linux-kernel - [PATCH] init/main.c: simplify repair_env

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Message-Id: <20171215213317.3151-1-msuchanek@suse.de>
Date:   Fri, 15 Dec 2017 22:33:17 +0100
From:   Michal Suchanek <msuchanek@...e.de>
To:     Hari Bathini <hbathini@...ux.vnet.ibm.com>,
        Ingo Molnar <mingo@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Kees Cook <keescook@...omium.org>,
        Peter Zijlstra <peterz@...radead.org>,
        "Steven Rostedt," <rostedt@...dmis.org>,
        Laura Abbott <lauraa@...eaurora.org>,
        Gargi Sharma <gs051095@...il.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Michal Suchanek <msuchanek@...e.de>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH] init/main.c: simplify repair_env_string

Quoting characters are now removed from the parameter so value always
follows directly after the NUL terminating parameter name.

Signed-off-by: Michal Suchanek <msuchanek@...e.de>
---
 init/main.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

Since the previous "[PATCH v9 3/8] lib/cmdline.c: add backslash support to
kernel commandline parsing" adds the memmove in lib/cmdline.c it is now
superfluous in init/main.c

diff --git a/init/main.c b/init/main.c
index 1f5fdedbb293..1e5b1dc940d9 100644
--- a/init/main.c
+++ b/init/main.c
@@ -244,15 +244,10 @@ static int __init repair_env_string(char *param, char *val,
 				    const char *unused, void *arg)
 {
 	if (val) {
-		/* param=val or param="val"? */
-		if (val == param+strlen(param)+1)
-			val[-1] = '=';
-		else if (val == param+strlen(param)+2) {
-			val[-2] = '=';
-			memmove(val-1, val, strlen(val)+1);
-			val--;
-		} else
-			BUG();
+		int parm_len = strlen(param);
+
+		param[parm_len] = '=';
+		BUG_ON(val != param + parm_len + 1);
 	}
 	return 0;
 }
-- 
2.13.6