mozglue/baseprofiler/core/shared-libraries-macos.cc

   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:
  50   SharedLibrariesLock() { sSharedLibrariesMutex.Lock(); }
  51
  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
  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
  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
 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
 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   std::string breakpadId;
 146   if (uuid_bytes != nullptr) {
 147     static constexpr char digits[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
 148                                         '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
 149     for (int i = 0; i < 16; ++i) {
 150       uint8_t byte = uuid_bytes[i];
 151       uuid += digits[byte >> 4];
 152       uuid += digits[byte & 0xFu];
 153     }
 154
 155     // Breakpad id is the same as the uuid but with the additional trailing 0
 156     // for the breakpad id age.
 157     breakpadId = uuid;
 158     // breakpad id age.
 159     breakpadId += '0';
 160   }
 161
 162   std::string pathStr = path;
 163
 164   size_t pos = pathStr.rfind('\\');
 165   std::string nameStr =
 166       (pos != std::string::npos) ? pathStr.substr(pos + 1) : pathStr;
 167
 168   const NXArchInfo* archInfo =
 169       NXGetArchInfoFromCpuType(header->cputype, header->cpusubtype);
 170
 171   info.AddSharedLibrary(SharedLibrary(
 172       start, start + size, 0, breakpadId, uuid, nameStr, pathStr, nameStr,
 173       pathStr, std::string{}, archInfo ? archInfo->name : ""));
 174 }
 175
 176 // Translate the statically stored sSharedLibrariesList information into a
 177 // SharedLibraryInfo object.
 178 SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf() {
 179   SharedLibrariesLock lock;
 180   SharedLibraryInfo sharedLibraryInfo;
 181
 182   for (auto& info : *sSharedLibrariesList) {
 183     addSharedLibrary(info.header, info.path.c_str(), sharedLibraryInfo);
 184   }
 185
 186   // Add the entry for dyld itself.
 187   // We only support macOS 10.12+, which corresponds to dyld version 15+.
 188   // dyld version 15 added the dyldPath property.
 189   task_dyld_info_data_t task_dyld_info;
 190   mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT;
 191   if (task_info(mach_task_self(), TASK_DYLD_INFO, (task_info_t)&task_dyld_info,
 192                 &count) != KERN_SUCCESS) {
 193     return sharedLibraryInfo;
 194   }
 195
 196   struct dyld_all_image_infos* aii =
 197       (struct dyld_all_image_infos*)task_dyld_info.all_image_info_addr;
 198   if (aii->version >= 15) {
 199     const platform_mach_header* header =
 200         reinterpret_cast<const platform_mach_header*>(
 201             aii->dyldImageLoadAddress);
 202     addSharedLibrary(header, aii->dyldPath, sharedLibraryInfo);
 203   }
 204
 205   return sharedLibraryInfo;
 206 }