Module Name: src
Committed By: riastradh
Date: Sun Dec 19 01:50:40 UTC 2021
Modified Files:
src/sys/external/bsd/drm2/linux: linux_dma_fence.c
Log Message:
Issue __insn_barrier in dma_fence_get_rcu.
This way it is safe to use as dma_fence_get_rcu(*p) when concurrent
writes to *p might be happening, so that we load *p only once before
using the value.
To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/sys/external/bsd/drm2/linux/linux_dma_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/linux/linux_dma_fence.c
diff -u src/sys/external/bsd/drm2/linux/linux_dma_fence.c:1.7 src/sys/external/bsd/drm2/linux/linux_dma_fence.c:1.8
--- src/sys/external/bsd/drm2/linux/linux_dma_fence.c:1.7 Sun Dec 19 01:48:22 2021
+++ src/sys/external/bsd/drm2/linux/linux_dma_fence.c Sun Dec 19 01:50:40 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_dma_fence.c,v 1.7 2021/12/19 01:48:22 riastradh Exp $ */
+/* $NetBSD: linux_dma_fence.c,v 1.8 2021/12/19 01:50:40 riastradh Exp $ */
/*-
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_dma_fence.c,v 1.7 2021/12/19 01:48:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_dma_fence.c,v 1.8 2021/12/19 01:50:40 riastradh Exp $");
#include <sys/atomic.h>
#include <sys/condvar.h>
@@ -196,6 +196,7 @@ struct dma_fence *
dma_fence_get_rcu(struct dma_fence *fence)
{
+ __insn_barrier();
if (!kref_get_unless_zero(&fence->refcount))
return NULL;
return fence;
