From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756378AbaDHLR6 (ORCPT ); Tue, 8 Apr 2014 07:17:58 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:62725 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756126AbaDHLR4 (ORCPT ); Tue, 8 Apr 2014 07:17:56 -0400 From: "Rafael J. Wysocki" To: "Srivatsa S. Bhat" , Ming Lei Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Paolo Bonzini , Christoffer Dall , "Rafael J. Wysocki" , "ego@linux.vnet.ibm.com" Subject: Re: [PATCH] arm, kvm: fix double lock on cpu_add_remove_lock Date: Tue, 08 Apr 2014 13:33:55 +0200 Message-ID: <2948858.2iSmOgt3H2@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.14.0-rc7+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <53424946.4000504@linux.vnet.ibm.com> References: <1396805768-18669-1-git-send-email-tom.leiming@gmail.com> <53424946.4000504@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, April 07, 2014 12:14:22 PM Srivatsa S. Bhat wrote: > On 04/06/2014 11:06 PM, Ming Lei wrote: > > The patch of "arm, kvm: Fix CPU hotplug callback registration" > > in -next tree holds the lock before calling the two functions: > > > > kvm_vgic_hyp_init() > > kvm_timer_hyp_init() > > > > and both the two functions are calling register_cpu_notifier() > > to register cpu notifier, so cause double lock on cpu_add_remove_lock. > > > > Considered that both two functions are only called inside > > kvm_arch_init() with holding cpu_add_remove_lock, so simply use > > __register_cpu_notifier() to fix the problem. > > > > Cc: Paolo Bonzini > > Cc: Christoffer Dall > > Cc: Srivatsa S. Bhat > > Cc: Rafael J. Wysocki > > Signed-off-by: Ming Lei > > Sorry for missing that, and thank you for the fix! > > Reviewed-by: Srivatsa S. Bhat Applied, thanks! I'm going to include this into my next pull request. > > --- > > virt/kvm/arm/arch_timer.c | 2 +- > > virt/kvm/arm/vgic.c | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c > > index 5081e80..22fa819 100644 > > --- a/virt/kvm/arm/arch_timer.c > > +++ b/virt/kvm/arm/arch_timer.c > > @@ -277,7 +277,7 @@ int kvm_timer_hyp_init(void) > > > > host_vtimer_irq = ppi; > > > > - err = register_cpu_notifier(&kvm_timer_cpu_nb); > > + err = __register_cpu_notifier(&kvm_timer_cpu_nb); > > if (err) { > > kvm_err("Cannot register timer CPU notifier\n"); > > goto out_free; > > diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c > > index 8ca405c..47b2983 100644 > > --- a/virt/kvm/arm/vgic.c > > +++ b/virt/kvm/arm/vgic.c > > @@ -1496,7 +1496,7 @@ int kvm_vgic_hyp_init(void) > > goto out; > > } > > > > - ret = register_cpu_notifier(&vgic_cpu_nb); > > + ret = __register_cpu_notifier(&vgic_cpu_nb); > > if (ret) { > > kvm_err("Cannot register vgic CPU notifier\n"); > > goto out_free_irq; > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.