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#include <stdint.h>
28
29#ifdef __cplusplus
30extern "C" {
31#endif
32
33/* Stores information about a process that is used for several different
34 * ptrace() based operations. */
35typedef struct {
36    map_info_t* map_info_list;
37} ptrace_context_t;
38
39/* Describes how to access memory from a process. */
40typedef struct {
41    pid_t tid;
42    const map_info_t* map_info_list;
43} memory_t;
44
45#if __i386__
46/* ptrace() register context. */
47typedef struct pt_regs_x86 {
48    uint32_t ebx;
49    uint32_t ecx;
50    uint32_t edx;
51    uint32_t esi;
52    uint32_t edi;
53    uint32_t ebp;
54    uint32_t eax;
55    uint32_t xds;
56    uint32_t xes;
57    uint32_t xfs;
58    uint32_t xgs;
59    uint32_t orig_eax;
60    uint32_t eip;
61    uint32_t xcs;
62    uint32_t eflags;
63    uint32_t esp;
64    uint32_t xss;
65} pt_regs_x86_t;
66#endif
67
68#if __mips__
69/* ptrace() GET_REGS context. */
70typedef struct pt_regs_mips {
71    uint64_t regs[32];
72    uint64_t lo;
73    uint64_t hi;
74    uint64_t cp0_epc;
75    uint64_t cp0_badvaddr;
76    uint64_t cp0_status;
77    uint64_t cp0_cause;
78} pt_regs_mips_t;
79#endif
80
81/*
82 * Initializes a memory structure for accessing memory from this process.
83 */
84void init_memory(memory_t* memory, const map_info_t* map_info_list);
85
86/*
87 * Initializes a memory structure for accessing memory from another process
88 * using ptrace().
89 */
90void init_memory_ptrace(memory_t* memory, pid_t tid);
91
92/*
93 * Reads a word of memory safely.
94 * If the memory is local, ensures that the address is readable before dereferencing it.
95 * Returns false and a value of 0xffffffff if the word could not be read.
96 */
97bool try_get_word(const memory_t* memory, uintptr_t ptr, uint32_t* out_value);
98
99/*
100 * Reads a word of memory safely using ptrace().
101 * Returns false and a value of 0xffffffff if the word could not be read.
102 */
103bool try_get_word_ptrace(pid_t tid, uintptr_t ptr, uint32_t* out_value);
104
105/*
106 * Loads information needed for examining a remote process using ptrace().
107 * The caller must already have successfully attached to the process
108 * using ptrace().
109 *
110 * The context can be used for any threads belonging to that process
111 * assuming ptrace() is attached to them before performing the actual
112 * unwinding.  The context can continue to be used to decode backtraces
113 * even after ptrace() has been detached from the process.
114 */
115ptrace_context_t* load_ptrace_context(pid_t pid);
116
117/*
118 * Frees a ptrace context.
119 */
120void free_ptrace_context(ptrace_context_t* context);
121
122/*
123 * Finds a symbol using ptrace.
124 * Returns the containing map and information about the symbol, or
125 * NULL if one or the other is not available.
126 */
127void find_symbol_ptrace(const ptrace_context_t* context,
128        uintptr_t addr, const map_info_t** out_map_info, const symbol_t** out_symbol);
129
130#ifdef __cplusplus
131}
132#endif
133
134#endif // _CORKSCREW_PTRACE_H
135