restore lost packages from 0.2.3 + fix overwritten 0.2.4 files

- Restore 29 recipe symlinks (libdrm, qtbase, dbus, sddm, pipewire, etc.) - Restore 33 patches (KDE, libdrm, mesa, pipewire, sddm, wireplumber) - Restore 20+ local/scripts (audit, lint, test, build helpers) - Restore src/cook/scheduler.rs, status.rs, gnu-config/ - Restore scripts/patch-inclusion-gate.sh, run_mini1.sh, validate-collision-log.sh - Recover TLC source from HEAD (was overwritten by 0.2.3 checkout) - Recover 11 local/docs plans from HEAD (were overwritten) - Recover qt6-wayland-smoke symlink from HEAD - Fix MOTD: remove garbled ASCII art, use clean text - Update version: 0.2.0 -> 0.2.4 in os-release, motd, config - Reduce filesystem_size: 1536 -> 512 MiB - Add ABSOLUTE RULE to AGENTS.md: never delete/ignore packages - Reduce pcid scheme log verbosity: info -> debug
2026-06-19 12:39:14 +03:00
parent ffbe098ef8
commit dc68054305
6418 changed files with 7066233 additions and 8670 deletions
@@ -0,0 +1,670 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_MM_INLINE_H
+#define LINUX_MM_INLINE_H
+
+#include <linux/atomic.h>
+#include <linux/huge_mm.h>
+#include <linux/mm_types.h>
+#include <linux/swap.h>
+#include <linux/string.h>
+#include <linux/userfaultfd_k.h>
+#include <linux/leafops.h>
+
+/**
+ * folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
+ * @folio: The folio to test.
+ *
+ * We would like to get this info without a page flag, but the state
+ * needs to survive until the folio is last deleted from the LRU, which
+ * could be as far down as __page_cache_release.
+ *
+ * Return: An integer (not a boolean!) used to sort a folio onto the
+ * right LRU list and to account folios correctly.
+ * 1 if @folio is a regular filesystem backed page cache folio
+ * or a lazily freed anonymous folio (e.g. via MADV_FREE).
+ * 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise
+ * ram or swap backed folio.
+ */
+static inline int folio_is_file_lru(const struct folio *folio)
+{
+	return !folio_test_swapbacked(folio);
+}
+
+static __always_inline void __update_lru_size(struct lruvec *lruvec,
+				enum lru_list lru, enum zone_type zid,
+				long nr_pages)
+{
+	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
+
+	lockdep_assert_held(&lruvec->lru_lock);
+	WARN_ON_ONCE(nr_pages != (int)nr_pages);
+
+	mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
+	__mod_zone_page_state(&pgdat->node_zones[zid],
+				NR_ZONE_LRU_BASE + lru, nr_pages);
+}
+
+static __always_inline void update_lru_size(struct lruvec *lruvec,
+				enum lru_list lru, enum zone_type zid,
+				long nr_pages)
+{
+	__update_lru_size(lruvec, lru, zid, nr_pages);
+#ifdef CONFIG_MEMCG
+	mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
+#endif
+}
+
+/**
+ * __folio_clear_lru_flags - Clear page lru flags before releasing a page.
+ * @folio: The folio that was on lru and now has a zero reference.
+ */
+static __always_inline void __folio_clear_lru_flags(struct folio *folio)
+{
+	VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);
+
+	__folio_clear_lru(folio);
+
+	/* this shouldn't happen, so leave the flags to bad_page() */
+	if (folio_test_active(folio) && folio_test_unevictable(folio))
+		return;
+
+	__folio_clear_active(folio);
+	__folio_clear_unevictable(folio);
+}
+
+/**
+ * folio_lru_list - Which LRU list should a folio be on?
+ * @folio: The folio to test.
+ *
+ * Return: The LRU list a folio should be on, as an index
+ * into the array of LRU lists.
+ */
+static __always_inline enum lru_list folio_lru_list(const struct folio *folio)
+{
+	enum lru_list lru;
+
+	VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
+
+	if (folio_test_unevictable(folio))
+		return LRU_UNEVICTABLE;
+
+	lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
+	if (folio_test_active(folio))
+		lru += LRU_ACTIVE;
+
+	return lru;
+}
+
+#ifdef CONFIG_LRU_GEN
+
+static inline bool lru_gen_switching(void)
+{
+	DECLARE_STATIC_KEY_FALSE(lru_switch);
+
+	return static_branch_unlikely(&lru_switch);
+}
+#ifdef CONFIG_LRU_GEN_ENABLED
+static inline bool lru_gen_enabled(void)
+{
+	DECLARE_STATIC_KEY_TRUE(lru_gen_caps[NR_LRU_GEN_CAPS]);
+
+	return static_branch_likely(&lru_gen_caps[LRU_GEN_CORE]);
+}
+#else
+static inline bool lru_gen_enabled(void)
+{
+	DECLARE_STATIC_KEY_FALSE(lru_gen_caps[NR_LRU_GEN_CAPS]);
+
+	return static_branch_unlikely(&lru_gen_caps[LRU_GEN_CORE]);
+}
+#endif
+
+static inline bool lru_gen_in_fault(void)
+{
+	return current->in_lru_fault;
+}
+
+static inline int lru_gen_from_seq(unsigned long seq)
+{
+	return seq % MAX_NR_GENS;
+}
+
+static inline int lru_hist_from_seq(unsigned long seq)
+{
+	return seq % NR_HIST_GENS;
+}
+
+static inline int lru_tier_from_refs(int refs, bool workingset)
+{
+	VM_WARN_ON_ONCE(refs > BIT(LRU_REFS_WIDTH));
+
+	/* see the comment on MAX_NR_TIERS */
+	return workingset ? MAX_NR_TIERS - 1 : order_base_2(refs);
+}
+
+static inline int folio_lru_refs(const struct folio *folio)
+{
+	unsigned long flags = READ_ONCE(folio->flags.f);
+
+	if (!(flags & BIT(PG_referenced)))
+		return 0;
+	/*
+	 * Return the total number of accesses including PG_referenced. Also see
+	 * the comment on LRU_REFS_FLAGS.
+	 */
+	return ((flags & LRU_REFS_MASK) >> LRU_REFS_PGOFF) + 1;
+}
+
+static inline int folio_lru_gen(const struct folio *folio)
+{
+	unsigned long flags = READ_ONCE(folio->flags.f);
+
+	return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
+}
+
+static inline bool lru_gen_is_active(const struct lruvec *lruvec, int gen)
+{
+	unsigned long max_seq = lruvec->lrugen.max_seq;
+
+	VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);
+
+	/* see the comment on MIN_NR_GENS */
+	return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
+}
+
+static inline void lru_gen_update_size(struct lruvec *lruvec, struct folio *folio,
+				       int old_gen, int new_gen)
+{
+	int type = folio_is_file_lru(folio);
+	int zone = folio_zonenum(folio);
+	int delta = folio_nr_pages(folio);
+	enum lru_list lru = type * LRU_INACTIVE_FILE;
+	struct lru_gen_folio *lrugen = &lruvec->lrugen;
+
+	VM_WARN_ON_ONCE(old_gen != -1 && old_gen >= MAX_NR_GENS);
+	VM_WARN_ON_ONCE(new_gen != -1 && new_gen >= MAX_NR_GENS);
+	VM_WARN_ON_ONCE(old_gen == -1 && new_gen == -1);
+
+	if (old_gen >= 0)
+		WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],
+			   lrugen->nr_pages[old_gen][type][zone] - delta);
+	if (new_gen >= 0)
+		WRITE_ONCE(lrugen->nr_pages[new_gen][type][zone],
+			   lrugen->nr_pages[new_gen][type][zone] + delta);
+
+	/* addition */
+	if (old_gen < 0) {
+		if (lru_gen_is_active(lruvec, new_gen))
+			lru += LRU_ACTIVE;
+		__update_lru_size(lruvec, lru, zone, delta);
+		return;
+	}
+
+	/* deletion */
+	if (new_gen < 0) {
+		if (lru_gen_is_active(lruvec, old_gen))
+			lru += LRU_ACTIVE;
+		__update_lru_size(lruvec, lru, zone, -delta);
+		return;
+	}
+
+	/* promotion */
+	if (!lru_gen_is_active(lruvec, old_gen) && lru_gen_is_active(lruvec, new_gen)) {
+		__update_lru_size(lruvec, lru, zone, -delta);
+		__update_lru_size(lruvec, lru + LRU_ACTIVE, zone, delta);
+	}
+
+	/* demotion requires isolation, e.g., lru_deactivate_fn() */
+	VM_WARN_ON_ONCE(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));
+}
+
+static inline unsigned long lru_gen_folio_seq(const struct lruvec *lruvec,
+					      const struct folio *folio,
+					      bool reclaiming)
+{
+	int gen;
+	int type = folio_is_file_lru(folio);
+	const struct lru_gen_folio *lrugen = &lruvec->lrugen;
+
+	/*
+	 * +-----------------------------------+-----------------------------------+
+	 * | Accessed through page tables and  | Accessed through file descriptors |
+	 * | promoted by folio_update_gen()    | and protected by folio_inc_gen()  |
+	 * +-----------------------------------+-----------------------------------+
+	 * | PG_active (set while isolated)    |                                   |
+	 * +-----------------+-----------------+-----------------+-----------------+
+	 * |  PG_workingset  |  PG_referenced  |  PG_workingset  |  LRU_REFS_FLAGS |
+	 * +-----------------------------------+-----------------------------------+
+	 * |<---------- MIN_NR_GENS ---------->|                                   |
+	 * |<---------------------------- MAX_NR_GENS ---------------------------->|
+	 */
+	if (folio_test_active(folio))
+		gen = MIN_NR_GENS - folio_test_workingset(folio);
+	else if (reclaiming)
+		gen = MAX_NR_GENS;
+	else if ((!folio_is_file_lru(folio) && !folio_test_swapcache(folio)) ||
+		 (folio_test_reclaim(folio) &&
+		  (folio_test_dirty(folio) || folio_test_writeback(folio))))
+		gen = MIN_NR_GENS;
+	else
+		gen = MAX_NR_GENS - folio_test_workingset(folio);
+
+	return max(READ_ONCE(lrugen->max_seq) - gen + 1, READ_ONCE(lrugen->min_seq[type]));
+}
+
+static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	unsigned long seq;
+	unsigned long flags;
+	int gen = folio_lru_gen(folio);
+	int type = folio_is_file_lru(folio);
+	int zone = folio_zonenum(folio);
+	struct lru_gen_folio *lrugen = &lruvec->lrugen;
+
+	VM_WARN_ON_ONCE_FOLIO(gen != -1, folio);
+
+	if (folio_test_unevictable(folio) || !lrugen->enabled)
+		return false;
+
+	seq = lru_gen_folio_seq(lruvec, folio, reclaiming);
+	gen = lru_gen_from_seq(seq);
+	flags = (gen + 1UL) << LRU_GEN_PGOFF;
+	/* see the comment on MIN_NR_GENS about PG_active */
+	set_mask_bits(&folio->flags.f, LRU_GEN_MASK | BIT(PG_active), flags);
+
+	lru_gen_update_size(lruvec, folio, -1, gen);
+	/* for folio_rotate_reclaimable() */
+	if (reclaiming)
+		list_add_tail(&folio->lru, &lrugen->folios[gen][type][zone]);
+	else
+		list_add(&folio->lru, &lrugen->folios[gen][type][zone]);
+
+	return true;
+}
+
+static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	unsigned long flags;
+	int gen = folio_lru_gen(folio);
+
+	if (gen < 0)
+		return false;
+
+	VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio);
+	VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio);
+
+	/* for folio_migrate_flags() */
+	flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;
+	flags = set_mask_bits(&folio->flags.f, LRU_GEN_MASK, flags);
+	gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
+
+	lru_gen_update_size(lruvec, folio, gen, -1);
+	list_del(&folio->lru);
+
+	return true;
+}
+
+static inline void folio_migrate_refs(struct folio *new, const struct folio *old)
+{
+	unsigned long refs = READ_ONCE(old->flags.f) & LRU_REFS_MASK;
+
+	set_mask_bits(&new->flags.f, LRU_REFS_MASK, refs);
+}
+#else /* !CONFIG_LRU_GEN */
+
+static inline bool lru_gen_enabled(void)
+{
+	return false;
+}
+
+static inline bool lru_gen_switching(void)
+{
+	return false;
+}
+
+static inline bool lru_gen_in_fault(void)
+{
+	return false;
+}
+
+static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	return false;
+}
+
+static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	return false;
+}
+
+static inline void folio_migrate_refs(struct folio *new, const struct folio *old)
+{
+
+}
+#endif /* CONFIG_LRU_GEN */
+
+static __always_inline
+void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
+{
+	enum lru_list lru = folio_lru_list(folio);
+
+	VM_WARN_ON_ONCE_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
+	if (lru_gen_add_folio(lruvec, folio, false))
+		return;
+
+	update_lru_size(lruvec, lru, folio_zonenum(folio),
+			folio_nr_pages(folio));
+	if (lru != LRU_UNEVICTABLE)
+		list_add(&folio->lru, &lruvec->lists[lru]);
+}
+
+static __always_inline
+void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
+{
+	enum lru_list lru = folio_lru_list(folio);
+
+	VM_WARN_ON_ONCE_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
+	if (lru_gen_add_folio(lruvec, folio, true))
+		return;
+
+	update_lru_size(lruvec, lru, folio_zonenum(folio),
+			folio_nr_pages(folio));
+	/* This is not expected to be used on LRU_UNEVICTABLE */
+	list_add_tail(&folio->lru, &lruvec->lists[lru]);
+}
+
+static __always_inline
+void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
+{
+	enum lru_list lru = folio_lru_list(folio);
+
+	VM_WARN_ON_ONCE_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
+	if (lru_gen_del_folio(lruvec, folio, false))
+		return;
+
+	if (lru != LRU_UNEVICTABLE)
+		list_del(&folio->lru);
+	update_lru_size(lruvec, lru, folio_zonenum(folio),
+			-folio_nr_pages(folio));
+}
+
+#ifdef CONFIG_ANON_VMA_NAME
+/* mmap_lock should be read-locked */
+static inline void anon_vma_name_get(struct anon_vma_name *anon_name)
+{
+	if (anon_name)
+		kref_get(&anon_name->kref);
+}
+
+static inline void anon_vma_name_put(struct anon_vma_name *anon_name)
+{
+	if (anon_name)
+		kref_put(&anon_name->kref, anon_vma_name_free);
+}
+
+static inline
+struct anon_vma_name *anon_vma_name_reuse(struct anon_vma_name *anon_name)
+{
+	/* Prevent anon_name refcount saturation early on */
+	if (kref_read(&anon_name->kref) < REFCOUNT_MAX) {
+		anon_vma_name_get(anon_name);
+		return anon_name;
+
+	}
+	return anon_vma_name_alloc(anon_name->name);
+}
+
+static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
+				     struct vm_area_struct *new_vma)
+{
+	struct anon_vma_name *anon_name = anon_vma_name(orig_vma);
+
+	if (anon_name)
+		new_vma->anon_name = anon_vma_name_reuse(anon_name);
+}
+
+static inline void free_anon_vma_name(struct vm_area_struct *vma)
+{
+	/*
+	 * Not using anon_vma_name because it generates a warning if mmap_lock
+	 * is not held, which might be the case here.
+	 */
+	anon_vma_name_put(vma->anon_name);
+}
+
+static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
+				    struct anon_vma_name *anon_name2)
+{
+	if (anon_name1 == anon_name2)
+		return true;
+
+	return anon_name1 && anon_name2 &&
+		!strcmp(anon_name1->name, anon_name2->name);
+}
+
+#else /* CONFIG_ANON_VMA_NAME */
+static inline void anon_vma_name_get(struct anon_vma_name *anon_name) {}
+static inline void anon_vma_name_put(struct anon_vma_name *anon_name) {}
+static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
+				     struct vm_area_struct *new_vma) {}
+static inline void free_anon_vma_name(struct vm_area_struct *vma) {}
+
+static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
+				    struct anon_vma_name *anon_name2)
+{
+	return true;
+}
+
+#endif  /* CONFIG_ANON_VMA_NAME */
+
+void pfnmap_track_ctx_release(struct kref *ref);
+
+static inline void init_tlb_flush_pending(struct mm_struct *mm)
+{
+	atomic_set(&mm->tlb_flush_pending, 0);
+}
+
+static inline void inc_tlb_flush_pending(struct mm_struct *mm)
+{
+	atomic_inc(&mm->tlb_flush_pending);
+	/*
+	 * The only time this value is relevant is when there are indeed pages
+	 * to flush. And we'll only flush pages after changing them, which
+	 * requires the PTL.
+	 *
+	 * So the ordering here is:
+	 *
+	 *	atomic_inc(&mm->tlb_flush_pending);
+	 *	spin_lock(&ptl);
+	 *	...
+	 *	set_pte_at();
+	 *	spin_unlock(&ptl);
+	 *
+	 *				spin_lock(&ptl)
+	 *				mm_tlb_flush_pending();
+	 *				....
+	 *				spin_unlock(&ptl);
+	 *
+	 *	flush_tlb_range();
+	 *	atomic_dec(&mm->tlb_flush_pending);
+	 *
+	 * Where the increment if constrained by the PTL unlock, it thus
+	 * ensures that the increment is visible if the PTE modification is
+	 * visible. After all, if there is no PTE modification, nobody cares
+	 * about TLB flushes either.
+	 *
+	 * This very much relies on users (mm_tlb_flush_pending() and
+	 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
+	 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
+	 * locks (PPC) the unlock of one doesn't order against the lock of
+	 * another PTL.
+	 *
+	 * The decrement is ordered by the flush_tlb_range(), such that
+	 * mm_tlb_flush_pending() will not return false unless all flushes have
+	 * completed.
+	 */
+}
+
+static inline void dec_tlb_flush_pending(struct mm_struct *mm)
+{
+	/*
+	 * See inc_tlb_flush_pending().
+	 *
+	 * This cannot be smp_mb__before_atomic() because smp_mb() simply does
+	 * not order against TLB invalidate completion, which is what we need.
+	 *
+	 * Therefore we must rely on tlb_flush_*() to guarantee order.
+	 */
+	atomic_dec(&mm->tlb_flush_pending);
+}
+
+static inline bool mm_tlb_flush_pending(const struct mm_struct *mm)
+{
+	/*
+	 * Must be called after having acquired the PTL; orders against that
+	 * PTLs release and therefore ensures that if we observe the modified
+	 * PTE we must also observe the increment from inc_tlb_flush_pending().
+	 *
+	 * That is, it only guarantees to return true if there is a flush
+	 * pending for _this_ PTL.
+	 */
+	return atomic_read(&mm->tlb_flush_pending);
+}
+
+static inline bool mm_tlb_flush_nested(const struct mm_struct *mm)
+{
+	/*
+	 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL
+	 * for which there is a TLB flush pending in order to guarantee
+	 * we've seen both that PTE modification and the increment.
+	 *
+	 * (no requirement on actually still holding the PTL, that is irrelevant)
+	 */
+	return atomic_read(&mm->tlb_flush_pending) > 1;
+}
+
+#ifdef CONFIG_MMU
+/*
+ * Computes the pte marker to copy from the given source entry into dst_vma.
+ * If no marker should be copied, returns 0.
+ * The caller should insert a new pte created with make_pte_marker().
+ */
+static inline pte_marker copy_pte_marker(
+		softleaf_t entry, struct vm_area_struct *dst_vma)
+{
+	const pte_marker srcm = softleaf_to_marker(entry);
+	/* Always copy error entries. */
+	pte_marker dstm = srcm & (PTE_MARKER_POISONED | PTE_MARKER_GUARD);
+
+	/* Only copy PTE markers if UFFD register matches. */
+	if ((srcm & PTE_MARKER_UFFD_WP) && userfaultfd_wp(dst_vma))
+		dstm |= PTE_MARKER_UFFD_WP;
+
+	return dstm;
+}
+
+/*
+ * If this pte is wr-protected by uffd-wp in any form, arm the special pte to
+ * replace a none pte.  NOTE!  This should only be called when *pte is already
+ * cleared so we will never accidentally replace something valuable.  Meanwhile
+ * none pte also means we are not demoting the pte so tlb flushed is not needed.
+ * E.g., when pte cleared the caller should have taken care of the tlb flush.
+ *
+ * Must be called with pgtable lock held so that no thread will see the none
+ * pte, and if they see it, they'll fault and serialize at the pgtable lock.
+ *
+ * Returns true if an uffd-wp pte was installed, false otherwise.
+ */
+static inline bool
+pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,
+			      pte_t *pte, pte_t pteval)
+{
+	bool arm_uffd_pte = false;
+
+	if (!uffd_supports_wp_marker())
+		return false;
+
+	/* The current status of the pte should be "cleared" before calling */
+	WARN_ON_ONCE(!pte_none(ptep_get(pte)));
+
+	/*
+	 * NOTE: userfaultfd_wp_unpopulated() doesn't need this whole
+	 * thing, because when zapping either it means it's dropping the
+	 * page, or in TTU where the present pte will be quickly replaced
+	 * with a swap pte.  There's no way of leaking the bit.
+	 */
+	if (vma_is_anonymous(vma) || !userfaultfd_wp(vma))
+		return false;
+
+	/* A uffd-wp wr-protected normal pte */
+	if (unlikely(pte_present(pteval) && pte_uffd_wp(pteval)))
+		arm_uffd_pte = true;
+
+	/*
+	 * A uffd-wp wr-protected swap pte.  Note: this should even cover an
+	 * existing pte marker with uffd-wp bit set.
+	 */
+	if (unlikely(pte_swp_uffd_wp_any(pteval)))
+		arm_uffd_pte = true;
+
+	if (unlikely(arm_uffd_pte)) {
+		set_pte_at(vma->vm_mm, addr, pte,
+			   make_pte_marker(PTE_MARKER_UFFD_WP));
+		return true;
+	}
+
+	return false;
+}
+
+static inline bool vma_has_recency(const struct vm_area_struct *vma)
+{
+	if (vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ))
+		return false;
+
+	if (vma->vm_file && (vma->vm_file->f_mode & FMODE_NOREUSE))
+		return false;
+
+	return true;
+}
+#endif
+
+/**
+ * num_pages_contiguous() - determine the number of contiguous pages
+ *			    that represent contiguous PFNs
+ * @pages: an array of page pointers
+ * @nr_pages: length of the array, at least 1
+ *
+ * Determine the number of contiguous pages that represent contiguous PFNs
+ * in @pages, starting from the first page.
+ *
+ * In some kernel configs contiguous PFNs will not have contiguous struct
+ * pages. In these configurations num_pages_contiguous() will return a num
+ * smaller than ideal number. The caller should continue to check for pfn
+ * contiguity after each call to num_pages_contiguous().
+ *
+ * Returns the number of contiguous pages.
+ */
+static inline size_t num_pages_contiguous(struct page **pages, size_t nr_pages)
+{
+	struct page *cur_page = pages[0];
+	unsigned long section = memdesc_section(cur_page->flags);
+	size_t i;
+
+	for (i = 1; i < nr_pages; i++) {
+		if (++cur_page != pages[i])
+			break;
+		/*
+		 * In unproblematic kernel configs, page_to_section() == 0 and
+		 * the whole check will get optimized out.
+		 */
+		if (memdesc_section(cur_page->flags) != section)
+			break;
+	}
+
+	return i;
+}
+
+#endif