Messages in this thread | | | Date | Tue, 1 Mar 2022 21:17:49 +0100 | Subject | Re: [PATCH AUTOSEL 5.15 05/23] KVM: Fix lockdep false negative during host resume | From | Paolo Bonzini <> |
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On 3/1/22 21:16, Sasha Levin wrote: > From: Wanpeng Li <wanpengli@tencent.com> > > [ Upstream commit 4cb9a998b1ce25fad74a82f5a5c45a4ef40de337 ] > > I saw the below splatting after the host suspended and resumed. > > WARNING: CPU: 0 PID: 2943 at kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:5531 kvm_resume+0x2c/0x30 [kvm] > CPU: 0 PID: 2943 Comm: step_after_susp Tainted: G W IOE 5.17.0-rc3+ #4 > RIP: 0010:kvm_resume+0x2c/0x30 [kvm] > Call Trace: > <TASK> > syscore_resume+0x90/0x340 > suspend_devices_and_enter+0xaee/0xe90 > pm_suspend.cold+0x36b/0x3c2 > state_store+0x82/0xf0 > kernfs_fop_write_iter+0x1b6/0x260 > new_sync_write+0x258/0x370 > vfs_write+0x33f/0x510 > ksys_write+0xc9/0x160 > do_syscall_64+0x3b/0xc0 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > lockdep_is_held() can return -1 when lockdep is disabled which triggers > this warning. Let's use lockdep_assert_not_held() which can detect > incorrect calls while holding a lock and it also avoids false negatives > when lockdep is disabled. > > Signed-off-by: Wanpeng Li <wanpengli@tencent.com> > Message-Id: <1644920142-81249-1-git-send-email-wanpengli@tencent.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > Signed-off-by: Sasha Levin <sashal@kernel.org> > --- > virt/kvm/kvm_main.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 13aff136e6eef..5309b3eaa0470 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -5416,9 +5416,7 @@ static int kvm_suspend(void) > static void kvm_resume(void) > { > if (kvm_usage_count) { > -#ifdef CONFIG_LOCKDEP > - WARN_ON(lockdep_is_held(&kvm_count_lock)); > -#endif > + lockdep_assert_not_held(&kvm_count_lock); > hardware_enable_nolock(NULL); > } > }
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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