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From: "lizhijian@fujitsu.com" <lizhijian@fujitsu.com>
To: Christian Brauner <christian.brauner@ubuntu.com>,
	"lizhijian@fujitsu.com" <lizhijian@fujitsu.com>
Cc: "linux-kselftest@vger.kernel.org"
	<linux-kselftest@vger.kernel.org>,
	"shuah@kernel.org" <shuah@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Will Drewry <wad@chromium.org>,
	Christian Brauner <christian@brauner.io>,
	Philip Li <philip.li@intel.com>,
	"xuyang2018.jy@fujitsu.com" <xuyang2018.jy@fujitsu.com>
Subject: Re: [PATCH 1/2] kselftest: signal all child processes
Date: Fri, 29 Oct 2021 08:41:47 +0000	[thread overview]
Message-ID: <b73d003a-efc6-7c33-f213-e9cdb925f8b4@fujitsu.com> (raw)
In-Reply-To: <20211029083110.syhqfc3ivaj53ygl@wittgenstein>



On 29/10/2021 16:31, Christian Brauner wrote:
> On Fri, Oct 29, 2021 at 10:45:27AM +0800, Li Zhijian wrote:
>> We have some many cases that will create child process as well, such as
>> pidfd_wait. Previously, we will signal/kill the parent process when it
>> is time out, but this signal will not be sent to its child process. In
>> such case, if child process doesn't terminate itself, ksefltest framework
>> will hang forever.
>>
>> below ps tree show the situation when ksefltest is blocking:
>> root      1172  0.0  0.0   5996  2500 ?        S    07:03   0:00  \_ /bin/bash /lkp/lkp/src/tests/kernel-selftests
>> root      1216  0.0  0.0   4392  1976 ?        S    07:03   0:00      \_ make run_tests -C pidfd
>> root      1218  0.0  0.0   2396  1652 ?        S    07:03   0:00          \_ /bin/sh -c BASE_DIR="/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests"; . /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/kselftest/runner.sh; if [ "X" != "X" ]; then per_test_logging=1; fi; run_many  /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_fdinfo_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_open_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_poll_test /usr/src/perf_selftests-x86_64-rhel-8.
>> root     12491  0.0  0.0   2396   132 ?        S    07:03   0:00              \_ /bin/sh -c BASE_DIR="/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests"; . /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/kselftest/runner.sh; if [ "X" != "X" ]; then per_test_logging=1; fi; run_many  /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_fdinfo_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_open_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_poll_test /usr/src/perf_selftests-x86_64-rhe
>> root     12492  0.0  0.0   2396   132 ?        S    07:03   0:00                  \_ /bin/sh -c BASE_DIR="/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests"; . /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/kselftest/runner.sh; if [ "X" != "X" ]; then per_test_logging=1; fi; run_many  /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_fdinfo_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_open_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_poll_test /usr/src/perf_selftests-x86_64
>> root     12493  0.0  0.0   2396   132 ?        S    07:03   0:00                      \_ /bin/sh -c BASE_DIR="/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests"; . /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/kselftest/runner.sh; if [ "X" != "X" ]; then per_test_logging=1; fi; run_many  /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_fdinfo_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_open_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_poll_test /usr/src/perf_selftests-x8
>> root     12496  0.0  0.0   2396   132 ?        S    07:03   0:00                          \_ /bin/sh -c BASE_DIR="/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests"; . /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/kselftest/runner.sh; if [ "X" != "X" ]; then per_test_logging=1; fi; run_many  /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_fdinfo_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_open_test /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/pidfd/pidfd_poll_test /usr/src/perf_selftest
>> root     12498  0.0  0.0  10564  6116 ?        S    07:03   0:00                              \_ perl /usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-519d81956ee277b4419c723adfb154603c2565ba/tools/testing/selftests/kselftest/prefix.pl
>> root     12503  0.0  0.0   2452   112 ?        T    07:03   0:00 ./pidfd_wait
>> root     12621  0.0  0.0   2372  1600 ?        SLs  07:04   0:00 /usr/sbin/watchdog
>> root     19438  0.0  0.0    992    60 ?        Ss   07:39   0:00 /lkp/lkp/src/bin/event/wakeup activate-monitor
>>
>> Here we group all its child processes so that kill() can signal all of
>> them in timeout.
>>
>> CC: Kees Cook <keescook@chromium.org>
>> CC: Andy Lutomirski <luto@amacapital.net>
>> CC: Will Drewry <wad@chromium.org>
>> CC: Shuah Khan <shuah@kernel.org>
>> CC: Christian Brauner <christian@brauner.io>
>> CC: Philip Li <philip.li@intel.com>
>> Suggested-by: yang xu <xuyang2018.jy@cn.fujitsu.com>
>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>> ---
> Seems sensible. Is it guaranteed that t->pid is neither 0 nor 1?
that's true, we fire the timer(reach here) only if fork() succeeds.


Thanks
Zhijian


>   If not
> then maybe sanity check t->pid at least for not being 1 as negating that
> would mean "signal everything that you have permission to signal". :)
>
> Otherwise,
> Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
>
>>   tools/testing/selftests/kselftest_harness.h | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
>> index ae0f0f33b2a6..c7251396e7ee 100644
>> --- a/tools/testing/selftests/kselftest_harness.h
>> +++ b/tools/testing/selftests/kselftest_harness.h
>> @@ -875,7 +875,8 @@ static void __timeout_handler(int sig, siginfo_t *info, void *ucontext)
>>   	}
>>   
>>   	t->timed_out = true;
>> -	kill(t->pid, SIGKILL);
>> +	// signal process group
>> +	kill(-(t->pid), SIGKILL);
>>   }
>>   
>>   void __wait_for_test(struct __test_metadata *t)
>> @@ -985,6 +986,7 @@ void __run_test(struct __fixture_metadata *f,
>>   		ksft_print_msg("ERROR SPAWNING TEST CHILD\n");
>>   		t->passed = 0;
>>   	} else if (t->pid == 0) {
>> +		setpgrp();
>>   		t->fn(t, variant);
>>   		if (t->skip)
>>   			_exit(255);
>> -- 
>> 2.33.0
>>
>>
>>
>


  reply	other threads:[~2021-10-29  8:41 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-29  2:45 Li Zhijian
2021-10-29  2:45 ` [PATCH 2/2] ksefltest: pidfd: Fix wait_states: Test terminated by timeout Li Zhijian
2021-10-29  8:32   ` Christian Brauner
2021-12-03 17:03     ` Shuah Khan
2021-12-06  6:01       ` lizhijian
2021-10-29  8:31 ` [PATCH 1/2] kselftest: signal all child processes Christian Brauner
2021-10-29  8:41   ` lizhijian [this message]
2021-12-03  3:05   ` lizhijian
2021-12-03 17:03     ` Shuah Khan
2021-12-17  9:35       ` lizhijian

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