dyld3/RootsChecker.h

   1 /*
   2  * Copyright (c) 2020 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_ROOTS_CHECKER_H__
  27 #define __DYLD_ROOTS_CHECKER_H__
  28
  29 #include <TargetConditionals.h>
  30
  31 #if TARGET_OS_OSX && (BUILDING_DYLD || BUILDING_CLOSURE_UTIL) && !TARGET_OS_SIMULATOR
  32 #define DYLD_SIMULATOR_ROOTS_SUPPORT 1
  33 #else
  34 #define DYLD_SIMULATOR_ROOTS_SUPPORT 0
  35 #endif
  36
  37 class DyldSharedCache;
  38
  39 namespace dyld3 {
  40
  41 namespace closure {
  42 class FileSystem;
  43 struct Image;
  44 }
  45
  46 #define VIS_HIDDEN __attribute__((visibility("hidden")))
  47
  48 class VIS_HIDDEN RootsChecker
  49 {
  50 public:
  51     RootsChecker() = default;
  52
  53     // Does a on-disk binary represent a root.
  54     // If the cache expects dylibs on disk, then so long as the dylib matches
  55     // the mod time and inode in the cache, it is not a root.
  56     // For the macOS simulator support dylibs, which are on disk, whether they
  57     // are roots depends on the state we are tracking in the comm page.
  58     // For all other dylibs and all other platforms, on-disk dylibs are always roots
  59     bool onDiskFileIsRoot(const char* path, const DyldSharedCache* cache, const closure::Image* image,
  60                           const closure::FileSystem* fileSystem,
  61                           uint64_t inode, uint64_t modtime) const;
  62
  63 #if DYLD_SIMULATOR_ROOTS_SUPPORT
  64     static bool uuidMatchesSharedCache(const char* path, const closure::FileSystem* fileSystem,
  65                                        const DyldSharedCache* cache);
  66
  67     void setLibsystemKernelIsRoot(bool v) {
  68         libsystemKernelIsRoot = v;
  69     }
  70     void setLibsystemPlatformIsRoot(bool v) {
  71         libsystemPlatformIsRoot = v;
  72     }
  73     void setLibsystemPThreadIsRoot(bool v) {
  74         libsystemPThreadIsRoot = v;
  75     }
  76     void setFileSystemCanBeModified(bool v) {
  77         fileSystemCanBeModified = v;
  78     }
  79 #endif
  80
  81 private:
  82     // By default, assume nothing is a root, but that the file system is writable.
  83     // This should be conservatively correct.
  84 #if DYLD_SIMULATOR_ROOTS_SUPPORT
  85     bool libsystemKernelIsRoot      = false;
  86     bool libsystemPlatformIsRoot    = false;
  87     bool libsystemPThreadIsRoot     = false;
  88     bool fileSystemCanBeModified    = true;
  89 #endif
  90 };
  91
  92 } // namespace dyld3
  93
  94 #endif // __DYLD_ROOTS_CHECKER_H__