[syserr] Covert all linuxerr returns to error type.

Change the linuxerr.ErrorFromErrno to return an error type and not
a *errors.Error type. The latter results in problems comparing to nil
as <nil><nil> != <nil><*errors.Error>.

In a follow up, there will be a change to remove *errors.Error.Errno(),
which will also encourage users to not use Errnos to reference linuxerr.

PiperOrigin-RevId: 406444419

1 files changed, 2 insertions, 2 deletions

diff --git a/pkg/sentry/kernel/task_syscall.go b/pkg/sentry/kernel/task_syscall.go
index 2b1d7e114..2b85fe1ca 100644
--- a/pkg/sentry/kernel/task_syscall.go
+++ b/pkg/sentry/kernel/task_syscall.go
@@ -381,7 +381,7 @@ func ExtractErrno(err error, sysno int) int {
 	case unix.Errno:
 		return int(err)
 	case *errors.Error:
-		return int(err.Errno())
+		return int(linuxerr.ToUnix(err))
 	case *memmap.BusError:
 		// Bus errors may generate SIGBUS, but for syscalls they still
 		// return EFAULT. See case in task_run.go where the fault is
@@ -395,7 +395,7 @@ func ExtractErrno(err error, sysno int) int {
 		return ExtractErrno(err.Err, sysno)
 	default:
 		if errno, ok := linuxerr.TranslateError(err); ok {
-			return int(errno.Errno())
+			return int(linuxerr.ToUnix(errno))
 		}
 	}
 	panic(fmt.Sprintf("Unknown syscall %d error: %v", sysno, err))