Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - almost all of the rest of MM

 - misc bits

 - KASAN updates

 - procfs

 - lib/ updates

 - checkpatch updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (124 commits)
  checkpatch: remove false unbalanced braces warning
  checkpatch: notice unbalanced else braces in a patch
  checkpatch: add another old address for the FSF
  checkpatch: update $logFunctions
  checkpatch: warn on logging continuations
  checkpatch: warn on embedded function names
  lib/lz4: remove back-compat wrappers
  fs/pstore: fs/squashfs: change usage of LZ4 to work with new LZ4 version
  crypto: change LZ4 modules to work with new LZ4 module version
  lib/decompress_unlz4: change module to work with new LZ4 module version
  lib: update LZ4 compressor module
  lib/test_sort.c: make it explicitly non-modular
  lib: add CONFIG_TEST_SORT to enable self-test of sort()
  rbtree: use designated initializers
  linux/kernel.h: fix DIV_ROUND_CLOSEST to support negative divisors
  lib/find_bit.c: micro-optimise find_next_*_bit
  lib: add module support to atomic64 tests
  lib: add module support to glob tests
  lib: add module support to crc32 tests
  kernel/ksysfs.c: add __ro_after_init to bin_attribute structure
  ...

kernel/events/core.c

@@ -4925,9 +4925,9 @@ unlock:
 	rcu_read_unlock();
 }
 
-static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+static int perf_mmap_fault(struct vm_fault *vmf)
 {
-	struct perf_event *event = vma->vm_file->private_data;
+	struct perf_event *event = vmf->vma->vm_file->private_data;
 	struct ring_buffer *rb;
 	int ret = VM_FAULT_SIGBUS;
 
@@ -4950,7 +4950,7 @@ static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		goto unlock;
 
 	get_page(vmf->page);
-	vmf->page->mapping = vma->vm_file->f_mapping;
+	vmf->page->mapping = vmf->vma->vm_file->f_mapping;
 	vmf->page->index   = vmf->pgoff;
 
 	ret = 0;

kernel/events/uprobes.c

@@ -153,14 +153,19 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 				struct page *old_page, struct page *new_page)
 {
 	struct mm_struct *mm = vma->vm_mm;
-	spinlock_t *ptl;
-	pte_t *ptep;
+	struct page_vma_mapped_walk pvmw = {
+		.page = old_page,
+		.vma = vma,
+		.address = addr,
+	};
 	int err;
 	/* For mmu_notifiers */
 	const unsigned long mmun_start = addr;
 	const unsigned long mmun_end   = addr + PAGE_SIZE;
 	struct mem_cgroup *memcg;
 
+	VM_BUG_ON_PAGE(PageTransHuge(old_page), old_page);
+
 	err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, &memcg,
 			false);
 	if (err)
@@ -171,11 +176,11 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 
 	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
 	err = -EAGAIN;
-	ptep = page_check_address(old_page, mm, addr, &ptl, 0);
-	if (!ptep) {
+	if (!page_vma_mapped_walk(&pvmw)) {
 		mem_cgroup_cancel_charge(new_page, memcg, false);
 		goto unlock;
 	}
+	VM_BUG_ON_PAGE(addr != pvmw.address, old_page);
 
 	get_page(new_page);
 	page_add_new_anon_rmap(new_page, vma, addr, false);
@@ -187,14 +192,15 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 		inc_mm_counter(mm, MM_ANONPAGES);
 	}
 
-	flush_cache_page(vma, addr, pte_pfn(*ptep));
-	ptep_clear_flush_notify(vma, addr, ptep);
-	set_pte_at_notify(mm, addr, ptep, mk_pte(new_page, vma->vm_page_prot));
+	flush_cache_page(vma, addr, pte_pfn(*pvmw.pte));
+	ptep_clear_flush_notify(vma, addr, pvmw.pte);
+	set_pte_at_notify(mm, addr, pvmw.pte,
+			mk_pte(new_page, vma->vm_page_prot));
 
 	page_remove_rmap(old_page, false);
 	if (!page_mapped(old_page))
 		try_to_free_swap(old_page);
-	pte_unmap_unlock(ptep, ptl);
+	page_vma_mapped_walk_done(&pvmw);
 
 	if (vma->vm_flags & VM_LOCKED)
 		munlock_vma_page(old_page);
@@ -300,8 +306,8 @@ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr,
 
 retry:
 	/* Read the page with vaddr into memory */
-	ret = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &old_page,
-			&vma, NULL);
+	ret = get_user_pages_remote(NULL, mm, vaddr, 1,
+			FOLL_FORCE | FOLL_SPLIT, &old_page, &vma, NULL);
 	if (ret <= 0)
 		return ret;
 

kernel/exit.c

@@ -45,6 +45,7 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/tracehook.h>
 #include <linux/fs_struct.h>
+#include <linux/userfaultfd_k.h>
 #include <linux/init_task.h>
 #include <linux/perf_event.h>
 #include <trace/events/sched.h>
@@ -547,6 +548,7 @@ static void exit_mm(void)
 	enter_lazy_tlb(mm, current);
 	task_unlock(current);
 	mm_update_next_owner(mm);
+	userfaultfd_exit(mm);
 	mmput(mm);
 	if (test_thread_flag(TIF_MEMDIE))
 		exit_oom_victim();

kernel/ksysfs.c

@@ -195,7 +195,7 @@ static ssize_t notes_read(struct file *filp, struct kobject *kobj,
 	return count;
 }
 
-static struct bin_attribute notes_attr = {
+static struct bin_attribute notes_attr __ro_after_init  = {
 	.attr = {
 		.name = "notes",
 		.mode = S_IRUGO,

kernel/memremap.c

@@ -246,9 +246,13 @@ static void devm_memremap_pages_release(struct device *dev, void *data)
 	/* pages are dead and unused, undo the arch mapping */
 	align_start = res->start & ~(SECTION_SIZE - 1);
 	align_size = ALIGN(resource_size(res), SECTION_SIZE);
+
+	lock_device_hotplug();
 	mem_hotplug_begin();
 	arch_remove_memory(align_start, align_size);
 	mem_hotplug_done();
+	unlock_device_hotplug();
+
 	untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
 	pgmap_radix_release(res);
 	dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc,
@@ -360,9 +364,11 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
 	if (error)
 		goto err_pfn_remap;
 
+	lock_device_hotplug();
 	mem_hotplug_begin();
 	error = arch_add_memory(nid, align_start, align_size, true);
 	mem_hotplug_done();
+	unlock_device_hotplug();
 	if (error)
 		goto err_add_memory;
 

kernel/notifier.c

@@ -95,7 +95,7 @@ static int notifier_call_chain(struct notifier_block **nl,
 		if (nr_calls)
 			(*nr_calls)++;
 
-		if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK)
+		if (ret & NOTIFY_STOP_MASK)
 			break;
 		nb = next_nb;
 		nr_to_call--;

kernel/relay.c

@@ -39,10 +39,10 @@ static void relay_file_mmap_close(struct vm_area_struct *vma)
 /*
  * fault() vm_op implementation for relay file mapping.
  */
-static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+static int relay_buf_fault(struct vm_fault *vmf)
 {
 	struct page *page;
-	struct rchan_buf *buf = vma->vm_private_data;
+	struct rchan_buf *buf = vmf->vma->vm_private_data;
 	pgoff_t pgoff = vmf->pgoff;
 
 	if (!buf)