1 // Copyright 2012 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 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 >= Assembler::kCallSequenceLength); 52 rinfo()->PatchCodeWithCall( 53 Isolate::Current()->debug()->debug_break_return()->entry(), 54 Assembler::kJSReturnSequenceLength - Assembler::kCallSequenceLength); 55 } 56 57 58 // Restore the JS frame exit code. 59 void BreakLocationIterator::ClearDebugBreakAtReturn() { 60 rinfo()->PatchCode(original_rinfo()->pc(), 61 Assembler::kJSReturnSequenceLength); 62 } 63 64 65 // A debug break in the frame exit code is identified by the JS frame exit code 66 // having been patched with a call instruction. 67 bool Debug::IsDebugBreakAtReturn(v8::internal::RelocInfo* rinfo) { 68 ASSERT(RelocInfo::IsJSReturn(rinfo->rmode())); 69 return rinfo->IsPatchedReturnSequence(); 70 } 71 72 73 bool BreakLocationIterator::IsDebugBreakAtSlot() { 74 ASSERT(IsDebugBreakSlot()); 75 // Check whether the debug break slot instructions have been patched. 76 return !Assembler::IsNop(rinfo()->pc()); 77 } 78 79 80 void BreakLocationIterator::SetDebugBreakAtSlot() { 81 ASSERT(IsDebugBreakSlot()); 82 rinfo()->PatchCodeWithCall( 83 Isolate::Current()->debug()->debug_break_slot()->entry(), 84 Assembler::kDebugBreakSlotLength - Assembler::kCallSequenceLength); 85 } 86 87 88 void BreakLocationIterator::ClearDebugBreakAtSlot() { 89 ASSERT(IsDebugBreakSlot()); 90 rinfo()->PatchCode(original_rinfo()->pc(), Assembler::kDebugBreakSlotLength); 91 } 92 93 const bool Debug::FramePaddingLayout::kIsSupported = true; 94 95 96 #define __ ACCESS_MASM(masm) 97 98 99 static void Generate_DebugBreakCallHelper(MacroAssembler* masm, 100 RegList object_regs, 101 RegList non_object_regs, 102 bool convert_call_to_jmp) { 103 // Enter an internal frame. 104 { 105 FrameScope scope(masm, StackFrame::INTERNAL); 106 107 // Load padding words on stack. 108 for (int i = 0; i < Debug::FramePaddingLayout::kInitialSize; i++) { 109 __ Push(Smi::FromInt(Debug::FramePaddingLayout::kPaddingValue)); 110 } 111 __ Push(Smi::FromInt(Debug::FramePaddingLayout::kInitialSize)); 112 113 // Store the registers containing live values on the expression stack to 114 // make sure that these are correctly updated during GC. Non object values 115 // are stored as as two smis causing it to be untouched by GC. 116 ASSERT((object_regs & ~kJSCallerSaved) == 0); 117 ASSERT((non_object_regs & ~kJSCallerSaved) == 0); 118 ASSERT((object_regs & non_object_regs) == 0); 119 for (int i = 0; i < kNumJSCallerSaved; i++) { 120 int r = JSCallerSavedCode(i); 121 Register reg = { r }; 122 ASSERT(!reg.is(kScratchRegister)); 123 if ((object_regs & (1 << r)) != 0) { 124 __ push(reg); 125 } 126 // Store the 64-bit value as two smis. 127 if ((non_object_regs & (1 << r)) != 0) { 128 __ movq(kScratchRegister, reg); 129 __ Integer32ToSmi(reg, reg); 130 __ push(reg); 131 __ sar(kScratchRegister, Immediate(32)); 132 __ Integer32ToSmi(kScratchRegister, kScratchRegister); 133 __ push(kScratchRegister); 134 } 135 } 136 137 #ifdef DEBUG 138 __ RecordComment("// Calling from debug break to runtime - come in - over"); 139 #endif 140 __ Set(rax, 0); // No arguments (argc == 0). 141 __ movq(rbx, ExternalReference::debug_break(masm->isolate())); 142 143 CEntryStub ceb(1); 144 __ CallStub(&ceb); 145 146 // Restore the register values from the expression stack. 147 for (int i = kNumJSCallerSaved - 1; i >= 0; i--) { 148 int r = JSCallerSavedCode(i); 149 Register reg = { r }; 150 if (FLAG_debug_code) { 151 __ Set(reg, kDebugZapValue); 152 } 153 if ((object_regs & (1 << r)) != 0) { 154 __ pop(reg); 155 } 156 // Reconstruct the 64-bit value from two smis. 157 if ((non_object_regs & (1 << r)) != 0) { 158 __ pop(kScratchRegister); 159 __ SmiToInteger32(kScratchRegister, kScratchRegister); 160 __ shl(kScratchRegister, Immediate(32)); 161 __ pop(reg); 162 __ SmiToInteger32(reg, reg); 163 __ or_(reg, kScratchRegister); 164 } 165 } 166 167 // Read current padding counter and skip corresponding number of words. 168 __ pop(kScratchRegister); 169 __ SmiToInteger32(kScratchRegister, kScratchRegister); 170 __ lea(rsp, Operand(rsp, kScratchRegister, times_pointer_size, 0)); 171 172 // Get rid of the internal frame. 173 } 174 175 // If this call did not replace a call but patched other code then there will 176 // be an unwanted return address left on the stack. Here we get rid of that. 177 if (convert_call_to_jmp) { 178 __ addq(rsp, Immediate(kPointerSize)); 179 } 180 181 // Now that the break point has been handled, resume normal execution by 182 // jumping to the target address intended by the caller and that was 183 // overwritten by the address of DebugBreakXXX. 184 ExternalReference after_break_target = 185 ExternalReference(Debug_Address::AfterBreakTarget(), masm->isolate()); 186 __ movq(kScratchRegister, after_break_target); 187 __ jmp(Operand(kScratchRegister, 0)); 188 } 189 190 191 void Debug::GenerateLoadICDebugBreak(MacroAssembler* masm) { 192 // Register state for IC load call (from ic-x64.cc). 193 // ----------- S t a t e ------------- 194 // -- rax : receiver 195 // -- rcx : name 196 // ----------------------------------- 197 Generate_DebugBreakCallHelper(masm, rax.bit() | rcx.bit(), 0, false); 198 } 199 200 201 void Debug::GenerateStoreICDebugBreak(MacroAssembler* masm) { 202 // Register state for IC store call (from ic-x64.cc). 203 // ----------- S t a t e ------------- 204 // -- rax : value 205 // -- rcx : name 206 // -- rdx : receiver 207 // ----------------------------------- 208 Generate_DebugBreakCallHelper( 209 masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false); 210 } 211 212 213 void Debug::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) { 214 // Register state for keyed IC load call (from ic-x64.cc). 215 // ----------- S t a t e ------------- 216 // -- rax : key 217 // -- rdx : receiver 218 // ----------------------------------- 219 Generate_DebugBreakCallHelper(masm, rax.bit() | rdx.bit(), 0, false); 220 } 221 222 223 void Debug::GenerateKeyedStoreICDebugBreak(MacroAssembler* masm) { 224 // Register state for keyed IC load call (from ic-x64.cc). 225 // ----------- S t a t e ------------- 226 // -- rax : value 227 // -- rcx : key 228 // -- rdx : receiver 229 // ----------------------------------- 230 Generate_DebugBreakCallHelper( 231 masm, rax.bit() | rcx.bit() | rdx.bit(), 0, false); 232 } 233 234 235 void Debug::GenerateCompareNilICDebugBreak(MacroAssembler* masm) { 236 // Register state for CompareNil IC 237 // ----------- S t a t e ------------- 238 // -- rax : value 239 // ----------------------------------- 240 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, false); 241 } 242 243 244 void Debug::GenerateCallICDebugBreak(MacroAssembler* masm) { 245 // Register state for IC call call (from ic-x64.cc) 246 // ----------- S t a t e ------------- 247 // -- rcx: function name 248 // ----------------------------------- 249 Generate_DebugBreakCallHelper(masm, rcx.bit(), 0, false); 250 } 251 252 253 void Debug::GenerateReturnDebugBreak(MacroAssembler* masm) { 254 // Register state just before return from JS function (from codegen-x64.cc). 255 // ----------- S t a t e ------------- 256 // -- rax: return value 257 // ----------------------------------- 258 Generate_DebugBreakCallHelper(masm, rax.bit(), 0, true); 259 } 260 261 262 void Debug::GenerateCallFunctionStubDebugBreak(MacroAssembler* masm) { 263 // Register state for CallFunctionStub (from code-stubs-x64.cc). 264 // ----------- S t a t e ------------- 265 // -- rdi : function 266 // ----------------------------------- 267 Generate_DebugBreakCallHelper(masm, rdi.bit(), 0, false); 268 } 269 270 271 void Debug::GenerateCallFunctionStubRecordDebugBreak(MacroAssembler* masm) { 272 // Register state for CallFunctionStub (from code-stubs-x64.cc). 273 // ----------- S t a t e ------------- 274 // -- rdi : function 275 // -- rbx: cache cell for call target 276 // ----------------------------------- 277 Generate_DebugBreakCallHelper(masm, rbx.bit() | rdi.bit(), 0, false); 278 } 279 280 281 void Debug::GenerateCallConstructStubDebugBreak(MacroAssembler* masm) { 282 // Register state for CallConstructStub (from code-stubs-x64.cc). 283 // rax is the actual number of arguments not encoded as a smi, see comment 284 // above IC call. 285 // ----------- S t a t e ------------- 286 // -- rax: number of arguments 287 // ----------------------------------- 288 // The number of arguments in rax is not smi encoded. 289 Generate_DebugBreakCallHelper(masm, rdi.bit(), rax.bit(), false); 290 } 291 292 293 void Debug::GenerateCallConstructStubRecordDebugBreak(MacroAssembler* masm) { 294 // Register state for CallConstructStub (from code-stubs-x64.cc). 295 // rax is the actual number of arguments not encoded as a smi, see comment 296 // above IC call. 297 // ----------- S t a t e ------------- 298 // -- rax: number of arguments 299 // -- rbx: cache cell for call target 300 // ----------------------------------- 301 // The number of arguments in rax is not smi encoded. 302 Generate_DebugBreakCallHelper(masm, rbx.bit() | rdi.bit(), rax.bit(), false); 303 } 304 305 306 void Debug::GenerateSlot(MacroAssembler* masm) { 307 // Generate enough nop's to make space for a call instruction. 308 Label check_codesize; 309 __ bind(&check_codesize); 310 __ RecordDebugBreakSlot(); 311 __ Nop(Assembler::kDebugBreakSlotLength); 312 ASSERT_EQ(Assembler::kDebugBreakSlotLength, 313 masm->SizeOfCodeGeneratedSince(&check_codesize)); 314 } 315 316 317 void Debug::GenerateSlotDebugBreak(MacroAssembler* masm) { 318 // In the places where a debug break slot is inserted no registers can contain 319 // object pointers. 320 Generate_DebugBreakCallHelper(masm, 0, 0, true); 321 } 322 323 324 void Debug::GeneratePlainReturnLiveEdit(MacroAssembler* masm) { 325 masm->ret(0); 326 } 327 328 329 void Debug::GenerateFrameDropperLiveEdit(MacroAssembler* masm) { 330 ExternalReference restarter_frame_function_slot = 331 ExternalReference(Debug_Address::RestarterFrameFunctionPointer(), 332 masm->isolate()); 333 __ movq(rax, restarter_frame_function_slot); 334 __ movq(Operand(rax, 0), Immediate(0)); 335 336 // We do not know our frame height, but set rsp based on rbp. 337 __ lea(rsp, Operand(rbp, -1 * kPointerSize)); 338 339 __ pop(rdi); // Function. 340 __ pop(rbp); 341 342 // Load context from the function. 343 __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset)); 344 345 // Get function code. 346 __ movq(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset)); 347 __ movq(rdx, FieldOperand(rdx, SharedFunctionInfo::kCodeOffset)); 348 __ lea(rdx, FieldOperand(rdx, Code::kHeaderSize)); 349 350 // Re-run JSFunction, rdi is function, rsi is context. 351 __ jmp(rdx); 352 } 353 354 const bool Debug::kFrameDropperSupported = true; 355 356 #undef __ 357 358 #endif // ENABLE_DEBUGGER_SUPPORT 359 360 } } // namespace v8::internal 361 362 #endif // V8_TARGET_ARCH_X64 363
