From: Nicolas Boichat <nicolas@boichat.ch>
Date: Sat, 7 Jun 2014 13:38:00 +0000 (+0800)
Subject: umount: Make sure exit code does not overflow
X-Git-Tag: v2.25-rc1~44
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9add961e9e95350171488925582e469e44bb2b5;p=thirdparty%2Futil-linux.git

umount: Make sure exit code does not overflow

POSIX exit code is only 8-bit, and since umount sums up error
codes, it can sometimes report success (exit code 0) even though
a number of operations failed.

For example, running, in an empty directory:
 umount `seq 1 7`
returns 224 (7*32), since none of the 7 mount point exists but
 umount `seq 1 8`
returns 0 (8*32=256)

This patch clips the return value to 255.

Signed-off-by: Nicolas Boichat <nicolas@boichat.ch>
---

diff --git a/sys-utils/umount.c b/sys-utils/umount.c
index 1ad9e6aeb9..a75ff9ec19 100644
--- a/sys-utils/umount.c
+++ b/sys-utils/umount.c
@@ -646,6 +646,6 @@ int main(int argc, char **argv)
 	}
 
 	mnt_free_context(cxt);
-	return rc;
+	return (rc < 256) ? rc : 255;
 }