test_sysctl: add simple proc_dointvec() case

Test against a simple proc_dointvec() case.  While at it, add a test
against INT_MAX.  Make sure INT_MAX works, and INT_MAX+1 will fail.
Also test negative values work.

Link: http://lkml.kernel.org/r/20170630224431.17374-5-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, 62 insertions, 0 deletions

diff --git a/tools/testing/selftests/sysctl/sysctl.sh b/tools/testing/selftests/sysctl/sysctl.sh
index 6ec807576f7c..7ba3fa2bbd54 100644
--- a/tools/testing/selftests/sysctl/sysctl.sh
+++ b/tools/testing/selftests/sysctl/sysctl.sh
@@ -31,6 +31,7 @@ TEST_FILE=$(mktemp)
 # we have tons of space.
 ALL_TESTS="0001:1:1"
 ALL_TESTS="$ALL_TESTS 0002:1:1"
+ALL_TESTS="$ALL_TESTS 0003:1:1"
 
 test_modprobe()
 {
@@ -82,6 +83,9 @@ function check_production_sysctl_writes_strict()
         if [ -z $MAX_DIGITS ]; then
                 MAX_DIGITS=$(($PAGE_SIZE/8))
         fi
+        if [ -z $INT_MAX ]; then
+                INT_MAX=$(getconf INT_MAX)
+        fi
 }
 
 test_reqs()
@@ -122,6 +126,9 @@ reset_vals()
                 int_0001)
                         VAL="60"
                         ;;
+                int_0002)
+                        VAL="1"
+                        ;;
                 string_0001)
                         VAL="(none)"
                         ;;
@@ -296,6 +303,48 @@ run_limit_digit()
         test_rc
 }
 
+# You are using an int
+run_limit_digit_int()
+{
+        echo -n "Testing INT_MAX works ..."
+        reset_vals
+        TEST_STR="$INT_MAX"
+        echo -n $TEST_STR > $TARGET
+
+        if ! verify "${TARGET}"; then
+                echo "FAIL" >&2
+                rc=1
+        else
+                echo "ok"
+        fi
+        test_rc
+
+        echo -n "Testing INT_MAX + 1 will fail as expected..."
+        reset_vals
+        let TEST_STR=$INT_MAX+1
+        echo -n $TEST_STR > $TARGET 2> /dev/null
+
+        if verify "${TARGET}"; then
+                echo "FAIL" >&2
+                rc=1
+        else
+                echo "ok"
+        fi
+        test_rc
+
+        echo -n "Testing negative values will work as expected..."
+        reset_vals
+        TEST_STR="-3"
+        echo -n $TEST_STR > $TARGET 2> /dev/null
+        if ! verify "${TARGET}"; then
+                echo "FAIL" >&2
+                rc=1
+        else
+                echo "ok"
+        fi
+        test_rc
+}
+
 run_stringtests()
 {
         echo -n "Writing entire sysctl in short writes ... "
@@ -389,6 +438,18 @@ sysctl_test_0002()
         run_stringtests
 }
 
+sysctl_test_0003()
+{
+        TARGET="${SYSCTL}/int_0002"
+        reset_vals
+        ORIG=$(cat "${TARGET}")
+        TEST_STR=$(( $ORIG + 1 ))
+
+        run_numerictests
+        run_limit_digit
+        run_limit_digit_int
+}
+
 list_tests()
 {
         echo "Test ID list:"
@@ -399,6 +460,7 @@ list_tests()
         echo
         echo "0001 x $(get_test_count 0001) - tests proc_dointvec_minmax()"
         echo "0002 x $(get_test_count 0002) - tests proc_dostring()"
+        echo "0003 x $(get_test_count 0003) - tests proc_dointvec()"
 }
 
 test_reqs