From 2667ab1954fcb89613a5e4ed23e1904af976be49 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon, 11 May 2020 11:35:47 +0200
Subject: drm/gem: WARN if drm_gem_get_pages is called on a private obj
Git-commit: e0b3d2140ec6f04335eb20f4651ca2b705084268
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
No real functional change, since this just converts an annoying Oops
into a more harmless WARNING backtrace. It's still a driver bug.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200511093554.211493-3-daniel.vetter@ffwll.ch
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/drm_gem.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 5e7231fc870b..48a6127b7424 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -548,6 +548,10 @@ static void drm_gem_check_release_pagevec(struct pagevec *pvec)
* set during initialization. If you have special zone constraints, set them
* after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care
* to keep pages in the required zone during swap-in.
+ *
+ * This function is only valid on objects initialized with
+ * drm_gem_object_init(), but not for those initialized with
+ * drm_gem_private_object_init() only.
*/
struct page **drm_gem_get_pages(struct drm_gem_object *obj)
{
@@ -556,6 +560,10 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj)
struct pagevec pvec;
int i, npages;
+
+ if (WARN_ON(!obj->filp))
+ return ERR_PTR(-EINVAL);
+
/* This is the shared memory object that backs the GEM resource */
mapping = obj->filp->f_mapping;
--
2.29.2