Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - the rest of MM

 - KASAN updates

 - procfs updates

 - exit, fork updates

 - printk updates

 - lib/ updates

 - radix-tree testsuite updates

 - checkpatch updates

 - kprobes updates

 - a few other misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  samples/kprobes: print out the symbol name for the hooks
  samples/kprobes: add a new module parameter
  kprobes: add the "tls" argument for j_do_fork
  init/main.c: simplify initcall_blacklisted()
  fs/efs/super.c: fix return value
  checkpatch: improve --git <commit-count> shortcut
  checkpatch: reduce number of `git log` calls with --git
  checkpatch: add support to check already applied git commits
  checkpatch: add --list-types to show message types to show or ignore
  checkpatch: advertise the --fix and --fix-inplace options more
  checkpatch: whine about ACCESS_ONCE
  checkpatch: add test for keywords not starting on tabstops
  checkpatch: improve CONSTANT_COMPARISON test for structure members
  checkpatch: add PREFER_IS_ENABLED test
  lib/GCD.c: use binary GCD algorithm instead of Euclidean
  radix-tree: free up the bottom bit of exceptional entries for reuse
  dax: move RADIX_DAX_ definitions to dax.c
  radix-tree: make radix_tree_descend() more useful
  radix-tree: introduce radix_tree_replace_clear_tags()
  radix-tree: tidy up __radix_tree_create()
  ...

1 files changed, 38 insertions, 16 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 3e8451527cbe..103d78fd8f75 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -699,6 +699,26 @@ void __mmdrop(struct mm_struct *mm)
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
 
+static inline void __mmput(struct mm_struct *mm)
+{
+	VM_BUG_ON(atomic_read(&mm->mm_users));
+
+	uprobe_clear_state(mm);
+	exit_aio(mm);
+	ksm_exit(mm);
+	khugepaged_exit(mm); /* must run before exit_mmap */
+	exit_mmap(mm);
+	set_mm_exe_file(mm, NULL);
+	if (!list_empty(&mm->mmlist)) {
+		spin_lock(&mmlist_lock);
+		list_del(&mm->mmlist);
+		spin_unlock(&mmlist_lock);
+	}
+	if (mm->binfmt)
+		module_put(mm->binfmt->module);
+	mmdrop(mm);
+}
+
 /*
  * Decrement the use count and release all resources for an mm.
  */
@@ -706,24 +726,24 @@ void mmput(struct mm_struct *mm)
 {
 	might_sleep();
 
+	if (atomic_dec_and_test(&mm->mm_users))
+		__mmput(mm);
+}
+EXPORT_SYMBOL_GPL(mmput);
+
+static void mmput_async_fn(struct work_struct *work)
+{
+	struct mm_struct *mm = container_of(work, struct mm_struct, async_put_work);
+	__mmput(mm);
+}
+
+void mmput_async(struct mm_struct *mm)
+{
 	if (atomic_dec_and_test(&mm->mm_users)) {
-		uprobe_clear_state(mm);
-		exit_aio(mm);
-		ksm_exit(mm);
-		khugepaged_exit(mm); /* must run before exit_mmap */
-		exit_mmap(mm);
-		set_mm_exe_file(mm, NULL);
-		if (!list_empty(&mm->mmlist)) {
-			spin_lock(&mmlist_lock);
-			list_del(&mm->mmlist);
-			spin_unlock(&mmlist_lock);
-		}
-		if (mm->binfmt)
-			module_put(mm->binfmt->module);
-		mmdrop(mm);
+		INIT_WORK(&mm->async_put_work, mmput_async_fn);
+		schedule_work(&mm->async_put_work);
 	}
 }
-EXPORT_SYMBOL_GPL(mmput);
 
 /**
  * set_mm_exe_file - change a reference to the mm's executable file
@@ -1470,7 +1490,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 		pid = alloc_pid(p->nsproxy->pid_ns_for_children);
 		if (IS_ERR(pid)) {
 			retval = PTR_ERR(pid);
-			goto bad_fork_cleanup_io;
+			goto bad_fork_cleanup_thread;
 		}
 	}
 
@@ -1632,6 +1652,8 @@ bad_fork_cancel_cgroup:
 bad_fork_free_pid:
 	if (pid != &init_struct_pid)
 		free_pid(pid);
+bad_fork_cleanup_thread:
+	exit_thread(p);
 bad_fork_cleanup_io:
 	if (p->io_context)
 		exit_io_context(p);