*/
 #include <linux/sched.h>
 #include <linux/stacktrace.h>
+#include <linux/module.h>
+#include <asm/stacktrace.h>
 
-#include <asm/smp.h>
-
-static inline int
-in_range(unsigned long start, unsigned long addr, unsigned long end)
+static void save_stack_warning(void *data, char *msg)
 {
-       return addr >= start && addr <= end;
 }
 
-static unsigned long
-get_stack_end(struct task_struct *task, unsigned long stack)
+static void
+save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
 {
-       unsigned long stack_start, stack_end, flags;
-       int i, cpu;
-
-       /*
-        * The most common case is that we are in the task stack:
-        */
-       stack_start = (unsigned long)task->thread_info;
-       stack_end = stack_start + THREAD_SIZE;
-
-       if (in_range(stack_start, stack, stack_end))
-               return stack_end;
-
-       /*
-        * We are in an interrupt if irqstackptr is set:
-        */
-       raw_local_irq_save(flags);
-       cpu = safe_smp_processor_id();
-       stack_end = (unsigned long)cpu_pda(cpu)->irqstackptr;
-
-       if (stack_end) {
-               stack_start = stack_end & ~(IRQSTACKSIZE-1);
-               if (in_range(stack_start, stack, stack_end))
-                       goto out_restore;
-               /*
-                * We get here if we are in an IRQ context but we
-                * are also in an exception stack.
-                */
-       }
-
-       /*
-        * Iterate over all exception stacks, and figure out whether
-        * 'stack' is in one of them:
-        */
-       for (i = 0; i < N_EXCEPTION_STACKS; i++) {
-               /*
-                * set 'end' to the end of the exception stack.
-                */
-               stack_end = per_cpu(init_tss, cpu).ist[i];
-               stack_start = stack_end - EXCEPTION_STKSZ;
-
-               /*
-                * Is 'stack' above this exception frame's end?
-                * If yes then skip to the next frame.
-                */
-               if (stack >= stack_end)
-                       continue;
-               /*
-                * Is 'stack' above this exception frame's start address?
-                * If yes then we found the right frame.
-                */
-               if (stack >= stack_start)
-                       goto out_restore;
-
-               /*
-                * If this is a debug stack, and if it has a larger size than
-                * the usual exception stacks, then 'stack' might still
-                * be within the lower portion of the debug stack:
-                */
-#if DEBUG_STKSZ > EXCEPTION_STKSZ
-               if (i == DEBUG_STACK - 1 && stack >= stack_end - DEBUG_STKSZ) {
-                       /*
-                        * Black magic. A large debug stack is composed of
-                        * multiple exception stack entries, which we
-                        * iterate through now. Dont look:
-                        */
-                       do {
-                               stack_end -= EXCEPTION_STKSZ;
-                               stack_start -= EXCEPTION_STKSZ;
-                       } while (stack < stack_start);
-
-                       goto out_restore;
-               }
-#endif
-       }
-       /*
-        * Ok, 'stack' is not pointing to any of the system stacks.
-        */
-       stack_end = 0;
-
-out_restore:
-       raw_local_irq_restore(flags);
-
-       return stack_end;
 }
 
-
-/*
- * Save stack-backtrace addresses into a stack_trace buffer:
- */
-static inline unsigned long
-save_context_stack(struct stack_trace *trace,
-                  unsigned long stack, unsigned long stack_end)
+static int save_stack_stack(void *data, char *name)
 {
-       int skip = trace->skip;
-       unsigned long addr;
-
-#ifdef CONFIG_FRAME_POINTER
-       unsigned long prev_stack = 0;
+       struct stack_trace *trace = (struct stack_trace *)data;
+       return trace->all_contexts ? 0 : -1;
+}
 
-       while (in_range(prev_stack, stack, stack_end)) {
-               pr_debug("stack:          %p\n", (void *)stack);
-               addr = (unsigned long)(((unsigned long *)stack)[1]);
-               pr_debug("addr:           %p\n", (void *)addr);
-               if (!skip)
-                       trace->entries[trace->nr_entries++] = addr-1;
-               else
-                       skip--;
-               if (trace->nr_entries >= trace->max_entries)
-                       break;
-               if (!addr)
-                       return 0;
-               /*
-                * Stack frames must go forwards (otherwise a loop could
-                * happen if the stackframe is corrupted), so we move
-                * prev_stack forwards:
-                */
-               prev_stack = stack;
-               stack = (unsigned long)(((unsigned long *)stack)[0]);
-       }
-       pr_debug("invalid:        %p\n", (void *)stack);
-#else
-       while (stack < stack_end) {
-               addr = ((unsigned long *)stack)[0];
-               stack += sizeof(long);
-               if (__kernel_text_address(addr)) {
-                       if (!skip)
-                               trace->entries[trace->nr_entries++] = addr-1;
-                       else
-                               skip--;
-                       if (trace->nr_entries >= trace->max_entries)
-                               break;
-               }
+static void save_stack_address(void *data, unsigned long addr)
+{
+       struct stack_trace *trace = (struct stack_trace *)data;
+       if (trace->skip > 0) {
+               trace->skip--;
+               return;
        }
-#endif
-       return stack;
+       if (trace->nr_entries < trace->max_entries - 1)
+               trace->entries[trace->nr_entries++] = addr;
 }
 
-#define MAX_STACKS 10
+static struct stacktrace_ops save_stack_ops = {
+       .warning = save_stack_warning,
+       .warning_symbol = save_stack_warning_symbol,
+       .stack = save_stack_stack,
+       .address = save_stack_address,
+};
 
 /*
  * Save stack-backtrace addresses into a stack_trace buffer.
  */
 void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
 {
-       unsigned long stack = (unsigned long)&stack;
-       int i, nr_stacks = 0, stacks_done[MAX_STACKS];
-
-       WARN_ON(trace->nr_entries || !trace->max_entries);
-
-       if (!task)
-               task = current;
-
-       pr_debug("task: %p, ti: %p\n", task, task->thread_info);
-
-       if (!task || task == current) {
-               /* Grab rbp right from our regs: */
-               asm ("mov %%rbp, %0" : "=r" (stack));
-               pr_debug("rbp:            %p\n", (void *)stack);
-       } else {
-               /* rbp is the last reg pushed by switch_to(): */
-               stack = task->thread.rsp;
-               pr_debug("other task rsp: %p\n", (void *)stack);
-               stack = (unsigned long)(((unsigned long *)stack)[0]);
-               pr_debug("other task rbp: %p\n", (void *)stack);
-       }
-
-       while (1) {
-               unsigned long stack_end = get_stack_end(task, stack);
-
-               pr_debug("stack:          %p\n", (void *)stack);
-               pr_debug("stack end:      %p\n", (void *)stack_end);
-
-               /*
-                * Invalid stack addres?
-                */
-               if (!stack_end)
-                       return;
-               /*
-                * Were we in this stack already? (recursion)
-                */
-               for (i = 0; i < nr_stacks; i++)
-                       if (stacks_done[i] == stack_end)
-                               return;
-               stacks_done[nr_stacks] = stack_end;
-
-               stack = save_context_stack(trace, stack, stack_end);
-               if (!stack || trace->nr_entries >= trace->max_entries)
-                       return;
-               trace->entries[trace->nr_entries++] = ULONG_MAX;
-               if (trace->nr_entries >= trace->max_entries)
-                       return;
-               if (++nr_stacks >= MAX_STACKS)
-                       return;
-       }
+       dump_trace(task, NULL, NULL, &save_stack_ops, trace);
+       trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
+EXPORT_SYMBOL(save_stack_trace);
 
 
 #include <asm/pda.h>
 #include <asm/proto.h>
 #include <asm/nmi.h>
+#include <asm/stacktrace.h>
 
 asmlinkage void divide_error(void);
 asmlinkage void debug(void);
 #endif
 
 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
-                                       unsigned *usedp, const char **idp)
+                                       unsigned *usedp, char **idp)
 {
        static char ids[][8] = {
                [DEBUG_STACK - 1] = "#DB",
        return NULL;
 }
 
-static int show_trace_unwind(struct unwind_frame_info *info, void *context)
+struct ops_and_data {
+       struct stacktrace_ops *ops;
+       void *data;
+};
+
+static int dump_trace_unwind(struct unwind_frame_info *info, void *context)
 {
+       struct ops_and_data *oad = (struct ops_and_data *)context;
        int n = 0;
 
        while (unwind(info) == 0 && UNW_PC(info)) {
                n++;
-               printk_address(UNW_PC(info));
+               oad->ops->address(oad->data, UNW_PC(info));
                if (arch_unw_user_mode(info))
                        break;
        }
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  */
 
-void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack)
+void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack,
+               struct stacktrace_ops *ops, void *data)
 {
        const unsigned cpu = safe_smp_processor_id();
        unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
        unsigned used = 0;
 
-       printk("\nCall Trace:\n");
-
        if (!tsk)
                tsk = current;
 
        if (call_trace >= 0) {
                int unw_ret = 0;
                struct unwind_frame_info info;
+               struct ops_and_data oad = { .ops = ops, .data = data };
 
                if (regs) {
                        if (unwind_init_frame_info(&info, tsk, regs) == 0)
-                               unw_ret = show_trace_unwind(&info, NULL);
+                               unw_ret = dump_trace_unwind(&info, &oad);
                } else if (tsk == current)
-                       unw_ret = unwind_init_running(&info, show_trace_unwind, NULL);
+                       unw_ret = unwind_init_running(&info, dump_trace_unwind, &oad);
                else {
                        if (unwind_init_blocked(&info, tsk) == 0)
-                               unw_ret = show_trace_unwind(&info, NULL);
+                               unw_ret = dump_trace_unwind(&info, &oad);
                }
                if (unw_ret > 0) {
                        if (call_trace == 1 && !arch_unw_user_mode(&info)) {
-                               print_symbol("DWARF2 unwinder stuck at %s\n",
+                               ops->warning_symbol(data, "DWARF2 unwinder stuck at %s\n",
                                             UNW_PC(&info));
                                if ((long)UNW_SP(&info) < 0) {
-                                       printk("Leftover inexact backtrace:\n");
+                                       ops->warning(data, "Leftover inexact backtrace:\n");
                                        stack = (unsigned long *)UNW_SP(&info);
                                } else
-                                       printk("Full inexact backtrace again:\n");
+                                       ops->warning(data, "Full inexact backtrace again:\n");
                        } else if (call_trace >= 1)
                                return;
                        else
-                               printk("Full inexact backtrace again:\n");
+                               ops->warning(data, "Full inexact backtrace again:\n");
                } else
-                       printk("Inexact backtrace:\n");
+                       ops->warning(data, "Inexact backtrace:\n");
+       }
+       if (!stack) {
+               unsigned long dummy;
+               stack = &dummy;
+               if (tsk && tsk != current)
+                       stack = (unsigned long *)tsk->thread.rsp;
        }
 
        /*
                         * down the cause of the crash will be able to figure \
                         * out the call path that was taken. \
                         */ \
-                       printk_address(addr); \
+                       ops->address(data, addr);   \
                } \
        } while (0)
 
         * current stack address. If the stacks consist of nested
         * exceptions
         */
-       for ( ; ; ) {
-               const char *id;
+       for (;;) {
+               char *id;
                unsigned long *estack_end;
                estack_end = in_exception_stack(cpu, (unsigned long)stack,
                                                &used, &id);
 
                if (estack_end) {
-                       printk(" <%s>", id);
+                       if (ops->stack(data, id) < 0)
+                               break;
                        HANDLE_STACK (stack < estack_end);
-                       printk(" <EOE>");
+                       ops->stack(data, "<EOE>");
                        /*
                         * We link to the next stack via the
                         * second-to-last pointer (index -2 to end) in the
                                (IRQSTACKSIZE - 64) / sizeof(*irqstack);
 
                        if (stack >= irqstack && stack < irqstack_end) {
-                               printk(" <IRQ>");
+                               if (ops->stack(data, "IRQ") < 0)
+                                       break;
                                HANDLE_STACK (stack < irqstack_end);
                                /*
                                 * We link to the next stack (which would be
                                 */
                                stack = (unsigned long *) (irqstack_end[-1]);
                                irqstack_end = NULL;
-                               printk(" <EOI>");
+                               ops->stack(data, "EOI");
                                continue;
                        }
                }
        }
 
        /*
-        * This prints the process stack:
+        * This handles the process stack:
         */
        HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
 #undef HANDLE_STACK
+}
+EXPORT_SYMBOL(dump_trace);
 
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+       print_symbol(msg, symbol);
+       printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+       printk("%s\n", msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+       printk(" <%s> ", name);
+       return 0;
+}
+
+static void print_trace_address(void *data, unsigned long addr)
+{
+       printk_address(addr);
+}
+
+static struct stacktrace_ops print_trace_ops = {
+       .warning = print_trace_warning,
+       .warning_symbol = print_trace_warning_symbol,
+       .stack = print_trace_stack,
+       .address = print_trace_address,
+};
+
+void
+show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
+{
+       printk("\nCall Trace:\n");
+       dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
        printk("\n");
 }
 
-static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long * rsp)
+static void
+_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
 {
        unsigned long *stack;
        int i;