merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes

4 files changed, 35 insertions, 9 deletions

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 20284387b841..e718dbe928ba 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -25,9 +25,6 @@ static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
 #endif
 
 vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf);
-struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
-				   unsigned long addr, pmd_t *pmd,
-				   unsigned int flags);
 bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			   pmd_t *pmd, unsigned long addr, unsigned long next);
 int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 88ac4cf9d3ec..55eb2789794e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3496,15 +3496,24 @@ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
  * Indicates whether GUP can follow a PROT_NONE mapped page, or whether
  * a (NUMA hinting) fault is required.
  */
-static inline bool gup_can_follow_protnone(unsigned int flags)
+static inline bool gup_can_follow_protnone(struct vm_area_struct *vma,
+					   unsigned int flags)
 {
 	/*
-	 * FOLL_FORCE has to be able to make progress even if the VMA is
-	 * inaccessible. Further, FOLL_FORCE access usually does not represent
-	 * application behaviour and we should avoid triggering NUMA hinting
-	 * faults.
+	 * If callers don't want to honor NUMA hinting faults, no need to
+	 * determine if we would actually have to trigger a NUMA hinting fault.
 	 */
-	return flags & FOLL_FORCE;
+	if (!(flags & FOLL_HONOR_NUMA_FAULT))
+		return true;
+
+	/*
+	 * NUMA hinting faults don't apply in inaccessible (PROT_NONE) VMAs.
+	 *
+	 * Requiring a fault here even for inaccessible VMAs would mean that
+	 * FOLL_FORCE cannot make any progress, because handle_mm_fault()
+	 * refuses to process NUMA hinting faults in inaccessible VMAs.
+	 */
+	return !vma_is_accessible(vma);
 }
 
 typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 369b7fd35d03..de5ac95572c8 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -1356,6 +1356,15 @@ enum {
 	FOLL_PCI_P2PDMA = 1 << 10,
 	/* allow interrupts from generic signals */
 	FOLL_INTERRUPTIBLE = 1 << 11,
+	/*
+	 * Always honor (trigger) NUMA hinting faults.
+	 *
+	 * FOLL_WRITE implicitly honors NUMA hinting faults because a
+	 * PROT_NONE-mapped page is not writable (exceptions with FOLL_FORCE
+	 * apply). get_user_pages_fast_only() always implicitly honors NUMA
+	 * hinting faults.
+	 */
+	FOLL_HONOR_NUMA_FAULT = 1 << 12,
 
 	/* See also internal only FOLL flags in mm/internal.h */
 };
diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h
index 27a6df448ee5..27cd1e59ccf7 100644
--- a/include/linux/pagewalk.h
+++ b/include/linux/pagewalk.h
@@ -6,6 +6,16 @@
 
 struct mm_walk;
 
+/* Locking requirement during a page walk. */
+enum page_walk_lock {
+	/* mmap_lock should be locked for read to stabilize the vma tree */
+	PGWALK_RDLOCK = 0,
+	/* vma will be write-locked during the walk */
+	PGWALK_WRLOCK = 1,
+	/* vma is expected to be already write-locked during the walk */
+	PGWALK_WRLOCK_VERIFY = 2,
+};
+
 /**
  * struct mm_walk_ops - callbacks for walk_page_range
  * @pgd_entry:		if set, called for each non-empty PGD (top-level) entry
@@ -66,6 +76,7 @@ struct mm_walk_ops {
 	int (*pre_vma)(unsigned long start, unsigned long end,
 		       struct mm_walk *walk);
 	void (*post_vma)(struct mm_walk *walk);
+	enum page_walk_lock walk_lock;
 };
 
 /*