order
= vm_area_page_order(area
);
2487 int flush_reset
= area
->flags
& VM_FLUSH_RESET_PERMS
;
2491 remove_vm_area(area
->addr
);
2493 /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
2498 * If not deallocating pages, just do the flush of the VM area and
2501 if (!deallocate_pages
) {
2507 * If execution gets here, flush the vm mapping and reset the direct
2508 * map. Find the start and end range of the direct mappings to make sure
2509 * the vm_unmap_aliases() flush includes the direct map.
2511 for (i
= 0; i
< area
->nr_pages
; i
+= 1U << page_order
) {
2512 unsigned long addr
= (unsigned long)page_address(area
->pages
[i
]);
2514 unsigned long page_size
;
2516 page_size
= PAGE_SIZE
<< page_order
;
2517 start
= min(addr
, start
);
2518 end
= max(addr
+ page_size
, end
);
2524 * Set direct map to something invalid so that it won't be cached if
2525 * there are any accesses after the TLB flush, then flush the TLB and
2526 * reset the direct map permissions to the default.
2528 set_area_direct_map(area
, set_direct_map_invalid_noflush
);
2529 _vm_unmap_aliases(start
, end
, flush_dmap
);
2530 set_area_direct_map(area
, set_direct_map_default_noflush
);
2533 static void __vunmap(const void *addr
, int deallocate_pages
)
2535 struct vm_struct
*area
;
2540 if (WARN(!PAGE_ALIGNED(addr
), "Trying to vfree() bad address (%p)\n",
2544 area
= find_vm_area(addr
);
2545 if (unlikely(!area
)) {
2546 WARN(1, KERN_ERR
"Trying to vfree() nonexistent vm area (%p)\n",
2551 debug_check_no_locks_freed(area
->addr
, get_vm_area_size(area
));
2552 debug_check_no_obj_freed(area
->addr
, get_vm_area_size(area
));
2554 kasan_poison_vmalloc(area
->addr
, get_vm_area_size(area
));
2556 vm_remove_mappings(area
, deallocate_pages
);
2558 if (deallocate_pages
) {
2559 unsigned int page_order
= vm_area_page_order(area
);
2562 for (i
= 0; i
< area
->nr_pages
; i
+= 1U << page_order
) {
2563 struct page
*page
= area
->pages
[i
];
2566 __free_pages(page
, page_order
);
2568 atomic_long_sub(area
->nr_pages
, &nr_vmalloc_pages
);
2570 kvfree(area
->pages
);
2576 static inline void __vfree_deferred(const void *addr
)
2579 * Use raw_cpu_ptr() because this can be called from preemptible
2580 * context. Preemption is absolutely fine here, because the llist_add()
2581 * implementation is lockless, so it works even if we are adding to
2582 * another cpu's list. schedule_work() should be fine with this too.
2584 struct vfree_deferred
*p
= raw_cpu_ptr(&vfree_deferred
);
2586 if (llist_add((struct llist_node
*)addr
, &p
->list
))
2587 schedule_work(&p
->wq
);
2591 * vfree_atomic - release memory allocated by vmalloc()
2592 * @addr: memory base address
2594 * This one is just like vfree() but can be called in any atomic context
2597 void vfree_atomic(const void *addr
)
2601 kmemleak_free(addr
);
2605 __vfree_deferred(addr
);
2608 static void __vfree(const void *addr
)
2610 if (unlikely(in_interrupt()))
2611 __vfree_deferred(addr
);
2617 * vfree - Release memory allocated by vmalloc()
2618 * @addr: Memory base address
2620 * Free the virtually continuous memory area starting at @addr, as obtained
2621 * from one of the vmalloc() family of APIs. This will usually also free the
2622 * physical memory underlying the virtual allocation, but that memory is
2623 * reference counted, so it will not be freed until the last user goes away.
2625 * If @addr is NULL, no operation is performed.
2628 * May sleep if called *not* from interrupt context.
2629 * Must not be called in NMI context (strictly speaking, it could be
2630 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2631 * conventions for vfree() arch-dependent would be a really bad idea).
2633 void vfree(const void *addr
)
2637 kmemleak_free(addr
);
2639 might_sleep_if(!in_interrupt());
2646 EXPORT_SYMBOL(vfree
);
2649 * vunmap - release virtual mapping obtained by vmap()
2650 * @addr: memory base address
2652 * Free the virtually contiguous memory area starting at @addr,
2653 * which was created from the page array passed to vmap().
2655 * Must not be called in interrupt context.
2657 void vunmap(const void *addr
)
2659 BUG_ON(in_interrupt());
2664 EXPORT_SYMBOL(vunmap
);
2667 * vmap - map an array of pages into virtually contiguous space
2668 * @pages: array of page pointers
2669 * @count: number of pages to map
2670 * @flags: vm_area->flags
2671 * @prot: page protection for the mapping
2673 * Maps @count pages from @pages into contiguous kernel virtual space.
2674 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
2675 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
2676 * are transferred from the caller to vmap(), and will be freed / dropped when
2677 * vfree() is called on the return value.
2679 * Return: the address of the area or %NULL on failure
2681 void *vmap(struct page
**pages
, unsigned int count
,
2682 unsigned long flags
, pgprot_t prot
)
2684 struct vm_struct
*area
;
2686 unsigned long size
; /* In bytes */
2690 if (count
> totalram_pages())
2693 size
= (unsigned long)count
<< PAGE_SHIFT
;
2694 area
= get_vm_area_caller(size
, flags
, __builtin_return_address(0));
2698 addr
= (unsigned long)area
->addr
;
2699 if (vmap_pages_range(addr
, addr
+ size
, pgprot_nx(prot
),
2700 pages
, PAGE_SHIFT
) < 0) {
2705 if (flags
& VM_MAP_PUT_PAGES
) {
2706 area
->pages
= pages
;
2707 area
->nr_pages
= count
;
2711 EXPORT_SYMBOL(vmap
);
2713 #ifdef CONFIG_VMAP_PFN
2714 struct vmap_pfn_data
{
2715 unsigned long *pfns
;
2720 static int vmap_pfn_apply(pte_t
*pte
, unsigned long addr
, void *private)
2722 struct vmap_pfn_data
*data
= private;
2724 if (WARN_ON_ONCE(pfn_valid(data
->pfns
[data
->idx
])))
2726 *pte
= pte_mkspecial(pfn_pte(data
->pfns
[data
->idx
++], data
->prot
));
2731 * vmap_pfn - map an array of PFNs into virtually contiguous space
2732 * @pfns: array of PFNs
2733 * @count: number of pages to map
2734 * @prot: page protection for the mapping
2736 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
2737 * the start address of the mapping.
2739 void *vmap_pfn(unsigned long *pfns
, unsigned int count
, pgprot_t prot
)
2741 struct vmap_pfn_data data
= { .pfns
= pfns
, .prot
= pgprot_nx(prot
) };
2742 struct vm_struct
*area
;
2744 area
= get_vm_area_caller(count
* PAGE_SIZE
, VM_IOREMAP
,
2745 __builtin_return_address(0));
2748 if (apply_to_page_range(&init_mm
, (unsigned long)area
->addr
,
2749 count
* PAGE_SIZE
, vmap_pfn_apply
, &data
)) {
2755 EXPORT_SYMBOL_GPL(vmap_pfn
);
2756 #endif /* CONFIG_VMAP_PFN */
2758 static void *__vmalloc_area_node(struct vm_struct
*area
, gfp_t gfp_mask
,
2759 pgprot_t prot
, unsigned int page_shift
,
2762 const gfp_t nested_gfp
= (gfp_mask
& GFP_RECLAIM_MASK
) | __GFP_ZERO
;
2763 unsigned long addr
= (unsigned long)area
->addr
;
2764 unsigned long size
= get_vm_area_size(area
);
2765 unsigned long array_size
;
2766 unsigned int nr_small_pages
= size
>> PAGE_SHIFT
;
2767 unsigned int page_order
;
2768 struct page
**pages
;
2771 array_size
= (unsigned long)nr_small_pages
* sizeof(struct page
*);
2772 gfp_mask
|= __GFP_NOWARN
;
2773 if (!(gfp_mask
& (GFP_DMA
| GFP_DMA32
)))
2774 gfp_mask
|= __GFP_HIGHMEM
;
2776 /* Please note that the recursion is strictly bounded. */
2777 if (array_size
> PAGE_SIZE
) {
2778 pages
= __vmalloc_node(array_size
, 1, nested_gfp
, node
,
2781 pages
= kmalloc_node(array_size
, nested_gfp
, node
);
2786 warn_alloc(gfp_mask
, NULL
,
2787 "vmalloc size %lu allocation failure: "
2788 "page array size %lu allocation failed",
2789 nr_small_pages
* PAGE_SIZE
, array_size
);
2793 area
->pages
= pages
;
2794 area
->nr_pages
= nr_small_pages
;
2795 set_vm_area_page_order(area
, page_shift
- PAGE_SHIFT
);
2797 page_order
= vm_area_page_order(area
);
2800 * Careful, we allocate and map page_order pages, but tracking is done
2801 * per PAGE_SIZE page so as to keep the vm_struct APIs independent of
2802 * the physical/mapped size.
2804 for (i
= 0; i
< area
->nr_pages
; i
+= 1U << page_order
) {
2808 /* Compound pages required for remap_vmalloc_page */
2809 page
= alloc_pages_node(node
, gfp_mask
| __GFP_COMP
, page_order
);
2810 if (unlikely(!page
)) {
2811 /* Successfully allocated i pages, free them in __vfree() */
2813 atomic_long_add(area
->nr_pages
, &nr_vmalloc_pages
);
2814 warn_alloc(gfp_mask
, NULL
,
2815 "vmalloc size %lu allocation failure: "
2816 "page order %u allocation failed",
2817 area
->nr_pages
* PAGE_SIZE
, page_order
);
2821 for (p
= 0; p
< (1U << page_order
); p
++)
2822 area
->pages
[i
+ p
] = page
+ p
;
2824 if (gfpflags_allow_blocking(gfp_mask
))
2827 atomic_long_add(area
->nr_pages
, &nr_vmalloc_pages
);
2829 if (vmap_pages_range(addr
, addr
+ size
, prot
, pages
, page_shift
) < 0) {
2830 warn_alloc(gfp_mask
, NULL
,
2831 "vmalloc size %lu allocation failure: "
2832 "failed to map pages",
2833 area
->nr_pages
* PAGE_SIZE
);
2840 __vfree(area
->addr
);
2845 * __vmalloc_node_range - allocate virtually contiguous memory
2846 * @size: allocation size
2847 * @align: desired alignment
2848 * @start: vm area range start
2849 * @end: vm area range end
2850 * @gfp_mask: flags for the page level allocator
2851 * @prot: protection mask for the allocated pages
2852 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
2853 * @node: node to use for allocation or NUMA_NO_NODE
2854 * @caller: caller's return address
2856 * Allocate enough pages to cover @size from the page level
2857 * allocator with @gfp_mask flags. Map them into contiguous
2858 * kernel virtual space, using a pagetable protection of @prot.
2860 * Return: the address of the area or %NULL on failure
2862 void *__vmalloc_node_range(unsigned long size
, unsigned long align
,
2863 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
2864 pgprot_t prot
, unsigned long vm_flags
, int node
,
2867 struct vm_struct
*area
;
2869 unsigned long real_size
= size
;
2870 unsigned long real_align
= align
;
2871 unsigned int shift
= PAGE_SHIFT
;
2873 if (WARN_ON_ONCE(!size
))
2876 if ((size
>> PAGE_SHIFT
) > totalram_pages()) {
2877 warn_alloc(gfp_mask
, NULL
,
2878 "vmalloc size %lu allocation failure: "
2879 "exceeds total pages", real_size
);
2883 if (vmap_allow_huge
&& !(vm_flags
& VM_NO_HUGE_VMAP
) &&
2884 arch_vmap_pmd_supported(prot
)) {
2885 unsigned long size_per_node
;
2888 * Try huge pages. Only try for PAGE_KERNEL allocations,
2889 * others like modules don't yet expect huge pages in
2890 * their allocations due to apply_to_page_range not
2894 size_per_node
= size
;
2895 if (node
== NUMA_NO_NODE
)
2896 size_per_node
/= num_online_nodes();
2897 if (size_per_node
>= PMD_SIZE
) {
2899 align
= max(real_align
, 1UL << shift
);
2900 size
= ALIGN(real_size
, 1UL << shift
);
2905 size
= PAGE_ALIGN(size
);
2906 area
= __get_vm_area_node(size
, align
, VM_ALLOC
| VM_UNINITIALIZED
|
2907 vm_flags
, start
, end
, node
, gfp_mask
, caller
);
2909 warn_alloc(gfp_mask
, NULL
,
2910 "vmalloc size %lu allocation failure: "
2911 "vm_struct allocation failed", real_size
);
2915 addr
= __vmalloc_area_node(area
, gfp_mask
, prot
, shift
, node
);
2920 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
2921 * flag. It means that vm_struct is not fully initialized.
2922 * Now, it is fully initialized, so remove this flag here.
2924 clear_vm_uninitialized_flag(area
);
2926 kmemleak_vmalloc(area
, size
, gfp_mask
);
2931 if (shift
> PAGE_SHIFT
) {
2942 * __vmalloc_node - allocate virtually contiguous memory
2943 * @size: allocation size
2944 * @align: desired alignment
2945 * @gfp_mask: flags for the page level allocator
2946 * @node: node to use for allocation or NUMA_NO_NODE
2947 * @caller: caller's return address
2949 * Allocate enough pages to cover @size from the page level allocator with
2950 * @gfp_mask flags. Map them into contiguous kernel virtual space.
2952 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
2953 * and __GFP_NOFAIL are not supported
2955 * Any use of gfp flags outside of GFP_KERNEL should be consulted
2958 * Return: pointer to the allocated memory or %NULL on error
2960 void *__vmalloc_node(unsigned long size
, unsigned long align
,
2961 gfp_t gfp_mask
, int node
, const void *caller
)
2963 return __vmalloc_node_range(size
, align
, VMALLOC_START
, VMALLOC_END
,
2964 gfp_mask
, PAGE_KERNEL
, 0, node
, caller
);
2967 * This is only for performance analysis of vmalloc and stress purpose.
2968 * It is required by vmalloc test module, therefore do not use it other
2971 #ifdef CONFIG_TEST_VMALLOC_MODULE
2972 EXPORT_SYMBOL_GPL(__vmalloc_node
);
2975 void *__vmalloc(unsigned long size
, gfp_t gfp_mask
)
2977 return __vmalloc_node(size
, 1, gfp_mask
, NUMA_NO_NODE
,
2978 __builtin_return_address(0));
2980 EXPORT_SYMBOL(__vmalloc
);
2983 * vmalloc - allocate virtually contiguous memory
2984 * @size: allocation size
2986 * Allocate enough pages to cover @size from the page level
2987 * allocator and map them into contiguous kernel virtual space.
2989 * For tight control over page level allocator and protection flags
2990 * use __vmalloc() instead.
2992 * Return: pointer to the allocated memory or %NULL on error
2994 void *vmalloc(unsigned long size
)
2996 return __vmalloc_node(size
, 1, GFP_KERNEL
, NUMA_NO_NODE
,
2997 __builtin_return_address(0));
2999 EXPORT_SYMBOL(vmalloc
);
3002 * vzalloc - allocate virtually contiguous memory with zero fill
3003 * @size: allocation size
3005 * Allocate enough pages to cover @size from the page level
3006 * allocator and map them into contiguous kernel virtual space.
3007 * The memory allocated is set to zero.
3009 * For tight control over page level allocator and protection flags
3010 * use __vmalloc() instead.
3012 * Return: pointer to the allocated memory or %NULL on error
3014 void *vzalloc(unsigned long size
)
3016 return __vmalloc_node(size
, 1, GFP_KERNEL
| __GFP_ZERO
, NUMA_NO_NODE
,
3017 __builtin_return_address(0));
3019 EXPORT_SYMBOL(vzalloc
);
3022 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3023 * @size: allocation size
3025 * The resulting memory area is zeroed so it can be mapped to userspace
3026 * without leaking data.
3028 * Return: pointer to the allocated memory or %NULL on error
3030 void *vmalloc_user(unsigned long size
)
3032 return __vmalloc_node_range(size
, SHMLBA
, VMALLOC_START
, VMALLOC_END
,
3033 GFP_KERNEL
| __GFP_ZERO
, PAGE_KERNEL
,
3034 VM_USERMAP
, NUMA_NO_NODE
,
3035 __builtin_return_address(0));
3037 EXPORT_SYMBOL(vmalloc_user
);
3040 * vmalloc_node - allocate memory on a specific node
3041 * @size: allocation size
3044 * Allocate enough pages to cover @size from the page level
3045 * allocator and map them into contiguous kernel virtual space.
3047 * For tight control over page level allocator and protection flags
3048 * use __vmalloc() instead.
3050 * Return: pointer to the allocated memory or %NULL on error
3052 void *vmalloc_node(unsigned long size
, int node
)
3054 return __vmalloc_node(size
, 1, GFP_KERNEL
, node
,
3055 __builtin_return_address(0));
3057 EXPORT_SYMBOL(vmalloc_node
);
3060 * vzalloc_node - allocate memory on a specific node with zero fill
3061 * @size: allocation size
3064 * Allocate enough pages to cover @size from the page level
3065 * allocator and map them into contiguous kernel virtual space.
3066 * The memory allocated is set to zero.
3068 * Return: pointer to the allocated memory or %NULL on error
3070 void *vzalloc_node(unsigned long size
, int node
)
3072 return __vmalloc_node(size
, 1, GFP_KERNEL
| __GFP_ZERO
, node
,
3073 __builtin_return_address(0));
3075 EXPORT_SYMBOL(vzalloc_node
);
3077 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
3078 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3079 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
3080 #define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
3083 * 64b systems should always have either DMA or DMA32 zones. For others
3084 * GFP_DMA32 should do the right thing and use the normal zone.
3086 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3090 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
3091 * @size: allocation size
3093 * Allocate enough 32bit PA addressable pages to cover @size from the
3094 * page level allocator and map them into contiguous kernel virtual space.
3096 * Return: pointer to the allocated memory or %NULL on error
3098 void *vmalloc_32(unsigned long size
)
3100 return __vmalloc_node(size
, 1, GFP_VMALLOC32
, NUMA_NO_NODE
,
3101 __builtin_return_address(0));
3103 EXPORT_SYMBOL(vmalloc_32
);
3106 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
3107 * @size: allocation size
3109 * The resulting memory area is 32bit addressable and zeroed so it can be
3110 * mapped to userspace without leaking data.
3112 * Return: pointer to the allocated memory or %NULL on error
3114 void *vmalloc_32_user(unsigned long size
)
3116 return __vmalloc_node_range(size
, SHMLBA
, VMALLOC_START
, VMALLOC_END
,
3117 GFP_VMALLOC32
| __GFP_ZERO
, PAGE_KERNEL
,
3118 VM_USERMAP
, NUMA_NO_NODE
,
3119 __builtin_return_address(0));
3121 EXPORT_SYMBOL(vmalloc_32_user
);
3124 * small helper routine , copy contents to buf from addr.
3125 * If the page is not present, fill zero.
3128 static int aligned_vread(char *buf
, char *addr
, unsigned long count
)
3134 unsigned long offset
, length
;
3136 offset
= offset_in_page(addr
);
3137 length
= PAGE_SIZE
- offset
;
3140 p
= vmalloc_to_page(addr
);
3142 * To do safe access to this _mapped_ area, we need
3143 * lock. But adding lock here means that we need to add
3144 * overhead of vmalloc()/vfree() calls for this _debug_
3145 * interface, rarely used. Instead of that, we'll use
3146 * kmap() and get small overhead in this access function.
3149 /* We can expect USER0 is not used -- see vread() */
3150 void *map
= kmap_atomic(p
);
3151 memcpy(buf
, map
+ offset
, length
);
3154 memset(buf
, 0, length
);
3165 * vread() - read vmalloc area in a safe way.
3166 * @buf: buffer for reading data
3167 * @addr: vm address.
3168 * @count: number of bytes to be read.
3170 * This function checks that addr is a valid vmalloc'ed area, and
3171 * copy data from that area to a given buffer. If the given memory range
3172 * of [addr...addr+count) includes some valid address, data is copied to
3173 * proper area of @buf. If there are memory holes, they'll be zero-filled.
3174 * IOREMAP area is treated as memory hole and no copy is done.
3176 * If [addr...addr+count) doesn't includes any intersects with alive
3177 * vm_struct area, returns 0. @buf should be kernel's buffer.
3179 * Note: In usual ops, vread() is never necessary because the caller
3180 * should know vmalloc() area is valid and can use memcpy().
3181 * This is for routines which have to access vmalloc area without
3182 * any information, as /proc/kcore.
3184 * Return: number of bytes for which addr and buf should be increased
3185 * (same number as @count) or %0 if [addr...addr+count) doesn't
3186 * include any intersection with valid vmalloc area
3188 long vread(char *buf
, char *addr
, unsigned long count
)
3190 struct vmap_area
*va
;
3191 struct vm_struct
*vm
;
3192 char *vaddr
, *buf_start
= buf
;
3193 unsigned long buflen
= count
;
3196 /* Don't allow overflow */
3197 if ((unsigned long) addr
+ count
< count
)
3198 count
= -(unsigned long) addr
;
3200 spin_lock(&vmap_area_lock
);
3201 va
= __find_vmap_area((unsigned long)addr
);
3204 list_for_each_entry_from(va
, &vmap_area_list
, list
) {
3212 vaddr
= (char *) vm
->addr
;
3213 if (addr
>= vaddr
+ get_vm_area_size(vm
))
3215 while (addr
< vaddr
) {
3223 n
= vaddr
+ get_vm_area_size(vm
) - addr
;
3226 if (!(vm
->flags
& VM_IOREMAP
))
3227 aligned_vread(buf
, addr
, n
);
3228 else /* IOREMAP area is treated as memory hole */
3235 spin_unlock(&vmap_area_lock
);
3237 if (buf
== buf_start
)
3239 /* zero-fill memory holes */
3240 if (buf
!= buf_start
+ buflen
)
3241 memset(buf
, 0, buflen
- (buf
- buf_start
));
3247 * remap_vmalloc_range_partial - map vmalloc pages to userspace
3248 * @vma: vma to cover
3249 * @uaddr: target user address to start at
3250 * @kaddr: virtual address of vmalloc kernel memory
3251 * @pgoff: offset from @kaddr to start at
3252 * @size: size of map area
3254 * Returns: 0 for success, -Exxx on failure
3256 * This function checks that @kaddr is a valid vmalloc'ed area,
3257 * and that it is big enough to cover the range starting at
3258 * @uaddr in @vma. Will return failure if that criteria isn't
3261 * Similar to remap_pfn_range() (see mm/memory.c)
3263 int remap_vmalloc_range_partial(struct vm_area_struct
*vma
, unsigned long uaddr
,
3264 void *kaddr
, unsigned long pgoff
,
3267 struct vm_struct
*area
;
3269 unsigned long end_index
;
3271 if (check_shl_overflow(pgoff
, PAGE_SHIFT
, &off
))
3274 size
= PAGE_ALIGN(size
);
3276 if (!PAGE_ALIGNED(uaddr
) || !PAGE_ALIGNED(kaddr
))
3279 area
= find_vm_area(kaddr
);
3283 if (!(area
->flags
& (VM_USERMAP
| VM_DMA_COHERENT
)))
3286 if (check_add_overflow(size
, off
, &end_index
) ||
3287 end_index
> get_vm_area_size(area
))
3292 struct page
*page
= vmalloc_to_page(kaddr
);
3295 ret
= vm_insert_page(vma
, uaddr
, page
);
3304 vma
->vm_flags
|= VM_DONTEXPAND
| VM_DONTDUMP
;
3310 * remap_vmalloc_range - map vmalloc pages to userspace
3311 * @vma: vma to cover (map full range of vma)
3312 * @addr: vmalloc memory
3313 * @pgoff: number of pages into addr before first page to map
3315 * Returns: 0 for success, -Exxx on failure
3317 * This function checks that addr is a valid vmalloc'ed area, and
3318 * that it is big enough to cover the vma. Will return failure if
3319 * that criteria isn't met.
3321 * Similar to remap_pfn_range() (see mm/memory.c)
3323 int remap_vmalloc_range(struct vm_area_struct
*vma
, void *addr
,
3324 unsigned long pgoff
)
3326 return remap_vmalloc_range_partial(vma
, vma
->vm_start
,
3328 vma
->vm_end
- vma
->vm_start
);
3330 EXPORT_SYMBOL(remap_vmalloc_range
);
3332 void free_vm_area(struct vm_struct
*area
)
3334 struct vm_struct
*ret
;
3335 ret
= remove_vm_area(area
->addr
);
3336 BUG_ON(ret
!= area
);
3339 EXPORT_SYMBOL_GPL(free_vm_area
);
3342 static struct vmap_area
*node_to_va(struct rb_node
*n
)
3344 return rb_entry_safe(n
, struct vmap_area
, rb_node
);
3348 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
3349 * @addr: target address
3351 * Returns: vmap_area if it is found. If there is no such area
3352 * the first highest(reverse order) vmap_area is returned
3353 * i.e. va->va_start < addr && va->va_end < addr or NULL
3354 * if there are no any areas before @addr.
3356 static struct vmap_area
*
3357 pvm_find_va_enclose_addr(unsigned long addr
)
3359 struct vmap_area
*va
, *tmp
;
3362 n
= free_vmap_area_root
.rb_node
;
3366 tmp
= rb_entry(n
, struct vmap_area
, rb_node
);
3367 if (tmp
->va_start
<= addr
) {
3369 if (tmp
->va_end
>= addr
)
3382 * pvm_determine_end_from_reverse - find the highest aligned address
3383 * of free block below VMALLOC_END
3385 * in - the VA we start the search(reverse order);
3386 * out - the VA with the highest aligned end address.
3387 * @align: alignment for required highest address
3389 * Returns: determined end address within vmap_area
3391 static unsigned long
3392 pvm_determine_end_from_reverse(struct vmap_area
**va
, unsigned long align
)
3394 unsigned long vmalloc_end
= VMALLOC_END
& ~(align
- 1);
3398 list_for_each_entry_from_reverse((*va
),
3399 &free_vmap_area_list
, list
) {
3400 addr
= min((*va
)->va_end
& ~(align
- 1), vmalloc_end
);
3401 if ((*va
)->va_start
< addr
)
3410 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
3411 * @offsets: array containing offset of each area
3412 * @sizes: array containing size of each area
3413 * @nr_vms: the number of areas to allocate
3414 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
3416 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
3417 * vm_structs on success, %NULL on failure
3419 * Percpu allocator wants to use congruent vm areas so that it can
3420 * maintain the offsets among percpu areas. This function allocates
3421 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
3422 * be scattered pretty far, distance between two areas easily going up
3423 * to gigabytes. To avoid interacting with regular vmallocs, these
3424 * areas are allocated from top.
3426 * Despite its complicated look, this allocator is rather simple. It
3427 * does everything top-down and scans free blocks from the end looking
3428 * for matching base. While scanning, if any of the areas do not fit the
3429 * base address is pulled down to fit the area. Scanning is repeated till
3430 * all the areas fit and then all necessary data structures are inserted
3431 * and the result is returned.
3433 struct vm_struct
**pcpu_get_vm_areas(const unsigned long *offsets
,
3434 const size_t *sizes
, int nr_vms
,
3437 const unsigned long vmalloc_start
= ALIGN(VMALLOC_START
, align
);
3438 const unsigned long vmalloc_end
= VMALLOC_END
& ~(align
- 1);
3439 struct vmap_area
**vas
, *va
;
3440 struct vm_struct
**vms
;
3441 int area
, area2
, last_area
, term_area
;
3442 unsigned long base
, start
, size
, end
, last_end
, orig_start
, orig_end
;
3443 bool purged
= false;
3446 /* verify parameters and allocate data structures */
3447 BUG_ON(offset_in_page(align
) || !is_power_of_2(align
));
3448 for (last_area
= 0, area
= 0; area
< nr_vms
; area
++) {
3449 start
= offsets
[area
];
3450 end
= start
+ sizes
[area
];
3452 /* is everything aligned properly? */
3453 BUG_ON(!IS_ALIGNED(offsets
[area
], align
));
3454 BUG_ON(!IS_ALIGNED(sizes
[area
], align
));
3456 /* detect the area with the highest address */
3457 if (start
> offsets
[last_area
])
3460 for (area2
= area
+ 1; area2
< nr_vms
; area2
++) {
3461 unsigned long start2
= offsets
[area2
];
3462 unsigned long end2
= start2
+ sizes
[area2
];
3464 BUG_ON(start2
< end
&& start
< end2
);
3467 last_end
= offsets
[last_area
] + sizes
[last_area
];
3469 if (vmalloc_end
- vmalloc_start
< last_end
) {
3474 vms
= kcalloc(nr_vms
, sizeof(vms
[0]), GFP_KERNEL
);
3475 vas
= kcalloc(nr_vms
, sizeof(vas
[0]), GFP_KERNEL
);
3479 for (area
= 0; area
< nr_vms
; area
++) {
3480 vas
[area
] = kmem_cache_zalloc(vmap_area_cachep
, GFP_KERNEL
);
3481 vms
[area
] = kzalloc(sizeof(struct vm_struct
), GFP_KERNEL
);
3482 if (!vas
[area
] || !vms
[area
])
3486 spin_lock(&free_vmap_area_lock
);
3488 /* start scanning - we scan from the top, begin with the last area */
3489 area
= term_area
= last_area
;
3490 start
= offsets
[area
];
3491 end
= start
+ sizes
[area
];
3493 va
= pvm_find_va_enclose_addr(vmalloc_end
);
3494 base
= pvm_determine_end_from_reverse(&va
, align
) - end
;
3498 * base might have underflowed, add last_end before
3501 if (base
+ last_end
< vmalloc_start
+ last_end
)
3505 * Fitting base has not been found.
3511 * If required width exceeds current VA block, move
3512 * base downwards and then recheck.
3514 if (base
+ end
> va
->va_end
) {
3515 base
= pvm_determine_end_from_reverse(&va
, align
) - end
;
3521 * If this VA does not fit, move base downwards and recheck.
3523 if (base
+ start
< va
->va_start
) {
3524 va
= node_to_va(rb_prev(&va
->rb_node
));
3525 base
= pvm_determine_end_from_reverse(&va
, align
) - end
;
3531 * This area fits, move on to the previous one. If
3532 * the previous one is the terminal one, we're done.
3534 area
= (area
+ nr_vms
- 1) % nr_vms
;
3535 if (area
== term_area
)
3538 start
= offsets
[area
];
3539 end
= start
+ sizes
[area
];
3540 va
= pvm_find_va_enclose_addr(base
+ end
);
3543 /* we've found a fitting base, insert all va's */
3544 for (area
= 0; area
< nr_vms
; area
++) {
3547 start
= base
+ offsets
[area
];
3550 va
= pvm_find_va_enclose_addr(start
);
3551 if (WARN_ON_ONCE(va
== NULL
))
3552 /* It is a BUG(), but trigger recovery instead. */
3555 type
= classify_va_fit_type(va
, start
, size
);
3556 if (WARN_ON_ONCE(type
== NOTHING_FIT
))
3557 /* It is a BUG(), but trigger recovery instead. */
3560 ret
= adjust_va_to_fit_type(va
, start
, size
, type
);
3564 /* Allocated area. */
3566 va
->va_start
= start
;
3567 va
->va_end
= start
+ size
;
3570 spin_unlock(&free_vmap_area_lock
);
3572 /* populate the kasan shadow space */
3573 for (area
= 0; area
< nr_vms
; area
++) {
3574 if (kasan_populate_vmalloc(vas
[area
]->va_start
, sizes
[area
]))
3575 goto err_free_shadow
;
3577 kasan_unpoison_vmalloc((void *)vas
[area
]->va_start
,
3581 /* insert all vm's */
3582 spin_lock(&vmap_area_lock
);
3583 for (area
= 0; area
< nr_vms
; area
++) {
3584 insert_vmap_area(vas
[area
], &vmap_area_root
, &vmap_area_list
);
3586 setup_vmalloc_vm_locked(vms
[area
], vas
[area
], VM_ALLOC
,
3589 spin_unlock(&vmap_area_lock
);
3596 * Remove previously allocated areas. There is no
3597 * need in removing these areas from the busy tree,
3598 * because they are inserted only on the final step
3599 * and when pcpu_get_vm_areas() is success.
3602 orig_start
= vas
[area
]->va_start
;
3603 orig_end
= vas
[area
]->va_end
;
3604 va
= merge_or_add_vmap_area_augment(vas
[area
], &free_vmap_area_root
,
3605 &free_vmap_area_list
);
3607 kasan_release_vmalloc(orig_start
, orig_end
,
3608 va
->va_start
, va
->va_end
);
3613 spin_unlock(&free_vmap_area_lock
);
3615 purge_vmap_area_lazy();
3618 /* Before "retry", check if we recover. */
3619 for (area
= 0; area
< nr_vms
; area
++) {
3623 vas
[area
] = kmem_cache_zalloc(
3624 vmap_area_cachep
, GFP_KERNEL
);
3633 for (area
= 0; area
< nr_vms
; area
++) {
3635 kmem_cache_free(vmap_area_cachep
, vas
[area
]);
3645 spin_lock(&free_vmap_area_lock
);
3647 * We release all the vmalloc shadows, even the ones for regions that
3648 * hadn't been successfully added. This relies on kasan_release_vmalloc
3649 * being able to tolerate this case.
3651 for (area
= 0; area
< nr_vms
; area
++) {
3652 orig_start
= vas
[area
]->va_start
;
3653 orig_end
= vas
[area
]->va_end
;
3654 va
= merge_or_add_vmap_area_augment(vas
[area
], &free_vmap_area_root
,
3655 &free_vmap_area_list
);
3657 kasan_release_vmalloc(orig_start
, orig_end
,
3658 va
->va_start
, va
->va_end
);
3662 spin_unlock(&free_vmap_area_lock
);
3669 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
3670 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
3671 * @nr_vms: the number of allocated areas
3673 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
3675 void pcpu_free_vm_areas(struct vm_struct
**vms
, int nr_vms
)
3679 for (i
= 0; i
< nr_vms
; i
++)
3680 free_vm_area(vms
[i
]);
3683 #endif /* CONFIG_SMP */
3685 #ifdef CONFIG_PRINTK
3686 bool vmalloc_dump_obj(void *object
)
3688 struct vm_struct
*vm
;
3689 void *objp
= (void *)PAGE_ALIGN((unsigned long)object
);
3691 vm
= find_vm_area(objp
);
3694 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
3695 vm
->nr_pages
, (unsigned long)vm
->addr
, vm
->caller
);
3700 #ifdef CONFIG_PROC_FS
3701 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
3702 __acquires(&vmap_purge_lock
)
3703 __acquires(&vmap_area_lock
)
3705 mutex_lock(&vmap_purge_lock
);
3706 spin_lock(&vmap_area_lock
);
3708 return seq_list_start(&vmap_area_list
, *pos
);
3711 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
3713 return seq_list_next(p
, &vmap_area_list
, pos
);
3716 static void s_stop(struct seq_file
*m
, void *p
)
3717 __releases(&vmap_area_lock
)
3718 __releases(&vmap_purge_lock
)
3720 spin_unlock(&vmap_area_lock
);
3721 mutex_unlock(&vmap_purge_lock
);
3724 static void show_numa_info(struct seq_file
*m
, struct vm_struct
*v
)
3726 if (IS_ENABLED(CONFIG_NUMA
)) {
3727 unsigned int nr
, *counters
= m
->private;
3732 if (v
->flags
& VM_UNINITIALIZED
)
3734 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
3737 memset(counters
, 0, nr_node_ids
* sizeof(unsigned int));
3739 for (nr
= 0; nr
< v
->nr_pages
; nr
++)
3740 counters
[page_to_nid(v
->pages
[nr
])]++;
3742 for_each_node_state(nr
, N_HIGH_MEMORY
)
3744 seq_printf(m
, " N%u=%u", nr
, counters
[nr
]);
3748 static void show_purge_info(struct seq_file
*m
)
3750 struct vmap_area
*va
;
3752 spin_lock(&purge_vmap_area_lock
);
3753 list_for_each_entry(va
, &purge_vmap_area_list
, list
) {
3754 seq_printf(m
, "0x%pK-0x%pK %7ld unpurged vm_area\n",
3755 (void *)va
->va_start
, (void *)va
->va_end
,
3756 va
->va_end
- va
->va_start
);
3758 spin_unlock(&purge_vmap_area_lock
);
3761 static int s_show(struct seq_file
*m
, void *p
)
3763 struct vmap_area
*va
;
3764 struct vm_struct
*v
;
3766 va
= list_entry(p
, struct vmap_area
, list
);
3769 * s_show can encounter race with remove_vm_area, !vm on behalf
3770 * of vmap area is being tear down or vm_map_ram allocation.
3773 seq_printf(m
, "0x%pK-0x%pK %7ld vm_map_ram\n",
3774 (void *)va
->va_start
, (void *)va
->va_end
,
3775 va
->va_end
- va
->va_start
);
3782 seq_printf(m
, "0x%pK-0x%pK %7ld",
3783 v
->addr
, v
->addr
+ v
->size
, v
->size
);
3786 seq_printf(m
, " %pS", v
->caller
);
3789 seq_printf(m
, " pages=%d", v
->nr_pages
);
3792 seq_printf(m
, " phys=%pa", &v
->phys_addr
);
3794 if (v
->flags
& VM_IOREMAP
)
3795 seq_puts(m
, " ioremap");
3797 if (v
->flags
& VM_ALLOC
)
3798 seq_puts(m
, " vmalloc");
3800 if (v
->flags
& VM_MAP
)
3801 seq_puts(m
, " vmap");
3803 if (v
->flags
& VM_USERMAP
)
3804 seq_puts(m
, " user");
3806 if (v
->flags
& VM_DMA_COHERENT
)
3807 seq_puts(m
, " dma-coherent");
3809 if (is_vmalloc_addr(v
->pages
))
3810 seq_puts(m
, " vpages");
3812 show_numa_info(m
, v
);
3816 * As a final step, dump "unpurged" areas.
3818 if (list_is_last(&va
->list
, &vmap_area_list
))
3824 static const struct seq_operations vmalloc_op
= {
3831 static int __init
proc_vmalloc_init(void)
3833 if (IS_ENABLED(CONFIG_NUMA
))
3834 proc_create_seq_private("vmallocinfo", 0400, NULL
,
3836 nr_node_ids
* sizeof(unsigned int), NULL
);
3838 proc_create_seq("vmallocinfo", 0400, NULL
, &vmalloc_op
);
3841 module_init(proc_vmalloc_init
);