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/i386/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 #include <substrate.h>
  37
  38 extern "C" void _pthread_start(pthread_t, mach_port_t, void *(*)(void *), void *, size_t, unsigned int);
  39
  40 void InjectLibrary(pid_t pid) {
  41     const char *library(CY_LIBRARY);
  42
  43     static const size_t Stack_(8 * 1024);
  44     size_t length(strlen(library) + 1), depth(sizeof(Baton) + length);
  45     depth = (depth + sizeof(uintptr_t) + 1) / sizeof(uintptr_t) * sizeof(uintptr_t);
  46
  47     CYPool pool;
  48     uint8_t *local(reinterpret_cast<uint8_t *>(apr_palloc(pool, depth)));
  49     Baton *baton(reinterpret_cast<Baton *>(local));
  50
  51     baton->_pthread_start = reinterpret_cast<void (*)(pthread_t, mach_port_t, void *(*)(void *), void *, size_t, unsigned int)>(MSFindSymbol(NULL, "__pthread_start"));
  52     baton->dlerror = &dlerror;
  53     baton->dlsym = &dlsym;
  54
  55     baton->pid = getpid();
  56     memcpy(baton->library, library, length);
  57
  58     vm_size_t size(depth + Stack_);
  59
  60     mach_port_t self(mach_task_self()), task;
  61     _krncall(task_for_pid(self, pid, &task));
  62
  63     vm_address_t stack;
  64     _krncall(vm_allocate(task, &stack, size, true));
  65     vm_address_t data(stack + Stack_);
  66
  67     vm_write(task, data, reinterpret_cast<vm_address_t>(baton), depth);
  68
  69     thread_act_t thread;
  70     _krncall(thread_create(task, &thread));
  71
  72     thread_state_flavor_t flavor;
  73     mach_msg_type_number_t count;
  74     size_t push;
  75
  76     Trampoline *trampoline;
  77
  78 #if defined(__arm__)
  79     trampoline = &Trampoline_arm_;
  80     arm_thread_state_t state;
  81     flavor = ARM_THREAD_STATE;
  82     count = ARM_THREAD_STATE_COUNT;
  83     push = 0;
  84 #elif defined(__i386__)
  85     trampoline = &Trampoline_i386_;
  86     i386_thread_state_t state;
  87     flavor = i386_THREAD_STATE;
  88     count = i386_THREAD_STATE_COUNT;
  89     push = 5;
  90 #elif defined(__x86_64__)
  91     trampoline = &Trampoline_x86_64_;
  92     x86_thread_state64_t state;
  93     flavor = x86_THREAD_STATE64;
  94     count = x86_THREAD_STATE64_COUNT;
  95     push = 2;
  96 #else
  97     #error XXX: implement
  98 #endif
  99
 100     vm_address_t code;
 101     _krncall(vm_allocate(task, &code, trampoline->size_, true));
 102     vm_write(task, code, reinterpret_cast<vm_address_t>(trampoline->data_), trampoline->size_);
 103     _krncall(vm_protect(task, code, trampoline->size_, false, VM_PROT_READ | VM_PROT_EXECUTE));
 104
 105     /*
 106     printf("_pts:%p\n", baton->_pthread_start);
 107     printf("dlerror:%p\n", baton->dlerror);
 108     printf("dlsym:%p\n", baton->dlsym);
 109     printf("code:%zx\n", (size_t) code);
 110     */
 111
 112     uint32_t frame[push];
 113     if (sizeof(frame) != 0)
 114         memset(frame, 0, sizeof(frame));
 115     memset(&state, 0, sizeof(state));
 116
 117     mach_msg_type_number_t read(count);
 118     _krncall(thread_get_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), &read));
 119     _assert(count == count);
 120
 121 #if defined(__arm__)
 122     state.r[0] = data;
 123     state.sp = stack + Stack_;
 124     state.pc = code + trampoline->entry_;
 125
 126     if ((state.pc & 0x1) != 0) {
 127         state.pc &= ~0x1;
 128         state.cpsr |= 0x20;
 129     }
 130 #elif defined(__i386__)
 131     frame[1] = data;
 132
 133     state.__eip = code + trampoline->entry_;
 134     state.__esp = stack + Stack_ - sizeof(frame);
 135 #elif defined(__x86_64__)
 136     frame[0] = 0xdeadbeef;
 137     state.__rdi = data;
 138     state.__rip = code + trampoline->entry_;
 139     state.__rsp = stack + Stack_ - sizeof(frame);
 140 #else
 141     #error XXX: implement
 142 #endif
 143
 144     if (sizeof(frame) != 0)
 145         vm_write(task, stack + Stack_ - sizeof(frame), reinterpret_cast<vm_address_t>(frame), sizeof(frame));
 146
 147     _krncall(thread_set_state(thread, flavor, reinterpret_cast<thread_state_t>(&state), count));
 148     _krncall(thread_resume(thread));
 149
 150     _krncall(mach_port_deallocate(self, task));
 151 }