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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 1993 Linus Torvalds
4 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
5 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
6 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
7 * Numa awareness, Christoph Lameter, SGI, June 2005
8 * Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019
9 */
10
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/sched/signal.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/set_memory.h>
22#include <linux/debugobjects.h>
23#include <linux/kallsyms.h>
24#include <linux/list.h>
25#include <linux/notifier.h>
26#include <linux/rbtree.h>
27#include <linux/xarray.h>
28#include <linux/io.h>
29#include <linux/rcupdate.h>
30#include <linux/pfn.h>
31#include <linux/kmemleak.h>
32#include <linux/atomic.h>
33#include <linux/compiler.h>
34#include <linux/memcontrol.h>
35#include <linux/llist.h>
36#include <linux/bitops.h>
37#include <linux/rbtree_augmented.h>
38#include <linux/overflow.h>
39#include <linux/pgtable.h>
40#include <linux/uaccess.h>
41#include <linux/hugetlb.h>
42#include <linux/sched/mm.h>
43#include <asm/tlbflush.h>
44#include <asm/shmparam.h>
45
46#define CREATE_TRACE_POINTS
47#include <trace/events/vmalloc.h>
48
49#include "internal.h"
50#include "pgalloc-track.h"
51
52#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
53static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1;
54
55static int __init set_nohugeiomap(char *str)
56{
57 ioremap_max_page_shift = PAGE_SHIFT;
58 return 0;
59}
60early_param("nohugeiomap", set_nohugeiomap);
61#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
62static const unsigned int ioremap_max_page_shift = PAGE_SHIFT;
63#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
64
65#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
66static bool __ro_after_init vmap_allow_huge = true;
67
68static int __init set_nohugevmalloc(char *str)
69{
70 vmap_allow_huge = false;
71 return 0;
72}
73early_param("nohugevmalloc", set_nohugevmalloc);
74#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
75static const bool vmap_allow_huge = false;
76#endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
77
78bool is_vmalloc_addr(const void *x)
79{
80 unsigned long addr = (unsigned long)kasan_reset_tag(x);
81
82 return addr >= VMALLOC_START && addr < VMALLOC_END;
83}
84EXPORT_SYMBOL(is_vmalloc_addr);
85
86struct vfree_deferred {
87 struct llist_head list;
88 struct work_struct wq;
89};
90static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
91
92static void __vunmap(const void *, int);
93
94static void free_work(struct work_struct *w)
95{
96 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
97 struct llist_node *t, *llnode;
98
99 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
100 __vunmap((void *)llnode, 1);
101}
102
103/*** Page table manipulation functions ***/
104static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
105 phys_addr_t phys_addr, pgprot_t prot,
106 unsigned int max_page_shift, pgtbl_mod_mask *mask)
107{
108 pte_t *pte;
109 u64 pfn;
110 unsigned long size = PAGE_SIZE;
111
112 pfn = phys_addr >> PAGE_SHIFT;
113 pte = pte_alloc_kernel_track(pmd, addr, mask);
114 if (!pte)
115 return -ENOMEM;
116 do {
117 BUG_ON(!pte_none(*pte));
118
119#ifdef CONFIG_HUGETLB_PAGE
120 size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
121 if (size != PAGE_SIZE) {
122 pte_t entry = pfn_pte(pfn, prot);
123
124 entry = arch_make_huge_pte(entry, ilog2(size), 0);
125 set_huge_pte_at(&init_mm, addr, pte, entry);
126 pfn += PFN_DOWN(size);
127 continue;
128 }
129#endif
130 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
131 pfn++;
132 } while (pte += PFN_DOWN(size), addr += size, addr != end);
133 *mask |= PGTBL_PTE_MODIFIED;
134 return 0;
135}
136
137static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
138 phys_addr_t phys_addr, pgprot_t prot,
139 unsigned int max_page_shift)
140{
141 if (max_page_shift < PMD_SHIFT)
142 return 0;
143
144 if (!arch_vmap_pmd_supported(prot))
145 return 0;
146
147 if ((end - addr) != PMD_SIZE)
148 return 0;
149
150 if (!IS_ALIGNED(addr, PMD_SIZE))
151 return 0;
152
153 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
154 return 0;
155
156 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
157 return 0;
158
159 return pmd_set_huge(pmd, phys_addr, prot);
160}
161
162static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
163 phys_addr_t phys_addr, pgprot_t prot,
164 unsigned int max_page_shift, pgtbl_mod_mask *mask)
165{
166 pmd_t *pmd;
167 unsigned long next;
168
169 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
170 if (!pmd)
171 return -ENOMEM;
172 do {
173 next = pmd_addr_end(addr, end);
174
175 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
176 max_page_shift)) {
177 *mask |= PGTBL_PMD_MODIFIED;
178 continue;
179 }
180
181 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
182 return -ENOMEM;
183 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
184 return 0;
185}
186
187static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
188 phys_addr_t phys_addr, pgprot_t prot,
189 unsigned int max_page_shift)
190{
191 if (max_page_shift < PUD_SHIFT)
192 return 0;
193
194 if (!arch_vmap_pud_supported(prot))
195 return 0;
196
197 if ((end - addr) != PUD_SIZE)
198 return 0;
199
200 if (!IS_ALIGNED(addr, PUD_SIZE))
201 return 0;
202
203 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
204 return 0;
205
206 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
207 return 0;
208
209 return pud_set_huge(pud, phys_addr, prot);
210}
211
212static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
213 phys_addr_t phys_addr, pgprot_t prot,
214 unsigned int max_page_shift, pgtbl_mod_mask *mask)
215{
216 pud_t *pud;
217 unsigned long next;
218
219 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
220 if (!pud)
221 return -ENOMEM;
222 do {
223 next = pud_addr_end(addr, end);
224
225 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
226 max_page_shift)) {
227 *mask |= PGTBL_PUD_MODIFIED;
228 continue;
229 }
230
231 if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
232 max_page_shift, mask))
233 return -ENOMEM;
234 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
235 return 0;
236}
237
238static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
239 phys_addr_t phys_addr, pgprot_t prot,
240 unsigned int max_page_shift)
241{
242 if (max_page_shift < P4D_SHIFT)
243 return 0;
244
245 if (!arch_vmap_p4d_supported(prot))
246 return 0;
247
248 if ((end - addr) != P4D_SIZE)
249 return 0;
250
251 if (!IS_ALIGNED(addr, P4D_SIZE))
252 return 0;
253
254 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
255 return 0;
256
257 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
258 return 0;
259
260 return p4d_set_huge(p4d, phys_addr, prot);
261}
262
263static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
264 phys_addr_t phys_addr, pgprot_t prot,
265 unsigned int max_page_shift, pgtbl_mod_mask *mask)
266{
267 p4d_t *p4d;
268 unsigned long next;
269
270 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
271 if (!p4d)
272 return -ENOMEM;
273 do {
274 next = p4d_addr_end(addr, end);
275
276 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
277 max_page_shift)) {
278 *mask |= PGTBL_P4D_MODIFIED;
279 continue;
280 }
281
282 if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
283 max_page_shift, mask))
284 return -ENOMEM;
285 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
286 return 0;
287}
288
289static int vmap_range_noflush(unsigned long addr, unsigned long end,
290 phys_addr_t phys_addr, pgprot_t prot,
291 unsigned int max_page_shift)
292{
293 pgd_t *pgd;
294 unsigned long start;
295 unsigned long next;
296 int err;
297 pgtbl_mod_mask mask = 0;
298
299 might_sleep();
300 BUG_ON(addr >= end);
301
302 start = addr;
303 pgd = pgd_offset_k(addr);
304 do {
305 next = pgd_addr_end(addr, end);
306 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
307 max_page_shift, &mask);
308 if (err)
309 break;
310 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
311
312 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
313 arch_sync_kernel_mappings(start, end);
314
315 return err;
316}
317
318int ioremap_page_range(unsigned long addr, unsigned long end,
319 phys_addr_t phys_addr, pgprot_t prot)
320{
321 int err;
322
323 err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot),
324 ioremap_max_page_shift);
325 flush_cache_vmap(addr, end);
326 if (!err)
327 kmsan_ioremap_page_range(addr, end, phys_addr, prot,
328 ioremap_max_page_shift);
329 return err;
330}
331
332static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
333 pgtbl_mod_mask *mask)
334{
335 pte_t *pte;
336
337 pte = pte_offset_kernel(pmd, addr);
338 do {
339 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
340 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
341 } while (pte++, addr += PAGE_SIZE, addr != end);
342 *mask |= PGTBL_PTE_MODIFIED;
343}
344
345static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
346 pgtbl_mod_mask *mask)
347{
348 pmd_t *pmd;
349 unsigned long next;
350 int cleared;
351
352 pmd = pmd_offset(pud, addr);
353 do {
354 next = pmd_addr_end(addr, end);
355
356 cleared = pmd_clear_huge(pmd);
357 if (cleared || pmd_bad(*pmd))
358 *mask |= PGTBL_PMD_MODIFIED;
359
360 if (cleared)
361 continue;
362 if (pmd_none_or_clear_bad(pmd))
363 continue;
364 vunmap_pte_range(pmd, addr, next, mask);
365
366 cond_resched();
367 } while (pmd++, addr = next, addr != end);
368}
369
370static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
371 pgtbl_mod_mask *mask)
372{
373 pud_t *pud;
374 unsigned long next;
375 int cleared;
376
377 pud = pud_offset(p4d, addr);
378 do {
379 next = pud_addr_end(addr, end);
380
381 cleared = pud_clear_huge(pud);
382 if (cleared || pud_bad(*pud))
383 *mask |= PGTBL_PUD_MODIFIED;
384
385 if (cleared)
386 continue;
387 if (pud_none_or_clear_bad(pud))
388 continue;
389 vunmap_pmd_range(pud, addr, next, mask);
390 } while (pud++, addr = next, addr != end);
391}
392
393static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
394 pgtbl_mod_mask *mask)
395{
396 p4d_t *p4d;
397 unsigned long next;
398
399 p4d = p4d_offset(pgd, addr);
400 do {
401 next = p4d_addr_end(addr, end);
402
403 p4d_clear_huge(p4d);
404 if (p4d_bad(*p4d))
405 *mask |= PGTBL_P4D_MODIFIED;
406
407 if (p4d_none_or_clear_bad(p4d))
408 continue;
409 vunmap_pud_range(p4d, addr, next, mask);
410 } while (p4d++, addr = next, addr != end);
411}
412
413/*
414 * vunmap_range_noflush is similar to vunmap_range, but does not
415 * flush caches or TLBs.
416 *
417 * The caller is responsible for calling flush_cache_vmap() before calling
418 * this function, and flush_tlb_kernel_range after it has returned
419 * successfully (and before the addresses are expected to cause a page fault
420 * or be re-mapped for something else, if TLB flushes are being delayed or
421 * coalesced).
422 *
423 * This is an internal function only. Do not use outside mm/.
424 */
425void __vunmap_range_noflush(unsigned long start, unsigned long end)
426{
427 unsigned long next;
428 pgd_t *pgd;
429 unsigned long addr = start;
430 pgtbl_mod_mask mask = 0;
431
432 BUG_ON(addr >= end);
433 pgd = pgd_offset_k(addr);
434 do {
435 next = pgd_addr_end(addr, end);
436 if (pgd_bad(*pgd))
437 mask |= PGTBL_PGD_MODIFIED;
438 if (pgd_none_or_clear_bad(pgd))
439 continue;
440 vunmap_p4d_range(pgd, addr, next, &mask);
441 } while (pgd++, addr = next, addr != end);
442
443 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
444 arch_sync_kernel_mappings(start, end);
445}
446
447void vunmap_range_noflush(unsigned long start, unsigned long end)
448{
449 kmsan_vunmap_range_noflush(start, end);
450 __vunmap_range_noflush(start, end);
451}
452
453/**
454 * vunmap_range - unmap kernel virtual addresses
455 * @addr: start of the VM area to unmap
456 * @end: end of the VM area to unmap (non-inclusive)
457 *
458 * Clears any present PTEs in the virtual address range, flushes TLBs and
459 * caches. Any subsequent access to the address before it has been re-mapped
460 * is a kernel bug.
461 */
462void vunmap_range(unsigned long addr, unsigned long end)
463{
464 flush_cache_vunmap(addr, end);
465 vunmap_range_noflush(addr, end);
466 flush_tlb_kernel_range(addr, end);
467}
468
469static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
470 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
471 pgtbl_mod_mask *mask)
472{
473 pte_t *pte;
474
475 /*
476 * nr is a running index into the array which helps higher level
477 * callers keep track of where we're up to.
478 */
479
480 pte = pte_alloc_kernel_track(pmd, addr, mask);
481 if (!pte)
482 return -ENOMEM;
483 do {
484 struct page *page = pages[*nr];
485
486 if (WARN_ON(!pte_none(*pte)))
487 return -EBUSY;
488 if (WARN_ON(!page))
489 return -ENOMEM;
490 if (WARN_ON(!pfn_valid(page_to_pfn(page))))
491 return -EINVAL;
492
493 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
494 (*nr)++;
495 } while (pte++, addr += PAGE_SIZE, addr != end);
496 *mask |= PGTBL_PTE_MODIFIED;
497 return 0;
498}
499
500static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
501 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
502 pgtbl_mod_mask *mask)
503{
504 pmd_t *pmd;
505 unsigned long next;
506
507 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
508 if (!pmd)
509 return -ENOMEM;
510 do {
511 next = pmd_addr_end(addr, end);
512 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
513 return -ENOMEM;
514 } while (pmd++, addr = next, addr != end);
515 return 0;
516}
517
518static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
519 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
520 pgtbl_mod_mask *mask)
521{
522 pud_t *pud;
523 unsigned long next;
524
525 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
526 if (!pud)
527 return -ENOMEM;
528 do {
529 next = pud_addr_end(addr, end);
530 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
531 return -ENOMEM;
532 } while (pud++, addr = next, addr != end);
533 return 0;
534}
535
536static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
537 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
538 pgtbl_mod_mask *mask)
539{
540 p4d_t *p4d;
541 unsigned long next;
542
543 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
544 if (!p4d)
545 return -ENOMEM;
546 do {
547 next = p4d_addr_end(addr, end);
548 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
549 return -ENOMEM;
550 } while (p4d++, addr = next, addr != end);
551 return 0;
552}
553
554static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
555 pgprot_t prot, struct page **pages)
556{
557 unsigned long start = addr;
558 pgd_t *pgd;
559 unsigned long next;
560 int err = 0;
561 int nr = 0;
562 pgtbl_mod_mask mask = 0;
563
564 BUG_ON(addr >= end);
565 pgd = pgd_offset_k(addr);
566 do {
567 next = pgd_addr_end(addr, end);
568 if (pgd_bad(*pgd))
569 mask |= PGTBL_PGD_MODIFIED;
570 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
571 if (err)
572 return err;
573 } while (pgd++, addr = next, addr != end);
574
575 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
576 arch_sync_kernel_mappings(start, end);
577
578 return 0;
579}
580
581/*
582 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
583 * flush caches.
584 *
585 * The caller is responsible for calling flush_cache_vmap() after this
586 * function returns successfully and before the addresses are accessed.
587 *
588 * This is an internal function only. Do not use outside mm/.
589 */
590int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
591 pgprot_t prot, struct page **pages, unsigned int page_shift)
592{
593 unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
594
595 WARN_ON(page_shift < PAGE_SHIFT);
596
597 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
598 page_shift == PAGE_SHIFT)
599 return vmap_small_pages_range_noflush(addr, end, prot, pages);
600
601 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
602 int err;
603
604 err = vmap_range_noflush(addr, addr + (1UL << page_shift),
605 page_to_phys(pages[i]), prot,
606 page_shift);
607 if (err)
608 return err;
609
610 addr += 1UL << page_shift;
611 }
612
613 return 0;
614}
615
616int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
617 pgprot_t prot, struct page **pages, unsigned int page_shift)
618{
619 kmsan_vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
620 return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
621}
622
623/**
624 * vmap_pages_range - map pages to a kernel virtual address
625 * @addr: start of the VM area to map
626 * @end: end of the VM area to map (non-inclusive)
627 * @prot: page protection flags to use
628 * @pages: pages to map (always PAGE_SIZE pages)
629 * @page_shift: maximum shift that the pages may be mapped with, @pages must
630 * be aligned and contiguous up to at least this shift.
631 *
632 * RETURNS:
633 * 0 on success, -errno on failure.
634 */
635static int vmap_pages_range(unsigned long addr, unsigned long end,
636 pgprot_t prot, struct page **pages, unsigned int page_shift)
637{
638 int err;
639
640 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
641 flush_cache_vmap(addr, end);
642 return err;
643}
644
645int is_vmalloc_or_module_addr(const void *x)
646{
647 /*
648 * ARM, x86-64 and sparc64 put modules in a special place,
649 * and fall back on vmalloc() if that fails. Others
650 * just put it in the vmalloc space.
651 */
652#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
653 unsigned long addr = (unsigned long)kasan_reset_tag(x);
654 if (addr >= MODULES_VADDR && addr < MODULES_END)
655 return 1;
656#endif
657 return is_vmalloc_addr(x);
658}
659
660/*
661 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
662 * return the tail page that corresponds to the base page address, which
663 * matches small vmap mappings.
664 */
665struct page *vmalloc_to_page(const void *vmalloc_addr)
666{
667 unsigned long addr = (unsigned long) vmalloc_addr;
668 struct page *page = NULL;
669 pgd_t *pgd = pgd_offset_k(addr);
670 p4d_t *p4d;
671 pud_t *pud;
672 pmd_t *pmd;
673 pte_t *ptep, pte;
674
675 /*
676 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
677 * architectures that do not vmalloc module space
678 */
679 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
680
681 if (pgd_none(*pgd))
682 return NULL;
683 if (WARN_ON_ONCE(pgd_leaf(*pgd)))
684 return NULL; /* XXX: no allowance for huge pgd */
685 if (WARN_ON_ONCE(pgd_bad(*pgd)))
686 return NULL;
687
688 p4d = p4d_offset(pgd, addr);
689 if (p4d_none(*p4d))
690 return NULL;
691 if (p4d_leaf(*p4d))
692 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
693 if (WARN_ON_ONCE(p4d_bad(*p4d)))
694 return NULL;
695
696 pud = pud_offset(p4d, addr);
697 if (pud_none(*pud))
698 return NULL;
699 if (pud_leaf(*pud))
700 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
701 if (WARN_ON_ONCE(pud_bad(*pud)))
702 return NULL;
703
704 pmd = pmd_offset(pud, addr);
705 if (pmd_none(*pmd))
706 return NULL;
707 if (pmd_leaf(*pmd))
708 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
709 if (WARN_ON_ONCE(pmd_bad(*pmd)))
710 return NULL;
711
712 ptep = pte_offset_map(pmd, addr);
713 pte = *ptep;
714 if (pte_present(pte))
715 page = pte_page(pte);
716 pte_unmap(ptep);
717
718 return page;
719}
720EXPORT_SYMBOL(vmalloc_to_page);
721
722/*
723 * Map a vmalloc()-space virtual address to the physical page frame number.
724 */
725unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
726{
727 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
728}
729EXPORT_SYMBOL(vmalloc_to_pfn);
730
731
732/*** Global kva allocator ***/
733
734#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
735#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
736
737
738static DEFINE_SPINLOCK(vmap_area_lock);
739static DEFINE_SPINLOCK(free_vmap_area_lock);
740/* Export for kexec only */
741LIST_HEAD(vmap_area_list);
742static struct rb_root vmap_area_root = RB_ROOT;
743static bool vmap_initialized __read_mostly;
744
745static struct rb_root purge_vmap_area_root = RB_ROOT;
746static LIST_HEAD(purge_vmap_area_list);
747static DEFINE_SPINLOCK(purge_vmap_area_lock);
748
749/*
750 * This kmem_cache is used for vmap_area objects. Instead of
751 * allocating from slab we reuse an object from this cache to
752 * make things faster. Especially in "no edge" splitting of
753 * free block.
754 */
755static struct kmem_cache *vmap_area_cachep;
756
757/*
758 * This linked list is used in pair with free_vmap_area_root.
759 * It gives O(1) access to prev/next to perform fast coalescing.
760 */
761static LIST_HEAD(free_vmap_area_list);
762
763/*
764 * This augment red-black tree represents the free vmap space.
765 * All vmap_area objects in this tree are sorted by va->va_start
766 * address. It is used for allocation and merging when a vmap
767 * object is released.
768 *
769 * Each vmap_area node contains a maximum available free block
770 * of its sub-tree, right or left. Therefore it is possible to
771 * find a lowest match of free area.
772 */
773static struct rb_root free_vmap_area_root = RB_ROOT;
774
775/*
776 * Preload a CPU with one object for "no edge" split case. The
777 * aim is to get rid of allocations from the atomic context, thus
778 * to use more permissive allocation masks.
779 */
780static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
781
782static __always_inline unsigned long
783va_size(struct vmap_area *va)
784{
785 return (va->va_end - va->va_start);
786}
787
788static __always_inline unsigned long
789get_subtree_max_size(struct rb_node *node)
790{
791 struct vmap_area *va;
792
793 va = rb_entry_safe(node, struct vmap_area, rb_node);
794 return va ? va->subtree_max_size : 0;
795}
796
797RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
798 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
799
800static void purge_vmap_area_lazy(void);
801static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
802static void drain_vmap_area_work(struct work_struct *work);
803static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work);
804
805static atomic_long_t nr_vmalloc_pages;
806
807unsigned long vmalloc_nr_pages(void)
808{
809 return atomic_long_read(&nr_vmalloc_pages);
810}
811
812/* Look up the first VA which satisfies addr < va_end, NULL if none. */
813static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
814{
815 struct vmap_area *va = NULL;
816 struct rb_node *n = vmap_area_root.rb_node;
817
818 addr = (unsigned long)kasan_reset_tag((void *)addr);
819
820 while (n) {
821 struct vmap_area *tmp;
822
823 tmp = rb_entry(n, struct vmap_area, rb_node);
824 if (tmp->va_end > addr) {
825 va = tmp;
826 if (tmp->va_start <= addr)
827 break;
828
829 n = n->rb_left;
830 } else
831 n = n->rb_right;
832 }
833
834 return va;
835}
836
837static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root)
838{
839 struct rb_node *n = root->rb_node;
840
841 addr = (unsigned long)kasan_reset_tag((void *)addr);
842
843 while (n) {
844 struct vmap_area *va;
845
846 va = rb_entry(n, struct vmap_area, rb_node);
847 if (addr < va->va_start)
848 n = n->rb_left;
849 else if (addr >= va->va_end)
850 n = n->rb_right;
851 else
852 return va;
853 }
854
855 return NULL;
856}
857
858/*
859 * This function returns back addresses of parent node
860 * and its left or right link for further processing.
861 *
862 * Otherwise NULL is returned. In that case all further
863 * steps regarding inserting of conflicting overlap range
864 * have to be declined and actually considered as a bug.
865 */
866static __always_inline struct rb_node **
867find_va_links(struct vmap_area *va,
868 struct rb_root *root, struct rb_node *from,
869 struct rb_node **parent)
870{
871 struct vmap_area *tmp_va;
872 struct rb_node **link;
873
874 if (root) {
875 link = &root->rb_node;
876 if (unlikely(!*link)) {
877 *parent = NULL;
878 return link;
879 }
880 } else {
881 link = &from;
882 }
883
884 /*
885 * Go to the bottom of the tree. When we hit the last point
886 * we end up with parent rb_node and correct direction, i name
887 * it link, where the new va->rb_node will be attached to.
888 */
889 do {
890 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
891
892 /*
893 * During the traversal we also do some sanity check.
894 * Trigger the BUG() if there are sides(left/right)
895 * or full overlaps.
896 */
897 if (va->va_end <= tmp_va->va_start)
898 link = &(*link)->rb_left;
899 else if (va->va_start >= tmp_va->va_end)
900 link = &(*link)->rb_right;
901 else {
902 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
903 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
904
905 return NULL;
906 }
907 } while (*link);
908
909 *parent = &tmp_va->rb_node;
910 return link;
911}
912
913static __always_inline struct list_head *
914get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
915{
916 struct list_head *list;
917
918 if (unlikely(!parent))
919 /*
920 * The red-black tree where we try to find VA neighbors
921 * before merging or inserting is empty, i.e. it means
922 * there is no free vmap space. Normally it does not
923 * happen but we handle this case anyway.
924 */
925 return NULL;
926
927 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
928 return (&parent->rb_right == link ? list->next : list);
929}
930
931static __always_inline void
932__link_va(struct vmap_area *va, struct rb_root *root,
933 struct rb_node *parent, struct rb_node **link,
934 struct list_head *head, bool augment)
935{
936 /*
937 * VA is still not in the list, but we can
938 * identify its future previous list_head node.
939 */
940 if (likely(parent)) {
941 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
942 if (&parent->rb_right != link)
943 head = head->prev;
944 }
945
946 /* Insert to the rb-tree */
947 rb_link_node(&va->rb_node, parent, link);
948 if (augment) {
949 /*
950 * Some explanation here. Just perform simple insertion
951 * to the tree. We do not set va->subtree_max_size to
952 * its current size before calling rb_insert_augmented().
953 * It is because we populate the tree from the bottom
954 * to parent levels when the node _is_ in the tree.
955 *
956 * Therefore we set subtree_max_size to zero after insertion,
957 * to let __augment_tree_propagate_from() puts everything to
958 * the correct order later on.
959 */
960 rb_insert_augmented(&va->rb_node,
961 root, &free_vmap_area_rb_augment_cb);
962 va->subtree_max_size = 0;
963 } else {
964 rb_insert_color(&va->rb_node, root);
965 }
966
967 /* Address-sort this list */
968 list_add(&va->list, head);
969}
970
971static __always_inline void
972link_va(struct vmap_area *va, struct rb_root *root,
973 struct rb_node *parent, struct rb_node **link,
974 struct list_head *head)
975{
976 __link_va(va, root, parent, link, head, false);
977}
978
979static __always_inline void
980link_va_augment(struct vmap_area *va, struct rb_root *root,
981 struct rb_node *parent, struct rb_node **link,
982 struct list_head *head)
983{
984 __link_va(va, root, parent, link, head, true);
985}
986
987static __always_inline void
988__unlink_va(struct vmap_area *va, struct rb_root *root, bool augment)
989{
990 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
991 return;
992
993 if (augment)
994 rb_erase_augmented(&va->rb_node,
995 root, &free_vmap_area_rb_augment_cb);
996 else
997 rb_erase(&va->rb_node, root);
998
999 list_del_init(&va->list);
1000 RB_CLEAR_NODE(&va->rb_node);
1001}
1002
1003static __always_inline void
1004unlink_va(struct vmap_area *va, struct rb_root *root)
1005{
1006 __unlink_va(va, root, false);
1007}
1008
1009static __always_inline void
1010unlink_va_augment(struct vmap_area *va, struct rb_root *root)
1011{
1012 __unlink_va(va, root, true);
1013}
1014
1015#if DEBUG_AUGMENT_PROPAGATE_CHECK
1016/*
1017 * Gets called when remove the node and rotate.
1018 */
1019static __always_inline unsigned long
1020compute_subtree_max_size(struct vmap_area *va)
1021{
1022 return max3(va_size(va),
1023 get_subtree_max_size(va->rb_node.rb_left),
1024 get_subtree_max_size(va->rb_node.rb_right));
1025}
1026
1027static void
1028augment_tree_propagate_check(void)
1029{
1030 struct vmap_area *va;
1031 unsigned long computed_size;
1032
1033 list_for_each_entry(va, &free_vmap_area_list, list) {
1034 computed_size = compute_subtree_max_size(va);
1035 if (computed_size != va->subtree_max_size)
1036 pr_emerg("tree is corrupted: %lu, %lu\n",
1037 va_size(va), va->subtree_max_size);
1038 }
1039}
1040#endif
1041
1042/*
1043 * This function populates subtree_max_size from bottom to upper
1044 * levels starting from VA point. The propagation must be done
1045 * when VA size is modified by changing its va_start/va_end. Or
1046 * in case of newly inserting of VA to the tree.
1047 *
1048 * It means that __augment_tree_propagate_from() must be called:
1049 * - After VA has been inserted to the tree(free path);
1050 * - After VA has been shrunk(allocation path);
1051 * - After VA has been increased(merging path).
1052 *
1053 * Please note that, it does not mean that upper parent nodes
1054 * and their subtree_max_size are recalculated all the time up
1055 * to the root node.
1056 *
1057 * 4--8
1058 * /\
1059 * / \
1060 * / \
1061 * 2--2 8--8
1062 *
1063 * For example if we modify the node 4, shrinking it to 2, then
1064 * no any modification is required. If we shrink the node 2 to 1
1065 * its subtree_max_size is updated only, and set to 1. If we shrink
1066 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
1067 * node becomes 4--6.
1068 */
1069static __always_inline void
1070augment_tree_propagate_from(struct vmap_area *va)
1071{
1072 /*
1073 * Populate the tree from bottom towards the root until
1074 * the calculated maximum available size of checked node
1075 * is equal to its current one.
1076 */
1077 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
1078
1079#if DEBUG_AUGMENT_PROPAGATE_CHECK
1080 augment_tree_propagate_check();
1081#endif
1082}
1083
1084static void
1085insert_vmap_area(struct vmap_area *va,
1086 struct rb_root *root, struct list_head *head)
1087{
1088 struct rb_node **link;
1089 struct rb_node *parent;
1090
1091 link = find_va_links(va, root, NULL, &parent);
1092 if (link)
1093 link_va(va, root, parent, link, head);
1094}
1095
1096static void
1097insert_vmap_area_augment(struct vmap_area *va,
1098 struct rb_node *from, struct rb_root *root,
1099 struct list_head *head)
1100{
1101 struct rb_node **link;
1102 struct rb_node *parent;
1103
1104 if (from)
1105 link = find_va_links(va, NULL, from, &parent);
1106 else
1107 link = find_va_links(va, root, NULL, &parent);
1108
1109 if (link) {
1110 link_va_augment(va, root, parent, link, head);
1111 augment_tree_propagate_from(va);
1112 }
1113}
1114
1115/*
1116 * Merge de-allocated chunk of VA memory with previous
1117 * and next free blocks. If coalesce is not done a new
1118 * free area is inserted. If VA has been merged, it is
1119 * freed.
1120 *
1121 * Please note, it can return NULL in case of overlap
1122 * ranges, followed by WARN() report. Despite it is a
1123 * buggy behaviour, a system can be alive and keep
1124 * ongoing.
1125 */
1126static __always_inline struct vmap_area *
1127__merge_or_add_vmap_area(struct vmap_area *va,
1128 struct rb_root *root, struct list_head *head, bool augment)
1129{
1130 struct vmap_area *sibling;
1131 struct list_head *next;
1132 struct rb_node **link;
1133 struct rb_node *parent;
1134 bool merged = false;
1135
1136 /*
1137 * Find a place in the tree where VA potentially will be
1138 * inserted, unless it is merged with its sibling/siblings.
1139 */
1140 link = find_va_links(va, root, NULL, &parent);
1141 if (!link)
1142 return NULL;
1143
1144 /*
1145 * Get next node of VA to check if merging can be done.
1146 */
1147 next = get_va_next_sibling(parent, link);
1148 if (unlikely(next == NULL))
1149 goto insert;
1150
1151 /*
1152 * start end
1153 * | |
1154 * |<------VA------>|<-----Next----->|
1155 * | |
1156 * start end
1157 */
1158 if (next != head) {
1159 sibling = list_entry(next, struct vmap_area, list);
1160 if (sibling->va_start == va->va_end) {
1161 sibling->va_start = va->va_start;
1162
1163 /* Free vmap_area object. */
1164 kmem_cache_free(vmap_area_cachep, va);
1165
1166 /* Point to the new merged area. */
1167 va = sibling;
1168 merged = true;
1169 }
1170 }
1171
1172 /*
1173 * start end
1174 * | |
1175 * |<-----Prev----->|<------VA------>|
1176 * | |
1177 * start end
1178 */
1179 if (next->prev != head) {
1180 sibling = list_entry(next->prev, struct vmap_area, list);
1181 if (sibling->va_end == va->va_start) {
1182 /*
1183 * If both neighbors are coalesced, it is important
1184 * to unlink the "next" node first, followed by merging
1185 * with "previous" one. Otherwise the tree might not be
1186 * fully populated if a sibling's augmented value is
1187 * "normalized" because of rotation operations.
1188 */
1189 if (merged)
1190 __unlink_va(va, root, augment);
1191
1192 sibling->va_end = va->va_end;
1193
1194 /* Free vmap_area object. */
1195 kmem_cache_free(vmap_area_cachep, va);
1196
1197 /* Point to the new merged area. */
1198 va = sibling;
1199 merged = true;
1200 }
1201 }
1202
1203insert:
1204 if (!merged)
1205 __link_va(va, root, parent, link, head, augment);
1206
1207 return va;
1208}
1209
1210static __always_inline struct vmap_area *
1211merge_or_add_vmap_area(struct vmap_area *va,
1212 struct rb_root *root, struct list_head *head)
1213{
1214 return __merge_or_add_vmap_area(va, root, head, false);
1215}
1216
1217static __always_inline struct vmap_area *
1218merge_or_add_vmap_area_augment(struct vmap_area *va,
1219 struct rb_root *root, struct list_head *head)
1220{
1221 va = __merge_or_add_vmap_area(va, root, head, true);
1222 if (va)
1223 augment_tree_propagate_from(va);
1224
1225 return va;
1226}
1227
1228static __always_inline bool
1229is_within_this_va(struct vmap_area *va, unsigned long size,
1230 unsigned long align, unsigned long vstart)
1231{
1232 unsigned long nva_start_addr;
1233
1234 if (va->va_start > vstart)
1235 nva_start_addr = ALIGN(va->va_start, align);
1236 else
1237 nva_start_addr = ALIGN(vstart, align);
1238
1239 /* Can be overflowed due to big size or alignment. */
1240 if (nva_start_addr + size < nva_start_addr ||
1241 nva_start_addr < vstart)
1242 return false;
1243
1244 return (nva_start_addr + size <= va->va_end);
1245}
1246
1247/*
1248 * Find the first free block(lowest start address) in the tree,
1249 * that will accomplish the request corresponding to passing
1250 * parameters. Please note, with an alignment bigger than PAGE_SIZE,
1251 * a search length is adjusted to account for worst case alignment
1252 * overhead.
1253 */
1254static __always_inline struct vmap_area *
1255find_vmap_lowest_match(struct rb_root *root, unsigned long size,
1256 unsigned long align, unsigned long vstart, bool adjust_search_size)
1257{
1258 struct vmap_area *va;
1259 struct rb_node *node;
1260 unsigned long length;
1261
1262 /* Start from the root. */
1263 node = root->rb_node;
1264
1265 /* Adjust the search size for alignment overhead. */
1266 length = adjust_search_size ? size + align - 1 : size;
1267
1268 while (node) {
1269 va = rb_entry(node, struct vmap_area, rb_node);
1270
1271 if (get_subtree_max_size(node->rb_left) >= length &&
1272 vstart < va->va_start) {
1273 node = node->rb_left;
1274 } else {
1275 if (is_within_this_va(va, size, align, vstart))
1276 return va;
1277
1278 /*
1279 * Does not make sense to go deeper towards the right
1280 * sub-tree if it does not have a free block that is
1281 * equal or bigger to the requested search length.
1282 */
1283 if (get_subtree_max_size(node->rb_right) >= length) {
1284 node = node->rb_right;
1285 continue;
1286 }
1287
1288 /*
1289 * OK. We roll back and find the first right sub-tree,
1290 * that will satisfy the search criteria. It can happen
1291 * due to "vstart" restriction or an alignment overhead
1292 * that is bigger then PAGE_SIZE.
1293 */
1294 while ((node = rb_parent(node))) {
1295 va = rb_entry(node, struct vmap_area, rb_node);
1296 if (is_within_this_va(va, size, align, vstart))
1297 return va;
1298
1299 if (get_subtree_max_size(node->rb_right) >= length &&
1300 vstart <= va->va_start) {
1301 /*
1302 * Shift the vstart forward. Please note, we update it with
1303 * parent's start address adding "1" because we do not want
1304 * to enter same sub-tree after it has already been checked
1305 * and no suitable free block found there.
1306 */
1307 vstart = va->va_start + 1;
1308 node = node->rb_right;
1309 break;
1310 }
1311 }
1312 }
1313 }
1314
1315 return NULL;
1316}
1317
1318#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1319#include <linux/random.h>
1320
1321static struct vmap_area *
1322find_vmap_lowest_linear_match(struct list_head *head, unsigned long size,
1323 unsigned long align, unsigned long vstart)
1324{
1325 struct vmap_area *va;
1326
1327 list_for_each_entry(va, head, list) {
1328 if (!is_within_this_va(va, size, align, vstart))
1329 continue;
1330
1331 return va;
1332 }
1333
1334 return NULL;
1335}
1336
1337static void
1338find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head,
1339 unsigned long size, unsigned long align)
1340{
1341 struct vmap_area *va_1, *va_2;
1342 unsigned long vstart;
1343 unsigned int rnd;
1344
1345 get_random_bytes(&rnd, sizeof(rnd));
1346 vstart = VMALLOC_START + rnd;
1347
1348 va_1 = find_vmap_lowest_match(root, size, align, vstart, false);
1349 va_2 = find_vmap_lowest_linear_match(head, size, align, vstart);
1350
1351 if (va_1 != va_2)
1352 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1353 va_1, va_2, vstart);
1354}
1355#endif
1356
1357enum fit_type {
1358 NOTHING_FIT = 0,
1359 FL_FIT_TYPE = 1, /* full fit */
1360 LE_FIT_TYPE = 2, /* left edge fit */
1361 RE_FIT_TYPE = 3, /* right edge fit */
1362 NE_FIT_TYPE = 4 /* no edge fit */
1363};
1364
1365static __always_inline enum fit_type
1366classify_va_fit_type(struct vmap_area *va,
1367 unsigned long nva_start_addr, unsigned long size)
1368{
1369 enum fit_type type;
1370
1371 /* Check if it is within VA. */
1372 if (nva_start_addr < va->va_start ||
1373 nva_start_addr + size > va->va_end)
1374 return NOTHING_FIT;
1375
1376 /* Now classify. */
1377 if (va->va_start == nva_start_addr) {
1378 if (va->va_end == nva_start_addr + size)
1379 type = FL_FIT_TYPE;
1380 else
1381 type = LE_FIT_TYPE;
1382 } else if (va->va_end == nva_start_addr + size) {
1383 type = RE_FIT_TYPE;
1384 } else {
1385 type = NE_FIT_TYPE;
1386 }
1387
1388 return type;
1389}
1390
1391static __always_inline int
1392adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
1393 struct vmap_area *va, unsigned long nva_start_addr,
1394 unsigned long size)
1395{
1396 struct vmap_area *lva = NULL;
1397 enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
1398
1399 if (type == FL_FIT_TYPE) {
1400 /*
1401 * No need to split VA, it fully fits.
1402 *
1403 * | |
1404 * V NVA V
1405 * |---------------|
1406 */
1407 unlink_va_augment(va, root);
1408 kmem_cache_free(vmap_area_cachep, va);
1409 } else if (type == LE_FIT_TYPE) {
1410 /*
1411 * Split left edge of fit VA.
1412 *
1413 * | |
1414 * V NVA V R
1415 * |-------|-------|
1416 */
1417 va->va_start += size;
1418 } else if (type == RE_FIT_TYPE) {
1419 /*
1420 * Split right edge of fit VA.
1421 *
1422 * | |
1423 * L V NVA V
1424 * |-------|-------|
1425 */
1426 va->va_end = nva_start_addr;
1427 } else if (type == NE_FIT_TYPE) {
1428 /*
1429 * Split no edge of fit VA.
1430 *
1431 * | |
1432 * L V NVA V R
1433 * |---|-------|---|
1434 */
1435 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
1436 if (unlikely(!lva)) {
1437 /*
1438 * For percpu allocator we do not do any pre-allocation
1439 * and leave it as it is. The reason is it most likely
1440 * never ends up with NE_FIT_TYPE splitting. In case of
1441 * percpu allocations offsets and sizes are aligned to
1442 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1443 * are its main fitting cases.
1444 *
1445 * There are a few exceptions though, as an example it is
1446 * a first allocation (early boot up) when we have "one"
1447 * big free space that has to be split.
1448 *
1449 * Also we can hit this path in case of regular "vmap"
1450 * allocations, if "this" current CPU was not preloaded.
1451 * See the comment in alloc_vmap_area() why. If so, then
1452 * GFP_NOWAIT is used instead to get an extra object for
1453 * split purpose. That is rare and most time does not
1454 * occur.
1455 *
1456 * What happens if an allocation gets failed. Basically,
1457 * an "overflow" path is triggered to purge lazily freed
1458 * areas to free some memory, then, the "retry" path is
1459 * triggered to repeat one more time. See more details
1460 * in alloc_vmap_area() function.
1461 */
1462 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
1463 if (!lva)
1464 return -1;
1465 }
1466
1467 /*
1468 * Build the remainder.
1469 */
1470 lva->va_start = va->va_start;
1471 lva->va_end = nva_start_addr;
1472
1473 /*
1474 * Shrink this VA to remaining size.
1475 */
1476 va->va_start = nva_start_addr + size;
1477 } else {
1478 return -1;
1479 }
1480
1481 if (type != FL_FIT_TYPE) {
1482 augment_tree_propagate_from(va);
1483
1484 if (lva) /* type == NE_FIT_TYPE */
1485 insert_vmap_area_augment(lva, &va->rb_node, root, head);
1486 }
1487
1488 return 0;
1489}
1490
1491/*
1492 * Returns a start address of the newly allocated area, if success.
1493 * Otherwise a vend is returned that indicates failure.
1494 */
1495static __always_inline unsigned long
1496__alloc_vmap_area(struct rb_root *root, struct list_head *head,
1497 unsigned long size, unsigned long align,
1498 unsigned long vstart, unsigned long vend)
1499{
1500 bool adjust_search_size = true;
1501 unsigned long nva_start_addr;
1502 struct vmap_area *va;
1503 int ret;
1504
1505 /*
1506 * Do not adjust when:
1507 * a) align <= PAGE_SIZE, because it does not make any sense.
1508 * All blocks(their start addresses) are at least PAGE_SIZE
1509 * aligned anyway;
1510 * b) a short range where a requested size corresponds to exactly
1511 * specified [vstart:vend] interval and an alignment > PAGE_SIZE.
1512 * With adjusted search length an allocation would not succeed.
1513 */
1514 if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size))
1515 adjust_search_size = false;
1516
1517 va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size);
1518 if (unlikely(!va))
1519 return vend;
1520
1521 if (va->va_start > vstart)
1522 nva_start_addr = ALIGN(va->va_start, align);
1523 else
1524 nva_start_addr = ALIGN(vstart, align);
1525
1526 /* Check the "vend" restriction. */
1527 if (nva_start_addr + size > vend)
1528 return vend;
1529
1530 /* Update the free vmap_area. */
1531 ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
1532 if (WARN_ON_ONCE(ret))
1533 return vend;
1534
1535#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1536 find_vmap_lowest_match_check(root, head, size, align);
1537#endif
1538
1539 return nva_start_addr;
1540}
1541
1542/*
1543 * Free a region of KVA allocated by alloc_vmap_area
1544 */
1545static void free_vmap_area(struct vmap_area *va)
1546{
1547 /*
1548 * Remove from the busy tree/list.
1549 */
1550 spin_lock(&vmap_area_lock);
1551 unlink_va(va, &vmap_area_root);
1552 spin_unlock(&vmap_area_lock);
1553
1554 /*
1555 * Insert/Merge it back to the free tree/list.
1556 */
1557 spin_lock(&free_vmap_area_lock);
1558 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
1559 spin_unlock(&free_vmap_area_lock);
1560}
1561
1562static inline void
1563preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
1564{
1565 struct vmap_area *va = NULL;
1566
1567 /*
1568 * Preload this CPU with one extra vmap_area object. It is used
1569 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1570 * a CPU that does an allocation is preloaded.
1571 *
1572 * We do it in non-atomic context, thus it allows us to use more
1573 * permissive allocation masks to be more stable under low memory
1574 * condition and high memory pressure.
1575 */
1576 if (!this_cpu_read(ne_fit_preload_node))
1577 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1578
1579 spin_lock(lock);
1580
1581 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va))
1582 kmem_cache_free(vmap_area_cachep, va);
1583}
1584
1585/*
1586 * Allocate a region of KVA of the specified size and alignment, within the
1587 * vstart and vend.
1588 */
1589static struct vmap_area *alloc_vmap_area(unsigned long size,
1590 unsigned long align,
1591 unsigned long vstart, unsigned long vend,
1592 int node, gfp_t gfp_mask)
1593{
1594 struct vmap_area *va;
1595 unsigned long freed;
1596 unsigned long addr;
1597 int purged = 0;
1598 int ret;
1599
1600 BUG_ON(!size);
1601 BUG_ON(offset_in_page(size));
1602 BUG_ON(!is_power_of_2(align));
1603
1604 if (unlikely(!vmap_initialized))
1605 return ERR_PTR(-EBUSY);
1606
1607 might_sleep();
1608 gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
1609
1610 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1611 if (unlikely(!va))
1612 return ERR_PTR(-ENOMEM);
1613
1614 /*
1615 * Only scan the relevant parts containing pointers to other objects
1616 * to avoid false negatives.
1617 */
1618 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
1619
1620retry:
1621 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
1622 addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list,
1623 size, align, vstart, vend);
1624 spin_unlock(&free_vmap_area_lock);
1625
1626 trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend);
1627
1628 /*
1629 * If an allocation fails, the "vend" address is
1630 * returned. Therefore trigger the overflow path.
1631 */
1632 if (unlikely(addr == vend))
1633 goto overflow;
1634
1635 va->va_start = addr;
1636 va->va_end = addr + size;
1637 va->vm = NULL;
1638
1639 spin_lock(&vmap_area_lock);
1640 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1641 spin_unlock(&vmap_area_lock);
1642
1643 BUG_ON(!IS_ALIGNED(va->va_start, align));
1644 BUG_ON(va->va_start < vstart);
1645 BUG_ON(va->va_end > vend);
1646
1647 ret = kasan_populate_vmalloc(addr, size);
1648 if (ret) {
1649 free_vmap_area(va);
1650 return ERR_PTR(ret);
1651 }
1652
1653 return va;
1654
1655overflow:
1656 if (!purged) {
1657 purge_vmap_area_lazy();
1658 purged = 1;
1659 goto retry;
1660 }
1661
1662 freed = 0;
1663 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
1664
1665 if (freed > 0) {
1666 purged = 0;
1667 goto retry;
1668 }
1669
1670 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
1671 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1672 size);
1673
1674 kmem_cache_free(vmap_area_cachep, va);
1675 return ERR_PTR(-EBUSY);
1676}
1677
1678int register_vmap_purge_notifier(struct notifier_block *nb)
1679{
1680 return blocking_notifier_chain_register(&vmap_notify_list, nb);
1681}
1682EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
1683
1684int unregister_vmap_purge_notifier(struct notifier_block *nb)
1685{
1686 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
1687}
1688EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
1689
1690/*
1691 * lazy_max_pages is the maximum amount of virtual address space we gather up
1692 * before attempting to purge with a TLB flush.
1693 *
1694 * There is a tradeoff here: a larger number will cover more kernel page tables
1695 * and take slightly longer to purge, but it will linearly reduce the number of
1696 * global TLB flushes that must be performed. It would seem natural to scale
1697 * this number up linearly with the number of CPUs (because vmapping activity
1698 * could also scale linearly with the number of CPUs), however it is likely
1699 * that in practice, workloads might be constrained in other ways that mean
1700 * vmap activity will not scale linearly with CPUs. Also, I want to be
1701 * conservative and not introduce a big latency on huge systems, so go with
1702 * a less aggressive log scale. It will still be an improvement over the old
1703 * code, and it will be simple to change the scale factor if we find that it
1704 * becomes a problem on bigger systems.
1705 */
1706static unsigned long lazy_max_pages(void)
1707{
1708 unsigned int log;
1709
1710 log = fls(num_online_cpus());
1711
1712 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
1713}
1714
1715static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
1716
1717/*
1718 * Serialize vmap purging. There is no actual critical section protected
1719 * by this lock, but we want to avoid concurrent calls for performance
1720 * reasons and to make the pcpu_get_vm_areas more deterministic.
1721 */
1722static DEFINE_MUTEX(vmap_purge_lock);
1723
1724/* for per-CPU blocks */
1725static void purge_fragmented_blocks_allcpus(void);
1726
1727/*
1728 * Purges all lazily-freed vmap areas.
1729 */
1730static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
1731{
1732 unsigned long resched_threshold;
1733 unsigned int num_purged_areas = 0;
1734 struct list_head local_purge_list;
1735 struct vmap_area *va, *n_va;
1736
1737 lockdep_assert_held(&vmap_purge_lock);
1738
1739 spin_lock(&purge_vmap_area_lock);
1740 purge_vmap_area_root = RB_ROOT;
1741 list_replace_init(&purge_vmap_area_list, &local_purge_list);
1742 spin_unlock(&purge_vmap_area_lock);
1743
1744 if (unlikely(list_empty(&local_purge_list)))
1745 goto out;
1746
1747 start = min(start,
1748 list_first_entry(&local_purge_list,
1749 struct vmap_area, list)->va_start);
1750
1751 end = max(end,
1752 list_last_entry(&local_purge_list,
1753 struct vmap_area, list)->va_end);
1754
1755 flush_tlb_kernel_range(start, end);
1756 resched_threshold = lazy_max_pages() << 1;
1757
1758 spin_lock(&free_vmap_area_lock);
1759 list_for_each_entry_safe(va, n_va, &local_purge_list, list) {
1760 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
1761 unsigned long orig_start = va->va_start;
1762 unsigned long orig_end = va->va_end;
1763
1764 /*
1765 * Finally insert or merge lazily-freed area. It is
1766 * detached and there is no need to "unlink" it from
1767 * anything.
1768 */
1769 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root,
1770 &free_vmap_area_list);
1771
1772 if (!va)
1773 continue;
1774
1775 if (is_vmalloc_or_module_addr((void *)orig_start))
1776 kasan_release_vmalloc(orig_start, orig_end,
1777 va->va_start, va->va_end);
1778
1779 atomic_long_sub(nr, &vmap_lazy_nr);
1780 num_purged_areas++;
1781
1782 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
1783 cond_resched_lock(&free_vmap_area_lock);
1784 }
1785 spin_unlock(&free_vmap_area_lock);
1786
1787out:
1788 trace_purge_vmap_area_lazy(start, end, num_purged_areas);
1789 return num_purged_areas > 0;
1790}
1791
1792/*
1793 * Kick off a purge of the outstanding lazy areas.
1794 */
1795static void purge_vmap_area_lazy(void)
1796{
1797 mutex_lock(&vmap_purge_lock);
1798 purge_fragmented_blocks_allcpus();
1799 __purge_vmap_area_lazy(ULONG_MAX, 0);
1800 mutex_unlock(&vmap_purge_lock);
1801}
1802
1803static void drain_vmap_area_work(struct work_struct *work)
1804{
1805 unsigned long nr_lazy;
1806
1807 do {
1808 mutex_lock(&vmap_purge_lock);
1809 __purge_vmap_area_lazy(ULONG_MAX, 0);
1810 mutex_unlock(&vmap_purge_lock);
1811
1812 /* Recheck if further work is required. */
1813 nr_lazy = atomic_long_read(&vmap_lazy_nr);
1814 } while (nr_lazy > lazy_max_pages());
1815}
1816
1817/*
1818 * Free a vmap area, caller ensuring that the area has been unmapped
1819 * and flush_cache_vunmap had been called for the correct range
1820 * previously.
1821 */
1822static void free_vmap_area_noflush(struct vmap_area *va)
1823{
1824 unsigned long nr_lazy_max = lazy_max_pages();
1825 unsigned long va_start = va->va_start;
1826 unsigned long nr_lazy;
1827
1828 spin_lock(&vmap_area_lock);
1829 unlink_va(va, &vmap_area_root);
1830 spin_unlock(&vmap_area_lock);
1831
1832 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
1833 PAGE_SHIFT, &vmap_lazy_nr);
1834
1835 /*
1836 * Merge or place it to the purge tree/list.
1837 */
1838 spin_lock(&purge_vmap_area_lock);
1839 merge_or_add_vmap_area(va,
1840 &purge_vmap_area_root, &purge_vmap_area_list);
1841 spin_unlock(&purge_vmap_area_lock);
1842
1843 trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max);
1844
1845 /* After this point, we may free va at any time */
1846 if (unlikely(nr_lazy > nr_lazy_max))
1847 schedule_work(&drain_vmap_work);
1848}
1849
1850/*
1851 * Free and unmap a vmap area
1852 */
1853static void free_unmap_vmap_area(struct vmap_area *va)
1854{
1855 flush_cache_vunmap(va->va_start, va->va_end);
1856 vunmap_range_noflush(va->va_start, va->va_end);
1857 if (debug_pagealloc_enabled_static())
1858 flush_tlb_kernel_range(va->va_start, va->va_end);
1859
1860 free_vmap_area_noflush(va);
1861}
1862
1863struct vmap_area *find_vmap_area(unsigned long addr)
1864{
1865 struct vmap_area *va;
1866
1867 spin_lock(&vmap_area_lock);
1868 va = __find_vmap_area(addr, &vmap_area_root);
1869 spin_unlock(&vmap_area_lock);
1870
1871 return va;
1872}
1873
1874/*** Per cpu kva allocator ***/
1875
1876/*
1877 * vmap space is limited especially on 32 bit architectures. Ensure there is
1878 * room for at least 16 percpu vmap blocks per CPU.
1879 */
1880/*
1881 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1882 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1883 * instead (we just need a rough idea)
1884 */
1885#if BITS_PER_LONG == 32
1886#define VMALLOC_SPACE (128UL*1024*1024)
1887#else
1888#define VMALLOC_SPACE (128UL*1024*1024*1024)
1889#endif
1890
1891#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1892#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1893#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1894#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1895#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1896#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1897#define VMAP_BBMAP_BITS \
1898 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1899 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1900 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1901
1902#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1903
1904struct vmap_block_queue {
1905 spinlock_t lock;
1906 struct list_head free;
1907};
1908
1909struct vmap_block {
1910 spinlock_t lock;
1911 struct vmap_area *va;
1912 unsigned long free, dirty;
1913 unsigned long dirty_min, dirty_max; /*< dirty range */
1914 struct list_head free_list;
1915 struct rcu_head rcu_head;
1916 struct list_head purge;
1917};
1918
1919/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
1920static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
1921
1922/*
1923 * XArray of vmap blocks, indexed by address, to quickly find a vmap block
1924 * in the free path. Could get rid of this if we change the API to return a
1925 * "cookie" from alloc, to be passed to free. But no big deal yet.
1926 */
1927static DEFINE_XARRAY(vmap_blocks);
1928
1929/*
1930 * We should probably have a fallback mechanism to allocate virtual memory
1931 * out of partially filled vmap blocks. However vmap block sizing should be
1932 * fairly reasonable according to the vmalloc size, so it shouldn't be a
1933 * big problem.
1934 */
1935
1936static unsigned long addr_to_vb_idx(unsigned long addr)
1937{
1938 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
1939 addr /= VMAP_BLOCK_SIZE;
1940 return addr;
1941}
1942
1943static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
1944{
1945 unsigned long addr;
1946
1947 addr = va_start + (pages_off << PAGE_SHIFT);
1948 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
1949 return (void *)addr;
1950}
1951
1952/**
1953 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
1954 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
1955 * @order: how many 2^order pages should be occupied in newly allocated block
1956 * @gfp_mask: flags for the page level allocator
1957 *
1958 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
1959 */
1960static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
1961{
1962 struct vmap_block_queue *vbq;
1963 struct vmap_block *vb;
1964 struct vmap_area *va;
1965 unsigned long vb_idx;
1966 int node, err;
1967 void *vaddr;
1968
1969 node = numa_node_id();
1970
1971 vb = kmalloc_node(sizeof(struct vmap_block),
1972 gfp_mask & GFP_RECLAIM_MASK, node);
1973 if (unlikely(!vb))
1974 return ERR_PTR(-ENOMEM);
1975
1976 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
1977 VMALLOC_START, VMALLOC_END,
1978 node, gfp_mask);
1979 if (IS_ERR(va)) {
1980 kfree(vb);
1981 return ERR_CAST(va);
1982 }
1983
1984 vaddr = vmap_block_vaddr(va->va_start, 0);
1985 spin_lock_init(&vb->lock);
1986 vb->va = va;
1987 /* At least something should be left free */
1988 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
1989 vb->free = VMAP_BBMAP_BITS - (1UL << order);
1990 vb->dirty = 0;
1991 vb->dirty_min = VMAP_BBMAP_BITS;
1992 vb->dirty_max = 0;
1993 INIT_LIST_HEAD(&vb->free_list);
1994
1995 vb_idx = addr_to_vb_idx(va->va_start);
1996 err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask);
1997 if (err) {
1998 kfree(vb);
1999 free_vmap_area(va);
2000 return ERR_PTR(err);
2001 }
2002
2003 vbq = raw_cpu_ptr(&vmap_block_queue);
2004 spin_lock(&vbq->lock);
2005 list_add_tail_rcu(&vb->free_list, &vbq->free);
2006 spin_unlock(&vbq->lock);
2007
2008 return vaddr;
2009}
2010
2011static void free_vmap_block(struct vmap_block *vb)
2012{
2013 struct vmap_block *tmp;
2014
2015 tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start));
2016 BUG_ON(tmp != vb);
2017
2018 free_vmap_area_noflush(vb->va);
2019 kfree_rcu(vb, rcu_head);
2020}
2021
2022static void purge_fragmented_blocks(int cpu)
2023{
2024 LIST_HEAD(purge);
2025 struct vmap_block *vb;
2026 struct vmap_block *n_vb;
2027 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2028
2029 rcu_read_lock();
2030 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2031
2032 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
2033 continue;
2034
2035 spin_lock(&vb->lock);
2036 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
2037 vb->free = 0; /* prevent further allocs after releasing lock */
2038 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
2039 vb->dirty_min = 0;
2040 vb->dirty_max = VMAP_BBMAP_BITS;
2041 spin_lock(&vbq->lock);
2042 list_del_rcu(&vb->free_list);
2043 spin_unlock(&vbq->lock);
2044 spin_unlock(&vb->lock);
2045 list_add_tail(&vb->purge, &purge);
2046 } else
2047 spin_unlock(&vb->lock);
2048 }
2049 rcu_read_unlock();
2050
2051 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
2052 list_del(&vb->purge);
2053 free_vmap_block(vb);
2054 }
2055}
2056
2057static void purge_fragmented_blocks_allcpus(void)
2058{
2059 int cpu;
2060
2061 for_each_possible_cpu(cpu)
2062 purge_fragmented_blocks(cpu);
2063}
2064
2065static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
2066{
2067 struct vmap_block_queue *vbq;
2068 struct vmap_block *vb;
2069 void *vaddr = NULL;
2070 unsigned int order;
2071
2072 BUG_ON(offset_in_page(size));
2073 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2074 if (WARN_ON(size == 0)) {
2075 /*
2076 * Allocating 0 bytes isn't what caller wants since
2077 * get_order(0) returns funny result. Just warn and terminate
2078 * early.
2079 */
2080 return NULL;
2081 }
2082 order = get_order(size);
2083
2084 rcu_read_lock();
2085 vbq = raw_cpu_ptr(&vmap_block_queue);
2086 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2087 unsigned long pages_off;
2088
2089 spin_lock(&vb->lock);
2090 if (vb->free < (1UL << order)) {
2091 spin_unlock(&vb->lock);
2092 continue;
2093 }
2094
2095 pages_off = VMAP_BBMAP_BITS - vb->free;
2096 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
2097 vb->free -= 1UL << order;
2098 if (vb->free == 0) {
2099 spin_lock(&vbq->lock);
2100 list_del_rcu(&vb->free_list);
2101 spin_unlock(&vbq->lock);
2102 }
2103
2104 spin_unlock(&vb->lock);
2105 break;
2106 }
2107
2108 rcu_read_unlock();
2109
2110 /* Allocate new block if nothing was found */
2111 if (!vaddr)
2112 vaddr = new_vmap_block(order, gfp_mask);
2113
2114 return vaddr;
2115}
2116
2117static void vb_free(unsigned long addr, unsigned long size)
2118{
2119 unsigned long offset;
2120 unsigned int order;
2121 struct vmap_block *vb;
2122
2123 BUG_ON(offset_in_page(size));
2124 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2125
2126 flush_cache_vunmap(addr, addr + size);
2127
2128 order = get_order(size);
2129 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
2130 vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr));
2131
2132 vunmap_range_noflush(addr, addr + size);
2133
2134 if (debug_pagealloc_enabled_static())
2135 flush_tlb_kernel_range(addr, addr + size);
2136
2137 spin_lock(&vb->lock);
2138
2139 /* Expand dirty range */
2140 vb->dirty_min = min(vb->dirty_min, offset);
2141 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
2142
2143 vb->dirty += 1UL << order;
2144 if (vb->dirty == VMAP_BBMAP_BITS) {
2145 BUG_ON(vb->free);
2146 spin_unlock(&vb->lock);
2147 free_vmap_block(vb);
2148 } else
2149 spin_unlock(&vb->lock);
2150}
2151
2152static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
2153{
2154 int cpu;
2155
2156 if (unlikely(!vmap_initialized))
2157 return;
2158
2159 might_sleep();
2160
2161 for_each_possible_cpu(cpu) {
2162 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2163 struct vmap_block *vb;
2164
2165 rcu_read_lock();
2166 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2167 spin_lock(&vb->lock);
2168 if (vb->dirty && vb->dirty != VMAP_BBMAP_BITS) {
2169 unsigned long va_start = vb->va->va_start;
2170 unsigned long s, e;
2171
2172 s = va_start + (vb->dirty_min << PAGE_SHIFT);
2173 e = va_start + (vb->dirty_max << PAGE_SHIFT);
2174
2175 start = min(s, start);
2176 end = max(e, end);
2177
2178 flush = 1;
2179 }
2180 spin_unlock(&vb->lock);
2181 }
2182 rcu_read_unlock();
2183 }
2184
2185 mutex_lock(&vmap_purge_lock);
2186 purge_fragmented_blocks_allcpus();
2187 if (!__purge_vmap_area_lazy(start, end) && flush)
2188 flush_tlb_kernel_range(start, end);
2189 mutex_unlock(&vmap_purge_lock);
2190}
2191
2192/**
2193 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2194 *
2195 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2196 * to amortize TLB flushing overheads. What this means is that any page you
2197 * have now, may, in a former life, have been mapped into kernel virtual
2198 * address by the vmap layer and so there might be some CPUs with TLB entries
2199 * still referencing that page (additional to the regular 1:1 kernel mapping).
2200 *
2201 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2202 * be sure that none of the pages we have control over will have any aliases
2203 * from the vmap layer.
2204 */
2205void vm_unmap_aliases(void)
2206{
2207 unsigned long start = ULONG_MAX, end = 0;
2208 int flush = 0;
2209
2210 _vm_unmap_aliases(start, end, flush);
2211}
2212EXPORT_SYMBOL_GPL(vm_unmap_aliases);
2213
2214/**
2215 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2216 * @mem: the pointer returned by vm_map_ram
2217 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2218 */
2219void vm_unmap_ram(const void *mem, unsigned int count)
2220{
2221 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2222 unsigned long addr = (unsigned long)kasan_reset_tag(mem);
2223 struct vmap_area *va;
2224
2225 might_sleep();
2226 BUG_ON(!addr);
2227 BUG_ON(addr < VMALLOC_START);
2228 BUG_ON(addr > VMALLOC_END);
2229 BUG_ON(!PAGE_ALIGNED(addr));
2230
2231 kasan_poison_vmalloc(mem, size);
2232
2233 if (likely(count <= VMAP_MAX_ALLOC)) {
2234 debug_check_no_locks_freed(mem, size);
2235 vb_free(addr, size);
2236 return;
2237 }
2238
2239 va = find_vmap_area(addr);
2240 BUG_ON(!va);
2241 debug_check_no_locks_freed((void *)va->va_start,
2242 (va->va_end - va->va_start));
2243 free_unmap_vmap_area(va);
2244}
2245EXPORT_SYMBOL(vm_unmap_ram);
2246
2247/**
2248 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2249 * @pages: an array of pointers to the pages to be mapped
2250 * @count: number of pages
2251 * @node: prefer to allocate data structures on this node
2252 *
2253 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2254 * faster than vmap so it's good. But if you mix long-life and short-life
2255 * objects with vm_map_ram(), it could consume lots of address space through
2256 * fragmentation (especially on a 32bit machine). You could see failures in
2257 * the end. Please use this function for short-lived objects.
2258 *
2259 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2260 */
2261void *vm_map_ram(struct page **pages, unsigned int count, int node)
2262{
2263 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2264 unsigned long addr;
2265 void *mem;
2266
2267 if (likely(count <= VMAP_MAX_ALLOC)) {
2268 mem = vb_alloc(size, GFP_KERNEL);
2269 if (IS_ERR(mem))
2270 return NULL;
2271 addr = (unsigned long)mem;
2272 } else {
2273 struct vmap_area *va;
2274 va = alloc_vmap_area(size, PAGE_SIZE,
2275 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
2276 if (IS_ERR(va))
2277 return NULL;
2278
2279 addr = va->va_start;
2280 mem = (void *)addr;
2281 }
2282
2283 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
2284 pages, PAGE_SHIFT) < 0) {
2285 vm_unmap_ram(mem, count);
2286 return NULL;
2287 }
2288
2289 /*
2290 * Mark the pages as accessible, now that they are mapped.
2291 * With hardware tag-based KASAN, marking is skipped for
2292 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
2293 */
2294 mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL);
2295
2296 return mem;
2297}
2298EXPORT_SYMBOL(vm_map_ram);
2299
2300static struct vm_struct *vmlist __initdata;
2301
2302static inline unsigned int vm_area_page_order(struct vm_struct *vm)
2303{
2304#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2305 return vm->page_order;
2306#else
2307 return 0;
2308#endif
2309}
2310
2311static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
2312{
2313#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2314 vm->page_order = order;
2315#else
2316 BUG_ON(order != 0);
2317#endif
2318}
2319
2320/**
2321 * vm_area_add_early - add vmap area early during boot
2322 * @vm: vm_struct to add
2323 *
2324 * This function is used to add fixed kernel vm area to vmlist before
2325 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
2326 * should contain proper values and the other fields should be zero.
2327 *
2328 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2329 */
2330void __init vm_area_add_early(struct vm_struct *vm)
2331{
2332 struct vm_struct *tmp, **p;
2333
2334 BUG_ON(vmap_initialized);
2335 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
2336 if (tmp->addr >= vm->addr) {
2337 BUG_ON(tmp->addr < vm->addr + vm->size);
2338 break;
2339 } else
2340 BUG_ON(tmp->addr + tmp->size > vm->addr);
2341 }
2342 vm->next = *p;
2343 *p = vm;
2344}
2345
2346/**
2347 * vm_area_register_early - register vmap area early during boot
2348 * @vm: vm_struct to register
2349 * @align: requested alignment
2350 *
2351 * This function is used to register kernel vm area before
2352 * vmalloc_init() is called. @vm->size and @vm->flags should contain
2353 * proper values on entry and other fields should be zero. On return,
2354 * vm->addr contains the allocated address.
2355 *
2356 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2357 */
2358void __init vm_area_register_early(struct vm_struct *vm, size_t align)
2359{
2360 unsigned long addr = ALIGN(VMALLOC_START, align);
2361 struct vm_struct *cur, **p;
2362
2363 BUG_ON(vmap_initialized);
2364
2365 for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) {
2366 if ((unsigned long)cur->addr - addr >= vm->size)
2367 break;
2368 addr = ALIGN((unsigned long)cur->addr + cur->size, align);
2369 }
2370
2371 BUG_ON(addr > VMALLOC_END - vm->size);
2372 vm->addr = (void *)addr;
2373 vm->next = *p;
2374 *p = vm;
2375 kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
2376}
2377
2378static void vmap_init_free_space(void)
2379{
2380 unsigned long vmap_start = 1;
2381 const unsigned long vmap_end = ULONG_MAX;
2382 struct vmap_area *busy, *free;
2383
2384 /*
2385 * B F B B B F
2386 * -|-----|.....|-----|-----|-----|.....|-
2387 * | The KVA space |
2388 * |<--------------------------------->|
2389 */
2390 list_for_each_entry(busy, &vmap_area_list, list) {
2391 if (busy->va_start - vmap_start > 0) {
2392 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2393 if (!WARN_ON_ONCE(!free)) {
2394 free->va_start = vmap_start;
2395 free->va_end = busy->va_start;
2396
2397 insert_vmap_area_augment(free, NULL,
2398 &free_vmap_area_root,
2399 &free_vmap_area_list);
2400 }
2401 }
2402
2403 vmap_start = busy->va_end;
2404 }
2405
2406 if (vmap_end - vmap_start > 0) {
2407 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2408 if (!WARN_ON_ONCE(!free)) {
2409 free->va_start = vmap_start;
2410 free->va_end = vmap_end;
2411
2412 insert_vmap_area_augment(free, NULL,
2413 &free_vmap_area_root,
2414 &free_vmap_area_list);
2415 }
2416 }
2417}
2418
2419void __init vmalloc_init(void)
2420{
2421 struct vmap_area *va;
2422 struct vm_struct *tmp;
2423 int i;
2424
2425 /*
2426 * Create the cache for vmap_area objects.
2427 */
2428 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
2429
2430 for_each_possible_cpu(i) {
2431 struct vmap_block_queue *vbq;
2432 struct vfree_deferred *p;
2433
2434 vbq = &per_cpu(vmap_block_queue, i);
2435 spin_lock_init(&vbq->lock);
2436 INIT_LIST_HEAD(&vbq->free);
2437 p = &per_cpu(vfree_deferred, i);
2438 init_llist_head(&p->list);
2439 INIT_WORK(&p->wq, free_work);
2440 }
2441
2442 /* Import existing vmlist entries. */
2443 for (tmp = vmlist; tmp; tmp = tmp->next) {
2444 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2445 if (WARN_ON_ONCE(!va))
2446 continue;
2447
2448 va->va_start = (unsigned long)tmp->addr;
2449 va->va_end = va->va_start + tmp->size;
2450 va->vm = tmp;
2451 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
2452 }
2453
2454 /*
2455 * Now we can initialize a free vmap space.
2456 */
2457 vmap_init_free_space();
2458 vmap_initialized = true;
2459}
2460
2461static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
2462 struct vmap_area *va, unsigned long flags, const void *caller)
2463{
2464 vm->flags = flags;
2465 vm->addr = (void *)va->va_start;
2466 vm->size = va->va_end - va->va_start;
2467 vm->caller = caller;
2468 va->vm = vm;
2469}
2470
2471static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
2472 unsigned long flags, const void *caller)
2473{
2474 spin_lock(&vmap_area_lock);
2475 setup_vmalloc_vm_locked(vm, va, flags, caller);
2476 spin_unlock(&vmap_area_lock);
2477}
2478
2479static void clear_vm_uninitialized_flag(struct vm_struct *vm)
2480{
2481 /*
2482 * Before removing VM_UNINITIALIZED,
2483 * we should make sure that vm has proper values.
2484 * Pair with smp_rmb() in show_numa_info().
2485 */
2486 smp_wmb();
2487 vm->flags &= ~VM_UNINITIALIZED;
2488}
2489
2490static struct vm_struct *__get_vm_area_node(unsigned long size,
2491 unsigned long align, unsigned long shift, unsigned long flags,
2492 unsigned long start, unsigned long end, int node,
2493 gfp_t gfp_mask, const void *caller)
2494{
2495 struct vmap_area *va;
2496 struct vm_struct *area;
2497 unsigned long requested_size = size;
2498
2499 BUG_ON(in_interrupt());
2500 size = ALIGN(size, 1ul << shift);
2501 if (unlikely(!size))
2502 return NULL;
2503
2504 if (flags & VM_IOREMAP)
2505 align = 1ul << clamp_t(int, get_count_order_long(size),
2506 PAGE_SHIFT, IOREMAP_MAX_ORDER);
2507
2508 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
2509 if (unlikely(!area))
2510 return NULL;
2511
2512 if (!(flags & VM_NO_GUARD))
2513 size += PAGE_SIZE;
2514
2515 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
2516 if (IS_ERR(va)) {
2517 kfree(area);
2518 return NULL;
2519 }
2520
2521 setup_vmalloc_vm(area, va, flags, caller);
2522
2523 /*
2524 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a
2525 * best-effort approach, as they can be mapped outside of vmalloc code.
2526 * For VM_ALLOC mappings, the pages are marked as accessible after
2527 * getting mapped in __vmalloc_node_range().
2528 * With hardware tag-based KASAN, marking is skipped for
2529 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
2530 */
2531 if (!(flags & VM_ALLOC))
2532 area->addr = kasan_unpoison_vmalloc(area->addr, requested_size,
2533 KASAN_VMALLOC_PROT_NORMAL);
2534
2535 return area;
2536}
2537
2538struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
2539 unsigned long start, unsigned long end,
2540 const void *caller)
2541{
2542 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
2543 NUMA_NO_NODE, GFP_KERNEL, caller);
2544}
2545
2546/**
2547 * get_vm_area - reserve a contiguous kernel virtual area
2548 * @size: size of the area
2549 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2550 *
2551 * Search an area of @size in the kernel virtual mapping area,
2552 * and reserved it for out purposes. Returns the area descriptor
2553 * on success or %NULL on failure.
2554 *
2555 * Return: the area descriptor on success or %NULL on failure.
2556 */
2557struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
2558{
2559 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2560 VMALLOC_START, VMALLOC_END,
2561 NUMA_NO_NODE, GFP_KERNEL,
2562 __builtin_return_address(0));
2563}
2564
2565struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
2566 const void *caller)
2567{
2568 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2569 VMALLOC_START, VMALLOC_END,
2570 NUMA_NO_NODE, GFP_KERNEL, caller);
2571}
2572
2573/**
2574 * find_vm_area - find a continuous kernel virtual area
2575 * @addr: base address
2576 *
2577 * Search for the kernel VM area starting at @addr, and return it.
2578 * It is up to the caller to do all required locking to keep the returned
2579 * pointer valid.
2580 *
2581 * Return: the area descriptor on success or %NULL on failure.
2582 */
2583struct vm_struct *find_vm_area(const void *addr)
2584{
2585 struct vmap_area *va;
2586
2587 va = find_vmap_area((unsigned long)addr);
2588 if (!va)
2589 return NULL;
2590
2591 return va->vm;
2592}
2593
2594/**
2595 * remove_vm_area - find and remove a continuous kernel virtual area
2596 * @addr: base address
2597 *
2598 * Search for the kernel VM area starting at @addr, and remove it.
2599 * This function returns the found VM area, but using it is NOT safe
2600 * on SMP machines, except for its size or flags.
2601 *
2602 * Return: the area descriptor on success or %NULL on failure.
2603 */
2604struct vm_struct *remove_vm_area(const void *addr)
2605{
2606 struct vmap_area *va;
2607
2608 might_sleep();
2609
2610 spin_lock(&vmap_area_lock);
2611 va = __find_vmap_area((unsigned long)addr, &vmap_area_root);
2612 if (va && va->vm) {
2613 struct vm_struct *vm = va->vm;
2614
2615 va->vm = NULL;
2616 spin_unlock(&vmap_area_lock);
2617
2618 kasan_free_module_shadow(vm);
2619 free_unmap_vmap_area(va);
2620
2621 return vm;
2622 }
2623
2624 spin_unlock(&vmap_area_lock);
2625 return NULL;
2626}
2627
2628static inline void set_area_direct_map(const struct vm_struct *area,
2629 int (*set_direct_map)(struct page *page))
2630{
2631 int i;
2632
2633 /* HUGE_VMALLOC passes small pages to set_direct_map */
2634 for (i = 0; i < area->nr_pages; i++)
2635 if (page_address(area->pages[i]))
2636 set_direct_map(area->pages[i]);
2637}
2638
2639/* Handle removing and resetting vm mappings related to the vm_struct. */
2640static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
2641{
2642 unsigned long start = ULONG_MAX, end = 0;
2643 unsigned int page_order = vm_area_page_order(area);
2644 int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
2645 int flush_dmap = 0;
2646 int i;
2647
2648 remove_vm_area(area->addr);
2649
2650 /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
2651 if (!flush_reset)
2652 return;
2653
2654 /*
2655 * If not deallocating pages, just do the flush of the VM area and
2656 * return.
2657 */
2658 if (!deallocate_pages) {
2659 vm_unmap_aliases();
2660 return;
2661 }
2662
2663 /*
2664 * If execution gets here, flush the vm mapping and reset the direct
2665 * map. Find the start and end range of the direct mappings to make sure
2666 * the vm_unmap_aliases() flush includes the direct map.
2667 */
2668 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2669 unsigned long addr = (unsigned long)page_address(area->pages[i]);
2670 if (addr) {
2671 unsigned long page_size;
2672
2673 page_size = PAGE_SIZE << page_order;
2674 start = min(addr, start);
2675 end = max(addr + page_size, end);
2676 flush_dmap = 1;
2677 }
2678 }
2679
2680 /*
2681 * Set direct map to something invalid so that it won't be cached if
2682 * there are any accesses after the TLB flush, then flush the TLB and
2683 * reset the direct map permissions to the default.
2684 */
2685 set_area_direct_map(area, set_direct_map_invalid_noflush);
2686 _vm_unmap_aliases(start, end, flush_dmap);
2687 set_area_direct_map(area, set_direct_map_default_noflush);
2688}
2689
2690static void __vunmap(const void *addr, int deallocate_pages)
2691{
2692 struct vm_struct *area;
2693
2694 if (!addr)
2695 return;
2696
2697 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
2698 addr))
2699 return;
2700
2701 area = find_vm_area(addr);
2702 if (unlikely(!area)) {
2703 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
2704 addr);
2705 return;
2706 }
2707
2708 debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
2709 debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
2710
2711 kasan_poison_vmalloc(area->addr, get_vm_area_size(area));
2712
2713 vm_remove_mappings(area, deallocate_pages);
2714
2715 if (deallocate_pages) {
2716 int i;
2717
2718 for (i = 0; i < area->nr_pages; i++) {
2719 struct page *page = area->pages[i];
2720
2721 BUG_ON(!page);
2722 mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
2723 /*
2724 * High-order allocs for huge vmallocs are split, so
2725 * can be freed as an array of order-0 allocations
2726 */
2727 __free_pages(page, 0);
2728 cond_resched();
2729 }
2730 atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
2731
2732 kvfree(area->pages);
2733 }
2734
2735 kfree(area);
2736}
2737
2738static inline void __vfree_deferred(const void *addr)
2739{
2740 /*
2741 * Use raw_cpu_ptr() because this can be called from preemptible
2742 * context. Preemption is absolutely fine here, because the llist_add()
2743 * implementation is lockless, so it works even if we are adding to
2744 * another cpu's list. schedule_work() should be fine with this too.
2745 */
2746 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
2747
2748 if (llist_add((struct llist_node *)addr, &p->list))
2749 schedule_work(&p->wq);
2750}
2751
2752/**
2753 * vfree_atomic - release memory allocated by vmalloc()
2754 * @addr: memory base address
2755 *
2756 * This one is just like vfree() but can be called in any atomic context
2757 * except NMIs.
2758 */
2759void vfree_atomic(const void *addr)
2760{
2761 BUG_ON(in_nmi());
2762
2763 kmemleak_free(addr);
2764
2765 if (!addr)
2766 return;
2767 __vfree_deferred(addr);
2768}
2769
2770static void __vfree(const void *addr)
2771{
2772 if (unlikely(in_interrupt()))
2773 __vfree_deferred(addr);
2774 else
2775 __vunmap(addr, 1);
2776}
2777
2778/**
2779 * vfree - Release memory allocated by vmalloc()
2780 * @addr: Memory base address
2781 *
2782 * Free the virtually continuous memory area starting at @addr, as obtained
2783 * from one of the vmalloc() family of APIs. This will usually also free the
2784 * physical memory underlying the virtual allocation, but that memory is
2785 * reference counted, so it will not be freed until the last user goes away.
2786 *
2787 * If @addr is NULL, no operation is performed.
2788 *
2789 * Context:
2790 * May sleep if called *not* from interrupt context.
2791 * Must not be called in NMI context (strictly speaking, it could be
2792 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2793 * conventions for vfree() arch-dependent would be a really bad idea).
2794 */
2795void vfree(const void *addr)
2796{
2797 BUG_ON(in_nmi());
2798
2799 kmemleak_free(addr);
2800
2801 might_sleep_if(!in_interrupt());
2802
2803 if (!addr)
2804 return;
2805
2806 __vfree(addr);
2807}
2808EXPORT_SYMBOL(vfree);
2809
2810/**
2811 * vunmap - release virtual mapping obtained by vmap()
2812 * @addr: memory base address
2813 *
2814 * Free the virtually contiguous memory area starting at @addr,
2815 * which was created from the page array passed to vmap().
2816 *
2817 * Must not be called in interrupt context.
2818 */
2819void vunmap(const void *addr)
2820{
2821 BUG_ON(in_interrupt());
2822 might_sleep();
2823 if (addr)
2824 __vunmap(addr, 0);
2825}
2826EXPORT_SYMBOL(vunmap);
2827
2828/**
2829 * vmap - map an array of pages into virtually contiguous space
2830 * @pages: array of page pointers
2831 * @count: number of pages to map
2832 * @flags: vm_area->flags
2833 * @prot: page protection for the mapping
2834 *
2835 * Maps @count pages from @pages into contiguous kernel virtual space.
2836 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
2837 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
2838 * are transferred from the caller to vmap(), and will be freed / dropped when
2839 * vfree() is called on the return value.
2840 *
2841 * Return: the address of the area or %NULL on failure
2842 */
2843void *vmap(struct page **pages, unsigned int count,
2844 unsigned long flags, pgprot_t prot)
2845{
2846 struct vm_struct *area;
2847 unsigned long addr;
2848 unsigned long size; /* In bytes */
2849
2850 might_sleep();
2851
2852 /*
2853 * Your top guard is someone else's bottom guard. Not having a top
2854 * guard compromises someone else's mappings too.
2855 */
2856 if (WARN_ON_ONCE(flags & VM_NO_GUARD))
2857 flags &= ~VM_NO_GUARD;
2858
2859 if (count > totalram_pages())
2860 return NULL;
2861
2862 size = (unsigned long)count << PAGE_SHIFT;
2863 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
2864 if (!area)
2865 return NULL;
2866
2867 addr = (unsigned long)area->addr;
2868 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
2869 pages, PAGE_SHIFT) < 0) {
2870 vunmap(area->addr);
2871 return NULL;
2872 }
2873
2874 if (flags & VM_MAP_PUT_PAGES) {
2875 area->pages = pages;
2876 area->nr_pages = count;
2877 }
2878 return area->addr;
2879}
2880EXPORT_SYMBOL(vmap);
2881
2882#ifdef CONFIG_VMAP_PFN
2883struct vmap_pfn_data {
2884 unsigned long *pfns;
2885 pgprot_t prot;
2886 unsigned int idx;
2887};
2888
2889static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
2890{
2891 struct vmap_pfn_data *data = private;
2892
2893 if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx])))
2894 return -EINVAL;
2895 *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
2896 return 0;
2897}
2898
2899/**
2900 * vmap_pfn - map an array of PFNs into virtually contiguous space
2901 * @pfns: array of PFNs
2902 * @count: number of pages to map
2903 * @prot: page protection for the mapping
2904 *
2905 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
2906 * the start address of the mapping.
2907 */
2908void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
2909{
2910 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
2911 struct vm_struct *area;
2912
2913 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
2914 __builtin_return_address(0));
2915 if (!area)
2916 return NULL;
2917 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2918 count * PAGE_SIZE, vmap_pfn_apply, &data)) {
2919 free_vm_area(area);
2920 return NULL;
2921 }
2922 return area->addr;
2923}
2924EXPORT_SYMBOL_GPL(vmap_pfn);
2925#endif /* CONFIG_VMAP_PFN */
2926
2927static inline unsigned int
2928vm_area_alloc_pages(gfp_t gfp, int nid,
2929 unsigned int order, unsigned int nr_pages, struct page **pages)
2930{
2931 unsigned int nr_allocated = 0;
2932 struct page *page;
2933 int i;
2934
2935 /*
2936 * For order-0 pages we make use of bulk allocator, if
2937 * the page array is partly or not at all populated due
2938 * to fails, fallback to a single page allocator that is
2939 * more permissive.
2940 */
2941 if (!order) {
2942 gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL;
2943
2944 while (nr_allocated < nr_pages) {
2945 unsigned int nr, nr_pages_request;
2946
2947 /*
2948 * A maximum allowed request is hard-coded and is 100
2949 * pages per call. That is done in order to prevent a
2950 * long preemption off scenario in the bulk-allocator
2951 * so the range is [1:100].
2952 */
2953 nr_pages_request = min(100U, nr_pages - nr_allocated);
2954
2955 /* memory allocation should consider mempolicy, we can't
2956 * wrongly use nearest node when nid == NUMA_NO_NODE,
2957 * otherwise memory may be allocated in only one node,
2958 * but mempolicy wants to alloc memory by interleaving.
2959 */
2960 if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
2961 nr = alloc_pages_bulk_array_mempolicy(bulk_gfp,
2962 nr_pages_request,
2963 pages + nr_allocated);
2964
2965 else
2966 nr = alloc_pages_bulk_array_node(bulk_gfp, nid,
2967 nr_pages_request,
2968 pages + nr_allocated);
2969
2970 nr_allocated += nr;
2971 cond_resched();
2972
2973 /*
2974 * If zero or pages were obtained partly,
2975 * fallback to a single page allocator.
2976 */
2977 if (nr != nr_pages_request)
2978 break;
2979 }
2980 }
2981
2982 /* High-order pages or fallback path if "bulk" fails. */
2983
2984 while (nr_allocated < nr_pages) {
2985 if (fatal_signal_pending(current))
2986 break;
2987
2988 if (nid == NUMA_NO_NODE)
2989 page = alloc_pages(gfp, order);
2990 else
2991 page = alloc_pages_node(nid, gfp, order);
2992 if (unlikely(!page))
2993 break;
2994 /*
2995 * Higher order allocations must be able to be treated as
2996 * indepdenent small pages by callers (as they can with
2997 * small-page vmallocs). Some drivers do their own refcounting
2998 * on vmalloc_to_page() pages, some use page->mapping,
2999 * page->lru, etc.
3000 */
3001 if (order)
3002 split_page(page, order);
3003
3004 /*
3005 * Careful, we allocate and map page-order pages, but
3006 * tracking is done per PAGE_SIZE page so as to keep the
3007 * vm_struct APIs independent of the physical/mapped size.
3008 */
3009 for (i = 0; i < (1U << order); i++)
3010 pages[nr_allocated + i] = page + i;
3011
3012 cond_resched();
3013 nr_allocated += 1U << order;
3014 }
3015
3016 return nr_allocated;
3017}
3018
3019static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
3020 pgprot_t prot, unsigned int page_shift,
3021 int node)
3022{
3023 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
3024 bool nofail = gfp_mask & __GFP_NOFAIL;
3025 unsigned long addr = (unsigned long)area->addr;
3026 unsigned long size = get_vm_area_size(area);
3027 unsigned long array_size;
3028 unsigned int nr_small_pages = size >> PAGE_SHIFT;
3029 unsigned int page_order;
3030 unsigned int flags;
3031 int ret;
3032
3033 array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
3034 gfp_mask |= __GFP_NOWARN;
3035 if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
3036 gfp_mask |= __GFP_HIGHMEM;
3037
3038 /* Please note that the recursion is strictly bounded. */
3039 if (array_size > PAGE_SIZE) {
3040 area->pages = __vmalloc_node(array_size, 1, nested_gfp, node,
3041 area->caller);
3042 } else {
3043 area->pages = kmalloc_node(array_size, nested_gfp, node);
3044 }
3045
3046 if (!area->pages) {
3047 warn_alloc(gfp_mask, NULL,
3048 "vmalloc error: size %lu, failed to allocated page array size %lu",
3049 nr_small_pages * PAGE_SIZE, array_size);
3050 free_vm_area(area);
3051 return NULL;
3052 }
3053
3054 set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
3055 page_order = vm_area_page_order(area);
3056
3057 area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN,
3058 node, page_order, nr_small_pages, area->pages);
3059
3060 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
3061 if (gfp_mask & __GFP_ACCOUNT) {
3062 int i;
3063
3064 for (i = 0; i < area->nr_pages; i++)
3065 mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1);
3066 }
3067
3068 /*
3069 * If not enough pages were obtained to accomplish an
3070 * allocation request, free them via __vfree() if any.
3071 */
3072 if (area->nr_pages != nr_small_pages) {
3073 warn_alloc(gfp_mask, NULL,
3074 "vmalloc error: size %lu, page order %u, failed to allocate pages",
3075 area->nr_pages * PAGE_SIZE, page_order);
3076 goto fail;
3077 }
3078
3079 /*
3080 * page tables allocations ignore external gfp mask, enforce it
3081 * by the scope API
3082 */
3083 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3084 flags = memalloc_nofs_save();
3085 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3086 flags = memalloc_noio_save();
3087
3088 do {
3089 ret = vmap_pages_range(addr, addr + size, prot, area->pages,
3090 page_shift);
3091 if (nofail && (ret < 0))
3092 schedule_timeout_uninterruptible(1);
3093 } while (nofail && (ret < 0));
3094
3095 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3096 memalloc_nofs_restore(flags);
3097 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3098 memalloc_noio_restore(flags);
3099
3100 if (ret < 0) {
3101 warn_alloc(gfp_mask, NULL,
3102 "vmalloc error: size %lu, failed to map pages",
3103 area->nr_pages * PAGE_SIZE);
3104 goto fail;
3105 }
3106
3107 return area->addr;
3108
3109fail:
3110 __vfree(area->addr);
3111 return NULL;
3112}
3113
3114/**
3115 * __vmalloc_node_range - allocate virtually contiguous memory
3116 * @size: allocation size
3117 * @align: desired alignment
3118 * @start: vm area range start
3119 * @end: vm area range end
3120 * @gfp_mask: flags for the page level allocator
3121 * @prot: protection mask for the allocated pages
3122 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
3123 * @node: node to use for allocation or NUMA_NO_NODE
3124 * @caller: caller's return address
3125 *
3126 * Allocate enough pages to cover @size from the page level
3127 * allocator with @gfp_mask flags. Please note that the full set of gfp
3128 * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all
3129 * supported.
3130 * Zone modifiers are not supported. From the reclaim modifiers
3131 * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported)
3132 * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and
3133 * __GFP_RETRY_MAYFAIL are not supported).
3134 *
3135 * __GFP_NOWARN can be used to suppress failures messages.
3136 *
3137 * Map them into contiguous kernel virtual space, using a pagetable
3138 * protection of @prot.
3139 *
3140 * Return: the address of the area or %NULL on failure
3141 */
3142void *__vmalloc_node_range(unsigned long size, unsigned long align,
3143 unsigned long start, unsigned long end, gfp_t gfp_mask,
3144 pgprot_t prot, unsigned long vm_flags, int node,
3145 const void *caller)
3146{
3147 struct vm_struct *area;
3148 void *ret;
3149 kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE;
3150 unsigned long real_size = size;
3151 unsigned long real_align = align;
3152 unsigned int shift = PAGE_SHIFT;
3153
3154 if (WARN_ON_ONCE(!size))
3155 return NULL;
3156
3157 if ((size >> PAGE_SHIFT) > totalram_pages()) {
3158 warn_alloc(gfp_mask, NULL,
3159 "vmalloc error: size %lu, exceeds total pages",
3160 real_size);
3161 return NULL;
3162 }
3163
3164 if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) {
3165 unsigned long size_per_node;
3166
3167 /*
3168 * Try huge pages. Only try for PAGE_KERNEL allocations,
3169 * others like modules don't yet expect huge pages in
3170 * their allocations due to apply_to_page_range not
3171 * supporting them.
3172 */
3173
3174 size_per_node = size;
3175 if (node == NUMA_NO_NODE)
3176 size_per_node /= num_online_nodes();
3177 if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
3178 shift = PMD_SHIFT;
3179 else
3180 shift = arch_vmap_pte_supported_shift(size_per_node);
3181
3182 align = max(real_align, 1UL << shift);
3183 size = ALIGN(real_size, 1UL << shift);
3184 }
3185
3186again:
3187 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
3188 VM_UNINITIALIZED | vm_flags, start, end, node,
3189 gfp_mask, caller);
3190 if (!area) {
3191 bool nofail = gfp_mask & __GFP_NOFAIL;
3192 warn_alloc(gfp_mask, NULL,
3193 "vmalloc error: size %lu, vm_struct allocation failed%s",
3194 real_size, (nofail) ? ". Retrying." : "");
3195 if (nofail) {
3196 schedule_timeout_uninterruptible(1);
3197 goto again;
3198 }
3199 goto fail;
3200 }
3201
3202 /*
3203 * Prepare arguments for __vmalloc_area_node() and
3204 * kasan_unpoison_vmalloc().
3205 */
3206 if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) {
3207 if (kasan_hw_tags_enabled()) {
3208 /*
3209 * Modify protection bits to allow tagging.
3210 * This must be done before mapping.
3211 */
3212 prot = arch_vmap_pgprot_tagged(prot);
3213
3214 /*
3215 * Skip page_alloc poisoning and zeroing for physical
3216 * pages backing VM_ALLOC mapping. Memory is instead
3217 * poisoned and zeroed by kasan_unpoison_vmalloc().
3218 */
3219 gfp_mask |= __GFP_SKIP_KASAN_UNPOISON | __GFP_SKIP_ZERO;
3220 }
3221
3222 /* Take note that the mapping is PAGE_KERNEL. */
3223 kasan_flags |= KASAN_VMALLOC_PROT_NORMAL;
3224 }
3225
3226 /* Allocate physical pages and map them into vmalloc space. */
3227 ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
3228 if (!ret)
3229 goto fail;
3230
3231 /*
3232 * Mark the pages as accessible, now that they are mapped.
3233 * The condition for setting KASAN_VMALLOC_INIT should complement the
3234 * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check
3235 * to make sure that memory is initialized under the same conditions.
3236 * Tag-based KASAN modes only assign tags to normal non-executable
3237 * allocations, see __kasan_unpoison_vmalloc().
3238 */
3239 kasan_flags |= KASAN_VMALLOC_VM_ALLOC;
3240 if (!want_init_on_free() && want_init_on_alloc(gfp_mask) &&
3241 (gfp_mask & __GFP_SKIP_ZERO))
3242 kasan_flags |= KASAN_VMALLOC_INIT;
3243 /* KASAN_VMALLOC_PROT_NORMAL already set if required. */
3244 area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags);
3245
3246 /*
3247 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
3248 * flag. It means that vm_struct is not fully initialized.
3249 * Now, it is fully initialized, so remove this flag here.
3250 */
3251 clear_vm_uninitialized_flag(area);
3252
3253 size = PAGE_ALIGN(size);
3254 if (!(vm_flags & VM_DEFER_KMEMLEAK))
3255 kmemleak_vmalloc(area, size, gfp_mask);
3256
3257 return area->addr;
3258
3259fail:
3260 if (shift > PAGE_SHIFT) {
3261 shift = PAGE_SHIFT;
3262 align = real_align;
3263 size = real_size;
3264 goto again;
3265 }
3266
3267 return NULL;
3268}
3269
3270/**
3271 * __vmalloc_node - allocate virtually contiguous memory
3272 * @size: allocation size
3273 * @align: desired alignment
3274 * @gfp_mask: flags for the page level allocator
3275 * @node: node to use for allocation or NUMA_NO_NODE
3276 * @caller: caller's return address
3277 *
3278 * Allocate enough pages to cover @size from the page level allocator with
3279 * @gfp_mask flags. Map them into contiguous kernel virtual space.
3280 *
3281 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
3282 * and __GFP_NOFAIL are not supported
3283 *
3284 * Any use of gfp flags outside of GFP_KERNEL should be consulted
3285 * with mm people.
3286 *
3287 * Return: pointer to the allocated memory or %NULL on error
3288 */
3289void *__vmalloc_node(unsigned long size, unsigned long align,
3290 gfp_t gfp_mask, int node, const void *caller)
3291{
3292 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
3293 gfp_mask, PAGE_KERNEL, 0, node, caller);
3294}
3295/*
3296 * This is only for performance analysis of vmalloc and stress purpose.
3297 * It is required by vmalloc test module, therefore do not use it other
3298 * than that.
3299 */
3300#ifdef CONFIG_TEST_VMALLOC_MODULE
3301EXPORT_SYMBOL_GPL(__vmalloc_node);
3302#endif
3303
3304void *__vmalloc(unsigned long size, gfp_t gfp_mask)
3305{
3306 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE,
3307 __builtin_return_address(0));
3308}
3309EXPORT_SYMBOL(__vmalloc);
3310
3311/**
3312 * vmalloc - allocate virtually contiguous memory
3313 * @size: allocation size
3314 *
3315 * Allocate enough pages to cover @size from the page level
3316 * allocator and map them into contiguous kernel virtual space.
3317 *
3318 * For tight control over page level allocator and protection flags
3319 * use __vmalloc() instead.
3320 *
3321 * Return: pointer to the allocated memory or %NULL on error
3322 */
3323void *vmalloc(unsigned long size)
3324{
3325 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE,
3326 __builtin_return_address(0));
3327}
3328EXPORT_SYMBOL(vmalloc);
3329
3330/**
3331 * vmalloc_huge - allocate virtually contiguous memory, allow huge pages
3332 * @size: allocation size
3333 * @gfp_mask: flags for the page level allocator
3334 *
3335 * Allocate enough pages to cover @size from the page level
3336 * allocator and map them into contiguous kernel virtual space.
3337 * If @size is greater than or equal to PMD_SIZE, allow using
3338 * huge pages for the memory
3339 *
3340 * Return: pointer to the allocated memory or %NULL on error
3341 */
3342void *vmalloc_huge(unsigned long size, gfp_t gfp_mask)
3343{
3344 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
3345 gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
3346 NUMA_NO_NODE, __builtin_return_address(0));
3347}
3348EXPORT_SYMBOL_GPL(vmalloc_huge);
3349
3350/**
3351 * vzalloc - allocate virtually contiguous memory with zero fill
3352 * @size: allocation size
3353 *
3354 * Allocate enough pages to cover @size from the page level
3355 * allocator and map them into contiguous kernel virtual space.
3356 * The memory allocated is set to zero.
3357 *
3358 * For tight control over page level allocator and protection flags
3359 * use __vmalloc() instead.
3360 *
3361 * Return: pointer to the allocated memory or %NULL on error
3362 */
3363void *vzalloc(unsigned long size)
3364{
3365 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
3366 __builtin_return_address(0));
3367}
3368EXPORT_SYMBOL(vzalloc);
3369
3370/**
3371 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3372 * @size: allocation size
3373 *
3374 * The resulting memory area is zeroed so it can be mapped to userspace
3375 * without leaking data.
3376 *
3377 * Return: pointer to the allocated memory or %NULL on error
3378 */
3379void *vmalloc_user(unsigned long size)
3380{
3381 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3382 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
3383 VM_USERMAP, NUMA_NO_NODE,
3384 __builtin_return_address(0));
3385}
3386EXPORT_SYMBOL(vmalloc_user);
3387
3388/**
3389 * vmalloc_node - allocate memory on a specific node
3390 * @size: allocation size
3391 * @node: numa node
3392 *
3393 * Allocate enough pages to cover @size from the page level
3394 * allocator and map them into contiguous kernel virtual space.
3395 *
3396 * For tight control over page level allocator and protection flags
3397 * use __vmalloc() instead.
3398 *
3399 * Return: pointer to the allocated memory or %NULL on error
3400 */
3401void *vmalloc_node(unsigned long size, int node)
3402{
3403 return __vmalloc_node(size, 1, GFP_KERNEL, node,
3404 __builtin_return_address(0));
3405}
3406EXPORT_SYMBOL(vmalloc_node);
3407
3408/**
3409 * vzalloc_node - allocate memory on a specific node with zero fill
3410 * @size: allocation size
3411 * @node: numa node
3412 *
3413 * Allocate enough pages to cover @size from the page level
3414 * allocator and map them into contiguous kernel virtual space.
3415 * The memory allocated is set to zero.
3416 *
3417 * Return: pointer to the allocated memory or %NULL on error
3418 */
3419void *vzalloc_node(unsigned long size, int node)
3420{
3421 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node,
3422 __builtin_return_address(0));
3423}
3424EXPORT_SYMBOL(vzalloc_node);
3425
3426#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
3427#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3428#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
3429#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
3430#else
3431/*
3432 * 64b systems should always have either DMA or DMA32 zones. For others
3433 * GFP_DMA32 should do the right thing and use the normal zone.
3434 */
3435#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3436#endif
3437
3438/**
3439 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
3440 * @size: allocation size
3441 *
3442 * Allocate enough 32bit PA addressable pages to cover @size from the
3443 * page level allocator and map them into contiguous kernel virtual space.
3444 *
3445 * Return: pointer to the allocated memory or %NULL on error
3446 */
3447void *vmalloc_32(unsigned long size)
3448{
3449 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
3450 __builtin_return_address(0));
3451}
3452EXPORT_SYMBOL(vmalloc_32);
3453
3454/**
3455 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
3456 * @size: allocation size
3457 *
3458 * The resulting memory area is 32bit addressable and zeroed so it can be
3459 * mapped to userspace without leaking data.
3460 *
3461 * Return: pointer to the allocated memory or %NULL on error
3462 */
3463void *vmalloc_32_user(unsigned long size)
3464{
3465 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3466 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
3467 VM_USERMAP, NUMA_NO_NODE,
3468 __builtin_return_address(0));
3469}
3470EXPORT_SYMBOL(vmalloc_32_user);
3471
3472/*
3473 * small helper routine , copy contents to buf from addr.
3474 * If the page is not present, fill zero.
3475 */
3476
3477static int aligned_vread(char *buf, char *addr, unsigned long count)
3478{
3479 struct page *p;
3480 int copied = 0;
3481
3482 while (count) {
3483 unsigned long offset, length;
3484
3485 offset = offset_in_page(addr);
3486 length = PAGE_SIZE - offset;
3487 if (length > count)
3488 length = count;
3489 p = vmalloc_to_page(addr);
3490 /*
3491 * To do safe access to this _mapped_ area, we need
3492 * lock. But adding lock here means that we need to add
3493 * overhead of vmalloc()/vfree() calls for this _debug_
3494 * interface, rarely used. Instead of that, we'll use
3495 * kmap() and get small overhead in this access function.
3496 */
3497 if (p) {
3498 /* We can expect USER0 is not used -- see vread() */
3499 void *map = kmap_atomic(p);
3500 memcpy(buf, map + offset, length);
3501 kunmap_atomic(map);
3502 } else
3503 memset(buf, 0, length);
3504
3505 addr += length;
3506 buf += length;
3507 copied += length;
3508 count -= length;
3509 }
3510 return copied;
3511}
3512
3513/**
3514 * vread() - read vmalloc area in a safe way.
3515 * @buf: buffer for reading data
3516 * @addr: vm address.
3517 * @count: number of bytes to be read.
3518 *
3519 * This function checks that addr is a valid vmalloc'ed area, and
3520 * copy data from that area to a given buffer. If the given memory range
3521 * of [addr...addr+count) includes some valid address, data is copied to
3522 * proper area of @buf. If there are memory holes, they'll be zero-filled.
3523 * IOREMAP area is treated as memory hole and no copy is done.
3524 *
3525 * If [addr...addr+count) doesn't includes any intersects with alive
3526 * vm_struct area, returns 0. @buf should be kernel's buffer.
3527 *
3528 * Note: In usual ops, vread() is never necessary because the caller
3529 * should know vmalloc() area is valid and can use memcpy().
3530 * This is for routines which have to access vmalloc area without
3531 * any information, as /proc/kcore.
3532 *
3533 * Return: number of bytes for which addr and buf should be increased
3534 * (same number as @count) or %0 if [addr...addr+count) doesn't
3535 * include any intersection with valid vmalloc area
3536 */
3537long vread(char *buf, char *addr, unsigned long count)
3538{
3539 struct vmap_area *va;
3540 struct vm_struct *vm;
3541 char *vaddr, *buf_start = buf;
3542 unsigned long buflen = count;
3543 unsigned long n;
3544
3545 addr = kasan_reset_tag(addr);
3546
3547 /* Don't allow overflow */
3548 if ((unsigned long) addr + count < count)
3549 count = -(unsigned long) addr;
3550
3551 spin_lock(&vmap_area_lock);
3552 va = find_vmap_area_exceed_addr((unsigned long)addr);
3553 if (!va)
3554 goto finished;
3555
3556 /* no intersects with alive vmap_area */
3557 if ((unsigned long)addr + count <= va->va_start)
3558 goto finished;
3559
3560 list_for_each_entry_from(va, &vmap_area_list, list) {
3561 if (!count)
3562 break;
3563
3564 if (!va->vm)
3565 continue;
3566
3567 vm = va->vm;
3568 vaddr = (char *) vm->addr;
3569 if (addr >= vaddr + get_vm_area_size(vm))
3570 continue;
3571 while (addr < vaddr) {
3572 if (count == 0)
3573 goto finished;
3574 *buf = '\0';
3575 buf++;
3576 addr++;
3577 count--;
3578 }
3579 n = vaddr + get_vm_area_size(vm) - addr;
3580 if (n > count)
3581 n = count;
3582 if (!(vm->flags & VM_IOREMAP))
3583 aligned_vread(buf, addr, n);
3584 else /* IOREMAP area is treated as memory hole */
3585 memset(buf, 0, n);
3586 buf += n;
3587 addr += n;
3588 count -= n;
3589 }
3590finished:
3591 spin_unlock(&vmap_area_lock);
3592
3593 if (buf == buf_start)
3594 return 0;
3595 /* zero-fill memory holes */
3596 if (buf != buf_start + buflen)
3597 memset(buf, 0, buflen - (buf - buf_start));
3598
3599 return buflen;
3600}
3601
3602/**
3603 * remap_vmalloc_range_partial - map vmalloc pages to userspace
3604 * @vma: vma to cover
3605 * @uaddr: target user address to start at
3606 * @kaddr: virtual address of vmalloc kernel memory
3607 * @pgoff: offset from @kaddr to start at
3608 * @size: size of map area
3609 *
3610 * Returns: 0 for success, -Exxx on failure
3611 *
3612 * This function checks that @kaddr is a valid vmalloc'ed area,
3613 * and that it is big enough to cover the range starting at
3614 * @uaddr in @vma. Will return failure if that criteria isn't
3615 * met.
3616 *
3617 * Similar to remap_pfn_range() (see mm/memory.c)
3618 */
3619int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
3620 void *kaddr, unsigned long pgoff,
3621 unsigned long size)
3622{
3623 struct vm_struct *area;
3624 unsigned long off;
3625 unsigned long end_index;
3626
3627 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
3628 return -EINVAL;
3629
3630 size = PAGE_ALIGN(size);
3631
3632 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
3633 return -EINVAL;
3634
3635 area = find_vm_area(kaddr);
3636 if (!area)
3637 return -EINVAL;
3638
3639 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
3640 return -EINVAL;
3641
3642 if (check_add_overflow(size, off, &end_index) ||
3643 end_index > get_vm_area_size(area))
3644 return -EINVAL;
3645 kaddr += off;
3646
3647 do {
3648 struct page *page = vmalloc_to_page(kaddr);
3649 int ret;
3650
3651 ret = vm_insert_page(vma, uaddr, page);
3652 if (ret)
3653 return ret;
3654
3655 uaddr += PAGE_SIZE;
3656 kaddr += PAGE_SIZE;
3657 size -= PAGE_SIZE;
3658 } while (size > 0);
3659
3660 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
3661
3662 return 0;
3663}
3664
3665/**
3666 * remap_vmalloc_range - map vmalloc pages to userspace
3667 * @vma: vma to cover (map full range of vma)
3668 * @addr: vmalloc memory
3669 * @pgoff: number of pages into addr before first page to map
3670 *
3671 * Returns: 0 for success, -Exxx on failure
3672 *
3673 * This function checks that addr is a valid vmalloc'ed area, and
3674 * that it is big enough to cover the vma. Will return failure if
3675 * that criteria isn't met.
3676 *
3677 * Similar to remap_pfn_range() (see mm/memory.c)
3678 */
3679int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
3680 unsigned long pgoff)
3681{
3682 return remap_vmalloc_range_partial(vma, vma->vm_start,
3683 addr, pgoff,
3684 vma->vm_end - vma->vm_start);
3685}
3686EXPORT_SYMBOL(remap_vmalloc_range);
3687
3688void free_vm_area(struct vm_struct *area)
3689{
3690 struct vm_struct *ret;
3691 ret = remove_vm_area(area->addr);
3692 BUG_ON(ret != area);
3693 kfree(area);
3694}
3695EXPORT_SYMBOL_GPL(free_vm_area);
3696
3697#ifdef CONFIG_SMP
3698static struct vmap_area *node_to_va(struct rb_node *n)
3699{
3700 return rb_entry_safe(n, struct vmap_area, rb_node);
3701}
3702
3703/**
3704 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
3705 * @addr: target address
3706 *
3707 * Returns: vmap_area if it is found. If there is no such area
3708 * the first highest(reverse order) vmap_area is returned
3709 * i.e. va->va_start < addr && va->va_end < addr or NULL
3710 * if there are no any areas before @addr.
3711 */
3712static struct vmap_area *
3713pvm_find_va_enclose_addr(unsigned long addr)
3714{
3715 struct vmap_area *va, *tmp;
3716 struct rb_node *n;
3717
3718 n = free_vmap_area_root.rb_node;
3719 va = NULL;
3720
3721 while (n) {
3722 tmp = rb_entry(n, struct vmap_area, rb_node);
3723 if (tmp->va_start <= addr) {
3724 va = tmp;
3725 if (tmp->va_end >= addr)
3726 break;
3727
3728 n = n->rb_right;
3729 } else {
3730 n = n->rb_left;
3731 }
3732 }
3733
3734 return va;
3735}
3736
3737/**
3738 * pvm_determine_end_from_reverse - find the highest aligned address
3739 * of free block below VMALLOC_END
3740 * @va:
3741 * in - the VA we start the search(reverse order);
3742 * out - the VA with the highest aligned end address.
3743 * @align: alignment for required highest address
3744 *
3745 * Returns: determined end address within vmap_area
3746 */
3747static unsigned long
3748pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
3749{
3750 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3751 unsigned long addr;
3752
3753 if (likely(*va)) {
3754 list_for_each_entry_from_reverse((*va),
3755 &free_vmap_area_list, list) {
3756 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
3757 if ((*va)->va_start < addr)
3758 return addr;
3759 }
3760 }
3761
3762 return 0;
3763}
3764
3765/**
3766 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
3767 * @offsets: array containing offset of each area
3768 * @sizes: array containing size of each area
3769 * @nr_vms: the number of areas to allocate
3770 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
3771 *
3772 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
3773 * vm_structs on success, %NULL on failure
3774 *
3775 * Percpu allocator wants to use congruent vm areas so that it can
3776 * maintain the offsets among percpu areas. This function allocates
3777 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
3778 * be scattered pretty far, distance between two areas easily going up
3779 * to gigabytes. To avoid interacting with regular vmallocs, these
3780 * areas are allocated from top.
3781 *
3782 * Despite its complicated look, this allocator is rather simple. It
3783 * does everything top-down and scans free blocks from the end looking
3784 * for matching base. While scanning, if any of the areas do not fit the
3785 * base address is pulled down to fit the area. Scanning is repeated till
3786 * all the areas fit and then all necessary data structures are inserted
3787 * and the result is returned.
3788 */
3789struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
3790 const size_t *sizes, int nr_vms,
3791 size_t align)
3792{
3793 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
3794 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3795 struct vmap_area **vas, *va;
3796 struct vm_struct **vms;
3797 int area, area2, last_area, term_area;
3798 unsigned long base, start, size, end, last_end, orig_start, orig_end;
3799 bool purged = false;
3800
3801 /* verify parameters and allocate data structures */
3802 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
3803 for (last_area = 0, area = 0; area < nr_vms; area++) {
3804 start = offsets[area];
3805 end = start + sizes[area];
3806
3807 /* is everything aligned properly? */
3808 BUG_ON(!IS_ALIGNED(offsets[area], align));
3809 BUG_ON(!IS_ALIGNED(sizes[area], align));
3810
3811 /* detect the area with the highest address */
3812 if (start > offsets[last_area])
3813 last_area = area;
3814
3815 for (area2 = area + 1; area2 < nr_vms; area2++) {
3816 unsigned long start2 = offsets[area2];
3817 unsigned long end2 = start2 + sizes[area2];
3818
3819 BUG_ON(start2 < end && start < end2);
3820 }
3821 }
3822 last_end = offsets[last_area] + sizes[last_area];
3823
3824 if (vmalloc_end - vmalloc_start < last_end) {
3825 WARN_ON(true);
3826 return NULL;
3827 }
3828
3829 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
3830 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
3831 if (!vas || !vms)
3832 goto err_free2;
3833
3834 for (area = 0; area < nr_vms; area++) {
3835 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
3836 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
3837 if (!vas[area] || !vms[area])
3838 goto err_free;
3839 }
3840retry:
3841 spin_lock(&free_vmap_area_lock);
3842
3843 /* start scanning - we scan from the top, begin with the last area */
3844 area = term_area = last_area;
3845 start = offsets[area];
3846 end = start + sizes[area];
3847
3848 va = pvm_find_va_enclose_addr(vmalloc_end);
3849 base = pvm_determine_end_from_reverse(&va, align) - end;
3850
3851 while (true) {
3852 /*
3853 * base might have underflowed, add last_end before
3854 * comparing.
3855 */
3856 if (base + last_end < vmalloc_start + last_end)
3857 goto overflow;
3858
3859 /*
3860 * Fitting base has not been found.
3861 */
3862 if (va == NULL)
3863 goto overflow;
3864
3865 /*
3866 * If required width exceeds current VA block, move
3867 * base downwards and then recheck.
3868 */
3869 if (base + end > va->va_end) {
3870 base = pvm_determine_end_from_reverse(&va, align) - end;
3871 term_area = area;
3872 continue;
3873 }
3874
3875 /*
3876 * If this VA does not fit, move base downwards and recheck.
3877 */
3878 if (base + start < va->va_start) {
3879 va = node_to_va(rb_prev(&va->rb_node));
3880 base = pvm_determine_end_from_reverse(&va, align) - end;
3881 term_area = area;
3882 continue;
3883 }
3884
3885 /*
3886 * This area fits, move on to the previous one. If
3887 * the previous one is the terminal one, we're done.
3888 */
3889 area = (area + nr_vms - 1) % nr_vms;
3890 if (area == term_area)
3891 break;
3892
3893 start = offsets[area];
3894 end = start + sizes[area];
3895 va = pvm_find_va_enclose_addr(base + end);
3896 }
3897
3898 /* we've found a fitting base, insert all va's */
3899 for (area = 0; area < nr_vms; area++) {
3900 int ret;
3901
3902 start = base + offsets[area];
3903 size = sizes[area];
3904
3905 va = pvm_find_va_enclose_addr(start);
3906 if (WARN_ON_ONCE(va == NULL))
3907 /* It is a BUG(), but trigger recovery instead. */
3908 goto recovery;
3909
3910 ret = adjust_va_to_fit_type(&free_vmap_area_root,
3911 &free_vmap_area_list,
3912 va, start, size);
3913 if (WARN_ON_ONCE(unlikely(ret)))
3914 /* It is a BUG(), but trigger recovery instead. */
3915 goto recovery;
3916
3917 /* Allocated area. */
3918 va = vas[area];
3919 va->va_start = start;
3920 va->va_end = start + size;
3921 }
3922
3923 spin_unlock(&free_vmap_area_lock);
3924
3925 /* populate the kasan shadow space */
3926 for (area = 0; area < nr_vms; area++) {
3927 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
3928 goto err_free_shadow;
3929 }
3930
3931 /* insert all vm's */
3932 spin_lock(&vmap_area_lock);
3933 for (area = 0; area < nr_vms; area++) {
3934 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
3935
3936 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
3937 pcpu_get_vm_areas);
3938 }
3939 spin_unlock(&vmap_area_lock);
3940
3941 /*
3942 * Mark allocated areas as accessible. Do it now as a best-effort
3943 * approach, as they can be mapped outside of vmalloc code.
3944 * With hardware tag-based KASAN, marking is skipped for
3945 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
3946 */
3947 for (area = 0; area < nr_vms; area++)
3948 vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr,
3949 vms[area]->size, KASAN_VMALLOC_PROT_NORMAL);
3950
3951 kfree(vas);
3952 return vms;
3953
3954recovery:
3955 /*
3956 * Remove previously allocated areas. There is no
3957 * need in removing these areas from the busy tree,
3958 * because they are inserted only on the final step
3959 * and when pcpu_get_vm_areas() is success.
3960 */
3961 while (area--) {
3962 orig_start = vas[area]->va_start;
3963 orig_end = vas[area]->va_end;
3964 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
3965 &free_vmap_area_list);
3966 if (va)
3967 kasan_release_vmalloc(orig_start, orig_end,
3968 va->va_start, va->va_end);
3969 vas[area] = NULL;
3970 }
3971
3972overflow:
3973 spin_unlock(&free_vmap_area_lock);
3974 if (!purged) {
3975 purge_vmap_area_lazy();
3976 purged = true;
3977
3978 /* Before "retry", check if we recover. */
3979 for (area = 0; area < nr_vms; area++) {
3980 if (vas[area])
3981 continue;
3982
3983 vas[area] = kmem_cache_zalloc(
3984 vmap_area_cachep, GFP_KERNEL);
3985 if (!vas[area])
3986 goto err_free;
3987 }
3988
3989 goto retry;
3990 }
3991
3992err_free:
3993 for (area = 0; area < nr_vms; area++) {
3994 if (vas[area])
3995 kmem_cache_free(vmap_area_cachep, vas[area]);
3996
3997 kfree(vms[area]);
3998 }
3999err_free2:
4000 kfree(vas);
4001 kfree(vms);
4002 return NULL;
4003
4004err_free_shadow:
4005 spin_lock(&free_vmap_area_lock);
4006 /*
4007 * We release all the vmalloc shadows, even the ones for regions that
4008 * hadn't been successfully added. This relies on kasan_release_vmalloc
4009 * being able to tolerate this case.
4010 */
4011 for (area = 0; area < nr_vms; area++) {
4012 orig_start = vas[area]->va_start;
4013 orig_end = vas[area]->va_end;
4014 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4015 &free_vmap_area_list);
4016 if (va)
4017 kasan_release_vmalloc(orig_start, orig_end,
4018 va->va_start, va->va_end);
4019 vas[area] = NULL;
4020 kfree(vms[area]);
4021 }
4022 spin_unlock(&free_vmap_area_lock);
4023 kfree(vas);
4024 kfree(vms);
4025 return NULL;
4026}
4027
4028/**
4029 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
4030 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
4031 * @nr_vms: the number of allocated areas
4032 *
4033 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
4034 */
4035void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
4036{
4037 int i;
4038
4039 for (i = 0; i < nr_vms; i++)
4040 free_vm_area(vms[i]);
4041 kfree(vms);
4042}
4043#endif /* CONFIG_SMP */
4044
4045#ifdef CONFIG_PRINTK
4046bool vmalloc_dump_obj(void *object)
4047{
4048 struct vm_struct *vm;
4049 void *objp = (void *)PAGE_ALIGN((unsigned long)object);
4050
4051 vm = find_vm_area(objp);
4052 if (!vm)
4053 return false;
4054 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
4055 vm->nr_pages, (unsigned long)vm->addr, vm->caller);
4056 return true;
4057}
4058#endif
4059
4060#ifdef CONFIG_PROC_FS
4061static void *s_start(struct seq_file *m, loff_t *pos)
4062 __acquires(&vmap_purge_lock)
4063 __acquires(&vmap_area_lock)
4064{
4065 mutex_lock(&vmap_purge_lock);
4066 spin_lock(&vmap_area_lock);
4067
4068 return seq_list_start(&vmap_area_list, *pos);
4069}
4070
4071static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4072{
4073 return seq_list_next(p, &vmap_area_list, pos);
4074}
4075
4076static void s_stop(struct seq_file *m, void *p)
4077 __releases(&vmap_area_lock)
4078 __releases(&vmap_purge_lock)
4079{
4080 spin_unlock(&vmap_area_lock);
4081 mutex_unlock(&vmap_purge_lock);
4082}
4083
4084static void show_numa_info(struct seq_file *m, struct vm_struct *v)
4085{
4086 if (IS_ENABLED(CONFIG_NUMA)) {
4087 unsigned int nr, *counters = m->private;
4088 unsigned int step = 1U << vm_area_page_order(v);
4089
4090 if (!counters)
4091 return;
4092
4093 if (v->flags & VM_UNINITIALIZED)
4094 return;
4095 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
4096 smp_rmb();
4097
4098 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
4099
4100 for (nr = 0; nr < v->nr_pages; nr += step)
4101 counters[page_to_nid(v->pages[nr])] += step;
4102 for_each_node_state(nr, N_HIGH_MEMORY)
4103 if (counters[nr])
4104 seq_printf(m, " N%u=%u", nr, counters[nr]);
4105 }
4106}
4107
4108static void show_purge_info(struct seq_file *m)
4109{
4110 struct vmap_area *va;
4111
4112 spin_lock(&purge_vmap_area_lock);
4113 list_for_each_entry(va, &purge_vmap_area_list, list) {
4114 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
4115 (void *)va->va_start, (void *)va->va_end,
4116 va->va_end - va->va_start);
4117 }
4118 spin_unlock(&purge_vmap_area_lock);
4119}
4120
4121static int s_show(struct seq_file *m, void *p)
4122{
4123 struct vmap_area *va;
4124 struct vm_struct *v;
4125
4126 va = list_entry(p, struct vmap_area, list);
4127
4128 /*
4129 * s_show can encounter race with remove_vm_area, !vm on behalf
4130 * of vmap area is being tear down or vm_map_ram allocation.
4131 */
4132 if (!va->vm) {
4133 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
4134 (void *)va->va_start, (void *)va->va_end,
4135 va->va_end - va->va_start);
4136
4137 goto final;
4138 }
4139
4140 v = va->vm;
4141
4142 seq_printf(m, "0x%pK-0x%pK %7ld",
4143 v->addr, v->addr + v->size, v->size);
4144
4145 if (v->caller)
4146 seq_printf(m, " %pS", v->caller);
4147
4148 if (v->nr_pages)
4149 seq_printf(m, " pages=%d", v->nr_pages);
4150
4151 if (v->phys_addr)
4152 seq_printf(m, " phys=%pa", &v->phys_addr);
4153
4154 if (v->flags & VM_IOREMAP)
4155 seq_puts(m, " ioremap");
4156
4157 if (v->flags & VM_ALLOC)
4158 seq_puts(m, " vmalloc");
4159
4160 if (v->flags & VM_MAP)
4161 seq_puts(m, " vmap");
4162
4163 if (v->flags & VM_USERMAP)
4164 seq_puts(m, " user");
4165
4166 if (v->flags & VM_DMA_COHERENT)
4167 seq_puts(m, " dma-coherent");
4168
4169 if (is_vmalloc_addr(v->pages))
4170 seq_puts(m, " vpages");
4171
4172 show_numa_info(m, v);
4173 seq_putc(m, '\n');
4174
4175 /*
4176 * As a final step, dump "unpurged" areas.
4177 */
4178final:
4179 if (list_is_last(&va->list, &vmap_area_list))
4180 show_purge_info(m);
4181
4182 return 0;
4183}
4184
4185static const struct seq_operations vmalloc_op = {
4186 .start = s_start,
4187 .next = s_next,
4188 .stop = s_stop,
4189 .show = s_show,
4190};
4191
4192static int __init proc_vmalloc_init(void)
4193{
4194 if (IS_ENABLED(CONFIG_NUMA))
4195 proc_create_seq_private("vmallocinfo", 0400, NULL,
4196 &vmalloc_op,
4197 nr_node_ids * sizeof(unsigned int), NULL);
4198 else
4199 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
4200 return 0;
4201}
4202module_init(proc_vmalloc_init);
4203
4204#endif
1/*
2 * linux/mm/vmalloc.c
3 *
4 * Copyright (C) 1993 Linus Torvalds
5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
7 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
8 * Numa awareness, Christoph Lameter, SGI, June 2005
9 */
10
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/sched.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/debugobjects.h>
22#include <linux/kallsyms.h>
23#include <linux/list.h>
24#include <linux/notifier.h>
25#include <linux/rbtree.h>
26#include <linux/radix-tree.h>
27#include <linux/rcupdate.h>
28#include <linux/pfn.h>
29#include <linux/kmemleak.h>
30#include <linux/atomic.h>
31#include <linux/compiler.h>
32#include <linux/llist.h>
33#include <linux/bitops.h>
34
35#include <linux/uaccess.h>
36#include <asm/tlbflush.h>
37#include <asm/shmparam.h>
38
39#include "internal.h"
40
41struct vfree_deferred {
42 struct llist_head list;
43 struct work_struct wq;
44};
45static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
46
47static void __vunmap(const void *, int);
48
49static void free_work(struct work_struct *w)
50{
51 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
52 struct llist_node *llnode = llist_del_all(&p->list);
53 while (llnode) {
54 void *p = llnode;
55 llnode = llist_next(llnode);
56 __vunmap(p, 1);
57 }
58}
59
60/*** Page table manipulation functions ***/
61
62static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
63{
64 pte_t *pte;
65
66 pte = pte_offset_kernel(pmd, addr);
67 do {
68 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
69 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
70 } while (pte++, addr += PAGE_SIZE, addr != end);
71}
72
73static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
74{
75 pmd_t *pmd;
76 unsigned long next;
77
78 pmd = pmd_offset(pud, addr);
79 do {
80 next = pmd_addr_end(addr, end);
81 if (pmd_clear_huge(pmd))
82 continue;
83 if (pmd_none_or_clear_bad(pmd))
84 continue;
85 vunmap_pte_range(pmd, addr, next);
86 } while (pmd++, addr = next, addr != end);
87}
88
89static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
90{
91 pud_t *pud;
92 unsigned long next;
93
94 pud = pud_offset(pgd, addr);
95 do {
96 next = pud_addr_end(addr, end);
97 if (pud_clear_huge(pud))
98 continue;
99 if (pud_none_or_clear_bad(pud))
100 continue;
101 vunmap_pmd_range(pud, addr, next);
102 } while (pud++, addr = next, addr != end);
103}
104
105static void vunmap_page_range(unsigned long addr, unsigned long end)
106{
107 pgd_t *pgd;
108 unsigned long next;
109
110 BUG_ON(addr >= end);
111 pgd = pgd_offset_k(addr);
112 do {
113 next = pgd_addr_end(addr, end);
114 if (pgd_none_or_clear_bad(pgd))
115 continue;
116 vunmap_pud_range(pgd, addr, next);
117 } while (pgd++, addr = next, addr != end);
118}
119
120static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
121 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
122{
123 pte_t *pte;
124
125 /*
126 * nr is a running index into the array which helps higher level
127 * callers keep track of where we're up to.
128 */
129
130 pte = pte_alloc_kernel(pmd, addr);
131 if (!pte)
132 return -ENOMEM;
133 do {
134 struct page *page = pages[*nr];
135
136 if (WARN_ON(!pte_none(*pte)))
137 return -EBUSY;
138 if (WARN_ON(!page))
139 return -ENOMEM;
140 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
141 (*nr)++;
142 } while (pte++, addr += PAGE_SIZE, addr != end);
143 return 0;
144}
145
146static int vmap_pmd_range(pud_t *pud, unsigned long addr,
147 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
148{
149 pmd_t *pmd;
150 unsigned long next;
151
152 pmd = pmd_alloc(&init_mm, pud, addr);
153 if (!pmd)
154 return -ENOMEM;
155 do {
156 next = pmd_addr_end(addr, end);
157 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
158 return -ENOMEM;
159 } while (pmd++, addr = next, addr != end);
160 return 0;
161}
162
163static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
164 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
165{
166 pud_t *pud;
167 unsigned long next;
168
169 pud = pud_alloc(&init_mm, pgd, addr);
170 if (!pud)
171 return -ENOMEM;
172 do {
173 next = pud_addr_end(addr, end);
174 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
175 return -ENOMEM;
176 } while (pud++, addr = next, addr != end);
177 return 0;
178}
179
180/*
181 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
182 * will have pfns corresponding to the "pages" array.
183 *
184 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
185 */
186static int vmap_page_range_noflush(unsigned long start, unsigned long end,
187 pgprot_t prot, struct page **pages)
188{
189 pgd_t *pgd;
190 unsigned long next;
191 unsigned long addr = start;
192 int err = 0;
193 int nr = 0;
194
195 BUG_ON(addr >= end);
196 pgd = pgd_offset_k(addr);
197 do {
198 next = pgd_addr_end(addr, end);
199 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
200 if (err)
201 return err;
202 } while (pgd++, addr = next, addr != end);
203
204 return nr;
205}
206
207static int vmap_page_range(unsigned long start, unsigned long end,
208 pgprot_t prot, struct page **pages)
209{
210 int ret;
211
212 ret = vmap_page_range_noflush(start, end, prot, pages);
213 flush_cache_vmap(start, end);
214 return ret;
215}
216
217int is_vmalloc_or_module_addr(const void *x)
218{
219 /*
220 * ARM, x86-64 and sparc64 put modules in a special place,
221 * and fall back on vmalloc() if that fails. Others
222 * just put it in the vmalloc space.
223 */
224#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
225 unsigned long addr = (unsigned long)x;
226 if (addr >= MODULES_VADDR && addr < MODULES_END)
227 return 1;
228#endif
229 return is_vmalloc_addr(x);
230}
231
232/*
233 * Walk a vmap address to the struct page it maps.
234 */
235struct page *vmalloc_to_page(const void *vmalloc_addr)
236{
237 unsigned long addr = (unsigned long) vmalloc_addr;
238 struct page *page = NULL;
239 pgd_t *pgd = pgd_offset_k(addr);
240
241 /*
242 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
243 * architectures that do not vmalloc module space
244 */
245 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
246
247 if (!pgd_none(*pgd)) {
248 pud_t *pud = pud_offset(pgd, addr);
249 if (!pud_none(*pud)) {
250 pmd_t *pmd = pmd_offset(pud, addr);
251 if (!pmd_none(*pmd)) {
252 pte_t *ptep, pte;
253
254 ptep = pte_offset_map(pmd, addr);
255 pte = *ptep;
256 if (pte_present(pte))
257 page = pte_page(pte);
258 pte_unmap(ptep);
259 }
260 }
261 }
262 return page;
263}
264EXPORT_SYMBOL(vmalloc_to_page);
265
266/*
267 * Map a vmalloc()-space virtual address to the physical page frame number.
268 */
269unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
270{
271 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
272}
273EXPORT_SYMBOL(vmalloc_to_pfn);
274
275
276/*** Global kva allocator ***/
277
278#define VM_VM_AREA 0x04
279
280static DEFINE_SPINLOCK(vmap_area_lock);
281/* Export for kexec only */
282LIST_HEAD(vmap_area_list);
283static LLIST_HEAD(vmap_purge_list);
284static struct rb_root vmap_area_root = RB_ROOT;
285
286/* The vmap cache globals are protected by vmap_area_lock */
287static struct rb_node *free_vmap_cache;
288static unsigned long cached_hole_size;
289static unsigned long cached_vstart;
290static unsigned long cached_align;
291
292static unsigned long vmap_area_pcpu_hole;
293
294static struct vmap_area *__find_vmap_area(unsigned long addr)
295{
296 struct rb_node *n = vmap_area_root.rb_node;
297
298 while (n) {
299 struct vmap_area *va;
300
301 va = rb_entry(n, struct vmap_area, rb_node);
302 if (addr < va->va_start)
303 n = n->rb_left;
304 else if (addr >= va->va_end)
305 n = n->rb_right;
306 else
307 return va;
308 }
309
310 return NULL;
311}
312
313static void __insert_vmap_area(struct vmap_area *va)
314{
315 struct rb_node **p = &vmap_area_root.rb_node;
316 struct rb_node *parent = NULL;
317 struct rb_node *tmp;
318
319 while (*p) {
320 struct vmap_area *tmp_va;
321
322 parent = *p;
323 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
324 if (va->va_start < tmp_va->va_end)
325 p = &(*p)->rb_left;
326 else if (va->va_end > tmp_va->va_start)
327 p = &(*p)->rb_right;
328 else
329 BUG();
330 }
331
332 rb_link_node(&va->rb_node, parent, p);
333 rb_insert_color(&va->rb_node, &vmap_area_root);
334
335 /* address-sort this list */
336 tmp = rb_prev(&va->rb_node);
337 if (tmp) {
338 struct vmap_area *prev;
339 prev = rb_entry(tmp, struct vmap_area, rb_node);
340 list_add_rcu(&va->list, &prev->list);
341 } else
342 list_add_rcu(&va->list, &vmap_area_list);
343}
344
345static void purge_vmap_area_lazy(void);
346
347static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
348
349/*
350 * Allocate a region of KVA of the specified size and alignment, within the
351 * vstart and vend.
352 */
353static struct vmap_area *alloc_vmap_area(unsigned long size,
354 unsigned long align,
355 unsigned long vstart, unsigned long vend,
356 int node, gfp_t gfp_mask)
357{
358 struct vmap_area *va;
359 struct rb_node *n;
360 unsigned long addr;
361 int purged = 0;
362 struct vmap_area *first;
363
364 BUG_ON(!size);
365 BUG_ON(offset_in_page(size));
366 BUG_ON(!is_power_of_2(align));
367
368 might_sleep();
369
370 va = kmalloc_node(sizeof(struct vmap_area),
371 gfp_mask & GFP_RECLAIM_MASK, node);
372 if (unlikely(!va))
373 return ERR_PTR(-ENOMEM);
374
375 /*
376 * Only scan the relevant parts containing pointers to other objects
377 * to avoid false negatives.
378 */
379 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
380
381retry:
382 spin_lock(&vmap_area_lock);
383 /*
384 * Invalidate cache if we have more permissive parameters.
385 * cached_hole_size notes the largest hole noticed _below_
386 * the vmap_area cached in free_vmap_cache: if size fits
387 * into that hole, we want to scan from vstart to reuse
388 * the hole instead of allocating above free_vmap_cache.
389 * Note that __free_vmap_area may update free_vmap_cache
390 * without updating cached_hole_size or cached_align.
391 */
392 if (!free_vmap_cache ||
393 size < cached_hole_size ||
394 vstart < cached_vstart ||
395 align < cached_align) {
396nocache:
397 cached_hole_size = 0;
398 free_vmap_cache = NULL;
399 }
400 /* record if we encounter less permissive parameters */
401 cached_vstart = vstart;
402 cached_align = align;
403
404 /* find starting point for our search */
405 if (free_vmap_cache) {
406 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
407 addr = ALIGN(first->va_end, align);
408 if (addr < vstart)
409 goto nocache;
410 if (addr + size < addr)
411 goto overflow;
412
413 } else {
414 addr = ALIGN(vstart, align);
415 if (addr + size < addr)
416 goto overflow;
417
418 n = vmap_area_root.rb_node;
419 first = NULL;
420
421 while (n) {
422 struct vmap_area *tmp;
423 tmp = rb_entry(n, struct vmap_area, rb_node);
424 if (tmp->va_end >= addr) {
425 first = tmp;
426 if (tmp->va_start <= addr)
427 break;
428 n = n->rb_left;
429 } else
430 n = n->rb_right;
431 }
432
433 if (!first)
434 goto found;
435 }
436
437 /* from the starting point, walk areas until a suitable hole is found */
438 while (addr + size > first->va_start && addr + size <= vend) {
439 if (addr + cached_hole_size < first->va_start)
440 cached_hole_size = first->va_start - addr;
441 addr = ALIGN(first->va_end, align);
442 if (addr + size < addr)
443 goto overflow;
444
445 if (list_is_last(&first->list, &vmap_area_list))
446 goto found;
447
448 first = list_next_entry(first, list);
449 }
450
451found:
452 if (addr + size > vend)
453 goto overflow;
454
455 va->va_start = addr;
456 va->va_end = addr + size;
457 va->flags = 0;
458 __insert_vmap_area(va);
459 free_vmap_cache = &va->rb_node;
460 spin_unlock(&vmap_area_lock);
461
462 BUG_ON(!IS_ALIGNED(va->va_start, align));
463 BUG_ON(va->va_start < vstart);
464 BUG_ON(va->va_end > vend);
465
466 return va;
467
468overflow:
469 spin_unlock(&vmap_area_lock);
470 if (!purged) {
471 purge_vmap_area_lazy();
472 purged = 1;
473 goto retry;
474 }
475
476 if (gfpflags_allow_blocking(gfp_mask)) {
477 unsigned long freed = 0;
478 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
479 if (freed > 0) {
480 purged = 0;
481 goto retry;
482 }
483 }
484
485 if (printk_ratelimit())
486 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
487 size);
488 kfree(va);
489 return ERR_PTR(-EBUSY);
490}
491
492int register_vmap_purge_notifier(struct notifier_block *nb)
493{
494 return blocking_notifier_chain_register(&vmap_notify_list, nb);
495}
496EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
497
498int unregister_vmap_purge_notifier(struct notifier_block *nb)
499{
500 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
501}
502EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
503
504static void __free_vmap_area(struct vmap_area *va)
505{
506 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
507
508 if (free_vmap_cache) {
509 if (va->va_end < cached_vstart) {
510 free_vmap_cache = NULL;
511 } else {
512 struct vmap_area *cache;
513 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
514 if (va->va_start <= cache->va_start) {
515 free_vmap_cache = rb_prev(&va->rb_node);
516 /*
517 * We don't try to update cached_hole_size or
518 * cached_align, but it won't go very wrong.
519 */
520 }
521 }
522 }
523 rb_erase(&va->rb_node, &vmap_area_root);
524 RB_CLEAR_NODE(&va->rb_node);
525 list_del_rcu(&va->list);
526
527 /*
528 * Track the highest possible candidate for pcpu area
529 * allocation. Areas outside of vmalloc area can be returned
530 * here too, consider only end addresses which fall inside
531 * vmalloc area proper.
532 */
533 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
534 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
535
536 kfree_rcu(va, rcu_head);
537}
538
539/*
540 * Free a region of KVA allocated by alloc_vmap_area
541 */
542static void free_vmap_area(struct vmap_area *va)
543{
544 spin_lock(&vmap_area_lock);
545 __free_vmap_area(va);
546 spin_unlock(&vmap_area_lock);
547}
548
549/*
550 * Clear the pagetable entries of a given vmap_area
551 */
552static void unmap_vmap_area(struct vmap_area *va)
553{
554 vunmap_page_range(va->va_start, va->va_end);
555}
556
557static void vmap_debug_free_range(unsigned long start, unsigned long end)
558{
559 /*
560 * Unmap page tables and force a TLB flush immediately if pagealloc
561 * debugging is enabled. This catches use after free bugs similarly to
562 * those in linear kernel virtual address space after a page has been
563 * freed.
564 *
565 * All the lazy freeing logic is still retained, in order to minimise
566 * intrusiveness of this debugging feature.
567 *
568 * This is going to be *slow* (linear kernel virtual address debugging
569 * doesn't do a broadcast TLB flush so it is a lot faster).
570 */
571 if (debug_pagealloc_enabled()) {
572 vunmap_page_range(start, end);
573 flush_tlb_kernel_range(start, end);
574 }
575}
576
577/*
578 * lazy_max_pages is the maximum amount of virtual address space we gather up
579 * before attempting to purge with a TLB flush.
580 *
581 * There is a tradeoff here: a larger number will cover more kernel page tables
582 * and take slightly longer to purge, but it will linearly reduce the number of
583 * global TLB flushes that must be performed. It would seem natural to scale
584 * this number up linearly with the number of CPUs (because vmapping activity
585 * could also scale linearly with the number of CPUs), however it is likely
586 * that in practice, workloads might be constrained in other ways that mean
587 * vmap activity will not scale linearly with CPUs. Also, I want to be
588 * conservative and not introduce a big latency on huge systems, so go with
589 * a less aggressive log scale. It will still be an improvement over the old
590 * code, and it will be simple to change the scale factor if we find that it
591 * becomes a problem on bigger systems.
592 */
593static unsigned long lazy_max_pages(void)
594{
595 unsigned int log;
596
597 log = fls(num_online_cpus());
598
599 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
600}
601
602static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
603
604/*
605 * Serialize vmap purging. There is no actual criticial section protected
606 * by this look, but we want to avoid concurrent calls for performance
607 * reasons and to make the pcpu_get_vm_areas more deterministic.
608 */
609static DEFINE_MUTEX(vmap_purge_lock);
610
611/* for per-CPU blocks */
612static void purge_fragmented_blocks_allcpus(void);
613
614/*
615 * called before a call to iounmap() if the caller wants vm_area_struct's
616 * immediately freed.
617 */
618void set_iounmap_nonlazy(void)
619{
620 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
621}
622
623/*
624 * Purges all lazily-freed vmap areas.
625 */
626static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
627{
628 struct llist_node *valist;
629 struct vmap_area *va;
630 struct vmap_area *n_va;
631 bool do_free = false;
632
633 lockdep_assert_held(&vmap_purge_lock);
634
635 valist = llist_del_all(&vmap_purge_list);
636 llist_for_each_entry(va, valist, purge_list) {
637 if (va->va_start < start)
638 start = va->va_start;
639 if (va->va_end > end)
640 end = va->va_end;
641 do_free = true;
642 }
643
644 if (!do_free)
645 return false;
646
647 flush_tlb_kernel_range(start, end);
648
649 spin_lock(&vmap_area_lock);
650 llist_for_each_entry_safe(va, n_va, valist, purge_list) {
651 int nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
652
653 __free_vmap_area(va);
654 atomic_sub(nr, &vmap_lazy_nr);
655 cond_resched_lock(&vmap_area_lock);
656 }
657 spin_unlock(&vmap_area_lock);
658 return true;
659}
660
661/*
662 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
663 * is already purging.
664 */
665static void try_purge_vmap_area_lazy(void)
666{
667 if (mutex_trylock(&vmap_purge_lock)) {
668 __purge_vmap_area_lazy(ULONG_MAX, 0);
669 mutex_unlock(&vmap_purge_lock);
670 }
671}
672
673/*
674 * Kick off a purge of the outstanding lazy areas.
675 */
676static void purge_vmap_area_lazy(void)
677{
678 mutex_lock(&vmap_purge_lock);
679 purge_fragmented_blocks_allcpus();
680 __purge_vmap_area_lazy(ULONG_MAX, 0);
681 mutex_unlock(&vmap_purge_lock);
682}
683
684/*
685 * Free a vmap area, caller ensuring that the area has been unmapped
686 * and flush_cache_vunmap had been called for the correct range
687 * previously.
688 */
689static void free_vmap_area_noflush(struct vmap_area *va)
690{
691 int nr_lazy;
692
693 nr_lazy = atomic_add_return((va->va_end - va->va_start) >> PAGE_SHIFT,
694 &vmap_lazy_nr);
695
696 /* After this point, we may free va at any time */
697 llist_add(&va->purge_list, &vmap_purge_list);
698
699 if (unlikely(nr_lazy > lazy_max_pages()))
700 try_purge_vmap_area_lazy();
701}
702
703/*
704 * Free and unmap a vmap area
705 */
706static void free_unmap_vmap_area(struct vmap_area *va)
707{
708 flush_cache_vunmap(va->va_start, va->va_end);
709 unmap_vmap_area(va);
710 free_vmap_area_noflush(va);
711}
712
713static struct vmap_area *find_vmap_area(unsigned long addr)
714{
715 struct vmap_area *va;
716
717 spin_lock(&vmap_area_lock);
718 va = __find_vmap_area(addr);
719 spin_unlock(&vmap_area_lock);
720
721 return va;
722}
723
724/*** Per cpu kva allocator ***/
725
726/*
727 * vmap space is limited especially on 32 bit architectures. Ensure there is
728 * room for at least 16 percpu vmap blocks per CPU.
729 */
730/*
731 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
732 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
733 * instead (we just need a rough idea)
734 */
735#if BITS_PER_LONG == 32
736#define VMALLOC_SPACE (128UL*1024*1024)
737#else
738#define VMALLOC_SPACE (128UL*1024*1024*1024)
739#endif
740
741#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
742#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
743#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
744#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
745#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
746#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
747#define VMAP_BBMAP_BITS \
748 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
749 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
750 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
751
752#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
753
754static bool vmap_initialized __read_mostly = false;
755
756struct vmap_block_queue {
757 spinlock_t lock;
758 struct list_head free;
759};
760
761struct vmap_block {
762 spinlock_t lock;
763 struct vmap_area *va;
764 unsigned long free, dirty;
765 unsigned long dirty_min, dirty_max; /*< dirty range */
766 struct list_head free_list;
767 struct rcu_head rcu_head;
768 struct list_head purge;
769};
770
771/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
772static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
773
774/*
775 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
776 * in the free path. Could get rid of this if we change the API to return a
777 * "cookie" from alloc, to be passed to free. But no big deal yet.
778 */
779static DEFINE_SPINLOCK(vmap_block_tree_lock);
780static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
781
782/*
783 * We should probably have a fallback mechanism to allocate virtual memory
784 * out of partially filled vmap blocks. However vmap block sizing should be
785 * fairly reasonable according to the vmalloc size, so it shouldn't be a
786 * big problem.
787 */
788
789static unsigned long addr_to_vb_idx(unsigned long addr)
790{
791 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
792 addr /= VMAP_BLOCK_SIZE;
793 return addr;
794}
795
796static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
797{
798 unsigned long addr;
799
800 addr = va_start + (pages_off << PAGE_SHIFT);
801 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
802 return (void *)addr;
803}
804
805/**
806 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
807 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
808 * @order: how many 2^order pages should be occupied in newly allocated block
809 * @gfp_mask: flags for the page level allocator
810 *
811 * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
812 */
813static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
814{
815 struct vmap_block_queue *vbq;
816 struct vmap_block *vb;
817 struct vmap_area *va;
818 unsigned long vb_idx;
819 int node, err;
820 void *vaddr;
821
822 node = numa_node_id();
823
824 vb = kmalloc_node(sizeof(struct vmap_block),
825 gfp_mask & GFP_RECLAIM_MASK, node);
826 if (unlikely(!vb))
827 return ERR_PTR(-ENOMEM);
828
829 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
830 VMALLOC_START, VMALLOC_END,
831 node, gfp_mask);
832 if (IS_ERR(va)) {
833 kfree(vb);
834 return ERR_CAST(va);
835 }
836
837 err = radix_tree_preload(gfp_mask);
838 if (unlikely(err)) {
839 kfree(vb);
840 free_vmap_area(va);
841 return ERR_PTR(err);
842 }
843
844 vaddr = vmap_block_vaddr(va->va_start, 0);
845 spin_lock_init(&vb->lock);
846 vb->va = va;
847 /* At least something should be left free */
848 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
849 vb->free = VMAP_BBMAP_BITS - (1UL << order);
850 vb->dirty = 0;
851 vb->dirty_min = VMAP_BBMAP_BITS;
852 vb->dirty_max = 0;
853 INIT_LIST_HEAD(&vb->free_list);
854
855 vb_idx = addr_to_vb_idx(va->va_start);
856 spin_lock(&vmap_block_tree_lock);
857 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
858 spin_unlock(&vmap_block_tree_lock);
859 BUG_ON(err);
860 radix_tree_preload_end();
861
862 vbq = &get_cpu_var(vmap_block_queue);
863 spin_lock(&vbq->lock);
864 list_add_tail_rcu(&vb->free_list, &vbq->free);
865 spin_unlock(&vbq->lock);
866 put_cpu_var(vmap_block_queue);
867
868 return vaddr;
869}
870
871static void free_vmap_block(struct vmap_block *vb)
872{
873 struct vmap_block *tmp;
874 unsigned long vb_idx;
875
876 vb_idx = addr_to_vb_idx(vb->va->va_start);
877 spin_lock(&vmap_block_tree_lock);
878 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
879 spin_unlock(&vmap_block_tree_lock);
880 BUG_ON(tmp != vb);
881
882 free_vmap_area_noflush(vb->va);
883 kfree_rcu(vb, rcu_head);
884}
885
886static void purge_fragmented_blocks(int cpu)
887{
888 LIST_HEAD(purge);
889 struct vmap_block *vb;
890 struct vmap_block *n_vb;
891 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
892
893 rcu_read_lock();
894 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
895
896 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
897 continue;
898
899 spin_lock(&vb->lock);
900 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
901 vb->free = 0; /* prevent further allocs after releasing lock */
902 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
903 vb->dirty_min = 0;
904 vb->dirty_max = VMAP_BBMAP_BITS;
905 spin_lock(&vbq->lock);
906 list_del_rcu(&vb->free_list);
907 spin_unlock(&vbq->lock);
908 spin_unlock(&vb->lock);
909 list_add_tail(&vb->purge, &purge);
910 } else
911 spin_unlock(&vb->lock);
912 }
913 rcu_read_unlock();
914
915 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
916 list_del(&vb->purge);
917 free_vmap_block(vb);
918 }
919}
920
921static void purge_fragmented_blocks_allcpus(void)
922{
923 int cpu;
924
925 for_each_possible_cpu(cpu)
926 purge_fragmented_blocks(cpu);
927}
928
929static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
930{
931 struct vmap_block_queue *vbq;
932 struct vmap_block *vb;
933 void *vaddr = NULL;
934 unsigned int order;
935
936 BUG_ON(offset_in_page(size));
937 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
938 if (WARN_ON(size == 0)) {
939 /*
940 * Allocating 0 bytes isn't what caller wants since
941 * get_order(0) returns funny result. Just warn and terminate
942 * early.
943 */
944 return NULL;
945 }
946 order = get_order(size);
947
948 rcu_read_lock();
949 vbq = &get_cpu_var(vmap_block_queue);
950 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
951 unsigned long pages_off;
952
953 spin_lock(&vb->lock);
954 if (vb->free < (1UL << order)) {
955 spin_unlock(&vb->lock);
956 continue;
957 }
958
959 pages_off = VMAP_BBMAP_BITS - vb->free;
960 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
961 vb->free -= 1UL << order;
962 if (vb->free == 0) {
963 spin_lock(&vbq->lock);
964 list_del_rcu(&vb->free_list);
965 spin_unlock(&vbq->lock);
966 }
967
968 spin_unlock(&vb->lock);
969 break;
970 }
971
972 put_cpu_var(vmap_block_queue);
973 rcu_read_unlock();
974
975 /* Allocate new block if nothing was found */
976 if (!vaddr)
977 vaddr = new_vmap_block(order, gfp_mask);
978
979 return vaddr;
980}
981
982static void vb_free(const void *addr, unsigned long size)
983{
984 unsigned long offset;
985 unsigned long vb_idx;
986 unsigned int order;
987 struct vmap_block *vb;
988
989 BUG_ON(offset_in_page(size));
990 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
991
992 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
993
994 order = get_order(size);
995
996 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
997 offset >>= PAGE_SHIFT;
998
999 vb_idx = addr_to_vb_idx((unsigned long)addr);
1000 rcu_read_lock();
1001 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
1002 rcu_read_unlock();
1003 BUG_ON(!vb);
1004
1005 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
1006
1007 spin_lock(&vb->lock);
1008
1009 /* Expand dirty range */
1010 vb->dirty_min = min(vb->dirty_min, offset);
1011 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1012
1013 vb->dirty += 1UL << order;
1014 if (vb->dirty == VMAP_BBMAP_BITS) {
1015 BUG_ON(vb->free);
1016 spin_unlock(&vb->lock);
1017 free_vmap_block(vb);
1018 } else
1019 spin_unlock(&vb->lock);
1020}
1021
1022/**
1023 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1024 *
1025 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1026 * to amortize TLB flushing overheads. What this means is that any page you
1027 * have now, may, in a former life, have been mapped into kernel virtual
1028 * address by the vmap layer and so there might be some CPUs with TLB entries
1029 * still referencing that page (additional to the regular 1:1 kernel mapping).
1030 *
1031 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1032 * be sure that none of the pages we have control over will have any aliases
1033 * from the vmap layer.
1034 */
1035void vm_unmap_aliases(void)
1036{
1037 unsigned long start = ULONG_MAX, end = 0;
1038 int cpu;
1039 int flush = 0;
1040
1041 if (unlikely(!vmap_initialized))
1042 return;
1043
1044 might_sleep();
1045
1046 for_each_possible_cpu(cpu) {
1047 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1048 struct vmap_block *vb;
1049
1050 rcu_read_lock();
1051 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1052 spin_lock(&vb->lock);
1053 if (vb->dirty) {
1054 unsigned long va_start = vb->va->va_start;
1055 unsigned long s, e;
1056
1057 s = va_start + (vb->dirty_min << PAGE_SHIFT);
1058 e = va_start + (vb->dirty_max << PAGE_SHIFT);
1059
1060 start = min(s, start);
1061 end = max(e, end);
1062
1063 flush = 1;
1064 }
1065 spin_unlock(&vb->lock);
1066 }
1067 rcu_read_unlock();
1068 }
1069
1070 mutex_lock(&vmap_purge_lock);
1071 purge_fragmented_blocks_allcpus();
1072 if (!__purge_vmap_area_lazy(start, end) && flush)
1073 flush_tlb_kernel_range(start, end);
1074 mutex_unlock(&vmap_purge_lock);
1075}
1076EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1077
1078/**
1079 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1080 * @mem: the pointer returned by vm_map_ram
1081 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1082 */
1083void vm_unmap_ram(const void *mem, unsigned int count)
1084{
1085 unsigned long size = (unsigned long)count << PAGE_SHIFT;
1086 unsigned long addr = (unsigned long)mem;
1087 struct vmap_area *va;
1088
1089 might_sleep();
1090 BUG_ON(!addr);
1091 BUG_ON(addr < VMALLOC_START);
1092 BUG_ON(addr > VMALLOC_END);
1093 BUG_ON(!PAGE_ALIGNED(addr));
1094
1095 debug_check_no_locks_freed(mem, size);
1096 vmap_debug_free_range(addr, addr+size);
1097
1098 if (likely(count <= VMAP_MAX_ALLOC)) {
1099 vb_free(mem, size);
1100 return;
1101 }
1102
1103 va = find_vmap_area(addr);
1104 BUG_ON(!va);
1105 free_unmap_vmap_area(va);
1106}
1107EXPORT_SYMBOL(vm_unmap_ram);
1108
1109/**
1110 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1111 * @pages: an array of pointers to the pages to be mapped
1112 * @count: number of pages
1113 * @node: prefer to allocate data structures on this node
1114 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1115 *
1116 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1117 * faster than vmap so it's good. But if you mix long-life and short-life
1118 * objects with vm_map_ram(), it could consume lots of address space through
1119 * fragmentation (especially on a 32bit machine). You could see failures in
1120 * the end. Please use this function for short-lived objects.
1121 *
1122 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1123 */
1124void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1125{
1126 unsigned long size = (unsigned long)count << PAGE_SHIFT;
1127 unsigned long addr;
1128 void *mem;
1129
1130 if (likely(count <= VMAP_MAX_ALLOC)) {
1131 mem = vb_alloc(size, GFP_KERNEL);
1132 if (IS_ERR(mem))
1133 return NULL;
1134 addr = (unsigned long)mem;
1135 } else {
1136 struct vmap_area *va;
1137 va = alloc_vmap_area(size, PAGE_SIZE,
1138 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1139 if (IS_ERR(va))
1140 return NULL;
1141
1142 addr = va->va_start;
1143 mem = (void *)addr;
1144 }
1145 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1146 vm_unmap_ram(mem, count);
1147 return NULL;
1148 }
1149 return mem;
1150}
1151EXPORT_SYMBOL(vm_map_ram);
1152
1153static struct vm_struct *vmlist __initdata;
1154/**
1155 * vm_area_add_early - add vmap area early during boot
1156 * @vm: vm_struct to add
1157 *
1158 * This function is used to add fixed kernel vm area to vmlist before
1159 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1160 * should contain proper values and the other fields should be zero.
1161 *
1162 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1163 */
1164void __init vm_area_add_early(struct vm_struct *vm)
1165{
1166 struct vm_struct *tmp, **p;
1167
1168 BUG_ON(vmap_initialized);
1169 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1170 if (tmp->addr >= vm->addr) {
1171 BUG_ON(tmp->addr < vm->addr + vm->size);
1172 break;
1173 } else
1174 BUG_ON(tmp->addr + tmp->size > vm->addr);
1175 }
1176 vm->next = *p;
1177 *p = vm;
1178}
1179
1180/**
1181 * vm_area_register_early - register vmap area early during boot
1182 * @vm: vm_struct to register
1183 * @align: requested alignment
1184 *
1185 * This function is used to register kernel vm area before
1186 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1187 * proper values on entry and other fields should be zero. On return,
1188 * vm->addr contains the allocated address.
1189 *
1190 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1191 */
1192void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1193{
1194 static size_t vm_init_off __initdata;
1195 unsigned long addr;
1196
1197 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1198 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1199
1200 vm->addr = (void *)addr;
1201
1202 vm_area_add_early(vm);
1203}
1204
1205void __init vmalloc_init(void)
1206{
1207 struct vmap_area *va;
1208 struct vm_struct *tmp;
1209 int i;
1210
1211 for_each_possible_cpu(i) {
1212 struct vmap_block_queue *vbq;
1213 struct vfree_deferred *p;
1214
1215 vbq = &per_cpu(vmap_block_queue, i);
1216 spin_lock_init(&vbq->lock);
1217 INIT_LIST_HEAD(&vbq->free);
1218 p = &per_cpu(vfree_deferred, i);
1219 init_llist_head(&p->list);
1220 INIT_WORK(&p->wq, free_work);
1221 }
1222
1223 /* Import existing vmlist entries. */
1224 for (tmp = vmlist; tmp; tmp = tmp->next) {
1225 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1226 va->flags = VM_VM_AREA;
1227 va->va_start = (unsigned long)tmp->addr;
1228 va->va_end = va->va_start + tmp->size;
1229 va->vm = tmp;
1230 __insert_vmap_area(va);
1231 }
1232
1233 vmap_area_pcpu_hole = VMALLOC_END;
1234
1235 vmap_initialized = true;
1236}
1237
1238/**
1239 * map_kernel_range_noflush - map kernel VM area with the specified pages
1240 * @addr: start of the VM area to map
1241 * @size: size of the VM area to map
1242 * @prot: page protection flags to use
1243 * @pages: pages to map
1244 *
1245 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1246 * specify should have been allocated using get_vm_area() and its
1247 * friends.
1248 *
1249 * NOTE:
1250 * This function does NOT do any cache flushing. The caller is
1251 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1252 * before calling this function.
1253 *
1254 * RETURNS:
1255 * The number of pages mapped on success, -errno on failure.
1256 */
1257int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1258 pgprot_t prot, struct page **pages)
1259{
1260 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1261}
1262
1263/**
1264 * unmap_kernel_range_noflush - unmap kernel VM area
1265 * @addr: start of the VM area to unmap
1266 * @size: size of the VM area to unmap
1267 *
1268 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1269 * specify should have been allocated using get_vm_area() and its
1270 * friends.
1271 *
1272 * NOTE:
1273 * This function does NOT do any cache flushing. The caller is
1274 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1275 * before calling this function and flush_tlb_kernel_range() after.
1276 */
1277void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1278{
1279 vunmap_page_range(addr, addr + size);
1280}
1281EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1282
1283/**
1284 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1285 * @addr: start of the VM area to unmap
1286 * @size: size of the VM area to unmap
1287 *
1288 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1289 * the unmapping and tlb after.
1290 */
1291void unmap_kernel_range(unsigned long addr, unsigned long size)
1292{
1293 unsigned long end = addr + size;
1294
1295 flush_cache_vunmap(addr, end);
1296 vunmap_page_range(addr, end);
1297 flush_tlb_kernel_range(addr, end);
1298}
1299EXPORT_SYMBOL_GPL(unmap_kernel_range);
1300
1301int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
1302{
1303 unsigned long addr = (unsigned long)area->addr;
1304 unsigned long end = addr + get_vm_area_size(area);
1305 int err;
1306
1307 err = vmap_page_range(addr, end, prot, pages);
1308
1309 return err > 0 ? 0 : err;
1310}
1311EXPORT_SYMBOL_GPL(map_vm_area);
1312
1313static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1314 unsigned long flags, const void *caller)
1315{
1316 spin_lock(&vmap_area_lock);
1317 vm->flags = flags;
1318 vm->addr = (void *)va->va_start;
1319 vm->size = va->va_end - va->va_start;
1320 vm->caller = caller;
1321 va->vm = vm;
1322 va->flags |= VM_VM_AREA;
1323 spin_unlock(&vmap_area_lock);
1324}
1325
1326static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1327{
1328 /*
1329 * Before removing VM_UNINITIALIZED,
1330 * we should make sure that vm has proper values.
1331 * Pair with smp_rmb() in show_numa_info().
1332 */
1333 smp_wmb();
1334 vm->flags &= ~VM_UNINITIALIZED;
1335}
1336
1337static struct vm_struct *__get_vm_area_node(unsigned long size,
1338 unsigned long align, unsigned long flags, unsigned long start,
1339 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1340{
1341 struct vmap_area *va;
1342 struct vm_struct *area;
1343
1344 BUG_ON(in_interrupt());
1345 size = PAGE_ALIGN(size);
1346 if (unlikely(!size))
1347 return NULL;
1348
1349 if (flags & VM_IOREMAP)
1350 align = 1ul << clamp_t(int, get_count_order_long(size),
1351 PAGE_SHIFT, IOREMAP_MAX_ORDER);
1352
1353 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1354 if (unlikely(!area))
1355 return NULL;
1356
1357 if (!(flags & VM_NO_GUARD))
1358 size += PAGE_SIZE;
1359
1360 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1361 if (IS_ERR(va)) {
1362 kfree(area);
1363 return NULL;
1364 }
1365
1366 setup_vmalloc_vm(area, va, flags, caller);
1367
1368 return area;
1369}
1370
1371struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1372 unsigned long start, unsigned long end)
1373{
1374 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1375 GFP_KERNEL, __builtin_return_address(0));
1376}
1377EXPORT_SYMBOL_GPL(__get_vm_area);
1378
1379struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1380 unsigned long start, unsigned long end,
1381 const void *caller)
1382{
1383 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1384 GFP_KERNEL, caller);
1385}
1386
1387/**
1388 * get_vm_area - reserve a contiguous kernel virtual area
1389 * @size: size of the area
1390 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1391 *
1392 * Search an area of @size in the kernel virtual mapping area,
1393 * and reserved it for out purposes. Returns the area descriptor
1394 * on success or %NULL on failure.
1395 */
1396struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1397{
1398 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1399 NUMA_NO_NODE, GFP_KERNEL,
1400 __builtin_return_address(0));
1401}
1402
1403struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1404 const void *caller)
1405{
1406 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1407 NUMA_NO_NODE, GFP_KERNEL, caller);
1408}
1409
1410/**
1411 * find_vm_area - find a continuous kernel virtual area
1412 * @addr: base address
1413 *
1414 * Search for the kernel VM area starting at @addr, and return it.
1415 * It is up to the caller to do all required locking to keep the returned
1416 * pointer valid.
1417 */
1418struct vm_struct *find_vm_area(const void *addr)
1419{
1420 struct vmap_area *va;
1421
1422 va = find_vmap_area((unsigned long)addr);
1423 if (va && va->flags & VM_VM_AREA)
1424 return va->vm;
1425
1426 return NULL;
1427}
1428
1429/**
1430 * remove_vm_area - find and remove a continuous kernel virtual area
1431 * @addr: base address
1432 *
1433 * Search for the kernel VM area starting at @addr, and remove it.
1434 * This function returns the found VM area, but using it is NOT safe
1435 * on SMP machines, except for its size or flags.
1436 */
1437struct vm_struct *remove_vm_area(const void *addr)
1438{
1439 struct vmap_area *va;
1440
1441 might_sleep();
1442
1443 va = find_vmap_area((unsigned long)addr);
1444 if (va && va->flags & VM_VM_AREA) {
1445 struct vm_struct *vm = va->vm;
1446
1447 spin_lock(&vmap_area_lock);
1448 va->vm = NULL;
1449 va->flags &= ~VM_VM_AREA;
1450 spin_unlock(&vmap_area_lock);
1451
1452 vmap_debug_free_range(va->va_start, va->va_end);
1453 kasan_free_shadow(vm);
1454 free_unmap_vmap_area(va);
1455
1456 return vm;
1457 }
1458 return NULL;
1459}
1460
1461static void __vunmap(const void *addr, int deallocate_pages)
1462{
1463 struct vm_struct *area;
1464
1465 if (!addr)
1466 return;
1467
1468 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
1469 addr))
1470 return;
1471
1472 area = remove_vm_area(addr);
1473 if (unlikely(!area)) {
1474 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1475 addr);
1476 return;
1477 }
1478
1479 debug_check_no_locks_freed(addr, get_vm_area_size(area));
1480 debug_check_no_obj_freed(addr, get_vm_area_size(area));
1481
1482 if (deallocate_pages) {
1483 int i;
1484
1485 for (i = 0; i < area->nr_pages; i++) {
1486 struct page *page = area->pages[i];
1487
1488 BUG_ON(!page);
1489 __free_pages(page, 0);
1490 }
1491
1492 kvfree(area->pages);
1493 }
1494
1495 kfree(area);
1496 return;
1497}
1498
1499static inline void __vfree_deferred(const void *addr)
1500{
1501 /*
1502 * Use raw_cpu_ptr() because this can be called from preemptible
1503 * context. Preemption is absolutely fine here, because the llist_add()
1504 * implementation is lockless, so it works even if we are adding to
1505 * nother cpu's list. schedule_work() should be fine with this too.
1506 */
1507 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
1508
1509 if (llist_add((struct llist_node *)addr, &p->list))
1510 schedule_work(&p->wq);
1511}
1512
1513/**
1514 * vfree_atomic - release memory allocated by vmalloc()
1515 * @addr: memory base address
1516 *
1517 * This one is just like vfree() but can be called in any atomic context
1518 * except NMIs.
1519 */
1520void vfree_atomic(const void *addr)
1521{
1522 BUG_ON(in_nmi());
1523
1524 kmemleak_free(addr);
1525
1526 if (!addr)
1527 return;
1528 __vfree_deferred(addr);
1529}
1530
1531/**
1532 * vfree - release memory allocated by vmalloc()
1533 * @addr: memory base address
1534 *
1535 * Free the virtually continuous memory area starting at @addr, as
1536 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1537 * NULL, no operation is performed.
1538 *
1539 * Must not be called in NMI context (strictly speaking, only if we don't
1540 * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
1541 * conventions for vfree() arch-depenedent would be a really bad idea)
1542 *
1543 * NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
1544 */
1545void vfree(const void *addr)
1546{
1547 BUG_ON(in_nmi());
1548
1549 kmemleak_free(addr);
1550
1551 if (!addr)
1552 return;
1553 if (unlikely(in_interrupt()))
1554 __vfree_deferred(addr);
1555 else
1556 __vunmap(addr, 1);
1557}
1558EXPORT_SYMBOL(vfree);
1559
1560/**
1561 * vunmap - release virtual mapping obtained by vmap()
1562 * @addr: memory base address
1563 *
1564 * Free the virtually contiguous memory area starting at @addr,
1565 * which was created from the page array passed to vmap().
1566 *
1567 * Must not be called in interrupt context.
1568 */
1569void vunmap(const void *addr)
1570{
1571 BUG_ON(in_interrupt());
1572 might_sleep();
1573 if (addr)
1574 __vunmap(addr, 0);
1575}
1576EXPORT_SYMBOL(vunmap);
1577
1578/**
1579 * vmap - map an array of pages into virtually contiguous space
1580 * @pages: array of page pointers
1581 * @count: number of pages to map
1582 * @flags: vm_area->flags
1583 * @prot: page protection for the mapping
1584 *
1585 * Maps @count pages from @pages into contiguous kernel virtual
1586 * space.
1587 */
1588void *vmap(struct page **pages, unsigned int count,
1589 unsigned long flags, pgprot_t prot)
1590{
1591 struct vm_struct *area;
1592 unsigned long size; /* In bytes */
1593
1594 might_sleep();
1595
1596 if (count > totalram_pages)
1597 return NULL;
1598
1599 size = (unsigned long)count << PAGE_SHIFT;
1600 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
1601 if (!area)
1602 return NULL;
1603
1604 if (map_vm_area(area, prot, pages)) {
1605 vunmap(area->addr);
1606 return NULL;
1607 }
1608
1609 return area->addr;
1610}
1611EXPORT_SYMBOL(vmap);
1612
1613static void *__vmalloc_node(unsigned long size, unsigned long align,
1614 gfp_t gfp_mask, pgprot_t prot,
1615 int node, const void *caller);
1616static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1617 pgprot_t prot, int node)
1618{
1619 struct page **pages;
1620 unsigned int nr_pages, array_size, i;
1621 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1622 const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
1623
1624 nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
1625 array_size = (nr_pages * sizeof(struct page *));
1626
1627 area->nr_pages = nr_pages;
1628 /* Please note that the recursion is strictly bounded. */
1629 if (array_size > PAGE_SIZE) {
1630 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1631 PAGE_KERNEL, node, area->caller);
1632 } else {
1633 pages = kmalloc_node(array_size, nested_gfp, node);
1634 }
1635 area->pages = pages;
1636 if (!area->pages) {
1637 remove_vm_area(area->addr);
1638 kfree(area);
1639 return NULL;
1640 }
1641
1642 for (i = 0; i < area->nr_pages; i++) {
1643 struct page *page;
1644
1645 if (node == NUMA_NO_NODE)
1646 page = alloc_page(alloc_mask);
1647 else
1648 page = alloc_pages_node(node, alloc_mask, 0);
1649
1650 if (unlikely(!page)) {
1651 /* Successfully allocated i pages, free them in __vunmap() */
1652 area->nr_pages = i;
1653 goto fail;
1654 }
1655 area->pages[i] = page;
1656 if (gfpflags_allow_blocking(gfp_mask))
1657 cond_resched();
1658 }
1659
1660 if (map_vm_area(area, prot, pages))
1661 goto fail;
1662 return area->addr;
1663
1664fail:
1665 warn_alloc(gfp_mask,
1666 "vmalloc: allocation failure, allocated %ld of %ld bytes",
1667 (area->nr_pages*PAGE_SIZE), area->size);
1668 vfree(area->addr);
1669 return NULL;
1670}
1671
1672/**
1673 * __vmalloc_node_range - allocate virtually contiguous memory
1674 * @size: allocation size
1675 * @align: desired alignment
1676 * @start: vm area range start
1677 * @end: vm area range end
1678 * @gfp_mask: flags for the page level allocator
1679 * @prot: protection mask for the allocated pages
1680 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
1681 * @node: node to use for allocation or NUMA_NO_NODE
1682 * @caller: caller's return address
1683 *
1684 * Allocate enough pages to cover @size from the page level
1685 * allocator with @gfp_mask flags. Map them into contiguous
1686 * kernel virtual space, using a pagetable protection of @prot.
1687 */
1688void *__vmalloc_node_range(unsigned long size, unsigned long align,
1689 unsigned long start, unsigned long end, gfp_t gfp_mask,
1690 pgprot_t prot, unsigned long vm_flags, int node,
1691 const void *caller)
1692{
1693 struct vm_struct *area;
1694 void *addr;
1695 unsigned long real_size = size;
1696
1697 size = PAGE_ALIGN(size);
1698 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1699 goto fail;
1700
1701 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
1702 vm_flags, start, end, node, gfp_mask, caller);
1703 if (!area)
1704 goto fail;
1705
1706 addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1707 if (!addr)
1708 return NULL;
1709
1710 /*
1711 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
1712 * flag. It means that vm_struct is not fully initialized.
1713 * Now, it is fully initialized, so remove this flag here.
1714 */
1715 clear_vm_uninitialized_flag(area);
1716
1717 /*
1718 * A ref_count = 2 is needed because vm_struct allocated in
1719 * __get_vm_area_node() contains a reference to the virtual address of
1720 * the vmalloc'ed block.
1721 */
1722 kmemleak_alloc(addr, real_size, 2, gfp_mask);
1723
1724 return addr;
1725
1726fail:
1727 warn_alloc(gfp_mask,
1728 "vmalloc: allocation failure: %lu bytes", real_size);
1729 return NULL;
1730}
1731
1732/**
1733 * __vmalloc_node - allocate virtually contiguous memory
1734 * @size: allocation size
1735 * @align: desired alignment
1736 * @gfp_mask: flags for the page level allocator
1737 * @prot: protection mask for the allocated pages
1738 * @node: node to use for allocation or NUMA_NO_NODE
1739 * @caller: caller's return address
1740 *
1741 * Allocate enough pages to cover @size from the page level
1742 * allocator with @gfp_mask flags. Map them into contiguous
1743 * kernel virtual space, using a pagetable protection of @prot.
1744 */
1745static void *__vmalloc_node(unsigned long size, unsigned long align,
1746 gfp_t gfp_mask, pgprot_t prot,
1747 int node, const void *caller)
1748{
1749 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1750 gfp_mask, prot, 0, node, caller);
1751}
1752
1753void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1754{
1755 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1756 __builtin_return_address(0));
1757}
1758EXPORT_SYMBOL(__vmalloc);
1759
1760static inline void *__vmalloc_node_flags(unsigned long size,
1761 int node, gfp_t flags)
1762{
1763 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1764 node, __builtin_return_address(0));
1765}
1766
1767/**
1768 * vmalloc - allocate virtually contiguous memory
1769 * @size: allocation size
1770 * Allocate enough pages to cover @size from the page level
1771 * allocator and map them into contiguous kernel virtual space.
1772 *
1773 * For tight control over page level allocator and protection flags
1774 * use __vmalloc() instead.
1775 */
1776void *vmalloc(unsigned long size)
1777{
1778 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1779 GFP_KERNEL | __GFP_HIGHMEM);
1780}
1781EXPORT_SYMBOL(vmalloc);
1782
1783/**
1784 * vzalloc - allocate virtually contiguous memory with zero fill
1785 * @size: allocation size
1786 * Allocate enough pages to cover @size from the page level
1787 * allocator and map them into contiguous kernel virtual space.
1788 * The memory allocated is set to zero.
1789 *
1790 * For tight control over page level allocator and protection flags
1791 * use __vmalloc() instead.
1792 */
1793void *vzalloc(unsigned long size)
1794{
1795 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1796 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1797}
1798EXPORT_SYMBOL(vzalloc);
1799
1800/**
1801 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1802 * @size: allocation size
1803 *
1804 * The resulting memory area is zeroed so it can be mapped to userspace
1805 * without leaking data.
1806 */
1807void *vmalloc_user(unsigned long size)
1808{
1809 struct vm_struct *area;
1810 void *ret;
1811
1812 ret = __vmalloc_node(size, SHMLBA,
1813 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1814 PAGE_KERNEL, NUMA_NO_NODE,
1815 __builtin_return_address(0));
1816 if (ret) {
1817 area = find_vm_area(ret);
1818 area->flags |= VM_USERMAP;
1819 }
1820 return ret;
1821}
1822EXPORT_SYMBOL(vmalloc_user);
1823
1824/**
1825 * vmalloc_node - allocate memory on a specific node
1826 * @size: allocation size
1827 * @node: numa node
1828 *
1829 * Allocate enough pages to cover @size from the page level
1830 * allocator and map them into contiguous kernel virtual space.
1831 *
1832 * For tight control over page level allocator and protection flags
1833 * use __vmalloc() instead.
1834 */
1835void *vmalloc_node(unsigned long size, int node)
1836{
1837 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1838 node, __builtin_return_address(0));
1839}
1840EXPORT_SYMBOL(vmalloc_node);
1841
1842/**
1843 * vzalloc_node - allocate memory on a specific node with zero fill
1844 * @size: allocation size
1845 * @node: numa node
1846 *
1847 * Allocate enough pages to cover @size from the page level
1848 * allocator and map them into contiguous kernel virtual space.
1849 * The memory allocated is set to zero.
1850 *
1851 * For tight control over page level allocator and protection flags
1852 * use __vmalloc_node() instead.
1853 */
1854void *vzalloc_node(unsigned long size, int node)
1855{
1856 return __vmalloc_node_flags(size, node,
1857 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1858}
1859EXPORT_SYMBOL(vzalloc_node);
1860
1861#ifndef PAGE_KERNEL_EXEC
1862# define PAGE_KERNEL_EXEC PAGE_KERNEL
1863#endif
1864
1865/**
1866 * vmalloc_exec - allocate virtually contiguous, executable memory
1867 * @size: allocation size
1868 *
1869 * Kernel-internal function to allocate enough pages to cover @size
1870 * the page level allocator and map them into contiguous and
1871 * executable kernel virtual space.
1872 *
1873 * For tight control over page level allocator and protection flags
1874 * use __vmalloc() instead.
1875 */
1876
1877void *vmalloc_exec(unsigned long size)
1878{
1879 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1880 NUMA_NO_NODE, __builtin_return_address(0));
1881}
1882
1883#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1884#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1885#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1886#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1887#else
1888#define GFP_VMALLOC32 GFP_KERNEL
1889#endif
1890
1891/**
1892 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1893 * @size: allocation size
1894 *
1895 * Allocate enough 32bit PA addressable pages to cover @size from the
1896 * page level allocator and map them into contiguous kernel virtual space.
1897 */
1898void *vmalloc_32(unsigned long size)
1899{
1900 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1901 NUMA_NO_NODE, __builtin_return_address(0));
1902}
1903EXPORT_SYMBOL(vmalloc_32);
1904
1905/**
1906 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1907 * @size: allocation size
1908 *
1909 * The resulting memory area is 32bit addressable and zeroed so it can be
1910 * mapped to userspace without leaking data.
1911 */
1912void *vmalloc_32_user(unsigned long size)
1913{
1914 struct vm_struct *area;
1915 void *ret;
1916
1917 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1918 NUMA_NO_NODE, __builtin_return_address(0));
1919 if (ret) {
1920 area = find_vm_area(ret);
1921 area->flags |= VM_USERMAP;
1922 }
1923 return ret;
1924}
1925EXPORT_SYMBOL(vmalloc_32_user);
1926
1927/*
1928 * small helper routine , copy contents to buf from addr.
1929 * If the page is not present, fill zero.
1930 */
1931
1932static int aligned_vread(char *buf, char *addr, unsigned long count)
1933{
1934 struct page *p;
1935 int copied = 0;
1936
1937 while (count) {
1938 unsigned long offset, length;
1939
1940 offset = offset_in_page(addr);
1941 length = PAGE_SIZE - offset;
1942 if (length > count)
1943 length = count;
1944 p = vmalloc_to_page(addr);
1945 /*
1946 * To do safe access to this _mapped_ area, we need
1947 * lock. But adding lock here means that we need to add
1948 * overhead of vmalloc()/vfree() calles for this _debug_
1949 * interface, rarely used. Instead of that, we'll use
1950 * kmap() and get small overhead in this access function.
1951 */
1952 if (p) {
1953 /*
1954 * we can expect USER0 is not used (see vread/vwrite's
1955 * function description)
1956 */
1957 void *map = kmap_atomic(p);
1958 memcpy(buf, map + offset, length);
1959 kunmap_atomic(map);
1960 } else
1961 memset(buf, 0, length);
1962
1963 addr += length;
1964 buf += length;
1965 copied += length;
1966 count -= length;
1967 }
1968 return copied;
1969}
1970
1971static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1972{
1973 struct page *p;
1974 int copied = 0;
1975
1976 while (count) {
1977 unsigned long offset, length;
1978
1979 offset = offset_in_page(addr);
1980 length = PAGE_SIZE - offset;
1981 if (length > count)
1982 length = count;
1983 p = vmalloc_to_page(addr);
1984 /*
1985 * To do safe access to this _mapped_ area, we need
1986 * lock. But adding lock here means that we need to add
1987 * overhead of vmalloc()/vfree() calles for this _debug_
1988 * interface, rarely used. Instead of that, we'll use
1989 * kmap() and get small overhead in this access function.
1990 */
1991 if (p) {
1992 /*
1993 * we can expect USER0 is not used (see vread/vwrite's
1994 * function description)
1995 */
1996 void *map = kmap_atomic(p);
1997 memcpy(map + offset, buf, length);
1998 kunmap_atomic(map);
1999 }
2000 addr += length;
2001 buf += length;
2002 copied += length;
2003 count -= length;
2004 }
2005 return copied;
2006}
2007
2008/**
2009 * vread() - read vmalloc area in a safe way.
2010 * @buf: buffer for reading data
2011 * @addr: vm address.
2012 * @count: number of bytes to be read.
2013 *
2014 * Returns # of bytes which addr and buf should be increased.
2015 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
2016 * includes any intersect with alive vmalloc area.
2017 *
2018 * This function checks that addr is a valid vmalloc'ed area, and
2019 * copy data from that area to a given buffer. If the given memory range
2020 * of [addr...addr+count) includes some valid address, data is copied to
2021 * proper area of @buf. If there are memory holes, they'll be zero-filled.
2022 * IOREMAP area is treated as memory hole and no copy is done.
2023 *
2024 * If [addr...addr+count) doesn't includes any intersects with alive
2025 * vm_struct area, returns 0. @buf should be kernel's buffer.
2026 *
2027 * Note: In usual ops, vread() is never necessary because the caller
2028 * should know vmalloc() area is valid and can use memcpy().
2029 * This is for routines which have to access vmalloc area without
2030 * any informaion, as /dev/kmem.
2031 *
2032 */
2033
2034long vread(char *buf, char *addr, unsigned long count)
2035{
2036 struct vmap_area *va;
2037 struct vm_struct *vm;
2038 char *vaddr, *buf_start = buf;
2039 unsigned long buflen = count;
2040 unsigned long n;
2041
2042 /* Don't allow overflow */
2043 if ((unsigned long) addr + count < count)
2044 count = -(unsigned long) addr;
2045
2046 spin_lock(&vmap_area_lock);
2047 list_for_each_entry(va, &vmap_area_list, list) {
2048 if (!count)
2049 break;
2050
2051 if (!(va->flags & VM_VM_AREA))
2052 continue;
2053
2054 vm = va->vm;
2055 vaddr = (char *) vm->addr;
2056 if (addr >= vaddr + get_vm_area_size(vm))
2057 continue;
2058 while (addr < vaddr) {
2059 if (count == 0)
2060 goto finished;
2061 *buf = '\0';
2062 buf++;
2063 addr++;
2064 count--;
2065 }
2066 n = vaddr + get_vm_area_size(vm) - addr;
2067 if (n > count)
2068 n = count;
2069 if (!(vm->flags & VM_IOREMAP))
2070 aligned_vread(buf, addr, n);
2071 else /* IOREMAP area is treated as memory hole */
2072 memset(buf, 0, n);
2073 buf += n;
2074 addr += n;
2075 count -= n;
2076 }
2077finished:
2078 spin_unlock(&vmap_area_lock);
2079
2080 if (buf == buf_start)
2081 return 0;
2082 /* zero-fill memory holes */
2083 if (buf != buf_start + buflen)
2084 memset(buf, 0, buflen - (buf - buf_start));
2085
2086 return buflen;
2087}
2088
2089/**
2090 * vwrite() - write vmalloc area in a safe way.
2091 * @buf: buffer for source data
2092 * @addr: vm address.
2093 * @count: number of bytes to be read.
2094 *
2095 * Returns # of bytes which addr and buf should be incresed.
2096 * (same number to @count).
2097 * If [addr...addr+count) doesn't includes any intersect with valid
2098 * vmalloc area, returns 0.
2099 *
2100 * This function checks that addr is a valid vmalloc'ed area, and
2101 * copy data from a buffer to the given addr. If specified range of
2102 * [addr...addr+count) includes some valid address, data is copied from
2103 * proper area of @buf. If there are memory holes, no copy to hole.
2104 * IOREMAP area is treated as memory hole and no copy is done.
2105 *
2106 * If [addr...addr+count) doesn't includes any intersects with alive
2107 * vm_struct area, returns 0. @buf should be kernel's buffer.
2108 *
2109 * Note: In usual ops, vwrite() is never necessary because the caller
2110 * should know vmalloc() area is valid and can use memcpy().
2111 * This is for routines which have to access vmalloc area without
2112 * any informaion, as /dev/kmem.
2113 */
2114
2115long vwrite(char *buf, char *addr, unsigned long count)
2116{
2117 struct vmap_area *va;
2118 struct vm_struct *vm;
2119 char *vaddr;
2120 unsigned long n, buflen;
2121 int copied = 0;
2122
2123 /* Don't allow overflow */
2124 if ((unsigned long) addr + count < count)
2125 count = -(unsigned long) addr;
2126 buflen = count;
2127
2128 spin_lock(&vmap_area_lock);
2129 list_for_each_entry(va, &vmap_area_list, list) {
2130 if (!count)
2131 break;
2132
2133 if (!(va->flags & VM_VM_AREA))
2134 continue;
2135
2136 vm = va->vm;
2137 vaddr = (char *) vm->addr;
2138 if (addr >= vaddr + get_vm_area_size(vm))
2139 continue;
2140 while (addr < vaddr) {
2141 if (count == 0)
2142 goto finished;
2143 buf++;
2144 addr++;
2145 count--;
2146 }
2147 n = vaddr + get_vm_area_size(vm) - addr;
2148 if (n > count)
2149 n = count;
2150 if (!(vm->flags & VM_IOREMAP)) {
2151 aligned_vwrite(buf, addr, n);
2152 copied++;
2153 }
2154 buf += n;
2155 addr += n;
2156 count -= n;
2157 }
2158finished:
2159 spin_unlock(&vmap_area_lock);
2160 if (!copied)
2161 return 0;
2162 return buflen;
2163}
2164
2165/**
2166 * remap_vmalloc_range_partial - map vmalloc pages to userspace
2167 * @vma: vma to cover
2168 * @uaddr: target user address to start at
2169 * @kaddr: virtual address of vmalloc kernel memory
2170 * @size: size of map area
2171 *
2172 * Returns: 0 for success, -Exxx on failure
2173 *
2174 * This function checks that @kaddr is a valid vmalloc'ed area,
2175 * and that it is big enough to cover the range starting at
2176 * @uaddr in @vma. Will return failure if that criteria isn't
2177 * met.
2178 *
2179 * Similar to remap_pfn_range() (see mm/memory.c)
2180 */
2181int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2182 void *kaddr, unsigned long size)
2183{
2184 struct vm_struct *area;
2185
2186 size = PAGE_ALIGN(size);
2187
2188 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2189 return -EINVAL;
2190
2191 area = find_vm_area(kaddr);
2192 if (!area)
2193 return -EINVAL;
2194
2195 if (!(area->flags & VM_USERMAP))
2196 return -EINVAL;
2197
2198 if (kaddr + size > area->addr + area->size)
2199 return -EINVAL;
2200
2201 do {
2202 struct page *page = vmalloc_to_page(kaddr);
2203 int ret;
2204
2205 ret = vm_insert_page(vma, uaddr, page);
2206 if (ret)
2207 return ret;
2208
2209 uaddr += PAGE_SIZE;
2210 kaddr += PAGE_SIZE;
2211 size -= PAGE_SIZE;
2212 } while (size > 0);
2213
2214 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2215
2216 return 0;
2217}
2218EXPORT_SYMBOL(remap_vmalloc_range_partial);
2219
2220/**
2221 * remap_vmalloc_range - map vmalloc pages to userspace
2222 * @vma: vma to cover (map full range of vma)
2223 * @addr: vmalloc memory
2224 * @pgoff: number of pages into addr before first page to map
2225 *
2226 * Returns: 0 for success, -Exxx on failure
2227 *
2228 * This function checks that addr is a valid vmalloc'ed area, and
2229 * that it is big enough to cover the vma. Will return failure if
2230 * that criteria isn't met.
2231 *
2232 * Similar to remap_pfn_range() (see mm/memory.c)
2233 */
2234int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2235 unsigned long pgoff)
2236{
2237 return remap_vmalloc_range_partial(vma, vma->vm_start,
2238 addr + (pgoff << PAGE_SHIFT),
2239 vma->vm_end - vma->vm_start);
2240}
2241EXPORT_SYMBOL(remap_vmalloc_range);
2242
2243/*
2244 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2245 * have one.
2246 */
2247void __weak vmalloc_sync_all(void)
2248{
2249}
2250
2251
2252static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2253{
2254 pte_t ***p = data;
2255
2256 if (p) {
2257 *(*p) = pte;
2258 (*p)++;
2259 }
2260 return 0;
2261}
2262
2263/**
2264 * alloc_vm_area - allocate a range of kernel address space
2265 * @size: size of the area
2266 * @ptes: returns the PTEs for the address space
2267 *
2268 * Returns: NULL on failure, vm_struct on success
2269 *
2270 * This function reserves a range of kernel address space, and
2271 * allocates pagetables to map that range. No actual mappings
2272 * are created.
2273 *
2274 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2275 * allocated for the VM area are returned.
2276 */
2277struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2278{
2279 struct vm_struct *area;
2280
2281 area = get_vm_area_caller(size, VM_IOREMAP,
2282 __builtin_return_address(0));
2283 if (area == NULL)
2284 return NULL;
2285
2286 /*
2287 * This ensures that page tables are constructed for this region
2288 * of kernel virtual address space and mapped into init_mm.
2289 */
2290 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2291 size, f, ptes ? &ptes : NULL)) {
2292 free_vm_area(area);
2293 return NULL;
2294 }
2295
2296 return area;
2297}
2298EXPORT_SYMBOL_GPL(alloc_vm_area);
2299
2300void free_vm_area(struct vm_struct *area)
2301{
2302 struct vm_struct *ret;
2303 ret = remove_vm_area(area->addr);
2304 BUG_ON(ret != area);
2305 kfree(area);
2306}
2307EXPORT_SYMBOL_GPL(free_vm_area);
2308
2309#ifdef CONFIG_SMP
2310static struct vmap_area *node_to_va(struct rb_node *n)
2311{
2312 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2313}
2314
2315/**
2316 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2317 * @end: target address
2318 * @pnext: out arg for the next vmap_area
2319 * @pprev: out arg for the previous vmap_area
2320 *
2321 * Returns: %true if either or both of next and prev are found,
2322 * %false if no vmap_area exists
2323 *
2324 * Find vmap_areas end addresses of which enclose @end. ie. if not
2325 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2326 */
2327static bool pvm_find_next_prev(unsigned long end,
2328 struct vmap_area **pnext,
2329 struct vmap_area **pprev)
2330{
2331 struct rb_node *n = vmap_area_root.rb_node;
2332 struct vmap_area *va = NULL;
2333
2334 while (n) {
2335 va = rb_entry(n, struct vmap_area, rb_node);
2336 if (end < va->va_end)
2337 n = n->rb_left;
2338 else if (end > va->va_end)
2339 n = n->rb_right;
2340 else
2341 break;
2342 }
2343
2344 if (!va)
2345 return false;
2346
2347 if (va->va_end > end) {
2348 *pnext = va;
2349 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2350 } else {
2351 *pprev = va;
2352 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2353 }
2354 return true;
2355}
2356
2357/**
2358 * pvm_determine_end - find the highest aligned address between two vmap_areas
2359 * @pnext: in/out arg for the next vmap_area
2360 * @pprev: in/out arg for the previous vmap_area
2361 * @align: alignment
2362 *
2363 * Returns: determined end address
2364 *
2365 * Find the highest aligned address between *@pnext and *@pprev below
2366 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2367 * down address is between the end addresses of the two vmap_areas.
2368 *
2369 * Please note that the address returned by this function may fall
2370 * inside *@pnext vmap_area. The caller is responsible for checking
2371 * that.
2372 */
2373static unsigned long pvm_determine_end(struct vmap_area **pnext,
2374 struct vmap_area **pprev,
2375 unsigned long align)
2376{
2377 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2378 unsigned long addr;
2379
2380 if (*pnext)
2381 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2382 else
2383 addr = vmalloc_end;
2384
2385 while (*pprev && (*pprev)->va_end > addr) {
2386 *pnext = *pprev;
2387 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2388 }
2389
2390 return addr;
2391}
2392
2393/**
2394 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2395 * @offsets: array containing offset of each area
2396 * @sizes: array containing size of each area
2397 * @nr_vms: the number of areas to allocate
2398 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2399 *
2400 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2401 * vm_structs on success, %NULL on failure
2402 *
2403 * Percpu allocator wants to use congruent vm areas so that it can
2404 * maintain the offsets among percpu areas. This function allocates
2405 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2406 * be scattered pretty far, distance between two areas easily going up
2407 * to gigabytes. To avoid interacting with regular vmallocs, these
2408 * areas are allocated from top.
2409 *
2410 * Despite its complicated look, this allocator is rather simple. It
2411 * does everything top-down and scans areas from the end looking for
2412 * matching slot. While scanning, if any of the areas overlaps with
2413 * existing vmap_area, the base address is pulled down to fit the
2414 * area. Scanning is repeated till all the areas fit and then all
2415 * necessary data structres are inserted and the result is returned.
2416 */
2417struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2418 const size_t *sizes, int nr_vms,
2419 size_t align)
2420{
2421 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2422 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2423 struct vmap_area **vas, *prev, *next;
2424 struct vm_struct **vms;
2425 int area, area2, last_area, term_area;
2426 unsigned long base, start, end, last_end;
2427 bool purged = false;
2428
2429 /* verify parameters and allocate data structures */
2430 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
2431 for (last_area = 0, area = 0; area < nr_vms; area++) {
2432 start = offsets[area];
2433 end = start + sizes[area];
2434
2435 /* is everything aligned properly? */
2436 BUG_ON(!IS_ALIGNED(offsets[area], align));
2437 BUG_ON(!IS_ALIGNED(sizes[area], align));
2438
2439 /* detect the area with the highest address */
2440 if (start > offsets[last_area])
2441 last_area = area;
2442
2443 for (area2 = 0; area2 < nr_vms; area2++) {
2444 unsigned long start2 = offsets[area2];
2445 unsigned long end2 = start2 + sizes[area2];
2446
2447 if (area2 == area)
2448 continue;
2449
2450 BUG_ON(start2 >= start && start2 < end);
2451 BUG_ON(end2 <= end && end2 > start);
2452 }
2453 }
2454 last_end = offsets[last_area] + sizes[last_area];
2455
2456 if (vmalloc_end - vmalloc_start < last_end) {
2457 WARN_ON(true);
2458 return NULL;
2459 }
2460
2461 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2462 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2463 if (!vas || !vms)
2464 goto err_free2;
2465
2466 for (area = 0; area < nr_vms; area++) {
2467 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2468 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2469 if (!vas[area] || !vms[area])
2470 goto err_free;
2471 }
2472retry:
2473 spin_lock(&vmap_area_lock);
2474
2475 /* start scanning - we scan from the top, begin with the last area */
2476 area = term_area = last_area;
2477 start = offsets[area];
2478 end = start + sizes[area];
2479
2480 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2481 base = vmalloc_end - last_end;
2482 goto found;
2483 }
2484 base = pvm_determine_end(&next, &prev, align) - end;
2485
2486 while (true) {
2487 BUG_ON(next && next->va_end <= base + end);
2488 BUG_ON(prev && prev->va_end > base + end);
2489
2490 /*
2491 * base might have underflowed, add last_end before
2492 * comparing.
2493 */
2494 if (base + last_end < vmalloc_start + last_end) {
2495 spin_unlock(&vmap_area_lock);
2496 if (!purged) {
2497 purge_vmap_area_lazy();
2498 purged = true;
2499 goto retry;
2500 }
2501 goto err_free;
2502 }
2503
2504 /*
2505 * If next overlaps, move base downwards so that it's
2506 * right below next and then recheck.
2507 */
2508 if (next && next->va_start < base + end) {
2509 base = pvm_determine_end(&next, &prev, align) - end;
2510 term_area = area;
2511 continue;
2512 }
2513
2514 /*
2515 * If prev overlaps, shift down next and prev and move
2516 * base so that it's right below new next and then
2517 * recheck.
2518 */
2519 if (prev && prev->va_end > base + start) {
2520 next = prev;
2521 prev = node_to_va(rb_prev(&next->rb_node));
2522 base = pvm_determine_end(&next, &prev, align) - end;
2523 term_area = area;
2524 continue;
2525 }
2526
2527 /*
2528 * This area fits, move on to the previous one. If
2529 * the previous one is the terminal one, we're done.
2530 */
2531 area = (area + nr_vms - 1) % nr_vms;
2532 if (area == term_area)
2533 break;
2534 start = offsets[area];
2535 end = start + sizes[area];
2536 pvm_find_next_prev(base + end, &next, &prev);
2537 }
2538found:
2539 /* we've found a fitting base, insert all va's */
2540 for (area = 0; area < nr_vms; area++) {
2541 struct vmap_area *va = vas[area];
2542
2543 va->va_start = base + offsets[area];
2544 va->va_end = va->va_start + sizes[area];
2545 __insert_vmap_area(va);
2546 }
2547
2548 vmap_area_pcpu_hole = base + offsets[last_area];
2549
2550 spin_unlock(&vmap_area_lock);
2551
2552 /* insert all vm's */
2553 for (area = 0; area < nr_vms; area++)
2554 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2555 pcpu_get_vm_areas);
2556
2557 kfree(vas);
2558 return vms;
2559
2560err_free:
2561 for (area = 0; area < nr_vms; area++) {
2562 kfree(vas[area]);
2563 kfree(vms[area]);
2564 }
2565err_free2:
2566 kfree(vas);
2567 kfree(vms);
2568 return NULL;
2569}
2570
2571/**
2572 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2573 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2574 * @nr_vms: the number of allocated areas
2575 *
2576 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2577 */
2578void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2579{
2580 int i;
2581
2582 for (i = 0; i < nr_vms; i++)
2583 free_vm_area(vms[i]);
2584 kfree(vms);
2585}
2586#endif /* CONFIG_SMP */
2587
2588#ifdef CONFIG_PROC_FS
2589static void *s_start(struct seq_file *m, loff_t *pos)
2590 __acquires(&vmap_area_lock)
2591{
2592 spin_lock(&vmap_area_lock);
2593 return seq_list_start(&vmap_area_list, *pos);
2594}
2595
2596static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2597{
2598 return seq_list_next(p, &vmap_area_list, pos);
2599}
2600
2601static void s_stop(struct seq_file *m, void *p)
2602 __releases(&vmap_area_lock)
2603{
2604 spin_unlock(&vmap_area_lock);
2605}
2606
2607static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2608{
2609 if (IS_ENABLED(CONFIG_NUMA)) {
2610 unsigned int nr, *counters = m->private;
2611
2612 if (!counters)
2613 return;
2614
2615 if (v->flags & VM_UNINITIALIZED)
2616 return;
2617 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
2618 smp_rmb();
2619
2620 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2621
2622 for (nr = 0; nr < v->nr_pages; nr++)
2623 counters[page_to_nid(v->pages[nr])]++;
2624
2625 for_each_node_state(nr, N_HIGH_MEMORY)
2626 if (counters[nr])
2627 seq_printf(m, " N%u=%u", nr, counters[nr]);
2628 }
2629}
2630
2631static int s_show(struct seq_file *m, void *p)
2632{
2633 struct vmap_area *va;
2634 struct vm_struct *v;
2635
2636 va = list_entry(p, struct vmap_area, list);
2637
2638 /*
2639 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
2640 * behalf of vmap area is being tear down or vm_map_ram allocation.
2641 */
2642 if (!(va->flags & VM_VM_AREA))
2643 return 0;
2644
2645 v = va->vm;
2646
2647 seq_printf(m, "0x%pK-0x%pK %7ld",
2648 v->addr, v->addr + v->size, v->size);
2649
2650 if (v->caller)
2651 seq_printf(m, " %pS", v->caller);
2652
2653 if (v->nr_pages)
2654 seq_printf(m, " pages=%d", v->nr_pages);
2655
2656 if (v->phys_addr)
2657 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2658
2659 if (v->flags & VM_IOREMAP)
2660 seq_puts(m, " ioremap");
2661
2662 if (v->flags & VM_ALLOC)
2663 seq_puts(m, " vmalloc");
2664
2665 if (v->flags & VM_MAP)
2666 seq_puts(m, " vmap");
2667
2668 if (v->flags & VM_USERMAP)
2669 seq_puts(m, " user");
2670
2671 if (is_vmalloc_addr(v->pages))
2672 seq_puts(m, " vpages");
2673
2674 show_numa_info(m, v);
2675 seq_putc(m, '\n');
2676 return 0;
2677}
2678
2679static const struct seq_operations vmalloc_op = {
2680 .start = s_start,
2681 .next = s_next,
2682 .stop = s_stop,
2683 .show = s_show,
2684};
2685
2686static int vmalloc_open(struct inode *inode, struct file *file)
2687{
2688 if (IS_ENABLED(CONFIG_NUMA))
2689 return seq_open_private(file, &vmalloc_op,
2690 nr_node_ids * sizeof(unsigned int));
2691 else
2692 return seq_open(file, &vmalloc_op);
2693}
2694
2695static const struct file_operations proc_vmalloc_operations = {
2696 .open = vmalloc_open,
2697 .read = seq_read,
2698 .llseek = seq_lseek,
2699 .release = seq_release_private,
2700};
2701
2702static int __init proc_vmalloc_init(void)
2703{
2704 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2705 return 0;
2706}
2707module_init(proc_vmalloc_init);
2708
2709#endif
2710