| // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #include "vm/code_patcher.h" |
| #include "vm/cpu.h" |
| #include "vm/instructions.h" |
| #include "vm/object.h" |
| #include "vm/virtual_memory.h" |
| |
| namespace dart { |
| |
| DEFINE_FLAG(bool, write_protect_code, true, "Write protect jitted code"); |
| |
| WritableInstructionsScope::WritableInstructionsScope(uword address, |
| intptr_t size) |
| : address_(address), size_(size) { |
| if (FLAG_write_protect_code) { |
| VirtualMemory::Protect(reinterpret_cast<void*>(address), size, |
| VirtualMemory::kReadWrite); |
| } |
| } |
| |
| WritableInstructionsScope::~WritableInstructionsScope() { |
| if (FLAG_write_protect_code) { |
| VirtualMemory::Protect(reinterpret_cast<void*>(address_), size_, |
| VirtualMemory::kReadExecute); |
| } |
| } |
| |
| bool MatchesPattern(uword end, int16_t* pattern, intptr_t size) { |
| // When breaking within generated code in GDB, it may overwrite individual |
| // instructions with trap instructions, which can cause this test to fail. |
| // |
| // Ignoring trap instructions would work well enough within GDB alone, but it |
| // doesn't work in RR, because the check for the trap instrution itself will |
| // cause replay to diverge from the original record. |
| if (FLAG_support_rr) return true; |
| |
| uint8_t* bytes = reinterpret_cast<uint8_t*>(end - size); |
| for (intptr_t i = 0; i < size; i++) { |
| int16_t val = pattern[i]; |
| if ((val >= 0) && (val != bytes[i])) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| } // namespace dart |