LXR linux/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
  14struct stackframe {
  15        unsigned long fp;
  16        unsigned long rets;
  17};
  18
  19/*
  20 * Save stack-backtrace addresses into a stack_trace buffer.
  21 */
  22void 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}
  52EXPORT_SYMBOL_GPL(save_stack_trace);
  53