params: don't ignore the rest of cmdline if parse_one() fails

parse_args() just aborts after it hits an error, so other args
at the same initcall level are simply ignored. This can lead to
other hard-to-understand problems, for example my testing machine
panics during the boot if I pass "locktorture.verbose=true".

Change parse_args() to save the err code for return and continue.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

kernel/params.c

@@ -223,7 +223,7 @@ char *parse_args(const char *doing,
 		 int (*unknown)(char *param, char *val,
 				const char *doing, void *arg))
 {
-	char *param, *val;
+	char *param, *val, *err = NULL;
 
 	/* Chew leading spaces */
 	args = skip_spaces(args);
@@ -238,7 +238,7 @@ char *parse_args(const char *doing,
 		args = next_arg(args, &param, &val);
 		/* Stop at -- */
 		if (!val && strcmp(param, "--") == 0)
-			return args;
+			return err ?: args;
 		irq_was_disabled = irqs_disabled();
 		ret = parse_one(param, val, doing, params, num,
 				min_level, max_level, arg, unknown);
@@ -247,24 +247,25 @@ char *parse_args(const char *doing,
 				doing, param);
 
 		switch (ret) {
+		case 0:
+			continue;
 		case -ENOENT:
 			pr_err("%s: Unknown parameter `%s'\n", doing, param);
-			return ERR_PTR(ret);
+			break;
 		case -ENOSPC:
 			pr_err("%s: `%s' too large for parameter `%s'\n",
 			       doing, val ?: "", param);
-			return ERR_PTR(ret);
-		case 0:
 			break;
 		default:
 			pr_err("%s: `%s' invalid for parameter `%s'\n",
 			       doing, val ?: "", param);
-			return ERR_PTR(ret);
+			break;
 		}
+
+		err = ERR_PTR(ret);
 	}
 
-	/* All parsed OK. */
-	return NULL;
+	return err;
 }
 
 /* Lazy bastard, eh? */