Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from ANdrew Morton:
 "8 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  revert "mm: make sure all file VMAs have ->vm_ops set"
  MAINTAINERS: update LTP mailing list
  userfaultfd: add missing mmput() in error path
  lib/string_helpers.c: fix infinite loop in string_get_size()
  alpha: lib: export __delay
  alpha: io: define ioremap_uc
  kasan: fix last shadow judgement in memory_is_poisoned_16()
  zram: fix possible use after free in zcomp_create()

8 files changed, 22 insertions, 20 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 7ba7ab749c853a..274f85405584e1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6452,11 +6452,11 @@ F:	drivers/hwmon/ltc4261.c
 LTP (Linux Test Project)
 M:	Mike Frysinger <vapier@gentoo.org>
 M:	Cyril Hrubis <chrubis@suse.cz>
-M:	Wanlong Gao <gaowanlong@cn.fujitsu.com>
+M:	Wanlong Gao <wanlong.gao@gmail.com>
 M:	Jan Stancek <jstancek@redhat.com>
 M:	Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
 M:	Alexey Kodanev <alexey.kodanev@oracle.com>
-L:	ltp-list@lists.sourceforge.net (subscribers-only)
+L:	ltp@lists.linux.it (subscribers-only)
 W:	http://linux-test-project.github.io/
 T:	git git://github.com/linux-test-project/ltp.git
 S:	Maintained
diff --git a/arch/alpha/include/asm/io.h b/arch/alpha/include/asm/io.h
index f05bdb4b1cb97e..ff4049155c840c 100644
--- a/arch/alpha/include/asm/io.h
+++ b/arch/alpha/include/asm/io.h
@@ -297,7 +297,9 @@ static inline void __iomem * ioremap_nocache(unsigned long offset,
 					     unsigned long size)
 {
 	return ioremap(offset, size);
-} 
+}
+
+#define ioremap_uc ioremap_nocache
 
 static inline void iounmap(volatile void __iomem *addr)
 {
diff --git a/arch/alpha/lib/udelay.c b/arch/alpha/lib/udelay.c
index 69d52aa37bae2c..f2d81ff38aa647 100644
--- a/arch/alpha/lib/udelay.c
+++ b/arch/alpha/lib/udelay.c
@@ -30,6 +30,7 @@ __delay(int loops)
 		"	bgt %0,1b"
 		: "=&r" (tmp), "=r" (loops) : "1"(loops));
 }
+EXPORT_SYMBOL(__delay);
 
 #ifdef CONFIG_SMP
 #define LPJ	 cpu_data[smp_processor_id()].loops_per_jiffy
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 965d1afb0eaa72..5cb13ca3a3acac 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -330,12 +330,14 @@ void zcomp_destroy(struct zcomp *comp)
  * allocate new zcomp and initialize it. return compressing
  * backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL)
  * if requested algorithm is not supported, ERR_PTR(-ENOMEM) in
- * case of allocation error.
+ * case of allocation error, or any other error potentially
+ * returned by functions zcomp_strm_{multi,single}_create.
  */
 struct zcomp *zcomp_create(const char *compress, int max_strm)
 {
 	struct zcomp *comp;
 	struct zcomp_backend *backend;
+	int error;
 
 	backend = find_backend(compress);
 	if (!backend)
@@ -347,12 +349,12 @@ struct zcomp *zcomp_create(const char *compress, int max_strm)
 
 	comp->backend = backend;
 	if (max_strm > 1)
-		zcomp_strm_multi_create(comp, max_strm);
+		error = zcomp_strm_multi_create(comp, max_strm);
 	else
-		zcomp_strm_single_create(comp);
-	if (!comp->stream) {
+		error = zcomp_strm_single_create(comp);
+	if (error) {
 		kfree(comp);
-		return ERR_PTR(-ENOMEM);
+		return ERR_PTR(error);
 	}
 	return comp;
 }
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 634e676072cb73..f9aeb40a719747 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1287,8 +1287,10 @@ static struct file *userfaultfd_file_create(int flags)
 
 	file = anon_inode_getfile("[userfaultfd]", &userfaultfd_fops, ctx,
 				  O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS));
-	if (IS_ERR(file))
+	if (IS_ERR(file)) {
+		mmput(ctx->mm);
 		kmem_cache_free(userfaultfd_ctx_cachep, ctx);
+	}
 out:
 	return file;
 }
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 54036ce2e2dd0a..5939f63d90cde7 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -59,7 +59,11 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
 	}
 
 	exp = divisor[units] / (u32)blk_size;
-	if (size >= exp) {
+	/*
+	 * size must be strictly greater than exp here to ensure that remainder
+	 * is greater than divisor[units] coming out of the if below.
+	 */
+	if (size > exp) {
 		remainder = do_div(size, divisor[units]);
 		remainder *= blk_size;
 		i++;
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 7b28e9cdf1c768..8da211411b57f1 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -135,12 +135,11 @@ static __always_inline bool memory_is_poisoned_16(unsigned long addr)
 
 	if (unlikely(*shadow_addr)) {
 		u16 shadow_first_bytes = *(u16 *)shadow_addr;
-		s8 last_byte = (addr + 15) & KASAN_SHADOW_MASK;
 
 		if (unlikely(shadow_first_bytes))
 			return true;
 
-		if (likely(!last_byte))
+		if (likely(IS_ALIGNED(addr, 8)))
 			return false;
 
 		return memory_is_poisoned_1(addr + 15);
diff --git a/mm/mmap.c b/mm/mmap.c
index 971dd2cb77d227..c739d6db7193e8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -612,8 +612,6 @@ static unsigned long count_vma_pages_range(struct mm_struct *mm,
 void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,
 		struct rb_node **rb_link, struct rb_node *rb_parent)
 {
-	WARN_ONCE(vma->vm_file && !vma->vm_ops, "missing vma->vm_ops");
-
 	/* Update tracking information for the gap following the new vma. */
 	if (vma->vm_next)
 		vma_gap_update(vma->vm_next);
@@ -1638,12 +1636,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 		 */
 		WARN_ON_ONCE(addr != vma->vm_start);
 
-		/* All file mapping must have ->vm_ops set */
-		if (!vma->vm_ops) {
-			static const struct vm_operations_struct dummy_ops = {};
-			vma->vm_ops = &dummy_ops;
-		}
-
 		addr = vma->vm_start;
 		vm_flags = vma->vm_flags;
 	} else if (vm_flags & VM_SHARED) {