From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755015AbYAPWRx (ORCPT ); Wed, 16 Jan 2008 17:17:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753459AbYAPWPL (ORCPT ); Wed, 16 Jan 2008 17:15:11 -0500 Received: from ns2.suse.de ([195.135.220.15]:38234 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751767AbYAPWPH (ORCPT ); Wed, 16 Jan 2008 17:15:07 -0500 From: Andi Kleen References: <200801161114.239449000@suse.de> In-Reply-To: <200801161114.239449000@suse.de> To: linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de, jbeulich@novell.com, venkatesh.pallipadi@intel.com Subject: [PATCH] [8/36] CPA: Do a simple self test at boot Message-Id: <20080116221506.DAB9A150C8@wotan.suse.de> Date: Wed, 16 Jan 2008 23:15:06 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When CONFIG_DEBUG_RODATA is enabled undo the ro mapping and redo it again. This gives some simple testing for change_page_attr() Optional patch, but I find it useful. Signed-off-by: Andi Kleen Acked-by: Jan Beulich --- arch/x86/Kconfig.debug | 5 +++++ arch/x86/mm/init_32.c | 26 ++++++++++++++++++++++++++ arch/x86/mm/init_64.c | 10 ++++++++++ 3 files changed, 41 insertions(+) Index: linux/arch/x86/mm/init_64.c =================================================================== --- linux.orig/arch/x86/mm/init_64.c +++ linux/arch/x86/mm/init_64.c @@ -744,6 +744,16 @@ void mark_rodata_ro(void) * of who is the culprit. */ global_flush_tlb(); + +#ifdef CONFIG_CPA_DEBUG + printk("Testing CPA: undo %lx-%lx\n", start, end); + change_page_attr_addr(start, (end - start) >> PAGE_SHIFT, PAGE_KERNEL); + global_flush_tlb(); + + printk("Testing CPA: again\n"); + change_page_attr_addr(start, (end - start) >> PAGE_SHIFT, PAGE_KERNEL_RO); + global_flush_tlb(); +#endif } #endif Index: linux/arch/x86/mm/init_32.c =================================================================== --- linux.orig/arch/x86/mm/init_32.c +++ linux/arch/x86/mm/init_32.c @@ -822,6 +822,20 @@ void mark_rodata_ro(void) change_page_attr(virt_to_page(start), size >> PAGE_SHIFT, PAGE_KERNEL_RX); printk("Write protecting the kernel text: %luk\n", size >> 10); + +#ifdef CONFIG_CPA_DEBUG + global_flush_tlb(); + + printk("Testing CPA: Reverting %lx-%lx\n", start, start+size); + change_page_attr(virt_to_page(start), size>>PAGE_SHIFT, + PAGE_KERNEL_EXEC); + global_flush_tlb(); + + printk("Testing CPA: write protecting again\n"); + change_page_attr(virt_to_page(start), size>>PAGE_SHIFT, + PAGE_KERNEL_RX); + global_flush_tlb(); +#endif } #endif start += size; @@ -838,6 +852,18 @@ void mark_rodata_ro(void) * of who is the culprit. */ global_flush_tlb(); + +#ifdef CONFIG_CPA_DEBUG + printk("Testing CPA: undo %lx-%lx\n", start, start + size); + change_page_attr(virt_to_page(start), size >> PAGE_SHIFT, + PAGE_KERNEL); + global_flush_tlb(); + + printk("Testing CPA: write protecting again\n"); + change_page_attr(virt_to_page(start), size >> PAGE_SHIFT, + PAGE_KERNEL_RO); + global_flush_tlb(); +#endif } #endif Index: linux/arch/x86/Kconfig.debug =================================================================== --- linux.orig/arch/x86/Kconfig.debug +++ linux/arch/x86/Kconfig.debug @@ -192,4 +192,9 @@ config DEBUG_BOOT_PARAMS help This option will cause struct boot_params to be exported via debugfs. +config CPA_DEBUG + bool "CPA self test code" + help + Do change_page_attr self tests at boot. + endmenu