int/linux: add/use Exec

Drop the libcontainer/system/exec, and use the linux.Exec instead.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Author: kolyshkin

internal/linux/linux.go

@@ -6,6 +6,17 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+// Exec wraps [unix.Exec].
+func Exec(cmd string, args []string, env []string) error {
+	err := retryOnEINTR(func() error {
+		return unix.Exec(cmd, args, env)
+	})
+	if err != nil {
+		return &os.PathError{Op: "exec", Path: cmd, Err: err}
+	}
+	return nil
+}
+
 // Getwd wraps [unix.Getwd].
 func Getwd() (wd string, err error) {
 	wd, err = retryOnEINTR2(unix.Getwd)

libcontainer/setns_init_linux.go

@@ -10,6 +10,7 @@ import (
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
 
+	"github.com/opencontainers/runc/internal/linux"
 	"github.com/opencontainers/runc/libcontainer/apparmor"
 	"github.com/opencontainers/runc/libcontainer/keys"
 	"github.com/opencontainers/runc/libcontainer/seccomp"
@@ -156,5 +157,5 @@ func (l *linuxSetnsInit) Init() error {
 	if err := utils.UnsafeCloseFrom(l.config.PassedFilesCount + 3); err != nil {
 		return err
 	}
-	return system.Exec(name, l.config.Args, l.config.Env)
+	return linux.Exec(name, l.config.Args, l.config.Env)
 }

libcontainer/standard_init_linux.go

@@ -11,6 +11,7 @@ import (
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
 
+	"github.com/opencontainers/runc/internal/linux"
 	"github.com/opencontainers/runc/libcontainer/apparmor"
 	"github.com/opencontainers/runc/libcontainer/configs"
 	"github.com/opencontainers/runc/libcontainer/keys"
@@ -298,5 +299,5 @@ func (l *linuxStandardInit) Init() error {
 	if err := utils.UnsafeCloseFrom(l.config.PassedFilesCount + 3); err != nil {
 		return err
 	}
-	return system.Exec(name, l.config.Args, l.config.Env)
+	return linux.Exec(name, l.config.Args, l.config.Env)
 }

libcontainer/system/linux.go

@@ -32,15 +32,6 @@ func (p ParentDeathSignal) Set() error {
 	return SetParentDeathSignal(uintptr(p))
 }
 
-func Exec(cmd string, args []string, env []string) error {
-	for {
-		err := unix.Exec(cmd, args, env)
-		if err != unix.EINTR {
-			return &os.PathError{Op: "exec", Path: cmd, Err: err}
-		}
-	}
-}
-
 func SetParentDeathSignal(sig uintptr) error {
 	if err := unix.Prctl(unix.PR_SET_PDEATHSIG, sig, 0, 0, 0); err != nil {
 		return err