Module Name: src
Committed By: riastradh
Date: Sun Dec 19 12:33:42 UTC 2021
Modified Files:
src/sys/external/bsd/drm2/linux: linux_dma_resv.c
Log Message:
drm: Paranoia: handle fencep=null, fence!=null, and 0 shared.
Not sure this is possible but I don't know the API well enough to
prove it can't happen.
To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/sys/external/bsd/drm2/linux/linux_dma_resv.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_resv.c
diff -u src/sys/external/bsd/drm2/linux/linux_dma_resv.c:1.19 src/sys/external/bsd/drm2/linux/linux_dma_resv.c:1.20
--- src/sys/external/bsd/drm2/linux/linux_dma_resv.c:1.19 Sun Dec 19 12:33:34 2021
+++ src/sys/external/bsd/drm2/linux/linux_dma_resv.c Sun Dec 19 12:33:42 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_dma_resv.c,v 1.19 2021/12/19 12:33:34 riastradh Exp $ */
+/* $NetBSD: linux_dma_resv.c,v 1.20 2021/12/19 12:33:42 riastradh Exp $ */
/*-
* Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_dma_resv.c,v 1.19 2021/12/19 12:33:34 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_dma_resv.c,v 1.20 2021/12/19 12:33:42 riastradh Exp $");
#include <sys/param.h>
#include <sys/poll.h>
@@ -758,7 +758,7 @@ dma_resv_get_fences_rcu(const struct dma
const struct dma_resv_list *list = NULL;
struct dma_fence *fence = NULL;
struct dma_fence **shared = NULL;
- unsigned shared_alloc, shared_count, i;
+ unsigned shared_alloc = 0, shared_count, i;
struct dma_resv_read_ticket ticket;
top: KASSERT(fence == NULL);
@@ -851,11 +851,19 @@ top: KASSERT(fence == NULL);
/* Success! */
rcu_read_unlock();
+ KASSERT(shared_count <= shared_alloc);
+ KASSERT(shared_alloc == 0 || shared_count < shared_alloc);
+ KASSERT(shared_alloc <= UINT_MAX);
if (fencep) {
*fencep = fence;
} else if (fence) {
- KASSERT(shared_count < UINT_MAX);
- shared[shared_count++] = fence;
+ if (shared_count) {
+ shared[shared_count++] = fence;
+ } else {
+ shared = kmalloc(sizeof(shared[0]), GFP_KERNEL);
+ shared[0] = fence;
+ shared_count = 1;
+ }
}
*nsharedp = shared_count;
*sharedp = shared;
