Guenter Roeck reports that the new slub kunit tests added by commit 4e1c44b3db79 ("kunit, slub: add test_kfree_rcu() and test_leak_destroy()") cause a lockup on boot on several architectures when the kunit tests are configured to be built-in and not modules.
These tests invoke kfree_rcu() and kvfree_rcu_barrier() and boot sequence inspection showed the runner for built-in kunit tests kunit_run_all_tests() is called before setting system_state to SYSTEM_RUNNING and calling rcu_end_inkernel_boot(), so this seems like a likely cause. So while I was unable to reproduce the problem myself, moving the call to kunit_run_all_tests() a bit later in the boot seems to have fixed the lockup problem according to Guenter's limited testing.
No kunit tests should be broken by calling the built-in executor a bit later, as when compiled as modules, they are still executed even later than this.
Fixes: 4e1c44b3db79 ("kunit, slub: add test_kfree_rcu() and test_leak_destroy()") Reported-by: Guenter Roeck linux@roeck-us.net Closes: https://lore.kernel.org/all/6fcb1252-7990-4f0d-8027-5e83f0fb9409@roeck-us.ne... Cc: "Paul E. McKenney" paulmck@kernel.org Cc: Boqun Feng boqun.feng@gmail.com Cc: Uladzislau Rezki urezki@gmail.com Cc: rcu@vger.kernel.org Cc: Brendan Higgins brendanhiggins@google.com Cc: David Gow davidgow@google.com Cc: Rae Moar rmoar@google.com Cc: linux-kselftest@vger.kernel.org Cc: kunit-dev@googlegroups.com Signed-off-by: Vlastimil Babka vbabka@suse.cz --- init/main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/init/main.c b/init/main.c index c4778edae7972f512d5eefe8400075ac35a70d1c..7890ebb00e84b8bd7bac28923fb1fe571b3e9ee2 100644 --- a/init/main.c +++ b/init/main.c @@ -1489,6 +1489,8 @@ static int __ref kernel_init(void *unused)
rcu_end_inkernel_boot();
+ kunit_run_all_tests(); + do_sysctl_args();
if (ramdisk_execute_command) { @@ -1579,8 +1581,6 @@ static noinline void __init kernel_init_freeable(void)
do_basic_setup();
- kunit_run_all_tests(); - wait_for_initramfs(); console_on_rootfs();