diff --git a/include/linux/hugetlb_inline.h b/include/linux/hugetlb_inline.h
index 0660a03d37d9..9e25283d6fc9 100644
--- a/include/linux/hugetlb_inline.h
+++ b/include/linux/hugetlb_inline.h
@@ -8,7 +8,7 @@
 
 static inline bool is_vm_hugetlb_page(struct vm_area_struct *vma)
 {
-	return !!(vma->vm_flags & VM_HUGETLB);
+	return !!(READ_ONCE(vma->vm_flags) & VM_HUGETLB);
 }
 
 #else
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f761a9c65c74..ec609cbad25a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -381,6 +381,7 @@ extern pgprot_t protection_map[16];
 #define FAULT_FLAG_USER		0x40	/* The fault originated in userspace */
 #define FAULT_FLAG_REMOTE	0x80	/* faulting for non current tsk/mm */
 #define FAULT_FLAG_INSTRUCTION  0x100	/* The fault was during an instruction fetch */
+#define FAULT_FLAG_SPECULATIVE	0x200	/* Speculative fault, not holding mmap_sem */
 
 #define FAULT_FLAG_TRACE \
 	{ FAULT_FLAG_WRITE,		"WRITE" }, \
@@ -409,6 +410,10 @@ struct vm_fault {
 	gfp_t gfp_mask;			/* gfp mask to be used for allocations */
 	pgoff_t pgoff;			/* Logical page offset based on vma */
 	unsigned long address;		/* Faulting virtual address */
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+	unsigned int sequence;
+	pmd_t orig_pmd;			/* value of PMD at the time of fault */
+#endif
 	pmd_t *pmd;			/* Pointer to pmd entry matching
 					 * the 'address' */
 	pud_t *pud;			/* Pointer to pud entry matching
@@ -1524,6 +1529,31 @@ int invalidate_inode_page(struct page *page);
 #ifdef CONFIG_MMU
 extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
 			unsigned long address, unsigned int flags);
+
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+extern vm_fault_t __handle_speculative_fault(struct mm_struct *mm,
+					     unsigned long address,
+					     unsigned int flags);
+static inline vm_fault_t handle_speculative_fault(struct mm_struct *mm,
+						  unsigned long address,
+						  unsigned int flags)
+{
+	/*
+	 * Try speculative page fault for multithreaded user space task only.
+	 */
+	if (!(flags & FAULT_FLAG_USER) || atomic_read(&mm->mm_users) == 1)
+		return VM_FAULT_RETRY;
+	return __handle_speculative_fault(mm, address, flags);
+}
+#else
+static inline vm_fault_t handle_speculative_fault(struct mm_struct *mm,
+						  unsigned long address,
+						  unsigned int flags)
+{
+	return VM_FAULT_RETRY;
+}
+#endif /* CONFIG_SPECULATIVE_PAGE_FAULT */
+
 extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
 			    unsigned long address, unsigned int fault_flags,
 			    bool *unlocked);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 2e8438a1216a..2fcfaa910007 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -457,8 +457,8 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
 	pgoff_t pgoff;
 	if (unlikely(is_vm_hugetlb_page(vma)))
 		return linear_hugepage_index(vma, address);
-	pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
-	pgoff += vma->vm_pgoff;
+	pgoff = (address - READ_ONCE(vma->vm_start)) >> PAGE_SHIFT;
+	pgoff += READ_ONCE(vma->vm_pgoff);
 	return pgoff;
 }
 
diff --git a/mm/internal.h b/mm/internal.h
index 1e368e4afe3c..ed91b199cb8c 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -58,6 +58,21 @@ static inline void put_vma(struct vm_area_struct *vma)
 extern struct vm_area_struct *find_vma_rcu(struct mm_struct *mm,
 					   unsigned long addr);
 
+
+static inline bool vma_has_changed(struct vm_fault *vmf)
+{
+	int ret = RB_EMPTY_NODE(&vmf->vma->vm_rb);
+	unsigned int seq = READ_ONCE(vmf->vma->vm_sequence.sequence);
+
+	/*
+	 * Matches both the wmb in write_seqlock_{begin,end}() and
+	 * the wmb in vma_rb_erase().
+	 */
+	smp_rmb();
+
+	return ret || seq != vmf->sequence;
+}
+
 #else /* CONFIG_SPECULATIVE_PAGE_FAULT */
 
 static inline void get_vma(struct vm_area_struct *vma)
diff --git a/mm/memory.c b/mm/memory.c
index 46f877b6abea..6e6bf61c0e5c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -522,7 +522,8 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
 	if (page)
 		dump_page(page, "bad pte");
 	pr_alert("addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n",
-		 (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index);
+		 (void *)addr, READ_ONCE(vma->vm_flags), vma->anon_vma,
+		 mapping, index);
 	pr_alert("file:%pD fault:%pf mmap:%pf readpage:%pf\n",
 		 vma->vm_file,
 		 vma->vm_ops ? vma->vm_ops->fault : NULL,
@@ -2082,6 +2083,118 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
 }
 EXPORT_SYMBOL_GPL(apply_to_page_range);
 
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+static bool pte_spinlock(struct vm_fault *vmf)
+{
+	bool ret = false;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	pmd_t pmdval;
+#endif
+
+	/* Check if vma is still valid */
+	if (!(vmf->flags & FAULT_FLAG_SPECULATIVE)) {
+		vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
+		spin_lock(vmf->ptl);
+		return true;
+	}
+
+again:
+	local_irq_disable();
+	if (vma_has_changed(vmf))
+		goto out;
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	/*
+	 * We check if the pmd value is still the same to ensure that there
+	 * is not a huge collapse operation in progress in our back.
+	 */
+	pmdval = READ_ONCE(*vmf->pmd);
+	if (!pmd_same(pmdval, vmf->orig_pmd))
+		goto out;
+#endif
+
+	vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
+	if (unlikely(!spin_trylock(vmf->ptl))) {
+		local_irq_enable();
+		goto again;
+	}
+
+	if (vma_has_changed(vmf)) {
+		spin_unlock(vmf->ptl);
+		goto out;
+	}
+
+	ret = true;
+out:
+	local_irq_enable();
+	return ret;
+}
+
+static bool pte_map_lock(struct vm_fault *vmf)
+{
+	bool ret = false;
+	pte_t *pte;
+	spinlock_t *ptl;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	pmd_t pmdval;
+#endif
+
+	if (!(vmf->flags & FAULT_FLAG_SPECULATIVE)) {
+		vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd,
+					       vmf->address, &vmf->ptl);
+		return true;
+	}
+
+	/*
+	 * The first vma_has_changed() guarantees the page-tables are still
+	 * valid, having IRQs disabled ensures they stay around, hence the
+	 * second vma_has_changed() to make sure they are still valid once
+	 * we've got the lock. After that a concurrent zap_pte_range() will
+	 * block on the PTL and thus we're safe.
+	 */
+again:
+	local_irq_disable();
+	if (vma_has_changed(vmf))
+		goto out;
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	/*
+	 * We check if the pmd value is still the same to ensure that there
+	 * is not a huge collapse operation in progress in our back.
+	 */
+	pmdval = READ_ONCE(*vmf->pmd);
+	if (!pmd_same(pmdval, vmf->orig_pmd))
+		goto out;
+#endif
+
+	/*
+	 * Same as pte_offset_map_lock() except that we call
+	 * spin_trylock() in place of spin_lock() to avoid race with
+	 * unmap path which may have the lock and wait for this CPU
+	 * to invalidate TLB but this CPU has irq disabled.
+	 * Since we are in a speculative patch, accept it could fail
+	 */
+	ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
+	pte = pte_offset_map(vmf->pmd, vmf->address);
+	if (unlikely(!spin_trylock(ptl))) {
+		pte_unmap(pte);
+		local_irq_enable();
+		goto again;
+	}
+
+	if (vma_has_changed(vmf)) {
+		pte_unmap_unlock(pte, ptl);
+		goto out;
+	}
+
+	vmf->pte = pte;
+	vmf->ptl = ptl;
+	ret = true;
+out:
+	local_irq_enable();
+	return ret;
+}
+#else
 static inline bool pte_spinlock(struct vm_fault *vmf)
 {
 	vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
@@ -2095,6 +2208,7 @@ static inline bool pte_map_lock(struct vm_fault *vmf)
 				       vmf->address, &vmf->ptl);
 	return true;
 }
+#endif /* CONFIG_SPECULATIVE_PAGE_FAULT */
 
 /*
  * handle_pte_fault chooses page fault handler according to an entry which was
@@ -2999,6 +3113,14 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 		ret = check_stable_address_space(vma->vm_mm);
 		if (ret)
 			goto unlock;
+		/*
+		 * Don't call the userfaultfd during the speculative path.
+		 * We already checked for the VMA to not be managed through
+		 * userfaultfd, but it may be set in our back once we have lock
+		 * the pte. In such a case we can ignore it this time.
+		 */
+		if (vmf->flags & FAULT_FLAG_SPECULATIVE)
+			goto setpte;
 		/* Deliver the page fault to userland, check inside PT lock */
 		if (userfaultfd_missing(vma)) {
 			pte_unmap_unlock(vmf->pte, vmf->ptl);
@@ -3041,7 +3163,8 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 		goto unlock_and_release;
 
 	/* Deliver the page fault to userland, check inside PT lock */
-	if (userfaultfd_missing(vma)) {
+	if (!(vmf->flags & FAULT_FLAG_SPECULATIVE) &&
+	    userfaultfd_missing(vma)) {
 		pte_unmap_unlock(vmf->pte, vmf->ptl);
 		mem_cgroup_cancel_charge(page, memcg, false);
 		put_page(page);
@@ -3836,6 +3959,15 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 	pte_t entry;
 
 	if (unlikely(pmd_none(*vmf->pmd))) {
+		/*
+		 * In the case of the speculative page fault handler we abort
+		 * the speculative path immediately as the pmd is probably
+		 * in the way to be converted in a huge one. We will try
+		 * again holding the mmap_sem (which implies that the collapse
+		 * operation is done).
+		 */
+		if (vmf->flags & FAULT_FLAG_SPECULATIVE)
+			return VM_FAULT_RETRY;
 		/*
 		 * Leave __pte_alloc() until later: because vm_ops->fault may
 		 * want to allocate huge page, and if we expose page table
@@ -3843,7 +3975,7 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 		 * concurrent faults and from rmap lookups.
 		 */
 		vmf->pte = NULL;
-	} else {
+	} else if (!(vmf->flags & FAULT_FLAG_SPECULATIVE)) {
 		/* See comment in pte_alloc_one_map() */
 		if (pmd_devmap_trans_unstable(vmf->pmd))
 			return 0;
@@ -3852,6 +3984,9 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 		 * pmd from under us anymore at this point because we hold the
 		 * mmap_sem read mode and khugepaged takes it in write mode.
 		 * So now it's safe to run pte_offset_map().
+		 * This is not applicable to the speculative page fault handler
+		 * but in that case, the pte is fetched earlier in
+		 * handle_speculative_fault().
 		 */
 		vmf->pte = pte_offset_map(vmf->pmd, vmf->address);
 		vmf->orig_pte = *vmf->pte;
@@ -3874,6 +4009,8 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
 	if (!vmf->pte) {
 		if (vma_is_anonymous(vmf->vma))
 			return do_anonymous_page(vmf);
+		else if (vmf->flags & FAULT_FLAG_SPECULATIVE)
+			return VM_FAULT_RETRY;
 		else
 			return do_fault(vmf);
 	}
@@ -3971,6 +4108,9 @@ static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
 	vmf.pmd = pmd_alloc(mm, vmf.pud, address);
 	if (!vmf.pmd)
 		return VM_FAULT_OOM;
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+	vmf.sequence = raw_read_seqcount(&vma->vm_sequence);
+#endif
 	if (pmd_none(*vmf.pmd) && __transparent_hugepage_enabled(vma)) {
 		ret = create_huge_pmd(&vmf);
 		if (!(ret & VM_FAULT_FALLBACK))
@@ -4004,6 +4144,204 @@ static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
 	return handle_pte_fault(&vmf);
 }
 
+#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
+/*
+ * Tries to handle the page fault in a speculative way, without grabbing the
+ * mmap_sem.
+ */
+vm_fault_t __handle_speculative_fault(struct mm_struct *mm,
+				      unsigned long address,
+				      unsigned int flags)
+{
+	struct vm_fault vmf = {
+		.address = address,
+	};
+	pgd_t *pgd, pgdval;
+	p4d_t *p4d, p4dval;
+	pud_t pudval;
+	int seq;
+	vm_fault_t ret = VM_FAULT_RETRY;
+	struct vm_area_struct *vma;
+#ifdef CONFIG_NUMA
+	struct mempolicy *pol;
+#endif
+
+	/* Clear flags that may lead to release the mmap_sem to retry */
+	flags &= ~(FAULT_FLAG_ALLOW_RETRY|FAULT_FLAG_KILLABLE);
+	flags |= FAULT_FLAG_SPECULATIVE;
+
+	vma = find_vma_rcu(mm, address);
+	if (!vma)
+		return ret;
+
+	/* rmb <-> seqlock,vma_rb_erase() */
+	seq = raw_read_seqcount(&vma->vm_sequence);
+	if (seq & 1)
+		goto out_put;
+
+	/*
+	 * Can't call vm_ops service has we don't know what they would do
+	 * with the VMA.
+	 * This include huge page from hugetlbfs.
+	 */
+	if (vma->vm_ops && vma->vm_ops->fault)
+		goto out_put;
+
+	/*
+	 * __anon_vma_prepare() requires the mmap_sem to be held
+	 * because vm_next and vm_prev must be safe. This can't be guaranteed
+	 * in the speculative path.
+	 */
+	if (unlikely(!vma->anon_vma))
+		goto out_put;
+
+	vmf.vma_flags = READ_ONCE(vma->vm_flags);
+	vmf.vma_page_prot = READ_ONCE(vma->vm_page_prot);
+
+	/* Can't call userland page fault handler in the speculative path */
+	if (unlikely(vmf.vma_flags & VM_UFFD_MISSING))
+		goto out_put;
+
+	if (vmf.vma_flags & VM_GROWSDOWN || vmf.vma_flags & VM_GROWSUP)
+		/*
+		 * This could be detected by the check address against VMA's
+		 * boundaries but we want to trace it as not supported instead
+		 * of changed.
+		 */
+		goto out_put;
+
+	if (address < READ_ONCE(vma->vm_start)
+	    || READ_ONCE(vma->vm_end) <= address)
+		goto out_put;
+
+	if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
+				       flags & FAULT_FLAG_INSTRUCTION,
+				       flags & FAULT_FLAG_REMOTE)) {
+		ret = VM_FAULT_SIGSEGV;
+		goto out_put;
+	}
+
+	/* This is one is required to check that the VMA has write access set */
+	if (flags & FAULT_FLAG_WRITE) {
+		if (unlikely(!(vmf.vma_flags & VM_WRITE))) {
+			ret = VM_FAULT_SIGSEGV;
+			goto out_put;
+		}
+	} else if (unlikely(!(vmf.vma_flags & (VM_READ|VM_EXEC|VM_WRITE)))) {
+		ret = VM_FAULT_SIGSEGV;
+		goto out_put;
+	}
+
+#ifdef CONFIG_NUMA
+	/*
+	 * MPOL_INTERLEAVE implies additional checks in
+	 * mpol_misplaced() which are not compatible with the
+	 *speculative page fault processing.
+	 */
+	pol = __get_vma_policy(vma, address);
+	if (!pol)
+		pol = get_task_policy(current);
+	if (pol && pol->mode == MPOL_INTERLEAVE)
+		goto out_put;
+#endif
+
+	/*
+	 * Do a speculative lookup of the PTE entry.
+	 */
+	local_irq_disable();
+	pgd = pgd_offset(mm, address);
+	pgdval = READ_ONCE(*pgd);
+	if (pgd_none(pgdval) || unlikely(pgd_bad(pgdval)))
+		goto out_walk;
+
+	p4d = p4d_offset(pgd, address);
+	p4dval = READ_ONCE(*p4d);
+	if (p4d_none(p4dval) || unlikely(p4d_bad(p4dval)))
+		goto out_walk;
+
+	vmf.pud = pud_offset(p4d, address);
+	pudval = READ_ONCE(*vmf.pud);
+	if (pud_none(pudval) || unlikely(pud_bad(pudval)))
+		goto out_walk;
+
+	/* Huge pages at PUD level are not supported. */
+	if (unlikely(pud_trans_huge(pudval)))
+		goto out_walk;
+
+	vmf.pmd = pmd_offset(vmf.pud, address);
+	vmf.orig_pmd = READ_ONCE(*vmf.pmd);
+	/*
+	 * pmd_none could mean that a hugepage collapse is in progress
+	 * in our back as collapse_huge_page() mark it before
+	 * invalidating the pte (which is done once the IPI is catched
+	 * by all CPU and we have interrupt disabled).
+	 * For this reason we cannot handle THP in a speculative way since we
+	 * can't safely identify an in progress collapse operation done in our
+	 * back on that PMD.
+	 * Regarding the order of the following checks, see comment in
+	 * pmd_devmap_trans_unstable()
+	 */
+	if (unlikely(pmd_devmap(vmf.orig_pmd) ||
+		     pmd_none(vmf.orig_pmd) || pmd_trans_huge(vmf.orig_pmd) ||
+		     is_swap_pmd(vmf.orig_pmd)))
+		goto out_walk;
+
+	/*
+	 * The above does not allocate/instantiate page-tables because doing so
+	 * would lead to the possibility of instantiating page-tables after
+	 * free_pgtables() -- and consequently leaking them.
+	 *
+	 * The result is that we take at least one !speculative fault per PMD
+	 * in order to instantiate it.
+	 */
+
+	vmf.pte = pte_offset_map(vmf.pmd, address);
+	vmf.orig_pte = READ_ONCE(*vmf.pte);
+	barrier(); /* See comment in handle_pte_fault() */
+	if (pte_none(vmf.orig_pte)) {
+		pte_unmap(vmf.pte);
+		vmf.pte = NULL;
+	}
+
+	vmf.vma = vma;
+	vmf.pgoff = linear_page_index(vma, address);
+	vmf.gfp_mask = __get_fault_gfp_mask(vma);
+	vmf.sequence = seq;
+	vmf.flags = flags;
+
+	local_irq_enable();
+
+	/*
+	 * We need to re-validate the VMA after checking the bounds, otherwise
+	 * we might have a false positive on the bounds.
+	 */
+	if (read_seqcount_retry(&vma->vm_sequence, seq))
+		goto out_put;
+
+	mem_cgroup_enter_user_fault();
+	ret = handle_pte_fault(&vmf);
+	mem_cgroup_exit_user_fault();
+
+	put_vma(vma);
+
+	/*
+	 * The task may have entered a memcg OOM situation but
+	 * if the allocation error was handled gracefully (no
+	 * VM_FAULT_OOM), there is no need to kill anything.
+	 * Just clean up the OOM state peacefully.
+	 */
+	if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM))
+		mem_cgroup_oom_synchronize(false);
+	return ret;
+
+out_walk:
+	local_irq_enable();
+out_put:
+	put_vma(vma);
+	return ret;
+}
+#endif /* CONFIG_SPECULATIVE_PAGE_FAULT */
+
 /*
  * By the time we get here, we already hold the mm semaphore
  *
