Merge tag 'v4.19.59-rt24' into toradex_4.19.y-rttoradex_4.19.y-rt

Linux 4.19.59-rt24

1 files changed, 18 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 65afd0c04622..6eba8c96f4bc 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1897,4 +1897,22 @@ static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
 
 extern struct trace_iterator *tracepoint_print_iter;
 
+/*
+ * Reset the state of the trace_iterator so that it can read consumed data.
+ * Normally, the trace_iterator is used for reading the data when it is not
+ * consumed, and must retain state.
+ */
+static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
+{
+	const size_t offset = offsetof(struct trace_iterator, seq);
+
+	/*
+	 * Keep gcc from complaining about overwriting more than just one
+	 * member in the structure.
+	 */
+	memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
+
+	iter->pos = -1;
+}
+
 #endif /* _LINUX_KERNEL_TRACE_H */