Move ERESTART* error definitions to syserror package.

This is needed to avoid circular dependencies between the vfs and kernel
packages.

PiperOrigin-RevId: 327355524

1 files changed, 1 insertions, 68 deletions

diff --git a/pkg/sentry/kernel/task_syscall.go b/pkg/sentry/kernel/task_syscall.go
index a5903b0b5..2dbf86547 100644
--- a/pkg/sentry/kernel/task_syscall.go
+++ b/pkg/sentry/kernel/task_syscall.go
@@ -29,75 +29,8 @@ import (
 	"gvisor.dev/gvisor/pkg/usermem"
 )
 
-// SyscallRestartErrno represents a ERESTART* errno defined in the Linux's kernel
-// include/linux/errno.h. These errnos are never returned to userspace
-// directly, but are used to communicate the expected behavior of an
-// interrupted syscall from the syscall to signal handling.
-type SyscallRestartErrno int
-
-// These numeric values are significant because ptrace syscall exit tracing can
-// observe them.
-//
-// For all of the following errnos, if the syscall is not interrupted by a
-// signal delivered to a user handler, the syscall is restarted.
-const (
-	// ERESTARTSYS is returned by an interrupted syscall to indicate that it
-	// should be converted to EINTR if interrupted by a signal delivered to a
-	// user handler without SA_RESTART set, and restarted otherwise.
-	ERESTARTSYS = SyscallRestartErrno(512)
-
-	// ERESTARTNOINTR is returned by an interrupted syscall to indicate that it
-	// should always be restarted.
-	ERESTARTNOINTR = SyscallRestartErrno(513)
-
-	// ERESTARTNOHAND is returned by an interrupted syscall to indicate that it
-	// should be converted to EINTR if interrupted by a signal delivered to a
-	// user handler, and restarted otherwise.
-	ERESTARTNOHAND = SyscallRestartErrno(514)
-
-	// ERESTART_RESTARTBLOCK is returned by an interrupted syscall to indicate
-	// that it should be restarted using a custom function. The interrupted
-	// syscall must register a custom restart function by calling
-	// Task.SetRestartSyscallFn.
-	ERESTART_RESTARTBLOCK = SyscallRestartErrno(516)
-)
-
 var vsyscallCount = metric.MustCreateNewUint64Metric("/kernel/vsyscall_count", false /* sync */, "Number of times vsyscalls were invoked by the application")
 
-// Error implements error.Error.
-func (e SyscallRestartErrno) Error() string {
-	// Descriptions are borrowed from strace.
-	switch e {
-	case ERESTARTSYS:
-		return "to be restarted if SA_RESTART is set"
-	case ERESTARTNOINTR:
-		return "to be restarted"
-	case ERESTARTNOHAND:
-		return "to be restarted if no handler"
-	case ERESTART_RESTARTBLOCK:
-		return "interrupted by signal"
-	default:
-		return "(unknown interrupt error)"
-	}
-}
-
-// SyscallRestartErrnoFromReturn returns the SyscallRestartErrno represented by
-// rv, the value in a syscall return register.
-func SyscallRestartErrnoFromReturn(rv uintptr) (SyscallRestartErrno, bool) {
-	switch int(rv) {
-	case -int(ERESTARTSYS):
-		return ERESTARTSYS, true
-	case -int(ERESTARTNOINTR):
-		return ERESTARTNOINTR, true
-	case -int(ERESTARTNOHAND):
-		return ERESTARTNOHAND, true
-	case -int(ERESTART_RESTARTBLOCK):
-		return ERESTART_RESTARTBLOCK, true
-	default:
-		return 0, false
-	}
-}
-
 // SyscallRestartBlock represents the restart block for a syscall restartable
 // with a custom function. It encapsulates the state required to restart a
 // syscall across a S/R.
@@ -447,7 +380,7 @@ func ExtractErrno(err error, sysno int) int {
 		return 0
 	case syscall.Errno:
 		return int(err)
-	case SyscallRestartErrno:
+	case syserror.SyscallRestartErrno:
 		return int(err)
 	case *memmap.BusError:
 		// Bus errors may generate SIGBUS, but for syscalls they still