[LTP] [PATCH] sysctl/sysctl02: Add new regression test for overflow file-max

[Yang Xu]

On upstream kernel, before commit[1], the max value in proc_get_long based on
the number of chars(21). It rejects values such as 184467440737095516160 (21 chars)
but accepts values such as 18446744073709551616 (20 chars). But we should reject all
because both are overflows. After this commit,the permitted max value is 2^64-1.

Before commit[2], when writing echo 18446744073709551616 > /proc/sys/fs/file-max
/proc/sys/fs/file-max will overflow and be set to 0.  It may crash the system. This
commit sets the max and min value for file-max. After this commit,the permitted max
value is 2^63-1.

Unfortunately, commit[2] introduced a new bug because the minimum value points at
the global 'zero' variable which is an int. It may crash system. This bug has been fixed
bt commit[3].

I will set 2^64 ,2^64-1,2^63 and 0 to file-max in case and test it.

[1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f2923c4f73f21cfd714d12a2d48de8c21f11cfe
[2]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=32a5ad9c22852e6bd9e74bdec5934ef9d1480bc5
[3]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9002b21465fa4d829edfc94a5a441005cffaa972

Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
---
 runtest/commands                      | 1 +
 testcases/commands/sysctl/sysctl01.sh | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/runtest/commands b/runtest/commands
index ac15e8b23..1870c4209 100644
--- a/runtest/commands
+++ b/runtest/commands
@@ -40,3 +40,4 @@ keyctl01_sh keyctl01.sh
 gdb01_sh gdb01.sh
 unshare01_sh unshare01.sh
 sysctl01_sh sysctl01.sh
+sysctl02_sh sysctl02.sh
diff --git a/testcases/commands/sysctl/sysctl01.sh b/testcases/commands/sysctl/sysctl01.sh
index 7522da53d..bf89a6d8d 100755
--- a/testcases/commands/sysctl/sysctl01.sh
+++ b/testcases/commands/sysctl/sysctl01.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-
+#
 # Copyright (c) 2018 FUJITSU LIMITED. All rights reserved.
 # Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
 #
-- 
2.18.1