4 files changed, 35 insertions, 22 deletions

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 82e0fd02af1c..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)
@@ -187,22 +191,21 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
                         if (unwind_init_blocked(&info, task) == 0)
                                 unw_ret = show_trace_unwind(&info, log_lvl);
                 }
-                if (unw_ret > 0 && !arch_unw_user_mode(&info)) {
-#ifdef CONFIG_STACK_UNWIND
-                        print_symbol("DWARF2 unwinder stuck at %s\n",
-                                     UNW_PC(&info));
-                        if (call_trace == 1) {
-                                printk("Leftover inexact backtrace:\n");
-                                if (UNW_SP(&info))
+                if (unw_ret > 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 if (call_trace > 1)
+                                } else
+                                        printk("Full inexact backtrace again:\n");
+                        } else if (call_trace >= 1)
                                 return;
                         else
                                 printk("Full inexact backtrace again:\n");
-#else
+                } else
                         printk("Inexact backtrace:\n");
-#endif
-                }
         }
 
         if (task == current) {
@@ -1241,6 +1244,7 @@ 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)
@@ -1254,3 +1258,4 @@ static int __init call_trace_setup(char *s)
         return 1;
 }
 __setup("call_trace=", call_trace_setup);
+#endif
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 14052f089814..5e00af54af65 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -107,7 +107,11 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
 }
 
 static int kstack_depth_to_print = 12;
+#ifdef CONFIG_STACK_UNWIND
 static int call_trace = 1;
+#else
+#define call_trace (-1)
+#endif
 
 #ifdef CONFIG_KALLSYMS
 # include <linux/kallsyms.h>
@@ -274,21 +278,21 @@ void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * s
                         if (unwind_init_blocked(&info, tsk) == 0)
                                 unw_ret = show_trace_unwind(&info, NULL);
                 }
-                if (unw_ret > 0 && !arch_unw_user_mode(&info)) {
-#ifdef CONFIG_STACK_UNWIND
-                        unsigned long rip = info.regs.rip;
-                        print_symbol("DWARF2 unwinder stuck at %s\n", rip);
-                        if (call_trace == 1) {
-                                printk("Leftover inexact backtrace:\n");
-                                stack = (unsigned long *)info.regs.rsp;
-                        } else if (call_trace > 1)
+                if (unw_ret > 0) {
+                        if (call_trace == 1 && !arch_unw_user_mode(&info)) {
+                                print_symbol("DWARF2 unwinder stuck at %s\n",
+                                             UNW_PC(&info));
+                                if ((long)UNW_SP(&info) < 0) {
+                                        printk("Leftover inexact backtrace:\n");
+                                        stack = (unsigned long *)UNW_SP(&info);
+                                } else
+                                        printk("Full inexact backtrace again:\n");
+                        } else if (call_trace >= 1)
                                 return;
                         else
                                 printk("Full inexact backtrace again:\n");
-#else
+                } else
                         printk("Inexact backtrace:\n");
-#endif
-                }
         }
 
         /*
@@ -1120,6 +1124,7 @@ 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)
@@ -1133,3 +1138,4 @@ static int __init call_trace_setup(char *s)
         return 1;
 }
 __setup("call_trace=", call_trace_setup);
+#endif
diff --git a/include/asm-i386/unwind.h b/include/asm-i386/unwind.h
index 69f0f1df6722..4c1a0b968569 100644
--- a/include/asm-i386/unwind.h
+++ b/include/asm-i386/unwind.h
@@ -87,6 +87,7 @@ static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
 #else
 
 #define UNW_PC(frame) ((void)(frame), 0)
+#define UNW_SP(frame) ((void)(frame), 0)
 
 static inline int arch_unw_user_mode(const void *info)
 {
diff --git a/include/asm-x86_64/unwind.h b/include/asm-x86_64/unwind.h
index f3e7124effe3..1f6e9bfb569e 100644
--- a/include/asm-x86_64/unwind.h
+++ b/include/asm-x86_64/unwind.h
@@ -95,6 +95,7 @@ static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
 #else
 
 #define UNW_PC(frame) ((void)(frame), 0)
+#define UNW_SP(frame) ((void)(frame), 0)
 
 static inline int arch_unw_user_mode(const void *info)
 {