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TOMOYO Linux Cross Reference
Linux/mm/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 <tigran@veritas.com>, May 2000
  7  *  Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
  8  *  Numa awareness, Christoph Lameter, SGI, June 2005
  9  */
 10 
 11 #include <linux/vmalloc.h>
 12 #include <linux/mm.h>
 13 #include <linux/module.h>
 14 #include <linux/highmem.h>
 15 #include <linux/sched/signal.h>
 16 #include <linux/slab.h>
 17 #include <linux/spinlock.h>
 18 #include <linux/interrupt.h>
 19 #include <linux/proc_fs.h>
 20 #include <linux/seq_file.h>
 21 #include <linux/debugobjects.h>
 22 #include <linux/kallsyms.h>
 23 #include <linux/list.h>
 24 #include <linux/notifier.h>
 25 #include <linux/rbtree.h>
 26 #include <linux/radix-tree.h>
 27 #include <linux/rcupdate.h>
 28 #include <linux/pfn.h>
 29 #include <linux/kmemleak.h>
 30 #include <linux/atomic.h>
 31 #include <linux/compiler.h>
 32 #include <linux/llist.h>
 33 #include <linux/bitops.h>
 34 
 35 #include <linux/uaccess.h>
 36 #include <asm/tlbflush.h>
 37 #include <asm/shmparam.h>
 38 
 39 #include "internal.h"
 40 
 41 struct vfree_deferred {
 42         struct llist_head list;
 43         struct work_struct wq;
 44 };
 45 static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
 46 
 47 static void __vunmap(const void *, int);
 48 
 49 static void free_work(struct work_struct *w)
 50 {
 51         struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
 52         struct llist_node *t, *llnode;
 53 
 54         llist_for_each_safe(llnode, t, llist_del_all(&p->list))
 55                 __vunmap((void *)llnode, 1);
 56 }
 57 
 58 /*** Page table manipulation functions ***/
 59 
 60 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
 61 {
 62         pte_t *pte;
 63 
 64         pte = pte_offset_kernel(pmd, addr);
 65         do {
 66                 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
 67                 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
 68         } while (pte++, addr += PAGE_SIZE, addr != end);
 69 }
 70 
 71 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
 72 {
 73         pmd_t *pmd;
 74         unsigned long next;
 75 
 76         pmd = pmd_offset(pud, addr);
 77         do {
 78                 next = pmd_addr_end(addr, end);
 79                 if (pmd_clear_huge(pmd))
 80                         continue;
 81                 if (pmd_none_or_clear_bad(pmd))
 82                         continue;
 83                 vunmap_pte_range(pmd, addr, next);
 84         } while (pmd++, addr = next, addr != end);
 85 }
 86 
 87 static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end)
 88 {
 89         pud_t *pud;
 90         unsigned long next;
 91 
 92         pud = pud_offset(p4d, addr);
 93         do {
 94                 next = pud_addr_end(addr, end);
 95                 if (pud_clear_huge(pud))
 96                         continue;
 97                 if (pud_none_or_clear_bad(pud))
 98                         continue;
 99                 vunmap_pmd_range(pud, addr, next);
100         } while (pud++, addr = next, addr != end);
101 }
102 
103 static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end)
104 {
105         p4d_t *p4d;
106         unsigned long next;
107 
108         p4d = p4d_offset(pgd, addr);
109         do {
110                 next = p4d_addr_end(addr, end);
111                 if (p4d_clear_huge(p4d))
112                         continue;
113                 if (p4d_none_or_clear_bad(p4d))
114                         continue;
115                 vunmap_pud_range(p4d, addr, next);
116         } while (p4d++, addr = next, addr != end);
117 }
118 
119 static void vunmap_page_range(unsigned long addr, unsigned long end)
120 {
121         pgd_t *pgd;
122         unsigned long next;
123 
124         BUG_ON(addr >= end);
125         pgd = pgd_offset_k(addr);
126         do {
127                 next = pgd_addr_end(addr, end);
128                 if (pgd_none_or_clear_bad(pgd))
129                         continue;
130                 vunmap_p4d_range(pgd, addr, next);
131         } while (pgd++, addr = next, addr != end);
132 }
133 
134 static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
135                 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
136 {
137         pte_t *pte;
138 
139         /*
140          * nr is a running index into the array which helps higher level
141          * callers keep track of where we're up to.
142          */
143 
144         pte = pte_alloc_kernel(pmd, addr);
145         if (!pte)
146                 return -ENOMEM;
147         do {
148                 struct page *page = pages[*nr];
149 
150                 if (WARN_ON(!pte_none(*pte)))
151                         return -EBUSY;
152                 if (WARN_ON(!page))
153                         return -ENOMEM;
154                 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
155                 (*nr)++;
156         } while (pte++, addr += PAGE_SIZE, addr != end);
157         return 0;
158 }
159 
160 static int vmap_pmd_range(pud_t *pud, unsigned long addr,
161                 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
162 {
163         pmd_t *pmd;
164         unsigned long next;
165 
166         pmd = pmd_alloc(&init_mm, pud, addr);
167         if (!pmd)
168                 return -ENOMEM;
169         do {
170                 next = pmd_addr_end(addr, end);
171                 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
172                         return -ENOMEM;
173         } while (pmd++, addr = next, addr != end);
174         return 0;
175 }
176 
177 static int vmap_pud_range(p4d_t *p4d, unsigned long addr,
178                 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
179 {
180         pud_t *pud;
181         unsigned long next;
182 
183         pud = pud_alloc(&init_mm, p4d, addr);
184         if (!pud)
185                 return -ENOMEM;
186         do {
187                 next = pud_addr_end(addr, end);
188                 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
189                         return -ENOMEM;
190         } while (pud++, addr = next, addr != end);
191         return 0;
192 }
193 
194 static int vmap_p4d_range(pgd_t *pgd, unsigned long addr,
195                 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
196 {
197         p4d_t *p4d;
198         unsigned long next;
199 
200         p4d = p4d_alloc(&init_mm, pgd, addr);
201         if (!p4d)
202                 return -ENOMEM;
203         do {
204                 next = p4d_addr_end(addr, end);
205                 if (vmap_pud_range(p4d, addr, next, prot, pages, nr))
206                         return -ENOMEM;
207         } while (p4d++, addr = next, addr != end);
208         return 0;
209 }
210 
211 /*
212  * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
213  * will have pfns corresponding to the "pages" array.
214  *
215  * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
216  */
217 static int vmap_page_range_noflush(unsigned long start, unsigned long end,
218                                    pgprot_t prot, struct page **pages)
219 {
220         pgd_t *pgd;
221         unsigned long next;
222         unsigned long addr = start;
223         int err = 0;
224         int nr = 0;
225 
226         BUG_ON(addr >= end);
227         pgd = pgd_offset_k(addr);
228         do {
229                 next = pgd_addr_end(addr, end);
230                 err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr);
231                 if (err)
232                         return err;
233         } while (pgd++, addr = next, addr != end);
234 
235         return nr;
236 }
237 
238 static int vmap_page_range(unsigned long start, unsigned long end,
239                            pgprot_t prot, struct page **pages)
240 {
241         int ret;
242 
243         ret = vmap_page_range_noflush(start, end, prot, pages);
244         flush_cache_vmap(start, end);
245         return ret;
246 }
247 
248 int is_vmalloc_or_module_addr(const void *x)
249 {
250         /*
251          * ARM, x86-64 and sparc64 put modules in a special place,
252          * and fall back on vmalloc() if that fails. Others
253          * just put it in the vmalloc space.
254          */
255 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
256         unsigned long addr = (unsigned long)x;
257         if (addr >= MODULES_VADDR && addr < MODULES_END)
258                 return 1;
259 #endif
260         return is_vmalloc_addr(x);
261 }
262 
263 /*
264  * Walk a vmap address to the struct page it maps.
265  */
266 struct page *vmalloc_to_page(const void *vmalloc_addr)
267 {
268         unsigned long addr = (unsigned long) vmalloc_addr;
269         struct page *page = NULL;
270         pgd_t *pgd = pgd_offset_k(addr);
271         p4d_t *p4d;
272         pud_t *pud;
273         pmd_t *pmd;
274         pte_t *ptep, pte;
275 
276         /*
277          * XXX we might need to change this if we add VIRTUAL_BUG_ON for
278          * architectures that do not vmalloc module space
279          */
280         VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
281 
282         if (pgd_none(*pgd))
283                 return NULL;
284         p4d = p4d_offset(pgd, addr);
285         if (p4d_none(*p4d))
286                 return NULL;
287         pud = pud_offset(p4d, addr);
288 
289         /*
290          * Don't dereference bad PUD or PMD (below) entries. This will also
291          * identify huge mappings, which we may encounter on architectures
292          * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be
293          * identified as vmalloc addresses by is_vmalloc_addr(), but are
294          * not [unambiguously] associated with a struct page, so there is
295          * no correct value to return for them.
296          */
297         WARN_ON_ONCE(pud_bad(*pud));
298         if (pud_none(*pud) || pud_bad(*pud))
299                 return NULL;
300         pmd = pmd_offset(pud, addr);
301         WARN_ON_ONCE(pmd_bad(*pmd));
302         if (pmd_none(*pmd) || pmd_bad(*pmd))
303                 return NULL;
304 
305         ptep = pte_offset_map(pmd, addr);
306         pte = *ptep;
307         if (pte_present(pte))
308                 page = pte_page(pte);
309         pte_unmap(ptep);
310         return page;
311 }
312 EXPORT_SYMBOL(vmalloc_to_page);
313 
314 /*
315  * Map a vmalloc()-space virtual address to the physical page frame number.
316  */
317 unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
318 {
319         return page_to_pfn(vmalloc_to_page(vmalloc_addr));
320 }
321 EXPORT_SYMBOL(vmalloc_to_pfn);
322 
323 
324 /*** Global kva allocator ***/
325 
326 #define VM_LAZY_FREE    0x02
327 #define VM_VM_AREA      0x04
328 
329 static DEFINE_SPINLOCK(vmap_area_lock);
330 /* Export for kexec only */
331 LIST_HEAD(vmap_area_list);
332 static LLIST_HEAD(vmap_purge_list);
333 static struct rb_root vmap_area_root = RB_ROOT;
334 
335 /* The vmap cache globals are protected by vmap_area_lock */
336 static struct rb_node *free_vmap_cache;
337 static unsigned long cached_hole_size;
338 static unsigned long cached_vstart;
339 static unsigned long cached_align;
340 
341 static unsigned long vmap_area_pcpu_hole;
342 
343 static struct vmap_area *__find_vmap_area(unsigned long addr)
344 {
345         struct rb_node *n = vmap_area_root.rb_node;
346 
347         while (n) {
348                 struct vmap_area *va;
349 
350                 va = rb_entry(n, struct vmap_area, rb_node);
351                 if (addr < va->va_start)
352                         n = n->rb_left;
353                 else if (addr >= va->va_end)
354                         n = n->rb_right;
355                 else
356                         return va;
357         }
358 
359         return NULL;
360 }
361 
362 static void __insert_vmap_area(struct vmap_area *va)
363 {
364         struct rb_node **p = &vmap_area_root.rb_node;
365         struct rb_node *parent = NULL;
366         struct rb_node *tmp;
367 
368         while (*p) {
369                 struct vmap_area *tmp_va;
370 
371                 parent = *p;
372                 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
373                 if (va->va_start < tmp_va->va_end)
374                         p = &(*p)->rb_left;
375                 else if (va->va_end > tmp_va->va_start)
376                         p = &(*p)->rb_right;
377                 else
378                         BUG();
379         }
380 
381         rb_link_node(&va->rb_node, parent, p);
382         rb_insert_color(&va->rb_node, &vmap_area_root);
383 
384         /* address-sort this list */
385         tmp = rb_prev(&va->rb_node);
386         if (tmp) {
387                 struct vmap_area *prev;
388                 prev = rb_entry(tmp, struct vmap_area, rb_node);
389                 list_add_rcu(&va->list, &prev->list);
390         } else
391                 list_add_rcu(&va->list, &vmap_area_list);
392 }
393 
394 static void purge_vmap_area_lazy(void);
395 
396 static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
397 
398 /*
399  * Allocate a region of KVA of the specified size and alignment, within the
400  * vstart and vend.
401  */
402 static struct vmap_area *alloc_vmap_area(unsigned long size,
403                                 unsigned long align,
404                                 unsigned long vstart, unsigned long vend,
405                                 int node, gfp_t gfp_mask)
406 {
407         struct vmap_area *va;
408         struct rb_node *n;
409         unsigned long addr;
410         int purged = 0;
411         struct vmap_area *first;
412 
413         BUG_ON(!size);
414         BUG_ON(offset_in_page(size));
415         BUG_ON(!is_power_of_2(align));
416 
417         might_sleep();
418 
419         va = kmalloc_node(sizeof(struct vmap_area),
420                         gfp_mask & GFP_RECLAIM_MASK, node);
421         if (unlikely(!va))
422                 return ERR_PTR(-ENOMEM);
423 
424         /*
425          * Only scan the relevant parts containing pointers to other objects
426          * to avoid false negatives.
427          */
428         kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
429 
430 retry:
431         spin_lock(&vmap_area_lock);
432         /*
433          * Invalidate cache if we have more permissive parameters.
434          * cached_hole_size notes the largest hole noticed _below_
435          * the vmap_area cached in free_vmap_cache: if size fits
436          * into that hole, we want to scan from vstart to reuse
437          * the hole instead of allocating above free_vmap_cache.
438          * Note that __free_vmap_area may update free_vmap_cache
439          * without updating cached_hole_size or cached_align.
440          */
441         if (!free_vmap_cache ||
442                         size < cached_hole_size ||
443                         vstart < cached_vstart ||
444                         align < cached_align) {
445 nocache:
446                 cached_hole_size = 0;
447                 free_vmap_cache = NULL;
448         }
449         /* record if we encounter less permissive parameters */
450         cached_vstart = vstart;
451         cached_align = align;
452 
453         /* find starting point for our search */
454         if (free_vmap_cache) {
455                 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
456                 addr = ALIGN(first->va_end, align);
457                 if (addr < vstart)
458                         goto nocache;
459                 if (addr + size < addr)
460                         goto overflow;
461 
462         } else {
463                 addr = ALIGN(vstart, align);
464                 if (addr + size < addr)
465                         goto overflow;
466 
467                 n = vmap_area_root.rb_node;
468                 first = NULL;
469 
470                 while (n) {
471                         struct vmap_area *tmp;
472                         tmp = rb_entry(n, struct vmap_area, rb_node);
473                         if (tmp->va_end >= addr) {
474                                 first = tmp;
475                                 if (tmp->va_start <= addr)
476                                         break;
477                                 n = n->rb_left;
478                         } else
479                                 n = n->rb_right;
480                 }
481 
482                 if (!first)
483                         goto found;
484         }
485 
486         /* from the starting point, walk areas until a suitable hole is found */
487         while (addr + size > first->va_start && addr + size <= vend) {
488                 if (addr + cached_hole_size < first->va_start)
489                         cached_hole_size = first->va_start - addr;
490                 addr = ALIGN(first->va_end, align);
491                 if (addr + size < addr)
492                         goto overflow;
493 
494                 if (list_is_last(&first->list, &vmap_area_list))
495                         goto found;
496 
497                 first = list_next_entry(first, list);
498         }
499 
500 found:
501         /*
502          * Check also calculated address against the vstart,
503          * because it can be 0 because of big align request.
504          */
505         if (addr + size > vend || addr < vstart)
506                 goto overflow;
507 
508         va->va_start = addr;
509         va->va_end = addr + size;
510         va->flags = 0;
511         __insert_vmap_area(va);
512         free_vmap_cache = &va->rb_node;
513         spin_unlock(&vmap_area_lock);
514 
515         BUG_ON(!IS_ALIGNED(va->va_start, align));
516         BUG_ON(va->va_start < vstart);
517         BUG_ON(va->va_end > vend);
518 
519         return va;
520 
521 overflow:
522         spin_unlock(&vmap_area_lock);
523         if (!purged) {
524                 purge_vmap_area_lazy();
525                 purged = 1;
526                 goto retry;
527         }
528 
529         if (gfpflags_allow_blocking(gfp_mask)) {
530                 unsigned long freed = 0;
531                 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
532                 if (freed > 0) {
533                         purged = 0;
534                         goto retry;
535                 }
536         }
537 
538         if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
539                 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
540                         size);
541         kfree(va);
542         return ERR_PTR(-EBUSY);
543 }
544 
545 int register_vmap_purge_notifier(struct notifier_block *nb)
546 {
547         return blocking_notifier_chain_register(&vmap_notify_list, nb);
548 }
549 EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
550 
551 int unregister_vmap_purge_notifier(struct notifier_block *nb)
552 {
553         return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
554 }
555 EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
556 
557 static void __free_vmap_area(struct vmap_area *va)
558 {
559         BUG_ON(RB_EMPTY_NODE(&va->rb_node));
560 
561         if (free_vmap_cache) {
562                 if (va->va_end < cached_vstart) {
563                         free_vmap_cache = NULL;
564                 } else {
565                         struct vmap_area *cache;
566                         cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
567                         if (va->va_start <= cache->va_start) {
568                                 free_vmap_cache = rb_prev(&va->rb_node);
569                                 /*
570                                  * We don't try to update cached_hole_size or
571                                  * cached_align, but it won't go very wrong.
572                                  */
573                         }
574                 }
575         }
576         rb_erase(&va->rb_node, &vmap_area_root);
577         RB_CLEAR_NODE(&va->rb_node);
578         list_del_rcu(&va->list);
579 
580         /*
581          * Track the highest possible candidate for pcpu area
582          * allocation.  Areas outside of vmalloc area can be returned
583          * here too, consider only end addresses which fall inside
584          * vmalloc area proper.
585          */
586         if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
587                 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
588 
589         kfree_rcu(va, rcu_head);
590 }
591 
592 /*
593  * Free a region of KVA allocated by alloc_vmap_area
594  */
595 static void free_vmap_area(struct vmap_area *va)
596 {
597         spin_lock(&vmap_area_lock);
598         __free_vmap_area(va);
599         spin_unlock(&vmap_area_lock);
600 }
601 
602 /*
603  * Clear the pagetable entries of a given vmap_area
604  */
605 static void unmap_vmap_area(struct vmap_area *va)
606 {
607         vunmap_page_range(va->va_start, va->va_end);
608 }
609 
610 /*
611  * lazy_max_pages is the maximum amount of virtual address space we gather up
612  * before attempting to purge with a TLB flush.
613  *
614  * There is a tradeoff here: a larger number will cover more kernel page tables
615  * and take slightly longer to purge, but it will linearly reduce the number of
616  * global TLB flushes that must be performed. It would seem natural to scale
617  * this number up linearly with the number of CPUs (because vmapping activity
618  * could also scale linearly with the number of CPUs), however it is likely
619  * that in practice, workloads might be constrained in other ways that mean
620  * vmap activity will not scale linearly with CPUs. Also, I want to be
621  * conservative and not introduce a big latency on huge systems, so go with
622  * a less aggressive log scale. It will still be an improvement over the old
623  * code, and it will be simple to change the scale factor if we find that it
624  * becomes a problem on bigger systems.
625  */
626 static unsigned long lazy_max_pages(void)
627 {
628         unsigned int log;
629 
630         log = fls(num_online_cpus());
631 
632         return log * (32UL * 1024 * 1024 / PAGE_SIZE);
633 }
634 
635 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
636 
637 /*
638  * Serialize vmap purging.  There is no actual criticial section protected
639  * by this look, but we want to avoid concurrent calls for performance
640  * reasons and to make the pcpu_get_vm_areas more deterministic.
641  */
642 static DEFINE_MUTEX(vmap_purge_lock);
643 
644 /* for per-CPU blocks */
645 static void purge_fragmented_blocks_allcpus(void);
646 
647 /*
648  * called before a call to iounmap() if the caller wants vm_area_struct's
649  * immediately freed.
650  */
651 void set_iounmap_nonlazy(void)
652 {
653         atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
654 }
655 
656 /*
657  * Purges all lazily-freed vmap areas.
658  */
659 static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
660 {
661         struct llist_node *valist;
662         struct vmap_area *va;
663         struct vmap_area *n_va;
664         bool do_free = false;
665 
666         lockdep_assert_held(&vmap_purge_lock);
667 
668         valist = llist_del_all(&vmap_purge_list);
669         llist_for_each_entry(va, valist, purge_list) {
670                 if (va->va_start < start)
671                         start = va->va_start;
672                 if (va->va_end > end)
673                         end = va->va_end;
674                 do_free = true;
675         }
676 
677         if (!do_free)
678                 return false;
679 
680         flush_tlb_kernel_range(start, end);
681 
682         spin_lock(&vmap_area_lock);
683         llist_for_each_entry_safe(va, n_va, valist, purge_list) {
684                 int nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
685 
686                 __free_vmap_area(va);
687                 atomic_sub(nr, &vmap_lazy_nr);
688                 cond_resched_lock(&vmap_area_lock);
689         }
690         spin_unlock(&vmap_area_lock);
691         return true;
692 }
693 
694 /*
695  * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
696  * is already purging.
697  */
698 static void try_purge_vmap_area_lazy(void)
699 {
700         if (mutex_trylock(&vmap_purge_lock)) {
701                 __purge_vmap_area_lazy(ULONG_MAX, 0);
702                 mutex_unlock(&vmap_purge_lock);
703         }
704 }
705 
706 /*
707  * Kick off a purge of the outstanding lazy areas.
708  */
709 static void purge_vmap_area_lazy(void)
710 {
711         mutex_lock(&vmap_purge_lock);
712         purge_fragmented_blocks_allcpus();
713         __purge_vmap_area_lazy(ULONG_MAX, 0);
714         mutex_unlock(&vmap_purge_lock);
715 }
716 
717 /*
718  * Free a vmap area, caller ensuring that the area has been unmapped
719  * and flush_cache_vunmap had been called for the correct range
720  * previously.
721  */
722 static void free_vmap_area_noflush(struct vmap_area *va)
723 {
724         int nr_lazy;
725 
726         nr_lazy = atomic_add_return((va->va_end - va->va_start) >> PAGE_SHIFT,
727                                     &vmap_lazy_nr);
728 
729         /* After this point, we may free va at any time */
730         llist_add(&va->purge_list, &vmap_purge_list);
731 
732         if (unlikely(nr_lazy > lazy_max_pages()))
733                 try_purge_vmap_area_lazy();
734 }
735 
736 /*
737  * Free and unmap a vmap area
738  */
739 static void free_unmap_vmap_area(struct vmap_area *va)
740 {
741         flush_cache_vunmap(va->va_start, va->va_end);
742         unmap_vmap_area(va);
743         if (debug_pagealloc_enabled())
744                 flush_tlb_kernel_range(va->va_start, va->va_end);
745 
746         free_vmap_area_noflush(va);
747 }
748 
749 static struct vmap_area *find_vmap_area(unsigned long addr)
750 {
751         struct vmap_area *va;
752 
753         spin_lock(&vmap_area_lock);
754         va = __find_vmap_area(addr);
755         spin_unlock(&vmap_area_lock);
756 
757         return va;
758 }
759 
760 /*** Per cpu kva allocator ***/
761 
762 /*
763  * vmap space is limited especially on 32 bit architectures. Ensure there is
764  * room for at least 16 percpu vmap blocks per CPU.
765  */
766 /*
767  * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
768  * to #define VMALLOC_SPACE             (VMALLOC_END-VMALLOC_START). Guess
769  * instead (we just need a rough idea)
770  */
771 #if BITS_PER_LONG == 32
772 #define VMALLOC_SPACE           (128UL*1024*1024)
773 #else
774 #define VMALLOC_SPACE           (128UL*1024*1024*1024)
775 #endif
776 
777 #define VMALLOC_PAGES           (VMALLOC_SPACE / PAGE_SIZE)
778 #define VMAP_MAX_ALLOC          BITS_PER_LONG   /* 256K with 4K pages */
779 #define VMAP_BBMAP_BITS_MAX     1024    /* 4MB with 4K pages */
780 #define VMAP_BBMAP_BITS_MIN     (VMAP_MAX_ALLOC*2)
781 #define VMAP_MIN(x, y)          ((x) < (y) ? (x) : (y)) /* can't use min() */
782 #define VMAP_MAX(x, y)          ((x) > (y) ? (x) : (y)) /* can't use max() */
783 #define VMAP_BBMAP_BITS         \
784                 VMAP_MIN(VMAP_BBMAP_BITS_MAX,   \
785                 VMAP_MAX(VMAP_BBMAP_BITS_MIN,   \
786                         VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
787 
788 #define VMAP_BLOCK_SIZE         (VMAP_BBMAP_BITS * PAGE_SIZE)
789 
790 static bool vmap_initialized __read_mostly = false;
791 
792 struct vmap_block_queue {
793         spinlock_t lock;
794         struct list_head free;
795 };
796 
797 struct vmap_block {
798         spinlock_t lock;
799         struct vmap_area *va;
800         unsigned long free, dirty;
801         unsigned long dirty_min, dirty_max; /*< dirty range */
802         struct list_head free_list;
803         struct rcu_head rcu_head;
804         struct list_head purge;
805 };
806 
807 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
808 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
809 
810 /*
811  * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
812  * in the free path. Could get rid of this if we change the API to return a
813  * "cookie" from alloc, to be passed to free. But no big deal yet.
814  */
815 static DEFINE_SPINLOCK(vmap_block_tree_lock);
816 static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
817 
818 /*
819  * We should probably have a fallback mechanism to allocate virtual memory
820  * out of partially filled vmap blocks. However vmap block sizing should be
821  * fairly reasonable according to the vmalloc size, so it shouldn't be a
822  * big problem.
823  */
824 
825 static unsigned long addr_to_vb_idx(unsigned long addr)
826 {
827         addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
828         addr /= VMAP_BLOCK_SIZE;
829         return addr;
830 }
831 
832 static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
833 {
834         unsigned long addr;
835 
836         addr = va_start + (pages_off << PAGE_SHIFT);
837         BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
838         return (void *)addr;
839 }
840 
841 /**
842  * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
843  *                  block. Of course pages number can't exceed VMAP_BBMAP_BITS
844  * @order:    how many 2^order pages should be occupied in newly allocated block
845  * @gfp_mask: flags for the page level allocator
846  *
847  * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
848  */
849 static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
850 {
851         struct vmap_block_queue *vbq;
852         struct vmap_block *vb;
853         struct vmap_area *va;
854         unsigned long vb_idx;
855         int node, err;
856         void *vaddr;
857 
858         node = numa_node_id();
859 
860         vb = kmalloc_node(sizeof(struct vmap_block),
861                         gfp_mask & GFP_RECLAIM_MASK, node);
862         if (unlikely(!vb))
863                 return ERR_PTR(-ENOMEM);
864 
865         va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
866                                         VMALLOC_START, VMALLOC_END,
867                                         node, gfp_mask);
868         if (IS_ERR(va)) {
869                 kfree(vb);
870                 return ERR_CAST(va);
871         }
872 
873         err = radix_tree_preload(gfp_mask);
874         if (unlikely(err)) {
875                 kfree(vb);
876                 free_vmap_area(va);
877                 return ERR_PTR(err);
878         }
879 
880         vaddr = vmap_block_vaddr(va->va_start, 0);
881         spin_lock_init(&vb->lock);
882         vb->va = va;
883         /* At least something should be left free */
884         BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
885         vb->free = VMAP_BBMAP_BITS - (1UL << order);
886         vb->dirty = 0;
887         vb->dirty_min = VMAP_BBMAP_BITS;
888         vb->dirty_max = 0;
889         INIT_LIST_HEAD(&vb->free_list);
890 
891         vb_idx = addr_to_vb_idx(va->va_start);
892         spin_lock(&vmap_block_tree_lock);
893         err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
894         spin_unlock(&vmap_block_tree_lock);
895         BUG_ON(err);
896         radix_tree_preload_end();
897 
898         vbq = &get_cpu_var(vmap_block_queue);
899         spin_lock(&vbq->lock);
900         list_add_tail_rcu(&vb->free_list, &vbq->free);
901         spin_unlock(&vbq->lock);
902         put_cpu_var(vmap_block_queue);
903 
904         return vaddr;
905 }
906 
907 static void free_vmap_block(struct vmap_block *vb)
908 {
909         struct vmap_block *tmp;
910         unsigned long vb_idx;
911 
912         vb_idx = addr_to_vb_idx(vb->va->va_start);
913         spin_lock(&vmap_block_tree_lock);
914         tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
915         spin_unlock(&vmap_block_tree_lock);
916         BUG_ON(tmp != vb);
917 
918         free_vmap_area_noflush(vb->va);
919         kfree_rcu(vb, rcu_head);
920 }
921 
922 static void purge_fragmented_blocks(int cpu)
923 {
924         LIST_HEAD(purge);
925         struct vmap_block *vb;
926         struct vmap_block *n_vb;
927         struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
928 
929         rcu_read_lock();
930         list_for_each_entry_rcu(vb, &vbq->free, free_list) {
931 
932                 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
933                         continue;
934 
935                 spin_lock(&vb->lock);
936                 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
937                         vb->free = 0; /* prevent further allocs after releasing lock */
938                         vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
939                         vb->dirty_min = 0;
940                         vb->dirty_max = VMAP_BBMAP_BITS;
941                         spin_lock(&vbq->lock);
942                         list_del_rcu(&vb->free_list);
943                         spin_unlock(&vbq->lock);
944                         spin_unlock(&vb->lock);
945                         list_add_tail(&vb->purge, &purge);
946                 } else
947                         spin_unlock(&vb->lock);
948         }
949         rcu_read_unlock();
950 
951         list_for_each_entry_safe(vb, n_vb, &purge, purge) {
952                 list_del(&vb->purge);
953                 free_vmap_block(vb);
954         }
955 }
956 
957 static void purge_fragmented_blocks_allcpus(void)
958 {
959         int cpu;
960 
961         for_each_possible_cpu(cpu)
962                 purge_fragmented_blocks(cpu);
963 }
964 
965 static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
966 {
967         struct vmap_block_queue *vbq;
968         struct vmap_block *vb;
969         void *vaddr = NULL;
970         unsigned int order;
971 
972         BUG_ON(offset_in_page(size));
973         BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
974         if (WARN_ON(size == 0)) {
975                 /*
976                  * Allocating 0 bytes isn't what caller wants since
977                  * get_order(0) returns funny result. Just warn and terminate
978                  * early.
979                  */
980                 return NULL;
981         }
982         order = get_order(size);
983 
984         rcu_read_lock();
985         vbq = &get_cpu_var(vmap_block_queue);
986         list_for_each_entry_rcu(vb, &vbq->free, free_list) {
987                 unsigned long pages_off;
988 
989                 spin_lock(&vb->lock);
990                 if (vb->free < (1UL << order)) {
991                         spin_unlock(&vb->lock);
992                         continue;
993                 }
994 
995                 pages_off = VMAP_BBMAP_BITS - vb->free;
996                 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
997                 vb->free -= 1UL << order;
998                 if (vb->free == 0) {
999                         spin_lock(&vbq->lock);
1000                         list_del_rcu(&vb->free_list);
1001                         spin_unlock(&vbq->lock);
1002                 }
1003 
1004                 spin_unlock(&vb->lock);
1005                 break;
1006         }
1007 
1008         put_cpu_var(vmap_block_queue);
1009         rcu_read_unlock();
1010 
1011         /* Allocate new block if nothing was found */
1012         if (!vaddr)
1013                 vaddr = new_vmap_block(order, gfp_mask);
1014 
1015         return vaddr;
1016 }
1017 
1018 static void vb_free(const void *addr, unsigned long size)
1019 {
1020         unsigned long offset;
1021         unsigned long vb_idx;
1022         unsigned int order;
1023         struct vmap_block *vb;
1024 
1025         BUG_ON(offset_in_page(size));
1026         BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
1027 
1028         flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
1029 
1030         order = get_order(size);
1031 
1032         offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
1033         offset >>= PAGE_SHIFT;
1034 
1035         vb_idx = addr_to_vb_idx((unsigned long)addr);
1036         rcu_read_lock();
1037         vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
1038         rcu_read_unlock();
1039         BUG_ON(!vb);
1040 
1041         vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
1042 
1043         if (debug_pagealloc_enabled())
1044                 flush_tlb_kernel_range((unsigned long)addr,
1045                                         (unsigned long)addr + size);
1046 
1047         spin_lock(&vb->lock);
1048 
1049         /* Expand dirty range */
1050         vb->dirty_min = min(vb->dirty_min, offset);
1051         vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1052 
1053         vb->dirty += 1UL << order;
1054         if (vb->dirty == VMAP_BBMAP_BITS) {
1055                 BUG_ON(vb->free);
1056                 spin_unlock(&vb->lock);
1057                 free_vmap_block(vb);
1058         } else
1059                 spin_unlock(&vb->lock);
1060 }
1061 
1062 /**
1063  * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1064  *
1065  * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1066  * to amortize TLB flushing overheads. What this means is that any page you
1067  * have now, may, in a former life, have been mapped into kernel virtual
1068  * address by the vmap layer and so there might be some CPUs with TLB entries
1069  * still referencing that page (additional to the regular 1:1 kernel mapping).
1070  *
1071  * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1072  * be sure that none of the pages we have control over will have any aliases
1073  * from the vmap layer.
1074  */
1075 void vm_unmap_aliases(void)
1076 {
1077         unsigned long start = ULONG_MAX, end = 0;
1078         int cpu;
1079         int flush = 0;
1080 
1081         if (unlikely(!vmap_initialized))
1082                 return;
1083 
1084         might_sleep();
1085 
1086         for_each_possible_cpu(cpu) {
1087                 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1088                 struct vmap_block *vb;
1089 
1090                 rcu_read_lock();
1091                 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1092                         spin_lock(&vb->lock);
1093                         if (vb->dirty) {
1094                                 unsigned long va_start = vb->va->va_start;
1095                                 unsigned long s, e;
1096 
1097                                 s = va_start + (vb->dirty_min << PAGE_SHIFT);
1098                                 e = va_start + (vb->dirty_max << PAGE_SHIFT);
1099 
1100                                 start = min(s, start);
1101                                 end   = max(e, end);
1102 
1103                                 flush = 1;
1104                         }
1105                         spin_unlock(&vb->lock);
1106                 }
1107                 rcu_read_unlock();
1108         }
1109 
1110         mutex_lock(&vmap_purge_lock);
1111         purge_fragmented_blocks_allcpus();
1112         if (!__purge_vmap_area_lazy(start, end) && flush)
1113                 flush_tlb_kernel_range(start, end);
1114         mutex_unlock(&vmap_purge_lock);
1115 }
1116 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1117 
1118 /**
1119  * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1120  * @mem: the pointer returned by vm_map_ram
1121  * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1122  */
1123 void vm_unmap_ram(const void *mem, unsigned int count)
1124 {
1125         unsigned long size = (unsigned long)count << PAGE_SHIFT;
1126         unsigned long addr = (unsigned long)mem;
1127         struct vmap_area *va;
1128 
1129         might_sleep();
1130         BUG_ON(!addr);
1131         BUG_ON(addr < VMALLOC_START);
1132         BUG_ON(addr > VMALLOC_END);
1133         BUG_ON(!PAGE_ALIGNED(addr));
1134 
1135         if (likely(count <= VMAP_MAX_ALLOC)) {
1136                 debug_check_no_locks_freed(mem, size);
1137                 vb_free(mem, size);
1138                 return;
1139         }
1140 
1141         va = find_vmap_area(addr);
1142         BUG_ON(!va);
1143         debug_check_no_locks_freed((void *)va->va_start,
1144                                     (va->va_end - va->va_start));
1145         free_unmap_vmap_area(va);
1146 }
1147 EXPORT_SYMBOL(vm_unmap_ram);
1148 
1149 /**
1150  * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1151  * @pages: an array of pointers to the pages to be mapped
1152  * @count: number of pages
1153  * @node: prefer to allocate data structures on this node
1154  * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1155  *
1156  * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1157  * faster than vmap so it's good.  But if you mix long-life and short-life
1158  * objects with vm_map_ram(), it could consume lots of address space through
1159  * fragmentation (especially on a 32bit machine).  You could see failures in
1160  * the end.  Please use this function for short-lived objects.
1161  *
1162  * Returns: a pointer to the address that has been mapped, or %NULL on failure
1163  */
1164 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1165 {
1166         unsigned long size = (unsigned long)count << PAGE_SHIFT;
1167         unsigned long addr;
1168         void *mem;
1169 
1170         if (likely(count <= VMAP_MAX_ALLOC)) {
1171                 mem = vb_alloc(size, GFP_KERNEL);
1172                 if (IS_ERR(mem))
1173                         return NULL;
1174                 addr = (unsigned long)mem;
1175         } else {
1176                 struct vmap_area *va;
1177                 va = alloc_vmap_area(size, PAGE_SIZE,
1178                                 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1179                 if (IS_ERR(va))
1180                         return NULL;
1181 
1182                 addr = va->va_start;
1183                 mem = (void *)addr;
1184         }
1185         if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1186                 vm_unmap_ram(mem, count);
1187                 return NULL;
1188         }
1189         return mem;
1190 }
1191 EXPORT_SYMBOL(vm_map_ram);
1192 
1193 static struct vm_struct *vmlist __initdata;
1194 
1195 /**
1196  * vm_area_add_early - add vmap area early during boot
1197  * @vm: vm_struct to add
1198  *
1199  * This function is used to add fixed kernel vm area to vmlist before
1200  * vmalloc_init() is called.  @vm->addr, @vm->size, and @vm->flags
1201  * should contain proper values and the other fields should be zero.
1202  *
1203  * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1204  */
1205 void __init vm_area_add_early(struct vm_struct *vm)
1206 {
1207         struct vm_struct *tmp, **p;
1208 
1209         BUG_ON(vmap_initialized);
1210         for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1211                 if (tmp->addr >= vm->addr) {
1212                         BUG_ON(tmp->addr < vm->addr + vm->size);
1213                         break;
1214                 } else
1215                         BUG_ON(tmp->addr + tmp->size > vm->addr);
1216         }
1217         vm->next = *p;
1218         *p = vm;
1219 }
1220 
1221 /**
1222  * vm_area_register_early - register vmap area early during boot
1223  * @vm: vm_struct to register
1224  * @align: requested alignment
1225  *
1226  * This function is used to register kernel vm area before
1227  * vmalloc_init() is called.  @vm->size and @vm->flags should contain
1228  * proper values on entry and other fields should be zero.  On return,
1229  * vm->addr contains the allocated address.
1230  *
1231  * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1232  */
1233 void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1234 {
1235         static size_t vm_init_off __initdata;
1236         unsigned long addr;
1237 
1238         addr = ALIGN(VMALLOC_START + vm_init_off, align);
1239         vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1240 
1241         vm->addr = (void *)addr;
1242 
1243         vm_area_add_early(vm);
1244 }
1245 
1246 void __init vmalloc_init(void)
1247 {
1248         struct vmap_area *va;
1249         struct vm_struct *tmp;
1250         int i;
1251 
1252         for_each_possible_cpu(i) {
1253                 struct vmap_block_queue *vbq;
1254                 struct vfree_deferred *p;
1255 
1256                 vbq = &per_cpu(vmap_block_queue, i);
1257                 spin_lock_init(&vbq->lock);
1258                 INIT_LIST_HEAD(&vbq->free);
1259                 p = &per_cpu(vfree_deferred, i);
1260                 init_llist_head(&p->list);
1261                 INIT_WORK(&p->wq, free_work);
1262         }
1263 
1264         /* Import existing vmlist entries. */
1265         for (tmp = vmlist; tmp; tmp = tmp->next) {
1266                 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1267                 va->flags = VM_VM_AREA;
1268                 va->va_start = (unsigned long)tmp->addr;
1269                 va->va_end = va->va_start + tmp->size;
1270                 va->vm = tmp;
1271                 __insert_vmap_area(va);
1272         }
1273 
1274         vmap_area_pcpu_hole = VMALLOC_END;
1275 
1276         vmap_initialized = true;
1277 }
1278 
1279 /**
1280  * map_kernel_range_noflush - map kernel VM area with the specified pages
1281  * @addr: start of the VM area to map
1282  * @size: size of the VM area to map
1283  * @prot: page protection flags to use
1284  * @pages: pages to map
1285  *
1286  * Map PFN_UP(@size) pages at @addr.  The VM area @addr and @size
1287  * specify should have been allocated using get_vm_area() and its
1288  * friends.
1289  *
1290  * NOTE:
1291  * This function does NOT do any cache flushing.  The caller is
1292  * responsible for calling flush_cache_vmap() on to-be-mapped areas
1293  * before calling this function.
1294  *
1295  * RETURNS:
1296  * The number of pages mapped on success, -errno on failure.
1297  */
1298 int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1299                              pgprot_t prot, struct page **pages)
1300 {
1301         return vmap_page_range_noflush(addr, addr + size, prot, pages);
1302 }
1303 
1304 /**
1305  * unmap_kernel_range_noflush - unmap kernel VM area
1306  * @addr: start of the VM area to unmap
1307  * @size: size of the VM area to unmap
1308  *
1309  * Unmap PFN_UP(@size) pages at @addr.  The VM area @addr and @size
1310  * specify should have been allocated using get_vm_area() and its
1311  * friends.
1312  *
1313  * NOTE:
1314  * This function does NOT do any cache flushing.  The caller is
1315  * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1316  * before calling this function and flush_tlb_kernel_range() after.
1317  */
1318 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1319 {
1320         vunmap_page_range(addr, addr + size);
1321 }
1322 EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1323 
1324 /**
1325  * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1326  * @addr: start of the VM area to unmap
1327  * @size: size of the VM area to unmap
1328  *
1329  * Similar to unmap_kernel_range_noflush() but flushes vcache before
1330  * the unmapping and tlb after.
1331  */
1332 void unmap_kernel_range(unsigned long addr, unsigned long size)
1333 {
1334         unsigned long end = addr + size;
1335 
1336         flush_cache_vunmap(addr, end);
1337         vunmap_page_range(addr, end);
1338         flush_tlb_kernel_range(addr, end);
1339 }
1340 EXPORT_SYMBOL_GPL(unmap_kernel_range);
1341 
1342 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
1343 {
1344         unsigned long addr = (unsigned long)area->addr;
1345         unsigned long end = addr + get_vm_area_size(area);
1346         int err;
1347 
1348         err = vmap_page_range(addr, end, prot, pages);
1349 
1350         return err > 0 ? 0 : err;
1351 }
1352 EXPORT_SYMBOL_GPL(map_vm_area);
1353 
1354 static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1355                               unsigned long flags, const void *caller)
1356 {
1357         spin_lock(&vmap_area_lock);
1358         vm->flags = flags;
1359         vm->addr = (void *)va->va_start;
1360         vm->size = va->va_end - va->va_start;
1361         vm->caller = caller;
1362         va->vm = vm;
1363         va->flags |= VM_VM_AREA;
1364         spin_unlock(&vmap_area_lock);
1365 }
1366 
1367 static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1368 {
1369         /*
1370          * Before removing VM_UNINITIALIZED,
1371          * we should make sure that vm has proper values.
1372          * Pair with smp_rmb() in show_numa_info().
1373          */
1374         smp_wmb();
1375         vm->flags &= ~VM_UNINITIALIZED;
1376 }
1377 
1378 static struct vm_struct *__get_vm_area_node(unsigned long size,
1379                 unsigned long align, unsigned long flags, unsigned long start,
1380                 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1381 {
1382         struct vmap_area *va;
1383         struct vm_struct *area;
1384 
1385         BUG_ON(in_interrupt());
1386         size = PAGE_ALIGN(size);
1387         if (unlikely(!size))
1388                 return NULL;
1389 
1390         if (flags & VM_IOREMAP)
1391                 align = 1ul << clamp_t(int, get_count_order_long(size),
1392                                        PAGE_SHIFT, IOREMAP_MAX_ORDER);
1393 
1394         area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1395         if (unlikely(!area))
1396                 return NULL;
1397 
1398         if (!(flags & VM_NO_GUARD))
1399                 size += PAGE_SIZE;
1400 
1401         va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1402         if (IS_ERR(va)) {
1403                 kfree(area);
1404                 return NULL;
1405         }
1406 
1407         setup_vmalloc_vm(area, va, flags, caller);
1408 
1409         return area;
1410 }
1411 
1412 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1413                                 unsigned long start, unsigned long end)
1414 {
1415         return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1416                                   GFP_KERNEL, __builtin_return_address(0));
1417 }
1418 EXPORT_SYMBOL_GPL(__get_vm_area);
1419 
1420 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1421                                        unsigned long start, unsigned long end,
1422                                        const void *caller)
1423 {
1424         return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1425                                   GFP_KERNEL, caller);
1426 }
1427 
1428 /**
1429  * get_vm_area - reserve a contiguous kernel virtual area
1430  * @size:        size of the area
1431  * @flags:       %VM_IOREMAP for I/O mappings or VM_ALLOC
1432  *
1433  * Search an area of @size in the kernel virtual mapping area,
1434  * and reserved it for out purposes.  Returns the area descriptor
1435  * on success or %NULL on failure.
1436  *
1437  * Return: the area descriptor on success or %NULL on failure.
1438  */
1439 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1440 {
1441         return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1442                                   NUMA_NO_NODE, GFP_KERNEL,
1443                                   __builtin_return_address(0));
1444 }
1445 
1446 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1447                                 const void *caller)
1448 {
1449         return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1450                                   NUMA_NO_NODE, GFP_KERNEL, caller);
1451 }
1452 
1453 /**
1454  * find_vm_area - find a continuous kernel virtual area
1455  * @addr:         base address
1456  *
1457  * Search for the kernel VM area starting at @addr, and return it.
1458  * It is up to the caller to do all required locking to keep the returned
1459  * pointer valid.
1460  *
1461  * Return: pointer to the found area or %NULL on faulure
1462  */
1463 struct vm_struct *find_vm_area(const void *addr)
1464 {
1465         struct vmap_area *va;
1466 
1467         va = find_vmap_area((unsigned long)addr);
1468         if (va && va->flags & VM_VM_AREA)
1469                 return va->vm;
1470 
1471         return NULL;
1472 }
1473 
1474 /**
1475  * remove_vm_area - find and remove a continuous kernel virtual area
1476  * @addr:           base address
1477  *
1478  * Search for the kernel VM area starting at @addr, and remove it.
1479  * This function returns the found VM area, but using it is NOT safe
1480  * on SMP machines, except for its size or flags.
1481  *
1482  * Return: pointer to the found area or %NULL on faulure
1483  */
1484 struct vm_struct *remove_vm_area(const void *addr)
1485 {
1486         struct vmap_area *va;
1487 
1488         might_sleep();
1489 
1490         va = find_vmap_area((unsigned long)addr);
1491         if (va && va->flags & VM_VM_AREA) {
1492                 struct vm_struct *vm = va->vm;
1493 
1494                 spin_lock(&vmap_area_lock);
1495                 va->vm = NULL;
1496                 va->flags &= ~VM_VM_AREA;
1497                 va->flags |= VM_LAZY_FREE;
1498                 spin_unlock(&vmap_area_lock);
1499 
1500                 kasan_free_shadow(vm);
1501                 free_unmap_vmap_area(va);
1502 
1503                 return vm;
1504         }
1505         return NULL;
1506 }
1507 
1508 static void __vunmap(const void *addr, int deallocate_pages)
1509 {
1510         struct vm_struct *area;
1511 
1512         if (!addr)
1513                 return;
1514 
1515         if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
1516                         addr))
1517                 return;
1518 
1519         area = find_vm_area(addr);
1520         if (unlikely(!area)) {
1521                 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1522                                 addr);
1523                 return;
1524         }
1525 
1526         debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
1527         debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
1528 
1529         remove_vm_area(addr);
1530         if (deallocate_pages) {
1531                 int i;
1532 
1533                 for (i = 0; i < area->nr_pages; i++) {
1534                         struct page *page = area->pages[i];
1535 
1536                         BUG_ON(!page);
1537                         __free_pages(page, 0);
1538                 }
1539 
1540                 kvfree(area->pages);
1541         }
1542 
1543         kfree(area);
1544         return;
1545 }
1546 
1547 static inline void __vfree_deferred(const void *addr)
1548 {
1549         /*
1550          * Use raw_cpu_ptr() because this can be called from preemptible
1551          * context. Preemption is absolutely fine here, because the llist_add()
1552          * implementation is lockless, so it works even if we are adding to
1553          * nother cpu's list.  schedule_work() should be fine with this too.
1554          */
1555         struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
1556 
1557         if (llist_add((struct llist_node *)addr, &p->list))
1558                 schedule_work(&p->wq);
1559 }
1560 
1561 /**
1562  * vfree_atomic - release memory allocated by vmalloc()
1563  * @addr:         memory base address
1564  *
1565  * This one is just like vfree() but can be called in any atomic context
1566  * except NMIs.
1567  */
1568 void vfree_atomic(const void *addr)
1569 {
1570         BUG_ON(in_nmi());
1571 
1572         kmemleak_free(addr);
1573 
1574         if (!addr)
1575                 return;
1576         __vfree_deferred(addr);
1577 }
1578 
1579 static void __vfree(const void *addr)
1580 {
1581         if (unlikely(in_interrupt()))
1582                 __vfree_deferred(addr);
1583         else
1584                 __vunmap(addr, 1);
1585 }
1586 
1587 /**
1588  * vfree - release memory allocated by vmalloc()
1589  * @addr:  memory base address
1590  *
1591  * Free the virtually continuous memory area starting at @addr, as
1592  * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1593  * NULL, no operation is performed.
1594  *
1595  * Must not be called in NMI context (strictly speaking, only if we don't
1596  * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
1597  * conventions for vfree() arch-depenedent would be a really bad idea)
1598  *
1599  * May sleep if called *not* from interrupt context.
1600  *
1601  * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
1602  */
1603 void vfree(const void *addr)
1604 {
1605         BUG_ON(in_nmi());
1606 
1607         kmemleak_free(addr);
1608 
1609         might_sleep_if(!in_interrupt());
1610 
1611         if (!addr)
1612                 return;
1613 
1614         __vfree(addr);
1615 }
1616 EXPORT_SYMBOL(vfree);
1617 
1618 /**
1619  * vunmap - release virtual mapping obtained by vmap()
1620  * @addr:   memory base address
1621  *
1622  * Free the virtually contiguous memory area starting at @addr,
1623  * which was created from the page array passed to vmap().
1624  *
1625  * Must not be called in interrupt context.
1626  */
1627 void vunmap(const void *addr)
1628 {
1629         BUG_ON(in_interrupt());
1630         might_sleep();
1631         if (addr)
1632                 __vunmap(addr, 0);
1633 }
1634 EXPORT_SYMBOL(vunmap);
1635 
1636 /**
1637  * vmap - map an array of pages into virtually contiguous space
1638  * @pages: array of page pointers
1639  * @count: number of pages to map
1640  * @flags: vm_area->flags
1641  * @prot: page protection for the mapping
1642  *
1643  * Maps @count pages from @pages into contiguous kernel virtual
1644  * space.
1645  *
1646  * Return: the address of the area or %NULL on failure
1647  */
1648 void *vmap(struct page **pages, unsigned int count,
1649            unsigned long flags, pgprot_t prot)
1650 {
1651         struct vm_struct *area;
1652         unsigned long size;             /* In bytes */
1653 
1654         might_sleep();
1655 
1656         if (count > totalram_pages())
1657                 return NULL;
1658 
1659         size = (unsigned long)count << PAGE_SHIFT;
1660         area = get_vm_area_caller(size, flags, __builtin_return_address(0));
1661         if (!area)
1662                 return NULL;
1663 
1664         if (map_vm_area(area, prot, pages)) {
1665                 vunmap(area->addr);
1666                 return NULL;
1667         }
1668 
1669         return area->addr;
1670 }
1671 EXPORT_SYMBOL(vmap);
1672 
1673 static void *__vmalloc_node(unsigned long size, unsigned long align,
1674                             gfp_t gfp_mask, pgprot_t prot,
1675                             int node, const void *caller);
1676 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1677                                  pgprot_t prot, int node)
1678 {
1679         struct page **pages;
1680         unsigned int nr_pages, array_size, i;
1681         const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1682         const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
1683         const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ?
1684                                         0 :
1685                                         __GFP_HIGHMEM;
1686 
1687         nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
1688         array_size = (nr_pages * sizeof(struct page *));
1689 
1690         area->nr_pages = nr_pages;
1691         /* Please note that the recursion is strictly bounded. */
1692         if (array_size > PAGE_SIZE) {
1693                 pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask,
1694                                 PAGE_KERNEL, node, area->caller);
1695         } else {
1696                 pages = kmalloc_node(array_size, nested_gfp, node);
1697         }
1698         area->pages = pages;
1699         if (!area->pages) {
1700                 remove_vm_area(area->addr);
1701                 kfree(area);
1702                 return NULL;
1703         }
1704 
1705         for (i = 0; i < area->nr_pages; i++) {
1706                 struct page *page;
1707 
1708                 if (node == NUMA_NO_NODE)
1709                         page = alloc_page(alloc_mask|highmem_mask);
1710                 else
1711                         page = alloc_pages_node(node, alloc_mask|highmem_mask, 0);
1712 
1713                 if (unlikely(!page)) {
1714                         /* Successfully allocated i pages, free them in __vunmap() */
1715                         area->nr_pages = i;
1716                         goto fail;
1717                 }
1718                 area->pages[i] = page;
1719                 if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
1720                         cond_resched();
1721         }
1722 
1723         if (map_vm_area(area, prot, pages))
1724                 goto fail;
1725         return area->addr;
1726 
1727 fail:
1728         warn_alloc(gfp_mask, NULL,
1729                           "vmalloc: allocation failure, allocated %ld of %ld bytes",
1730                           (area->nr_pages*PAGE_SIZE), area->size);
1731         __vfree(area->addr);
1732         return NULL;
1733 }
1734 
1735 /**
1736  * __vmalloc_node_range - allocate virtually contiguous memory
1737  * @size:                 allocation size
1738  * @align:                desired alignment
1739  * @start:                vm area range start
1740  * @end:                  vm area range end
1741  * @gfp_mask:             flags for the page level allocator
1742  * @prot:                 protection mask for the allocated pages
1743  * @vm_flags:             additional vm area flags (e.g. %VM_NO_GUARD)
1744  * @node:                 node to use for allocation or NUMA_NO_NODE
1745  * @caller:               caller's return address
1746  *
1747  * Allocate enough pages to cover @size from the page level
1748  * allocator with @gfp_mask flags.  Map them into contiguous
1749  * kernel virtual space, using a pagetable protection of @prot.
1750  *
1751  * Return: the address of the area or %NULL on failure
1752  */
1753 void *__vmalloc_node_range(unsigned long size, unsigned long align,
1754                         unsigned long start, unsigned long end, gfp_t gfp_mask,
1755                         pgprot_t prot, unsigned long vm_flags, int node,
1756                         const void *caller)
1757 {
1758         struct vm_struct *area;
1759         void *addr;
1760         unsigned long real_size = size;
1761 
1762         size = PAGE_ALIGN(size);
1763         if (!size || (size >> PAGE_SHIFT) > totalram_pages())
1764                 goto fail;
1765 
1766         area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
1767                                 vm_flags, start, end, node, gfp_mask, caller);
1768         if (!area)
1769                 goto fail;
1770 
1771         addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1772         if (!addr)
1773                 return NULL;
1774 
1775         /*
1776          * In this function, newly allocated vm_struct has VM_UNINITIALIZED
1777          * flag. It means that vm_struct is not fully initialized.
1778          * Now, it is fully initialized, so remove this flag here.
1779          */
1780         clear_vm_uninitialized_flag(area);
1781 
1782         kmemleak_vmalloc(area, size, gfp_mask);
1783 
1784         return addr;
1785 
1786 fail:
1787         warn_alloc(gfp_mask, NULL,
1788                           "vmalloc: allocation failure: %lu bytes", real_size);
1789         return NULL;
1790 }
1791 
1792 /*
1793  * This is only for performance analysis of vmalloc and stress purpose.
1794  * It is required by vmalloc test module, therefore do not use it other
1795  * than that.
1796  */
1797 #ifdef CONFIG_TEST_VMALLOC_MODULE
1798 EXPORT_SYMBOL_GPL(__vmalloc_node_range);
1799 #endif
1800 
1801 /**
1802  * __vmalloc_node - allocate virtually contiguous memory
1803  * @size:           allocation size
1804  * @align:          desired alignment
1805  * @gfp_mask:       flags for the page level allocator
1806  * @prot:           protection mask for the allocated pages
1807  * @node:           node to use for allocation or NUMA_NO_NODE
1808  * @caller:         caller's return address
1809  *
1810  * Allocate enough pages to cover @size from the page level
1811  * allocator with @gfp_mask flags.  Map them into contiguous
1812  * kernel virtual space, using a pagetable protection of @prot.
1813  *
1814  * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
1815  * and __GFP_NOFAIL are not supported
1816  *
1817  * Any use of gfp flags outside of GFP_KERNEL should be consulted
1818  * with mm people.
1819  *
1820  * Return: pointer to the allocated memory or %NULL on error
1821  */
1822 static void *__vmalloc_node(unsigned long size, unsigned long align,
1823                             gfp_t gfp_mask, pgprot_t prot,
1824                             int node, const void *caller)
1825 {
1826         return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1827                                 gfp_mask, prot, 0, node, caller);
1828 }
1829 
1830 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1831 {
1832         return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1833                                 __builtin_return_address(0));
1834 }
1835 EXPORT_SYMBOL(__vmalloc);
1836 
1837 static inline void *__vmalloc_node_flags(unsigned long size,
1838                                         int node, gfp_t flags)
1839 {
1840         return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1841                                         node, __builtin_return_address(0));
1842 }
1843 
1844 
1845 void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags,
1846                                   void *caller)
1847 {
1848         return __vmalloc_node(size, 1, flags, PAGE_KERNEL, node, caller);
1849 }
1850 
1851 /**
1852  * vmalloc - allocate virtually contiguous memory
1853  * @size:    allocation size
1854  *
1855  * Allocate enough pages to cover @size from the page level
1856  * allocator and map them into contiguous kernel virtual space.
1857  *
1858  * For tight control over page level allocator and protection flags
1859  * use __vmalloc() instead.
1860  *
1861  * Return: pointer to the allocated memory or %NULL on error
1862  */
1863 void *vmalloc(unsigned long size)
1864 {
1865         return __vmalloc_node_flags(size, NUMA_NO_NODE,
1866                                     GFP_KERNEL);
1867 }
1868 EXPORT_SYMBOL(vmalloc);
1869 
1870 /**
1871  * vzalloc - allocate virtually contiguous memory with zero fill
1872  * @size:    allocation size
1873  *
1874  * Allocate enough pages to cover @size from the page level
1875  * allocator and map them into contiguous kernel virtual space.
1876  * The memory allocated is set to zero.
1877  *
1878  * For tight control over page level allocator and protection flags
1879  * use __vmalloc() instead.
1880  *
1881  * Return: pointer to the allocated memory or %NULL on error
1882  */
1883 void *vzalloc(unsigned long size)
1884 {
1885         return __vmalloc_node_flags(size, NUMA_NO_NODE,
1886                                 GFP_KERNEL | __GFP_ZERO);
1887 }
1888 EXPORT_SYMBOL(vzalloc);
1889 
1890 /**
1891  * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1892  * @size: allocation size
1893  *
1894  * The resulting memory area is zeroed so it can be mapped to userspace
1895  * without leaking data.
1896  *
1897  * Return: pointer to the allocated memory or %NULL on error
1898  */
1899 void *vmalloc_user(unsigned long size)
1900 {
1901         return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
1902                                     GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
1903                                     VM_USERMAP, NUMA_NO_NODE,
1904                                     __builtin_return_address(0));
1905 }
1906 EXPORT_SYMBOL(vmalloc_user);
1907 
1908 /**
1909  * vmalloc_node - allocate memory on a specific node
1910  * @size:         allocation size
1911  * @node:         numa node
1912  *
1913  * Allocate enough pages to cover @size from the page level
1914  * allocator and map them into contiguous kernel virtual space.
1915  *
1916  * For tight control over page level allocator and protection flags
1917  * use __vmalloc() instead.
1918  *
1919  * Return: pointer to the allocated memory or %NULL on error
1920  */
1921 void *vmalloc_node(unsigned long size, int node)
1922 {
1923         return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL,
1924                                         node, __builtin_return_address(0));
1925 }
1926 EXPORT_SYMBOL(vmalloc_node);
1927 
1928 /**
1929  * vzalloc_node - allocate memory on a specific node with zero fill
1930  * @size:       allocation size
1931  * @node:       numa node
1932  *
1933  * Allocate enough pages to cover @size from the page level
1934  * allocator and map them into contiguous kernel virtual space.
1935  * The memory allocated is set to zero.
1936  *
1937  * For tight control over page level allocator and protection flags
1938  * use __vmalloc_node() instead.
1939  *
1940  * Return: pointer to the allocated memory or %NULL on error
1941  */
1942 void *vzalloc_node(unsigned long size, int node)
1943 {
1944         return __vmalloc_node_flags(size, node,
1945                          GFP_KERNEL | __GFP_ZERO);
1946 }
1947 EXPORT_SYMBOL(vzalloc_node);
1948 
1949 /**
1950  * vmalloc_exec - allocate virtually contiguous, executable memory
1951  * @size:         allocation size
1952  *
1953  * Kernel-internal function to allocate enough pages to cover @size
1954  * the page level allocator and map them into contiguous and
1955  * executable kernel virtual space.
1956  *
1957  * For tight control over page level allocator and protection flags
1958  * use __vmalloc() instead.
1959  *
1960  * Return: pointer to the allocated memory or %NULL on error
1961  */
1962 void *vmalloc_exec(unsigned long size)
1963 {
1964         return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC,
1965                               NUMA_NO_NODE, __builtin_return_address(0));
1966 }
1967 
1968 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1969 #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
1970 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1971 #define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
1972 #else
1973 /*
1974  * 64b systems should always have either DMA or DMA32 zones. For others
1975  * GFP_DMA32 should do the right thing and use the normal zone.
1976  */
1977 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1978 #endif
1979 
1980 /**
1981  * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1982  * @size:       allocation size
1983  *
1984  * Allocate enough 32bit PA addressable pages to cover @size from the
1985  * page level allocator and map them into contiguous kernel virtual space.
1986  *
1987  * Return: pointer to the allocated memory or %NULL on error
1988  */
1989 void *vmalloc_32(unsigned long size)
1990 {
1991         return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1992                               NUMA_NO_NODE, __builtin_return_address(0));
1993 }
1994 EXPORT_SYMBOL(vmalloc_32);
1995 
1996 /**
1997  * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1998  * @size:            allocation size
1999  *
2000  * The resulting memory area is 32bit addressable and zeroed so it can be
2001  * mapped to userspace without leaking data.
2002  *
2003  * Return: pointer to the allocated memory or %NULL on error
2004  */
2005 void *vmalloc_32_user(unsigned long size)
2006 {
2007         return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
2008                                     GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
2009                                     VM_USERMAP, NUMA_NO_NODE,
2010                                     __builtin_return_address(0));
2011 }
2012 EXPORT_SYMBOL(vmalloc_32_user);
2013 
2014 /*
2015  * small helper routine , copy contents to buf from addr.
2016  * If the page is not present, fill zero.
2017  */
2018 
2019 static int aligned_vread(char *buf, char *addr, unsigned long count)
2020 {
2021         struct page *p;
2022         int copied = 0;
2023 
2024         while (count) {
2025                 unsigned long offset, length;
2026 
2027                 offset = offset_in_page(addr);
2028                 length = PAGE_SIZE - offset;
2029                 if (length > count)
2030                         length = count;
2031                 p = vmalloc_to_page(addr);
2032                 /*
2033                  * To do safe access to this _mapped_ area, we need
2034                  * lock. But adding lock here means that we need to add
2035                  * overhead of vmalloc()/vfree() calles for this _debug_
2036                  * interface, rarely used. Instead of that, we'll use
2037                  * kmap() and get small overhead in this access function.
2038                  */
2039                 if (p) {
2040                         /*
2041                          * we can expect USER0 is not used (see vread/vwrite's
2042                          * function description)
2043                          */
2044                         void *map = kmap_atomic(p);
2045                         memcpy(buf, map + offset, length);
2046                         kunmap_atomic(map);
2047                 } else
2048                         memset(buf, 0, length);
2049 
2050                 addr += length;
2051                 buf += length;
2052                 copied += length;
2053                 count -= length;
2054         }
2055         return copied;
2056 }
2057 
2058 static int aligned_vwrite(char *buf, char *addr, unsigned long count)
2059 {
2060         struct page *p;
2061         int copied = 0;
2062 
2063         while (count) {
2064                 unsigned long offset, length;
2065 
2066                 offset = offset_in_page(addr);
2067                 length = PAGE_SIZE - offset;
2068                 if (length > count)
2069                         length = count;
2070                 p = vmalloc_to_page(addr);
2071                 /*
2072                  * To do safe access to this _mapped_ area, we need
2073                  * lock. But adding lock here means that we need to add
2074                  * overhead of vmalloc()/vfree() calles for this _debug_
2075                  * interface, rarely used. Instead of that, we'll use
2076                  * kmap() and get small overhead in this access function.
2077                  */
2078                 if (p) {
2079                         /*
2080                          * we can expect USER0 is not used (see vread/vwrite's
2081                          * function description)
2082                          */
2083                         void *map = kmap_atomic(p);
2084                         memcpy(map + offset, buf, length);
2085                         kunmap_atomic(map);
2086                 }
2087                 addr += length;
2088                 buf += length;
2089                 copied += length;
2090                 count -= length;
2091         }
2092         return copied;
2093 }
2094 
2095 /**
2096  * vread() - read vmalloc area in a safe way.
2097  * @buf:     buffer for reading data
2098  * @addr:    vm address.
2099  * @count:   number of bytes to be read.
2100  *
2101  * This function checks that addr is a valid vmalloc'ed area, and
2102  * copy data from that area to a given buffer. If the given memory range
2103  * of [addr...addr+count) includes some valid address, data is copied to
2104  * proper area of @buf. If there are memory holes, they'll be zero-filled.
2105  * IOREMAP area is treated as memory hole and no copy is done.
2106  *
2107  * If [addr...addr+count) doesn't includes any intersects with alive
2108  * vm_struct area, returns 0. @buf should be kernel's buffer.
2109  *
2110  * Note: In usual ops, vread() is never necessary because the caller
2111  * should know vmalloc() area is valid and can use memcpy().
2112  * This is for routines which have to access vmalloc area without
2113  * any informaion, as /dev/kmem.
2114  *
2115  * Return: number of bytes for which addr and buf should be increased
2116  * (same number as @count) or %0 if [addr...addr+count) doesn't
2117  * include any intersection with valid vmalloc area
2118  */
2119 long vread(char *buf, char *addr, unsigned long count)
2120 {
2121         struct vmap_area *va;
2122         struct vm_struct *vm;
2123         char *vaddr, *buf_start = buf;
2124         unsigned long buflen = count;
2125         unsigned long n;
2126 
2127         /* Don't allow overflow */
2128         if ((unsigned long) addr + count < count)
2129                 count = -(unsigned long) addr;
2130 
2131         spin_lock(&vmap_area_lock);
2132         list_for_each_entry(va, &vmap_area_list, list) {
2133                 if (!count)
2134                         break;
2135 
2136                 if (!(va->flags & VM_VM_AREA))
2137                         continue;
2138 
2139                 vm = va->vm;
2140                 vaddr = (char *) vm->addr;
2141                 if (addr >= vaddr + get_vm_area_size(vm))
2142                         continue;
2143                 while (addr < vaddr) {
2144                         if (count == 0)
2145                                 goto finished;
2146                         *buf = '\0';
2147                         buf++;
2148                         addr++;
2149                         count--;
2150                 }
2151                 n = vaddr + get_vm_area_size(vm) - addr;
2152                 if (n > count)
2153                         n = count;
2154                 if (!(vm->flags & VM_IOREMAP))
2155                         aligned_vread(buf, addr, n);
2156                 else /* IOREMAP area is treated as memory hole */
2157                         memset(buf, 0, n);
2158                 buf += n;
2159                 addr += n;
2160                 count -= n;
2161         }
2162 finished:
2163         spin_unlock(&vmap_area_lock);
2164 
2165         if (buf == buf_start)
2166                 return 0;
2167         /* zero-fill memory holes */
2168         if (buf != buf_start + buflen)
2169                 memset(buf, 0, buflen - (buf - buf_start));
2170 
2171         return buflen;
2172 }
2173 
2174 /**
2175  * vwrite() - write vmalloc area in a safe way.
2176  * @buf:      buffer for source data
2177  * @addr:     vm address.
2178  * @count:    number of bytes to be read.
2179  *
2180  * This function checks that addr is a valid vmalloc'ed area, and
2181  * copy data from a buffer to the given addr. If specified range of
2182  * [addr...addr+count) includes some valid address, data is copied from
2183  * proper area of @buf. If there are memory holes, no copy to hole.
2184  * IOREMAP area is treated as memory hole and no copy is done.
2185  *
2186  * If [addr...addr+count) doesn't includes any intersects with alive
2187  * vm_struct area, returns 0. @buf should be kernel's buffer.
2188  *
2189  * Note: In usual ops, vwrite() is never necessary because the caller
2190  * should know vmalloc() area is valid and can use memcpy().
2191  * This is for routines which have to access vmalloc area without
2192  * any informaion, as /dev/kmem.
2193  *
2194  * Return: number of bytes for which addr and buf should be
2195  * increased (same number as @count) or %0 if [addr...addr+count)
2196  * doesn't include any intersection with valid vmalloc area
2197  */
2198 long vwrite(char *buf, char *addr, unsigned long count)
2199 {
2200         struct vmap_area *va;
2201         struct vm_struct *vm;
2202         char *vaddr;
2203         unsigned long n, buflen;
2204         int copied = 0;
2205 
2206         /* Don't allow overflow */
2207         if ((unsigned long) addr + count < count)
2208                 count = -(unsigned long) addr;
2209         buflen = count;
2210 
2211         spin_lock(&vmap_area_lock);
2212         list_for_each_entry(va, &vmap_area_list, list) {
2213                 if (!count)
2214                         break;
2215 
2216                 if (!(va->flags & VM_VM_AREA))
2217                         continue;
2218 
2219                 vm = va->vm;
2220                 vaddr = (char *) vm->addr;
2221                 if (addr >= vaddr + get_vm_area_size(vm))
2222                         continue;
2223                 while (addr < vaddr) {
2224                         if (count == 0)
2225                                 goto finished;
2226                         buf++;
2227                         addr++;
2228                         count--;
2229                 }
2230                 n = vaddr + get_vm_area_size(vm) - addr;
2231                 if (n > count)
2232                         n = count;
2233                 if (!(vm->flags & VM_IOREMAP)) {
2234                         aligned_vwrite(buf, addr, n);
2235                         copied++;
2236                 }
2237                 buf += n;
2238                 addr += n;
2239                 count -= n;
2240         }
2241 finished:
2242         spin_unlock(&vmap_area_lock);
2243         if (!copied)
2244                 return 0;
2245         return buflen;
2246 }
2247 
2248 /**
2249  * remap_vmalloc_range_partial - map vmalloc pages to userspace
2250  * @vma:                vma to cover
2251  * @uaddr:              target user address to start at
2252  * @kaddr:              virtual address of vmalloc kernel memory
2253  * @size:               size of map area
2254  *
2255  * Returns:     0 for success, -Exxx on failure
2256  *
2257  * This function checks that @kaddr is a valid vmalloc'ed area,
2258  * and that it is big enough to cover the range starting at
2259  * @uaddr in @vma. Will return failure if that criteria isn't
2260  * met.
2261  *
2262  * Similar to remap_pfn_range() (see mm/memory.c)
2263  */
2264 int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2265                                 void *kaddr, unsigned long size)
2266 {
2267         struct vm_struct *area;
2268 
2269         size = PAGE_ALIGN(size);
2270 
2271         if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2272                 return -EINVAL;
2273 
2274         area = find_vm_area(kaddr);
2275         if (!area)
2276                 return -EINVAL;
2277 
2278         if (!(area->flags & VM_USERMAP))
2279                 return -EINVAL;
2280 
2281         if (kaddr + size > area->addr + get_vm_area_size(area))
2282                 return -EINVAL;
2283 
2284         do {
2285                 struct page *page = vmalloc_to_page(kaddr);
2286                 int ret;
2287 
2288                 ret = vm_insert_page(vma, uaddr, page);
2289                 if (ret)
2290                         return ret;
2291 
2292                 uaddr += PAGE_SIZE;
2293                 kaddr += PAGE_SIZE;
2294                 size -= PAGE_SIZE;
2295         } while (size > 0);
2296 
2297         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2298 
2299         return 0;
2300 }
2301 EXPORT_SYMBOL(remap_vmalloc_range_partial);
2302 
2303 /**
2304  * remap_vmalloc_range - map vmalloc pages to userspace
2305  * @vma:                vma to cover (map full range of vma)
2306  * @addr:               vmalloc memory
2307  * @pgoff:              number of pages into addr before first page to map
2308  *
2309  * Returns:     0 for success, -Exxx on failure
2310  *
2311  * This function checks that addr is a valid vmalloc'ed area, and
2312  * that it is big enough to cover the vma. Will return failure if
2313  * that criteria isn't met.
2314  *
2315  * Similar to remap_pfn_range() (see mm/memory.c)
2316  */
2317 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2318                                                 unsigned long pgoff)
2319 {
2320         return remap_vmalloc_range_partial(vma, vma->vm_start,
2321                                            addr + (pgoff << PAGE_SHIFT),
2322                                            vma->vm_end - vma->vm_start);
2323 }
2324 EXPORT_SYMBOL(remap_vmalloc_range);
2325 
2326 /*
2327  * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2328  * have one.
2329  */
2330 void __weak vmalloc_sync_all(void)
2331 {
2332 }
2333 
2334 
2335 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2336 {
2337         pte_t ***p = data;
2338 
2339         if (p) {
2340                 *(*p) = pte;
2341                 (*p)++;
2342         }
2343         return 0;
2344 }
2345 
2346 /**
2347  * alloc_vm_area - allocate a range of kernel address space
2348  * @size:          size of the area
2349  * @ptes:          returns the PTEs for the address space
2350  *
2351  * Returns:     NULL on failure, vm_struct on success
2352  *
2353  * This function reserves a range of kernel address space, and
2354  * allocates pagetables to map that range.  No actual mappings
2355  * are created.
2356  *
2357  * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2358  * allocated for the VM area are returned.
2359  */
2360 struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2361 {
2362         struct vm_struct *area;
2363 
2364         area = get_vm_area_caller(size, VM_IOREMAP,
2365                                 __builtin_return_address(0));
2366         if (area == NULL)
2367                 return NULL;
2368 
2369         /*
2370          * This ensures that page tables are constructed for this region
2371          * of kernel virtual address space and mapped into init_mm.
2372          */
2373         if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2374                                 size, f, ptes ? &ptes : NULL)) {
2375                 free_vm_area(area);
2376                 return NULL;
2377         }
2378 
2379         return area;
2380 }
2381 EXPORT_SYMBOL_GPL(alloc_vm_area);
2382 
2383 void free_vm_area(struct vm_struct *area)
2384 {
2385         struct vm_struct *ret;
2386         ret = remove_vm_area(area->addr);
2387         BUG_ON(ret != area);
2388         kfree(area);
2389 }
2390 EXPORT_SYMBOL_GPL(free_vm_area);
2391 
2392 #ifdef CONFIG_SMP
2393 static struct vmap_area *node_to_va(struct rb_node *n)
2394 {
2395         return rb_entry_safe(n, struct vmap_area, rb_node);
2396 }
2397 
2398 /**
2399  * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2400  * @end: target address
2401  * @pnext: out arg for the next vmap_area
2402  * @pprev: out arg for the previous vmap_area
2403  *
2404  * Returns: %true if either or both of next and prev are found,
2405  *          %false if no vmap_area exists
2406  *
2407  * Find vmap_areas end addresses of which enclose @end.  ie. if not
2408  * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2409  */
2410 static bool pvm_find_next_prev(unsigned long end,
2411                                struct vmap_area **pnext,
2412                                struct vmap_area **pprev)
2413 {
2414         struct rb_node *n = vmap_area_root.rb_node;
2415         struct vmap_area *va = NULL;
2416 
2417         while (n) {
2418                 va = rb_entry(n, struct vmap_area, rb_node);
2419                 if (end < va->va_end)
2420                         n = n->rb_left;
2421                 else if (end > va->va_end)
2422                         n = n->rb_right;
2423                 else
2424                         break;
2425         }
2426 
2427         if (!va)
2428                 return false;
2429 
2430         if (va->va_end > end) {
2431                 *pnext = va;
2432                 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2433         } else {
2434                 *pprev = va;
2435                 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2436         }
2437         return true;
2438 }
2439 
2440 /**
2441  * pvm_determine_end - find the highest aligned address between two vmap_areas
2442  * @pnext: in/out arg for the next vmap_area
2443  * @pprev: in/out arg for the previous vmap_area
2444  * @align: alignment
2445  *
2446  * Returns: determined end address
2447  *
2448  * Find the highest aligned address between *@pnext and *@pprev below
2449  * VMALLOC_END.  *@pnext and *@pprev are adjusted so that the aligned
2450  * down address is between the end addresses of the two vmap_areas.
2451  *
2452  * Please note that the address returned by this function may fall
2453  * inside *@pnext vmap_area.  The caller is responsible for checking
2454  * that.
2455  */
2456 static unsigned long pvm_determine_end(struct vmap_area **pnext,
2457                                        struct vmap_area **pprev,
2458                                        unsigned long align)
2459 {
2460         const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2461         unsigned long addr;
2462 
2463         if (*pnext)
2464                 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2465         else
2466                 addr = vmalloc_end;
2467 
2468         while (*pprev && (*pprev)->va_end > addr) {
2469                 *pnext = *pprev;
2470                 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2471         }
2472 
2473         return addr;
2474 }
2475 
2476 /**
2477  * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2478  * @offsets: array containing offset of each area
2479  * @sizes: array containing size of each area
2480  * @nr_vms: the number of areas to allocate
2481  * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2482  *
2483  * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2484  *          vm_structs on success, %NULL on failure
2485  *
2486  * Percpu allocator wants to use congruent vm areas so that it can
2487  * maintain the offsets among percpu areas.  This function allocates
2488  * congruent vmalloc areas for it with GFP_KERNEL.  These areas tend to
2489  * be scattered pretty far, distance between two areas easily going up
2490  * to gigabytes.  To avoid interacting with regular vmallocs, these
2491  * areas are allocated from top.
2492  *
2493  * Despite its complicated look, this allocator is rather simple.  It
2494  * does everything top-down and scans areas from the end looking for
2495  * matching slot.  While scanning, if any of the areas overlaps with
2496  * existing vmap_area, the base address is pulled down to fit the
2497  * area.  Scanning is repeated till all the areas fit and then all
2498  * necessary data structures are inserted and the result is returned.
2499  */
2500 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2501                                      const size_t *sizes, int nr_vms,
2502                                      size_t align)
2503 {
2504         const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2505         const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2506         struct vmap_area **vas, *prev, *next;
2507         struct vm_struct **vms;
2508         int area, area2, last_area, term_area;
2509         unsigned long base, start, end, last_end;
2510         bool purged = false;
2511 
2512         /* verify parameters and allocate data structures */
2513         BUG_ON(offset_in_page(align) || !is_power_of_2(align));
2514         for (last_area = 0, area = 0; area < nr_vms; area++) {
2515                 start = offsets[area];
2516                 end = start + sizes[area];
2517 
2518                 /* is everything aligned properly? */
2519                 BUG_ON(!IS_ALIGNED(offsets[area], align));
2520                 BUG_ON(!IS_ALIGNED(sizes[area], align));
2521 
2522                 /* detect the area with the highest address */
2523                 if (start > offsets[last_area])
2524                         last_area = area;
2525 
2526                 for (area2 = area + 1; area2 < nr_vms; area2++) {
2527                         unsigned long start2 = offsets[area2];
2528                         unsigned long end2 = start2 + sizes[area2];
2529 
2530                         BUG_ON(start2 < end && start < end2);
2531                 }
2532         }
2533         last_end = offsets[last_area] + sizes[last_area];
2534 
2535         if (vmalloc_end - vmalloc_start < last_end) {
2536                 WARN_ON(true);
2537                 return NULL;
2538         }
2539 
2540         vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2541         vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2542         if (!vas || !vms)
2543                 goto err_free2;
2544 
2545         for (area = 0; area < nr_vms; area++) {
2546                 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2547                 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2548                 if (!vas[area] || !vms[area])
2549                         goto err_free;
2550         }
2551 retry:
2552         spin_lock(&vmap_area_lock);
2553 
2554         /* start scanning - we scan from the top, begin with the last area */
2555         area = term_area = last_area;
2556         start = offsets[area];
2557         end = start + sizes[area];
2558 
2559         if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2560                 base = vmalloc_end - last_end;
2561                 goto found;
2562         }
2563         base = pvm_determine_end(&next, &prev, align) - end;
2564 
2565         while (true) {
2566                 BUG_ON(next && next->va_end <= base + end);
2567                 BUG_ON(prev && prev->va_end > base + end);
2568 
2569                 /*
2570                  * base might have underflowed, add last_end before
2571                  * comparing.
2572                  */
2573                 if (base + last_end < vmalloc_start + last_end) {
2574                         spin_unlock(&vmap_area_lock);
2575                         if (!purged) {
2576                                 purge_vmap_area_lazy();
2577                                 purged = true;
2578                                 goto retry;
2579                         }
2580                         goto err_free;
2581                 }
2582 
2583                 /*
2584                  * If next overlaps, move base downwards so that it's
2585                  * right below next and then recheck.
2586                  */
2587                 if (next && next->va_start < base + end) {
2588                         base = pvm_determine_end(&next, &prev, align) - end;
2589                         term_area = area;
2590                         continue;
2591                 }
2592 
2593                 /*
2594                  * If prev overlaps, shift down next and prev and move
2595                  * base so that it's right below new next and then
2596                  * recheck.
2597                  */
2598                 if (prev && prev->va_end > base + start)  {
2599                         next = prev;
2600                         prev = node_to_va(rb_prev(&next->rb_node));
2601                         base = pvm_determine_end(&next, &prev, align) - end;
2602                         term_area = area;
2603                         continue;
2604                 }
2605 
2606                 /*
2607                  * This area fits, move on to the previous one.  If
2608                  * the previous one is the terminal one, we're done.
2609                  */
2610                 area = (area + nr_vms - 1) % nr_vms;
2611                 if (area == term_area)
2612                         break;
2613                 start = offsets[area];
2614                 end = start + sizes[area];
2615                 pvm_find_next_prev(base + end, &next, &prev);
2616         }
2617 found:
2618         /* we've found a fitting base, insert all va's */
2619         for (area = 0; area < nr_vms; area++) {
2620                 struct vmap_area *va = vas[area];
2621 
2622                 va->va_start = base + offsets[area];
2623                 va->va_end = va->va_start + sizes[area];
2624                 __insert_vmap_area(va);
2625         }
2626 
2627         vmap_area_pcpu_hole = base + offsets[last_area];
2628 
2629         spin_unlock(&vmap_area_lock);
2630 
2631         /* insert all vm's */
2632         for (area = 0; area < nr_vms; area++)
2633                 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2634                                  pcpu_get_vm_areas);
2635 
2636         kfree(vas);
2637         return vms;
2638 
2639 err_free:
2640         for (area = 0; area < nr_vms; area++) {
2641                 kfree(vas[area]);
2642                 kfree(vms[area]);
2643         }
2644 err_free2:
2645         kfree(vas);
2646         kfree(vms);
2647         return NULL;
2648 }
2649 
2650 /**
2651  * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2652  * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2653  * @nr_vms: the number of allocated areas
2654  *
2655  * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2656  */
2657 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2658 {
2659         int i;
2660 
2661         for (i = 0; i < nr_vms; i++)
2662                 free_vm_area(vms[i]);
2663         kfree(vms);
2664 }
2665 #endif  /* CONFIG_SMP */
2666 
2667 #ifdef CONFIG_PROC_FS
2668 static void *s_start(struct seq_file *m, loff_t *pos)
2669         __acquires(&vmap_area_lock)
2670 {
2671         spin_lock(&vmap_area_lock);
2672         return seq_list_start(&vmap_area_list, *pos);
2673 }
2674 
2675 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2676 {
2677         return seq_list_next(p, &vmap_area_list, pos);
2678 }
2679 
2680 static void s_stop(struct seq_file *m, void *p)
2681         __releases(&vmap_area_lock)
2682 {
2683         spin_unlock(&vmap_area_lock);
2684 }
2685 
2686 static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2687 {
2688         if (IS_ENABLED(CONFIG_NUMA)) {
2689                 unsigned int nr, *counters = m->private;
2690 
2691                 if (!counters)
2692                         return;
2693 
2694                 if (v->flags & VM_UNINITIALIZED)
2695                         return;
2696                 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
2697                 smp_rmb();
2698 
2699                 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2700 
2701                 for (nr = 0; nr < v->nr_pages; nr++)
2702                         counters[page_to_nid(v->pages[nr])]++;
2703 
2704                 for_each_node_state(nr, N_HIGH_MEMORY)
2705                         if (counters[nr])
2706                                 seq_printf(m, " N%u=%u", nr, counters[nr]);
2707         }
2708 }
2709 
2710 static int s_show(struct seq_file *m, void *p)
2711 {
2712         struct vmap_area *va;
2713         struct vm_struct *v;
2714 
2715         va = list_entry(p, struct vmap_area, list);
2716 
2717         /*
2718          * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
2719          * behalf of vmap area is being tear down or vm_map_ram allocation.
2720          */
2721         if (!(va->flags & VM_VM_AREA)) {
2722                 seq_printf(m, "0x%pK-0x%pK %7ld %s\n",
2723                         (void *)va->va_start, (void *)va->va_end,
2724                         va->va_end - va->va_start,
2725                         va->flags & VM_LAZY_FREE ? "unpurged vm_area" : "vm_map_ram");
2726 
2727                 return 0;
2728         }
2729 
2730         v = va->vm;
2731 
2732         seq_printf(m, "0x%pK-0x%pK %7ld",
2733                 v->addr, v->addr + v->size, v->size);
2734 
2735         if (v->caller)
2736                 seq_printf(m, " %pS", v->caller);
2737 
2738         if (v->nr_pages)
2739                 seq_printf(m, " pages=%d", v->nr_pages);
2740 
2741         if (v->phys_addr)
2742                 seq_printf(m, " phys=%pa", &v->phys_addr);
2743 
2744         if (v->flags & VM_IOREMAP)
2745                 seq_puts(m, " ioremap");
2746 
2747         if (v->flags & VM_ALLOC)
2748                 seq_puts(m, " vmalloc");
2749 
2750         if (v->flags & VM_MAP)
2751                 seq_puts(m, " vmap");
2752 
2753         if (v->flags & VM_USERMAP)
2754                 seq_puts(m, " user");
2755 
2756         if (is_vmalloc_addr(v->pages))
2757                 seq_puts(m, " vpages");
2758 
2759         show_numa_info(m, v);
2760         seq_putc(m, '\n');
2761         return 0;
2762 }
2763 
2764 static const struct seq_operations vmalloc_op = {
2765         .start = s_start,
2766         .next = s_next,
2767         .stop = s_stop,
2768         .show = s_show,
2769 };
2770 
2771 static int __init proc_vmalloc_init(void)
2772 {
2773         if (IS_ENABLED(CONFIG_NUMA))
2774                 proc_create_seq_private("vmallocinfo", 0400, NULL,
2775                                 &vmalloc_op,
2776                                 nr_node_ids * sizeof(unsigned int), NULL);
2777         else
2778                 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
2779         return 0;
2780 }
2781 module_init(proc_vmalloc_init);
2782 
2783 #endif
2784 

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