kernel/linux.git/lib/kunit/try-catch.c, branch v6.18.21

kunit: Adjust kunit_test timeout based on test_{suite,case} speed

2025-06-25T02:47:39+00:00

Currently, the in-kernel kunit test case timeout is 300 seconds. (There is a separate timeout mechanism for the whole test execution in kunit.py, but that's unrelated.) However, tests marked 'slow' or 'very slow' may timeout, particularly on slower machines. Implement a multiplier to the test-case timeout, so that slower tests have longer to complete: - DEFAULT -> 1x default timeout - KUNIT_SPEED_SLOW -> 3x default timeout - KUNIT_SPEED_VERY_SLOW -> 12x default timeout A further change is planned to allow user configuration of the default/base timeout to allow people with faster or slower machines to adjust these to their use-cases. Link: https://lore.kernel.org/r/20250614084711.2654593-2-davidgow@google.com Signed-off-by: Ujwal Jain Co-developed-by: David Gow Signed-off-by: David Gow Reviewed-by: Rae Moar Signed-off-by: Shuah Khan

kunit: Fix race condition in try-catch completion

2024-05-06T20:22:02+00:00

KUnit's try-catch infrastructure now uses vfork_done, which is always set to a valid completion when a kthread is created, but which is set to NULL once the thread terminates. This creates a race condition, where the kthread exits before we can wait on it. Keep a copy of vfork_done, which is taken before we wake_up_process() and so valid, and wait on that instead. Fixes: 93533996100c ("kunit: Handle test faults") Reported-by: Linux Kernel Functional Testing Closes: https://lore.kernel.org/lkml/20240410102710.35911-1-naresh.kamboju@linaro.org/ Tested-by: Linux Kernel Functional Testing Acked-by: Mickaël Salaün Signed-off-by: David Gow Reviewed-by: Rae Moar Tested-by: Miguel Ojeda Signed-off-by: Shuah Khan

kunit: Print last test location on fault

2024-05-06T20:22:02+00:00

This helps identify the location of test faults with opportunistic calls to _KUNIT_SAVE_LOC(). This can be useful while writing tests or debugging them. It is possible to call KUNIT_SUCCESS() to explicit save last location. Cc: Brendan Higgins Cc: David Gow Cc: Rae Moar Cc: Shuah Khan Reviewed-by: Kees Cook Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20240408074625.65017-7-mic@digikod.net Signed-off-by: Shuah Khan

kunit: Handle test faults

2024-05-06T20:22:02+00:00

Previously, when a kernel test thread crashed (e.g. NULL pointer dereference, general protection fault), the KUnit test hanged for 30 seconds and exited with a timeout error. Fix this issue by waiting on task_struct->vfork_done instead of the custom kunit_try_catch.try_completion, and track the execution state by initially setting try_result with -EINTR and only setting it to 0 if the test passed. Fix kunit_generic_run_threadfn_adapter() signature by returning 0 instead of calling kthread_complete_and_exit(). Because thread's exit code is never checked, always set it to 0 to make it clear. To make this explicit, export kthread_exit() for KUnit tests built as module. Fix the -EINTR error message, which couldn't be reached until now. This is tested with a following patch. Cc: Brendan Higgins Cc: Eric W. Biederman Cc: Shuah Khan Reviewed-by: Kees Cook Reviewed-by: David Gow Tested-by: Rae Moar Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20240408074625.65017-5-mic@digikod.net Signed-off-by: Shuah Khan

kunit: Fix timeout message

2024-05-06T20:22:02+00:00

The exit code is always checked, so let's properly handle the -ETIMEDOUT error code. Cc: Brendan Higgins Cc: Shuah Khan Reviewed-by: Kees Cook Reviewed-by: David Gow Reviewed-by: Rae Moar Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20240408074625.65017-4-mic@digikod.net Signed-off-by: Shuah Khan

kunit: Fix kthread reference

2024-05-06T20:22:02+00:00

There is a race condition when a kthread finishes after the deadline and before the call to kthread_stop(), which may lead to use after free. Cc: Brendan Higgins Cc: Shuah Khan Reviewed-by: Kees Cook Fixes: adf505457032 ("kunit: fix UAF when run kfence test case test_gfpzero") Reviewed-by: David Gow Reviewed-by: Rae Moar Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20240408074625.65017-3-mic@digikod.net Signed-off-by: Shuah Khan

kunit: Handle thread creation error

2024-05-06T20:22:02+00:00

Previously, if a thread creation failed (e.g. -ENOMEM), the function was called (kunit_catch_run_case or kunit_catch_run_case_cleanup) without marking the test as failed. Instead, fill try_result with the error code returned by kthread_run(), which will mark the test as failed and print "internal error occurred...". Cc: Brendan Higgins Cc: Shuah Khan Reviewed-by: Kees Cook Reviewed-by: Rae Moar Reviewed-by: David Gow Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20240408074625.65017-2-mic@digikod.net Signed-off-by: Shuah Khan

kunit: make kunit_test_timeout compatible with comment

2022-03-22T22:57:11+00:00

In function kunit_test_timeout, it is declared "300 * MSEC_PER_SEC" represent 5min. However, it is wrong when dealing with arm64 whose default HZ = 250, or some other situations. Use msecs_to_jiffies to fix this, and kunit_test_timeout will work as desired. Link: https://lkml.kernel.org/r/20220309083753.1561921-3-liupeng256@huawei.com Fixes: 5f3e06208920 ("kunit: test: add support for test abort") Signed-off-by: Peng Liu Reviewed-by: Marco Elver Reviewed-by: Daniel Latypov Reviewed-by: Brendan Higgins Tested-by: Brendan Higgins Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Wang Kefeng Cc: David Gow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kunit: fix UAF when run kfence test case test_gfpzero

2022-03-22T22:57:11+00:00

Patch series "kunit: fix a UAF bug and do some optimization", v2. This series is to fix UAF (use after free) when running kfence test case test_gfpzero, which is time costly. This UAF bug can be easily triggered by setting CONFIG_KFENCE_NUM_OBJECTS = 65535. Furthermore, some optimization for kunit tests has been done. This patch (of 3): Kunit will create a new thread to run an actual test case, and the main process will wait for the completion of the actual test thread until overtime. The variable "struct kunit test" has local property in function kunit_try_catch_run, and will be used in the test case thread. Task kunit_try_catch_run will free "struct kunit test" when kunit runs overtime, but the actual test case is still run and an UAF bug will be triggered. The above problem has been both observed in a physical machine and qemu platform when running kfence kunit tests. The problem can be triggered when setting CONFIG_KFENCE_NUM_OBJECTS = 65535. Under this setting, the test case test_gfpzero will cost hours and kunit will run to overtime. The follows show the panic log. BUG: unable to handle page fault for address: ffffffff82d882e9 Call Trace: kunit_log_append+0x58/0xd0 ... test_alloc.constprop.0.cold+0x6b/0x8a [kfence_test] test_gfpzero.cold+0x61/0x8ab [kfence_test] kunit_try_run_case+0x4c/0x70 kunit_generic_run_threadfn_adapter+0x11/0x20 kthread+0x166/0x190 ret_from_fork+0x22/0x30 Kernel panic - not syncing: Fatal exception Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 To solve this problem, the test case thread should be stopped when the kunit frame runs overtime. The stop signal will send in function kunit_try_catch_run, and test_gfpzero will handle it. Link: https://lkml.kernel.org/r/20220309083753.1561921-1-liupeng256@huawei.com Link: https://lkml.kernel.org/r/20220309083753.1561921-2-liupeng256@huawei.com Signed-off-by: Peng Liu Reviewed-by: Marco Elver Reviewed-by: Brendan Higgins Tested-by: Brendan Higgins Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Wang Kefeng Cc: Daniel Latypov Cc: David Gow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

exit: Rename complete_and_exit to kthread_complete_and_exit

2021-12-13T18:04:45+00:00

Update complete_and_exit to call kthread_exit instead of do_exit. Change the name to reflect this change in functionality. All of the users of complete_and_exit are causing the current kthread to exit so this change makes it clear what is happening. Move the implementation of kthread_complete_and_exit from kernel/exit.c to to kernel/kthread.c. As this function is kthread specific it makes most sense to live with the kthread functions. There are no functional change. Signed-off-by: "Eric W. Biederman"