diff options
Diffstat (limited to 'test/syscalls/linux')
| -rw-r--r-- | test/syscalls/linux/BUILD | 37 | ||||
| -rw-r--r-- | test/syscalls/linux/pty.cc | 393 | ||||
| -rw-r--r-- | test/syscalls/linux/pty_root.cc | 68 | ||||
| -rw-r--r-- | test/syscalls/linux/signalfd.cc | 333 |
4 files changed, 812 insertions, 19 deletions
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index eac32850d..a4cebf46f 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1287,8 +1287,10 @@ cc_binary( srcs = ["pty.cc"], linkstatic = 1, deps = [ + "//test/util:capability_util", "//test/util:file_descriptor", "//test/util:posix_error", + "//test/util:pty_util", "//test/util:test_main", "//test/util:test_util", "//test/util:thread_util", @@ -1301,6 +1303,23 @@ cc_binary( ) cc_binary( + name = "pty_root_test", + testonly = 1, + srcs = ["pty_root.cc"], + linkstatic = 1, + deps = [ + "//test/util:capability_util", + "//test/util:file_descriptor", + "//test/util:posix_error", + "//test/util:pty_util", + "//test/util:test_main", + "//test/util:thread_util", + "@com_google_absl//absl/base:core_headers", + "@com_google_googletest//:gtest", + ], +) + +cc_binary( name = "partial_bad_buffer_test", testonly = 1, srcs = ["partial_bad_buffer.cc"], @@ -1964,6 +1983,24 @@ cc_binary( ) cc_binary( + name = "signalfd_test", + testonly = 1, + srcs = ["signalfd.cc"], + linkstatic = 1, + deps = [ + "//test/util:file_descriptor", + "//test/util:logging", + "//test/util:posix_error", + "//test/util:signal_util", + "//test/util:test_main", + "//test/util:test_util", + "//test/util:thread_util", + "@com_google_absl//absl/synchronization", + "@com_google_googletest//:gtest", + ], +) + +cc_binary( name = "sigprocmask_test", testonly = 1, srcs = ["sigprocmask.cc"], diff --git a/test/syscalls/linux/pty.cc b/test/syscalls/linux/pty.cc index d1ab4703f..286388316 100644 --- a/test/syscalls/linux/pty.cc +++ b/test/syscalls/linux/pty.cc @@ -13,13 +13,17 @@ // limitations under the License. #include <fcntl.h> +#include <linux/capability.h> #include <linux/major.h> #include <poll.h> +#include <sched.h> +#include <signal.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/stat.h> #include <sys/sysmacros.h> #include <sys/types.h> +#include <sys/wait.h> #include <termios.h> #include <unistd.h> @@ -31,8 +35,10 @@ #include "absl/synchronization/notification.h" #include "absl/time/clock.h" #include "absl/time/time.h" +#include "test/util/capability_util.h" #include "test/util/file_descriptor.h" #include "test/util/posix_error.h" +#include "test/util/pty_util.h" #include "test/util/test_util.h" #include "test/util/thread_util.h" @@ -370,25 +376,6 @@ PosixErrorOr<size_t> PollAndReadFd(int fd, void* buf, size_t count, return PosixError(ETIMEDOUT, "Poll timed out"); } -// Opens the slave end of the passed master as R/W and nonblocking. -PosixErrorOr<FileDescriptor> OpenSlave(const FileDescriptor& master) { - // Get pty index. - int n; - int ret = ioctl(master.get(), TIOCGPTN, &n); - if (ret < 0) { - return PosixError(errno, "ioctl(TIOCGPTN) failed"); - } - - // Unlock pts. - int unlock = 0; - ret = ioctl(master.get(), TIOCSPTLCK, &unlock); - if (ret < 0) { - return PosixError(errno, "ioctl(TIOSPTLCK) failed"); - } - - return Open(absl::StrCat("/dev/pts/", n), O_RDWR | O_NONBLOCK); -} - TEST(BasicPtyTest, StatUnopenedMaster) { struct stat s; ASSERT_THAT(stat("/dev/ptmx", &s), SyscallSucceeds()); @@ -1233,6 +1220,374 @@ TEST_F(PtyTest, SetMasterWindowSize) { EXPECT_EQ(retrieved_ws.ws_col, kCols); } +class JobControlTest : public ::testing::Test { + protected: + void SetUp() override { + master_ = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/ptmx", O_RDWR | O_NONBLOCK)); + slave_ = ASSERT_NO_ERRNO_AND_VALUE(OpenSlave(master_)); + + // Make this a session leader, which also drops the controlling terminal. + // In the gVisor test environment, this test will be run as the session + // leader already (as the sentry init process). + if (!IsRunningOnGvisor()) { + ASSERT_THAT(setsid(), SyscallSucceeds()); + } + } + + // Master and slave ends of the PTY. Non-blocking. + FileDescriptor master_; + FileDescriptor slave_; +}; + +TEST_F(JobControlTest, SetTTYMaster) { + ASSERT_THAT(ioctl(master_.get(), TIOCSCTTY, 0), SyscallSucceeds()); +} + +TEST_F(JobControlTest, SetTTY) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); +} + +TEST_F(JobControlTest, SetTTYNonLeader) { + // Fork a process that won't be the session leader. + pid_t child = fork(); + if (!child) { + // We shouldn't be able to set the terminal. + TEST_PCHECK(ioctl(slave_.get(), TIOCSCTTY, 0)); + _exit(0); + } + + int wstatus; + ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + ASSERT_EQ(wstatus, 0); +} + +TEST_F(JobControlTest, SetTTYBadArg) { + // Despite the man page saying arg should be 0 here, Linux doesn't actually + // check. + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 1), SyscallSucceeds()); +} + +TEST_F(JobControlTest, SetTTYDifferentSession) { + SKIP_IF(ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN))); + + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + // Fork, join a new session, and try to steal the parent's controlling + // terminal, which should fail. + pid_t child = fork(); + if (!child) { + TEST_PCHECK(setsid() >= 0); + // We shouldn't be able to steal the terminal. + TEST_PCHECK(ioctl(slave_.get(), TIOCSCTTY, 1)); + _exit(0); + } + + int wstatus; + ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + ASSERT_EQ(wstatus, 0); +} + +TEST_F(JobControlTest, ReleaseTTY) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + // Make sure we're ignoring SIGHUP, which will be sent to this process once we + // disconnect they TTY. + struct sigaction sa = { + .sa_handler = SIG_IGN, + .sa_flags = 0, + }; + sigemptyset(&sa.sa_mask); + struct sigaction old_sa; + EXPECT_THAT(sigaction(SIGHUP, &sa, &old_sa), SyscallSucceeds()); + EXPECT_THAT(ioctl(slave_.get(), TIOCNOTTY), SyscallSucceeds()); + EXPECT_THAT(sigaction(SIGHUP, &old_sa, NULL), SyscallSucceeds()); +} + +TEST_F(JobControlTest, ReleaseUnsetTTY) { + ASSERT_THAT(ioctl(slave_.get(), TIOCNOTTY), SyscallFailsWithErrno(ENOTTY)); +} + +TEST_F(JobControlTest, ReleaseWrongTTY) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + ASSERT_THAT(ioctl(master_.get(), TIOCNOTTY), SyscallFailsWithErrno(ENOTTY)); +} + +TEST_F(JobControlTest, ReleaseTTYNonLeader) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + pid_t child = fork(); + if (!child) { + TEST_PCHECK(!ioctl(slave_.get(), TIOCNOTTY)); + _exit(0); + } + + int wstatus; + ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + ASSERT_EQ(wstatus, 0); +} + +TEST_F(JobControlTest, ReleaseTTYDifferentSession) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + pid_t child = fork(); + if (!child) { + // Join a new session, then try to disconnect. + TEST_PCHECK(setsid() >= 0); + TEST_PCHECK(ioctl(slave_.get(), TIOCNOTTY)); + _exit(0); + } + + int wstatus; + ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + ASSERT_EQ(wstatus, 0); +} + +// Used by the child process spawned in ReleaseTTYSignals to track received +// signals. +static int received; + +void sig_handler(int signum) { received |= signum; } + +// When the session leader releases its controlling terminal, the foreground +// process group gets SIGHUP, then SIGCONT. This test: +// - Spawns 2 threads +// - Has thread 1 return 0 if it gets both SIGHUP and SIGCONT +// - Has thread 2 leave the foreground process group, and return non-zero if it +// receives any signals. +// - Has the parent thread release its controlling terminal +// - Checks that thread 1 got both signals +// - Checks that thread 2 didn't get any signals. +TEST_F(JobControlTest, ReleaseTTYSignals) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + received = 0; + struct sigaction sa = { + .sa_handler = sig_handler, + .sa_flags = 0, + }; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SIGHUP); + sigaddset(&sa.sa_mask, SIGCONT); + sigprocmask(SIG_BLOCK, &sa.sa_mask, NULL); + + pid_t same_pgrp_child = fork(); + if (!same_pgrp_child) { + // The child will wait for SIGHUP and SIGCONT, then return 0. It begins with + // SIGHUP and SIGCONT blocked. We install signal handlers for those signals, + // then use sigsuspend to wait for those specific signals. + TEST_PCHECK(!sigaction(SIGHUP, &sa, NULL)); + TEST_PCHECK(!sigaction(SIGCONT, &sa, NULL)); + sigset_t mask; + sigfillset(&mask); + sigdelset(&mask, SIGHUP); + sigdelset(&mask, SIGCONT); + while (received != (SIGHUP | SIGCONT)) { + sigsuspend(&mask); + } + _exit(0); + } + + // We don't want to block these anymore. + sigprocmask(SIG_UNBLOCK, &sa.sa_mask, NULL); + + // This child will return non-zero if either SIGHUP or SIGCONT are received. + pid_t diff_pgrp_child = fork(); + if (!diff_pgrp_child) { + TEST_PCHECK(!setpgid(0, 0)); + TEST_PCHECK(pause()); + _exit(1); + } + + EXPECT_THAT(setpgid(diff_pgrp_child, diff_pgrp_child), SyscallSucceeds()); + + // Make sure we're ignoring SIGHUP, which will be sent to this process once we + // disconnect they TTY. + struct sigaction sighup_sa = { + .sa_handler = SIG_IGN, + .sa_flags = 0, + }; + sigemptyset(&sighup_sa.sa_mask); + struct sigaction old_sa; + EXPECT_THAT(sigaction(SIGHUP, &sighup_sa, &old_sa), SyscallSucceeds()); + + // Release the controlling terminal, sending SIGHUP and SIGCONT to all other + // processes in this process group. + EXPECT_THAT(ioctl(slave_.get(), TIOCNOTTY), SyscallSucceeds()); + + EXPECT_THAT(sigaction(SIGHUP, &old_sa, NULL), SyscallSucceeds()); + + // The child in the same process group will get signaled. + int wstatus; + EXPECT_THAT(waitpid(same_pgrp_child, &wstatus, 0), + SyscallSucceedsWithValue(same_pgrp_child)); + EXPECT_EQ(wstatus, 0); + + // The other child will not get signaled. + EXPECT_THAT(waitpid(diff_pgrp_child, &wstatus, WNOHANG), + SyscallSucceedsWithValue(0)); + EXPECT_THAT(kill(diff_pgrp_child, SIGKILL), SyscallSucceeds()); +} + +TEST_F(JobControlTest, GetForegroundProcessGroup) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + pid_t foreground_pgid; + pid_t pid; + ASSERT_THAT(ioctl(slave_.get(), TIOCGPGRP, &foreground_pgid), + SyscallSucceeds()); + ASSERT_THAT(pid = getpid(), SyscallSucceeds()); + + ASSERT_EQ(foreground_pgid, pid); +} + +TEST_F(JobControlTest, GetForegroundProcessGroupNonControlling) { + // At this point there's no controlling terminal, so TIOCGPGRP should fail. + pid_t foreground_pgid; + ASSERT_THAT(ioctl(slave_.get(), TIOCGPGRP, &foreground_pgid), + SyscallFailsWithErrno(ENOTTY)); +} + +// This test: +// - sets itself as the foreground process group +// - creates a child process in a new process group +// - sets that child as the foreground process group +// - kills its child and sets itself as the foreground process group. +TEST_F(JobControlTest, SetForegroundProcessGroup) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + // Ignore SIGTTOU so that we don't stop ourself when calling tcsetpgrp. + struct sigaction sa = { + .sa_handler = SIG_IGN, + .sa_flags = 0, + }; + sigemptyset(&sa.sa_mask); + sigaction(SIGTTOU, &sa, NULL); + + // Set ourself as the foreground process group. + ASSERT_THAT(tcsetpgrp(slave_.get(), getpgid(0)), SyscallSucceeds()); + + // Create a new process that just waits to be signaled. + pid_t child = fork(); + if (!child) { + TEST_PCHECK(!pause()); + // We should never reach this. + _exit(1); + } + + // Make the child its own process group, then make it the controlling process + // group of the terminal. + ASSERT_THAT(setpgid(child, child), SyscallSucceeds()); + ASSERT_THAT(tcsetpgrp(slave_.get(), child), SyscallSucceeds()); + + // Sanity check - we're still the controlling session. + ASSERT_EQ(getsid(0), getsid(child)); + + // Signal the child, wait for it to exit, then retake the terminal. + ASSERT_THAT(kill(child, SIGTERM), SyscallSucceeds()); + int wstatus; + ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + ASSERT_TRUE(WIFSIGNALED(wstatus)); + ASSERT_EQ(WTERMSIG(wstatus), SIGTERM); + + // Set ourself as the foreground process. + pid_t pgid; + ASSERT_THAT(pgid = getpgid(0), SyscallSucceeds()); + ASSERT_THAT(tcsetpgrp(slave_.get(), pgid), SyscallSucceeds()); +} + +TEST_F(JobControlTest, SetForegroundProcessGroupWrongTTY) { + pid_t pid = getpid(); + ASSERT_THAT(ioctl(slave_.get(), TIOCSPGRP, &pid), + SyscallFailsWithErrno(ENOTTY)); +} + +TEST_F(JobControlTest, SetForegroundProcessGroupNegPgid) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + pid_t pid = -1; + ASSERT_THAT(ioctl(slave_.get(), TIOCSPGRP, &pid), + SyscallFailsWithErrno(EINVAL)); +} + +TEST_F(JobControlTest, SetForegroundProcessGroupEmptyProcessGroup) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + // Create a new process, put it in a new process group, make that group the + // foreground process group, then have the process wait. + pid_t child = fork(); + if (!child) { + TEST_PCHECK(!setpgid(0, 0)); + _exit(0); + } + + // Wait for the child to exit. + int wstatus; + EXPECT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + // The child's process group doesn't exist anymore - this should fail. + ASSERT_THAT(ioctl(slave_.get(), TIOCSPGRP, &child), + SyscallFailsWithErrno(ESRCH)); +} + +TEST_F(JobControlTest, SetForegroundProcessGroupDifferentSession) { + ASSERT_THAT(ioctl(slave_.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + // Create a new process and put it in a new session. + pid_t child = fork(); + if (!child) { + TEST_PCHECK(setsid() >= 0); + // Tell the parent we're in a new session. + TEST_PCHECK(!raise(SIGSTOP)); + TEST_PCHECK(!pause()); + _exit(1); + } + + // Wait for the child to tell us it's in a new session. + int wstatus; + EXPECT_THAT(waitpid(child, &wstatus, WUNTRACED), + SyscallSucceedsWithValue(child)); + EXPECT_TRUE(WSTOPSIG(wstatus)); + + // Child is in a new session, so we can't make it the foregroup process group. + EXPECT_THAT(ioctl(slave_.get(), TIOCSPGRP, &child), + SyscallFailsWithErrno(EPERM)); + + EXPECT_THAT(kill(child, SIGKILL), SyscallSucceeds()); +} + +// Verify that we don't hang when creating a new session from an orphaned +// process group (b/139968068). Calling setsid() creates an orphaned process +// group, as process groups that contain the session's leading process are +// orphans. +// +// We create 2 sessions in this test. The init process in gVisor is considered +// not to be an orphan (see sessions.go), so we have to create a session from +// which to create a session. The latter session is being created from an +// orphaned process group. +TEST_F(JobControlTest, OrphanRegression) { + pid_t session_2_leader = fork(); + if (!session_2_leader) { + TEST_PCHECK(setsid() >= 0); + + pid_t session_3_leader = fork(); + if (!session_3_leader) { + TEST_PCHECK(setsid() >= 0); + + _exit(0); + } + + int wstatus; + TEST_PCHECK(waitpid(session_3_leader, &wstatus, 0) == session_3_leader); + TEST_PCHECK(wstatus == 0); + + _exit(0); + } + + int wstatus; + ASSERT_THAT(waitpid(session_2_leader, &wstatus, 0), + SyscallSucceedsWithValue(session_2_leader)); + ASSERT_EQ(wstatus, 0); +} + } // namespace } // namespace testing } // namespace gvisor diff --git a/test/syscalls/linux/pty_root.cc b/test/syscalls/linux/pty_root.cc new file mode 100644 index 000000000..14a4af980 --- /dev/null +++ b/test/syscalls/linux/pty_root.cc @@ -0,0 +1,68 @@ +// 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 <sys/ioctl.h> +#include <termios.h> + +#include "gtest/gtest.h" +#include "absl/base/macros.h" +#include "test/util/capability_util.h" +#include "test/util/file_descriptor.h" +#include "test/util/posix_error.h" +#include "test/util/pty_util.h" + +namespace gvisor { +namespace testing { + +// These tests should be run as root. +namespace { + +TEST(JobControlRootTest, StealTTY) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN))); + + // Make this a session leader, which also drops the controlling terminal. + // In the gVisor test environment, this test will be run as the session + // leader already (as the sentry init process). + if (!IsRunningOnGvisor()) { + ASSERT_THAT(setsid(), SyscallSucceeds()); + } + + FileDescriptor master = + ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/ptmx", O_RDWR | O_NONBLOCK)); + FileDescriptor slave = ASSERT_NO_ERRNO_AND_VALUE(OpenSlave(master)); + + // Make slave the controlling terminal. + ASSERT_THAT(ioctl(slave.get(), TIOCSCTTY, 0), SyscallSucceeds()); + + // Fork, join a new session, and try to steal the parent's controlling + // terminal, which should succeed when we have CAP_SYS_ADMIN and pass an arg + // of 1. + pid_t child = fork(); + if (!child) { + ASSERT_THAT(setsid(), SyscallSucceeds()); + // We shouldn't be able to steal the terminal with the wrong arg value. + TEST_PCHECK(ioctl(slave.get(), TIOCSCTTY, 0)); + // We should be able to steal it here. + TEST_PCHECK(!ioctl(slave.get(), TIOCSCTTY, 1)); + _exit(0); + } + + int wstatus; + ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child)); + ASSERT_EQ(wstatus, 0); +} + +} // namespace +} // namespace testing +} // namespace gvisor diff --git a/test/syscalls/linux/signalfd.cc b/test/syscalls/linux/signalfd.cc new file mode 100644 index 000000000..54c598627 --- /dev/null +++ b/test/syscalls/linux/signalfd.cc @@ -0,0 +1,333 @@ +// Copyright 2019 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 <poll.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <sys/signalfd.h> +#include <unistd.h> + +#include <functional> +#include <vector> + +#include "gtest/gtest.h" +#include "gtest/gtest.h" +#include "absl/synchronization/mutex.h" +#include "test/util/file_descriptor.h" +#include "test/util/posix_error.h" +#include "test/util/signal_util.h" +#include "test/util/test_util.h" +#include "test/util/thread_util.h" + +using ::testing::KilledBySignal; + +namespace gvisor { +namespace testing { + +namespace { + +constexpr int kSigno = SIGUSR1; +constexpr int kSignoAlt = SIGUSR2; + +// Returns a new signalfd. +inline PosixErrorOr<FileDescriptor> NewSignalFD(sigset_t* mask, int flags = 0) { + int fd = signalfd(-1, mask, flags); + MaybeSave(); + if (fd < 0) { + return PosixError(errno, "signalfd"); + } + return FileDescriptor(fd); +} + +TEST(Signalfd, Basic) { + // Create the signalfd. + sigset_t mask; + sigemptyset(&mask); + sigaddset(&mask, kSigno); + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, 0)); + + // Deliver the blocked signal. + const auto scoped_sigmask = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, kSigno)); + ASSERT_THAT(tgkill(getpid(), gettid(), kSigno), SyscallSucceeds()); + + // We should now read the signal. + struct signalfd_siginfo rbuf; + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); + EXPECT_EQ(rbuf.ssi_signo, kSigno); +} + +TEST(Signalfd, MaskWorks) { + // Create two signalfds with different masks. + sigset_t mask1, mask2; + sigemptyset(&mask1); + sigemptyset(&mask2); + sigaddset(&mask1, kSigno); + sigaddset(&mask2, kSignoAlt); + FileDescriptor fd1 = ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask1, 0)); + FileDescriptor fd2 = ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask2, 0)); + + // Deliver the two signals. + const auto scoped_sigmask1 = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, kSigno)); + const auto scoped_sigmask2 = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, kSignoAlt)); + ASSERT_THAT(tgkill(getpid(), gettid(), kSigno), SyscallSucceeds()); + ASSERT_THAT(tgkill(getpid(), gettid(), kSignoAlt), SyscallSucceeds()); + + // We should see the signals on the appropriate signalfds. + // + // We read in the opposite order as the signals deliver above, to ensure that + // we don't happen to read the correct signal from the correct signalfd. + struct signalfd_siginfo rbuf1, rbuf2; + ASSERT_THAT(read(fd2.get(), &rbuf2, sizeof(rbuf2)), + SyscallSucceedsWithValue(sizeof(rbuf2))); + EXPECT_EQ(rbuf2.ssi_signo, kSignoAlt); + ASSERT_THAT(read(fd1.get(), &rbuf1, sizeof(rbuf1)), + SyscallSucceedsWithValue(sizeof(rbuf1))); + EXPECT_EQ(rbuf1.ssi_signo, kSigno); +} + +TEST(Signalfd, Cloexec) { + // Exec tests confirm that O_CLOEXEC has the intended effect. We just create a + // signalfd with the appropriate flag here and assert that the FD has it set. + sigset_t mask; + sigemptyset(&mask); + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, SFD_CLOEXEC)); + EXPECT_THAT(fcntl(fd.get(), F_GETFD), SyscallSucceedsWithValue(FD_CLOEXEC)); +} + +TEST(Signalfd, Blocking) { + // Create the signalfd in blocking mode. + sigset_t mask; + sigemptyset(&mask); + sigaddset(&mask, kSigno); + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, 0)); + + // Shared tid variable. + absl::Mutex mu; + bool has_tid; + pid_t tid; + + // Start a thread reading. + ScopedThread t([&] { + // Copy the tid and notify the caller. + { + absl::MutexLock ml(&mu); + tid = gettid(); + has_tid = true; + } + + // Read the signal from the signalfd. + struct signalfd_siginfo rbuf; + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); + EXPECT_EQ(rbuf.ssi_signo, kSigno); + }); + + // Wait until blocked. + absl::MutexLock ml(&mu); + mu.Await(absl::Condition(&has_tid)); + + // Deliver the signal to either the waiting thread, or + // to this thread. N.B. this is a bug in the core gVisor + // behavior for signalfd, and needs to be fixed. + // + // See gvisor.dev/issue/139. + if (IsRunningOnGvisor()) { + ASSERT_THAT(tgkill(getpid(), gettid(), kSigno), SyscallSucceeds()); + } else { + ASSERT_THAT(tgkill(getpid(), tid, kSigno), SyscallSucceeds()); + } + + // Ensure that it was received. + t.Join(); +} + +TEST(Signalfd, ThreadGroup) { + // Create the signalfd in blocking mode. + sigset_t mask; + sigemptyset(&mask); + sigaddset(&mask, kSigno); + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, 0)); + + // Shared variable. + absl::Mutex mu; + bool first = false; + bool second = false; + + // Start a thread reading. + ScopedThread t([&] { + // Read the signal from the signalfd. + struct signalfd_siginfo rbuf; + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); + EXPECT_EQ(rbuf.ssi_signo, kSigno); + + // Wait for the other thread. + absl::MutexLock ml(&mu); + first = true; + mu.Await(absl::Condition(&second)); + }); + + // Deliver the signal to the threadgroup. + ASSERT_THAT(kill(getpid(), kSigno), SyscallSucceeds()); + + // Wait for the first thread to process. + { + absl::MutexLock ml(&mu); + mu.Await(absl::Condition(&first)); + } + + // Deliver to the thread group again (other thread still exists). + ASSERT_THAT(kill(getpid(), kSigno), SyscallSucceeds()); + + // Ensure that we can also receive it. + struct signalfd_siginfo rbuf; + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); + EXPECT_EQ(rbuf.ssi_signo, kSigno); + + // Mark the test as done. + { + absl::MutexLock ml(&mu); + second = true; + } + + // The other thread should be joinable. + t.Join(); +} + +TEST(Signalfd, Nonblock) { + // Create the signalfd in non-blocking mode. + sigset_t mask; + sigemptyset(&mask); + sigaddset(&mask, kSigno); + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, SFD_NONBLOCK)); + + // We should return if we attempt to read. + struct signalfd_siginfo rbuf; + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallFailsWithErrno(EWOULDBLOCK)); + + // Block and deliver the signal. + const auto scoped_sigmask = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, kSigno)); + ASSERT_THAT(tgkill(getpid(), gettid(), kSigno), SyscallSucceeds()); + + // Ensure that a read actually works. + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); + EXPECT_EQ(rbuf.ssi_signo, kSigno); + + // Should block again. + EXPECT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallFailsWithErrno(EWOULDBLOCK)); +} + +TEST(Signalfd, SetMask) { + // Create the signalfd matching nothing. + sigset_t mask; + sigemptyset(&mask); + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, SFD_NONBLOCK)); + + // Block and deliver a signal. + const auto scoped_sigmask = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, kSigno)); + ASSERT_THAT(tgkill(getpid(), gettid(), kSigno), SyscallSucceeds()); + + // We should have nothing. + struct signalfd_siginfo rbuf; + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallFailsWithErrno(EWOULDBLOCK)); + + // Change the signal mask. + sigaddset(&mask, kSigno); + ASSERT_THAT(signalfd(fd.get(), &mask, 0), SyscallSucceeds()); + + // We should now have the signal. + ASSERT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); + EXPECT_EQ(rbuf.ssi_signo, kSigno); +} + +TEST(Signalfd, Poll) { + // Create the signalfd. + sigset_t mask; + sigemptyset(&mask); + sigaddset(&mask, kSigno); + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, 0)); + + // Block the signal, and start a thread to deliver it. + const auto scoped_sigmask = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, kSigno)); + pid_t orig_tid = gettid(); + ScopedThread t([&] { + absl::SleepFor(absl::Seconds(5)); + ASSERT_THAT(tgkill(getpid(), orig_tid, kSigno), SyscallSucceeds()); + }); + + // Start polling for the signal. We expect that it is not available at the + // outset, but then becomes available when the signal is sent. We give a + // timeout of 10000ms (or the delay above + 5 seconds of additional grace + // time). + struct pollfd poll_fd = {fd.get(), POLLIN, 0}; + EXPECT_THAT(RetryEINTR(poll)(&poll_fd, 1, 10000), + SyscallSucceedsWithValue(1)); + + // Actually read the signal to prevent delivery. + struct signalfd_siginfo rbuf; + EXPECT_THAT(read(fd.get(), &rbuf, sizeof(rbuf)), + SyscallSucceedsWithValue(sizeof(rbuf))); +} + +TEST(Signalfd, KillStillKills) { + sigset_t mask; + sigemptyset(&mask); + sigaddset(&mask, SIGKILL); + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(NewSignalFD(&mask, SFD_CLOEXEC)); + + // Just because there is a signalfd, we shouldn't see any change in behavior + // for unblockable signals. It's easier to test this with SIGKILL. + const auto scoped_sigmask = + ASSERT_NO_ERRNO_AND_VALUE(ScopedSignalMask(SIG_BLOCK, SIGKILL)); + EXPECT_EXIT(tgkill(getpid(), gettid(), SIGKILL), KilledBySignal(SIGKILL), ""); +} + +} // namespace + +} // namespace testing +} // namespace gvisor + +int main(int argc, char** argv) { + // These tests depend on delivering signals. Block them up front so that all + // other threads created by TestInit will also have them blocked, and they + // will not interface with the rest of the test. + sigset_t set; + sigemptyset(&set); + sigaddset(&set, gvisor::testing::kSigno); + sigaddset(&set, gvisor::testing::kSignoAlt); + TEST_PCHECK(sigprocmask(SIG_BLOCK, &set, nullptr) == 0); + + gvisor::testing::TestInit(&argc, &argv); + + return RUN_ALL_TESTS(); +} |