test_sysctl: test against int proc_dointvec() array support

Add a few initial respective tests for an array:

  o Echoing values separated by spaces works
  o Echoing only first elements will set first elements
  o Confirm PAGE_SIZE limit still applies even if an array is used

Link: http://lkml.kernel.org/r/20170630224431.17374-7-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c
index 53db3513ab08..3dd801c1c85b 100644
--- a/lib/test_sysctl.c
+++ b/lib/test_sysctl.c
@@ -42,6 +42,7 @@ static int i_one_hundred = 100;
 struct test_sysctl_data {
         int int_0001;
         int int_0002;
+        int int_0003[4];
 
         unsigned int uint_0001;
 
@@ -52,6 +53,11 @@ static struct test_sysctl_data test_data = {
         .int_0001 = 60,
         .int_0002 = 1,
 
+        .int_0003[0] = 0,
+        .int_0003[1] = 1,
+        .int_0003[2] = 2,
+        .int_0003[3] = 3,
+
         .uint_0001 = 314,
 
         .string_0001 = "(none)",
@@ -76,6 +82,13 @@ static struct ctl_table test_table[] = {
                 .proc_handler   = proc_dointvec,
         },
         {
+                .procname       = "int_0003",
+                .data           = &test_data.int_0003,
+                .maxlen         = sizeof(test_data.int_0003),
+                .mode           = 0644,
+                .proc_handler   = proc_dointvec,
+        },
+        {
                 .procname       = "uint_0001",
                 .data           = &test_data.uint_0001,
                 .maxlen         = sizeof(unsigned int),