} else {
cmd = exec.Command(os.Args[0], cs...)
}
-
- // Temporary code to try to resolve #25628.
- // TODO(iant): Remove this when we no longer need it.
- if runtime.GOARCH == "386" && runtime.GOOS == "linux" && testenv.Builder() != "" && len(s) == 1 && s[0] == "read3" {
- sctx := ctx
- if sctx == nil {
- sctx = context.Background()
- }
- cmd = exec.CommandContext(sctx, "/usr/bin/strace", append([]string{"-f", os.Args[0]}, cs...)...)
- }
-
cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
return cmd
}
return bytes.Count(lsof, []byte("\n")), lsof
}
-// basefds returns the number of expected file descriptors
-// to be present in a process at start.
-// stdin, stdout, stderr, epoll/kqueue, epoll/kqueue pipe, maybe testlog
-func basefds() uintptr {
- n := os.Stderr.Fd() + 1
- // The poll (epoll/kqueue) descriptor can be numerically
- // either between stderr and the testlog-fd, or after
- // testlog-fd.
- for poll.IsPollDescriptor(n) {
- n++
- }
- for _, arg := range os.Args {
- if strings.HasPrefix(arg, "-test.testlogfile=") {
- n++
- }
- }
- return n
-}
-
func TestExtraFilesFDShuffle(t *testing.T) {
t.Skip("flaky test; see https://golang.org/issue/5780")
switch runtime.GOOS {
}
testenv.MustHaveExec(t)
+ testenv.MustHaveGoBuild(t)
if runtime.GOOS == "windows" {
t.Skipf("skipping test on %q", runtime.GOOS)
t.Fatalf("Seek: %v", err)
}
+ tempdir := t.TempDir()
+ exe := filepath.Join(tempdir, "read3.exe")
+
+ c := exec.Command(testenv.GoToolPath(t), "build", "-o", exe, "read3.go")
+ // Build the test without cgo, so that C library functions don't
+ // open descriptors unexpectedly. See issue 25628.
+ c.Env = append(os.Environ(), "CGO_ENABLED=0")
+ if output, err := c.CombinedOutput(); err != nil {
+ t.Logf("go build -o %s read3.go\n%s", exe, output)
+ t.Fatalf("go build failed: %v", err)
+ }
+
// Use a deadline to try to get some output even if the program hangs.
ctx := context.Background()
if deadline, ok := t.Deadline(); ok {
ctx, cancel = context.WithDeadline(ctx, deadline)
defer cancel()
}
- c := helperCommandContext(t, ctx, "read3")
+
+ c = exec.CommandContext(ctx, exe)
var stdout, stderr bytes.Buffer
c.Stdout = &stdout
c.Stderr = &stderr
}
defer os.Exit(0)
- // Determine which command to use to display open files.
- ofcmd := "lsof"
- switch runtime.GOOS {
- case "dragonfly", "freebsd", "netbsd", "openbsd":
- ofcmd = "fstat"
- case "plan9":
- ofcmd = "/bin/cat"
- case "aix":
- ofcmd = "procfiles"
- }
-
args := os.Args
for len(args) > 0 {
if args[0] == "--" {
os.Exit(1)
}
os.Exit(0)
- case "read3": // read fd 3
- fd3 := os.NewFile(3, "fd3")
- bs, err := ioutil.ReadAll(fd3)
- if err != nil {
- fmt.Printf("ReadAll from fd 3: %v", err)
- os.Exit(1)
- }
- // Now verify that there are no other open fds.
- var files []*os.File
- for wantfd := basefds() + 1; wantfd <= 100; wantfd++ {
- if poll.IsPollDescriptor(wantfd) {
- continue
- }
- f, err := os.Open(os.Args[0])
- if err != nil {
- fmt.Printf("error opening file with expected fd %d: %v", wantfd, err)
- os.Exit(1)
- }
- if got := f.Fd(); got != wantfd {
- fmt.Printf("leaked parent file. fd = %d; want %d\n", got, wantfd)
- fdfile := fmt.Sprintf("/proc/self/fd/%d", wantfd)
- link, err := os.Readlink(fdfile)
- fmt.Printf("readlink(%q) = %q, %v\n", fdfile, link, err)
- var args []string
- switch runtime.GOOS {
- case "plan9":
- args = []string{fmt.Sprintf("/proc/%d/fd", os.Getpid())}
- case "aix":
- args = []string{fmt.Sprint(os.Getpid())}
- default:
- args = []string{"-p", fmt.Sprint(os.Getpid())}
- }
- cmd := exec.Command(ofcmd, args...)
- out, err := cmd.CombinedOutput()
- if err != nil {
- fmt.Fprintf(os.Stderr, "%s failed: %v\n", strings.Join(cmd.Args, " "), err)
- }
- fmt.Printf("%s", out)
- os.Exit(1)
- }
- files = append(files, f)
- }
- for _, f := range files {
- f.Close()
- }
- // Referring to fd3 here ensures that it is not
- // garbage collected, and therefore closed, while
- // executing the wantfd loop above. It doesn't matter
- // what we do with fd3 as long as we refer to it;
- // closing it is the easy choice.
- fd3.Close()
- os.Stdout.Write(bs)
case "exit":
n, _ := strconv.Atoi(args[0])
os.Exit(n)
--- /dev/null
+// Copyright 2020 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.
+
+// +build ignore
+
+// This is a test program that verifies that it can read from
+// descriptor 3 and that no other descriptors are open.
+// This is not done via TestHelperProcess and GO_WANT_HELPER_PROCESS
+// because we want to ensure that this program does not use cgo,
+// because C libraries can open file descriptors behind our backs
+// and confuse the test. See issue 25628.
+package main
+
+import (
+ "fmt"
+ "internal/poll"
+ "io/ioutil"
+ "os"
+ "os/exec"
+ "runtime"
+ "strings"
+)
+
+func main() {
+ fd3 := os.NewFile(3, "fd3")
+ bs, err := ioutil.ReadAll(fd3)
+ if err != nil {
+ fmt.Printf("ReadAll from fd 3: %v\n", err)
+ os.Exit(1)
+ }
+
+ // Now verify that there are no other open fds.
+ // stdin == 0
+ // stdout == 1
+ // stderr == 2
+ // descriptor from parent == 3
+ // All descriptors 4 and up should be available,
+ // except for any used by the network poller.
+ var files []*os.File
+ for wantfd := uintptr(4); wantfd <= 100; wantfd++ {
+ if poll.IsPollDescriptor(wantfd) {
+ continue
+ }
+ f, err := os.Open(os.Args[0])
+ if err != nil {
+ fmt.Printf("error opening file with expected fd %d: %v", wantfd, err)
+ os.Exit(1)
+ }
+ if got := f.Fd(); got != wantfd {
+ fmt.Printf("leaked parent file. fd = %d; want %d\n", got, wantfd)
+ fdfile := fmt.Sprintf("/proc/self/fd/%d", wantfd)
+ link, err := os.Readlink(fdfile)
+ fmt.Printf("readlink(%q) = %q, %v\n", fdfile, link, err)
+ var args []string
+ switch runtime.GOOS {
+ case "plan9":
+ args = []string{fmt.Sprintf("/proc/%d/fd", os.Getpid())}
+ case "aix":
+ args = []string{fmt.Sprint(os.Getpid())}
+ default:
+ args = []string{"-p", fmt.Sprint(os.Getpid())}
+ }
+
+ // Determine which command to use to display open files.
+ ofcmd := "lsof"
+ switch runtime.GOOS {
+ case "dragonfly", "freebsd", "netbsd", "openbsd":
+ ofcmd = "fstat"
+ case "plan9":
+ ofcmd = "/bin/cat"
+ case "aix":
+ ofcmd = "procfiles"
+ }
+
+ cmd := exec.Command(ofcmd, args...)
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "%s failed: %v\n", strings.Join(cmd.Args, " "), err)
+ }
+ fmt.Printf("%s", out)
+ os.Exit(1)
+ }
+ files = append(files, f)
+ }
+
+ for _, f := range files {
+ f.Close()
+ }
+
+ // Referring to fd3 here ensures that it is not
+ // garbage collected, and therefore closed, while
+ // executing the wantfd loop above. It doesn't matter
+ // what we do with fd3 as long as we refer to it;
+ // closing it is the easy choice.
+ fd3.Close()
+
+ os.Stdout.Write(bs)
+}