drm/etnaviv: reap idle mapping if it doesn't match the softpin address

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>
This commit is contained in:
Lucas Stach
2022-07-14 12:31:43 +02:00
committed by Han Gao/Revy/Rabenda
parent f87b29df53
commit 51464f6592

View File

@@ -269,7 +269,12 @@ 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);