Mach/Inject.cpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2010  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU Lesser General Public License, Version 3 {{{ */
   6 /*
   7  * Cycript is free software: you can redistribute it and/or modify it under
   8  * the terms of the GNU Lesser General Public License as published by the
   9  * Free Software Foundation, either version 3 of the License, or (at your
  10  * option) any later version.
  11  *
  12  * Cycript is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15  * License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with Cycript.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include <dlfcn.h>
  23 #include <mach/mach.h>
  24
  25 #include <mach/machine/thread_status.h>
  26
  27 #include <cstdio>
  28 #include <pthread.h>
  29 #include <unistd.h>
  30
  31 #include "Baton.hpp"
  32 #include "Exception.hpp"
  33 #include "Pooling.hpp"
  34 #include "Trampoline.t.hpp"
  35
  36 extern "C" void __pthread_set_self(pthread_t);
  37
  38 void InjectLibrary(pid_t pid) {
  39     const char *library(CY_LIBRARY);
  40
  41     static const size_t Stack_(8 * 1024);
  42     size_t length(strlen(library) + 1), depth(sizeof(Baton) + length);
  43     depth = (depth + sizeof(uintptr_t) + 1) / sizeof(uintptr_t) * sizeof(uintptr_t);
  44
  45     CYPool pool;
  46     uint8_t *local(reinterpret_cast<uint8_t *>(apr_palloc(pool, depth)));
  47     Baton *baton(reinterpret_cast<Baton *>(local));
  48
  49     baton->__pthread_set_self = &__pthread_set_self;
  50
  51     baton->pthread_create = &pthread_create;
  52     baton->pthread_join = &pthread_join;
  53
  54     baton->mach_thread_self = &mach_thread_self;
  55     baton->thread_terminate = &thread_terminate;
  56
  57     baton->dlerror = &dlerror;
  58     baton->dlsym = &dlsym;
  59
  60     baton->pid = getpid();
  61     memcpy(baton->library, library, length);
  62
  63     vm_size_t size(depth + Stack_);
  64
  65     mach_port_t self(mach_task_self()), task;
  66     _krncall(task_for_pid(self, pid, &task));
  67
  68     vm_address_t stack;
  69     _krncall(vm_allocate(task, &stack, size, true));
  70     vm_address_t data(stack + Stack_);
  71
  72     vm_write(task, data, reinterpret_cast<vm_address_t>(baton), depth);
  73
  74     thread_act_t thread;
  75     _krncall(thread_create(task, &thread));
  76
  77     thread_state_flavor_t flavor;
  78     mach_msg_type_number_t count;
  79     size_t push;
  80
  81     Trampoline *trampoline;
  82
  83 #if defined(__arm__)
  84     trampoline = &Trampoline_armv6_;
  85     arm_thread_state_t state;
  86     flavor = ARM_THREAD_STATE;
  87     count = ARM_THREAD_STATE_COUNT;
  88     push = 0;
  89 #elif defined(__i386__)
  90     trampoline = &Trampoline_i386_;
  91     i386_thread_state_t state;
  92     flavor = i386_THREAD_STATE;
  93     count = i386_THREAD_STATE_COUNT;
  94     push = 5;
  95 #elif defined(__x86_64__)
  96     trampoline = &Trampoline_x86_64_;
  97     x86_thread_state64_t state;
  98     flavor = x86_THREAD_STATE64;
  99     count = x86_THREAD_STATE64_COUNT;
 100     push = 2;
 101 #else
 102     #error XXX: implement
 103 #endif
 104
 105     vm_address_t code;
 106     _krncall(vm_allocate(task, &code, trampoline->size_, true));
 107     vm_write(task, code, reinterpret_cast<vm_address_t>(trampoline->data_), trampoline->size_);
 108     _krncall(vm_protect(task, code, trampoline->size_, false, VM_PROT_READ | VM_PROT_EXECUTE));
 109
 110     /*
 111     printf("_ptss:%p\n", baton->__pthread_set_self);
 112     printf("dlsym:%p\n", baton->dlsym);
 113     printf("code:%zx\n", (size_t) code);
 114     */
 115
 116     uint32_t frame[push];
 117     if (sizeof(frame) != 0)
 118         memset(frame, 0, sizeof(frame));
 119     memset(&state, 0, sizeof(state));
 120
 121     mach_msg_type_number_t read(count);
 122     _krncall(thread_get_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), &read));
 123     _assert(count == count);
 124
 125 #if defined(__arm__)
 126     state.__r[0] = data;
 127     state.__sp = stack + Stack_;
 128     state.__pc = code + trampoline->entry_;
 129
 130     if ((state.__pc & 0x1) != 0) {
 131         state.__pc &= ~0x1;
 132         state.__cpsr |= 0x20;
 133     }
 134 #elif defined(__i386__)
 135     frame[1] = data;
 136
 137     state.__eip = code + trampoline->entry_;
 138     state.__esp = stack + Stack_ - sizeof(frame);
 139 #elif defined(__x86_64__)
 140     frame[0] = 0xdeadbeef;
 141     state.__rdi = data;
 142     state.__rip = code + trampoline->entry_;
 143     state.__rsp = stack + Stack_ - sizeof(frame);
 144 #else
 145     #error XXX: implement
 146 #endif
 147
 148     if (sizeof(frame) != 0)
 149         vm_write(task, stack + Stack_ - sizeof(frame), reinterpret_cast<vm_address_t>(frame), sizeof(frame));
 150
 151     _krncall(thread_set_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), count));
 152     _krncall(thread_resume(thread));
 153
 154     _krncall(mach_port_deallocate(self, task));
 155 }