LXR linux/arch/nds32/kernel/stacktrace.c

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4#include <linux/sched/debug.h>
   5#include <linux/sched/task_stack.h>
   6#include <linux/stacktrace.h>
   7#include <linux/ftrace.h>
   8
   9void save_stack_trace(struct stack_trace *trace)
  10{
  11        save_stack_trace_tsk(current, trace);
  12}
  13EXPORT_SYMBOL_GPL(save_stack_trace);
  14
  15void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  16{
  17        unsigned long *fpn;
  18        int skip = trace->skip;
  19        int savesched;
  20        int graph_idx = 0;
  21
  22        if (tsk == current) {
  23                __asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(fpn));
  24                savesched = 1;
  25        } else {
  26                fpn = (unsigned long *)thread_saved_fp(tsk);
  27                savesched = 0;
  28        }
  29
  30        while (!kstack_end(fpn) && !((unsigned long)fpn & 0x3)
  31               && (fpn >= (unsigned long *)TASK_SIZE)) {
  32                unsigned long lpp, fpp;
  33
  34                lpp = fpn[LP_OFFSET];
  35                fpp = fpn[FP_OFFSET];
  36                if (!__kernel_text_address(lpp))
  37                        break;
  38                else
  39                        lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL);
  40
  41                if (savesched || !in_sched_functions(lpp)) {
  42                        if (skip) {
  43                                skip--;
  44                        } else {
  45                                trace->entries[trace->nr_entries++] = lpp;
  46                                if (trace->nr_entries >= trace->max_entries)
  47                                        break;
  48                        }
  49                }
  50                fpn = (unsigned long *)fpp;
  51        }
  52}
  53EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
  54