252 lines
8.6 KiB
C++
252 lines
8.6 KiB
C++
// Copyright 2018 The gVisor Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
#include <fcntl.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/types.h>
|
|
#include <sys/wait.h>
|
|
#include <unistd.h>
|
|
|
|
#include <string>
|
|
|
|
#include "gmock/gmock.h"
|
|
#include "gtest/gtest.h"
|
|
#include "test/util/file_descriptor.h"
|
|
#include "test/util/logging.h"
|
|
#include "test/util/memory_util.h"
|
|
#include "test/util/multiprocess_util.h"
|
|
#include "test/util/posix_error.h"
|
|
#include "test/util/temp_path.h"
|
|
#include "test/util/test_util.h"
|
|
|
|
namespace gvisor {
|
|
namespace testing {
|
|
|
|
namespace {
|
|
|
|
void ExpectAllMappingBytes(Mapping const& m, char c) {
|
|
auto const v = m.view();
|
|
for (size_t i = 0; i < kPageSize; i++) {
|
|
ASSERT_EQ(v[i], c) << "at offset " << i;
|
|
}
|
|
}
|
|
|
|
// Equivalent to ExpectAllMappingBytes but async-signal-safe and with less
|
|
// helpful failure messages.
|
|
void CheckAllMappingBytes(Mapping const& m, char c) {
|
|
auto const v = m.view();
|
|
for (size_t i = 0; i < kPageSize; i++) {
|
|
TEST_CHECK_MSG(v[i] == c, "mapping contains wrong value");
|
|
}
|
|
}
|
|
|
|
TEST(MadviseDontneedTest, ZerosPrivateAnonPage) {
|
|
auto m = ASSERT_NO_ERRNO_AND_VALUE(
|
|
MmapAnon(kPageSize, PROT_READ | PROT_WRITE, MAP_PRIVATE));
|
|
ExpectAllMappingBytes(m, 0);
|
|
memset(m.ptr(), 1, m.len());
|
|
ExpectAllMappingBytes(m, 1);
|
|
ASSERT_THAT(madvise(m.ptr(), m.len(), MADV_DONTNEED), SyscallSucceeds());
|
|
ExpectAllMappingBytes(m, 0);
|
|
}
|
|
|
|
TEST(MadviseDontneedTest, ZerosCOWAnonPageInCallerOnly) {
|
|
auto m = ASSERT_NO_ERRNO_AND_VALUE(
|
|
MmapAnon(kPageSize, PROT_READ | PROT_WRITE, MAP_PRIVATE));
|
|
ExpectAllMappingBytes(m, 0);
|
|
memset(m.ptr(), 2, m.len());
|
|
ExpectAllMappingBytes(m, 2);
|
|
|
|
// Do madvise in a child process.
|
|
pid_t pid = fork();
|
|
CheckAllMappingBytes(m, 2);
|
|
if (pid == 0) {
|
|
TEST_PCHECK(madvise(m.ptr(), m.len(), MADV_DONTNEED) == 0);
|
|
CheckAllMappingBytes(m, 0);
|
|
_exit(0);
|
|
}
|
|
|
|
ASSERT_THAT(pid, SyscallSucceeds());
|
|
|
|
int status = 0;
|
|
ASSERT_THAT(waitpid(-1, &status, 0), SyscallSucceedsWithValue(pid));
|
|
EXPECT_TRUE(WIFEXITED(status));
|
|
EXPECT_EQ(WEXITSTATUS(status), 0);
|
|
// The child's madvise should not have affected the parent.
|
|
ExpectAllMappingBytes(m, 2);
|
|
}
|
|
|
|
TEST(MadviseDontneedTest, DoesNotModifySharedAnonPage) {
|
|
auto m = ASSERT_NO_ERRNO_AND_VALUE(
|
|
MmapAnon(kPageSize, PROT_READ | PROT_WRITE, MAP_SHARED));
|
|
ExpectAllMappingBytes(m, 0);
|
|
memset(m.ptr(), 3, m.len());
|
|
ExpectAllMappingBytes(m, 3);
|
|
ASSERT_THAT(madvise(m.ptr(), m.len(), MADV_DONTNEED), SyscallSucceeds());
|
|
ExpectAllMappingBytes(m, 3);
|
|
}
|
|
|
|
TEST(MadviseDontneedTest, CleansPrivateFilePage) {
|
|
TempPath f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith(
|
|
/* parent = */ GetAbsoluteTestTmpdir(),
|
|
/* content = */ std::string(kPageSize, 4), TempPath::kDefaultFileMode));
|
|
FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDWR));
|
|
|
|
Mapping m = ASSERT_NO_ERRNO_AND_VALUE(Mmap(
|
|
nullptr, kPageSize, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd.get(), 0));
|
|
ExpectAllMappingBytes(m, 4);
|
|
memset(m.ptr(), 5, m.len());
|
|
ExpectAllMappingBytes(m, 5);
|
|
ASSERT_THAT(madvise(m.ptr(), m.len(), MADV_DONTNEED), SyscallSucceeds());
|
|
ExpectAllMappingBytes(m, 4);
|
|
}
|
|
|
|
TEST(MadviseDontneedTest, DoesNotModifySharedFilePage) {
|
|
TempPath f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith(
|
|
/* parent = */ GetAbsoluteTestTmpdir(),
|
|
/* content = */ std::string(kPageSize, 6), TempPath::kDefaultFileMode));
|
|
FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDWR));
|
|
|
|
Mapping m = ASSERT_NO_ERRNO_AND_VALUE(Mmap(
|
|
nullptr, kPageSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd.get(), 0));
|
|
ExpectAllMappingBytes(m, 6);
|
|
memset(m.ptr(), 7, m.len());
|
|
ExpectAllMappingBytes(m, 7);
|
|
ASSERT_THAT(madvise(m.ptr(), m.len(), MADV_DONTNEED), SyscallSucceeds());
|
|
ExpectAllMappingBytes(m, 7);
|
|
}
|
|
|
|
TEST(MadviseDontneedTest, IgnoresPermissions) {
|
|
auto m =
|
|
ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, MAP_PRIVATE));
|
|
EXPECT_THAT(madvise(m.ptr(), m.len(), MADV_DONTNEED), SyscallSucceeds());
|
|
}
|
|
|
|
TEST(MadviseDontforkTest, AddressLength) {
|
|
auto m =
|
|
ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, MAP_PRIVATE));
|
|
char *addr = static_cast<char *>(m.ptr());
|
|
|
|
// Address must be page aligned.
|
|
EXPECT_THAT(madvise(addr + 1, kPageSize, MADV_DONTFORK),
|
|
SyscallFailsWithErrno(EINVAL));
|
|
|
|
// Zero length madvise always succeeds.
|
|
EXPECT_THAT(madvise(addr, 0, MADV_DONTFORK), SyscallSucceeds());
|
|
|
|
// Length must not roll over after rounding up.
|
|
size_t badlen = std::numeric_limits<std::size_t>::max() - (kPageSize / 2);
|
|
EXPECT_THAT(madvise(0, badlen, MADV_DONTFORK), SyscallFailsWithErrno(EINVAL));
|
|
|
|
// Length need not be page aligned - it is implicitly rounded up.
|
|
EXPECT_THAT(madvise(addr, 1, MADV_DONTFORK), SyscallSucceeds());
|
|
EXPECT_THAT(madvise(addr, kPageSize, MADV_DONTFORK), SyscallSucceeds());
|
|
}
|
|
|
|
TEST(MadviseDontforkTest, DontforkShared) {
|
|
// Mmap two shared file-backed pages and MADV_DONTFORK the second page.
|
|
TempPath f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith(
|
|
/* parent = */ GetAbsoluteTestTmpdir(),
|
|
/* content = */ std::string(kPageSize * 2, 2),
|
|
TempPath::kDefaultFileMode));
|
|
FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDWR));
|
|
|
|
Mapping m = ASSERT_NO_ERRNO_AND_VALUE(Mmap(
|
|
nullptr, kPageSize * 2, PROT_READ | PROT_WRITE, MAP_SHARED, fd.get(), 0));
|
|
|
|
const Mapping ms1 = Mapping(reinterpret_cast<void *>(m.addr()), kPageSize);
|
|
const Mapping ms2 =
|
|
Mapping(reinterpret_cast<void *>(m.addr() + kPageSize), kPageSize);
|
|
m.release();
|
|
|
|
ASSERT_THAT(madvise(ms2.ptr(), kPageSize, MADV_DONTFORK), SyscallSucceeds());
|
|
|
|
const auto rest = [&] {
|
|
// First page is mapped in child and modifications are visible to parent
|
|
// via the shared mapping.
|
|
TEST_CHECK(IsMapped(ms1.addr()));
|
|
ExpectAllMappingBytes(ms1, 2);
|
|
memset(ms1.ptr(), 1, kPageSize);
|
|
ExpectAllMappingBytes(ms1, 1);
|
|
|
|
// Second page must not be mapped in child.
|
|
TEST_CHECK(!IsMapped(ms2.addr()));
|
|
};
|
|
|
|
EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
|
|
|
|
ExpectAllMappingBytes(ms1, 1); // page contents modified by child.
|
|
ExpectAllMappingBytes(ms2, 2); // page contents unchanged.
|
|
}
|
|
|
|
TEST(MadviseDontforkTest, DontforkAnonPrivate) {
|
|
// Mmap three anonymous pages and MADV_DONTFORK the middle page.
|
|
Mapping m = ASSERT_NO_ERRNO_AND_VALUE(
|
|
MmapAnon(kPageSize * 3, PROT_READ | PROT_WRITE, MAP_PRIVATE));
|
|
const Mapping mp1 = Mapping(reinterpret_cast<void *>(m.addr()), kPageSize);
|
|
const Mapping mp2 =
|
|
Mapping(reinterpret_cast<void *>(m.addr() + kPageSize), kPageSize);
|
|
const Mapping mp3 =
|
|
Mapping(reinterpret_cast<void *>(m.addr() + 2 * kPageSize), kPageSize);
|
|
m.release();
|
|
|
|
ASSERT_THAT(madvise(mp2.ptr(), kPageSize, MADV_DONTFORK), SyscallSucceeds());
|
|
|
|
// Verify that all pages are zeroed and memset the first, second and third
|
|
// pages to 1, 2, and 3 respectively.
|
|
ExpectAllMappingBytes(mp1, 0);
|
|
memset(mp1.ptr(), 1, kPageSize);
|
|
|
|
ExpectAllMappingBytes(mp2, 0);
|
|
memset(mp2.ptr(), 2, kPageSize);
|
|
|
|
ExpectAllMappingBytes(mp3, 0);
|
|
memset(mp3.ptr(), 3, kPageSize);
|
|
|
|
const auto rest = [&] {
|
|
// Verify first page is mapped, verify its contents and then modify the
|
|
// page. The mapping is private so the modifications are not visible to
|
|
// the parent.
|
|
TEST_CHECK(IsMapped(mp1.addr()));
|
|
ExpectAllMappingBytes(mp1, 1);
|
|
memset(mp1.ptr(), 11, kPageSize);
|
|
ExpectAllMappingBytes(mp1, 11);
|
|
|
|
// Verify second page is not mapped.
|
|
TEST_CHECK(!IsMapped(mp2.addr()));
|
|
|
|
// Verify third page is mapped, verify its contents and then modify the
|
|
// page. The mapping is private so the modifications are not visible to
|
|
// the parent.
|
|
TEST_CHECK(IsMapped(mp3.addr()));
|
|
ExpectAllMappingBytes(mp3, 3);
|
|
memset(mp3.ptr(), 13, kPageSize);
|
|
ExpectAllMappingBytes(mp3, 13);
|
|
};
|
|
EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
|
|
|
|
// The fork and COW by child should not affect the parent mappings.
|
|
ExpectAllMappingBytes(mp1, 1);
|
|
ExpectAllMappingBytes(mp2, 2);
|
|
ExpectAllMappingBytes(mp3, 3);
|
|
}
|
|
|
|
} // namespace
|
|
|
|
} // namespace testing
|
|
} // namespace gvisor
|