LXR linux/kernel/stacktrace.c

   1/*
   2 * 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/kernel.h>
  10#include <linux/export.h>
  11#include <linux/kallsyms.h>
  12#include <linux/stacktrace.h>
  13
  14void print_stack_trace(struct stack_trace *trace, int spaces)
  15{
  16        int i;
  17
  18        if (WARN_ON(!trace->entries))
  19                return;
  20
  21        for (i = 0; i < trace->nr_entries; i++) {
  22                printk("%*c", 1 + spaces, ' ');
  23                print_ip_sym(trace->entries[i]);
  24        }
  25}
  26EXPORT_SYMBOL_GPL(print_stack_trace);
  27
  28int snprint_stack_trace(char *buf, size_t size,
  29                        struct stack_trace *trace, int spaces)
  30{
  31        int i;
  32        unsigned long ip;
  33        int generated;
  34        int total = 0;
  35
  36        if (WARN_ON(!trace->entries))
  37                return 0;
  38
  39        for (i = 0; i < trace->nr_entries; i++) {
  40                ip = trace->entries[i];
  41                generated = snprintf(buf, size, "%*c[<%p>] %pS\n",
  42                                1 + spaces, ' ', (void *) ip, (void *) ip);
  43
  44                total += generated;
  45
  46                /* Assume that generated isn't a negative number */
  47                if (generated >= size) {
  48                        buf += size;
  49                        size = 0;
  50                } else {
  51                        buf += generated;
  52                        size -= generated;
  53                }
  54        }
  55
  56        return total;
  57}
  58EXPORT_SYMBOL_GPL(snprint_stack_trace);
  59
  60/*
  61 * Architectures that do not implement save_stack_trace_tsk or
  62 * save_stack_trace_regs get this weak alias and a once-per-bootup warning
  63 * (whenever this facility is utilized - for example by procfs):
  64 */
  65__weak void
  66save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  67{
  68        WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
  69}
  70
  71__weak void
  72save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
  73{
  74        WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
  75}
  76