1 /*
   2  * Copyright (c) 1997, 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/macroAssembler.inline.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "code/compiledIC.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "runtime/mutexLocker.hpp"
  33 #include "runtime/safepoint.hpp"
  34 
  35 // ----------------------------------------------------------------------------
  36 
  37 #define __ _masm.
  38 address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark) {
  39   // Stub is fixed up when the corresponding call is converted from
  40   // calling compiled code to calling interpreted code.
  41   // movq rbx, 0
  42   // jmp -5 # to self
  43 
  44   if (mark == NULL) {
  45     mark = cbuf.insts_mark();  // Get mark within main instrs section.
  46   }
  47 
  48   // Note that the code buffer's insts_mark is always relative to insts.
  49   // That's why we must use the macroassembler to generate a stub.
  50   MacroAssembler _masm(&cbuf);
  51 
  52   address base = __ start_a_stub(to_interp_stub_size());
  53   if (base == NULL) {
  54     return NULL;  // CodeBuffer::expand failed.
  55   }
  56   // Static stub relocation stores the instruction address of the call.
  57   __ relocate(static_stub_Relocation::spec(mark, false), Assembler::imm_operand);
  58   // Static stub relocation also tags the Method* in the code-stream.
  59   __ mov_metadata(rbx, (Metadata*) NULL);  // Method is zapped till fixup time.
  60   // This is recognized as unresolved by relocs/nativeinst/ic code.
  61   __ jump(RuntimeAddress(__ pc()));
  62 
  63   assert(__ pc() - base <= to_interp_stub_size(), "wrong stub size");
  64 
  65   // Update current stubs pointer and restore insts_end.
  66   __ end_a_stub();
  67   return base;
  68 }
  69 #undef __
  70 
  71 int CompiledStaticCall::to_interp_stub_size() {
  72   return NOT_LP64(10)    // movl; jmp
  73          LP64_ONLY(15);  // movq (1+1+8); jmp (1+4)
  74 }
  75 
  76 int CompiledStaticCall::to_trampoline_stub_size() {
  77   // x86 doesn't use trampolines.
  78   return 0;
  79 }
  80 
  81 // Relocation entries for call stub, compiled java to interpreter.
  82 int CompiledStaticCall::reloc_to_interp_stub() {
  83   return 4; // 3 in emit_to_interp_stub + 1 in emit_call
  84 }
  85 
  86 #if INCLUDE_AOT
  87 #define __ _masm.
  88 void CompiledStaticCall::emit_to_aot_stub(CodeBuffer &cbuf, address mark) {
  89   if (!UseAOT) {
  90     return;
  91   }
  92   // Stub is fixed up when the corresponding call is converted from
  93   // calling compiled code to calling aot code.
  94   // movq rax, imm64_aot_code_address
  95   // jmp  rax
  96 
  97   if (mark == NULL) {
  98     mark = cbuf.insts_mark();  // Get mark within main instrs section.
  99   }
 100 
 101   // Note that the code buffer's insts_mark is always relative to insts.
 102   // That's why we must use the macroassembler to generate a stub.
 103   MacroAssembler _masm(&cbuf);
 104 
 105   address base =
 106   __ start_a_stub(to_aot_stub_size());
 107   guarantee(base != NULL, "out of space");
 108 
 109   // Static stub relocation stores the instruction address of the call.
 110   __ relocate(static_stub_Relocation::spec(mark, true /* is_aot */), Assembler::imm_operand);
 111   // Load destination AOT code address.
 112 #ifdef _LP64
 113   __ mov64(rax, CONST64(0));  // address is zapped till fixup time.
 114 #else
 115   __ movl(rax, 0);  // address is zapped till fixup time.
 116 #endif
 117   // This is recognized as unresolved by relocs/nativeinst/ic code.
 118   __ jmp(rax);
 119 
 120   assert(__ pc() - base <= to_aot_stub_size(), "wrong stub size");
 121 
 122   // Update current stubs pointer and restore insts_end.
 123   __ end_a_stub();
 124 }
 125 #undef __
 126 
 127 int CompiledStaticCall::to_aot_stub_size() {
 128   if (UseAOT) {
 129     return NOT_LP64(7)    // movl; jmp
 130            LP64_ONLY(12);  // movq (1+1+8); jmp (2)
 131   } else {
 132     return 0;
 133   }
 134 }
 135 
 136 // Relocation entries for call stub, compiled java to aot.
 137 int CompiledStaticCall::reloc_to_aot_stub() {
 138   if (UseAOT) {
 139     return 2; // 1 in emit_to_aot_stub + 1 in emit_call
 140   } else {
 141     return 0;
 142   }
 143 }
 144 #endif // INCLUDE_AOT
 145 
 146 void CompiledDirectStaticCall::set_to_interpreted(const methodHandle& callee, address entry) {
 147   address stub = find_stub(false /* is_aot */);
 148   guarantee(stub != NULL, "stub not found");
 149 
 150   if (TraceICs) {
 151     ResourceMark rm;
 152     tty->print_cr("CompiledDirectStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
 153                   p2i(instruction_address()),
 154                   callee->name_and_sig_as_C_string());
 155   }
 156 
 157   // Creation also verifies the object.
 158   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
 159   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 160 
 161 #ifdef ASSERT
 162   // A generated lambda form might be deleted from the Lambdaform
 163   // cache in MethodTypeForm.  If a jit compiled lambdaform method
 164   // becomes not entrant and the cache access returns null, the new
 165   // resolve will lead to a new generated LambdaForm.
 166   Method* old_method = reinterpret_cast<Method*>(method_holder->data());
 167   assert(old_method == NULL || old_method == callee() ||
 168          callee->is_compiled_lambda_form() ||
 169          !old_method->method_holder()->is_loader_alive() ||
 170          old_method->is_old(),  // may be race patching deoptimized nmethod due to redefinition.
 171          "a) MT-unsafe modification of inline cache");
 172 
 173   address destination = jump->jump_destination();
 174   assert(destination == (address)-1 || destination == entry,
 175          "b) MT-unsafe modification of inline cache");
 176 #endif
 177 
 178   // Update stub.
 179   method_holder->set_data((intptr_t)callee());
 180   jump->set_jump_destination(entry);
 181 
 182   // Update jump to call.
 183   set_destination_mt_safe(stub);
 184 }
 185 
 186 void CompiledDirectStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
 187   assert(CompiledICLocker::is_safe(static_stub->addr()), "mt unsafe call");
 188   // Reset stub.
 189   address stub = static_stub->addr();
 190   assert(stub != NULL, "stub not found");
 191   // Creation also verifies the object.
 192   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
 193   method_holder->set_data(0);
 194   if (!static_stub->is_aot()) {
 195     NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
 196     jump->set_jump_destination((address)-1);
 197   }
 198 }
 199 
 200 
 201 //-----------------------------------------------------------------------------
 202 // Non-product mode code
 203 #ifndef PRODUCT
 204 
 205 void CompiledDirectStaticCall::verify() {
 206   // Verify call.
 207   _call->verify();
 208   _call->verify_alignment();
 209 
 210 #ifdef ASSERT
 211   CodeBlob *cb = CodeCache::find_blob_unsafe((address) _call);
 212   assert(cb && !cb->is_aot(), "CompiledDirectStaticCall cannot be used on AOTCompiledMethod");
 213 #endif
 214 
 215   // Verify stub.
 216   address stub = find_stub(false /* is_aot */);
 217   assert(stub != NULL, "no stub found for static call");
 218   // Creation also verifies the object.
 219   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
 220   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 221 
 222   // Verify state.
 223   assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
 224 }
 225 #endif // !PRODUCT