Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760055AbaLLGrQ (ORCPT ); Fri, 12 Dec 2014 01:47:16 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51787 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758829AbaLLGQy (ORCPT ); Fri, 12 Dec 2014 01:16:54 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "H. Peter Anvin" , "Yinghai Lu" Date: Fri, 12 Dec 2014 06:14:25 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 133/164] x86, 64bit, mm: Mark data/bss/brk to nx In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:c97:8151:cc89:c28d X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Yinghai Lu commit 72212675d1c96f5db8ec6fb35701879911193158 upstream. HPA said, we should not have RW and +x set at the time. for kernel layout: [ 0.000000] Kernel Layout: [ 0.000000] .text: [0x01000000-0x021434f8] [ 0.000000] .rodata: [0x02200000-0x02a13fff] [ 0.000000] .data: [0x02c00000-0x02dc763f] [ 0.000000] .init: [0x02dc9000-0x0312cfff] [ 0.000000] .bss: [0x0313b000-0x03dd6fff] [ 0.000000] .brk: [0x03dd7000-0x03dfffff] before the patch, we have ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff82200000 18M ro PSE GLB x pmd 0xffffffff82200000-0xffffffff82c00000 10M ro PSE GLB NX pmd 0xffffffff82c00000-0xffffffff82dc9000 1828K RW GLB x pte 0xffffffff82dc9000-0xffffffff82e00000 220K RW GLB NX pte 0xffffffff82e00000-0xffffffff83000000 2M RW PSE GLB NX pmd 0xffffffff83000000-0xffffffff8313a000 1256K RW GLB NX pte 0xffffffff8313a000-0xffffffff83200000 792K RW GLB x pte 0xffffffff83200000-0xffffffff83e00000 12M RW PSE GLB x pmd 0xffffffff83e00000-0xffffffffa0000000 450M pmd after patch,, we get ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff82200000 18M ro PSE GLB x pmd 0xffffffff82200000-0xffffffff82c00000 10M ro PSE GLB NX pmd 0xffffffff82c00000-0xffffffff82e00000 2M RW GLB NX pte 0xffffffff82e00000-0xffffffff83000000 2M RW PSE GLB NX pmd 0xffffffff83000000-0xffffffff83200000 2M RW GLB NX pte 0xffffffff83200000-0xffffffff83e00000 12M RW PSE GLB NX pmd 0xffffffff83e00000-0xffffffffa0000000 450M pmd so data, bss, brk get NX ... Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1359058816-7615-33-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin Signed-off-by: Ben Hutchings --- arch/x86/mm/init_64.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -778,6 +778,7 @@ void mark_rodata_ro(void) unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); unsigned long data_start = (unsigned long) &_sdata; + unsigned long all_end = PFN_ALIGN(&_end); printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", (end - start) >> 10); @@ -786,10 +787,10 @@ void mark_rodata_ro(void) kernel_set_to_readonly = 1; /* - * The rodata section (but not the kernel text!) should also be - * not-executable. + * The rodata/data/bss/brk section (but not the kernel text!) + * should also be not-executable. */ - set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); + set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT); rodata_test(); -- 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/