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 "BaseProfilerSharedLibraries.h"
7
8 #include "platform.h"
9
10 #include "mozilla/Unused.h"
11 #include <AvailabilityMacros.h>
12
13 #include <dlfcn.h>
14 #include <mach-o/arch.h>
15 #include <mach-o/dyld_images.h>
16 #include <mach-o/dyld.h>
17 #include <mach-o/loader.h>
18 #include <mach/mach_init.h>
19 #include <mach/mach_traps.h>
20 #include <mach/task_info.h>
21 #include <mach/task.h>
22 #include <sstream>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <vector>
26
27 // Architecture specific abstraction.
28 #if defined(GP_ARCH_x86)
29 typedef mach_header platform_mach_header;
30 typedef segment_command mach_segment_command_type;
31 # define MACHO_MAGIC_NUMBER MH_MAGIC
32 # define CMD_SEGMENT LC_SEGMENT
33 # define seg_size uint32_t
34 #else
35 typedef mach_header_64 platform_mach_header;
36 typedef segment_command_64 mach_segment_command_type;
37 # define MACHO_MAGIC_NUMBER MH_MAGIC_64
38 # define CMD_SEGMENT LC_SEGMENT_64
39 # define seg_size uint64_t
40 #endif
41
42 struct NativeSharedLibrary {
43 const platform_mach_header* header;
44 std::string path;
45 };
46 static std::vector<NativeSharedLibrary>* sSharedLibrariesList = nullptr;
47
48 class MOZ_RAII SharedLibrariesLock {
49 public:
SharedLibrariesLock()50 SharedLibrariesLock() { sSharedLibrariesMutex.Lock(); }
51
~SharedLibrariesLock()52 ~SharedLibrariesLock() { sSharedLibrariesMutex.Unlock(); }
53
54 SharedLibrariesLock(const SharedLibrariesLock&) = delete;
55 void operator=(const SharedLibrariesLock&) = delete;
56
57 private:
58 static mozilla::baseprofiler::detail::BaseProfilerMutex sSharedLibrariesMutex;
59 };
60
61 mozilla::baseprofiler::detail::BaseProfilerMutex
62 SharedLibrariesLock::sSharedLibrariesMutex;
63
SharedLibraryAddImage(const struct mach_header * mh,intptr_t vmaddr_slide)64 static void SharedLibraryAddImage(const struct mach_header* mh,
65 intptr_t vmaddr_slide) {
66 // NOTE: Presumably for backwards-compatibility reasons, this function accepts
67 // a mach_header even on 64-bit where it ought to be a mach_header_64. We cast
68 // it to the right type here.
69 auto header = reinterpret_cast<const platform_mach_header*>(mh);
70
71 Dl_info info;
72 if (!dladdr(header, &info)) {
73 return;
74 }
75
76 SharedLibrariesLock lock;
77 if (!sSharedLibrariesList) {
78 return;
79 }
80
81 NativeSharedLibrary lib = {header, info.dli_fname};
82 sSharedLibrariesList->push_back(lib);
83 }
84
SharedLibraryRemoveImage(const struct mach_header * mh,intptr_t vmaddr_slide)85 static void SharedLibraryRemoveImage(const struct mach_header* mh,
86 intptr_t vmaddr_slide) {
87 // NOTE: Presumably for backwards-compatibility reasons, this function accepts
88 // a mach_header even on 64-bit where it ought to be a mach_header_64. We cast
89 // it to the right type here.
90 auto header = reinterpret_cast<const platform_mach_header*>(mh);
91
92 SharedLibrariesLock lock;
93 if (!sSharedLibrariesList) {
94 return;
95 }
96
97 uint32_t count = sSharedLibrariesList->size();
98 for (uint32_t i = 0; i < count; ++i) {
99 if ((*sSharedLibrariesList)[i].header == header) {
100 sSharedLibrariesList->erase(sSharedLibrariesList->begin() + i);
101 return;
102 }
103 }
104 }
105
Initialize()106 void SharedLibraryInfo::Initialize() {
107 // NOTE: We intentionally leak this memory here. We're allocating dynamically
108 // in order to avoid static initializers.
109 sSharedLibrariesList = new std::vector<NativeSharedLibrary>();
110
111 _dyld_register_func_for_add_image(SharedLibraryAddImage);
112 _dyld_register_func_for_remove_image(SharedLibraryRemoveImage);
113 }
114
addSharedLibrary(const platform_mach_header * header,const char * path,SharedLibraryInfo & info)115 static void addSharedLibrary(const platform_mach_header* header,
116 const char* path, SharedLibraryInfo& info) {
117 const struct load_command* cmd =
118 reinterpret_cast<const struct load_command*>(header + 1);
119
120 seg_size size = 0;
121 unsigned long long start = reinterpret_cast<unsigned long long>(header);
122 // Find the cmd segment in the macho image. It will contain the offset we care
123 // about.
124 const uint8_t* uuid_bytes = nullptr;
125 for (unsigned int i = 0;
126 cmd && (i < header->ncmds) && (uuid_bytes == nullptr || size == 0);
127 ++i) {
128 if (cmd->cmd == CMD_SEGMENT) {
129 const mach_segment_command_type* seg =
130 reinterpret_cast<const mach_segment_command_type*>(cmd);
131
132 if (!strcmp(seg->segname, "__TEXT")) {
133 size = seg->vmsize;
134 }
135 } else if (cmd->cmd == LC_UUID) {
136 const uuid_command* ucmd = reinterpret_cast<const uuid_command*>(cmd);
137 uuid_bytes = ucmd->uuid;
138 }
139
140 cmd = reinterpret_cast<const struct load_command*>(
141 reinterpret_cast<const char*>(cmd) + cmd->cmdsize);
142 }
143
144 std::string uuid;
145 if (uuid_bytes != nullptr) {
146 static constexpr char digits[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
147 '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
148 for (int i = 0; i < 15; ++i) {
149 uint8_t byte = uuid_bytes[i];
150 uuid += digits[byte >> 4];
151 uuid += digits[byte & 0xFu];
152 }
153 // breakpad id age.
154 uuid += '0';
155 }
156
157 std::string pathStr = path;
158
159 size_t pos = pathStr.rfind('\\');
160 std::string nameStr =
161 (pos != std::string::npos) ? pathStr.substr(pos + 1) : pathStr;
162
163 const NXArchInfo* archInfo =
164 NXGetArchInfoFromCpuType(header->cputype, header->cpusubtype);
165
166 info.AddSharedLibrary(SharedLibrary(start, start + size, 0, uuid, nameStr,
167 pathStr, nameStr, pathStr, std::string{},
168 archInfo ? archInfo->name : ""));
169 }
170
171 // Translate the statically stored sSharedLibrariesList information into a
172 // SharedLibraryInfo object.
GetInfoForSelf()173 SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf() {
174 SharedLibrariesLock lock;
175 SharedLibraryInfo sharedLibraryInfo;
176
177 for (auto& info : *sSharedLibrariesList) {
178 addSharedLibrary(info.header, info.path.c_str(), sharedLibraryInfo);
179 }
180
181 // Add the entry for dyld itself.
182 // We only support macOS 10.12+, which corresponds to dyld version 15+.
183 // dyld version 15 added the dyldPath property.
184 task_dyld_info_data_t task_dyld_info;
185 mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT;
186 if (task_info(mach_task_self(), TASK_DYLD_INFO, (task_info_t)&task_dyld_info,
187 &count) != KERN_SUCCESS) {
188 return sharedLibraryInfo;
189 }
190
191 struct dyld_all_image_infos* aii =
192 (struct dyld_all_image_infos*)task_dyld_info.all_image_info_addr;
193 if (aii->version >= 15) {
194 const platform_mach_header* header =
195 reinterpret_cast<const platform_mach_header*>(
196 aii->dyldImageLoadAddress);
197 addSharedLibrary(header, aii->dyldPath, sharedLibraryInfo);
198 }
199
200 return sharedLibraryInfo;
201 }
202