From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D466C3F2D1 for ; Tue, 3 Mar 2020 00:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EA0F24677 for ; Tue, 3 Mar 2020 00:01:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727988AbgCCABL (ORCPT ); Mon, 2 Mar 2020 19:01:11 -0500 Received: from mga03.intel.com ([134.134.136.65]:17170 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727372AbgCBX51 (ORCPT ); Mon, 2 Mar 2020 18:57:27 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Mar 2020 15:57:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,509,1574150400"; d="scan'208";a="243384783" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga006.jf.intel.com with ESMTP; 02 Mar 2020 15:57:23 -0800 From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li Subject: [PATCH v2 53/66] KVM: x86: Do kvm_cpuid_array capacity checks in terminal functions Date: Mon, 2 Mar 2020 15:56:56 -0800 Message-Id: <20200302235709.27467-54-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200302235709.27467-1-sean.j.christopherson@intel.com> References: <20200302235709.27467-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Perform the capacity checks on the userspace provided kvm_cpuid_array in the lower __do_cpuid_func() and __do_cpuid_func_emulated(). Pre-checking the array in do_cpuid_func() no longer adds value now that __do_cpuid_func() has been trimmed down to size, i.e. doesn't invoke a big pile of retpolined functions before doing anything useful. Note, __do_cpuid_func() already checks the array capacity via do_host_cpuid(), "moving" the check to __do_cpuid_func() simply means removing a WARN_ON(). Suggested-by: Vitaly Kuznetsov Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index eebd7f613f67..f879fcbd6fb2 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -478,8 +478,12 @@ static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array, static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) { - struct kvm_cpuid_entry2 *entry = &array->entries[array->nent]; + struct kvm_cpuid_entry2 *entry; + if (array->nent >= array->maxnent) + return -E2BIG; + + entry = &array->entries[array->nent]; entry->function = func; entry->index = 0; entry->flags = 0; @@ -516,7 +520,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) r = -E2BIG; entry = do_host_cpuid(array, function, 0); - if (WARN_ON(!entry)) + if (!entry) goto out; switch (function) { @@ -787,9 +791,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) static int do_cpuid_func(struct kvm_cpuid_array *array, u32 func, unsigned int type) { - if (array->nent >= array->maxnent) - return -E2BIG; - if (type == KVM_GET_EMULATED_CPUID) return __do_cpuid_func_emulated(array, func); -- 2.24.1