Module Name: src
Committed By: riastradh
Date: Thu Aug 23 01:10:36 UTC 2018
Modified Files:
src/sys/external/bsd/drm2/dist/drm/nouveau: nouveau_fence.c
Log Message:
Fix edge case of reference counting, oops.
PR kern/53441
XXX pullup-7
XXX pullup-8
To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 \
src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_fence.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_fence.c
diff -u src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_fence.c:1.8 src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_fence.c:1.9
--- src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_fence.c:1.8 Thu Aug 23 01:10:28 2018
+++ src/sys/external/bsd/drm2/dist/drm/nouveau/nouveau_fence.c Thu Aug 23 01:10:36 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: nouveau_fence.c,v 1.8 2018/08/23 01:10:28 riastradh Exp $ */
+/* $NetBSD: nouveau_fence.c,v 1.9 2018/08/23 01:10:36 riastradh Exp $ */
/*
* Copyright (C) 2007 Ben Skeggs.
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nouveau_fence.c,v 1.8 2018/08/23 01:10:28 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nouveau_fence.c,v 1.9 2018/08/23 01:10:36 riastradh Exp $");
#include <sys/types.h>
#include <sys/xcall.h>
@@ -136,7 +136,7 @@ nouveau_fence_channel_release(struct nou
do {
old = fctx->refcnt;
- if (old == 0) {
+ if (old == 1) {
spin_lock(&fctx->lock);
if (atomic_dec_uint_nv(&fctx->refcnt) == 0)
DRM_SPIN_WAKEUP_ALL(&fctx->waitqueue,
@@ -216,8 +216,10 @@ nouveau_fence_context_del(struct nouveau
/* Wait for nouveau_fence_channel_acquire to complete on all CPUs. */
xc_wait(xc_broadcast(0, nouveau_fence_context_del_xc, NULL, NULL));
- /* Wait for any references to drain. */
+ /* Release our reference and wait for any others to drain. */
spin_lock(&fctx->lock);
+ KASSERT(fctx->refcnt > 0);
+ atomic_dec_uint(&fctx->refcnt);
DRM_SPIN_WAIT_NOINTR_UNTIL(ret, &fctx->waitqueue, &fctx->lock,
fctx->refcnt == 0);
BUG_ON(ret);
@@ -247,7 +249,7 @@ nouveau_fence_context_new(struct nouveau
INIT_LIST_HEAD(&fctx->done);
spin_lock_init(&fctx->lock);
DRM_INIT_WAITQUEUE(&fctx->waitqueue, "nvfnchan");
- fctx->refcnt = 0;
+ fctx->refcnt = 1;
}
/*
