arch/x86_64/kernel/stacktrace.c

   1 /*
   2  * arch/x86_64/kernel/stacktrace.c
   3  *
   4  * Stack trace management functions
   5  *
   6  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
   7  */
   8 #include <linux/sched.h>
   9 #include <linux/stacktrace.h>
  10 #include <linux/module.h>
  11 #include <asm/stacktrace.h>
  12
  13 static void save_stack_warning(void *data, char *msg)
  14 {
  15 }
  16
  17 static void
  18 save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
  19 {
  20 }
  21
  22 static int save_stack_stack(void *data, char *name)
  23 {
  24         struct stack_trace *trace = (struct stack_trace *)data;
  25         return trace->all_contexts ? 0 : -1;
  26 }
  27
  28 static void save_stack_address(void *data, unsigned long addr)
  29 {
  30         struct stack_trace *trace = (struct stack_trace *)data;
  31         if (trace->skip > 0) {
  32                 trace->skip--;
  33                 return;
  34         }
  35         if (trace->nr_entries < trace->max_entries - 1)
  36                 trace->entries[trace->nr_entries++] = addr;
  37 }
  38
  39 static struct stacktrace_ops save_stack_ops = {
  40         .warning = save_stack_warning,
  41         .warning_symbol = save_stack_warning_symbol,
  42         .stack = save_stack_stack,
  43         .address = save_stack_address,
  44 };
  45
  46 /*
  47  * Save stack-backtrace addresses into a stack_trace buffer.
  48  */
  49 void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
  50 {
  51         dump_trace(task, NULL, NULL, &save_stack_ops, trace);
  52         trace->entries[trace->nr_entries++] = ULONG_MAX;
  53 }
  54 EXPORT_SYMBOL(save_stack_trace);
  55