Trampoline.t.cpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2013  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU General Public License, Version 3 {{{ */
   6 /*
   7  * Cycript is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation, either version 3 of the License,
  10  * or (at your option) any later version.
  11  *
  12  * Cycript is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with Cycript.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include <TargetConditionals.h>
  23 #if defined(__arm__) || defined(__arm64__)
  24 #undef TARGET_IPHONE_SIMULATOR
  25 #define TARGET_IPHONE_SIMULATOR 1
  26 #endif
  27 #define _PTHREAD_ATTR_T
  28 #include <pthread_internals.h>
  29 #if defined(__arm__) || defined(__arm64__)
  30 #undef TARGET_IPHONE_SIMULATOR
  31 #endif
  32
  33 #include <mach-o/dyld.h>
  34 #include <mach-o/dyld_images.h>
  35 #include <mach-o/loader.h>
  36 #include <mach-o/nlist.h>
  37
  38 #include "Standard.hpp"
  39 #include "Baton.hpp"
  40
  41 static void $bzero(void *data, size_t size) {
  42     char *bytes(reinterpret_cast<char *>(data));
  43     for (size_t i(0); i != size; ++i)
  44         bytes[i] = 0;
  45 }
  46
  47 static int $strcmp(const char *lhs, const char *rhs) {
  48     while (*lhs == *rhs) {
  49         if (*lhs == '\0')
  50             return 0;
  51         ++lhs, ++rhs;
  52     } return *lhs < *rhs ? -1 : 1;
  53 }
  54
  55 #ifdef __LP64__
  56 typedef struct mach_header_64 mach_header_xx;
  57 typedef struct nlist_64 nlist_xx;
  58 typedef struct segment_command_64 segment_command_xx;
  59
  60 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT_64;
  61 static const uint32_t MH_MAGIC_XX = MH_MAGIC_64;
  62 #else
  63 typedef struct mach_header mach_header_xx;
  64 typedef struct nlist nlist_xx;
  65 typedef struct segment_command segment_command_xx;
  66
  67 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT;
  68 static const uint32_t MH_MAGIC_XX = MH_MAGIC;
  69 #endif
  70
  71 #define forlc(command, mach, lc, type) \
  72     if (const struct load_command *load_commands = reinterpret_cast<const struct load_command *>(mach + 1)) \
  73         if (const struct load_command *lcp = load_commands) \
  74             for (uint32_t i(0); i != mach->ncmds; ++i, lcp = reinterpret_cast<const struct load_command *>(reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize)) \
  75                 if ( \
  76                     lcp->cmdsize % sizeof(long) != 0 || lcp->cmdsize <= 0 || \
  77                     reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize > reinterpret_cast<const uint8_t *>(load_commands) + mach->sizeofcmds \
  78                 ) \
  79                     return NULL; \
  80                 else if (lcp->cmd != lc) \
  81                     continue; \
  82                 else if (lcp->cmdsize < sizeof(type)) \
  83                     return NULL; \
  84                 else if (const type *command = reinterpret_cast<const type *>(lcp))
  85
  86 static const mach_header_xx *Library(struct dyld_all_image_infos *infos, const char *name) {
  87     for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
  88         const dyld_image_info &info(infos->infoArray[i]);
  89         const mach_header_xx *mach(reinterpret_cast<const mach_header_xx *>(info.imageLoadAddress));
  90         if (mach->magic != MH_MAGIC_XX)
  91             continue;
  92
  93         const char *path(info.imageFilePath);
  94         forlc (dylib, mach, LC_ID_DYLIB, dylib_command)
  95             path = reinterpret_cast<const char *>(dylib) + dylib->dylib.name.offset;
  96         if ($strcmp(path, name) != 0)
  97             continue;
  98
  99         return mach;
 100     }
 101
 102     return NULL;
 103 }
 104
 105 static void *Symbol(const mach_header_xx *mach, const char *name) {
 106     const struct symtab_command *stp(NULL);
 107     forlc (command, mach, LC_SYMTAB, struct symtab_command)
 108         stp = command;
 109     if (stp == NULL)
 110         return NULL;
 111
 112     size_t slide(_not(size_t));
 113     const nlist_xx *symbols(NULL);
 114     const char *strings(NULL);
 115
 116     forlc (segment, mach, LC_SEGMENT_XX, segment_command_xx) {
 117         if (segment->fileoff == 0)
 118             slide = reinterpret_cast<size_t>(mach) - segment->vmaddr;
 119         if (stp->symoff >= segment->fileoff && stp->symoff < segment->fileoff + segment->filesize)
 120             symbols = reinterpret_cast<const nlist_xx *>(stp->symoff - segment->fileoff + segment->vmaddr + slide);
 121         if (stp->stroff >= segment->fileoff && stp->stroff < segment->fileoff + segment->filesize)
 122             strings = reinterpret_cast<const char *>(stp->stroff - segment->fileoff + segment->vmaddr + slide);
 123     }
 124
 125     if (slide == _not(size_t) || symbols == NULL || strings == NULL)
 126         return NULL;
 127
 128     for (size_t i(0); i != stp->nsyms; ++i) {
 129         const nlist_xx *symbol(&symbols[i]);
 130         if (symbol->n_un.n_strx == 0 || (symbol->n_type & N_STAB) != 0)
 131             continue;
 132
 133         const char *nambuf(strings + symbol->n_un.n_strx);
 134         if ($strcmp(name, nambuf) != 0)
 135             continue;
 136
 137         uintptr_t value(symbol->n_value);
 138         if (value == 0)
 139             continue;
 140
 141 #ifdef __arm__
 142         if ((symbol->n_desc & N_ARM_THUMB_DEF) != 0)
 143             value |= 0x00000001;
 144 #endif
 145
 146         value += slide;
 147         return reinterpret_cast<void *>(value);
 148     }
 149
 150     return NULL;
 151 }
 152
 153 template <typename Type_>
 154 static _finline void cyset(Type_ &function, const char *name, const mach_header_xx *mach) {
 155     function = reinterpret_cast<Type_>(Symbol(mach, name));
 156 }
 157
 158 static _finline const mach_header_xx *Library(Baton *baton, const char *name) {
 159     struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
 160     return Library(infos, name);
 161 }
 162
 163 void *Routine(void *arg) {
 164     Baton *baton(reinterpret_cast<Baton *>(arg));
 165
 166     const mach_header_xx *dyld(NULL);
 167     if (dyld == NULL)
 168         dyld = Library(baton, "/usr/lib/system/libdyld.dylib");
 169     if (dyld == NULL)
 170         dyld = Library(baton, "/usr/lib/libSystem.B.dylib");
 171
 172     char *(*$dlerror)();
 173     cyset($dlerror, "_dlerror", dyld);
 174
 175     void *(*$dlopen)(const char *, int);
 176     cyset($dlopen, "_dlopen", dyld);
 177
 178     void *handle($dlopen(baton->library, RTLD_LAZY | RTLD_LOCAL));
 179     if (handle == NULL) {
 180         $dlerror();
 181         return NULL;
 182     }
 183
 184     void *(*$dlsym)(void *, const char *);
 185     cyset($dlsym, "_dlsym", dyld);
 186
 187     void (*CYHandleServer)(pid_t);
 188     CYHandleServer = reinterpret_cast<void (*)(pid_t)>($dlsym(handle, "CYHandleServer"));
 189     if (CYHandleServer == NULL) {
 190         $dlerror();
 191         return NULL;
 192     }
 193
 194     CYHandleServer(baton->pid);
 195     return NULL;
 196 }
 197
 198 extern "C" void Start(Baton *baton) {
 199     struct _pthread self;
 200     $bzero(&self, sizeof(self));
 201
 202     const mach_header_xx *pthread(NULL);
 203     if (pthread == NULL)
 204         pthread = Library(baton, "/usr/lib/system/libsystem_pthread.dylib");
 205     if (pthread == NULL)
 206         pthread = Library(baton, "/usr/lib/system/libsystem_c.dylib");
 207     if (pthread == NULL)
 208         pthread = Library(baton, "/usr/lib/libSystem.B.dylib");
 209
 210     void (*$__pthread_set_self)(pthread_t);
 211     cyset($__pthread_set_self, "___pthread_set_self", pthread);
 212
 213     self.tsd[0] = &self;
 214     $__pthread_set_self(&self);
 215
 216     int (*$pthread_attr_init)(pthread_attr_t *);
 217     cyset($pthread_attr_init, "_pthread_attr_init", pthread);
 218
 219 #if 0
 220     pthread_attr_t attr;
 221     $pthread_attr_init(&attr);
 222
 223     int (*$pthread_attr_setdetachstate)(pthread_attr_t *, int);
 224     cyset($pthread_attr_setdetachstate, "_pthread_attr_setdetachstate", pthread);
 225
 226     $pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 227 #endif
 228
 229     int (*$pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
 230     cyset($pthread_create, "_pthread_create", pthread);
 231
 232     pthread_t thread;
 233     $pthread_create(&thread, NULL, &Routine, baton);
 234
 235 #if 0
 236     int (*$pthread_attr_destroy)(pthread_attr_t *);
 237     cyset($pthread_attr_destroy, "_pthread_attr_destroy", pthread);
 238
 239     $pthread_attr_destroy(&attr);
 240 #endif
 241
 242 #if defined(__arm__) || defined(__arm64__)
 243     uintptr_t tpid;
 244 #if defined(__arm__)
 245     __asm__ ("mrc p15, 0, %0, c13, c0, 3\n" : "=r" (tpid));
 246 #elif defined(__arm64__)
 247     __asm__ ("mrs %0, tpidrro_el0\n" : "=r" (tpid));
 248 #else
 249 #error XXX
 250 #endif
 251
 252     void **tsd;
 253     tsd = reinterpret_cast<void **>(tpid & ~3);
 254     if (tsd != NULL)
 255         tsd[0] = &self;
 256 #else
 257     _pthread_setspecific_direct(0, &self);
 258 #endif
 259
 260     int (*$pthread_join)(pthread_t, void **);
 261     cyset($pthread_join, "_pthread_join", pthread);
 262
 263     void *status;
 264     $pthread_join(thread, &status);
 265
 266     const mach_header_xx *kernel(NULL);
 267     if (kernel == NULL)
 268         kernel = Library(baton, "/usr/lib/system/libsystem_kernel.dylib");
 269     if (kernel == NULL)
 270         kernel = Library(baton, "/usr/lib/libSystem.B.dylib");
 271
 272     mach_port_t (*$mach_thread_self)();
 273     cyset($mach_thread_self, "_mach_thread_self", kernel);
 274
 275     kern_return_t (*$thread_terminate)(thread_act_t);
 276     cyset($thread_terminate, "_thread_terminate", kernel);
 277
 278     $thread_terminate($mach_thread_self());
 279 }