From f8871496b97e9cd485de048d4ce1d987425081c5 Mon Sep 17 00:00:00 2001 From: "kfraser@localhost.localdomain" Date: Wed, 17 Jan 2007 14:45:00 +0000 Subject: [PATCH] linux/i386: enhance dump_fault_path() in the highpte case As long as the pte page isn't really located in highmem, there is no reason to not access it, in order to print the complete page table hierarchy. A functionally similar patch will go to lkml for native Linux. Signed-off-by: Jan Beulich --- linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c b/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c index cd40fabc08..7e52b47b04 100644 --- a/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c +++ b/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c @@ -232,9 +232,12 @@ static void dump_fault_path(unsigned long address) p += (address >> 21) * 2; printk(KERN_ALERT "%08lx -> *pme = %08lx:%08lx\n", page, p[1], p[0]); -#ifndef CONFIG_HIGHPTE + mfn = (p[0] >> PAGE_SHIFT) | (p[1] << 20); +#ifdef CONFIG_HIGHPTE + if (mfn_to_pfn(mfn) >= highstart_pfn) + return; +#endif if (p[0] & 1) { - mfn = (p[0] >> PAGE_SHIFT) | (p[1] << 20); page = mfn_to_pfn(mfn) << PAGE_SHIFT; p = (unsigned long *) __va(page); address &= 0x001fffff; @@ -242,7 +245,6 @@ static void dump_fault_path(unsigned long address) printk(KERN_ALERT "%08lx -> *pte = %08lx:%08lx\n", page, p[1], p[0]); } -#endif } } #else @@ -254,13 +256,16 @@ static void dump_fault_path(unsigned long address) page = ((unsigned long *) __va(page))[address >> 22]; printk(KERN_ALERT "*pde = ma %08lx pa %08lx\n", page, machine_to_phys(page)); +#ifdef CONFIG_HIGHPTE /* * We must not directly access the pte in the highpte - * case, the page table might be allocated in highmem. + * case if the page table is located in highmem. * And lets rather not kmap-atomic the pte, just in case * it's allocated already. */ -#ifndef CONFIG_HIGHPTE + if ((page >> PAGE_SHIFT) >= highstart_pfn) + return; +#endif if (page & 1) { page &= PAGE_MASK; address &= 0x003ff000; @@ -269,7 +274,6 @@ static void dump_fault_path(unsigned long address) printk(KERN_ALERT "*pte = ma %08lx pa %08lx\n", page, machine_to_phys(page)); } -#endif } #endif -- 2.30.2