2 files changed, 23 insertions, 29 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 3f2b8962cbd0..31e8730fa246 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -640,24 +640,23 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
         }
 
 
-#ifdef CONFIG_X86_32
-        /* It's safe to allow irq's after cr2 has been saved and the vmalloc
-           fault has been handled. */
-        if (regs->flags & (X86_EFLAGS_IF | X86_VM_MASK))
-                local_irq_enable();
-
         /*
-         * If we're in an interrupt, have no user context or are running in an
-         * atomic region then we must not take the fault.
+         * It's safe to allow irq's after cr2 has been saved and the
+         * vmalloc fault has been handled.
+         *
+         * User-mode registers count as a user access even for any
+         * potential system fault or CPU buglet.
          */
-        if (in_atomic() || !mm)
-                goto bad_area_nosemaphore;
-#else /* CONFIG_X86_64 */
-        if (likely(regs->flags & X86_EFLAGS_IF))
+        if (user_mode_vm(regs)) {
+                local_irq_enable();
+                error_code |= PF_USER;
+        } else if (regs->flags & X86_EFLAGS_IF)
                 local_irq_enable();
 
+#ifdef CONFIG_X86_64
         if (unlikely(error_code & PF_RSVD))
                 pgtable_bad(address, regs, error_code);
+#endif
 
         /*
          * If we're in an interrupt, have no user context or are running in an
@@ -666,15 +665,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
         if (unlikely(in_atomic() || !mm))
                 goto bad_area_nosemaphore;
 
-        /*
-         * User-mode registers count as a user access even for any
-         * potential system fault or CPU buglet.
-         */
-        if (user_mode_vm(regs))
-                error_code |= PF_USER;
 again:
-#endif
-        /* When running in the kernel we expect faults to occur only to
+        /*
+         * When running in the kernel we expect faults to occur only to
          * addresses in user space.  All other faults represent errors in the
          * kernel and should generate an OOPS.  Unfortunately, in the case of an
          * erroneous fault occurring in a code path which already holds mmap_sem
@@ -737,9 +730,6 @@ good_area:
                         goto bad_area;
         }
 
-#ifdef CONFIG_X86_32
-survive:
-#endif
         /*
          * If for any reason at all we couldn't handle the fault,
          * make sure we exit gracefully rather than endlessly redo
@@ -874,12 +864,11 @@ out_of_memory:
         up_read(&mm->mmap_sem);
         if (is_global_init(tsk)) {
                 yield();
-#ifdef CONFIG_X86_32
-                down_read(&mm->mmap_sem);
-                goto survive;
-#else
+                /*
+                 * Re-lookup the vma - in theory the vma tree might
+                 * have changed:
+                 */
                 goto again;
-#endif
         }
 
         printk("VM: killing process %s\n", tsk->comm);
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
index 182f9d4c570f..88a53b1a17f0 100644
--- a/include/asm-x86/pgtable.h
+++ b/include/asm-x86/pgtable.h
@@ -148,8 +148,13 @@
 #ifdef CONFIG_X86_64
 #define __PAGE_KERNEL_IDENT_LARGE_EXEC  __PAGE_KERNEL_LARGE_EXEC
 #else
+/*
+ * For PDE_IDENT_ATTR include USER bit. As the PDE and PTE protection
+ * bits are combined, this will alow user to access the high address mapped
+ * VDSO in the presence of CONFIG_COMPAT_VDSO
+ */
 #define PTE_IDENT_ATTR   0x003          /* PRESENT+RW */
-#define PDE_IDENT_ATTR   0x063          /* PRESENT+RW+DIRTY+ACCESSED */
+#define PDE_IDENT_ATTR   0x067          /* PRESENT+RW+USER+DIRTY+ACCESSED */
 #define PGD_IDENT_ATTR   0x001          /* PRESENT (no other attributes) */
 #endif