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vmalloc.c
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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 <[email protected]>, 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/rbtree.h>
25 #include <linux/radix-tree.h>
26 #include <linux/rcupdate.h>
27 #include <linux/pfn.h>
28 #include <linux/kmemleak.h>
29 #include <linux/atomic.h>
30 #include <asm/uaccess.h>
31 #include <asm/tlbflush.h>
32 #include <asm/shmparam.h>
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  return err;
172  } while (pgd++, addr = next, addr != end);
173 
174  return nr;
175 }
176 
177 static int vmap_page_range(unsigned long start, unsigned long end,
178  pgprot_t prot, struct page **pages)
179 {
180  int ret;
181 
182  ret = vmap_page_range_noflush(start, end, prot, pages);
183  flush_cache_vmap(start, end);
184  return ret;
185 }
186 
187 int is_vmalloc_or_module_addr(const void *x)
188 {
189  /*
190  * ARM, x86-64 and sparc64 put modules in a special place,
191  * and fall back on vmalloc() if that fails. Others
192  * just put it in the vmalloc space.
193  */
194 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
195  unsigned long addr = (unsigned long)x;
196  if (addr >= MODULES_VADDR && addr < MODULES_END)
197  return 1;
198 #endif
199  return is_vmalloc_addr(x);
200 }
201 
202 /*
203  * Walk a vmap address to the struct page it maps.
204  */
205 struct page *vmalloc_to_page(const void *vmalloc_addr)
206 {
207  unsigned long addr = (unsigned long) vmalloc_addr;
208  struct page *page = NULL;
209  pgd_t *pgd = pgd_offset_k(addr);
210 
211  /*
212  * XXX we might need to change this if we add VIRTUAL_BUG_ON for
213  * architectures that do not vmalloc module space
214  */
216 
217  if (!pgd_none(*pgd)) {
218  pud_t *pud = pud_offset(pgd, addr);
219  if (!pud_none(*pud)) {
220  pmd_t *pmd = pmd_offset(pud, addr);
221  if (!pmd_none(*pmd)) {
222  pte_t *ptep, pte;
223 
224  ptep = pte_offset_map(pmd, addr);
225  pte = *ptep;
226  if (pte_present(pte))
227  page = pte_page(pte);
228  pte_unmap(ptep);
229  }
230  }
231  }
232  return page;
233 }
235 
236 /*
237  * Map a vmalloc()-space virtual address to the physical page frame number.
238  */
239 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
240 {
241  return page_to_pfn(vmalloc_to_page(vmalloc_addr));
242 }
244 
245 
246 /*** Global kva allocator ***/
247 
248 #define VM_LAZY_FREE 0x01
249 #define VM_LAZY_FREEING 0x02
250 #define VM_VM_AREA 0x04
251 
252 struct vmap_area {
253  unsigned long va_start;
254  unsigned long va_end;
255  unsigned long flags;
256  struct rb_node rb_node; /* address sorted rbtree */
257  struct list_head list; /* address sorted list */
258  struct list_head purge_list; /* "lazy purge" list */
259  struct vm_struct *vm;
261 };
262 
263 static DEFINE_SPINLOCK(vmap_area_lock);
264 static LIST_HEAD(vmap_area_list);
265 static struct rb_root vmap_area_root = RB_ROOT;
266 
267 /* The vmap cache globals are protected by vmap_area_lock */
268 static struct rb_node *free_vmap_cache;
269 static unsigned long cached_hole_size;
270 static unsigned long cached_vstart;
271 static unsigned long cached_align;
272 
273 static unsigned long vmap_area_pcpu_hole;
274 
275 static struct vmap_area *__find_vmap_area(unsigned long addr)
276 {
277  struct rb_node *n = vmap_area_root.rb_node;
278 
279  while (n) {
280  struct vmap_area *va;
281 
282  va = rb_entry(n, struct vmap_area, rb_node);
283  if (addr < va->va_start)
284  n = n->rb_left;
285  else if (addr > va->va_start)
286  n = n->rb_right;
287  else
288  return va;
289  }
290 
291  return NULL;
292 }
293 
294 static void __insert_vmap_area(struct vmap_area *va)
295 {
296  struct rb_node **p = &vmap_area_root.rb_node;
297  struct rb_node *parent = NULL;
298  struct rb_node *tmp;
299 
300  while (*p) {
301  struct vmap_area *tmp_va;
302 
303  parent = *p;
304  tmp_va = rb_entry(parent, struct vmap_area, rb_node);
305  if (va->va_start < tmp_va->va_end)
306  p = &(*p)->rb_left;
307  else if (va->va_end > tmp_va->va_start)
308  p = &(*p)->rb_right;
309  else
310  BUG();
311  }
312 
313  rb_link_node(&va->rb_node, parent, p);
314  rb_insert_color(&va->rb_node, &vmap_area_root);
315 
316  /* address-sort this list so it is usable like the vmlist */
317  tmp = rb_prev(&va->rb_node);
318  if (tmp) {
319  struct vmap_area *prev;
320  prev = rb_entry(tmp, struct vmap_area, rb_node);
321  list_add_rcu(&va->list, &prev->list);
322  } else
323  list_add_rcu(&va->list, &vmap_area_list);
324 }
325 
326 static void purge_vmap_area_lazy(void);
327 
328 /*
329  * Allocate a region of KVA of the specified size and alignment, within the
330  * vstart and vend.
331  */
332 static struct vmap_area *alloc_vmap_area(unsigned long size,
333  unsigned long align,
334  unsigned long vstart, unsigned long vend,
335  int node, gfp_t gfp_mask)
336 {
337  struct vmap_area *va;
338  struct rb_node *n;
339  unsigned long addr;
340  int purged = 0;
341  struct vmap_area *first;
342 
343  BUG_ON(!size);
344  BUG_ON(size & ~PAGE_MASK);
345  BUG_ON(!is_power_of_2(align));
346 
347  va = kmalloc_node(sizeof(struct vmap_area),
348  gfp_mask & GFP_RECLAIM_MASK, node);
349  if (unlikely(!va))
350  return ERR_PTR(-ENOMEM);
351 
352 retry:
353  spin_lock(&vmap_area_lock);
354  /*
355  * Invalidate cache if we have more permissive parameters.
356  * cached_hole_size notes the largest hole noticed _below_
357  * the vmap_area cached in free_vmap_cache: if size fits
358  * into that hole, we want to scan from vstart to reuse
359  * the hole instead of allocating above free_vmap_cache.
360  * Note that __free_vmap_area may update free_vmap_cache
361  * without updating cached_hole_size or cached_align.
362  */
363  if (!free_vmap_cache ||
364  size < cached_hole_size ||
365  vstart < cached_vstart ||
366  align < cached_align) {
367 nocache:
368  cached_hole_size = 0;
369  free_vmap_cache = NULL;
370  }
371  /* record if we encounter less permissive parameters */
372  cached_vstart = vstart;
373  cached_align = align;
374 
375  /* find starting point for our search */
376  if (free_vmap_cache) {
377  first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
378  addr = ALIGN(first->va_end, align);
379  if (addr < vstart)
380  goto nocache;
381  if (addr + size - 1 < addr)
382  goto overflow;
383 
384  } else {
385  addr = ALIGN(vstart, align);
386  if (addr + size - 1 < addr)
387  goto overflow;
388 
389  n = vmap_area_root.rb_node;
390  first = NULL;
391 
392  while (n) {
393  struct vmap_area *tmp;
394  tmp = rb_entry(n, struct vmap_area, rb_node);
395  if (tmp->va_end >= addr) {
396  first = tmp;
397  if (tmp->va_start <= addr)
398  break;
399  n = n->rb_left;
400  } else
401  n = n->rb_right;
402  }
403 
404  if (!first)
405  goto found;
406  }
407 
408  /* from the starting point, walk areas until a suitable hole is found */
409  while (addr + size > first->va_start && addr + size <= vend) {
410  if (addr + cached_hole_size < first->va_start)
411  cached_hole_size = first->va_start - addr;
412  addr = ALIGN(first->va_end, align);
413  if (addr + size - 1 < addr)
414  goto overflow;
415 
416  if (list_is_last(&first->list, &vmap_area_list))
417  goto found;
418 
419  first = list_entry(first->list.next,
420  struct vmap_area, list);
421  }
422 
423 found:
424  if (addr + size > vend)
425  goto overflow;
426 
427  va->va_start = addr;
428  va->va_end = addr + size;
429  va->flags = 0;
430  __insert_vmap_area(va);
431  free_vmap_cache = &va->rb_node;
432  spin_unlock(&vmap_area_lock);
433 
434  BUG_ON(va->va_start & (align-1));
435  BUG_ON(va->va_start < vstart);
436  BUG_ON(va->va_end > vend);
437 
438  return va;
439 
440 overflow:
441  spin_unlock(&vmap_area_lock);
442  if (!purged) {
443  purge_vmap_area_lazy();
444  purged = 1;
445  goto retry;
446  }
447  if (printk_ratelimit())
449  "vmap allocation for size %lu failed: "
450  "use vmalloc=<size> to increase size.\n", size);
451  kfree(va);
452  return ERR_PTR(-EBUSY);
453 }
454 
455 static void __free_vmap_area(struct vmap_area *va)
456 {
458 
459  if (free_vmap_cache) {
460  if (va->va_end < cached_vstart) {
461  free_vmap_cache = NULL;
462  } else {
463  struct vmap_area *cache;
464  cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
465  if (va->va_start <= cache->va_start) {
466  free_vmap_cache = rb_prev(&va->rb_node);
467  /*
468  * We don't try to update cached_hole_size or
469  * cached_align, but it won't go very wrong.
470  */
471  }
472  }
473  }
474  rb_erase(&va->rb_node, &vmap_area_root);
475  RB_CLEAR_NODE(&va->rb_node);
476  list_del_rcu(&va->list);
477 
478  /*
479  * Track the highest possible candidate for pcpu area
480  * allocation. Areas outside of vmalloc area can be returned
481  * here too, consider only end addresses which fall inside
482  * vmalloc area proper.
483  */
484  if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
485  vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
486 
487  kfree_rcu(va, rcu_head);
488 }
489 
490 /*
491  * Free a region of KVA allocated by alloc_vmap_area
492  */
493 static void free_vmap_area(struct vmap_area *va)
494 {
495  spin_lock(&vmap_area_lock);
496  __free_vmap_area(va);
497  spin_unlock(&vmap_area_lock);
498 }
499 
500 /*
501  * Clear the pagetable entries of a given vmap_area
502  */
503 static void unmap_vmap_area(struct vmap_area *va)
504 {
505  vunmap_page_range(va->va_start, va->va_end);
506 }
507 
508 static void vmap_debug_free_range(unsigned long start, unsigned long end)
509 {
510  /*
511  * Unmap page tables and force a TLB flush immediately if
512  * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
513  * bugs similarly to those in linear kernel virtual address
514  * space after a page has been freed.
515  *
516  * All the lazy freeing logic is still retained, in order to
517  * minimise intrusiveness of this debugging feature.
518  *
519  * This is going to be *slow* (linear kernel virtual address
520  * debugging doesn't do a broadcast TLB flush so it is a lot
521  * faster).
522  */
523 #ifdef CONFIG_DEBUG_PAGEALLOC
524  vunmap_page_range(start, end);
525  flush_tlb_kernel_range(start, end);
526 #endif
527 }
528 
529 /*
530  * lazy_max_pages is the maximum amount of virtual address space we gather up
531  * before attempting to purge with a TLB flush.
532  *
533  * There is a tradeoff here: a larger number will cover more kernel page tables
534  * and take slightly longer to purge, but it will linearly reduce the number of
535  * global TLB flushes that must be performed. It would seem natural to scale
536  * this number up linearly with the number of CPUs (because vmapping activity
537  * could also scale linearly with the number of CPUs), however it is likely
538  * that in practice, workloads might be constrained in other ways that mean
539  * vmap activity will not scale linearly with CPUs. Also, I want to be
540  * conservative and not introduce a big latency on huge systems, so go with
541  * a less aggressive log scale. It will still be an improvement over the old
542  * code, and it will be simple to change the scale factor if we find that it
543  * becomes a problem on bigger systems.
544  */
545 static unsigned long lazy_max_pages(void)
546 {
547  unsigned int log;
548 
549  log = fls(num_online_cpus());
550 
551  return log * (32UL * 1024 * 1024 / PAGE_SIZE);
552 }
553 
554 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
555 
556 /* for per-CPU blocks */
557 static void purge_fragmented_blocks_allcpus(void);
558 
559 /*
560  * called before a call to iounmap() if the caller wants vm_area_struct's
561  * immediately freed.
562  */
564 {
565  atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
566 }
567 
568 /*
569  * Purges all lazily-freed vmap areas.
570  *
571  * If sync is 0 then don't purge if there is already a purge in progress.
572  * If force_flush is 1, then flush kernel TLBs between *start and *end even
573  * if we found no lazy vmap areas to unmap (callers can use this to optimise
574  * their own TLB flushing).
575  * Returns with *start = min(*start, lowest purged address)
576  * *end = max(*end, highest purged address)
577  */
578 static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
579  int sync, int force_flush)
580 {
581  static DEFINE_SPINLOCK(purge_lock);
582  LIST_HEAD(valist);
583  struct vmap_area *va;
584  struct vmap_area *n_va;
585  int nr = 0;
586 
587  /*
588  * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
589  * should not expect such behaviour. This just simplifies locking for
590  * the case that isn't actually used at the moment anyway.
591  */
592  if (!sync && !force_flush) {
593  if (!spin_trylock(&purge_lock))
594  return;
595  } else
596  spin_lock(&purge_lock);
597 
598  if (sync)
599  purge_fragmented_blocks_allcpus();
600 
601  rcu_read_lock();
602  list_for_each_entry_rcu(va, &vmap_area_list, list) {
603  if (va->flags & VM_LAZY_FREE) {
604  if (va->va_start < *start)
605  *start = va->va_start;
606  if (va->va_end > *end)
607  *end = va->va_end;
608  nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
609  list_add_tail(&va->purge_list, &valist);
610  va->flags |= VM_LAZY_FREEING;
611  va->flags &= ~VM_LAZY_FREE;
612  }
613  }
614  rcu_read_unlock();
615 
616  if (nr)
617  atomic_sub(nr, &vmap_lazy_nr);
618 
619  if (nr || force_flush)
620  flush_tlb_kernel_range(*start, *end);
621 
622  if (nr) {
623  spin_lock(&vmap_area_lock);
624  list_for_each_entry_safe(va, n_va, &valist, purge_list)
625  __free_vmap_area(va);
626  spin_unlock(&vmap_area_lock);
627  }
628  spin_unlock(&purge_lock);
629 }
630 
631 /*
632  * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
633  * is already purging.
634  */
635 static void try_purge_vmap_area_lazy(void)
636 {
637  unsigned long start = ULONG_MAX, end = 0;
638 
639  __purge_vmap_area_lazy(&start, &end, 0, 0);
640 }
641 
642 /*
643  * Kick off a purge of the outstanding lazy areas.
644  */
645 static void purge_vmap_area_lazy(void)
646 {
647  unsigned long start = ULONG_MAX, end = 0;
648 
649  __purge_vmap_area_lazy(&start, &end, 1, 0);
650 }
651 
652 /*
653  * Free a vmap area, caller ensuring that the area has been unmapped
654  * and flush_cache_vunmap had been called for the correct range
655  * previously.
656  */
657 static void free_vmap_area_noflush(struct vmap_area *va)
658 {
659  va->flags |= VM_LAZY_FREE;
660  atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
661  if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
662  try_purge_vmap_area_lazy();
663 }
664 
665 /*
666  * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
667  * called for the correct range previously.
668  */
669 static void free_unmap_vmap_area_noflush(struct vmap_area *va)
670 {
671  unmap_vmap_area(va);
672  free_vmap_area_noflush(va);
673 }
674 
675 /*
676  * Free and unmap a vmap area
677  */
678 static void free_unmap_vmap_area(struct vmap_area *va)
679 {
681  free_unmap_vmap_area_noflush(va);
682 }
683 
684 static struct vmap_area *find_vmap_area(unsigned long addr)
685 {
686  struct vmap_area *va;
687 
688  spin_lock(&vmap_area_lock);
689  va = __find_vmap_area(addr);
690  spin_unlock(&vmap_area_lock);
691 
692  return va;
693 }
694 
695 static void free_unmap_vmap_area_addr(unsigned long addr)
696 {
697  struct vmap_area *va;
698 
699  va = find_vmap_area(addr);
700  BUG_ON(!va);
701  free_unmap_vmap_area(va);
702 }
703 
704 
705 /*** Per cpu kva allocator ***/
706 
707 /*
708  * vmap space is limited especially on 32 bit architectures. Ensure there is
709  * room for at least 16 percpu vmap blocks per CPU.
710  */
711 /*
712  * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
713  * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
714  * instead (we just need a rough idea)
715  */
716 #if BITS_PER_LONG == 32
717 #define VMALLOC_SPACE (128UL*1024*1024)
718 #else
719 #define VMALLOC_SPACE (128UL*1024*1024*1024)
720 #endif
721 
722 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
723 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
724 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
725 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
726 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
727 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
728 #define VMAP_BBMAP_BITS \
729  VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
730  VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
731  VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
732 
733 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
734 
735 static bool vmap_initialized __read_mostly = false;
736 
739  struct list_head free;
740 };
741 
742 struct vmap_block {
744  struct vmap_area *va;
746  unsigned long free, dirty;
747  DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
748  DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
751  struct list_head purge;
752 };
753 
754 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
756 
757 /*
758  * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
759  * in the free path. Could get rid of this if we change the API to return a
760  * "cookie" from alloc, to be passed to free. But no big deal yet.
761  */
762 static DEFINE_SPINLOCK(vmap_block_tree_lock);
763 static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
764 
765 /*
766  * We should probably have a fallback mechanism to allocate virtual memory
767  * out of partially filled vmap blocks. However vmap block sizing should be
768  * fairly reasonable according to the vmalloc size, so it shouldn't be a
769  * big problem.
770  */
771 
772 static unsigned long addr_to_vb_idx(unsigned long addr)
773 {
774  addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
775  addr /= VMAP_BLOCK_SIZE;
776  return addr;
777 }
778 
779 static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
780 {
781  struct vmap_block_queue *vbq;
782  struct vmap_block *vb;
783  struct vmap_area *va;
784  unsigned long vb_idx;
785  int node, err;
786 
787  node = numa_node_id();
788 
789  vb = kmalloc_node(sizeof(struct vmap_block),
790  gfp_mask & GFP_RECLAIM_MASK, node);
791  if (unlikely(!vb))
792  return ERR_PTR(-ENOMEM);
793 
794  va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
796  node, gfp_mask);
797  if (IS_ERR(va)) {
798  kfree(vb);
799  return ERR_CAST(va);
800  }
801 
802  err = radix_tree_preload(gfp_mask);
803  if (unlikely(err)) {
804  kfree(vb);
805  free_vmap_area(va);
806  return ERR_PTR(err);
807  }
808 
809  spin_lock_init(&vb->lock);
810  vb->va = va;
811  vb->free = VMAP_BBMAP_BITS;
812  vb->dirty = 0;
813  bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
814  bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
815  INIT_LIST_HEAD(&vb->free_list);
816 
817  vb_idx = addr_to_vb_idx(va->va_start);
818  spin_lock(&vmap_block_tree_lock);
819  err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
820  spin_unlock(&vmap_block_tree_lock);
821  BUG_ON(err);
822  radix_tree_preload_end();
823 
825  vb->vbq = vbq;
826  spin_lock(&vbq->lock);
827  list_add_rcu(&vb->free_list, &vbq->free);
828  spin_unlock(&vbq->lock);
830 
831  return vb;
832 }
833 
834 static void free_vmap_block(struct vmap_block *vb)
835 {
836  struct vmap_block *tmp;
837  unsigned long vb_idx;
838 
839  vb_idx = addr_to_vb_idx(vb->va->va_start);
840  spin_lock(&vmap_block_tree_lock);
841  tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
842  spin_unlock(&vmap_block_tree_lock);
843  BUG_ON(tmp != vb);
844 
845  free_vmap_area_noflush(vb->va);
846  kfree_rcu(vb, rcu_head);
847 }
848 
849 static void purge_fragmented_blocks(int cpu)
850 {
851  LIST_HEAD(purge);
852  struct vmap_block *vb;
853  struct vmap_block *n_vb;
854  struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
855 
856  rcu_read_lock();
857  list_for_each_entry_rcu(vb, &vbq->free, free_list) {
858 
859  if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
860  continue;
861 
862  spin_lock(&vb->lock);
863  if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
864  vb->free = 0; /* prevent further allocs after releasing lock */
865  vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
866  bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
867  bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
868  spin_lock(&vbq->lock);
869  list_del_rcu(&vb->free_list);
870  spin_unlock(&vbq->lock);
871  spin_unlock(&vb->lock);
872  list_add_tail(&vb->purge, &purge);
873  } else
874  spin_unlock(&vb->lock);
875  }
876  rcu_read_unlock();
877 
878  list_for_each_entry_safe(vb, n_vb, &purge, purge) {
879  list_del(&vb->purge);
880  free_vmap_block(vb);
881  }
882 }
883 
884 static void purge_fragmented_blocks_thiscpu(void)
885 {
886  purge_fragmented_blocks(smp_processor_id());
887 }
888 
889 static void purge_fragmented_blocks_allcpus(void)
890 {
891  int cpu;
892 
894  purge_fragmented_blocks(cpu);
895 }
896 
897 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
898 {
899  struct vmap_block_queue *vbq;
900  struct vmap_block *vb;
901  unsigned long addr = 0;
902  unsigned int order;
903  int purge = 0;
904 
905  BUG_ON(size & ~PAGE_MASK);
907  if (WARN_ON(size == 0)) {
908  /*
909  * Allocating 0 bytes isn't what caller wants since
910  * get_order(0) returns funny result. Just warn and terminate
911  * early.
912  */
913  return NULL;
914  }
915  order = get_order(size);
916 
917 again:
918  rcu_read_lock();
920  list_for_each_entry_rcu(vb, &vbq->free, free_list) {
921  int i;
922 
923  spin_lock(&vb->lock);
924  if (vb->free < 1UL << order)
925  goto next;
926 
927  i = bitmap_find_free_region(vb->alloc_map,
928  VMAP_BBMAP_BITS, order);
929 
930  if (i < 0) {
931  if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
932  /* fragmented and no outstanding allocations */
933  BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
934  purge = 1;
935  }
936  goto next;
937  }
938  addr = vb->va->va_start + (i << PAGE_SHIFT);
939  BUG_ON(addr_to_vb_idx(addr) !=
940  addr_to_vb_idx(vb->va->va_start));
941  vb->free -= 1UL << order;
942  if (vb->free == 0) {
943  spin_lock(&vbq->lock);
944  list_del_rcu(&vb->free_list);
945  spin_unlock(&vbq->lock);
946  }
947  spin_unlock(&vb->lock);
948  break;
949 next:
950  spin_unlock(&vb->lock);
951  }
952 
953  if (purge)
954  purge_fragmented_blocks_thiscpu();
955 
957  rcu_read_unlock();
958 
959  if (!addr) {
960  vb = new_vmap_block(gfp_mask);
961  if (IS_ERR(vb))
962  return vb;
963  goto again;
964  }
965 
966  return (void *)addr;
967 }
968 
969 static void vb_free(const void *addr, unsigned long size)
970 {
971  unsigned long offset;
972  unsigned long vb_idx;
973  unsigned int order;
974  struct vmap_block *vb;
975 
976  BUG_ON(size & ~PAGE_MASK);
978 
979  flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
980 
981  order = get_order(size);
982 
983  offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
984 
985  vb_idx = addr_to_vb_idx((unsigned long)addr);
986  rcu_read_lock();
987  vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
988  rcu_read_unlock();
989  BUG_ON(!vb);
990 
991  vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
992 
993  spin_lock(&vb->lock);
994  BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
995 
996  vb->dirty += 1UL << order;
997  if (vb->dirty == VMAP_BBMAP_BITS) {
998  BUG_ON(vb->free);
999  spin_unlock(&vb->lock);
1000  free_vmap_block(vb);
1001  } else
1002  spin_unlock(&vb->lock);
1003 }
1004 
1019 {
1020  unsigned long start = ULONG_MAX, end = 0;
1021  int cpu;
1022  int flush = 0;
1023 
1024  if (unlikely(!vmap_initialized))
1025  return;
1026 
1027  for_each_possible_cpu(cpu) {
1028  struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1029  struct vmap_block *vb;
1030 
1031  rcu_read_lock();
1032  list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1033  int i;
1034 
1035  spin_lock(&vb->lock);
1036  i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1037  while (i < VMAP_BBMAP_BITS) {
1038  unsigned long s, e;
1039  int j;
1040  j = find_next_zero_bit(vb->dirty_map,
1041  VMAP_BBMAP_BITS, i);
1042 
1043  s = vb->va->va_start + (i << PAGE_SHIFT);
1044  e = vb->va->va_start + (j << PAGE_SHIFT);
1045  flush = 1;
1046 
1047  if (s < start)
1048  start = s;
1049  if (e > end)
1050  end = e;
1051 
1052  i = j;
1053  i = find_next_bit(vb->dirty_map,
1054  VMAP_BBMAP_BITS, i);
1055  }
1056  spin_unlock(&vb->lock);
1057  }
1058  rcu_read_unlock();
1059  }
1060 
1061  __purge_vmap_area_lazy(&start, &end, 1, flush);
1062 }
1064 
1070 void vm_unmap_ram(const void *mem, unsigned int count)
1071 {
1072  unsigned long size = count << PAGE_SHIFT;
1073  unsigned long addr = (unsigned long)mem;
1074 
1075  BUG_ON(!addr);
1076  BUG_ON(addr < VMALLOC_START);
1077  BUG_ON(addr > VMALLOC_END);
1078  BUG_ON(addr & (PAGE_SIZE-1));
1079 
1080  debug_check_no_locks_freed(mem, size);
1081  vmap_debug_free_range(addr, addr+size);
1082 
1083  if (likely(count <= VMAP_MAX_ALLOC))
1084  vb_free(mem, size);
1085  else
1086  free_unmap_vmap_area_addr(addr);
1087 }
1089 
1099 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1100 {
1101  unsigned long size = count << PAGE_SHIFT;
1102  unsigned long addr;
1103  void *mem;
1104 
1105  if (likely(count <= VMAP_MAX_ALLOC)) {
1106  mem = vb_alloc(size, GFP_KERNEL);
1107  if (IS_ERR(mem))
1108  return NULL;
1109  addr = (unsigned long)mem;
1110  } else {
1111  struct vmap_area *va;
1112  va = alloc_vmap_area(size, PAGE_SIZE,
1114  if (IS_ERR(va))
1115  return NULL;
1116 
1117  addr = va->va_start;
1118  mem = (void *)addr;
1119  }
1120  if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1121  vm_unmap_ram(mem, count);
1122  return NULL;
1123  }
1124  return mem;
1125 }
1127 
1139 {
1140  struct vm_struct *tmp, **p;
1141 
1142  BUG_ON(vmap_initialized);
1143  for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1144  if (tmp->addr >= vm->addr) {
1145  BUG_ON(tmp->addr < vm->addr + vm->size);
1146  break;
1147  } else
1148  BUG_ON(tmp->addr + tmp->size > vm->addr);
1149  }
1150  vm->next = *p;
1151  *p = vm;
1152 }
1153 
1166 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1167 {
1168  static size_t vm_init_off __initdata;
1169  unsigned long addr;
1170 
1171  addr = ALIGN(VMALLOC_START + vm_init_off, align);
1172  vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1173 
1174  vm->addr = (void *)addr;
1175 
1176  vm_area_add_early(vm);
1177 }
1178 
1180 {
1181  struct vmap_area *va;
1182  struct vm_struct *tmp;
1183  int i;
1184 
1186  struct vmap_block_queue *vbq;
1187 
1188  vbq = &per_cpu(vmap_block_queue, i);
1189  spin_lock_init(&vbq->lock);
1190  INIT_LIST_HEAD(&vbq->free);
1191  }
1192 
1193  /* Import existing vmlist entries. */
1194  for (tmp = vmlist; tmp; tmp = tmp->next) {
1195  va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1196  va->flags = VM_VM_AREA;
1197  va->va_start = (unsigned long)tmp->addr;
1198  va->va_end = va->va_start + tmp->size;
1199  va->vm = tmp;
1200  __insert_vmap_area(va);
1201  }
1202 
1203  vmap_area_pcpu_hole = VMALLOC_END;
1204 
1205  vmap_initialized = true;
1206 }
1207 
1227 int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1228  pgprot_t prot, struct page **pages)
1229 {
1230  return vmap_page_range_noflush(addr, addr + size, prot, pages);
1231 }
1232 
1247 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1248 {
1249  vunmap_page_range(addr, addr + size);
1250 }
1252 
1261 void unmap_kernel_range(unsigned long addr, unsigned long size)
1262 {
1263  unsigned long end = addr + size;
1264 
1265  flush_cache_vunmap(addr, end);
1266  vunmap_page_range(addr, end);
1267  flush_tlb_kernel_range(addr, end);
1268 }
1269 
1270 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1271 {
1272  unsigned long addr = (unsigned long)area->addr;
1273  unsigned long end = addr + area->size - PAGE_SIZE;
1274  int err;
1275 
1276  err = vmap_page_range(addr, end, prot, *pages);
1277  if (err > 0) {
1278  *pages += err;
1279  err = 0;
1280  }
1281 
1282  return err;
1283 }
1285 
1286 /*** Old vmalloc interfaces ***/
1287 DEFINE_RWLOCK(vmlist_lock);
1289 
1290 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1291  unsigned long flags, const void *caller)
1292 {
1293  vm->flags = flags;
1294  vm->addr = (void *)va->va_start;
1295  vm->size = va->va_end - va->va_start;
1296  vm->caller = caller;
1297  va->vm = vm;
1298  va->flags |= VM_VM_AREA;
1299 }
1300 
1301 static void insert_vmalloc_vmlist(struct vm_struct *vm)
1302 {
1303  struct vm_struct *tmp, **p;
1304 
1305  vm->flags &= ~VM_UNLIST;
1306  write_lock(&vmlist_lock);
1307  for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1308  if (tmp->addr >= vm->addr)
1309  break;
1310  }
1311  vm->next = *p;
1312  *p = vm;
1313  write_unlock(&vmlist_lock);
1314 }
1315 
1316 static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1317  unsigned long flags, const void *caller)
1318 {
1319  setup_vmalloc_vm(vm, va, flags, caller);
1320  insert_vmalloc_vmlist(vm);
1321 }
1322 
1323 static struct vm_struct *__get_vm_area_node(unsigned long size,
1324  unsigned long align, unsigned long flags, unsigned long start,
1325  unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1326 {
1327  struct vmap_area *va;
1328  struct vm_struct *area;
1329 
1330  BUG_ON(in_interrupt());
1331  if (flags & VM_IOREMAP) {
1332  int bit = fls(size);
1333 
1334  if (bit > IOREMAP_MAX_ORDER)
1335  bit = IOREMAP_MAX_ORDER;
1336  else if (bit < PAGE_SHIFT)
1337  bit = PAGE_SHIFT;
1338 
1339  align = 1ul << bit;
1340  }
1341 
1342  size = PAGE_ALIGN(size);
1343  if (unlikely(!size))
1344  return NULL;
1345 
1346  area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1347  if (unlikely(!area))
1348  return NULL;
1349 
1350  /*
1351  * We always allocate a guard page.
1352  */
1353  size += PAGE_SIZE;
1354 
1355  va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1356  if (IS_ERR(va)) {
1357  kfree(area);
1358  return NULL;
1359  }
1360 
1361  /*
1362  * When this function is called from __vmalloc_node_range,
1363  * we do not add vm_struct to vmlist here to avoid
1364  * accessing uninitialized members of vm_struct such as
1365  * pages and nr_pages fields. They will be set later.
1366  * To distinguish it from others, we use a VM_UNLIST flag.
1367  */
1368  if (flags & VM_UNLIST)
1369  setup_vmalloc_vm(area, va, flags, caller);
1370  else
1371  insert_vmalloc_vm(area, va, flags, caller);
1372 
1373  return area;
1374 }
1375 
1376 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1377  unsigned long start, unsigned long end)
1378 {
1379  return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1380  __builtin_return_address(0));
1381 }
1383 
1384 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1385  unsigned long start, unsigned long end,
1386  const void *caller)
1387 {
1388  return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1389  caller);
1390 }
1391 
1401 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1402 {
1403  return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1404  -1, GFP_KERNEL, __builtin_return_address(0));
1405 }
1406 
1407 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1408  const void *caller)
1409 {
1410  return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1411  -1, GFP_KERNEL, caller);
1412 }
1413 
1422 struct vm_struct *find_vm_area(const void *addr)
1423 {
1424  struct vmap_area *va;
1425 
1426  va = find_vmap_area((unsigned long)addr);
1427  if (va && va->flags & VM_VM_AREA)
1428  return va->vm;
1429 
1430  return NULL;
1431 }
1432 
1441 struct vm_struct *remove_vm_area(const void *addr)
1442 {
1443  struct vmap_area *va;
1444 
1445  va = find_vmap_area((unsigned long)addr);
1446  if (va && va->flags & VM_VM_AREA) {
1447  struct vm_struct *vm = va->vm;
1448 
1449  if (!(vm->flags & VM_UNLIST)) {
1450  struct vm_struct *tmp, **p;
1451  /*
1452  * remove from list and disallow access to
1453  * this vm_struct before unmap. (address range
1454  * confliction is maintained by vmap.)
1455  */
1457  for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1458  ;
1459  *p = tmp->next;
1461  }
1462 
1463  vmap_debug_free_range(va->va_start, va->va_end);
1464  free_unmap_vmap_area(va);
1465  vm->size -= PAGE_SIZE;
1466 
1467  return vm;
1468  }
1469  return NULL;
1470 }
1471 
1472 static void __vunmap(const void *addr, int deallocate_pages)
1473 {
1474  struct vm_struct *area;
1475 
1476  if (!addr)
1477  return;
1478 
1479  if ((PAGE_SIZE-1) & (unsigned long)addr) {
1480  WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1481  return;
1482  }
1483 
1484  area = remove_vm_area(addr);
1485  if (unlikely(!area)) {
1486  WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1487  addr);
1488  return;
1489  }
1490 
1491  debug_check_no_locks_freed(addr, area->size);
1492  debug_check_no_obj_freed(addr, area->size);
1493 
1494  if (deallocate_pages) {
1495  int i;
1496 
1497  for (i = 0; i < area->nr_pages; i++) {
1498  struct page *page = area->pages[i];
1499 
1500  BUG_ON(!page);
1501  __free_page(page);
1502  }
1503 
1504  if (area->flags & VM_VPAGES)
1505  vfree(area->pages);
1506  else
1507  kfree(area->pages);
1508  }
1509 
1510  kfree(area);
1511  return;
1512 }
1513 
1524 void vfree(const void *addr)
1525 {
1526  BUG_ON(in_interrupt());
1527 
1528  kmemleak_free(addr);
1529 
1530  __vunmap(addr, 1);
1531 }
1533 
1543 void vunmap(const void *addr)
1544 {
1545  BUG_ON(in_interrupt());
1546  might_sleep();
1547  __vunmap(addr, 0);
1548 }
1550 
1561 void *vmap(struct page **pages, unsigned int count,
1562  unsigned long flags, pgprot_t prot)
1563 {
1564  struct vm_struct *area;
1565 
1566  might_sleep();
1567 
1568  if (count > totalram_pages)
1569  return NULL;
1570 
1571  area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1572  __builtin_return_address(0));
1573  if (!area)
1574  return NULL;
1575 
1576  if (map_vm_area(area, prot, &pages)) {
1577  vunmap(area->addr);
1578  return NULL;
1579  }
1580 
1581  return area->addr;
1582 }
1584 
1585 static void *__vmalloc_node(unsigned long size, unsigned long align,
1586  gfp_t gfp_mask, pgprot_t prot,
1587  int node, const void *caller);
1588 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1589  pgprot_t prot, int node, const void *caller)
1590 {
1591  const int order = 0;
1592  struct page **pages;
1593  unsigned int nr_pages, array_size, i;
1594  gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1595 
1596  nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1597  array_size = (nr_pages * sizeof(struct page *));
1598 
1599  area->nr_pages = nr_pages;
1600  /* Please note that the recursion is strictly bounded. */
1601  if (array_size > PAGE_SIZE) {
1602  pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1603  PAGE_KERNEL, node, caller);
1604  area->flags |= VM_VPAGES;
1605  } else {
1606  pages = kmalloc_node(array_size, nested_gfp, node);
1607  }
1608  area->pages = pages;
1609  area->caller = caller;
1610  if (!area->pages) {
1611  remove_vm_area(area->addr);
1612  kfree(area);
1613  return NULL;
1614  }
1615 
1616  for (i = 0; i < area->nr_pages; i++) {
1617  struct page *page;
1618  gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1619 
1620  if (node < 0)
1621  page = alloc_page(tmp_mask);
1622  else
1623  page = alloc_pages_node(node, tmp_mask, order);
1624 
1625  if (unlikely(!page)) {
1626  /* Successfully allocated i pages, free them in __vunmap() */
1627  area->nr_pages = i;
1628  goto fail;
1629  }
1630  area->pages[i] = page;
1631  }
1632 
1633  if (map_vm_area(area, prot, &pages))
1634  goto fail;
1635  return area->addr;
1636 
1637 fail:
1638  warn_alloc_failed(gfp_mask, order,
1639  "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1640  (area->nr_pages*PAGE_SIZE), area->size);
1641  vfree(area->addr);
1642  return NULL;
1643 }
1644 
1660 void *__vmalloc_node_range(unsigned long size, unsigned long align,
1661  unsigned long start, unsigned long end, gfp_t gfp_mask,
1662  pgprot_t prot, int node, const void *caller)
1663 {
1664  struct vm_struct *area;
1665  void *addr;
1666  unsigned long real_size = size;
1667 
1668  size = PAGE_ALIGN(size);
1669  if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1670  goto fail;
1671 
1672  area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
1673  start, end, node, gfp_mask, caller);
1674  if (!area)
1675  goto fail;
1676 
1677  addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1678  if (!addr)
1679  return NULL;
1680 
1681  /*
1682  * In this function, newly allocated vm_struct is not added
1683  * to vmlist at __get_vm_area_node(). so, it is added here.
1684  */
1685  insert_vmalloc_vmlist(area);
1686 
1687  /*
1688  * A ref_count = 3 is needed because the vm_struct and vmap_area
1689  * structures allocated in the __get_vm_area_node() function contain
1690  * references to the virtual address of the vmalloc'ed block.
1691  */
1692  kmemleak_alloc(addr, real_size, 3, gfp_mask);
1693 
1694  return addr;
1695 
1696 fail:
1697  warn_alloc_failed(gfp_mask, 0,
1698  "vmalloc: allocation failure: %lu bytes\n",
1699  real_size);
1700  return NULL;
1701 }
1702 
1716 static void *__vmalloc_node(unsigned long size, unsigned long align,
1717  gfp_t gfp_mask, pgprot_t prot,
1718  int node, const void *caller)
1719 {
1720  return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1721  gfp_mask, prot, node, caller);
1722 }
1723 
1724 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1725 {
1726  return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1727  __builtin_return_address(0));
1728 }
1730 
1731 static inline void *__vmalloc_node_flags(unsigned long size,
1732  int node, gfp_t flags)
1733 {
1734  return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1735  node, __builtin_return_address(0));
1736 }
1737 
1747 void *vmalloc(unsigned long size)
1748 {
1749  return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
1750 }
1752 
1763 void *vzalloc(unsigned long size)
1764 {
1765  return __vmalloc_node_flags(size, -1,
1767 }
1769 
1777 void *vmalloc_user(unsigned long size)
1778 {
1779  struct vm_struct *area;
1780  void *ret;
1781 
1782  ret = __vmalloc_node(size, SHMLBA,
1784  PAGE_KERNEL, -1, __builtin_return_address(0));
1785  if (ret) {
1786  area = find_vm_area(ret);
1787  area->flags |= VM_USERMAP;
1788  }
1789  return ret;
1790 }
1792 
1804 void *vmalloc_node(unsigned long size, int node)
1805 {
1806  return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1807  node, __builtin_return_address(0));
1808 }
1810 
1823 void *vzalloc_node(unsigned long size, int node)
1824 {
1825  return __vmalloc_node_flags(size, node,
1827 }
1829 
1830 #ifndef PAGE_KERNEL_EXEC
1831 # define PAGE_KERNEL_EXEC PAGE_KERNEL
1832 #endif
1833 
1846 void *vmalloc_exec(unsigned long size)
1847 {
1848  return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1849  -1, __builtin_return_address(0));
1850 }
1851 
1852 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1853 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1854 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1855 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1856 #else
1857 #define GFP_VMALLOC32 GFP_KERNEL
1858 #endif
1859 
1867 void *vmalloc_32(unsigned long size)
1868 {
1869  return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1870  -1, __builtin_return_address(0));
1871 }
1873 
1881 void *vmalloc_32_user(unsigned long size)
1882 {
1883  struct vm_struct *area;
1884  void *ret;
1885 
1886  ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1887  -1, __builtin_return_address(0));
1888  if (ret) {
1889  area = find_vm_area(ret);
1890  area->flags |= VM_USERMAP;
1891  }
1892  return ret;
1893 }
1895 
1896 /*
1897  * small helper routine , copy contents to buf from addr.
1898  * If the page is not present, fill zero.
1899  */
1900 
1901 static int aligned_vread(char *buf, char *addr, unsigned long count)
1902 {
1903  struct page *p;
1904  int copied = 0;
1905 
1906  while (count) {
1907  unsigned long offset, length;
1908 
1909  offset = (unsigned long)addr & ~PAGE_MASK;
1910  length = PAGE_SIZE - offset;
1911  if (length > count)
1912  length = count;
1913  p = vmalloc_to_page(addr);
1914  /*
1915  * To do safe access to this _mapped_ area, we need
1916  * lock. But adding lock here means that we need to add
1917  * overhead of vmalloc()/vfree() calles for this _debug_
1918  * interface, rarely used. Instead of that, we'll use
1919  * kmap() and get small overhead in this access function.
1920  */
1921  if (p) {
1922  /*
1923  * we can expect USER0 is not used (see vread/vwrite's
1924  * function description)
1925  */
1926  void *map = kmap_atomic(p);
1927  memcpy(buf, map + offset, length);
1928  kunmap_atomic(map);
1929  } else
1930  memset(buf, 0, length);
1931 
1932  addr += length;
1933  buf += length;
1934  copied += length;
1935  count -= length;
1936  }
1937  return copied;
1938 }
1939 
1940 static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1941 {
1942  struct page *p;
1943  int copied = 0;
1944 
1945  while (count) {
1946  unsigned long offset, length;
1947 
1948  offset = (unsigned long)addr & ~PAGE_MASK;
1949  length = PAGE_SIZE - offset;
1950  if (length > count)
1951  length = count;
1952  p = vmalloc_to_page(addr);
1953  /*
1954  * To do safe access to this _mapped_ area, we need
1955  * lock. But adding lock here means that we need to add
1956  * overhead of vmalloc()/vfree() calles for this _debug_
1957  * interface, rarely used. Instead of that, we'll use
1958  * kmap() and get small overhead in this access function.
1959  */
1960  if (p) {
1961  /*
1962  * we can expect USER0 is not used (see vread/vwrite's
1963  * function description)
1964  */
1965  void *map = kmap_atomic(p);
1966  memcpy(map + offset, buf, length);
1967  kunmap_atomic(map);
1968  }
1969  addr += length;
1970  buf += length;
1971  copied += length;
1972  count -= length;
1973  }
1974  return copied;
1975 }
1976 
2003 long vread(char *buf, char *addr, unsigned long count)
2004 {
2005  struct vm_struct *tmp;
2006  char *vaddr, *buf_start = buf;
2007  unsigned long buflen = count;
2008  unsigned long n;
2009 
2010  /* Don't allow overflow */
2011  if ((unsigned long) addr + count < count)
2012  count = -(unsigned long) addr;
2013 
2015  for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2016  vaddr = (char *) tmp->addr;
2017  if (addr >= vaddr + tmp->size - PAGE_SIZE)
2018  continue;
2019  while (addr < vaddr) {
2020  if (count == 0)
2021  goto finished;
2022  *buf = '\0';
2023  buf++;
2024  addr++;
2025  count--;
2026  }
2027  n = vaddr + tmp->size - PAGE_SIZE - addr;
2028  if (n > count)
2029  n = count;
2030  if (!(tmp->flags & VM_IOREMAP))
2031  aligned_vread(buf, addr, n);
2032  else /* IOREMAP area is treated as memory hole */
2033  memset(buf, 0, n);
2034  buf += n;
2035  addr += n;
2036  count -= n;
2037  }
2038 finished:
2040 
2041  if (buf == buf_start)
2042  return 0;
2043  /* zero-fill memory holes */
2044  if (buf != buf_start + buflen)
2045  memset(buf, 0, buflen - (buf - buf_start));
2046 
2047  return buflen;
2048 }
2049 
2076 long vwrite(char *buf, char *addr, unsigned long count)
2077 {
2078  struct vm_struct *tmp;
2079  char *vaddr;
2080  unsigned long n, buflen;
2081  int copied = 0;
2082 
2083  /* Don't allow overflow */
2084  if ((unsigned long) addr + count < count)
2085  count = -(unsigned long) addr;
2086  buflen = count;
2087 
2089  for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2090  vaddr = (char *) tmp->addr;
2091  if (addr >= vaddr + tmp->size - PAGE_SIZE)
2092  continue;
2093  while (addr < vaddr) {
2094  if (count == 0)
2095  goto finished;
2096  buf++;
2097  addr++;
2098  count--;
2099  }
2100  n = vaddr + tmp->size - PAGE_SIZE - addr;
2101  if (n > count)
2102  n = count;
2103  if (!(tmp->flags & VM_IOREMAP)) {
2104  aligned_vwrite(buf, addr, n);
2105  copied++;
2106  }
2107  buf += n;
2108  addr += n;
2109  count -= n;
2110  }
2111 finished:
2113  if (!copied)
2114  return 0;
2115  return buflen;
2116 }
2117 
2132 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2133  unsigned long pgoff)
2134 {
2135  struct vm_struct *area;
2136  unsigned long uaddr = vma->vm_start;
2137  unsigned long usize = vma->vm_end - vma->vm_start;
2138 
2139  if ((PAGE_SIZE-1) & (unsigned long)addr)
2140  return -EINVAL;
2141 
2142  area = find_vm_area(addr);
2143  if (!area)
2144  return -EINVAL;
2145 
2146  if (!(area->flags & VM_USERMAP))
2147  return -EINVAL;
2148 
2149  if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
2150  return -EINVAL;
2151 
2152  addr += pgoff << PAGE_SHIFT;
2153  do {
2154  struct page *page = vmalloc_to_page(addr);
2155  int ret;
2156 
2157  ret = vm_insert_page(vma, uaddr, page);
2158  if (ret)
2159  return ret;
2160 
2161  uaddr += PAGE_SIZE;
2162  addr += PAGE_SIZE;
2163  usize -= PAGE_SIZE;
2164  } while (usize > 0);
2165 
2166  vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2167 
2168  return 0;
2169 }
2171 
2172 /*
2173  * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2174  * have one.
2175  */
2177 {
2178 }
2179 
2180 
2181 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2182 {
2183  pte_t ***p = data;
2184 
2185  if (p) {
2186  *(*p) = pte;
2187  (*p)++;
2188  }
2189  return 0;
2190 }
2191 
2206 struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2207 {
2208  struct vm_struct *area;
2209 
2210  area = get_vm_area_caller(size, VM_IOREMAP,
2211  __builtin_return_address(0));
2212  if (area == NULL)
2213  return NULL;
2214 
2215  /*
2216  * This ensures that page tables are constructed for this region
2217  * of kernel virtual address space and mapped into init_mm.
2218  */
2219  if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2220  size, f, ptes ? &ptes : NULL)) {
2221  free_vm_area(area);
2222  return NULL;
2223  }
2224 
2225  return area;
2226 }
2228 
2229 void free_vm_area(struct vm_struct *area)
2230 {
2231  struct vm_struct *ret;
2232  ret = remove_vm_area(area->addr);
2233  BUG_ON(ret != area);
2234  kfree(area);
2235 }
2237 
2238 #ifdef CONFIG_SMP
2239 static struct vmap_area *node_to_va(struct rb_node *n)
2240 {
2241  return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2242 }
2243 
2256 static bool pvm_find_next_prev(unsigned long end,
2257  struct vmap_area **pnext,
2258  struct vmap_area **pprev)
2259 {
2260  struct rb_node *n = vmap_area_root.rb_node;
2261  struct vmap_area *va = NULL;
2262 
2263  while (n) {
2264  va = rb_entry(n, struct vmap_area, rb_node);
2265  if (end < va->va_end)
2266  n = n->rb_left;
2267  else if (end > va->va_end)
2268  n = n->rb_right;
2269  else
2270  break;
2271  }
2272 
2273  if (!va)
2274  return false;
2275 
2276  if (va->va_end > end) {
2277  *pnext = va;
2278  *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2279  } else {
2280  *pprev = va;
2281  *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2282  }
2283  return true;
2284 }
2285 
2302 static unsigned long pvm_determine_end(struct vmap_area **pnext,
2303  struct vmap_area **pprev,
2304  unsigned long align)
2305 {
2306  const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2307  unsigned long addr;
2308 
2309  if (*pnext)
2310  addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2311  else
2312  addr = vmalloc_end;
2313 
2314  while (*pprev && (*pprev)->va_end > addr) {
2315  *pnext = *pprev;
2316  *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2317  }
2318 
2319  return addr;
2320 }
2321 
2346 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2347  const size_t *sizes, int nr_vms,
2348  size_t align)
2349 {
2350  const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2351  const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2352  struct vmap_area **vas, *prev, *next;
2353  struct vm_struct **vms;
2354  int area, area2, last_area, term_area;
2355  unsigned long base, start, end, last_end;
2356  bool purged = false;
2357 
2358  /* verify parameters and allocate data structures */
2359  BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2360  for (last_area = 0, area = 0; area < nr_vms; area++) {
2361  start = offsets[area];
2362  end = start + sizes[area];
2363 
2364  /* is everything aligned properly? */
2365  BUG_ON(!IS_ALIGNED(offsets[area], align));
2366  BUG_ON(!IS_ALIGNED(sizes[area], align));
2367 
2368  /* detect the area with the highest address */
2369  if (start > offsets[last_area])
2370  last_area = area;
2371 
2372  for (area2 = 0; area2 < nr_vms; area2++) {
2373  unsigned long start2 = offsets[area2];
2374  unsigned long end2 = start2 + sizes[area2];
2375 
2376  if (area2 == area)
2377  continue;
2378 
2379  BUG_ON(start2 >= start && start2 < end);
2380  BUG_ON(end2 <= end && end2 > start);
2381  }
2382  }
2383  last_end = offsets[last_area] + sizes[last_area];
2384 
2385  if (vmalloc_end - vmalloc_start < last_end) {
2386  WARN_ON(true);
2387  return NULL;
2388  }
2389 
2390  vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2391  vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2392  if (!vas || !vms)
2393  goto err_free2;
2394 
2395  for (area = 0; area < nr_vms; area++) {
2396  vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2397  vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2398  if (!vas[area] || !vms[area])
2399  goto err_free;
2400  }
2401 retry:
2402  spin_lock(&vmap_area_lock);
2403 
2404  /* start scanning - we scan from the top, begin with the last area */
2405  area = term_area = last_area;
2406  start = offsets[area];
2407  end = start + sizes[area];
2408 
2409  if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2410  base = vmalloc_end - last_end;
2411  goto found;
2412  }
2413  base = pvm_determine_end(&next, &prev, align) - end;
2414 
2415  while (true) {
2416  BUG_ON(next && next->va_end <= base + end);
2417  BUG_ON(prev && prev->va_end > base + end);
2418 
2419  /*
2420  * base might have underflowed, add last_end before
2421  * comparing.
2422  */
2423  if (base + last_end < vmalloc_start + last_end) {
2424  spin_unlock(&vmap_area_lock);
2425  if (!purged) {
2426  purge_vmap_area_lazy();
2427  purged = true;
2428  goto retry;
2429  }
2430  goto err_free;
2431  }
2432 
2433  /*
2434  * If next overlaps, move base downwards so that it's
2435  * right below next and then recheck.
2436  */
2437  if (next && next->va_start < base + end) {
2438  base = pvm_determine_end(&next, &prev, align) - end;
2439  term_area = area;
2440  continue;
2441  }
2442 
2443  /*
2444  * If prev overlaps, shift down next and prev and move
2445  * base so that it's right below new next and then
2446  * recheck.
2447  */
2448  if (prev && prev->va_end > base + start) {
2449  next = prev;
2450  prev = node_to_va(rb_prev(&next->rb_node));
2451  base = pvm_determine_end(&next, &prev, align) - end;
2452  term_area = area;
2453  continue;
2454  }
2455 
2456  /*
2457  * This area fits, move on to the previous one. If
2458  * the previous one is the terminal one, we're done.
2459  */
2460  area = (area + nr_vms - 1) % nr_vms;
2461  if (area == term_area)
2462  break;
2463  start = offsets[area];
2464  end = start + sizes[area];
2465  pvm_find_next_prev(base + end, &next, &prev);
2466  }
2467 found:
2468  /* we've found a fitting base, insert all va's */
2469  for (area = 0; area < nr_vms; area++) {
2470  struct vmap_area *va = vas[area];
2471 
2472  va->va_start = base + offsets[area];
2473  va->va_end = va->va_start + sizes[area];
2474  __insert_vmap_area(va);
2475  }
2476 
2477  vmap_area_pcpu_hole = base + offsets[last_area];
2478 
2479  spin_unlock(&vmap_area_lock);
2480 
2481  /* insert all vm's */
2482  for (area = 0; area < nr_vms; area++)
2483  insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2484  pcpu_get_vm_areas);
2485 
2486  kfree(vas);
2487  return vms;
2488 
2489 err_free:
2490  for (area = 0; area < nr_vms; area++) {
2491  kfree(vas[area]);
2492  kfree(vms[area]);
2493  }
2494 err_free2:
2495  kfree(vas);
2496  kfree(vms);
2497  return NULL;
2498 }
2499 
2507 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2508 {
2509  int i;
2510 
2511  for (i = 0; i < nr_vms; i++)
2512  free_vm_area(vms[i]);
2513  kfree(vms);
2514 }
2515 #endif /* CONFIG_SMP */
2516 
2517 #ifdef CONFIG_PROC_FS
2518 static void *s_start(struct seq_file *m, loff_t *pos)
2519  __acquires(&vmlist_lock)
2520 {
2521  loff_t n = *pos;
2522  struct vm_struct *v;
2523 
2524  read_lock(&vmlist_lock);
2525  v = vmlist;
2526  while (n > 0 && v) {
2527  n--;
2528  v = v->next;
2529  }
2530  if (!n)
2531  return v;
2532 
2533  return NULL;
2534 
2535 }
2536 
2537 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2538 {
2539  struct vm_struct *v = p;
2540 
2541  ++*pos;
2542  return v->next;
2543 }
2544 
2545 static void s_stop(struct seq_file *m, void *p)
2546  __releases(&vmlist_lock)
2547 {
2548  read_unlock(&vmlist_lock);
2549 }
2550 
2551 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2552 {
2553  if (NUMA_BUILD) {
2554  unsigned int nr, *counters = m->private;
2555 
2556  if (!counters)
2557  return;
2558 
2559  memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2560 
2561  for (nr = 0; nr < v->nr_pages; nr++)
2562  counters[page_to_nid(v->pages[nr])]++;
2563 
2565  if (counters[nr])
2566  seq_printf(m, " N%u=%u", nr, counters[nr]);
2567  }
2568 }
2569 
2570 static int s_show(struct seq_file *m, void *p)
2571 {
2572  struct vm_struct *v = p;
2573 
2574  seq_printf(m, "0x%pK-0x%pK %7ld",
2575  v->addr, v->addr + v->size, v->size);
2576 
2577  if (v->caller)
2578  seq_printf(m, " %pS", v->caller);
2579 
2580  if (v->nr_pages)
2581  seq_printf(m, " pages=%d", v->nr_pages);
2582 
2583  if (v->phys_addr)
2584  seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2585 
2586  if (v->flags & VM_IOREMAP)
2587  seq_printf(m, " ioremap");
2588 
2589  if (v->flags & VM_ALLOC)
2590  seq_printf(m, " vmalloc");
2591 
2592  if (v->flags & VM_MAP)
2593  seq_printf(m, " vmap");
2594 
2595  if (v->flags & VM_USERMAP)
2596  seq_printf(m, " user");
2597 
2598  if (v->flags & VM_VPAGES)
2599  seq_printf(m, " vpages");
2600 
2601  show_numa_info(m, v);
2602  seq_putc(m, '\n');
2603  return 0;
2604 }
2605 
2606 static const struct seq_operations vmalloc_op = {
2607  .start = s_start,
2608  .next = s_next,
2609  .stop = s_stop,
2610  .show = s_show,
2611 };
2612 
2613 static int vmalloc_open(struct inode *inode, struct file *file)
2614 {
2615  unsigned int *ptr = NULL;
2616  int ret;
2617 
2618  if (NUMA_BUILD) {
2619  ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2620  if (ptr == NULL)
2621  return -ENOMEM;
2622  }
2623  ret = seq_open(file, &vmalloc_op);
2624  if (!ret) {
2625  struct seq_file *m = file->private_data;
2626  m->private = ptr;
2627  } else
2628  kfree(ptr);
2629  return ret;
2630 }
2631 
2632 static const struct file_operations proc_vmalloc_operations = {
2633  .open = vmalloc_open,
2634  .read = seq_read,
2635  .llseek = seq_lseek,
2636  .release = seq_release_private,
2637 };
2638 
2639 static int __init proc_vmalloc_init(void)
2640 {
2641  proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2642  return 0;
2643 }
2644 module_init(proc_vmalloc_init);
2645 #endif
2646