Re: [linus:master] [selftests] 465b05bae5: kernel-selftests.landlock.audit_test.audit.tsync_override_log_subdomains_off.fail

Re: [linus:master] [selftests] 465b05bae5: kernel-selftests.landlock.audit_test.audit.tsync_override_log_subdomains_off.fail

[Thomas Weißschuh]

Hi Mickaël and Günther,

I received the following report about a failing landlock selftest from
the 0day bot.

On Mon, May 11, 2026 at 10:15:00PM +0800, kernel test robot wrote:
> kernel test robot noticed "kernel-selftests.landlock.audit_test.audit.tsync_override_log_subdomains_off.fail" on:
> 
> commit: 465b05bae5ac553c13315681c1490dc565337771 ("selftests: harness: Restore order of test functions")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> 
> 
> in testcase: kernel-selftests
> version: kernel-selftests-x86_64-9f2693489ef8-1_20260201
> with following parameters:
> 
> 	group: landlock
> 
> config: x86_64-rhel-9.4-kselftests
> compiler: gcc-14
> test machine: 16 threads Intel(R) Core(TM) i7-13620H (Raptor Lake) with 32G memory
> 
> (please refer to attached dmesg/kmsg for entire log/backtrace)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202605111649.a8b30a62-lkp@intel.com

I was unable to run the landlock selftests myself, on my machines they are
failing at runtime with all kinds of colorful errors. Are the requirements
explained somewhere?

> # #  RUN           audit.tsync_override_log_subdomains_off ...
> # # audit_test.c:591:tsync_override_log_subdomains_off:Expected 0 (0) == matches_log_signal(_metadata, self->audit_fd, child_data.parent_pid, NULL) (-11)

This error number means "EAGAIN 11 Resource temporarily unavailable",
so it could be a temporary error.

Can you reproduce this issue? Is it really dependent on my patch as
blamed above? If so, does the selftest rely on the previous, incorrect order?

> # # tsync_override_log_subdomains_off: Test failed
> # #          FAIL  audit.tsync_override_log_subdomains_off
> # not ok 5 audit.tsync_override_log_subdomains_off


Thomas

Re: [linus:master] [selftests] 465b05bae5: kernel-selftests.landlock.audit_test.audit.tsync_override_log_subdomains_off.fail

[Mickaël Salaün]

Hi Thomas,

Thanks for the report.

On Tue, May 12, 2026 at 11:27:42AM +0200, Thomas Weißschuh wrote:
> Hi Mickaël and Günther,
> 
> I received the following report about a failing landlock selftest from
> the 0day bot.
> 
> On Mon, May 11, 2026 at 10:15:00PM +0800, kernel test robot wrote:
> > kernel test robot noticed "kernel-selftests.landlock.audit_test.audit.tsync_override_log_subdomains_off.fail" on:
> > 
> > commit: 465b05bae5ac553c13315681c1490dc565337771 ("selftests: harness: Restore order of test functions")
> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> > 
> > 
> > in testcase: kernel-selftests
> > version: kernel-selftests-x86_64-9f2693489ef8-1_20260201
> > with following parameters:
> > 
> > 	group: landlock

This group is correct but I'm wondering why the maintainer (me) and the
reviewer (Günther) weren't in Cc.

What do we need to do to subscribe to such report?  Why isn't
automatically inferred from the MAINTAINER file?

> > 
> > config: x86_64-rhel-9.4-kselftests
> > compiler: gcc-14
> > test machine: 16 threads Intel(R) Core(TM) i7-13620H (Raptor Lake) with 32G memory
> > 
> > (please refer to attached dmesg/kmsg for entire log/backtrace)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <oliver.sang@intel.com>
> > | Closes: https://lore.kernel.org/oe-lkp/202605111649.a8b30a62-lkp@intel.com
> 
> I was unable to run the landlock selftests myself, on my machines they are
> failing at runtime with all kinds of colorful errors. Are the requirements
> explained somewhere?

I'm curious about the errors you get.  They are standard kselftests that
should work following this workflow:

  make TARGETS=landlock O=build kselftest-gen_tar

and then running ./build/kselftests/kselftest_install/run_kselftest.sh
as root in a VM.  The required kernel configuration is listed in
tools/testing/selftests/landlock/config

To make it easier, we wrote a wrapper to test everything with UML:
https://github.com/landlock-lsm/landlock-test-tools (see check-linux.sh)

> 
> > # #  RUN           audit.tsync_override_log_subdomains_off ...
> > # # audit_test.c:591:tsync_override_log_subdomains_off:Expected 0 (0) == matches_log_signal(_metadata, self->audit_fd, child_data.parent_pid, NULL) (-11)
> 
> This error number means "EAGAIN 11 Resource temporarily unavailable",
> so it could be a temporary error.

Yes, the test is flaky under pressure.

> 
> Can you reproduce this issue? Is it really dependent on my patch as
> blamed above? If so, does the selftest rely on the previous, incorrect order?

I don't think it directly depends on your patch but it might be a side
effect.  Anyway, I've been working on fixing this kind of issue and just
sent a fix:
https://lore.kernel.org/r/20260513105112.140137-2-mic@digikod.net

> 
> > # # tsync_override_log_subdomains_off: Test failed
> > # #          FAIL  audit.tsync_override_log_subdomains_off
> > # not ok 5 audit.tsync_override_log_subdomains_off
> 
> 
> Thomas