blob: 3546b60ee2de585780079d5a877694665aef97ec [file] [log] [blame] [edit]
// 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