From 12cfb0c1c27e8699581388514513a92fabda5379 Mon Sep 17 00:00:00 2001
From: Lucas Stach <l.stach@pengutronix.de>
Date: Thu, 14 Jul 2022 12:31:43 +0200
Subject: [PATCH] drm/etnaviv: reap idle mapping if it doesn't match the
softpin address
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commit 332f847212e43d584019a8264895f25cf92aa647 upstream.
When a idle BO, which is held open by another process, gets freed by
userspace and subsequently referenced again by e.g. importing it again,
userspace may assign a different softpin VA than the last time around.
As the kernel GEM object still exists, we likely have a idle mapping
with the old VA still cached, if it hasn't been reaped in the meantime.
As the context matches, we then simply try to resurrect this mapping by
increasing the refcount. As the VA in this mapping does not match the
new softpin address, we consequently fail the otherwise valid submit.
Instead of failing, reap the idle mapping.
Cc: stable@vger.kernel.org # 5.19
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/etnaviv/etnaviv_gem.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index cc386f8a7116..5cf13e52f7c9 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -258,7 +258,12 @@ struct etnaviv_vram_mapping *etnaviv_gem_mapping_get(
if (mapping->use == 0) {
mutex_lock(&mmu_context->lock);
if (mapping->context == mmu_context)
- mapping->use += 1;
+ if (va && mapping->iova != va) {
+ etnaviv_iommu_reap_mapping(mapping);
+ mapping = NULL;
+ } else {
+ mapping->use += 1;
+ }
else
mapping = NULL;
mutex_unlock(&mmu_context->lock);