comms/opencbm-kmod: Add error handling for copyin() and copyout() calls

This will be required soon as my intent is to annotate copyin() and
related functions with __result_use_check.  Moreover, the lack of error
handling here is a real bug.

The patch was submitted upstream as well.

PR:		275986
Approved by:	zirias
Differential Revision:	https://reviews.freebsd.org/D43273

comms/opencbm-kmod/Makefile

@@ -1,5 +1,6 @@
 PORTNAME=	opencbm-kmod
 PORTVERSION=	${OCBM_VERSION}
+PORTREVISION=	1
 CATEGORIES=	comms archivers
 
 MAINTAINER=	zirias@FreeBSD.org

comms/opencbm-kmod/files/patch-opencbm.c

@@ -0,0 +1,54 @@
+--- opencbm.c.orig	2022-01-22 22:01:25 UTC
++++ opencbm.c
+@@ -133,8 +133,6 @@ static struct cdevsw cbm_cdevsw = {
+     .d_name = CBM_NAME
+ };
+
+-static devclass_t cbm_devclass;
+-
+ /* forward references for parallel burst routines */
+ int cbm_parallel_burst_read_track(struct cbm_data *sc, device_t ppbus,
+         unsigned char *buffer);
+@@ -699,7 +697,7 @@ cbm_ioctl(struct cdev *dev, u_long cmd, caddr_t data, 
+                     break;
+                 }
+                 rv = !cbm_parallel_burst_read_track(sc, ppbus, sc->sc_buf);
+-                if (!rv) copyout(sc->sc_buf, val->buffer, BUFFER_SIZE);
++                if (!rv) rv = copyout(sc->sc_buf, val->buffer, BUFFER_SIZE);
+                 break;
+
+         case CBMCTRL_PARBURST_READ_TRACK_VAR:
+@@ -710,7 +708,7 @@ cbm_ioctl(struct cdev *dev, u_long cmd, caddr_t data, 
+                     break;
+                 }
+                 rv = !cbm_parallel_burst_read_track_var(sc, ppbus, sc->sc_buf);
+-                if (!rv) copyout(sc->sc_buf, val->buffer, BUFFER_SIZE);
++                if (!rv) rv = copyout(sc->sc_buf, val->buffer, BUFFER_SIZE);
+                 break;
+
+         case CBMCTRL_PARBURST_WRITE_TRACK:
+@@ -720,7 +718,9 @@ cbm_ioctl(struct cdev *dev, u_long cmd, caddr_t data, 
+                     rv = EINVAL;
+                     break;
+                 }
+-                copyin(val->buffer, sc->sc_buf, val->length);
++                rv = copyin(val->buffer, sc->sc_buf, val->length);
++                if (rv)
++                    break;
+                 rv = !cbm_parallel_burst_write_track(sc, ppbus,
+                         val->buffer, val->length);
+                 break;
+@@ -930,7 +930,13 @@ static driver_t cbm_driver = {
+     sizeof(struct cbm_data)
+ };
+
++#if __FreeBSD_version >= 1400058
++DRIVER_MODULE(cbm, ppbus, cbm_driver, 0, 0);
++#else
++static devclass_t cbm_devclass;
++
+ DRIVER_MODULE(cbm, ppbus, cbm_driver, cbm_devclass, 0, 0);
++#endif
+ MODULE_DEPEND(cbm, ppbus, 1, 1, 1);
+
+ /*