pkg/ipc: create default config based on target

Pass actual target to DefaultConfig, that's what we really want,
not the stray ipc flag.

pkg/ipc/ipc.go

@@ -12,7 +12,6 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"runtime"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -68,7 +67,6 @@ var (
 	flagAbortSignal = flag.Int("abort_signal", 0, "initial signal to send to executor"+
 		" in error conditions; upgrades to SIGKILL if executor does not exit")
 	flagBufferSize = flag.Uint64("buffer_size", 0, "internal buffer size (in bytes) for executor output")
-	flagIPC        = flag.String("ipc", "", "ipc scheme (pipe/shmem)")
 )
 
 type ExecOpts struct {
@@ -103,7 +101,7 @@ type Config struct {
 	BufferSize uint64
 }
 
-func DefaultConfig() (*Config, *ExecOpts, error) {
+func DefaultConfig(target *prog.Target) (*Config, *ExecOpts, error) {
 	c := &Config{
 		Executor:    *flagExecutor,
 		Timeout:     *flagTimeout,
@@ -126,22 +124,13 @@ func DefaultConfig() (*Config, *ExecOpts, error) {
 		return nil, nil, fmt.Errorf("flag sandbox must contain one of none/setuid/namespace")
 	}
 
-	sysTarget := targets.Get(runtime.GOOS, runtime.GOARCH)
+	sysTarget := targets.Get(target.OS, target.Arch)
 	if sysTarget.ExecutorUsesShmem {
 		c.Flags |= FlagUseShmem
 	}
 	if sysTarget.ExecutorUsesForkServer {
 		c.Flags |= FlagUseForkServer
 	}
-	switch *flagIPC {
-	case "":
-	case "pipe":
-		c.Flags &^= FlagUseShmem
-	case "shmem":
-		c.Flags |= FlagUseShmem
-	default:
-		return nil, nil, fmt.Errorf("unknown ipc scheme: %v", *flagIPC)
-	}
 
 	opts := &ExecOpts{
 		Flags: FlagDedupCover,

pkg/ipc/ipc_test.go

@@ -41,7 +41,7 @@ func initTest(t *testing.T) (*prog.Target, rand.Source, int, EnvFlags) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	cfg, _, err := DefaultConfig()
+	cfg, _, err := DefaultConfig(target)
 	if err != nil {
 		t.Fatal(err)
 	}

syz-fuzzer/fuzzer.go

@@ -94,6 +94,7 @@ func main() {
 
 	var (
 		flagName    = flag.String("name", "test", "unique name for manager")
+		flagOS      = flag.String("os", runtime.GOOS, "target OS")
 		flagArch    = flag.String("arch", runtime.GOARCH, "target arch")
 		flagManager = flag.String("manager", "", "manager rpc address")
 		flagProcs   = flag.Int("procs", 1, "number of parallel test processes")
@@ -118,12 +119,12 @@ func main() {
 	}
 	log.Logf(0, "fuzzer started")
 
-	target, err := prog.GetTarget(runtime.GOOS, *flagArch)
+	target, err := prog.GetTarget(*flagOS, *flagArch)
 	if err != nil {
 		log.Fatalf("%v", err)
 	}
 
-	config, execOpts, err := ipc.DefaultConfig()
+	config, execOpts, err := ipc.DefaultConfig(target)
 	if err != nil {
 		log.Fatalf("failed to create default ipc config: %v", err)
 	}

tools/syz-execprog/execprog.go

@@ -61,8 +61,7 @@ func main() {
 	if _, err = host.Setup(features); err != nil {
 		log.Fatalf("%v", err)
 	}
-
-	config, execOpts := createConfig(entries, features)
+	config, execOpts := createConfig(target, entries, features)
 
 	var wg sync.WaitGroup
 	wg.Add(*flagProcs)
@@ -206,8 +205,9 @@ func loadPrograms(target *prog.Target, files []string) []*prog.LogEntry {
 	return entries
 }
 
-func createConfig(entries []*prog.LogEntry, features *host.Features) (*ipc.Config, *ipc.ExecOpts) {
-	config, execOpts, err := ipc.DefaultConfig()
+func createConfig(target *prog.Target, entries []*prog.LogEntry, features *host.Features) (
+	*ipc.Config, *ipc.ExecOpts) {
+	config, execOpts, err := ipc.DefaultConfig(target)
 	if err != nil {
 		log.Fatalf("%v", err)
 	}

tools/syz-stress/stress.go

@@ -60,7 +60,7 @@ func main() {
 	prios := target.CalculatePriorities(corpus)
 	ct := target.BuildChoiceTable(prios, calls)
 
-	config, execOpts, err := ipc.DefaultConfig()
+	config, execOpts, err := ipc.DefaultConfig(target)
 	if err != nil {
 		log.Fatalf("%v", err)
 	}