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/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/interrupt.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/debugobjects.h>
21 #include <linux/kallsyms.h>
22 #include <linux/list.h>
23 #include <linux/rbtree.h>
24 #include <linux/radix-tree.h>
25 #include <linux/rcupdate.h>
26 #include <linux/pfn.h>
27 #include <linux/kmemleak.h>
28
29 #include <asm/atomic.h>
30 #include <asm/uaccess.h>
31 #include <asm/tlbflush.h>
32
33
34 /*** Page table manipulation functions ***/
35
36 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
37 {
38 pte_t *pte;
39
40 pte = pte_offset_kernel(pmd, addr);
41 do {
42 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
43 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
44 } while (pte++, addr += PAGE_SIZE, addr != end);
45 }
46
47 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
48 {
49 pmd_t *pmd;
50 unsigned long next;
51
52 pmd = pmd_offset(pud, addr);
53 do {
54 next = pmd_addr_end(addr, end);
55 if (pmd_none_or_clear_bad(pmd))
56 continue;
57 vunmap_pte_range(pmd, addr, next);
58 } while (pmd++, addr = next, addr != end);
59 }
60
61 static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
62 {
63 pud_t *pud;
64 unsigned long next;
65
66 pud = pud_offset(pgd, addr);
67 do {
68 next = pud_addr_end(addr, end);
69 if (pud_none_or_clear_bad(pud))
70 continue;
71 vunmap_pmd_range(pud, addr, next);
72 } while (pud++, addr = next, addr != end);
73 }
74
75 static void vunmap_page_range(unsigned long addr, unsigned long end)
76 {
77 pgd_t *pgd;
78 unsigned long next;
79
80 BUG_ON(addr >= end);
81 pgd = pgd_offset_k(addr);
82 do {
83 next = pgd_addr_end(addr, end);
84 if (pgd_none_or_clear_bad(pgd))
85 continue;
86 vunmap_pud_range(pgd, addr, next);
87 } while (pgd++, addr = next, addr != end);
88 }
89
90 static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
91 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
92 {
93 pte_t *pte;
94
95 /*
96 * nr is a running index into the array which helps higher level
97 * callers keep track of where we're up to.
98 */
99
100 pte = pte_alloc_kernel(pmd, addr);
101 if (!pte)
102 return -ENOMEM;
103 do {
104 struct page *page = pages[*nr];
105
106 if (WARN_ON(!pte_none(*pte)))
107 return -EBUSY;
108 if (WARN_ON(!page))
109 return -ENOMEM;
110 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
111 (*nr)++;
112 } while (pte++, addr += PAGE_SIZE, addr != end);
113 return 0;
114 }
115
116 static int vmap_pmd_range(pud_t *pud, unsigned long addr,
117 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
118 {
119 pmd_t *pmd;
120 unsigned long next;
121
122 pmd = pmd_alloc(&init_mm, pud, addr);
123 if (!pmd)
124 return -ENOMEM;
125 do {
126 next = pmd_addr_end(addr, end);
127 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
128 return -ENOMEM;
129 } while (pmd++, addr = next, addr != end);
130 return 0;
131 }
132
133 static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
134 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
135 {
136 pud_t *pud;
137 unsigned long next;
138
139 pud = pud_alloc(&init_mm, pgd, addr);
140 if (!pud)
141 return -ENOMEM;
142 do {
143 next = pud_addr_end(addr, end);
144 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
145 return -ENOMEM;
146 } while (pud++, addr = next, addr != end);
147 return 0;
148 }
149
150 /*
151 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
152 * will have pfns corresponding to the "pages" array.
153 *
154 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
155 */
156 static int vmap_page_range_noflush(unsigned long start, unsigned long end,
157 pgprot_t prot, struct page **pages)
158 {
159 pgd_t *pgd;
160 unsigned long next;
161 unsigned long addr = start;
162 int err = 0;
163 int nr = 0;
164
165 BUG_ON(addr >= end);
166 pgd = pgd_offset_k(addr);
167 do {
168 next = pgd_addr_end(addr, end);
169 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
170 if (err)
171 break;
172 } while (pgd++, addr = next, addr != end);
173
174 if (unlikely(err))
175 return err;
176 return nr;
177 }
178
179 static int vmap_page_range(unsigned long start, unsigned long end,
180 pgprot_t prot, struct page **pages)
181 {
182 int ret;
183
184 ret = vmap_page_range_noflush(start, end, prot, pages);
185 flush_cache_vmap(start, end);
186 return ret;
187 }
188
189 static inline int is_vmalloc_or_module_addr(const void *x)
190 {
191 /*
192 * ARM, x86-64 and sparc64 put modules in a special place,
193 * and fall back on vmalloc() if that fails. Others
194 * just put it in the vmalloc space.
195 */
196 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
197 unsigned long addr = (unsigned long)x;
198 if (addr >= MODULES_VADDR && addr < MODULES_END)
199 return 1;
200 #endif
201 return is_vmalloc_addr(x);
202 }
203
204 /*
205 * Walk a vmap address to the struct page it maps.
206 */
207 struct page *vmalloc_to_page(const void *vmalloc_addr)
208 {
209 unsigned long addr = (unsigned long) vmalloc_addr;
210 struct page *page = NULL;
211 pgd_t *pgd = pgd_offset_k(addr);
212
213 /*
214 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
215 * architectures that do not vmalloc module space
216 */
217 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
218
219 if (!pgd_none(*pgd)) {
220 pud_t *pud = pud_offset(pgd, addr);
221 if (!pud_none(*pud)) {
222 pmd_t *pmd = pmd_offset(pud, addr);
223 if (!pmd_none(*pmd)) {
224 pte_t *ptep, pte;
225
226 ptep = pte_offset_map(pmd, addr);
227 pte = *ptep;
228 if (pte_present(pte))
229 page = pte_page(pte);
230 pte_unmap(ptep);
231 }
232 }
233 }
234 return page;
235 }
236 EXPORT_SYMBOL(vmalloc_to_page);
237
238 /*
239 * Map a vmalloc()-space virtual address to the physical page frame number.
240 */
241 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
242 {
243 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
244 }
245 EXPORT_SYMBOL(vmalloc_to_pfn);
246
247
248 /*** Global kva allocator ***/
249
250 #define VM_LAZY_FREE 0x01
251 #define VM_LAZY_FREEING 0x02
252 #define VM_VM_AREA 0x04
253
254 struct vmap_area {
255 unsigned long va_start;
256 unsigned long va_end;
257 unsigned long flags;
258 struct rb_node rb_node; /* address sorted rbtree */
259 struct list_head list; /* address sorted list */
260 struct list_head purge_list; /* "lazy purge" list */
261 void *private;
262 struct rcu_head rcu_head;
263 };
264
265 static DEFINE_SPINLOCK(vmap_area_lock);
266 static struct rb_root vmap_area_root = RB_ROOT;
267 static LIST_HEAD(vmap_area_list);
268
269 static struct vmap_area *__find_vmap_area(unsigned long addr)
270 {
271 struct rb_node *n = vmap_area_root.rb_node;
272
273 while (n) {
274 struct vmap_area *va;
275
276 va = rb_entry(n, struct vmap_area, rb_node);
277 if (addr < va->va_start)
278 n = n->rb_left;
279 else if (addr > va->va_start)
280 n = n->rb_right;
281 else
282 return va;
283 }
284
285 return NULL;
286 }
287
288 static void __insert_vmap_area(struct vmap_area *va)
289 {
290 struct rb_node **p = &vmap_area_root.rb_node;
291 struct rb_node *parent = NULL;
292 struct rb_node *tmp;
293
294 while (*p) {
295 struct vmap_area *tmp;
296
297 parent = *p;
298 tmp = rb_entry(parent, struct vmap_area, rb_node);
299 if (va->va_start < tmp->va_end)
300 p = &(*p)->rb_left;
301 else if (va->va_end > tmp->va_start)
302 p = &(*p)->rb_right;
303 else
304 BUG();
305 }
306
307 rb_link_node(&va->rb_node, parent, p);
308 rb_insert_color(&va->rb_node, &vmap_area_root);
309
310 /* address-sort this list so it is usable like the vmlist */
311 tmp = rb_prev(&va->rb_node);
312 if (tmp) {
313 struct vmap_area *prev;
314 prev = rb_entry(tmp, struct vmap_area, rb_node);
315 list_add_rcu(&va->list, &prev->list);
316 } else
317 list_add_rcu(&va->list, &vmap_area_list);
318 }
319
320 static void purge_vmap_area_lazy(void);
321
322 /*
323 * Allocate a region of KVA of the specified size and alignment, within the
324 * vstart and vend.
325 */
326 static struct vmap_area *alloc_vmap_area(unsigned long size,
327 unsigned long align,
328 unsigned long vstart, unsigned long vend,
329 int node, gfp_t gfp_mask)
330 {
331 struct vmap_area *va;
332 struct rb_node *n;
333 unsigned long addr;
334 int purged = 0;
335
336 BUG_ON(!size);
337 BUG_ON(size & ~PAGE_MASK);
338
339 va = kmalloc_node(sizeof(struct vmap_area),
340 gfp_mask & GFP_RECLAIM_MASK, node);
341 if (unlikely(!va))
342 return ERR_PTR(-ENOMEM);
343
344 retry:
345 addr = ALIGN(vstart, align);
346
347 spin_lock(&vmap_area_lock);
348 if (addr + size - 1 < addr)
349 goto overflow;
350
351 /* XXX: could have a last_hole cache */
352 n = vmap_area_root.rb_node;
353 if (n) {
354 struct vmap_area *first = NULL;
355
356 do {
357 struct vmap_area *tmp;
358 tmp = rb_entry(n, struct vmap_area, rb_node);
359 if (tmp->va_end >= addr) {
360 if (!first && tmp->va_start < addr + size)
361 first = tmp;
362 n = n->rb_left;
363 } else {
364 first = tmp;
365 n = n->rb_right;
366 }
367 } while (n);
368
369 if (!first)
370 goto found;
371
372 if (first->va_end < addr) {
373 n = rb_next(&first->rb_node);
374 if (n)
375 first = rb_entry(n, struct vmap_area, rb_node);
376 else
377 goto found;
378 }
379
380 while (addr + size > first->va_start && addr + size <= vend) {
381 addr = ALIGN(first->va_end + PAGE_SIZE, align);
382 if (addr + size - 1 < addr)
383 goto overflow;
384
385 n = rb_next(&first->rb_node);
386 if (n)
387 first = rb_entry(n, struct vmap_area, rb_node);
388 else
389 goto found;
390 }
391 }
392 found:
393 if (addr + size > vend) {
394 overflow:
395 spin_unlock(&vmap_area_lock);
396 if (!purged) {
397 purge_vmap_area_lazy();
398 purged = 1;
399 goto retry;
400 }
401 if (printk_ratelimit())
402 printk(KERN_WARNING
403 "vmap allocation for size %lu failed: "
404 "use vmalloc=<size> to increase size.\n", size);
405 kfree(va);
406 return ERR_PTR(-EBUSY);
407 }
408
409 BUG_ON(addr & (align-1));
410
411 va->va_start = addr;
412 va->va_end = addr + size;
413 va->flags = 0;
414 __insert_vmap_area(va);
415 spin_unlock(&vmap_area_lock);
416
417 return va;
418 }
419
420 static void rcu_free_va(struct rcu_head *head)
421 {
422 struct vmap_area *va = container_of(head, struct vmap_area, rcu_head);
423
424 kfree(va);
425 }
426
427 static void __free_vmap_area(struct vmap_area *va)
428 {
429 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
430 rb_erase(&va->rb_node, &vmap_area_root);
431 RB_CLEAR_NODE(&va->rb_node);
432 list_del_rcu(&va->list);
433
434 call_rcu(&va->rcu_head, rcu_free_va);
435 }
436
437 /*
438 * Free a region of KVA allocated by alloc_vmap_area
439 */
440 static void free_vmap_area(struct vmap_area *va)
441 {
442 spin_lock(&vmap_area_lock);
443 __free_vmap_area(va);
444 spin_unlock(&vmap_area_lock);
445 }
446
447 /*
448 * Clear the pagetable entries of a given vmap_area
449 */
450 static void unmap_vmap_area(struct vmap_area *va)
451 {
452 vunmap_page_range(va->va_start, va->va_end);
453 }
454
455 static void vmap_debug_free_range(unsigned long start, unsigned long end)
456 {
457 /*
458 * Unmap page tables and force a TLB flush immediately if
459 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
460 * bugs similarly to those in linear kernel virtual address
461 * space after a page has been freed.
462 *
463 * All the lazy freeing logic is still retained, in order to
464 * minimise intrusiveness of this debugging feature.
465 *
466 * This is going to be *slow* (linear kernel virtual address
467 * debugging doesn't do a broadcast TLB flush so it is a lot
468 * faster).
469 */
470 #ifdef CONFIG_DEBUG_PAGEALLOC
471 vunmap_page_range(start, end);
472 flush_tlb_kernel_range(start, end);
473 #endif
474 }
475
476 /*
477 * lazy_max_pages is the maximum amount of virtual address space we gather up
478 * before attempting to purge with a TLB flush.
479 *
480 * There is a tradeoff here: a larger number will cover more kernel page tables
481 * and take slightly longer to purge, but it will linearly reduce the number of
482 * global TLB flushes that must be performed. It would seem natural to scale
483 * this number up linearly with the number of CPUs (because vmapping activity
484 * could also scale linearly with the number of CPUs), however it is likely
485 * that in practice, workloads might be constrained in other ways that mean
486 * vmap activity will not scale linearly with CPUs. Also, I want to be
487 * conservative and not introduce a big latency on huge systems, so go with
488 * a less aggressive log scale. It will still be an improvement over the old
489 * code, and it will be simple to change the scale factor if we find that it
490 * becomes a problem on bigger systems.
491 */
492 static unsigned long lazy_max_pages(void)
493 {
494 unsigned int log;
495
496 log = fls(num_online_cpus());
497
498 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
499 }
500
501 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
502
503 /*
504 * Purges all lazily-freed vmap areas.
505 *
506 * If sync is 0 then don't purge if there is already a purge in progress.
507 * If force_flush is 1, then flush kernel TLBs between *start and *end even
508 * if we found no lazy vmap areas to unmap (callers can use this to optimise
509 * their own TLB flushing).
510 * Returns with *start = min(*start, lowest purged address)
511 * *end = max(*end, highest purged address)
512 */
513 static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
514 int sync, int force_flush)
515 {
516 static DEFINE_SPINLOCK(purge_lock);
517 LIST_HEAD(valist);
518 struct vmap_area *va;
519 struct vmap_area *n_va;
520 int nr = 0;
521
522 /*
523 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
524 * should not expect such behaviour. This just simplifies locking for
525 * the case that isn't actually used at the moment anyway.
526 */
527 if (!sync && !force_flush) {
528 if (!spin_trylock(&purge_lock))
529 return;
530 } else
531 spin_lock(&purge_lock);
532
533 rcu_read_lock();
534 list_for_each_entry_rcu(va, &vmap_area_list, list) {
535 if (va->flags & VM_LAZY_FREE) {
536 if (va->va_start < *start)
537 *start = va->va_start;
538 if (va->va_end > *end)
539 *end = va->va_end;
540 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
541 unmap_vmap_area(va);
542 list_add_tail(&va->purge_list, &valist);
543 va->flags |= VM_LAZY_FREEING;
544 va->flags &= ~VM_LAZY_FREE;
545 }
546 }
547 rcu_read_unlock();
548
549 if (nr)
550 atomic_sub(nr, &vmap_lazy_nr);
551
552 if (nr || force_flush)
553 flush_tlb_kernel_range(*start, *end);
554
555 if (nr) {
556 spin_lock(&vmap_area_lock);
557 list_for_each_entry_safe(va, n_va, &valist, purge_list)
558 __free_vmap_area(va);
559 spin_unlock(&vmap_area_lock);
560 }
561 spin_unlock(&purge_lock);
562 }
563
564 /*
565 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
566 * is already purging.
567 */
568 static void try_purge_vmap_area_lazy(void)
569 {
570 unsigned long start = ULONG_MAX, end = 0;
571
572 __purge_vmap_area_lazy(&start, &end, 0, 0);
573 }
574
575 /*
576 * Kick off a purge of the outstanding lazy areas.
577 */
578 static void purge_vmap_area_lazy(void)
579 {
580 unsigned long start = ULONG_MAX, end = 0;
581
582 __purge_vmap_area_lazy(&start, &end, 1, 0);
583 }
584
585 /*
586 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
587 * called for the correct range previously.
588 */
589 static void free_unmap_vmap_area_noflush(struct vmap_area *va)
590 {
591 va->flags |= VM_LAZY_FREE;
592 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
593 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
594 try_purge_vmap_area_lazy();
595 }
596
597 /*
598 * Free and unmap a vmap area
599 */
600 static void free_unmap_vmap_area(struct vmap_area *va)
601 {
602 flush_cache_vunmap(va->va_start, va->va_end);
603 free_unmap_vmap_area_noflush(va);
604 }
605
606 static struct vmap_area *find_vmap_area(unsigned long addr)
607 {
608 struct vmap_area *va;
609
610 spin_lock(&vmap_area_lock);
611 va = __find_vmap_area(addr);
612 spin_unlock(&vmap_area_lock);
613
614 return va;
615 }
616
617 static void free_unmap_vmap_area_addr(unsigned long addr)
618 {
619 struct vmap_area *va;
620
621 va = find_vmap_area(addr);
622 BUG_ON(!va);
623 free_unmap_vmap_area(va);
624 }
625
626
627 /*** Per cpu kva allocator ***/
628
629 /*
630 * vmap space is limited especially on 32 bit architectures. Ensure there is
631 * room for at least 16 percpu vmap blocks per CPU.
632 */
633 /*
634 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
635 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
636 * instead (we just need a rough idea)
637 */
638 #if BITS_PER_LONG == 32
639 #define VMALLOC_SPACE (128UL*1024*1024)
640 #else
641 #define VMALLOC_SPACE (128UL*1024*1024*1024)
642 #endif
643
644 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
645 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
646 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
647 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
648 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
649 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
650 #define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
651 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
652 VMALLOC_PAGES / NR_CPUS / 16))
653
654 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
655
656 static bool vmap_initialized __read_mostly = false;
657
658 struct vmap_block_queue {
659 spinlock_t lock;
660 struct list_head free;
661 struct list_head dirty;
662 unsigned int nr_dirty;
663 };
664
665 struct vmap_block {
666 spinlock_t lock;
667 struct vmap_area *va;
668 struct vmap_block_queue *vbq;
669 unsigned long free, dirty;
670 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
671 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
672 union {
673 struct list_head free_list;
674 struct rcu_head rcu_head;
675 };
676 };
677
678 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
679 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
680
681 /*
682 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
683 * in the free path. Could get rid of this if we change the API to return a
684 * "cookie" from alloc, to be passed to free. But no big deal yet.
685 */
686 static DEFINE_SPINLOCK(vmap_block_tree_lock);
687 static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
688
689 /*
690 * We should probably have a fallback mechanism to allocate virtual memory
691 * out of partially filled vmap blocks. However vmap block sizing should be
692 * fairly reasonable according to the vmalloc size, so it shouldn't be a
693 * big problem.
694 */
695
696 static unsigned long addr_to_vb_idx(unsigned long addr)
697 {
698 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
699 addr /= VMAP_BLOCK_SIZE;
700 return addr;
701 }
702
703 static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
704 {
705 struct vmap_block_queue *vbq;
706 struct vmap_block *vb;
707 struct vmap_area *va;
708 unsigned long vb_idx;
709 int node, err;
710
711 node = numa_node_id();
712
713 vb = kmalloc_node(sizeof(struct vmap_block),
714 gfp_mask & GFP_RECLAIM_MASK, node);
715 if (unlikely(!vb))
716 return ERR_PTR(-ENOMEM);
717
718 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
719 VMALLOC_START, VMALLOC_END,
720 node, gfp_mask);
721 if (unlikely(IS_ERR(va))) {
722 kfree(vb);
723 return ERR_PTR(PTR_ERR(va));
724 }
725
726 err = radix_tree_preload(gfp_mask);
727 if (unlikely(err)) {
728 kfree(vb);
729 free_vmap_area(va);
730 return ERR_PTR(err);
731 }
732
733 spin_lock_init(&vb->lock);
734 vb->va = va;
735 vb->free = VMAP_BBMAP_BITS;
736 vb->dirty = 0;
737 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
738 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
739 INIT_LIST_HEAD(&vb->free_list);
740
741 vb_idx = addr_to_vb_idx(va->va_start);
742 spin_lock(&vmap_block_tree_lock);
743 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
744 spin_unlock(&vmap_block_tree_lock);
745 BUG_ON(err);
746 radix_tree_preload_end();
747
748 vbq = &get_cpu_var(vmap_block_queue);
749 vb->vbq = vbq;
750 spin_lock(&vbq->lock);
751 list_add(&vb->free_list, &vbq->free);
752 spin_unlock(&vbq->lock);
753 put_cpu_var(vmap_cpu_blocks);
754
755 return vb;
756 }
757
758 static void rcu_free_vb(struct rcu_head *head)
759 {
760 struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head);
761
762 kfree(vb);
763 }
764
765 static void free_vmap_block(struct vmap_block *vb)
766 {
767 struct vmap_block *tmp;
768 unsigned long vb_idx;
769
770 BUG_ON(!list_empty(&vb->free_list));
771
772 vb_idx = addr_to_vb_idx(vb->va->va_start);
773 spin_lock(&vmap_block_tree_lock);
774 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
775 spin_unlock(&vmap_block_tree_lock);
776 BUG_ON(tmp != vb);
777
778 free_unmap_vmap_area_noflush(vb->va);
779 call_rcu(&vb->rcu_head, rcu_free_vb);
780 }
781
782 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
783 {
784 struct vmap_block_queue *vbq;
785 struct vmap_block *vb;
786 unsigned long addr = 0;
787 unsigned int order;
788
789 BUG_ON(size & ~PAGE_MASK);
790 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
791 order = get_order(size);
792
793 again:
794 rcu_read_lock();
795 vbq = &get_cpu_var(vmap_block_queue);
796 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
797 int i;
798
799 spin_lock(&vb->lock);
800 i = bitmap_find_free_region(vb->alloc_map,
801 VMAP_BBMAP_BITS, order);
802
803 if (i >= 0) {
804 addr = vb->va->va_start + (i << PAGE_SHIFT);
805 BUG_ON(addr_to_vb_idx(addr) !=
806 addr_to_vb_idx(vb->va->va_start));
807 vb->free -= 1UL << order;
808 if (vb->free == 0) {
809 spin_lock(&vbq->lock);
810 list_del_init(&vb->free_list);
811 spin_unlock(&vbq->lock);
812 }
813 spin_unlock(&vb->lock);
814 break;
815 }
816 spin_unlock(&vb->lock);
817 }
818 put_cpu_var(vmap_cpu_blocks);
819 rcu_read_unlock();
820
821 if (!addr) {
822 vb = new_vmap_block(gfp_mask);
823 if (IS_ERR(vb))
824 return vb;
825 goto again;
826 }
827
828 return (void *)addr;
829 }
830
831 static void vb_free(const void *addr, unsigned long size)
832 {
833 unsigned long offset;
834 unsigned long vb_idx;
835 unsigned int order;
836 struct vmap_block *vb;
837
838 BUG_ON(size & ~PAGE_MASK);
839 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
840
841 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
842
843 order = get_order(size);
844
845 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
846
847 vb_idx = addr_to_vb_idx((unsigned long)addr);
848 rcu_read_lock();
849 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
850 rcu_read_unlock();
851 BUG_ON(!vb);
852
853 spin_lock(&vb->lock);
854 bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order);
855
856 vb->dirty += 1UL << order;
857 if (vb->dirty == VMAP_BBMAP_BITS) {
858 BUG_ON(vb->free || !list_empty(&vb->free_list));
859 spin_unlock(&vb->lock);
860 free_vmap_block(vb);
861 } else
862 spin_unlock(&vb->lock);
863 }
864
865 /**
866 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
867 *
868 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
869 * to amortize TLB flushing overheads. What this means is that any page you
870 * have now, may, in a former life, have been mapped into kernel virtual
871 * address by the vmap layer and so there might be some CPUs with TLB entries
872 * still referencing that page (additional to the regular 1:1 kernel mapping).
873 *
874 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
875 * be sure that none of the pages we have control over will have any aliases
876 * from the vmap layer.
877 */
878 void vm_unmap_aliases(void)
879 {
880 unsigned long start = ULONG_MAX, end = 0;
881 int cpu;
882 int flush = 0;
883
884 if (unlikely(!vmap_initialized))
885 return;
886
887 for_each_possible_cpu(cpu) {
888 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
889 struct vmap_block *vb;
890
891 rcu_read_lock();
892 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
893 int i;
894
895 spin_lock(&vb->lock);
896 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
897 while (i < VMAP_BBMAP_BITS) {
898 unsigned long s, e;
899 int j;
900 j = find_next_zero_bit(vb->dirty_map,
901 VMAP_BBMAP_BITS, i);
902
903 s = vb->va->va_start + (i << PAGE_SHIFT);
904 e = vb->va->va_start + (j << PAGE_SHIFT);
905 vunmap_page_range(s, e);
906 flush = 1;
907
908 if (s < start)
909 start = s;
910 if (e > end)
911 end = e;
912
913 i = j;
914 i = find_next_bit(vb->dirty_map,
915 VMAP_BBMAP_BITS, i);
916 }
917 spin_unlock(&vb->lock);
918 }
919 rcu_read_unlock();
920 }
921
922 __purge_vmap_area_lazy(&start, &end, 1, flush);
923 }
924 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
925
926 /**
927 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
928 * @mem: the pointer returned by vm_map_ram
929 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
930 */
931 void vm_unmap_ram(const void *mem, unsigned int count)
932 {
933 unsigned long size = count << PAGE_SHIFT;
934 unsigned long addr = (unsigned long)mem;
935
936 BUG_ON(!addr);
937 BUG_ON(addr < VMALLOC_START);
938 BUG_ON(addr > VMALLOC_END);
939 BUG_ON(addr & (PAGE_SIZE-1));
940
941 debug_check_no_locks_freed(mem, size);
942 vmap_debug_free_range(addr, addr+size);
943
944 if (likely(count <= VMAP_MAX_ALLOC))
945 vb_free(mem, size);
946 else
947 free_unmap_vmap_area_addr(addr);
948 }
949 EXPORT_SYMBOL(vm_unmap_ram);
950
951 /**
952 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
953 * @pages: an array of pointers to the pages to be mapped
954 * @count: number of pages
955 * @node: prefer to allocate data structures on this node
956 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
957 *
958 * Returns: a pointer to the address that has been mapped, or %NULL on failure
959 */
960 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
961 {
962 unsigned long size = count << PAGE_SHIFT;
963 unsigned long addr;
964 void *mem;
965
966 if (likely(count <= VMAP_MAX_ALLOC)) {
967 mem = vb_alloc(size, GFP_KERNEL);
968 if (IS_ERR(mem))
969 return NULL;
970 addr = (unsigned long)mem;
971 } else {
972 struct vmap_area *va;
973 va = alloc_vmap_area(size, PAGE_SIZE,
974 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
975 if (IS_ERR(va))
976 return NULL;
977
978 addr = va->va_start;
979 mem = (void *)addr;
980 }
981 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
982 vm_unmap_ram(mem, count);
983 return NULL;
984 }
985 return mem;
986 }
987 EXPORT_SYMBOL(vm_map_ram);
988
989 /**
990 * vm_area_register_early - register vmap area early during boot
991 * @vm: vm_struct to register
992 * @align: requested alignment
993 *
994 * This function is used to register kernel vm area before
995 * vmalloc_init() is called. @vm->size and @vm->flags should contain
996 * proper values on entry and other fields should be zero. On return,
997 * vm->addr contains the allocated address.
998 *
999 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1000 */
1001 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1002 {
1003 static size_t vm_init_off __initdata;
1004 unsigned long addr;
1005
1006 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1007 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1008
1009 vm->addr = (void *)addr;
1010
1011 vm->next = vmlist;
1012 vmlist = vm;
1013 }
1014
1015 void __init vmalloc_init(void)
1016 {
1017 struct vmap_area *va;
1018 struct vm_struct *tmp;
1019 int i;
1020
1021 for_each_possible_cpu(i) {
1022 struct vmap_block_queue *vbq;
1023
1024 vbq = &per_cpu(vmap_block_queue, i);
1025 spin_lock_init(&vbq->lock);
1026 INIT_LIST_HEAD(&vbq->free);
1027 INIT_LIST_HEAD(&vbq->dirty);
1028 vbq->nr_dirty = 0;
1029 }
1030
1031 /* Import existing vmlist entries. */
1032 for (tmp = vmlist; tmp; tmp = tmp->next) {
1033 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1034 va->flags = tmp->flags | VM_VM_AREA;
1035 va->va_start = (unsigned long)tmp->addr;
1036 va->va_end = va->va_start + tmp->size;
1037 __insert_vmap_area(va);
1038 }
1039 vmap_initialized = true;
1040 }
1041
1042 /**
1043 * map_kernel_range_noflush - map kernel VM area with the specified pages
1044 * @addr: start of the VM area to map
1045 * @size: size of the VM area to map
1046 * @prot: page protection flags to use
1047 * @pages: pages to map
1048 *
1049 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1050 * specify should have been allocated using get_vm_area() and its
1051 * friends.
1052 *
1053 * NOTE:
1054 * This function does NOT do any cache flushing. The caller is
1055 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1056 * before calling this function.
1057 *
1058 * RETURNS:
1059 * The number of pages mapped on success, -errno on failure.
1060 */
1061 int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1062 pgprot_t prot, struct page **pages)
1063 {
1064 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1065 }
1066
1067 /**
1068 * unmap_kernel_range_noflush - unmap kernel VM area
1069 * @addr: start of the VM area to unmap
1070 * @size: size of the VM area to unmap
1071 *
1072 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1073 * specify should have been allocated using get_vm_area() and its
1074 * friends.
1075 *
1076 * NOTE:
1077 * This function does NOT do any cache flushing. The caller is
1078 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1079 * before calling this function and flush_tlb_kernel_range() after.
1080 */
1081 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1082 {
1083 vunmap_page_range(addr, addr + size);
1084 }
1085
1086 /**
1087 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1088 * @addr: start of the VM area to unmap
1089 * @size: size of the VM area to unmap
1090 *
1091 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1092 * the unmapping and tlb after.
1093 */
1094 void unmap_kernel_range(unsigned long addr, unsigned long size)
1095 {
1096 unsigned long end = addr + size;
1097
1098 flush_cache_vunmap(addr, end);
1099 vunmap_page_range(addr, end);
1100 flush_tlb_kernel_range(addr, end);
1101 }
1102
1103 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1104 {
1105 unsigned long addr = (unsigned long)area->addr;
1106 unsigned long end = addr + area->size - PAGE_SIZE;
1107 int err;
1108
1109 err = vmap_page_range(addr, end, prot, *pages);
1110 if (err > 0) {
1111 *pages += err;
1112 err = 0;
1113 }
1114
1115 return err;
1116 }
1117 EXPORT_SYMBOL_GPL(map_vm_area);
1118
1119 /*** Old vmalloc interfaces ***/
1120 DEFINE_RWLOCK(vmlist_lock);
1121 struct vm_struct *vmlist;
1122
1123 static struct vm_struct *__get_vm_area_node(unsigned long size,
1124 unsigned long flags, unsigned long start, unsigned long end,
1125 int node, gfp_t gfp_mask, void *caller)
1126 {
1127 static struct vmap_area *va;
1128 struct vm_struct *area;
1129 struct vm_struct *tmp, **p;
1130 unsigned long align = 1;
1131
1132 BUG_ON(in_interrupt());
1133 if (flags & VM_IOREMAP) {
1134 int bit = fls(size);
1135
1136 if (bit > IOREMAP_MAX_ORDER)
1137 bit = IOREMAP_MAX_ORDER;
1138 else if (bit < PAGE_SHIFT)
1139 bit = PAGE_SHIFT;
1140
1141 align = 1ul << bit;
1142 }
1143
1144 size = PAGE_ALIGN(size);
1145 if (unlikely(!size))
1146 return NULL;
1147
1148 area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1149 if (unlikely(!area))
1150 return NULL;
1151
1152 /*
1153 * We always allocate a guard page.
1154 */
1155 size += PAGE_SIZE;
1156
1157 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1158 if (IS_ERR(va)) {
1159 kfree(area);
1160 return NULL;
1161 }
1162
1163 area->flags = flags;
1164 area->addr = (void *)va->va_start;
1165 area->size = size;
1166 area->pages = NULL;
1167 area->nr_pages = 0;
1168 area->phys_addr = 0;
1169 area->caller = caller;
1170 va->private = area;
1171 va->flags |= VM_VM_AREA;
1172
1173 write_lock(&vmlist_lock);
1174 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1175 if (tmp->addr >= area->addr)
1176 break;
1177 }
1178 area->next = *p;
1179 *p = area;
1180 write_unlock(&vmlist_lock);
1181
1182 return area;
1183 }
1184
1185 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1186 unsigned long start, unsigned long end)
1187 {
1188 return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
1189 __builtin_return_address(0));
1190 }
1191 EXPORT_SYMBOL_GPL(__get_vm_area);
1192
1193 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1194 unsigned long start, unsigned long end,
1195 void *caller)
1196 {
1197 return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
1198 caller);
1199 }
1200
1201 /**
1202 * get_vm_area - reserve a contiguous kernel virtual area
1203 * @size: size of the area
1204 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1205 *
1206 * Search an area of @size in the kernel virtual mapping area,
1207 * and reserved it for out purposes. Returns the area descriptor
1208 * on success or %NULL on failure.
1209 */
1210 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1211 {
1212 return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
1213 -1, GFP_KERNEL, __builtin_return_address(0));
1214 }
1215
1216 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1217 void *caller)
1218 {
1219 return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
1220 -1, GFP_KERNEL, caller);
1221 }
1222
1223 struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
1224 int node, gfp_t gfp_mask)
1225 {
1226 return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
1227 gfp_mask, __builtin_return_address(0));
1228 }
1229
1230 static struct vm_struct *find_vm_area(const void *addr)
1231 {
1232 struct vmap_area *va;
1233
1234 va = find_vmap_area((unsigned long)addr);
1235 if (va && va->flags & VM_VM_AREA)
1236 return va->private;
1237
1238 return NULL;
1239 }
1240
1241 /**
1242 * remove_vm_area - find and remove a continuous kernel virtual area
1243 * @addr: base address
1244 *
1245 * Search for the kernel VM area starting at @addr, and remove it.
1246 * This function returns the found VM area, but using it is NOT safe
1247 * on SMP machines, except for its size or flags.
1248 */
1249 struct vm_struct *remove_vm_area(const void *addr)
1250 {
1251 struct vmap_area *va;
1252
1253 va = find_vmap_area((unsigned long)addr);
1254 if (va && va->flags & VM_VM_AREA) {
1255 struct vm_struct *vm = va->private;
1256 struct vm_struct *tmp, **p;
1257
1258 vmap_debug_free_range(va->va_start, va->va_end);
1259 free_unmap_vmap_area(va);
1260 vm->size -= PAGE_SIZE;
1261
1262 write_lock(&vmlist_lock);
1263 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1264 ;
1265 *p = tmp->next;
1266 write_unlock(&vmlist_lock);
1267
1268 return vm;
1269 }
1270 return NULL;
1271 }
1272
1273 static void __vunmap(const void *addr, int deallocate_pages)
1274 {
1275 struct vm_struct *area;
1276
1277 if (!addr)
1278 return;
1279
1280 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1281 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1282 return;
1283 }
1284
1285 area = remove_vm_area(addr);
1286 if (unlikely(!area)) {
1287 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1288 addr);
1289 return;
1290 }
1291
1292 debug_check_no_locks_freed(addr, area->size);
1293 debug_check_no_obj_freed(addr, area->size);
1294
1295 if (deallocate_pages) {
1296 int i;
1297
1298 for (i = 0; i < area->nr_pages; i++) {
1299 struct page *page = area->pages[i];
1300
1301 BUG_ON(!page);
1302 __free_page(page);
1303 }
1304
1305 if (area->flags & VM_VPAGES)
1306 vfree(area->pages);
1307 else
1308 kfree(area->pages);
1309 }
1310
1311 kfree(area);
1312 return;
1313 }
1314
1315 /**
1316 * vfree - release memory allocated by vmalloc()
1317 * @addr: memory base address
1318 *
1319 * Free the virtually continuous memory area starting at @addr, as
1320 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1321 * NULL, no operation is performed.
1322 *
1323 * Must not be called in interrupt context.
1324 */
1325 void vfree(const void *addr)
1326 {
1327 BUG_ON(in_interrupt());
1328
1329 kmemleak_free(addr);
1330
1331 __vunmap(addr, 1);
1332 }
1333 EXPORT_SYMBOL(vfree);
1334
1335 /**
1336 * vunmap - release virtual mapping obtained by vmap()
1337 * @addr: memory base address
1338 *
1339 * Free the virtually contiguous memory area starting at @addr,
1340 * which was created from the page array passed to vmap().
1341 *
1342 * Must not be called in interrupt context.
1343 */
1344 void vunmap(const void *addr)
1345 {
1346 BUG_ON(in_interrupt());
1347 might_sleep();
1348 __vunmap(addr, 0);
1349 }
1350 EXPORT_SYMBOL(vunmap);
1351
1352 /**
1353 * vmap - map an array of pages into virtually contiguous space
1354 * @pages: array of page pointers
1355 * @count: number of pages to map
1356 * @flags: vm_area->flags
1357 * @prot: page protection for the mapping
1358 *
1359 * Maps @count pages from @pages into contiguous kernel virtual
1360 * space.
1361 */
1362 void *vmap(struct page **pages, unsigned int count,
1363 unsigned long flags, pgprot_t prot)
1364 {
1365 struct vm_struct *area;
1366
1367 might_sleep();
1368
1369 if (count > totalram_pages)
1370 return NULL;
1371
1372 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1373 __builtin_return_address(0));
1374 if (!area)
1375 return NULL;
1376
1377 if (map_vm_area(area, prot, &pages)) {
1378 vunmap(area->addr);
1379 return NULL;
1380 }
1381
1382 return area->addr;
1383 }
1384 EXPORT_SYMBOL(vmap);
1385
1386 static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
1387 int node, void *caller);
1388 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1389 pgprot_t prot, int node, void *caller)
1390 {
1391 struct page **pages;
1392 unsigned int nr_pages, array_size, i;
1393
1394 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1395 array_size = (nr_pages * sizeof(struct page *));
1396
1397 area->nr_pages = nr_pages;
1398 /* Please note that the recursion is strictly bounded. */
1399 if (array_size > PAGE_SIZE) {
1400 pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
1401 PAGE_KERNEL, node, caller);
1402 area->flags |= VM_VPAGES;
1403 } else {
1404 pages = kmalloc_node(array_size,
1405 (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO,
1406 node);
1407 }
1408 area->pages = pages;
1409 area->caller = caller;
1410 if (!area->pages) {
1411 remove_vm_area(area->addr);
1412 kfree(area);
1413 return NULL;
1414 }
1415
1416 for (i = 0; i < area->nr_pages; i++) {
1417 struct page *page;
1418
1419 if (node < 0)
1420 page = alloc_page(gfp_mask);
1421 else
1422 page = alloc_pages_node(node, gfp_mask, 0);
1423
1424 if (unlikely(!page)) {
1425 /* Successfully allocated i pages, free them in __vunmap() */
1426 area->nr_pages = i;
1427 goto fail;
1428 }
1429 area->pages[i] = page;
1430 }
1431
1432 if (map_vm_area(area, prot, &pages))
1433 goto fail;
1434 return area->addr;
1435
1436 fail:
1437 vfree(area->addr);
1438 return NULL;
1439 }
1440
1441 void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
1442 {
1443 void *addr = __vmalloc_area_node(area, gfp_mask, prot, -1,
1444 __builtin_return_address(0));
1445
1446 /*
1447 * A ref_count = 3 is needed because the vm_struct and vmap_area
1448 * structures allocated in the __get_vm_area_node() function contain
1449 * references to the virtual address of the vmalloc'ed block.
1450 */
1451 kmemleak_alloc(addr, area->size - PAGE_SIZE, 3, gfp_mask);
1452
1453 return addr;
1454 }
1455
1456 /**
1457 * __vmalloc_node - allocate virtually contiguous memory
1458 * @size: allocation size
1459 * @gfp_mask: flags for the page level allocator
1460 * @prot: protection mask for the allocated pages
1461 * @node: node to use for allocation or -1
1462 * @caller: caller's return address
1463 *
1464 * Allocate enough pages to cover @size from the page level
1465 * allocator with @gfp_mask flags. Map them into contiguous
1466 * kernel virtual space, using a pagetable protection of @prot.
1467 */
1468 static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
1469 int node, void *caller)
1470 {
1471 struct vm_struct *area;
1472 void *addr;
1473 unsigned long real_size = size;
1474
1475 size = PAGE_ALIGN(size);
1476 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1477 return NULL;
1478
1479 area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
1480 node, gfp_mask, caller);
1481
1482 if (!area)
1483 return NULL;
1484
1485 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1486
1487 /*
1488 * A ref_count = 3 is needed because the vm_struct and vmap_area
1489 * structures allocated in the __get_vm_area_node() function contain
1490 * references to the virtual address of the vmalloc'ed block.
1491 */
1492 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1493
1494 return addr;
1495 }
1496
1497 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1498 {
1499 return __vmalloc_node(size, gfp_mask, prot, -1,
1500 __builtin_return_address(0));
1501 }
1502 EXPORT_SYMBOL(__vmalloc);
1503
1504 /**
1505 * vmalloc - allocate virtually contiguous memory
1506 * @size: allocation size
1507 * Allocate enough pages to cover @size from the page level
1508 * allocator and map them into contiguous kernel virtual space.
1509 *
1510 * For tight control over page level allocator and protection flags
1511 * use __vmalloc() instead.
1512 */
1513 void *vmalloc(unsigned long size)
1514 {
1515 return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1516 -1, __builtin_return_address(0));
1517 }
1518 EXPORT_SYMBOL(vmalloc);
1519
1520 /**
1521 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1522 * @size: allocation size
1523 *
1524 * The resulting memory area is zeroed so it can be mapped to userspace
1525 * without leaking data.
1526 */
1527 void *vmalloc_user(unsigned long size)
1528 {
1529 struct vm_struct *area;
1530 void *ret;
1531
1532 ret = __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1533 PAGE_KERNEL, -1, __builtin_return_address(0));
1534 if (ret) {
1535 area = find_vm_area(ret);
1536 area->flags |= VM_USERMAP;
1537 }
1538 return ret;
1539 }
1540 EXPORT_SYMBOL(vmalloc_user);
1541
1542 /**
1543 * vmalloc_node - allocate memory on a specific node
1544 * @size: allocation size
1545 * @node: numa node
1546 *
1547 * Allocate enough pages to cover @size from the page level
1548 * allocator and map them into contiguous kernel virtual space.
1549 *
1550 * For tight control over page level allocator and protection flags
1551 * use __vmalloc() instead.
1552 */
1553 void *vmalloc_node(unsigned long size, int node)
1554 {
1555 return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1556 node, __builtin_return_address(0));
1557 }
1558 EXPORT_SYMBOL(vmalloc_node);
1559
1560 #ifndef PAGE_KERNEL_EXEC
1561 # define PAGE_KERNEL_EXEC PAGE_KERNEL
1562 #endif
1563
1564 /**
1565 * vmalloc_exec - allocate virtually contiguous, executable memory
1566 * @size: allocation size
1567 *
1568 * Kernel-internal function to allocate enough pages to cover @size
1569 * the page level allocator and map them into contiguous and
1570 * executable kernel virtual space.
1571 *
1572 * For tight control over page level allocator and protection flags
1573 * use __vmalloc() instead.
1574 */
1575
1576 void *vmalloc_exec(unsigned long size)
1577 {
1578 return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1579 -1, __builtin_return_address(0));
1580 }
1581
1582 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1583 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1584 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1585 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1586 #else
1587 #define GFP_VMALLOC32 GFP_KERNEL
1588 #endif
1589
1590 /**
1591 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1592 * @size: allocation size
1593 *
1594 * Allocate enough 32bit PA addressable pages to cover @size from the
1595 * page level allocator and map them into contiguous kernel virtual space.
1596 */
1597 void *vmalloc_32(unsigned long size)
1598 {
1599 return __vmalloc_node(size, GFP_VMALLOC32, PAGE_KERNEL,
1600 -1, __builtin_return_address(0));
1601 }
1602 EXPORT_SYMBOL(vmalloc_32);
1603
1604 /**
1605 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1606 * @size: allocation size
1607 *
1608 * The resulting memory area is 32bit addressable and zeroed so it can be
1609 * mapped to userspace without leaking data.
1610 */
1611 void *vmalloc_32_user(unsigned long size)
1612 {
1613 struct vm_struct *area;
1614 void *ret;
1615
1616 ret = __vmalloc_node(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1617 -1, __builtin_return_address(0));
1618 if (ret) {
1619 area = find_vm_area(ret);
1620 area->flags |= VM_USERMAP;
1621 }
1622 return ret;
1623 }
1624 EXPORT_SYMBOL(vmalloc_32_user);
1625
1626 long vread(char *buf, char *addr, unsigned long count)
1627 {
1628 struct vm_struct *tmp;
1629 char *vaddr, *buf_start = buf;
1630 unsigned long n;
1631
1632 /* Don't allow overflow */
1633 if ((unsigned long) addr + count < count)
1634 count = -(unsigned long) addr;
1635
1636 read_lock(&vmlist_lock);
1637 for (tmp = vmlist; tmp; tmp = tmp->next) {
1638 vaddr = (char *) tmp->addr;
1639 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1640 continue;
1641 while (addr < vaddr) {
1642 if (count == 0)
1643 goto finished;
1644 *buf = '\0';
1645 buf++;
1646 addr++;
1647 count--;
1648 }
1649 n = vaddr + tmp->size - PAGE_SIZE - addr;
1650 do {
1651 if (count == 0)
1652 goto finished;
1653 *buf = *addr;
1654 buf++;
1655 addr++;
1656 count--;
1657 } while (--n > 0);
1658 }
1659 finished:
1660 read_unlock(&vmlist_lock);
1661 return buf - buf_start;
1662 }
1663
1664 long vwrite(char *buf, char *addr, unsigned long count)
1665 {
1666 struct vm_struct *tmp;
1667 char *vaddr, *buf_start = buf;
1668 unsigned long n;
1669
1670 /* Don't allow overflow */
1671 if ((unsigned long) addr + count < count)
1672 count = -(unsigned long) addr;
1673
1674 read_lock(&vmlist_lock);
1675 for (tmp = vmlist; tmp; tmp = tmp->next) {
1676 vaddr = (char *) tmp->addr;
1677 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1678 continue;
1679 while (addr < vaddr) {
1680 if (count == 0)
1681 goto finished;
1682 buf++;
1683 addr++;
1684 count--;
1685 }
1686 n = vaddr + tmp->size - PAGE_SIZE - addr;
1687 do {
1688 if (count == 0)
1689 goto finished;
1690 *addr = *buf;
1691 buf++;
1692 addr++;
1693 count--;
1694 } while (--n > 0);
1695 }
1696 finished:
1697 read_unlock(&vmlist_lock);
1698 return buf - buf_start;
1699 }
1700
1701 /**
1702 * remap_vmalloc_range - map vmalloc pages to userspace
1703 * @vma: vma to cover (map full range of vma)
1704 * @addr: vmalloc memory
1705 * @pgoff: number of pages into addr before first page to map
1706 *
1707 * Returns: 0 for success, -Exxx on failure
1708 *
1709 * This function checks that addr is a valid vmalloc'ed area, and
1710 * that it is big enough to cover the vma. Will return failure if
1711 * that criteria isn't met.
1712 *
1713 * Similar to remap_pfn_range() (see mm/memory.c)
1714 */
1715 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
1716 unsigned long pgoff)
1717 {
1718 struct vm_struct *area;
1719 unsigned long uaddr = vma->vm_start;
1720 unsigned long usize = vma->vm_end - vma->vm_start;
1721
1722 if ((PAGE_SIZE-1) & (unsigned long)addr)
1723 return -EINVAL;
1724
1725 area = find_vm_area(addr);
1726 if (!area)
1727 return -EINVAL;
1728
1729 if (!(area->flags & VM_USERMAP))
1730 return -EINVAL;
1731
1732 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
1733 return -EINVAL;
1734
1735 addr += pgoff << PAGE_SHIFT;
1736 do {
1737 struct page *page = vmalloc_to_page(addr);
1738 int ret;
1739
1740 ret = vm_insert_page(vma, uaddr, page);
1741 if (ret)
1742 return ret;
1743
1744 uaddr += PAGE_SIZE;
1745 addr += PAGE_SIZE;
1746 usize -= PAGE_SIZE;
1747 } while (usize > 0);
1748
1749 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
1750 vma->vm_flags |= VM_RESERVED;
1751
1752 return 0;
1753 }
1754 EXPORT_SYMBOL(remap_vmalloc_range);
1755
1756 /*
1757 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
1758 * have one.
1759 */
1760 void __attribute__((weak)) vmalloc_sync_all(void)
1761 {
1762 }
1763
1764
1765 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
1766 {
1767 /* apply_to_page_range() does all the hard work. */
1768 return 0;
1769 }
1770
1771 /**
1772 * alloc_vm_area - allocate a range of kernel address space
1773 * @size: size of the area
1774 *
1775 * Returns: NULL on failure, vm_struct on success
1776 *
1777 * This function reserves a range of kernel address space, and
1778 * allocates pagetables to map that range. No actual mappings
1779 * are created. If the kernel address space is not shared
1780 * between processes, it syncs the pagetable across all
1781 * processes.
1782 */
1783 struct vm_struct *alloc_vm_area(size_t size)
1784 {
1785 struct vm_struct *area;
1786
1787 area = get_vm_area_caller(size, VM_IOREMAP,
1788 __builtin_return_address(0));
1789 if (area == NULL)
1790 return NULL;
1791
1792 /*
1793 * This ensures that page tables are constructed for this region
1794 * of kernel virtual address space and mapped into init_mm.
1795 */
1796 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
1797 area->size, f, NULL)) {
1798 free_vm_area(area);
1799 return NULL;
1800 }
1801
1802 /* Make sure the pagetables are constructed in process kernel
1803 mappings */
1804 vmalloc_sync_all();
1805
1806 return area;
1807 }
1808 EXPORT_SYMBOL_GPL(alloc_vm_area);
1809
1810 void free_vm_area(struct vm_struct *area)
1811 {
1812 struct vm_struct *ret;
1813 ret = remove_vm_area(area->addr);
1814 BUG_ON(ret != area);
1815 kfree(area);
1816 }
1817 EXPORT_SYMBOL_GPL(free_vm_area);
1818
1819
1820 #ifdef CONFIG_PROC_FS
1821 static void *s_start(struct seq_file *m, loff_t *pos)
1822 {
1823 loff_t n = *pos;
1824 struct vm_struct *v;
1825
1826 read_lock(&vmlist_lock);
1827 v = vmlist;
1828 while (n > 0 && v) {
1829 n--;
1830 v = v->next;
1831 }
1832 if (!n)
1833 return v;
1834
1835 return NULL;
1836
1837 }
1838
1839 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
1840 {
1841 struct vm_struct *v = p;
1842
1843 ++*pos;
1844 return v->next;
1845 }
1846
1847 static void s_stop(struct seq_file *m, void *p)
1848 {
1849 read_unlock(&vmlist_lock);
1850 }
1851
1852 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
1853 {
1854 if (NUMA_BUILD) {
1855 unsigned int nr, *counters = m->private;
1856
1857 if (!counters)
1858 return;
1859
1860 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
1861
1862 for (nr = 0; nr < v->nr_pages; nr++)
1863 counters[page_to_nid(v->pages[nr])]++;
1864
1865 for_each_node_state(nr, N_HIGH_MEMORY)
1866 if (counters[nr])
1867 seq_printf(m, " N%u=%u", nr, counters[nr]);
1868 }
1869 }
1870
1871 static int s_show(struct seq_file *m, void *p)
1872 {
1873 struct vm_struct *v = p;
1874
1875 seq_printf(m, "0x%p-0x%p %7ld",
1876 v->addr, v->addr + v->size, v->size);
1877
1878 if (v->caller) {
1879 char buff[KSYM_SYMBOL_LEN];
1880
1881 seq_putc(m, ' ');
1882 sprint_symbol(buff, (unsigned long)v->caller);
1883 seq_puts(m, buff);
1884 }
1885
1886 if (v->nr_pages)
1887 seq_printf(m, " pages=%d", v->nr_pages);
1888
1889 if (v->phys_addr)
1890 seq_printf(m, " phys=%lx", v->phys_addr);
1891
1892 if (v->flags & VM_IOREMAP)
1893 seq_printf(m, " ioremap");
1894
1895 if (v->flags & VM_ALLOC)
1896 seq_printf(m, " vmalloc");
1897
1898 if (v->flags & VM_MAP)
1899 seq_printf(m, " vmap");
1900
1901 if (v->flags & VM_USERMAP)
1902 seq_printf(m, " user");
1903
1904 if (v->flags & VM_VPAGES)
1905 seq_printf(m, " vpages");
1906
1907 show_numa_info(m, v);
1908 seq_putc(m, '\n');
1909 return 0;
1910 }
1911
1912 static const struct seq_operations vmalloc_op = {
1913 .start = s_start,
1914 .next = s_next,
1915 .stop = s_stop,
1916 .show = s_show,
1917 };
1918
1919 static int vmalloc_open(struct inode *inode, struct file *file)
1920 {
1921 unsigned int *ptr = NULL;
1922 int ret;
1923
1924 if (NUMA_BUILD)
1925 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
1926 ret = seq_open(file, &vmalloc_op);
1927 if (!ret) {
1928 struct seq_file *m = file->private_data;
1929 m->private = ptr;
1930 } else
1931 kfree(ptr);
1932 return ret;
1933 }
1934
1935 static const struct file_operations proc_vmalloc_operations = {
1936 .open = vmalloc_open,
1937 .read = seq_read,
1938 .llseek = seq_lseek,
1939 .release = seq_release_private,
1940 };
1941
1942 static int __init proc_vmalloc_init(void)
1943 {
1944 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
1945 return 0;
1946 }
1947 module_init(proc_vmalloc_init);
1948 #endif
1949
1950
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