x86: Clean up dump_pagetable()

Use pgtable access helpers for 32-bit version dump_pagetable()
and get rid of __typeof__() operators. This needs to make
pmd_pfn() available for 2-level pgtable.

Also, remove some casts for 64-bit version dump_pagetable().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090627063514.GA2834@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 21 insertions, 30 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 78a5fff857b..9bf7e52c286 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -285,26 +285,25 @@ check_v8086_mode(struct pt_regs *regs, unsigned long address,
 		tsk->thread.screen_bitmap |= 1 << bit;
 }
 
-static void dump_pagetable(unsigned long address)
+static bool low_pfn(unsigned long pfn)
 {
-	__typeof__(pte_val(__pte(0))) page;
+	return pfn < max_low_pfn;
+}
 
-	page = read_cr3();
-	page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT];
+static void dump_pagetable(unsigned long address)
+{
+	pgd_t *base = __va(read_cr3());
+	pgd_t *pgd = &base[pgd_index(address)];
+	pmd_t *pmd;
+	pte_t *pte;
 
 #ifdef CONFIG_X86_PAE
-	printk("*pdpt = %016Lx ", page);
-	if ((page >> PAGE_SHIFT) < max_low_pfn
-	    && page & _PAGE_PRESENT) {
-		page &= PAGE_MASK;
-		page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT)
-							& (PTRS_PER_PMD - 1)];
-		printk(KERN_CONT "*pde = %016Lx ", page);
-		page &= ~_PAGE_NX;
-	}
-#else
-	printk("*pde = %08lx ", page);
+	printk("*pdpt = %016Lx ", pgd_val(*pgd));
+	if (!low_pfn(pgd_val(*pgd) >> PAGE_SHIFT) || !pgd_present(*pgd))
+		goto out;
 #endif
+	pmd = pmd_offset(pud_offset(pgd, address), address);
+	printk(KERN_CONT "*pde = %0*Lx ", sizeof(*pmd) * 2, (u64)pmd_val(*pmd));
 
 	/*
 	 * We must not directly access the pte in the highpte
@@ -312,16 +311,12 @@ static void dump_pagetable(unsigned long address)
 	 * And let's rather not kmap-atomic the pte, just in case
 	 * it's allocated already:
 	 */
-	if ((page >> PAGE_SHIFT) < max_low_pfn
-	    && (page & _PAGE_PRESENT)
-	    && !(page & _PAGE_PSE)) {
-
-		page &= PAGE_MASK;
-		page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT)
-							& (PTRS_PER_PTE - 1)];
-		printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page);
-	}
+	if (!low_pfn(pmd_pfn(*pmd)) || !pmd_present(*pmd) || pmd_large(*pmd))
+		goto out;
 
+	pte = pte_offset_kernel(pmd, address);
+	printk("*pte = %0*Lx ", sizeof(*pte) * 2, (u64)pte_val(*pte));
+out:
 	printk("\n");
 }
 
@@ -449,16 +444,12 @@ static int bad_address(void *p)
 
 static void dump_pagetable(unsigned long address)
 {
-	pgd_t *pgd;
+	pgd_t *base = __va(read_cr3() & PHYSICAL_PAGE_MASK);
+	pgd_t *pgd = base + pgd_index(address);
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
 
-	pgd = (pgd_t *)read_cr3();
-
-	pgd = __va((unsigned long)pgd & PHYSICAL_PAGE_MASK);
-
-	pgd += pgd_index(address);
 	if (bad_address(pgd))
 		goto bad;