Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH] [8/36] CPA: Do a simple self test at boot | Date | Wed, 16 Jan 2008 23:15:06 +0100 (CET) |
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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 <ak@suse.de> Acked-by: Jan Beulich <jbeulich@novell.com>
--- 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
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