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
   8 void save_stack_trace(struct stack_trace *trace)
   9 {
  10         save_stack_trace_tsk(current, trace);
  11 }
  12 EXPORT_SYMBOL_GPL(save_stack_trace);
  13
  14 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  15 {
  16         unsigned long *fpn;
  17         int skip = trace->skip;
  18         int savesched;
  19
  20         if (tsk == current) {
  21                 __asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(fpn));
  22                 savesched = 1;
  23         } else {
  24                 fpn = (unsigned long *)thread_saved_fp(tsk);
  25                 savesched = 0;
  26         }
  27
  28         while (!kstack_end(fpn) && !((unsigned long)fpn & 0x3)
  29                && (fpn >= (unsigned long *)TASK_SIZE)) {
  30                 unsigned long lpp, fpp;
  31
  32                 lpp = fpn[-1];
  33                 fpp = fpn[FP_OFFSET];
  34                 if (!__kernel_text_address(lpp))
  35                         break;
  36
  37                 if (savesched || !in_sched_functions(lpp)) {
  38                         if (skip) {
  39                                 skip--;
  40                         } else {
  41                                 trace->entries[trace->nr_entries++] = lpp;
  42                                 if (trace->nr_entries >= trace->max_entries)
  43                                         break;
  44                         }
  45                 }
  46                 fpn = (unsigned long *)fpp;
  47         }
  48 }
  49 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);