From: Sean Christopherson <sean.j.christopherson@intel.com>
To: syzbot <syzbot+f2ca20d4aa1408b0385a@syzkaller.appspotmail.com>
Cc: alexander.deucher@amd.com, bigeasy@linutronix.de, bp@alien8.de,
dave.hansen@intel.com, dvyukov@google.com, hpa@zytor.com,
linmiaohe@huawei.com, linux-kernel@vger.kernel.org,
mingo@redhat.com, nicholas.kazlauskas@amd.com,
pbonzini@redhat.com, riel@surriel.com, sunpeng.li@amd.com,
syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
x86@kernel.org, zhan.liu@amd.com
Subject: Re: WARNING in switch_fpu_return
Date: Mon, 23 Mar 2020 08:01:08 -0700 [thread overview]
Message-ID: <20200323150107.GB28711@linux.intel.com> (raw)
In-Reply-To: <000000000000ac36ba05a1793693@google.com>
On Sun, Mar 22, 2020 at 03:41:03PM -0700, syzbot wrote:
> syzbot suspects this bug was fixed by commit:
>
> commit 3009afc6e39e78708d8fb444ae50544b3bcd3a3f
> Author: Sean Christopherson <sean.j.christopherson@intel.com>
> Date: Wed Jan 22 04:43:39 2020 +0000
>
> KVM: x86: Use a typedef for fastop functions
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1667aa4be00000
> start commit: bf8d1cd4 Merge tag 'scsi-fixes' of git://git.kernel.org/pu..
> git tree: upstream
> kernel config: https://syzkaller.appspot.com/x/.config?x=ed9d672709340e35
> dashboard link: https://syzkaller.appspot.com/bug?extid=f2ca20d4aa1408b0385a
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=151d549ee00000
>
> If the result looks correct, please mark the bug fixed by replying with:
>
> #syz fix: KVM: x86: Use a typedef for fastop functions
Ha, fat chance of that.
The offending call to switch_fpu_return() in kvm_arch_vcpu_load() was
removed by commit 2620fe268e80 ("KVM: x86: Revert "KVM: X86: Fix fpu state
crash in kvm guest"")
RIP: 0010:__fpregs_load_activate arch/x86/include/asm/fpu/internal.h:539 [inline]
RIP: 0010:switch_fpu_return+0x437/0x4f0 arch/x86/kernel/fpu/core.c:343
kvm_arch_vcpu_load+0x66e/0x950 arch/x86/kvm/x86.c:3463
vcpu_load+0x43/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:201
kvm_unload_vcpu_mmu arch/x86/kvm/x86.c:9543 [inline]
kvm_free_vcpus arch/x86/kvm/x86.c:9558 [inline]
kvm_arch_destroy_vm+0x184/0x5f0 arch/x86/kvm/x86.c:9663
kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:816 [inline]
kvm_put_kvm+0x5a5/0xcc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:837
async_pf_execute+0x3bf/0x800 arch/x86/kvm/../../../virt/kvm/async_pf.c:101
process_one_work+0x9af/0x1740 kernel/workqueue.c:2264
worker_thread+0x98/0xe40 kernel/workqueue.c:2410
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
So
#syz fix: KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest"
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
prev parent reply other threads:[~2020-03-23 15:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-02 2:25 WARNING in switch_fpu_return syzbot
2020-01-07 20:53 ` Sebastian Andrzej Siewior
2020-01-08 4:28 ` Dmitry Vyukov
2020-01-08 8:55 ` Sebastian Andrzej Siewior
2020-01-08 9:03 ` Dmitry Vyukov
2020-03-22 22:41 ` syzbot
2020-03-23 15:01 ` Sean Christopherson [this message]
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