The step_after_suspend_test verifies that the system successfully
suspended and resumed by setting a timerfd and checking whether the
timer fully expired. However, this method is unreliable due to timing
races.
In practice, the system may take time to enter suspend, during which the
timer may expire just before or during the transition. As a result,
the remaining time after resume may show non-zero nanoseconds, even if
suspend/resume completed successfully. This leads to false test failures.
Replace the timer-based check with a read from
/sys/power/suspend_stats/success. This counter is incremented only
after a full suspend/resume cycle, providing a reliable and race-free
indicator.
Also remove the unused file descriptor for /sys/power/state, which
remained after switching to a system() call to trigger suspend [1].
[1] https://lore.kernel.org/all/20240930224025.2858767-1-yifei.l.liu@oracle.com/
Link: https://lore.kernel.org/r/20250626191626.36794-1-moonhee.lee.ca@gmail.com
Fixes: c66be905cd ("selftests: breakpoints: use remaining time to check if suspend succeed")
Signed-off-by: Moon Hee Lee <moonhee.lee.ca@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
step_after_suspend_test fails with device busy error while
writing to /sys/power/state to start suspend. The test believes
it failed to enter suspend state with
$ sudo ./step_after_suspend_test
TAP version 13
Bail out! Failed to enter Suspend state
However, in the kernel message, I indeed see the system get
suspended and then wake up later.
[611172.033108] PM: suspend entry (s2idle)
[611172.044940] Filesystems sync: 0.006 seconds
[611172.052254] Freezing user space processes
[611172.059319] Freezing user space processes completed (elapsed 0.001 seconds)
[611172.067920] OOM killer disabled.
[611172.072465] Freezing remaining freezable tasks
[611172.080332] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[611172.089724] printk: Suspending console(s) (use no_console_suspend to debug)
[611172.117126] serial 00:03: disabled
some other hardware get reconnected
[611203.136277] OOM killer enabled.
[611203.140637] Restarting tasks ...
[611203.141135] usb 1-8.1: USB disconnect, device number 7
[611203.141755] done.
[611203.155268] random: crng reseeded on system resumption
[611203.162059] PM: suspend exit
After investigation, I noticed that for the code block
if (write(power_state_fd, "mem", strlen("mem")) != strlen("mem"))
ksft_exit_fail_msg("Failed to enter Suspend state\n");
The write will return -1 and errno is set to 16 (device busy).
It should be caused by the write function is not successfully returned
before the system suspend and the return value get messed when waking up.
As a result, It may be better to check the time passed of those few
instructions to determine whether the suspend is executed correctly for
it is pretty hard to execute those few lines for 5 seconds.
The timer to wake up the system is set to expire after 5 seconds and
no re-arm. If the timer remaining time is 0 second and 0 nano secomd,
it means the timer expired and wake the system up. Otherwise, the system
could be considered to enter the suspend state failed if there is any
remaining time.
After appling this patch, the test would not fail for it believes the
system does not go to suspend by mistake. It now could continue to the
rest part of the test after suspend.
Fixes: bfd092b8c2 ("selftests: breakpoint: add step_after_suspend_test")
Reported-by: Sinadin Shan <sinadin.shan@oracle.com>
Signed-off-by: Yifei Liu <yifei.l.liu@oracle.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This variable is never referenced in the code, just remove them
that this problem was discovered by reading the code
Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
In the function 'tools/testing/selftests/breakpoints/run_test' within
step_after_suspend_test.c, the ksft_print_msg function call incorrectly
used '$s' as a format specifier. This commit corrects this typo to use the
proper '%s' format specifier, ensuring the error message from
waitpid() is correctly displayed.
The issue manifested as a compilation warning (too many arguments
for format [-Wformat-extra-args]), potentially obscuring actual
runtime errors and complicating debugging processes.
This fix enhances the clarity of error messages during test failures
and ensures compliance with standard C format string conventions.
Signed-off-by: angquan yu <angquan21@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Calling ksft_exit_skip after ksft_set_plan results in executing fewer tests
than planned. Use ksft_test_result_skip for the individual tests.
The call in suspend() is fine, but ksft_set_plan should be after it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The computation of the test plan uses the available_cpus bitset
before calling sched_getaffinity to fill it in. The resulting
plan is bogus, fix it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Based on 1 normalized pattern(s):
this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 285 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The test plan for TAP needs to be declared immediately after the header.
This adds the test plan API to kselftest.h and updates all callers to
declare their expected test counts.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
When step_after_suspend_test is skipped because of unmet dependencies
and/or unsupported configuration, it exits with error which is treated
as a fail by the Kselftest framework. This leads to false negative result
even when the test could not be run.
Change it to return kselftest skip code when a test gets skipped to clearly
report that the test could not be run.
Change it to use ksft_exit_skip() when a non-root user runs the test and
add an explicit check for root and a clear message, instead of failing
the test when /sys/power/state file open fails.
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Use ksft_* var arg msg to include strerror() info. in test output and
simplify test_result and exit_* using var arg msg api.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Make the three tests that did use the old ksft_ext_skip()
(breakpoints/breakpoint_test_arm64, breakpoints/step_after_suspend_test,
and membarrier_test) use the new one, with an output for the
reason for skipping all the tests.
Signed-off-by: Paul Elder <paul.elder@pitt.edu>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Make the step_after_suspend test output in the TAP13 format by using the
TAP13 output functions defined in kselftest.h
Signed-off-by: Paul Elder <paul.elder@pitt.edu>
Signed-off-by: Alice Ferrazzi <alice.ferrazzi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Commit e56d82a116 ("arm64: cpu hotplug: ensure we mask out
CPU_TASKS_FROZEN in notifiers") fixed a long-standing ARM64 bug that
broke single-stepping after a suspend/resume cycle. Add a kernel
selftest to make sure this doesn't regress or affect other platforms.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
