tracing: Update print fmt check to handle new __get_sockaddr() macro

A helper macro was added to make reading socket addresses easier in trace
events. It pairs %pISpc with __get_sockaddr() that reads the socket
address from the ring buffer into a human readable format.

The boot up check that makes sure that trace events do not reference
pointers to memory that can later be freed when the trace event is read,
incorrectly flagged this as a delayed reference. Update the check to
handle "__get_sockaddr" and not report an error on it.

Link: https://lore.kernel.org/all/20220125160505.068dbb52@canb.auug.org.au/

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

kernel/trace/trace_events.c

@@ -384,6 +384,12 @@ static void test_event_printk(struct trace_event_call *call)
 			if (!(dereference_flags & (1ULL << arg)))
 				goto next_arg;
 
+			/* Check for __get_sockaddr */;
+			if (str_has_prefix(fmt + i, "__get_sockaddr(")) {
+				dereference_flags &= ~(1ULL << arg);
+				goto next_arg;
+			}
+
 			/* Find the REC-> in the argument */
 			c = strchr(fmt + i, ',');
 			r = strstr(fmt + i, "REC->");