Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "10 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: move pcp and lru-pcp draining into single wq
  mailmap: update Yakir Yang email address
  mm, swap_cgroup: reschedule when neeed in swap_cgroup_swapoff()
  dax: fix radix tree insertion race
  mm, thp: fix setting of defer+madvise thp defrag mode
  ptrace: fix PTRACE_LISTEN race corrupting task->state
  vmlinux.lds: add missing VMLINUX_SYMBOL macros
  mm/page_alloc.c: fix print order in show_free_areas()
  userfaultfd: report actual registered features in fdinfo
  mm: fix page_vma_mapped_walk() for ksm pages

12 files changed, 85 insertions, 60 deletions

diff --git a/.mailmap b/.mailmap
index 67dc22ffc9a8..e229922dc7f0 100644
--- a/.mailmap
+++ b/.mailmap
@@ -171,6 +171,7 @@ Vlad Dogaru <ddvlad@gmail.com> <vlad.dogaru@intel.com>
 Vladimir Davydov <vdavydov.dev@gmail.com> <vdavydov@virtuozzo.com>
 Vladimir Davydov <vdavydov.dev@gmail.com> <vdavydov@parallels.com>
 Takashi YOSHII <takashi.yoshii.zj@renesas.com>
+Yakir Yang <kuankuan.y@gmail.com> <ykk@rock-chips.com>
 Yusuke Goda <goda.yusuke@renesas.com>
 Gustavo Padovan <gustavo@las.ic.unicamp.br>
 Gustavo Padovan <padovan@profusion.mobi>
diff --git a/fs/dax.c b/fs/dax.c
index de622d4282a6..85abd741253d 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -373,6 +373,22 @@ restart:
 		}
 		spin_lock_irq(&mapping->tree_lock);
 
+		if (!entry) {
+			/*
+			 * We needed to drop the page_tree lock while calling
+			 * radix_tree_preload() and we didn't have an entry to
+			 * lock.  See if another thread inserted an entry at
+			 * our index during this time.
+			 */
+			entry = __radix_tree_lookup(&mapping->page_tree, index,
+					NULL, &slot);
+			if (entry) {
+				radix_tree_preload_end();
+				spin_unlock_irq(&mapping->tree_lock);
+				goto restart;
+			}
+		}
+
 		if (pmd_downgrade) {
 			radix_tree_delete(&mapping->page_tree, index);
 			mapping->nrexceptional--;
@@ -388,19 +404,12 @@ restart:
 		if (err) {
 			spin_unlock_irq(&mapping->tree_lock);
 			/*
-			 * Someone already created the entry?  This is a
-			 * normal failure when inserting PMDs in a range
-			 * that already contains PTEs.  In that case we want
-			 * to return -EEXIST immediately.
-			 */
-			if (err == -EEXIST && !(size_flag & RADIX_DAX_PMD))
-				goto restart;
-			/*
-			 * Our insertion of a DAX PMD entry failed, most
-			 * likely because it collided with a PTE sized entry
-			 * at a different index in the PMD range.  We haven't
-			 * inserted anything into the radix tree and have no
-			 * waiters to wake.
+			 * Our insertion of a DAX entry failed, most likely
+			 * because we were inserting a PMD entry and it
+			 * collided with a PTE sized entry at a different
+			 * index in the PMD range.  We haven't inserted
+			 * anything into the radix tree and have no waiters to
+			 * wake.
 			 */
 			return ERR_PTR(err);
 		}
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 1d227b0fcf49..f7555fc25877 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1756,7 +1756,7 @@ static void userfaultfd_show_fdinfo(struct seq_file *m, struct file *f)
 	 *	protocols: aa:... bb:...
 	 */
 	seq_printf(m, "pending:\t%lu\ntotal:\t%lu\nAPI:\t%Lx:%x:%Lx\n",
-		   pending, total, UFFD_API, UFFD_API_FEATURES,
+		   pending, total, UFFD_API, ctx->features,
 		   UFFD_API_IOCTLS|UFFD_API_RANGE_IOCTLS);
 }
 #endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 7cdfe167074f..143db9c523e2 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -261,9 +261,9 @@
  */
 #ifndef RO_AFTER_INIT_DATA
 #define RO_AFTER_INIT_DATA						\
-	__start_ro_after_init = .;					\
+	VMLINUX_SYMBOL(__start_ro_after_init) = .;			\
 	*(.data..ro_after_init)						\
-	__end_ro_after_init = .;
+	VMLINUX_SYMBOL(__end_ro_after_init) = .;
 #endif
 
 /*
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 0af928712174..266ddcc1d8bb 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -184,11 +184,17 @@ static void ptrace_unfreeze_traced(struct task_struct *task)
 
 	WARN_ON(!task->ptrace || task->parent != current);
 
+	/*
+	 * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
+	 * Recheck state under the lock to close this race.
+	 */
 	spin_lock_irq(&task->sighand->siglock);
-	if (__fatal_signal_pending(task))
-		wake_up_state(task, __TASK_TRACED);
-	else
-		task->state = TASK_TRACED;
+	if (task->state == __TASK_TRACED) {
+		if (__fatal_signal_pending(task))
+			wake_up_state(task, __TASK_TRACED);
+		else
+			task->state = TASK_TRACED;
+	}
 	spin_unlock_irq(&task->sighand->siglock);
 }
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1ebc93e179f3..fef4cf210cc7 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -240,18 +240,18 @@ static ssize_t defrag_store(struct kobject *kobj,
 		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);
 		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);
 		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);
-	} else if (!memcmp("defer", buf,
-		    min(sizeof("defer")-1, count))) {
-		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);
-		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);
-		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);
-		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags);
 	} else if (!memcmp("defer+madvise", buf,
 		    min(sizeof("defer+madvise")-1, count))) {
 		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);
 		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags);
 		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);
 		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);
+	} else if (!memcmp("defer", buf,
+		    min(sizeof("defer")-1, count))) {
+		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);
+		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);
+		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags);
+		set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags);
 	} else if (!memcmp("madvise", buf,
 			   min(sizeof("madvise")-1, count))) {
 		clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags);
diff --git a/mm/internal.h b/mm/internal.h
index ccfc2a2969f4..266efaeaa370 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -481,6 +481,13 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 enum ttu_flags;
 struct tlbflush_unmap_batch;
 
+
+/*
+ * only for MM internal work items which do not depend on
+ * any allocations or locks which might depend on allocations
+ */
+extern struct workqueue_struct *mm_percpu_wq;
+
 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 void try_to_unmap_flush(void);
 void try_to_unmap_flush_dirty(void);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6cbde310abed..f3d603cef2c0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2373,6 +2373,13 @@ void drain_all_pages(struct zone *zone)
 	 */
 	static cpumask_t cpus_with_pcps;
 
+	/*
+	 * Make sure nobody triggers this path before mm_percpu_wq is fully
+	 * initialized.
+	 */
+	if (WARN_ON_ONCE(!mm_percpu_wq))
+		return;
+
 	/* Workqueues cannot recurse */
 	if (current->flags & PF_WQ_WORKER)
 		return;
@@ -2422,7 +2429,7 @@ void drain_all_pages(struct zone *zone)
 	for_each_cpu(cpu, &cpus_with_pcps) {
 		struct work_struct *work = per_cpu_ptr(&pcpu_drain, cpu);
 		INIT_WORK(work, drain_local_pages_wq);
-		schedule_work_on(cpu, work);
+		queue_work_on(cpu, mm_percpu_wq, work);
 	}
 	for_each_cpu(cpu, &cpus_with_pcps)
 		flush_work(per_cpu_ptr(&pcpu_drain, cpu));
@@ -4519,13 +4526,13 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 			K(node_page_state(pgdat, NR_FILE_MAPPED)),
 			K(node_page_state(pgdat, NR_FILE_DIRTY)),
 			K(node_page_state(pgdat, NR_WRITEBACK)),
+			K(node_page_state(pgdat, NR_SHMEM)),
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 			K(node_page_state(pgdat, NR_SHMEM_THPS) * HPAGE_PMD_NR),
 			K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)
 					* HPAGE_PMD_NR),
 			K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
 #endif
-			K(node_page_state(pgdat, NR_SHMEM)),
 			K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
 			K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
 			node_page_state(pgdat, NR_PAGES_SCANNED),
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index c4c9def8ffea..de9c40d7304a 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -111,12 +111,8 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
 	if (pvmw->pmd && !pvmw->pte)
 		return not_found(pvmw);
 
-	/* Only for THP, seek to next pte entry makes sense */
-	if (pvmw->pte) {
-		if (!PageTransHuge(pvmw->page) || PageHuge(pvmw->page))
-			return not_found(pvmw);
+	if (pvmw->pte)
 		goto next_pte;
-	}
 
 	if (unlikely(PageHuge(pvmw->page))) {
 		/* when pud is not present, pte will be NULL */
@@ -165,9 +161,14 @@ restart:
 	while (1) {
 		if (check_pte(pvmw))
 			return true;
-next_pte:	do {
+next_pte:
+		/* Seek to next pte only makes sense for THP */
+		if (!PageTransHuge(pvmw->page) || PageHuge(pvmw->page))
+			return not_found(pvmw);
+		do {
 			pvmw->address += PAGE_SIZE;
-			if (pvmw->address >=
+			if (pvmw->address >= pvmw->vma->vm_end ||
+			    pvmw->address >=
 					__vma_address(pvmw->page, pvmw->vma) +
 					hpage_nr_pages(pvmw->page) * PAGE_SIZE)
 				return not_found(pvmw);
diff --git a/mm/swap.c b/mm/swap.c
index c4910f14f957..5dabf444d724 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -670,30 +670,19 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy)
 
 static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
 
-/*
- * lru_add_drain_wq is used to do lru_add_drain_all() from a WQ_MEM_RECLAIM
- * workqueue, aiding in getting memory freed.
- */
-static struct workqueue_struct *lru_add_drain_wq;
-
-static int __init lru_init(void)
-{
-	lru_add_drain_wq = alloc_workqueue("lru-add-drain", WQ_MEM_RECLAIM, 0);
-
-	if (WARN(!lru_add_drain_wq,
-		"Failed to create workqueue lru_add_drain_wq"))
-		return -ENOMEM;
-
-	return 0;
-}
-early_initcall(lru_init);
-
 void lru_add_drain_all(void)
 {
 	static DEFINE_MUTEX(lock);
 	static struct cpumask has_work;
 	int cpu;
 
+	/*
+	 * Make sure nobody triggers this path before mm_percpu_wq is fully
+	 * initialized.
+	 */
+	if (WARN_ON(!mm_percpu_wq))
+		return;
+
 	mutex_lock(&lock);
 	get_online_cpus();
 	cpumask_clear(&has_work);
@@ -707,7 +696,7 @@ void lru_add_drain_all(void)
 		    pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
 		    need_activate_page_drain(cpu)) {
 			INIT_WORK(work, lru_add_drain_per_cpu);
-			queue_work_on(cpu, lru_add_drain_wq, work);
+			queue_work_on(cpu, mm_percpu_wq, work);
 			cpumask_set_cpu(cpu, &has_work);
 		}
 	}
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index 310ac0b8f974..ac6318a064d3 100644
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -201,6 +201,8 @@ void swap_cgroup_swapoff(int type)
 			struct page *page = map[i];
 			if (page)
 				__free_page(page);
+			if (!(i % SWAP_CLUSTER_MAX))
+				cond_resched();
 		}
 		vfree(map);
 	}
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 89f95396ec46..809025ed97ea 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1552,7 +1552,6 @@ static const struct file_operations proc_vmstat_file_operations = {
 #endif /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_SMP
-static struct workqueue_struct *vmstat_wq;
 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
 int sysctl_stat_interval __read_mostly = HZ;
 
@@ -1623,7 +1622,7 @@ static void vmstat_update(struct work_struct *w)
 		 * to occur in the future. Keep on running the
 		 * update worker thread.
 		 */
-		queue_delayed_work_on(smp_processor_id(), vmstat_wq,
+		queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
 				this_cpu_ptr(&vmstat_work),
 				round_jiffies_relative(sysctl_stat_interval));
 	}
@@ -1702,7 +1701,7 @@ static void vmstat_shepherd(struct work_struct *w)
 		struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
 
 		if (!delayed_work_pending(dw) && need_update(cpu))
-			queue_delayed_work_on(cpu, vmstat_wq, dw, 0);
+			queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
 	}
 	put_online_cpus();
 
@@ -1718,7 +1717,6 @@ static void __init start_shepherd_timer(void)
 		INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
 			vmstat_update);
 
-	vmstat_wq = alloc_workqueue("vmstat", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
 	schedule_delayed_work(&shepherd,
 		round_jiffies_relative(sysctl_stat_interval));
 }
@@ -1764,11 +1762,16 @@ static int vmstat_cpu_dead(unsigned int cpu)
 
 #endif
 
+struct workqueue_struct *mm_percpu_wq;
+
 void __init init_mm_internals(void)
 {
-#ifdef CONFIG_SMP
-	int ret;
+	int ret __maybe_unused;
 
+	mm_percpu_wq = alloc_workqueue("mm_percpu_wq",
+				       WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
+
+#ifdef CONFIG_SMP
 	ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",
 					NULL, vmstat_cpu_dead);
 	if (ret < 0)