Re: [PATCH v9 7/9] liveupdate: kho: move to kernel/liveupdate

[kernel test robot <oliver.sang@intel.com>]

Hello,


as we understand, this commit is not the root cause of the WARNING. but just
changes the stats as below table [1]

we just report FYI there is a WARNING caused by related code in our tests, in
case anybody think it's worth to look further. thanks


kernel test robot noticed "WARNING:at_kernel/liveupdate/kexec_handover.c:#kho_add_subtree" on:

commit: 91cb1aaea4b8276323b3814d35f6e62133f64c1b ("[PATCH v9 7/9] liveupdate: kho: move to kernel/liveupdate")
url: https://github.com/intel-lab-lkp/linux/commits/Pasha-Tatashin/kho-make-debugfs-interface-optional/20251101-222610
patch link: https://lore.kernel.org/all/20251101142325.1326536-8-pasha.tatashin@soleen.com/
patch subject: [PATCH v9 7/9] liveupdate: kho: move to kernel/liveupdate

in testcase: boot

config: x86_64-randconfig-001-20251015
compiler: gcc-14
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)

[1]
+--------------------------------------------------------------------------------------+------------+------------+
|                                                                                      | dc74e80622 | 91cb1aaea4 |
+--------------------------------------------------------------------------------------+------------+------------+
| WARNING:at_kernel/kexec_handover.c:#kho_add_subtree                                  | 8          |            |
| WARNING:at_kernel/liveupdate/kexec_handover.c:#kho_add_subtree                       | 0          | 11         |
+--------------------------------------------------------------------------------------+------------+------------+


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/202511061443.64dd159-lkp@intel.com


[   12.679864][    T1] ------------[ cut here ]------------
[   12.680514][    T1] WARNING: CPU: 0 PID: 1 at kernel/liveupdate/kexec_handover.c:711 kho_add_subtree (kernel/liveupdate/kexec_handover.c:711)
[   12.681526][    T1] Modules linked in:
[   12.681957][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.0-rc3-00216-g91cb1aaea4b8 #1 VOLUNTARY
[   12.682956][    T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[   12.683951][    T1] RIP: 0010:kho_add_subtree (kernel/liveupdate/kexec_handover.c:711)
[   12.684514][    T1] Code: c7 58 2e a7 85 31 ed e8 31 1a 00 00 48 c7 c7 c0 12 c9 86 85 c0 89 c3 40 0f 95 c5 31 c9 31 d2 89 ee e8 57 a0 13 00 85 db 74 02 <0f> 0b b9 01 00 00 00 31 d2 89 ee 48 c7 c7 90 12 c9 86 e8 3c a0 13
All code
========
   0:	c7                   	(bad)
   1:	58                   	pop    %rax
   2:	2e a7                	cmpsl  %es:(%rdi),%ds:(%rsi)
   4:	85 31                	test   %esi,(%rcx)
   6:	ed                   	in     (%dx),%eax
   7:	e8 31 1a 00 00       	call   0x1a3d
   c:	48 c7 c7 c0 12 c9 86 	mov    $0xffffffff86c912c0,%rdi
  13:	85 c0                	test   %eax,%eax
  15:	89 c3                	mov    %eax,%ebx
  17:	40 0f 95 c5          	setne  %bpl
  1b:	31 c9                	xor    %ecx,%ecx
  1d:	31 d2                	xor    %edx,%edx
  1f:	89 ee                	mov    %ebp,%esi
  21:	e8 57 a0 13 00       	call   0x13a07d
  26:	85 db                	test   %ebx,%ebx
  28:	74 02                	je     0x2c
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	b9 01 00 00 00       	mov    $0x1,%ecx
  31:	31 d2                	xor    %edx,%edx
  33:	89 ee                	mov    %ebp,%esi
  35:	48 c7 c7 90 12 c9 86 	mov    $0xffffffff86c91290,%rdi
  3c:	e8                   	.byte 0xe8
  3d:	3c a0                	cmp    $0xa0,%al
  3f:	13                   	.byte 0x13

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	b9 01 00 00 00       	mov    $0x1,%ecx
   7:	31 d2                	xor    %edx,%edx
   9:	89 ee                	mov    %ebp,%esi
   b:	48 c7 c7 90 12 c9 86 	mov    $0xffffffff86c91290,%rdi
  12:	e8                   	.byte 0xe8
  13:	3c a0                	cmp    $0xa0,%al
  15:	13                   	.byte 0x13
[   12.686315][    T1] RSP: 0018:ffffc9000001fc58 EFLAGS: 00010286
[   12.687184][    T1] RAX: dffffc0000000000 RBX: 00000000ffffffff RCX: 0000000000000000
[   12.688370][    T1] RDX: 1ffffffff0d9225c RSI: 0000000000000001 RDI: ffffffff86c912e0
[   12.689572][    T1] RBP: 0000000000000001 R08: 0000000000000008 R09: fffffbfff0dfac6c
[   12.690762][    T1] R10: 0000000000000000 R11: ffffffff86fd6367 R12: ffff888133ce6000
[   12.691996][    T1] R13: ffffffff85a72d60 R14: ffff88810ce59888 R15: dffffc0000000000
[   12.693231][    T1] FS:  0000000000000000(0000) GS:ffff888426da0000(0000) knlGS:0000000000000000
[   12.694585][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   12.695569][    T1] CR2: 00007f6d5dc8f0ac CR3: 00000000054ea000 CR4: 00000000000406f0
[   12.696832][    T1] Call Trace:
[   12.697400][    T1]  <TASK>
[   12.697922][    T1]  kho_test_preserve+0x2fa/0x360
[   12.698835][    T1]  ? folio_order (arch/x86/kvm/../../../virt/kvm/guest_memfd.c:181 (discriminator 3))
[   12.699556][    T1]  ? kho_test_generate_data+0x107/0x180
[   12.700561][    T1]  kho_test_init (lib/test_kho.c:222 lib/test_kho.c:327)
[   12.701312][    T1]  ? vmalloc_test_init (lib/test_kho.c:314)
[   12.702100][    T1]  ? add_device_randomness (drivers/char/random.c:944)
[   12.702924][    T1]  ? mix_pool_bytes (drivers/char/random.c:944)
[   12.703646][    T1]  ? trace_initcall_start (include/trace/events/initcall.h:27 (discriminator 3))
[   12.704499][    T1]  ? vmalloc_test_init (lib/test_kho.c:314)
[   12.705291][    T1]  do_one_initcall (init/main.c:1284)
[   12.706047][    T1]  ? trace_initcall_start (init/main.c:1274)
[   12.706897][    T1]  ? parse_one (kernel/params.c:143)
[   12.707623][    T1]  ? kasan_save_track (mm/kasan/common.c:69 (discriminator 1) mm/kasan/common.c:78 (discriminator 1))
[   12.708394][    T1]  ? __kmalloc_noprof (mm/slub.c:5659)
[   12.709218][    T1]  do_initcalls (init/main.c:1344 (discriminator 3) init/main.c:1361 (discriminator 3))
[   12.709976][    T1]  kernel_init_freeable (init/main.c:1595)
[   12.710752][    T1]  ? rest_init (init/main.c:1475)
[   12.711473][    T1]  kernel_init (init/main.c:1485)
[   12.712165][    T1]  ? rest_init (init/main.c:1475)
[   12.712871][    T1]  ret_from_fork (arch/x86/kernel/process.c:164)
[   12.713609][    T1]  ? rest_init (init/main.c:1475)
[   12.714326][    T1]  ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
[   12.715029][    T1]  </TASK>
[   12.715548][    T1] irq event stamp: 131753
[   12.716243][    T1] hardirqs last  enabled at (131763): __up_console_sem (arch/x86/include/asm/irqflags.h:26 arch/x86/include/asm/irqflags.h:109 arch/x86/include/asm/irqflags.h:151 kernel/printk/printk.c:345)
[   12.717702][    T1] hardirqs last disabled at (131776): __up_console_sem (kernel/printk/printk.c:343 (discriminator 3))
[   12.719185][    T1] softirqs last  enabled at (131460): handle_softirqs (kernel/softirq.c:469 (discriminator 1) kernel/softirq.c:650 (discriminator 1))
[   12.720632][    T1] softirqs last disabled at (131455): __irq_exit_rcu (kernel/softirq.c:496 kernel/softirq.c:723)
[   12.721755][    T1] ---[ end trace 0000000000000000 ]---


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20251106/202511061443.64dd159-lkp@intel.com



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki