Zero sized buffer objects tend to make various bits of the GEM infrastructure complain:
WARNING: CPU: 1 PID: 2323 at drivers/gpu/drm/drm_mm.c:389 drm_mm_insert_node_generic+0x258/0x2f0 Modules linked in:
CPU: 1 PID: 2323 Comm: drm-api-test Tainted: G W 4.9.0-rc4-00906-g693af44 #213 Hardware name: Qualcomm Technologies, Inc. DB820c (DT) task: ffff8000d7353400 task.stack: ffff8000d7720000 PC is at drm_mm_insert_node_generic+0x258/0x2f0 LR is at drm_vma_offset_add+0x4c/0x70
Zero sized buffers serve no appreciable value to the user so disallow them at create time.
Signed-off-by: Jordan Crouse jcrouse@codeaurora.org --- drivers/gpu/drm/msm/msm_gem.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 4c3e6ef..e819b83 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -874,6 +874,12 @@ struct drm_gem_object *msm_gem_new(struct drm_device *dev,
size = PAGE_ALIGN(size);
+ /* Disallow zero sized objects as they make the underlying + * infrastructure grumpy + */ + if (size == 0) + return ERR_PTR(-EINVAL); + ret = msm_gem_new_impl(dev, size, flags, NULL, &obj); if (ret) goto fail;