From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757258AbdJMIQa (ORCPT ); Fri, 13 Oct 2017 04:16:30 -0400 Received: from mail-wm0-f44.google.com ([74.125.82.44]:43258 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756708AbdJMIQ1 (ORCPT ); Fri, 13 Oct 2017 04:16:27 -0400 X-Google-Smtp-Source: AOwi7QA8BESvyLWmlqOMBIyLM2R7hEbdboxW6cxq/h91PFm2c1Awoq12G+6Yo/L+xa6PyAjgFlng7g== Date: Fri, 13 Oct 2017 10:16:32 +0200 From: Christoffer Dall To: "Tobin C. Harding" Cc: Christoffer Dall , Marc Zyngier , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: remove printing of vcpu address Message-ID: <20171013081632.GB8927@cbox> References: <1507530701-10777-1-git-send-email-me@tobin.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1507530701-10777-1-git-send-email-me@tobin.cc> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 09, 2017 at 05:31:41PM +1100, Tobin C. Harding wrote: > Code currently prints the address of the kvm_vcpu structure in an error > message. It is not immediately clear what value this address adds to > the error string, we can use the vcpu ID instead. I would say it's not immediately clear how the vcpu ID is more valuable. The pointer identifies a unique vcpu across all VMs, vcpu ID does not. > Printing unnecessary > kernel addresses to dmesg poses a security risk. Is this really a concern we have for error messages? I understand you can get a single pointer revealed if you have broken hardware or if we have a bug, but I see numerious other examples in the kernel. If anything, we can remote printing the vcpu pointer entirely. Thanks, -Christoffer > > Remove the address from error message output, show vcpu ID instead. > > Signed-off-by: Tobin C. Harding > --- > virt/kvm/arm/arch_timer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c > index 8e89d63005c7..ca6c331cad28 100644 > --- a/virt/kvm/arm/arch_timer.c > +++ b/virt/kvm/arm/arch_timer.c > @@ -88,7 +88,7 @@ static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) > * interrupt at this point is a sure sign of some major > * breakage. > */ > - pr_warn("Unexpected interrupt %d on vcpu %p\n", irq, vcpu); > + pr_warn("Unexpected interrupt %d on vcpu ID %d\n", irq, vcpu->vcpu_id); > return IRQ_HANDLED; > } > > -- > 2.7.4 >