ptrace.h revision 231e3c83a3a70b11160fb0da108ebf2e0e7470e2 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/* Useful ptrace() utility functions. */
18
19#ifndef _CORKSCREW_PTRACE_H
20#define _CORKSCREW_PTRACE_H
21
22#include <corkscrew/map_info.h>
23#include <corkscrew/symbol_table.h>
24
25#include <sys/types.h>
26#include <stdbool.h>
27
28#ifdef __cplusplus
29extern "C" {
30#endif
31
32/* Stores information about a process that is used for several different
33 * ptrace() based operations. */
34typedef struct {
35    map_info_t* map_info_list;
36} ptrace_context_t;
37
38/* Describes how to access memory from a process. */
39typedef struct {
40    pid_t tid;
41    const map_info_t* map_info_list;
42} memory_t;
43
44#if __i386__
45/* ptrace() register context. */
46typedef struct pt_regs_x86 {
47    uint32_t ebx;
48    uint32_t ecx;
49    uint32_t edx;
50    uint32_t esi;
51    uint32_t edi;
52    uint32_t ebp;
53    uint32_t eax;
54    uint32_t xds;
55    uint32_t xes;
56    uint32_t xfs;
57    uint32_t xgs;
58    uint32_t orig_eax;
59    uint32_t eip;
60    uint32_t xcs;
61    uint32_t eflags;
62    uint32_t esp;
63    uint32_t xss;
64} pt_regs_x86_t;
65#endif
66
67#if __mips__
68/* ptrace() GET_REGS context. */
69typedef struct pt_regs_mips {
70    uint64_t regs[32];
71    uint64_t lo;
72    uint64_t hi;
73    uint64_t cp0_epc;
74    uint64_t cp0_badvaddr;
75    uint64_t cp0_status;
76    uint64_t cp0_cause;
77} pt_regs_mips_t;
78#endif
79
80/*
81 * Initializes a memory structure for accessing memory from this process.
82 */
83void init_memory(memory_t* memory, const map_info_t* map_info_list);
84
85/*
86 * Initializes a memory structure for accessing memory from another process
87 * using ptrace().
88 */
89void init_memory_ptrace(memory_t* memory, pid_t tid);
90
91/*
92 * Reads a word of memory safely.
93 * If the memory is local, ensures that the address is readable before dereferencing it.
94 * Returns false and a value of 0xffffffff if the word could not be read.
95 */
96bool try_get_word(const memory_t* memory, uintptr_t ptr, uint32_t* out_value);
97
98/*
99 * Reads a word of memory safely using ptrace().
100 * Returns false and a value of 0xffffffff if the word could not be read.
101 */
102bool try_get_word_ptrace(pid_t tid, uintptr_t ptr, uint32_t* out_value);
103
104/*
105 * Loads information needed for examining a remote process using ptrace().
106 * The caller must already have successfully attached to the process
107 * using ptrace().
108 *
109 * The context can be used for any threads belonging to that process
110 * assuming ptrace() is attached to them before performing the actual
111 * unwinding.  The context can continue to be used to decode backtraces
112 * even after ptrace() has been detached from the process.
113 */
114ptrace_context_t* load_ptrace_context(pid_t pid);
115
116/*
117 * Frees a ptrace context.
118 */
119void free_ptrace_context(ptrace_context_t* context);
120
121/*
122 * Finds a symbol using ptrace.
123 * Returns the containing map and information about the symbol, or
124 * NULL if one or the other is not available.
125 */
126void find_symbol_ptrace(const ptrace_context_t* context,
127        uintptr_t addr, const map_info_t** out_map_info, const symbol_t** out_symbol);
128
129#ifdef __cplusplus
130}
131#endif
132
133#endif // _CORKSCREW_PTRACE_H
134