Re: [RFC v2 1/4] kunit: Add 'kunit_shutdown' option

From: Daniel Latypov
Date: Thu Apr 29 2021 - 17:53:04 EST


On Thu, Apr 29, 2021 at 1:51 PM Brendan Higgins
<brendanhiggins@xxxxxxxxxx> wrote:
>
> From: David Gow <davidgow@xxxxxxxxxx>
>
> Add a new kernel command-line option, 'kunit_shutdown', which allows the
> user to specify that the kernel poweroff, halt, or reboot after
> completing all KUnit tests; this is very handy for running KUnit tests
> on UML or a VM so that the UML/VM process exits cleanly immediately
> after running all tests without needing a special initramfs.
>
> Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
> Signed-off-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
> Reviewed-by: Stephen Boyd <sboyd@xxxxxxxxxx>

Tested-By: Daniel Latypov <dlatypov@xxxxxxxxxx>

Testing this out, I think this also helps fix coverage on UML.
I used to have to hack in something like this:

diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index 07327425d06e..e13763faedd9 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -146,7 +146,7 @@ void os_dump_core(void)
while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
os_kill_ptraced_process(pid, 0);

- uml_abort();
+ exit(127);
}

void um_early_printk(const char *s, unsigned int n)

And afaict, this patch removes the need to do so.
(But I made a few mistakes when initially trying to test that out, so
I'm not 100% certain I didn't make another).

> ---
> lib/kunit/executor.c | 20 ++++++++++++++++++++
> tools/testing/kunit/kunit_kernel.py | 2 +-
> tools/testing/kunit/kunit_parser.py | 2 +-
> 3 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
> index 15832ed446685..7db619624437c 100644
> --- a/lib/kunit/executor.c
> +++ b/lib/kunit/executor.c
> @@ -1,5 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
>
> +#include <linux/reboot.h>
> #include <kunit/test.h>
> #include <linux/glob.h>
> #include <linux/moduleparam.h>
> @@ -18,6 +19,9 @@ module_param(filter_glob, charp, 0);
> MODULE_PARM_DESC(filter_glob,
> "Filter which KUnit test suites run at boot-time, e.g. list*");
>
> +static char *kunit_shutdown;
> +core_param(kunit_shutdown, kunit_shutdown, charp, 0644);
> +
> static struct kunit_suite * const *
> kunit_filter_subsuite(struct kunit_suite * const * const subsuite)
> {
> @@ -82,6 +86,20 @@ static struct suite_set kunit_filter_suites(void)
> return filtered;
> }
>
> +static void kunit_handle_shutdown(void)
> +{
> + if (!kunit_shutdown)
> + return;
> +
> + if (!strcmp(kunit_shutdown, "poweroff"))
> + kernel_power_off();
> + else if (!strcmp(kunit_shutdown, "halt"))
> + kernel_halt();
> + else if (!strcmp(kunit_shutdown, "reboot"))
> + kernel_restart(NULL);
> +
> +}
> +
> static void kunit_print_tap_header(struct suite_set *suite_set)
> {
> struct kunit_suite * const * const *suites, * const *subsuite;
> @@ -112,6 +130,8 @@ int kunit_run_all_tests(void)
> kfree(suite_set.start);
> }
>
> + kunit_handle_shutdown();
> +
> return 0;
> }
>
> diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
> index f309a33256cd3..7d5b77967d48f 100644
> --- a/tools/testing/kunit/kunit_kernel.py
> +++ b/tools/testing/kunit/kunit_kernel.py
> @@ -206,7 +206,7 @@ class LinuxSourceTree(object):
> def run_kernel(self, args=None, build_dir='', filter_glob='', timeout=None) -> Iterator[str]:
> if not args:
> args = []
> - args.extend(['mem=1G', 'console=tty'])
> + args.extend(['mem=1G', 'console=tty','kunit_shutdown=halt'])
> if filter_glob:
> args.append('kunit.filter_glob='+filter_glob)
> self._ops.linux_bin(args, timeout, build_dir)
> diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
> index e8bcc139702e2..8d8d4d70b39dd 100644
> --- a/tools/testing/kunit/kunit_parser.py
> +++ b/tools/testing/kunit/kunit_parser.py
> @@ -49,7 +49,7 @@ class TestStatus(Enum):
>
> kunit_start_re = re.compile(r'TAP version [0-9]+$')
> kunit_end_re = re.compile('(List of all partitions:|'
> - 'Kernel panic - not syncing: VFS:)')
> + 'Kernel panic - not syncing: VFS:|reboot: System halted)')
>
> def isolate_kunit_output(kernel_output) -> Iterator[str]:
> started = False
> --
> 2.31.1.498.g6c1eba8ee3d-goog
>