Avoid segments greater than maxsegsz during map merging

Found with hints from kettenis@

Tested on Sun-Fire-V215.
Also tested on U2 and UltraBook IIe by miod@

ok miod@

diff --git a/sys/arch/sparc64/dev/iommu.c b/sys/arch/sparc64/dev/iommu.c
index 1e2c7c2..7730925 100644 (file)
--- a/sys/arch/sparc64/dev/iommu.c
+++ b/sys/arch/sparc64/dev/iommu.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: iommu.c,v 1.82 2021/05/16 15:10:19 deraadt Exp $      */
+/*     $OpenBSD: iommu.c,v 1.83 2023/10/18 14:24:29 jan Exp $  */
 /*     $NetBSD: iommu.c,v 1.47 2002/02/08 20:03:45 eeh Exp $   */
 
 /*
@@ -1143,7 +1143,8 @@ iommu_dvmamap_insert(bus_dma_tag_t t, bus_dmamap_t map,
         */
        if (i > 0) {
                seg = &map->dm_segs[i - 1];
-               if (sgstart == seg->ds_addr + seg->ds_len) {
+               if (sgstart == seg->ds_addr + seg->ds_len &&
+                   length + seg->ds_len <= map->_dm_maxsegsz) {
                        length += seg->ds_len;
                        sgstart = seg->ds_addr;
                        sgend = sgstart + length - 1;