Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "19 patches.

  Subsystems affected by this patch series: mm (userfaultfd, migration,
  memblock, mempolicy, slub, secretmem, and thp), ocfs2, binfmt, vfs,
  and misc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mailmap: add Andrej Shadura
  mm/thp: decrease nr_thps in file's mapping on THP split
  mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem()
  vfs: check fd has read access in kernel_read_file_from_fd()
  elfcore: correct reference to CONFIG_UML
  mm, slub: fix incorrect memcg slab count for bulk free
  mm, slub: fix potential use-after-free in slab_debugfs_fops
  mm, slub: fix potential memoryleak in kmem_cache_open()
  mm, slub: fix mismatch between reconstructed freelist depth and cnt
  mm, slub: fix two bugs in slab_debug_trace_open()
  mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()
  memblock: check memory total_size
  ocfs2: mount fails with buffer overflow in strlen
  ocfs2: fix data corruption after conversion from inline format
  mm/migrate: fix CPUHP state to update node demotion order
  mm/migrate: add CPU hotplug to demotion #ifdef
  mm/migrate: optimize hotplug-time demotion order updates
  userfaultfd: fix a race between writeprotect and exit_mmap()
  mm/userfaultfd: selftests: fix memory corruption with thp enabled

4 files changed, 10 insertions, 3 deletions

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 832d8a74fa59..991911048857 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -72,6 +72,8 @@ enum cpuhp_state {
 	CPUHP_SLUB_DEAD,
 	CPUHP_DEBUG_OBJ_DEAD,
 	CPUHP_MM_WRITEBACK_DEAD,
+	/* Must be after CPUHP_MM_VMSTAT_DEAD */
+	CPUHP_MM_DEMOTION_DEAD,
 	CPUHP_MM_VMSTAT_DEAD,
 	CPUHP_SOFTIRQ_DEAD,
 	CPUHP_NET_MVNETA_DEAD,
@@ -240,6 +242,8 @@ enum cpuhp_state {
 	CPUHP_AP_BASE_CACHEINFO_ONLINE,
 	CPUHP_AP_ONLINE_DYN,
 	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,
+	/* Must be after CPUHP_AP_ONLINE_DYN for node_states[N_CPU] update */
+	CPUHP_AP_MM_DEMOTION_ONLINE,
 	CPUHP_AP_X86_HPET_ONLINE,
 	CPUHP_AP_X86_KVM_CLK_ONLINE,
 	CPUHP_AP_DTPM_CPU_ONLINE,
diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h
index 2aaa15779d50..957ebec35aad 100644
--- a/include/linux/elfcore.h
+++ b/include/linux/elfcore.h
@@ -109,7 +109,7 @@ static inline int elf_core_copy_task_fpregs(struct task_struct *t, struct pt_reg
 #endif
 }
 
-#if defined(CONFIG_UM) || defined(CONFIG_IA64)
+#if (defined(CONFIG_UML) && defined(CONFIG_X86_32)) || defined(CONFIG_IA64)
 /*
  * These functions parameterize elf_core_dump in fs/binfmt_elf.c to write out
  * extra segments containing the gate DSO contents.  Dumping its
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 7efc0a7c14c9..182c606adb06 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -160,7 +160,10 @@ int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
 #define register_hotmemory_notifier(nb)		register_memory_notifier(nb)
 #define unregister_hotmemory_notifier(nb) 	unregister_memory_notifier(nb)
 #else
-#define hotplug_memory_notifier(fn, pri)	({ 0; })
+static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri)
+{
+	return 0;
+}
 /* These aren't inline functions due to a GCC bug. */
 #define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 #define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
diff --git a/include/linux/secretmem.h b/include/linux/secretmem.h
index 21c3771e6a56..988528b5da43 100644
--- a/include/linux/secretmem.h
+++ b/include/linux/secretmem.h
@@ -23,7 +23,7 @@ static inline bool page_is_secretmem(struct page *page)
 	mapping = (struct address_space *)
 		((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS);
 
-	if (mapping != page->mapping)
+	if (!mapping || mapping != page->mapping)
 		return false;
 
 	return mapping->a_ops == &secretmem_aops;