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

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4 * Copyright (C) 2013 Richard Weinberger <richard@nod.at>
   5 * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com>
   6 */
   7
   8#include <linux/kallsyms.h>
   9#include <linux/kernel.h>
  10#include <linux/sched.h>
  11#include <linux/stacktrace.h>
  12#include <linux/module.h>
  13#include <linux/uaccess.h>
  14#include <asm/stacktrace.h>
  15
  16void dump_trace(struct task_struct *tsk,
  17                const struct stacktrace_ops *ops,
  18                void *data)
  19{
  20        int reliable = 0;
  21        unsigned long *sp, bp, addr;
  22        struct pt_regs *segv_regs = tsk->thread.segv_regs;
  23        struct stack_frame *frame;
  24
  25        bp = get_frame_pointer(tsk, segv_regs);
  26        sp = get_stack_pointer(tsk, segv_regs);
  27
  28        frame = (struct stack_frame *)bp;
  29        while (((long) sp & (THREAD_SIZE-1)) != 0) {
  30                addr = *sp;
  31                if (__kernel_text_address(addr)) {
  32                        reliable = 0;
  33                        if ((unsigned long) sp == bp + sizeof(long)) {
  34                                frame = frame ? frame->next_frame : NULL;
  35                                bp = (unsigned long)frame;
  36                                reliable = 1;
  37                        }
  38                        ops->address(data, addr, reliable);
  39                }
  40                sp++;
  41        }
  42}
  43
  44static void save_addr(void *data, unsigned long address, int reliable)
  45{
  46        struct stack_trace *trace = data;
  47
  48        if (!reliable)
  49                return;
  50        if (trace->nr_entries >= trace->max_entries)
  51                return;
  52
  53        trace->entries[trace->nr_entries++] = address;
  54}
  55
  56static const struct stacktrace_ops dump_ops = {
  57        .address = save_addr
  58};
  59
  60static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace)
  61{
  62        dump_trace(tsk, &dump_ops, trace);
  63}
  64
  65void save_stack_trace(struct stack_trace *trace)
  66{
  67        __save_stack_trace(current, trace);
  68}
  69EXPORT_SYMBOL_GPL(save_stack_trace);
  70
  71void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  72{
  73        __save_stack_trace(tsk, trace);
  74}
  75EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
  76