Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "Subsystems affected by this patch series: mm (memremap, memcg,
  slab-generic, kasan, mempolicy, pagecache, oom-kill, pagemap),
  kthread, signals, lib, epoll, and core-kernel"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kernel/hung_task.c: make type annotations consistent
  epoll: add a selftest for epoll timeout race
  mm: always have io_remap_pfn_range() set pgprot_decrypted()
  mm, oom: keep oom_adj under or at upper limit when printing
  kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled
  mm/truncate.c: make __invalidate_mapping_pages() static
  lib/crc32test: remove extra local_irq_disable/enable
  ptrace: fix task_join_group_stop() for the case when current is traced
  mm: mempolicy: fix potential pte_unmap_unlock pte error
  kasan: adopt KUNIT tests to SW_TAGS mode
  mm: memcg: link page counters to root if use_hierarchy is false
  mm: memcontrol: correct the NR_ANON_THPS counter of hierarchical memcg
  hugetlb_cgroup: fix reservation accounting
  mm/mremap_pages: fix static key devmap_managed_key updates

1 files changed, 95 insertions, 0 deletions

diff --git a/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c b/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c
index d979ff14775a..8f82f99f7748 100644
--- a/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c
+++ b/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c
@@ -3282,4 +3282,99 @@ TEST(epoll60)
 	close(ctx.epfd);
 }
 
+struct epoll61_ctx {
+	int epfd;
+	int evfd;
+};
+
+static void *epoll61_write_eventfd(void *ctx_)
+{
+	struct epoll61_ctx *ctx = ctx_;
+	int64_t l = 1;
+
+	usleep(10950);
+	write(ctx->evfd, &l, sizeof(l));
+	return NULL;
+}
+
+static void *epoll61_epoll_with_timeout(void *ctx_)
+{
+	struct epoll61_ctx *ctx = ctx_;
+	struct epoll_event events[1];
+	int n;
+
+	n = epoll_wait(ctx->epfd, events, 1, 11);
+	/*
+	 * If epoll returned the eventfd, write on the eventfd to wake up the
+	 * blocking poller.
+	 */
+	if (n == 1) {
+		int64_t l = 1;
+
+		write(ctx->evfd, &l, sizeof(l));
+	}
+	return NULL;
+}
+
+static void *epoll61_blocking_epoll(void *ctx_)
+{
+	struct epoll61_ctx *ctx = ctx_;
+	struct epoll_event events[1];
+
+	epoll_wait(ctx->epfd, events, 1, -1);
+	return NULL;
+}
+
+TEST(epoll61)
+{
+	struct epoll61_ctx ctx;
+	struct epoll_event ev;
+	int i, r;
+
+	ctx.epfd = epoll_create1(0);
+	ASSERT_GE(ctx.epfd, 0);
+	ctx.evfd = eventfd(0, EFD_NONBLOCK);
+	ASSERT_GE(ctx.evfd, 0);
+
+	ev.events = EPOLLIN | EPOLLET | EPOLLERR | EPOLLHUP;
+	ev.data.ptr = NULL;
+	r = epoll_ctl(ctx.epfd, EPOLL_CTL_ADD, ctx.evfd, &ev);
+	ASSERT_EQ(r, 0);
+
+	/*
+	 * We are testing a race.  Repeat the test case 1000 times to make it
+	 * more likely to fail in case of a bug.
+	 */
+	for (i = 0; i < 1000; i++) {
+		pthread_t threads[3];
+		int n;
+
+		/*
+		 * Start 3 threads:
+		 * Thread 1 sleeps for 10.9ms and writes to the evenfd.
+		 * Thread 2 calls epoll with a timeout of 11ms.
+		 * Thread 3 calls epoll with a timeout of -1.
+		 *
+		 * The eventfd write by Thread 1 should either wakeup Thread 2
+		 * or Thread 3.  If it wakes up Thread 2, Thread 2 writes on the
+		 * eventfd to wake up Thread 3.
+		 *
+		 * If no events are missed, all three threads should eventually
+		 * be joinable.
+		 */
+		ASSERT_EQ(pthread_create(&threads[0], NULL,
+					 epoll61_write_eventfd, &ctx), 0);
+		ASSERT_EQ(pthread_create(&threads[1], NULL,
+					 epoll61_epoll_with_timeout, &ctx), 0);
+		ASSERT_EQ(pthread_create(&threads[2], NULL,
+					 epoll61_blocking_epoll, &ctx), 0);
+
+		for (n = 0; n < ARRAY_SIZE(threads); ++n)
+			ASSERT_EQ(pthread_join(threads[n], NULL), 0);
+	}
+
+	close(ctx.epfd);
+	close(ctx.evfd);
+}
+
 TEST_HARNESS_MAIN