dyld3/Loading.h

   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
  25
  26 #ifndef __DYLD_LOADING_H__
  27 #define __DYLD_LOADING_H__
  28
  29 #include <string.h>
  30 #include <stdint.h>
  31 #include <mach/mach.h>
  32 #include <_simple.h>
  33
  34 #include "Closure.h"
  35 #include "MachOLoaded.h"
  36
  37 namespace objc_opt {
  38 struct objc_clsopt_t;
  39 struct objc_selopt_t;
  40 }
  41
  42 namespace dyld3 {
  43
  44
  45 //
  46 // Tuple of info about a loaded image. Contains the loaded address, Image*, and state.
  47 //
  48 class VIS_HIDDEN LoadedImage {
  49 public:
  50     enum class State { unmapped=0, mapped=1, fixedUp=2, beingInited=3, inited=4 };
  51
  52     static LoadedImage      make(const closure::Image* img)         { LoadedImage result; result._image = img; return result; }
  53     static LoadedImage      make(const closure::Image* img, const MachOLoaded* mh)
  54                                                                     { LoadedImage result; result._image = img; result.setLoadedAddress(mh); return result; }
  55
  56     const closure::Image*   image() const                           { return _image; }
  57     const MachOLoaded*      loadedAddress() const                   { return (MachOLoaded*)(_loadAddr & (-4096)); }
  58     void                    setLoadedAddress(const MachOLoaded* a)  { _loadAddr |= ((uintptr_t)a & (-4096)); }
  59     State                   state() const                           { return (State)(asBits().state); }
  60     void                    setState(State s)                       { asBits().state = (int)s; }
  61     bool                    hideFromFlatSearch() const              { return asBits().hide; }
  62     void                    setHideFromFlatSearch(bool h)           { asBits().hide = h; }
  63     bool                    leaveMapped() const                     { return asBits().leaveMapped; }
  64     void                    markLeaveMapped()                       { asBits().leaveMapped = true; }
  65
  66 private:
  67     // since loaded MachO files are always page aligned, that means at least low 12-bits are always zero
  68     // so we don't need to record the low 12 bits, instead those bits hold various flags in the _loadeAddr field
  69     struct AddrBits {
  70         uintptr_t    state       :  3,
  71                      hide        :  1,
  72                      leaveMapped :  1,
  73                      extra       :  7,
  74           #if __LP64__
  75                      addr        : 52;
  76           #else
  77                      addr        : 20;
  78           #endif
  79     };
  80     AddrBits&               asBits()       { return *((AddrBits*)&_loadAddr); }
  81     const AddrBits&         asBits() const { return *((AddrBits*)&_loadAddr); }
  82
  83     // Note: this must be statically initializable so as to not cause static initializers
  84     const closure::Image*   _image      = nullptr;
  85     uintptr_t               _loadAddr   = 0;        // really AddrBits
  86 };
  87
  88
  89 //
  90 // Utility class to recursively load dependents
  91 //
  92 class VIS_HIDDEN Loader {
  93 public:
  94         typedef bool (*LogFunc)(const char*, ...) __attribute__((format(printf, 1, 2)));
  95
  96                         Loader(const Array<LoadedImage>& existingImages, Array<LoadedImage>& newImagesStorage,
  97                                const void* cacheAddress, const Array<const dyld3::closure::ImageArray*>& imagesArrays,
  98                                const closure::ObjCSelectorOpt* selOpt, const Array<closure::Image::ObjCSelectorImage>& selImages,
  99                                LogFunc log_loads, LogFunc log_segments, LogFunc log_fixups, LogFunc log_dofs);
 100
 101     void                addImage(const LoadedImage&);
 102     void                completeAllDependents(Diagnostics& diag, bool& someCacheImageOverridden);
 103     void                mapAndFixupAllImages(Diagnostics& diag, bool processDOFs, bool fromOFI=false);
 104     uintptr_t           resolveTarget(closure::Image::ResolvedSymbolTarget target);
 105     LoadedImage*        findImage(closure::ImageNum targetImageNum);
 106
 107     static void         unmapImage(LoadedImage& info);
 108     static bool         dtraceUserProbesEnabled();
 109     static void         vmAccountingSetSuspended(bool suspend, LogFunc);
 110
 111 private:
 112
 113     struct ImageOverride
 114     {
 115         closure::ImageNum  inCache;
 116         closure::ImageNum  replacement;
 117     };
 118
 119     struct DOFInfo {
 120         const void*            dof;
 121         const mach_header*     imageHeader;
 122         const char*            imageShortName;
 123     };
 124
 125 #if BUILDING_DYLD
 126     struct LaunchImagesCache {
 127         LoadedImage*                    findImage(closure::ImageNum targetImageNum,
 128                                                   Array<LoadedImage>& images) const;
 129         void                            tryAddImage(closure::ImageNum targetImageNum, uint64_t allImagesIndex);
 130
 131         static const uint64_t           _cacheSize = 128;
 132         static const closure::ImageNum  _firstImageNum = closure::kFirstLaunchClosureImageNum;
 133         static const closure::ImageNum  _lastImageNum = closure::kFirstLaunchClosureImageNum + _cacheSize;
 134
 135         // Note, the cache stores "indices + 1" into the _allImages array.
 136         // 0 means we haven't cached an entry yet
 137         uint32_t                        _cacheStorage[_cacheSize] = { 0 };
 138         Array<uint32_t>                 _imageIndices = { &_cacheStorage[0], _cacheSize, _cacheSize };
 139     };
 140 #endif
 141
 142     void                mapImage(Diagnostics& diag, LoadedImage& info, bool fromOFI);
 143     void                applyFixupsToImage(Diagnostics& diag, LoadedImage& info);
 144     void                registerDOFs(const Array<DOFInfo>& dofs);
 145     void                setSegmentProtects(const LoadedImage& info, bool write);
 146         bool                sandboxBlockedMmap(const char* path);
 147     bool                sandboxBlockedOpen(const char* path);
 148     bool                sandboxBlockedStat(const char* path);
 149     bool                sandboxBlocked(const char* path, const char* kind);
 150
 151     const Array<LoadedImage>&                       _existingImages;
 152     Array<LoadedImage>&                             _newImages;
 153     const Array<const closure::ImageArray*>&        _imagesArrays;
 154     const void*                                     _dyldCacheAddress;
 155     const objc_opt::objc_selopt_t*                  _dyldCacheSelectorOpt;
 156     const closure::ObjCSelectorOpt*                 _closureSelectorOpt;
 157     const Array<closure::Image::ObjCSelectorImage>& _closureSelectorImages;
 158 #if BUILDING_DYLD
 159     LaunchImagesCache                               _launchImagesCache;
 160 #endif
 161     LogFunc                                         _logLoads;
 162     LogFunc                                         _logSegments;
 163     LogFunc                                         _logFixups;
 164     LogFunc                                         _logDofs;
 165 };
 166
 167
 168
 169 #if (BUILDING_LIBDYLD || BUILDING_DYLD)
 170 bool internalInstall();
 171 #endif
 172 #if BUILDING_DYLD
 173 void forEachLineInFile(const char* path, void (^lineHandler)(const char* line, bool& stop));
 174 void forEachLineInFile(const char* buffer, size_t bufferLen, void (^lineHandler)(const char* line, bool& stop));
 175 #endif
 176
 177 } // namespace dyld3
 178
 179 #endif // __DYLD_LOADING_H__
 180
 181