Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 785 insertions, 0 deletions

diff --git a/mm/mlock.c b/mm/mlock.c
new file mode 100644
index 0000000000..06bdfab83b
--- /dev/null
+++ b/mm/mlock.c
@@ -0,0 +1,785 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *	linux/mm/mlock.c
+ *
+ *  (C) Copyright 1995 Linus Torvalds
+ *  (C) Copyright 2002 Christoph Hellwig
+ */
+
+#include <linux/capability.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/sched/user.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/pagewalk.h>
+#include <linux/mempolicy.h>
+#include <linux/syscalls.h>
+#include <linux/sched.h>
+#include <linux/export.h>
+#include <linux/rmap.h>
+#include <linux/mmzone.h>
+#include <linux/hugetlb.h>
+#include <linux/memcontrol.h>
+#include <linux/mm_inline.h>
+#include <linux/secretmem.h>
+
+#include "internal.h"
+
+struct mlock_fbatch {
+	local_lock_t lock;
+	struct folio_batch fbatch;
+};
+
+static DEFINE_PER_CPU(struct mlock_fbatch, mlock_fbatch) = {
+	.lock = INIT_LOCAL_LOCK(lock),
+};
+
+bool can_do_mlock(void)
+{
+	if (rlimit(RLIMIT_MEMLOCK) != 0)
+		return true;
+	if (capable(CAP_IPC_LOCK))
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(can_do_mlock);
+
+/*
+ * Mlocked folios are marked with the PG_mlocked flag for efficient testing
+ * in vmscan and, possibly, the fault path; and to support semi-accurate
+ * statistics.
+ *
+ * An mlocked folio [folio_test_mlocked(folio)] is unevictable.  As such, it
+ * will be ostensibly placed on the LRU "unevictable" list (actually no such
+ * list exists), rather than the [in]active lists. PG_unevictable is set to
+ * indicate the unevictable state.
+ */
+
+static struct lruvec *__mlock_folio(struct folio *folio, struct lruvec *lruvec)
+{
+	/* There is nothing more we can do while it's off LRU */
+	if (!folio_test_clear_lru(folio))
+		return lruvec;
+
+	lruvec = folio_lruvec_relock_irq(folio, lruvec);
+
+	if (unlikely(folio_evictable(folio))) {
+		/*
+		 * This is a little surprising, but quite possible: PG_mlocked
+		 * must have got cleared already by another CPU.  Could this
+		 * folio be unevictable?  I'm not sure, but move it now if so.
+		 */
+		if (folio_test_unevictable(folio)) {
+			lruvec_del_folio(lruvec, folio);
+			folio_clear_unevictable(folio);
+			lruvec_add_folio(lruvec, folio);
+
+			__count_vm_events(UNEVICTABLE_PGRESCUED,
+					  folio_nr_pages(folio));
+		}
+		goto out;
+	}
+
+	if (folio_test_unevictable(folio)) {
+		if (folio_test_mlocked(folio))
+			folio->mlock_count++;
+		goto out;
+	}
+
+	lruvec_del_folio(lruvec, folio);
+	folio_clear_active(folio);
+	folio_set_unevictable(folio);
+	folio->mlock_count = !!folio_test_mlocked(folio);
+	lruvec_add_folio(lruvec, folio);
+	__count_vm_events(UNEVICTABLE_PGCULLED, folio_nr_pages(folio));
+out:
+	folio_set_lru(folio);
+	return lruvec;
+}
+
+static struct lruvec *__mlock_new_folio(struct folio *folio, struct lruvec *lruvec)
+{
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
+
+	lruvec = folio_lruvec_relock_irq(folio, lruvec);
+
+	/* As above, this is a little surprising, but possible */
+	if (unlikely(folio_evictable(folio)))
+		goto out;
+
+	folio_set_unevictable(folio);
+	folio->mlock_count = !!folio_test_mlocked(folio);
+	__count_vm_events(UNEVICTABLE_PGCULLED, folio_nr_pages(folio));
+out:
+	lruvec_add_folio(lruvec, folio);
+	folio_set_lru(folio);
+	return lruvec;
+}
+
+static struct lruvec *__munlock_folio(struct folio *folio, struct lruvec *lruvec)
+{
+	int nr_pages = folio_nr_pages(folio);
+	bool isolated = false;
+
+	if (!folio_test_clear_lru(folio))
+		goto munlock;
+
+	isolated = true;
+	lruvec = folio_lruvec_relock_irq(folio, lruvec);
+
+	if (folio_test_unevictable(folio)) {
+		/* Then mlock_count is maintained, but might undercount */
+		if (folio->mlock_count)
+			folio->mlock_count--;
+		if (folio->mlock_count)
+			goto out;
+	}
+	/* else assume that was the last mlock: reclaim will fix it if not */
+
+munlock:
+	if (folio_test_clear_mlocked(folio)) {
+		__zone_stat_mod_folio(folio, NR_MLOCK, -nr_pages);
+		if (isolated || !folio_test_unevictable(folio))
+			__count_vm_events(UNEVICTABLE_PGMUNLOCKED, nr_pages);
+		else
+			__count_vm_events(UNEVICTABLE_PGSTRANDED, nr_pages);
+	}
+
+	/* folio_evictable() has to be checked *after* clearing Mlocked */
+	if (isolated && folio_test_unevictable(folio) && folio_evictable(folio)) {
+		lruvec_del_folio(lruvec, folio);
+		folio_clear_unevictable(folio);
+		lruvec_add_folio(lruvec, folio);
+		__count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
+	}
+out:
+	if (isolated)
+		folio_set_lru(folio);
+	return lruvec;
+}
+
+/*
+ * Flags held in the low bits of a struct folio pointer on the mlock_fbatch.
+ */
+#define LRU_FOLIO 0x1
+#define NEW_FOLIO 0x2
+static inline struct folio *mlock_lru(struct folio *folio)
+{
+	return (struct folio *)((unsigned long)folio + LRU_FOLIO);
+}
+
+static inline struct folio *mlock_new(struct folio *folio)
+{
+	return (struct folio *)((unsigned long)folio + NEW_FOLIO);
+}
+
+/*
+ * mlock_folio_batch() is derived from folio_batch_move_lru(): perhaps that can
+ * make use of such folio pointer flags in future, but for now just keep it for
+ * mlock.  We could use three separate folio batches instead, but one feels
+ * better (munlocking a full folio batch does not need to drain mlocking folio
+ * batches first).
+ */
+static void mlock_folio_batch(struct folio_batch *fbatch)
+{
+	struct lruvec *lruvec = NULL;
+	unsigned long mlock;
+	struct folio *folio;
+	int i;
+
+	for (i = 0; i < folio_batch_count(fbatch); i++) {
+		folio = fbatch->folios[i];
+		mlock = (unsigned long)folio & (LRU_FOLIO | NEW_FOLIO);
+		folio = (struct folio *)((unsigned long)folio - mlock);
+		fbatch->folios[i] = folio;
+
+		if (mlock & LRU_FOLIO)
+			lruvec = __mlock_folio(folio, lruvec);
+		else if (mlock & NEW_FOLIO)
+			lruvec = __mlock_new_folio(folio, lruvec);
+		else
+			lruvec = __munlock_folio(folio, lruvec);
+	}
+
+	if (lruvec)
+		unlock_page_lruvec_irq(lruvec);
+	folios_put(fbatch->folios, folio_batch_count(fbatch));
+	folio_batch_reinit(fbatch);
+}
+
+void mlock_drain_local(void)
+{
+	struct folio_batch *fbatch;
+
+	local_lock(&mlock_fbatch.lock);
+	fbatch = this_cpu_ptr(&mlock_fbatch.fbatch);
+	if (folio_batch_count(fbatch))
+		mlock_folio_batch(fbatch);
+	local_unlock(&mlock_fbatch.lock);
+}
+
+void mlock_drain_remote(int cpu)
+{
+	struct folio_batch *fbatch;
+
+	WARN_ON_ONCE(cpu_online(cpu));
+	fbatch = &per_cpu(mlock_fbatch.fbatch, cpu);
+	if (folio_batch_count(fbatch))
+		mlock_folio_batch(fbatch);
+}
+
+bool need_mlock_drain(int cpu)
+{
+	return folio_batch_count(&per_cpu(mlock_fbatch.fbatch, cpu));
+}
+
+/**
+ * mlock_folio - mlock a folio already on (or temporarily off) LRU
+ * @folio: folio to be mlocked.
+ */
+void mlock_folio(struct folio *folio)
+{
+	struct folio_batch *fbatch;
+
+	local_lock(&mlock_fbatch.lock);
+	fbatch = this_cpu_ptr(&mlock_fbatch.fbatch);
+
+	if (!folio_test_set_mlocked(folio)) {
+		int nr_pages = folio_nr_pages(folio);
+
+		zone_stat_mod_folio(folio, NR_MLOCK, nr_pages);
+		__count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages);
+	}
+
+	folio_get(folio);
+	if (!folio_batch_add(fbatch, mlock_lru(folio)) ||
+	    folio_test_large(folio) || lru_cache_disabled())
+		mlock_folio_batch(fbatch);
+	local_unlock(&mlock_fbatch.lock);
+}
+
+/**
+ * mlock_new_folio - mlock a newly allocated folio not yet on LRU
+ * @folio: folio to be mlocked, either normal or a THP head.
+ */
+void mlock_new_folio(struct folio *folio)
+{
+	struct folio_batch *fbatch;
+	int nr_pages = folio_nr_pages(folio);
+
+	local_lock(&mlock_fbatch.lock);
+	fbatch = this_cpu_ptr(&mlock_fbatch.fbatch);
+	folio_set_mlocked(folio);
+
+	zone_stat_mod_folio(folio, NR_MLOCK, nr_pages);
+	__count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages);
+
+	folio_get(folio);
+	if (!folio_batch_add(fbatch, mlock_new(folio)) ||
+	    folio_test_large(folio) || lru_cache_disabled())
+		mlock_folio_batch(fbatch);
+	local_unlock(&mlock_fbatch.lock);
+}
+
+/**
+ * munlock_folio - munlock a folio
+ * @folio: folio to be munlocked, either normal or a THP head.
+ */
+void munlock_folio(struct folio *folio)
+{
+	struct folio_batch *fbatch;
+
+	local_lock(&mlock_fbatch.lock);
+	fbatch = this_cpu_ptr(&mlock_fbatch.fbatch);
+	/*
+	 * folio_test_clear_mlocked(folio) must be left to __munlock_folio(),
+	 * which will check whether the folio is multiply mlocked.
+	 */
+	folio_get(folio);
+	if (!folio_batch_add(fbatch, folio) ||
+	    folio_test_large(folio) || lru_cache_disabled())
+		mlock_folio_batch(fbatch);
+	local_unlock(&mlock_fbatch.lock);
+}
+
+static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
+			   unsigned long end, struct mm_walk *walk)
+
+{
+	struct vm_area_struct *vma = walk->vma;
+	spinlock_t *ptl;
+	pte_t *start_pte, *pte;
+	pte_t ptent;
+	struct folio *folio;
+
+	ptl = pmd_trans_huge_lock(pmd, vma);
+	if (ptl) {
+		if (!pmd_present(*pmd))
+			goto out;
+		if (is_huge_zero_pmd(*pmd))
+			goto out;
+		folio = page_folio(pmd_page(*pmd));
+		if (vma->vm_flags & VM_LOCKED)
+			mlock_folio(folio);
+		else
+			munlock_folio(folio);
+		goto out;
+	}
+
+	start_pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+	if (!start_pte) {
+		walk->action = ACTION_AGAIN;
+		return 0;
+	}
+	for (pte = start_pte; addr != end; pte++, addr += PAGE_SIZE) {
+		ptent = ptep_get(pte);
+		if (!pte_present(ptent))
+			continue;
+		folio = vm_normal_folio(vma, addr, ptent);
+		if (!folio || folio_is_zone_device(folio))
+			continue;
+		if (folio_test_large(folio))
+			continue;
+		if (vma->vm_flags & VM_LOCKED)
+			mlock_folio(folio);
+		else
+			munlock_folio(folio);
+	}
+	pte_unmap(start_pte);
+out:
+	spin_unlock(ptl);
+	cond_resched();
+	return 0;
+}
+
+/*
+ * mlock_vma_pages_range() - mlock any pages already in the range,
+ *                           or munlock all pages in the range.
+ * @vma - vma containing range to be mlock()ed or munlock()ed
+ * @start - start address in @vma of the range
+ * @end - end of range in @vma
+ * @newflags - the new set of flags for @vma.
+ *
+ * Called for mlock(), mlock2() and mlockall(), to set @vma VM_LOCKED;
+ * called for munlock() and munlockall(), to clear VM_LOCKED from @vma.
+ */
+static void mlock_vma_pages_range(struct vm_area_struct *vma,
+	unsigned long start, unsigned long end, vm_flags_t newflags)
+{
+	static const struct mm_walk_ops mlock_walk_ops = {
+		.pmd_entry = mlock_pte_range,
+		.walk_lock = PGWALK_WRLOCK_VERIFY,
+	};
+
+	/*
+	 * There is a slight chance that concurrent page migration,
+	 * or page reclaim finding a page of this now-VM_LOCKED vma,
+	 * will call mlock_vma_folio() and raise page's mlock_count:
+	 * double counting, leaving the page unevictable indefinitely.
+	 * Communicate this danger to mlock_vma_folio() with VM_IO,
+	 * which is a VM_SPECIAL flag not allowed on VM_LOCKED vmas.
+	 * mmap_lock is held in write mode here, so this weird
+	 * combination should not be visible to other mmap_lock users;
+	 * but WRITE_ONCE so rmap walkers must see VM_IO if VM_LOCKED.
+	 */
+	if (newflags & VM_LOCKED)
+		newflags |= VM_IO;
+	vma_start_write(vma);
+	vm_flags_reset_once(vma, newflags);
+
+	lru_add_drain();
+	walk_page_range(vma->vm_mm, start, end, &mlock_walk_ops, NULL);
+	lru_add_drain();
+
+	if (newflags & VM_IO) {
+		newflags &= ~VM_IO;
+		vm_flags_reset_once(vma, newflags);
+	}
+}
+
+/*
+ * mlock_fixup  - handle mlock[all]/munlock[all] requests.
+ *
+ * Filters out "special" vmas -- VM_LOCKED never gets set for these, and
+ * munlock is a no-op.  However, for some special vmas, we go ahead and
+ * populate the ptes.
+ *
+ * For vmas that pass the filters, merge/split as appropriate.
+ */
+static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
+	       struct vm_area_struct **prev, unsigned long start,
+	       unsigned long end, vm_flags_t newflags)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	pgoff_t pgoff;
+	int nr_pages;
+	int ret = 0;
+	vm_flags_t oldflags = vma->vm_flags;
+
+	if (newflags == oldflags || (oldflags & VM_SPECIAL) ||
+	    is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) ||
+	    vma_is_dax(vma) || vma_is_secretmem(vma))
+		/* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */
+		goto out;
+
+	pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+	*prev = vma_merge(vmi, mm, *prev, start, end, newflags,
+			vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
+			vma->vm_userfaultfd_ctx, anon_vma_name(vma));
+	if (*prev) {
+		vma = *prev;
+		goto success;
+	}
+
+	if (start != vma->vm_start) {
+		ret = split_vma(vmi, vma, start, 1);
+		if (ret)
+			goto out;
+	}
+
+	if (end != vma->vm_end) {
+		ret = split_vma(vmi, vma, end, 0);
+		if (ret)
+			goto out;
+	}
+
+success:
+	/*
+	 * Keep track of amount of locked VM.
+	 */
+	nr_pages = (end - start) >> PAGE_SHIFT;
+	if (!(newflags & VM_LOCKED))
+		nr_pages = -nr_pages;
+	else if (oldflags & VM_LOCKED)
+		nr_pages = 0;
+	mm->locked_vm += nr_pages;
+
+	/*
+	 * vm_flags is protected by the mmap_lock held in write mode.
+	 * It's okay if try_to_unmap_one unmaps a page just after we
+	 * set VM_LOCKED, populate_vma_page_range will bring it back.
+	 */
+	if ((newflags & VM_LOCKED) && (oldflags & VM_LOCKED)) {
+		/* No work to do, and mlocking twice would be wrong */
+		vma_start_write(vma);
+		vm_flags_reset(vma, newflags);
+	} else {
+		mlock_vma_pages_range(vma, start, end, newflags);
+	}
+out:
+	*prev = vma;
+	return ret;
+}
+
+static int apply_vma_lock_flags(unsigned long start, size_t len,
+				vm_flags_t flags)
+{
+	unsigned long nstart, end, tmp;
+	struct vm_area_struct *vma, *prev;
+	VMA_ITERATOR(vmi, current->mm, start);
+
+	VM_BUG_ON(offset_in_page(start));
+	VM_BUG_ON(len != PAGE_ALIGN(len));
+	end = start + len;
+	if (end < start)
+		return -EINVAL;
+	if (end == start)
+		return 0;
+	vma = vma_iter_load(&vmi);
+	if (!vma)
+		return -ENOMEM;
+
+	prev = vma_prev(&vmi);
+	if (start > vma->vm_start)
+		prev = vma;
+
+	nstart = start;
+	tmp = vma->vm_start;
+	for_each_vma_range(vmi, vma, end) {
+		int error;
+		vm_flags_t newflags;
+
+		if (vma->vm_start != tmp)
+			return -ENOMEM;
+
+		newflags = vma->vm_flags & ~VM_LOCKED_MASK;
+		newflags |= flags;
+		/* Here we know that  vma->vm_start <= nstart < vma->vm_end. */
+		tmp = vma->vm_end;
+		if (tmp > end)
+			tmp = end;
+		error = mlock_fixup(&vmi, vma, &prev, nstart, tmp, newflags);
+		if (error)
+			return error;
+		tmp = vma_iter_end(&vmi);
+		nstart = tmp;
+	}
+
+	if (tmp < end)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/*
+ * Go through vma areas and sum size of mlocked
+ * vma pages, as return value.
+ * Note deferred memory locking case(mlock2(,,MLOCK_ONFAULT)
+ * is also counted.
+ * Return value: previously mlocked page counts
+ */
+static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm,
+		unsigned long start, size_t len)
+{
+	struct vm_area_struct *vma;
+	unsigned long count = 0;
+	unsigned long end;
+	VMA_ITERATOR(vmi, mm, start);
+
+	/* Don't overflow past ULONG_MAX */
+	if (unlikely(ULONG_MAX - len < start))
+		end = ULONG_MAX;
+	else
+		end = start + len;
+
+	for_each_vma_range(vmi, vma, end) {
+		if (vma->vm_flags & VM_LOCKED) {
+			if (start > vma->vm_start)
+				count -= (start - vma->vm_start);
+			if (end < vma->vm_end) {
+				count += end - vma->vm_start;
+				break;
+			}
+			count += vma->vm_end - vma->vm_start;
+		}
+	}
+
+	return count >> PAGE_SHIFT;
+}
+
+/*
+ * convert get_user_pages() return value to posix mlock() error
+ */
+static int __mlock_posix_error_return(long retval)
+{
+	if (retval == -EFAULT)
+		retval = -ENOMEM;
+	else if (retval == -ENOMEM)
+		retval = -EAGAIN;
+	return retval;
+}
+
+static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags)
+{
+	unsigned long locked;
+	unsigned long lock_limit;
+	int error = -ENOMEM;
+
+	start = untagged_addr(start);
+
+	if (!can_do_mlock())
+		return -EPERM;
+
+	len = PAGE_ALIGN(len + (offset_in_page(start)));
+	start &= PAGE_MASK;
+
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
+	lock_limit >>= PAGE_SHIFT;
+	locked = len >> PAGE_SHIFT;
+
+	if (mmap_write_lock_killable(current->mm))
+		return -EINTR;
+
+	locked += current->mm->locked_vm;
+	if ((locked > lock_limit) && (!capable(CAP_IPC_LOCK))) {
+		/*
+		 * It is possible that the regions requested intersect with
+		 * previously mlocked areas, that part area in "mm->locked_vm"
+		 * should not be counted to new mlock increment count. So check
+		 * and adjust locked count if necessary.
+		 */
+		locked -= count_mm_mlocked_page_nr(current->mm,
+				start, len);
+	}
+
+	/* check against resource limits */
+	if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))
+		error = apply_vma_lock_flags(start, len, flags);
+
+	mmap_write_unlock(current->mm);
+	if (error)
+		return error;
+
+	error = __mm_populate(start, len, 0);
+	if (error)
+		return __mlock_posix_error_return(error);
+	return 0;
+}
+
+SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
+{
+	return do_mlock(start, len, VM_LOCKED);
+}
+
+SYSCALL_DEFINE3(mlock2, unsigned long, start, size_t, len, int, flags)
+{
+	vm_flags_t vm_flags = VM_LOCKED;
+
+	if (flags & ~MLOCK_ONFAULT)
+		return -EINVAL;
+
+	if (flags & MLOCK_ONFAULT)
+		vm_flags |= VM_LOCKONFAULT;
+
+	return do_mlock(start, len, vm_flags);
+}
+
+SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
+{
+	int ret;
+
+	start = untagged_addr(start);
+
+	len = PAGE_ALIGN(len + (offset_in_page(start)));
+	start &= PAGE_MASK;
+
+	if (mmap_write_lock_killable(current->mm))
+		return -EINTR;
+	ret = apply_vma_lock_flags(start, len, 0);
+	mmap_write_unlock(current->mm);
+
+	return ret;
+}
+
+/*
+ * Take the MCL_* flags passed into mlockall (or 0 if called from munlockall)
+ * and translate into the appropriate modifications to mm->def_flags and/or the
+ * flags for all current VMAs.
+ *
+ * There are a couple of subtleties with this.  If mlockall() is called multiple
+ * times with different flags, the values do not necessarily stack.  If mlockall
+ * is called once including the MCL_FUTURE flag and then a second time without
+ * it, VM_LOCKED and VM_LOCKONFAULT will be cleared from mm->def_flags.
+ */
+static int apply_mlockall_flags(int flags)
+{
+	VMA_ITERATOR(vmi, current->mm, 0);
+	struct vm_area_struct *vma, *prev = NULL;
+	vm_flags_t to_add = 0;
+
+	current->mm->def_flags &= ~VM_LOCKED_MASK;
+	if (flags & MCL_FUTURE) {
+		current->mm->def_flags |= VM_LOCKED;
+
+		if (flags & MCL_ONFAULT)
+			current->mm->def_flags |= VM_LOCKONFAULT;
+
+		if (!(flags & MCL_CURRENT))
+			goto out;
+	}
+
+	if (flags & MCL_CURRENT) {
+		to_add |= VM_LOCKED;
+		if (flags & MCL_ONFAULT)
+			to_add |= VM_LOCKONFAULT;
+	}
+
+	for_each_vma(vmi, vma) {
+		vm_flags_t newflags;
+
+		newflags = vma->vm_flags & ~VM_LOCKED_MASK;
+		newflags |= to_add;
+
+		/* Ignore errors */
+		mlock_fixup(&vmi, vma, &prev, vma->vm_start, vma->vm_end,
+			    newflags);
+		cond_resched();
+	}
+out:
+	return 0;
+}
+
+SYSCALL_DEFINE1(mlockall, int, flags)
+{
+	unsigned long lock_limit;
+	int ret;
+
+	if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT)) ||
+	    flags == MCL_ONFAULT)
+		return -EINVAL;
+
+	if (!can_do_mlock())
+		return -EPERM;
+
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
+	lock_limit >>= PAGE_SHIFT;
+
+	if (mmap_write_lock_killable(current->mm))
+		return -EINTR;
+
+	ret = -ENOMEM;
+	if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
+	    capable(CAP_IPC_LOCK))
+		ret = apply_mlockall_flags(flags);
+	mmap_write_unlock(current->mm);
+	if (!ret && (flags & MCL_CURRENT))
+		mm_populate(0, TASK_SIZE);
+
+	return ret;
+}
+
+SYSCALL_DEFINE0(munlockall)
+{
+	int ret;
+
+	if (mmap_write_lock_killable(current->mm))
+		return -EINTR;
+	ret = apply_mlockall_flags(0);
+	mmap_write_unlock(current->mm);
+	return ret;
+}
+
+/*
+ * Objects with different lifetime than processes (SHM_LOCK and SHM_HUGETLB
+ * shm segments) get accounted against the user_struct instead.
+ */
+static DEFINE_SPINLOCK(shmlock_user_lock);
+
+int user_shm_lock(size_t size, struct ucounts *ucounts)
+{
+	unsigned long lock_limit, locked;
+	long memlock;
+	int allowed = 0;
+
+	locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
+	if (lock_limit != RLIM_INFINITY)
+		lock_limit >>= PAGE_SHIFT;
+	spin_lock(&shmlock_user_lock);
+	memlock = inc_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked);
+
+	if ((memlock == LONG_MAX || memlock > lock_limit) && !capable(CAP_IPC_LOCK)) {
+		dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked);
+		goto out;
+	}
+	if (!get_ucounts(ucounts)) {
+		dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked);
+		allowed = 0;
+		goto out;
+	}
+	allowed = 1;
+out:
+	spin_unlock(&shmlock_user_lock);
+	return allowed;
+}
+
+void user_shm_unlock(size_t size, struct ucounts *ucounts)
+{
+	spin_lock(&shmlock_user_lock);
+	dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, (size + PAGE_SIZE - 1) >> PAGE_SHIFT);
+	spin_unlock(&shmlock_user_lock);
+	put_ucounts(ucounts);
+}