dyld3/libdyldEntryVector.cpp

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <stdarg.h>
  25 #include <mach-o/dyld_priv.h>
  26 #include <mach-o/dyld_images.h>
  27
  28 #include "libdyldEntryVector.h"
  29 #include "AllImages.h"
  30 #include "Array.h"
  31 #include "Loading.h"
  32 #include "Logging.h"
  33 #include "PathOverrides.h"
  34 #include "StartGlue.h"
  35 #include "dyld_process_info_internal.h"
  36
  37 extern "C" char start;
  38
  39 VIS_HIDDEN const char** appleParams;
  40
  41 extern bool gUseDyld3;
  42
  43 namespace dyld3 {
  44
  45
  46 AllImages::ProgramVars sVars;
  47 static void (*sChildForkFunction)();
  48
  49 static const char* leafName(const char* argv0)
  50 {
  51     if ( argv0 == nullptr )
  52        return "";
  53
  54     if ( const char* lastSlash = strrchr(argv0, '/') )
  55         return lastSlash+1;
  56     else
  57         return argv0;
  58 }
  59
  60 static void entry_setVars(const mach_header* mainMH, int argc, const char* argv[], const char* envp[], const char* apple[])
  61 {
  62     NXArgc       = argc;
  63     NXArgv       = argv;
  64     environ      = (char**)envp;
  65     appleParams  = apple;
  66     __progname   = leafName(argv[0]);
  67
  68     sVars.mh            = mainMH;
  69     sVars.NXArgcPtr     = &NXArgc;
  70     sVars.NXArgvPtr     = &NXArgv;
  71     sVars.environPtr    = (const char***)&environ;
  72     sVars.__prognamePtr = &__progname;
  73     gAllImages.setProgramVars(&sVars);
  74
  75     gUseDyld3 = true;
  76
  77     setLoggingFromEnvs(envp);
  78 }
  79
  80 static void entry_setHaltFunction(void (*func)(const char* message) __attribute__((noreturn)) )
  81 {
  82     setHaltFunction(func);
  83 }
  84
  85 static void entry_setLogFunction(void (*logFunction)(const char* format, va_list list))
  86 {
  87     setLoggingFunction(logFunction);
  88 }
  89
  90 static void entry_setOldAllImageInfo(dyld_all_image_infos* old)
  91 {
  92     gAllImages.setOldAllImageInfo(old);
  93 }
  94
  95 static void entry_setNotifyMonitoringDyldMain(void (*notifyMonitoringDyldMain)()) {
  96 #if !TARGET_OS_DRIVERKIT
  97     setNotifyMonitoringDyldMain(notifyMonitoringDyldMain);
  98 #endif
  99 }
 100
 101 static void entry_setNotifyMonitoringDyld(void (*notifyMonitoringDyld)(bool unloading,unsigned imageCount,
 102                                                                                const struct mach_header* loadAddresses[],
 103                                                                                const char* imagePaths[])) {
 104 #if !TARGET_OS_DRIVERKIT
 105     setNotifyMonitoringDyld(notifyMonitoringDyld);
 106 #endif
 107 }
 108
 109 static void entry_setInitialImageList(const closure::LaunchClosure* closure,
 110                                 const DyldSharedCache* dyldCacheLoadAddress, const char* dyldCachePath,
 111                                 const Array<LoadedImage>& initialImages, LoadedImage& libSystem)
 112 {
 113     gAllImages.init(closure, dyldCacheLoadAddress, dyldCachePath, initialImages);
 114     gAllImages.applyInterposingToDyldCache(closure);
 115
 116     // run initializer for libSytem.B.dylib
 117     // this calls back into _dyld_initializer which calls gAllIimages.addImages()
 118     gAllImages.runLibSystemInitializer(libSystem);
 119
 120     // now that malloc is available, parse DYLD_ env vars
 121     closure::gPathOverrides.setEnvVars((const char**)environ, gAllImages.mainExecutable(), gAllImages.mainExecutableImage()->path());
 122 }
 123
 124 static void entry_runInitialzersBottomUp(const mach_header* mainExecutableImageLoadAddress)
 125 {
 126     gAllImages.runStartupInitialzers();
 127 #if !TARGET_OS_DRIVERKIT
 128     gAllImages.notifyMonitorMain();
 129 #endif
 130 }
 131
 132 static void entry_setChildForkFunction(void (*func)() )
 133 {
 134     sChildForkFunction = func;
 135 }
 136
 137 static void entry_setRestrictions(bool allowAtPaths, bool allowEnvPaths, bool allowFallbackPaths)
 138 {
 139     gAllImages.setRestrictions(allowAtPaths, allowEnvPaths);
 140     closure::gPathOverrides.setFallbackPathHandling(allowFallbackPaths ?
 141                                                     dyld3::closure::PathOverrides::FallbackPathMode::classic :
 142                                                     dyld3::closure::PathOverrides::FallbackPathMode::restricted);
 143 }
 144
 145 static void entry_setHasCacheOverrides(bool someCacheImageOverriden)
 146 {
 147     gAllImages.setHasCacheOverrides(someCacheImageOverriden);
 148 }
 149
 150 static_assert((closure::kFormatVersion & LibDyldEntryVector::kBinaryFormatVersionMask) == closure::kFormatVersion, "binary format version overflow");
 151
 152 const LibDyldEntryVector entryVectorForDyld = {
 153     LibDyldEntryVector::kCurrentVectorVersion,
 154     closure::kFormatVersion,
 155     &entry_setVars,
 156     &entry_setHaltFunction,
 157     &entry_setOldAllImageInfo,
 158     &entry_setInitialImageList,
 159     &entry_runInitialzersBottomUp,
 160     (__typeof(LibDyldEntryVector::startFunc))address_of_start,
 161     &entry_setChildForkFunction,
 162     &entry_setLogFunction,
 163     &entry_setRestrictions,
 164     &entry_setNotifyMonitoringDyldMain,
 165     &entry_setNotifyMonitoringDyld,
 166     &entry_setHasCacheOverrides
 167 };
 168
 169 VIS_HIDDEN void _dyld_atfork_prepare()
 170 {
 171     gAllImages.takeLockBeforeFork();
 172 }
 173
 174 VIS_HIDDEN void _dyld_atfork_parent()
 175 {
 176     gAllImages.releaseLockInForkParent();
 177 }
 178
 179 VIS_HIDDEN void _dyld_fork_child()
 180 {
 181     // Note the child fork function updates the data structures inside dyld
 182     (*sChildForkFunction)();
 183
 184     // And we then need to update the structures for dyld3 in libdyld
 185     gAllImages.resetLockInForkChild();
 186 }
 187
 188
 189 } // namespace dyld3
 190