Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...

1 files changed, 9 insertions, 7 deletions

diff --git a/kernel/task_work.c b/kernel/task_work.c
index dff75bcde151..065e1ef8fc8d 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -47,12 +47,12 @@ int task_work_add(struct task_struct *task, struct callback_head *work,
 	/* record the work call stack in order to print it in KASAN reports */
 	kasan_record_aux_stack(work);
 
+	head = READ_ONCE(task->task_works);
 	do {
-		head = READ_ONCE(task->task_works);
 		if (unlikely(head == &work_exited))
 			return -ESRCH;
 		work->next = head;
-	} while (cmpxchg(&task->task_works, head, work) != head);
+	} while (!try_cmpxchg(&task->task_works, &head, work));
 
 	switch (notify) {
 	case TWA_NONE:
@@ -100,10 +100,12 @@ task_work_cancel_match(struct task_struct *task,
 	 * we raced with task_work_run(), *pprev == NULL/exited.
 	 */
 	raw_spin_lock_irqsave(&task->pi_lock, flags);
-	while ((work = READ_ONCE(*pprev))) {
-		if (!match(work, data))
+	work = READ_ONCE(*pprev);
+	while (work) {
+		if (!match(work, data)) {
 			pprev = &work->next;
-		else if (cmpxchg(pprev, work, work->next) == work)
+			work = READ_ONCE(*pprev);
+		} else if (try_cmpxchg(pprev, &work, work->next))
 			break;
 	}
 	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
@@ -151,16 +153,16 @@ void task_work_run(void)
 		 * work->func() can do task_work_add(), do not set
 		 * work_exited unless the list is empty.
 		 */
+		work = READ_ONCE(task->task_works);
 		do {
 			head = NULL;
-			work = READ_ONCE(task->task_works);
 			if (!work) {
 				if (task->flags & PF_EXITING)
 					head = &work_exited;
 				else
 					break;
 			}
-		} while (cmpxchg(&task->task_works, work, head) != work);
+		} while (!try_cmpxchg(&task->task_works, &work, head));
 
 		if (!work)
 			break;