X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Ftrace%2Ftrace.c;h=e71a8be4a6ee9decd1429eb13159885f8c567469;hb=722a300bf84ebebe21da164e75024c0ce7ca1868;hp=4d79485b3237597a3657b3f2b98b4fca1f40d3a6;hpb=ae6c138353fe822cb720231a707a9f0e0426e0f2;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4d79485b3237..e71a8be4a6ee 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -652,8 +652,6 @@ static struct {
 	ARCH_TRACE_CLOCKS
 };
 
-int trace_clock_id;
-
 /*
  * trace_parser_get_init - gets the buffer for trace parser
  */
@@ -843,7 +841,15 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 
 	memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
 	max_data->pid = tsk->pid;
-	max_data->uid = task_uid(tsk);
+	/*
+	 * If tsk == current, then use current_uid(), as that does not use
+	 * RCU. The irq tracer can be called out of RCU scope.
+	 */
+	if (tsk == current)
+		max_data->uid = current_uid();
+	else
+		max_data->uid = task_uid(tsk);
+
 	max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
 	max_data->policy = tsk->policy;
 	max_data->rt_priority = tsk->rt_priority;
@@ -2818,7 +2824,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 		iter->iter_flags |= TRACE_FILE_ANNOTATE;
 
 	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
-	if (trace_clocks[trace_clock_id].in_ns)
+	if (trace_clocks[tr->clock_id].in_ns)
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
 	/* stop the trace while dumping if we are not opening "snapshot" */
@@ -3817,7 +3823,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
 		iter->iter_flags |= TRACE_FILE_LAT_FMT;
 
 	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
-	if (trace_clocks[trace_clock_id].in_ns)
+	if (trace_clocks[tr->clock_id].in_ns)
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
 	iter->cpu_file = tc->cpu;
@@ -5087,7 +5093,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 	cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu);
 	trace_seq_printf(s, "bytes: %ld\n", cnt);
 
-	if (trace_clocks[trace_clock_id].in_ns) {
+	if (trace_clocks[tr->clock_id].in_ns) {
 		/* local or global for trace_clock */
 		t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
 		usec_rem = do_div(t, USEC_PER_SEC);