[src/trunk]: src/sys/dev/sbus Fix an issue with FIOCSCURSOR FB_CUR_SETCMAP on...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e029fe7e5c01
branches:  trunk
changeset: 997577:e029fe7e5c01
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Wed Mar 13 22:12:46 2019 +0000

description:
Fix an issue with FIOCSCURSOR FB_CUR_SETCMAP on zx described here:

    http://mail-index.netbsd.org/port-sparc/2019/02/11/msg002134.html

by replacing the fubyte() calls with copyin() into temporary buffers.

The other issue in zx_cursor_color() mentioned in that message will
be addressed separately.

diffstat:

 sys/dev/sbus/zx.c |  32 ++++++++++++++++++++------------
 1 files changed, 20 insertions(+), 12 deletions(-)

diffs (53 lines):

diff -r 55c1c6450f1b -r e029fe7e5c01 sys/dev/sbus/zx.c
--- a/sys/dev/sbus/zx.c Wed Mar 13 20:56:33 2019 +0000
+++ b/sys/dev/sbus/zx.c Wed Mar 13 22:12:46 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: zx.c,v 1.42 2018/09/03 16:29:33 riastradh Exp $        */
+/*     $NetBSD: zx.c,v 1.43 2019/03/13 22:12:46 thorpej Exp $  */
 
 /*
  *  Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -42,7 +42,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: zx.c,v 1.42 2018/09/03 16:29:33 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: zx.c,v 1.43 2019/03/13 22:12:46 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -475,16 +475,24 @@
                        if (cu->cmap.index > 2 ||
                            cu->cmap.count > 2 - cu->cmap.index)
                                return (EINVAL);
-                       for (i = 0; i < cu->cmap.count; i++) {
-                               if ((v = fubyte(&cu->cmap.red[i])) < 0)
-                                       return (EFAULT);
-                               sc->sc_curcmap[i + cu->cmap.index + 0] = v;
-                               if ((v = fubyte(&cu->cmap.green[i])) < 0)
-                                       return (EFAULT);
-                               sc->sc_curcmap[i + cu->cmap.index + 2] = v;
-                               if ((v = fubyte(&cu->cmap.blue[i])) < 0)
-                                       return (EFAULT);
-                               sc->sc_curcmap[i + cu->cmap.index + 4] = v;
+
+                       uint8_t red[2], green[2], blue[2];
+                       const u_int cnt = cu->cmap.count;
+
+                       if (cnt &&
+                           ((error = copyin(cu->cmap.red,   red,   cnt)) ||
+                            (error = copyin(cu->cmap.green, green, cnt)) ||
+                            (error = copyin(cu->cmap.blue,  blue,  cnt)))) {
+                               return error;
+                       }
+
+                       for (i = 0; i < cnt; i++) {
+                               sc->sc_curcmap[i + cu->cmap.index + 0] =
+                                   red[i];
+                               sc->sc_curcmap[i + cu->cmap.index + 2] =
+                                   green[i];
+                               sc->sc_curcmap[i + cu->cmap.index + 4] =
+                                   blue[i];
                        }
                        zx_cursor_color(sc);
                }