test_sysctl: add simple proc_douintvec() case

Test against a simple proc_douintvec() case.  While at it, add a test
against UINT_MAX.  Make sure UINT_MAX works, and UINT_MAX+1 will fail
and that negative values are not accepted.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Luis R. Rodriguez <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c
index 1472e1a..53db3513 100644
--- a/lib/test_sysctl.c
+++ b/lib/test_sysctl.c
@@ -43,6 +43,8 @@ struct test_sysctl_data {
 	int int_0001;
 	int int_0002;
 
+	unsigned int uint_0001;
+
 	char string_0001[65];
 };
 
@@ -50,6 +52,8 @@ static struct test_sysctl_data test_data = {
 	.int_0001 = 60,
 	.int_0002 = 1,
 
+	.uint_0001 = 314,
+
 	.string_0001 = "(none)",
 };
 
@@ -72,6 +76,13 @@ static struct ctl_table test_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 	{
+		.procname	= "uint_0001",
+		.data		= &test_data.uint_0001,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec,
+	},
+	{
 		.procname	= "string_0001",
 		.data		= &test_data.string_0001,
 		.maxlen		= sizeof(test_data.string_0001),