tracing/uprobes: Check the return value of kstrdup() for tu->filename

kstrdup() returns NULL when some internal memory errors happen, it is
better to check the return value of it so to catch the memory error in
time.

Link: https://lkml.kernel.org/r/tencent_3C2E330722056D7891D2C83F29C802734B06@qq.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 33ea4b2 ("perf/core: Implement the 'perf_uprobe' PMU")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace_uprobe.c

@@ -1609,6 +1609,11 @@ create_local_trace_uprobe(char *name, unsigned long offs,
 	tu->path = path;
 	tu->ref_ctr_offset = ref_ctr_offset;
 	tu->filename = kstrdup(name, GFP_KERNEL);
+	if (!tu->filename) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
 	init_trace_event_call(tu);
 
 	ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;