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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 BF769C433E0 for ; Tue, 16 Jun 2020 09:55:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A03F52071A for ; Tue, 16 Jun 2020 09:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728101AbgFPJzz (ORCPT ); Tue, 16 Jun 2020 05:55:55 -0400 Received: from verein.lst.de ([213.95.11.211]:37309 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728204AbgFPJzy (ORCPT ); Tue, 16 Jun 2020 05:55:54 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id B8EE268AFE; Tue, 16 Jun 2020 11:55:49 +0200 (CEST) Date: Tue, 16 Jun 2020 11:55:49 +0200 From: Christoph Hellwig To: Vitaly Kuznetsov Cc: Dexuan Cui , Christoph Hellwig , Stephen Hemminger , Andy Lutomirski , Peter Zijlstra , Andy Lutomirski , Michael Kelley , Ju-Hyoung Lee , "x86@kernel.org" , "linux-hyperv@vger.kernel.org" , "linux-kernel@vger.kernel.org" , KY Srinivasan Subject: Re: hv_hypercall_pg page permissios Message-ID: <20200616095549.GA27917@lst.de> References: <20200407073830.GA29279@lst.de> <87y2ooiv5k.fsf@vitty.brq.redhat.com> <87blljicjm.fsf@vitty.brq.redhat.com> <20200616093341.GA26400@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200616093341.GA26400@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org Actually, what do you think of this one: --- >From a5ee278f4244c6bfc0ce2d2b2fd4f99358dbde4d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 16 Jun 2020 11:50:59 +0200 Subject: x86/hyperv: allocate the hypercall page with only read and execute bits Avoid a W^X violation cause by the fact that PAGE_KERNEL_EXEC includes the writable bit. Fixes: 78bb17f76edc ("x86/hyperv: use vmalloc_exec for the hypercall page") Reported-by: Dexuan Cui Signed-off-by: Christoph Hellwig --- arch/x86/hyperv/hv_init.c | 4 +++- arch/x86/include/asm/pgtable_types.h | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index a54c6a401581dd..f4875bf05c17ff 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -375,7 +375,9 @@ void __init hyperv_init(void) guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id); - hv_hypercall_pg = vmalloc_exec(PAGE_SIZE); + hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, + VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_RX, + VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, __func__); if (hv_hypercall_pg == NULL) { wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); goto remove_cpuhp_state; diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 2da1f95b88d761..591b5c92a66249 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -194,6 +194,7 @@ enum page_cache_mode { #define _PAGE_TABLE_NOENC (__PP|__RW|_USR|___A| 0|___D| 0| 0) #define _PAGE_TABLE (__PP|__RW|_USR|___A| 0|___D| 0| 0| _ENC) #define __PAGE_KERNEL_RO (__PP| 0| 0|___A|__NX|___D| 0|___G) +#define __PAGE_KERNEL_RX (__PP| 0| 0|___A| 0|___D| 0|___G) #define __PAGE_KERNEL_NOCACHE (__PP|__RW| 0|___A|__NX|___D| 0|___G| __NC) #define __PAGE_KERNEL_VVAR (__PP| 0|_USR|___A|__NX|___D| 0|___G) #define __PAGE_KERNEL_LARGE (__PP|__RW| 0|___A|__NX|___D|_PSE|___G) @@ -219,6 +220,7 @@ enum page_cache_mode { #define PAGE_KERNEL_RO __pgprot_mask(__PAGE_KERNEL_RO | _ENC) #define PAGE_KERNEL_EXEC __pgprot_mask(__PAGE_KERNEL_EXEC | _ENC) #define PAGE_KERNEL_EXEC_NOENC __pgprot_mask(__PAGE_KERNEL_EXEC | 0) +#define PAGE_KERNEL_RX __pgprot_mask(__PAGE_KERNEL_RX | _ENC) #define PAGE_KERNEL_NOCACHE __pgprot_mask(__PAGE_KERNEL_NOCACHE | _ENC) #define PAGE_KERNEL_LARGE __pgprot_mask(__PAGE_KERNEL_LARGE | _ENC) #define PAGE_KERNEL_LARGE_EXEC __pgprot_mask(__PAGE_KERNEL_LARGE_EXEC | _ENC) -- 2.26.2