1 files changed, 401 insertions, 0 deletions
diff --git a/src/syscall/exec_unix_test.go b/src/syscall/exec_unix_test.go
new file mode 100644
index 0000000..9627317
--- /dev/null
+++ b/src/syscall/exec_unix_test.go
@@ -0,0 +1,401 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package syscall_test
+
+import (
+	"bytes"
+	"fmt"
+	"internal/testenv"
+	"io"
+	"math/rand"
+	"os"
+	"os/exec"
+	"os/signal"
+	"strconv"
+	"syscall"
+	"testing"
+	"time"
+	"unsafe"
+)
+
+type command struct {
+	pipe io.WriteCloser
+	proc *exec.Cmd
+	test *testing.T
+}
+
+func (c *command) Info() (pid, pgrp int) {
+	pid = c.proc.Process.Pid
+
+	pgrp, err := syscall.Getpgid(pid)
+	if err != nil {
+		c.test.Fatal(err)
+	}
+
+	return
+}
+
+func (c *command) Start() {
+	if err := c.proc.Start(); err != nil {
+		c.test.Fatal(err)
+	}
+}
+
+func (c *command) Stop() {
+	c.pipe.Close()
+	if err := c.proc.Wait(); err != nil {
+		c.test.Fatal(err)
+	}
+}
+
+func create(t *testing.T) *command {
+	testenv.MustHaveExec(t)
+
+	proc := exec.Command("cat")
+	stdin, err := proc.StdinPipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return &command{stdin, proc, t}
+}
+
+func parent() (pid, pgrp int) {
+	return syscall.Getpid(), syscall.Getpgrp()
+}
+
+func TestZeroSysProcAttr(t *testing.T) {
+	ppid, ppgrp := parent()
+
+	cmd := create(t)
+
+	cmd.Start()
+	defer cmd.Stop()
+
+	cpid, cpgrp := cmd.Info()
+
+	if cpid == ppid {
+		t.Fatalf("Parent and child have the same process ID")
+	}
+
+	if cpgrp != ppgrp {
+		t.Fatalf("Child is not in parent's process group")
+	}
+}
+
+func TestSetpgid(t *testing.T) {
+	ppid, ppgrp := parent()
+
+	cmd := create(t)
+
+	cmd.proc.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	cmd.Start()
+	defer cmd.Stop()
+
+	cpid, cpgrp := cmd.Info()
+
+	if cpid == ppid {
+		t.Fatalf("Parent and child have the same process ID")
+	}
+
+	if cpgrp == ppgrp {
+		t.Fatalf("Parent and child are in the same process group")
+	}
+
+	if cpid != cpgrp {
+		t.Fatalf("Child's process group is not the child's process ID")
+	}
+}
+
+func TestPgid(t *testing.T) {
+	ppid, ppgrp := parent()
+
+	cmd1 := create(t)
+
+	cmd1.proc.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	cmd1.Start()
+	defer cmd1.Stop()
+
+	cpid1, cpgrp1 := cmd1.Info()
+
+	if cpid1 == ppid {
+		t.Fatalf("Parent and child 1 have the same process ID")
+	}
+
+	if cpgrp1 == ppgrp {
+		t.Fatalf("Parent and child 1 are in the same process group")
+	}
+
+	if cpid1 != cpgrp1 {
+		t.Fatalf("Child 1's process group is not its process ID")
+	}
+
+	cmd2 := create(t)
+
+	cmd2.proc.SysProcAttr = &syscall.SysProcAttr{
+		Setpgid: true,
+		Pgid:    cpgrp1,
+	}
+	cmd2.Start()
+	defer cmd2.Stop()
+
+	cpid2, cpgrp2 := cmd2.Info()
+
+	if cpid2 == ppid {
+		t.Fatalf("Parent and child 2 have the same process ID")
+	}
+
+	if cpgrp2 == ppgrp {
+		t.Fatalf("Parent and child 2 are in the same process group")
+	}
+
+	if cpid2 == cpgrp2 {
+		t.Fatalf("Child 2's process group is its process ID")
+	}
+
+	if cpid1 == cpid2 {
+		t.Fatalf("Child 1 and 2 have the same process ID")
+	}
+
+	if cpgrp1 != cpgrp2 {
+		t.Fatalf("Child 1 and 2 are not in the same process group")
+	}
+}
+
+func TestForeground(t *testing.T) {
+	signal.Ignore(syscall.SIGTTIN, syscall.SIGTTOU)
+	defer signal.Reset()
+
+	tty, err := os.OpenFile("/dev/tty", os.O_RDWR, 0)
+	if err != nil {
+		t.Skipf("Can't test Foreground. Couldn't open /dev/tty: %s", err)
+	}
+	defer tty.Close()
+
+	// This should really be pid_t, however _C_int (aka int32) is generally
+	// equivalent.
+	fpgrp := int32(0)
+
+	errno := syscall.IoctlPtr(tty.Fd(), syscall.TIOCGPGRP, unsafe.Pointer(&fpgrp))
+	if errno != 0 {
+		t.Fatalf("TIOCGPGRP failed with error code: %s", errno)
+	}
+
+	if fpgrp == 0 {
+		t.Fatalf("Foreground process group is zero")
+	}
+
+	ppid, ppgrp := parent()
+
+	cmd := create(t)
+
+	cmd.proc.SysProcAttr = &syscall.SysProcAttr{
+		Ctty:       int(tty.Fd()),
+		Foreground: true,
+	}
+	cmd.Start()
+
+	cpid, cpgrp := cmd.Info()
+
+	if cpid == ppid {
+		t.Fatalf("Parent and child have the same process ID")
+	}
+
+	if cpgrp == ppgrp {
+		t.Fatalf("Parent and child are in the same process group")
+	}
+
+	if cpid != cpgrp {
+		t.Fatalf("Child's process group is not the child's process ID")
+	}
+
+	cmd.Stop()
+
+	// This call fails on darwin/arm64. The failure doesn't matter, though.
+	// This is just best effort.
+	syscall.IoctlPtr(tty.Fd(), syscall.TIOCSPGRP, unsafe.Pointer(&fpgrp))
+}
+
+func TestForegroundSignal(t *testing.T) {
+	tty, err := os.OpenFile("/dev/tty", os.O_RDWR, 0)
+	if err != nil {
+		t.Skipf("couldn't open /dev/tty: %s", err)
+	}
+	defer tty.Close()
+
+	// This should really be pid_t, however _C_int (aka int32) is generally
+	// equivalent.
+	fpgrp := int32(0)
+
+	errno := syscall.IoctlPtr(tty.Fd(), syscall.TIOCGPGRP, unsafe.Pointer(&fpgrp))
+	if errno != 0 {
+		t.Fatalf("TIOCGPGRP failed with error code: %s", errno)
+	}
+
+	if fpgrp == 0 {
+		t.Fatalf("Foreground process group is zero")
+	}
+
+	defer func() {
+		signal.Ignore(syscall.SIGTTIN, syscall.SIGTTOU)
+		syscall.IoctlPtr(tty.Fd(), syscall.TIOCSPGRP, unsafe.Pointer(&fpgrp))
+		signal.Reset()
+	}()
+
+	ch1 := make(chan os.Signal, 1)
+	ch2 := make(chan bool)
+
+	signal.Notify(ch1, syscall.SIGTTIN, syscall.SIGTTOU)
+	defer signal.Stop(ch1)
+
+	cmd := create(t)
+
+	go func() {
+		cmd.proc.SysProcAttr = &syscall.SysProcAttr{
+			Ctty:       int(tty.Fd()),
+			Foreground: true,
+		}
+		cmd.Start()
+		cmd.Stop()
+		close(ch2)
+	}()
+
+	timer := time.NewTimer(30 * time.Second)
+	defer timer.Stop()
+	for {
+		select {
+		case sig := <-ch1:
+			t.Errorf("unexpected signal %v", sig)
+		case <-ch2:
+			// Success.
+			return
+		case <-timer.C:
+			t.Fatal("timed out waiting for child process")
+		}
+	}
+}
+
+// Test a couple of cases that SysProcAttr can't handle. Issue 29458.
+func TestInvalidExec(t *testing.T) {
+	t.Parallel()
+	t.Run("SetCtty-Foreground", func(t *testing.T) {
+		t.Parallel()
+		cmd := create(t)
+		cmd.proc.SysProcAttr = &syscall.SysProcAttr{
+			Setctty:    true,
+			Foreground: true,
+			Ctty:       0,
+		}
+		if err := cmd.proc.Start(); err == nil {
+			t.Error("expected error setting both SetCtty and Foreground")
+		}
+	})
+	t.Run("invalid-Ctty", func(t *testing.T) {
+		t.Parallel()
+		cmd := create(t)
+		cmd.proc.SysProcAttr = &syscall.SysProcAttr{
+			Setctty: true,
+			Ctty:    3,
+		}
+		if err := cmd.proc.Start(); err == nil {
+			t.Error("expected error with invalid Ctty value")
+		}
+	})
+}
+
+// TestExec is for issue #41702.
+func TestExec(t *testing.T) {
+	testenv.MustHaveExec(t)
+	cmd := exec.Command(os.Args[0], "-test.run=TestExecHelper")
+	cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=2")
+	o, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Errorf("%s\n%v", o, err)
+	}
+}
+
+// TestExecHelper is used by TestExec. It does nothing by itself.
+// In testing on macOS 10.14, this used to fail with
+// "signal: illegal instruction" more than half the time.
+func TestExecHelper(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "2" {
+		return
+	}
+
+	// We don't have to worry about restoring these values.
+	// We are in a child process that only runs this test,
+	// and we are going to call syscall.Exec anyhow.
+	os.Setenv("GO_WANT_HELPER_PROCESS", "3")
+
+	stop := time.Now().Add(time.Second)
+	for i := 0; i < 100; i++ {
+		go func(i int) {
+			r := rand.New(rand.NewSource(int64(i)))
+			for time.Now().Before(stop) {
+				r.Uint64()
+			}
+		}(i)
+	}
+
+	time.Sleep(10 * time.Millisecond)
+
+	argv := []string{os.Args[0], "-test.run=TestExecHelper"}
+	syscall.Exec(os.Args[0], argv, os.Environ())
+
+	t.Error("syscall.Exec returned")
+}
+
+// Test that rlimit values are restored by exec.
+func TestRlimitRestored(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "" {
+		fmt.Println(syscall.OrigRlimitNofile().Cur)
+		os.Exit(0)
+	}
+
+	orig := syscall.OrigRlimitNofile()
+	if orig.Cur == 0 {
+		t.Skip("skipping test because rlimit not adjusted at startup")
+	}
+
+	executable, err := os.Executable()
+	if err != nil {
+		executable = os.Args[0]
+	}
+
+	cmd := testenv.Command(t, executable, "-test.run=TestRlimitRestored")
+	cmd = testenv.CleanCmdEnv(cmd)
+	cmd.Env = append(cmd.Env, "GO_WANT_HELPER_PROCESS=1")
+
+	out, err := cmd.CombinedOutput()
+	if len(out) > 0 {
+		t.Logf("%s", out)
+	}
+	if err != nil {
+		t.Fatalf("subprocess failed: %v", err)
+	}
+	s := string(bytes.TrimSpace(out))
+	v, err := strconv.ParseUint(s, 10, 64)
+	if err != nil {
+		t.Fatalf("could not parse %q as number: %v", s, v)
+	}
+
+	if v != uint64(orig.Cur) {
+		t.Errorf("exec rlimit = %d, want %d", v, orig)
+	}
+}
+
+func TestForkExecNilArgv(t *testing.T) {
+	defer func() {
+		if p := recover(); p != nil {
+			t.Fatal("forkExec panicked")
+		}
+	}()
+
+	// We don't really care what the result of forkExec is, just that it doesn't
+	// panic, so we choose something we know won't actually spawn a process (probably).
+	syscall.ForkExec("/dev/null", nil, nil)
+}