libct: fix mips compilation

On MIPS arches, Rdev is uint32 so we have to convert it.

Fixes issue 4962.

Fixes: 8476df8 ("libct: add/use isDevNull, verifyDevNull")
Fixes: de87203 ("console: verify /dev/pts/ptmx before use")
Fixes: 398955b ("console: add fallback for pre-TIOCGPTPEER kernels")
Reported-by: Tianon Gravi <[email protected]>
Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

libcontainer/console_linux.go

@@ -33,9 +33,10 @@ func checkPtmxHandle(ptmx *os.File) error {
 		if stat.Ino != PTMX_INO {
 			return fmt.Errorf("ptmx handle has wrong inode number: %v", stat.Ino)
 		}
-		if stat.Mode&unix.S_IFMT != unix.S_IFCHR || stat.Rdev != unix.Mkdev(PTMX_MAJOR, PTMX_MINOR) {
+		rdev := uint64(stat.Rdev) //nolint:unconvert // Rdev is uint32 on MIPS.
+		if stat.Mode&unix.S_IFMT != unix.S_IFCHR || rdev != unix.Mkdev(PTMX_MAJOR, PTMX_MINOR) {
 			return fmt.Errorf("ptmx handle is not a real char ptmx device: ftype %#x %d:%d",
-				stat.Mode&unix.S_IFMT, unix.Major(stat.Rdev), unix.Minor(stat.Rdev))
+				stat.Mode&unix.S_IFMT, unix.Major(rdev), unix.Minor(rdev))
 		}
 		return nil
 	})
@@ -79,9 +80,10 @@ func getPtyPeer(pty console.Console, unsafePeerPath string, flags int) (*os.File
 		if statfs.Type != unix.DEVPTS_SUPER_MAGIC {
 			return fmt.Errorf("pty peer handle is not on a real devpts mount: super magic is %#x", statfs.Type)
 		}
-		if stat.Mode&unix.S_IFMT != unix.S_IFCHR || stat.Rdev != wantPeerDev {
+		rdev := uint64(stat.Rdev) //nolint:unconvert // Rdev is uint32 on MIPS.
+		if stat.Mode&unix.S_IFMT != unix.S_IFCHR || rdev != wantPeerDev {
 			return fmt.Errorf("pty peer handle is not the real char device for pty %d: ftype %#x %d:%d",
-				peerNum, stat.Mode&unix.S_IFMT, unix.Major(stat.Rdev), unix.Minor(stat.Rdev))
+				peerNum, stat.Mode&unix.S_IFMT, unix.Major(rdev), unix.Minor(rdev))
 		}
 		return nil
 	}); err != nil {

libcontainer/rootfs_linux.go

@@ -1044,10 +1044,10 @@ func mknodDevice(destDir *os.File, destName string, node *devices.Device) error
 				node.Type, node.Path,
 				stat.Mode&unix.S_IFMT, fileMode&unix.S_IFMT)
 		}
-		if stat.Rdev != dev {
+		if rdev := uint64(stat.Rdev); rdev != dev { //nolint:unconvert // Rdev is uint32 on MIPS.
 			return fmt.Errorf("new %c device inode %s has incorrect major:minor: %d:%d doesn't match expected %d:%d",
 				node.Type, node.Path,
-				unix.Major(stat.Rdev), unix.Minor(stat.Rdev),
+				unix.Major(rdev), unix.Minor(rdev),
 				unix.Major(dev), unix.Minor(dev))
 		}
 		return nil
@@ -1318,7 +1318,8 @@ func remountReadonly(m *configs.Mount) error {
 }
 
 func isDevNull(st *unix.Stat_t) bool {
-	return st.Mode&unix.S_IFMT == unix.S_IFCHR && st.Rdev == unix.Mkdev(1, 3)
+	//nolint:unconvert // Rdev is uint32 on MIPS.
+	return st.Mode&unix.S_IFMT == unix.S_IFCHR && uint64(st.Rdev) == unix.Mkdev(1, 3)
 }
 
 func verifyDevNull(f *os.File) error {