The linux-next commit a0b0fd53e1e6 ("locking/lockdep: Free lock classes that are no longer in use") let init_data_structures_once() call init_rcu_head(). As the result, smp_setup_processor_id() calls debug_object_init() before debug_objects_early_init() triggering errors below on arm64 and ppc64le. Since debug_objects_early_init() depends on smp_setup_processor_id(), so it is not straightforward to move the former earlier in start_kernel(). Hence, just skip all debugobjects creations in init_data_structures_once() as a good trade-off by losing track of some RCU list heads debugging.
BUG: spinlock bad magic on CPU#0, swapper/0 lock: obj_hash+0xc3048/0x100000, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc8-next-20190301+ #1 Call trace: dump_backtrace+0x0/0x450 show_stack+0x20/0x2c dump_stack+0xe0/0x16c spin_bug+0x200/0x224 do_raw_spin_lock+0x1bc/0x23c _raw_spin_lock_irqsave+0xac/0xd0 __debug_object_init+0xf0/0x19dc debug_object_init+0x54/0x6c init_rcu_head+0x24/0x30 init_data_structures_once+0xb0/0x41c register_lock_class+0x70c/0x1454 __lock_acquire+0xc4/0x235c lock_acquire+0x508/0x668 _raw_spin_lock+0x88/0xac vprintk_emit+0x33c/0x53c vprintk_default+0x54/0x7c vprintk_func+0x320/0x40c printk+0x64/0x8c smp_setup_processor_id+0x6c/0x84 start_kernel+0x38/0x8f8 ODEBUG: Out of memory. ODEBUG disabled Signed-off-by: Qian Cai <c...@lca.pw> --- kernel/locking/lockdep.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 21cb81fe6359..1309a6fe88ee 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -988,7 +988,6 @@ static void init_data_structures_once(void) initialization_happened = true; - init_rcu_head(&delayed_free.rcu_head); INIT_LIST_HEAD(&delayed_free.pf[0].zapped); INIT_LIST_HEAD(&delayed_free.pf[1].zapped); -- 2.17.2 (Apple Git-113)