arch/hexagon/kernel/stacktrace.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Stacktrace support for Hexagon
   4  *
   5  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   6  */
   7
   8 #include <linux/sched.h>
   9 #include <linux/sched/task_stack.h>
  10 #include <linux/stacktrace.h>
  11 #include <linux/thread_info.h>
  12 #include <linux/module.h>
  13
  14 struct stackframe {
  15         unsigned long fp;
  16         unsigned long rets;
  17 };
  18
  19 /*
  20  * Save stack-backtrace addresses into a stack_trace buffer.
  21  */
  22 void save_stack_trace(struct stack_trace *trace)
  23 {
  24         unsigned long low, high;
  25         unsigned long fp;
  26         struct stackframe *frame;
  27         int skip = trace->skip;
  28
  29         low = (unsigned long)task_stack_page(current);
  30         high = low + THREAD_SIZE;
  31         fp = (unsigned long)__builtin_frame_address(0);
  32
  33         while (fp >= low && fp <= (high - sizeof(*frame))) {
  34                 frame = (struct stackframe *)fp;
  35
  36                 if (skip) {
  37                         skip--;
  38                 } else {
  39                         trace->entries[trace->nr_entries++] = frame->rets;
  40                         if (trace->nr_entries >= trace->max_entries)
  41                                 break;
  42                 }
  43
  44                 /*
  45                  * The next frame must be at a higher address than the
  46                  * current frame.
  47                  */
  48                 low = fp + sizeof(*frame);
  49                 fp = frame->fp;
  50         }
  51 }
  52 EXPORT_SYMBOL_GPL(save_stack_trace);