internal/outcome/shim: check full behaviour

This took significant effort to stub out, and achieves full coverage after c5aefe5e9d.

Signed-off-by: Ophestra <cat@gensokyo.uk>

3 files changed, 424 insertions, 31 deletions

diff --git a/internal/outcome/dispatcher_test.go b/internal/outcome/dispatcher_test.go
index e01946c1..96822fa7 100644
--- a/internal/outcome/dispatcher_test.go
+++ b/internal/outcome/dispatcher_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"io"
 	"io/fs"
 	"log"
@@ -193,8 +194,8 @@ func checkOpBehaviour(t *testing.T, testCases []opBehaviourTestCase) {
 			}
 
 			wantConfig := tc.newConfig()
-			k := &kstub{panicDispatcher{}, stub.New(t,
-				func(s *stub.Stub[syscallDispatcher]) syscallDispatcher { return &kstub{panicDispatcher{}, s} },
+			k := &kstub{nil, nil, panicDispatcher{}, stub.New(t,
+				func(s *stub.Stub[syscallDispatcher]) syscallDispatcher { return &kstub{nil, nil, panicDispatcher{}, s} },
 				stub.Expect{Calls: wantCallsFull},
 			)}
 			defer stub.HandleExit(t)
@@ -297,7 +298,12 @@ func checkSimple(t *testing.T, fname string, testCases []simpleTestCase) {
 			t.Parallel()
 
 			defer stub.HandleExit(t)
-			k := &kstub{panicDispatcher{}, stub.New(t, func(s *stub.Stub[syscallDispatcher]) syscallDispatcher { return &kstub{panicDispatcher{}, s} }, tc.want)}
+
+			uNotifyContext, uShimReader := make(chan struct{}), make(chan struct{})
+			k := &kstub{uNotifyContext, uShimReader, panicDispatcher{},
+				stub.New(t, func(s *stub.Stub[syscallDispatcher]) syscallDispatcher {
+					return &kstub{uNotifyContext, uShimReader, panicDispatcher{}, s}
+				}, tc.want)}
 			if err := tc.f(k); !reflect.DeepEqual(err, tc.wantErr) {
 				t.Errorf("%s: error = %#v, want %#v", fname, err, tc.wantErr)
 			}
@@ -312,6 +318,11 @@ func checkSimple(t *testing.T, fname string, testCases []simpleTestCase) {
 
 // kstub partially implements syscallDispatcher via [stub.Stub].
 type kstub struct {
+	// notifyContext blocks on unblockNotifyContext if provided with a kstub.Stub track.
+	unblockNotifyContext chan struct{}
+	// stubTrackReader blocks on unblockShimReader if unblocking notifyContext.
+	unblockShimReader chan struct{}
+
 	panicDispatcher
 	*stub.Stub[syscallDispatcher]
 }
@@ -354,6 +365,19 @@ func (k *kstub) readdir(name string) ([]os.DirEntry, error) {
 		stub.CheckArg(k.Stub, "name", name, 0))
 }
 func (k *kstub) tempdir() string { k.Helper(); return k.Expects("tempdir").Ret.(string) }
+func (k *kstub) exit(code int) {
+	k.Helper()
+	expect := k.Expects("exit")
+
+	if errors.Is(expect.Err, unblockNotifyContext) {
+		close(k.unblockNotifyContext)
+	}
+
+	if !stub.CheckArg(k.Stub, "code", code, 0) {
+		k.FailNow()
+	}
+	panic(expect.Ret.(int))
+}
 func (k *kstub) evalSymlinks(path string) (string, error) {
 	k.Helper()
 	expect := k.Expects("evalSymlinks")
@@ -388,16 +412,17 @@ func (k *kstub) receive(key string, e any, fdp *uintptr) (closeFunc func() error
 
 func (k *kstub) expectCheckContainer(expect *stub.Call, z *container.Container) error {
 	k.Helper()
-	err := expect.Error(
-		stub.CheckArgReflect(k.Stub, "params", &z.Params, 0))
-	if err != nil {
+	if !stub.CheckArgReflect(k.Stub, "params", &z.Params, 0) {
 		k.Errorf("params:\n%s\n%s", mustMarshal(&z.Params), mustMarshal(expect.Args[0]))
 	}
-	return err
+	return expect.Err
 }
 
 func (k *kstub) containerStart(z *container.Container) error {
 	k.Helper()
+	if k.unblockShimReader != nil {
+		close(k.unblockShimReader)
+	}
 	return k.expectCheckContainer(k.Expects("containerStart"), z)
 }
 func (k *kstub) containerServe(z *container.Container) error {
@@ -428,12 +453,25 @@ func (k *kstub) cmdOutput(cmd *exec.Cmd) ([]byte, error) {
 
 func (k *kstub) notifyContext(parent context.Context, signals ...os.Signal) (ctx context.Context, stop context.CancelFunc) {
 	k.Helper()
-	if k.Expects("notifyContext").Error(
+	expect := k.Expects("notifyContext")
+
+	if expect.Error(
 		stub.CheckArgReflect(k.Stub, "parent", parent, 0),
 		stub.CheckArgReflect(k.Stub, "signals", signals, 1)) != nil {
 		k.FailNow()
 	}
-	return k.Context(), func() { k.Helper(); k.Expects("notifyContextStop") }
+
+	if sub, ok := expect.Ret.(int); ok && sub >= 0 {
+		subVal := reflect.ValueOf(k.Stub).Elem().FieldByName("sub")
+		ks := &kstub{nil, nil, panicDispatcher{}, reflect.
+			NewAt(subVal.Type(), unsafe.Pointer(subVal.UnsafeAddr())).Elem().
+			Interface().([]*stub.Stub[syscallDispatcher])[sub]}
+
+		<-k.unblockNotifyContext
+		return k.Context(), func() { k.Helper(); ks.Expects("notifyContextStop") }
+	}
+
+	return k.Context(), func() { panic("unexpected call to stop") }
 }
 
 func (k *kstub) mustHsuPath() *check.Absolute {
@@ -457,26 +495,51 @@ type stubTrackReader struct {
 	*kstub
 }
 
+// unblockNotifyContext is passed via call and must be handled by stubTrackReader.Read
+var unblockNotifyContext = errors.New("this error unblocks notifyContext and must not be returned")
+
 func (r *stubTrackReader) Read(p []byte) (n int, err error) {
 	r.subOnce.Do(func() {
 		subVal := reflect.ValueOf(r.kstub.Stub).Elem().FieldByName("sub")
-		r.kstub = &kstub{panicDispatcher{}, reflect.
+		r.kstub = &kstub{r.kstub.unblockNotifyContext, r.kstub.unblockShimReader, panicDispatcher{}, reflect.
 			NewAt(subVal.Type(), unsafe.Pointer(subVal.UnsafeAddr())).Elem().
 			Interface().([]*stub.Stub[syscallDispatcher])[r.sub]}
 	})
 
-	return r.kstub.Read(p)
+	n, err = r.kstub.Read(p)
+	if errors.Is(err, unblockNotifyContext) {
+		err = nil
+		close(r.unblockNotifyContext)
+		<-r.unblockShimReader
+	}
+	return n, err
 }
 
 func (k *kstub) setupContSignal(pid int) (io.ReadCloser, func(), error) {
 	k.Helper()
 	expect := k.Expects("setupContSignal")
-	return &stubTrackReader{sub: expect.Ret.(int), kstub: k}, func() { k.Expects("wKeepAlive") }, expect.Error(
+	return &stubTrackReader{sub: expect.Ret.(int), kstub: k}, func() { k.Helper(); k.Expects("wKeepAlive") }, expect.Error(
 		stub.CheckArg(k.Stub, "pid", pid, 0))
 }
 
 func (k *kstub) getMsg() message.Msg { k.Helper(); k.Expects("getMsg"); return k }
 
+func (k *kstub) fatal(v ...any) {
+	if k.Expects("fatal").Error(
+		stub.CheckArgReflect(k.Stub, "v", v, 0)) != nil {
+		k.FailNow()
+	}
+	panic(stub.PanicExit)
+}
+func (k *kstub) fatalf(format string, v ...any) {
+	if k.Expects("fatalf").Error(
+		stub.CheckArg(k.Stub, "format", format, 0),
+		stub.CheckArgReflect(k.Stub, "v", v, 1)) != nil {
+		k.FailNow()
+	}
+	panic(stub.PanicExit)
+}
+
 func (k *kstub) Close() error { k.Helper(); return k.Expects("rcClose").Err }
 func (k *kstub) Read(p []byte) (n int, err error) {
 	k.Helper()
diff --git a/internal/outcome/shim.go b/internal/outcome/shim.go
index a2dcb15e..1a83f8e2 100644
--- a/internal/outcome/shim.go
+++ b/internal/outcome/shim.go
@@ -93,7 +93,7 @@ func shimEntrypoint(k syscallDispatcher) {
 	}
 
 	if err := k.setDumpable(container.SUID_DUMP_DISABLE); err != nil {
-		k.fatalf("cannot set SUID_DUMP_DISABLE: %s", err)
+		k.fatalf("cannot set SUID_DUMP_DISABLE: %v", err)
 	}
 
 	var (
@@ -114,11 +114,8 @@ func shimEntrypoint(k syscallDispatcher) {
 		closeSetup = f
 
 		if err = state.populateLocal(k, msg); err != nil {
-			if m, ok := message.GetMessage(err); ok {
-				k.fatal(m)
-			} else {
-				k.fatalf("cannot populate local state: %v", err)
-			}
+			printMessageError(func(v ...any) { k.fatal(fmt.Sprintln(v...)) },
+				"cannot populate local state:", err)
 		}
 	}
 
@@ -138,7 +135,6 @@ func shimEntrypoint(k syscallDispatcher) {
 			k.fatalf("cannot set up exit request: %v", err)
 			return
 		}
-
 	} else {
 		defer wKeepAlive()
 		signalPipe = r
@@ -152,15 +148,12 @@ func shimEntrypoint(k syscallDispatcher) {
 	stateParams := state.newParams()
 	for _, op := range state.Shim.Ops {
 		if err := op.toContainer(stateParams); err != nil {
-			if m, ok := message.GetMessage(err); ok {
-				k.fatal(m)
-			} else {
-				k.fatalf("cannot create container state: %v", err)
-			}
+			printMessageError(func(v ...any) { k.fatal(fmt.Sprintln(v...)) },
+				"cannot create container state:", err)
 		}
 	}
-	if stateParams.params.Ops == nil { // unreachable
-		k.fatal("invalid container params")
+	if stateParams.params.Ops == nil { // only reachable with corrupted outcomeState
+		k.fatal("invalid container state")
 	}
 
 	// shim exit outcomes
@@ -226,7 +219,8 @@ func shimEntrypoint(k syscallDispatcher) {
 		k.exit(hst.ExitFailure)
 	}
 	if err := k.containerServe(z); err != nil {
-		printMessageError(func(v ...any) { k.fatal(fmt.Sprintln(v...)) }, "cannot configure container:", err)
+		printMessageError(func(v ...any) { k.fatal(fmt.Sprintln(v...)) },
+			"cannot configure container:", err)
 	}
 
 	if err := k.seccompLoad(
diff --git a/internal/outcome/shim_test.go b/internal/outcome/shim_test.go
index 046c22b6..9626b6cb 100644
--- a/internal/outcome/shim_test.go
+++ b/internal/outcome/shim_test.go
@@ -106,8 +106,8 @@ func TestShimEntrypoint(t *testing.T) {
 			Remount(fhs.AbsRoot, syscall.MS_RDONLY),
 	}
 
-	templateState := outcomeState{
-		Shim: &shimParams{PrivPID: 0xbad, WaitDelay: 0xf, Verbose: true, Ops: []outcomeOp{
+	newShimParams := func() *shimParams {
+		return &shimParams{PrivPID: 0xbad, WaitDelay: 0xf, Verbose: true, Ops: []outcomeOp{
 			&spParamsOp{"xterm-256color", true},
 			&spRuntimeOp{sessionTypeWayland},
 			spTmpdirOp{},
@@ -116,8 +116,11 @@ func TestShimEntrypoint(t *testing.T) {
 			&spPulseOp{(*[pulseCookieSizeMax]byte)(bytes.Repeat([]byte{0}, pulseCookieSizeMax)), pulseCookieSizeMax},
 			&spDBusOp{true},
 			&spFilesystemOp{},
-		}},
+		}}
+	}
 
+	templateState := outcomeState{
+		Shim:      newShimParams(),
 		ID:        &checkExpectInstanceId,
 		Identity:  hst.IdentityMax,
 		UserID:    10,
@@ -128,6 +131,333 @@ func TestShimEntrypoint(t *testing.T) {
 	}
 
 	checkSimple(t, "shimEntrypoint", []simpleTestCase{
+		{"dumpable", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, new(log.Logger), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, stub.UniqueError(11)),
+			call("fatalf", stub.ExpectArgs{"cannot set SUID_DUMP_DISABLE: %v", []any{stub.UniqueError(11)}}, nil, nil),
+		}}, nil},
+
+		{"receive fd", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", outcomeState{}, nil}, nil, syscall.EBADF),
+			call("fatal", stub.ExpectArgs{[]any{"invalid config descriptor"}}, nil, nil),
+		}}, nil},
+
+		{"receive env", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", outcomeState{}, nil}, nil, container.ErrReceiveEnv),
+			call("fatal", stub.ExpectArgs{[]any{"HAKUREI_SHIM not set"}}, nil, nil),
+		}}, nil},
+
+		{"receive strange", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", outcomeState{}, nil}, nil, stub.UniqueError(10)),
+			call("fatalf", stub.ExpectArgs{"cannot receive shim setup params: %v", []any{stub.UniqueError(10)}}, nil, nil),
+		}}, nil},
+
+		{"invalid state", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", func() outcomeState {
+				state := templateState
+				state.Shim = newShimParams()
+				state.Shim.PrivPID = 0
+				return state
+			}(), nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("fatal", stub.ExpectArgs{[]any{"impossible outcome state reached\n"}}, nil, nil),
+		}}, nil},
+
+		{"sigaction pipe", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, &os.SyscallError{Syscall: "pipe2", Err: stub.UniqueError(9)}),
+			call("fatal", stub.ExpectArgs{[]any{"pipe2: unique error 9 injected by the test suite"}}, nil, nil),
+		}}, nil},
+
+		{"sigaction cgo", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, syscall.ENOTRECOVERABLE),
+			call("fatalf", stub.ExpectArgs{"cannot install SIGCONT handler: %v", []any{syscall.ENOTRECOVERABLE}}, nil, nil),
+		}}, nil},
+
+		{"sigaction strange", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, stub.UniqueError(8)),
+			call("fatalf", stub.ExpectArgs{"cannot set up exit request: %v", []any{stub.UniqueError(8)}}, nil, nil),
+		}}, nil},
+
+		{"prctl", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, stub.UniqueError(7)),
+			call("fatalf", stub.ExpectArgs{"cannot set parent-death signal: %v", []any{stub.UniqueError(7)}}, nil, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}}, nil},
+
+		{"toContainer", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", func() outcomeState {
+				state := templateState
+				state.Shim = newShimParams()
+				state.Shim.Ops = []outcomeOp{errorOp(6)}
+				return state
+			}(), nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("fatal", stub.ExpectArgs{[]any{"cannot create container state: unique error 6 injected by the test suite\n"}}, nil, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}}, nil},
+
+		{"bad ops", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", func() outcomeState {
+				state := templateState
+				state.Shim = newShimParams()
+				state.Shim.Ops = nil
+				return state
+			}(), nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("fatal", stub.ExpectArgs{[]any{"invalid container state"}}, nil, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}}, nil},
+
+		{"start", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, stub.UniqueError(5)),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("verbose", stub.ExpectArgs{[]any{"cannot start container: unique error 5 injected by the test suite\n"}}, nil, nil),
+			call("exit", stub.ExpectArgs{hst.ExitFailure}, stub.PanicExit, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, nil, nil), // stub terminates this goroutine
+		}}}}, nil},
+
+		{"start logger signalread", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, stub.UniqueError(5)),
+			call("getLogger", stub.ExpectArgs{}, log.Default(), nil),
+			call("exit", stub.ExpectArgs{hst.ExitFailure}, stub.PanicExit, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, []byte{}, stub.UniqueError(4)),
+			call("fatalf", stub.ExpectArgs{"cannot read from signal pipe: %v", []any{stub.UniqueError(4)}}, nil, nil),
+		}}}}, nil},
+
+		{"serve", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
+			call("containerServe", stub.ExpectArgs{templateParams}, nil, stub.UniqueError(3)),
+			call("fatal", stub.ExpectArgs{[]any{"cannot configure container: unique error 3 injected by the test suite\n"}}, nil, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, nil, nil), // stub terminates this goroutine
+		}}}}, nil},
+
+		{"seccomp", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
+			call("containerServe", stub.ExpectArgs{templateParams}, nil, nil),
+			call("seccompLoad", stub.ExpectArgs{shimPreset, seccomp.AllowMultiarch}, nil, stub.UniqueError(2)),
+			call("fatalf", stub.ExpectArgs{"cannot load syscall filter: %v", []any{stub.UniqueError(2)}}, nil, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, nil, nil), // stub terminates this goroutine
+		}}}}, nil},
+
+		{"exited closesetup earlyrequested", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, stub.UniqueError(1)),
+			call("verbosef", stub.ExpectArgs{"cannot close setup pipe: %v", []any{stub.UniqueError(1)}}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, 0, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
+			call("containerServe", stub.ExpectArgs{templateParams}, nil, nil),
+			call("seccompLoad", stub.ExpectArgs{shimPreset, seccomp.AllowMultiarch}, nil, nil),
+			call("containerWait", stub.ExpectArgs{templateParams}, nil, makeExitError(1<<8)),
+			call("exit", stub.ExpectArgs{1}, stub.PanicExit, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, []byte{shimMsgExitRequested}, nil),
+			call("exit", stub.ExpectArgs{hst.ExitRequest}, stub.PanicExit, unblockNotifyContext),
+		}}}}, nil},
+
+		{"exited requested", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, 0, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
+			call("containerServe", stub.ExpectArgs{templateParams}, nil, nil),
+			call("seccompLoad", stub.ExpectArgs{shimPreset, seccomp.AllowMultiarch}, nil, nil),
+			call("containerWait", stub.ExpectArgs{templateParams}, nil, makeExitError(1<<8)),
+			call("exit", stub.ExpectArgs{1}, stub.PanicExit, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, []byte{shimMsgExitRequested}, unblockNotifyContext),
+			call("notifyContextStop", stub.ExpectArgs{}, nil, nil),
+			call("rcRead", stub.ExpectArgs{}, nil, nil), // stub terminates this goroutine
+		}}}}, nil},
+
+		{"canceled orphaned", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
+			call("containerServe", stub.ExpectArgs{templateParams}, nil, nil),
+			call("seccompLoad", stub.ExpectArgs{shimPreset, seccomp.AllowMultiarch}, nil, nil),
+			call("containerWait", stub.ExpectArgs{templateParams}, nil, context.Canceled),
+			call("exit", stub.ExpectArgs{hst.ExitCancel}, stub.PanicExit, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, []byte{shimMsgOrphaned}, nil),
+			call("exit", stub.ExpectArgs{hst.ExitOrphan}, stub.PanicExit, nil),
+		}}}}, nil},
+
+		{"strangewait invalidmsg", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
+			call("getMsg", stub.ExpectArgs{}, nil, nil),
+			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
+			call("setDumpable", stub.ExpectArgs{uintptr(container.SUID_DUMP_DISABLE)}, nil, nil),
+			call("receive", stub.ExpectArgs{"HAKUREI_SHIM", templateState, nil}, nil, nil),
+			call("swapVerbose", stub.ExpectArgs{true}, false, nil),
+			call("verbosef", stub.ExpectArgs{"process share directory at %q, runtime directory at %q", []any{m("/tmp/hakurei.10"), m("/run/user/1000/hakurei")}}, nil, nil),
+			call("setupContSignal", stub.ExpectArgs{0xbad}, 0, nil),
+			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
+			call("New", stub.ExpectArgs{}, nil, nil),
+			call("closeReceive", stub.ExpectArgs{}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
+			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
+			call("containerServe", stub.ExpectArgs{templateParams}, nil, nil),
+			call("seccompLoad", stub.ExpectArgs{shimPreset, seccomp.AllowMultiarch}, nil, nil),
+			call("containerWait", stub.ExpectArgs{templateParams}, nil, stub.UniqueError(0)),
+			call("verbosef", stub.ExpectArgs{"cannot wait: %v", []any{stub.UniqueError(0)}}, nil, nil),
+			call("exit", stub.ExpectArgs{127}, stub.PanicExit, nil),
+
+			// deferred
+			call("wKeepAlive", stub.ExpectArgs{}, nil, nil),
+		}, Tracks: []stub.Expect{{Calls: []stub.Call{
+			call("rcRead", stub.ExpectArgs{}, []byte{0xff}, nil),
+			call("fatalf", stub.ExpectArgs{"got invalid message %d from signal handler", []any{byte(0xff)}}, nil, nil),
+		}}}}, nil},
+
 		{"success", func(k *kstub) error { shimEntrypoint(k); return nil }, stub.Expect{Calls: []stub.Call{
 			call("getMsg", stub.ExpectArgs{}, nil, nil),
 			call("getLogger", stub.ExpectArgs{}, (*log.Logger)(nil), nil),
@@ -139,7 +469,7 @@ func TestShimEntrypoint(t *testing.T) {
 			call("prctl", stub.ExpectArgs{uintptr(syscall.PR_SET_PDEATHSIG), uintptr(syscall.SIGCONT), uintptr(0)}, nil, nil),
 			call("New", stub.ExpectArgs{}, nil, nil),
 			call("closeReceive", stub.ExpectArgs{}, nil, nil),
-			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, nil, nil),
+			call("notifyContext", stub.ExpectArgs{context.Background(), []os.Signal{os.Interrupt, syscall.SIGTERM}}, -1, nil),
 			call("containerStart", stub.ExpectArgs{templateParams}, nil, nil),
 			call("containerServe", stub.ExpectArgs{templateParams}, nil, nil),
 			call("seccompLoad", stub.ExpectArgs{shimPreset, seccomp.AllowMultiarch}, nil, nil),
@@ -156,3 +486,9 @@ func TestShimEntrypoint(t *testing.T) {
 		}}}}, nil},
 	})
 }
+
+// errorOp implements a noop outcomeOp that unconditionally returns [stub.UniqueError].
+type errorOp stub.UniqueError
+
+func (e errorOp) toSystem(*outcomeStateSys) error       { return stub.UniqueError(e) }
+func (e errorOp) toContainer(*outcomeStateParams) error { return stub.UniqueError(e) }