1 /*
2 *
3 * honggfuzz - architecture dependent code (LINUX/UNWIND)
4 * -----------------------------------------
5 *
6 * Author: Robert Swiecki <swiecki@google.com>
7 *
8 * Copyright 2010-2015 by Google Inc. All Rights Reserved.
9 *
10 * Licensed under the Apache License, Version 2.0 (the "License"); you may
11 * not use this file except in compliance with the License. You may obtain
12 * a copy of the License at
13 *
14 * http://www.apache.org/licenses/LICENSE-2.0
15 *
16 * Unless required by applicable law or agreed to in writing, software
17 * distributed under the License is distributed on an "AS IS" BASIS,
18 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
19 * implied. See the License for the specific language governing
20 * permissions and limitations under the License.
21 *
22 */
23
24 #include "common.h"
25 #include "linux/unwind.h"
26
27 #include <libunwind-ptrace.h>
28
29 #include "log.h"
30
31 #if defined(__ANDROID__)
32 #include <sys/endian.h> /* For __BYTE_ORDER */
33 #endif
34
35 /*
36 * WARNING: Ensure that _UPT-info structs are not shared between threads
37 * http://www.nongnu.org/libunwind/man/libunwind-ptrace(3).html
38 */
39
40 // libunwind error codes used for debugging
41 static const char *UNW_ER[] = {
42 "UNW_ESUCCESS", /* no error */
43 "UNW_EUNSPEC", /* unspecified (general) error */
44 "UNW_ENOMEM", /* out of memory */
45 "UNW_EBADREG", /* bad register number */
46 "UNW_EREADONLYREG", /* attempt to write read-only register */
47 "UNW_ESTOPUNWIND", /* stop unwinding */
48 "UNW_EINVALIDIP", /* invalid IP */
49 "UNW_EBADFRAME", /* bad frame */
50 "UNW_EINVAL", /* unsupported operation or bad value */
51 "UNW_EBADVERSION", /* unwind info has unsupported version */
52 "UNW_ENOINFO" /* no unwind info found */
53 };
54
55 #ifndef __ANDROID__
arch_unwindStack(pid_t pid,funcs_t * funcs)56 size_t arch_unwindStack(pid_t pid, funcs_t * funcs)
57 {
58 size_t num_frames = 0;
59 void *ui = NULL;
60
61 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, __BYTE_ORDER);
62 if (!as) {
63 LOG_E("[pid='%d'] unw_create_addr_space failed", pid);
64 goto out;
65 }
66
67 ui = _UPT_create(pid);
68 if (ui == NULL) {
69 LOG_E("[pid='%d'] _UPT_create failed", pid);
70 goto out;
71 }
72
73 unw_cursor_t c;
74 int ret = unw_init_remote(&c, as, ui);
75 if (ret < 0) {
76 LOG_E("[pid='%d'] unw_init_remote failed (%s)", pid, UNW_ER[-ret]);
77 goto out;
78 }
79
80 for (num_frames = 0; unw_step(&c) > 0 && num_frames < _HF_MAX_FUNCS; num_frames++) {
81 unw_word_t ip;
82 ret = unw_get_reg(&c, UNW_REG_IP, &ip);
83 if (ret < 0) {
84 LOG_E("[pid='%d'] [%zd] failed to read IP (%s)", pid, num_frames, UNW_ER[-ret]);
85 funcs[num_frames].pc = 0;
86 } else
87 funcs[num_frames].pc = (void *)ip;
88 }
89
90 out:
91 ui ? _UPT_destroy(ui) : 0;
92 as ? unw_destroy_addr_space(as) : 0;
93
94 return num_frames;
95 }
96
97 #else /* !defined(__ANDROID__) */
arch_unwindStack(pid_t pid,funcs_t * funcs)98 size_t arch_unwindStack(pid_t pid, funcs_t * funcs)
99 {
100 size_t num_frames = 0;
101 struct UPT_info *ui = NULL;
102 unw_addr_space_t as = NULL;
103
104 as = unw_create_addr_space(&_UPT_accessors, __BYTE_ORDER);
105 if (!as) {
106 LOG_E("[pid='%d'] unw_create_addr_space failed", pid);
107 goto out;
108 }
109
110 ui = (struct UPT_info *)_UPT_create(pid);
111 if (ui == NULL) {
112 LOG_E("[pid='%d'] _UPT_create failed", pid);
113 goto out;
114 }
115
116 unw_cursor_t cursor;
117 int ret = unw_init_remote(&cursor, as, ui);
118 if (ret < 0) {
119 LOG_E("[pid='%d'] unw_init_remote failed (%s)", pid, UNW_ER[-ret]);
120 goto out;
121 }
122
123 do {
124 unw_word_t pc = 0, offset = 0;
125 char buf[_HF_FUNC_NAME_SZ] = { 0 };
126
127 ret = unw_get_reg(&cursor, UNW_REG_IP, &pc);
128 if (ret < 0) {
129 LOG_E("[pid='%d'] [%zd] failed to read IP (%s)", pid, num_frames, UNW_ER[-ret]);
130 // We don't want to try to extract info from an arbitrary IP
131 // TODO: Maybe abort completely (goto out))
132 goto skip_frame_info;
133 }
134
135 unw_proc_info_t frameInfo;
136 ret = unw_get_proc_info(&cursor, &frameInfo);
137 if (ret < 0) {
138 LOG_D("[pid='%d'] [%zd] unw_get_proc_info (%s)", pid, num_frames, UNW_ER[-ret]);
139 // Not safe to keep parsing frameInfo
140 goto skip_frame_info;
141 }
142
143 ret = unw_get_proc_name(&cursor, buf, sizeof(buf), &offset);
144 if (ret < 0) {
145 LOG_D("[pid='%d'] [%zd] unw_get_proc_name() failed (%s)", pid, num_frames,
146 UNW_ER[-ret]);
147 buf[0] = '\0';
148 }
149
150 skip_frame_info:
151 // Compared to bfd, line var plays the role of offset from func_name
152 // Reports format is adjusted accordingly to reflect in saved file
153 funcs[num_frames].line = offset;
154 funcs[num_frames].pc = (void *)pc;
155 memcpy(funcs[num_frames].func, buf, sizeof(funcs[num_frames].func));
156
157 num_frames++;
158
159 ret = unw_step(&cursor);
160 } while (ret > 0 && num_frames < _HF_MAX_FUNCS);
161
162 out:
163 ui ? _UPT_destroy(ui) : NULL;
164 as ? unw_destroy_addr_space(as) : NULL;
165
166 ui = NULL;
167 as = NULL;
168
169 return num_frames;
170 }
171 #endif /* defined(__ANDROID__) */
172