Author: marius
Date: Sun Dec 27 15:55:15 2015
New Revision: 292778
URL: https://svnweb.freebsd.org/changeset/base/292778
Log:
MFC: r286785, r291088, r291120
- Reformat x86 bounce buffer synchronization code to reduce indentation.
No functional change.
- Avoid a NULL pointer dereference in bounce_bus_dmamap_sync() when the
map has been created via bounce_bus_dmamem_alloc(). Even for coherent
DMA - which bus_dmamem_alloc(9) typically is used for -, calling of
bus_dmamap_sync(9) isn't optional. [1]
- Avoid a NULL pointer dereference in bounce_bus_dmamap_unload() when
the map has been created via bounce_bus_dmamem_alloc(). In that case
bus_dmamap_unload(9) typically isn't called during normal operation
but still should be during detach, cleanup from failed attach etc. [2]
PR: 188899 (non-original problem) [1]
Submitted by: yongari [2]
Modified:
stable/9/sys/x86/x86/busdma_machdep.c
Directory Properties:
stable/9/sys/ (props changed)
Modified: stable/9/sys/x86/x86/busdma_machdep.c
==============================================================================
--- stable/9/sys/x86/x86/busdma_machdep.c Sun Dec 27 15:37:07 2015
(r292777)
+++ stable/9/sys/x86/x86/busdma_machdep.c Sun Dec 27 15:55:15 2015
(r292778)
@@ -888,6 +888,9 @@ _bus_dmamap_unload(bus_dma_tag_t dmat, b
{
struct bounce_page *bpage;
+ if (map == NULL)
+ return;
+
while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
STAILQ_REMOVE_HEAD(&map->bpages, links);
free_bounce_page(dmat, bpage);
@@ -899,44 +902,43 @@ _bus_dmamap_sync(bus_dma_tag_t dmat, bus
{
struct bounce_page *bpage;
- if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
- /*
- * Handle data bouncing. We might also
- * want to add support for invalidating
- * the caches on broken hardware
- */
- CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
- "performing bounce", __func__, op, dmat, dmat->flags);
+ if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
+ return;
- if (op & BUS_DMASYNC_PREWRITE) {
- while (bpage != NULL) {
- if (bpage->datavaddr != 0)
- bcopy((void *)bpage->datavaddr,
- (void *)bpage->vaddr,
- bpage->datacount);
- else
- physcopyout(bpage->dataaddr,
- (void *)bpage->vaddr,
- bpage->datacount);
- bpage = STAILQ_NEXT(bpage, links);
+ /*
+ * Handle data bouncing. We might also want to add support for
+ * invalidating the caches on broken hardware.
+ */
+ CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
+ "performing bounce", __func__, op, dmat, dmat->flags);
+
+ if ((op & BUS_DMASYNC_PREWRITE) != 0) {
+ while (bpage != NULL) {
+ if (bpage->datavaddr != 0) {
+ bcopy((void *)bpage->datavaddr,
+ (void *)bpage->vaddr, bpage->datacount);
+ } else {
+ physcopyout(bpage->dataaddr,
+ (void *)bpage->vaddr, bpage->datacount);
}
- dmat->bounce_zone->total_bounced++;
+ bpage = STAILQ_NEXT(bpage, links);
}
+ dmat->bounce_zone->total_bounced++;
+ }
- if (op & BUS_DMASYNC_POSTREAD) {
- while (bpage != NULL) {
- if (bpage->datavaddr != 0)
- bcopy((void *)bpage->vaddr,
- (void *)bpage->datavaddr,
- bpage->datacount);
- else
- physcopyin((void *)bpage->vaddr,
- bpage->dataaddr,
- bpage->datacount);
- bpage = STAILQ_NEXT(bpage, links);
+ if ((op & BUS_DMASYNC_POSTREAD) != 0) {
+ while (bpage != NULL) {
+ if (bpage->datavaddr != 0) {
+ bcopy((void *)bpage->vaddr,
+ (void *)bpage->datavaddr,
+ bpage->datacount);
+ } else {
+ physcopyin((void *)bpage->vaddr,
+ bpage->dataaddr, bpage->datacount);
}
- dmat->bounce_zone->total_bounced++;
+ bpage = STAILQ_NEXT(bpage, links);
}
+ dmat->bounce_zone->total_bounced++;
}
}
@@ -955,12 +957,14 @@ SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_AN
static struct sysctl_ctx_list *
busdma_sysctl_tree(struct bounce_zone *bz)
{
+
return (&bz->sysctl_tree);
}
static struct sysctl_oid *
busdma_sysctl_tree_top(struct bounce_zone *bz)
{
+
return (bz->sysctl_tree_top);
}
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