1 files changed, 95 insertions, 75 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 34a842a8eb6a..5795cb82e27c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -246,13 +246,13 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 		else if (pte_swp_uffd_wp(*pvmw.pte))
 			pte = pte_mkuffd_wp(pte);
 
-		if (unlikely(is_zone_device_page(new))) {
-			if (is_device_private_page(new)) {
-				entry = make_device_private_entry(new, pte_write(pte));
-				pte = swp_entry_to_pte(entry);
-				if (pte_swp_uffd_wp(*pvmw.pte))
-					pte = pte_mkuffd_wp(pte);
-			}
+		if (unlikely(is_device_private_page(new))) {
+			entry = make_device_private_entry(new, pte_write(pte));
+			pte = swp_entry_to_pte(entry);
+			if (pte_swp_soft_dirty(*pvmw.pte))
+				pte = pte_swp_mksoft_dirty(pte);
+			if (pte_swp_uffd_wp(*pvmw.pte))
+				pte = pte_swp_mkuffd_wp(pte);
 		}
 
 #ifdef CONFIG_HUGETLB_PAGE
@@ -381,7 +381,7 @@ static int expected_page_refs(struct address_space *mapping, struct page *page)
 	int expected_count = 1;
 
 	/*
-	 * Device public or private pages have an extra refcount as they are
+	 * Device private pages have an extra refcount as they are
 	 * ZONE_DEVICE pages.
 	 */
 	expected_count += is_device_private_page(page);
@@ -503,7 +503,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 			__dec_lruvec_state(old_lruvec, NR_SHMEM);
 			__inc_lruvec_state(new_lruvec, NR_SHMEM);
 		}
-		if (dirty && mapping_cap_account_dirty(mapping)) {
+		if (dirty && mapping_can_writeback(mapping)) {
 			__dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY);
 			__dec_zone_state(oldzone, NR_ZONE_WRITE_PENDING);
 			__inc_node_state(newzone->zone_pgdat, NR_FILE_DIRTY);
@@ -668,7 +668,8 @@ void migrate_page_states(struct page *newpage, struct page *page)
 
 	copy_page_owner(page, newpage);
 
-	mem_cgroup_migrate(page, newpage);
+	if (!PageHuge(page))
+		mem_cgroup_migrate(page, newpage);
 }
 EXPORT_SYMBOL(migrate_page_states);
 
@@ -1222,16 +1223,11 @@ out:
 	 * we want to retry.
 	 */
 	if (rc == MIGRATEPAGE_SUCCESS) {
-		put_page(page);
-		if (reason == MR_MEMORY_FAILURE) {
+		if (reason != MR_MEMORY_FAILURE)
 			/*
-			 * Set PG_HWPoison on just freed page
-			 * intentionally. Although it's rather weird,
-			 * it's how HWPoison flag works at the moment.
+			 * We release the page in page_handle_poison.
 			 */
-			if (set_hwpoison_free_buddy_page(page))
-				num_poisoned_pages_inc();
-		}
+			put_page(page);
 	} else {
 		if (rc != -EAGAIN) {
 			if (likely(!__PageMovable(page))) {
@@ -1332,34 +1328,38 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
 		goto put_anon;
 
 	if (page_mapped(hpage)) {
-		/*
-		 * try_to_unmap could potentially call huge_pmd_unshare.
-		 * Because of this, take semaphore in write mode here and
-		 * set TTU_RMAP_LOCKED to let lower levels know we have
-		 * taken the lock.
-		 */
-		mapping = hugetlb_page_mapping_lock_write(hpage);
-		if (unlikely(!mapping))
-			goto unlock_put_anon;
+		bool mapping_locked = false;
+		enum ttu_flags ttu = TTU_MIGRATION|TTU_IGNORE_MLOCK|
+					TTU_IGNORE_ACCESS;
+
+		if (!PageAnon(hpage)) {
+			/*
+			 * In shared mappings, try_to_unmap could potentially
+			 * call huge_pmd_unshare.  Because of this, take
+			 * semaphore in write mode here and set TTU_RMAP_LOCKED
+			 * to let lower levels know we have taken the lock.
+			 */
+			mapping = hugetlb_page_mapping_lock_write(hpage);
+			if (unlikely(!mapping))
+				goto unlock_put_anon;
 
-		try_to_unmap(hpage,
-			TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS|
-			TTU_RMAP_LOCKED);
+			mapping_locked = true;
+			ttu |= TTU_RMAP_LOCKED;
+		}
+
+		try_to_unmap(hpage, ttu);
 		page_was_mapped = 1;
-		/*
-		 * Leave mapping locked until after subsequent call to
-		 * remove_migration_ptes()
-		 */
+
+		if (mapping_locked)
+			i_mmap_unlock_write(mapping);
 	}
 
 	if (!page_mapped(hpage))
 		rc = move_to_new_page(new_hpage, hpage, mode);
 
-	if (page_was_mapped) {
+	if (page_was_mapped)
 		remove_migration_ptes(hpage,
-			rc == MIGRATEPAGE_SUCCESS ? new_hpage : hpage, true);
-		i_mmap_unlock_write(mapping);
-	}
+			rc == MIGRATEPAGE_SUCCESS ? new_hpage : hpage, false);
 
 unlock_put_anon:
 	unlock_page(new_hpage);
@@ -1445,7 +1445,7 @@ retry:
 			 * Capture required information that might get lost
 			 * during migration.
 			 */
-			is_thp = PageTransHuge(page);
+			is_thp = PageTransHuge(page) && !PageHuge(page);
 			nr_subpages = thp_nr_pages(page);
 			cond_resched();
 
@@ -1471,7 +1471,7 @@ retry:
 				 * we encounter them after the rest of the list
 				 * is processed.
 				 */
-				if (PageTransHuge(page) && !PageHuge(page)) {
+				if (is_thp) {
 					lock_page(page);
 					rc = split_huge_page_to_list(page, from);
 					unlock_page(page);
@@ -1480,8 +1480,7 @@ retry:
 						nr_thp_split++;
 						goto retry;
 					}
-				}
-				if (is_thp) {
+
 					nr_thp_failed++;
 					nr_failed += nr_subpages;
 					goto out;
@@ -1869,33 +1868,27 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
 	return nr_pages ? -EFAULT : 0;
 }
 
-/*
- * Move a list of pages in the address space of the currently executing
- * process.
- */
-static int kernel_move_pages(pid_t pid, unsigned long nr_pages,
-			     const void __user * __user *pages,
-			     const int __user *nodes,
-			     int __user *status, int flags)
+static struct mm_struct *find_mm_struct(pid_t pid, nodemask_t *mem_nodes)
 {
 	struct task_struct *task;
 	struct mm_struct *mm;
-	int err;
-	nodemask_t task_nodes;
-
-	/* Check flags */
-	if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
-		return -EINVAL;
 
-	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
-		return -EPERM;
+	/*
+	 * There is no need to check if current process has the right to modify
+	 * the specified process when they are same.
+	 */
+	if (!pid) {
+		mmget(current->mm);
+		*mem_nodes = cpuset_mems_allowed(current);
+		return current->mm;
+	}
 
 	/* Find the mm_struct */
 	rcu_read_lock();
-	task = pid ? find_task_by_vpid(pid) : current;
+	task = find_task_by_vpid(pid);
 	if (!task) {
 		rcu_read_unlock();
-		return -ESRCH;
+		return ERR_PTR(-ESRCH);
 	}
 	get_task_struct(task);
 
@@ -1905,22 +1898,47 @@ static int kernel_move_pages(pid_t pid, unsigned long nr_pages,
 	 */
 	if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) {
 		rcu_read_unlock();
-		err = -EPERM;
+		mm = ERR_PTR(-EPERM);
 		goto out;
 	}
 	rcu_read_unlock();
 
- 	err = security_task_movememory(task);
- 	if (err)
+	mm = ERR_PTR(security_task_movememory(task));
+	if (IS_ERR(mm))
 		goto out;
-
-	task_nodes = cpuset_mems_allowed(task);
+	*mem_nodes = cpuset_mems_allowed(task);
 	mm = get_task_mm(task);
+out:
 	put_task_struct(task);
-
 	if (!mm)
+		mm = ERR_PTR(-EINVAL);
+	return mm;
+}
+
+/*
+ * Move a list of pages in the address space of the currently executing
+ * process.
+ */
+static int kernel_move_pages(pid_t pid, unsigned long nr_pages,
+			     const void __user * __user *pages,
+			     const int __user *nodes,
+			     int __user *status, int flags)
+{
+	struct mm_struct *mm;
+	int err;
+	nodemask_t task_nodes;
+
+	/* Check flags */
+	if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
 		return -EINVAL;
 
+	if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
+		return -EPERM;
+
+	mm = find_mm_struct(pid, &task_nodes);
+	if (IS_ERR(mm))
+		return PTR_ERR(mm);
+
 	if (nodes)
 		err = do_pages_move(mm, task_nodes, nr_pages, pages,
 				    nodes, status, flags);
@@ -1929,10 +1947,6 @@ static int kernel_move_pages(pid_t pid, unsigned long nr_pages,
 
 	mmput(mm);
 	return err;
-
-out:
-	put_task_struct(task);
-	return err;
 }
 
 SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
@@ -2427,10 +2441,17 @@ again:
 			entry = make_migration_entry(page, mpfn &
 						     MIGRATE_PFN_WRITE);
 			swp_pte = swp_entry_to_pte(entry);
-			if (pte_soft_dirty(pte))
-				swp_pte = pte_swp_mksoft_dirty(swp_pte);
-			if (pte_uffd_wp(pte))
-				swp_pte = pte_swp_mkuffd_wp(swp_pte);
+			if (pte_present(pte)) {
+				if (pte_soft_dirty(pte))
+					swp_pte = pte_swp_mksoft_dirty(swp_pte);
+				if (pte_uffd_wp(pte))
+					swp_pte = pte_swp_mkuffd_wp(swp_pte);
+			} else {
+				if (pte_swp_soft_dirty(pte))
+					swp_pte = pte_swp_mksoft_dirty(swp_pte);
+				if (pte_swp_uffd_wp(pte))
+					swp_pte = pte_swp_mkuffd_wp(swp_pte);
+			}
 			set_pte_at(mm, addr, ptep, swp_pte);
 
 			/*
@@ -3070,7 +3091,6 @@ void migrate_vma_finalize(struct migrate_vma *migrate)
 
 		remove_migration_ptes(page, newpage, false);
 		unlock_page(page);
-		migrate->cpages--;
 
 		if (is_zone_device_page(page))
 			put_page(page);