| Message ID | 20240502210926.145539-1-mic@digikod.net |
|---|---|
| Headers | show |
| Series | Fix Kselftest's vfork() side effects | expand |
On Thu, May 02, 2024 at 03:45:22PM GMT, Sean Christopherson wrote: > On Thu, May 02, 2024, Mickaël Salaün wrote: > > @@ -462,8 +462,10 @@ static inline pid_t clone3_vfork(void) > > munmap(teardown, sizeof(*teardown)); \ > > if (self && fixture_name##_teardown_parent) \ > > munmap(self, sizeof(*self)); \ > > - if (!WIFEXITED(status) && WIFSIGNALED(status)) \ > > - /* Forward signal to __wait_for_test(). */ \ > > + /* Forward exit codes and signals to __wait_for_test(). */ \ > > + if (WIFEXITED(status)) \ > > + _exit(_metadata->exit_code); \ > > This needs to be: > > if (WIFEXITED(status)) \ > _exit(WEXITSTATUS(status)); \ > > otherwise existing tests that communicate FAIL/SKIP via exit() continue to yield > exit(0) and thus false passes. Yes of course. > > If that conflicts with tests that want to communicate via _metadata->exit_code, > then maybe this? > > if (WIFEXITED(status)) \ > _exit(WEXITSTATUS(status) ?: _metadata->exit_code); \ I prefer this approach handling failed expectations in the fixture teardown too. However, the direct call to _exit() doesn't handle failed asserts. I'll fix that. > > Or I suppose _metadata->exit_code could have priority, but that seems weird to > me, e.g. if a test sets exit_code and then explodes, it seems like the explosion > should be reported. > > > + if (WIFSIGNALED(status)) \ > > kill(getpid(), WTERMSIG(status)); \ > > __test_check_assert(_metadata); \ > > } \ > > -- > > 2.45.0 > > >
Hi, As reported by Kernel Test Robot [1], some pidfd tests fail. This is due to the use of vfork() which introduced some side effects. Similarly, while making it more generic, a previous commit made some Landlock file system tests flaky, and subject to the host's file system mount configuration. This series fixes all these side effects by replacing vfork() with clone3() and CLONE_VFORK, which is cleaner (no arbitrary shared memory) and makes the Kselftest framework more robust. I tried different approaches and I found this one to be the cleaner and less invasive for current test cases. This fourth series add a patch from Sean Christopherson that fixes KVM tests. I successfully ran the following tests (using TEST_F and fork/clone/clone3) with this series: - landlock:fs_test - landlock:net_test - landlock:ptrace_test - move_mount_set_group:move_mount_set_group_test - net/af_unix:scm_pidfd - perf_events:remove_on_exec - pidfd:pidfd_getfd_test - pidfd:pidfd_setns_test - seccomp:seccomp_bpf - user_events:abi_test [1] https://lore.kernel.org/oe-lkp/202403291015.1fcfa957-oliver.sang@intel.com Previous versions: v1: https://lore.kernel.org/r/20240426172252.1862930-1-mic@digikod.net v2: https://lore.kernel.org/r/20240429130931.2394118-1-mic@digikod.net v3: https://lore.kernel.org/r/20240429191911.2552580-1-mic@digikod.net Regards, Mickaël Salaün (10): selftests/pidfd: Fix config for pidfd_setns_test selftests/landlock: Fix FS tests when run on a private mount point selftests/harness: Fix fixture teardown selftests/harness: Fix interleaved scheduling leading to race conditions selftests/landlock: Do not allocate memory in fixture data selftests/harness: Constify fixture variants selftests/pidfd: Fix wrong expectation selftests/harness: Share _metadata between forked processes selftests/harness: Fix vfork() side effects selftests/harness: Fix TEST_F()'s exit codes tools/testing/selftests/kselftest_harness.h | 123 +++++++++++++----- tools/testing/selftests/landlock/fs_test.c | 83 +++++++----- tools/testing/selftests/pidfd/config | 2 + .../selftests/pidfd/pidfd_setns_test.c | 2 +- 4 files changed, 141 insertions(+), 69 deletions(-) base-commit: e67572cd2204894179d89bd7b984072f19313b03