From 94eb1e10a34d3c7fc42208faaa4954fe482ac091 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 12 Jul 2019 09:03:13 +0100
Subject: dma-buf: Expand reservation_list to fill allocation
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Git-commit: 94eb1e10a34d3c7fc42208faaa4954fe482ac091
Patch-mainline: v5.4-rc1
References: bsc#1152472
Since kmalloc() will round up the allocation to the next slab size or
page, it will normally return a pointer to a memory block bigger than we
asked for. We can query for the actual size of the allocated block using
ksize() and expand our variable size reservation_list to take advantage
of that extra space.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian König <christian.koenig@amd.com>
Cc: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712080314.21018-1-chris@chris-wilson.co.uk
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/dma-buf/reservation.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index a6ac2b3a0185..80ecc1283d15 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -153,7 +153,9 @@ int reservation_object_reserve_shared(struct reservation_object *obj,
RCU_INIT_POINTER(new->shared[j++], fence);
}
new->shared_count = j;
- new->shared_max = max;
+ new->shared_max =
+ (ksize(new) - offsetof(typeof(*new), shared)) /
+ sizeof(*new->shared);
preempt_disable();
write_seqcount_begin(&obj->seq);
@@ -169,7 +171,7 @@ int reservation_object_reserve_shared(struct reservation_object *obj,
return 0;
/* Drop the references to the signaled fences */
- for (i = k; i < new->shared_max; ++i) {
+ for (i = k; i < max; ++i) {
struct dma_fence *fence;
fence = rcu_dereference_protected(new->shared[i],
--
2.28.0