From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933726AbXH0Vqj (ORCPT ); Mon, 27 Aug 2007 17:46:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932641AbXH0VbW (ORCPT ); Mon, 27 Aug 2007 17:31:22 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:47206 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765620AbXH0VbR (ORCPT ); Mon, 27 Aug 2007 17:31:17 -0400 From: "Rafael J. Wysocki" To: Andrew Morton Subject: [PATCH -mm 4/4] Hibernation: Use temporary page tables for kernel text mapping on x86_64 Date: Mon, 27 Aug 2007 23:39:32 +0200 User-Agent: KMail/1.9.5 Cc: Andi Kleen , Johannes Berg , LKML , Pavel Machek , pm list References: <200708272331.28584.rjw@sisk.pl> In-Reply-To: <200708272331.28584.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200708272339.32772.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Use temporary page tables for the kernel text mapping during hibernation restore on x86_64. Without the patch, the original boot kernel's page tables that represent the kernel text mapping are used while the core of the image kernel is being restored. However, in principle, if the boot kernel is not identical to the image kernel, the location of these page tables in the image kernel need not be the same, so we should create a safe copy of the kernel text mapping prior to restoring the core of the image kernel. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek --- arch/x86_64/kernel/suspend.c | 39 +++++++++++++++++++++++++++++++++------ 1 file changed, 33 insertions(+), 6 deletions(-) Index: linux-2.6.23-rc3/arch/x86_64/kernel/suspend.c =================================================================== --- linux-2.6.23-rc3.orig/arch/x86_64/kernel/suspend.c 2007-08-25 22:51:56.000000000 +0200 +++ linux-2.6.23-rc3/arch/x86_64/kernel/suspend.c 2007-08-25 22:53:01.000000000 +0200 @@ -191,25 +191,42 @@ static int res_phys_pud_init(pud_t *pud, return 0; } +static int res_kernel_text_pud_init(pud_t *pud, unsigned long start) +{ + pmd_t *pmd; + unsigned long paddr; + + pmd = (pmd_t *)get_safe_page(GFP_ATOMIC); + if (!pmd) + return -ENOMEM; + set_pud(pud + pud_index(start), __pud(__pa(pmd) | _KERNPG_TABLE)); + for (paddr = 0; paddr < KERNEL_TEXT_SIZE; pmd++, paddr += PMD_SIZE) { + unsigned long pe; + + pe = __PAGE_KERNEL_LARGE_EXEC | _PAGE_GLOBAL | paddr; + pe &= __supported_pte_mask; + set_pmd(pmd, __pmd(pe)); + } + + return 0; +} + static int set_up_temporary_mappings(void) { unsigned long start, end, next; + pud_t *pud; int error; temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC); if (!temp_level4_pgt) return -ENOMEM; - /* It is safe to reuse the original kernel mapping */ - set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map), - init_level4_pgt[pgd_index(__START_KERNEL_map)]); - /* Set up the direct mapping from scratch */ start = (unsigned long)pfn_to_kaddr(0); end = (unsigned long)pfn_to_kaddr(end_pfn); for (; start < end; start = next) { - pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC); + pud = (pud_t *)get_safe_page(GFP_ATOMIC); if (!pud) return -ENOMEM; next = start + PGDIR_SIZE; @@ -220,7 +237,17 @@ static int set_up_temporary_mappings(voi set_pgd(temp_level4_pgt + pgd_index(start), mk_kernel_pgd(__pa(pud))); } - return 0; + + /* Set up the kernel text mapping from scratch */ + pud = (pud_t *)get_safe_page(GFP_ATOMIC); + if (!pud) + return -ENOMEM; + error = res_kernel_text_pud_init(pud, __START_KERNEL_map); + if (!error) + set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map), + __pgd(__pa(pud) | _PAGE_TABLE)); + + return error; } int swsusp_arch_resume(void)