[src/trunk]: src/sys/dev/rasops Fix unaligned word write's to buffer, introdu...

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

details:   https://anonhg.NetBSD.org/src/rev/bc53bef2e579
branches:  trunk
changeset: 964467:bc53bef2e579
user:      rin <rin%NetBSD.org@localhost>
date:      Fri Aug 02 23:05:42 2019 +0000

description:
Fix unaligned word write's to buffer, introduced in rev 1.42:
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/dev/rasops/rasops24.c#rev1.42

diffstat:

 sys/dev/rasops/rasops24.c |  38 +++++++-------------------------------
 1 files changed, 7 insertions(+), 31 deletions(-)

diffs (74 lines):

diff -r f8f02ee5c586 -r bc53bef2e579 sys/dev/rasops/rasops24.c
--- a/sys/dev/rasops/rasops24.c Fri Aug 02 22:46:44 2019 +0000
+++ b/sys/dev/rasops/rasops24.c Fri Aug 02 23:05:42 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rasops24.c,v 1.44 2019/08/02 04:39:09 rin Exp $        */
+/*     $NetBSD: rasops24.c,v 1.45 2019/08/02 23:05:42 rin Exp $        */
 
 /*-
  * Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rasops24.c,v 1.44 2019/08/02 04:39:09 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rasops24.c,v 1.45 2019/08/02 23:05:42 rin Exp $");
 
 #include "opt_rasops.h"
 
@@ -276,8 +276,8 @@
 rasops24_erasecols(void *cookie, int row, int col, int num, long attr)
 {
        struct rasops_info *ri = (struct rasops_info *)cookie;
-       uint8_t *buf = (uint8_t *)ri->ri_buf;
-       int height, cnt, full, slop1, slop2, clr, stamp[3];
+       void *buf = ri->ri_buf;
+       int height, cnt, clr, stamp[3];
        uint32_t *dp;
        uint8_t *rp, *hp, *dbp;
 
@@ -319,33 +319,9 @@
        clr = ri->ri_devcmap[((uint32_t)attr >> 16) & 0xf] & 0xffffff;
        rasops24_makestamp1(ri, stamp, clr, clr, clr, clr);
 
-       /*
-        * The current byte offset mod 4 tells us the number of 24-bit pels
-        * we need to write for alignment to 32-bits. Once we're aligned on
-        * a 32-bit boundary, we're also aligned on a 4 pixel boundary, so
-        * the stamp does not need to be rotated. The following shows the
-        * layout of 4 pels in a 3 word region and illustrates this:
-        *
-        *      aaab bbcc cddd
-        */
-       slop1 = (uintptr_t)rp & 3;
-       cnt = slop1;
-       full = (num /* - cnt */) / 4;
-       cnt += full * 4;
-       slop2 = num - cnt;
-
-       /* Align to 4 bytes */
-       /* XXX handle with masks, bring under control of RI_BSWAP */
-       dbp = buf;
-       for (cnt = slop1; cnt; cnt--) {
-               *dbp++ = (clr >> 16);
-               *dbp++ = (clr >> 8);
-               *dbp++ =  clr;
-       }
-
        /* 4 pels per loop */
-       dp = (uint32_t *)dbp;
-       for (cnt = full; cnt; cnt--) {
+       dp = (uint32_t *)buf;
+       for (cnt = num >> 2; cnt; cnt--) {
                dp[0] = stamp[0];
                dp[1] = stamp[1];
                dp[2] = stamp[2];
@@ -355,7 +331,7 @@
        /* Trailing slop */
        /* XXX handle with masks, bring under control of RI_BSWAP */
        dbp = (uint8_t *)dp;
-       for (cnt = slop2; cnt; cnt--) {
+       for (cnt = num & 3; cnt; cnt--) {
                *dbp++ = (clr >> 16);
                *dbp++ = (clr >> 8);
                *dbp++ =  clr;