xref: /linux/include/linux/mm_inline.h (revision 08148805)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef LINUX_MM_INLINE_H
3 #define LINUX_MM_INLINE_H
4 
5 #include <linux/atomic.h>
6 #include <linux/huge_mm.h>
7 #include <linux/mm_types.h>
8 #include <linux/swap.h>
9 #include <linux/string.h>
10 #include <linux/userfaultfd_k.h>
11 #include <linux/swapops.h>
12 
13 /**
14  * folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
15  * @folio: The folio to test.
16  *
17  * We would like to get this info without a page flag, but the state
18  * needs to survive until the folio is last deleted from the LRU, which
19  * could be as far down as __page_cache_release.
20  *
21  * Return: An integer (not a boolean!) used to sort a folio onto the
22  * right LRU list and to account folios correctly.
23  * 1 if @folio is a regular filesystem backed page cache folio
24  * or a lazily freed anonymous folio (e.g. via MADV_FREE).
25  * 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise
26  * ram or swap backed folio.
27  */
folio_is_file_lru(struct folio * folio)28 static inline int folio_is_file_lru(struct folio *folio)
29 {
30 	return !folio_test_swapbacked(folio);
31 }
32 
page_is_file_lru(struct page * page)33 static inline int page_is_file_lru(struct page *page)
34 {
35 	return folio_is_file_lru(page_folio(page));
36 }
37 
__update_lru_size(struct lruvec * lruvec,enum lru_list lru,enum zone_type zid,long nr_pages)38 static __always_inline void __update_lru_size(struct lruvec *lruvec,
39 				enum lru_list lru, enum zone_type zid,
40 				long nr_pages)
41 {
42 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
43 
44 	lockdep_assert_held(&lruvec->lru_lock);
45 	WARN_ON_ONCE(nr_pages != (int)nr_pages);
46 
47 	__mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
48 	__mod_zone_page_state(&pgdat->node_zones[zid],
49 				NR_ZONE_LRU_BASE + lru, nr_pages);
50 }
51 
update_lru_size(struct lruvec * lruvec,enum lru_list lru,enum zone_type zid,long nr_pages)52 static __always_inline void update_lru_size(struct lruvec *lruvec,
53 				enum lru_list lru, enum zone_type zid,
54 				long nr_pages)
55 {
56 	__update_lru_size(lruvec, lru, zid, nr_pages);
57 #ifdef CONFIG_MEMCG
58 	mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
59 #endif
60 }
61 
62 /**
63  * __folio_clear_lru_flags - Clear page lru flags before releasing a page.
64  * @folio: The folio that was on lru and now has a zero reference.
65  */
__folio_clear_lru_flags(struct folio * folio)66 static __always_inline void __folio_clear_lru_flags(struct folio *folio)
67 {
68 	VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);
69 
70 	__folio_clear_lru(folio);
71 
72 	/* this shouldn't happen, so leave the flags to bad_page() */
73 	if (folio_test_active(folio) && folio_test_unevictable(folio))
74 		return;
75 
76 	__folio_clear_active(folio);
77 	__folio_clear_unevictable(folio);
78 }
79 
80 /**
81  * folio_lru_list - Which LRU list should a folio be on?
82  * @folio: The folio to test.
83  *
84  * Return: The LRU list a folio should be on, as an index
85  * into the array of LRU lists.
86  */
folio_lru_list(struct folio * folio)87 static __always_inline enum lru_list folio_lru_list(struct folio *folio)
88 {
89 	enum lru_list lru;
90 
91 	VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
92 
93 	if (folio_test_unevictable(folio))
94 		return LRU_UNEVICTABLE;
95 
96 	lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
97 	if (folio_test_active(folio))
98 		lru += LRU_ACTIVE;
99 
100 	return lru;
101 }
102 
103 #ifdef CONFIG_LRU_GEN
104 
105 #ifdef CONFIG_LRU_GEN_ENABLED
lru_gen_enabled(void)106 static inline bool lru_gen_enabled(void)
107 {
108 	DECLARE_STATIC_KEY_TRUE(lru_gen_caps[NR_LRU_GEN_CAPS]);
109 
110 	return static_branch_likely(&lru_gen_caps[LRU_GEN_CORE]);
111 }
112 #else
lru_gen_enabled(void)113 static inline bool lru_gen_enabled(void)
114 {
115 	DECLARE_STATIC_KEY_FALSE(lru_gen_caps[NR_LRU_GEN_CAPS]);
116 
117 	return static_branch_unlikely(&lru_gen_caps[LRU_GEN_CORE]);
118 }
119 #endif
120 
lru_gen_in_fault(void)121 static inline bool lru_gen_in_fault(void)
122 {
123 	return current->in_lru_fault;
124 }
125 
lru_gen_from_seq(unsigned long seq)126 static inline int lru_gen_from_seq(unsigned long seq)
127 {
128 	return seq % MAX_NR_GENS;
129 }
130 
lru_hist_from_seq(unsigned long seq)131 static inline int lru_hist_from_seq(unsigned long seq)
132 {
133 	return seq % NR_HIST_GENS;
134 }
135 
lru_tier_from_refs(int refs)136 static inline int lru_tier_from_refs(int refs)
137 {
138 	VM_WARN_ON_ONCE(refs > BIT(LRU_REFS_WIDTH));
139 
140 	/* see the comment in folio_lru_refs() */
141 	return order_base_2(refs + 1);
142 }
143 
folio_lru_refs(struct folio * folio)144 static inline int folio_lru_refs(struct folio *folio)
145 {
146 	unsigned long flags = READ_ONCE(folio->flags);
147 	bool workingset = flags & BIT(PG_workingset);
148 
149 	/*
150 	 * Return the number of accesses beyond PG_referenced, i.e., N-1 if the
151 	 * total number of accesses is N>1, since N=0,1 both map to the first
152 	 * tier. lru_tier_from_refs() will account for this off-by-one. Also see
153 	 * the comment on MAX_NR_TIERS.
154 	 */
155 	return ((flags & LRU_REFS_MASK) >> LRU_REFS_PGOFF) + workingset;
156 }
157 
folio_lru_gen(struct folio * folio)158 static inline int folio_lru_gen(struct folio *folio)
159 {
160 	unsigned long flags = READ_ONCE(folio->flags);
161 
162 	return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
163 }
164 
lru_gen_is_active(struct lruvec * lruvec,int gen)165 static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)
166 {
167 	unsigned long max_seq = lruvec->lrugen.max_seq;
168 
169 	VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);
170 
171 	/* see the comment on MIN_NR_GENS */
172 	return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
173 }
174 
lru_gen_update_size(struct lruvec * lruvec,struct folio * folio,int old_gen,int new_gen)175 static inline void lru_gen_update_size(struct lruvec *lruvec, struct folio *folio,
176 				       int old_gen, int new_gen)
177 {
178 	int type = folio_is_file_lru(folio);
179 	int zone = folio_zonenum(folio);
180 	int delta = folio_nr_pages(folio);
181 	enum lru_list lru = type * LRU_INACTIVE_FILE;
182 	struct lru_gen_folio *lrugen = &lruvec->lrugen;
183 
184 	VM_WARN_ON_ONCE(old_gen != -1 && old_gen >= MAX_NR_GENS);
185 	VM_WARN_ON_ONCE(new_gen != -1 && new_gen >= MAX_NR_GENS);
186 	VM_WARN_ON_ONCE(old_gen == -1 && new_gen == -1);
187 
188 	if (old_gen >= 0)
189 		WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],
190 			   lrugen->nr_pages[old_gen][type][zone] - delta);
191 	if (new_gen >= 0)
192 		WRITE_ONCE(lrugen->nr_pages[new_gen][type][zone],
193 			   lrugen->nr_pages[new_gen][type][zone] + delta);
194 
195 	/* addition */
196 	if (old_gen < 0) {
197 		if (lru_gen_is_active(lruvec, new_gen))
198 			lru += LRU_ACTIVE;
199 		__update_lru_size(lruvec, lru, zone, delta);
200 		return;
201 	}
202 
203 	/* deletion */
204 	if (new_gen < 0) {
205 		if (lru_gen_is_active(lruvec, old_gen))
206 			lru += LRU_ACTIVE;
207 		__update_lru_size(lruvec, lru, zone, -delta);
208 		return;
209 	}
210 
211 	/* promotion */
212 	if (!lru_gen_is_active(lruvec, old_gen) && lru_gen_is_active(lruvec, new_gen)) {
213 		__update_lru_size(lruvec, lru, zone, -delta);
214 		__update_lru_size(lruvec, lru + LRU_ACTIVE, zone, delta);
215 	}
216 
217 	/* demotion requires isolation, e.g., lru_deactivate_fn() */
218 	VM_WARN_ON_ONCE(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));
219 }
220 
lru_gen_add_folio(struct lruvec * lruvec,struct folio * folio,bool reclaiming)221 static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
222 {
223 	unsigned long seq;
224 	unsigned long flags;
225 	int gen = folio_lru_gen(folio);
226 	int type = folio_is_file_lru(folio);
227 	int zone = folio_zonenum(folio);
228 	struct lru_gen_folio *lrugen = &lruvec->lrugen;
229 
230 	VM_WARN_ON_ONCE_FOLIO(gen != -1, folio);
231 
232 	if (folio_test_unevictable(folio) || !lrugen->enabled)
233 		return false;
234 	/*
235 	 * There are four common cases for this page:
236 	 * 1. If it's hot, i.e., freshly faulted in, add it to the youngest
237 	 *    generation, and it's protected over the rest below.
238 	 * 2. If it can't be evicted immediately, i.e., a dirty page pending
239 	 *    writeback, add it to the second youngest generation.
240 	 * 3. If it should be evicted first, e.g., cold and clean from
241 	 *    folio_rotate_reclaimable(), add it to the oldest generation.
242 	 * 4. Everything else falls between 2 & 3 above and is added to the
243 	 *    second oldest generation if it's considered inactive, or the
244 	 *    oldest generation otherwise. See lru_gen_is_active().
245 	 */
246 	if (folio_test_active(folio))
247 		seq = lrugen->max_seq;
248 	else if ((type == LRU_GEN_ANON && !folio_test_swapcache(folio)) ||
249 		 (folio_test_reclaim(folio) &&
250 		  (folio_test_dirty(folio) || folio_test_writeback(folio))))
251 		seq = lrugen->max_seq - 1;
252 	else if (reclaiming || lrugen->min_seq[type] + MIN_NR_GENS >= lrugen->max_seq)
253 		seq = lrugen->min_seq[type];
254 	else
255 		seq = lrugen->min_seq[type] + 1;
256 
257 	gen = lru_gen_from_seq(seq);
258 	flags = (gen + 1UL) << LRU_GEN_PGOFF;
259 	/* see the comment on MIN_NR_GENS about PG_active */
260 	set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags);
261 
262 	lru_gen_update_size(lruvec, folio, -1, gen);
263 	/* for folio_rotate_reclaimable() */
264 	if (reclaiming)
265 		list_add_tail(&folio->lru, &lrugen->folios[gen][type][zone]);
266 	else
267 		list_add(&folio->lru, &lrugen->folios[gen][type][zone]);
268 
269 	return true;
270 }
271 
lru_gen_del_folio(struct lruvec * lruvec,struct folio * folio,bool reclaiming)272 static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
273 {
274 	unsigned long flags;
275 	int gen = folio_lru_gen(folio);
276 
277 	if (gen < 0)
278 		return false;
279 
280 	VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio);
281 	VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio);
282 
283 	/* for folio_migrate_flags() */
284 	flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;
285 	flags = set_mask_bits(&folio->flags, LRU_GEN_MASK, flags);
286 	gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
287 
288 	lru_gen_update_size(lruvec, folio, gen, -1);
289 	list_del(&folio->lru);
290 
291 	return true;
292 }
293 
294 #else /* !CONFIG_LRU_GEN */
295 
lru_gen_enabled(void)296 static inline bool lru_gen_enabled(void)
297 {
298 	return false;
299 }
300 
lru_gen_in_fault(void)301 static inline bool lru_gen_in_fault(void)
302 {
303 	return false;
304 }
305 
lru_gen_add_folio(struct lruvec * lruvec,struct folio * folio,bool reclaiming)306 static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
307 {
308 	return false;
309 }
310 
lru_gen_del_folio(struct lruvec * lruvec,struct folio * folio,bool reclaiming)311 static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
312 {
313 	return false;
314 }
315 
316 #endif /* CONFIG_LRU_GEN */
317 
318 static __always_inline
lruvec_add_folio(struct lruvec * lruvec,struct folio * folio)319 void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
320 {
321 	enum lru_list lru = folio_lru_list(folio);
322 
323 	if (lru_gen_add_folio(lruvec, folio, false))
324 		return;
325 
326 	update_lru_size(lruvec, lru, folio_zonenum(folio),
327 			folio_nr_pages(folio));
328 	if (lru != LRU_UNEVICTABLE)
329 		list_add(&folio->lru, &lruvec->lists[lru]);
330 }
331 
332 static __always_inline
lruvec_add_folio_tail(struct lruvec * lruvec,struct folio * folio)333 void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
334 {
335 	enum lru_list lru = folio_lru_list(folio);
336 
337 	if (lru_gen_add_folio(lruvec, folio, true))
338 		return;
339 
340 	update_lru_size(lruvec, lru, folio_zonenum(folio),
341 			folio_nr_pages(folio));
342 	/* This is not expected to be used on LRU_UNEVICTABLE */
343 	list_add_tail(&folio->lru, &lruvec->lists[lru]);
344 }
345 
346 static __always_inline
lruvec_del_folio(struct lruvec * lruvec,struct folio * folio)347 void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
348 {
349 	enum lru_list lru = folio_lru_list(folio);
350 
351 	if (lru_gen_del_folio(lruvec, folio, false))
352 		return;
353 
354 	if (lru != LRU_UNEVICTABLE)
355 		list_del(&folio->lru);
356 	update_lru_size(lruvec, lru, folio_zonenum(folio),
357 			-folio_nr_pages(folio));
358 }
359 
360 #ifdef CONFIG_ANON_VMA_NAME
361 /* mmap_lock should be read-locked */
anon_vma_name_get(struct anon_vma_name * anon_name)362 static inline void anon_vma_name_get(struct anon_vma_name *anon_name)
363 {
364 	if (anon_name)
365 		kref_get(&anon_name->kref);
366 }
367 
anon_vma_name_put(struct anon_vma_name * anon_name)368 static inline void anon_vma_name_put(struct anon_vma_name *anon_name)
369 {
370 	if (anon_name)
371 		kref_put(&anon_name->kref, anon_vma_name_free);
372 }
373 
374 static inline
anon_vma_name_reuse(struct anon_vma_name * anon_name)375 struct anon_vma_name *anon_vma_name_reuse(struct anon_vma_name *anon_name)
376 {
377 	/* Prevent anon_name refcount saturation early on */
378 	if (kref_read(&anon_name->kref) < REFCOUNT_MAX) {
379 		anon_vma_name_get(anon_name);
380 		return anon_name;
381 
382 	}
383 	return anon_vma_name_alloc(anon_name->name);
384 }
385 
dup_anon_vma_name(struct vm_area_struct * orig_vma,struct vm_area_struct * new_vma)386 static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
387 				     struct vm_area_struct *new_vma)
388 {
389 	struct anon_vma_name *anon_name = anon_vma_name(orig_vma);
390 
391 	if (anon_name)
392 		new_vma->anon_name = anon_vma_name_reuse(anon_name);
393 }
394 
free_anon_vma_name(struct vm_area_struct * vma)395 static inline void free_anon_vma_name(struct vm_area_struct *vma)
396 {
397 	/*
398 	 * Not using anon_vma_name because it generates a warning if mmap_lock
399 	 * is not held, which might be the case here.
400 	 */
401 	anon_vma_name_put(vma->anon_name);
402 }
403 
anon_vma_name_eq(struct anon_vma_name * anon_name1,struct anon_vma_name * anon_name2)404 static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
405 				    struct anon_vma_name *anon_name2)
406 {
407 	if (anon_name1 == anon_name2)
408 		return true;
409 
410 	return anon_name1 && anon_name2 &&
411 		!strcmp(anon_name1->name, anon_name2->name);
412 }
413 
414 #else /* CONFIG_ANON_VMA_NAME */
anon_vma_name_get(struct anon_vma_name * anon_name)415 static inline void anon_vma_name_get(struct anon_vma_name *anon_name) {}
anon_vma_name_put(struct anon_vma_name * anon_name)416 static inline void anon_vma_name_put(struct anon_vma_name *anon_name) {}
dup_anon_vma_name(struct vm_area_struct * orig_vma,struct vm_area_struct * new_vma)417 static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
418 				     struct vm_area_struct *new_vma) {}
free_anon_vma_name(struct vm_area_struct * vma)419 static inline void free_anon_vma_name(struct vm_area_struct *vma) {}
420 
anon_vma_name_eq(struct anon_vma_name * anon_name1,struct anon_vma_name * anon_name2)421 static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
422 				    struct anon_vma_name *anon_name2)
423 {
424 	return true;
425 }
426 
427 #endif  /* CONFIG_ANON_VMA_NAME */
428 
init_tlb_flush_pending(struct mm_struct * mm)429 static inline void init_tlb_flush_pending(struct mm_struct *mm)
430 {
431 	atomic_set(&mm->tlb_flush_pending, 0);
432 }
433 
inc_tlb_flush_pending(struct mm_struct * mm)434 static inline void inc_tlb_flush_pending(struct mm_struct *mm)
435 {
436 	atomic_inc(&mm->tlb_flush_pending);
437 	/*
438 	 * The only time this value is relevant is when there are indeed pages
439 	 * to flush. And we'll only flush pages after changing them, which
440 	 * requires the PTL.
441 	 *
442 	 * So the ordering here is:
443 	 *
444 	 *	atomic_inc(&mm->tlb_flush_pending);
445 	 *	spin_lock(&ptl);
446 	 *	...
447 	 *	set_pte_at();
448 	 *	spin_unlock(&ptl);
449 	 *
450 	 *				spin_lock(&ptl)
451 	 *				mm_tlb_flush_pending();
452 	 *				....
453 	 *				spin_unlock(&ptl);
454 	 *
455 	 *	flush_tlb_range();
456 	 *	atomic_dec(&mm->tlb_flush_pending);
457 	 *
458 	 * Where the increment if constrained by the PTL unlock, it thus
459 	 * ensures that the increment is visible if the PTE modification is
460 	 * visible. After all, if there is no PTE modification, nobody cares
461 	 * about TLB flushes either.
462 	 *
463 	 * This very much relies on users (mm_tlb_flush_pending() and
464 	 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
465 	 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
466 	 * locks (PPC) the unlock of one doesn't order against the lock of
467 	 * another PTL.
468 	 *
469 	 * The decrement is ordered by the flush_tlb_range(), such that
470 	 * mm_tlb_flush_pending() will not return false unless all flushes have
471 	 * completed.
472 	 */
473 }
474 
dec_tlb_flush_pending(struct mm_struct * mm)475 static inline void dec_tlb_flush_pending(struct mm_struct *mm)
476 {
477 	/*
478 	 * See inc_tlb_flush_pending().
479 	 *
480 	 * This cannot be smp_mb__before_atomic() because smp_mb() simply does
481 	 * not order against TLB invalidate completion, which is what we need.
482 	 *
483 	 * Therefore we must rely on tlb_flush_*() to guarantee order.
484 	 */
485 	atomic_dec(&mm->tlb_flush_pending);
486 }
487 
mm_tlb_flush_pending(struct mm_struct * mm)488 static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
489 {
490 	/*
491 	 * Must be called after having acquired the PTL; orders against that
492 	 * PTLs release and therefore ensures that if we observe the modified
493 	 * PTE we must also observe the increment from inc_tlb_flush_pending().
494 	 *
495 	 * That is, it only guarantees to return true if there is a flush
496 	 * pending for _this_ PTL.
497 	 */
498 	return atomic_read(&mm->tlb_flush_pending);
499 }
500 
mm_tlb_flush_nested(struct mm_struct * mm)501 static inline bool mm_tlb_flush_nested(struct mm_struct *mm)
502 {
503 	/*
504 	 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL
505 	 * for which there is a TLB flush pending in order to guarantee
506 	 * we've seen both that PTE modification and the increment.
507 	 *
508 	 * (no requirement on actually still holding the PTL, that is irrelevant)
509 	 */
510 	return atomic_read(&mm->tlb_flush_pending) > 1;
511 }
512 
513 #ifdef CONFIG_MMU
514 /*
515  * Computes the pte marker to copy from the given source entry into dst_vma.
516  * If no marker should be copied, returns 0.
517  * The caller should insert a new pte created with make_pte_marker().
518  */
copy_pte_marker(swp_entry_t entry,struct vm_area_struct * dst_vma)519 static inline pte_marker copy_pte_marker(
520 		swp_entry_t entry, struct vm_area_struct *dst_vma)
521 {
522 	pte_marker srcm = pte_marker_get(entry);
523 	/* Always copy error entries. */
524 	pte_marker dstm = srcm & PTE_MARKER_POISONED;
525 
526 	/* Only copy PTE markers if UFFD register matches. */
527 	if ((srcm & PTE_MARKER_UFFD_WP) && userfaultfd_wp(dst_vma))
528 		dstm |= PTE_MARKER_UFFD_WP;
529 
530 	return dstm;
531 }
532 #endif
533 
534 /*
535  * If this pte is wr-protected by uffd-wp in any form, arm the special pte to
536  * replace a none pte.  NOTE!  This should only be called when *pte is already
537  * cleared so we will never accidentally replace something valuable.  Meanwhile
538  * none pte also means we are not demoting the pte so tlb flushed is not needed.
539  * E.g., when pte cleared the caller should have taken care of the tlb flush.
540  *
541  * Must be called with pgtable lock held so that no thread will see the none
542  * pte, and if they see it, they'll fault and serialize at the pgtable lock.
543  *
544  * This function is a no-op if PTE_MARKER_UFFD_WP is not enabled.
545  */
546 static inline void
pte_install_uffd_wp_if_needed(struct vm_area_struct * vma,unsigned long addr,pte_t * pte,pte_t pteval)547 pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,
548 			      pte_t *pte, pte_t pteval)
549 {
550 #ifdef CONFIG_PTE_MARKER_UFFD_WP
551 	bool arm_uffd_pte = false;
552 
553 	/* The current status of the pte should be "cleared" before calling */
554 	WARN_ON_ONCE(!pte_none(ptep_get(pte)));
555 
556 	/*
557 	 * NOTE: userfaultfd_wp_unpopulated() doesn't need this whole
558 	 * thing, because when zapping either it means it's dropping the
559 	 * page, or in TTU where the present pte will be quickly replaced
560 	 * with a swap pte.  There's no way of leaking the bit.
561 	 */
562 	if (vma_is_anonymous(vma) || !userfaultfd_wp(vma))
563 		return;
564 
565 	/* A uffd-wp wr-protected normal pte */
566 	if (unlikely(pte_present(pteval) && pte_uffd_wp(pteval)))
567 		arm_uffd_pte = true;
568 
569 	/*
570 	 * A uffd-wp wr-protected swap pte.  Note: this should even cover an
571 	 * existing pte marker with uffd-wp bit set.
572 	 */
573 	if (unlikely(pte_swp_uffd_wp_any(pteval)))
574 		arm_uffd_pte = true;
575 
576 	if (unlikely(arm_uffd_pte))
577 		set_pte_at(vma->vm_mm, addr, pte,
578 			   make_pte_marker(PTE_MARKER_UFFD_WP));
579 #endif
580 }
581 
vma_has_recency(struct vm_area_struct * vma)582 static inline bool vma_has_recency(struct vm_area_struct *vma)
583 {
584 	if (vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ))
585 		return false;
586 
587 	if (vma->vm_file && (vma->vm_file->f_mode & FMODE_NOREUSE))
588 		return false;
589 
590 	return true;
591 }
592 
593 #endif
594