From: Dave Airlie airlied@redhat.com
commit b30a43ac7132cdda833ac4b13dd1ebd35ace14b7 upstream.
There was a nouveau DDX that relied on legacy context ioctls to work, but we fixed it years ago, give distros that have a modern DDX the option to break the uAPI and close the mess of holes that legacy context support is.
Full context of the story:
commit 0e975980d435d58df2d430d688b8c18778b42218 Author: Peter Antoine peter.antoine@intel.com Date: Tue Jun 23 08:18:49 2015 +0100
drm: Turn off Legacy Context Functions
The context functions are not used by the i915 driver and should not be used by modeset drivers. These driver functions contain several bugs and security holes. This change makes these functions optional can be turned on by a setting, they are turned off by default for modeset driver with the exception of the nouvea driver that may require them with an old version of libdrm.
The previous attempt was
commit 7c510133d93dd6f15ca040733ba7b2891ed61fd1 Author: Daniel Vetter daniel.vetter@ffwll.ch Date: Thu Aug 8 15:41:21 2013 +0200
drm: mark context support as a legacy subsystem
but this had to be reverted
commit c21eb21cb50d58e7cbdcb8b9e7ff68b85cfa5095 Author: Dave Airlie airlied@redhat.com Date: Fri Sep 20 08:32:59 2013 +1000
Revert "drm: mark context support as a legacy subsystem"
v2: remove returns from void function, and formatting (Daniel Vetter)
v3: - s/Nova/nouveau/ in the commit message, and add references to the previous attempts - drop the part touching the drm hw lock, that should be a separate patch.
Signed-off-by: Peter Antoine peter.antoine@intel.com (v2) Cc: Peter Antoine peter.antoine@intel.com (v2) Reviewed-by: Peter Antoine peter.antoine@intel.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch
v2: move DRM_VM dependency into legacy config. v3: fix missing dep (kbuild robot)
Cc: stable@vger.kernel.org Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Dave Airlie airlied@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/nouveau/Kconfig | 13 ++++++++++++- drivers/gpu/drm/nouveau/nouveau_drm.c | 7 +++++-- 2 files changed, 17 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/nouveau/Kconfig +++ b/drivers/gpu/drm/nouveau/Kconfig @@ -16,10 +16,21 @@ config DRM_NOUVEAU select INPUT if ACPI && X86 select THERMAL if ACPI && X86 select ACPI_VIDEO if ACPI && X86 - select DRM_VM help Choose this option for open-source NVIDIA support.
+config NOUVEAU_LEGACY_CTX_SUPPORT + bool "Nouveau legacy context support" + depends on DRM_NOUVEAU + select DRM_VM + default y + help + There was a version of the nouveau DDX that relied on legacy + ctx ioctls not erroring out. But that was back in time a long + ways, so offer a way to disable it now. For uapi compat with + old nouveau ddx this should be on by default, but modern distros + should consider turning it off. + config NOUVEAU_PLATFORM_DRIVER bool "Nouveau (NVIDIA) SoC GPUs" depends on DRM_NOUVEAU && ARCH_TEGRA --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -967,8 +967,11 @@ nouveau_driver_fops = { static struct drm_driver driver_stub = { .driver_features = - DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER | - DRIVER_KMS_LEGACY_CONTEXT, + DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER +#if defined(CONFIG_NOUVEAU_LEGACY_CTX_SUPPORT) + | DRIVER_KMS_LEGACY_CONTEXT +#endif + ,
.load = nouveau_drm_load, .unload = nouveau_drm_unload,