Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: fix memory hotplug during boot
  kasan: free allocated shadow memory on MEM_CANCEL_ONLINE
  checkpatch: fix macro argument precedence test
  init/main.c: include <linux/mem_encrypt.h>
  kernel/sys.c: fix potential Spectre v1 issue
  mm/memory_hotplug: fix leftover use of struct page during hotplug
  proc: fix smaps and meminfo alignment
  mm: do not warn on offline nodes unless the specific node is explicitly requested
  mm, memory_hotplug: make has_unmovable_pages more robust
  mm/kasan: don't vfree() nonexistent vm_area
  MAINTAINERS: change hugetlbfs maintainer and update files
  ipc/shm: fix shmat() nil address after round-down when remapping
  Revert "ipc/shm: Fix shmat mmap nil-page protection"
  idr: fix invalid ptr dereference on item delete
  ocfs2: revert "ocfs2/o2hb: check len for bio_add_page() to avoid getting incorrect bio"
  mm: fix nr_rotate_swap leak in swapon() error case

4 files changed, 80 insertions, 11 deletions

diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index bc0e68f7dc75..f185455b3406 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -792,6 +792,40 @@ DEFINE_ASAN_SET_SHADOW(f5);
 DEFINE_ASAN_SET_SHADOW(f8);
 
 #ifdef CONFIG_MEMORY_HOTPLUG
+static bool shadow_mapped(unsigned long addr)
+{
+	pgd_t *pgd = pgd_offset_k(addr);
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	if (pgd_none(*pgd))
+		return false;
+	p4d = p4d_offset(pgd, addr);
+	if (p4d_none(*p4d))
+		return false;
+	pud = pud_offset(p4d, addr);
+	if (pud_none(*pud))
+		return false;
+
+	/*
+	 * We can't use pud_large() or pud_huge(), the first one is
+	 * arch-specific, the last one depends on HUGETLB_PAGE.  So let's abuse
+	 * pud_bad(), if pud is bad then it's bad because it's huge.
+	 */
+	if (pud_bad(*pud))
+		return true;
+	pmd = pmd_offset(pud, addr);
+	if (pmd_none(*pmd))
+		return false;
+
+	if (pmd_bad(*pmd))
+		return true;
+	pte = pte_offset_kernel(pmd, addr);
+	return !pte_none(*pte);
+}
+
 static int __meminit kasan_mem_notifier(struct notifier_block *nb,
 			unsigned long action, void *data)
 {
@@ -813,6 +847,14 @@ static int __meminit kasan_mem_notifier(struct notifier_block *nb,
 	case MEM_GOING_ONLINE: {
 		void *ret;
 
+		/*
+		 * If shadow is mapped already than it must have been mapped
+		 * during the boot. This could happen if we onlining previously
+		 * offlined memory.
+		 */
+		if (shadow_mapped(shadow_start))
+			return NOTIFY_OK;
+
 		ret = __vmalloc_node_range(shadow_size, PAGE_SIZE, shadow_start,
 					shadow_end, GFP_KERNEL,
 					PAGE_KERNEL, VM_NO_GUARD,
@@ -824,8 +866,26 @@ static int __meminit kasan_mem_notifier(struct notifier_block *nb,
 		kmemleak_ignore(ret);
 		return NOTIFY_OK;
 	}
-	case MEM_OFFLINE:
-		vfree((void *)shadow_start);
+	case MEM_CANCEL_ONLINE:
+	case MEM_OFFLINE: {
+		struct vm_struct *vm;
+
+		/*
+		 * shadow_start was either mapped during boot by kasan_init()
+		 * or during memory online by __vmalloc_node_range().
+		 * In the latter case we can use vfree() to free shadow.
+		 * Non-NULL result of the find_vm_area() will tell us if
+		 * that was the second case.
+		 *
+		 * Currently it's not possible to free shadow mapped
+		 * during boot by kasan_init(). It's because the code
+		 * to do that hasn't been written yet. So we'll just
+		 * leak the memory.
+		 */
+		vm = find_vm_area((void *)shadow_start);
+		if (vm)
+			vfree((void *)shadow_start);
+	}
 	}
 
 	return NOTIFY_OK;
@@ -838,5 +898,5 @@ static int __init kasan_memhotplug_init(void)
 	return 0;
 }
 
-module_init(kasan_memhotplug_init);
+core_initcall(kasan_memhotplug_init);
 #endif
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index f74826cdceea..25982467800b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1158,7 +1158,7 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
 		 * nodes have to go through register_node.
 		 * TODO clean up this mess.
 		 */
-		ret = link_mem_sections(nid, start_pfn, nr_pages);
+		ret = link_mem_sections(nid, start_pfn, nr_pages, false);
 register_fail:
 		/*
 		 * If sysfs file of new node can't create, cpu on the node
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 511a7124d7f9..22320ea27489 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7598,11 +7598,12 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
 	unsigned long pfn, iter, found;
 
 	/*
-	 * For avoiding noise data, lru_add_drain_all() should be called
-	 * If ZONE_MOVABLE, the zone never contains unmovable pages
+	 * TODO we could make this much more efficient by not checking every
+	 * page in the range if we know all of them are in MOVABLE_ZONE and
+	 * that the movable zone guarantees that pages are migratable but
+	 * the later is not the case right now unfortunatelly. E.g. movablecore
+	 * can still lead to having bootmem allocations in zone_movable.
 	 */
-	if (zone_idx(zone) == ZONE_MOVABLE)
-		return false;
 
 	/*
 	 * CMA allocations (alloc_contig_range) really need to mark isolate
@@ -7623,7 +7624,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
 		page = pfn_to_page(check);
 
 		if (PageReserved(page))
-			return true;
+			goto unmovable;
 
 		/*
 		 * Hugepages are not in LRU lists, but they're movable.
@@ -7673,9 +7674,12 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
 		 * page at boot.
 		 */
 		if (found > count)
-			return true;
+			goto unmovable;
 	}
 	return false;
+unmovable:
+	WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE);
+	return true;
 }
 
 bool is_pageblock_removable_nolock(struct page *page)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index cc2cf04d9018..78a015fcec3b 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3112,6 +3112,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	unsigned long *frontswap_map = NULL;
 	struct page *page = NULL;
 	struct inode *inode = NULL;
+	bool inced_nr_rotate_swap = false;
 
 	if (swap_flags & ~SWAP_FLAGS_VALID)
 		return -EINVAL;
@@ -3215,8 +3216,10 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 			cluster = per_cpu_ptr(p->percpu_cluster, cpu);
 			cluster_set_null(&cluster->index);
 		}
-	} else
+	} else {
 		atomic_inc(&nr_rotate_swap);
+		inced_nr_rotate_swap = true;
+	}
 
 	error = swap_cgroup_swapon(p->type, maxpages);
 	if (error)
@@ -3307,6 +3310,8 @@ bad_swap:
 	vfree(swap_map);
 	kvfree(cluster_info);
 	kvfree(frontswap_map);
+	if (inced_nr_rotate_swap)
+		atomic_dec(&nr_rotate_swap);
 	if (swap_file) {
 		if (inode && S_ISREG(inode->i_mode)) {
 			inode_unlock(inode);