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 #undef TARGET_IPHONE_SIMULATOR
  24 #define TARGET_IPHONE_SIMULATOR 1
  25 #define _PTHREAD_ATTR_T
  26 #include <pthread_internals.h>
  27 #undef TARGET_IPHONE_SIMULATOR
  28 #define TARGET_IPHONE_SIMULATOR 0
  29
  30 #include <mach-o/dyld.h>
  31 #include <mach-o/dyld_images.h>
  32 #include <mach-o/loader.h>
  33 #include <mach-o/nlist.h>
  34
  35 #include "Standard.hpp"
  36 #include "Baton.hpp"
  37
  38 static void $bzero(void *data, size_t size) {
  39     char *bytes(reinterpret_cast<char *>(data));
  40     for (size_t i(0); i != size; ++i)
  41         bytes[i] = 0;
  42 }
  43
  44 static int $strcmp(const char *lhs, const char *rhs) {
  45     while (*lhs == *rhs) {
  46         if (*lhs == '\0')
  47             return 0;
  48         ++lhs, ++rhs;
  49     } return *lhs < *rhs ? -1 : 1;
  50 }
  51
  52 #ifdef __LP64__
  53 typedef struct mach_header_64 mach_header_xx;
  54 typedef struct nlist_64 nlist_xx;
  55 typedef struct segment_command_64 segment_command_xx;
  56
  57 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT_64;
  58 static const uint32_t MH_MAGIC_XX = MH_MAGIC_64;
  59 #else
  60 typedef struct mach_header mach_header_xx;
  61 typedef struct nlist nlist_xx;
  62 typedef struct segment_command segment_command_xx;
  63
  64 static const uint32_t LC_SEGMENT_XX = LC_SEGMENT;
  65 static const uint32_t MH_MAGIC_XX = MH_MAGIC;
  66 #endif
  67
  68 #define forlc(command, mach, lc, type) \
  69     if (const struct load_command *load_commands = reinterpret_cast<const struct load_command *>(mach + 1)) \
  70         if (const struct load_command *lcp = load_commands) \
  71             for (uint32_t i(0); i != mach->ncmds; ++i, lcp = reinterpret_cast<const struct load_command *>(reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize)) \
  72                 if ( \
  73                     lcp->cmdsize % sizeof(long) != 0 || lcp->cmdsize <= 0 || \
  74                     reinterpret_cast<const uint8_t *>(lcp) + lcp->cmdsize > reinterpret_cast<const uint8_t *>(load_commands) + mach->sizeofcmds \
  75                 ) \
  76                     return NULL; \
  77                 else if (lcp->cmd != lc) \
  78                     continue; \
  79                 else if (lcp->cmdsize < sizeof(type)) \
  80                     return NULL; \
  81                 else if (const type *command = reinterpret_cast<const type *>(lcp))
  82
  83 static const mach_header_xx *Library(struct dyld_all_image_infos *infos, const char *name) {
  84     for (uint32_t i(0); i != infos->infoArrayCount; ++i) {
  85         const dyld_image_info &info(infos->infoArray[i]);
  86         const mach_header_xx *mach(reinterpret_cast<const mach_header_xx *>(info.imageLoadAddress));
  87         if (mach->magic != MH_MAGIC_XX)
  88             continue;
  89
  90         const char *path(info.imageFilePath);
  91         forlc (dylib, mach, LC_ID_DYLIB, dylib_command)
  92             path = reinterpret_cast<const char *>(dylib) + dylib->dylib.name.offset;
  93         if ($strcmp(path, name) != 0)
  94             continue;
  95
  96         return mach;
  97     }
  98
  99     return NULL;
 100 }
 101
 102 static void *Symbol(const mach_header_xx *mach, const char *name) {
 103     const struct symtab_command *stp(NULL);
 104     forlc (command, mach, LC_SYMTAB, struct symtab_command)
 105         stp = command;
 106     if (stp == NULL)
 107         return NULL;
 108
 109     size_t slide(_not(size_t));
 110     const nlist_xx *symbols(NULL);
 111     const char *strings(NULL);
 112
 113     forlc (segment, mach, LC_SEGMENT_XX, segment_command_xx) {
 114         if (segment->fileoff == 0)
 115             slide = reinterpret_cast<size_t>(mach) - segment->vmaddr;
 116         if (stp->symoff >= segment->fileoff && stp->symoff < segment->fileoff + segment->filesize)
 117             symbols = reinterpret_cast<const nlist_xx *>(stp->symoff - segment->fileoff + segment->vmaddr + slide);
 118         if (stp->stroff >= segment->fileoff && stp->stroff < segment->fileoff + segment->filesize)
 119             strings = reinterpret_cast<const char *>(stp->stroff - segment->fileoff + segment->vmaddr + slide);
 120     }
 121
 122     if (slide == _not(size_t) || symbols == NULL || strings == NULL)
 123         return NULL;
 124
 125     for (size_t i(0); i != stp->nsyms; ++i) {
 126         const nlist_xx *symbol(&symbols[i]);
 127         if (symbol->n_un.n_strx == 0 || (symbol->n_type & N_STAB) != 0)
 128             continue;
 129
 130         const char *nambuf(strings + symbol->n_un.n_strx);
 131         if ($strcmp(name, nambuf) != 0)
 132             continue;
 133
 134         uintptr_t value(symbol->n_value);
 135         if (value == 0)
 136             continue;
 137
 138 #ifdef __arm__
 139         if ((symbol->n_desc & N_ARM_THUMB_DEF) != 0)
 140             value |= 0x00000001;
 141 #endif
 142
 143         value += slide;
 144         return reinterpret_cast<void *>(value);
 145     }
 146
 147     return NULL;
 148 }
 149
 150 template <typename Type_>
 151 static _finline void cyset(Type_ &function, const char *name, const mach_header_xx *mach) {
 152     function = reinterpret_cast<Type_>(Symbol(mach, name));
 153 }
 154
 155 static _finline const mach_header_xx *Library(Baton *baton, const char *name) {
 156     struct dyld_all_image_infos *infos(reinterpret_cast<struct dyld_all_image_infos *>(baton->dyld));
 157     return Library(infos, name);
 158 }
 159
 160 void *Routine(void *arg) {
 161     Baton *baton(reinterpret_cast<Baton *>(arg));
 162
 163     const mach_header_xx *dyld(NULL);
 164     if (dyld == NULL)
 165         dyld = Library(baton, "/usr/lib/system/libdyld.dylib");
 166     if (dyld == NULL)
 167         dyld = Library(baton, "/usr/lib/libSystem.B.dylib");
 168
 169     char *(*$dlerror)();
 170     cyset($dlerror, "_dlerror", dyld);
 171
 172     void *(*$dlopen)(const char *, int);
 173     cyset($dlopen, "_dlopen", dyld);
 174
 175     void *handle($dlopen(baton->library, RTLD_LAZY | RTLD_LOCAL));
 176     if (handle == NULL) {
 177         $dlerror();
 178         return NULL;
 179     }
 180
 181     void *(*$dlsym)(void *, const char *);
 182     cyset($dlsym, "_dlsym", dyld);
 183
 184     void (*CYHandleServer)(pid_t);
 185     CYHandleServer = reinterpret_cast<void (*)(pid_t)>($dlsym(handle, "CYHandleServer"));
 186     if (CYHandleServer == NULL) {
 187         $dlerror();
 188         return NULL;
 189     }
 190
 191     CYHandleServer(baton->pid);
 192     return NULL;
 193 }
 194
 195 extern "C" void Start(Baton *baton) {
 196     struct _pthread self;
 197     $bzero(&self, sizeof(self));
 198
 199     const mach_header_xx *pthread(NULL);
 200     if (pthread == NULL)
 201         pthread = Library(baton, "/usr/lib/system/libsystem_pthread.dylib");
 202     if (pthread == NULL)
 203         pthread = Library(baton, "/usr/lib/system/libsystem_c.dylib");
 204     if (pthread == NULL)
 205         pthread = Library(baton, "/usr/lib/libSystem.B.dylib");
 206
 207     void (*$__pthread_set_self)(pthread_t);
 208     cyset($__pthread_set_self, "___pthread_set_self", pthread);
 209
 210     self.tsd[0] = &self;
 211     $__pthread_set_self(&self);
 212
 213     int (*$pthread_attr_init)(pthread_attr_t *);
 214     cyset($pthread_attr_init, "_pthread_attr_init", pthread);
 215
 216 #if 0
 217     pthread_attr_t attr;
 218     $pthread_attr_init(&attr);
 219
 220     int (*$pthread_attr_setdetachstate)(pthread_attr_t *, int);
 221     cyset($pthread_attr_setdetachstate, "_pthread_attr_setdetachstate", pthread);
 222
 223     $pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 224 #endif
 225
 226     int (*$pthread_create)(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
 227     cyset($pthread_create, "_pthread_create", pthread);
 228
 229     pthread_t thread;
 230     $pthread_create(&thread, NULL, &Routine, baton);
 231
 232 #if 0
 233     int (*$pthread_attr_destroy)(pthread_attr_t *);
 234     cyset($pthread_attr_destroy, "_pthread_attr_destroy", pthread);
 235
 236     $pthread_attr_destroy(&attr);
 237 #endif
 238
 239 #if defined(__arm__) || defined(__arm64__)
 240     uintptr_t tpid;
 241 #if defined(__arm__)
 242     __asm__ ("mrc p15, 0, %0, c13, c0, 3\n" : "=r" (tpid));
 243 #elif defined(__arm64__)
 244     __asm__ ("mrs %0, tpidrro_el0\n" : "=r" (tpid));
 245 #else
 246 #error XXX
 247 #endif
 248
 249     void **tsd;
 250     tsd = reinterpret_cast<void **>(tpid & ~3);
 251     if (tsd != NULL)
 252         tsd[0] = &self;
 253 #endif
 254
 255     int (*$pthread_join)(pthread_t, void **);
 256     cyset($pthread_join, "_pthread_join", pthread);
 257
 258     void *status;
 259     $pthread_join(thread, &status);
 260
 261     const mach_header_xx *kernel(NULL);
 262     if (kernel == NULL)
 263         kernel = Library(baton, "/usr/lib/system/libsystem_kernel.dylib");
 264     if (kernel == NULL)
 265         kernel = Library(baton, "/usr/lib/libSystem.B.dylib");
 266
 267     mach_port_t (*$mach_thread_self)();
 268     cyset($mach_thread_self, "_mach_thread_self", kernel);
 269
 270     kern_return_t (*$thread_terminate)(thread_act_t);
 271     cyset($thread_terminate, "_thread_terminate", kernel);
 272
 273     $thread_terminate($mach_thread_self());
 274 }