Module Name: src
Committed By: riastradh
Date: Sun Dec 19 12:31:34 UTC 2021
Modified Files:
src/sys/external/bsd/drm2/linux: linux_dma_resv.c
Log Message:
drm: Implement drm_resv_get_fences_rcu with null fencep.
To generate a diff of this commit:
cvs rdiff -u -r1.16 -r1.17 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:1.16 src/sys/external/bsd/drm2/linux/linux_dma_resv.c:1.17
--- src/sys/external/bsd/drm2/linux/linux_dma_resv.c:1.16 Sun Dec 19 12:26:39 2021
+++ src/sys/external/bsd/drm2/linux/linux_dma_resv.c Sun Dec 19 12:31:34 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: linux_dma_resv.c,v 1.16 2021/12/19 12:26:39 riastradh Exp $ */
+/* $NetBSD: linux_dma_resv.c,v 1.17 2021/12/19 12:31:34 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 1.16 2021/12/19 12:26:39 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_dma_resv.c,v 1.17 2021/12/19 12:31:34 riastradh Exp $");
#include <sys/param.h>
#include <sys/poll.h>
@@ -745,6 +745,8 @@ dma_resv_get_excl_rcu(const struct dma_r
* Get a snapshot of the exclusive and shared fences of robj. The
* shared fences are returned as a pointer *sharedp to an array,
* to be freed by the caller with kfree, of *nsharedp elements.
+ * If fencep is null, then add the exclusive fence, if any, at the
+ * end of the array instead.
*
* Returns zero on success, negative (Linux-style) error code on
* failure. On failure, *fencep, *nsharedp, and *sharedp are
@@ -771,13 +773,24 @@ top: KASSERT(fence == NULL);
goto restart;
if (list != NULL) {
+ /*
+ * Avoid arithmetic overflow with `+ 1' below.
+ * Strictly speaking we don't need this if the caller
+ * specified fencep or if there is no exclusive fence,
+ * but it is simpler to not have to consider those
+ * cases.
+ */
+ KASSERT(shared_count <= list->shared_max);
+ if (list->shared_max == UINT_MAX)
+ return -ENOMEM;
+
/* Check whether we have a buffer. */
if (shared == NULL) {
/*
* We don't have a buffer yet. Try to allocate
* one without waiting.
*/
- shared_alloc = list->shared_max;
+ shared_alloc = list->shared_max + 1;
shared = kcalloc(shared_alloc, sizeof(shared[0]),
GFP_NOWAIT);
if (shared == NULL) {
@@ -793,13 +806,13 @@ top: KASSERT(fence == NULL);
return -ENOMEM;
goto top;
}
- } else if (shared_alloc < list->shared_max) {
+ } else if (shared_alloc < list->shared_max + 1) {
/*
* We have a buffer but it's too small. We're
* already racing in this case, so just back
* out and wait to allocate a bigger one.
*/
- shared_alloc = list->shared_max;
+ shared_alloc = list->shared_max + 1;
rcu_read_unlock();
kfree(shared);
shared = kcalloc(shared_alloc, sizeof(shared[0]),
@@ -838,7 +851,12 @@ top: KASSERT(fence == NULL);
/* Success! */
rcu_read_unlock();
- *fencep = fence;
+ if (fencep) {
+ *fencep = fence;
+ } else if (fence) {
+ KASSERT(shared_count < UINT_MAX);
+ shared[shared_count++] = fence;
+ }
*nsharedp = shared_count;
*sharedp = shared;
return 0;
