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