1 files changed, 24 insertions, 8 deletions

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 313ac1f7dc5a..7e9edafffd8a 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -92,7 +92,11 @@ asmlinkage void spurious_interrupt_bug(void);
 asmlinkage void machine_check(void);
 
 static int kstack_depth_to_print = 24;
+#ifdef CONFIG_STACK_UNWIND
 static int call_trace = 1;
+#else
+#define call_trace (-1)
+#endif
 ATOMIC_NOTIFIER_HEAD(i386die_chain);
 
 int register_die_notifier(struct notifier_block *nb)
@@ -188,10 +192,20 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
                                 unw_ret = show_trace_unwind(&info, log_lvl);
                 }
                 if (unw_ret > 0) {
-                        if (call_trace > 0)
+                        if (call_trace == 1 && !arch_unw_user_mode(&info)) {
+                                print_symbol("DWARF2 unwinder stuck at %s\n",
+                                             UNW_PC(&info));
+                                if (UNW_SP(&info) >= PAGE_OFFSET) {
+                                        printk("Leftover inexact backtrace:\n");
+                                        stack = (void *)UNW_SP(&info);
+                                } else
+                                        printk("Full inexact backtrace again:\n");
+                        } else if (call_trace >= 1)
                                 return;
-                        printk("%sLegacy call trace:\n", log_lvl);
-                }
+                        else
+                                printk("Full inexact backtrace again:\n");
+                } else
+                        printk("Inexact backtrace:\n");
         }
 
         if (task == current) {
@@ -442,11 +456,9 @@ void die(const char * str, struct pt_regs * regs, long err)
         if (in_interrupt())
                 panic("Fatal exception in interrupt");
 
-        if (panic_on_oops) {
-                printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
-                ssleep(5);
+        if (panic_on_oops)
                 panic("Fatal exception");
-        }
+
         oops_exit();
         do_exit(SIGSEGV);
 }
@@ -1232,14 +1244,18 @@ static int __init kstack_setup(char *s)
 }
 __setup("kstack=", kstack_setup);
 
+#ifdef CONFIG_STACK_UNWIND
 static int __init call_trace_setup(char *s)
 {
         if (strcmp(s, "old") == 0)
                 call_trace = -1;
         else if (strcmp(s, "both") == 0)
                 call_trace = 0;
-        else if (strcmp(s, "new") == 0)
+        else if (strcmp(s, "newfallback") == 0)
                 call_trace = 1;
+        else if (strcmp(s, "new") == 2)
+                call_trace = 2;
         return 1;
 }
 __setup("call_trace=", call_trace_setup);
+#endif