1 files changed, 17 insertions, 10 deletions

diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c
index d494ff647cac..2776a074c6f1 100644
--- a/arch/ia64/kernel/unwind.c
+++ b/arch/ia64/kernel/unwind.c
@@ -1943,23 +1943,30 @@ EXPORT_SYMBOL(unw_unwind);
 int
 unw_unwind_to_user (struct unw_frame_info *info)
 {
-        unsigned long ip, sp;
+        unsigned long ip, sp, pr = 0;
 
         while (unw_unwind(info) >= 0) {
-                if (unw_get_rp(info, &ip) < 0) {
-                        unw_get_ip(info, &ip);
-                        UNW_DPRINT(0, "unwind.%s: failed to read return pointer (ip=0x%lx)\n",
-                                   __FUNCTION__, ip);
-                        return -1;
-                }
                 unw_get_sp(info, &sp);
-                if (sp >= (unsigned long)info->task + IA64_STK_OFFSET)
+                if ((long)((unsigned long)info->task + IA64_STK_OFFSET - sp)
+                    < IA64_PT_REGS_SIZE) {
+                        UNW_DPRINT(0, "unwind.%s: ran off the top of the kernel stack\n",
+                                   __FUNCTION__);
                         break;
-                if (ip < FIXADDR_USER_END)
+                }
+                if (unw_is_intr_frame(info) &&
+                    (pr & (1UL << PRED_USER_STACK)))
                         return 0;
+                if (unw_get_pr (info, &pr) < 0) {
+                        unw_get_rp(info, &ip);
+                        UNW_DPRINT(0, "unwind.%s: failed to read "
+                                   "predicate register (ip=0x%lx)\n",
+                                __FUNCTION__, ip);
+                        return -1;
+                }
         }
         unw_get_ip(info, &ip);
-        UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n", __FUNCTION__, ip);
+        UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n",
+                   __FUNCTION__, ip);
         return -1;
 }
 EXPORT_SYMBOL(unw_unwind_to_user);