os: request appropriate access rights before calling windows TerminateProcess

Fixes #5615.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/9651047

src/pkg/os/exec_windows.go

@@ -42,13 +42,22 @@ func (p *Process) wait() (ps *ProcessState, err error) {
 	return &ProcessState{p.Pid, syscall.WaitStatus{ExitCode: ec}, &u}, nil
 }
 
+func terminateProcess(pid, exitcode int) error {
+	h, e := syscall.OpenProcess(syscall.PROCESS_TERMINATE, false, uint32(pid))
+	if e != nil {
+		return NewSyscallError("OpenProcess", e)
+	}
+	defer syscall.CloseHandle(h)
+	e = syscall.TerminateProcess(h, uint32(exitcode))
+	return NewSyscallError("TerminateProcess", e)
+}
+
 func (p *Process) signal(sig Signal) error {
 	if p.done() {
 		return errors.New("os: process already finished")
 	}
 	if sig == Kill {
-		e := syscall.TerminateProcess(syscall.Handle(p.handle), 1)
-		return NewSyscallError("TerminateProcess", e)
+		return terminateProcess(p.Pid, 1)
 	}
 	// TODO(rsc): Handle Interrupt too?
 	return syscall.Errno(syscall.EWINDOWS)

src/pkg/os/os_test.go

@@ -11,11 +11,13 @@ import (
 	"io"
 	"io/ioutil"
 	. "os"
+	osexec "os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"syscall"
 	"testing"
+	"text/template"
 	"time"
 )
 
@@ -1130,3 +1132,72 @@ func TestReadAtEOF(t *testing.T) {
 		t.Fatalf("ReadAt failed: %s", err)
 	}
 }
+
+func testKillProcess(t *testing.T, processKiller func(p *Process)) {
+	dir, err := ioutil.TempDir("", "go-build")
+	if err != nil {
+		t.Fatalf("Failed to create temp directory: %v", err)
+	}
+	defer RemoveAll(dir)
+
+	src := filepath.Join(dir, "main.go")
+	f, err := Create(src)
+	if err != nil {
+		t.Fatalf("Failed to create %v: %v", src, err)
+	}
+	st := template.Must(template.New("source").Parse(`
+package main
+import "time"
+func main() {
+	time.Sleep(time.Second)
+}
+`))
+	err = st.Execute(f, nil)
+	if err != nil {
+		f.Close()
+		t.Fatalf("Failed to execute template: %v", err)
+	}
+	f.Close()
+
+	exe := filepath.Join(dir, "main.exe")
+	output, err := osexec.Command("go", "build", "-o", exe, src).CombinedOutput()
+	if err != nil {
+		t.Fatalf("Failed to build exe %v: %v %v", exe, err, string(output))
+	}
+
+	cmd := osexec.Command(exe)
+	err = cmd.Start()
+	if err != nil {
+		t.Fatalf("Failed to start test process: %v", err)
+	}
+	go func() {
+		time.Sleep(100 * time.Millisecond)
+		processKiller(cmd.Process)
+	}()
+	err = cmd.Wait()
+	if err == nil {
+		t.Errorf("Test process succeeded, but expected to fail")
+	}
+}
+
+func TestKillStartProcess(t *testing.T) {
+	testKillProcess(t, func(p *Process) {
+		err := p.Kill()
+		if err != nil {
+			t.Fatalf("Failed to kill test process: %v", err)
+		}
+	})
+}
+
+func TestKillFindProcess(t *testing.T) {
+	testKillProcess(t, func(p *Process) {
+		p2, err := FindProcess(p.Pid)
+		if err != nil {
+			t.Fatalf("Failed to find test process: %v", err)
+		}
+		err = p2.Kill()
+		if err != nil {
+			t.Fatalf("Failed to kill test process: %v", err)
+		}
+	})
+}

src/pkg/syscall/ztypes_windows.go

@@ -151,6 +151,7 @@ const (
 	CREATE_NEW_PROCESS_GROUP   = 0x00000200
 	CREATE_UNICODE_ENVIRONMENT = 0x00000400
 
+	PROCESS_TERMINATE         = 1
 	PROCESS_QUERY_INFORMATION = 0x00000400
 	SYNCHRONIZE               = 0x00100000