Re: [BUG] KASAN "INFO: trying to register non-static key"

["Liam R. Howlett" <Liam.Howlett@Oracle.com>]

* Paul E. McKenney <paulmck@kernel.org> [240109 09:04]:
> Hello!
> 
> I get the splat shown below when running rcutorture on next-20240108
> (and some less-recent -next versions) on scenarios that run KASAN and
> that also enable CONFIG_DEBUG_LOCK_ALLOC=y.  I am running gcc 8.5.0.
> 
> Bisection fingers this commit:
> 
> a414d4286f34 ("kasan: handle concurrent kasan_record_aux_stack calls")
> 
> This commit does not appear to be trying to change the annotation
> required of KASAN users, so I suspect that the commit is at fault.  I am
> including Liam in case Maple Tree is the bad guy, and should call_rcu()
> need adjustment, here I am.  ;-)
> 
> Thoughts?


I think this is ma_free_rcu() registering mt_free_rcu() in
lib/maple_tree.c.

The commit you point to saves and restores the irq state in
__kasan_record_aux_stack(), but the trace below shows it is called prior
to irqs being initialized.  This isn't what lockdep is yelling about, so
what am I missing?  Maybe it will be caught after this issue is
resolved?

I am also guessing maple tree shows up in the stack trace because it is
the very first rcu user at boot (just like the rcutiny issue last time).
I'm just keeping everyone honest/angry.

> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> [    0.174878] INFO: trying to register non-static key.
> [    0.174879] The code is fine but needs lockdep annotation, or maybe
> [    0.174880] you didn't initialize this object before use?
> [    0.174881] turning off the locking correctness validator.
> [    0.174884] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.7.0-rc4-00331-ga414d4286f34 #39616
> [    0.174888] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
> [    0.174891] Call Trace:
> [    0.174892]  <TASK>
> [    0.174895]  dump_stack_lvl+0x36/0x50
> [    0.174903]  register_lock_class+0x1240/0x1880
> [    0.174910]  ? kasan_save_stack+0x2e/0x40
> [    0.174916]  ? kasan_save_stack+0x20/0x40
> [    0.174919]  ? __kasan_record_aux_stack+0x91/0xe0
> [    0.174923]  ? __call_rcu_common.constprop.84+0x99/0x740
> [    0.174927]  ? mas_wr_node_store+0x8c6/0x1700
> [    0.174931]  ? mas_wr_modify+0x274/0x2500
> [    0.174934]  ? mas_wr_store_entry+0x3fa/0x1830
> [    0.174938]  ? mas_store_gfp+0xaa/0x140
> [    0.174941]  ? __pfx_register_lock_class+0x10/0x10
> [    0.174945]  ? x86_64_start_reservations+0x18/0x30
> [    0.174952]  ? x86_64_start_kernel+0x91/0xa0
> [    0.174956]  ? secondary_startup_64_no_verify+0x178/0x17b
> [    0.174961]  ? __pfx_lock_release+0x10/0x10
> [    0.174965]  ? do_raw_spin_lock+0x125/0x290
> [    0.174968]  ? __pfx_do_raw_spin_lock+0x10/0x10
> [    0.174971]  __lock_acquire.isra.27+0x81/0x10d0
> [    0.174976]  ? _raw_spin_unlock_irqrestore+0x22/0x50
> [    0.174982]  ? debug_object_active_state+0x2e7/0x430
> [    0.174988]  lock_acquire+0x11e/0x280
> [    0.174992]  ? __kasan_record_aux_stack+0xa1/0xe0
> [    0.174996]  _raw_spin_lock_irqsave+0x2f/0x50
> [    0.175000]  ? __kasan_record_aux_stack+0xa1/0xe0
> [    0.175003]  __kasan_record_aux_stack+0xa1/0xe0
> [    0.175006]  ? __pfx_mt_free_rcu+0x10/0x10
> [    0.175009]  __call_rcu_common.constprop.84+0x99/0x740
> [    0.175012]  ? mas_alloc_nodes+0x3e7/0x750
> [    0.175015]  ? mas_pop_node+0x192/0x290
> [    0.175018]  mas_wr_node_store+0x8c6/0x1700
> [    0.175022]  ? __free_zapped_classes+0x2af/0x2f0
> [    0.175026]  ? lock_release+0x1e3/0x660
> [    0.175030]  ? __pfx_mas_wr_node_store+0x10/0x10
> [    0.175033]  ? __pfx_lock_release+0x10/0x10
> [    0.175038]  ? lock_acquire+0x11e/0x280
> [    0.175042]  ? stack_depot_save_flags+0x148/0x650
> [    0.175047]  ? find_held_lock+0x33/0x1c0
> [    0.175051]  ? lock_release+0x1e3/0x660
> [    0.175054]  ? pcpu_alloc+0x81d/0xa30
> [    0.175059]  ? stack_depot_save_flags+0x1da/0x650
> [    0.175062]  ? __pfx_lock_release+0x10/0x10
> [    0.175066]  ? register_lock_class+0xc9/0x1880
> [    0.175070]  ? pcpu_alloc+0x60e/0xa30
> [    0.175074]  mas_wr_modify+0x274/0x2500
> [    0.175078]  ? __mutex_unlock_slowpath+0x176/0x660
> [    0.175083]  mas_wr_store_entry+0x3fa/0x1830
> [    0.175088]  mas_store_gfp+0xaa/0x140
> [    0.175092]  ? __pfx_mas_store_gfp+0x10/0x10
> [    0.175097]  ? lockdep_init_map_type+0x2c8/0x7a0
> [    0.175101]  irq_insert_desc+0xaf/0x100
> [    0.175107]  ? __pfx_irq_insert_desc+0x10/0x10
> [    0.175110]  ? kobject_init+0x68/0x1e0
> [    0.175115]  ? kmem_cache_create_usercopy+0xce/0x240
> [    0.175119]  early_irq_init+0x10f/0x140

IRQs are not enabled at this point.

> [    0.175125]  start_kernel+0x177/0x3a0
> [    0.175129]  x86_64_start_reservations+0x18/0x30
> [    0.175133]  x86_64_start_kernel+0x91/0xa0
> [    0.175138]  secondary_startup_64_no_verify+0x178/0x17b
> [    0.175143]  </TASK>
>