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>

2 files changed, 26 insertions, 35 deletions

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 3cc06e3fceb8..af5481e94863 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -134,6 +134,11 @@ static inline unsigned long pte_pfn(pte_t pte)
         return (pte_val(pte) & PTE_PFN_MASK) >> PAGE_SHIFT;
 }
 
+static inline unsigned long pmd_pfn(pmd_t pmd)
+{
+        return (pmd_val(pmd) & PTE_PFN_MASK) >> PAGE_SHIFT;
+}
+
 #define pte_page(pte)   pfn_to_page(pte_pfn(pte))
 
 static inline int pmd_large(pmd_t pte)
@@ -422,11 +427,6 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
         return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
 }
 
-static inline unsigned long pmd_pfn(pmd_t pmd)
-{
-        return (pmd_val(pmd) & PTE_PFN_MASK) >> PAGE_SHIFT;
-}
-
 static inline int pud_large(pud_t pud)
 {
         return (pud_val(pud) & (_PAGE_PSE | _PAGE_PRESENT)) ==
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 78a5fff857be..9bf7e52c2869 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;