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-rw-r--r--src/syscall/syscall_linux_test.go656
1 files changed, 656 insertions, 0 deletions
diff --git a/src/syscall/syscall_linux_test.go b/src/syscall/syscall_linux_test.go
new file mode 100644
index 0000000..1300fc0
--- /dev/null
+++ b/src/syscall/syscall_linux_test.go
@@ -0,0 +1,656 @@
+// 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.
+
+package syscall_test
+
+import (
+ "fmt"
+ "internal/testenv"
+ "io"
+ "io/fs"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "runtime"
+ "sort"
+ "strconv"
+ "strings"
+ "sync"
+ "syscall"
+ "testing"
+ "unsafe"
+)
+
+// chtmpdir changes the working directory to a new temporary directory and
+// provides a cleanup function. Used when PWD is read-only.
+func chtmpdir(t *testing.T) func() {
+ oldwd, err := os.Getwd()
+ if err != nil {
+ t.Fatalf("chtmpdir: %v", err)
+ }
+ d, err := os.MkdirTemp("", "test")
+ if err != nil {
+ t.Fatalf("chtmpdir: %v", err)
+ }
+ if err := os.Chdir(d); err != nil {
+ t.Fatalf("chtmpdir: %v", err)
+ }
+ return func() {
+ if err := os.Chdir(oldwd); err != nil {
+ t.Fatalf("chtmpdir: %v", err)
+ }
+ os.RemoveAll(d)
+ }
+}
+
+func touch(t *testing.T, name string) {
+ f, err := os.Create(name)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if err := f.Close(); err != nil {
+ t.Fatal(err)
+ }
+}
+
+const (
+ _AT_SYMLINK_NOFOLLOW = 0x100
+ _AT_FDCWD = -0x64
+ _AT_EACCESS = 0x200
+ _F_OK = 0
+ _R_OK = 4
+)
+
+func TestFaccessat(t *testing.T) {
+ defer chtmpdir(t)()
+ touch(t, "file1")
+
+ err := syscall.Faccessat(_AT_FDCWD, "file1", _R_OK, 0)
+ if err != nil {
+ t.Errorf("Faccessat: unexpected error: %v", err)
+ }
+
+ err = syscall.Faccessat(_AT_FDCWD, "file1", _R_OK, 2)
+ if err != syscall.EINVAL {
+ t.Errorf("Faccessat: unexpected error: %v, want EINVAL", err)
+ }
+
+ err = syscall.Faccessat(_AT_FDCWD, "file1", _R_OK, _AT_EACCESS)
+ if err != nil {
+ t.Errorf("Faccessat: unexpected error: %v", err)
+ }
+
+ err = os.Symlink("file1", "symlink1")
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ err = syscall.Faccessat(_AT_FDCWD, "symlink1", _R_OK, _AT_SYMLINK_NOFOLLOW)
+ if err != nil {
+ t.Errorf("Faccessat SYMLINK_NOFOLLOW: unexpected error %v", err)
+ }
+
+ // We can't really test _AT_SYMLINK_NOFOLLOW, because there
+ // doesn't seem to be any way to change the mode of a symlink.
+ // We don't test _AT_EACCESS because such tests are only
+ // meaningful if run as root.
+
+ err = syscall.Fchmodat(_AT_FDCWD, "file1", 0, 0)
+ if err != nil {
+ t.Errorf("Fchmodat: unexpected error %v", err)
+ }
+
+ err = syscall.Faccessat(_AT_FDCWD, "file1", _F_OK, _AT_SYMLINK_NOFOLLOW)
+ if err != nil {
+ t.Errorf("Faccessat: unexpected error: %v", err)
+ }
+
+ err = syscall.Faccessat(_AT_FDCWD, "file1", _R_OK, _AT_SYMLINK_NOFOLLOW)
+ if err != syscall.EACCES {
+ if syscall.Getuid() != 0 {
+ t.Errorf("Faccessat: unexpected error: %v, want EACCES", err)
+ }
+ }
+}
+
+func TestFchmodat(t *testing.T) {
+ defer chtmpdir(t)()
+
+ touch(t, "file1")
+ os.Symlink("file1", "symlink1")
+
+ err := syscall.Fchmodat(_AT_FDCWD, "symlink1", 0444, 0)
+ if err != nil {
+ t.Fatalf("Fchmodat: unexpected error: %v", err)
+ }
+
+ fi, err := os.Stat("file1")
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ if fi.Mode() != 0444 {
+ t.Errorf("Fchmodat: failed to change mode: expected %v, got %v", 0444, fi.Mode())
+ }
+
+ err = syscall.Fchmodat(_AT_FDCWD, "symlink1", 0444, _AT_SYMLINK_NOFOLLOW)
+ if err != syscall.EOPNOTSUPP {
+ t.Fatalf("Fchmodat: unexpected error: %v, expected EOPNOTSUPP", err)
+ }
+}
+
+func TestMain(m *testing.M) {
+ if os.Getenv("GO_DEATHSIG_PARENT") == "1" {
+ deathSignalParent()
+ } else if os.Getenv("GO_DEATHSIG_CHILD") == "1" {
+ deathSignalChild()
+ } else if os.Getenv("GO_SYSCALL_NOERROR") == "1" {
+ syscallNoError()
+ }
+
+ os.Exit(m.Run())
+}
+
+func TestParseNetlinkMessage(t *testing.T) {
+ for i, b := range [][]byte{
+ {103, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 11, 0, 1, 0, 0, 0, 0, 5, 8, 0, 3,
+ 0, 8, 0, 6, 0, 0, 0, 0, 1, 63, 0, 10, 0, 69, 16, 0, 59, 39, 82, 64, 0, 64, 6, 21, 89, 127, 0, 0,
+ 1, 127, 0, 0, 1, 230, 228, 31, 144, 32, 186, 155, 211, 185, 151, 209, 179, 128, 24, 1, 86,
+ 53, 119, 0, 0, 1, 1, 8, 10, 0, 17, 234, 12, 0, 17, 189, 126, 107, 106, 108, 107, 106, 13, 10,
+ },
+ {106, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 11, 0, 1, 0, 0, 0, 0, 3, 8, 0, 3,
+ 0, 8, 0, 6, 0, 0, 0, 0, 1, 66, 0, 10, 0, 69, 0, 0, 62, 230, 255, 64, 0, 64, 6, 85, 184, 127, 0, 0,
+ 1, 127, 0, 0, 1, 237, 206, 31, 144, 73, 197, 128, 65, 250, 60, 192, 97, 128, 24, 1, 86, 253, 21, 0,
+ 0, 1, 1, 8, 10, 0, 51, 106, 89, 0, 51, 102, 198, 108, 104, 106, 108, 107, 104, 108, 107, 104, 10,
+ },
+ {102, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 11, 0, 1, 0, 0, 0, 0, 1, 8, 0, 3, 0,
+ 8, 0, 6, 0, 0, 0, 0, 1, 62, 0, 10, 0, 69, 0, 0, 58, 231, 2, 64, 0, 64, 6, 85, 185, 127, 0, 0, 1, 127,
+ 0, 0, 1, 237, 206, 31, 144, 73, 197, 128, 86, 250, 60, 192, 97, 128, 24, 1, 86, 104, 64, 0, 0, 1, 1, 8,
+ 10, 0, 52, 198, 200, 0, 51, 135, 232, 101, 115, 97, 103, 103, 10,
+ },
+ } {
+ m, err := syscall.ParseNetlinkMessage(b)
+ if err != syscall.EINVAL {
+ t.Errorf("#%d: got %v; want EINVAL", i, err)
+ }
+ if m != nil {
+ t.Errorf("#%d: got %v; want nil", i, m)
+ }
+ }
+}
+
+func TestSyscallNoError(t *testing.T) {
+ // On Linux there are currently no syscalls which don't fail and return
+ // a value larger than 0xfffffffffffff001 so we could test RawSyscall
+ // vs. RawSyscallNoError on 64bit architectures.
+ if unsafe.Sizeof(uintptr(0)) != 4 {
+ t.Skip("skipping on non-32bit architecture")
+ }
+
+ // See https://golang.org/issue/35422
+ // On MIPS, Linux returns whether the syscall had an error in a separate
+ // register (R7), not using a negative return value as on other
+ // architectures.
+ if runtime.GOARCH == "mips" || runtime.GOARCH == "mipsle" {
+ t.Skipf("skipping on %s", runtime.GOARCH)
+ }
+
+ if os.Getuid() != 0 {
+ t.Skip("skipping root only test")
+ }
+ if testing.Short() && testenv.Builder() != "" && os.Getenv("USER") == "swarming" {
+ // The Go build system's swarming user is known not to be root.
+ // Unfortunately, it sometimes appears as root due the current
+ // implementation of a no-network check using 'unshare -n -r'.
+ // Since this test does need root to work, we need to skip it.
+ t.Skip("skipping root only test on a non-root builder")
+ }
+
+ if runtime.GOOS == "android" {
+ t.Skip("skipping on rooted android, see issue 27364")
+ }
+
+ // Copy the test binary to a location that a non-root user can read/execute
+ // after we drop privileges
+ tempDir, err := os.MkdirTemp("", "TestSyscallNoError")
+ if err != nil {
+ t.Fatalf("cannot create temporary directory: %v", err)
+ }
+ defer os.RemoveAll(tempDir)
+ os.Chmod(tempDir, 0755)
+
+ tmpBinary := filepath.Join(tempDir, filepath.Base(os.Args[0]))
+
+ src, err := os.Open(os.Args[0])
+ if err != nil {
+ t.Fatalf("cannot open binary %q, %v", os.Args[0], err)
+ }
+ defer src.Close()
+
+ dst, err := os.OpenFile(tmpBinary, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
+ if err != nil {
+ t.Fatalf("cannot create temporary binary %q, %v", tmpBinary, err)
+ }
+ if _, err := io.Copy(dst, src); err != nil {
+ t.Fatalf("failed to copy test binary to %q, %v", tmpBinary, err)
+ }
+ err = dst.Close()
+ if err != nil {
+ t.Fatalf("failed to close test binary %q, %v", tmpBinary, err)
+ }
+
+ uid := uint32(0xfffffffe)
+ err = os.Chown(tmpBinary, int(uid), -1)
+ if err != nil {
+ t.Fatalf("failed to chown test binary %q, %v", tmpBinary, err)
+ }
+
+ err = os.Chmod(tmpBinary, 0755|fs.ModeSetuid)
+ if err != nil {
+ t.Fatalf("failed to set setuid bit on test binary %q, %v", tmpBinary, err)
+ }
+
+ cmd := exec.Command(tmpBinary)
+ cmd.Env = append(os.Environ(), "GO_SYSCALL_NOERROR=1")
+
+ out, err := cmd.CombinedOutput()
+ if err != nil {
+ t.Fatalf("failed to start first child process: %v", err)
+ }
+
+ got := strings.TrimSpace(string(out))
+ want := strconv.FormatUint(uint64(uid)+1, 10) + " / " +
+ strconv.FormatUint(uint64(-uid), 10) + " / " +
+ strconv.FormatUint(uint64(uid), 10)
+ if got != want {
+ if filesystemIsNoSUID(tmpBinary) {
+ t.Skip("skipping test when temp dir is mounted nosuid")
+ }
+ // formatted so the values are aligned for easier comparison
+ t.Errorf("expected %s,\ngot %s", want, got)
+ }
+}
+
+// filesystemIsNoSUID reports whether the filesystem for the given
+// path is mounted nosuid.
+func filesystemIsNoSUID(path string) bool {
+ var st syscall.Statfs_t
+ if syscall.Statfs(path, &st) != nil {
+ return false
+ }
+ return st.Flags&syscall.MS_NOSUID != 0
+}
+
+func syscallNoError() {
+ // Test that the return value from SYS_GETEUID32 (which cannot fail)
+ // doesn't get treated as an error (see https://golang.org/issue/22924)
+ euid1, _, e := syscall.RawSyscall(syscall.Sys_GETEUID, 0, 0, 0)
+ euid2, _ := syscall.RawSyscallNoError(syscall.Sys_GETEUID, 0, 0, 0)
+
+ fmt.Println(uintptr(euid1), "/", int(e), "/", uintptr(euid2))
+ os.Exit(0)
+}
+
+// reference uapi/linux/prctl.h
+const (
+ PR_GET_KEEPCAPS uintptr = 7
+ PR_SET_KEEPCAPS = 8
+)
+
+// TestAllThreadsSyscall tests that the go runtime can perform
+// syscalls that execute on all OSThreads - with which to support
+// POSIX semantics for security state changes.
+func TestAllThreadsSyscall(t *testing.T) {
+ if _, _, err := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, 0, 0); err == syscall.ENOTSUP {
+ t.Skip("AllThreadsSyscall disabled with cgo")
+ }
+
+ fns := []struct {
+ label string
+ fn func(uintptr) error
+ }{
+ {
+ label: "prctl<3-args>",
+ fn: func(v uintptr) error {
+ _, _, e := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, v, 0)
+ if e != 0 {
+ return e
+ }
+ return nil
+ },
+ },
+ {
+ label: "prctl<6-args>",
+ fn: func(v uintptr) error {
+ _, _, e := syscall.AllThreadsSyscall6(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, v, 0, 0, 0, 0)
+ if e != 0 {
+ return e
+ }
+ return nil
+ },
+ },
+ }
+
+ waiter := func(q <-chan uintptr, r chan<- uintptr, once bool) {
+ for x := range q {
+ runtime.LockOSThread()
+ v, _, e := syscall.Syscall(syscall.SYS_PRCTL, PR_GET_KEEPCAPS, 0, 0)
+ if e != 0 {
+ t.Errorf("tid=%d prctl(PR_GET_KEEPCAPS) failed: %v", syscall.Gettid(), e)
+ } else if x != v {
+ t.Errorf("tid=%d prctl(PR_GET_KEEPCAPS) mismatch: got=%d want=%d", syscall.Gettid(), v, x)
+ }
+ r <- v
+ if once {
+ break
+ }
+ runtime.UnlockOSThread()
+ }
+ }
+
+ // launches per fns member.
+ const launches = 11
+ question := make(chan uintptr)
+ response := make(chan uintptr)
+ defer close(question)
+
+ routines := 0
+ for i, v := range fns {
+ for j := 0; j < launches; j++ {
+ // Add another goroutine - the closest thing
+ // we can do to encourage more OS thread
+ // creation - while the test is running. The
+ // actual thread creation may or may not be
+ // needed, based on the number of available
+ // unlocked OS threads at the time waiter
+ // calls runtime.LockOSThread(), but the goal
+ // of doing this every time through the loop
+ // is to race thread creation with v.fn(want)
+ // being executed. Via the once boolean we
+ // also encourage one in 5 waiters to return
+ // locked after participating in only one
+ // question response sequence. This allows the
+ // test to race thread destruction too.
+ once := routines%5 == 4
+ go waiter(question, response, once)
+
+ // Keep a count of how many goroutines are
+ // going to participate in the
+ // question/response test. This will count up
+ // towards 2*launches minus the count of
+ // routines that have been invoked with
+ // once=true.
+ routines++
+
+ // Decide what value we want to set the
+ // process-shared KEEPCAPS. Note, there is
+ // an explicit repeat of 0 when we change the
+ // variant of the syscall being used.
+ want := uintptr(j & 1)
+
+ // Invoke the AllThreadsSyscall* variant.
+ if err := v.fn(want); err != nil {
+ t.Errorf("[%d,%d] %s(PR_SET_KEEPCAPS, %d, ...): %v", i, j, v.label, j&1, err)
+ }
+
+ // At this point, we want all launched Go
+ // routines to confirm that they see the
+ // wanted value for KEEPCAPS.
+ for k := 0; k < routines; k++ {
+ question <- want
+ }
+
+ // At this point, we should have a large
+ // number of locked OS threads all wanting to
+ // reply.
+ for k := 0; k < routines; k++ {
+ if got := <-response; got != want {
+ t.Errorf("[%d,%d,%d] waiter result got=%d, want=%d", i, j, k, got, want)
+ }
+ }
+
+ // Provide an explicit opportunity for this Go
+ // routine to change Ms.
+ runtime.Gosched()
+
+ if once {
+ // One waiter routine will have exited.
+ routines--
+ }
+
+ // Whatever M we are now running on, confirm
+ // we see the wanted value too.
+ if v, _, e := syscall.Syscall(syscall.SYS_PRCTL, PR_GET_KEEPCAPS, 0, 0); e != 0 {
+ t.Errorf("[%d,%d] prctl(PR_GET_KEEPCAPS) failed: %v", i, j, e)
+ } else if v != want {
+ t.Errorf("[%d,%d] prctl(PR_GET_KEEPCAPS) gave wrong value: got=%v, want=1", i, j, v)
+ }
+ }
+ }
+}
+
+// compareStatus is used to confirm the contents of the thread
+// specific status files match expectations.
+func compareStatus(filter, expect string) error {
+ expected := filter + expect
+ pid := syscall.Getpid()
+ fs, err := os.ReadDir(fmt.Sprintf("/proc/%d/task", pid))
+ if err != nil {
+ return fmt.Errorf("unable to find %d tasks: %v", pid, err)
+ }
+ expectedProc := fmt.Sprintf("Pid:\t%d", pid)
+ foundAThread := false
+ for _, f := range fs {
+ tf := fmt.Sprintf("/proc/%s/status", f.Name())
+ d, err := os.ReadFile(tf)
+ if err != nil {
+ // There are a surprising number of ways this
+ // can error out on linux. We've seen all of
+ // the following, so treat any error here as
+ // equivalent to the "process is gone":
+ // os.IsNotExist(err),
+ // "... : no such process",
+ // "... : bad file descriptor.
+ continue
+ }
+ lines := strings.Split(string(d), "\n")
+ for _, line := range lines {
+ // Different kernel vintages pad differently.
+ line = strings.TrimSpace(line)
+ if strings.HasPrefix(line, "Pid:\t") {
+ // On loaded systems, it is possible
+ // for a TID to be reused really
+ // quickly. As such, we need to
+ // validate that the thread status
+ // info we just read is a task of the
+ // same process PID as we are
+ // currently running, and not a
+ // recently terminated thread
+ // resurfaced in a different process.
+ if line != expectedProc {
+ break
+ }
+ // Fall through in the unlikely case
+ // that filter at some point is
+ // "Pid:\t".
+ }
+ if strings.HasPrefix(line, filter) {
+ if line == expected {
+ foundAThread = true
+ break
+ }
+ if filter == "Groups:" && strings.HasPrefix(line, "Groups:\t") {
+ // https://github.com/golang/go/issues/46145
+ // Containers don't reliably output this line in sorted order so manually sort and compare that.
+ a := strings.Split(line[8:], " ")
+ sort.Strings(a)
+ got := strings.Join(a, " ")
+ if got == expected[8:] {
+ foundAThread = true
+ break
+ }
+
+ }
+ return fmt.Errorf("%q got:%q want:%q (bad) [pid=%d file:'%s' %v]\n", tf, line, expected, pid, string(d), expectedProc)
+ }
+ }
+ }
+ if !foundAThread {
+ return fmt.Errorf("found no thread /proc/<TID>/status files for process %q", expectedProc)
+ }
+ return nil
+}
+
+// killAThread locks the goroutine to an OS thread and exits; this
+// causes an OS thread to terminate.
+func killAThread(c <-chan struct{}) {
+ runtime.LockOSThread()
+ <-c
+ return
+}
+
+// TestSetuidEtc performs tests on all of the wrapped system calls
+// that mirror to the 9 glibc syscalls with POSIX semantics. The test
+// here is considered authoritative and should compile and run
+// CGO_ENABLED=0 or 1. Note, there is an extended copy of this same
+// test in ../../misc/cgo/test/issue1435.go which requires
+// CGO_ENABLED=1 and launches pthreads from C that run concurrently
+// with the Go code of the test - and the test validates that these
+// pthreads are also kept in sync with the security state changed with
+// the syscalls. Care should be taken to mirror any enhancements to
+// this test here in that file too.
+func TestSetuidEtc(t *testing.T) {
+ if syscall.Getuid() != 0 {
+ t.Skip("skipping root only test")
+ }
+ if testing.Short() && testenv.Builder() != "" && os.Getenv("USER") == "swarming" {
+ // The Go build system's swarming user is known not to be root.
+ // Unfortunately, it sometimes appears as root due the current
+ // implementation of a no-network check using 'unshare -n -r'.
+ // Since this test does need root to work, we need to skip it.
+ t.Skip("skipping root only test on a non-root builder")
+ }
+ if _, err := os.Stat("/etc/alpine-release"); err == nil {
+ t.Skip("skipping glibc test on alpine - go.dev/issue/19938")
+ }
+ vs := []struct {
+ call string
+ fn func() error
+ filter, expect string
+ }{
+ {call: "Setegid(1)", fn: func() error { return syscall.Setegid(1) }, filter: "Gid:", expect: "\t0\t1\t0\t1"},
+ {call: "Setegid(0)", fn: func() error { return syscall.Setegid(0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"},
+
+ {call: "Seteuid(1)", fn: func() error { return syscall.Seteuid(1) }, filter: "Uid:", expect: "\t0\t1\t0\t1"},
+ {call: "Setuid(0)", fn: func() error { return syscall.Setuid(0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"},
+
+ {call: "Setgid(1)", fn: func() error { return syscall.Setgid(1) }, filter: "Gid:", expect: "\t1\t1\t1\t1"},
+ {call: "Setgid(0)", fn: func() error { return syscall.Setgid(0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"},
+
+ {call: "Setgroups([]int{0,1,2,3})", fn: func() error { return syscall.Setgroups([]int{0, 1, 2, 3}) }, filter: "Groups:", expect: "\t0 1 2 3"},
+ {call: "Setgroups(nil)", fn: func() error { return syscall.Setgroups(nil) }, filter: "Groups:", expect: ""},
+ {call: "Setgroups([]int{0})", fn: func() error { return syscall.Setgroups([]int{0}) }, filter: "Groups:", expect: "\t0"},
+
+ {call: "Setregid(101,0)", fn: func() error { return syscall.Setregid(101, 0) }, filter: "Gid:", expect: "\t101\t0\t0\t0"},
+ {call: "Setregid(0,102)", fn: func() error { return syscall.Setregid(0, 102) }, filter: "Gid:", expect: "\t0\t102\t102\t102"},
+ {call: "Setregid(0,0)", fn: func() error { return syscall.Setregid(0, 0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"},
+
+ {call: "Setreuid(1,0)", fn: func() error { return syscall.Setreuid(1, 0) }, filter: "Uid:", expect: "\t1\t0\t0\t0"},
+ {call: "Setreuid(0,2)", fn: func() error { return syscall.Setreuid(0, 2) }, filter: "Uid:", expect: "\t0\t2\t2\t2"},
+ {call: "Setreuid(0,0)", fn: func() error { return syscall.Setreuid(0, 0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"},
+
+ {call: "Setresgid(101,0,102)", fn: func() error { return syscall.Setresgid(101, 0, 102) }, filter: "Gid:", expect: "\t101\t0\t102\t0"},
+ {call: "Setresgid(0,102,101)", fn: func() error { return syscall.Setresgid(0, 102, 101) }, filter: "Gid:", expect: "\t0\t102\t101\t102"},
+ {call: "Setresgid(0,0,0)", fn: func() error { return syscall.Setresgid(0, 0, 0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"},
+
+ {call: "Setresuid(1,0,2)", fn: func() error { return syscall.Setresuid(1, 0, 2) }, filter: "Uid:", expect: "\t1\t0\t2\t0"},
+ {call: "Setresuid(0,2,1)", fn: func() error { return syscall.Setresuid(0, 2, 1) }, filter: "Uid:", expect: "\t0\t2\t1\t2"},
+ {call: "Setresuid(0,0,0)", fn: func() error { return syscall.Setresuid(0, 0, 0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"},
+ }
+
+ for i, v := range vs {
+ // Generate some thread churn as we execute the tests.
+ c := make(chan struct{})
+ go killAThread(c)
+ close(c)
+
+ if err := v.fn(); err != nil {
+ t.Errorf("[%d] %q failed: %v", i, v.call, err)
+ continue
+ }
+ if err := compareStatus(v.filter, v.expect); err != nil {
+ t.Errorf("[%d] %q comparison: %v", i, v.call, err)
+ }
+ }
+}
+
+// TestAllThreadsSyscallError verifies that errors are properly returned when
+// the syscall fails on the original thread.
+func TestAllThreadsSyscallError(t *testing.T) {
+ // SYS_CAPGET takes pointers as the first two arguments. Since we pass
+ // 0, we expect to get EFAULT back.
+ r1, r2, err := syscall.AllThreadsSyscall(syscall.SYS_CAPGET, 0, 0, 0)
+ if err == syscall.ENOTSUP {
+ t.Skip("AllThreadsSyscall disabled with cgo")
+ }
+ if err != syscall.EFAULT {
+ t.Errorf("AllThreadSyscall(SYS_CAPGET) got %d, %d, %v, want err %v", r1, r2, err, syscall.EFAULT)
+ }
+}
+
+// TestAllThreadsSyscallBlockedSyscall confirms that AllThreadsSyscall
+// can interrupt threads in long-running system calls. This test will
+// deadlock if this doesn't work correctly.
+func TestAllThreadsSyscallBlockedSyscall(t *testing.T) {
+ if _, _, err := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_KEEPCAPS, 0, 0); err == syscall.ENOTSUP {
+ t.Skip("AllThreadsSyscall disabled with cgo")
+ }
+
+ rd, wr, err := os.Pipe()
+ if err != nil {
+ t.Fatalf("unable to obtain a pipe: %v", err)
+ }
+
+ // Perform a blocking read on the pipe.
+ var wg sync.WaitGroup
+ ready := make(chan bool)
+ wg.Add(1)
+ go func() {
+ data := make([]byte, 1)
+
+ // To narrow the window we have to wait for this
+ // goroutine to block in read, synchronize just before
+ // calling read.
+ ready <- true
+
+ // We use syscall.Read directly to avoid the poller.
+ // This will return when the write side is closed.
+ n, err := syscall.Read(int(rd.Fd()), data)
+ if !(n == 0 && err == nil) {
+ t.Errorf("expected read to return 0, got %d, %s", n, err)
+ }
+
+ // Clean up rd and also ensure rd stays reachable so
+ // it doesn't get closed by GC.
+ rd.Close()
+ wg.Done()
+ }()
+ <-ready
+
+ // Loop here to give the goroutine more time to block in read.
+ // Generally this will trigger on the first iteration anyway.
+ pid := syscall.Getpid()
+ for i := 0; i < 100; i++ {
+ if id, _, e := syscall.AllThreadsSyscall(syscall.SYS_GETPID, 0, 0, 0); e != 0 {
+ t.Errorf("[%d] getpid failed: %v", i, e)
+ } else if int(id) != pid {
+ t.Errorf("[%d] getpid got=%d, want=%d", i, id, pid)
+ }
+ // Provide an explicit opportunity for this goroutine
+ // to change Ms.
+ runtime.Gosched()
+ }
+ wr.Close()
+ wg.Wait()
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 15:07:51 +0000