Merge tag 'linux-kselftest-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:

- ftrace and safesetid test fixes from Masami Hiramatsu

- Kunit fixes from Brendan Higgins, Iurii Zaikin, and Heidi Fahim

- Kselftest framework fixes from SeongJae Park and Michael Ellerman

* tag 'linux-kselftest-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
kselftest: Support old perl versions
kselftest/runner: Print new line in print of timeout log
selftests: Fix dangling documentation references to kselftest_module.sh
Documentation: kunit: add documentation for kunit_tool
Documentation: kunit: fix typos and gramatical errors
kunit: testing kunit: Bug fix in test_run_timeout function
fs/ext4/inode-test: Fix inode test on 32 bit platforms.
selftests: safesetid: Fix Makefile to set correct test program
selftests: safesetid: Check the return value of setuid/setgid
selftests: safesetid: Move link library to LDLIBS
selftests/ftrace: Fix multiple kprobe testcase
selftests/ftrace: Do not to use absolute debugfs path
selftests/ftrace: Fix ftrace test cases to check unsupported
selftests/ftrace: Fix to check the existence of set_ftrace_filter

Documentation/dev-tools/kselftest.rst

···
 Kselftest tests the kernel from userspace.  Sometimes things need
 testing from within the kernel, one method of doing this is to create a
 test module.  We can tie the module into the kselftest framework by
-using a shell script test runner.  ``kselftest_module.sh`` is designed
+using a shell script test runner.  ``kselftest/module.sh`` is designed
 to facilitate this process.  There is also a header file provided to
 assist writing kernel modules that are for use with kselftest:
 
 - ``tools/testing/kselftest/kselftest_module.h``
-- ``tools/testing/kselftest/kselftest_module.sh``
+- ``tools/testing/kselftest/kselftest/module.sh``
 
 How to use
 ----------
···
 
    #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-   #include "../tools/testing/selftests/kselftest_module.h"
+   #include "../tools/testing/selftests/kselftest/module.h"
 
    KSTM_MODULE_GLOBALS();
 
···
 
     #!/bin/bash
     # SPDX-License-Identifier: GPL-2.0+
-    $(dirname $0)/../kselftest_module.sh "foo" test_foo
+    $(dirname $0)/../kselftest/module.sh "foo" test_foo
 
 
 Test Harness

Documentation/dev-tools/kunit/index.rst

···
 
 	start
 	usage
+	kunit-tool
 	api/index
 	faq
 

Documentation/dev-tools/kunit/kunit-tool.rst

···
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+kunit_tool How-To
+=================
+
+What is kunit_tool?
+===================
+
+kunit_tool is a script (``tools/testing/kunit/kunit.py``) that aids in building
+the Linux kernel as UML (`User Mode Linux
+<http://user-mode-linux.sourceforge.net/>`_), running KUnit tests, parsing
+the test results and displaying them in a user friendly manner.
+
+What is a kunitconfig?
+======================
+
+It's just a defconfig that kunit_tool looks for in the base directory.
+kunit_tool uses it to generate a .config as you might expect. In addition, it
+verifies that the generated .config contains the CONFIG options in the
+kunitconfig; the reason it does this is so that it is easy to be sure that a
+CONFIG that enables a test actually ends up in the .config.
+
+How do I use kunit_tool?
+========================
+
+If a kunitconfig is present at the root directory, all you have to do is:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run
+
+However, you most likely want to use it with the following options:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all`
+
+- ``--timeout`` sets a maximum amount of time to allow tests to run.
+- ``--jobs`` sets the number of threads to use to build the kernel.
+
+If you just want to use the defconfig that ships with the kernel, you can
+append the ``--defconfig`` flag as well:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all` --defconfig
+
+.. note::
+	This command is particularly helpful for getting started because it
+	just works. No kunitconfig needs to be present.
+
+For a list of all the flags supported by kunit_tool, you can run:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py run --help

Documentation/dev-tools/kunit/start.rst

···
 
 .. code-block:: bash
 
-   ./tools/testing/kunit/kunit.py run
+	./tools/testing/kunit/kunit.py run --defconfig
+
+For more information on this wrapper (also called kunit_tool) checkout the
+:doc:`kunit-tool` page.
 
 Creating a kunitconfig
 ======================
-The Python script is a thin wrapper around Kbuild as such, it needs to be
+The Python script is a thin wrapper around Kbuild. As such, it needs to be
 configured with a ``kunitconfig`` file. This file essentially contains the
 regular Kernel config, with the specific test targets as well.
 
···
 followed by a list of tests that are run. All of them should be passing.
 
 .. note::
-   Because it is building a lot of sources for the first time, the ``Building
-   kunit kernel`` step may take a while.
+	Because it is building a lot of sources for the first time, the
+	``Building KUnit kernel`` step may take a while.
 
 Writing your first test
 =======================
···
 
 .. code-block:: bash
 
-	./tools/testing/kunit/kunit.py
+	./tools/testing/kunit/kunit.py run
 
 You should see the following failure:
 

Documentation/dev-tools/kunit/usage.rst

···
 =============================
 
 This document is organized into two main sections: Testing and Isolating
-Behavior. The first covers what a unit test is and how to use KUnit to write
+Behavior. The first covers what unit tests are and how to use KUnit to write
 them. The second covers how to use KUnit to isolate code and make it possible
 to unit test code that was otherwise un-unit-testable.
 
···
 ~~~~~~~~~~~
 
 Now obviously one unit test isn't very helpful; the power comes from having
-many test cases covering all of your behaviors. Consequently it is common to
-have many *similar* tests; in order to reduce duplication in these closely
-related tests most unit testing frameworks provide the concept of a *test
-suite*, in KUnit we call it a *test suite*; all it is is just a collection of
-test cases for a unit of code with a set up function that gets invoked before
-every test cases and then a tear down function that gets invoked after every
-test case completes.
+many test cases covering all of a unit's behaviors. Consequently it is common
+to have many *similar* tests; in order to reduce duplication in these closely
+related tests most unit testing frameworks - including KUnit - provide the
+concept of a *test suite*. A *test suite* is just a collection of test cases
+for a unit of code with a set up function that gets invoked before every test
+case and then a tear down function that gets invoked after every test case
+completes.
 
 Example:
 
···
 .. note::
    A test case will only be run if it is associated with a test suite.
 
-For a more information on these types of things see the :doc:`api/test`.
+For more information on these types of things see the :doc:`api/test`.
 
 Isolating Behavior
 ==================
···
 		return count;
 	}
 
-	ssize_t fake_eeprom_write(struct eeprom *this, size_t offset, const char *buffer, size_t count)
+	ssize_t fake_eeprom_write(struct eeprom *parent, size_t offset, const char *buffer, size_t count)
 	{
 		struct fake_eeprom *this = container_of(parent, struct fake_eeprom, parent);
 
···
 By default KUnit uses UML as a way to provide dependencies for code under test.
 Under most circumstances KUnit's usage of UML should be treated as an
 implementation detail of how KUnit works under the hood. Nevertheless, there
-are instances where being able to run architecture specific code, or test
+are instances where being able to run architecture specific code or test
 against real hardware is desirable. For these reasons KUnit supports running on
 other architectures.
 
···
 .. important::
    Always prefer tests that run on UML to tests that only run under a particular
    architecture, and always prefer tests that run under QEMU or another easy
-   (and monitarily free) to obtain software environment to a specific piece of
+   (and monetarily free) to obtain software environment to a specific piece of
    hardware.
 
 Nevertheless, there are still valid reasons to write an architecture or hardware

fs/ext4/inode-test.c

···
  * For constructing the negative timestamp lower bound value.
  * binary: 10000000 00000000 00000000 00000000
  */
-#define LOWER_MSB_1 (-0x80000000L)
+#define LOWER_MSB_1 (-(UPPER_MSB_0) - 1L)  /* avoid overflow */
 /*
  * For constructing the negative timestamp upper bound value.
  * binary: 11111111 11111111 11111111 11111111

tools/testing/kunit/kunit_tool_test.py

···
 		timeout = 3453
 		kunit.main(['run', '--timeout', str(timeout)], self.linux_source_mock)
 		assert self.linux_source_mock.build_reconfig.call_count == 1
-		self.linux_source_mock.run_kernel.assert_called_once_with(timeout=timeout)
+		self.linux_source_mock.run_kernel.assert_called_once_with(build_dir=None, timeout=timeout)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 if __name__ == '__main__':

tools/testing/selftests/ftrace/test.d/ftrace/func-filter-stacktrace.tc

···
 # description: ftrace - stacktrace filter command
 # flags: instance
 
+[ ! -f set_ftrace_filter ] && exit_unsupported
+
 echo _do_fork:stacktrace >> set_ftrace_filter
 
 grep -q "_do_fork:stacktrace:unlimited" set_ftrace_filter

tools/testing/selftests/ftrace/test.d/ftrace/func_cpumask.tc

···
   exit_unresolved
 fi
 
+if ! grep -q "function" available_tracers ; then
+  echo "Function trace is not enabled"
+  exit_unsupported
+fi
+
 ORIG_CPUMASK=`cat tracing_cpumask`
 
 do_reset() {

tools/testing/selftests/ftrace/test.d/functions

···
 }
 
 reset_ftrace_filter() { # reset all triggers in set_ftrace_filter
+    if [ ! -f set_ftrace_filter ]; then
+      return 0
+    fi
     echo > set_ftrace_filter
     grep -v '^#' set_ftrace_filter | while read t; do
 	tr=`echo $t | cut -d: -f2`
···
     disable_events
     [ -f set_event_pid ] && echo > set_event_pid
     [ -f set_ftrace_pid ] && echo > set_ftrace_pid
-    [ -f set_ftrace_filter ] && echo | tee set_ftrace_*
+    [ -f set_ftrace_notrace ] && echo > set_ftrace_notrace
     [ -f set_graph_function ] && echo | tee set_graph_*
     [ -f stack_trace_filter ] && echo > stack_trace_filter
     [ -f kprobe_events ] && echo > kprobe_events

tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc

···
   test $N -eq 256 && break
 done
 
-L=`wc -l kprobe_events`
-if [ $L -ne $N ]; then
-  echo "The number of kprobes events ($L) is not $N"
+L=`cat kprobe_events | wc -l`
+if [ $L -ne 256 ]; then
+  echo "The number of kprobes events ($L) is not 256"
   exit_fail
 fi
 

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-action-hist-xfail.tc

···
 
 echo "Test expected snapshot action failure"
 
-echo 'hist:keys=comm:onmatch(sched.sched_wakeup).snapshot()' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger && exit_fail
+echo 'hist:keys=comm:onmatch(sched.sched_wakeup).snapshot()' >> events/sched/sched_waking/trigger && exit_fail
 
 echo "Test expected save action failure"
 
-echo 'hist:keys=comm:onmatch(sched.sched_wakeup).save(comm,prio)' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger && exit_fail
+echo 'hist:keys=comm:onmatch(sched.sched_wakeup).save(comm,prio)' >> events/sched/sched_waking/trigger && exit_fail
 
 exit_xfail

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onchange-action-hist.tc

···
 
 echo "Test onchange action"
 
-echo 'hist:keys=comm:newprio=prio:onchange($newprio).save(comm,prio) if comm=="ping"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
+echo 'hist:keys=comm:newprio=prio:onchange($newprio).save(comm,prio) if comm=="ping"' >> events/sched/sched_waking/trigger
 
 ping $LOCALHOST -c 3
 nice -n 1 ping $LOCALHOST -c 3

tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-snapshot-action-hist.tc

···
 
 echo "Test snapshot action"
 
-echo 1 > /sys/kernel/debug/tracing/events/sched/enable
+echo 1 > events/sched/enable
 
-echo 'hist:keys=comm:newprio=prio:onchange($newprio).save(comm,prio):onchange($newprio).snapshot() if comm=="ping"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
+echo 'hist:keys=comm:newprio=prio:onchange($newprio).save(comm,prio):onchange($newprio).snapshot() if comm=="ping"' >> events/sched/sched_waking/trigger
 
 ping $LOCALHOST -c 3
 nice -n 1 ping $LOCALHOST -c 3

tools/testing/selftests/kselftest/module.sh

···
 #
 #   #!/bin/sh
 #   SPDX-License-Identifier: GPL-2.0+
-#   $(dirname $0)/../kselftest_module.sh "description" module_name
+#   $(dirname $0)/../kselftest/module.sh "description" module_name
 #
 # Example: tools/testing/selftests/lib/printf.sh
 

tools/testing/selftests/kselftest/prefix.pl

···
 # Prefix all lines with "# ", unbuffered. Command being piped in may need
 # to have unbuffering forced with "stdbuf -i0 -o0 -e0 $cmd".
 use strict;
+use IO::Handle;
 
 binmode STDIN;
 binmode STDOUT;

tools/testing/selftests/kselftest/runner.sh

···
 		if [ $rc -eq $skip_rc ]; then	\
 			echo "not ok $test_num $TEST_HDR_MSG # SKIP"
 		elif [ $rc -eq $timeout_rc ]; then \
+			echo "#"
 			echo "not ok $test_num $TEST_HDR_MSG # TIMEOUT"
 		else
 			echo "not ok $test_num $TEST_HDR_MSG # exit=$rc"

tools/testing/selftests/safesetid/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for mount selftests.
-CFLAGS = -Wall -lcap -O2
+CFLAGS = -Wall -O2
+LDLIBS = -lcap
 
-TEST_PROGS := run_tests.sh
+TEST_PROGS := safesetid-test.sh
 TEST_GEN_FILES := safesetid-test
 
 include ../lib.mk

tools/testing/selftests/safesetid/safesetid-test.c

···
 	}
 
 	if (cpid == 0) {	    /* Code executed by child */
-		setuid(child_uid);
+		if (setuid(child_uid) < 0)
+			exit(EXIT_FAILURE);
 		if (getuid() == child_uid)
 			exit(EXIT_SUCCESS);
 		else
···
 
 	// First test to make sure we can write userns mappings from a user
 	// that doesn't have any restrictions (as long as it has CAP_SETUID);
-	setuid(NO_POLICY_USER);
-	setgid(NO_POLICY_USER);
+	if (setuid(NO_POLICY_USER) < 0)
+		die("Error with set uid(%d)\n", NO_POLICY_USER);
+	if (setgid(NO_POLICY_USER) < 0)
+		die("Error with set gid(%d)\n", NO_POLICY_USER);
 
 	// Take away all but setid caps
 	drop_caps(true);
···
 		die("test_userns failed when it should work\n");
 	}
 
-	setuid(RESTRICTED_PARENT);
-	setgid(RESTRICTED_PARENT);
+	if (setuid(RESTRICTED_PARENT) < 0)
+		die("Error with set uid(%d)\n", RESTRICTED_PARENT);
+	if (setgid(RESTRICTED_PARENT) < 0)
+		die("Error with set gid(%d)\n", RESTRICTED_PARENT);
 
 	test_setuid(ROOT_USER, false);
 	test_setuid(ALLOWED_CHILD1, true);