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

   1/*
   2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3 * Copyright (C) 2013 Richard Weinberger <richard@nod.at>
   4 * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10
  11#include <linux/kallsyms.h>
  12#include <linux/kernel.h>
  13#include <linux/sched.h>
  14#include <linux/stacktrace.h>
  15#include <linux/module.h>
  16#include <linux/uaccess.h>
  17#include <asm/stacktrace.h>
  18
  19void dump_trace(struct task_struct *tsk,
  20                const struct stacktrace_ops *ops,
  21                void *data)
  22{
  23        int reliable = 0;
  24        unsigned long *sp, bp, addr;
  25        struct pt_regs *segv_regs = tsk->thread.segv_regs;
  26        struct stack_frame *frame;
  27
  28        bp = get_frame_pointer(tsk, segv_regs);
  29        sp = get_stack_pointer(tsk, segv_regs);
  30
  31        frame = (struct stack_frame *)bp;
  32        while (((long) sp & (THREAD_SIZE-1)) != 0) {
  33                addr = *sp;
  34                if (__kernel_text_address(addr)) {
  35                        reliable = 0;
  36                        if ((unsigned long) sp == bp + sizeof(long)) {
  37                                frame = frame ? frame->next_frame : NULL;
  38                                bp = (unsigned long)frame;
  39                                reliable = 1;
  40                        }
  41                        ops->address(data, addr, reliable);
  42                }
  43                sp++;
  44        }
  45}
  46
  47static void save_addr(void *data, unsigned long address, int reliable)
  48{
  49        struct stack_trace *trace = data;
  50
  51        if (!reliable)
  52                return;
  53        if (trace->nr_entries >= trace->max_entries)
  54                return;
  55
  56        trace->entries[trace->nr_entries++] = address;
  57}
  58
  59static const struct stacktrace_ops dump_ops = {
  60        .address = save_addr
  61};
  62
  63static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace)
  64{
  65        dump_trace(tsk, &dump_ops, trace);
  66        if (trace->nr_entries < trace->max_entries)
  67                trace->entries[trace->nr_entries++] = ULONG_MAX;
  68}
  69
  70void save_stack_trace(struct stack_trace *trace)
  71{
  72        __save_stack_trace(current, trace);
  73}
  74EXPORT_SYMBOL_GPL(save_stack_trace);
  75
  76void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  77{
  78        __save_stack_trace(tsk, trace);
  79}
  80EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
  81