1 /*
   2  * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "code/relocInfo.hpp"
  28 #include "nativeInst_x86.hpp"
  29 #include "oops/oop.inline.hpp"
  30 #include "runtime/safepoint.hpp"
  31 
  32 
  33 void Relocation::pd_set_data_value(address x, intptr_t o, bool verify_only) {
  34 #ifdef AMD64
  35   x += o;
  36   typedef Assembler::WhichOperand WhichOperand;
  37   WhichOperand which = (WhichOperand) format(); // that is, disp32 or imm, call32, narrow oop
  38   assert(which == Assembler::disp32_operand ||
  39          which == Assembler::narrow_oop_operand ||
  40          which == Assembler::imm_operand, "format unpacks ok");
  41   if (which == Assembler::imm_operand) {
  42     if (verify_only) {
  43       assert(*pd_address_in_code() == x, "instructions must match");
  44     } else {
  45       *pd_address_in_code() = x;
  46     }
  47   } else if (which == Assembler::narrow_oop_operand) {
  48     address disp = Assembler::locate_operand(addr(), which);
  49     // both compressed oops and compressed classes look the same
  50     if (Universe::heap()->is_in_reserved((oop)x)) {
  51     if (verify_only) {
  52       assert(*(uint32_t*) disp == oopDesc::encode_heap_oop((oop)x), "instructions must match");
  53     } else {
  54       *(int32_t*) disp = oopDesc::encode_heap_oop((oop)x);
  55     }
  56   } else {
  57       if (verify_only) {
  58         assert(*(uint32_t*) disp == oopDesc::encode_klass((Klass*)x), "instructions must match");
  59       } else {
  60         *(int32_t*) disp = oopDesc::encode_klass((Klass*)x);
  61       }
  62     }
  63   } else {
  64     // Note:  Use runtime_call_type relocations for call32_operand.
  65     address ip = addr();
  66     address disp = Assembler::locate_operand(ip, which);
  67     address next_ip = Assembler::locate_next_instruction(ip);
  68     if (verify_only) {
  69       assert(*(int32_t*) disp == (x - next_ip), "instructions must match");
  70     } else {
  71       *(int32_t*) disp = x - next_ip;
  72     }
  73   }
  74 #else
  75   if (verify_only) {
  76     assert(*pd_address_in_code() == (x + o), "instructions must match");
  77   } else {
  78     *pd_address_in_code() = x + o;
  79   }
  80 #endif // AMD64
  81 }
  82 
  83 
  84 address Relocation::pd_call_destination(address orig_addr) {
  85   intptr_t adj = 0;
  86   if (orig_addr != NULL) {
  87     // We just moved this call instruction from orig_addr to addr().
  88     // This means its target will appear to have grown by addr() - orig_addr.
  89     adj = -( addr() - orig_addr );
  90   }
  91   NativeInstruction* ni = nativeInstruction_at(addr());
  92   if (ni->is_call()) {
  93     return nativeCall_at(addr())->destination() + adj;
  94   } else if (ni->is_jump()) {
  95     return nativeJump_at(addr())->jump_destination() + adj;
  96   } else if (ni->is_cond_jump()) {
  97     return nativeGeneralJump_at(addr())->jump_destination() + adj;
  98   } else if (ni->is_mov_literal64()) {
  99     return (address) ((NativeMovConstReg*)ni)->data();
 100   } else {
 101     ShouldNotReachHere();
 102     return NULL;
 103   }
 104 }
 105 
 106 
 107 void Relocation::pd_set_call_destination(address x) {
 108   NativeInstruction* ni = nativeInstruction_at(addr());
 109   if (ni->is_call()) {
 110     nativeCall_at(addr())->set_destination(x);
 111   } else if (ni->is_jump()) {
 112     NativeJump* nj = nativeJump_at(addr());
 113 
 114     // Unresolved jumps are recognized by a destination of -1
 115     // However 64bit can't actually produce such an address
 116     // and encodes a jump to self but jump_destination will
 117     // return a -1 as the signal. We must not relocate this
 118     // jmp or the ic code will not see it as unresolved.
 119 
 120     if (nj->jump_destination() == (address) -1) {
 121       x = addr(); // jump to self
 122     }
 123     nj->set_jump_destination(x);
 124   } else if (ni->is_cond_jump()) {
 125     // %%%% kludge this, for now, until we get a jump_destination method
 126     address old_dest = nativeGeneralJump_at(addr())->jump_destination();
 127     address disp = Assembler::locate_operand(addr(), Assembler::call32_operand);
 128     *(jint*)disp += (x - old_dest);
 129   } else if (ni->is_mov_literal64()) {
 130     ((NativeMovConstReg*)ni)->set_data((intptr_t)x);
 131   } else {
 132     ShouldNotReachHere();
 133   }
 134 }
 135 
 136 
 137 address* Relocation::pd_address_in_code() {
 138   // All embedded Intel addresses are stored in 32-bit words.
 139   // Since the addr points at the start of the instruction,
 140   // we must parse the instruction a bit to find the embedded word.
 141   assert(is_data(), "must be a DataRelocation");
 142   typedef Assembler::WhichOperand WhichOperand;
 143   WhichOperand which = (WhichOperand) format(); // that is, disp32 or imm/imm32
 144 #ifdef AMD64
 145   assert(which == Assembler::disp32_operand ||
 146          which == Assembler::call32_operand ||
 147          which == Assembler::imm_operand, "format unpacks ok");
 148   if (which != Assembler::imm_operand) {
 149     // The "address" in the code is a displacement can't return it as
 150     // and address* since it is really a jint*
 151     ShouldNotReachHere();
 152     return NULL;
 153   }
 154 #else
 155   assert(which == Assembler::disp32_operand || which == Assembler::imm_operand, "format unpacks ok");
 156 #endif // AMD64
 157   return (address*) Assembler::locate_operand(addr(), which);
 158 }
 159 
 160 
 161 address Relocation::pd_get_address_from_code() {
 162 #ifdef AMD64
 163   // All embedded Intel addresses are stored in 32-bit words.
 164   // Since the addr points at the start of the instruction,
 165   // we must parse the instruction a bit to find the embedded word.
 166   assert(is_data(), "must be a DataRelocation");
 167   typedef Assembler::WhichOperand WhichOperand;
 168   WhichOperand which = (WhichOperand) format(); // that is, disp32 or imm/imm32
 169   assert(which == Assembler::disp32_operand ||
 170          which == Assembler::call32_operand ||
 171          which == Assembler::imm_operand, "format unpacks ok");
 172   if (which != Assembler::imm_operand) {
 173     address ip = addr();
 174     address disp = Assembler::locate_operand(ip, which);
 175     address next_ip = Assembler::locate_next_instruction(ip);
 176     address a = next_ip + *(int32_t*) disp;
 177     return a;
 178   }
 179 #endif // AMD64
 180   return *pd_address_in_code();
 181 }
 182 
 183 int Relocation::pd_breakpoint_size() {
 184   // minimum breakpoint size, in short words
 185   return NativeIllegalInstruction::instruction_size / sizeof(short);
 186 }
 187 
 188 void Relocation::pd_swap_in_breakpoint(address x, short* instrs, int instrlen) {
 189   Untested("pd_swap_in_breakpoint");
 190   if (instrs != NULL) {
 191     assert(instrlen * sizeof(short) == NativeIllegalInstruction::instruction_size, "enough instrlen in reloc. data");
 192     for (int i = 0; i < instrlen; i++) {
 193       instrs[i] = ((short*)x)[i];
 194     }
 195   }
 196   NativeIllegalInstruction::insert(x);
 197 }
 198 
 199 
 200 void Relocation::pd_swap_out_breakpoint(address x, short* instrs, int instrlen) {
 201   Untested("pd_swap_out_breakpoint");
 202   assert(NativeIllegalInstruction::instruction_size == sizeof(short), "right address unit for update");
 203   NativeInstruction* ni = nativeInstruction_at(x);
 204   *(short*)ni->addr_at(0) = instrs[0];
 205 }
 206 
 207 void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 208 #ifdef _LP64
 209   if (!Assembler::is_polling_page_far()) {
 210     typedef Assembler::WhichOperand WhichOperand;
 211     WhichOperand which = (WhichOperand) format();
 212     // This format is imm but it is really disp32
 213     which = Assembler::disp32_operand;
 214     address orig_addr = old_addr_for(addr(), src, dest);
 215     NativeInstruction* oni = nativeInstruction_at(orig_addr);
 216     int32_t* orig_disp = (int32_t*) Assembler::locate_operand(orig_addr, which);
 217     // This poll_addr is incorrect by the size of the instruction it is irrelevant
 218     intptr_t poll_addr = (intptr_t)oni + *orig_disp;
 219 
 220     NativeInstruction* ni = nativeInstruction_at(addr());
 221     intptr_t new_disp = poll_addr - (intptr_t) ni;
 222 
 223     int32_t* disp = (int32_t*) Assembler::locate_operand(addr(), which);
 224     * disp = (int32_t)new_disp;
 225   }
 226 #endif // _LP64
 227 }
 228 
 229 void poll_return_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 230 #ifdef _LP64
 231   if (!Assembler::is_polling_page_far()) {
 232     typedef Assembler::WhichOperand WhichOperand;
 233     WhichOperand which = (WhichOperand) format();
 234     // This format is imm but it is really disp32
 235     which = Assembler::disp32_operand;
 236     address orig_addr = old_addr_for(addr(), src, dest);
 237     NativeInstruction* oni = nativeInstruction_at(orig_addr);
 238     int32_t* orig_disp = (int32_t*) Assembler::locate_operand(orig_addr, which);
 239     // This poll_addr is incorrect by the size of the instruction it is irrelevant
 240     intptr_t poll_addr = (intptr_t)oni + *orig_disp;
 241 
 242     NativeInstruction* ni = nativeInstruction_at(addr());
 243     intptr_t new_disp = poll_addr - (intptr_t) ni;
 244 
 245     int32_t* disp = (int32_t*) Assembler::locate_operand(addr(), which);
 246     * disp = (int32_t)new_disp;
 247   }
 248 #endif // _LP64
 249 }
 250 
 251 void metadata_Relocation::pd_fix_value(address x) {
 252 }