test_sysctl: add generic script to expand on tests

This adds a generic script to let us more easily add more tests cases.
Since we really have only two types of tests cases just fold them into
the one file.  Each test unit is now identified into its separate
function:

    # ./sysctl.sh -l
  Test ID list:

  TEST_ID x NUM_TEST
  TEST_ID:   Test ID
  NUM_TESTS: Number of recommended times to run the test

  0001 x 1 - tests proc_dointvec_minmax()
  0002 x 1 - tests proc_dostring()

For now we start off with what we had before, and run only each test
once.  We can now watch a test case until it fails:

  ./sysctl.sh -w 0002

We can also run a test case x number of times, say we want to run a test
case 100 times:

  ./sysctl.sh -c 0001 100

To run a test case only once, for example:

  ./sysctl.sh -s 0002

The default settings are specified at the top of sysctl.sh.

Link: http://lkml.kernel.org/r/20170630224431.17374-3-mcgrof@kernel.orgSigned-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>

tools/testing/selftests/sysctl/Makefile

@@ -4,8 +4,7 @@
 # No binaries, but make sure arg-less "make" doesn't trigger "run_tests".
 all:
 
-TEST_PROGS := run_numerictests run_stringtests
-TEST_FILES := common_tests
+TEST_PROGS := sysctl.sh
 
 include ../lib.mk
 

tools/testing/selftests/sysctl/common_tests

-#!/bin/sh
-
-TEST_FILE=$(mktemp)
-
-echo "== Testing sysctl behavior against ${TARGET} =="
-
-set_orig()
-{
-	echo "${ORIG}" > "${TARGET}"
-}
-
-set_test()
-{
-	echo "${TEST_STR}" > "${TARGET}"
-}
-
-verify()
-{
-	local seen
-	seen=$(cat "$1")
-	if [ "${seen}" != "${TEST_STR}" ]; then
-		return 1
-	fi
-	return 0
-}
-
-exit_test()
-{
-	if [ ! -z ${old_strict} ]; then
-		echo ${old_strict} > ${WRITES_STRICT}
-	fi
-	exit $rc
-}
-
-trap 'set_orig; rm -f "${TEST_FILE}"' EXIT
-
-rc=0
-
-echo -n "Writing test file ... "
-echo "${TEST_STR}" > "${TEST_FILE}"
-if ! verify "${TEST_FILE}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl is not set to test value ... "
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Writing sysctl from shell ... "
-set_test
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Resetting sysctl to original value ... "
-set_orig
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	exit 1
-else
-	echo "ok"
-fi
-
-echo -n "Checking write strict setting ... "
-WRITES_STRICT="${SYSCTL}/kernel/sysctl_writes_strict"
-if [ ! -e ${WRITES_STRICT} ]; then
-	echo "FAIL, but skip in case of old kernel" >&2
-else
-	old_strict=$(cat ${WRITES_STRICT})
-	if [ "$old_strict" = "1" ]; then
-		echo "ok"
-	else
-		echo "FAIL, strict value is 0 but force to 1 to continue" >&2
-		echo "1" > ${WRITES_STRICT}
-	fi
-fi
-
-# Now that we've validated the sanity of "set_test" and "set_orig",
-# we can use those functions to set starting states before running
-# specific behavioral tests.
-
-echo -n "Writing entire sysctl in single write ... "
-set_orig
-dd if="${TEST_FILE}" of="${TARGET}" bs=4096 2>/dev/null
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Writing middle of sysctl after synchronized seek ... "
-set_test
-dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 skip=1 2>/dev/null
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Writing beyond end of sysctl ... "
-set_orig
-dd if="${TEST_FILE}" of="${TARGET}" bs=20 seek=2 2>/dev/null
-if verify "${TARGET}"; then
-        echo "FAIL" >&2
-        rc=1
-else
-        echo "ok"
-fi
-
-echo -n "Writing sysctl with multiple long writes ... "
-set_orig
-(perl -e 'print "A" x 50;'; echo "${TEST_STR}") | \
-	dd of="${TARGET}" bs=50 2>/dev/null
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi

tools/testing/selftests/sysctl/run_numerictests

-#!/bin/sh
-
-SYSCTL="/proc/sys/debug/test_sysctl/"
-TARGET="${SYSCTL}/int_0001"
-ORIG=$(cat "${TARGET}")
-TEST_STR=$(( $ORIG + 1 ))
-
-. ./common_tests
-
-exit_test

tools/testing/selftests/sysctl/run_stringtests

-#!/bin/sh
-
-SYSCTL="/proc/sys/debug/test_sysctl/"
-TARGET="${SYSCTL}/string_0001"
-ORIG=$(cat "${TARGET}")
-TEST_STR="Testing sysctl"
-
-. ./common_tests
-
-# Only string sysctls support seeking/appending.
-MAXLEN=65
-
-echo -n "Writing entire sysctl in short writes ... "
-set_orig
-dd if="${TEST_FILE}" of="${TARGET}" bs=1 2>/dev/null
-if ! verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Writing middle of sysctl after unsynchronized seek ... "
-set_test
-dd if="${TEST_FILE}" of="${TARGET}" bs=1 seek=1 2>/dev/null
-if verify "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl maxlen is at least $MAXLEN ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-2), "B";' | \
-	dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
-if ! grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl keeps original string on overflow append ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
-	dd of="${TARGET}" bs=$(( MAXLEN - 1 )) 2>/dev/null
-if grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl stays NULL terminated on write ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-1), "B";' | \
-	dd of="${TARGET}" bs="${MAXLEN}" 2>/dev/null
-if grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-echo -n "Checking sysctl stays NULL terminated on overwrite ... "
-set_orig
-perl -e 'print "A" x ('"${MAXLEN}"'-1), "BB";' | \
-	dd of="${TARGET}" bs=$(( $MAXLEN + 1 )) 2>/dev/null
-if grep -q B "${TARGET}"; then
-	echo "FAIL" >&2
-	rc=1
-else
-	echo "ok"
-fi
-
-exit_test