1 /*
   2  * Copyright (c) 2008, 2018, 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/assembler.inline.hpp"
  27 #include "assembler_arm.inline.hpp"
  28 #include "code/relocInfo.hpp"
  29 #include "nativeInst_arm.hpp"
  30 #include "oops/compressedOops.inline.hpp"
  31 #include "oops/oop.hpp"
  32 #include "runtime/orderAccess.hpp"
  33 #include "runtime/safepoint.hpp"
  34 
  35 void Relocation::pd_set_data_value(address x, intptr_t o, bool verify_only) {
  36 
  37   NativeMovConstReg* ni = nativeMovConstReg_at(addr());
  38   if (verify_only) {
  39     guarantee(ni->data() == (intptr_t)(x + o), "instructions must match");
  40   } else {
  41     ni->set_data((intptr_t)(x + o));
  42   }
  43 }
  44 
  45 address Relocation::pd_call_destination(address orig_addr) {
  46   address pc = addr();
  47 
  48   int adj = 0;
  49   if (orig_addr != NULL) {
  50     // We just moved this call instruction from orig_addr to addr().
  51     // This means that, when relative, its target will appear to have grown by addr() - orig_addr.
  52     adj = orig_addr - pc;
  53   }
  54 
  55   RawNativeInstruction* ni = rawNativeInstruction_at(pc);
  56 
  57   if (ni->is_add_lr()) {
  58     // Skip the optional 'add LR, PC, #offset'
  59     // (Allowing the jump support code to handle fat_call)
  60     pc = ni->next_raw_instruction_address();
  61     ni = nativeInstruction_at(pc);
  62   }
  63 
  64   if (ni->is_bl()) {
  65     // Fat_call are handled by is_jump for the new 'ni',
  66     // requiring only to support is_bl.
  67     return rawNativeCall_at(pc)->destination(adj);
  68   }
  69 
  70   if (ni->is_jump()) {
  71     return rawNativeJump_at(pc)->jump_destination(adj);
  72   }
  73   ShouldNotReachHere();
  74   return NULL;
  75 }
  76 
  77 void Relocation::pd_set_call_destination(address x) {
  78   address pc = addr();
  79   NativeInstruction* ni = nativeInstruction_at(pc);
  80 
  81   if (ni->is_add_lr()) {
  82     // Skip the optional 'add LR, PC, #offset'
  83     // (Allowing the jump support code to handle fat_call)
  84     pc = ni->next_raw_instruction_address();
  85     ni = nativeInstruction_at(pc);
  86   }
  87 
  88   if (ni->is_bl()) {
  89     // Fat_call are handled by is_jump for the new 'ni',
  90     // requiring only to support is_bl.
  91     rawNativeCall_at(pc)->set_destination(x);
  92     return;
  93   }
  94 
  95   if (ni->is_jump()) { // raw jump
  96     rawNativeJump_at(pc)->set_jump_destination(x);
  97     return;
  98   }
  99   ShouldNotReachHere();
 100 }
 101 
 102 
 103 address* Relocation::pd_address_in_code() {
 104   return (address*)addr();
 105 }
 106 
 107 address Relocation::pd_get_address_from_code() {
 108   return *pd_address_in_code();
 109 }
 110 
 111 void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 112 }
 113 
 114 void metadata_Relocation::pd_fix_value(address x) {
 115   assert(! addr_in_const(), "Do not use");
 116   if (!VM_Version::supports_movw()) {
 117     set_value(x);
 118 #ifdef ASSERT
 119   } else {
 120     // the movw/movt data should be correct
 121     NativeMovConstReg* ni = nativeMovConstReg_at(addr());
 122     assert(ni->is_movw(), "not a movw");
 123     // The following assert should be correct but the shared code
 124     // currently 'fixes' the metadata instructions before the
 125     // metadata_table is copied in the new method (see
 126     // JDK-8042845). This means that 'x' (which comes from the table)
 127     // does not match the value inlined in the code (which is
 128     // correct). Failure can be temporarily ignored since the code is
 129     // correct and the table is copied shortly afterward.
 130     //
 131     // assert(ni->data() == (int)x, "metadata relocation mismatch");
 132 #endif
 133   }
 134 }