[PATCH v3] drm: Replace NULL with error value in drm_prime_pages_to_sg

From: Oleksandr Andrushchenko
Date: Thu Jul 19 2018 - 05:37:29 EST


From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Dan Carpenter has reported that there is the following static checker
warning:
drivers/gpu/drm/drm_prime.c:317 drm_gem_map_dma_buf()
warn: 'sgt' can also be NULL

314 sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
315
316 if (!IS_ERR(sgt)) {
317 if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,

Problematic functions are xen_drm_front_gem_get_sg_table and
drm_gem_cma_prime_get_sg_table. Fix those by replacing NULL with error value.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/gpu/drm/drm_gem_cma_helper.c | 4 ++--
drivers/gpu/drm/xen/xen_drm_front_gem.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 80a5115c3846..1d2ced882b66 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -436,7 +436,7 @@ struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj)

sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
if (!sgt)
- return NULL;
+ return ERR_PTR(-ENOMEM);

ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr,
cma_obj->paddr, obj->size);
@@ -447,7 +447,7 @@ struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj)

out:
kfree(sgt);
- return NULL;
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index c85bfe7571cb..47ff019d3aef 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -179,7 +179,7 @@ struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object *gem_obj)
struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);

if (!xen_obj->pages)
- return NULL;
+ return ERR_PTR(-ENOMEM);

return drm_prime_pages_to_sg(xen_obj->pages, xen_obj->num_pages);
}
--
2.18.0