Fwd: why are init's arguments wiped ?

[Mike Frysinger]

On 01 Feb 2016 08:09, Nicolas CARRIER wrote:
> I wrote a little patch which adds the option not to wipe the arguments, but
> the result is a little bit odd, some 0 are inserted between "init" and the
> rest of the arguments. I must be because "/bin/init" is replaced with
> "init".
> So the proper patch should either :
>  * inhibit this argv[0] modification too
>  * perform a memmove to wipe those extra zeros
> 
> Which one do you think is best ?

what do you mean "some 0" ?  can you copy & paste the exact terminal
output you're seeing ?

argv settings has always been ugly in Linux ... the location of argv
is static as is the size.  there's no way to tell the kernel to use
a different location so you're force to screw with the existing mem.

that said, i would just start with the simple answer: don't mess with
anything at all.
-mike

--- a/init/init.c
+++ b/init/init.c
@@ -1139,11 +1139,13 @@ int init_main(int argc UNUSED_PARAM, char **argv)
 	}
 #endif
 
-	/* Make the command line just say "init"  - thats all, nothing else */
-	strncpy(argv[0], "init", strlen(argv[0]));
-	/* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
-	while (*++argv)
-		nuke_str(*argv);
+	if (FEATURE_INIT_ARGV_REWRITE) {
+		/* Make the command line just say "init"  - thats all, nothing else */
+		strncpy(argv[0], "init", strlen(argv[0]));
+		/* Wipe argv[1]-argv[N] so they don't clutter the ps listing */
+		while (*++argv)
+			nuke_str(*argv);
+	}
 
 	/* Set up signal handlers */
 	if (!DEBUG_INIT) {
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