v8/test/cctest/test-platform-linux.cc
Ulan Degenbaev 0640cbf378 [heap] Rework ASLR for base::Platform::VirtualMemory
Currently every VirtualMemory allocation on 64-bit systems
uses a random 46-bit address hint for ASLR.

This leads to wired page leak on MacOS discovered by Erik Chen (see
crbug.com/700928 and https://chromium-review.googlesource.com/c/557958/):
"The Darwin kernel [as of macOS 10.12.5] does not clean up page directory
entries [PDE] created from mmap or mach_vm_allocate, even after
the region is destroyed. Using a virtual address space that is too large
causes a leak of about 1 wired [can never be paged out] page per call to
mmap(). The page is only reclaimed when the process is killed."

This patch changes VirtualMemory to accept the hint parameter explicitly.

On MacOS the hints are confined to 4GB contiguous region. Algorithm:
- On startup, set heap.mmap_region_base_ to a random address.
- For each mmap use heap.mmap_region_base_ + (random_offset % (4*GB)).

BUG=chromium:700928

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I2ae6a024e02fbe63f940105d7920b57c19abacc6
Reviewed-on: https://chromium-review.googlesource.com/558876
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46656}
2017-07-14 07:15:40 +00:00

55 lines
2.2 KiB
C++

// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Tests of the TokenLock class from lock.h
#include <pthread.h>
#include <stdlib.h>
#include <unistd.h> // for usleep()
#include "src/v8.h"
#include "src/base/platform/platform.h"
#include "test/cctest/cctest.h"
using namespace ::v8::internal;
TEST(VirtualMemory) {
v8::base::VirtualMemory* vm =
new v8::base::VirtualMemory(1 * MB, v8::base::OS::GetRandomMmapAddr());
CHECK(vm->IsReserved());
void* block_addr = vm->address();
size_t block_size = 4 * KB;
CHECK(vm->Commit(block_addr, block_size, false));
// Check whether we can write to memory.
int* addr = static_cast<int*>(block_addr);
addr[KB-1] = 2;
CHECK(vm->Uncommit(block_addr, block_size));
delete vm;
}