dyndbg: accept query terms like file=bar and module=foo

Current code expects "keyword" "arg" as 2 words, space separated.
Change to also accept "keyword=arg" form as well, and drop !(nwords%2)
requirement.  Then in rest of function, use new keyword, arg variables
instead of word[i], word[i+1]

Acked-by: <jbaron@akamai.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-15-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/admin-guide/dynamic-debug-howto.rst

@@ -156,6 +156,7 @@ against.  Possible keywords are:::
   ``line-range`` cannot contain space, e.g.
   "1-30" is valid range but "1 - 30" is not.
 
+  ``module=foo`` combined keyword=value form is interchangably accepted
 
 The meanings of each keyword are:
 

lib/dynamic_debug.c

@@ -341,7 +341,8 @@ static int check_set(const char **dest, char *src, char *name)
 
 /*
  * Parse words[] as a ddebug query specification, which is a series
- * of (keyword, value) pairs chosen from these possibilities:
+ * of (keyword, value) pairs or combined keyword=value terms,
+ * chosen from these possibilities:
  *
  * func <function-name>
  * file <full-pathname>
@@ -360,22 +361,34 @@ static int ddebug_parse_query(char *words[], int nwords,
 	unsigned int i;
 	int rc = 0;
 	char *fline;
-
-	/* check we have an even number of words */
-	if (nwords % 2 != 0) {
-		pr_err("expecting pairs of match-spec <value>\n");
-		return -EINVAL;
-	}
+	char *keyword, *arg;
 
 	if (modname)
 		/* support $modname.dyndbg=<multiple queries> */
 		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"))
+	for (i = 0; i < nwords; i++) {
+		/* accept keyword=arg */
+		vpr_info("%d w:%s\n", i, words[i]);
+
+		keyword = words[i];
+		arg = strchr(keyword, '=');
+		if (arg) {
+			*arg++ = '\0';
+		} else {
+			i++; /* next word is arg */
+			if (!(i < nwords)) {
+				pr_err("missing arg to keyword: %s\n", keyword);
+				return -EINVAL;
+			}
+			arg = words[i];
+		}
+		vpr_info("%d key:%s arg:%s\n", i, keyword, arg);
+
+		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 */
@@ -391,18 +404,18 @@ 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)