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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// 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 six 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 * weighted interleave
23 * Allocate memory interleaved over a set of nodes based on
24 * a set of weights (per-node), with normal fallback if it
25 * fails. Otherwise operates the same as interleave.
26 * Example: nodeset(0,1) & weights (2,1) - 2 pages allocated
27 * on node 0 for every 1 page allocated on node 1.
28 *
29 * bind Only allocate memory on a specific set of nodes,
30 * no fallback.
31 * FIXME: memory is allocated starting with the first node
32 * to the last. It would be better if bind would truly restrict
33 * the allocation to memory nodes instead
34 *
35 * preferred Try a specific node first before normal fallback.
36 * As a special case NUMA_NO_NODE here means do the allocation
37 * on the local CPU. This is normally identical to default,
38 * but useful to set in a VMA when you have a non default
39 * process policy.
40 *
41 * preferred many Try a set of nodes first before normal fallback. This is
42 * similar to preferred without the special case.
43 *
44 * default Allocate on the local node first, or when on a VMA
45 * use the process policy. This is what Linux always did
46 * in a NUMA aware kernel and still does by, ahem, default.
47 *
48 * The process policy is applied for most non interrupt memory allocations
49 * in that process' context. Interrupts ignore the policies and always
50 * try to allocate on the local CPU. The VMA policy is only applied for memory
51 * allocations for a VMA in the VM.
52 *
53 * Currently there are a few corner cases in swapping where the policy
54 * is not applied, but the majority should be handled. When process policy
55 * is used it is not remembered over swap outs/swap ins.
56 *
57 * Only the highest zone in the zone hierarchy gets policied. Allocations
58 * requesting a lower zone just use default policy. This implies that
59 * on systems with highmem kernel lowmem allocation don't get policied.
60 * Same with GFP_DMA allocations.
61 *
62 * For shmem/tmpfs shared memory the policy is shared between
63 * all users and remembered even when nobody has memory mapped.
64 */
65
66/* Notebook:
67 fix mmap readahead to honour policy and enable policy for any page cache
68 object
69 statistics for bigpages
70 global policy for page cache? currently it uses process policy. Requires
71 first item above.
72 handle mremap for shared memory (currently ignored for the policy)
73 grows down?
74 make bind policy root only? It can trigger oom much faster and the
75 kernel is not always grateful with that.
76*/
77
78#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
79
80#include <linux/mempolicy.h>
81#include <linux/pagewalk.h>
82#include <linux/highmem.h>
83#include <linux/hugetlb.h>
84#include <linux/kernel.h>
85#include <linux/sched.h>
86#include <linux/sched/mm.h>
87#include <linux/sched/numa_balancing.h>
88#include <linux/sched/task.h>
89#include <linux/nodemask.h>
90#include <linux/cpuset.h>
91#include <linux/slab.h>
92#include <linux/string.h>
93#include <linux/export.h>
94#include <linux/nsproxy.h>
95#include <linux/interrupt.h>
96#include <linux/init.h>
97#include <linux/compat.h>
98#include <linux/ptrace.h>
99#include <linux/swap.h>
100#include <linux/seq_file.h>
101#include <linux/proc_fs.h>
102#include <linux/migrate.h>
103#include <linux/ksm.h>
104#include <linux/rmap.h>
105#include <linux/security.h>
106#include <linux/syscalls.h>
107#include <linux/ctype.h>
108#include <linux/mm_inline.h>
109#include <linux/mmu_notifier.h>
110#include <linux/printk.h>
111#include <linux/swapops.h>
112
113#include <asm/tlbflush.h>
114#include <asm/tlb.h>
115#include <linux/uaccess.h>
116
117#include "internal.h"
118
119/* Internal flags */
120#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
121#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
122#define MPOL_MF_WRLOCK (MPOL_MF_INTERNAL << 2) /* Write-lock walked vmas */
123
124static struct kmem_cache *policy_cache;
125static struct kmem_cache *sn_cache;
126
127/* Highest zone. An specific allocation for a zone below that is not
128 policied. */
129enum zone_type policy_zone = 0;
130
131/*
132 * run-time system-wide default policy => local allocation
133 */
134static struct mempolicy default_policy = {
135 .refcnt = ATOMIC_INIT(1), /* never free it */
136 .mode = MPOL_LOCAL,
137};
138
139static struct mempolicy preferred_node_policy[MAX_NUMNODES];
140
141/*
142 * iw_table is the sysfs-set interleave weight table, a value of 0 denotes
143 * system-default value should be used. A NULL iw_table also denotes that
144 * system-default values should be used. Until the system-default table
145 * is implemented, the system-default is always 1.
146 *
147 * iw_table is RCU protected
148 */
149static u8 __rcu *iw_table;
150static DEFINE_MUTEX(iw_table_lock);
151
152static u8 get_il_weight(int node)
153{
154 u8 *table;
155 u8 weight;
156
157 rcu_read_lock();
158 table = rcu_dereference(iw_table);
159 /* if no iw_table, use system default */
160 weight = table ? table[node] : 1;
161 /* if value in iw_table is 0, use system default */
162 weight = weight ? weight : 1;
163 rcu_read_unlock();
164 return weight;
165}
166
167/**
168 * numa_nearest_node - Find nearest node by state
169 * @node: Node id to start the search
170 * @state: State to filter the search
171 *
172 * Lookup the closest node by distance if @nid is not in state.
173 *
174 * Return: this @node if it is in state, otherwise the closest node by distance
175 */
176int numa_nearest_node(int node, unsigned int state)
177{
178 int min_dist = INT_MAX, dist, n, min_node;
179
180 if (state >= NR_NODE_STATES)
181 return -EINVAL;
182
183 if (node == NUMA_NO_NODE || node_state(node, state))
184 return node;
185
186 min_node = node;
187 for_each_node_state(n, state) {
188 dist = node_distance(node, n);
189 if (dist < min_dist) {
190 min_dist = dist;
191 min_node = n;
192 }
193 }
194
195 return min_node;
196}
197EXPORT_SYMBOL_GPL(numa_nearest_node);
198
199struct mempolicy *get_task_policy(struct task_struct *p)
200{
201 struct mempolicy *pol = p->mempolicy;
202 int node;
203
204 if (pol)
205 return pol;
206
207 node = numa_node_id();
208 if (node != NUMA_NO_NODE) {
209 pol = &preferred_node_policy[node];
210 /* preferred_node_policy is not initialised early in boot */
211 if (pol->mode)
212 return pol;
213 }
214
215 return &default_policy;
216}
217
218static const struct mempolicy_operations {
219 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
220 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes);
221} mpol_ops[MPOL_MAX];
222
223static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
224{
225 return pol->flags & MPOL_MODE_FLAGS;
226}
227
228static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
229 const nodemask_t *rel)
230{
231 nodemask_t tmp;
232 nodes_fold(tmp, *orig, nodes_weight(*rel));
233 nodes_onto(*ret, tmp, *rel);
234}
235
236static int mpol_new_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
237{
238 if (nodes_empty(*nodes))
239 return -EINVAL;
240 pol->nodes = *nodes;
241 return 0;
242}
243
244static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
245{
246 if (nodes_empty(*nodes))
247 return -EINVAL;
248
249 nodes_clear(pol->nodes);
250 node_set(first_node(*nodes), pol->nodes);
251 return 0;
252}
253
254/*
255 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
256 * any, for the new policy. mpol_new() has already validated the nodes
257 * parameter with respect to the policy mode and flags.
258 *
259 * Must be called holding task's alloc_lock to protect task's mems_allowed
260 * and mempolicy. May also be called holding the mmap_lock for write.
261 */
262static int mpol_set_nodemask(struct mempolicy *pol,
263 const nodemask_t *nodes, struct nodemask_scratch *nsc)
264{
265 int ret;
266
267 /*
268 * Default (pol==NULL) resp. local memory policies are not a
269 * subject of any remapping. They also do not need any special
270 * constructor.
271 */
272 if (!pol || pol->mode == MPOL_LOCAL)
273 return 0;
274
275 /* Check N_MEMORY */
276 nodes_and(nsc->mask1,
277 cpuset_current_mems_allowed, node_states[N_MEMORY]);
278
279 VM_BUG_ON(!nodes);
280
281 if (pol->flags & MPOL_F_RELATIVE_NODES)
282 mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
283 else
284 nodes_and(nsc->mask2, *nodes, nsc->mask1);
285
286 if (mpol_store_user_nodemask(pol))
287 pol->w.user_nodemask = *nodes;
288 else
289 pol->w.cpuset_mems_allowed = cpuset_current_mems_allowed;
290
291 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
292 return ret;
293}
294
295/*
296 * This function just creates a new policy, does some check and simple
297 * initialization. You must invoke mpol_set_nodemask() to set nodes.
298 */
299static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
300 nodemask_t *nodes)
301{
302 struct mempolicy *policy;
303
304 if (mode == MPOL_DEFAULT) {
305 if (nodes && !nodes_empty(*nodes))
306 return ERR_PTR(-EINVAL);
307 return NULL;
308 }
309 VM_BUG_ON(!nodes);
310
311 /*
312 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
313 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
314 * All other modes require a valid pointer to a non-empty nodemask.
315 */
316 if (mode == MPOL_PREFERRED) {
317 if (nodes_empty(*nodes)) {
318 if (((flags & MPOL_F_STATIC_NODES) ||
319 (flags & MPOL_F_RELATIVE_NODES)))
320 return ERR_PTR(-EINVAL);
321
322 mode = MPOL_LOCAL;
323 }
324 } else if (mode == MPOL_LOCAL) {
325 if (!nodes_empty(*nodes) ||
326 (flags & MPOL_F_STATIC_NODES) ||
327 (flags & MPOL_F_RELATIVE_NODES))
328 return ERR_PTR(-EINVAL);
329 } else if (nodes_empty(*nodes))
330 return ERR_PTR(-EINVAL);
331
332 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
333 if (!policy)
334 return ERR_PTR(-ENOMEM);
335 atomic_set(&policy->refcnt, 1);
336 policy->mode = mode;
337 policy->flags = flags;
338 policy->home_node = NUMA_NO_NODE;
339
340 return policy;
341}
342
343/* Slow path of a mpol destructor. */
344void __mpol_put(struct mempolicy *pol)
345{
346 if (!atomic_dec_and_test(&pol->refcnt))
347 return;
348 kmem_cache_free(policy_cache, pol);
349}
350
351static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
352{
353}
354
355static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
356{
357 nodemask_t tmp;
358
359 if (pol->flags & MPOL_F_STATIC_NODES)
360 nodes_and(tmp, pol->w.user_nodemask, *nodes);
361 else if (pol->flags & MPOL_F_RELATIVE_NODES)
362 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
363 else {
364 nodes_remap(tmp, pol->nodes, pol->w.cpuset_mems_allowed,
365 *nodes);
366 pol->w.cpuset_mems_allowed = *nodes;
367 }
368
369 if (nodes_empty(tmp))
370 tmp = *nodes;
371
372 pol->nodes = tmp;
373}
374
375static void mpol_rebind_preferred(struct mempolicy *pol,
376 const nodemask_t *nodes)
377{
378 pol->w.cpuset_mems_allowed = *nodes;
379}
380
381/*
382 * mpol_rebind_policy - Migrate a policy to a different set of nodes
383 *
384 * Per-vma policies are protected by mmap_lock. Allocations using per-task
385 * policies are protected by task->mems_allowed_seq to prevent a premature
386 * OOM/allocation failure due to parallel nodemask modification.
387 */
388static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
389{
390 if (!pol || pol->mode == MPOL_LOCAL)
391 return;
392 if (!mpol_store_user_nodemask(pol) &&
393 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
394 return;
395
396 mpol_ops[pol->mode].rebind(pol, newmask);
397}
398
399/*
400 * Wrapper for mpol_rebind_policy() that just requires task
401 * pointer, and updates task mempolicy.
402 *
403 * Called with task's alloc_lock held.
404 */
405void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
406{
407 mpol_rebind_policy(tsk->mempolicy, new);
408}
409
410/*
411 * Rebind each vma in mm to new nodemask.
412 *
413 * Call holding a reference to mm. Takes mm->mmap_lock during call.
414 */
415void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
416{
417 struct vm_area_struct *vma;
418 VMA_ITERATOR(vmi, mm, 0);
419
420 mmap_write_lock(mm);
421 for_each_vma(vmi, vma) {
422 vma_start_write(vma);
423 mpol_rebind_policy(vma->vm_policy, new);
424 }
425 mmap_write_unlock(mm);
426}
427
428static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
429 [MPOL_DEFAULT] = {
430 .rebind = mpol_rebind_default,
431 },
432 [MPOL_INTERLEAVE] = {
433 .create = mpol_new_nodemask,
434 .rebind = mpol_rebind_nodemask,
435 },
436 [MPOL_PREFERRED] = {
437 .create = mpol_new_preferred,
438 .rebind = mpol_rebind_preferred,
439 },
440 [MPOL_BIND] = {
441 .create = mpol_new_nodemask,
442 .rebind = mpol_rebind_nodemask,
443 },
444 [MPOL_LOCAL] = {
445 .rebind = mpol_rebind_default,
446 },
447 [MPOL_PREFERRED_MANY] = {
448 .create = mpol_new_nodemask,
449 .rebind = mpol_rebind_preferred,
450 },
451 [MPOL_WEIGHTED_INTERLEAVE] = {
452 .create = mpol_new_nodemask,
453 .rebind = mpol_rebind_nodemask,
454 },
455};
456
457static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist,
458 unsigned long flags);
459static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *pol,
460 pgoff_t ilx, int *nid);
461
462static bool strictly_unmovable(unsigned long flags)
463{
464 /*
465 * STRICT without MOVE flags lets do_mbind() fail immediately with -EIO
466 * if any misplaced page is found.
467 */
468 return (flags & (MPOL_MF_STRICT | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ==
469 MPOL_MF_STRICT;
470}
471
472struct migration_mpol { /* for alloc_migration_target_by_mpol() */
473 struct mempolicy *pol;
474 pgoff_t ilx;
475};
476
477struct queue_pages {
478 struct list_head *pagelist;
479 unsigned long flags;
480 nodemask_t *nmask;
481 unsigned long start;
482 unsigned long end;
483 struct vm_area_struct *first;
484 struct folio *large; /* note last large folio encountered */
485 long nr_failed; /* could not be isolated at this time */
486};
487
488/*
489 * Check if the folio's nid is in qp->nmask.
490 *
491 * If MPOL_MF_INVERT is set in qp->flags, check if the nid is
492 * in the invert of qp->nmask.
493 */
494static inline bool queue_folio_required(struct folio *folio,
495 struct queue_pages *qp)
496{
497 int nid = folio_nid(folio);
498 unsigned long flags = qp->flags;
499
500 return node_isset(nid, *qp->nmask) == !(flags & MPOL_MF_INVERT);
501}
502
503static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk)
504{
505 struct folio *folio;
506 struct queue_pages *qp = walk->private;
507
508 if (unlikely(is_pmd_migration_entry(*pmd))) {
509 qp->nr_failed++;
510 return;
511 }
512 folio = pmd_folio(*pmd);
513 if (is_huge_zero_folio(folio)) {
514 walk->action = ACTION_CONTINUE;
515 return;
516 }
517 if (!queue_folio_required(folio, qp))
518 return;
519 if (!(qp->flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ||
520 !vma_migratable(walk->vma) ||
521 !migrate_folio_add(folio, qp->pagelist, qp->flags))
522 qp->nr_failed++;
523}
524
525/*
526 * Scan through folios, checking if they satisfy the required conditions,
527 * moving them from LRU to local pagelist for migration if they do (or not).
528 *
529 * queue_folios_pte_range() has two possible return values:
530 * 0 - continue walking to scan for more, even if an existing folio on the
531 * wrong node could not be isolated and queued for migration.
532 * -EIO - only MPOL_MF_STRICT was specified, without MPOL_MF_MOVE or ..._ALL,
533 * and an existing folio was on a node that does not follow the policy.
534 */
535static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
536 unsigned long end, struct mm_walk *walk)
537{
538 struct vm_area_struct *vma = walk->vma;
539 struct folio *folio;
540 struct queue_pages *qp = walk->private;
541 unsigned long flags = qp->flags;
542 pte_t *pte, *mapped_pte;
543 pte_t ptent;
544 spinlock_t *ptl;
545
546 ptl = pmd_trans_huge_lock(pmd, vma);
547 if (ptl) {
548 queue_folios_pmd(pmd, walk);
549 spin_unlock(ptl);
550 goto out;
551 }
552
553 mapped_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
554 if (!pte) {
555 walk->action = ACTION_AGAIN;
556 return 0;
557 }
558 for (; addr != end; pte++, addr += PAGE_SIZE) {
559 ptent = ptep_get(pte);
560 if (pte_none(ptent))
561 continue;
562 if (!pte_present(ptent)) {
563 if (is_migration_entry(pte_to_swp_entry(ptent)))
564 qp->nr_failed++;
565 continue;
566 }
567 folio = vm_normal_folio(vma, addr, ptent);
568 if (!folio || folio_is_zone_device(folio))
569 continue;
570 /*
571 * vm_normal_folio() filters out zero pages, but there might
572 * still be reserved folios to skip, perhaps in a VDSO.
573 */
574 if (folio_test_reserved(folio))
575 continue;
576 if (!queue_folio_required(folio, qp))
577 continue;
578 if (folio_test_large(folio)) {
579 /*
580 * A large folio can only be isolated from LRU once,
581 * but may be mapped by many PTEs (and Copy-On-Write may
582 * intersperse PTEs of other, order 0, folios). This is
583 * a common case, so don't mistake it for failure (but
584 * there can be other cases of multi-mapped pages which
585 * this quick check does not help to filter out - and a
586 * search of the pagelist might grow to be prohibitive).
587 *
588 * migrate_pages(&pagelist) returns nr_failed folios, so
589 * check "large" now so that queue_pages_range() returns
590 * a comparable nr_failed folios. This does imply that
591 * if folio could not be isolated for some racy reason
592 * at its first PTE, later PTEs will not give it another
593 * chance of isolation; but keeps the accounting simple.
594 */
595 if (folio == qp->large)
596 continue;
597 qp->large = folio;
598 }
599 if (!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ||
600 !vma_migratable(vma) ||
601 !migrate_folio_add(folio, qp->pagelist, flags)) {
602 qp->nr_failed++;
603 if (strictly_unmovable(flags))
604 break;
605 }
606 }
607 pte_unmap_unlock(mapped_pte, ptl);
608 cond_resched();
609out:
610 if (qp->nr_failed && strictly_unmovable(flags))
611 return -EIO;
612 return 0;
613}
614
615static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
616 unsigned long addr, unsigned long end,
617 struct mm_walk *walk)
618{
619#ifdef CONFIG_HUGETLB_PAGE
620 struct queue_pages *qp = walk->private;
621 unsigned long flags = qp->flags;
622 struct folio *folio;
623 spinlock_t *ptl;
624 pte_t entry;
625
626 ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
627 entry = huge_ptep_get(walk->mm, addr, pte);
628 if (!pte_present(entry)) {
629 if (unlikely(is_hugetlb_entry_migration(entry)))
630 qp->nr_failed++;
631 goto unlock;
632 }
633 folio = pfn_folio(pte_pfn(entry));
634 if (!queue_folio_required(folio, qp))
635 goto unlock;
636 if (!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ||
637 !vma_migratable(walk->vma)) {
638 qp->nr_failed++;
639 goto unlock;
640 }
641 /*
642 * Unless MPOL_MF_MOVE_ALL, we try to avoid migrating a shared folio.
643 * Choosing not to migrate a shared folio is not counted as a failure.
644 *
645 * See folio_likely_mapped_shared() on possible imprecision when we
646 * cannot easily detect if a folio is shared.
647 */
648 if ((flags & MPOL_MF_MOVE_ALL) ||
649 (!folio_likely_mapped_shared(folio) && !hugetlb_pmd_shared(pte)))
650 if (!isolate_hugetlb(folio, qp->pagelist))
651 qp->nr_failed++;
652unlock:
653 spin_unlock(ptl);
654 if (qp->nr_failed && strictly_unmovable(flags))
655 return -EIO;
656#endif
657 return 0;
658}
659
660#ifdef CONFIG_NUMA_BALANCING
661/*
662 * This is used to mark a range of virtual addresses to be inaccessible.
663 * These are later cleared by a NUMA hinting fault. Depending on these
664 * faults, pages may be migrated for better NUMA placement.
665 *
666 * This is assuming that NUMA faults are handled using PROT_NONE. If
667 * an architecture makes a different choice, it will need further
668 * changes to the core.
669 */
670unsigned long change_prot_numa(struct vm_area_struct *vma,
671 unsigned long addr, unsigned long end)
672{
673 struct mmu_gather tlb;
674 long nr_updated;
675
676 tlb_gather_mmu(&tlb, vma->vm_mm);
677
678 nr_updated = change_protection(&tlb, vma, addr, end, MM_CP_PROT_NUMA);
679 if (nr_updated > 0) {
680 count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
681 count_memcg_events_mm(vma->vm_mm, NUMA_PTE_UPDATES, nr_updated);
682 }
683
684 tlb_finish_mmu(&tlb);
685
686 return nr_updated;
687}
688#endif /* CONFIG_NUMA_BALANCING */
689
690static int queue_pages_test_walk(unsigned long start, unsigned long end,
691 struct mm_walk *walk)
692{
693 struct vm_area_struct *next, *vma = walk->vma;
694 struct queue_pages *qp = walk->private;
695 unsigned long flags = qp->flags;
696
697 /* range check first */
698 VM_BUG_ON_VMA(!range_in_vma(vma, start, end), vma);
699
700 if (!qp->first) {
701 qp->first = vma;
702 if (!(flags & MPOL_MF_DISCONTIG_OK) &&
703 (qp->start < vma->vm_start))
704 /* hole at head side of range */
705 return -EFAULT;
706 }
707 next = find_vma(vma->vm_mm, vma->vm_end);
708 if (!(flags & MPOL_MF_DISCONTIG_OK) &&
709 ((vma->vm_end < qp->end) &&
710 (!next || vma->vm_end < next->vm_start)))
711 /* hole at middle or tail of range */
712 return -EFAULT;
713
714 /*
715 * Need check MPOL_MF_STRICT to return -EIO if possible
716 * regardless of vma_migratable
717 */
718 if (!vma_migratable(vma) &&
719 !(flags & MPOL_MF_STRICT))
720 return 1;
721
722 /*
723 * Check page nodes, and queue pages to move, in the current vma.
724 * But if no moving, and no strict checking, the scan can be skipped.
725 */
726 if (flags & (MPOL_MF_STRICT | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
727 return 0;
728 return 1;
729}
730
731static const struct mm_walk_ops queue_pages_walk_ops = {
732 .hugetlb_entry = queue_folios_hugetlb,
733 .pmd_entry = queue_folios_pte_range,
734 .test_walk = queue_pages_test_walk,
735 .walk_lock = PGWALK_RDLOCK,
736};
737
738static const struct mm_walk_ops queue_pages_lock_vma_walk_ops = {
739 .hugetlb_entry = queue_folios_hugetlb,
740 .pmd_entry = queue_folios_pte_range,
741 .test_walk = queue_pages_test_walk,
742 .walk_lock = PGWALK_WRLOCK,
743};
744
745/*
746 * Walk through page tables and collect pages to be migrated.
747 *
748 * If pages found in a given range are not on the required set of @nodes,
749 * and migration is allowed, they are isolated and queued to @pagelist.
750 *
751 * queue_pages_range() may return:
752 * 0 - all pages already on the right node, or successfully queued for moving
753 * (or neither strict checking nor moving requested: only range checking).
754 * >0 - this number of misplaced folios could not be queued for moving
755 * (a hugetlbfs page or a transparent huge page being counted as 1).
756 * -EIO - a misplaced page found, when MPOL_MF_STRICT specified without MOVEs.
757 * -EFAULT - a hole in the memory range, when MPOL_MF_DISCONTIG_OK unspecified.
758 */
759static long
760queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
761 nodemask_t *nodes, unsigned long flags,
762 struct list_head *pagelist)
763{
764 int err;
765 struct queue_pages qp = {
766 .pagelist = pagelist,
767 .flags = flags,
768 .nmask = nodes,
769 .start = start,
770 .end = end,
771 .first = NULL,
772 };
773 const struct mm_walk_ops *ops = (flags & MPOL_MF_WRLOCK) ?
774 &queue_pages_lock_vma_walk_ops : &queue_pages_walk_ops;
775
776 err = walk_page_range(mm, start, end, ops, &qp);
777
778 if (!qp.first)
779 /* whole range in hole */
780 err = -EFAULT;
781
782 return err ? : qp.nr_failed;
783}
784
785/*
786 * Apply policy to a single VMA
787 * This must be called with the mmap_lock held for writing.
788 */
789static int vma_replace_policy(struct vm_area_struct *vma,
790 struct mempolicy *pol)
791{
792 int err;
793 struct mempolicy *old;
794 struct mempolicy *new;
795
796 vma_assert_write_locked(vma);
797
798 new = mpol_dup(pol);
799 if (IS_ERR(new))
800 return PTR_ERR(new);
801
802 if (vma->vm_ops && vma->vm_ops->set_policy) {
803 err = vma->vm_ops->set_policy(vma, new);
804 if (err)
805 goto err_out;
806 }
807
808 old = vma->vm_policy;
809 vma->vm_policy = new; /* protected by mmap_lock */
810 mpol_put(old);
811
812 return 0;
813 err_out:
814 mpol_put(new);
815 return err;
816}
817
818/* Split or merge the VMA (if required) and apply the new policy */
819static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma,
820 struct vm_area_struct **prev, unsigned long start,
821 unsigned long end, struct mempolicy *new_pol)
822{
823 unsigned long vmstart, vmend;
824
825 vmend = min(end, vma->vm_end);
826 if (start > vma->vm_start) {
827 *prev = vma;
828 vmstart = start;
829 } else {
830 vmstart = vma->vm_start;
831 }
832
833 if (mpol_equal(vma->vm_policy, new_pol)) {
834 *prev = vma;
835 return 0;
836 }
837
838 vma = vma_modify_policy(vmi, *prev, vma, vmstart, vmend, new_pol);
839 if (IS_ERR(vma))
840 return PTR_ERR(vma);
841
842 *prev = vma;
843 return vma_replace_policy(vma, new_pol);
844}
845
846/* Set the process memory policy */
847static long do_set_mempolicy(unsigned short mode, unsigned short flags,
848 nodemask_t *nodes)
849{
850 struct mempolicy *new, *old;
851 NODEMASK_SCRATCH(scratch);
852 int ret;
853
854 if (!scratch)
855 return -ENOMEM;
856
857 new = mpol_new(mode, flags, nodes);
858 if (IS_ERR(new)) {
859 ret = PTR_ERR(new);
860 goto out;
861 }
862
863 task_lock(current);
864 ret = mpol_set_nodemask(new, nodes, scratch);
865 if (ret) {
866 task_unlock(current);
867 mpol_put(new);
868 goto out;
869 }
870
871 old = current->mempolicy;
872 current->mempolicy = new;
873 if (new && (new->mode == MPOL_INTERLEAVE ||
874 new->mode == MPOL_WEIGHTED_INTERLEAVE)) {
875 current->il_prev = MAX_NUMNODES-1;
876 current->il_weight = 0;
877 }
878 task_unlock(current);
879 mpol_put(old);
880 ret = 0;
881out:
882 NODEMASK_SCRATCH_FREE(scratch);
883 return ret;
884}
885
886/*
887 * Return nodemask for policy for get_mempolicy() query
888 *
889 * Called with task's alloc_lock held
890 */
891static void get_policy_nodemask(struct mempolicy *pol, nodemask_t *nodes)
892{
893 nodes_clear(*nodes);
894 if (pol == &default_policy)
895 return;
896
897 switch (pol->mode) {
898 case MPOL_BIND:
899 case MPOL_INTERLEAVE:
900 case MPOL_PREFERRED:
901 case MPOL_PREFERRED_MANY:
902 case MPOL_WEIGHTED_INTERLEAVE:
903 *nodes = pol->nodes;
904 break;
905 case MPOL_LOCAL:
906 /* return empty node mask for local allocation */
907 break;
908 default:
909 BUG();
910 }
911}
912
913static int lookup_node(struct mm_struct *mm, unsigned long addr)
914{
915 struct page *p = NULL;
916 int ret;
917
918 ret = get_user_pages_fast(addr & PAGE_MASK, 1, 0, &p);
919 if (ret > 0) {
920 ret = page_to_nid(p);
921 put_page(p);
922 }
923 return ret;
924}
925
926/* Retrieve NUMA policy */
927static long do_get_mempolicy(int *policy, nodemask_t *nmask,
928 unsigned long addr, unsigned long flags)
929{
930 int err;
931 struct mm_struct *mm = current->mm;
932 struct vm_area_struct *vma = NULL;
933 struct mempolicy *pol = current->mempolicy, *pol_refcount = NULL;
934
935 if (flags &
936 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
937 return -EINVAL;
938
939 if (flags & MPOL_F_MEMS_ALLOWED) {
940 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
941 return -EINVAL;
942 *policy = 0; /* just so it's initialized */
943 task_lock(current);
944 *nmask = cpuset_current_mems_allowed;
945 task_unlock(current);
946 return 0;
947 }
948
949 if (flags & MPOL_F_ADDR) {
950 pgoff_t ilx; /* ignored here */
951 /*
952 * Do NOT fall back to task policy if the
953 * vma/shared policy at addr is NULL. We
954 * want to return MPOL_DEFAULT in this case.
955 */
956 mmap_read_lock(mm);
957 vma = vma_lookup(mm, addr);
958 if (!vma) {
959 mmap_read_unlock(mm);
960 return -EFAULT;
961 }
962 pol = __get_vma_policy(vma, addr, &ilx);
963 } else if (addr)
964 return -EINVAL;
965
966 if (!pol)
967 pol = &default_policy; /* indicates default behavior */
968
969 if (flags & MPOL_F_NODE) {
970 if (flags & MPOL_F_ADDR) {
971 /*
972 * Take a refcount on the mpol, because we are about to
973 * drop the mmap_lock, after which only "pol" remains
974 * valid, "vma" is stale.
975 */
976 pol_refcount = pol;
977 vma = NULL;
978 mpol_get(pol);
979 mmap_read_unlock(mm);
980 err = lookup_node(mm, addr);
981 if (err < 0)
982 goto out;
983 *policy = err;
984 } else if (pol == current->mempolicy &&
985 pol->mode == MPOL_INTERLEAVE) {
986 *policy = next_node_in(current->il_prev, pol->nodes);
987 } else if (pol == current->mempolicy &&
988 pol->mode == MPOL_WEIGHTED_INTERLEAVE) {
989 if (current->il_weight)
990 *policy = current->il_prev;
991 else
992 *policy = next_node_in(current->il_prev,
993 pol->nodes);
994 } else {
995 err = -EINVAL;
996 goto out;
997 }
998 } else {
999 *policy = pol == &default_policy ? MPOL_DEFAULT :
1000 pol->mode;
1001 /*
1002 * Internal mempolicy flags must be masked off before exposing
1003 * the policy to userspace.
1004 */
1005 *policy |= (pol->flags & MPOL_MODE_FLAGS);
1006 }
1007
1008 err = 0;
1009 if (nmask) {
1010 if (mpol_store_user_nodemask(pol)) {
1011 *nmask = pol->w.user_nodemask;
1012 } else {
1013 task_lock(current);
1014 get_policy_nodemask(pol, nmask);
1015 task_unlock(current);
1016 }
1017 }
1018
1019 out:
1020 mpol_cond_put(pol);
1021 if (vma)
1022 mmap_read_unlock(mm);
1023 if (pol_refcount)
1024 mpol_put(pol_refcount);
1025 return err;
1026}
1027
1028#ifdef CONFIG_MIGRATION
1029static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist,
1030 unsigned long flags)
1031{
1032 /*
1033 * Unless MPOL_MF_MOVE_ALL, we try to avoid migrating a shared folio.
1034 * Choosing not to migrate a shared folio is not counted as a failure.
1035 *
1036 * See folio_likely_mapped_shared() on possible imprecision when we
1037 * cannot easily detect if a folio is shared.
1038 */
1039 if ((flags & MPOL_MF_MOVE_ALL) || !folio_likely_mapped_shared(folio)) {
1040 if (folio_isolate_lru(folio)) {
1041 list_add_tail(&folio->lru, foliolist);
1042 node_stat_mod_folio(folio,
1043 NR_ISOLATED_ANON + folio_is_file_lru(folio),
1044 folio_nr_pages(folio));
1045 } else {
1046 /*
1047 * Non-movable folio may reach here. And, there may be
1048 * temporary off LRU folios or non-LRU movable folios.
1049 * Treat them as unmovable folios since they can't be
1050 * isolated, so they can't be moved at the moment.
1051 */
1052 return false;
1053 }
1054 }
1055 return true;
1056}
1057
1058/*
1059 * Migrate pages from one node to a target node.
1060 * Returns error or the number of pages not migrated.
1061 */
1062static long migrate_to_node(struct mm_struct *mm, int source, int dest,
1063 int flags)
1064{
1065 nodemask_t nmask;
1066 struct vm_area_struct *vma;
1067 LIST_HEAD(pagelist);
1068 long nr_failed;
1069 long err = 0;
1070 struct migration_target_control mtc = {
1071 .nid = dest,
1072 .gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
1073 .reason = MR_SYSCALL,
1074 };
1075
1076 nodes_clear(nmask);
1077 node_set(source, nmask);
1078
1079 VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
1080
1081 mmap_read_lock(mm);
1082 vma = find_vma(mm, 0);
1083 if (unlikely(!vma)) {
1084 mmap_read_unlock(mm);
1085 return 0;
1086 }
1087
1088 /*
1089 * This does not migrate the range, but isolates all pages that
1090 * need migration. Between passing in the full user address
1091 * space range and MPOL_MF_DISCONTIG_OK, this call cannot fail,
1092 * but passes back the count of pages which could not be isolated.
1093 */
1094 nr_failed = queue_pages_range(mm, vma->vm_start, mm->task_size, &nmask,
1095 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
1096 mmap_read_unlock(mm);
1097
1098 if (!list_empty(&pagelist)) {
1099 err = migrate_pages(&pagelist, alloc_migration_target, NULL,
1100 (unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL);
1101 if (err)
1102 putback_movable_pages(&pagelist);
1103 }
1104
1105 if (err >= 0)
1106 err += nr_failed;
1107 return err;
1108}
1109
1110/*
1111 * Move pages between the two nodesets so as to preserve the physical
1112 * layout as much as possible.
1113 *
1114 * Returns the number of page that could not be moved.
1115 */
1116int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1117 const nodemask_t *to, int flags)
1118{
1119 long nr_failed = 0;
1120 long err = 0;
1121 nodemask_t tmp;
1122
1123 lru_cache_disable();
1124
1125 /*
1126 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
1127 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
1128 * bit in 'tmp', and return that <source, dest> pair for migration.
1129 * The pair of nodemasks 'to' and 'from' define the map.
1130 *
1131 * If no pair of bits is found that way, fallback to picking some
1132 * pair of 'source' and 'dest' bits that are not the same. If the
1133 * 'source' and 'dest' bits are the same, this represents a node
1134 * that will be migrating to itself, so no pages need move.
1135 *
1136 * If no bits are left in 'tmp', or if all remaining bits left
1137 * in 'tmp' correspond to the same bit in 'to', return false
1138 * (nothing left to migrate).
1139 *
1140 * This lets us pick a pair of nodes to migrate between, such that
1141 * if possible the dest node is not already occupied by some other
1142 * source node, minimizing the risk of overloading the memory on a
1143 * node that would happen if we migrated incoming memory to a node
1144 * before migrating outgoing memory source that same node.
1145 *
1146 * A single scan of tmp is sufficient. As we go, we remember the
1147 * most recent <s, d> pair that moved (s != d). If we find a pair
1148 * that not only moved, but what's better, moved to an empty slot
1149 * (d is not set in tmp), then we break out then, with that pair.
1150 * Otherwise when we finish scanning from_tmp, we at least have the
1151 * most recent <s, d> pair that moved. If we get all the way through
1152 * the scan of tmp without finding any node that moved, much less
1153 * moved to an empty node, then there is nothing left worth migrating.
1154 */
1155
1156 tmp = *from;
1157 while (!nodes_empty(tmp)) {
1158 int s, d;
1159 int source = NUMA_NO_NODE;
1160 int dest = 0;
1161
1162 for_each_node_mask(s, tmp) {
1163
1164 /*
1165 * do_migrate_pages() tries to maintain the relative
1166 * node relationship of the pages established between
1167 * threads and memory areas.
1168 *
1169 * However if the number of source nodes is not equal to
1170 * the number of destination nodes we can not preserve
1171 * this node relative relationship. In that case, skip
1172 * copying memory from a node that is in the destination
1173 * mask.
1174 *
1175 * Example: [2,3,4] -> [3,4,5] moves everything.
1176 * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
1177 */
1178
1179 if ((nodes_weight(*from) != nodes_weight(*to)) &&
1180 (node_isset(s, *to)))
1181 continue;
1182
1183 d = node_remap(s, *from, *to);
1184 if (s == d)
1185 continue;
1186
1187 source = s; /* Node moved. Memorize */
1188 dest = d;
1189
1190 /* dest not in remaining from nodes? */
1191 if (!node_isset(dest, tmp))
1192 break;
1193 }
1194 if (source == NUMA_NO_NODE)
1195 break;
1196
1197 node_clear(source, tmp);
1198 err = migrate_to_node(mm, source, dest, flags);
1199 if (err > 0)
1200 nr_failed += err;
1201 if (err < 0)
1202 break;
1203 }
1204
1205 lru_cache_enable();
1206 if (err < 0)
1207 return err;
1208 return (nr_failed < INT_MAX) ? nr_failed : INT_MAX;
1209}
1210
1211/*
1212 * Allocate a new folio for page migration, according to NUMA mempolicy.
1213 */
1214static struct folio *alloc_migration_target_by_mpol(struct folio *src,
1215 unsigned long private)
1216{
1217 struct migration_mpol *mmpol = (struct migration_mpol *)private;
1218 struct mempolicy *pol = mmpol->pol;
1219 pgoff_t ilx = mmpol->ilx;
1220 unsigned int order;
1221 int nid = numa_node_id();
1222 gfp_t gfp;
1223
1224 order = folio_order(src);
1225 ilx += src->index >> order;
1226
1227 if (folio_test_hugetlb(src)) {
1228 nodemask_t *nodemask;
1229 struct hstate *h;
1230
1231 h = folio_hstate(src);
1232 gfp = htlb_alloc_mask(h);
1233 nodemask = policy_nodemask(gfp, pol, ilx, &nid);
1234 return alloc_hugetlb_folio_nodemask(h, nid, nodemask, gfp,
1235 htlb_allow_alloc_fallback(MR_MEMPOLICY_MBIND));
1236 }
1237
1238 if (folio_test_large(src))
1239 gfp = GFP_TRANSHUGE;
1240 else
1241 gfp = GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL | __GFP_COMP;
1242
1243 return folio_alloc_mpol(gfp, order, pol, ilx, nid);
1244}
1245#else
1246
1247static bool migrate_folio_add(struct folio *folio, struct list_head *foliolist,
1248 unsigned long flags)
1249{
1250 return false;
1251}
1252
1253int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1254 const nodemask_t *to, int flags)
1255{
1256 return -ENOSYS;
1257}
1258
1259static struct folio *alloc_migration_target_by_mpol(struct folio *src,
1260 unsigned long private)
1261{
1262 return NULL;
1263}
1264#endif
1265
1266static long do_mbind(unsigned long start, unsigned long len,
1267 unsigned short mode, unsigned short mode_flags,
1268 nodemask_t *nmask, unsigned long flags)
1269{
1270 struct mm_struct *mm = current->mm;
1271 struct vm_area_struct *vma, *prev;
1272 struct vma_iterator vmi;
1273 struct migration_mpol mmpol;
1274 struct mempolicy *new;
1275 unsigned long end;
1276 long err;
1277 long nr_failed;
1278 LIST_HEAD(pagelist);
1279
1280 if (flags & ~(unsigned long)MPOL_MF_VALID)
1281 return -EINVAL;
1282 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1283 return -EPERM;
1284
1285 if (start & ~PAGE_MASK)
1286 return -EINVAL;
1287
1288 if (mode == MPOL_DEFAULT)
1289 flags &= ~MPOL_MF_STRICT;
1290
1291 len = PAGE_ALIGN(len);
1292 end = start + len;
1293
1294 if (end < start)
1295 return -EINVAL;
1296 if (end == start)
1297 return 0;
1298
1299 new = mpol_new(mode, mode_flags, nmask);
1300 if (IS_ERR(new))
1301 return PTR_ERR(new);
1302
1303 /*
1304 * If we are using the default policy then operation
1305 * on discontinuous address spaces is okay after all
1306 */
1307 if (!new)
1308 flags |= MPOL_MF_DISCONTIG_OK;
1309
1310 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
1311 lru_cache_disable();
1312 {
1313 NODEMASK_SCRATCH(scratch);
1314 if (scratch) {
1315 mmap_write_lock(mm);
1316 err = mpol_set_nodemask(new, nmask, scratch);
1317 if (err)
1318 mmap_write_unlock(mm);
1319 } else
1320 err = -ENOMEM;
1321 NODEMASK_SCRATCH_FREE(scratch);
1322 }
1323 if (err)
1324 goto mpol_out;
1325
1326 /*
1327 * Lock the VMAs before scanning for pages to migrate,
1328 * to ensure we don't miss a concurrently inserted page.
1329 */
1330 nr_failed = queue_pages_range(mm, start, end, nmask,
1331 flags | MPOL_MF_INVERT | MPOL_MF_WRLOCK, &pagelist);
1332
1333 if (nr_failed < 0) {
1334 err = nr_failed;
1335 nr_failed = 0;
1336 } else {
1337 vma_iter_init(&vmi, mm, start);
1338 prev = vma_prev(&vmi);
1339 for_each_vma_range(vmi, vma, end) {
1340 err = mbind_range(&vmi, vma, &prev, start, end, new);
1341 if (err)
1342 break;
1343 }
1344 }
1345
1346 if (!err && !list_empty(&pagelist)) {
1347 /* Convert MPOL_DEFAULT's NULL to task or default policy */
1348 if (!new) {
1349 new = get_task_policy(current);
1350 mpol_get(new);
1351 }
1352 mmpol.pol = new;
1353 mmpol.ilx = 0;
1354
1355 /*
1356 * In the interleaved case, attempt to allocate on exactly the
1357 * targeted nodes, for the first VMA to be migrated; for later
1358 * VMAs, the nodes will still be interleaved from the targeted
1359 * nodemask, but one by one may be selected differently.
1360 */
1361 if (new->mode == MPOL_INTERLEAVE ||
1362 new->mode == MPOL_WEIGHTED_INTERLEAVE) {
1363 struct folio *folio;
1364 unsigned int order;
1365 unsigned long addr = -EFAULT;
1366
1367 list_for_each_entry(folio, &pagelist, lru) {
1368 if (!folio_test_ksm(folio))
1369 break;
1370 }
1371 if (!list_entry_is_head(folio, &pagelist, lru)) {
1372 vma_iter_init(&vmi, mm, start);
1373 for_each_vma_range(vmi, vma, end) {
1374 addr = page_address_in_vma(folio,
1375 folio_page(folio, 0), vma);
1376 if (addr != -EFAULT)
1377 break;
1378 }
1379 }
1380 if (addr != -EFAULT) {
1381 order = folio_order(folio);
1382 /* We already know the pol, but not the ilx */
1383 mpol_cond_put(get_vma_policy(vma, addr, order,
1384 &mmpol.ilx));
1385 /* Set base from which to increment by index */
1386 mmpol.ilx -= folio->index >> order;
1387 }
1388 }
1389 }
1390
1391 mmap_write_unlock(mm);
1392
1393 if (!err && !list_empty(&pagelist)) {
1394 nr_failed |= migrate_pages(&pagelist,
1395 alloc_migration_target_by_mpol, NULL,
1396 (unsigned long)&mmpol, MIGRATE_SYNC,
1397 MR_MEMPOLICY_MBIND, NULL);
1398 }
1399
1400 if (nr_failed && (flags & MPOL_MF_STRICT))
1401 err = -EIO;
1402 if (!list_empty(&pagelist))
1403 putback_movable_pages(&pagelist);
1404mpol_out:
1405 mpol_put(new);
1406 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
1407 lru_cache_enable();
1408 return err;
1409}
1410
1411/*
1412 * User space interface with variable sized bitmaps for nodelists.
1413 */
1414static int get_bitmap(unsigned long *mask, const unsigned long __user *nmask,
1415 unsigned long maxnode)
1416{
1417 unsigned long nlongs = BITS_TO_LONGS(maxnode);
1418 int ret;
1419
1420 if (in_compat_syscall())
1421 ret = compat_get_bitmap(mask,
1422 (const compat_ulong_t __user *)nmask,
1423 maxnode);
1424 else
1425 ret = copy_from_user(mask, nmask,
1426 nlongs * sizeof(unsigned long));
1427
1428 if (ret)
1429 return -EFAULT;
1430
1431 if (maxnode % BITS_PER_LONG)
1432 mask[nlongs - 1] &= (1UL << (maxnode % BITS_PER_LONG)) - 1;
1433
1434 return 0;
1435}
1436
1437/* Copy a node mask from user space. */
1438static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1439 unsigned long maxnode)
1440{
1441 --maxnode;
1442 nodes_clear(*nodes);
1443 if (maxnode == 0 || !nmask)
1444 return 0;
1445 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
1446 return -EINVAL;
1447
1448 /*
1449 * When the user specified more nodes than supported just check
1450 * if the non supported part is all zero, one word at a time,
1451 * starting at the end.
1452 */
1453 while (maxnode > MAX_NUMNODES) {
1454 unsigned long bits = min_t(unsigned long, maxnode, BITS_PER_LONG);
1455 unsigned long t;
1456
1457 if (get_bitmap(&t, &nmask[(maxnode - 1) / BITS_PER_LONG], bits))
1458 return -EFAULT;
1459
1460 if (maxnode - bits >= MAX_NUMNODES) {
1461 maxnode -= bits;
1462 } else {
1463 maxnode = MAX_NUMNODES;
1464 t &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
1465 }
1466 if (t)
1467 return -EINVAL;
1468 }
1469
1470 return get_bitmap(nodes_addr(*nodes), nmask, maxnode);
1471}
1472
1473/* Copy a kernel node mask to user space */
1474static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1475 nodemask_t *nodes)
1476{
1477 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1478 unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long);
1479 bool compat = in_compat_syscall();
1480
1481 if (compat)
1482 nbytes = BITS_TO_COMPAT_LONGS(nr_node_ids) * sizeof(compat_long_t);
1483
1484 if (copy > nbytes) {
1485 if (copy > PAGE_SIZE)
1486 return -EINVAL;
1487 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1488 return -EFAULT;
1489 copy = nbytes;
1490 maxnode = nr_node_ids;
1491 }
1492
1493 if (compat)
1494 return compat_put_bitmap((compat_ulong_t __user *)mask,
1495 nodes_addr(*nodes), maxnode);
1496
1497 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1498}
1499
1500/* Basic parameter sanity check used by both mbind() and set_mempolicy() */
1501static inline int sanitize_mpol_flags(int *mode, unsigned short *flags)
1502{
1503 *flags = *mode & MPOL_MODE_FLAGS;
1504 *mode &= ~MPOL_MODE_FLAGS;
1505
1506 if ((unsigned int)(*mode) >= MPOL_MAX)
1507 return -EINVAL;
1508 if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES))
1509 return -EINVAL;
1510 if (*flags & MPOL_F_NUMA_BALANCING) {
1511 if (*mode == MPOL_BIND || *mode == MPOL_PREFERRED_MANY)
1512 *flags |= (MPOL_F_MOF | MPOL_F_MORON);
1513 else
1514 return -EINVAL;
1515 }
1516 return 0;
1517}
1518
1519static long kernel_mbind(unsigned long start, unsigned long len,
1520 unsigned long mode, const unsigned long __user *nmask,
1521 unsigned long maxnode, unsigned int flags)
1522{
1523 unsigned short mode_flags;
1524 nodemask_t nodes;
1525 int lmode = mode;
1526 int err;
1527
1528 start = untagged_addr(start);
1529 err = sanitize_mpol_flags(&lmode, &mode_flags);
1530 if (err)
1531 return err;
1532
1533 err = get_nodes(&nodes, nmask, maxnode);
1534 if (err)
1535 return err;
1536
1537 return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
1538}
1539
1540SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned long, start, unsigned long, len,
1541 unsigned long, home_node, unsigned long, flags)
1542{
1543 struct mm_struct *mm = current->mm;
1544 struct vm_area_struct *vma, *prev;
1545 struct mempolicy *new, *old;
1546 unsigned long end;
1547 int err = -ENOENT;
1548 VMA_ITERATOR(vmi, mm, start);
1549
1550 start = untagged_addr(start);
1551 if (start & ~PAGE_MASK)
1552 return -EINVAL;
1553 /*
1554 * flags is used for future extension if any.
1555 */
1556 if (flags != 0)
1557 return -EINVAL;
1558
1559 /*
1560 * Check home_node is online to avoid accessing uninitialized
1561 * NODE_DATA.
1562 */
1563 if (home_node >= MAX_NUMNODES || !node_online(home_node))
1564 return -EINVAL;
1565
1566 len = PAGE_ALIGN(len);
1567 end = start + len;
1568
1569 if (end < start)
1570 return -EINVAL;
1571 if (end == start)
1572 return 0;
1573 mmap_write_lock(mm);
1574 prev = vma_prev(&vmi);
1575 for_each_vma_range(vmi, vma, end) {
1576 /*
1577 * If any vma in the range got policy other than MPOL_BIND
1578 * or MPOL_PREFERRED_MANY we return error. We don't reset
1579 * the home node for vmas we already updated before.
1580 */
1581 old = vma_policy(vma);
1582 if (!old) {
1583 prev = vma;
1584 continue;
1585 }
1586 if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) {
1587 err = -EOPNOTSUPP;
1588 break;
1589 }
1590 new = mpol_dup(old);
1591 if (IS_ERR(new)) {
1592 err = PTR_ERR(new);
1593 break;
1594 }
1595
1596 vma_start_write(vma);
1597 new->home_node = home_node;
1598 err = mbind_range(&vmi, vma, &prev, start, end, new);
1599 mpol_put(new);
1600 if (err)
1601 break;
1602 }
1603 mmap_write_unlock(mm);
1604 return err;
1605}
1606
1607SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1608 unsigned long, mode, const unsigned long __user *, nmask,
1609 unsigned long, maxnode, unsigned int, flags)
1610{
1611 return kernel_mbind(start, len, mode, nmask, maxnode, flags);
1612}
1613
1614/* Set the process memory policy */
1615static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
1616 unsigned long maxnode)
1617{
1618 unsigned short mode_flags;
1619 nodemask_t nodes;
1620 int lmode = mode;
1621 int err;
1622
1623 err = sanitize_mpol_flags(&lmode, &mode_flags);
1624 if (err)
1625 return err;
1626
1627 err = get_nodes(&nodes, nmask, maxnode);
1628 if (err)
1629 return err;
1630
1631 return do_set_mempolicy(lmode, mode_flags, &nodes);
1632}
1633
1634SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
1635 unsigned long, maxnode)
1636{
1637 return kernel_set_mempolicy(mode, nmask, maxnode);
1638}
1639
1640static int kernel_migrate_pages(pid_t pid, unsigned long maxnode,
1641 const unsigned long __user *old_nodes,
1642 const unsigned long __user *new_nodes)
1643{
1644 struct mm_struct *mm = NULL;
1645 struct task_struct *task;
1646 nodemask_t task_nodes;
1647 int err;
1648 nodemask_t *old;
1649 nodemask_t *new;
1650 NODEMASK_SCRATCH(scratch);
1651
1652 if (!scratch)
1653 return -ENOMEM;
1654
1655 old = &scratch->mask1;
1656 new = &scratch->mask2;
1657
1658 err = get_nodes(old, old_nodes, maxnode);
1659 if (err)
1660 goto out;
1661
1662 err = get_nodes(new, new_nodes, maxnode);
1663 if (err)
1664 goto out;
1665
1666 /* Find the mm_struct */
1667 rcu_read_lock();
1668 task = pid ? find_task_by_vpid(pid) : current;
1669 if (!task) {
1670 rcu_read_unlock();
1671 err = -ESRCH;
1672 goto out;
1673 }
1674 get_task_struct(task);
1675
1676 err = -EINVAL;
1677
1678 /*
1679 * Check if this process has the right to modify the specified process.
1680 * Use the regular "ptrace_may_access()" checks.
1681 */
1682 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) {
1683 rcu_read_unlock();
1684 err = -EPERM;
1685 goto out_put;
1686 }
1687 rcu_read_unlock();
1688
1689 task_nodes = cpuset_mems_allowed(task);
1690 /* Is the user allowed to access the target nodes? */
1691 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
1692 err = -EPERM;
1693 goto out_put;
1694 }
1695
1696 task_nodes = cpuset_mems_allowed(current);
1697 nodes_and(*new, *new, task_nodes);
1698 if (nodes_empty(*new))
1699 goto out_put;
1700
1701 err = security_task_movememory(task);
1702 if (err)
1703 goto out_put;
1704
1705 mm = get_task_mm(task);
1706 put_task_struct(task);
1707
1708 if (!mm) {
1709 err = -EINVAL;
1710 goto out;
1711 }
1712
1713 err = do_migrate_pages(mm, old, new,
1714 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1715
1716 mmput(mm);
1717out:
1718 NODEMASK_SCRATCH_FREE(scratch);
1719
1720 return err;
1721
1722out_put:
1723 put_task_struct(task);
1724 goto out;
1725}
1726
1727SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1728 const unsigned long __user *, old_nodes,
1729 const unsigned long __user *, new_nodes)
1730{
1731 return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes);
1732}
1733
1734/* Retrieve NUMA policy */
1735static int kernel_get_mempolicy(int __user *policy,
1736 unsigned long __user *nmask,
1737 unsigned long maxnode,
1738 unsigned long addr,
1739 unsigned long flags)
1740{
1741 int err;
1742 int pval;
1743 nodemask_t nodes;
1744
1745 if (nmask != NULL && maxnode < nr_node_ids)
1746 return -EINVAL;
1747
1748 addr = untagged_addr(addr);
1749
1750 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1751
1752 if (err)
1753 return err;
1754
1755 if (policy && put_user(pval, policy))
1756 return -EFAULT;
1757
1758 if (nmask)
1759 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1760
1761 return err;
1762}
1763
1764SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1765 unsigned long __user *, nmask, unsigned long, maxnode,
1766 unsigned long, addr, unsigned long, flags)
1767{
1768 return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags);
1769}
1770
1771bool vma_migratable(struct vm_area_struct *vma)
1772{
1773 if (vma->vm_flags & (VM_IO | VM_PFNMAP))
1774 return false;
1775
1776 /*
1777 * DAX device mappings require predictable access latency, so avoid
1778 * incurring periodic faults.
1779 */
1780 if (vma_is_dax(vma))
1781 return false;
1782
1783 if (is_vm_hugetlb_page(vma) &&
1784 !hugepage_migration_supported(hstate_vma(vma)))
1785 return false;
1786
1787 /*
1788 * Migration allocates pages in the highest zone. If we cannot
1789 * do so then migration (at least from node to node) is not
1790 * possible.
1791 */
1792 if (vma->vm_file &&
1793 gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
1794 < policy_zone)
1795 return false;
1796 return true;
1797}
1798
1799struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
1800 unsigned long addr, pgoff_t *ilx)
1801{
1802 *ilx = 0;
1803 return (vma->vm_ops && vma->vm_ops->get_policy) ?
1804 vma->vm_ops->get_policy(vma, addr, ilx) : vma->vm_policy;
1805}
1806
1807/*
1808 * get_vma_policy(@vma, @addr, @order, @ilx)
1809 * @vma: virtual memory area whose policy is sought
1810 * @addr: address in @vma for shared policy lookup
1811 * @order: 0, or appropriate huge_page_order for interleaving
1812 * @ilx: interleave index (output), for use only when MPOL_INTERLEAVE or
1813 * MPOL_WEIGHTED_INTERLEAVE
1814 *
1815 * Returns effective policy for a VMA at specified address.
1816 * Falls back to current->mempolicy or system default policy, as necessary.
1817 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1818 * count--added by the get_policy() vm_op, as appropriate--to protect against
1819 * freeing by another task. It is the caller's responsibility to free the
1820 * extra reference for shared policies.
1821 */
1822struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
1823 unsigned long addr, int order, pgoff_t *ilx)
1824{
1825 struct mempolicy *pol;
1826
1827 pol = __get_vma_policy(vma, addr, ilx);
1828 if (!pol)
1829 pol = get_task_policy(current);
1830 if (pol->mode == MPOL_INTERLEAVE ||
1831 pol->mode == MPOL_WEIGHTED_INTERLEAVE) {
1832 *ilx += vma->vm_pgoff >> order;
1833 *ilx += (addr - vma->vm_start) >> (PAGE_SHIFT + order);
1834 }
1835 return pol;
1836}
1837
1838bool vma_policy_mof(struct vm_area_struct *vma)
1839{
1840 struct mempolicy *pol;
1841
1842 if (vma->vm_ops && vma->vm_ops->get_policy) {
1843 bool ret = false;
1844 pgoff_t ilx; /* ignored here */
1845
1846 pol = vma->vm_ops->get_policy(vma, vma->vm_start, &ilx);
1847 if (pol && (pol->flags & MPOL_F_MOF))
1848 ret = true;
1849 mpol_cond_put(pol);
1850
1851 return ret;
1852 }
1853
1854 pol = vma->vm_policy;
1855 if (!pol)
1856 pol = get_task_policy(current);
1857
1858 return pol->flags & MPOL_F_MOF;
1859}
1860
1861bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
1862{
1863 enum zone_type dynamic_policy_zone = policy_zone;
1864
1865 BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
1866
1867 /*
1868 * if policy->nodes has movable memory only,
1869 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
1870 *
1871 * policy->nodes is intersect with node_states[N_MEMORY].
1872 * so if the following test fails, it implies
1873 * policy->nodes has movable memory only.
1874 */
1875 if (!nodes_intersects(policy->nodes, node_states[N_HIGH_MEMORY]))
1876 dynamic_policy_zone = ZONE_MOVABLE;
1877
1878 return zone >= dynamic_policy_zone;
1879}
1880
1881static unsigned int weighted_interleave_nodes(struct mempolicy *policy)
1882{
1883 unsigned int node;
1884 unsigned int cpuset_mems_cookie;
1885
1886retry:
1887 /* to prevent miscount use tsk->mems_allowed_seq to detect rebind */
1888 cpuset_mems_cookie = read_mems_allowed_begin();
1889 node = current->il_prev;
1890 if (!current->il_weight || !node_isset(node, policy->nodes)) {
1891 node = next_node_in(node, policy->nodes);
1892 if (read_mems_allowed_retry(cpuset_mems_cookie))
1893 goto retry;
1894 if (node == MAX_NUMNODES)
1895 return node;
1896 current->il_prev = node;
1897 current->il_weight = get_il_weight(node);
1898 }
1899 current->il_weight--;
1900 return node;
1901}
1902
1903/* Do dynamic interleaving for a process */
1904static unsigned int interleave_nodes(struct mempolicy *policy)
1905{
1906 unsigned int nid;
1907 unsigned int cpuset_mems_cookie;
1908
1909 /* to prevent miscount, use tsk->mems_allowed_seq to detect rebind */
1910 do {
1911 cpuset_mems_cookie = read_mems_allowed_begin();
1912 nid = next_node_in(current->il_prev, policy->nodes);
1913 } while (read_mems_allowed_retry(cpuset_mems_cookie));
1914
1915 if (nid < MAX_NUMNODES)
1916 current->il_prev = nid;
1917 return nid;
1918}
1919
1920/*
1921 * Depending on the memory policy provide a node from which to allocate the
1922 * next slab entry.
1923 */
1924unsigned int mempolicy_slab_node(void)
1925{
1926 struct mempolicy *policy;
1927 int node = numa_mem_id();
1928
1929 if (!in_task())
1930 return node;
1931
1932 policy = current->mempolicy;
1933 if (!policy)
1934 return node;
1935
1936 switch (policy->mode) {
1937 case MPOL_PREFERRED:
1938 return first_node(policy->nodes);
1939
1940 case MPOL_INTERLEAVE:
1941 return interleave_nodes(policy);
1942
1943 case MPOL_WEIGHTED_INTERLEAVE:
1944 return weighted_interleave_nodes(policy);
1945
1946 case MPOL_BIND:
1947 case MPOL_PREFERRED_MANY:
1948 {
1949 struct zoneref *z;
1950
1951 /*
1952 * Follow bind policy behavior and start allocation at the
1953 * first node.
1954 */
1955 struct zonelist *zonelist;
1956 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1957 zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
1958 z = first_zones_zonelist(zonelist, highest_zoneidx,
1959 &policy->nodes);
1960 return zonelist_zone(z) ? zonelist_node_idx(z) : node;
1961 }
1962 case MPOL_LOCAL:
1963 return node;
1964
1965 default:
1966 BUG();
1967 }
1968}
1969
1970static unsigned int read_once_policy_nodemask(struct mempolicy *pol,
1971 nodemask_t *mask)
1972{
1973 /*
1974 * barrier stabilizes the nodemask locally so that it can be iterated
1975 * over safely without concern for changes. Allocators validate node
1976 * selection does not violate mems_allowed, so this is safe.
1977 */
1978 barrier();
1979 memcpy(mask, &pol->nodes, sizeof(nodemask_t));
1980 barrier();
1981 return nodes_weight(*mask);
1982}
1983
1984static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx)
1985{
1986 nodemask_t nodemask;
1987 unsigned int target, nr_nodes;
1988 u8 *table;
1989 unsigned int weight_total = 0;
1990 u8 weight;
1991 int nid;
1992
1993 nr_nodes = read_once_policy_nodemask(pol, &nodemask);
1994 if (!nr_nodes)
1995 return numa_node_id();
1996
1997 rcu_read_lock();
1998 table = rcu_dereference(iw_table);
1999 /* calculate the total weight */
2000 for_each_node_mask(nid, nodemask) {
2001 /* detect system default usage */
2002 weight = table ? table[nid] : 1;
2003 weight = weight ? weight : 1;
2004 weight_total += weight;
2005 }
2006
2007 /* Calculate the node offset based on totals */
2008 target = ilx % weight_total;
2009 nid = first_node(nodemask);
2010 while (target) {
2011 /* detect system default usage */
2012 weight = table ? table[nid] : 1;
2013 weight = weight ? weight : 1;
2014 if (target < weight)
2015 break;
2016 target -= weight;
2017 nid = next_node_in(nid, nodemask);
2018 }
2019 rcu_read_unlock();
2020 return nid;
2021}
2022
2023/*
2024 * Do static interleaving for interleave index @ilx. Returns the ilx'th
2025 * node in pol->nodes (starting from ilx=0), wrapping around if ilx
2026 * exceeds the number of present nodes.
2027 */
2028static unsigned int interleave_nid(struct mempolicy *pol, pgoff_t ilx)
2029{
2030 nodemask_t nodemask;
2031 unsigned int target, nnodes;
2032 int i;
2033 int nid;
2034
2035 nnodes = read_once_policy_nodemask(pol, &nodemask);
2036 if (!nnodes)
2037 return numa_node_id();
2038 target = ilx % nnodes;
2039 nid = first_node(nodemask);
2040 for (i = 0; i < target; i++)
2041 nid = next_node(nid, nodemask);
2042 return nid;
2043}
2044
2045/*
2046 * Return a nodemask representing a mempolicy for filtering nodes for
2047 * page allocation, together with preferred node id (or the input node id).
2048 */
2049static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *pol,
2050 pgoff_t ilx, int *nid)
2051{
2052 nodemask_t *nodemask = NULL;
2053
2054 switch (pol->mode) {
2055 case MPOL_PREFERRED:
2056 /* Override input node id */
2057 *nid = first_node(pol->nodes);
2058 break;
2059 case MPOL_PREFERRED_MANY:
2060 nodemask = &pol->nodes;
2061 if (pol->home_node != NUMA_NO_NODE)
2062 *nid = pol->home_node;
2063 break;
2064 case MPOL_BIND:
2065 /* Restrict to nodemask (but not on lower zones) */
2066 if (apply_policy_zone(pol, gfp_zone(gfp)) &&
2067 cpuset_nodemask_valid_mems_allowed(&pol->nodes))
2068 nodemask = &pol->nodes;
2069 if (pol->home_node != NUMA_NO_NODE)
2070 *nid = pol->home_node;
2071 /*
2072 * __GFP_THISNODE shouldn't even be used with the bind policy
2073 * because we might easily break the expectation to stay on the
2074 * requested node and not break the policy.
2075 */
2076 WARN_ON_ONCE(gfp & __GFP_THISNODE);
2077 break;
2078 case MPOL_INTERLEAVE:
2079 /* Override input node id */
2080 *nid = (ilx == NO_INTERLEAVE_INDEX) ?
2081 interleave_nodes(pol) : interleave_nid(pol, ilx);
2082 break;
2083 case MPOL_WEIGHTED_INTERLEAVE:
2084 *nid = (ilx == NO_INTERLEAVE_INDEX) ?
2085 weighted_interleave_nodes(pol) :
2086 weighted_interleave_nid(pol, ilx);
2087 break;
2088 }
2089
2090 return nodemask;
2091}
2092
2093#ifdef CONFIG_HUGETLBFS
2094/*
2095 * huge_node(@vma, @addr, @gfp_flags, @mpol)
2096 * @vma: virtual memory area whose policy is sought
2097 * @addr: address in @vma for shared policy lookup and interleave policy
2098 * @gfp_flags: for requested zone
2099 * @mpol: pointer to mempolicy pointer for reference counted mempolicy
2100 * @nodemask: pointer to nodemask pointer for 'bind' and 'prefer-many' policy
2101 *
2102 * Returns a nid suitable for a huge page allocation and a pointer
2103 * to the struct mempolicy for conditional unref after allocation.
2104 * If the effective policy is 'bind' or 'prefer-many', returns a pointer
2105 * to the mempolicy's @nodemask for filtering the zonelist.
2106 */
2107int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
2108 struct mempolicy **mpol, nodemask_t **nodemask)
2109{
2110 pgoff_t ilx;
2111 int nid;
2112
2113 nid = numa_node_id();
2114 *mpol = get_vma_policy(vma, addr, hstate_vma(vma)->order, &ilx);
2115 *nodemask = policy_nodemask(gfp_flags, *mpol, ilx, &nid);
2116 return nid;
2117}
2118
2119/*
2120 * init_nodemask_of_mempolicy
2121 *
2122 * If the current task's mempolicy is "default" [NULL], return 'false'
2123 * to indicate default policy. Otherwise, extract the policy nodemask
2124 * for 'bind' or 'interleave' policy into the argument nodemask, or
2125 * initialize the argument nodemask to contain the single node for
2126 * 'preferred' or 'local' policy and return 'true' to indicate presence
2127 * of non-default mempolicy.
2128 *
2129 * We don't bother with reference counting the mempolicy [mpol_get/put]
2130 * because the current task is examining it's own mempolicy and a task's
2131 * mempolicy is only ever changed by the task itself.
2132 *
2133 * N.B., it is the caller's responsibility to free a returned nodemask.
2134 */
2135bool init_nodemask_of_mempolicy(nodemask_t *mask)
2136{
2137 struct mempolicy *mempolicy;
2138
2139 if (!(mask && current->mempolicy))
2140 return false;
2141
2142 task_lock(current);
2143 mempolicy = current->mempolicy;
2144 switch (mempolicy->mode) {
2145 case MPOL_PREFERRED:
2146 case MPOL_PREFERRED_MANY:
2147 case MPOL_BIND:
2148 case MPOL_INTERLEAVE:
2149 case MPOL_WEIGHTED_INTERLEAVE:
2150 *mask = mempolicy->nodes;
2151 break;
2152
2153 case MPOL_LOCAL:
2154 init_nodemask_of_node(mask, numa_node_id());
2155 break;
2156
2157 default:
2158 BUG();
2159 }
2160 task_unlock(current);
2161
2162 return true;
2163}
2164#endif
2165
2166/*
2167 * mempolicy_in_oom_domain
2168 *
2169 * If tsk's mempolicy is "bind", check for intersection between mask and
2170 * the policy nodemask. Otherwise, return true for all other policies
2171 * including "interleave", as a tsk with "interleave" policy may have
2172 * memory allocated from all nodes in system.
2173 *
2174 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
2175 */
2176bool mempolicy_in_oom_domain(struct task_struct *tsk,
2177 const nodemask_t *mask)
2178{
2179 struct mempolicy *mempolicy;
2180 bool ret = true;
2181
2182 if (!mask)
2183 return ret;
2184
2185 task_lock(tsk);
2186 mempolicy = tsk->mempolicy;
2187 if (mempolicy && mempolicy->mode == MPOL_BIND)
2188 ret = nodes_intersects(mempolicy->nodes, *mask);
2189 task_unlock(tsk);
2190
2191 return ret;
2192}
2193
2194static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order,
2195 int nid, nodemask_t *nodemask)
2196{
2197 struct page *page;
2198 gfp_t preferred_gfp;
2199
2200 /*
2201 * This is a two pass approach. The first pass will only try the
2202 * preferred nodes but skip the direct reclaim and allow the
2203 * allocation to fail, while the second pass will try all the
2204 * nodes in system.
2205 */
2206 preferred_gfp = gfp | __GFP_NOWARN;
2207 preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
2208 page = __alloc_pages_noprof(preferred_gfp, order, nid, nodemask);
2209 if (!page)
2210 page = __alloc_pages_noprof(gfp, order, nid, NULL);
2211
2212 return page;
2213}
2214
2215/**
2216 * alloc_pages_mpol - Allocate pages according to NUMA mempolicy.
2217 * @gfp: GFP flags.
2218 * @order: Order of the page allocation.
2219 * @pol: Pointer to the NUMA mempolicy.
2220 * @ilx: Index for interleave mempolicy (also distinguishes alloc_pages()).
2221 * @nid: Preferred node (usually numa_node_id() but @mpol may override it).
2222 *
2223 * Return: The page on success or NULL if allocation fails.
2224 */
2225struct page *alloc_pages_mpol_noprof(gfp_t gfp, unsigned int order,
2226 struct mempolicy *pol, pgoff_t ilx, int nid)
2227{
2228 nodemask_t *nodemask;
2229 struct page *page;
2230
2231 nodemask = policy_nodemask(gfp, pol, ilx, &nid);
2232
2233 if (pol->mode == MPOL_PREFERRED_MANY)
2234 return alloc_pages_preferred_many(gfp, order, nid, nodemask);
2235
2236 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
2237 /* filter "hugepage" allocation, unless from alloc_pages() */
2238 order == HPAGE_PMD_ORDER && ilx != NO_INTERLEAVE_INDEX) {
2239 /*
2240 * For hugepage allocation and non-interleave policy which
2241 * allows the current node (or other explicitly preferred
2242 * node) we only try to allocate from the current/preferred
2243 * node and don't fall back to other nodes, as the cost of
2244 * remote accesses would likely offset THP benefits.
2245 *
2246 * If the policy is interleave or does not allow the current
2247 * node in its nodemask, we allocate the standard way.
2248 */
2249 if (pol->mode != MPOL_INTERLEAVE &&
2250 pol->mode != MPOL_WEIGHTED_INTERLEAVE &&
2251 (!nodemask || node_isset(nid, *nodemask))) {
2252 /*
2253 * First, try to allocate THP only on local node, but
2254 * don't reclaim unnecessarily, just compact.
2255 */
2256 page = __alloc_pages_node_noprof(nid,
2257 gfp | __GFP_THISNODE | __GFP_NORETRY, order);
2258 if (page || !(gfp & __GFP_DIRECT_RECLAIM))
2259 return page;
2260 /*
2261 * If hugepage allocations are configured to always
2262 * synchronous compact or the vma has been madvised
2263 * to prefer hugepage backing, retry allowing remote
2264 * memory with both reclaim and compact as well.
2265 */
2266 }
2267 }
2268
2269 page = __alloc_pages_noprof(gfp, order, nid, nodemask);
2270
2271 if (unlikely(pol->mode == MPOL_INTERLEAVE ||
2272 pol->mode == MPOL_WEIGHTED_INTERLEAVE) && page) {
2273 /* skip NUMA_INTERLEAVE_HIT update if numa stats is disabled */
2274 if (static_branch_likely(&vm_numa_stat_key) &&
2275 page_to_nid(page) == nid) {
2276 preempt_disable();
2277 __count_numa_event(page_zone(page), NUMA_INTERLEAVE_HIT);
2278 preempt_enable();
2279 }
2280 }
2281
2282 return page;
2283}
2284
2285struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
2286 struct mempolicy *pol, pgoff_t ilx, int nid)
2287{
2288 return page_rmappable_folio(alloc_pages_mpol_noprof(gfp | __GFP_COMP,
2289 order, pol, ilx, nid));
2290}
2291
2292/**
2293 * vma_alloc_folio - Allocate a folio for a VMA.
2294 * @gfp: GFP flags.
2295 * @order: Order of the folio.
2296 * @vma: Pointer to VMA.
2297 * @addr: Virtual address of the allocation. Must be inside @vma.
2298 *
2299 * Allocate a folio for a specific address in @vma, using the appropriate
2300 * NUMA policy. The caller must hold the mmap_lock of the mm_struct of the
2301 * VMA to prevent it from going away. Should be used for all allocations
2302 * for folios that will be mapped into user space, excepting hugetlbfs, and
2303 * excepting where direct use of alloc_pages_mpol() is more appropriate.
2304 *
2305 * Return: The folio on success or NULL if allocation fails.
2306 */
2307struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order, struct vm_area_struct *vma,
2308 unsigned long addr)
2309{
2310 struct mempolicy *pol;
2311 pgoff_t ilx;
2312 struct folio *folio;
2313
2314 if (vma->vm_flags & VM_DROPPABLE)
2315 gfp |= __GFP_NOWARN;
2316
2317 pol = get_vma_policy(vma, addr, order, &ilx);
2318 folio = folio_alloc_mpol_noprof(gfp, order, pol, ilx, numa_node_id());
2319 mpol_cond_put(pol);
2320 return folio;
2321}
2322EXPORT_SYMBOL(vma_alloc_folio_noprof);
2323
2324/**
2325 * alloc_pages - Allocate pages.
2326 * @gfp: GFP flags.
2327 * @order: Power of two of number of pages to allocate.
2328 *
2329 * Allocate 1 << @order contiguous pages. The physical address of the
2330 * first page is naturally aligned (eg an order-3 allocation will be aligned
2331 * to a multiple of 8 * PAGE_SIZE bytes). The NUMA policy of the current
2332 * process is honoured when in process context.
2333 *
2334 * Context: Can be called from any context, providing the appropriate GFP
2335 * flags are used.
2336 * Return: The page on success or NULL if allocation fails.
2337 */
2338struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order)
2339{
2340 struct mempolicy *pol = &default_policy;
2341
2342 /*
2343 * No reference counting needed for current->mempolicy
2344 * nor system default_policy
2345 */
2346 if (!in_interrupt() && !(gfp & __GFP_THISNODE))
2347 pol = get_task_policy(current);
2348
2349 return alloc_pages_mpol_noprof(gfp, order, pol, NO_INTERLEAVE_INDEX,
2350 numa_node_id());
2351}
2352EXPORT_SYMBOL(alloc_pages_noprof);
2353
2354struct folio *folio_alloc_noprof(gfp_t gfp, unsigned int order)
2355{
2356 return page_rmappable_folio(alloc_pages_noprof(gfp | __GFP_COMP, order));
2357}
2358EXPORT_SYMBOL(folio_alloc_noprof);
2359
2360static unsigned long alloc_pages_bulk_array_interleave(gfp_t gfp,
2361 struct mempolicy *pol, unsigned long nr_pages,
2362 struct page **page_array)
2363{
2364 int nodes;
2365 unsigned long nr_pages_per_node;
2366 int delta;
2367 int i;
2368 unsigned long nr_allocated;
2369 unsigned long total_allocated = 0;
2370
2371 nodes = nodes_weight(pol->nodes);
2372 nr_pages_per_node = nr_pages / nodes;
2373 delta = nr_pages - nodes * nr_pages_per_node;
2374
2375 for (i = 0; i < nodes; i++) {
2376 if (delta) {
2377 nr_allocated = alloc_pages_bulk_noprof(gfp,
2378 interleave_nodes(pol), NULL,
2379 nr_pages_per_node + 1, NULL,
2380 page_array);
2381 delta--;
2382 } else {
2383 nr_allocated = alloc_pages_bulk_noprof(gfp,
2384 interleave_nodes(pol), NULL,
2385 nr_pages_per_node, NULL, page_array);
2386 }
2387
2388 page_array += nr_allocated;
2389 total_allocated += nr_allocated;
2390 }
2391
2392 return total_allocated;
2393}
2394
2395static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp,
2396 struct mempolicy *pol, unsigned long nr_pages,
2397 struct page **page_array)
2398{
2399 struct task_struct *me = current;
2400 unsigned int cpuset_mems_cookie;
2401 unsigned long total_allocated = 0;
2402 unsigned long nr_allocated = 0;
2403 unsigned long rounds;
2404 unsigned long node_pages, delta;
2405 u8 *table, *weights, weight;
2406 unsigned int weight_total = 0;
2407 unsigned long rem_pages = nr_pages;
2408 nodemask_t nodes;
2409 int nnodes, node;
2410 int resume_node = MAX_NUMNODES - 1;
2411 u8 resume_weight = 0;
2412 int prev_node;
2413 int i;
2414
2415 if (!nr_pages)
2416 return 0;
2417
2418 /* read the nodes onto the stack, retry if done during rebind */
2419 do {
2420 cpuset_mems_cookie = read_mems_allowed_begin();
2421 nnodes = read_once_policy_nodemask(pol, &nodes);
2422 } while (read_mems_allowed_retry(cpuset_mems_cookie));
2423
2424 /* if the nodemask has become invalid, we cannot do anything */
2425 if (!nnodes)
2426 return 0;
2427
2428 /* Continue allocating from most recent node and adjust the nr_pages */
2429 node = me->il_prev;
2430 weight = me->il_weight;
2431 if (weight && node_isset(node, nodes)) {
2432 node_pages = min(rem_pages, weight);
2433 nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
2434 NULL, page_array);
2435 page_array += nr_allocated;
2436 total_allocated += nr_allocated;
2437 /* if that's all the pages, no need to interleave */
2438 if (rem_pages <= weight) {
2439 me->il_weight -= rem_pages;
2440 return total_allocated;
2441 }
2442 /* Otherwise we adjust remaining pages, continue from there */
2443 rem_pages -= weight;
2444 }
2445 /* clear active weight in case of an allocation failure */
2446 me->il_weight = 0;
2447 prev_node = node;
2448
2449 /* create a local copy of node weights to operate on outside rcu */
2450 weights = kzalloc(nr_node_ids, GFP_KERNEL);
2451 if (!weights)
2452 return total_allocated;
2453
2454 rcu_read_lock();
2455 table = rcu_dereference(iw_table);
2456 if (table)
2457 memcpy(weights, table, nr_node_ids);
2458 rcu_read_unlock();
2459
2460 /* calculate total, detect system default usage */
2461 for_each_node_mask(node, nodes) {
2462 if (!weights[node])
2463 weights[node] = 1;
2464 weight_total += weights[node];
2465 }
2466
2467 /*
2468 * Calculate rounds/partial rounds to minimize __alloc_pages_bulk calls.
2469 * Track which node weighted interleave should resume from.
2470 *
2471 * if (rounds > 0) and (delta == 0), resume_node will always be
2472 * the node following prev_node and its weight.
2473 */
2474 rounds = rem_pages / weight_total;
2475 delta = rem_pages % weight_total;
2476 resume_node = next_node_in(prev_node, nodes);
2477 resume_weight = weights[resume_node];
2478 for (i = 0; i < nnodes; i++) {
2479 node = next_node_in(prev_node, nodes);
2480 weight = weights[node];
2481 node_pages = weight * rounds;
2482 /* If a delta exists, add this node's portion of the delta */
2483 if (delta > weight) {
2484 node_pages += weight;
2485 delta -= weight;
2486 } else if (delta) {
2487 /* when delta is depleted, resume from that node */
2488 node_pages += delta;
2489 resume_node = node;
2490 resume_weight = weight - delta;
2491 delta = 0;
2492 }
2493 /* node_pages can be 0 if an allocation fails and rounds == 0 */
2494 if (!node_pages)
2495 break;
2496 nr_allocated = __alloc_pages_bulk(gfp, node, NULL, node_pages,
2497 NULL, page_array);
2498 page_array += nr_allocated;
2499 total_allocated += nr_allocated;
2500 if (total_allocated == nr_pages)
2501 break;
2502 prev_node = node;
2503 }
2504 me->il_prev = resume_node;
2505 me->il_weight = resume_weight;
2506 kfree(weights);
2507 return total_allocated;
2508}
2509
2510static unsigned long alloc_pages_bulk_array_preferred_many(gfp_t gfp, int nid,
2511 struct mempolicy *pol, unsigned long nr_pages,
2512 struct page **page_array)
2513{
2514 gfp_t preferred_gfp;
2515 unsigned long nr_allocated = 0;
2516
2517 preferred_gfp = gfp | __GFP_NOWARN;
2518 preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
2519
2520 nr_allocated = alloc_pages_bulk_noprof(preferred_gfp, nid, &pol->nodes,
2521 nr_pages, NULL, page_array);
2522
2523 if (nr_allocated < nr_pages)
2524 nr_allocated += alloc_pages_bulk_noprof(gfp, numa_node_id(), NULL,
2525 nr_pages - nr_allocated, NULL,
2526 page_array + nr_allocated);
2527 return nr_allocated;
2528}
2529
2530/* alloc pages bulk and mempolicy should be considered at the
2531 * same time in some situation such as vmalloc.
2532 *
2533 * It can accelerate memory allocation especially interleaving
2534 * allocate memory.
2535 */
2536unsigned long alloc_pages_bulk_array_mempolicy_noprof(gfp_t gfp,
2537 unsigned long nr_pages, struct page **page_array)
2538{
2539 struct mempolicy *pol = &default_policy;
2540 nodemask_t *nodemask;
2541 int nid;
2542
2543 if (!in_interrupt() && !(gfp & __GFP_THISNODE))
2544 pol = get_task_policy(current);
2545
2546 if (pol->mode == MPOL_INTERLEAVE)
2547 return alloc_pages_bulk_array_interleave(gfp, pol,
2548 nr_pages, page_array);
2549
2550 if (pol->mode == MPOL_WEIGHTED_INTERLEAVE)
2551 return alloc_pages_bulk_array_weighted_interleave(
2552 gfp, pol, nr_pages, page_array);
2553
2554 if (pol->mode == MPOL_PREFERRED_MANY)
2555 return alloc_pages_bulk_array_preferred_many(gfp,
2556 numa_node_id(), pol, nr_pages, page_array);
2557
2558 nid = numa_node_id();
2559 nodemask = policy_nodemask(gfp, pol, NO_INTERLEAVE_INDEX, &nid);
2560 return alloc_pages_bulk_noprof(gfp, nid, nodemask,
2561 nr_pages, NULL, page_array);
2562}
2563
2564int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
2565{
2566 struct mempolicy *pol = mpol_dup(src->vm_policy);
2567
2568 if (IS_ERR(pol))
2569 return PTR_ERR(pol);
2570 dst->vm_policy = pol;
2571 return 0;
2572}
2573
2574/*
2575 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
2576 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
2577 * with the mems_allowed returned by cpuset_mems_allowed(). This
2578 * keeps mempolicies cpuset relative after its cpuset moves. See
2579 * further kernel/cpuset.c update_nodemask().
2580 *
2581 * current's mempolicy may be rebinded by the other task(the task that changes
2582 * cpuset's mems), so we needn't do rebind work for current task.
2583 */
2584
2585/* Slow path of a mempolicy duplicate */
2586struct mempolicy *__mpol_dup(struct mempolicy *old)
2587{
2588 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2589
2590 if (!new)
2591 return ERR_PTR(-ENOMEM);
2592
2593 /* task's mempolicy is protected by alloc_lock */
2594 if (old == current->mempolicy) {
2595 task_lock(current);
2596 *new = *old;
2597 task_unlock(current);
2598 } else
2599 *new = *old;
2600
2601 if (current_cpuset_is_being_rebound()) {
2602 nodemask_t mems = cpuset_mems_allowed(current);
2603 mpol_rebind_policy(new, &mems);
2604 }
2605 atomic_set(&new->refcnt, 1);
2606 return new;
2607}
2608
2609/* Slow path of a mempolicy comparison */
2610bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
2611{
2612 if (!a || !b)
2613 return false;
2614 if (a->mode != b->mode)
2615 return false;
2616 if (a->flags != b->flags)
2617 return false;
2618 if (a->home_node != b->home_node)
2619 return false;
2620 if (mpol_store_user_nodemask(a))
2621 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
2622 return false;
2623
2624 switch (a->mode) {
2625 case MPOL_BIND:
2626 case MPOL_INTERLEAVE:
2627 case MPOL_PREFERRED:
2628 case MPOL_PREFERRED_MANY:
2629 case MPOL_WEIGHTED_INTERLEAVE:
2630 return !!nodes_equal(a->nodes, b->nodes);
2631 case MPOL_LOCAL:
2632 return true;
2633 default:
2634 BUG();
2635 return false;
2636 }
2637}
2638
2639/*
2640 * Shared memory backing store policy support.
2641 *
2642 * Remember policies even when nobody has shared memory mapped.
2643 * The policies are kept in Red-Black tree linked from the inode.
2644 * They are protected by the sp->lock rwlock, which should be held
2645 * for any accesses to the tree.
2646 */
2647
2648/*
2649 * lookup first element intersecting start-end. Caller holds sp->lock for
2650 * reading or for writing
2651 */
2652static struct sp_node *sp_lookup(struct shared_policy *sp,
2653 pgoff_t start, pgoff_t end)
2654{
2655 struct rb_node *n = sp->root.rb_node;
2656
2657 while (n) {
2658 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2659
2660 if (start >= p->end)
2661 n = n->rb_right;
2662 else if (end <= p->start)
2663 n = n->rb_left;
2664 else
2665 break;
2666 }
2667 if (!n)
2668 return NULL;
2669 for (;;) {
2670 struct sp_node *w = NULL;
2671 struct rb_node *prev = rb_prev(n);
2672 if (!prev)
2673 break;
2674 w = rb_entry(prev, struct sp_node, nd);
2675 if (w->end <= start)
2676 break;
2677 n = prev;
2678 }
2679 return rb_entry(n, struct sp_node, nd);
2680}
2681
2682/*
2683 * Insert a new shared policy into the list. Caller holds sp->lock for
2684 * writing.
2685 */
2686static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2687{
2688 struct rb_node **p = &sp->root.rb_node;
2689 struct rb_node *parent = NULL;
2690 struct sp_node *nd;
2691
2692 while (*p) {
2693 parent = *p;
2694 nd = rb_entry(parent, struct sp_node, nd);
2695 if (new->start < nd->start)
2696 p = &(*p)->rb_left;
2697 else if (new->end > nd->end)
2698 p = &(*p)->rb_right;
2699 else
2700 BUG();
2701 }
2702 rb_link_node(&new->nd, parent, p);
2703 rb_insert_color(&new->nd, &sp->root);
2704}
2705
2706/* Find shared policy intersecting idx */
2707struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
2708 pgoff_t idx)
2709{
2710 struct mempolicy *pol = NULL;
2711 struct sp_node *sn;
2712
2713 if (!sp->root.rb_node)
2714 return NULL;
2715 read_lock(&sp->lock);
2716 sn = sp_lookup(sp, idx, idx+1);
2717 if (sn) {
2718 mpol_get(sn->policy);
2719 pol = sn->policy;
2720 }
2721 read_unlock(&sp->lock);
2722 return pol;
2723}
2724
2725static void sp_free(struct sp_node *n)
2726{
2727 mpol_put(n->policy);
2728 kmem_cache_free(sn_cache, n);
2729}
2730
2731/**
2732 * mpol_misplaced - check whether current folio node is valid in policy
2733 *
2734 * @folio: folio to be checked
2735 * @vmf: structure describing the fault
2736 * @addr: virtual address in @vma for shared policy lookup and interleave policy
2737 *
2738 * Lookup current policy node id for vma,addr and "compare to" folio's
2739 * node id. Policy determination "mimics" alloc_page_vma().
2740 * Called from fault path where we know the vma and faulting address.
2741 *
2742 * Return: NUMA_NO_NODE if the page is in a node that is valid for this
2743 * policy, or a suitable node ID to allocate a replacement folio from.
2744 */
2745int mpol_misplaced(struct folio *folio, struct vm_fault *vmf,
2746 unsigned long addr)
2747{
2748 struct mempolicy *pol;
2749 pgoff_t ilx;
2750 struct zoneref *z;
2751 int curnid = folio_nid(folio);
2752 struct vm_area_struct *vma = vmf->vma;
2753 int thiscpu = raw_smp_processor_id();
2754 int thisnid = numa_node_id();
2755 int polnid = NUMA_NO_NODE;
2756 int ret = NUMA_NO_NODE;
2757
2758 /*
2759 * Make sure ptl is held so that we don't preempt and we
2760 * have a stable smp processor id
2761 */
2762 lockdep_assert_held(vmf->ptl);
2763 pol = get_vma_policy(vma, addr, folio_order(folio), &ilx);
2764 if (!(pol->flags & MPOL_F_MOF))
2765 goto out;
2766
2767 switch (pol->mode) {
2768 case MPOL_INTERLEAVE:
2769 polnid = interleave_nid(pol, ilx);
2770 break;
2771
2772 case MPOL_WEIGHTED_INTERLEAVE:
2773 polnid = weighted_interleave_nid(pol, ilx);
2774 break;
2775
2776 case MPOL_PREFERRED:
2777 if (node_isset(curnid, pol->nodes))
2778 goto out;
2779 polnid = first_node(pol->nodes);
2780 break;
2781
2782 case MPOL_LOCAL:
2783 polnid = numa_node_id();
2784 break;
2785
2786 case MPOL_BIND:
2787 case MPOL_PREFERRED_MANY:
2788 /*
2789 * Even though MPOL_PREFERRED_MANY can allocate pages outside
2790 * policy nodemask we don't allow numa migration to nodes
2791 * outside policy nodemask for now. This is done so that if we
2792 * want demotion to slow memory to happen, before allocating
2793 * from some DRAM node say 'x', we will end up using a
2794 * MPOL_PREFERRED_MANY mask excluding node 'x'. In such scenario
2795 * we should not promote to node 'x' from slow memory node.
2796 */
2797 if (pol->flags & MPOL_F_MORON) {
2798 /*
2799 * Optimize placement among multiple nodes
2800 * via NUMA balancing
2801 */
2802 if (node_isset(thisnid, pol->nodes))
2803 break;
2804 goto out;
2805 }
2806
2807 /*
2808 * use current page if in policy nodemask,
2809 * else select nearest allowed node, if any.
2810 * If no allowed nodes, use current [!misplaced].
2811 */
2812 if (node_isset(curnid, pol->nodes))
2813 goto out;
2814 z = first_zones_zonelist(
2815 node_zonelist(thisnid, GFP_HIGHUSER),
2816 gfp_zone(GFP_HIGHUSER),
2817 &pol->nodes);
2818 polnid = zonelist_node_idx(z);
2819 break;
2820
2821 default:
2822 BUG();
2823 }
2824
2825 /* Migrate the folio towards the node whose CPU is referencing it */
2826 if (pol->flags & MPOL_F_MORON) {
2827 polnid = thisnid;
2828
2829 if (!should_numa_migrate_memory(current, folio, curnid,
2830 thiscpu))
2831 goto out;
2832 }
2833
2834 if (curnid != polnid)
2835 ret = polnid;
2836out:
2837 mpol_cond_put(pol);
2838
2839 return ret;
2840}
2841
2842/*
2843 * Drop the (possibly final) reference to task->mempolicy. It needs to be
2844 * dropped after task->mempolicy is set to NULL so that any allocation done as
2845 * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed
2846 * policy.
2847 */
2848void mpol_put_task_policy(struct task_struct *task)
2849{
2850 struct mempolicy *pol;
2851
2852 task_lock(task);
2853 pol = task->mempolicy;
2854 task->mempolicy = NULL;
2855 task_unlock(task);
2856 mpol_put(pol);
2857}
2858
2859static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2860{
2861 rb_erase(&n->nd, &sp->root);
2862 sp_free(n);
2863}
2864
2865static void sp_node_init(struct sp_node *node, unsigned long start,
2866 unsigned long end, struct mempolicy *pol)
2867{
2868 node->start = start;
2869 node->end = end;
2870 node->policy = pol;
2871}
2872
2873static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2874 struct mempolicy *pol)
2875{
2876 struct sp_node *n;
2877 struct mempolicy *newpol;
2878
2879 n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2880 if (!n)
2881 return NULL;
2882
2883 newpol = mpol_dup(pol);
2884 if (IS_ERR(newpol)) {
2885 kmem_cache_free(sn_cache, n);
2886 return NULL;
2887 }
2888 newpol->flags |= MPOL_F_SHARED;
2889 sp_node_init(n, start, end, newpol);
2890
2891 return n;
2892}
2893
2894/* Replace a policy range. */
2895static int shared_policy_replace(struct shared_policy *sp, pgoff_t start,
2896 pgoff_t end, struct sp_node *new)
2897{
2898 struct sp_node *n;
2899 struct sp_node *n_new = NULL;
2900 struct mempolicy *mpol_new = NULL;
2901 int ret = 0;
2902
2903restart:
2904 write_lock(&sp->lock);
2905 n = sp_lookup(sp, start, end);
2906 /* Take care of old policies in the same range. */
2907 while (n && n->start < end) {
2908 struct rb_node *next = rb_next(&n->nd);
2909 if (n->start >= start) {
2910 if (n->end <= end)
2911 sp_delete(sp, n);
2912 else
2913 n->start = end;
2914 } else {
2915 /* Old policy spanning whole new range. */
2916 if (n->end > end) {
2917 if (!n_new)
2918 goto alloc_new;
2919
2920 *mpol_new = *n->policy;
2921 atomic_set(&mpol_new->refcnt, 1);
2922 sp_node_init(n_new, end, n->end, mpol_new);
2923 n->end = start;
2924 sp_insert(sp, n_new);
2925 n_new = NULL;
2926 mpol_new = NULL;
2927 break;
2928 } else
2929 n->end = start;
2930 }
2931 if (!next)
2932 break;
2933 n = rb_entry(next, struct sp_node, nd);
2934 }
2935 if (new)
2936 sp_insert(sp, new);
2937 write_unlock(&sp->lock);
2938 ret = 0;
2939
2940err_out:
2941 if (mpol_new)
2942 mpol_put(mpol_new);
2943 if (n_new)
2944 kmem_cache_free(sn_cache, n_new);
2945
2946 return ret;
2947
2948alloc_new:
2949 write_unlock(&sp->lock);
2950 ret = -ENOMEM;
2951 n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2952 if (!n_new)
2953 goto err_out;
2954 mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2955 if (!mpol_new)
2956 goto err_out;
2957 atomic_set(&mpol_new->refcnt, 1);
2958 goto restart;
2959}
2960
2961/**
2962 * mpol_shared_policy_init - initialize shared policy for inode
2963 * @sp: pointer to inode shared policy
2964 * @mpol: struct mempolicy to install
2965 *
2966 * Install non-NULL @mpol in inode's shared policy rb-tree.
2967 * On entry, the current task has a reference on a non-NULL @mpol.
2968 * This must be released on exit.
2969 * This is called at get_inode() calls and we can use GFP_KERNEL.
2970 */
2971void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
2972{
2973 int ret;
2974
2975 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2976 rwlock_init(&sp->lock);
2977
2978 if (mpol) {
2979 struct sp_node *sn;
2980 struct mempolicy *npol;
2981 NODEMASK_SCRATCH(scratch);
2982
2983 if (!scratch)
2984 goto put_mpol;
2985
2986 /* contextualize the tmpfs mount point mempolicy to this file */
2987 npol = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2988 if (IS_ERR(npol))
2989 goto free_scratch; /* no valid nodemask intersection */
2990
2991 task_lock(current);
2992 ret = mpol_set_nodemask(npol, &mpol->w.user_nodemask, scratch);
2993 task_unlock(current);
2994 if (ret)
2995 goto put_npol;
2996
2997 /* alloc node covering entire file; adds ref to file's npol */
2998 sn = sp_alloc(0, MAX_LFS_FILESIZE >> PAGE_SHIFT, npol);
2999 if (sn)
3000 sp_insert(sp, sn);
3001put_npol:
3002 mpol_put(npol); /* drop initial ref on file's npol */
3003free_scratch:
3004 NODEMASK_SCRATCH_FREE(scratch);
3005put_mpol:
3006 mpol_put(mpol); /* drop our incoming ref on sb mpol */
3007 }
3008}
3009
3010int mpol_set_shared_policy(struct shared_policy *sp,
3011 struct vm_area_struct *vma, struct mempolicy *pol)
3012{
3013 int err;
3014 struct sp_node *new = NULL;
3015 unsigned long sz = vma_pages(vma);
3016
3017 if (pol) {
3018 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, pol);
3019 if (!new)
3020 return -ENOMEM;
3021 }
3022 err = shared_policy_replace(sp, vma->vm_pgoff, vma->vm_pgoff + sz, new);
3023 if (err && new)
3024 sp_free(new);
3025 return err;
3026}
3027
3028/* Free a backing policy store on inode delete. */
3029void mpol_free_shared_policy(struct shared_policy *sp)
3030{
3031 struct sp_node *n;
3032 struct rb_node *next;
3033
3034 if (!sp->root.rb_node)
3035 return;
3036 write_lock(&sp->lock);
3037 next = rb_first(&sp->root);
3038 while (next) {
3039 n = rb_entry(next, struct sp_node, nd);
3040 next = rb_next(&n->nd);
3041 sp_delete(sp, n);
3042 }
3043 write_unlock(&sp->lock);
3044}
3045
3046#ifdef CONFIG_NUMA_BALANCING
3047static int __initdata numabalancing_override;
3048
3049static void __init check_numabalancing_enable(void)
3050{
3051 bool numabalancing_default = false;
3052
3053 if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
3054 numabalancing_default = true;
3055
3056 /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
3057 if (numabalancing_override)
3058 set_numabalancing_state(numabalancing_override == 1);
3059
3060 if (num_online_nodes() > 1 && !numabalancing_override) {
3061 pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n",
3062 numabalancing_default ? "Enabling" : "Disabling");
3063 set_numabalancing_state(numabalancing_default);
3064 }
3065}
3066
3067static int __init setup_numabalancing(char *str)
3068{
3069 int ret = 0;
3070 if (!str)
3071 goto out;
3072
3073 if (!strcmp(str, "enable")) {
3074 numabalancing_override = 1;
3075 ret = 1;
3076 } else if (!strcmp(str, "disable")) {
3077 numabalancing_override = -1;
3078 ret = 1;
3079 }
3080out:
3081 if (!ret)
3082 pr_warn("Unable to parse numa_balancing=\n");
3083
3084 return ret;
3085}
3086__setup("numa_balancing=", setup_numabalancing);
3087#else
3088static inline void __init check_numabalancing_enable(void)
3089{
3090}
3091#endif /* CONFIG_NUMA_BALANCING */
3092
3093void __init numa_policy_init(void)
3094{
3095 nodemask_t interleave_nodes;
3096 unsigned long largest = 0;
3097 int nid, prefer = 0;
3098
3099 policy_cache = kmem_cache_create("numa_policy",
3100 sizeof(struct mempolicy),
3101 0, SLAB_PANIC, NULL);
3102
3103 sn_cache = kmem_cache_create("shared_policy_node",
3104 sizeof(struct sp_node),
3105 0, SLAB_PANIC, NULL);
3106
3107 for_each_node(nid) {
3108 preferred_node_policy[nid] = (struct mempolicy) {
3109 .refcnt = ATOMIC_INIT(1),
3110 .mode = MPOL_PREFERRED,
3111 .flags = MPOL_F_MOF | MPOL_F_MORON,
3112 .nodes = nodemask_of_node(nid),
3113 };
3114 }
3115
3116 /*
3117 * Set interleaving policy for system init. Interleaving is only
3118 * enabled across suitably sized nodes (default is >= 16MB), or
3119 * fall back to the largest node if they're all smaller.
3120 */
3121 nodes_clear(interleave_nodes);
3122 for_each_node_state(nid, N_MEMORY) {
3123 unsigned long total_pages = node_present_pages(nid);
3124
3125 /* Preserve the largest node */
3126 if (largest < total_pages) {
3127 largest = total_pages;
3128 prefer = nid;
3129 }
3130
3131 /* Interleave this node? */
3132 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
3133 node_set(nid, interleave_nodes);
3134 }
3135
3136 /* All too small, use the largest */
3137 if (unlikely(nodes_empty(interleave_nodes)))
3138 node_set(prefer, interleave_nodes);
3139
3140 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
3141 pr_err("%s: interleaving failed\n", __func__);
3142
3143 check_numabalancing_enable();
3144}
3145
3146/* Reset policy of current process to default */
3147void numa_default_policy(void)
3148{
3149 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
3150}
3151
3152/*
3153 * Parse and format mempolicy from/to strings
3154 */
3155static const char * const policy_modes[] =
3156{
3157 [MPOL_DEFAULT] = "default",
3158 [MPOL_PREFERRED] = "prefer",
3159 [MPOL_BIND] = "bind",
3160 [MPOL_INTERLEAVE] = "interleave",
3161 [MPOL_WEIGHTED_INTERLEAVE] = "weighted interleave",
3162 [MPOL_LOCAL] = "local",
3163 [MPOL_PREFERRED_MANY] = "prefer (many)",
3164};
3165
3166#ifdef CONFIG_TMPFS
3167/**
3168 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
3169 * @str: string containing mempolicy to parse
3170 * @mpol: pointer to struct mempolicy pointer, returned on success.
3171 *
3172 * Format of input:
3173 * <mode>[=<flags>][:<nodelist>]
3174 *
3175 * Return: %0 on success, else %1
3176 */
3177int mpol_parse_str(char *str, struct mempolicy **mpol)
3178{
3179 struct mempolicy *new = NULL;
3180 unsigned short mode_flags;
3181 nodemask_t nodes;
3182 char *nodelist = strchr(str, ':');
3183 char *flags = strchr(str, '=');
3184 int err = 1, mode;
3185
3186 if (flags)
3187 *flags++ = '\0'; /* terminate mode string */
3188
3189 if (nodelist) {
3190 /* NUL-terminate mode or flags string */
3191 *nodelist++ = '\0';
3192 if (nodelist_parse(nodelist, nodes))
3193 goto out;
3194 if (!nodes_subset(nodes, node_states[N_MEMORY]))
3195 goto out;
3196 } else
3197 nodes_clear(nodes);
3198
3199 mode = match_string(policy_modes, MPOL_MAX, str);
3200 if (mode < 0)
3201 goto out;
3202
3203 switch (mode) {
3204 case MPOL_PREFERRED:
3205 /*
3206 * Insist on a nodelist of one node only, although later
3207 * we use first_node(nodes) to grab a single node, so here
3208 * nodelist (or nodes) cannot be empty.
3209 */
3210 if (nodelist) {
3211 char *rest = nodelist;
3212 while (isdigit(*rest))
3213 rest++;
3214 if (*rest)
3215 goto out;
3216 if (nodes_empty(nodes))
3217 goto out;
3218 }
3219 break;
3220 case MPOL_INTERLEAVE:
3221 case MPOL_WEIGHTED_INTERLEAVE:
3222 /*
3223 * Default to online nodes with memory if no nodelist
3224 */
3225 if (!nodelist)
3226 nodes = node_states[N_MEMORY];
3227 break;
3228 case MPOL_LOCAL:
3229 /*
3230 * Don't allow a nodelist; mpol_new() checks flags
3231 */
3232 if (nodelist)
3233 goto out;
3234 break;
3235 case MPOL_DEFAULT:
3236 /*
3237 * Insist on a empty nodelist
3238 */
3239 if (!nodelist)
3240 err = 0;
3241 goto out;
3242 case MPOL_PREFERRED_MANY:
3243 case MPOL_BIND:
3244 /*
3245 * Insist on a nodelist
3246 */
3247 if (!nodelist)
3248 goto out;
3249 }
3250
3251 mode_flags = 0;
3252 if (flags) {
3253 /*
3254 * Currently, we only support two mutually exclusive
3255 * mode flags.
3256 */
3257 if (!strcmp(flags, "static"))
3258 mode_flags |= MPOL_F_STATIC_NODES;
3259 else if (!strcmp(flags, "relative"))
3260 mode_flags |= MPOL_F_RELATIVE_NODES;
3261 else
3262 goto out;
3263 }
3264
3265 new = mpol_new(mode, mode_flags, &nodes);
3266 if (IS_ERR(new))
3267 goto out;
3268
3269 /*
3270 * Save nodes for mpol_to_str() to show the tmpfs mount options
3271 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
3272 */
3273 if (mode != MPOL_PREFERRED) {
3274 new->nodes = nodes;
3275 } else if (nodelist) {
3276 nodes_clear(new->nodes);
3277 node_set(first_node(nodes), new->nodes);
3278 } else {
3279 new->mode = MPOL_LOCAL;
3280 }
3281
3282 /*
3283 * Save nodes for contextualization: this will be used to "clone"
3284 * the mempolicy in a specific context [cpuset] at a later time.
3285 */
3286 new->w.user_nodemask = nodes;
3287
3288 err = 0;
3289
3290out:
3291 /* Restore string for error message */
3292 if (nodelist)
3293 *--nodelist = ':';
3294 if (flags)
3295 *--flags = '=';
3296 if (!err)
3297 *mpol = new;
3298 return err;
3299}
3300#endif /* CONFIG_TMPFS */
3301
3302/**
3303 * mpol_to_str - format a mempolicy structure for printing
3304 * @buffer: to contain formatted mempolicy string
3305 * @maxlen: length of @buffer
3306 * @pol: pointer to mempolicy to be formatted
3307 *
3308 * Convert @pol into a string. If @buffer is too short, truncate the string.
3309 * Recommend a @maxlen of at least 51 for the longest mode, "weighted
3310 * interleave", plus the longest flag flags, "relative|balancing", and to
3311 * display at least a few node ids.
3312 */
3313void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
3314{
3315 char *p = buffer;
3316 nodemask_t nodes = NODE_MASK_NONE;
3317 unsigned short mode = MPOL_DEFAULT;
3318 unsigned short flags = 0;
3319
3320 if (pol &&
3321 pol != &default_policy &&
3322 !(pol >= &preferred_node_policy[0] &&
3323 pol <= &preferred_node_policy[ARRAY_SIZE(preferred_node_policy) - 1])) {
3324 mode = pol->mode;
3325 flags = pol->flags;
3326 }
3327
3328 switch (mode) {
3329 case MPOL_DEFAULT:
3330 case MPOL_LOCAL:
3331 break;
3332 case MPOL_PREFERRED:
3333 case MPOL_PREFERRED_MANY:
3334 case MPOL_BIND:
3335 case MPOL_INTERLEAVE:
3336 case MPOL_WEIGHTED_INTERLEAVE:
3337 nodes = pol->nodes;
3338 break;
3339 default:
3340 WARN_ON_ONCE(1);
3341 snprintf(p, maxlen, "unknown");
3342 return;
3343 }
3344
3345 p += snprintf(p, maxlen, "%s", policy_modes[mode]);
3346
3347 if (flags & MPOL_MODE_FLAGS) {
3348 p += snprintf(p, buffer + maxlen - p, "=");
3349
3350 /*
3351 * Static and relative are mutually exclusive.
3352 */
3353 if (flags & MPOL_F_STATIC_NODES)
3354 p += snprintf(p, buffer + maxlen - p, "static");
3355 else if (flags & MPOL_F_RELATIVE_NODES)
3356 p += snprintf(p, buffer + maxlen - p, "relative");
3357
3358 if (flags & MPOL_F_NUMA_BALANCING) {
3359 if (!is_power_of_2(flags & MPOL_MODE_FLAGS))
3360 p += snprintf(p, buffer + maxlen - p, "|");
3361 p += snprintf(p, buffer + maxlen - p, "balancing");
3362 }
3363 }
3364
3365 if (!nodes_empty(nodes))
3366 p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
3367 nodemask_pr_args(&nodes));
3368}
3369
3370#ifdef CONFIG_SYSFS
3371struct iw_node_attr {
3372 struct kobj_attribute kobj_attr;
3373 int nid;
3374};
3375
3376static ssize_t node_show(struct kobject *kobj, struct kobj_attribute *attr,
3377 char *buf)
3378{
3379 struct iw_node_attr *node_attr;
3380 u8 weight;
3381
3382 node_attr = container_of(attr, struct iw_node_attr, kobj_attr);
3383 weight = get_il_weight(node_attr->nid);
3384 return sysfs_emit(buf, "%d\n", weight);
3385}
3386
3387static ssize_t node_store(struct kobject *kobj, struct kobj_attribute *attr,
3388 const char *buf, size_t count)
3389{
3390 struct iw_node_attr *node_attr;
3391 u8 *new;
3392 u8 *old;
3393 u8 weight = 0;
3394
3395 node_attr = container_of(attr, struct iw_node_attr, kobj_attr);
3396 if (count == 0 || sysfs_streq(buf, ""))
3397 weight = 0;
3398 else if (kstrtou8(buf, 0, &weight))
3399 return -EINVAL;
3400
3401 new = kzalloc(nr_node_ids, GFP_KERNEL);
3402 if (!new)
3403 return -ENOMEM;
3404
3405 mutex_lock(&iw_table_lock);
3406 old = rcu_dereference_protected(iw_table,
3407 lockdep_is_held(&iw_table_lock));
3408 if (old)
3409 memcpy(new, old, nr_node_ids);
3410 new[node_attr->nid] = weight;
3411 rcu_assign_pointer(iw_table, new);
3412 mutex_unlock(&iw_table_lock);
3413 synchronize_rcu();
3414 kfree(old);
3415 return count;
3416}
3417
3418static struct iw_node_attr **node_attrs;
3419
3420static void sysfs_wi_node_release(struct iw_node_attr *node_attr,
3421 struct kobject *parent)
3422{
3423 if (!node_attr)
3424 return;
3425 sysfs_remove_file(parent, &node_attr->kobj_attr.attr);
3426 kfree(node_attr->kobj_attr.attr.name);
3427 kfree(node_attr);
3428}
3429
3430static void sysfs_wi_release(struct kobject *wi_kobj)
3431{
3432 int i;
3433
3434 for (i = 0; i < nr_node_ids; i++)
3435 sysfs_wi_node_release(node_attrs[i], wi_kobj);
3436 kobject_put(wi_kobj);
3437}
3438
3439static const struct kobj_type wi_ktype = {
3440 .sysfs_ops = &kobj_sysfs_ops,
3441 .release = sysfs_wi_release,
3442};
3443
3444static int add_weight_node(int nid, struct kobject *wi_kobj)
3445{
3446 struct iw_node_attr *node_attr;
3447 char *name;
3448
3449 node_attr = kzalloc(sizeof(*node_attr), GFP_KERNEL);
3450 if (!node_attr)
3451 return -ENOMEM;
3452
3453 name = kasprintf(GFP_KERNEL, "node%d", nid);
3454 if (!name) {
3455 kfree(node_attr);
3456 return -ENOMEM;
3457 }
3458
3459 sysfs_attr_init(&node_attr->kobj_attr.attr);
3460 node_attr->kobj_attr.attr.name = name;
3461 node_attr->kobj_attr.attr.mode = 0644;
3462 node_attr->kobj_attr.show = node_show;
3463 node_attr->kobj_attr.store = node_store;
3464 node_attr->nid = nid;
3465
3466 if (sysfs_create_file(wi_kobj, &node_attr->kobj_attr.attr)) {
3467 kfree(node_attr->kobj_attr.attr.name);
3468 kfree(node_attr);
3469 pr_err("failed to add attribute to weighted_interleave\n");
3470 return -ENOMEM;
3471 }
3472
3473 node_attrs[nid] = node_attr;
3474 return 0;
3475}
3476
3477static int add_weighted_interleave_group(struct kobject *root_kobj)
3478{
3479 struct kobject *wi_kobj;
3480 int nid, err;
3481
3482 wi_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
3483 if (!wi_kobj)
3484 return -ENOMEM;
3485
3486 err = kobject_init_and_add(wi_kobj, &wi_ktype, root_kobj,
3487 "weighted_interleave");
3488 if (err) {
3489 kfree(wi_kobj);
3490 return err;
3491 }
3492
3493 for_each_node_state(nid, N_POSSIBLE) {
3494 err = add_weight_node(nid, wi_kobj);
3495 if (err) {
3496 pr_err("failed to add sysfs [node%d]\n", nid);
3497 break;
3498 }
3499 }
3500 if (err)
3501 kobject_put(wi_kobj);
3502 return 0;
3503}
3504
3505static void mempolicy_kobj_release(struct kobject *kobj)
3506{
3507 u8 *old;
3508
3509 mutex_lock(&iw_table_lock);
3510 old = rcu_dereference_protected(iw_table,
3511 lockdep_is_held(&iw_table_lock));
3512 rcu_assign_pointer(iw_table, NULL);
3513 mutex_unlock(&iw_table_lock);
3514 synchronize_rcu();
3515 kfree(old);
3516 kfree(node_attrs);
3517 kfree(kobj);
3518}
3519
3520static const struct kobj_type mempolicy_ktype = {
3521 .release = mempolicy_kobj_release
3522};
3523
3524static int __init mempolicy_sysfs_init(void)
3525{
3526 int err;
3527 static struct kobject *mempolicy_kobj;
3528
3529 mempolicy_kobj = kzalloc(sizeof(*mempolicy_kobj), GFP_KERNEL);
3530 if (!mempolicy_kobj) {
3531 err = -ENOMEM;
3532 goto err_out;
3533 }
3534
3535 node_attrs = kcalloc(nr_node_ids, sizeof(struct iw_node_attr *),
3536 GFP_KERNEL);
3537 if (!node_attrs) {
3538 err = -ENOMEM;
3539 goto mempol_out;
3540 }
3541
3542 err = kobject_init_and_add(mempolicy_kobj, &mempolicy_ktype, mm_kobj,
3543 "mempolicy");
3544 if (err)
3545 goto node_out;
3546
3547 err = add_weighted_interleave_group(mempolicy_kobj);
3548 if (err) {
3549 pr_err("mempolicy sysfs structure failed to initialize\n");
3550 kobject_put(mempolicy_kobj);
3551 return err;
3552 }
3553
3554 return err;
3555node_out:
3556 kfree(node_attrs);
3557mempol_out:
3558 kfree(mempolicy_kobj);
3559err_out:
3560 pr_err("failed to add mempolicy kobject to the system\n");
3561 return err;
3562}
3563
3564late_initcall(mempolicy_sysfs_init);
3565#endif /* CONFIG_SYSFS */