initialise the state kept between calls to dmamap_load_buffer to 0. there

was an extremely small chance that random stack garbage coudl be used which
could corrupt a dmamap.

this is the same as the change made to amd64 in
src/sys/arch/amd64/amd64/bus_dma.c r1.10.

ok miod@ kettenis@

diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 95bd7c2..63811f1 100644 (file)
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: machdep.c,v 1.434 2008/07/07 13:41:59 jsg Exp $       */
+/*     $OpenBSD: machdep.c,v 1.435 2008/07/11 03:03:07 dlg Exp $       */
 /*     $NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $    */
 
 /*-
@@ -3731,7 +3731,7 @@ int
 _bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
     bus_size_t buflen, struct proc *p, int flags)
 {
-       bus_addr_t lastaddr;
+       bus_addr_t lastaddr = 0;
        int seg, error;
 
        /*
@@ -3760,7 +3760,7 @@ int
 _bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
     int flags)
 {
-       paddr_t lastaddr;
+       paddr_t lastaddr = 0;
        int seg, error, first;
        struct mbuf *m;
 
@@ -3802,7 +3802,7 @@ int
 _bus_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio,
     int flags)
 {
-       paddr_t lastaddr;
+       paddr_t lastaddr = 0;
        int seg, i, error, first;
        bus_size_t minlen, resid;
        struct proc *p = NULL;