1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #include "v8.h" 29 30 #if defined(V8_TARGET_ARCH_X64) 31 32 #include "assembler.h" 33 #include "codegen.h" 34 #include "debug.h" 35 36 37 namespace v8 { 38 namespace internal { 39 40 #ifdef ENABLE_DEBUGGER_SUPPORT 41 42 bool BreakLocationIterator::IsDebugBreakAtReturn() { 43 return Debug::IsDebugBreakAtReturn(rinfo()); 44 } 45 46 47 // Patch the JS frame exit code with a debug break call. See 48 // CodeGenerator::VisitReturnStatement and VirtualFrame::Exit in codegen-x64.cc 49 // for the precise return instructions sequence. 50 void BreakLocationIterator::SetDebugBreakAtReturn() { 51 ASSERT(Assembler::kJSReturnSequenceLength >= 52 Assembler::kCallInstructionLength); 53 rinfo()->PatchCodeWithCall( 54 Isolate::Current()->debug()->debug_break_return()->entry(), 55 Assembler::kJSReturnSequenceLength - Assembler::kCallInstructionLength); 56 } 57 58 59 // Restore the JS frame exit code. 60 void BreakLocationIterator::ClearDebugBreakAtReturn() { 61 rinfo()->PatchCode(original_rinfo()->pc(), 62 Assembler::kJSReturnSequenceLength); 63 } 64 65 66 // A debug break in the frame exit code is identified by the JS frame exit code 67 // having been patched with a call instruction. 68 bool Debug::IsDebugBreakAtReturn(v8::internal::RelocInfo* rinfo) { 69 ASSERT(RelocInfo::IsJSReturn(rinfo->rmode())); 70 return rinfo->IsPatchedReturnSequence(); 71 } 72 73 74 bool BreakLocationIterator::IsDebugBreakAtSlot() { 75 ASSERT(IsDebugBreakSlot()); 76 // Check whether the debug break slot instructions have been patched. 77 return !Assembler::IsNop(rinfo()->pc()); 78 } 79 80 81 void BreakLocationIterator::SetDebugBreakAtSlot() { 82 ASSERT(IsDebugBreakSlot()); 83 rinfo()->PatchCodeWithCall( 84 Isolate::Current()->debug()->debug_break_slot()->entry(), 85 Assembler::kDebugBreakSlotLength - Assembler::kCallInstructionLength); 86 } 87 88 89 void BreakLocationIterator::ClearDebugBreakAtSlot() { 90 ASSERT(IsDebugBreakSlot()); 91 rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength); 92 } 93 94 95 #define __ ACCESS_MASM(masm) 96 97 98 static void Generate_DebugBreakCallHelper(MacroAssembler* masm, 99 RegList object_regs, 100 RegList non_object_regs, 101 bool convert_call_to_jmp) { 102 // Enter an internal frame. 103 { 104 FrameScope scope(masm, StackFrame::INTERNAL); 105 106 // Store the registers containing live values on the expression stack to 107 // make sure that these are correctly updated during GC. Non object values 108 // are stored as as two smis causing it to be untouched by GC. 109 ASSERT((object_regs & ~kJSCallerSaved) == 0); 110 ASSERT((non_object_regs & ~kJSCallerSaved) == 0); 111 ASSERT((object_regs & non_object_regs) == 0); 112 for (int i = 0; i < kNumJSCallerSaved; i++) { 113 int r = JSCallerSavedCode(i); 114 Register reg = { r }; 115 ASSERT(!reg.is(kScratchRegister)); 116 if ((object_regs & (1 << r)) != 0) { 117 __ push(reg); 118 } 119 // Store the 64-bit value as two smis. 120 if ((non_object_regs & (1 << r)) != 0) { 121 __ movq(kScratchRegister, reg); 122 __ Integer32ToSmi(reg, reg); 123 __ push(reg); 124 __ sar(kScratchRegister, Immediate(32)); 125 __ Integer32ToSmi(kScratchRegister, kScratchRegister); 126 __ push(kScratchRegister); 127 } 128 } 129 130 #ifdef DEBUG 131 __ RecordComment("// Calling from debug break to runtime - come in - over"); 132 #endif 133 __ Set(rax, 0); // No arguments (argc == 0). 134 __ movq(rbx, ExternalReference::debug_break(masm->isolate())); 135 136 CEntryStub ceb(1); 137 __ CallStub(&ceb); 138 139 // Restore the register values from the expression stack. 140 for (int i = kNumJSCallerSaved - 1; i >= 0; i--) { 141 int r = JSCallerSavedCode(i); 142 Register reg = { r }; 143 if (FLAG_debug_code) { 144 __ Set(reg, kDebugZapValue); 145 } 146 if ((object_regs & (1 << r)) != 0) { 147 __ pop(reg); 148 } 149 // Reconstruct the 64-bit value from two smis. 150 if ((non_object_regs & (1 << r)) != 0) { 151 __ pop(kScratchRegister); 152 __ SmiToInteger32(kScratchRegister, kScratchRegister); 153 __ shl(kScratchRegister, Immediate(32)); 154 __ pop(reg); 155 __ SmiToInteger32(reg, reg); 156 __ or_(reg, kScratchRegister); 157 } 158 } 159 160 // Get rid of the internal frame. 161 } 162 163 // If this call did not replace a call but patched other code then there will 164 // be an unwanted return address left on the stack. Here we get rid of that. 165 if (convert_call_to_jmp) { 166 __ addq(rsp, Immediate(kPointerSize)); 167 } 168 169 // Now that the break point has been handled, resume normal execution by 170 // jumping to the target address intended by the caller and that was 171 // overwritten by the address of DebugBreakXXX. 172 ExternalReference after_break_target = 173 ExternalReference(Debug_Address::AfterBreakTarget(), masm->isolate()); 174 __ movq(kScratchRegister, after_break_target); 175 __ jmp(Operand(kScratchRegister, 0)); 176 } 177 178 179 void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) { 180 // Register state for IC load call (from ic-x64.cc). 181 // ----------- S t a t e ------------- 182 // -- rax : receiver 183 // -- rcx : name 184 // ----------------------------------- 185 Generate_DebugBreakCallHelper(masm, rax.bit() | rcx.bit(), 0, false); 186 } 187 188 189 void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) { 190 // Register state for IC store call (from ic-x64.cc). 191 // ----------- S t a t e ------------- 192 // -- rax : value 193 // -- rcx : name 194 // -- rdx : receiver 195 // ----------------------------------- 196 Generate_DebugBreakCallHelper( 197 masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false); 198 } 199 200 201 void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { 202 // Register state for keyed IC load call (from ic-x64.cc). 203 // ----------- S t a t e ------------- 204 // -- rax : key 205 // -- rdx : receiver 206 // ----------------------------------- 207 Generate_DebugBreakCallHelper(masm, rax.bit() | rdx.bit(), 0, false); 208 } 209 210 211 void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { 212 // Register state for keyed IC load call (from ic-x64.cc). 213 // ----------- S t a t e ------------- 214 // -- rax : value 215 // -- rcx : key 216 // -- rdx : receiver 217 // ----------------------------------- 218 Generate_DebugBreakCallHelper( 219 masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false); 220 } 221 222 223 void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) { 224 // Register state for IC call call (from ic-x64.cc) 225 // ----------- S t a t e ------------- 226 // -- rcx: function name 227 // ----------------------------------- 228 Generate_DebugBreakCallHelper(masm, rcx.bit(), 0, false); 229 } 230 231 232 void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) { 233 // Register state just before return from JS function (from codegen-x64.cc). 234 // ----------- S t a t e ------------- 235 // -- rax: return value 236 // ----------------------------------- 237 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, true); 238 } 239 240 241 void Debug::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) { 242 // Register state for CallFunctionStub (from code-stubs-x64.cc). 243 // ----------- S t a t e ------------- 244 // -- rdi : function 245 // ----------------------------------- 246 Generate_DebugBreakCallHelper(masm, rdi.bit(), 0, false); 247 } 248 249 250 void Debug::GenerateCallFunctionStubRecordDebugBreak(MacroAssembler* masm) { 251 // Register state for CallFunctionStub (from code-stubs-x64.cc). 252 // ----------- S t a t e ------------- 253 // -- rdi : function 254 // -- rbx: cache cell for call target 255 // ----------------------------------- 256 Generate_DebugBreakCallHelper(masm, rbx.bit() | rdi.bit(), 0, false); 257 } 258 259 260 void Debug::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) { 261 // Register state for CallConstructStub (from code-stubs-x64.cc). 262 // rax is the actual number of arguments not encoded as a smi, see comment 263 // above IC call. 264 // ----------- S t a t e ------------- 265 // -- rax: number of arguments 266 // ----------------------------------- 267 // The number of arguments in rax is not smi encoded. 268 Generate_DebugBreakCallHelper(masm, rdi.bit(), rax.bit(), false); 269 } 270 271 272 void Debug::GenerateCallConstructStubRecordDebugBreak(MacroAssembler* masm) { 273 // Register state for CallConstructStub (from code-stubs-x64.cc). 274 // rax is the actual number of arguments not encoded as a smi, see comment 275 // above IC call. 276 // ----------- S t a t e ------------- 277 // -- rax: number of arguments 278 // -- rbx: cache cell for call target 279 // ----------------------------------- 280 // The number of arguments in rax is not smi encoded. 281 Generate_DebugBreakCallHelper(masm, rbx.bit() | rdi.bit(), rax.bit(), false); 282 } 283 284 285 void Debug::GenerateSlot(MacroAssembler* masm) { 286 // Generate enough nop's to make space for a call instruction. 287 Label check_codesize; 288 __ bind(&check_codesize); 289 __ RecordDebugBreakSlot(); 290 __ Nop(Assembler::kDebugBreakSlotLength); 291 ASSERT_EQ(Assembler::kDebugBreakSlotLength, 292 masm->SizeOfCodeGeneratedSince(&check_codesize)); 293 } 294 295 296 void Debug::GenerateSlotDebugBreak(MacroAssembler* masm) { 297 // In the places where a debug break slot is inserted no registers can contain 298 // object pointers. 299 Generate_DebugBreakCallHelper(masm, 0, 0, true); 300 } 301 302 303 void Debug::GeneratePlainReturnLiveEdit(MacroAssembler* masm) { 304 masm->ret(0); 305 } 306 307 308 void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { 309 ExternalReference restarter_frame_function_slot = 310 ExternalReference(Debug_Address::RestarterFrameFunctionPointer(), 311 masm->isolate()); 312 __ movq(rax, restarter_frame_function_slot); 313 __ movq(Operand(rax, 0), Immediate(0)); 314 315 // We do not know our frame height, but set rsp based on rbp. 316 __ lea(rsp, Operand(rbp, -1 * kPointerSize)); 317 318 __ pop(rdi); // Function. 319 __ pop(rbp); 320 321 // Load context from the function. 322 __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset)); 323 324 // Get function code. 325 __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset)); 326 __ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset)); 327 __ lea(rdx, FieldOperand(rdx, Code::kHeaderSize)); 328 329 // Re-run JSFunction, rdi is function, rsi is context. 330 __ jmp(rdx); 331 } 332 333 const bool Debug::kFrameDropperSupported = true; 334 335 #undef __ 336 337 #endif // ENABLE_DEBUGGER_SUPPORT 338 339 } } // namespace v8::internal 340 341 #endif // V8_TARGET_ARCH_X64 342
