From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57704 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728504AbeHPVsw (ORCPT ); Thu, 16 Aug 2018 17:48:52 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vitaly Kuznetsov , Thomas Gleixner , Michael Kelley , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , "Michael Kelley (EOSG)" , devel@linuxdriverproject.org, "H. Peter Anvin" Subject: [PATCH 4.18 03/22] x86/hyper-v: Check for VP_INVAL in hyperv_flush_tlb_others() Date: Thu, 16 Aug 2018 20:45:19 +0200 Message-Id: <20180816171556.628980028@linuxfoundation.org> In-Reply-To: <20180816171556.502583508@linuxfoundation.org> References: <20180816171556.502583508@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vitaly Kuznetsov commit 110d2a7fc39725d2c29d2fede4f34a35a4f98882 upstream. Commit 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI enlightenment") pre-filled hv_vp_index with VP_INVAL so it is now (theoretically) possible to observe hv_cpu_number_to_vp_number() returning VP_INVAL. We need to check for that in hyperv_flush_tlb_others(). Not checking for VP_INVAL on the first call site where we do if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64) goto do_ex_hypercall; is OK, in case we're eligible for non-ex hypercall we'll catch the issue later in for_each_cpu() cycle and in case we'll be doing ex- hypercall cpumask_to_vpset() will fail. It would be nice to change hv_cpu_number_to_vp_number() return value's type to 'u32' but this will likely be a bigger change as all call sites need to be checked first. Fixes: 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI enlightenment") Signed-off-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: "Michael Kelley (EOSG)" Cc: devel@linuxdriverproject.org Cc: "H. Peter Anvin" Link: https://lkml.kernel.org/r/20180709174012.17429-3-vkuznets@redhat.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/hyperv/mmu.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/x86/hyperv/mmu.c +++ b/arch/x86/hyperv/mmu.c @@ -95,6 +95,11 @@ static void hyperv_flush_tlb_others(cons } else { for_each_cpu(cpu, cpus) { vcpu = hv_cpu_number_to_vp_number(cpu); + if (vcpu == VP_INVAL) { + local_irq_restore(flags); + goto do_native; + } + if (vcpu >= 64) goto do_native;