Better XenLinux page fault debug output for PAE.

Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/xen/i386/mm/fault.c b/linux-2.6-xen-sparse/arch/xen/i386/mm/fault.c
index 6a89be621ba5876777701b0006dfb3a3b1e7a383..a826b7e38fe96a9dc13d89c76da3718f708a6150 100644 (file)
--- a/linux-2.6-xen-sparse/arch/xen/i386/mm/fault.c
+++ b/linux-2.6-xen-sparse/arch/xen/i386/mm/fault.c
@@ -204,6 +204,63 @@ static inline int is_prefetch(struct pt_regs *regs, unsigned long addr,
 
 fastcall void do_invalid_op(struct pt_regs *, unsigned long);
 
+#ifdef CONFIG_X86_PAE
+static void dump_fault_path(unsigned long address)
+{
+       unsigned long *p, page;
+
+        page = __pa(per_cpu(cur_pgd, smp_processor_id()));
+       p  = (unsigned long *)__va(page);
+       p += (address >> 30) * 2;
+       printk(KERN_ALERT "%08lx -> *pde = %08lx:%08lx\n", page, p[1], p[0]);
+       if (p[0] & 1) {
+               page = p[0] & PAGE_MASK;
+               address &= 0x3fffffff;
+               page = machine_to_phys(page);
+               p  = (unsigned long *)__va(page);
+               p += (address >> 21) * 2;
+               printk(KERN_ALERT "%08lx -> *pme = %08lx:%08lx\n", page, p[1], p[0]);
+#ifndef CONFIG_HIGHPTE
+               if (p[0] & 1) {
+                       page = p[0] & PAGE_MASK;
+                       address &= 0x001fffff;
+                       page = machine_to_phys(page);
+                       p  = (unsigned long *) __va(page);
+                       p += (address >> 12) * 2;
+                       printk(KERN_ALERT "%08lx -> *pte = %08lx:%08lx\n", page, p[1], p[0]);
+               }
+#endif
+       }
+}
+#else
+static void dump_fault_path(unsigned long address)
+{
+       unsigned long page;
+
+       page = ((unsigned long *) per_cpu(cur_pgd, smp_processor_id()))
+           [address >> 22];
+       printk(KERN_ALERT "*pde = ma %08lx pa %08lx\n", page,
+              machine_to_phys(page));
+       /*
+        * We must not directly access the pte in the highpte
+        * case, the page table might be allocated in highmem.
+        * And lets rather not kmap-atomic the pte, just in case
+        * it's allocated already.
+        */
+#ifndef CONFIG_HIGHPTE
+       if (page & 1) {
+               page &= PAGE_MASK;
+               address &= 0x003ff000;
+               page = machine_to_phys(page);
+               page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT];
+               printk(KERN_ALERT "*pte = ma %08lx pa %08lx\n", page,
+                      machine_to_phys(page));
+       }
+#endif
+}
+#endif
+
+
 /*
  * This routine handles page faults.  It determines the address,
  * and the problem, and then passes it off to one of the appropriate
@@ -220,7 +277,6 @@ fastcall void do_page_fault(struct pt_regs *regs, unsigned long error_code,
        struct task_struct *tsk;
        struct mm_struct *mm;
        struct vm_area_struct * vma;
-       unsigned long page;
        int write;
        siginfo_t info;
 
@@ -454,26 +510,7 @@ no_context:
        printk(" at virtual address %08lx\n",address);
        printk(KERN_ALERT " printing eip:\n");
        printk("%08lx\n", regs->eip);
-       page = ((unsigned long *) per_cpu(cur_pgd, smp_processor_id()))
-           [address >> 22];
-       printk(KERN_ALERT "*pde = ma %08lx pa %08lx\n", page,
-              machine_to_phys(page));
-       /*
-        * We must not directly access the pte in the highpte
-        * case, the page table might be allocated in highmem.
-        * And lets rather not kmap-atomic the pte, just in case
-        * it's allocated already.
-        */
-#ifndef CONFIG_HIGHPTE
-       if (page & 1) {
-               page &= PAGE_MASK;
-               address &= 0x003ff000;
-               page = machine_to_phys(page);
-               page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT];
-               printk(KERN_ALERT "*pte = ma %08lx pa %08lx\n", page,
-                      machine_to_phys(page));
-       }
-#endif
+       dump_fault_path(address);
        die("Oops", regs, error_code);
        bust_spinlocks(0);
        do_exit(SIGKILL);