1 files changed, 79 insertions, 3 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index e755e09805ab..21aef22a8489 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -708,6 +708,38 @@ static struct notifier_block trace_kprobe_module_nb = {
 	.priority = 1	/* Invoked after kprobe module callback */
 };
 
+struct count_symbols_struct {
+	const char *func_name;
+	unsigned int count;
+};
+
+static int count_symbols(void *data, const char *name, struct module *unused0,
+			 unsigned long unused1)
+{
+	struct count_symbols_struct *args = data;
+
+	if (strcmp(args->func_name, name))
+		return 0;
+
+	args->count++;
+
+	return 0;
+}
+
+static unsigned int number_of_same_symbols(char *func_name)
+{
+	struct count_symbols_struct args = {
+		.func_name = func_name,
+		.count = 0,
+	};
+
+	kallsyms_on_each_symbol(count_symbols, &args);
+
+	module_kallsyms_on_each_symbol(count_symbols, &args);
+
+	return args.count;
+}
+
 static int __trace_kprobe_create(int argc, const char *argv[])
 {
 	/*
@@ -836,6 +868,31 @@ static int __trace_kprobe_create(int argc, const char *argv[])
 		}
 	}
 
+	if (symbol && !strchr(symbol, ':')) {
+		unsigned int count;
+
+		count = number_of_same_symbols(symbol);
+		if (count > 1) {
+			/*
+			 * Users should use ADDR to remove the ambiguity of
+			 * using KSYM only.
+			 */
+			trace_probe_log_err(0, NON_UNIQ_SYMBOL);
+			ret = -EADDRNOTAVAIL;
+
+			goto error;
+		} else if (count == 0) {
+			/*
+			 * We can return ENOENT earlier than when register the
+			 * kprobe.
+			 */
+			trace_probe_log_err(0, BAD_PROBE_ADDR);
+			ret = -ENOENT;
+
+			goto error;
+		}
+	}
+
 	trace_probe_log_set_index(0);
 	if (event) {
 		ret = traceprobe_parse_event_name(&event, &group, buf,
@@ -942,10 +999,10 @@ EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
 /**
  * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
  * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @kretprobe: Is this a return probe?
  * @name: The name of the kprobe event
  * @loc: The location of the kprobe event
- * @kretprobe: Is this a return probe?
- * @args: Variable number of arg (pairs), one pair for each field
+ * @...: Variable number of arg (pairs), one pair for each field
  *
  * NOTE: Users normally won't want to call this function directly, but
  * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
@@ -1018,7 +1075,7 @@ EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
 /**
  * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
  * @cmd: A pointer to the dynevent_cmd struct representing the new event
- * @args: Variable number of arg (pairs), one pair for each field
+ * @...: Variable number of arg (pairs), one pair for each field
  *
  * NOTE: Users normally won't want to call this function directly, but
  * rather use the kprobe_event_add_fields() wrapper, which
@@ -1755,6 +1812,7 @@ static int unregister_kprobe_event(struct trace_kprobe *tk)
 }
 
 #ifdef CONFIG_PERF_EVENTS
+
 /* create a trace_kprobe, but don't add it to global lists */
 struct trace_event_call *
 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
@@ -1765,6 +1823,24 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 	int ret;
 	char *event;
 
+	if (func) {
+		unsigned int count;
+
+		count = number_of_same_symbols(func);
+		if (count > 1)
+			/*
+			 * Users should use addr to remove the ambiguity of
+			 * using func only.
+			 */
+			return ERR_PTR(-EADDRNOTAVAIL);
+		else if (count == 0)
+			/*
+			 * We can return ENOENT earlier than when register the
+			 * kprobe.
+			 */
+			return ERR_PTR(-ENOENT);
+	}
+
 	/*
 	 * local trace_kprobes are not added to dyn_event, so they are never
 	 * searched in find_trace_kprobe(). Therefore, there is no concern of