Files
sdk/runtime/vm/code_patcher.cc
T
Vyacheslav Egorov 9ff0a654ca Revert "Reland "[VM runtime] Dual mapping of executable pages.""
This reverts commit 6da340bf76.

Reason for revert: almost all benchmarks are now failing on Golem linux-x64 target. Flutter Golem build is broken 

Original change's description:
> Reland "[VM runtime] Dual mapping of executable pages."
> 
> This is a reland of 44186dfdcd
> 
> Original change's description:
> > [VM runtime] Dual mapping of executable pages.
> > 
> > Change-Id: Iaad78d324e25462ce951f4df26974a6a368c50b7
> > Reviewed-on: https://dart-review.googlesource.com/c/93377
> > Commit-Queue: Régis Crelier <regis@google.com>
> > Reviewed-by: Ryan Macnak <rmacnak@google.com>
> 
> Change-Id: I7a0caa078950637d9fe831732577fd2467061099
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/95263
> Reviewed-by: Ryan Macnak <rmacnak@google.com>

TBR=rmacnak@google.com,regis@google.com

Change-Id: I3342de2584537269ffe9a53946bef27cb25a69fc
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/96161
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
2019-03-09 14:15:39 +00:00

51 lines
1.7 KiB
C++

// 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, const 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