[PATCH v2 3/3] drm/msm: Validate lazy VM in GEM_NEW

[Rob Clark <robin.clark@oss.qualcomm.com>]

Otherwise creating a _NO_SHARE BO before any BOs are mapped could cause
a NPE.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: b58e12a66e47 ("drm/msm: Add _NO_SHARE flag")
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_gem.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index efd3d3c9a449..733a094354e1 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -1147,7 +1147,12 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 
 	if (flags & MSM_BO_NO_SHARE) {
 		struct msm_context *ctx = file->driver_priv;
-		struct drm_gem_object *r_obj = drm_gpuvm_resv_obj(ctx->vm);
+		struct drm_gpuvm *vm = msm_context_vm(dev, ctx);
+
+		if (!vm)
+			return UERR(EINVAL, dev, "not supported with shared VM");
+
+		struct drm_gem_object *r_obj = drm_gpuvm_resv_obj(vm);
 
 		drm_gem_object_get(r_obj);
 
-- 
2.54.0