1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6 #include "shared-libraries.h"
7
8 #include "ClearOnShutdown.h"
9 #include "mozilla/StaticMutex.h"
10 #include "mozilla/Unused.h"
11 #include "nsNativeCharsetUtils.h"
12 #include <AvailabilityMacros.h>
13
14 #include <dlfcn.h>
15 #include <mach-o/arch.h>
16 #include <mach-o/dyld_images.h>
17 #include <mach-o/dyld.h>
18 #include <mach-o/loader.h>
19 #include <mach/mach_init.h>
20 #include <mach/mach_traps.h>
21 #include <mach/task_info.h>
22 #include <mach/task.h>
23 #include <sstream>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <vector>
27
28 // Architecture specific abstraction.
29 #if defined(GP_ARCH_x86)
30 typedef mach_header platform_mach_header;
31 typedef segment_command mach_segment_command_type;
32 # define MACHO_MAGIC_NUMBER MH_MAGIC
33 # define CMD_SEGMENT LC_SEGMENT
34 # define seg_size uint32_t
35 #else
36 typedef mach_header_64 platform_mach_header;
37 typedef segment_command_64 mach_segment_command_type;
38 # define MACHO_MAGIC_NUMBER MH_MAGIC_64
39 # define CMD_SEGMENT LC_SEGMENT_64
40 # define seg_size uint64_t
41 #endif
42
43 struct NativeSharedLibrary {
44 const platform_mach_header* header;
45 std::string path;
46 };
47 static std::vector<NativeSharedLibrary>* sSharedLibrariesList = nullptr;
48 static mozilla::StaticMutex sSharedLibrariesMutex;
49
SharedLibraryAddImage(const struct mach_header * mh,intptr_t vmaddr_slide)50 static void SharedLibraryAddImage(const struct mach_header* mh,
51 intptr_t vmaddr_slide) {
52 // NOTE: Presumably for backwards-compatibility reasons, this function accepts
53 // a mach_header even on 64-bit where it ought to be a mach_header_64. We cast
54 // it to the right type here.
55 auto header = reinterpret_cast<const platform_mach_header*>(mh);
56
57 Dl_info info;
58 if (!dladdr(header, &info)) {
59 return;
60 }
61
62 mozilla::StaticMutexAutoLock lock(sSharedLibrariesMutex);
63 if (!sSharedLibrariesList) {
64 return;
65 }
66
67 NativeSharedLibrary lib = {header, info.dli_fname};
68 sSharedLibrariesList->push_back(lib);
69 }
70
SharedLibraryRemoveImage(const struct mach_header * mh,intptr_t vmaddr_slide)71 static void SharedLibraryRemoveImage(const struct mach_header* mh,
72 intptr_t vmaddr_slide) {
73 // NOTE: Presumably for backwards-compatibility reasons, this function accepts
74 // a mach_header even on 64-bit where it ought to be a mach_header_64. We cast
75 // it to the right type here.
76 auto header = reinterpret_cast<const platform_mach_header*>(mh);
77
78 mozilla::StaticMutexAutoLock lock(sSharedLibrariesMutex);
79 if (!sSharedLibrariesList) {
80 return;
81 }
82
83 uint32_t count = sSharedLibrariesList->size();
84 for (uint32_t i = 0; i < count; ++i) {
85 if ((*sSharedLibrariesList)[i].header == header) {
86 sSharedLibrariesList->erase(sSharedLibrariesList->begin() + i);
87 return;
88 }
89 }
90 }
91
Initialize()92 void SharedLibraryInfo::Initialize() {
93 // NOTE: We intentionally leak this memory here. We're allocating dynamically
94 // in order to avoid static initializers.
95 sSharedLibrariesList = new std::vector<NativeSharedLibrary>();
96
97 _dyld_register_func_for_add_image(SharedLibraryAddImage);
98 _dyld_register_func_for_remove_image(SharedLibraryRemoveImage);
99 }
100
addSharedLibrary(const platform_mach_header * header,const char * path,SharedLibraryInfo & info)101 static void addSharedLibrary(const platform_mach_header* header,
102 const char* path, SharedLibraryInfo& info) {
103 const struct load_command* cmd =
104 reinterpret_cast<const struct load_command*>(header + 1);
105
106 seg_size size = 0;
107 unsigned long long start = reinterpret_cast<unsigned long long>(header);
108 // Find the cmd segment in the macho image. It will contain the offset we care
109 // about.
110 const uint8_t* uuid_bytes = nullptr;
111 for (unsigned int i = 0;
112 cmd && (i < header->ncmds) && (uuid_bytes == nullptr || size == 0);
113 ++i) {
114 if (cmd->cmd == CMD_SEGMENT) {
115 const mach_segment_command_type* seg =
116 reinterpret_cast<const mach_segment_command_type*>(cmd);
117
118 if (!strcmp(seg->segname, "__TEXT")) {
119 size = seg->vmsize;
120 }
121 } else if (cmd->cmd == LC_UUID) {
122 const uuid_command* ucmd = reinterpret_cast<const uuid_command*>(cmd);
123 uuid_bytes = ucmd->uuid;
124 }
125
126 cmd = reinterpret_cast<const struct load_command*>(
127 reinterpret_cast<const char*>(cmd) + cmd->cmdsize);
128 }
129
130 nsAutoCString uuid;
131 if (uuid_bytes != nullptr) {
132 uuid.AppendPrintf(
133 "%02X"
134 "%02X"
135 "%02X"
136 "%02X"
137 "%02X"
138 "%02X"
139 "%02X"
140 "%02X"
141 "%02X"
142 "%02X"
143 "%02X"
144 "%02X"
145 "%02X"
146 "%02X"
147 "%02X"
148 "%02X"
149 "0" /* breakpad id age */,
150 uuid_bytes[0], uuid_bytes[1], uuid_bytes[2], uuid_bytes[3],
151 uuid_bytes[4], uuid_bytes[5], uuid_bytes[6], uuid_bytes[7],
152 uuid_bytes[8], uuid_bytes[9], uuid_bytes[10], uuid_bytes[11],
153 uuid_bytes[12], uuid_bytes[13], uuid_bytes[14], uuid_bytes[15]);
154 }
155
156 nsAutoString pathStr;
157 mozilla::Unused << NS_WARN_IF(
158 NS_FAILED(NS_CopyNativeToUnicode(nsDependentCString(path), pathStr)));
159
160 nsAutoString nameStr = pathStr;
161 int32_t pos = nameStr.RFindChar('/');
162 if (pos != kNotFound) {
163 nameStr.Cut(0, pos + 1);
164 }
165
166 const NXArchInfo* archInfo =
167 NXGetArchInfoFromCpuType(header->cputype, header->cpusubtype);
168
169 info.AddSharedLibrary(SharedLibrary(start, start + size, 0, uuid, nameStr,
170 pathStr, nameStr, pathStr, ""_ns,
171 archInfo ? archInfo->name : ""));
172 }
173
174 // Translate the statically stored sSharedLibrariesList information into a
175 // SharedLibraryInfo object.
GetInfoForSelf()176 SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf() {
177 mozilla::StaticMutexAutoLock lock(sSharedLibrariesMutex);
178 SharedLibraryInfo sharedLibraryInfo;
179
180 for (auto& info : *sSharedLibrariesList) {
181 addSharedLibrary(info.header, info.path.c_str(), sharedLibraryInfo);
182 }
183
184 // Add the entry for dyld itself.
185 // We only support macOS 10.12+, which corresponds to dyld version 15+.
186 // dyld version 15 added the dyldPath property.
187 task_dyld_info_data_t task_dyld_info;
188 mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT;
189 if (task_info(mach_task_self(), TASK_DYLD_INFO, (task_info_t)&task_dyld_info,
190 &count) != KERN_SUCCESS) {
191 return sharedLibraryInfo;
192 }
193
194 struct dyld_all_image_infos* aii =
195 (struct dyld_all_image_infos*)task_dyld_info.all_image_info_addr;
196 if (aii->version >= 15) {
197 const platform_mach_header* header =
198 reinterpret_cast<const platform_mach_header*>(
199 aii->dyldImageLoadAddress);
200 addSharedLibrary(header, aii->dyldPath, sharedLibraryInfo);
201 }
202
203 return sharedLibraryInfo;
204 }
205