From: Lucas Stach <dev@lynxeye.de>
Date: Tue, 6 Jun 2017 09:17:08 +0200
Subject: drm/etnaviv: populate GEM objects on cpu_prep
Git-commit: 8cc47b3ea0822175deb8bf436e4c59a7f128ac30
Patch-mainline: v4.14-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

CPU prep is the point where we can reasonably return an error to userspace
when something goes wrong while populating the object. If we leave the
object unpopulated at this point, the allocation will happen in the
fault handler when userspace accesses the object through the mmap space,
where we don't have any other option than to OOM the system.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -413,6 +413,16 @@ int etnaviv_gem_cpu_prep(struct drm_gem_
 	bool write = !!(op & ETNA_PREP_WRITE);
 	int ret;
 
+	if (!etnaviv_obj->sgt) {
+		void *ret;
+
+		mutex_lock(&etnaviv_obj->lock);
+		ret = etnaviv_gem_get_pages(etnaviv_obj);
+		mutex_unlock(&etnaviv_obj->lock);
+		if (IS_ERR(ret))
+			return PTR_ERR(ret);
+	}
+
 	if (op & ETNA_PREP_NOSYNC) {
 		if (!reservation_object_test_signaled_rcu(etnaviv_obj->resv,
 							  write))
@@ -427,16 +437,6 @@ int etnaviv_gem_cpu_prep(struct drm_gem_
 	}
 
 	if (etnaviv_obj->flags & ETNA_BO_CACHED) {
-		if (!etnaviv_obj->sgt) {
-			void *ret;
-
-			mutex_lock(&etnaviv_obj->lock);
-			ret = etnaviv_gem_get_pages(etnaviv_obj);
-			mutex_unlock(&etnaviv_obj->lock);
-			if (IS_ERR(ret))
-				return PTR_ERR(ret);
-		}
-
 		dma_sync_sg_for_cpu(dev->dev, etnaviv_obj->sgt->sgl,
 				    etnaviv_obj->sgt->nents,
 				    etnaviv_op_to_dma_dir(op));