Re: [PATCH] efi: pstore: Support late setup with TEE-backed efivars ops

Ard Biesheuvel
2025-12-10T09:13:29Z

On Wed, 10 Dec 2025 at 17:41, kernel test robot <oliver.sang@intel.com> wrote:
>
>
>
> Hello,
>
> kernel test robot noticed "WARNING:at_kernel/locking/rwsem.c:#__down_write_trylock" on:
>
> commit: 6f473fefec79a8ba24013a5676a93934ee5ac922 ("[PATCH] efi: pstore: Support late setup with TEE-backed efivars ops")
> url: https://github.com/intel-lab-lkp/linux/commits/Val-Packett/efi-pstore-Support-late-setup-with-TEE-backed-efivars-ops/20251203-123406
> base: https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git for-next/pstore
> patch link: https://lore.kernel.org/all/20251203042850.14210-1-val@packett.cool/
> patch subject: [PATCH] efi: pstore: Support late setup with TEE-backed efivars ops
>
> in testcase: boot
>
> config: i386-randconfig-015-20251207
> compiler: clang-20
> test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G
>
> (please refer to attached dmesg/kmsg for entire log/backtrace)
>
>
> +---------------------------------------------------------+------------+------------+
> | | b692553573 | 6f473fefec |
> +---------------------------------------------------------+------------+------------+
> | WARNING:at_kernel/locking/rwsem.c:#__down_write_trylock | 0 | 18 |
> | EIP:__down_write_trylock | 0 | 18 |
> | WARNING:at_kernel/locking/rwsem.c:#up_write | 0 | 18 |
> | EIP:up_write | 0 | 18 |
> +---------------------------------------------------------+------------+------------+
>

This seems to be a non-EFI boot, in which case the notifier chain is
never initialized.

Kees, can you drop this from your branch so we can get it fixed? I
also had some review feedback that hasn't been taken into account yet.

>
> 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/202512101632.a94de49b-lkp@intel.com
>
>
> [ 7.731121][ T1] ------------[ cut here ]------------
> [ 7.731800][ T1] DEBUG_RWSEMS_WARN_ON(sem->magic != sem): count = 0x0, magic = 0x0, owner = 0x0, curr 0xc0288000, list not empty
> [ 7.733282][ T1] WARNING: CPU: 0 PID: 1 at kernel/locking/rwsem.c:1339 __down_write_trylock (kernel/locking/rwsem.c:1339)
> [ 7.734420][ T1] Modules linked in:
> [ 7.734903][ T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.0-rc2-00002-g6f473fefec79 #1 PREEMPT(none)
> [ 7.736185][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> [ 7.737529][ T1] EIP: __down_write_trylock (kernel/locking/rwsem.c:1339)
> [ 7.738173][ T1] Code: c1 92 28 c2 bf 39 3e 26 c2 0f 44 fa 57 50 ff 71 04 56 ff 31 68 dc f4 35 c2 68 fe 5b 35 c2 89 cf e8 81 d1 e8 ff 89 f9 83 c4 1c <0f> 0b 39 ce 0f 85 4b ff ff ff e9 4f ff ff ff 0f 0b eb 8b 90 90 90
> All code
> ========
> 0: c1 92 28 c2 bf 39 3e rcll $0x3e,0x39bfc228(%rdx)
> 7: 26 c2 0f 44 es ret $0x440f
> b: fa cli
> c: 57 push %rdi
> d: 50 push %rax
> e: ff 71 04 push 0x4(%rcx)
> 11: 56 push %rsi
> 12: ff 31 push (%rcx)
> 14: 68 dc f4 35 c2 push $0xffffffffc235f4dc
> 19: 68 fe 5b 35 c2 push $0xffffffffc2355bfe
> 1e: 89 cf mov %ecx,%edi
> 20: e8 81 d1 e8 ff call 0xffffffffffe8d1a6
> 25: 89 f9 mov %edi,%ecx
> 27: 83 c4 1c add $0x1c,%esp
> 2a:* 0f 0b ud2 <-- trapping instruction
> 2c: 39 ce cmp %ecx,%esi
> 2e: 0f 85 4b ff ff ff jne 0xffffffffffffff7f
> 34: e9 4f ff ff ff jmp 0xffffffffffffff88
> 39: 0f 0b ud2
> 3b: eb 8b jmp 0xffffffffffffffc8
> 3d: 90 nop
> 3e: 90 nop
> 3f: 90 nop
>
> Code starting with the faulting instruction
> ===========================================
> 0: 0f 0b ud2
> 2: 39 ce cmp %ecx,%esi
> 4: 0f 85 4b ff ff ff jne 0xffffffffffffff55
> a: e9 4f ff ff ff jmp 0xffffffffffffff5e
> f: 0f 0b ud2
> 11: eb 8b jmp 0xffffffffffffff9e
> 13: 90 nop
> 14: 90 nop
> 15: 90 nop
> [ 7.740468][ T1] EAX: 58e1ae7d EBX: c33977c0 ECX: c33977c0 EDX: 00000000
> [ 7.741422][ T1] ESI: 00000000 EDI: c33977c0 EBP: c0293bf0 ESP: c0293be8
> [ 7.742277][ T1] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010296
> [ 7.743199][ T1] CR0: 80050033 CR2: ffd38000 CR3: 02b87000 CR4: 000406d0
> [ 7.744043][ T1] Call Trace:
> [ 7.744429][ T1] ? blocking_notifier_chain_register (kernel/notifier.c:264)
> [ 7.745251][ T1] down_write (kernel/locking/rwsem.c:1591)
> [ 7.745755][ T1] blocking_notifier_chain_register (kernel/notifier.c:264)
> [ 7.746473][ T1] efivars_pstore_init (drivers/firmware/efi/efi-pstore.c:258 drivers/firmware/efi/efi-pstore.c:306)
> [ 7.747059][ T1] do_one_initcall (init/main.c:1283)
> [ 7.747623][ T1] ? last_attempt_status_show (drivers/firmware/efi/efi-pstore.c:299)
> [ 7.748291][ T1] ? local_clock (arch/x86/include/asm/preempt.h:95 kernel/sched/clock.c:319)
> [ 7.748949][ T1] ? kvm_sched_clock_read (arch/x86/kernel/kvmclock.c:91)
> [ 7.749590][ T1] ? kvm_sched_clock_read (arch/x86/kernel/kvmclock.c:91)
> [ 7.750218][ T1] ? sched_clock_noinstr (arch/x86/kernel/tsc.c:271)
> [ 7.750828][ T1] ? local_clock_noinstr (kernel/sched/clock.c:272 kernel/sched/clock.c:309)
> [ 7.751477][ T1] ? local_clock (arch/x86/include/asm/preempt.h:95 kernel/sched/clock.c:319)
> [ 7.752042][ T1] ? ktime_get (include/linux/seqlock.h:226)
> [ 7.752565][ T1] ? kvm_clock_get_cycles (arch/x86/include/asm/preempt.h:95 arch/x86/kernel/kvmclock.c:80 arch/x86/kernel/kvmclock.c:86)
> [ 7.753268][ T1] ? ktime_get (kernel/time/timekeeping.c:295 kernel/time/timekeeping.c:404 kernel/time/timekeeping.c:826)
> [ 7.753775][ T1] ? local_clock_noinstr (kernel/sched/clock.c:272 kernel/sched/clock.c:309)
> [ 7.754393][ T1] ? clockevents_program_event (kernel/time/clockevents.c:336)
> [ 7.755098][ T1] ? tick_program_event (kernel/time/tick-oneshot.c:44)
> [ 7.755720][ T1] ? hrtimer_interrupt (kernel/time/hrtimer.c:1916)
> [ 7.756331][ T1] ? irqentry_exit (kernel/entry/common.c:?)
> [ 7.756993][ T1] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1052)
> [ 7.757704][ T1] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:80)
> [ 7.758306][ T1] ? irqentry_exit (kernel/entry/common.c:?)
> [ 7.758860][ T1] ? sysvec_call_function_single (arch/x86/kernel/apic/apic.c:1052)
> [ 7.759562][ T1] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1052)
> [ 7.760261][ T1] ? handle_exception (arch/x86/entry/entry_32.S:1048)
> [ 7.760967][ T1] ? __get_immptr (arch/x86/lib/insn.c:632)
> [ 7.761517][ T1] ? parameq (kernel/params.c:81 kernel/params.c:91 kernel/params.c:99)
> [ 7.762011][ T1] ? __get_immptr (arch/x86/lib/insn.c:632)
> [ 7.762540][ T1] ? next_arg (lib/cmdline.c:273)
> [ 7.763050][ T1] ? parameq (kernel/params.c:90 kernel/params.c:99)
> [ 7.763551][ T1] ? parse_args (kernel/params.c:153)
> [ 7.764127][ T1] do_initcall_level (init/main.c:1344)
> [ 7.764819][ T1] do_initcalls (init/main.c:1358)
> [ 7.765347][ T1] ? kernel_init (init/main.c:1485)
> [ 7.765895][ T1] do_basic_setup (init/main.c:1381)
> [ 7.766432][ T1] kernel_init_freeable (init/main.c:1597)
> [ 7.767049][ T1] ? rest_init (init/main.c:1475)
> [ 7.767587][ T1] ? rest_init (init/main.c:1475)
> [ 7.768125][ T1] kernel_init (init/main.c:1485)
> [ 7.768686][ T1] ret_from_fork (arch/x86/kernel/process.c:164)
> [ 7.769276][ T1] ? __switch_to_asm (arch/x86/entry/entry_32.S:704)
> [ 7.769852][ T1] ? __switch_to_asm (arch/x86/entry/entry_32.S:704)
> [ 7.770427][ T1] ? __switch_to_asm (arch/x86/entry/entry_32.S:704)
> [ 7.771001][ T1] ? rest_init (init/main.c:1475)
> [ 7.771535][ T1] ret_from_fork_asm (arch/x86/entry/entry_32.S:737)
> [ 7.771957][ T1] entry_INT80_32 (arch/x86/entry/entry_32.S:945)
> [ 7.772338][ T1] irq event stamp: 108765
> [ 7.772712][ T1] hardirqs last enabled at (108773): __console_unlock (arch/x86/include/asm/irqflags.h:19 arch/x86/include/asm/irqflags.h:109 arch/x86/include/asm/irqflags.h:151 kernel/printk/printk.c:345 kernel/printk/printk.c:2858)
> [ 7.773432][ T1] hardirqs last disabled at (108782): __console_unlock (kernel/printk/printk.c:343)
> [ 7.774123][ T1] softirqs last enabled at (108714): __do_softirq (kernel/softirq.c:657)
> [ 7.774782][ T1] softirqs last disabled at (108699): __do_softirq (kernel/softirq.c:657)
> [ 7.775441][ T1] ---[ end trace 0000000000000000 ]---
>
>
> The kernel config and materials to reproduce are available at:
> https://download.01.org/0day-ci/archive/20251210/202512101632.a94de49b-lkp@intel.com
>
>
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>