1 files changed, 22 insertions, 14 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 2d4dfd44b0fa5..c70d6347afa2b 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -384,10 +384,13 @@ static int ddebug_parse_query(char *words[], int nwords,
 		query->module = modname;
 
 	for (i = 0; i < nwords; i += 2) {
-		if (!strcmp(words[i], "func")) {
-			rc = check_set(&query->function, words[i+1], "func");
-		} else if (!strcmp(words[i], "file")) {
-			if (check_set(&query->filename, words[i+1], "file"))
+		char *keyword = words[i];
+		char *arg = words[i+1];
+
+		if (!strcmp(keyword, "func")) {
+			rc = check_set(&query->function, arg, "func");
+		} else if (!strcmp(keyword, "file")) {
+			if (check_set(&query->filename, arg, "file"))
 				return -EINVAL;
 
 			/* tail :$info is function or line-range */
@@ -403,18 +406,18 @@ static int ddebug_parse_query(char *words[], int nwords,
 				if (parse_linerange(query, fline))
 					return -EINVAL;
 			}
-		} else if (!strcmp(words[i], "module")) {
-			rc = check_set(&query->module, words[i+1], "module");
-		} else if (!strcmp(words[i], "format")) {
-			string_unescape_inplace(words[i+1], UNESCAPE_SPACE |
+		} else if (!strcmp(keyword, "module")) {
+			rc = check_set(&query->module, arg, "module");
+		} else if (!strcmp(keyword, "format")) {
+			string_unescape_inplace(arg, UNESCAPE_SPACE |
 							    UNESCAPE_OCTAL |
 							    UNESCAPE_SPECIAL);
-			rc = check_set(&query->format, words[i+1], "format");
-		} else if (!strcmp(words[i], "line")) {
-			if (parse_linerange(query, words[i+1]))
+			rc = check_set(&query->format, arg, "format");
+		} else if (!strcmp(keyword, "line")) {
+			if (parse_linerange(query, arg))
 				return -EINVAL;
 		} else {
-			pr_err("unknown keyword \"%s\"\n", words[i]);
+			pr_err("unknown keyword \"%s\"\n", keyword);
 			return -EINVAL;
 		}
 		if (rc)
@@ -558,9 +561,14 @@ static int ddebug_exec_queries(char *query, const char *modname)
 int dynamic_debug_exec_queries(const char *query, const char *modname)
 {
 	int rc;
-	char *qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
+	char *qry; /* writable copy of query */
 
-	if (!query)
+	if (!query) {
+		pr_err("non-null query/command string expected\n");
+		return -EINVAL;
+	}
+	qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
+	if (!qry)
 		return -ENOMEM;
 
 	rc = ddebug_exec_queries(qry, modname);