From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA3992264A1; Tue, 8 Jul 2025 09:55:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751968522; cv=none; b=ATy77HSv3F+ejH3ElF5AV1gOy0WtpJF37pNVmyFoR1EmkBS62//ge1lU1Cv5tlRjBmxtMGdSJFDZTPqObdcstp7sBcDZ4T6oR0VIcpEs1OhMShdZUuBxlci5lIm7brx8DdQ8LoBP8AMmnmYvmzSSALIg/2462rW72uDr342Gx1g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751968522; c=relaxed/simple; bh=TnuXVt8sQH4n2YkcEcjhrZpj0P2l3YZxxcugvdMkiHQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XE9b+dmfUYztYLiHle0N2SKuOrT+UOOTfy9qxQSWw64FNtfFE+Y4edjrdJB/4vUo5nJ+jQHBT9bsp/vvEgQa/E+C49DYFX+5EaqmiwErUxyFR2yI24o+Hlw2NArYOpUrG/8AiBddcqXBQxaE1PIUlGWcr5cVv4Juub9Spe9L9hc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Jwi1LOFh; arc=none smtp.client-ip=198.175.65.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Jwi1LOFh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1751968521; x=1783504521; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=TnuXVt8sQH4n2YkcEcjhrZpj0P2l3YZxxcugvdMkiHQ=; b=Jwi1LOFhGrl8xfRC/plIeIM2XAhWorclau6RcJpH1tPtwiElINnyoSWq M82SRVKuEx+kpDuQn7V6gCKa8gH+iDUP8N1dlYdgGOScgnMLuRSJQx0fo cgM4drZbszNjUOJjI5aHm2Pbg2nVoNTnD5c0y2H+VhfNe+sm+ja9YorPF gu6nqiADm2d/3q2DsO4dBM93r/vamdjkXTKLr4DqxvUTpV1VZQdj9koJD aA7Yj1ZOMrM8SXEu6BkzYn2vf4cmyQHwczq3ZYXV9n0UKoKQETNNRVYgY wf3N5qwc5aU9DbLP9uXxN0qtctbPAIqsjQAwYa3FZbDk8t7JDACpT3qSV Q==; X-CSE-ConnectionGUID: zHz7BPuBTUiOLunFhaYstQ== X-CSE-MsgGUID: JnhEpVoSQVusMLMNYCnlaA== X-IronPort-AV: E=McAfee;i="6800,10657,11487"; a="54329063" X-IronPort-AV: E=Sophos;i="6.16,297,1744095600"; d="scan'208";a="54329063" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2025 02:55:18 -0700 X-CSE-ConnectionGUID: GzIoR7VbRxSGcOABFQq/PA== X-CSE-MsgGUID: DJ8igr/FQiavFgX8/pMZOQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,297,1744095600"; d="scan'208";a="159719222" Received: from dapengmi-mobl1.ccr.corp.intel.com (HELO [10.124.240.37]) ([10.124.240.37]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2025 02:55:15 -0700 Message-ID: <25132107-09d6-45f2-9e09-1ebeaa1d3637@linux.intel.com> Date: Tue, 8 Jul 2025 17:54:59 +0800 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [linus:master] [perf] 9734e25fbf: BUG:kernel_NULL_pointer_dereference,address To: kernel test robot , Kan Liang Cc: oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, "Peter Zijlstra (Intel)" , Namhyung Kim , linux-perf-users@vger.kernel.org, dapeng1.mi@linux.intel.com References: <202507042103.a15d2923-lkp@intel.com> Content-Language: en-US From: "Mi, Dapeng" In-Reply-To: <202507042103.a15d2923-lkp@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Base on the call trace, it looks the bug is directly caused by the below code in setup_pebs_adaptive_sample_data(). sample_type = event->attr.sample_type; the "event" pointer becomes NULL accidentally when running this code and trigger an invalid memory access. The helper setup_pebs_adaptive_sample_data() is only called by helper intel_pmu_drain_pebs_icl(), the "event" pointer comes from the below assignment. event = cpuc->events[bit]; It looks the "cpuc->events[bit]" is assigned to NULL as some reason when the issue happens. Since I can't reproduce this issue locally, so I can't certainly say what caused the issue, but 0day figures out the issue should be introduced by the commit '9734e25fbf5a ("perf: Fix the throttle logic for a group")'. Just go through this commit, the most probably place causing this issue is the below code. @@ -10084,8 +10111,7 @@ __perf_event_account_interrupt(struct perf_event *event, int throttle)         if (unlikely(throttle && hwc->interrupts >= max_samples_per_tick)) {                 __this_cpu_inc(perf_throttled_count);                 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); -               hwc->interrupts = MAX_INTERRUPTS; -               perf_log_throttle(event, 0); +               perf_event_throttle_group(event);                 ret = 1;         } With this change, all events in the group could be possible to be stopped. The call chain is perf_event_throttle_group() -> perf_event_throttle() -> event->pmu->stop() -> x86_pmu_stop(). In x86_pmu_stop() , the event would be disabled and corresponding item in cpuc->events[] array is cleared to NULL.     if (test_bit(hwc->idx, cpuc->active_mask)) {         static_call(x86_pmu_disable)(event);         __clear_bit(hwc->idx, cpuc->active_mask);         cpuc->events[hwc->idx] = NULL;         WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);         hwc->state |= PERF_HES_STOPPED;     } The __perf_event_account_interrupt() helper could be called in PMI handler (perf_event_overflow() -> __perf_event_overflow() -> __perf_event_account_interrupt()) and PMI is a NMI on x86 platform. So PMI handler could interrupt perf code (like setup_pebs_adaptive_sample_data()) and clear the cpuc->events[hwc->idx] and then setup_pebs_adaptive_sample_data() finds the cpuc->events[bit] is NULL and crashes. @Oliver, I would cook a patch to add NULL check for cpuc->events[*] pointer before accessing it. Could you please help to verify it? Thanks. On 7/4/2025 9:52 PM, kernel test robot wrote: > Hello, > > kernel test robot noticed "BUG:kernel_NULL_pointer_dereference,address" on: > > commit: 9734e25fbf5ae68eb04234b2cd14a4b36ab89141 ("perf: Fix the throttle logic for a group") > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > [test failed on linus/master 66701750d5565c574af42bef0b789ce0203e3071] > [test failed on linux-next/master 3f804361f3b9af33e00b90ec9cb5afcc96831e60] > [test failed on fix commit bc4394e5e79cdda1b0997e0be1d65e242f523f02] > > > in testcase: stress-ng > version: stress-ng-x86_64-f76f86ffb-1_20250412 > with following parameters: > > nr_threads: 100% > testtime: 60s > test: memthrash > cpufreq_governor: performance > > > > config: x86_64-rhel-9.4 > compiler: gcc-12 > test machine: 192 threads 2 sockets Intel(R) Xeon(R) Platinum 8468V CPU @ 2.4GHz (Sapphire Rapids) with 384G memory > > (please refer to attached dmesg/kmsg for entire log/backtrace) > > > > 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 > | Closes: https://lore.kernel.org/oe-lkp/202507042103.a15d2923-lkp@intel.com > > > [ 93.379225][ C143] BUG: kernel NULL pointer dereference, address: 00000000000000f0 > [ 93.379247][ C143] #PF: supervisor read access in kernel mode > [ 93.379253][ C143] #PF: error_code(0x0000) - not-present page > [ 93.379259][ C143] PGD 161558067 P4D 0 > [ 93.379263][ C143] Oops: Oops: 0000 [#1] SMP NOPTI > [ 93.379274][ C143] CPU: 143 UID: 0 PID: 3944 Comm: perf Not tainted 6.15.0-rc3-00069-g9734e25fbf5a #1 VOLUNTARY > [ 93.379281][ C143] Hardware name: KAYTUS NF5280-M7-A0-R0-00/NF5280-M7-A0-R0-00, BIOS 06.08.01 12/24/2024 > [ 93.379286][ C143] RIP: 0010:setup_pebs_adaptive_sample_data (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/intel/ds.c:2083) > [ 93.379325][ C143] Code: 04 24 48 85 d2 0f 84 81 02 00 00 49 89 d5 49 89 fe 49 89 f4 48 89 ce 49 c7 80 a8 00 00 00 00 00 00 00 8b 02 4c 89 c5 48 89 cb <4c> 8b bf f0 00 00 00 89 44 24 0c 48 89 44 24 10 48 8b 87 08 02 00 > All code > ======== > 0: 04 24 add $0x24,%al > 2: 48 85 d2 test %rdx,%rdx > 5: 0f 84 81 02 00 00 je 0x28c > b: 49 89 d5 mov %rdx,%r13 > e: 49 89 fe mov %rdi,%r14 > 11: 49 89 f4 mov %rsi,%r12 > 14: 48 89 ce mov %rcx,%rsi > 17: 49 c7 80 a8 00 00 00 movq $0x0,0xa8(%r8) > 1e: 00 00 00 00 > 22: 8b 02 mov (%rdx),%eax > 24: 4c 89 c5 mov %r8,%rbp > 27: 48 89 cb mov %rcx,%rbx > 2a:* 4c 8b bf f0 00 00 00 mov 0xf0(%rdi),%r15 <-- trapping instruction > 31: 89 44 24 0c mov %eax,0xc(%rsp) > 35: 48 89 44 24 10 mov %rax,0x10(%rsp) > 3a: 48 rex.W > 3b: 8b .byte 0x8b > 3c: 87 08 xchg %ecx,(%rax) > 3e: 02 00 add (%rax),%al > > Code starting with the faulting instruction > =========================================== > 0: 4c 8b bf f0 00 00 00 mov 0xf0(%rdi),%r15 > 7: 89 44 24 0c mov %eax,0xc(%rsp) > b: 48 89 44 24 10 mov %rax,0x10(%rsp) > 10: 48 rex.W > 11: 8b .byte 0x8b > 12: 87 08 xchg %ecx,(%rax) > 14: 02 00 add (%rax),%al > [ 93.379327][ C143] RSP: 0018:fffffe00021028f0 EFLAGS: 00010082 > [ 93.379332][ C143] RAX: 0000000000000001 RBX: fffffe0002102c80 RCX: fffffe0002102c80 > [ 93.379338][ C143] RDX: fffffe0002121040 RSI: fffffe0002102c80 RDI: 0000000000000000 > [ 93.379340][ C143] RBP: fffffe0002102970 R08: fffffe0002102970 R09: 0000000000000001 > [ 93.379345][ C143] R10: 0000000000000013 R11: 0000000000000008 R12: fffffe0002102ef8 > [ 93.379349][ C143] R13: fffffe0002121040 R14: 0000000000000000 R15: ff110001a0a69500 > [ 93.379356][ C143] FS: 00007f539e726840(0000) GS:ff1100303c39f000(0000) knlGS:0000000000000000 > [ 93.379359][ C143] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 93.379362][ C143] CR2: 00000000000000f0 CR3: 0000000180052002 CR4: 0000000000f73ff0 > [ 93.379363][ C143] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 93.379364][ C143] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 > [ 93.379365][ C143] PKRU: 55555554 > [ 93.379366][ C143] Call Trace: > [ 93.379377][ C143] > [ 93.379380][ C143] ? x86_perf_event_set_period (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/core.c:1442) > [ 93.379410][ C143] intel_pmu_drain_pebs_icl (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/intel/ds.c:2356 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/intel/ds.c:2666) > [ 93.379424][ C143] ? shmem_write_end (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/bitops.h:55 kbuild/obj/consumer/x86_64-rhel-9.4/include/asm-generic/bitops/instrumented-atomic.h:29 kbuild/obj/consumer/x86_64-rhel-9.4/include/linux/page-flags.h:835 kbuild/obj/consumer/x86_64-rhel-9.4/mm/shmem.c:3319) > [ 93.379436][ C143] handle_pmi_common (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/intel/core.c:3206) > [ 93.379440][ C143] ? shmem_write_end (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/bitops.h:55 kbuild/obj/consumer/x86_64-rhel-9.4/include/asm-generic/bitops/instrumented-atomic.h:29 kbuild/obj/consumer/x86_64-rhel-9.4/include/linux/page-flags.h:835 kbuild/obj/consumer/x86_64-rhel-9.4/mm/shmem.c:3319) > [ 93.379443][ C143] ? set_pte_vaddr_p4d (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/init_64.c:307 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/init_64.c:315) > [ 93.379462][ C143] ? flush_tlb_one_kernel (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/paravirt.h:85 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/tlb.c:1544 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/tlb.c:1499) > [ 93.379489][ C143] ? native_set_fixmap (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/pgtable.c:652 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/pgtable.c:661) > [ 93.379492][ C143] ? ghes_copy_tofrom_phys (kbuild/obj/consumer/x86_64-rhel-9.4/drivers/acpi/apei/ghes.c:345) > [ 93.379500][ C143] ? __ghes_peek_estatus+0x49/0xb0 > [ 93.379503][ C143] intel_pmu_handle_irq (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/msr.h:86 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/msr.h:120 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/intel/core.c:2504 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/intel/core.c:3351) > [ 93.379507][ C143] perf_event_nmi_handler (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/core.c:1767 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/events/core.c:1753) > [ 93.379518][ C143] nmi_handle (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/kernel/nmi.c:184) > [ 93.379529][ C143] default_do_nmi (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/kernel/nmi.c:152 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/kernel/nmi.c:393) > [ 93.379541][ C143] exc_nmi (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/kernel/nmi.c:588) > [ 93.379545][ C143] end_repeat_nmi (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/entry/entry_64.S:1409) > [ 93.379558][ C143] RIP: 0010:shmem_write_end (kbuild/obj/consumer/x86_64-rhel-9.4/mm/shmem.c:3321) > [ 93.379564][ C143] Code: 48 8b 13 83 e2 08 75 41 48 8b 13 83 e2 40 ba 00 10 00 00 74 0c 0f b6 4b 40 ba 00 10 00 00 48 d3 e2 48 39 d0 72 25 f0 80 0b 08 <48> 89 df e8 23 fd fd ff 48 89 df e8 db 1e fd ff f0 ff 4b 34 74 54 > All code > ======== > 0: 48 8b 13 mov (%rbx),%rdx > 3: 83 e2 08 and $0x8,%edx > 6: 75 41 jne 0x49 > 8: 48 8b 13 mov (%rbx),%rdx > b: 83 e2 40 and $0x40,%edx > e: ba 00 10 00 00 mov $0x1000,%edx > 13: 74 0c je 0x21 > 15: 0f b6 4b 40 movzbl 0x40(%rbx),%ecx > 19: ba 00 10 00 00 mov $0x1000,%edx > 1e: 48 d3 e2 shl %cl,%rdx > 21: 48 39 d0 cmp %rdx,%rax > 24: 72 25 jb 0x4b > 26: f0 80 0b 08 lock orb $0x8,(%rbx) > 2a:* 48 89 df mov %rbx,%rdi <-- trapping instruction > 2d: e8 23 fd fd ff call 0xfffffffffffdfd55 > 32: 48 89 df mov %rbx,%rdi > 35: e8 db 1e fd ff call 0xfffffffffffd1f15 > 3a: f0 ff 4b 34 lock decl 0x34(%rbx) > 3e: 74 54 je 0x94 > > Code starting with the faulting instruction > =========================================== > 0: 48 89 df mov %rbx,%rdi > 3: e8 23 fd fd ff call 0xfffffffffffdfd2b > 8: 48 89 df mov %rbx,%rdi > b: e8 db 1e fd ff call 0xfffffffffffd1eeb > 10: f0 ff 4b 34 lock decl 0x34(%rbx) > 14: 74 54 je 0x6a > [ 93.379572][ C143] RSP: 0018:ffa00000187bfd48 EFLAGS: 00000206 > [ 93.379575][ C143] RAX: 0000000000001000 RBX: ffd4000005435680 RCX: 0000000001128000 > [ 93.379580][ C143] RDX: 0000000000001000 RSI: 0000000001127000 RDI: ff1100011221d8c0 > [ 93.379580][ C143] RBP: 0000000000001000 R08: 0000000000001000 R09: ffd4000005435680 > [ 93.379581][ C143] R10: 0000000000000001 R11: 0000000000000003 R12: ff1100014115e5d0 > [ 93.379588][ C143] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000001000 > [ 93.379592][ C143] ? shmem_write_end (kbuild/obj/consumer/x86_64-rhel-9.4/mm/shmem.c:3321) > [ 93.379600][ C143] ? shmem_write_end (kbuild/obj/consumer/x86_64-rhel-9.4/mm/shmem.c:3321) > [ 93.379604][ C143] > [ 93.379605][ C143] > [ 93.379607][ C143] generic_perform_write (kbuild/obj/consumer/x86_64-rhel-9.4/mm/filemap.c:4124) > [ 93.379633][ C143] shmem_file_write_iter (kbuild/obj/consumer/x86_64-rhel-9.4/mm/shmem.c:3464) > [ 93.379636][ C143] vfs_write (kbuild/obj/consumer/x86_64-rhel-9.4/fs/read_write.c:591 kbuild/obj/consumer/x86_64-rhel-9.4/fs/read_write.c:684) > [ 93.379644][ C143] ksys_write (kbuild/obj/consumer/x86_64-rhel-9.4/fs/read_write.c:736) > [ 93.379651][ C143] do_syscall_64 (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/entry/syscall_64.c:63 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/entry/syscall_64.c:94) > [ 93.379656][ C143] ? exc_page_fault (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/irqflags.h:37 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/include/asm/irqflags.h:114 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/fault.c:1488 kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/mm/fault.c:1538) > [ 93.379659][ C143] entry_SYSCALL_64_after_hwframe (kbuild/obj/consumer/x86_64-rhel-9.4/arch/x86/entry/entry_64.S:130) > [ 93.379662][ C143] RIP: 0033:0x7f53aa05f27f > [ 93.379672][ C143] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 d5 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 8c d5 f8 ff 48 > All code > ======== > 0: 89 54 24 18 mov %edx,0x18(%rsp) > 4: 48 89 74 24 10 mov %rsi,0x10(%rsp) > 9: 89 7c 24 08 mov %edi,0x8(%rsp) > d: e8 39 d5 f8 ff call 0xfffffffffff8d54b > 12: 48 8b 54 24 18 mov 0x18(%rsp),%rdx > 17: 48 8b 74 24 10 mov 0x10(%rsp),%rsi > 1c: 41 89 c0 mov %eax,%r8d > 1f: 8b 7c 24 08 mov 0x8(%rsp),%edi > 23: b8 01 00 00 00 mov $0x1,%eax > 28: 0f 05 syscall > 2a:* 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax <-- trapping instruction > 30: 77 31 ja 0x63 > 32: 44 89 c7 mov %r8d,%edi > 35: 48 89 44 24 08 mov %rax,0x8(%rsp) > 3a: e8 8c d5 f8 ff call 0xfffffffffff8d5cb > 3f: 48 rex.W > > Code starting with the faulting instruction > =========================================== > 0: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax > 6: 77 31 ja 0x39 > 8: 44 89 c7 mov %r8d,%edi > b: 48 89 44 24 08 mov %rax,0x8(%rsp) > 10: e8 8c d5 f8 ff call 0xfffffffffff8d5a1 > 15: 48 rex.W > > > The kernel config and materials to reproduce are available at: > https://download.01.org/0day-ci/archive/20250704/202507042103.a15d2923-lkp@intel.com > > >