[PATCH] init: Reject bare rodata parameter before architecture parsing

[Thorsten Blum <blum@kernel.org>]

When a bare rodata parameter is specified on the kernel command line
without the '=' separator, early parameter parsing passes NULL to
set_debug_rodata().

Current hooks already handle NULL safely. Reject NULL before calling
arch_parse_debug_rodata() so architecture hooks always receive a
non-NULL string.

Return -EINVAL to report the malformed option instead of falling through
to the existing warning. Also remove the now-redundant NULL checks from
the "on" and "off" comparisons.

Signed-off-by: Thorsten Blum <blum@kernel.org>
---
 init/main.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/init/main.c b/init/main.c
index 7b0c8c34e6a9..768b65f2498f 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1566,12 +1566,15 @@ static inline bool arch_parse_debug_rodata(char *str) { return false; }
 
 static int __init set_debug_rodata(char *str)
 {
+	if (!str)
+		return -EINVAL;
+
 	if (arch_parse_debug_rodata(str))
 		return 0;
 
-	if (str && !strcmp(str, "on"))
+	if (!strcmp(str, "on"))
 		rodata_enabled = true;
-	else if (str && !strcmp(str, "off"))
+	else if (!strcmp(str, "off"))
 		rodata_enabled = false;
 	else
 		pr_warn("Invalid option string for rodata: '%s'\n", str);