diff options
Diffstat (limited to 'test/syscalls/linux')
-rw-r--r-- | test/syscalls/linux/BUILD | 4 | ||||
-rw-r--r-- | test/syscalls/linux/read.cc | 40 | ||||
-rw-r--r-- | test/syscalls/linux/setgid.cc | 95 | ||||
-rw-r--r-- | test/syscalls/linux/socket_inet_loopback.cc | 111 | ||||
-rw-r--r-- | test/syscalls/linux/write.cc | 78 |
5 files changed, 298 insertions, 30 deletions
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 4509b5e55..043ada583 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1922,7 +1922,9 @@ cc_binary( linkstatic = 1, deps = [ "//test/util:file_descriptor", + "@com_google_absl//absl/base:core_headers", gtest, + "//test/util:cleanup", "//test/util:temp_path", "//test/util:test_main", "//test/util:test_util", @@ -2162,6 +2164,7 @@ cc_binary( "//test/util:temp_path", "//test/util:test_main", "//test/util:test_util", + "@com_google_absl//absl/flags:flag", "@com_google_absl//absl/strings", gtest, ], @@ -3990,6 +3993,7 @@ cc_binary( linkstatic = 1, deps = [ "//test/util:cleanup", + "@com_google_absl//absl/base:core_headers", gtest, "//test/util:temp_path", "//test/util:test_main", diff --git a/test/syscalls/linux/read.cc b/test/syscalls/linux/read.cc index 98d5e432d..087262535 100644 --- a/test/syscalls/linux/read.cc +++ b/test/syscalls/linux/read.cc @@ -13,11 +13,14 @@ // limitations under the License. #include <fcntl.h> +#include <sys/mman.h> #include <unistd.h> #include <vector> #include "gtest/gtest.h" +#include "absl/base/macros.h" +#include "test/util/cleanup.h" #include "test/util/file_descriptor.h" #include "test/util/temp_path.h" #include "test/util/test_util.h" @@ -121,6 +124,43 @@ TEST_F(ReadTest, ReadWithOpath) { EXPECT_THAT(ReadFd(fd.get(), buf.data(), 1), SyscallFailsWithErrno(EBADF)); } +// Test that partial writes that hit SIGSEGV are correctly handled and return +// partial write. +TEST_F(ReadTest, PartialReadSIGSEGV) { + // Allocate 2 pages and remove permission from the second. + const size_t size = 2 * kPageSize; + void* addr = + mmap(0, size, PROT_WRITE | PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + ASSERT_NE(addr, MAP_FAILED); + auto cleanup = Cleanup( + [addr, size] { EXPECT_THAT(munmap(addr, size), SyscallSucceeds()); }); + + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(name_.c_str(), O_RDWR, 0666)); + for (size_t i = 0; i < 2; i++) { + EXPECT_THAT(pwrite(fd.get(), addr, size, 0), + SyscallSucceedsWithValue(size)); + } + + void* badAddr = reinterpret_cast<char*>(addr) + kPageSize; + ASSERT_THAT(mprotect(badAddr, kPageSize, PROT_NONE), SyscallSucceeds()); + + // Attempt to read to both pages. Create a non-contiguous iovec pair to + // ensure operation is done in 2 steps. + struct iovec iov[] = { + { + .iov_base = addr, + .iov_len = kPageSize, + }, + { + .iov_base = addr, + .iov_len = size, + }, + }; + EXPECT_THAT(preadv(fd.get(), iov, ABSL_ARRAYSIZE(iov), 0), + SyscallSucceedsWithValue(size)); +} + } // namespace } // namespace testing diff --git a/test/syscalls/linux/setgid.cc b/test/syscalls/linux/setgid.cc index cd030b094..98f8f3dfe 100644 --- a/test/syscalls/linux/setgid.cc +++ b/test/syscalls/linux/setgid.cc @@ -17,6 +17,7 @@ #include <unistd.h> #include "gtest/gtest.h" +#include "absl/flags/flag.h" #include "test/util/capability_util.h" #include "test/util/cleanup.h" #include "test/util/fs_util.h" @@ -24,6 +25,11 @@ #include "test/util/temp_path.h" #include "test/util/test_util.h" +ABSL_FLAG(std::vector<std::string>, groups, std::vector<std::string>({}), + "groups the test can use"); + +constexpr gid_t kNobody = 65534; + namespace gvisor { namespace testing { @@ -46,6 +52,18 @@ PosixErrorOr<Cleanup> Setegid(gid_t egid) { // Returns a pair of groups that the user is a member of. PosixErrorOr<std::pair<gid_t, gid_t>> Groups() { + // Were we explicitly passed GIDs? + std::vector<std::string> flagged_groups = absl::GetFlag(FLAGS_groups); + if (flagged_groups.size() >= 2) { + int group1; + int group2; + if (!absl::SimpleAtoi(flagged_groups[0], &group1) || + !absl::SimpleAtoi(flagged_groups[1], &group2)) { + return PosixError(EINVAL, "failed converting group flags to ints"); + } + return std::pair<gid_t, gid_t>(group1, group2); + } + // See whether the user is a member of at least 2 groups. std::vector<gid_t> groups(64); for (; groups.size() <= NGROUPS_MAX; groups.resize(groups.size() * 2)) { @@ -58,26 +76,47 @@ PosixErrorOr<std::pair<gid_t, gid_t>> Groups() { return PosixError(errno, absl::StrFormat("getgroups(%d, %p)", groups.size(), groups.data())); } - if (ngroups >= 2) { - return std::pair<gid_t, gid_t>(groups[0], groups[1]); + + if (ngroups < 2) { + // There aren't enough groups. + break; + } + + // TODO(b/181878080): Read /proc/sys/fs/overflowgid once it is supported in + // gVisor. + if (groups[0] == kNobody || groups[1] == kNobody) { + // These groups aren't mapped into our user namespace, so we can't use + // them. + break; } - // There aren't enough groups. - break; + return std::pair<gid_t, gid_t>(groups[0], groups[1]); } - // If we're root in the root user namespace, we can set our GID to whatever we - // want. Try that before giving up. - constexpr gid_t kGID1 = 1111; - constexpr gid_t kGID2 = 2222; - auto cleanup1 = Setegid(kGID1); + // If we're running in gVisor and are root in the root user namespace, we can + // set our GID to whatever we want. Try that before giving up. + // + // This won't work in native tests, as despite having CAP_SETGID, the gofer + // process will be sandboxed and unable to change file GIDs. + if (!IsRunningOnGvisor()) { + return PosixError(EPERM, "no valid groups for native testing"); + } + PosixErrorOr<bool> capable = HaveCapability(CAP_SETGID); + if (!capable.ok()) { + return capable.error(); + } + if (!capable.ValueOrDie()) { + return PosixError(EPERM, "missing CAP_SETGID"); + } + gid_t gid = getegid(); + auto cleanup1 = Setegid(gid); if (!cleanup1.ok()) { return cleanup1.error(); } - auto cleanup2 = Setegid(kGID2); + auto cleanup2 = Setegid(kNobody); if (!cleanup2.ok()) { return cleanup2.error(); } - return std::pair<gid_t, gid_t>(kGID1, kGID2); + return std::pair<gid_t, gid_t>(gid, kNobody); } class SetgidDirTest : public ::testing::Test { @@ -85,17 +124,21 @@ class SetgidDirTest : public ::testing::Test { void SetUp() override { original_gid_ = getegid(); - // TODO(b/175325250): Enable when setgid directories are supported. SKIP_IF(IsRunningWithVFS1()); - SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SETGID))); + // If we can't find two usable groups, we're in an unsupporting environment. + // Skip the test. + PosixErrorOr<std::pair<gid_t, gid_t>> groups = Groups(); + SKIP_IF(!groups.ok()); + groups_ = groups.ValueOrDie(); + + auto cleanup = Setegid(groups_.first); temp_dir_ = ASSERT_NO_ERRNO_AND_VALUE( TempPath::CreateDirWith(GetAbsoluteTestTmpdir(), 0777 /* mode */)); - groups_ = ASSERT_NO_ERRNO_AND_VALUE(Groups()); } void TearDown() override { - ASSERT_THAT(setegid(original_gid_), SyscallSucceeds()); + EXPECT_THAT(setegid(original_gid_), SyscallSucceeds()); } void MkdirAsGid(gid_t gid, const std::string& path, mode_t mode) { @@ -131,7 +174,7 @@ TEST_F(SetgidDirTest, Control) { ASSERT_NO_FATAL_FAILURE(MkdirAsGid(groups_.first, g1owned, 0777)); // Set group to G2, create a file in g1owned, and confirm that G2 owns it. - ASSERT_THAT(setegid(groups_.second), SyscallSucceeds()); + auto cleanup = ASSERT_NO_ERRNO_AND_VALUE(Setegid(groups_.second)); FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE( Open(JoinPath(g1owned, "g2owned").c_str(), O_CREAT | O_RDWR, 0777)); struct stat stats = ASSERT_NO_ERRNO_AND_VALUE(Stat(fd)); @@ -146,7 +189,7 @@ TEST_F(SetgidDirTest, CreateFile) { ASSERT_THAT(chmod(g1owned.c_str(), kDirmodeSgid), SyscallSucceeds()); // Set group to G2, create a file, and confirm that G1 owns it. - ASSERT_THAT(setegid(groups_.second), SyscallSucceeds()); + auto cleanup = ASSERT_NO_ERRNO_AND_VALUE(Setegid(groups_.second)); FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE( Open(JoinPath(g1owned, "g2created").c_str(), O_CREAT | O_RDWR, 0666)); struct stat stats = ASSERT_NO_ERRNO_AND_VALUE(Stat(fd)); @@ -194,7 +237,7 @@ TEST_F(SetgidDirTest, OldFile) { ASSERT_THAT(chmod(g1owned.c_str(), kDirmodeNoSgid), SyscallSucceeds()); // Set group to G2, create a file, confirm that G2 owns it. - ASSERT_THAT(setegid(groups_.second), SyscallSucceeds()); + auto cleanup = ASSERT_NO_ERRNO_AND_VALUE(Setegid(groups_.second)); FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE( Open(JoinPath(g1owned, "g2created").c_str(), O_CREAT | O_RDWR, 0666)); struct stat stats = ASSERT_NO_ERRNO_AND_VALUE(Stat(fd)); @@ -217,7 +260,7 @@ TEST_F(SetgidDirTest, OldDir) { ASSERT_THAT(chmod(g1owned.c_str(), kDirmodeNoSgid), SyscallSucceeds()); // Set group to G2, create a directory, confirm that G2 owns it. - ASSERT_THAT(setegid(groups_.second), SyscallSucceeds()); + auto cleanup = ASSERT_NO_ERRNO_AND_VALUE(Setegid(groups_.second)); auto g2created = JoinPath(g1owned, "g2created"); ASSERT_NO_FATAL_FAILURE(MkdirAsGid(groups_.second, g2created, 0666)); struct stat stats = ASSERT_NO_ERRNO_AND_VALUE(Stat(g2created)); @@ -306,6 +349,10 @@ class FileModeTest : public ::testing::TestWithParam<FileModeTestcase> {}; TEST_P(FileModeTest, WriteToFile) { SKIP_IF(IsRunningWithVFS1()); + PosixErrorOr<std::pair<gid_t, gid_t>> groups = Groups(); + SKIP_IF(!groups.ok()); + + auto cleanup = Setegid(groups.ValueOrDie().first); auto temp_dir = ASSERT_NO_ERRNO_AND_VALUE( TempPath::CreateDirWith(GetAbsoluteTestTmpdir(), 0777 /* mode */)); auto path = JoinPath(temp_dir.path(), GetParam().name); @@ -329,26 +376,28 @@ TEST_P(FileModeTest, WriteToFile) { TEST_P(FileModeTest, TruncateFile) { SKIP_IF(IsRunningWithVFS1()); + PosixErrorOr<std::pair<gid_t, gid_t>> groups = Groups(); + SKIP_IF(!groups.ok()); + + auto cleanup = Setegid(groups.ValueOrDie().first); auto temp_dir = ASSERT_NO_ERRNO_AND_VALUE( TempPath::CreateDirWith(GetAbsoluteTestTmpdir(), 0777 /* mode */)); auto path = JoinPath(temp_dir.path(), GetParam().name); FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(path.c_str(), O_CREAT | O_RDWR, 0666)); - ASSERT_THAT(fchmod(fd.get(), GetParam().mode), SyscallSucceeds()); - struct stat stats; - ASSERT_THAT(fstat(fd.get(), &stats), SyscallSucceeds()); - EXPECT_EQ(stats.st_mode & kDirmodeMask, GetParam().mode); // Write something to the file, as truncating an empty file is a no-op. constexpr char c = 'M'; ASSERT_THAT(write(fd.get(), &c, sizeof(c)), SyscallSucceedsWithValue(sizeof(c))); + ASSERT_THAT(fchmod(fd.get(), GetParam().mode), SyscallSucceeds()); // For security reasons, truncating the file clears the SUID bit, and clears // the SGID bit when the group executable bit is unset (which is not a true // SGID binary). ASSERT_THAT(ftruncate(fd.get(), 0), SyscallSucceeds()); + struct stat stats; ASSERT_THAT(fstat(fd.get(), &stats), SyscallSucceeds()); EXPECT_EQ(stats.st_mode & kDirmodeMask, GetParam().result_mode); } diff --git a/test/syscalls/linux/socket_inet_loopback.cc b/test/syscalls/linux/socket_inet_loopback.cc index 54b45b075..597b5bcb1 100644 --- a/test/syscalls/linux/socket_inet_loopback.cc +++ b/test/syscalls/linux/socket_inet_loopback.cc @@ -490,7 +490,11 @@ void TestListenWhileConnect(const TestParam& param, TestAddress const& connector = param.connector; constexpr int kBacklog = 2; - constexpr int kClients = kBacklog + 1; + // Linux completes one more connection than the listen backlog argument. + // To ensure that there is at least one client connection that stays in + // connecting state, keep 2 more client connections than the listen backlog. + // gVisor differs in this behavior though, gvisor.dev/issue/3153. + constexpr int kClients = kBacklog + 2; // Create the listening socket. FileDescriptor listen_fd = ASSERT_NO_ERRNO_AND_VALUE( @@ -527,7 +531,7 @@ void TestListenWhileConnect(const TestParam& param, for (auto& client : clients) { constexpr int kTimeout = 10000; - struct pollfd pfd = { + pollfd pfd = { .fd = client.get(), .events = POLLIN, }; @@ -543,6 +547,10 @@ void TestListenWhileConnect(const TestParam& param, ASSERT_THAT(read(client.get(), &c, sizeof(c)), AnyOf(SyscallFailsWithErrno(ECONNRESET), SyscallFailsWithErrno(ECONNREFUSED))); + // The last client connection would be in connecting (SYN_SENT) state. + if (client.get() == clients[kClients - 1].get()) { + ASSERT_EQ(errno, ECONNREFUSED) << strerror(errno); + } } } @@ -598,7 +606,7 @@ TEST_P(SocketInetLoopbackTest, TCPbacklog_NoRandomSave) { connector.addr_len); if (ret != 0) { EXPECT_THAT(ret, SyscallFailsWithErrno(EINPROGRESS)); - struct pollfd pfd = { + pollfd pfd = { .fd = conn_fd.get(), .events = POLLOUT, }; @@ -623,6 +631,95 @@ TEST_P(SocketInetLoopbackTest, TCPbacklog_NoRandomSave) { } } +// Test if the stack completes atmost listen backlog number of client +// connections. It exercises the path of the stack that enqueues completed +// connections to accept queue vs new incoming SYNs. +TEST_P(SocketInetLoopbackTest, TCPConnectBacklog_NoRandomSave) { + const auto& param = GetParam(); + const TestAddress& listener = param.listener; + const TestAddress& connector = param.connector; + + constexpr int kBacklog = 1; + // Keep the number of client connections more than the listen backlog. + // Linux completes one more connection than the listen backlog argument. + // gVisor differs in this behavior though, gvisor.dev/issue/3153. + int kClients = kBacklog + 2; + if (IsRunningOnGvisor()) { + kClients--; + } + + // Run the following test for few iterations to test race between accept queue + // getting filled with incoming SYNs. + for (int num = 0; num < 10; num++) { + FileDescriptor listen_fd = ASSERT_NO_ERRNO_AND_VALUE( + Socket(listener.family(), SOCK_STREAM, IPPROTO_TCP)); + sockaddr_storage listen_addr = listener.addr; + ASSERT_THAT(bind(listen_fd.get(), reinterpret_cast<sockaddr*>(&listen_addr), + listener.addr_len), + SyscallSucceeds()); + ASSERT_THAT(listen(listen_fd.get(), kBacklog), SyscallSucceeds()); + + socklen_t addrlen = listener.addr_len; + ASSERT_THAT( + getsockname(listen_fd.get(), reinterpret_cast<sockaddr*>(&listen_addr), + &addrlen), + SyscallSucceeds()); + uint16_t const port = + ASSERT_NO_ERRNO_AND_VALUE(AddrPort(listener.family(), listen_addr)); + sockaddr_storage conn_addr = connector.addr; + ASSERT_NO_ERRNO(SetAddrPort(connector.family(), &conn_addr, port)); + + std::vector<FileDescriptor> clients; + // Issue multiple non-blocking client connects. + for (int i = 0; i < kClients; i++) { + FileDescriptor client = ASSERT_NO_ERRNO_AND_VALUE( + Socket(connector.family(), SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP)); + int ret = connect(client.get(), reinterpret_cast<sockaddr*>(&conn_addr), + connector.addr_len); + if (ret != 0) { + EXPECT_THAT(ret, SyscallFailsWithErrno(EINPROGRESS)); + } + clients.push_back(std::move(client)); + } + + // Now that client connects are issued, wait for the accept queue to get + // filled and ensure no new client connection is completed. + for (int i = 0; i < kClients; i++) { + pollfd pfd = { + .fd = clients[i].get(), + .events = POLLOUT, + }; + if (i < kClients - 1) { + // Poll for client side connection completions with a large timeout. + // We cannot poll on the listener side without calling accept as poll + // stays level triggered with non-zero accept queue length. + // + // Client side poll would not guarantee that the completed connection + // has been enqueued in to the acccept queue, but the fact that the + // listener ACKd the SYN, means that it cannot complete any new incoming + // SYNs when it has already ACKd for > backlog number of SYNs. + ASSERT_THAT(poll(&pfd, 1, 10000), SyscallSucceedsWithValue(1)) + << "num=" << num << " i=" << i << " kClients=" << kClients; + ASSERT_EQ(pfd.revents, POLLOUT) << "num=" << num << " i=" << i; + } else { + // Now that we expect accept queue filled up, ensure that the last + // client connection never completes with a smaller poll timeout. + ASSERT_THAT(poll(&pfd, 1, 1000), SyscallSucceedsWithValue(0)) + << "num=" << num << " i=" << i; + } + + ASSERT_THAT(close(clients[i].release()), SyscallSucceedsWithValue(0)) + << "num=" << num << " i=" << i; + } + clients.clear(); + // We close the listening side and open a new listener. We could instead + // drain the accept queue by calling accept() and reuse the listener, but + // that is racy as the retransmitted SYNs could get ACKd as we make room in + // the accept queue. + ASSERT_THAT(close(listen_fd.release()), SyscallSucceedsWithValue(0)); + } +} + // TCPFinWait2Test creates a pair of connected sockets then closes one end to // trigger FIN_WAIT2 state for the closed endpoint. Then it binds the same local // IP/port on a new socket and tries to connect. The connect should fail w/ @@ -937,7 +1034,7 @@ void setupTimeWaitClose(const TestAddress* listener, ASSERT_THAT(shutdown(active_closefd.get(), SHUT_WR), SyscallSucceeds()); { constexpr int kTimeout = 10000; - struct pollfd pfd = { + pollfd pfd = { .fd = passive_closefd.get(), .events = POLLIN, }; @@ -948,7 +1045,7 @@ void setupTimeWaitClose(const TestAddress* listener, { constexpr int kTimeout = 10000; constexpr int16_t want_events = POLLHUP; - struct pollfd pfd = { + pollfd pfd = { .fd = active_closefd.get(), .events = want_events, }; @@ -1181,7 +1278,7 @@ TEST_P(SocketInetLoopbackTest, TCPAcceptAfterReset) { // Wait for accept_fd to process the RST. constexpr int kTimeout = 10000; - struct pollfd pfd = { + pollfd pfd = { .fd = accept_fd.get(), .events = POLLIN, }; @@ -1705,7 +1802,7 @@ TEST_P(SocketInetReusePortTest, UdpPortReuseMultiThreadShort_NoRandomSave) { SyscallSucceedsWithValue(sizeof(i))); } - struct pollfd pollfds[kThreadCount]; + pollfd pollfds[kThreadCount]; for (int i = 0; i < kThreadCount; i++) { pollfds[i].fd = listener_fds[i].get(); pollfds[i].events = POLLIN; diff --git a/test/syscalls/linux/write.cc b/test/syscalls/linux/write.cc index 740992d0a..3373ba72b 100644 --- a/test/syscalls/linux/write.cc +++ b/test/syscalls/linux/write.cc @@ -15,6 +15,7 @@ #include <errno.h> #include <fcntl.h> #include <signal.h> +#include <sys/mman.h> #include <sys/resource.h> #include <sys/stat.h> #include <sys/types.h> @@ -23,6 +24,7 @@ #include "gmock/gmock.h" #include "gtest/gtest.h" +#include "absl/base/macros.h" #include "test/util/cleanup.h" #include "test/util/temp_path.h" #include "test/util/test_util.h" @@ -256,6 +258,82 @@ TEST_F(WriteTest, PwriteWithOpath) { SyscallFailsWithErrno(EBADF)); } +// Test that partial writes that hit SIGSEGV are correctly handled and return +// partial write. +TEST_F(WriteTest, PartialWriteSIGSEGV) { + // Allocate 2 pages and remove permission from the second. + const size_t size = 2 * kPageSize; + void* addr = mmap(0, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + ASSERT_NE(addr, MAP_FAILED); + auto cleanup = Cleanup( + [addr, size] { EXPECT_THAT(munmap(addr, size), SyscallSucceeds()); }); + + void* badAddr = reinterpret_cast<char*>(addr) + kPageSize; + ASSERT_THAT(mprotect(badAddr, kPageSize, PROT_NONE), SyscallSucceeds()); + + TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path().c_str(), O_WRONLY)); + + // Attempt to write both pages to the file. Create a non-contiguous iovec pair + // to ensure operation is done in 2 steps. + struct iovec iov[] = { + { + .iov_base = addr, + .iov_len = kPageSize, + }, + { + .iov_base = addr, + .iov_len = size, + }, + }; + // Write should succeed for the first iovec and half of the second (=2 pages). + EXPECT_THAT(pwritev(fd.get(), iov, ABSL_ARRAYSIZE(iov), 0), + SyscallSucceedsWithValue(2 * kPageSize)); +} + +// Test that partial writes that hit SIGBUS are correctly handled and return +// partial write. +TEST_F(WriteTest, PartialWriteSIGBUS) { + SKIP_IF(getenv("GVISOR_GOFER_UNCACHED")); // Can't mmap from uncached files. + + TempPath mapfile = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + FileDescriptor fd_map = + ASSERT_NO_ERRNO_AND_VALUE(Open(mapfile.path().c_str(), O_RDWR)); + + // Let the first page be read to force a partial write. + ASSERT_THAT(ftruncate(fd_map.get(), kPageSize), SyscallSucceeds()); + + // Map 2 pages, one of which is not allocated in the backing file. Reading + // from it will trigger a SIGBUS. + const size_t size = 2 * kPageSize; + void* addr = + mmap(NULL, size, PROT_READ, MAP_FILE | MAP_PRIVATE, fd_map.get(), 0); + ASSERT_NE(addr, MAP_FAILED); + auto cleanup = Cleanup( + [addr, size] { EXPECT_THAT(munmap(addr, size), SyscallSucceeds()); }); + + TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path().c_str(), O_WRONLY)); + + // Attempt to write both pages to the file. Create a non-contiguous iovec pair + // to ensure operation is done in 2 steps. + struct iovec iov[] = { + { + .iov_base = addr, + .iov_len = kPageSize, + }, + { + .iov_base = addr, + .iov_len = size, + }, + }; + // Write should succeed for the first iovec and half of the second (=2 pages). + ASSERT_THAT(pwritev(fd.get(), iov, ABSL_ARRAYSIZE(iov), 0), + SyscallSucceedsWithValue(2 * kPageSize)); +} + } // namespace } // namespace testing |