text: /*
   * Copyright (C) 2011 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /* Useful ptrace() utility functions. */
  
  #ifndef _CORKSCREW_PTRACE_H
  #define _CORKSCREW_PTRACE_H
  
  #include "map_info.h"
  #include "symbol_table.h"
  
  #include <sys/types.h>
  #include <stdbool.h>
  #include <stdint.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /* Stores information about a process that is used for several different
   * ptrace() based operations. */
  typedef struct {
      map_info_t* map_info_list;
  } ptrace_context_t;
  
  /* Describes how to access memory from a process. */
  typedef struct {
      pid_t tid;
      const map_info_t* map_info_list;
  } memory_t;
  
  #if __i386__
  /* ptrace() register context. */
  typedef struct pt_regs_x86 {
      uint32_t ebx;
      uint32_t ecx;
      uint32_t edx;
      uint32_t esi;
      uint32_t edi;
      uint32_t ebp;
      uint32_t eax;
      uint32_t xds;
      uint32_t xes;
      uint32_t xfs;
      uint32_t xgs;
      uint32_t orig_eax;
      uint32_t eip;
      uint32_t xcs;
      uint32_t eflags;
      uint32_t esp;
      uint32_t xss;
  } pt_regs_x86_t;
  #endif
  
  #if __mips__
  /* ptrace() GET_REGS context. */
  typedef struct pt_regs_mips {
      uint64_t regs[32];
      uint64_t lo;
      uint64_t hi;
      uint64_t cp0_epc;
      uint64_t cp0_badvaddr;
      uint64_t cp0_status;
      uint64_t cp0_cause;
  } pt_regs_mips_t;
  #endif
  
  /*
   * Initializes a memory structure for accessing memory from this process.
   */
  void init_memory(memory_t* memory, const map_info_t* map_info_list);
  
  /*
   * Initializes a memory structure for accessing memory from another process
   * using ptrace().
   */
  void init_memory_ptrace(memory_t* memory, pid_t tid);
  
  /*
   * Reads a word of memory safely.
   * If the memory is local, ensures that the address is readable before dereferencing it.
   * Returns false and a value of 0xffffffff if the word could not be read.
   */
  bool try_get_word(const memory_t* memory, uintptr_t ptr, uint32_t* out_value);
  
  /*
   * Reads a word of memory safely using ptrace().
   * Returns false and a value of 0xffffffff if the word could not be read.
   */
  bool try_get_word_ptrace(pid_t tid, uintptr_t ptr, uint32_t* out_value);
  
  /*
   * Loads information needed for examining a remote process using ptrace().
   * The caller must already have successfully attached to the process
   * using ptrace().
   *
   * The context can be used for any threads belonging to that process
   * assuming ptrace() is attached to them before performing the actual
   * unwinding.  The context can continue to be used to decode backtraces
   * even after ptrace() has been detached from the process.
   */
  ptrace_context_t* load_ptrace_context(pid_t pid);
  
  /*
   * Frees a ptrace context.
   */
  void free_ptrace_context(ptrace_context_t* context);
  
  /*
   * Finds a symbol using ptrace.
   * Returns the containing map and information about the symbol, or
   * NULL if one or the other is not available.
   */
  void find_symbol_ptrace(const ptrace_context_t* context,
          uintptr_t addr, const map_info_t** out_map_info, const symbol_t** out_symbol);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif // _CORKSCREW_PTRACE_H
  