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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Simple NUMA memory policy for the Linux kernel.
4 *
5 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
6 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
7 *
8 * NUMA policy allows the user to give hints in which node(s) memory should
9 * be allocated.
10 *
11 * Support four policies per VMA and per process:
12 *
13 * The VMA policy has priority over the process policy for a page fault.
14 *
15 * interleave Allocate memory interleaved over a set of nodes,
16 * with normal fallback if it fails.
17 * For VMA based allocations this interleaves based on the
18 * offset into the backing object or offset into the mapping
19 * for anonymous memory. For process policy an process counter
20 * is used.
21 *
22 * bind Only allocate memory on a specific set of nodes,
23 * no fallback.
24 * FIXME: memory is allocated starting with the first node
25 * to the last. It would be better if bind would truly restrict
26 * the allocation to memory nodes instead
27 *
28 * preferred Try a specific node first before normal fallback.
29 * As a special case NUMA_NO_NODE here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
32 * process policy.
33 *
34 * default Allocate on the local node first, or when on a VMA
35 * use the process policy. This is what Linux always did
36 * in a NUMA aware kernel and still does by, ahem, default.
37 *
38 * The process policy is applied for most non interrupt memory allocations
39 * in that process' context. Interrupts ignore the policies and always
40 * try to allocate on the local CPU. The VMA policy is only applied for memory
41 * allocations for a VMA in the VM.
42 *
43 * Currently there are a few corner cases in swapping where the policy
44 * is not applied, but the majority should be handled. When process policy
45 * is used it is not remembered over swap outs/swap ins.
46 *
47 * Only the highest zone in the zone hierarchy gets policied. Allocations
48 * requesting a lower zone just use default policy. This implies that
49 * on systems with highmem kernel lowmem allocation don't get policied.
50 * Same with GFP_DMA allocations.
51 *
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
54 */
55
56/* Notebook:
57 fix mmap readahead to honour policy and enable policy for any page cache
58 object
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
61 first item above.
62 handle mremap for shared memory (currently ignored for the policy)
63 grows down?
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
66*/
67
68#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
69
70#include <linux/mempolicy.h>
71#include <linux/pagewalk.h>
72#include <linux/highmem.h>
73#include <linux/hugetlb.h>
74#include <linux/kernel.h>
75#include <linux/sched.h>
76#include <linux/sched/mm.h>
77#include <linux/sched/numa_balancing.h>
78#include <linux/sched/task.h>
79#include <linux/nodemask.h>
80#include <linux/cpuset.h>
81#include <linux/slab.h>
82#include <linux/string.h>
83#include <linux/export.h>
84#include <linux/nsproxy.h>
85#include <linux/interrupt.h>
86#include <linux/init.h>
87#include <linux/compat.h>
88#include <linux/ptrace.h>
89#include <linux/swap.h>
90#include <linux/seq_file.h>
91#include <linux/proc_fs.h>
92#include <linux/migrate.h>
93#include <linux/ksm.h>
94#include <linux/rmap.h>
95#include <linux/security.h>
96#include <linux/syscalls.h>
97#include <linux/ctype.h>
98#include <linux/mm_inline.h>
99#include <linux/mmu_notifier.h>
100#include <linux/printk.h>
101#include <linux/swapops.h>
102
103#include <asm/tlbflush.h>
104#include <linux/uaccess.h>
105
106#include "internal.h"
107
108/* Internal flags */
109#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
110#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
111
112static struct kmem_cache *policy_cache;
113static struct kmem_cache *sn_cache;
114
115/* Highest zone. An specific allocation for a zone below that is not
116 policied. */
117enum zone_type policy_zone = 0;
118
119/*
120 * run-time system-wide default policy => local allocation
121 */
122static struct mempolicy default_policy = {
123 .refcnt = ATOMIC_INIT(1), /* never free it */
124 .mode = MPOL_PREFERRED,
125 .flags = MPOL_F_LOCAL,
126};
127
128static struct mempolicy preferred_node_policy[MAX_NUMNODES];
129
130struct mempolicy *get_task_policy(struct task_struct *p)
131{
132 struct mempolicy *pol = p->mempolicy;
133 int node;
134
135 if (pol)
136 return pol;
137
138 node = numa_node_id();
139 if (node != NUMA_NO_NODE) {
140 pol = &preferred_node_policy[node];
141 /* preferred_node_policy is not initialised early in boot */
142 if (pol->mode)
143 return pol;
144 }
145
146 return &default_policy;
147}
148
149static const struct mempolicy_operations {
150 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
151 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes);
152} mpol_ops[MPOL_MAX];
153
154static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
155{
156 return pol->flags & MPOL_MODE_FLAGS;
157}
158
159static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
160 const nodemask_t *rel)
161{
162 nodemask_t tmp;
163 nodes_fold(tmp, *orig, nodes_weight(*rel));
164 nodes_onto(*ret, tmp, *rel);
165}
166
167static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
168{
169 if (nodes_empty(*nodes))
170 return -EINVAL;
171 pol->v.nodes = *nodes;
172 return 0;
173}
174
175static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
176{
177 if (!nodes)
178 pol->flags |= MPOL_F_LOCAL; /* local allocation */
179 else if (nodes_empty(*nodes))
180 return -EINVAL; /* no allowed nodes */
181 else
182 pol->v.preferred_node = first_node(*nodes);
183 return 0;
184}
185
186static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
187{
188 if (nodes_empty(*nodes))
189 return -EINVAL;
190 pol->v.nodes = *nodes;
191 return 0;
192}
193
194/*
195 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
196 * any, for the new policy. mpol_new() has already validated the nodes
197 * parameter with respect to the policy mode and flags. But, we need to
198 * handle an empty nodemask with MPOL_PREFERRED here.
199 *
200 * Must be called holding task's alloc_lock to protect task's mems_allowed
201 * and mempolicy. May also be called holding the mmap_semaphore for write.
202 */
203static int mpol_set_nodemask(struct mempolicy *pol,
204 const nodemask_t *nodes, struct nodemask_scratch *nsc)
205{
206 int ret;
207
208 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
209 if (pol == NULL)
210 return 0;
211 /* Check N_MEMORY */
212 nodes_and(nsc->mask1,
213 cpuset_current_mems_allowed, node_states[N_MEMORY]);
214
215 VM_BUG_ON(!nodes);
216 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
217 nodes = NULL; /* explicit local allocation */
218 else {
219 if (pol->flags & MPOL_F_RELATIVE_NODES)
220 mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
221 else
222 nodes_and(nsc->mask2, *nodes, nsc->mask1);
223
224 if (mpol_store_user_nodemask(pol))
225 pol->w.user_nodemask = *nodes;
226 else
227 pol->w.cpuset_mems_allowed =
228 cpuset_current_mems_allowed;
229 }
230
231 if (nodes)
232 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
233 else
234 ret = mpol_ops[pol->mode].create(pol, NULL);
235 return ret;
236}
237
238/*
239 * This function just creates a new policy, does some check and simple
240 * initialization. You must invoke mpol_set_nodemask() to set nodes.
241 */
242static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
243 nodemask_t *nodes)
244{
245 struct mempolicy *policy;
246
247 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
248 mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE);
249
250 if (mode == MPOL_DEFAULT) {
251 if (nodes && !nodes_empty(*nodes))
252 return ERR_PTR(-EINVAL);
253 return NULL;
254 }
255 VM_BUG_ON(!nodes);
256
257 /*
258 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
259 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
260 * All other modes require a valid pointer to a non-empty nodemask.
261 */
262 if (mode == MPOL_PREFERRED) {
263 if (nodes_empty(*nodes)) {
264 if (((flags & MPOL_F_STATIC_NODES) ||
265 (flags & MPOL_F_RELATIVE_NODES)))
266 return ERR_PTR(-EINVAL);
267 }
268 } else if (mode == MPOL_LOCAL) {
269 if (!nodes_empty(*nodes) ||
270 (flags & MPOL_F_STATIC_NODES) ||
271 (flags & MPOL_F_RELATIVE_NODES))
272 return ERR_PTR(-EINVAL);
273 mode = MPOL_PREFERRED;
274 } else if (nodes_empty(*nodes))
275 return ERR_PTR(-EINVAL);
276 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
277 if (!policy)
278 return ERR_PTR(-ENOMEM);
279 atomic_set(&policy->refcnt, 1);
280 policy->mode = mode;
281 policy->flags = flags;
282
283 return policy;
284}
285
286/* Slow path of a mpol destructor. */
287void __mpol_put(struct mempolicy *p)
288{
289 if (!atomic_dec_and_test(&p->refcnt))
290 return;
291 kmem_cache_free(policy_cache, p);
292}
293
294static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
295{
296}
297
298static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
299{
300 nodemask_t tmp;
301
302 if (pol->flags & MPOL_F_STATIC_NODES)
303 nodes_and(tmp, pol->w.user_nodemask, *nodes);
304 else if (pol->flags & MPOL_F_RELATIVE_NODES)
305 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
306 else {
307 nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed,
308 *nodes);
309 pol->w.cpuset_mems_allowed = *nodes;
310 }
311
312 if (nodes_empty(tmp))
313 tmp = *nodes;
314
315 pol->v.nodes = tmp;
316}
317
318static void mpol_rebind_preferred(struct mempolicy *pol,
319 const nodemask_t *nodes)
320{
321 nodemask_t tmp;
322
323 if (pol->flags & MPOL_F_STATIC_NODES) {
324 int node = first_node(pol->w.user_nodemask);
325
326 if (node_isset(node, *nodes)) {
327 pol->v.preferred_node = node;
328 pol->flags &= ~MPOL_F_LOCAL;
329 } else
330 pol->flags |= MPOL_F_LOCAL;
331 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
332 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
333 pol->v.preferred_node = first_node(tmp);
334 } else if (!(pol->flags & MPOL_F_LOCAL)) {
335 pol->v.preferred_node = node_remap(pol->v.preferred_node,
336 pol->w.cpuset_mems_allowed,
337 *nodes);
338 pol->w.cpuset_mems_allowed = *nodes;
339 }
340}
341
342/*
343 * mpol_rebind_policy - Migrate a policy to a different set of nodes
344 *
345 * Per-vma policies are protected by mmap_sem. Allocations using per-task
346 * policies are protected by task->mems_allowed_seq to prevent a premature
347 * OOM/allocation failure due to parallel nodemask modification.
348 */
349static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
350{
351 if (!pol)
352 return;
353 if (!mpol_store_user_nodemask(pol) && !(pol->flags & MPOL_F_LOCAL) &&
354 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
355 return;
356
357 mpol_ops[pol->mode].rebind(pol, newmask);
358}
359
360/*
361 * Wrapper for mpol_rebind_policy() that just requires task
362 * pointer, and updates task mempolicy.
363 *
364 * Called with task's alloc_lock held.
365 */
366
367void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
368{
369 mpol_rebind_policy(tsk->mempolicy, new);
370}
371
372/*
373 * Rebind each vma in mm to new nodemask.
374 *
375 * Call holding a reference to mm. Takes mm->mmap_sem during call.
376 */
377
378void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
379{
380 struct vm_area_struct *vma;
381
382 down_write(&mm->mmap_sem);
383 for (vma = mm->mmap; vma; vma = vma->vm_next)
384 mpol_rebind_policy(vma->vm_policy, new);
385 up_write(&mm->mmap_sem);
386}
387
388static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
389 [MPOL_DEFAULT] = {
390 .rebind = mpol_rebind_default,
391 },
392 [MPOL_INTERLEAVE] = {
393 .create = mpol_new_interleave,
394 .rebind = mpol_rebind_nodemask,
395 },
396 [MPOL_PREFERRED] = {
397 .create = mpol_new_preferred,
398 .rebind = mpol_rebind_preferred,
399 },
400 [MPOL_BIND] = {
401 .create = mpol_new_bind,
402 .rebind = mpol_rebind_nodemask,
403 },
404};
405
406static int migrate_page_add(struct page *page, struct list_head *pagelist,
407 unsigned long flags);
408
409struct queue_pages {
410 struct list_head *pagelist;
411 unsigned long flags;
412 nodemask_t *nmask;
413 struct vm_area_struct *prev;
414};
415
416/*
417 * Check if the page's nid is in qp->nmask.
418 *
419 * If MPOL_MF_INVERT is set in qp->flags, check if the nid is
420 * in the invert of qp->nmask.
421 */
422static inline bool queue_pages_required(struct page *page,
423 struct queue_pages *qp)
424{
425 int nid = page_to_nid(page);
426 unsigned long flags = qp->flags;
427
428 return node_isset(nid, *qp->nmask) == !(flags & MPOL_MF_INVERT);
429}
430
431/*
432 * queue_pages_pmd() has four possible return values:
433 * 0 - pages are placed on the right node or queued successfully.
434 * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
435 * specified.
436 * 2 - THP was split.
437 * -EIO - is migration entry or only MPOL_MF_STRICT was specified and an
438 * existing page was already on a node that does not follow the
439 * policy.
440 */
441static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
442 unsigned long end, struct mm_walk *walk)
443{
444 int ret = 0;
445 struct page *page;
446 struct queue_pages *qp = walk->private;
447 unsigned long flags;
448
449 if (unlikely(is_pmd_migration_entry(*pmd))) {
450 ret = -EIO;
451 goto unlock;
452 }
453 page = pmd_page(*pmd);
454 if (is_huge_zero_page(page)) {
455 spin_unlock(ptl);
456 __split_huge_pmd(walk->vma, pmd, addr, false, NULL);
457 ret = 2;
458 goto out;
459 }
460 if (!queue_pages_required(page, qp))
461 goto unlock;
462
463 flags = qp->flags;
464 /* go to thp migration */
465 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
466 if (!vma_migratable(walk->vma) ||
467 migrate_page_add(page, qp->pagelist, flags)) {
468 ret = 1;
469 goto unlock;
470 }
471 } else
472 ret = -EIO;
473unlock:
474 spin_unlock(ptl);
475out:
476 return ret;
477}
478
479/*
480 * Scan through pages checking if pages follow certain conditions,
481 * and move them to the pagelist if they do.
482 *
483 * queue_pages_pte_range() has three possible return values:
484 * 0 - pages are placed on the right node or queued successfully.
485 * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
486 * specified.
487 * -EIO - only MPOL_MF_STRICT was specified and an existing page was already
488 * on a node that does not follow the policy.
489 */
490static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
491 unsigned long end, struct mm_walk *walk)
492{
493 struct vm_area_struct *vma = walk->vma;
494 struct page *page;
495 struct queue_pages *qp = walk->private;
496 unsigned long flags = qp->flags;
497 int ret;
498 bool has_unmovable = false;
499 pte_t *pte;
500 spinlock_t *ptl;
501
502 ptl = pmd_trans_huge_lock(pmd, vma);
503 if (ptl) {
504 ret = queue_pages_pmd(pmd, ptl, addr, end, walk);
505 if (ret != 2)
506 return ret;
507 }
508 /* THP was split, fall through to pte walk */
509
510 if (pmd_trans_unstable(pmd))
511 return 0;
512
513 pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
514 for (; addr != end; pte++, addr += PAGE_SIZE) {
515 if (!pte_present(*pte))
516 continue;
517 page = vm_normal_page(vma, addr, *pte);
518 if (!page)
519 continue;
520 /*
521 * vm_normal_page() filters out zero pages, but there might
522 * still be PageReserved pages to skip, perhaps in a VDSO.
523 */
524 if (PageReserved(page))
525 continue;
526 if (!queue_pages_required(page, qp))
527 continue;
528 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
529 /* MPOL_MF_STRICT must be specified if we get here */
530 if (!vma_migratable(vma)) {
531 has_unmovable = true;
532 break;
533 }
534
535 /*
536 * Do not abort immediately since there may be
537 * temporary off LRU pages in the range. Still
538 * need migrate other LRU pages.
539 */
540 if (migrate_page_add(page, qp->pagelist, flags))
541 has_unmovable = true;
542 } else
543 break;
544 }
545 pte_unmap_unlock(pte - 1, ptl);
546 cond_resched();
547
548 if (has_unmovable)
549 return 1;
550
551 return addr != end ? -EIO : 0;
552}
553
554static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
555 unsigned long addr, unsigned long end,
556 struct mm_walk *walk)
557{
558#ifdef CONFIG_HUGETLB_PAGE
559 struct queue_pages *qp = walk->private;
560 unsigned long flags = qp->flags;
561 struct page *page;
562 spinlock_t *ptl;
563 pte_t entry;
564
565 ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
566 entry = huge_ptep_get(pte);
567 if (!pte_present(entry))
568 goto unlock;
569 page = pte_page(entry);
570 if (!queue_pages_required(page, qp))
571 goto unlock;
572 /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
573 if (flags & (MPOL_MF_MOVE_ALL) ||
574 (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
575 isolate_huge_page(page, qp->pagelist);
576unlock:
577 spin_unlock(ptl);
578#else
579 BUG();
580#endif
581 return 0;
582}
583
584#ifdef CONFIG_NUMA_BALANCING
585/*
586 * This is used to mark a range of virtual addresses to be inaccessible.
587 * These are later cleared by a NUMA hinting fault. Depending on these
588 * faults, pages may be migrated for better NUMA placement.
589 *
590 * This is assuming that NUMA faults are handled using PROT_NONE. If
591 * an architecture makes a different choice, it will need further
592 * changes to the core.
593 */
594unsigned long change_prot_numa(struct vm_area_struct *vma,
595 unsigned long addr, unsigned long end)
596{
597 int nr_updated;
598
599 nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1);
600 if (nr_updated)
601 count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
602
603 return nr_updated;
604}
605#else
606static unsigned long change_prot_numa(struct vm_area_struct *vma,
607 unsigned long addr, unsigned long end)
608{
609 return 0;
610}
611#endif /* CONFIG_NUMA_BALANCING */
612
613static int queue_pages_test_walk(unsigned long start, unsigned long end,
614 struct mm_walk *walk)
615{
616 struct vm_area_struct *vma = walk->vma;
617 struct queue_pages *qp = walk->private;
618 unsigned long endvma = vma->vm_end;
619 unsigned long flags = qp->flags;
620
621 /*
622 * Need check MPOL_MF_STRICT to return -EIO if possible
623 * regardless of vma_migratable
624 */
625 if (!vma_migratable(vma) &&
626 !(flags & MPOL_MF_STRICT))
627 return 1;
628
629 if (endvma > end)
630 endvma = end;
631 if (vma->vm_start > start)
632 start = vma->vm_start;
633
634 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
635 if (!vma->vm_next && vma->vm_end < end)
636 return -EFAULT;
637 if (qp->prev && qp->prev->vm_end < vma->vm_start)
638 return -EFAULT;
639 }
640
641 qp->prev = vma;
642
643 if (flags & MPOL_MF_LAZY) {
644 /* Similar to task_numa_work, skip inaccessible VMAs */
645 if (!is_vm_hugetlb_page(vma) &&
646 (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) &&
647 !(vma->vm_flags & VM_MIXEDMAP))
648 change_prot_numa(vma, start, endvma);
649 return 1;
650 }
651
652 /* queue pages from current vma */
653 if (flags & MPOL_MF_VALID)
654 return 0;
655 return 1;
656}
657
658static const struct mm_walk_ops queue_pages_walk_ops = {
659 .hugetlb_entry = queue_pages_hugetlb,
660 .pmd_entry = queue_pages_pte_range,
661 .test_walk = queue_pages_test_walk,
662};
663
664/*
665 * Walk through page tables and collect pages to be migrated.
666 *
667 * If pages found in a given range are on a set of nodes (determined by
668 * @nodes and @flags,) it's isolated and queued to the pagelist which is
669 * passed via @private.
670 *
671 * queue_pages_range() has three possible return values:
672 * 1 - there is unmovable page, but MPOL_MF_MOVE* & MPOL_MF_STRICT were
673 * specified.
674 * 0 - queue pages successfully or no misplaced page.
675 * errno - i.e. misplaced pages with MPOL_MF_STRICT specified (-EIO) or
676 * memory range specified by nodemask and maxnode points outside
677 * your accessible address space (-EFAULT)
678 */
679static int
680queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
681 nodemask_t *nodes, unsigned long flags,
682 struct list_head *pagelist)
683{
684 struct queue_pages qp = {
685 .pagelist = pagelist,
686 .flags = flags,
687 .nmask = nodes,
688 .prev = NULL,
689 };
690
691 return walk_page_range(mm, start, end, &queue_pages_walk_ops, &qp);
692}
693
694/*
695 * Apply policy to a single VMA
696 * This must be called with the mmap_sem held for writing.
697 */
698static int vma_replace_policy(struct vm_area_struct *vma,
699 struct mempolicy *pol)
700{
701 int err;
702 struct mempolicy *old;
703 struct mempolicy *new;
704
705 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
706 vma->vm_start, vma->vm_end, vma->vm_pgoff,
707 vma->vm_ops, vma->vm_file,
708 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
709
710 new = mpol_dup(pol);
711 if (IS_ERR(new))
712 return PTR_ERR(new);
713
714 if (vma->vm_ops && vma->vm_ops->set_policy) {
715 err = vma->vm_ops->set_policy(vma, new);
716 if (err)
717 goto err_out;
718 }
719
720 old = vma->vm_policy;
721 vma->vm_policy = new; /* protected by mmap_sem */
722 mpol_put(old);
723
724 return 0;
725 err_out:
726 mpol_put(new);
727 return err;
728}
729
730/* Step 2: apply policy to a range and do splits. */
731static int mbind_range(struct mm_struct *mm, unsigned long start,
732 unsigned long end, struct mempolicy *new_pol)
733{
734 struct vm_area_struct *next;
735 struct vm_area_struct *prev;
736 struct vm_area_struct *vma;
737 int err = 0;
738 pgoff_t pgoff;
739 unsigned long vmstart;
740 unsigned long vmend;
741
742 vma = find_vma(mm, start);
743 if (!vma || vma->vm_start > start)
744 return -EFAULT;
745
746 prev = vma->vm_prev;
747 if (start > vma->vm_start)
748 prev = vma;
749
750 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
751 next = vma->vm_next;
752 vmstart = max(start, vma->vm_start);
753 vmend = min(end, vma->vm_end);
754
755 if (mpol_equal(vma_policy(vma), new_pol))
756 continue;
757
758 pgoff = vma->vm_pgoff +
759 ((vmstart - vma->vm_start) >> PAGE_SHIFT);
760 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
761 vma->anon_vma, vma->vm_file, pgoff,
762 new_pol, vma->vm_userfaultfd_ctx);
763 if (prev) {
764 vma = prev;
765 next = vma->vm_next;
766 if (mpol_equal(vma_policy(vma), new_pol))
767 continue;
768 /* vma_merge() joined vma && vma->next, case 8 */
769 goto replace;
770 }
771 if (vma->vm_start != vmstart) {
772 err = split_vma(vma->vm_mm, vma, vmstart, 1);
773 if (err)
774 goto out;
775 }
776 if (vma->vm_end != vmend) {
777 err = split_vma(vma->vm_mm, vma, vmend, 0);
778 if (err)
779 goto out;
780 }
781 replace:
782 err = vma_replace_policy(vma, new_pol);
783 if (err)
784 goto out;
785 }
786
787 out:
788 return err;
789}
790
791/* Set the process memory policy */
792static long do_set_mempolicy(unsigned short mode, unsigned short flags,
793 nodemask_t *nodes)
794{
795 struct mempolicy *new, *old;
796 NODEMASK_SCRATCH(scratch);
797 int ret;
798
799 if (!scratch)
800 return -ENOMEM;
801
802 new = mpol_new(mode, flags, nodes);
803 if (IS_ERR(new)) {
804 ret = PTR_ERR(new);
805 goto out;
806 }
807
808 task_lock(current);
809 ret = mpol_set_nodemask(new, nodes, scratch);
810 if (ret) {
811 task_unlock(current);
812 mpol_put(new);
813 goto out;
814 }
815 old = current->mempolicy;
816 current->mempolicy = new;
817 if (new && new->mode == MPOL_INTERLEAVE)
818 current->il_prev = MAX_NUMNODES-1;
819 task_unlock(current);
820 mpol_put(old);
821 ret = 0;
822out:
823 NODEMASK_SCRATCH_FREE(scratch);
824 return ret;
825}
826
827/*
828 * Return nodemask for policy for get_mempolicy() query
829 *
830 * Called with task's alloc_lock held
831 */
832static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
833{
834 nodes_clear(*nodes);
835 if (p == &default_policy)
836 return;
837
838 switch (p->mode) {
839 case MPOL_BIND:
840 /* Fall through */
841 case MPOL_INTERLEAVE:
842 *nodes = p->v.nodes;
843 break;
844 case MPOL_PREFERRED:
845 if (!(p->flags & MPOL_F_LOCAL))
846 node_set(p->v.preferred_node, *nodes);
847 /* else return empty node mask for local allocation */
848 break;
849 default:
850 BUG();
851 }
852}
853
854static int lookup_node(struct mm_struct *mm, unsigned long addr)
855{
856 struct page *p;
857 int err;
858
859 int locked = 1;
860 err = get_user_pages_locked(addr & PAGE_MASK, 1, 0, &p, &locked);
861 if (err >= 0) {
862 err = page_to_nid(p);
863 put_page(p);
864 }
865 if (locked)
866 up_read(&mm->mmap_sem);
867 return err;
868}
869
870/* Retrieve NUMA policy */
871static long do_get_mempolicy(int *policy, nodemask_t *nmask,
872 unsigned long addr, unsigned long flags)
873{
874 int err;
875 struct mm_struct *mm = current->mm;
876 struct vm_area_struct *vma = NULL;
877 struct mempolicy *pol = current->mempolicy, *pol_refcount = NULL;
878
879 if (flags &
880 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
881 return -EINVAL;
882
883 if (flags & MPOL_F_MEMS_ALLOWED) {
884 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
885 return -EINVAL;
886 *policy = 0; /* just so it's initialized */
887 task_lock(current);
888 *nmask = cpuset_current_mems_allowed;
889 task_unlock(current);
890 return 0;
891 }
892
893 if (flags & MPOL_F_ADDR) {
894 /*
895 * Do NOT fall back to task policy if the
896 * vma/shared policy at addr is NULL. We
897 * want to return MPOL_DEFAULT in this case.
898 */
899 down_read(&mm->mmap_sem);
900 vma = find_vma_intersection(mm, addr, addr+1);
901 if (!vma) {
902 up_read(&mm->mmap_sem);
903 return -EFAULT;
904 }
905 if (vma->vm_ops && vma->vm_ops->get_policy)
906 pol = vma->vm_ops->get_policy(vma, addr);
907 else
908 pol = vma->vm_policy;
909 } else if (addr)
910 return -EINVAL;
911
912 if (!pol)
913 pol = &default_policy; /* indicates default behavior */
914
915 if (flags & MPOL_F_NODE) {
916 if (flags & MPOL_F_ADDR) {
917 /*
918 * Take a refcount on the mpol, lookup_node()
919 * wil drop the mmap_sem, so after calling
920 * lookup_node() only "pol" remains valid, "vma"
921 * is stale.
922 */
923 pol_refcount = pol;
924 vma = NULL;
925 mpol_get(pol);
926 err = lookup_node(mm, addr);
927 if (err < 0)
928 goto out;
929 *policy = err;
930 } else if (pol == current->mempolicy &&
931 pol->mode == MPOL_INTERLEAVE) {
932 *policy = next_node_in(current->il_prev, pol->v.nodes);
933 } else {
934 err = -EINVAL;
935 goto out;
936 }
937 } else {
938 *policy = pol == &default_policy ? MPOL_DEFAULT :
939 pol->mode;
940 /*
941 * Internal mempolicy flags must be masked off before exposing
942 * the policy to userspace.
943 */
944 *policy |= (pol->flags & MPOL_MODE_FLAGS);
945 }
946
947 err = 0;
948 if (nmask) {
949 if (mpol_store_user_nodemask(pol)) {
950 *nmask = pol->w.user_nodemask;
951 } else {
952 task_lock(current);
953 get_policy_nodemask(pol, nmask);
954 task_unlock(current);
955 }
956 }
957
958 out:
959 mpol_cond_put(pol);
960 if (vma)
961 up_read(&mm->mmap_sem);
962 if (pol_refcount)
963 mpol_put(pol_refcount);
964 return err;
965}
966
967#ifdef CONFIG_MIGRATION
968/*
969 * page migration, thp tail pages can be passed.
970 */
971static int migrate_page_add(struct page *page, struct list_head *pagelist,
972 unsigned long flags)
973{
974 struct page *head = compound_head(page);
975 /*
976 * Avoid migrating a page that is shared with others.
977 */
978 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(head) == 1) {
979 if (!isolate_lru_page(head)) {
980 list_add_tail(&head->lru, pagelist);
981 mod_node_page_state(page_pgdat(head),
982 NR_ISOLATED_ANON + page_is_file_cache(head),
983 hpage_nr_pages(head));
984 } else if (flags & MPOL_MF_STRICT) {
985 /*
986 * Non-movable page may reach here. And, there may be
987 * temporary off LRU pages or non-LRU movable pages.
988 * Treat them as unmovable pages since they can't be
989 * isolated, so they can't be moved at the moment. It
990 * should return -EIO for this case too.
991 */
992 return -EIO;
993 }
994 }
995
996 return 0;
997}
998
999/* page allocation callback for NUMA node migration */
1000struct page *alloc_new_node_page(struct page *page, unsigned long node)
1001{
1002 if (PageHuge(page))
1003 return alloc_huge_page_node(page_hstate(compound_head(page)),
1004 node);
1005 else if (PageTransHuge(page)) {
1006 struct page *thp;
1007
1008 thp = alloc_pages_node(node,
1009 (GFP_TRANSHUGE | __GFP_THISNODE),
1010 HPAGE_PMD_ORDER);
1011 if (!thp)
1012 return NULL;
1013 prep_transhuge_page(thp);
1014 return thp;
1015 } else
1016 return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE |
1017 __GFP_THISNODE, 0);
1018}
1019
1020/*
1021 * Migrate pages from one node to a target node.
1022 * Returns error or the number of pages not migrated.
1023 */
1024static int migrate_to_node(struct mm_struct *mm, int source, int dest,
1025 int flags)
1026{
1027 nodemask_t nmask;
1028 LIST_HEAD(pagelist);
1029 int err = 0;
1030
1031 nodes_clear(nmask);
1032 node_set(source, nmask);
1033
1034 /*
1035 * This does not "check" the range but isolates all pages that
1036 * need migration. Between passing in the full user address
1037 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
1038 */
1039 VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
1040 queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
1041 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
1042
1043 if (!list_empty(&pagelist)) {
1044 err = migrate_pages(&pagelist, alloc_new_node_page, NULL, dest,
1045 MIGRATE_SYNC, MR_SYSCALL);
1046 if (err)
1047 putback_movable_pages(&pagelist);
1048 }
1049
1050 return err;
1051}
1052
1053/*
1054 * Move pages between the two nodesets so as to preserve the physical
1055 * layout as much as possible.
1056 *
1057 * Returns the number of page that could not be moved.
1058 */
1059int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1060 const nodemask_t *to, int flags)
1061{
1062 int busy = 0;
1063 int err;
1064 nodemask_t tmp;
1065
1066 err = migrate_prep();
1067 if (err)
1068 return err;
1069
1070 down_read(&mm->mmap_sem);
1071
1072 /*
1073 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
1074 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
1075 * bit in 'tmp', and return that <source, dest> pair for migration.
1076 * The pair of nodemasks 'to' and 'from' define the map.
1077 *
1078 * If no pair of bits is found that way, fallback to picking some
1079 * pair of 'source' and 'dest' bits that are not the same. If the
1080 * 'source' and 'dest' bits are the same, this represents a node
1081 * that will be migrating to itself, so no pages need move.
1082 *
1083 * If no bits are left in 'tmp', or if all remaining bits left
1084 * in 'tmp' correspond to the same bit in 'to', return false
1085 * (nothing left to migrate).
1086 *
1087 * This lets us pick a pair of nodes to migrate between, such that
1088 * if possible the dest node is not already occupied by some other
1089 * source node, minimizing the risk of overloading the memory on a
1090 * node that would happen if we migrated incoming memory to a node
1091 * before migrating outgoing memory source that same node.
1092 *
1093 * A single scan of tmp is sufficient. As we go, we remember the
1094 * most recent <s, d> pair that moved (s != d). If we find a pair
1095 * that not only moved, but what's better, moved to an empty slot
1096 * (d is not set in tmp), then we break out then, with that pair.
1097 * Otherwise when we finish scanning from_tmp, we at least have the
1098 * most recent <s, d> pair that moved. If we get all the way through
1099 * the scan of tmp without finding any node that moved, much less
1100 * moved to an empty node, then there is nothing left worth migrating.
1101 */
1102
1103 tmp = *from;
1104 while (!nodes_empty(tmp)) {
1105 int s,d;
1106 int source = NUMA_NO_NODE;
1107 int dest = 0;
1108
1109 for_each_node_mask(s, tmp) {
1110
1111 /*
1112 * do_migrate_pages() tries to maintain the relative
1113 * node relationship of the pages established between
1114 * threads and memory areas.
1115 *
1116 * However if the number of source nodes is not equal to
1117 * the number of destination nodes we can not preserve
1118 * this node relative relationship. In that case, skip
1119 * copying memory from a node that is in the destination
1120 * mask.
1121 *
1122 * Example: [2,3,4] -> [3,4,5] moves everything.
1123 * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
1124 */
1125
1126 if ((nodes_weight(*from) != nodes_weight(*to)) &&
1127 (node_isset(s, *to)))
1128 continue;
1129
1130 d = node_remap(s, *from, *to);
1131 if (s == d)
1132 continue;
1133
1134 source = s; /* Node moved. Memorize */
1135 dest = d;
1136
1137 /* dest not in remaining from nodes? */
1138 if (!node_isset(dest, tmp))
1139 break;
1140 }
1141 if (source == NUMA_NO_NODE)
1142 break;
1143
1144 node_clear(source, tmp);
1145 err = migrate_to_node(mm, source, dest, flags);
1146 if (err > 0)
1147 busy += err;
1148 if (err < 0)
1149 break;
1150 }
1151 up_read(&mm->mmap_sem);
1152 if (err < 0)
1153 return err;
1154 return busy;
1155
1156}
1157
1158/*
1159 * Allocate a new page for page migration based on vma policy.
1160 * Start by assuming the page is mapped by the same vma as contains @start.
1161 * Search forward from there, if not. N.B., this assumes that the
1162 * list of pages handed to migrate_pages()--which is how we get here--
1163 * is in virtual address order.
1164 */
1165static struct page *new_page(struct page *page, unsigned long start)
1166{
1167 struct vm_area_struct *vma;
1168 unsigned long uninitialized_var(address);
1169
1170 vma = find_vma(current->mm, start);
1171 while (vma) {
1172 address = page_address_in_vma(page, vma);
1173 if (address != -EFAULT)
1174 break;
1175 vma = vma->vm_next;
1176 }
1177
1178 if (PageHuge(page)) {
1179 return alloc_huge_page_vma(page_hstate(compound_head(page)),
1180 vma, address);
1181 } else if (PageTransHuge(page)) {
1182 struct page *thp;
1183
1184 thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
1185 HPAGE_PMD_ORDER);
1186 if (!thp)
1187 return NULL;
1188 prep_transhuge_page(thp);
1189 return thp;
1190 }
1191 /*
1192 * if !vma, alloc_page_vma() will use task or system default policy
1193 */
1194 return alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL,
1195 vma, address);
1196}
1197#else
1198
1199static int migrate_page_add(struct page *page, struct list_head *pagelist,
1200 unsigned long flags)
1201{
1202 return -EIO;
1203}
1204
1205int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1206 const nodemask_t *to, int flags)
1207{
1208 return -ENOSYS;
1209}
1210
1211static struct page *new_page(struct page *page, unsigned long start)
1212{
1213 return NULL;
1214}
1215#endif
1216
1217static long do_mbind(unsigned long start, unsigned long len,
1218 unsigned short mode, unsigned short mode_flags,
1219 nodemask_t *nmask, unsigned long flags)
1220{
1221 struct mm_struct *mm = current->mm;
1222 struct mempolicy *new;
1223 unsigned long end;
1224 int err;
1225 int ret;
1226 LIST_HEAD(pagelist);
1227
1228 if (flags & ~(unsigned long)MPOL_MF_VALID)
1229 return -EINVAL;
1230 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1231 return -EPERM;
1232
1233 if (start & ~PAGE_MASK)
1234 return -EINVAL;
1235
1236 if (mode == MPOL_DEFAULT)
1237 flags &= ~MPOL_MF_STRICT;
1238
1239 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1240 end = start + len;
1241
1242 if (end < start)
1243 return -EINVAL;
1244 if (end == start)
1245 return 0;
1246
1247 new = mpol_new(mode, mode_flags, nmask);
1248 if (IS_ERR(new))
1249 return PTR_ERR(new);
1250
1251 if (flags & MPOL_MF_LAZY)
1252 new->flags |= MPOL_F_MOF;
1253
1254 /*
1255 * If we are using the default policy then operation
1256 * on discontinuous address spaces is okay after all
1257 */
1258 if (!new)
1259 flags |= MPOL_MF_DISCONTIG_OK;
1260
1261 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1262 start, start + len, mode, mode_flags,
1263 nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE);
1264
1265 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1266
1267 err = migrate_prep();
1268 if (err)
1269 goto mpol_out;
1270 }
1271 {
1272 NODEMASK_SCRATCH(scratch);
1273 if (scratch) {
1274 down_write(&mm->mmap_sem);
1275 task_lock(current);
1276 err = mpol_set_nodemask(new, nmask, scratch);
1277 task_unlock(current);
1278 if (err)
1279 up_write(&mm->mmap_sem);
1280 } else
1281 err = -ENOMEM;
1282 NODEMASK_SCRATCH_FREE(scratch);
1283 }
1284 if (err)
1285 goto mpol_out;
1286
1287 ret = queue_pages_range(mm, start, end, nmask,
1288 flags | MPOL_MF_INVERT, &pagelist);
1289
1290 if (ret < 0) {
1291 err = ret;
1292 goto up_out;
1293 }
1294
1295 err = mbind_range(mm, start, end, new);
1296
1297 if (!err) {
1298 int nr_failed = 0;
1299
1300 if (!list_empty(&pagelist)) {
1301 WARN_ON_ONCE(flags & MPOL_MF_LAZY);
1302 nr_failed = migrate_pages(&pagelist, new_page, NULL,
1303 start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
1304 if (nr_failed)
1305 putback_movable_pages(&pagelist);
1306 }
1307
1308 if ((ret > 0) || (nr_failed && (flags & MPOL_MF_STRICT)))
1309 err = -EIO;
1310 } else {
1311up_out:
1312 if (!list_empty(&pagelist))
1313 putback_movable_pages(&pagelist);
1314 }
1315
1316 up_write(&mm->mmap_sem);
1317mpol_out:
1318 mpol_put(new);
1319 return err;
1320}
1321
1322/*
1323 * User space interface with variable sized bitmaps for nodelists.
1324 */
1325
1326/* Copy a node mask from user space. */
1327static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1328 unsigned long maxnode)
1329{
1330 unsigned long k;
1331 unsigned long t;
1332 unsigned long nlongs;
1333 unsigned long endmask;
1334
1335 --maxnode;
1336 nodes_clear(*nodes);
1337 if (maxnode == 0 || !nmask)
1338 return 0;
1339 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
1340 return -EINVAL;
1341
1342 nlongs = BITS_TO_LONGS(maxnode);
1343 if ((maxnode % BITS_PER_LONG) == 0)
1344 endmask = ~0UL;
1345 else
1346 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1347
1348 /*
1349 * When the user specified more nodes than supported just check
1350 * if the non supported part is all zero.
1351 *
1352 * If maxnode have more longs than MAX_NUMNODES, check
1353 * the bits in that area first. And then go through to
1354 * check the rest bits which equal or bigger than MAX_NUMNODES.
1355 * Otherwise, just check bits [MAX_NUMNODES, maxnode).
1356 */
1357 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1358 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1359 if (get_user(t, nmask + k))
1360 return -EFAULT;
1361 if (k == nlongs - 1) {
1362 if (t & endmask)
1363 return -EINVAL;
1364 } else if (t)
1365 return -EINVAL;
1366 }
1367 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1368 endmask = ~0UL;
1369 }
1370
1371 if (maxnode > MAX_NUMNODES && MAX_NUMNODES % BITS_PER_LONG != 0) {
1372 unsigned long valid_mask = endmask;
1373
1374 valid_mask &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
1375 if (get_user(t, nmask + nlongs - 1))
1376 return -EFAULT;
1377 if (t & valid_mask)
1378 return -EINVAL;
1379 }
1380
1381 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1382 return -EFAULT;
1383 nodes_addr(*nodes)[nlongs-1] &= endmask;
1384 return 0;
1385}
1386
1387/* Copy a kernel node mask to user space */
1388static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1389 nodemask_t *nodes)
1390{
1391 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1392 unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long);
1393
1394 if (copy > nbytes) {
1395 if (copy > PAGE_SIZE)
1396 return -EINVAL;
1397 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1398 return -EFAULT;
1399 copy = nbytes;
1400 }
1401 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1402}
1403
1404static long kernel_mbind(unsigned long start, unsigned long len,
1405 unsigned long mode, const unsigned long __user *nmask,
1406 unsigned long maxnode, unsigned int flags)
1407{
1408 nodemask_t nodes;
1409 int err;
1410 unsigned short mode_flags;
1411
1412 start = untagged_addr(start);
1413 mode_flags = mode & MPOL_MODE_FLAGS;
1414 mode &= ~MPOL_MODE_FLAGS;
1415 if (mode >= MPOL_MAX)
1416 return -EINVAL;
1417 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1418 (mode_flags & MPOL_F_RELATIVE_NODES))
1419 return -EINVAL;
1420 err = get_nodes(&nodes, nmask, maxnode);
1421 if (err)
1422 return err;
1423 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1424}
1425
1426SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1427 unsigned long, mode, const unsigned long __user *, nmask,
1428 unsigned long, maxnode, unsigned int, flags)
1429{
1430 return kernel_mbind(start, len, mode, nmask, maxnode, flags);
1431}
1432
1433/* Set the process memory policy */
1434static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
1435 unsigned long maxnode)
1436{
1437 int err;
1438 nodemask_t nodes;
1439 unsigned short flags;
1440
1441 flags = mode & MPOL_MODE_FLAGS;
1442 mode &= ~MPOL_MODE_FLAGS;
1443 if ((unsigned int)mode >= MPOL_MAX)
1444 return -EINVAL;
1445 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1446 return -EINVAL;
1447 err = get_nodes(&nodes, nmask, maxnode);
1448 if (err)
1449 return err;
1450 return do_set_mempolicy(mode, flags, &nodes);
1451}
1452
1453SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
1454 unsigned long, maxnode)
1455{
1456 return kernel_set_mempolicy(mode, nmask, maxnode);
1457}
1458
1459static int kernel_migrate_pages(pid_t pid, unsigned long maxnode,
1460 const unsigned long __user *old_nodes,
1461 const unsigned long __user *new_nodes)
1462{
1463 struct mm_struct *mm = NULL;
1464 struct task_struct *task;
1465 nodemask_t task_nodes;
1466 int err;
1467 nodemask_t *old;
1468 nodemask_t *new;
1469 NODEMASK_SCRATCH(scratch);
1470
1471 if (!scratch)
1472 return -ENOMEM;
1473
1474 old = &scratch->mask1;
1475 new = &scratch->mask2;
1476
1477 err = get_nodes(old, old_nodes, maxnode);
1478 if (err)
1479 goto out;
1480
1481 err = get_nodes(new, new_nodes, maxnode);
1482 if (err)
1483 goto out;
1484
1485 /* Find the mm_struct */
1486 rcu_read_lock();
1487 task = pid ? find_task_by_vpid(pid) : current;
1488 if (!task) {
1489 rcu_read_unlock();
1490 err = -ESRCH;
1491 goto out;
1492 }
1493 get_task_struct(task);
1494
1495 err = -EINVAL;
1496
1497 /*
1498 * Check if this process has the right to modify the specified process.
1499 * Use the regular "ptrace_may_access()" checks.
1500 */
1501 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) {
1502 rcu_read_unlock();
1503 err = -EPERM;
1504 goto out_put;
1505 }
1506 rcu_read_unlock();
1507
1508 task_nodes = cpuset_mems_allowed(task);
1509 /* Is the user allowed to access the target nodes? */
1510 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
1511 err = -EPERM;
1512 goto out_put;
1513 }
1514
1515 task_nodes = cpuset_mems_allowed(current);
1516 nodes_and(*new, *new, task_nodes);
1517 if (nodes_empty(*new))
1518 goto out_put;
1519
1520 err = security_task_movememory(task);
1521 if (err)
1522 goto out_put;
1523
1524 mm = get_task_mm(task);
1525 put_task_struct(task);
1526
1527 if (!mm) {
1528 err = -EINVAL;
1529 goto out;
1530 }
1531
1532 err = do_migrate_pages(mm, old, new,
1533 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1534
1535 mmput(mm);
1536out:
1537 NODEMASK_SCRATCH_FREE(scratch);
1538
1539 return err;
1540
1541out_put:
1542 put_task_struct(task);
1543 goto out;
1544
1545}
1546
1547SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1548 const unsigned long __user *, old_nodes,
1549 const unsigned long __user *, new_nodes)
1550{
1551 return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes);
1552}
1553
1554
1555/* Retrieve NUMA policy */
1556static int kernel_get_mempolicy(int __user *policy,
1557 unsigned long __user *nmask,
1558 unsigned long maxnode,
1559 unsigned long addr,
1560 unsigned long flags)
1561{
1562 int err;
1563 int uninitialized_var(pval);
1564 nodemask_t nodes;
1565
1566 addr = untagged_addr(addr);
1567
1568 if (nmask != NULL && maxnode < nr_node_ids)
1569 return -EINVAL;
1570
1571 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1572
1573 if (err)
1574 return err;
1575
1576 if (policy && put_user(pval, policy))
1577 return -EFAULT;
1578
1579 if (nmask)
1580 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1581
1582 return err;
1583}
1584
1585SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1586 unsigned long __user *, nmask, unsigned long, maxnode,
1587 unsigned long, addr, unsigned long, flags)
1588{
1589 return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags);
1590}
1591
1592#ifdef CONFIG_COMPAT
1593
1594COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1595 compat_ulong_t __user *, nmask,
1596 compat_ulong_t, maxnode,
1597 compat_ulong_t, addr, compat_ulong_t, flags)
1598{
1599 long err;
1600 unsigned long __user *nm = NULL;
1601 unsigned long nr_bits, alloc_size;
1602 DECLARE_BITMAP(bm, MAX_NUMNODES);
1603
1604 nr_bits = min_t(unsigned long, maxnode-1, nr_node_ids);
1605 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1606
1607 if (nmask)
1608 nm = compat_alloc_user_space(alloc_size);
1609
1610 err = kernel_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1611
1612 if (!err && nmask) {
1613 unsigned long copy_size;
1614 copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
1615 err = copy_from_user(bm, nm, copy_size);
1616 /* ensure entire bitmap is zeroed */
1617 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1618 err |= compat_put_bitmap(nmask, bm, nr_bits);
1619 }
1620
1621 return err;
1622}
1623
1624COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
1625 compat_ulong_t, maxnode)
1626{
1627 unsigned long __user *nm = NULL;
1628 unsigned long nr_bits, alloc_size;
1629 DECLARE_BITMAP(bm, MAX_NUMNODES);
1630
1631 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1632 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1633
1634 if (nmask) {
1635 if (compat_get_bitmap(bm, nmask, nr_bits))
1636 return -EFAULT;
1637 nm = compat_alloc_user_space(alloc_size);
1638 if (copy_to_user(nm, bm, alloc_size))
1639 return -EFAULT;
1640 }
1641
1642 return kernel_set_mempolicy(mode, nm, nr_bits+1);
1643}
1644
1645COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
1646 compat_ulong_t, mode, compat_ulong_t __user *, nmask,
1647 compat_ulong_t, maxnode, compat_ulong_t, flags)
1648{
1649 unsigned long __user *nm = NULL;
1650 unsigned long nr_bits, alloc_size;
1651 nodemask_t bm;
1652
1653 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1654 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1655
1656 if (nmask) {
1657 if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
1658 return -EFAULT;
1659 nm = compat_alloc_user_space(alloc_size);
1660 if (copy_to_user(nm, nodes_addr(bm), alloc_size))
1661 return -EFAULT;
1662 }
1663
1664 return kernel_mbind(start, len, mode, nm, nr_bits+1, flags);
1665}
1666
1667COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
1668 compat_ulong_t, maxnode,
1669 const compat_ulong_t __user *, old_nodes,
1670 const compat_ulong_t __user *, new_nodes)
1671{
1672 unsigned long __user *old = NULL;
1673 unsigned long __user *new = NULL;
1674 nodemask_t tmp_mask;
1675 unsigned long nr_bits;
1676 unsigned long size;
1677
1678 nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
1679 size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1680 if (old_nodes) {
1681 if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
1682 return -EFAULT;
1683 old = compat_alloc_user_space(new_nodes ? size * 2 : size);
1684 if (new_nodes)
1685 new = old + size / sizeof(unsigned long);
1686 if (copy_to_user(old, nodes_addr(tmp_mask), size))
1687 return -EFAULT;
1688 }
1689 if (new_nodes) {
1690 if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
1691 return -EFAULT;
1692 if (new == NULL)
1693 new = compat_alloc_user_space(size);
1694 if (copy_to_user(new, nodes_addr(tmp_mask), size))
1695 return -EFAULT;
1696 }
1697 return kernel_migrate_pages(pid, nr_bits + 1, old, new);
1698}
1699
1700#endif /* CONFIG_COMPAT */
1701
1702struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
1703 unsigned long addr)
1704{
1705 struct mempolicy *pol = NULL;
1706
1707 if (vma) {
1708 if (vma->vm_ops && vma->vm_ops->get_policy) {
1709 pol = vma->vm_ops->get_policy(vma, addr);
1710 } else if (vma->vm_policy) {
1711 pol = vma->vm_policy;
1712
1713 /*
1714 * shmem_alloc_page() passes MPOL_F_SHARED policy with
1715 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
1716 * count on these policies which will be dropped by
1717 * mpol_cond_put() later
1718 */
1719 if (mpol_needs_cond_ref(pol))
1720 mpol_get(pol);
1721 }
1722 }
1723
1724 return pol;
1725}
1726
1727/*
1728 * get_vma_policy(@vma, @addr)
1729 * @vma: virtual memory area whose policy is sought
1730 * @addr: address in @vma for shared policy lookup
1731 *
1732 * Returns effective policy for a VMA at specified address.
1733 * Falls back to current->mempolicy or system default policy, as necessary.
1734 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1735 * count--added by the get_policy() vm_op, as appropriate--to protect against
1736 * freeing by another task. It is the caller's responsibility to free the
1737 * extra reference for shared policies.
1738 */
1739static struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
1740 unsigned long addr)
1741{
1742 struct mempolicy *pol = __get_vma_policy(vma, addr);
1743
1744 if (!pol)
1745 pol = get_task_policy(current);
1746
1747 return pol;
1748}
1749
1750bool vma_policy_mof(struct vm_area_struct *vma)
1751{
1752 struct mempolicy *pol;
1753
1754 if (vma->vm_ops && vma->vm_ops->get_policy) {
1755 bool ret = false;
1756
1757 pol = vma->vm_ops->get_policy(vma, vma->vm_start);
1758 if (pol && (pol->flags & MPOL_F_MOF))
1759 ret = true;
1760 mpol_cond_put(pol);
1761
1762 return ret;
1763 }
1764
1765 pol = vma->vm_policy;
1766 if (!pol)
1767 pol = get_task_policy(current);
1768
1769 return pol->flags & MPOL_F_MOF;
1770}
1771
1772static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
1773{
1774 enum zone_type dynamic_policy_zone = policy_zone;
1775
1776 BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
1777
1778 /*
1779 * if policy->v.nodes has movable memory only,
1780 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
1781 *
1782 * policy->v.nodes is intersect with node_states[N_MEMORY].
1783 * so if the following test faile, it implies
1784 * policy->v.nodes has movable memory only.
1785 */
1786 if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
1787 dynamic_policy_zone = ZONE_MOVABLE;
1788
1789 return zone >= dynamic_policy_zone;
1790}
1791
1792/*
1793 * Return a nodemask representing a mempolicy for filtering nodes for
1794 * page allocation
1795 */
1796static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1797{
1798 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1799 if (unlikely(policy->mode == MPOL_BIND) &&
1800 apply_policy_zone(policy, gfp_zone(gfp)) &&
1801 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1802 return &policy->v.nodes;
1803
1804 return NULL;
1805}
1806
1807/* Return the node id preferred by the given mempolicy, or the given id */
1808static int policy_node(gfp_t gfp, struct mempolicy *policy,
1809 int nd)
1810{
1811 if (policy->mode == MPOL_PREFERRED && !(policy->flags & MPOL_F_LOCAL))
1812 nd = policy->v.preferred_node;
1813 else {
1814 /*
1815 * __GFP_THISNODE shouldn't even be used with the bind policy
1816 * because we might easily break the expectation to stay on the
1817 * requested node and not break the policy.
1818 */
1819 WARN_ON_ONCE(policy->mode == MPOL_BIND && (gfp & __GFP_THISNODE));
1820 }
1821
1822 return nd;
1823}
1824
1825/* Do dynamic interleaving for a process */
1826static unsigned interleave_nodes(struct mempolicy *policy)
1827{
1828 unsigned next;
1829 struct task_struct *me = current;
1830
1831 next = next_node_in(me->il_prev, policy->v.nodes);
1832 if (next < MAX_NUMNODES)
1833 me->il_prev = next;
1834 return next;
1835}
1836
1837/*
1838 * Depending on the memory policy provide a node from which to allocate the
1839 * next slab entry.
1840 */
1841unsigned int mempolicy_slab_node(void)
1842{
1843 struct mempolicy *policy;
1844 int node = numa_mem_id();
1845
1846 if (in_interrupt())
1847 return node;
1848
1849 policy = current->mempolicy;
1850 if (!policy || policy->flags & MPOL_F_LOCAL)
1851 return node;
1852
1853 switch (policy->mode) {
1854 case MPOL_PREFERRED:
1855 /*
1856 * handled MPOL_F_LOCAL above
1857 */
1858 return policy->v.preferred_node;
1859
1860 case MPOL_INTERLEAVE:
1861 return interleave_nodes(policy);
1862
1863 case MPOL_BIND: {
1864 struct zoneref *z;
1865
1866 /*
1867 * Follow bind policy behavior and start allocation at the
1868 * first node.
1869 */
1870 struct zonelist *zonelist;
1871 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1872 zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
1873 z = first_zones_zonelist(zonelist, highest_zoneidx,
1874 &policy->v.nodes);
1875 return z->zone ? zone_to_nid(z->zone) : node;
1876 }
1877
1878 default:
1879 BUG();
1880 }
1881}
1882
1883/*
1884 * Do static interleaving for a VMA with known offset @n. Returns the n'th
1885 * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the
1886 * number of present nodes.
1887 */
1888static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
1889{
1890 unsigned nnodes = nodes_weight(pol->v.nodes);
1891 unsigned target;
1892 int i;
1893 int nid;
1894
1895 if (!nnodes)
1896 return numa_node_id();
1897 target = (unsigned int)n % nnodes;
1898 nid = first_node(pol->v.nodes);
1899 for (i = 0; i < target; i++)
1900 nid = next_node(nid, pol->v.nodes);
1901 return nid;
1902}
1903
1904/* Determine a node number for interleave */
1905static inline unsigned interleave_nid(struct mempolicy *pol,
1906 struct vm_area_struct *vma, unsigned long addr, int shift)
1907{
1908 if (vma) {
1909 unsigned long off;
1910
1911 /*
1912 * for small pages, there is no difference between
1913 * shift and PAGE_SHIFT, so the bit-shift is safe.
1914 * for huge pages, since vm_pgoff is in units of small
1915 * pages, we need to shift off the always 0 bits to get
1916 * a useful offset.
1917 */
1918 BUG_ON(shift < PAGE_SHIFT);
1919 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
1920 off += (addr - vma->vm_start) >> shift;
1921 return offset_il_node(pol, off);
1922 } else
1923 return interleave_nodes(pol);
1924}
1925
1926#ifdef CONFIG_HUGETLBFS
1927/*
1928 * huge_node(@vma, @addr, @gfp_flags, @mpol)
1929 * @vma: virtual memory area whose policy is sought
1930 * @addr: address in @vma for shared policy lookup and interleave policy
1931 * @gfp_flags: for requested zone
1932 * @mpol: pointer to mempolicy pointer for reference counted mempolicy
1933 * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask
1934 *
1935 * Returns a nid suitable for a huge page allocation and a pointer
1936 * to the struct mempolicy for conditional unref after allocation.
1937 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1938 * @nodemask for filtering the zonelist.
1939 *
1940 * Must be protected by read_mems_allowed_begin()
1941 */
1942int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
1943 struct mempolicy **mpol, nodemask_t **nodemask)
1944{
1945 int nid;
1946
1947 *mpol = get_vma_policy(vma, addr);
1948 *nodemask = NULL; /* assume !MPOL_BIND */
1949
1950 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1951 nid = interleave_nid(*mpol, vma, addr,
1952 huge_page_shift(hstate_vma(vma)));
1953 } else {
1954 nid = policy_node(gfp_flags, *mpol, numa_node_id());
1955 if ((*mpol)->mode == MPOL_BIND)
1956 *nodemask = &(*mpol)->v.nodes;
1957 }
1958 return nid;
1959}
1960
1961/*
1962 * init_nodemask_of_mempolicy
1963 *
1964 * If the current task's mempolicy is "default" [NULL], return 'false'
1965 * to indicate default policy. Otherwise, extract the policy nodemask
1966 * for 'bind' or 'interleave' policy into the argument nodemask, or
1967 * initialize the argument nodemask to contain the single node for
1968 * 'preferred' or 'local' policy and return 'true' to indicate presence
1969 * of non-default mempolicy.
1970 *
1971 * We don't bother with reference counting the mempolicy [mpol_get/put]
1972 * because the current task is examining it's own mempolicy and a task's
1973 * mempolicy is only ever changed by the task itself.
1974 *
1975 * N.B., it is the caller's responsibility to free a returned nodemask.
1976 */
1977bool init_nodemask_of_mempolicy(nodemask_t *mask)
1978{
1979 struct mempolicy *mempolicy;
1980 int nid;
1981
1982 if (!(mask && current->mempolicy))
1983 return false;
1984
1985 task_lock(current);
1986 mempolicy = current->mempolicy;
1987 switch (mempolicy->mode) {
1988 case MPOL_PREFERRED:
1989 if (mempolicy->flags & MPOL_F_LOCAL)
1990 nid = numa_node_id();
1991 else
1992 nid = mempolicy->v.preferred_node;
1993 init_nodemask_of_node(mask, nid);
1994 break;
1995
1996 case MPOL_BIND:
1997 /* Fall through */
1998 case MPOL_INTERLEAVE:
1999 *mask = mempolicy->v.nodes;
2000 break;
2001
2002 default:
2003 BUG();
2004 }
2005 task_unlock(current);
2006
2007 return true;
2008}
2009#endif
2010
2011/*
2012 * mempolicy_nodemask_intersects
2013 *
2014 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
2015 * policy. Otherwise, check for intersection between mask and the policy
2016 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
2017 * policy, always return true since it may allocate elsewhere on fallback.
2018 *
2019 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
2020 */
2021bool mempolicy_nodemask_intersects(struct task_struct *tsk,
2022 const nodemask_t *mask)
2023{
2024 struct mempolicy *mempolicy;
2025 bool ret = true;
2026
2027 if (!mask)
2028 return ret;
2029 task_lock(tsk);
2030 mempolicy = tsk->mempolicy;
2031 if (!mempolicy)
2032 goto out;
2033
2034 switch (mempolicy->mode) {
2035 case MPOL_PREFERRED:
2036 /*
2037 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
2038 * allocate from, they may fallback to other nodes when oom.
2039 * Thus, it's possible for tsk to have allocated memory from
2040 * nodes in mask.
2041 */
2042 break;
2043 case MPOL_BIND:
2044 case MPOL_INTERLEAVE:
2045 ret = nodes_intersects(mempolicy->v.nodes, *mask);
2046 break;
2047 default:
2048 BUG();
2049 }
2050out:
2051 task_unlock(tsk);
2052 return ret;
2053}
2054
2055/* Allocate a page in interleaved policy.
2056 Own path because it needs to do special accounting. */
2057static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
2058 unsigned nid)
2059{
2060 struct page *page;
2061
2062 page = __alloc_pages(gfp, order, nid);
2063 /* skip NUMA_INTERLEAVE_HIT counter update if numa stats is disabled */
2064 if (!static_branch_likely(&vm_numa_stat_key))
2065 return page;
2066 if (page && page_to_nid(page) == nid) {
2067 preempt_disable();
2068 __inc_numa_state(page_zone(page), NUMA_INTERLEAVE_HIT);
2069 preempt_enable();
2070 }
2071 return page;
2072}
2073
2074/**
2075 * alloc_pages_vma - Allocate a page for a VMA.
2076 *
2077 * @gfp:
2078 * %GFP_USER user allocation.
2079 * %GFP_KERNEL kernel allocations,
2080 * %GFP_HIGHMEM highmem/user allocations,
2081 * %GFP_FS allocation should not call back into a file system.
2082 * %GFP_ATOMIC don't sleep.
2083 *
2084 * @order:Order of the GFP allocation.
2085 * @vma: Pointer to VMA or NULL if not available.
2086 * @addr: Virtual Address of the allocation. Must be inside the VMA.
2087 * @node: Which node to prefer for allocation (modulo policy).
2088 * @hugepage: for hugepages try only the preferred node if possible
2089 *
2090 * This function allocates a page from the kernel page pool and applies
2091 * a NUMA policy associated with the VMA or the current process.
2092 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
2093 * mm_struct of the VMA to prevent it from going away. Should be used for
2094 * all allocations for pages that will be mapped into user space. Returns
2095 * NULL when no page can be allocated.
2096 */
2097struct page *
2098alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
2099 unsigned long addr, int node, bool hugepage)
2100{
2101 struct mempolicy *pol;
2102 struct page *page;
2103 int preferred_nid;
2104 nodemask_t *nmask;
2105
2106 pol = get_vma_policy(vma, addr);
2107
2108 if (pol->mode == MPOL_INTERLEAVE) {
2109 unsigned nid;
2110
2111 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
2112 mpol_cond_put(pol);
2113 page = alloc_page_interleave(gfp, order, nid);
2114 goto out;
2115 }
2116
2117 if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
2118 int hpage_node = node;
2119
2120 /*
2121 * For hugepage allocation and non-interleave policy which
2122 * allows the current node (or other explicitly preferred
2123 * node) we only try to allocate from the current/preferred
2124 * node and don't fall back to other nodes, as the cost of
2125 * remote accesses would likely offset THP benefits.
2126 *
2127 * If the policy is interleave, or does not allow the current
2128 * node in its nodemask, we allocate the standard way.
2129 */
2130 if (pol->mode == MPOL_PREFERRED && !(pol->flags & MPOL_F_LOCAL))
2131 hpage_node = pol->v.preferred_node;
2132
2133 nmask = policy_nodemask(gfp, pol);
2134 if (!nmask || node_isset(hpage_node, *nmask)) {
2135 mpol_cond_put(pol);
2136 page = __alloc_pages_node(hpage_node,
2137 gfp | __GFP_THISNODE, order);
2138
2139 /*
2140 * If hugepage allocations are configured to always
2141 * synchronous compact or the vma has been madvised
2142 * to prefer hugepage backing, retry allowing remote
2143 * memory as well.
2144 */
2145 if (!page && (gfp & __GFP_DIRECT_RECLAIM))
2146 page = __alloc_pages_node(hpage_node,
2147 gfp | __GFP_NORETRY, order);
2148
2149 goto out;
2150 }
2151 }
2152
2153 nmask = policy_nodemask(gfp, pol);
2154 preferred_nid = policy_node(gfp, pol, node);
2155 page = __alloc_pages_nodemask(gfp, order, preferred_nid, nmask);
2156 mpol_cond_put(pol);
2157out:
2158 return page;
2159}
2160EXPORT_SYMBOL(alloc_pages_vma);
2161
2162/**
2163 * alloc_pages_current - Allocate pages.
2164 *
2165 * @gfp:
2166 * %GFP_USER user allocation,
2167 * %GFP_KERNEL kernel allocation,
2168 * %GFP_HIGHMEM highmem allocation,
2169 * %GFP_FS don't call back into a file system.
2170 * %GFP_ATOMIC don't sleep.
2171 * @order: Power of two of allocation size in pages. 0 is a single page.
2172 *
2173 * Allocate a page from the kernel page pool. When not in
2174 * interrupt context and apply the current process NUMA policy.
2175 * Returns NULL when no page can be allocated.
2176 */
2177struct page *alloc_pages_current(gfp_t gfp, unsigned order)
2178{
2179 struct mempolicy *pol = &default_policy;
2180 struct page *page;
2181
2182 if (!in_interrupt() && !(gfp & __GFP_THISNODE))
2183 pol = get_task_policy(current);
2184
2185 /*
2186 * No reference counting needed for current->mempolicy
2187 * nor system default_policy
2188 */
2189 if (pol->mode == MPOL_INTERLEAVE)
2190 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
2191 else
2192 page = __alloc_pages_nodemask(gfp, order,
2193 policy_node(gfp, pol, numa_node_id()),
2194 policy_nodemask(gfp, pol));
2195
2196 return page;
2197}
2198EXPORT_SYMBOL(alloc_pages_current);
2199
2200int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
2201{
2202 struct mempolicy *pol = mpol_dup(vma_policy(src));
2203
2204 if (IS_ERR(pol))
2205 return PTR_ERR(pol);
2206 dst->vm_policy = pol;
2207 return 0;
2208}
2209
2210/*
2211 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
2212 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
2213 * with the mems_allowed returned by cpuset_mems_allowed(). This
2214 * keeps mempolicies cpuset relative after its cpuset moves. See
2215 * further kernel/cpuset.c update_nodemask().
2216 *
2217 * current's mempolicy may be rebinded by the other task(the task that changes
2218 * cpuset's mems), so we needn't do rebind work for current task.
2219 */
2220
2221/* Slow path of a mempolicy duplicate */
2222struct mempolicy *__mpol_dup(struct mempolicy *old)
2223{
2224 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2225
2226 if (!new)
2227 return ERR_PTR(-ENOMEM);
2228
2229 /* task's mempolicy is protected by alloc_lock */
2230 if (old == current->mempolicy) {
2231 task_lock(current);
2232 *new = *old;
2233 task_unlock(current);
2234 } else
2235 *new = *old;
2236
2237 if (current_cpuset_is_being_rebound()) {
2238 nodemask_t mems = cpuset_mems_allowed(current);
2239 mpol_rebind_policy(new, &mems);
2240 }
2241 atomic_set(&new->refcnt, 1);
2242 return new;
2243}
2244
2245/* Slow path of a mempolicy comparison */
2246bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
2247{
2248 if (!a || !b)
2249 return false;
2250 if (a->mode != b->mode)
2251 return false;
2252 if (a->flags != b->flags)
2253 return false;
2254 if (mpol_store_user_nodemask(a))
2255 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
2256 return false;
2257
2258 switch (a->mode) {
2259 case MPOL_BIND:
2260 /* Fall through */
2261 case MPOL_INTERLEAVE:
2262 return !!nodes_equal(a->v.nodes, b->v.nodes);
2263 case MPOL_PREFERRED:
2264 /* a's ->flags is the same as b's */
2265 if (a->flags & MPOL_F_LOCAL)
2266 return true;
2267 return a->v.preferred_node == b->v.preferred_node;
2268 default:
2269 BUG();
2270 return false;
2271 }
2272}
2273
2274/*
2275 * Shared memory backing store policy support.
2276 *
2277 * Remember policies even when nobody has shared memory mapped.
2278 * The policies are kept in Red-Black tree linked from the inode.
2279 * They are protected by the sp->lock rwlock, which should be held
2280 * for any accesses to the tree.
2281 */
2282
2283/*
2284 * lookup first element intersecting start-end. Caller holds sp->lock for
2285 * reading or for writing
2286 */
2287static struct sp_node *
2288sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
2289{
2290 struct rb_node *n = sp->root.rb_node;
2291
2292 while (n) {
2293 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2294
2295 if (start >= p->end)
2296 n = n->rb_right;
2297 else if (end <= p->start)
2298 n = n->rb_left;
2299 else
2300 break;
2301 }
2302 if (!n)
2303 return NULL;
2304 for (;;) {
2305 struct sp_node *w = NULL;
2306 struct rb_node *prev = rb_prev(n);
2307 if (!prev)
2308 break;
2309 w = rb_entry(prev, struct sp_node, nd);
2310 if (w->end <= start)
2311 break;
2312 n = prev;
2313 }
2314 return rb_entry(n, struct sp_node, nd);
2315}
2316
2317/*
2318 * Insert a new shared policy into the list. Caller holds sp->lock for
2319 * writing.
2320 */
2321static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2322{
2323 struct rb_node **p = &sp->root.rb_node;
2324 struct rb_node *parent = NULL;
2325 struct sp_node *nd;
2326
2327 while (*p) {
2328 parent = *p;
2329 nd = rb_entry(parent, struct sp_node, nd);
2330 if (new->start < nd->start)
2331 p = &(*p)->rb_left;
2332 else if (new->end > nd->end)
2333 p = &(*p)->rb_right;
2334 else
2335 BUG();
2336 }
2337 rb_link_node(&new->nd, parent, p);
2338 rb_insert_color(&new->nd, &sp->root);
2339 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
2340 new->policy ? new->policy->mode : 0);
2341}
2342
2343/* Find shared policy intersecting idx */
2344struct mempolicy *
2345mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2346{
2347 struct mempolicy *pol = NULL;
2348 struct sp_node *sn;
2349
2350 if (!sp->root.rb_node)
2351 return NULL;
2352 read_lock(&sp->lock);
2353 sn = sp_lookup(sp, idx, idx+1);
2354 if (sn) {
2355 mpol_get(sn->policy);
2356 pol = sn->policy;
2357 }
2358 read_unlock(&sp->lock);
2359 return pol;
2360}
2361
2362static void sp_free(struct sp_node *n)
2363{
2364 mpol_put(n->policy);
2365 kmem_cache_free(sn_cache, n);
2366}
2367
2368/**
2369 * mpol_misplaced - check whether current page node is valid in policy
2370 *
2371 * @page: page to be checked
2372 * @vma: vm area where page mapped
2373 * @addr: virtual address where page mapped
2374 *
2375 * Lookup current policy node id for vma,addr and "compare to" page's
2376 * node id.
2377 *
2378 * Returns:
2379 * -1 - not misplaced, page is in the right node
2380 * node - node id where the page should be
2381 *
2382 * Policy determination "mimics" alloc_page_vma().
2383 * Called from fault path where we know the vma and faulting address.
2384 */
2385int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
2386{
2387 struct mempolicy *pol;
2388 struct zoneref *z;
2389 int curnid = page_to_nid(page);
2390 unsigned long pgoff;
2391 int thiscpu = raw_smp_processor_id();
2392 int thisnid = cpu_to_node(thiscpu);
2393 int polnid = NUMA_NO_NODE;
2394 int ret = -1;
2395
2396 pol = get_vma_policy(vma, addr);
2397 if (!(pol->flags & MPOL_F_MOF))
2398 goto out;
2399
2400 switch (pol->mode) {
2401 case MPOL_INTERLEAVE:
2402 pgoff = vma->vm_pgoff;
2403 pgoff += (addr - vma->vm_start) >> PAGE_SHIFT;
2404 polnid = offset_il_node(pol, pgoff);
2405 break;
2406
2407 case MPOL_PREFERRED:
2408 if (pol->flags & MPOL_F_LOCAL)
2409 polnid = numa_node_id();
2410 else
2411 polnid = pol->v.preferred_node;
2412 break;
2413
2414 case MPOL_BIND:
2415
2416 /*
2417 * allows binding to multiple nodes.
2418 * use current page if in policy nodemask,
2419 * else select nearest allowed node, if any.
2420 * If no allowed nodes, use current [!misplaced].
2421 */
2422 if (node_isset(curnid, pol->v.nodes))
2423 goto out;
2424 z = first_zones_zonelist(
2425 node_zonelist(numa_node_id(), GFP_HIGHUSER),
2426 gfp_zone(GFP_HIGHUSER),
2427 &pol->v.nodes);
2428 polnid = zone_to_nid(z->zone);
2429 break;
2430
2431 default:
2432 BUG();
2433 }
2434
2435 /* Migrate the page towards the node whose CPU is referencing it */
2436 if (pol->flags & MPOL_F_MORON) {
2437 polnid = thisnid;
2438
2439 if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
2440 goto out;
2441 }
2442
2443 if (curnid != polnid)
2444 ret = polnid;
2445out:
2446 mpol_cond_put(pol);
2447
2448 return ret;
2449}
2450
2451/*
2452 * Drop the (possibly final) reference to task->mempolicy. It needs to be
2453 * dropped after task->mempolicy is set to NULL so that any allocation done as
2454 * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed
2455 * policy.
2456 */
2457void mpol_put_task_policy(struct task_struct *task)
2458{
2459 struct mempolicy *pol;
2460
2461 task_lock(task);
2462 pol = task->mempolicy;
2463 task->mempolicy = NULL;
2464 task_unlock(task);
2465 mpol_put(pol);
2466}
2467
2468static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2469{
2470 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
2471 rb_erase(&n->nd, &sp->root);
2472 sp_free(n);
2473}
2474
2475static void sp_node_init(struct sp_node *node, unsigned long start,
2476 unsigned long end, struct mempolicy *pol)
2477{
2478 node->start = start;
2479 node->end = end;
2480 node->policy = pol;
2481}
2482
2483static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2484 struct mempolicy *pol)
2485{
2486 struct sp_node *n;
2487 struct mempolicy *newpol;
2488
2489 n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2490 if (!n)
2491 return NULL;
2492
2493 newpol = mpol_dup(pol);
2494 if (IS_ERR(newpol)) {
2495 kmem_cache_free(sn_cache, n);
2496 return NULL;
2497 }
2498 newpol->flags |= MPOL_F_SHARED;
2499 sp_node_init(n, start, end, newpol);
2500
2501 return n;
2502}
2503
2504/* Replace a policy range. */
2505static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2506 unsigned long end, struct sp_node *new)
2507{
2508 struct sp_node *n;
2509 struct sp_node *n_new = NULL;
2510 struct mempolicy *mpol_new = NULL;
2511 int ret = 0;
2512
2513restart:
2514 write_lock(&sp->lock);
2515 n = sp_lookup(sp, start, end);
2516 /* Take care of old policies in the same range. */
2517 while (n && n->start < end) {
2518 struct rb_node *next = rb_next(&n->nd);
2519 if (n->start >= start) {
2520 if (n->end <= end)
2521 sp_delete(sp, n);
2522 else
2523 n->start = end;
2524 } else {
2525 /* Old policy spanning whole new range. */
2526 if (n->end > end) {
2527 if (!n_new)
2528 goto alloc_new;
2529
2530 *mpol_new = *n->policy;
2531 atomic_set(&mpol_new->refcnt, 1);
2532 sp_node_init(n_new, end, n->end, mpol_new);
2533 n->end = start;
2534 sp_insert(sp, n_new);
2535 n_new = NULL;
2536 mpol_new = NULL;
2537 break;
2538 } else
2539 n->end = start;
2540 }
2541 if (!next)
2542 break;
2543 n = rb_entry(next, struct sp_node, nd);
2544 }
2545 if (new)
2546 sp_insert(sp, new);
2547 write_unlock(&sp->lock);
2548 ret = 0;
2549
2550err_out:
2551 if (mpol_new)
2552 mpol_put(mpol_new);
2553 if (n_new)
2554 kmem_cache_free(sn_cache, n_new);
2555
2556 return ret;
2557
2558alloc_new:
2559 write_unlock(&sp->lock);
2560 ret = -ENOMEM;
2561 n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2562 if (!n_new)
2563 goto err_out;
2564 mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2565 if (!mpol_new)
2566 goto err_out;
2567 goto restart;
2568}
2569
2570/**
2571 * mpol_shared_policy_init - initialize shared policy for inode
2572 * @sp: pointer to inode shared policy
2573 * @mpol: struct mempolicy to install
2574 *
2575 * Install non-NULL @mpol in inode's shared policy rb-tree.
2576 * On entry, the current task has a reference on a non-NULL @mpol.
2577 * This must be released on exit.
2578 * This is called at get_inode() calls and we can use GFP_KERNEL.
2579 */
2580void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
2581{
2582 int ret;
2583
2584 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2585 rwlock_init(&sp->lock);
2586
2587 if (mpol) {
2588 struct vm_area_struct pvma;
2589 struct mempolicy *new;
2590 NODEMASK_SCRATCH(scratch);
2591
2592 if (!scratch)
2593 goto put_mpol;
2594 /* contextualize the tmpfs mount point mempolicy */
2595 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2596 if (IS_ERR(new))
2597 goto free_scratch; /* no valid nodemask intersection */
2598
2599 task_lock(current);
2600 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
2601 task_unlock(current);
2602 if (ret)
2603 goto put_new;
2604
2605 /* Create pseudo-vma that contains just the policy */
2606 vma_init(&pvma, NULL);
2607 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2608 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
2609
2610put_new:
2611 mpol_put(new); /* drop initial ref */
2612free_scratch:
2613 NODEMASK_SCRATCH_FREE(scratch);
2614put_mpol:
2615 mpol_put(mpol); /* drop our incoming ref on sb mpol */
2616 }
2617}
2618
2619int mpol_set_shared_policy(struct shared_policy *info,
2620 struct vm_area_struct *vma, struct mempolicy *npol)
2621{
2622 int err;
2623 struct sp_node *new = NULL;
2624 unsigned long sz = vma_pages(vma);
2625
2626 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
2627 vma->vm_pgoff,
2628 sz, npol ? npol->mode : -1,
2629 npol ? npol->flags : -1,
2630 npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
2631
2632 if (npol) {
2633 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2634 if (!new)
2635 return -ENOMEM;
2636 }
2637 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2638 if (err && new)
2639 sp_free(new);
2640 return err;
2641}
2642
2643/* Free a backing policy store on inode delete. */
2644void mpol_free_shared_policy(struct shared_policy *p)
2645{
2646 struct sp_node *n;
2647 struct rb_node *next;
2648
2649 if (!p->root.rb_node)
2650 return;
2651 write_lock(&p->lock);
2652 next = rb_first(&p->root);
2653 while (next) {
2654 n = rb_entry(next, struct sp_node, nd);
2655 next = rb_next(&n->nd);
2656 sp_delete(p, n);
2657 }
2658 write_unlock(&p->lock);
2659}
2660
2661#ifdef CONFIG_NUMA_BALANCING
2662static int __initdata numabalancing_override;
2663
2664static void __init check_numabalancing_enable(void)
2665{
2666 bool numabalancing_default = false;
2667
2668 if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
2669 numabalancing_default = true;
2670
2671 /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
2672 if (numabalancing_override)
2673 set_numabalancing_state(numabalancing_override == 1);
2674
2675 if (num_online_nodes() > 1 && !numabalancing_override) {
2676 pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n",
2677 numabalancing_default ? "Enabling" : "Disabling");
2678 set_numabalancing_state(numabalancing_default);
2679 }
2680}
2681
2682static int __init setup_numabalancing(char *str)
2683{
2684 int ret = 0;
2685 if (!str)
2686 goto out;
2687
2688 if (!strcmp(str, "enable")) {
2689 numabalancing_override = 1;
2690 ret = 1;
2691 } else if (!strcmp(str, "disable")) {
2692 numabalancing_override = -1;
2693 ret = 1;
2694 }
2695out:
2696 if (!ret)
2697 pr_warn("Unable to parse numa_balancing=\n");
2698
2699 return ret;
2700}
2701__setup("numa_balancing=", setup_numabalancing);
2702#else
2703static inline void __init check_numabalancing_enable(void)
2704{
2705}
2706#endif /* CONFIG_NUMA_BALANCING */
2707
2708/* assumes fs == KERNEL_DS */
2709void __init numa_policy_init(void)
2710{
2711 nodemask_t interleave_nodes;
2712 unsigned long largest = 0;
2713 int nid, prefer = 0;
2714
2715 policy_cache = kmem_cache_create("numa_policy",
2716 sizeof(struct mempolicy),
2717 0, SLAB_PANIC, NULL);
2718
2719 sn_cache = kmem_cache_create("shared_policy_node",
2720 sizeof(struct sp_node),
2721 0, SLAB_PANIC, NULL);
2722
2723 for_each_node(nid) {
2724 preferred_node_policy[nid] = (struct mempolicy) {
2725 .refcnt = ATOMIC_INIT(1),
2726 .mode = MPOL_PREFERRED,
2727 .flags = MPOL_F_MOF | MPOL_F_MORON,
2728 .v = { .preferred_node = nid, },
2729 };
2730 }
2731
2732 /*
2733 * Set interleaving policy for system init. Interleaving is only
2734 * enabled across suitably sized nodes (default is >= 16MB), or
2735 * fall back to the largest node if they're all smaller.
2736 */
2737 nodes_clear(interleave_nodes);
2738 for_each_node_state(nid, N_MEMORY) {
2739 unsigned long total_pages = node_present_pages(nid);
2740
2741 /* Preserve the largest node */
2742 if (largest < total_pages) {
2743 largest = total_pages;
2744 prefer = nid;
2745 }
2746
2747 /* Interleave this node? */
2748 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2749 node_set(nid, interleave_nodes);
2750 }
2751
2752 /* All too small, use the largest */
2753 if (unlikely(nodes_empty(interleave_nodes)))
2754 node_set(prefer, interleave_nodes);
2755
2756 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
2757 pr_err("%s: interleaving failed\n", __func__);
2758
2759 check_numabalancing_enable();
2760}
2761
2762/* Reset policy of current process to default */
2763void numa_default_policy(void)
2764{
2765 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
2766}
2767
2768/*
2769 * Parse and format mempolicy from/to strings
2770 */
2771
2772/*
2773 * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
2774 */
2775static const char * const policy_modes[] =
2776{
2777 [MPOL_DEFAULT] = "default",
2778 [MPOL_PREFERRED] = "prefer",
2779 [MPOL_BIND] = "bind",
2780 [MPOL_INTERLEAVE] = "interleave",
2781 [MPOL_LOCAL] = "local",
2782};
2783
2784
2785#ifdef CONFIG_TMPFS
2786/**
2787 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
2788 * @str: string containing mempolicy to parse
2789 * @mpol: pointer to struct mempolicy pointer, returned on success.
2790 *
2791 * Format of input:
2792 * <mode>[=<flags>][:<nodelist>]
2793 *
2794 * On success, returns 0, else 1
2795 */
2796int mpol_parse_str(char *str, struct mempolicy **mpol)
2797{
2798 struct mempolicy *new = NULL;
2799 unsigned short mode_flags;
2800 nodemask_t nodes;
2801 char *nodelist = strchr(str, ':');
2802 char *flags = strchr(str, '=');
2803 int err = 1, mode;
2804
2805 if (nodelist) {
2806 /* NUL-terminate mode or flags string */
2807 *nodelist++ = '\0';
2808 if (nodelist_parse(nodelist, nodes))
2809 goto out;
2810 if (!nodes_subset(nodes, node_states[N_MEMORY]))
2811 goto out;
2812 } else
2813 nodes_clear(nodes);
2814
2815 if (flags)
2816 *flags++ = '\0'; /* terminate mode string */
2817
2818 mode = match_string(policy_modes, MPOL_MAX, str);
2819 if (mode < 0)
2820 goto out;
2821
2822 switch (mode) {
2823 case MPOL_PREFERRED:
2824 /*
2825 * Insist on a nodelist of one node only
2826 */
2827 if (nodelist) {
2828 char *rest = nodelist;
2829 while (isdigit(*rest))
2830 rest++;
2831 if (*rest)
2832 goto out;
2833 }
2834 break;
2835 case MPOL_INTERLEAVE:
2836 /*
2837 * Default to online nodes with memory if no nodelist
2838 */
2839 if (!nodelist)
2840 nodes = node_states[N_MEMORY];
2841 break;
2842 case MPOL_LOCAL:
2843 /*
2844 * Don't allow a nodelist; mpol_new() checks flags
2845 */
2846 if (nodelist)
2847 goto out;
2848 mode = MPOL_PREFERRED;
2849 break;
2850 case MPOL_DEFAULT:
2851 /*
2852 * Insist on a empty nodelist
2853 */
2854 if (!nodelist)
2855 err = 0;
2856 goto out;
2857 case MPOL_BIND:
2858 /*
2859 * Insist on a nodelist
2860 */
2861 if (!nodelist)
2862 goto out;
2863 }
2864
2865 mode_flags = 0;
2866 if (flags) {
2867 /*
2868 * Currently, we only support two mutually exclusive
2869 * mode flags.
2870 */
2871 if (!strcmp(flags, "static"))
2872 mode_flags |= MPOL_F_STATIC_NODES;
2873 else if (!strcmp(flags, "relative"))
2874 mode_flags |= MPOL_F_RELATIVE_NODES;
2875 else
2876 goto out;
2877 }
2878
2879 new = mpol_new(mode, mode_flags, &nodes);
2880 if (IS_ERR(new))
2881 goto out;
2882
2883 /*
2884 * Save nodes for mpol_to_str() to show the tmpfs mount options
2885 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
2886 */
2887 if (mode != MPOL_PREFERRED)
2888 new->v.nodes = nodes;
2889 else if (nodelist)
2890 new->v.preferred_node = first_node(nodes);
2891 else
2892 new->flags |= MPOL_F_LOCAL;
2893
2894 /*
2895 * Save nodes for contextualization: this will be used to "clone"
2896 * the mempolicy in a specific context [cpuset] at a later time.
2897 */
2898 new->w.user_nodemask = nodes;
2899
2900 err = 0;
2901
2902out:
2903 /* Restore string for error message */
2904 if (nodelist)
2905 *--nodelist = ':';
2906 if (flags)
2907 *--flags = '=';
2908 if (!err)
2909 *mpol = new;
2910 return err;
2911}
2912#endif /* CONFIG_TMPFS */
2913
2914/**
2915 * mpol_to_str - format a mempolicy structure for printing
2916 * @buffer: to contain formatted mempolicy string
2917 * @maxlen: length of @buffer
2918 * @pol: pointer to mempolicy to be formatted
2919 *
2920 * Convert @pol into a string. If @buffer is too short, truncate the string.
2921 * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
2922 * longest flag, "relative", and to display at least a few node ids.
2923 */
2924void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
2925{
2926 char *p = buffer;
2927 nodemask_t nodes = NODE_MASK_NONE;
2928 unsigned short mode = MPOL_DEFAULT;
2929 unsigned short flags = 0;
2930
2931 if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) {
2932 mode = pol->mode;
2933 flags = pol->flags;
2934 }
2935
2936 switch (mode) {
2937 case MPOL_DEFAULT:
2938 break;
2939 case MPOL_PREFERRED:
2940 if (flags & MPOL_F_LOCAL)
2941 mode = MPOL_LOCAL;
2942 else
2943 node_set(pol->v.preferred_node, nodes);
2944 break;
2945 case MPOL_BIND:
2946 case MPOL_INTERLEAVE:
2947 nodes = pol->v.nodes;
2948 break;
2949 default:
2950 WARN_ON_ONCE(1);
2951 snprintf(p, maxlen, "unknown");
2952 return;
2953 }
2954
2955 p += snprintf(p, maxlen, "%s", policy_modes[mode]);
2956
2957 if (flags & MPOL_MODE_FLAGS) {
2958 p += snprintf(p, buffer + maxlen - p, "=");
2959
2960 /*
2961 * Currently, the only defined flags are mutually exclusive
2962 */
2963 if (flags & MPOL_F_STATIC_NODES)
2964 p += snprintf(p, buffer + maxlen - p, "static");
2965 else if (flags & MPOL_F_RELATIVE_NODES)
2966 p += snprintf(p, buffer + maxlen - p, "relative");
2967 }
2968
2969 if (!nodes_empty(nodes))
2970 p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
2971 nodemask_pr_args(&nodes));
2972}
1/*
2 * Simple NUMA memory policy for the Linux kernel.
3 *
4 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
5 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
6 * Subject to the GNU Public License, version 2.
7 *
8 * NUMA policy allows the user to give hints in which node(s) memory should
9 * be allocated.
10 *
11 * Support four policies per VMA and per process:
12 *
13 * The VMA policy has priority over the process policy for a page fault.
14 *
15 * interleave Allocate memory interleaved over a set of nodes,
16 * with normal fallback if it fails.
17 * For VMA based allocations this interleaves based on the
18 * offset into the backing object or offset into the mapping
19 * for anonymous memory. For process policy an process counter
20 * is used.
21 *
22 * bind Only allocate memory on a specific set of nodes,
23 * no fallback.
24 * FIXME: memory is allocated starting with the first node
25 * to the last. It would be better if bind would truly restrict
26 * the allocation to memory nodes instead
27 *
28 * preferred Try a specific node first before normal fallback.
29 * As a special case NUMA_NO_NODE here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
32 * process policy.
33 *
34 * default Allocate on the local node first, or when on a VMA
35 * use the process policy. This is what Linux always did
36 * in a NUMA aware kernel and still does by, ahem, default.
37 *
38 * The process policy is applied for most non interrupt memory allocations
39 * in that process' context. Interrupts ignore the policies and always
40 * try to allocate on the local CPU. The VMA policy is only applied for memory
41 * allocations for a VMA in the VM.
42 *
43 * Currently there are a few corner cases in swapping where the policy
44 * is not applied, but the majority should be handled. When process policy
45 * is used it is not remembered over swap outs/swap ins.
46 *
47 * Only the highest zone in the zone hierarchy gets policied. Allocations
48 * requesting a lower zone just use default policy. This implies that
49 * on systems with highmem kernel lowmem allocation don't get policied.
50 * Same with GFP_DMA allocations.
51 *
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
54 */
55
56/* Notebook:
57 fix mmap readahead to honour policy and enable policy for any page cache
58 object
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
61 first item above.
62 handle mremap for shared memory (currently ignored for the policy)
63 grows down?
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
66*/
67
68#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
69
70#include <linux/mempolicy.h>
71#include <linux/mm.h>
72#include <linux/highmem.h>
73#include <linux/hugetlb.h>
74#include <linux/kernel.h>
75#include <linux/sched.h>
76#include <linux/nodemask.h>
77#include <linux/cpuset.h>
78#include <linux/slab.h>
79#include <linux/string.h>
80#include <linux/export.h>
81#include <linux/nsproxy.h>
82#include <linux/interrupt.h>
83#include <linux/init.h>
84#include <linux/compat.h>
85#include <linux/swap.h>
86#include <linux/seq_file.h>
87#include <linux/proc_fs.h>
88#include <linux/migrate.h>
89#include <linux/ksm.h>
90#include <linux/rmap.h>
91#include <linux/security.h>
92#include <linux/syscalls.h>
93#include <linux/ctype.h>
94#include <linux/mm_inline.h>
95#include <linux/mmu_notifier.h>
96#include <linux/printk.h>
97
98#include <asm/tlbflush.h>
99#include <linux/uaccess.h>
100
101#include "internal.h"
102
103/* Internal flags */
104#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
105#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
106
107static struct kmem_cache *policy_cache;
108static struct kmem_cache *sn_cache;
109
110/* Highest zone. An specific allocation for a zone below that is not
111 policied. */
112enum zone_type policy_zone = 0;
113
114/*
115 * run-time system-wide default policy => local allocation
116 */
117static struct mempolicy default_policy = {
118 .refcnt = ATOMIC_INIT(1), /* never free it */
119 .mode = MPOL_PREFERRED,
120 .flags = MPOL_F_LOCAL,
121};
122
123static struct mempolicy preferred_node_policy[MAX_NUMNODES];
124
125struct mempolicy *get_task_policy(struct task_struct *p)
126{
127 struct mempolicy *pol = p->mempolicy;
128 int node;
129
130 if (pol)
131 return pol;
132
133 node = numa_node_id();
134 if (node != NUMA_NO_NODE) {
135 pol = &preferred_node_policy[node];
136 /* preferred_node_policy is not initialised early in boot */
137 if (pol->mode)
138 return pol;
139 }
140
141 return &default_policy;
142}
143
144static const struct mempolicy_operations {
145 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
146 /*
147 * If read-side task has no lock to protect task->mempolicy, write-side
148 * task will rebind the task->mempolicy by two step. The first step is
149 * setting all the newly nodes, and the second step is cleaning all the
150 * disallowed nodes. In this way, we can avoid finding no node to alloc
151 * page.
152 * If we have a lock to protect task->mempolicy in read-side, we do
153 * rebind directly.
154 *
155 * step:
156 * MPOL_REBIND_ONCE - do rebind work at once
157 * MPOL_REBIND_STEP1 - set all the newly nodes
158 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
159 */
160 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
161 enum mpol_rebind_step step);
162} mpol_ops[MPOL_MAX];
163
164static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
165{
166 return pol->flags & MPOL_MODE_FLAGS;
167}
168
169static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
170 const nodemask_t *rel)
171{
172 nodemask_t tmp;
173 nodes_fold(tmp, *orig, nodes_weight(*rel));
174 nodes_onto(*ret, tmp, *rel);
175}
176
177static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
178{
179 if (nodes_empty(*nodes))
180 return -EINVAL;
181 pol->v.nodes = *nodes;
182 return 0;
183}
184
185static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
186{
187 if (!nodes)
188 pol->flags |= MPOL_F_LOCAL; /* local allocation */
189 else if (nodes_empty(*nodes))
190 return -EINVAL; /* no allowed nodes */
191 else
192 pol->v.preferred_node = first_node(*nodes);
193 return 0;
194}
195
196static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
197{
198 if (nodes_empty(*nodes))
199 return -EINVAL;
200 pol->v.nodes = *nodes;
201 return 0;
202}
203
204/*
205 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
206 * any, for the new policy. mpol_new() has already validated the nodes
207 * parameter with respect to the policy mode and flags. But, we need to
208 * handle an empty nodemask with MPOL_PREFERRED here.
209 *
210 * Must be called holding task's alloc_lock to protect task's mems_allowed
211 * and mempolicy. May also be called holding the mmap_semaphore for write.
212 */
213static int mpol_set_nodemask(struct mempolicy *pol,
214 const nodemask_t *nodes, struct nodemask_scratch *nsc)
215{
216 int ret;
217
218 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
219 if (pol == NULL)
220 return 0;
221 /* Check N_MEMORY */
222 nodes_and(nsc->mask1,
223 cpuset_current_mems_allowed, node_states[N_MEMORY]);
224
225 VM_BUG_ON(!nodes);
226 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
227 nodes = NULL; /* explicit local allocation */
228 else {
229 if (pol->flags & MPOL_F_RELATIVE_NODES)
230 mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
231 else
232 nodes_and(nsc->mask2, *nodes, nsc->mask1);
233
234 if (mpol_store_user_nodemask(pol))
235 pol->w.user_nodemask = *nodes;
236 else
237 pol->w.cpuset_mems_allowed =
238 cpuset_current_mems_allowed;
239 }
240
241 if (nodes)
242 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
243 else
244 ret = mpol_ops[pol->mode].create(pol, NULL);
245 return ret;
246}
247
248/*
249 * This function just creates a new policy, does some check and simple
250 * initialization. You must invoke mpol_set_nodemask() to set nodes.
251 */
252static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
253 nodemask_t *nodes)
254{
255 struct mempolicy *policy;
256
257 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
258 mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE);
259
260 if (mode == MPOL_DEFAULT) {
261 if (nodes && !nodes_empty(*nodes))
262 return ERR_PTR(-EINVAL);
263 return NULL;
264 }
265 VM_BUG_ON(!nodes);
266
267 /*
268 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
269 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
270 * All other modes require a valid pointer to a non-empty nodemask.
271 */
272 if (mode == MPOL_PREFERRED) {
273 if (nodes_empty(*nodes)) {
274 if (((flags & MPOL_F_STATIC_NODES) ||
275 (flags & MPOL_F_RELATIVE_NODES)))
276 return ERR_PTR(-EINVAL);
277 }
278 } else if (mode == MPOL_LOCAL) {
279 if (!nodes_empty(*nodes) ||
280 (flags & MPOL_F_STATIC_NODES) ||
281 (flags & MPOL_F_RELATIVE_NODES))
282 return ERR_PTR(-EINVAL);
283 mode = MPOL_PREFERRED;
284 } else if (nodes_empty(*nodes))
285 return ERR_PTR(-EINVAL);
286 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
287 if (!policy)
288 return ERR_PTR(-ENOMEM);
289 atomic_set(&policy->refcnt, 1);
290 policy->mode = mode;
291 policy->flags = flags;
292
293 return policy;
294}
295
296/* Slow path of a mpol destructor. */
297void __mpol_put(struct mempolicy *p)
298{
299 if (!atomic_dec_and_test(&p->refcnt))
300 return;
301 kmem_cache_free(policy_cache, p);
302}
303
304static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
305 enum mpol_rebind_step step)
306{
307}
308
309/*
310 * step:
311 * MPOL_REBIND_ONCE - do rebind work at once
312 * MPOL_REBIND_STEP1 - set all the newly nodes
313 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
314 */
315static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
316 enum mpol_rebind_step step)
317{
318 nodemask_t tmp;
319
320 if (pol->flags & MPOL_F_STATIC_NODES)
321 nodes_and(tmp, pol->w.user_nodemask, *nodes);
322 else if (pol->flags & MPOL_F_RELATIVE_NODES)
323 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
324 else {
325 /*
326 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
327 * result
328 */
329 if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
330 nodes_remap(tmp, pol->v.nodes,
331 pol->w.cpuset_mems_allowed, *nodes);
332 pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
333 } else if (step == MPOL_REBIND_STEP2) {
334 tmp = pol->w.cpuset_mems_allowed;
335 pol->w.cpuset_mems_allowed = *nodes;
336 } else
337 BUG();
338 }
339
340 if (nodes_empty(tmp))
341 tmp = *nodes;
342
343 if (step == MPOL_REBIND_STEP1)
344 nodes_or(pol->v.nodes, pol->v.nodes, tmp);
345 else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
346 pol->v.nodes = tmp;
347 else
348 BUG();
349
350 if (!node_isset(current->il_next, tmp)) {
351 current->il_next = next_node_in(current->il_next, tmp);
352 if (current->il_next >= MAX_NUMNODES)
353 current->il_next = numa_node_id();
354 }
355}
356
357static void mpol_rebind_preferred(struct mempolicy *pol,
358 const nodemask_t *nodes,
359 enum mpol_rebind_step step)
360{
361 nodemask_t tmp;
362
363 if (pol->flags & MPOL_F_STATIC_NODES) {
364 int node = first_node(pol->w.user_nodemask);
365
366 if (node_isset(node, *nodes)) {
367 pol->v.preferred_node = node;
368 pol->flags &= ~MPOL_F_LOCAL;
369 } else
370 pol->flags |= MPOL_F_LOCAL;
371 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
372 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
373 pol->v.preferred_node = first_node(tmp);
374 } else if (!(pol->flags & MPOL_F_LOCAL)) {
375 pol->v.preferred_node = node_remap(pol->v.preferred_node,
376 pol->w.cpuset_mems_allowed,
377 *nodes);
378 pol->w.cpuset_mems_allowed = *nodes;
379 }
380}
381
382/*
383 * mpol_rebind_policy - Migrate a policy to a different set of nodes
384 *
385 * If read-side task has no lock to protect task->mempolicy, write-side
386 * task will rebind the task->mempolicy by two step. The first step is
387 * setting all the newly nodes, and the second step is cleaning all the
388 * disallowed nodes. In this way, we can avoid finding no node to alloc
389 * page.
390 * If we have a lock to protect task->mempolicy in read-side, we do
391 * rebind directly.
392 *
393 * step:
394 * MPOL_REBIND_ONCE - do rebind work at once
395 * MPOL_REBIND_STEP1 - set all the newly nodes
396 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
397 */
398static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
399 enum mpol_rebind_step step)
400{
401 if (!pol)
402 return;
403 if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE &&
404 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
405 return;
406
407 if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
408 return;
409
410 if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
411 BUG();
412
413 if (step == MPOL_REBIND_STEP1)
414 pol->flags |= MPOL_F_REBINDING;
415 else if (step == MPOL_REBIND_STEP2)
416 pol->flags &= ~MPOL_F_REBINDING;
417 else if (step >= MPOL_REBIND_NSTEP)
418 BUG();
419
420 mpol_ops[pol->mode].rebind(pol, newmask, step);
421}
422
423/*
424 * Wrapper for mpol_rebind_policy() that just requires task
425 * pointer, and updates task mempolicy.
426 *
427 * Called with task's alloc_lock held.
428 */
429
430void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
431 enum mpol_rebind_step step)
432{
433 mpol_rebind_policy(tsk->mempolicy, new, step);
434}
435
436/*
437 * Rebind each vma in mm to new nodemask.
438 *
439 * Call holding a reference to mm. Takes mm->mmap_sem during call.
440 */
441
442void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
443{
444 struct vm_area_struct *vma;
445
446 down_write(&mm->mmap_sem);
447 for (vma = mm->mmap; vma; vma = vma->vm_next)
448 mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
449 up_write(&mm->mmap_sem);
450}
451
452static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
453 [MPOL_DEFAULT] = {
454 .rebind = mpol_rebind_default,
455 },
456 [MPOL_INTERLEAVE] = {
457 .create = mpol_new_interleave,
458 .rebind = mpol_rebind_nodemask,
459 },
460 [MPOL_PREFERRED] = {
461 .create = mpol_new_preferred,
462 .rebind = mpol_rebind_preferred,
463 },
464 [MPOL_BIND] = {
465 .create = mpol_new_bind,
466 .rebind = mpol_rebind_nodemask,
467 },
468};
469
470static void migrate_page_add(struct page *page, struct list_head *pagelist,
471 unsigned long flags);
472
473struct queue_pages {
474 struct list_head *pagelist;
475 unsigned long flags;
476 nodemask_t *nmask;
477 struct vm_area_struct *prev;
478};
479
480/*
481 * Scan through pages checking if pages follow certain conditions,
482 * and move them to the pagelist if they do.
483 */
484static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
485 unsigned long end, struct mm_walk *walk)
486{
487 struct vm_area_struct *vma = walk->vma;
488 struct page *page;
489 struct queue_pages *qp = walk->private;
490 unsigned long flags = qp->flags;
491 int nid, ret;
492 pte_t *pte;
493 spinlock_t *ptl;
494
495 if (pmd_trans_huge(*pmd)) {
496 ptl = pmd_lock(walk->mm, pmd);
497 if (pmd_trans_huge(*pmd)) {
498 page = pmd_page(*pmd);
499 if (is_huge_zero_page(page)) {
500 spin_unlock(ptl);
501 __split_huge_pmd(vma, pmd, addr, false, NULL);
502 } else {
503 get_page(page);
504 spin_unlock(ptl);
505 lock_page(page);
506 ret = split_huge_page(page);
507 unlock_page(page);
508 put_page(page);
509 if (ret)
510 return 0;
511 }
512 } else {
513 spin_unlock(ptl);
514 }
515 }
516
517 if (pmd_trans_unstable(pmd))
518 return 0;
519retry:
520 pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
521 for (; addr != end; pte++, addr += PAGE_SIZE) {
522 if (!pte_present(*pte))
523 continue;
524 page = vm_normal_page(vma, addr, *pte);
525 if (!page)
526 continue;
527 /*
528 * vm_normal_page() filters out zero pages, but there might
529 * still be PageReserved pages to skip, perhaps in a VDSO.
530 */
531 if (PageReserved(page))
532 continue;
533 nid = page_to_nid(page);
534 if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
535 continue;
536 if (PageTransCompound(page)) {
537 get_page(page);
538 pte_unmap_unlock(pte, ptl);
539 lock_page(page);
540 ret = split_huge_page(page);
541 unlock_page(page);
542 put_page(page);
543 /* Failed to split -- skip. */
544 if (ret) {
545 pte = pte_offset_map_lock(walk->mm, pmd,
546 addr, &ptl);
547 continue;
548 }
549 goto retry;
550 }
551
552 migrate_page_add(page, qp->pagelist, flags);
553 }
554 pte_unmap_unlock(pte - 1, ptl);
555 cond_resched();
556 return 0;
557}
558
559static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
560 unsigned long addr, unsigned long end,
561 struct mm_walk *walk)
562{
563#ifdef CONFIG_HUGETLB_PAGE
564 struct queue_pages *qp = walk->private;
565 unsigned long flags = qp->flags;
566 int nid;
567 struct page *page;
568 spinlock_t *ptl;
569 pte_t entry;
570
571 ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
572 entry = huge_ptep_get(pte);
573 if (!pte_present(entry))
574 goto unlock;
575 page = pte_page(entry);
576 nid = page_to_nid(page);
577 if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
578 goto unlock;
579 /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
580 if (flags & (MPOL_MF_MOVE_ALL) ||
581 (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
582 isolate_huge_page(page, qp->pagelist);
583unlock:
584 spin_unlock(ptl);
585#else
586 BUG();
587#endif
588 return 0;
589}
590
591#ifdef CONFIG_NUMA_BALANCING
592/*
593 * This is used to mark a range of virtual addresses to be inaccessible.
594 * These are later cleared by a NUMA hinting fault. Depending on these
595 * faults, pages may be migrated for better NUMA placement.
596 *
597 * This is assuming that NUMA faults are handled using PROT_NONE. If
598 * an architecture makes a different choice, it will need further
599 * changes to the core.
600 */
601unsigned long change_prot_numa(struct vm_area_struct *vma,
602 unsigned long addr, unsigned long end)
603{
604 int nr_updated;
605
606 nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1);
607 if (nr_updated)
608 count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
609
610 return nr_updated;
611}
612#else
613static unsigned long change_prot_numa(struct vm_area_struct *vma,
614 unsigned long addr, unsigned long end)
615{
616 return 0;
617}
618#endif /* CONFIG_NUMA_BALANCING */
619
620static int queue_pages_test_walk(unsigned long start, unsigned long end,
621 struct mm_walk *walk)
622{
623 struct vm_area_struct *vma = walk->vma;
624 struct queue_pages *qp = walk->private;
625 unsigned long endvma = vma->vm_end;
626 unsigned long flags = qp->flags;
627
628 if (!vma_migratable(vma))
629 return 1;
630
631 if (endvma > end)
632 endvma = end;
633 if (vma->vm_start > start)
634 start = vma->vm_start;
635
636 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
637 if (!vma->vm_next && vma->vm_end < end)
638 return -EFAULT;
639 if (qp->prev && qp->prev->vm_end < vma->vm_start)
640 return -EFAULT;
641 }
642
643 qp->prev = vma;
644
645 if (flags & MPOL_MF_LAZY) {
646 /* Similar to task_numa_work, skip inaccessible VMAs */
647 if (!is_vm_hugetlb_page(vma) &&
648 (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) &&
649 !(vma->vm_flags & VM_MIXEDMAP))
650 change_prot_numa(vma, start, endvma);
651 return 1;
652 }
653
654 /* queue pages from current vma */
655 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
656 return 0;
657 return 1;
658}
659
660/*
661 * Walk through page tables and collect pages to be migrated.
662 *
663 * If pages found in a given range are on a set of nodes (determined by
664 * @nodes and @flags,) it's isolated and queued to the pagelist which is
665 * passed via @private.)
666 */
667static int
668queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
669 nodemask_t *nodes, unsigned long flags,
670 struct list_head *pagelist)
671{
672 struct queue_pages qp = {
673 .pagelist = pagelist,
674 .flags = flags,
675 .nmask = nodes,
676 .prev = NULL,
677 };
678 struct mm_walk queue_pages_walk = {
679 .hugetlb_entry = queue_pages_hugetlb,
680 .pmd_entry = queue_pages_pte_range,
681 .test_walk = queue_pages_test_walk,
682 .mm = mm,
683 .private = &qp,
684 };
685
686 return walk_page_range(start, end, &queue_pages_walk);
687}
688
689/*
690 * Apply policy to a single VMA
691 * This must be called with the mmap_sem held for writing.
692 */
693static int vma_replace_policy(struct vm_area_struct *vma,
694 struct mempolicy *pol)
695{
696 int err;
697 struct mempolicy *old;
698 struct mempolicy *new;
699
700 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
701 vma->vm_start, vma->vm_end, vma->vm_pgoff,
702 vma->vm_ops, vma->vm_file,
703 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
704
705 new = mpol_dup(pol);
706 if (IS_ERR(new))
707 return PTR_ERR(new);
708
709 if (vma->vm_ops && vma->vm_ops->set_policy) {
710 err = vma->vm_ops->set_policy(vma, new);
711 if (err)
712 goto err_out;
713 }
714
715 old = vma->vm_policy;
716 vma->vm_policy = new; /* protected by mmap_sem */
717 mpol_put(old);
718
719 return 0;
720 err_out:
721 mpol_put(new);
722 return err;
723}
724
725/* Step 2: apply policy to a range and do splits. */
726static int mbind_range(struct mm_struct *mm, unsigned long start,
727 unsigned long end, struct mempolicy *new_pol)
728{
729 struct vm_area_struct *next;
730 struct vm_area_struct *prev;
731 struct vm_area_struct *vma;
732 int err = 0;
733 pgoff_t pgoff;
734 unsigned long vmstart;
735 unsigned long vmend;
736
737 vma = find_vma(mm, start);
738 if (!vma || vma->vm_start > start)
739 return -EFAULT;
740
741 prev = vma->vm_prev;
742 if (start > vma->vm_start)
743 prev = vma;
744
745 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
746 next = vma->vm_next;
747 vmstart = max(start, vma->vm_start);
748 vmend = min(end, vma->vm_end);
749
750 if (mpol_equal(vma_policy(vma), new_pol))
751 continue;
752
753 pgoff = vma->vm_pgoff +
754 ((vmstart - vma->vm_start) >> PAGE_SHIFT);
755 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
756 vma->anon_vma, vma->vm_file, pgoff,
757 new_pol, vma->vm_userfaultfd_ctx);
758 if (prev) {
759 vma = prev;
760 next = vma->vm_next;
761 if (mpol_equal(vma_policy(vma), new_pol))
762 continue;
763 /* vma_merge() joined vma && vma->next, case 8 */
764 goto replace;
765 }
766 if (vma->vm_start != vmstart) {
767 err = split_vma(vma->vm_mm, vma, vmstart, 1);
768 if (err)
769 goto out;
770 }
771 if (vma->vm_end != vmend) {
772 err = split_vma(vma->vm_mm, vma, vmend, 0);
773 if (err)
774 goto out;
775 }
776 replace:
777 err = vma_replace_policy(vma, new_pol);
778 if (err)
779 goto out;
780 }
781
782 out:
783 return err;
784}
785
786/* Set the process memory policy */
787static long do_set_mempolicy(unsigned short mode, unsigned short flags,
788 nodemask_t *nodes)
789{
790 struct mempolicy *new, *old;
791 NODEMASK_SCRATCH(scratch);
792 int ret;
793
794 if (!scratch)
795 return -ENOMEM;
796
797 new = mpol_new(mode, flags, nodes);
798 if (IS_ERR(new)) {
799 ret = PTR_ERR(new);
800 goto out;
801 }
802
803 task_lock(current);
804 ret = mpol_set_nodemask(new, nodes, scratch);
805 if (ret) {
806 task_unlock(current);
807 mpol_put(new);
808 goto out;
809 }
810 old = current->mempolicy;
811 current->mempolicy = new;
812 if (new && new->mode == MPOL_INTERLEAVE &&
813 nodes_weight(new->v.nodes))
814 current->il_next = first_node(new->v.nodes);
815 task_unlock(current);
816 mpol_put(old);
817 ret = 0;
818out:
819 NODEMASK_SCRATCH_FREE(scratch);
820 return ret;
821}
822
823/*
824 * Return nodemask for policy for get_mempolicy() query
825 *
826 * Called with task's alloc_lock held
827 */
828static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
829{
830 nodes_clear(*nodes);
831 if (p == &default_policy)
832 return;
833
834 switch (p->mode) {
835 case MPOL_BIND:
836 /* Fall through */
837 case MPOL_INTERLEAVE:
838 *nodes = p->v.nodes;
839 break;
840 case MPOL_PREFERRED:
841 if (!(p->flags & MPOL_F_LOCAL))
842 node_set(p->v.preferred_node, *nodes);
843 /* else return empty node mask for local allocation */
844 break;
845 default:
846 BUG();
847 }
848}
849
850static int lookup_node(unsigned long addr)
851{
852 struct page *p;
853 int err;
854
855 err = get_user_pages(addr & PAGE_MASK, 1, 0, &p, NULL);
856 if (err >= 0) {
857 err = page_to_nid(p);
858 put_page(p);
859 }
860 return err;
861}
862
863/* Retrieve NUMA policy */
864static long do_get_mempolicy(int *policy, nodemask_t *nmask,
865 unsigned long addr, unsigned long flags)
866{
867 int err;
868 struct mm_struct *mm = current->mm;
869 struct vm_area_struct *vma = NULL;
870 struct mempolicy *pol = current->mempolicy;
871
872 if (flags &
873 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
874 return -EINVAL;
875
876 if (flags & MPOL_F_MEMS_ALLOWED) {
877 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
878 return -EINVAL;
879 *policy = 0; /* just so it's initialized */
880 task_lock(current);
881 *nmask = cpuset_current_mems_allowed;
882 task_unlock(current);
883 return 0;
884 }
885
886 if (flags & MPOL_F_ADDR) {
887 /*
888 * Do NOT fall back to task policy if the
889 * vma/shared policy at addr is NULL. We
890 * want to return MPOL_DEFAULT in this case.
891 */
892 down_read(&mm->mmap_sem);
893 vma = find_vma_intersection(mm, addr, addr+1);
894 if (!vma) {
895 up_read(&mm->mmap_sem);
896 return -EFAULT;
897 }
898 if (vma->vm_ops && vma->vm_ops->get_policy)
899 pol = vma->vm_ops->get_policy(vma, addr);
900 else
901 pol = vma->vm_policy;
902 } else if (addr)
903 return -EINVAL;
904
905 if (!pol)
906 pol = &default_policy; /* indicates default behavior */
907
908 if (flags & MPOL_F_NODE) {
909 if (flags & MPOL_F_ADDR) {
910 err = lookup_node(addr);
911 if (err < 0)
912 goto out;
913 *policy = err;
914 } else if (pol == current->mempolicy &&
915 pol->mode == MPOL_INTERLEAVE) {
916 *policy = current->il_next;
917 } else {
918 err = -EINVAL;
919 goto out;
920 }
921 } else {
922 *policy = pol == &default_policy ? MPOL_DEFAULT :
923 pol->mode;
924 /*
925 * Internal mempolicy flags must be masked off before exposing
926 * the policy to userspace.
927 */
928 *policy |= (pol->flags & MPOL_MODE_FLAGS);
929 }
930
931 if (vma) {
932 up_read(¤t->mm->mmap_sem);
933 vma = NULL;
934 }
935
936 err = 0;
937 if (nmask) {
938 if (mpol_store_user_nodemask(pol)) {
939 *nmask = pol->w.user_nodemask;
940 } else {
941 task_lock(current);
942 get_policy_nodemask(pol, nmask);
943 task_unlock(current);
944 }
945 }
946
947 out:
948 mpol_cond_put(pol);
949 if (vma)
950 up_read(¤t->mm->mmap_sem);
951 return err;
952}
953
954#ifdef CONFIG_MIGRATION
955/*
956 * page migration
957 */
958static void migrate_page_add(struct page *page, struct list_head *pagelist,
959 unsigned long flags)
960{
961 /*
962 * Avoid migrating a page that is shared with others.
963 */
964 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
965 if (!isolate_lru_page(page)) {
966 list_add_tail(&page->lru, pagelist);
967 inc_node_page_state(page, NR_ISOLATED_ANON +
968 page_is_file_cache(page));
969 }
970 }
971}
972
973static struct page *new_node_page(struct page *page, unsigned long node, int **x)
974{
975 if (PageHuge(page))
976 return alloc_huge_page_node(page_hstate(compound_head(page)),
977 node);
978 else
979 return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE |
980 __GFP_THISNODE, 0);
981}
982
983/*
984 * Migrate pages from one node to a target node.
985 * Returns error or the number of pages not migrated.
986 */
987static int migrate_to_node(struct mm_struct *mm, int source, int dest,
988 int flags)
989{
990 nodemask_t nmask;
991 LIST_HEAD(pagelist);
992 int err = 0;
993
994 nodes_clear(nmask);
995 node_set(source, nmask);
996
997 /*
998 * This does not "check" the range but isolates all pages that
999 * need migration. Between passing in the full user address
1000 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
1001 */
1002 VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
1003 queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
1004 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
1005
1006 if (!list_empty(&pagelist)) {
1007 err = migrate_pages(&pagelist, new_node_page, NULL, dest,
1008 MIGRATE_SYNC, MR_SYSCALL);
1009 if (err)
1010 putback_movable_pages(&pagelist);
1011 }
1012
1013 return err;
1014}
1015
1016/*
1017 * Move pages between the two nodesets so as to preserve the physical
1018 * layout as much as possible.
1019 *
1020 * Returns the number of page that could not be moved.
1021 */
1022int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1023 const nodemask_t *to, int flags)
1024{
1025 int busy = 0;
1026 int err;
1027 nodemask_t tmp;
1028
1029 err = migrate_prep();
1030 if (err)
1031 return err;
1032
1033 down_read(&mm->mmap_sem);
1034
1035 /*
1036 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
1037 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
1038 * bit in 'tmp', and return that <source, dest> pair for migration.
1039 * The pair of nodemasks 'to' and 'from' define the map.
1040 *
1041 * If no pair of bits is found that way, fallback to picking some
1042 * pair of 'source' and 'dest' bits that are not the same. If the
1043 * 'source' and 'dest' bits are the same, this represents a node
1044 * that will be migrating to itself, so no pages need move.
1045 *
1046 * If no bits are left in 'tmp', or if all remaining bits left
1047 * in 'tmp' correspond to the same bit in 'to', return false
1048 * (nothing left to migrate).
1049 *
1050 * This lets us pick a pair of nodes to migrate between, such that
1051 * if possible the dest node is not already occupied by some other
1052 * source node, minimizing the risk of overloading the memory on a
1053 * node that would happen if we migrated incoming memory to a node
1054 * before migrating outgoing memory source that same node.
1055 *
1056 * A single scan of tmp is sufficient. As we go, we remember the
1057 * most recent <s, d> pair that moved (s != d). If we find a pair
1058 * that not only moved, but what's better, moved to an empty slot
1059 * (d is not set in tmp), then we break out then, with that pair.
1060 * Otherwise when we finish scanning from_tmp, we at least have the
1061 * most recent <s, d> pair that moved. If we get all the way through
1062 * the scan of tmp without finding any node that moved, much less
1063 * moved to an empty node, then there is nothing left worth migrating.
1064 */
1065
1066 tmp = *from;
1067 while (!nodes_empty(tmp)) {
1068 int s,d;
1069 int source = NUMA_NO_NODE;
1070 int dest = 0;
1071
1072 for_each_node_mask(s, tmp) {
1073
1074 /*
1075 * do_migrate_pages() tries to maintain the relative
1076 * node relationship of the pages established between
1077 * threads and memory areas.
1078 *
1079 * However if the number of source nodes is not equal to
1080 * the number of destination nodes we can not preserve
1081 * this node relative relationship. In that case, skip
1082 * copying memory from a node that is in the destination
1083 * mask.
1084 *
1085 * Example: [2,3,4] -> [3,4,5] moves everything.
1086 * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
1087 */
1088
1089 if ((nodes_weight(*from) != nodes_weight(*to)) &&
1090 (node_isset(s, *to)))
1091 continue;
1092
1093 d = node_remap(s, *from, *to);
1094 if (s == d)
1095 continue;
1096
1097 source = s; /* Node moved. Memorize */
1098 dest = d;
1099
1100 /* dest not in remaining from nodes? */
1101 if (!node_isset(dest, tmp))
1102 break;
1103 }
1104 if (source == NUMA_NO_NODE)
1105 break;
1106
1107 node_clear(source, tmp);
1108 err = migrate_to_node(mm, source, dest, flags);
1109 if (err > 0)
1110 busy += err;
1111 if (err < 0)
1112 break;
1113 }
1114 up_read(&mm->mmap_sem);
1115 if (err < 0)
1116 return err;
1117 return busy;
1118
1119}
1120
1121/*
1122 * Allocate a new page for page migration based on vma policy.
1123 * Start by assuming the page is mapped by the same vma as contains @start.
1124 * Search forward from there, if not. N.B., this assumes that the
1125 * list of pages handed to migrate_pages()--which is how we get here--
1126 * is in virtual address order.
1127 */
1128static struct page *new_page(struct page *page, unsigned long start, int **x)
1129{
1130 struct vm_area_struct *vma;
1131 unsigned long uninitialized_var(address);
1132
1133 vma = find_vma(current->mm, start);
1134 while (vma) {
1135 address = page_address_in_vma(page, vma);
1136 if (address != -EFAULT)
1137 break;
1138 vma = vma->vm_next;
1139 }
1140
1141 if (PageHuge(page)) {
1142 BUG_ON(!vma);
1143 return alloc_huge_page_noerr(vma, address, 1);
1144 }
1145 /*
1146 * if !vma, alloc_page_vma() will use task or system default policy
1147 */
1148 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
1149}
1150#else
1151
1152static void migrate_page_add(struct page *page, struct list_head *pagelist,
1153 unsigned long flags)
1154{
1155}
1156
1157int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1158 const nodemask_t *to, int flags)
1159{
1160 return -ENOSYS;
1161}
1162
1163static struct page *new_page(struct page *page, unsigned long start, int **x)
1164{
1165 return NULL;
1166}
1167#endif
1168
1169static long do_mbind(unsigned long start, unsigned long len,
1170 unsigned short mode, unsigned short mode_flags,
1171 nodemask_t *nmask, unsigned long flags)
1172{
1173 struct mm_struct *mm = current->mm;
1174 struct mempolicy *new;
1175 unsigned long end;
1176 int err;
1177 LIST_HEAD(pagelist);
1178
1179 if (flags & ~(unsigned long)MPOL_MF_VALID)
1180 return -EINVAL;
1181 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1182 return -EPERM;
1183
1184 if (start & ~PAGE_MASK)
1185 return -EINVAL;
1186
1187 if (mode == MPOL_DEFAULT)
1188 flags &= ~MPOL_MF_STRICT;
1189
1190 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1191 end = start + len;
1192
1193 if (end < start)
1194 return -EINVAL;
1195 if (end == start)
1196 return 0;
1197
1198 new = mpol_new(mode, mode_flags, nmask);
1199 if (IS_ERR(new))
1200 return PTR_ERR(new);
1201
1202 if (flags & MPOL_MF_LAZY)
1203 new->flags |= MPOL_F_MOF;
1204
1205 /*
1206 * If we are using the default policy then operation
1207 * on discontinuous address spaces is okay after all
1208 */
1209 if (!new)
1210 flags |= MPOL_MF_DISCONTIG_OK;
1211
1212 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1213 start, start + len, mode, mode_flags,
1214 nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE);
1215
1216 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1217
1218 err = migrate_prep();
1219 if (err)
1220 goto mpol_out;
1221 }
1222 {
1223 NODEMASK_SCRATCH(scratch);
1224 if (scratch) {
1225 down_write(&mm->mmap_sem);
1226 task_lock(current);
1227 err = mpol_set_nodemask(new, nmask, scratch);
1228 task_unlock(current);
1229 if (err)
1230 up_write(&mm->mmap_sem);
1231 } else
1232 err = -ENOMEM;
1233 NODEMASK_SCRATCH_FREE(scratch);
1234 }
1235 if (err)
1236 goto mpol_out;
1237
1238 err = queue_pages_range(mm, start, end, nmask,
1239 flags | MPOL_MF_INVERT, &pagelist);
1240 if (!err)
1241 err = mbind_range(mm, start, end, new);
1242
1243 if (!err) {
1244 int nr_failed = 0;
1245
1246 if (!list_empty(&pagelist)) {
1247 WARN_ON_ONCE(flags & MPOL_MF_LAZY);
1248 nr_failed = migrate_pages(&pagelist, new_page, NULL,
1249 start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
1250 if (nr_failed)
1251 putback_movable_pages(&pagelist);
1252 }
1253
1254 if (nr_failed && (flags & MPOL_MF_STRICT))
1255 err = -EIO;
1256 } else
1257 putback_movable_pages(&pagelist);
1258
1259 up_write(&mm->mmap_sem);
1260 mpol_out:
1261 mpol_put(new);
1262 return err;
1263}
1264
1265/*
1266 * User space interface with variable sized bitmaps for nodelists.
1267 */
1268
1269/* Copy a node mask from user space. */
1270static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1271 unsigned long maxnode)
1272{
1273 unsigned long k;
1274 unsigned long nlongs;
1275 unsigned long endmask;
1276
1277 --maxnode;
1278 nodes_clear(*nodes);
1279 if (maxnode == 0 || !nmask)
1280 return 0;
1281 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
1282 return -EINVAL;
1283
1284 nlongs = BITS_TO_LONGS(maxnode);
1285 if ((maxnode % BITS_PER_LONG) == 0)
1286 endmask = ~0UL;
1287 else
1288 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1289
1290 /* When the user specified more nodes than supported just check
1291 if the non supported part is all zero. */
1292 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1293 if (nlongs > PAGE_SIZE/sizeof(long))
1294 return -EINVAL;
1295 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1296 unsigned long t;
1297 if (get_user(t, nmask + k))
1298 return -EFAULT;
1299 if (k == nlongs - 1) {
1300 if (t & endmask)
1301 return -EINVAL;
1302 } else if (t)
1303 return -EINVAL;
1304 }
1305 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1306 endmask = ~0UL;
1307 }
1308
1309 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1310 return -EFAULT;
1311 nodes_addr(*nodes)[nlongs-1] &= endmask;
1312 return 0;
1313}
1314
1315/* Copy a kernel node mask to user space */
1316static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1317 nodemask_t *nodes)
1318{
1319 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1320 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
1321
1322 if (copy > nbytes) {
1323 if (copy > PAGE_SIZE)
1324 return -EINVAL;
1325 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1326 return -EFAULT;
1327 copy = nbytes;
1328 }
1329 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1330}
1331
1332SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1333 unsigned long, mode, const unsigned long __user *, nmask,
1334 unsigned long, maxnode, unsigned, flags)
1335{
1336 nodemask_t nodes;
1337 int err;
1338 unsigned short mode_flags;
1339
1340 mode_flags = mode & MPOL_MODE_FLAGS;
1341 mode &= ~MPOL_MODE_FLAGS;
1342 if (mode >= MPOL_MAX)
1343 return -EINVAL;
1344 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1345 (mode_flags & MPOL_F_RELATIVE_NODES))
1346 return -EINVAL;
1347 err = get_nodes(&nodes, nmask, maxnode);
1348 if (err)
1349 return err;
1350 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1351}
1352
1353/* Set the process memory policy */
1354SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
1355 unsigned long, maxnode)
1356{
1357 int err;
1358 nodemask_t nodes;
1359 unsigned short flags;
1360
1361 flags = mode & MPOL_MODE_FLAGS;
1362 mode &= ~MPOL_MODE_FLAGS;
1363 if ((unsigned int)mode >= MPOL_MAX)
1364 return -EINVAL;
1365 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1366 return -EINVAL;
1367 err = get_nodes(&nodes, nmask, maxnode);
1368 if (err)
1369 return err;
1370 return do_set_mempolicy(mode, flags, &nodes);
1371}
1372
1373SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1374 const unsigned long __user *, old_nodes,
1375 const unsigned long __user *, new_nodes)
1376{
1377 const struct cred *cred = current_cred(), *tcred;
1378 struct mm_struct *mm = NULL;
1379 struct task_struct *task;
1380 nodemask_t task_nodes;
1381 int err;
1382 nodemask_t *old;
1383 nodemask_t *new;
1384 NODEMASK_SCRATCH(scratch);
1385
1386 if (!scratch)
1387 return -ENOMEM;
1388
1389 old = &scratch->mask1;
1390 new = &scratch->mask2;
1391
1392 err = get_nodes(old, old_nodes, maxnode);
1393 if (err)
1394 goto out;
1395
1396 err = get_nodes(new, new_nodes, maxnode);
1397 if (err)
1398 goto out;
1399
1400 /* Find the mm_struct */
1401 rcu_read_lock();
1402 task = pid ? find_task_by_vpid(pid) : current;
1403 if (!task) {
1404 rcu_read_unlock();
1405 err = -ESRCH;
1406 goto out;
1407 }
1408 get_task_struct(task);
1409
1410 err = -EINVAL;
1411
1412 /*
1413 * Check if this process has the right to modify the specified
1414 * process. The right exists if the process has administrative
1415 * capabilities, superuser privileges or the same
1416 * userid as the target process.
1417 */
1418 tcred = __task_cred(task);
1419 if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
1420 !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) &&
1421 !capable(CAP_SYS_NICE)) {
1422 rcu_read_unlock();
1423 err = -EPERM;
1424 goto out_put;
1425 }
1426 rcu_read_unlock();
1427
1428 task_nodes = cpuset_mems_allowed(task);
1429 /* Is the user allowed to access the target nodes? */
1430 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
1431 err = -EPERM;
1432 goto out_put;
1433 }
1434
1435 if (!nodes_subset(*new, node_states[N_MEMORY])) {
1436 err = -EINVAL;
1437 goto out_put;
1438 }
1439
1440 err = security_task_movememory(task);
1441 if (err)
1442 goto out_put;
1443
1444 mm = get_task_mm(task);
1445 put_task_struct(task);
1446
1447 if (!mm) {
1448 err = -EINVAL;
1449 goto out;
1450 }
1451
1452 err = do_migrate_pages(mm, old, new,
1453 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1454
1455 mmput(mm);
1456out:
1457 NODEMASK_SCRATCH_FREE(scratch);
1458
1459 return err;
1460
1461out_put:
1462 put_task_struct(task);
1463 goto out;
1464
1465}
1466
1467
1468/* Retrieve NUMA policy */
1469SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1470 unsigned long __user *, nmask, unsigned long, maxnode,
1471 unsigned long, addr, unsigned long, flags)
1472{
1473 int err;
1474 int uninitialized_var(pval);
1475 nodemask_t nodes;
1476
1477 if (nmask != NULL && maxnode < MAX_NUMNODES)
1478 return -EINVAL;
1479
1480 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1481
1482 if (err)
1483 return err;
1484
1485 if (policy && put_user(pval, policy))
1486 return -EFAULT;
1487
1488 if (nmask)
1489 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1490
1491 return err;
1492}
1493
1494#ifdef CONFIG_COMPAT
1495
1496COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1497 compat_ulong_t __user *, nmask,
1498 compat_ulong_t, maxnode,
1499 compat_ulong_t, addr, compat_ulong_t, flags)
1500{
1501 long err;
1502 unsigned long __user *nm = NULL;
1503 unsigned long nr_bits, alloc_size;
1504 DECLARE_BITMAP(bm, MAX_NUMNODES);
1505
1506 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1507 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1508
1509 if (nmask)
1510 nm = compat_alloc_user_space(alloc_size);
1511
1512 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1513
1514 if (!err && nmask) {
1515 unsigned long copy_size;
1516 copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
1517 err = copy_from_user(bm, nm, copy_size);
1518 /* ensure entire bitmap is zeroed */
1519 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1520 err |= compat_put_bitmap(nmask, bm, nr_bits);
1521 }
1522
1523 return err;
1524}
1525
1526COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
1527 compat_ulong_t, maxnode)
1528{
1529 unsigned long __user *nm = NULL;
1530 unsigned long nr_bits, alloc_size;
1531 DECLARE_BITMAP(bm, MAX_NUMNODES);
1532
1533 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1534 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1535
1536 if (nmask) {
1537 if (compat_get_bitmap(bm, nmask, nr_bits))
1538 return -EFAULT;
1539 nm = compat_alloc_user_space(alloc_size);
1540 if (copy_to_user(nm, bm, alloc_size))
1541 return -EFAULT;
1542 }
1543
1544 return sys_set_mempolicy(mode, nm, nr_bits+1);
1545}
1546
1547COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
1548 compat_ulong_t, mode, compat_ulong_t __user *, nmask,
1549 compat_ulong_t, maxnode, compat_ulong_t, flags)
1550{
1551 unsigned long __user *nm = NULL;
1552 unsigned long nr_bits, alloc_size;
1553 nodemask_t bm;
1554
1555 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1556 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1557
1558 if (nmask) {
1559 if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
1560 return -EFAULT;
1561 nm = compat_alloc_user_space(alloc_size);
1562 if (copy_to_user(nm, nodes_addr(bm), alloc_size))
1563 return -EFAULT;
1564 }
1565
1566 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1567}
1568
1569#endif
1570
1571struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
1572 unsigned long addr)
1573{
1574 struct mempolicy *pol = NULL;
1575
1576 if (vma) {
1577 if (vma->vm_ops && vma->vm_ops->get_policy) {
1578 pol = vma->vm_ops->get_policy(vma, addr);
1579 } else if (vma->vm_policy) {
1580 pol = vma->vm_policy;
1581
1582 /*
1583 * shmem_alloc_page() passes MPOL_F_SHARED policy with
1584 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
1585 * count on these policies which will be dropped by
1586 * mpol_cond_put() later
1587 */
1588 if (mpol_needs_cond_ref(pol))
1589 mpol_get(pol);
1590 }
1591 }
1592
1593 return pol;
1594}
1595
1596/*
1597 * get_vma_policy(@vma, @addr)
1598 * @vma: virtual memory area whose policy is sought
1599 * @addr: address in @vma for shared policy lookup
1600 *
1601 * Returns effective policy for a VMA at specified address.
1602 * Falls back to current->mempolicy or system default policy, as necessary.
1603 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1604 * count--added by the get_policy() vm_op, as appropriate--to protect against
1605 * freeing by another task. It is the caller's responsibility to free the
1606 * extra reference for shared policies.
1607 */
1608static struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
1609 unsigned long addr)
1610{
1611 struct mempolicy *pol = __get_vma_policy(vma, addr);
1612
1613 if (!pol)
1614 pol = get_task_policy(current);
1615
1616 return pol;
1617}
1618
1619bool vma_policy_mof(struct vm_area_struct *vma)
1620{
1621 struct mempolicy *pol;
1622
1623 if (vma->vm_ops && vma->vm_ops->get_policy) {
1624 bool ret = false;
1625
1626 pol = vma->vm_ops->get_policy(vma, vma->vm_start);
1627 if (pol && (pol->flags & MPOL_F_MOF))
1628 ret = true;
1629 mpol_cond_put(pol);
1630
1631 return ret;
1632 }
1633
1634 pol = vma->vm_policy;
1635 if (!pol)
1636 pol = get_task_policy(current);
1637
1638 return pol->flags & MPOL_F_MOF;
1639}
1640
1641static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
1642{
1643 enum zone_type dynamic_policy_zone = policy_zone;
1644
1645 BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
1646
1647 /*
1648 * if policy->v.nodes has movable memory only,
1649 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
1650 *
1651 * policy->v.nodes is intersect with node_states[N_MEMORY].
1652 * so if the following test faile, it implies
1653 * policy->v.nodes has movable memory only.
1654 */
1655 if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
1656 dynamic_policy_zone = ZONE_MOVABLE;
1657
1658 return zone >= dynamic_policy_zone;
1659}
1660
1661/*
1662 * Return a nodemask representing a mempolicy for filtering nodes for
1663 * page allocation
1664 */
1665static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1666{
1667 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1668 if (unlikely(policy->mode == MPOL_BIND) &&
1669 apply_policy_zone(policy, gfp_zone(gfp)) &&
1670 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1671 return &policy->v.nodes;
1672
1673 return NULL;
1674}
1675
1676/* Return a zonelist indicated by gfp for node representing a mempolicy */
1677static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
1678 int nd)
1679{
1680 if (policy->mode == MPOL_PREFERRED && !(policy->flags & MPOL_F_LOCAL))
1681 nd = policy->v.preferred_node;
1682 else {
1683 /*
1684 * __GFP_THISNODE shouldn't even be used with the bind policy
1685 * because we might easily break the expectation to stay on the
1686 * requested node and not break the policy.
1687 */
1688 WARN_ON_ONCE(policy->mode == MPOL_BIND && (gfp & __GFP_THISNODE));
1689 }
1690
1691 return node_zonelist(nd, gfp);
1692}
1693
1694/* Do dynamic interleaving for a process */
1695static unsigned interleave_nodes(struct mempolicy *policy)
1696{
1697 unsigned nid, next;
1698 struct task_struct *me = current;
1699
1700 nid = me->il_next;
1701 next = next_node_in(nid, policy->v.nodes);
1702 if (next < MAX_NUMNODES)
1703 me->il_next = next;
1704 return nid;
1705}
1706
1707/*
1708 * Depending on the memory policy provide a node from which to allocate the
1709 * next slab entry.
1710 */
1711unsigned int mempolicy_slab_node(void)
1712{
1713 struct mempolicy *policy;
1714 int node = numa_mem_id();
1715
1716 if (in_interrupt())
1717 return node;
1718
1719 policy = current->mempolicy;
1720 if (!policy || policy->flags & MPOL_F_LOCAL)
1721 return node;
1722
1723 switch (policy->mode) {
1724 case MPOL_PREFERRED:
1725 /*
1726 * handled MPOL_F_LOCAL above
1727 */
1728 return policy->v.preferred_node;
1729
1730 case MPOL_INTERLEAVE:
1731 return interleave_nodes(policy);
1732
1733 case MPOL_BIND: {
1734 struct zoneref *z;
1735
1736 /*
1737 * Follow bind policy behavior and start allocation at the
1738 * first node.
1739 */
1740 struct zonelist *zonelist;
1741 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1742 zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
1743 z = first_zones_zonelist(zonelist, highest_zoneidx,
1744 &policy->v.nodes);
1745 return z->zone ? z->zone->node : node;
1746 }
1747
1748 default:
1749 BUG();
1750 }
1751}
1752
1753/*
1754 * Do static interleaving for a VMA with known offset @n. Returns the n'th
1755 * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the
1756 * number of present nodes.
1757 */
1758static unsigned offset_il_node(struct mempolicy *pol,
1759 struct vm_area_struct *vma, unsigned long n)
1760{
1761 unsigned nnodes = nodes_weight(pol->v.nodes);
1762 unsigned target;
1763 int i;
1764 int nid;
1765
1766 if (!nnodes)
1767 return numa_node_id();
1768 target = (unsigned int)n % nnodes;
1769 nid = first_node(pol->v.nodes);
1770 for (i = 0; i < target; i++)
1771 nid = next_node(nid, pol->v.nodes);
1772 return nid;
1773}
1774
1775/* Determine a node number for interleave */
1776static inline unsigned interleave_nid(struct mempolicy *pol,
1777 struct vm_area_struct *vma, unsigned long addr, int shift)
1778{
1779 if (vma) {
1780 unsigned long off;
1781
1782 /*
1783 * for small pages, there is no difference between
1784 * shift and PAGE_SHIFT, so the bit-shift is safe.
1785 * for huge pages, since vm_pgoff is in units of small
1786 * pages, we need to shift off the always 0 bits to get
1787 * a useful offset.
1788 */
1789 BUG_ON(shift < PAGE_SHIFT);
1790 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
1791 off += (addr - vma->vm_start) >> shift;
1792 return offset_il_node(pol, vma, off);
1793 } else
1794 return interleave_nodes(pol);
1795}
1796
1797#ifdef CONFIG_HUGETLBFS
1798/*
1799 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1800 * @vma: virtual memory area whose policy is sought
1801 * @addr: address in @vma for shared policy lookup and interleave policy
1802 * @gfp_flags: for requested zone
1803 * @mpol: pointer to mempolicy pointer for reference counted mempolicy
1804 * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask
1805 *
1806 * Returns a zonelist suitable for a huge page allocation and a pointer
1807 * to the struct mempolicy for conditional unref after allocation.
1808 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1809 * @nodemask for filtering the zonelist.
1810 *
1811 * Must be protected by read_mems_allowed_begin()
1812 */
1813struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
1814 gfp_t gfp_flags, struct mempolicy **mpol,
1815 nodemask_t **nodemask)
1816{
1817 struct zonelist *zl;
1818
1819 *mpol = get_vma_policy(vma, addr);
1820 *nodemask = NULL; /* assume !MPOL_BIND */
1821
1822 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1823 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
1824 huge_page_shift(hstate_vma(vma))), gfp_flags);
1825 } else {
1826 zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
1827 if ((*mpol)->mode == MPOL_BIND)
1828 *nodemask = &(*mpol)->v.nodes;
1829 }
1830 return zl;
1831}
1832
1833/*
1834 * init_nodemask_of_mempolicy
1835 *
1836 * If the current task's mempolicy is "default" [NULL], return 'false'
1837 * to indicate default policy. Otherwise, extract the policy nodemask
1838 * for 'bind' or 'interleave' policy into the argument nodemask, or
1839 * initialize the argument nodemask to contain the single node for
1840 * 'preferred' or 'local' policy and return 'true' to indicate presence
1841 * of non-default mempolicy.
1842 *
1843 * We don't bother with reference counting the mempolicy [mpol_get/put]
1844 * because the current task is examining it's own mempolicy and a task's
1845 * mempolicy is only ever changed by the task itself.
1846 *
1847 * N.B., it is the caller's responsibility to free a returned nodemask.
1848 */
1849bool init_nodemask_of_mempolicy(nodemask_t *mask)
1850{
1851 struct mempolicy *mempolicy;
1852 int nid;
1853
1854 if (!(mask && current->mempolicy))
1855 return false;
1856
1857 task_lock(current);
1858 mempolicy = current->mempolicy;
1859 switch (mempolicy->mode) {
1860 case MPOL_PREFERRED:
1861 if (mempolicy->flags & MPOL_F_LOCAL)
1862 nid = numa_node_id();
1863 else
1864 nid = mempolicy->v.preferred_node;
1865 init_nodemask_of_node(mask, nid);
1866 break;
1867
1868 case MPOL_BIND:
1869 /* Fall through */
1870 case MPOL_INTERLEAVE:
1871 *mask = mempolicy->v.nodes;
1872 break;
1873
1874 default:
1875 BUG();
1876 }
1877 task_unlock(current);
1878
1879 return true;
1880}
1881#endif
1882
1883/*
1884 * mempolicy_nodemask_intersects
1885 *
1886 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1887 * policy. Otherwise, check for intersection between mask and the policy
1888 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1889 * policy, always return true since it may allocate elsewhere on fallback.
1890 *
1891 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1892 */
1893bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1894 const nodemask_t *mask)
1895{
1896 struct mempolicy *mempolicy;
1897 bool ret = true;
1898
1899 if (!mask)
1900 return ret;
1901 task_lock(tsk);
1902 mempolicy = tsk->mempolicy;
1903 if (!mempolicy)
1904 goto out;
1905
1906 switch (mempolicy->mode) {
1907 case MPOL_PREFERRED:
1908 /*
1909 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1910 * allocate from, they may fallback to other nodes when oom.
1911 * Thus, it's possible for tsk to have allocated memory from
1912 * nodes in mask.
1913 */
1914 break;
1915 case MPOL_BIND:
1916 case MPOL_INTERLEAVE:
1917 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1918 break;
1919 default:
1920 BUG();
1921 }
1922out:
1923 task_unlock(tsk);
1924 return ret;
1925}
1926
1927/* Allocate a page in interleaved policy.
1928 Own path because it needs to do special accounting. */
1929static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1930 unsigned nid)
1931{
1932 struct zonelist *zl;
1933 struct page *page;
1934
1935 zl = node_zonelist(nid, gfp);
1936 page = __alloc_pages(gfp, order, zl);
1937 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
1938 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
1939 return page;
1940}
1941
1942/**
1943 * alloc_pages_vma - Allocate a page for a VMA.
1944 *
1945 * @gfp:
1946 * %GFP_USER user allocation.
1947 * %GFP_KERNEL kernel allocations,
1948 * %GFP_HIGHMEM highmem/user allocations,
1949 * %GFP_FS allocation should not call back into a file system.
1950 * %GFP_ATOMIC don't sleep.
1951 *
1952 * @order:Order of the GFP allocation.
1953 * @vma: Pointer to VMA or NULL if not available.
1954 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1955 * @node: Which node to prefer for allocation (modulo policy).
1956 * @hugepage: for hugepages try only the preferred node if possible
1957 *
1958 * This function allocates a page from the kernel page pool and applies
1959 * a NUMA policy associated with the VMA or the current process.
1960 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1961 * mm_struct of the VMA to prevent it from going away. Should be used for
1962 * all allocations for pages that will be mapped into user space. Returns
1963 * NULL when no page can be allocated.
1964 */
1965struct page *
1966alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
1967 unsigned long addr, int node, bool hugepage)
1968{
1969 struct mempolicy *pol;
1970 struct page *page;
1971 unsigned int cpuset_mems_cookie;
1972 struct zonelist *zl;
1973 nodemask_t *nmask;
1974
1975retry_cpuset:
1976 pol = get_vma_policy(vma, addr);
1977 cpuset_mems_cookie = read_mems_allowed_begin();
1978
1979 if (pol->mode == MPOL_INTERLEAVE) {
1980 unsigned nid;
1981
1982 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
1983 mpol_cond_put(pol);
1984 page = alloc_page_interleave(gfp, order, nid);
1985 goto out;
1986 }
1987
1988 if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
1989 int hpage_node = node;
1990
1991 /*
1992 * For hugepage allocation and non-interleave policy which
1993 * allows the current node (or other explicitly preferred
1994 * node) we only try to allocate from the current/preferred
1995 * node and don't fall back to other nodes, as the cost of
1996 * remote accesses would likely offset THP benefits.
1997 *
1998 * If the policy is interleave, or does not allow the current
1999 * node in its nodemask, we allocate the standard way.
2000 */
2001 if (pol->mode == MPOL_PREFERRED &&
2002 !(pol->flags & MPOL_F_LOCAL))
2003 hpage_node = pol->v.preferred_node;
2004
2005 nmask = policy_nodemask(gfp, pol);
2006 if (!nmask || node_isset(hpage_node, *nmask)) {
2007 mpol_cond_put(pol);
2008 page = __alloc_pages_node(hpage_node,
2009 gfp | __GFP_THISNODE, order);
2010 goto out;
2011 }
2012 }
2013
2014 nmask = policy_nodemask(gfp, pol);
2015 zl = policy_zonelist(gfp, pol, node);
2016 page = __alloc_pages_nodemask(gfp, order, zl, nmask);
2017 mpol_cond_put(pol);
2018out:
2019 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2020 goto retry_cpuset;
2021 return page;
2022}
2023
2024/**
2025 * alloc_pages_current - Allocate pages.
2026 *
2027 * @gfp:
2028 * %GFP_USER user allocation,
2029 * %GFP_KERNEL kernel allocation,
2030 * %GFP_HIGHMEM highmem allocation,
2031 * %GFP_FS don't call back into a file system.
2032 * %GFP_ATOMIC don't sleep.
2033 * @order: Power of two of allocation size in pages. 0 is a single page.
2034 *
2035 * Allocate a page from the kernel page pool. When not in
2036 * interrupt context and apply the current process NUMA policy.
2037 * Returns NULL when no page can be allocated.
2038 *
2039 * Don't call cpuset_update_task_memory_state() unless
2040 * 1) it's ok to take cpuset_sem (can WAIT), and
2041 * 2) allocating for current task (not interrupt).
2042 */
2043struct page *alloc_pages_current(gfp_t gfp, unsigned order)
2044{
2045 struct mempolicy *pol = &default_policy;
2046 struct page *page;
2047 unsigned int cpuset_mems_cookie;
2048
2049 if (!in_interrupt() && !(gfp & __GFP_THISNODE))
2050 pol = get_task_policy(current);
2051
2052retry_cpuset:
2053 cpuset_mems_cookie = read_mems_allowed_begin();
2054
2055 /*
2056 * No reference counting needed for current->mempolicy
2057 * nor system default_policy
2058 */
2059 if (pol->mode == MPOL_INTERLEAVE)
2060 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
2061 else
2062 page = __alloc_pages_nodemask(gfp, order,
2063 policy_zonelist(gfp, pol, numa_node_id()),
2064 policy_nodemask(gfp, pol));
2065
2066 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2067 goto retry_cpuset;
2068
2069 return page;
2070}
2071EXPORT_SYMBOL(alloc_pages_current);
2072
2073int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
2074{
2075 struct mempolicy *pol = mpol_dup(vma_policy(src));
2076
2077 if (IS_ERR(pol))
2078 return PTR_ERR(pol);
2079 dst->vm_policy = pol;
2080 return 0;
2081}
2082
2083/*
2084 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
2085 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
2086 * with the mems_allowed returned by cpuset_mems_allowed(). This
2087 * keeps mempolicies cpuset relative after its cpuset moves. See
2088 * further kernel/cpuset.c update_nodemask().
2089 *
2090 * current's mempolicy may be rebinded by the other task(the task that changes
2091 * cpuset's mems), so we needn't do rebind work for current task.
2092 */
2093
2094/* Slow path of a mempolicy duplicate */
2095struct mempolicy *__mpol_dup(struct mempolicy *old)
2096{
2097 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2098
2099 if (!new)
2100 return ERR_PTR(-ENOMEM);
2101
2102 /* task's mempolicy is protected by alloc_lock */
2103 if (old == current->mempolicy) {
2104 task_lock(current);
2105 *new = *old;
2106 task_unlock(current);
2107 } else
2108 *new = *old;
2109
2110 if (current_cpuset_is_being_rebound()) {
2111 nodemask_t mems = cpuset_mems_allowed(current);
2112 if (new->flags & MPOL_F_REBINDING)
2113 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
2114 else
2115 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
2116 }
2117 atomic_set(&new->refcnt, 1);
2118 return new;
2119}
2120
2121/* Slow path of a mempolicy comparison */
2122bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
2123{
2124 if (!a || !b)
2125 return false;
2126 if (a->mode != b->mode)
2127 return false;
2128 if (a->flags != b->flags)
2129 return false;
2130 if (mpol_store_user_nodemask(a))
2131 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
2132 return false;
2133
2134 switch (a->mode) {
2135 case MPOL_BIND:
2136 /* Fall through */
2137 case MPOL_INTERLEAVE:
2138 return !!nodes_equal(a->v.nodes, b->v.nodes);
2139 case MPOL_PREFERRED:
2140 return a->v.preferred_node == b->v.preferred_node;
2141 default:
2142 BUG();
2143 return false;
2144 }
2145}
2146
2147/*
2148 * Shared memory backing store policy support.
2149 *
2150 * Remember policies even when nobody has shared memory mapped.
2151 * The policies are kept in Red-Black tree linked from the inode.
2152 * They are protected by the sp->lock rwlock, which should be held
2153 * for any accesses to the tree.
2154 */
2155
2156/*
2157 * lookup first element intersecting start-end. Caller holds sp->lock for
2158 * reading or for writing
2159 */
2160static struct sp_node *
2161sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
2162{
2163 struct rb_node *n = sp->root.rb_node;
2164
2165 while (n) {
2166 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2167
2168 if (start >= p->end)
2169 n = n->rb_right;
2170 else if (end <= p->start)
2171 n = n->rb_left;
2172 else
2173 break;
2174 }
2175 if (!n)
2176 return NULL;
2177 for (;;) {
2178 struct sp_node *w = NULL;
2179 struct rb_node *prev = rb_prev(n);
2180 if (!prev)
2181 break;
2182 w = rb_entry(prev, struct sp_node, nd);
2183 if (w->end <= start)
2184 break;
2185 n = prev;
2186 }
2187 return rb_entry(n, struct sp_node, nd);
2188}
2189
2190/*
2191 * Insert a new shared policy into the list. Caller holds sp->lock for
2192 * writing.
2193 */
2194static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2195{
2196 struct rb_node **p = &sp->root.rb_node;
2197 struct rb_node *parent = NULL;
2198 struct sp_node *nd;
2199
2200 while (*p) {
2201 parent = *p;
2202 nd = rb_entry(parent, struct sp_node, nd);
2203 if (new->start < nd->start)
2204 p = &(*p)->rb_left;
2205 else if (new->end > nd->end)
2206 p = &(*p)->rb_right;
2207 else
2208 BUG();
2209 }
2210 rb_link_node(&new->nd, parent, p);
2211 rb_insert_color(&new->nd, &sp->root);
2212 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
2213 new->policy ? new->policy->mode : 0);
2214}
2215
2216/* Find shared policy intersecting idx */
2217struct mempolicy *
2218mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2219{
2220 struct mempolicy *pol = NULL;
2221 struct sp_node *sn;
2222
2223 if (!sp->root.rb_node)
2224 return NULL;
2225 read_lock(&sp->lock);
2226 sn = sp_lookup(sp, idx, idx+1);
2227 if (sn) {
2228 mpol_get(sn->policy);
2229 pol = sn->policy;
2230 }
2231 read_unlock(&sp->lock);
2232 return pol;
2233}
2234
2235static void sp_free(struct sp_node *n)
2236{
2237 mpol_put(n->policy);
2238 kmem_cache_free(sn_cache, n);
2239}
2240
2241/**
2242 * mpol_misplaced - check whether current page node is valid in policy
2243 *
2244 * @page: page to be checked
2245 * @vma: vm area where page mapped
2246 * @addr: virtual address where page mapped
2247 *
2248 * Lookup current policy node id for vma,addr and "compare to" page's
2249 * node id.
2250 *
2251 * Returns:
2252 * -1 - not misplaced, page is in the right node
2253 * node - node id where the page should be
2254 *
2255 * Policy determination "mimics" alloc_page_vma().
2256 * Called from fault path where we know the vma and faulting address.
2257 */
2258int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
2259{
2260 struct mempolicy *pol;
2261 struct zoneref *z;
2262 int curnid = page_to_nid(page);
2263 unsigned long pgoff;
2264 int thiscpu = raw_smp_processor_id();
2265 int thisnid = cpu_to_node(thiscpu);
2266 int polnid = -1;
2267 int ret = -1;
2268
2269 BUG_ON(!vma);
2270
2271 pol = get_vma_policy(vma, addr);
2272 if (!(pol->flags & MPOL_F_MOF))
2273 goto out;
2274
2275 switch (pol->mode) {
2276 case MPOL_INTERLEAVE:
2277 BUG_ON(addr >= vma->vm_end);
2278 BUG_ON(addr < vma->vm_start);
2279
2280 pgoff = vma->vm_pgoff;
2281 pgoff += (addr - vma->vm_start) >> PAGE_SHIFT;
2282 polnid = offset_il_node(pol, vma, pgoff);
2283 break;
2284
2285 case MPOL_PREFERRED:
2286 if (pol->flags & MPOL_F_LOCAL)
2287 polnid = numa_node_id();
2288 else
2289 polnid = pol->v.preferred_node;
2290 break;
2291
2292 case MPOL_BIND:
2293
2294 /*
2295 * allows binding to multiple nodes.
2296 * use current page if in policy nodemask,
2297 * else select nearest allowed node, if any.
2298 * If no allowed nodes, use current [!misplaced].
2299 */
2300 if (node_isset(curnid, pol->v.nodes))
2301 goto out;
2302 z = first_zones_zonelist(
2303 node_zonelist(numa_node_id(), GFP_HIGHUSER),
2304 gfp_zone(GFP_HIGHUSER),
2305 &pol->v.nodes);
2306 polnid = z->zone->node;
2307 break;
2308
2309 default:
2310 BUG();
2311 }
2312
2313 /* Migrate the page towards the node whose CPU is referencing it */
2314 if (pol->flags & MPOL_F_MORON) {
2315 polnid = thisnid;
2316
2317 if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
2318 goto out;
2319 }
2320
2321 if (curnid != polnid)
2322 ret = polnid;
2323out:
2324 mpol_cond_put(pol);
2325
2326 return ret;
2327}
2328
2329/*
2330 * Drop the (possibly final) reference to task->mempolicy. It needs to be
2331 * dropped after task->mempolicy is set to NULL so that any allocation done as
2332 * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed
2333 * policy.
2334 */
2335void mpol_put_task_policy(struct task_struct *task)
2336{
2337 struct mempolicy *pol;
2338
2339 task_lock(task);
2340 pol = task->mempolicy;
2341 task->mempolicy = NULL;
2342 task_unlock(task);
2343 mpol_put(pol);
2344}
2345
2346static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2347{
2348 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
2349 rb_erase(&n->nd, &sp->root);
2350 sp_free(n);
2351}
2352
2353static void sp_node_init(struct sp_node *node, unsigned long start,
2354 unsigned long end, struct mempolicy *pol)
2355{
2356 node->start = start;
2357 node->end = end;
2358 node->policy = pol;
2359}
2360
2361static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2362 struct mempolicy *pol)
2363{
2364 struct sp_node *n;
2365 struct mempolicy *newpol;
2366
2367 n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2368 if (!n)
2369 return NULL;
2370
2371 newpol = mpol_dup(pol);
2372 if (IS_ERR(newpol)) {
2373 kmem_cache_free(sn_cache, n);
2374 return NULL;
2375 }
2376 newpol->flags |= MPOL_F_SHARED;
2377 sp_node_init(n, start, end, newpol);
2378
2379 return n;
2380}
2381
2382/* Replace a policy range. */
2383static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2384 unsigned long end, struct sp_node *new)
2385{
2386 struct sp_node *n;
2387 struct sp_node *n_new = NULL;
2388 struct mempolicy *mpol_new = NULL;
2389 int ret = 0;
2390
2391restart:
2392 write_lock(&sp->lock);
2393 n = sp_lookup(sp, start, end);
2394 /* Take care of old policies in the same range. */
2395 while (n && n->start < end) {
2396 struct rb_node *next = rb_next(&n->nd);
2397 if (n->start >= start) {
2398 if (n->end <= end)
2399 sp_delete(sp, n);
2400 else
2401 n->start = end;
2402 } else {
2403 /* Old policy spanning whole new range. */
2404 if (n->end > end) {
2405 if (!n_new)
2406 goto alloc_new;
2407
2408 *mpol_new = *n->policy;
2409 atomic_set(&mpol_new->refcnt, 1);
2410 sp_node_init(n_new, end, n->end, mpol_new);
2411 n->end = start;
2412 sp_insert(sp, n_new);
2413 n_new = NULL;
2414 mpol_new = NULL;
2415 break;
2416 } else
2417 n->end = start;
2418 }
2419 if (!next)
2420 break;
2421 n = rb_entry(next, struct sp_node, nd);
2422 }
2423 if (new)
2424 sp_insert(sp, new);
2425 write_unlock(&sp->lock);
2426 ret = 0;
2427
2428err_out:
2429 if (mpol_new)
2430 mpol_put(mpol_new);
2431 if (n_new)
2432 kmem_cache_free(sn_cache, n_new);
2433
2434 return ret;
2435
2436alloc_new:
2437 write_unlock(&sp->lock);
2438 ret = -ENOMEM;
2439 n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2440 if (!n_new)
2441 goto err_out;
2442 mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2443 if (!mpol_new)
2444 goto err_out;
2445 goto restart;
2446}
2447
2448/**
2449 * mpol_shared_policy_init - initialize shared policy for inode
2450 * @sp: pointer to inode shared policy
2451 * @mpol: struct mempolicy to install
2452 *
2453 * Install non-NULL @mpol in inode's shared policy rb-tree.
2454 * On entry, the current task has a reference on a non-NULL @mpol.
2455 * This must be released on exit.
2456 * This is called at get_inode() calls and we can use GFP_KERNEL.
2457 */
2458void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
2459{
2460 int ret;
2461
2462 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2463 rwlock_init(&sp->lock);
2464
2465 if (mpol) {
2466 struct vm_area_struct pvma;
2467 struct mempolicy *new;
2468 NODEMASK_SCRATCH(scratch);
2469
2470 if (!scratch)
2471 goto put_mpol;
2472 /* contextualize the tmpfs mount point mempolicy */
2473 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2474 if (IS_ERR(new))
2475 goto free_scratch; /* no valid nodemask intersection */
2476
2477 task_lock(current);
2478 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
2479 task_unlock(current);
2480 if (ret)
2481 goto put_new;
2482
2483 /* Create pseudo-vma that contains just the policy */
2484 memset(&pvma, 0, sizeof(struct vm_area_struct));
2485 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2486 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
2487
2488put_new:
2489 mpol_put(new); /* drop initial ref */
2490free_scratch:
2491 NODEMASK_SCRATCH_FREE(scratch);
2492put_mpol:
2493 mpol_put(mpol); /* drop our incoming ref on sb mpol */
2494 }
2495}
2496
2497int mpol_set_shared_policy(struct shared_policy *info,
2498 struct vm_area_struct *vma, struct mempolicy *npol)
2499{
2500 int err;
2501 struct sp_node *new = NULL;
2502 unsigned long sz = vma_pages(vma);
2503
2504 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
2505 vma->vm_pgoff,
2506 sz, npol ? npol->mode : -1,
2507 npol ? npol->flags : -1,
2508 npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
2509
2510 if (npol) {
2511 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2512 if (!new)
2513 return -ENOMEM;
2514 }
2515 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2516 if (err && new)
2517 sp_free(new);
2518 return err;
2519}
2520
2521/* Free a backing policy store on inode delete. */
2522void mpol_free_shared_policy(struct shared_policy *p)
2523{
2524 struct sp_node *n;
2525 struct rb_node *next;
2526
2527 if (!p->root.rb_node)
2528 return;
2529 write_lock(&p->lock);
2530 next = rb_first(&p->root);
2531 while (next) {
2532 n = rb_entry(next, struct sp_node, nd);
2533 next = rb_next(&n->nd);
2534 sp_delete(p, n);
2535 }
2536 write_unlock(&p->lock);
2537}
2538
2539#ifdef CONFIG_NUMA_BALANCING
2540static int __initdata numabalancing_override;
2541
2542static void __init check_numabalancing_enable(void)
2543{
2544 bool numabalancing_default = false;
2545
2546 if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
2547 numabalancing_default = true;
2548
2549 /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
2550 if (numabalancing_override)
2551 set_numabalancing_state(numabalancing_override == 1);
2552
2553 if (num_online_nodes() > 1 && !numabalancing_override) {
2554 pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n",
2555 numabalancing_default ? "Enabling" : "Disabling");
2556 set_numabalancing_state(numabalancing_default);
2557 }
2558}
2559
2560static int __init setup_numabalancing(char *str)
2561{
2562 int ret = 0;
2563 if (!str)
2564 goto out;
2565
2566 if (!strcmp(str, "enable")) {
2567 numabalancing_override = 1;
2568 ret = 1;
2569 } else if (!strcmp(str, "disable")) {
2570 numabalancing_override = -1;
2571 ret = 1;
2572 }
2573out:
2574 if (!ret)
2575 pr_warn("Unable to parse numa_balancing=\n");
2576
2577 return ret;
2578}
2579__setup("numa_balancing=", setup_numabalancing);
2580#else
2581static inline void __init check_numabalancing_enable(void)
2582{
2583}
2584#endif /* CONFIG_NUMA_BALANCING */
2585
2586/* assumes fs == KERNEL_DS */
2587void __init numa_policy_init(void)
2588{
2589 nodemask_t interleave_nodes;
2590 unsigned long largest = 0;
2591 int nid, prefer = 0;
2592
2593 policy_cache = kmem_cache_create("numa_policy",
2594 sizeof(struct mempolicy),
2595 0, SLAB_PANIC, NULL);
2596
2597 sn_cache = kmem_cache_create("shared_policy_node",
2598 sizeof(struct sp_node),
2599 0, SLAB_PANIC, NULL);
2600
2601 for_each_node(nid) {
2602 preferred_node_policy[nid] = (struct mempolicy) {
2603 .refcnt = ATOMIC_INIT(1),
2604 .mode = MPOL_PREFERRED,
2605 .flags = MPOL_F_MOF | MPOL_F_MORON,
2606 .v = { .preferred_node = nid, },
2607 };
2608 }
2609
2610 /*
2611 * Set interleaving policy for system init. Interleaving is only
2612 * enabled across suitably sized nodes (default is >= 16MB), or
2613 * fall back to the largest node if they're all smaller.
2614 */
2615 nodes_clear(interleave_nodes);
2616 for_each_node_state(nid, N_MEMORY) {
2617 unsigned long total_pages = node_present_pages(nid);
2618
2619 /* Preserve the largest node */
2620 if (largest < total_pages) {
2621 largest = total_pages;
2622 prefer = nid;
2623 }
2624
2625 /* Interleave this node? */
2626 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2627 node_set(nid, interleave_nodes);
2628 }
2629
2630 /* All too small, use the largest */
2631 if (unlikely(nodes_empty(interleave_nodes)))
2632 node_set(prefer, interleave_nodes);
2633
2634 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
2635 pr_err("%s: interleaving failed\n", __func__);
2636
2637 check_numabalancing_enable();
2638}
2639
2640/* Reset policy of current process to default */
2641void numa_default_policy(void)
2642{
2643 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
2644}
2645
2646/*
2647 * Parse and format mempolicy from/to strings
2648 */
2649
2650/*
2651 * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
2652 */
2653static const char * const policy_modes[] =
2654{
2655 [MPOL_DEFAULT] = "default",
2656 [MPOL_PREFERRED] = "prefer",
2657 [MPOL_BIND] = "bind",
2658 [MPOL_INTERLEAVE] = "interleave",
2659 [MPOL_LOCAL] = "local",
2660};
2661
2662
2663#ifdef CONFIG_TMPFS
2664/**
2665 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
2666 * @str: string containing mempolicy to parse
2667 * @mpol: pointer to struct mempolicy pointer, returned on success.
2668 *
2669 * Format of input:
2670 * <mode>[=<flags>][:<nodelist>]
2671 *
2672 * On success, returns 0, else 1
2673 */
2674int mpol_parse_str(char *str, struct mempolicy **mpol)
2675{
2676 struct mempolicy *new = NULL;
2677 unsigned short mode;
2678 unsigned short mode_flags;
2679 nodemask_t nodes;
2680 char *nodelist = strchr(str, ':');
2681 char *flags = strchr(str, '=');
2682 int err = 1;
2683
2684 if (nodelist) {
2685 /* NUL-terminate mode or flags string */
2686 *nodelist++ = '\0';
2687 if (nodelist_parse(nodelist, nodes))
2688 goto out;
2689 if (!nodes_subset(nodes, node_states[N_MEMORY]))
2690 goto out;
2691 } else
2692 nodes_clear(nodes);
2693
2694 if (flags)
2695 *flags++ = '\0'; /* terminate mode string */
2696
2697 for (mode = 0; mode < MPOL_MAX; mode++) {
2698 if (!strcmp(str, policy_modes[mode])) {
2699 break;
2700 }
2701 }
2702 if (mode >= MPOL_MAX)
2703 goto out;
2704
2705 switch (mode) {
2706 case MPOL_PREFERRED:
2707 /*
2708 * Insist on a nodelist of one node only
2709 */
2710 if (nodelist) {
2711 char *rest = nodelist;
2712 while (isdigit(*rest))
2713 rest++;
2714 if (*rest)
2715 goto out;
2716 }
2717 break;
2718 case MPOL_INTERLEAVE:
2719 /*
2720 * Default to online nodes with memory if no nodelist
2721 */
2722 if (!nodelist)
2723 nodes = node_states[N_MEMORY];
2724 break;
2725 case MPOL_LOCAL:
2726 /*
2727 * Don't allow a nodelist; mpol_new() checks flags
2728 */
2729 if (nodelist)
2730 goto out;
2731 mode = MPOL_PREFERRED;
2732 break;
2733 case MPOL_DEFAULT:
2734 /*
2735 * Insist on a empty nodelist
2736 */
2737 if (!nodelist)
2738 err = 0;
2739 goto out;
2740 case MPOL_BIND:
2741 /*
2742 * Insist on a nodelist
2743 */
2744 if (!nodelist)
2745 goto out;
2746 }
2747
2748 mode_flags = 0;
2749 if (flags) {
2750 /*
2751 * Currently, we only support two mutually exclusive
2752 * mode flags.
2753 */
2754 if (!strcmp(flags, "static"))
2755 mode_flags |= MPOL_F_STATIC_NODES;
2756 else if (!strcmp(flags, "relative"))
2757 mode_flags |= MPOL_F_RELATIVE_NODES;
2758 else
2759 goto out;
2760 }
2761
2762 new = mpol_new(mode, mode_flags, &nodes);
2763 if (IS_ERR(new))
2764 goto out;
2765
2766 /*
2767 * Save nodes for mpol_to_str() to show the tmpfs mount options
2768 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
2769 */
2770 if (mode != MPOL_PREFERRED)
2771 new->v.nodes = nodes;
2772 else if (nodelist)
2773 new->v.preferred_node = first_node(nodes);
2774 else
2775 new->flags |= MPOL_F_LOCAL;
2776
2777 /*
2778 * Save nodes for contextualization: this will be used to "clone"
2779 * the mempolicy in a specific context [cpuset] at a later time.
2780 */
2781 new->w.user_nodemask = nodes;
2782
2783 err = 0;
2784
2785out:
2786 /* Restore string for error message */
2787 if (nodelist)
2788 *--nodelist = ':';
2789 if (flags)
2790 *--flags = '=';
2791 if (!err)
2792 *mpol = new;
2793 return err;
2794}
2795#endif /* CONFIG_TMPFS */
2796
2797/**
2798 * mpol_to_str - format a mempolicy structure for printing
2799 * @buffer: to contain formatted mempolicy string
2800 * @maxlen: length of @buffer
2801 * @pol: pointer to mempolicy to be formatted
2802 *
2803 * Convert @pol into a string. If @buffer is too short, truncate the string.
2804 * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
2805 * longest flag, "relative", and to display at least a few node ids.
2806 */
2807void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
2808{
2809 char *p = buffer;
2810 nodemask_t nodes = NODE_MASK_NONE;
2811 unsigned short mode = MPOL_DEFAULT;
2812 unsigned short flags = 0;
2813
2814 if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) {
2815 mode = pol->mode;
2816 flags = pol->flags;
2817 }
2818
2819 switch (mode) {
2820 case MPOL_DEFAULT:
2821 break;
2822 case MPOL_PREFERRED:
2823 if (flags & MPOL_F_LOCAL)
2824 mode = MPOL_LOCAL;
2825 else
2826 node_set(pol->v.preferred_node, nodes);
2827 break;
2828 case MPOL_BIND:
2829 case MPOL_INTERLEAVE:
2830 nodes = pol->v.nodes;
2831 break;
2832 default:
2833 WARN_ON_ONCE(1);
2834 snprintf(p, maxlen, "unknown");
2835 return;
2836 }
2837
2838 p += snprintf(p, maxlen, "%s", policy_modes[mode]);
2839
2840 if (flags & MPOL_MODE_FLAGS) {
2841 p += snprintf(p, buffer + maxlen - p, "=");
2842
2843 /*
2844 * Currently, the only defined flags are mutually exclusive
2845 */
2846 if (flags & MPOL_F_STATIC_NODES)
2847 p += snprintf(p, buffer + maxlen - p, "static");
2848 else if (flags & MPOL_F_RELATIVE_NODES)
2849 p += snprintf(p, buffer + maxlen - p, "relative");
2850 }
2851
2852 if (!nodes_empty(nodes))
2853 p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
2854 nodemask_pr_args(&nodes));
2855}