From: Vasily Gorbik <gor@linux.ibm.com>
Date: Mon, 19 Aug 2019 15:13:04 +0000 (+0200)
Subject: s390/sclp: avoid using strncmp with hardcoded length
X-Git-Tag: v5.4-rc1~156^2~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54fb07d030e1b2fa9d903a748f84398bbe6f213d;p=thirdparty%2Flinux.git

s390/sclp: avoid using strncmp with hardcoded length

"earlyprintk" option documentation does not clearly state which
platform supports which additional values (e.g. ",keep"). Preserve old
option behaviour and reuse str_has_prefix instead of strncmp for prefix
testing.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---

diff --git a/arch/s390/kernel/early_printk.c b/arch/s390/kernel/early_printk.c
index 40c1dfec944e6..6f24d83bc5dc0 100644
--- a/arch/s390/kernel/early_printk.c
+++ b/arch/s390/kernel/early_printk.c
@@ -25,7 +25,7 @@ static int __init setup_early_printk(char *buf)
 	if (early_console)
 		return 0;
 	/* Accept only "earlyprintk" and "earlyprintk=sclp" */
-	if (buf && strncmp(buf, "sclp", 4))
+	if (buf && !str_has_prefix(buf, "sclp"))
 		return 0;
 	if (!sclp.has_linemode && !sclp.has_vt220)
 		return 0;