LXR linux/arch/parisc/kernel/stacktrace.c

   1/*
   2 * Stack trace management functions
   3 *
   4 *  Copyright (C) 2009 Helge Deller <deller@gmx.de>
   5 *  based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
   6 *  and parisc unwind functions by Randolph Chung <tausq@debian.org>
   7 *
   8 *  TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
   9 */
  10#include <linux/module.h>
  11#include <linux/stacktrace.h>
  12
  13#include <asm/unwind.h>
  14
  15static void dump_trace(struct task_struct *task, struct stack_trace *trace)
  16{
  17        struct unwind_frame_info info;
  18
  19        /* initialize unwind info */
  20        if (task == current) {
  21                unsigned long sp;
  22                struct pt_regs r;
  23HERE:
  24                asm volatile ("copy %%r30, %0" : "=r"(sp));
  25                memset(&r, 0, sizeof(struct pt_regs));
  26                r.iaoq[0] = (unsigned long)&&HERE;
  27                r.gr[2] = (unsigned long)__builtin_return_address(0);
  28                r.gr[30] = sp;
  29                unwind_frame_init(&info, task, &r);
  30        } else {
  31                unwind_frame_init_from_blocked_task(&info, task);
  32        }
  33
  34        /* unwind stack and save entries in stack_trace struct */
  35        trace->nr_entries = 0;
  36        while (trace->nr_entries < trace->max_entries) {
  37                if (unwind_once(&info) < 0 || info.ip == 0)
  38                        break;
  39
  40                if (__kernel_text_address(info.ip))
  41                        trace->entries[trace->nr_entries++] = info.ip;
  42        }
  43}
  44
  45
  46/*
  47 * Save stack-backtrace addresses into a stack_trace buffer.
  48 */
  49void save_stack_trace(struct stack_trace *trace)
  50{
  51        dump_trace(current, trace);
  52        if (trace->nr_entries < trace->max_entries)
  53                trace->entries[trace->nr_entries++] = ULONG_MAX;
  54}
  55EXPORT_SYMBOL_GPL(save_stack_trace);
  56
  57void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  58{
  59        dump_trace(tsk, trace);
  60        if (trace->nr_entries < trace->max_entries)
  61                trace->entries[trace->nr_entries++] = ULONG_MAX;
  62}
  63EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
  64