Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/kernel/kernel/trace/trace_events.c b/kernel/kernel/trace/trace_events.c
index 0e508e99b..5bd79b347 100644
--- a/kernel/kernel/trace/trace_events.c
+++ b/kernel/kernel/trace/trace_events.c
@@ -246,6 +246,14 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
 
 	local_save_flags(fbuffer->flags);
 	fbuffer->pc = preempt_count();
+	/*
+	 * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables
+	 * preemption (adding one to the preempt_count). Since we are
+	 * interested in the preempt_count at the time the tracepoint was
+	 * hit, we need to subtract one to offset the increment.
+	 */
+	if (IS_ENABLED(CONFIG_PREEMPT))
+		fbuffer->pc--;
 	fbuffer->trace_file = trace_file;
 
 	fbuffer->event =
@@ -2109,8 +2117,13 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
 	trace_create_file("filter", 0644, file->dir, file,
 			  &ftrace_event_filter_fops);
 
-	trace_create_file("trigger", 0644, file->dir, file,
-			  &event_trigger_fops);
+	/*
+	 * Only event directories that can be enabled should have
+	 * triggers.
+	 */
+	if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
+		trace_create_file("trigger", 0644, file->dir, file,
+				  &event_trigger_fops);
 
 	trace_create_file("format", 0444, file->dir, call,
 			  &ftrace_event_format_fops);