Merge branch 'akpm/master'

44 files changed, 392 insertions, 136 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 1f25f3c168f4..bee86ed96a92 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6787,6 +6787,14 @@ W:	http://www.mellanox.com
 Q:	http://patchwork.ozlabs.org/project/netdev/list/
 F:	drivers/net/ethernet/mellanox/mlxsw/
 
+MEMBARRIER SUPPORT
+M:	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
+L:	linux-kernel@vger.kernel.org
+S:	Supported
+F:	kernel/membarrier.c
+F:	include/uapi/linux/membarrier.h
+
 MEMORY MANAGEMENT
 L:	linux-mm@kvack.org
 W:	http://www.linux-mm.org
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 41e72a50c2ed..24310bbf8688 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -382,3 +382,4 @@
 373	i386	shutdown		sys_shutdown
 374	i386	userfaultfd		sys_userfaultfd
 375	i386	mlock2			sys_mlock2
+376	i386	membarrier		sys_membarrier
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 23669007b85d..6a8737e6f15e 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -331,6 +331,7 @@
 322	64	execveat		stub_execveat
 323	common	userfaultfd		sys_userfaultfd
 324	common	mlock2			sys_mlock2
+325	common	membarrier		sys_membarrier
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 26a46f44e298..b160c0c6baed 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -277,7 +277,7 @@ static const char *gate_vma_name(struct vm_area_struct *vma)
 {
 	return "[vsyscall]";
 }
-static struct vm_operations_struct gate_vma_ops = {
+static const struct vm_operations_struct gate_vma_ops = {
 	.name = gate_vma_name,
 };
 static struct vm_area_struct gate_vma = {
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index db1b0bc5017c..134948b0926f 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -42,58 +42,21 @@ static inline unsigned long mpx_bt_size_bytes(struct mm_struct *mm)
  */
 static unsigned long mpx_mmap(unsigned long len)
 {
-	unsigned long ret;
-	unsigned long addr, pgoff;
 	struct mm_struct *mm = current->mm;
-	vm_flags_t vm_flags;
-	struct vm_area_struct *vma;
+	unsigned long addr, populate;
 
 	/* Only bounds table can be allocated here */
 	if (len != mpx_bt_size_bytes(mm))
 		return -EINVAL;
 
 	down_write(&mm->mmap_sem);
-
-	/* Too many mappings? */
-	if (mm->map_count > sysctl_max_map_count) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	/* Obtain the address to map to. we verify (or select) it and ensure
-	 * that it represents a valid section of the address space.
-	 */
-	addr = get_unmapped_area(NULL, 0, len, 0, MAP_ANONYMOUS | MAP_PRIVATE);
-	if (addr & ~PAGE_MASK) {
-		ret = addr;
-		goto out;
-	}
-
-	vm_flags = VM_READ | VM_WRITE | VM_MPX |
-			mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
-
-	/* Set pgoff according to addr for anon_vma */
-	pgoff = addr >> PAGE_SHIFT;
-
-	ret = mmap_region(NULL, addr, len, vm_flags, pgoff);
-	if (IS_ERR_VALUE(ret))
-		goto out;
-
-	vma = find_vma(mm, ret);
-	if (!vma) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	if (vm_flags & VM_LOCKED) {
-		up_write(&mm->mmap_sem);
-		mm_populate(ret, len);
-		return ret;
-	}
-
-out:
+	addr = do_mmap(NULL, 0, len, PROT_READ | PROT_WRITE,
+			MAP_ANONYMOUS | MAP_PRIVATE, VM_MPX, 0, &populate);
 	up_write(&mm->mmap_sem);
-	return ret;
+	if (populate)
+		mm_populate(addr, populate);
+
+	return addr;
 }
 
 enum reg_type {
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 6607f3c6ace1..a39e85f9efa9 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2834,7 +2834,7 @@ static int binder_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-static struct vm_operations_struct binder_vm_ops = {
+static const struct vm_operations_struct binder_vm_ops = {
 	.open = binder_vma_open,
 	.close = binder_vma_close,
 	.fault = binder_vm_fault,
diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index 6394547cf67a..860062ef8814 100644
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -125,7 +125,7 @@ static int vgem_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	}
 }
 
-static struct vm_operations_struct vgem_gem_vm_ops = {
+static const struct vm_operations_struct vgem_gem_vm_ops = {
 	.fault = vgem_gem_fault,
 	.open = drm_gem_vm_open,
 	.close = drm_gem_vm_close,
diff --git a/drivers/hsi/clients/cmt_speech.c b/drivers/hsi/clients/cmt_speech.c
index d04643f9548b..95638df73d1c 100644
--- a/drivers/hsi/clients/cmt_speech.c
+++ b/drivers/hsi/clients/cmt_speech.c
@@ -1110,7 +1110,7 @@ static int cs_char_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	return 0;
 }
 
-static struct vm_operations_struct cs_char_vm_ops = {
+static const struct vm_operations_struct cs_char_vm_ops = {
 	.fault	= cs_char_vma_fault,
 };
 
diff --git a/drivers/infiniband/hw/qib/qib_file_ops.c b/drivers/infiniband/hw/qib/qib_file_ops.c
index 725881890c4a..e449e394963f 100644
--- a/drivers/infiniband/hw/qib/qib_file_ops.c
+++ b/drivers/infiniband/hw/qib/qib_file_ops.c
@@ -908,7 +908,7 @@ static int qib_file_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	return 0;
 }
 
-static struct vm_operations_struct qib_file_vm_ops = {
+static const struct vm_operations_struct qib_file_vm_ops = {
 	.fault = qib_file_vma_fault,
 };
 
diff --git a/drivers/infiniband/hw/qib/qib_mmap.c b/drivers/infiniband/hw/qib/qib_mmap.c
index 146cf29a2e1d..34927b700b0e 100644
--- a/drivers/infiniband/hw/qib/qib_mmap.c
+++ b/drivers/infiniband/hw/qib/qib_mmap.c
@@ -75,7 +75,7 @@ static void qib_vma_close(struct vm_area_struct *vma)
 	kref_put(&ip->ref, qib_release_mmap_info);
 }
 
-static struct vm_operations_struct qib_vm_ops = {
+static const struct vm_operations_struct qib_vm_ops = {
 	.open =     qib_vma_open,
 	.close =    qib_vma_close,
 };
diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index 0717aa96ce39..9bc20e2119a3 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -135,8 +135,9 @@ __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
 static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
 			     struct seq_file *s)
 {
-	return seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
+	seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
 			  (cr->cam & MMU_CAM_P) ? 1 : 0);
+	return 0;
 }
 
 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
diff --git a/drivers/media/platform/omap/omap_vout.c b/drivers/media/platform/omap/omap_vout.c
index 7feb6394f111..70c28d19ea04 100644
--- a/drivers/media/platform/omap/omap_vout.c
+++ b/drivers/media/platform/omap/omap_vout.c
@@ -865,7 +865,7 @@ static void omap_vout_vm_close(struct vm_area_struct *vma)
 	vout->mmap_count--;
 }
 
-static struct vm_operations_struct omap_vout_vm_ops = {
+static const struct vm_operations_struct omap_vout_vm_ops = {
 	.open	= omap_vout_vm_open,
 	.close	= omap_vout_vm_close,
 };
diff --git a/drivers/misc/genwqe/card_dev.c b/drivers/misc/genwqe/card_dev.c
index c49d244265ec..70e62d6a3231 100644
--- a/drivers/misc/genwqe/card_dev.c
+++ b/drivers/misc/genwqe/card_dev.c
@@ -418,7 +418,7 @@ static void genwqe_vma_close(struct vm_area_struct *vma)
 	kfree(dma_map);
 }
 
-static struct vm_operations_struct genwqe_vma_ops = {
+static const struct vm_operations_struct genwqe_vma_ops = {
 	.open   = genwqe_vma_open,
 	.close  = genwqe_vma_close,
 };
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index eec878e183f5..217aa537c4eb 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -997,7 +997,7 @@ static void ion_vm_close(struct vm_area_struct *vma)
 	mutex_unlock(&buffer->lock);
 }
 
-static struct vm_operations_struct ion_vma_ops = {
+static const struct vm_operations_struct ion_vma_ops = {
 	.open = ion_vm_open,
 	.close = ion_vm_close,
 	.fault = ion_vm_fault,
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index fd54d098ab02..0e8a45102933 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -2156,7 +2156,7 @@ static void comedi_vm_close(struct vm_area_struct *area)
 	comedi_buf_map_put(bm);
 }
 
-static struct vm_operations_struct comedi_vm_ops = {
+static const struct vm_operations_struct comedi_vm_ops = {
 	.open = comedi_vm_open,
 	.close = comedi_vm_close,
 };
diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-main.c b/drivers/video/fbdev/omap2/omapfb/omapfb-main.c
index 4f0cbb54d4db..d3af01c94a58 100644
--- a/drivers/video/fbdev/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/fbdev/omap2/omapfb/omapfb-main.c
@@ -1091,7 +1091,7 @@ static void mmap_user_close(struct vm_area_struct *vma)
 	omapfb_put_mem_region(rg);
 }
 
-static struct vm_operations_struct mmap_user_ops = {
+static const struct vm_operations_struct mmap_user_ops = {
 	.open = mmap_user_open,
 	.close = mmap_user_close,
 };
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 47249a30eae3..20f766afa4c7 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -91,8 +91,7 @@ static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
 	err = device_register(&dev->dev);
 	if (err) {
 		pr_err("Failed to register master device. err=%d\n", err);
-		memset(dev, 0, sizeof(struct w1_master));
-		kfree(dev);
+		put_device(&dev->dev);
 		dev = NULL;
 	}
 
diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c
index 14370df9ac1c..4547a91bca67 100644
--- a/drivers/xen/gntalloc.c
+++ b/drivers/xen/gntalloc.c
@@ -494,7 +494,7 @@ static void gntalloc_vma_close(struct vm_area_struct *vma)
 	mutex_unlock(&gref_mutex);
 }
 
-static struct vm_operations_struct gntalloc_vmops = {
+static const struct vm_operations_struct gntalloc_vmops = {
 	.open = gntalloc_vma_open,
 	.close = gntalloc_vma_close,
 };
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 0dbb222daaf1..2ea0b3b2a91d 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -433,7 +433,7 @@ static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma,
 	return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT];
 }
 
-static struct vm_operations_struct gntdev_vmops = {
+static const struct vm_operations_struct gntdev_vmops = {
 	.open = gntdev_vma_open,
 	.close = gntdev_vma_close,
 	.find_special_page = gntdev_vma_find_special_page,
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index c6deb87c5c69..5e9adac928e6 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -414,7 +414,7 @@ static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs)
 	return 0;
 }
 
-static struct vm_operations_struct privcmd_vm_ops;
+static const struct vm_operations_struct privcmd_vm_ops;
 
 static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
 {
@@ -605,7 +605,7 @@ static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-static struct vm_operations_struct privcmd_vm_ops = {
+static const struct vm_operations_struct privcmd_vm_ops = {
 	.close = privcmd_close,
 	.fault = privcmd_fault
 };
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 890c50971a69..a268abfe60ac 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1593,7 +1593,7 @@ out:
 	return err;
 }
 
-static struct vm_operations_struct ceph_vmops = {
+static const struct vm_operations_struct ceph_vmops = {
 	.fault		= ceph_filemap_fault,
 	.page_mkwrite	= ceph_page_mkwrite,
 };
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 2ac2d8471393..94f81962368c 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3216,7 +3216,7 @@ cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	return VM_FAULT_LOCKED;
 }
 
-static struct vm_operations_struct cifs_file_vm_ops = {
+static const struct vm_operations_struct cifs_file_vm_ops = {
 	.fault = filemap_fault,
 	.map_pages = filemap_map_pages,
 	.page_mkwrite = cifs_page_mkwrite,
diff --git a/fs/namei.c b/fs/namei.c
index 034fc7d9d04c..d68c21fe4598 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2512,7 +2512,7 @@ done:
 
 /**
  * path_mountpoint - look up a path to be umounted
- * @nameidata:	lookup context
+ * @nd:		lookup context
  * @flags:	lookup flags
  * @path:	pointer to container for result
  *
diff --git a/fs/nsfs.c b/fs/nsfs.c
index e4905fbf3396..8f20d6016e20 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -142,7 +142,8 @@ static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
 	struct inode *inode = d_inode(dentry);
 	const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
 
-	return seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino);
+	seq_printf(seq, "%s:[%lu]", ns_ops->name, inode->i_ino);
+	return 0;
 }
 
 static const struct super_operations nsfs_ops = {
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 263b125dbcf4..225586e141ca 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -372,16 +372,16 @@ EXPORT_SYMBOL(seq_release);
  *	@esc:	set of characters that need escaping
  *
  *	Puts string into buffer, replacing each occurrence of character from
- *	@esc with usual octal escape.  Returns 0 in case of success, -1 - in
- *	case of overflow.
+ *	@esc with usual octal escape.
+ *	Use seq_has_overflowed() to check for errors.
  */
-int seq_escape(struct seq_file *m, const char *s, const char *esc)
+void seq_escape(struct seq_file *m, const char *s, const char *esc)
 {
 	char *end = m->buf + m->size;
-        char *p;
+	char *p;
 	char c;
 
-        for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) {
+	for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) {
 		if (!strchr(esc, c)) {
 			*p++ = c;
 			continue;
@@ -394,14 +394,13 @@ int seq_escape(struct seq_file *m, const char *s, const char *esc)
 			continue;
 		}
 		seq_set_overflow(m);
-		return -1;
-        }
+		return;
+	}
 	m->count = p - m->buf;
-        return 0;
 }
 EXPORT_SYMBOL(seq_escape);
 
-int seq_vprintf(struct seq_file *m, const char *f, va_list args)
+void seq_vprintf(struct seq_file *m, const char *f, va_list args)
 {
 	int len;
 
@@ -409,24 +408,20 @@ int seq_vprintf(struct seq_file *m, const char *f, va_list args)
 		len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
 		if (m->count + len < m->size) {
 			m->count += len;
-			return 0;
+			return;
 		}
 	}
 	seq_set_overflow(m);
-	return -1;
 }
 EXPORT_SYMBOL(seq_vprintf);
 
-int seq_printf(struct seq_file *m, const char *f, ...)
+void seq_printf(struct seq_file *m, const char *f, ...)
 {
-	int ret;
 	va_list args;
 
 	va_start(args, f);
-	ret = seq_vprintf(m, f, args);
+	seq_vprintf(m, f, args);
 	va_end(args);
-
-	return ret;
 }
 EXPORT_SYMBOL(seq_printf);
 
@@ -664,26 +659,25 @@ int seq_open_private(struct file *filp, const struct seq_operations *ops,
 }
 EXPORT_SYMBOL(seq_open_private);
 
-int seq_putc(struct seq_file *m, char c)
+void seq_putc(struct seq_file *m, char c)
 {
-	if (m->count < m->size) {
-		m->buf[m->count++] = c;
-		return 0;
-	}
-	return -1;
+	if (m->count >= m->size)
+		return;
+
+	m->buf[m->count++] = c;
 }
 EXPORT_SYMBOL(seq_putc);
 
-int seq_puts(struct seq_file *m, const char *s)
+void seq_puts(struct seq_file *m, const char *s)
 {
 	int len = strlen(s);
-	if (m->count + len < m->size) {
-		memcpy(m->buf + m->count, s, len);
-		m->count += len;
-		return 0;
+
+	if (m->count + len >= m->size) {
+		seq_set_overflow(m);
+		return;
 	}
-	seq_set_overflow(m);
-	return -1;
+	memcpy(m->buf + m->count, s, len);
+	m->count += len;
 }
 EXPORT_SYMBOL(seq_puts);
 
@@ -694,8 +688,8 @@ EXPORT_SYMBOL(seq_puts);
  * This routine is very quick when you show lots of numbers.
  * In usual cases, it will be better to use seq_printf(). It's easier to read.
  */
-int seq_put_decimal_ull(struct seq_file *m, char delimiter,
-			unsigned long long num)
+void seq_put_decimal_ull(struct seq_file *m, char delimiter,
+			 unsigned long long num)
 {
 	int len;
 
@@ -707,35 +701,33 @@ int seq_put_decimal_ull(struct seq_file *m, char delimiter,
 
 	if (num < 10) {
 		m->buf[m->count++] = num + '0';
-		return 0;
+		return;
 	}
 
 	len = num_to_str(m->buf + m->count, m->size - m->count, num);
 	if (!len)
 		goto overflow;
 	m->count += len;
-	return 0;
+	return;
+
 overflow:
 	seq_set_overflow(m);
-	return -1;
 }
 EXPORT_SYMBOL(seq_put_decimal_ull);
 
-int seq_put_decimal_ll(struct seq_file *m, char delimiter,
-			long long num)
+void seq_put_decimal_ll(struct seq_file *m, char delimiter, long long num)
 {
 	if (num < 0) {
 		if (m->count + 3 >= m->size) {
 			seq_set_overflow(m);
-			return -1;
+			return;
 		}
 		if (delimiter)
 			m->buf[m->count++] = delimiter;
 		num = -num;
 		delimiter = '-';
 	}
-	return seq_put_decimal_ull(m, delimiter, num);
-
+	seq_put_decimal_ull(m, delimiter, num);
 }
 EXPORT_SYMBOL(seq_put_decimal_ll);
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9dd5da678005..d34da8f5e278 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1878,11 +1878,19 @@ extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned lo
 
 extern unsigned long mmap_region(struct file *file, unsigned long addr,
 	unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
-extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
+extern unsigned long do_mmap(struct file *file, unsigned long addr,
 	unsigned long len, unsigned long prot, unsigned long flags,
-	unsigned long pgoff, unsigned long *populate);
+	vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate);
 extern int do_munmap(struct mm_struct *, unsigned long, size_t);
 
+static inline unsigned long
+do_mmap_pgoff(struct file *file, unsigned long addr,
+	unsigned long len, unsigned long prot, unsigned long flags,
+	unsigned long pgoff, unsigned long *populate)
+{
+	return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate);
+}
+
 #ifdef CONFIG_MMU
 extern int __mm_populate(unsigned long addr, unsigned long len,
 			 int ignore_errors);
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index adeadbd6d7bf..dde00defbaa5 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -114,13 +114,18 @@ int seq_open(struct file *, const struct seq_operations *);
 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
 loff_t seq_lseek(struct file *, loff_t, int);
 int seq_release(struct inode *, struct file *);
-int seq_escape(struct seq_file *, const char *, const char *);
-int seq_putc(struct seq_file *m, char c);
-int seq_puts(struct seq_file *m, const char *s);
 int seq_write(struct seq_file *seq, const void *data, size_t len);
 
-__printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
-__printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
+__printf(2, 0)
+void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
+__printf(2, 3)
+void seq_printf(struct seq_file *m, const char *fmt, ...);
+void seq_putc(struct seq_file *m, char c);
+void seq_puts(struct seq_file *m, const char *s);
+void seq_put_decimal_ull(struct seq_file *m, char delimiter,
+			 unsigned long long num);
+void seq_put_decimal_ll(struct seq_file *m, char delimiter, long long num);
+void seq_escape(struct seq_file *m, const char *s, const char *esc);
 
 void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
 		  int rowsize, int groupsize, const void *buf, size_t len,
@@ -138,10 +143,6 @@ int single_release(struct inode *, struct file *);
 void *__seq_open_private(struct file *, const struct seq_operations *, int);
 int seq_open_private(struct file *, const struct seq_operations *, int);
 int seq_release_private(struct inode *, struct file *);
-int seq_put_decimal_ull(struct seq_file *m, char delimiter,
-			unsigned long long num);
-int seq_put_decimal_ll(struct seq_file *m, char delimiter,
-			long long num);
 
 static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
 {
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 890632cbf353..9ca6a26558b8 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -887,4 +887,6 @@ asmlinkage long sys_execveat(int dfd, const char __user *filename,
 
 asmlinkage long sys_mlock2(unsigned long start, size_t len, int flags);
 
+asmlinkage long sys_membarrier(int cmd, int flags);
+
 #endif
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 14a6013cbdac..2803f41d8a7e 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -711,9 +711,11 @@ __SYSCALL(__NR_bpf, sys_bpf)
 __SC_COMP(__NR_execveat, sys_execveat, compat_sys_execveat)
 #define __NR_mlock2 282
 __SYSCALL(__NR_mlock2, sys_mlock2)
+#define __NR_membarrier 283
+__SYSCALL(__NR_membarrier, sys_membarrier)
 
 #undef __NR_syscalls
-#define __NR_syscalls 283
+#define __NR_syscalls 284
 
 /*
  * All syscalls below here should go away really,
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index ba94b9bb7bee..e77707802dcc 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -253,6 +253,7 @@ header-y += mdio.h
 header-y += media.h
 header-y += media-bus-format.h
 header-y += mei.h
+header-y += membarrier.h
 header-y += memfd.h
 header-y += mempolicy.h
 header-y += meye.h
diff --git a/include/uapi/linux/membarrier.h b/include/uapi/linux/membarrier.h
new file mode 100644
index 000000000000..e0b108bd2624
--- /dev/null
+++ b/include/uapi/linux/membarrier.h
@@ -0,0 +1,53 @@
+#ifndef _UAPI_LINUX_MEMBARRIER_H
+#define _UAPI_LINUX_MEMBARRIER_H
+
+/*
+ * linux/membarrier.h
+ *
+ * membarrier system call API
+ *
+ * Copyright (c) 2010, 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * enum membarrier_cmd - membarrier system call command
+ * @MEMBARRIER_CMD_QUERY:   Query the set of supported commands. It returns
+ *                          a bitmask of valid commands.
+ * @MEMBARRIER_CMD_SHARED:  Execute a memory barrier on all running threads.
+ *                          Upon return from system call, the caller thread
+ *                          is ensured that all running threads have passed
+ *                          through a state where all memory accesses to
+ *                          user-space addresses match program order between
+ *                          entry to and return from the system call
+ *                          (non-running threads are de facto in such a
+ *                          state). This covers threads from all processes
+ *                          running on the system. This command returns 0.
+ *
+ * Command to be passed to the membarrier system call. The commands need to
+ * be a single bit each, except for MEMBARRIER_CMD_QUERY which is assigned to
+ * the value 0.
+ */
+enum membarrier_cmd {
+	MEMBARRIER_CMD_QUERY = 0,
+	MEMBARRIER_CMD_SHARED = (1 << 0),
+};
+
+#endif /* _UAPI_LINUX_MEMBARRIER_H */
diff --git a/init/Kconfig b/init/Kconfig
index 88ee0fe59048..7a645f7380d2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1690,6 +1690,18 @@ config PCI_QUIRKS
 	  bugs/quirks. Disable this only if your target machine is
 	  unaffected by PCI quirks.
 
+config MEMBARRIER
+	bool "Enable membarrier() system call" if EXPERT
+	default y
+	help
+	  Enable the membarrier() system call that allows issuing memory
+	  barriers across all running threads, which can be used to distribute
+	  the cost of user-space memory barriers asymmetrically by transforming
+	  pairs of memory barriers into pairs consisting of membarrier() and a
+	  compiler barrier.
+
+	  If unsure, say Y.
+
 config EMBEDDED
 	bool "Embedded system"
 	option allnoconfig_y
diff --git a/kernel/Makefile b/kernel/Makefile
index 0edb1d10b800..f07f8d18b3d6 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -101,6 +101,7 @@ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
 obj-$(CONFIG_JUMP_LABEL) += jump_label.o
 obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
 obj-$(CONFIG_TORTURE_TEST) += torture.o
+obj-$(CONFIG_MEMBARRIER) += membarrier.o
 
 obj-$(CONFIG_HAS_IOMEM) += memremap.o
 
diff --git a/kernel/membarrier.c b/kernel/membarrier.c
new file mode 100644
index 000000000000..536c727a56e9
--- /dev/null
+++ b/kernel/membarrier.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2010, 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * membarrier system call
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/syscalls.h>
+#include <linux/membarrier.h>
+
+/*
+ * Bitmask made from a "or" of all commands within enum membarrier_cmd,
+ * except MEMBARRIER_CMD_QUERY.
+ */
+#define MEMBARRIER_CMD_BITMASK	(MEMBARRIER_CMD_SHARED)
+
+/**
+ * sys_membarrier - issue memory barriers on a set of threads
+ * @cmd:   Takes command values defined in enum membarrier_cmd.
+ * @flags: Currently needs to be 0. For future extensions.
+ *
+ * If this system call is not implemented, -ENOSYS is returned. If the
+ * command specified does not exist, or if the command argument is invalid,
+ * this system call returns -EINVAL. For a given command, with flags argument
+ * set to 0, this system call is guaranteed to always return the same value
+ * until reboot.
+ *
+ * All memory accesses performed in program order from each targeted thread
+ * is guaranteed to be ordered with respect to sys_membarrier(). If we use
+ * the semantic "barrier()" to represent a compiler barrier forcing memory
+ * accesses to be performed in program order across the barrier, and
+ * smp_mb() to represent explicit memory barriers forcing full memory
+ * ordering across the barrier, we have the following ordering table for
+ * each pair of barrier(), sys_membarrier() and smp_mb():
+ *
+ * The pair ordering is detailed as (O: ordered, X: not ordered):
+ *
+ *                        barrier()   smp_mb() sys_membarrier()
+ *        barrier()          X           X            O
+ *        smp_mb()           X           O            O
+ *        sys_membarrier()   O           O            O
+ */
+SYSCALL_DEFINE2(membarrier, int, cmd, int, flags)
+{
+	if (unlikely(flags))
+		return -EINVAL;
+	switch (cmd) {
+	case MEMBARRIER_CMD_QUERY:
+		return MEMBARRIER_CMD_BITMASK;
+	case MEMBARRIER_CMD_SHARED:
+		if (num_online_cpus() > 1)
+			synchronize_sched();
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 8de5b2645796..0623787ec67a 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -246,3 +246,6 @@ cond_syscall(sys_bpf);
 
 /* execveat */
 cond_syscall(sys_execveat);
+
+/* membarrier */
+cond_syscall(sys_membarrier);
diff --git a/mm/madvise.c b/mm/madvise.c
index fa6479aca0c9..16441f550cdf 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -393,7 +393,7 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
 		return -EINVAL;
 
 	/* MADV_FREE works for only anon vma at the moment */
-	if (vma->vm_file)
+	if (!vma_is_anonymous(vma))
 		return -EINVAL;
 
 	start = max(vma->vm_start, start_addr);
diff --git a/mm/memory.c b/mm/memory.c
index 558ee16167d9..7f6a9563d5a6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3233,7 +3233,7 @@ out:
 static int create_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long address, pmd_t *pmd, unsigned int flags)
 {
-	if (!vma->vm_ops)
+	if (vma_is_anonymous(vma))
 		return do_huge_pmd_anonymous_page(mm, vma, address, pmd, flags);
 	if (vma->vm_ops->pmd_fault)
 		return vma->vm_ops->pmd_fault(vma, address, pmd, flags);
@@ -3244,7 +3244,7 @@ static int wp_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long address, pmd_t *pmd, pmd_t orig_pmd,
 			unsigned int flags)
 {
-	if (!vma->vm_ops)
+	if (vma_is_anonymous(vma))
 		return do_huge_pmd_wp_page(mm, vma, address, pmd, orig_pmd);
 	if (vma->vm_ops->pmd_fault)
 		return vma->vm_ops->pmd_fault(vma, address, pmd, flags);
diff --git a/mm/mmap.c b/mm/mmap.c
index 76ada5dd968b..8e0366e0bd1d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -612,6 +612,8 @@ 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);
@@ -1260,14 +1262,12 @@ static inline int mlock_future_check(struct mm_struct *mm,
 /*
  * The caller must hold down_write(&current->mm->mmap_sem).
  */
-
-unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
+unsigned long do_mmap(struct file *file, unsigned long addr,
 			unsigned long len, unsigned long prot,
-			unsigned long flags, unsigned long pgoff,
-			unsigned long *populate)
+			unsigned long flags, vm_flags_t vm_flags,
+			unsigned long pgoff, unsigned long *populate)
 {
 	struct mm_struct *mm = current->mm;
-	vm_flags_t vm_flags;
 
 	*populate = 0;
 
@@ -1311,7 +1311,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
 	 * to. we assume access permissions have been handled by the open
 	 * of the memory object, so we don't do any here.
 	 */
-	vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
+	vm_flags |= calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
 			mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
 
 	if (flags & MAP_LOCKED)
@@ -1638,6 +1638,12 @@ 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) {
diff --git a/mm/nommu.c b/mm/nommu.c
index 1cc0709fcaa5..ab14a2014dea 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1233,18 +1233,19 @@ enomem:
 /*
  * handle mapping creation for uClinux
  */
-unsigned long do_mmap_pgoff(struct file *file,
-			    unsigned long addr,
-			    unsigned long len,
-			    unsigned long prot,
-			    unsigned long flags,
-			    unsigned long pgoff,
-			    unsigned long *populate)
+unsigned long do_mmap(struct file *file,
+			unsigned long addr,
+			unsigned long len,
+			unsigned long prot,
+			unsigned long flags,
+			vm_flags_t vm_flags,
+			unsigned long pgoff,
+			unsigned long *populate)
 {
 	struct vm_area_struct *vma;
 	struct vm_region *region;
 	struct rb_node *rb;
-	unsigned long capabilities, vm_flags, result;
+	unsigned long capabilities, result;
 	int ret;
 
 	*populate = 0;
@@ -1262,7 +1263,7 @@ unsigned long do_mmap_pgoff(struct file *file,
 
 	/* we've determined that we can make the mapping, now translate what we
 	 * now know into VMA flags */
-	vm_flags = determine_vm_flags(file, prot, flags, capabilities);
+	vm_flags |= determine_vm_flags(file, prot, flags, capabilities);
 
 	/* we're going to need to record the mapping */
 	region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 3d2201413028..5bed7716f8ab 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -472,7 +472,7 @@ static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 	return 0;
 }
 
-static struct vm_operations_struct sel_mmap_policy_ops = {
+static const struct vm_operations_struct sel_mmap_policy_ops = {
 	.fault = sel_mmap_policy_fault,
 	.page_mkwrite = sel_mmap_policy_fault,
 };
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 2cb20b7188ae..87b4609eb817 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -7,6 +7,7 @@ TARGETS += ftrace
 TARGETS += futex
 TARGETS += kcmp
 TARGETS += kdbus
+TARGETS += membarrier
 TARGETS += memfd
 TARGETS += memory-hotplug
 TARGETS += mount
diff --git a/tools/testing/selftests/membarrier/.gitignore b/tools/testing/selftests/membarrier/.gitignore
new file mode 100644
index 000000000000..020c44f49a9e
--- /dev/null
+++ b/tools/testing/selftests/membarrier/.gitignore
@@ -0,0 +1 @@
+membarrier_test
diff --git a/tools/testing/selftests/membarrier/Makefile b/tools/testing/selftests/membarrier/Makefile
new file mode 100644
index 000000000000..877a50355d7f
--- /dev/null
+++ b/tools/testing/selftests/membarrier/Makefile
@@ -0,0 +1,11 @@
+CFLAGS += -g -I../../../../usr/include/
+
+all:
+	$(CC) $(CFLAGS) membarrier_test.c -o membarrier_test
+
+TEST_PROGS := membarrier_test
+
+include ../lib.mk
+
+clean:
+	$(RM) membarrier_test
diff --git a/tools/testing/selftests/membarrier/membarrier_test.c b/tools/testing/selftests/membarrier/membarrier_test.c
new file mode 100644
index 000000000000..dde312508007
--- /dev/null
+++ b/tools/testing/selftests/membarrier/membarrier_test.c
@@ -0,0 +1,121 @@
+#define _GNU_SOURCE
+#define __EXPORTED_HEADERS__
+
+#include <linux/membarrier.h>
+#include <asm-generic/unistd.h>
+#include <sys/syscall.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#include "../kselftest.h"
+
+enum test_membarrier_status {
+	TEST_MEMBARRIER_PASS = 0,
+	TEST_MEMBARRIER_FAIL,
+	TEST_MEMBARRIER_SKIP,
+};
+
+static int sys_membarrier(int cmd, int flags)
+{
+	return syscall(__NR_membarrier, cmd, flags);
+}
+
+static enum test_membarrier_status test_membarrier_cmd_fail(void)
+{
+	int cmd = -1, flags = 0;
+
+	if (sys_membarrier(cmd, flags) != -1) {
+		printf("membarrier: Wrong command should fail but passed.\n");
+		return TEST_MEMBARRIER_FAIL;
+	}
+	return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier_flags_fail(void)
+{
+	int cmd = MEMBARRIER_CMD_QUERY, flags = 1;
+
+	if (sys_membarrier(cmd, flags) != -1) {
+		printf("membarrier: Wrong flags should fail but passed.\n");
+		return TEST_MEMBARRIER_FAIL;
+	}
+	return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier_success(void)
+{
+	int cmd = MEMBARRIER_CMD_SHARED, flags = 0;
+
+	if (sys_membarrier(cmd, flags) != 0) {
+		printf("membarrier: Executing MEMBARRIER_CMD_SHARED failed. %s.\n",
+				strerror(errno));
+		return TEST_MEMBARRIER_FAIL;
+	}
+
+	printf("membarrier: MEMBARRIER_CMD_SHARED success.\n");
+	return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier(void)
+{
+	enum test_membarrier_status status;
+
+	status = test_membarrier_cmd_fail();
+	if (status)
+		return status;
+	status = test_membarrier_flags_fail();
+	if (status)
+		return status;
+	status = test_membarrier_success();
+	if (status)
+		return status;
+	return TEST_MEMBARRIER_PASS;
+}
+
+static enum test_membarrier_status test_membarrier_query(void)
+{
+	int flags = 0, ret;
+
+	printf("membarrier MEMBARRIER_CMD_QUERY ");
+	ret = sys_membarrier(MEMBARRIER_CMD_QUERY, flags);
+	if (ret < 0) {
+		printf("failed. %s.\n", strerror(errno));
+		switch (errno) {
+		case ENOSYS:
+			/*
+			 * It is valid to build a kernel with
+			 * CONFIG_MEMBARRIER=n. However, this skips the tests.
+			 */
+			return TEST_MEMBARRIER_SKIP;
+		case EINVAL:
+		default:
+			return TEST_MEMBARRIER_FAIL;
+		}
+	}
+	if (!(ret & MEMBARRIER_CMD_SHARED)) {
+		printf("command MEMBARRIER_CMD_SHARED is not supported.\n");
+		return TEST_MEMBARRIER_FAIL;
+	}
+	printf("syscall available.\n");
+	return TEST_MEMBARRIER_PASS;
+}
+
+int main(int argc, char **argv)
+{
+	switch (test_membarrier_query()) {
+	case TEST_MEMBARRIER_FAIL:
+		return ksft_exit_fail();
+	case TEST_MEMBARRIER_SKIP:
+		return ksft_exit_skip();
+	}
+	switch (test_membarrier()) {
+	case TEST_MEMBARRIER_FAIL:
+		return ksft_exit_fail();
+	case TEST_MEMBARRIER_SKIP:
+		return ksft_exit_skip();
+	}
+
+	printf("membarrier: tests done!\n");
+	return ksft_exit_pass();
+}