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