Merge tag 'v4.1.41' into 4.1-2.0.x-imx

Linux 4.1.41

* tag 'v4.1.41': (473 commits)
  Linux 4.1.41
  mm/huge_memory.c: respect FOLL_FORCE/FOLL_COW for thp
  xc2028: Fix use-after-free bug properly
  iio: proximity: as3935: fix as3935_write
  ipx: call ipxitf_put() in ioctl error path
  sched/fair: Initialize throttle_count for new task-groups lazily
  sched/fair: Do not announce throttled next buddy in dequeue_task_fair()
  iio: dac: ad7303: fix channel description
  mwifiex: pcie: fix cmd_buf use-after-free in remove/reset
  rtlwifi: rtl8821ae: setup 8812ae RFE according to device type
  ARM: tegra: paz00: Mark panel regulator as enabled on boot
  fs/xattr.c: zero out memory copied to userspace in getxattr
  vfio/type1: Remove locked page accounting workqueue
  crypto: algif_aead - Require setkey before accept(2)
  staging: gdm724x: gdm_mux: fix use-after-free on module unload
  drm/ttm: fix use-after-free races in vm fault handling
  f2fs: sanity check segment count
  ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf
  ipv6: initialize route null entry in addrconf_init()
  rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME string
  ...

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>

1 files changed, 18 insertions, 6 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index fb147c7811d2..75c5271a56c2 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3446,11 +3446,23 @@ EXPORT_SYMBOL_GPL(ring_buffer_iter_reset);
 int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
+	struct buffer_page *reader;
+	struct buffer_page *head_page;
+	struct buffer_page *commit_page;
+	unsigned commit;
 
 	cpu_buffer = iter->cpu_buffer;
 
-	return iter->head_page == cpu_buffer->commit_page &&
-		iter->head == rb_commit_index(cpu_buffer);
+	/* Remember, trace recording is off when iterator is in use */
+	reader = cpu_buffer->reader_page;
+	head_page = cpu_buffer->head_page;
+	commit_page = cpu_buffer->commit_page;
+	commit = rb_page_commit(commit_page);
+
+	return ((iter->head_page == commit_page && iter->head == commit) ||
+		(iter->head_page == reader && commit_page == head_page &&
+		 head_page->read == commit &&
+		 iter->head == rb_page_commit(cpu_buffer->reader_page)));
 }
 EXPORT_SYMBOL_GPL(ring_buffer_iter_empty);
 
@@ -4878,9 +4890,9 @@ static __init int test_ringbuffer(void)
 		rb_data[cpu].cnt = cpu;
 		rb_threads[cpu] = kthread_create(rb_test, &rb_data[cpu],
 						 "rbtester/%d", cpu);
-		if (WARN_ON(!rb_threads[cpu])) {
+		if (WARN_ON(IS_ERR(rb_threads[cpu]))) {
 			pr_cont("FAILED\n");
-			ret = -1;
+			ret = PTR_ERR(rb_threads[cpu]);
 			goto out_free;
 		}
 
@@ -4890,9 +4902,9 @@ static __init int test_ringbuffer(void)
 
 	/* Now create the rb hammer! */
 	rb_hammer = kthread_run(rb_hammer_test, NULL, "rbhammer");
-	if (WARN_ON(!rb_hammer)) {
+	if (WARN_ON(IS_ERR(rb_hammer))) {
 		pr_cont("FAILED\n");
-		ret = -1;
+		ret = PTR_ERR(rb_hammer);
 		goto out_free;
 	}