1 files changed, 0 insertions, 503 deletions
diff --git a/test/syscalls/linux/mremap.cc b/test/syscalls/linux/mremap.cc
deleted file mode 100644
index 64e435cb7..000000000
--- a/test/syscalls/linux/mremap.cc
+++ /dev/null
@@ -1,503 +0,0 @@
-// 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 <errno.h>
-#include <string.h>
-#include <sys/mman.h>
-
-#include <string>
-
-#include "gmock/gmock.h"
-#include "absl/strings/string_view.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"
-
-using ::testing::_;
-
-namespace gvisor {
-namespace testing {
-
-namespace {
-
-// Wrapper for mremap that returns a PosixErrorOr<>, since the return type of
-// void* isn't directly compatible with SyscallSucceeds.
-PosixErrorOr<void*> Mremap(void* old_address, size_t old_size, size_t new_size,
-                           int flags, void* new_address) {
-  void* rv = mremap(old_address, old_size, new_size, flags, new_address);
-  if (rv == MAP_FAILED) {
-    return PosixError(errno, "mremap failed");
-  }
-  return rv;
-}
-
-// Fixture for mremap tests parameterized by mmap flags.
-using MremapParamTest = ::testing::TestWithParam<int>;
-
-TEST_P(MremapParamTest, Noop) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-
-  ASSERT_THAT(Mremap(m.ptr(), kPageSize, kPageSize, 0, nullptr),
-              IsPosixErrorOkAndHolds(m.ptr()));
-  EXPECT_TRUE(IsMapped(m.addr()));
-}
-
-TEST_P(MremapParamTest, InPlace_ShrinkingWholeVMA) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // N.B. we must be in a single-threaded subprocess to ensure a
-    // background thread doesn't concurrently map the second page.
-    void* addr = mremap(m.ptr(), 2 * kPageSize, kPageSize, 0, nullptr);
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == m.ptr());
-    MaybeSave();
-
-    TEST_CHECK(IsMapped(m.addr()));
-    TEST_CHECK(!IsMapped(m.addr() + kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, InPlace_ShrinkingPartialVMA) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(3 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    void* addr = mremap(m.ptr(), 2 * kPageSize, kPageSize, 0, nullptr);
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == m.ptr());
-    MaybeSave();
-
-    TEST_CHECK(IsMapped(m.addr()));
-    TEST_CHECK(!IsMapped(m.addr() + kPageSize));
-    TEST_CHECK(IsMapped(m.addr() + 2 * kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, InPlace_ShrinkingAcrossVMAs) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(3 * kPageSize, PROT_READ, GetParam()));
-  // Changing permissions on the first page forces it to become a separate vma.
-  ASSERT_THAT(mprotect(m.ptr(), kPageSize, PROT_NONE), SyscallSucceeds());
-
-  const auto rest = [&] {
-    // Both old_size and new_size now span two vmas; mremap
-    // shouldn't care.
-    void* addr = mremap(m.ptr(), 3 * kPageSize, 2 * kPageSize, 0, nullptr);
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == m.ptr());
-    MaybeSave();
-
-    TEST_CHECK(IsMapped(m.addr()));
-    TEST_CHECK(IsMapped(m.addr() + kPageSize));
-    TEST_CHECK(!IsMapped(m.addr() + 2 * kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, InPlace_ExpansionSuccess) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap the second page so that the first can be expanded back into it.
-    //
-    // N.B. we must be in a single-threaded subprocess to ensure a
-    // background thread doesn't concurrently map this page.
-    TEST_PCHECK(
-        munmap(reinterpret_cast<void*>(m.addr() + kPageSize), kPageSize) == 0);
-    MaybeSave();
-
-    void* addr = mremap(m.ptr(), kPageSize, 2 * kPageSize, 0, nullptr);
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == m.ptr());
-    MaybeSave();
-
-    TEST_CHECK(IsMapped(m.addr()));
-    TEST_CHECK(IsMapped(m.addr() + kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, InPlace_ExpansionFailure) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(3 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap the second page, leaving a one-page hole. Trying to expand the
-    // first page to three pages should fail since the original third page
-    // is still mapped.
-    TEST_PCHECK(
-        munmap(reinterpret_cast<void*>(m.addr() + kPageSize), kPageSize) == 0);
-    MaybeSave();
-
-    void* addr = mremap(m.ptr(), kPageSize, 3 * kPageSize, 0, nullptr);
-    TEST_CHECK_MSG(addr == MAP_FAILED, "mremap unexpectedly succeeded");
-    TEST_PCHECK_MSG(errno == ENOMEM, "mremap failed with wrong errno");
-    MaybeSave();
-
-    TEST_CHECK(IsMapped(m.addr()));
-    TEST_CHECK(!IsMapped(m.addr() + kPageSize));
-    TEST_CHECK(IsMapped(m.addr() + 2 * kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, MayMove_Expansion) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(3 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap the second page, leaving a one-page hole. Trying to expand the
-    // first page to three pages with MREMAP_MAYMOVE should force the
-    // mapping to be relocated since the original third page is still
-    // mapped.
-    TEST_PCHECK(
-        munmap(reinterpret_cast<void*>(m.addr() + kPageSize), kPageSize) == 0);
-    MaybeSave();
-
-    void* addr2 =
-        mremap(m.ptr(), kPageSize, 3 * kPageSize, MREMAP_MAYMOVE, nullptr);
-    TEST_PCHECK_MSG(addr2 != MAP_FAILED, "mremap failed");
-    MaybeSave();
-
-    const Mapping m2 = Mapping(addr2, 3 * kPageSize);
-    TEST_CHECK(m.addr() != m2.addr());
-
-    TEST_CHECK(!IsMapped(m.addr()));
-    TEST_CHECK(!IsMapped(m.addr() + kPageSize));
-    TEST_CHECK(IsMapped(m.addr() + 2 * kPageSize));
-    TEST_CHECK(IsMapped(m2.addr()));
-    TEST_CHECK(IsMapped(m2.addr() + kPageSize));
-    TEST_CHECK(IsMapped(m2.addr() + 2 * kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, Fixed_SourceAndDestinationCannotOverlap) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-
-  ASSERT_THAT(Mremap(m.ptr(), kPageSize, kPageSize,
-                     MREMAP_MAYMOVE | MREMAP_FIXED, m.ptr()),
-              PosixErrorIs(EINVAL, _));
-  EXPECT_TRUE(IsMapped(m.addr()));
-}
-
-TEST_P(MremapParamTest, Fixed_SameSize) {
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap dst to create a hole.
-    TEST_PCHECK(munmap(dst.ptr(), kPageSize) == 0);
-    MaybeSave();
-
-    void* addr = mremap(src.ptr(), kPageSize, kPageSize,
-                        MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr());
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == dst.ptr());
-    MaybeSave();
-
-    TEST_CHECK(!IsMapped(src.addr()));
-    TEST_CHECK(IsMapped(dst.addr()));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, Fixed_SameSize_Unmapping) {
-  // Like the Fixed_SameSize case, but expect mremap to unmap the destination
-  // automatically.
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    void* addr = mremap(src.ptr(), kPageSize, kPageSize,
-                        MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr());
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == dst.ptr());
-    MaybeSave();
-
-    TEST_CHECK(!IsMapped(src.addr()));
-    TEST_CHECK(IsMapped(dst.addr()));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, Fixed_ShrinkingWholeVMA) {
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap dst so we can check that mremap does not keep the
-    // second page.
-    TEST_PCHECK(munmap(dst.ptr(), 2 * kPageSize) == 0);
-    MaybeSave();
-
-    void* addr = mremap(src.ptr(), 2 * kPageSize, kPageSize,
-                        MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr());
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == dst.ptr());
-    MaybeSave();
-
-    TEST_CHECK(!IsMapped(src.addr()));
-    TEST_CHECK(!IsMapped(src.addr() + kPageSize));
-    TEST_CHECK(IsMapped(dst.addr()));
-    TEST_CHECK(!IsMapped(dst.addr() + kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, Fixed_ShrinkingPartialVMA) {
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(3 * kPageSize, PROT_NONE, GetParam()));
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap dst so we can check that mremap does not keep the
-    // second page.
-    TEST_PCHECK(munmap(dst.ptr(), 2 * kPageSize) == 0);
-    MaybeSave();
-
-    void* addr = mremap(src.ptr(), 2 * kPageSize, kPageSize,
-                        MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr());
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == dst.ptr());
-    MaybeSave();
-
-    TEST_CHECK(!IsMapped(src.addr()));
-    TEST_CHECK(!IsMapped(src.addr() + kPageSize));
-    TEST_CHECK(IsMapped(src.addr() + 2 * kPageSize));
-    TEST_CHECK(IsMapped(dst.addr()));
-    TEST_CHECK(!IsMapped(dst.addr() + kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, Fixed_ShrinkingAcrossVMAs) {
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(3 * kPageSize, PROT_READ, GetParam()));
-  // Changing permissions on the first page forces it to become a separate vma.
-  ASSERT_THAT(mprotect(src.ptr(), kPageSize, PROT_NONE), SyscallSucceeds());
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unlike flags=0, MREMAP_FIXED requires that [old_address,
-    // old_address+new_size) only spans a single vma.
-    void* addr = mremap(src.ptr(), 3 * kPageSize, 2 * kPageSize,
-                        MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr());
-    TEST_CHECK_MSG(addr == MAP_FAILED, "mremap unexpectedly succeeded");
-    TEST_PCHECK_MSG(errno == EFAULT, "mremap failed with wrong errno");
-    MaybeSave();
-
-    TEST_CHECK(IsMapped(src.addr()));
-    TEST_CHECK(IsMapped(src.addr() + kPageSize));
-    // Despite failing, mremap should have unmapped [old_address+new_size,
-    // old_address+old_size) (i.e. the third page).
-    TEST_CHECK(!IsMapped(src.addr() + 2 * kPageSize));
-    // Despite failing, mremap should have unmapped the destination pages.
-    TEST_CHECK(!IsMapped(dst.addr()));
-    TEST_CHECK(!IsMapped(dst.addr() + kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST_P(MremapParamTest, Fixed_Expansion) {
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, GetParam()));
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(2 * kPageSize, PROT_NONE, GetParam()));
-
-  const auto rest = [&] {
-    // Unmap dst so we can check that mremap actually maps all pages
-    // at the destination.
-    TEST_PCHECK(munmap(dst.ptr(), 2 * kPageSize) == 0);
-    MaybeSave();
-
-    void* addr = mremap(src.ptr(), kPageSize, 2 * kPageSize,
-                        MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr());
-    TEST_PCHECK_MSG(addr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(addr == dst.ptr());
-    MaybeSave();
-
-    TEST_CHECK(!IsMapped(src.addr()));
-    TEST_CHECK(IsMapped(dst.addr()));
-    TEST_CHECK(IsMapped(dst.addr() + kPageSize));
-  };
-
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-INSTANTIATE_TEST_SUITE_P(PrivateShared, MremapParamTest,
-                         ::testing::Values(MAP_PRIVATE, MAP_SHARED));
-
-// mremap with old_size == 0 only works with MAP_SHARED after Linux 4.14
-// (dba58d3b8c50 "mm/mremap: fail map duplication attempts for private
-// mappings").
-
-TEST(MremapTest, InPlace_Copy) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, MAP_SHARED));
-  EXPECT_THAT(Mremap(m.ptr(), 0, kPageSize, 0, nullptr),
-              PosixErrorIs(ENOMEM, _));
-}
-
-TEST(MremapTest, MayMove_Copy) {
-  Mapping const m =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, MAP_SHARED));
-
-  // Remainder of this test executes in a subprocess to ensure that if mremap
-  // incorrectly removes m, it is not remapped by another thread.
-  const auto rest = [&] {
-    void* ptr = mremap(m.ptr(), 0, kPageSize, MREMAP_MAYMOVE, nullptr);
-    MaybeSave();
-    TEST_PCHECK_MSG(ptr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(ptr != m.ptr());
-    TEST_CHECK(IsMapped(m.addr()));
-    TEST_CHECK(IsMapped(reinterpret_cast<uintptr_t>(ptr)));
-  };
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-TEST(MremapTest, MustMove_Copy) {
-  Mapping const src =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, MAP_SHARED));
-  Mapping const dst =
-      ASSERT_NO_ERRNO_AND_VALUE(MmapAnon(kPageSize, PROT_NONE, MAP_PRIVATE));
-
-  // Remainder of this test executes in a subprocess to ensure that if mremap
-  // incorrectly removes src, it is not remapped by another thread.
-  const auto rest = [&] {
-    void* ptr = mremap(src.ptr(), 0, kPageSize, MREMAP_MAYMOVE | MREMAP_FIXED,
-                       dst.ptr());
-    MaybeSave();
-    TEST_PCHECK_MSG(ptr != MAP_FAILED, "mremap failed");
-    TEST_CHECK(ptr == dst.ptr());
-    TEST_CHECK(IsMapped(src.addr()));
-    TEST_CHECK(IsMapped(dst.addr()));
-  };
-  EXPECT_THAT(InForkedProcess(rest), IsPosixErrorOkAndHolds(0));
-}
-
-void ExpectAllBytesAre(absl::string_view v, char c) {
-  for (size_t i = 0; i < v.size(); i++) {
-    ASSERT_EQ(v[i], c) << "at offset " << i;
-  }
-}
-
-TEST(MremapTest, ExpansionPreservesCOWPagesAndExposesNewFilePages) {
-  // Create a file with 3 pages. The first is filled with 'a', the second is
-  // filled with 'b', and the third is filled with 'c'.
-  TempPath const file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
-  const FileDescriptor fd =
-      ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDWR));
-  ASSERT_THAT(WriteFd(fd.get(), std::string(kPageSize, 'a').c_str(), kPageSize),
-              SyscallSucceedsWithValue(kPageSize));
-  ASSERT_THAT(WriteFd(fd.get(), std::string(kPageSize, 'b').c_str(), kPageSize),
-              SyscallSucceedsWithValue(kPageSize));
-  ASSERT_THAT(WriteFd(fd.get(), std::string(kPageSize, 'c').c_str(), kPageSize),
-              SyscallSucceedsWithValue(kPageSize));
-
-  // Create a private mapping of the first 2 pages, and fill the second page
-  // with 'd'.
-  Mapping const src = ASSERT_NO_ERRNO_AND_VALUE(Mmap(nullptr, 2 * kPageSize,
-                                                     PROT_READ | PROT_WRITE,
-                                                     MAP_PRIVATE, fd.get(), 0));
-  memset(reinterpret_cast<void*>(src.addr() + kPageSize), 'd', kPageSize);
-  MaybeSave();
-
-  // Move the mapping while expanding it to 3 pages. The resulting mapping
-  // should contain the original first page of the file (filled with 'a'),
-  // followed by the private copy of the second page (filled with 'd'), followed
-  // by the newly-mapped third page of the file (filled with 'c').
-  Mapping const dst = ASSERT_NO_ERRNO_AND_VALUE(
-      MmapAnon(3 * kPageSize, PROT_NONE, MAP_PRIVATE));
-  ASSERT_THAT(Mremap(src.ptr(), 2 * kPageSize, 3 * kPageSize,
-                     MREMAP_MAYMOVE | MREMAP_FIXED, dst.ptr()),
-              IsPosixErrorOkAndHolds(dst.ptr()));
-  auto const v = dst.view();
-  ExpectAllBytesAre(v.substr(0, kPageSize), 'a');
-  ExpectAllBytesAre(v.substr(kPageSize, kPageSize), 'd');
-  ExpectAllBytesAre(v.substr(2 * kPageSize, kPageSize), 'c');
-}
-
-TEST(MremapDeathTest, SharedAnon) {
-  SetupGvisorDeathTest();
-
-  // Reserve 4 pages of address space.
-  Mapping const reserved = ASSERT_NO_ERRNO_AND_VALUE(
-      MmapAnon(4 * kPageSize, PROT_NONE, MAP_PRIVATE));
-
-  // Create a 2-page shared anonymous mapping at the beginning of the
-  // reservation. Fill the first page with 'a' and the second with 'b'.
-  Mapping const m = ASSERT_NO_ERRNO_AND_VALUE(
-      Mmap(reserved.ptr(), 2 * kPageSize, PROT_READ | PROT_WRITE,
-           MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0));
-  memset(m.ptr(), 'a', kPageSize);
-  memset(reinterpret_cast<void*>(m.addr() + kPageSize), 'b', kPageSize);
-  MaybeSave();
-
-  // Shrink the mapping to 1 page in-place.
-  ASSERT_THAT(Mremap(m.ptr(), 2 * kPageSize, kPageSize, 0, m.ptr()),
-              IsPosixErrorOkAndHolds(m.ptr()));
-
-  // Expand the mapping to 3 pages, moving it forward by 1 page in the process
-  // since the old and new mappings can't overlap.
-  void* const new_m = reinterpret_cast<void*>(m.addr() + kPageSize);
-  ASSERT_THAT(Mremap(m.ptr(), kPageSize, 3 * kPageSize,
-                     MREMAP_MAYMOVE | MREMAP_FIXED, new_m),
-              IsPosixErrorOkAndHolds(new_m));
-
-  // The first 2 pages of the mapping should still contain the data we wrote
-  // (i.e. shrinking should not have discarded the second page's data), while
-  // touching the third page should raise SIGBUS.
-  auto const v =
-      absl::string_view(static_cast<char const*>(new_m), 3 * kPageSize);
-  ExpectAllBytesAre(v.substr(0, kPageSize), 'a');
-  ExpectAllBytesAre(v.substr(kPageSize, kPageSize), 'b');
-  EXPECT_EXIT(ExpectAllBytesAre(v.substr(2 * kPageSize, kPageSize), '\0'),
-              ::testing::KilledBySignal(SIGBUS), "");
-}
-
-}  // namespace
-
-}  // namespace testing
-}  // namespace gvisor