[PATCH 1/3] drm: Turn off Legacy Context Functions

Antoine, Peter peter.antoine at intel.com
Tue Jun 23 06:14:43 PDT 2015


On Tue, 2015-06-23 at 11:37 +0200, Daniel Vetter wrote:
> From: Peter Antoine <peter.antoine at intel.com>
> 
> 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 at 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 at 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 at intel.com> (v2)
> Cc: Peter Antoine <peter.antoine at intel.com> (v2)
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/drm_context.c         | 48 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_drv.c             | 13 ++++++----
>  drivers/gpu/drm/nouveau/nouveau_drm.c |  3 ++-
>  include/drm/drmP.h                    | 23 +++++++++--------
>  4 files changed, 70 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_context.c b/drivers/gpu/drm/drm_context.c
> index 9b23525c0ed0..32958dabd7b0 100644
> --- a/drivers/gpu/drm/drm_context.c
> +++ b/drivers/gpu/drm/drm_context.c
> @@ -53,6 +53,10 @@ struct drm_ctx_list {
>   */
>  void drm_legacy_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
>  {
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return;
> +
>  	mutex_lock(&dev->struct_mutex);
>  	idr_remove(&dev->ctx_idr, ctx_handle);
>  	mutex_unlock(&dev->struct_mutex);
> @@ -87,6 +91,10 @@ static int drm_legacy_ctxbitmap_next(struct drm_device * dev)
>   */
>  int drm_legacy_ctxbitmap_init(struct drm_device * dev)
>  {
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	idr_init(&dev->ctx_idr);
>  	return 0;
>  }
> @@ -101,6 +109,10 @@ int drm_legacy_ctxbitmap_init(struct drm_device * dev)
>   */
>  void drm_legacy_ctxbitmap_cleanup(struct drm_device * dev)
>  {
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return;
> +
>  	mutex_lock(&dev->struct_mutex);
>  	idr_destroy(&dev->ctx_idr);
>  	mutex_unlock(&dev->struct_mutex);
> @@ -119,6 +131,10 @@ void drm_legacy_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
>  {
>  	struct drm_ctx_list *pos, *tmp;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return;
> +
>  	mutex_lock(&dev->ctxlist_mutex);
>  
>  	list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
> @@ -161,6 +177,10 @@ int drm_legacy_getsareactx(struct drm_device *dev, void *data,
>  	struct drm_local_map *map;
>  	struct drm_map_list *_entry;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	mutex_lock(&dev->struct_mutex);
>  
>  	map = idr_find(&dev->ctx_idr, request->ctx_id);
> @@ -205,6 +225,10 @@ int drm_legacy_setsareactx(struct drm_device *dev, void *data,
>  	struct drm_local_map *map = NULL;
>  	struct drm_map_list *r_list = NULL;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	mutex_lock(&dev->struct_mutex);
>  	list_for_each_entry(r_list, &dev->maplist, head) {
>  		if (r_list->map
> @@ -305,6 +329,10 @@ int drm_legacy_resctx(struct drm_device *dev, void *data,
>  	struct drm_ctx ctx;
>  	int i;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	if (res->count >= DRM_RESERVED_CONTEXTS) {
>  		memset(&ctx, 0, sizeof(ctx));
>  		for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
> @@ -335,6 +363,10 @@ int drm_legacy_addctx(struct drm_device *dev, void *data,
>  	struct drm_ctx_list *ctx_entry;
>  	struct drm_ctx *ctx = data;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	ctx->handle = drm_legacy_ctxbitmap_next(dev);
>  	if (ctx->handle == DRM_KERNEL_CONTEXT) {
>  		/* Skip kernel's context and get a new one. */
> @@ -378,6 +410,10 @@ int drm_legacy_getctx(struct drm_device *dev, void *data,
>  {
>  	struct drm_ctx *ctx = data;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	/* This is 0, because we don't handle any context flags */
>  	ctx->flags = 0;
>  
> @@ -400,6 +436,10 @@ int drm_legacy_switchctx(struct drm_device *dev, void *data,
>  {
>  	struct drm_ctx *ctx = data;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	DRM_DEBUG("%d\n", ctx->handle);
>  	return drm_context_switch(dev, dev->last_context, ctx->handle);
>  }
> @@ -420,6 +460,10 @@ int drm_legacy_newctx(struct drm_device *dev, void *data,
>  {
>  	struct drm_ctx *ctx = data;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	DRM_DEBUG("%d\n", ctx->handle);
>  	drm_context_switch_complete(dev, file_priv, ctx->handle);
>  
> @@ -442,6 +486,10 @@ int drm_legacy_rmctx(struct drm_device *dev, void *data,
>  {
>  	struct drm_ctx *ctx = data;
>  
> +	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +	    drm_core_check_feature(dev, DRIVER_MODESET))
> +		return -EINVAL;
> +
>  	DRM_DEBUG("%d\n", ctx->handle);
>  	if (ctx->handle != DRM_KERNEL_CONTEXT) {
>  		if (dev->driver->context_dtor)
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 3b3c4f537e95..e5717116346d 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -584,11 +584,14 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver,
>  	if (drm_ht_create(&dev->map_hash, 12))
>  		goto err_minors;
>  
> -	ret = drm_legacy_ctxbitmap_init(dev);
> -	if (ret) {
> -		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
> -		goto err_ht;
> -	}
> +	if (drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) ||
> +		!drm_core_check_feature(dev, DRIVER_MODESET))
> +		ret = drm_legacy_ctxbitmap_init(dev);
> +		if (ret) {
> +			DRM_ERROR(
> +				"Cannot allocate memory for context bitmap.\n");
> +			goto err_ht;
> +		}
>  
>  	if (drm_core_check_feature(dev, DRIVER_GEM)) {
>  		ret = drm_gem_init(dev);
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> index 89049335b738..9624b3827c34 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> @@ -941,7 +941,8 @@ static struct drm_driver
>  driver_stub = {
>  	.driver_features =
>  		DRIVER_USE_AGP |
> -		DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER,
> +		DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER |
> +		DRIVER_KMS_LEGACY_CONTEXT,
>  
>  	.load = nouveau_drm_load,
>  	.unload = nouveau_drm_unload,
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index 48db6a56975f..3dc7c16c18f2 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -137,17 +137,18 @@ void drm_err(const char *format, ...);
>  /*@{*/
>  
>  /* driver capabilities and requirements mask */
> -#define DRIVER_USE_AGP     0x1
> -#define DRIVER_PCI_DMA     0x8
> -#define DRIVER_SG          0x10
> -#define DRIVER_HAVE_DMA    0x20
> -#define DRIVER_HAVE_IRQ    0x40
> -#define DRIVER_IRQ_SHARED  0x80
> -#define DRIVER_GEM         0x1000
> -#define DRIVER_MODESET     0x2000
> -#define DRIVER_PRIME       0x4000
> -#define DRIVER_RENDER      0x8000
> -#define DRIVER_ATOMIC      0x10000
> +#define DRIVER_USE_AGP			0x1
> +#define DRIVER_PCI_DMA			0x8
> +#define DRIVER_SG			0x10
> +#define DRIVER_HAVE_DMA			0x20
> +#define DRIVER_HAVE_IRQ			0x40
> +#define DRIVER_IRQ_SHARED		0x80
> +#define DRIVER_GEM			0x1000
> +#define DRIVER_MODESET			0x2000
> +#define DRIVER_PRIME			0x4000
> +#define DRIVER_RENDER			0x8000
> +#define DRIVER_ATOMIC			0x10000
> +#define DRIVER_KMS_LEGACY_CONTEXT	0x20000
>  
>  /***********************************************************************/
>  /** \name Macros to make printk easier */

Reviewed-by: Peter Antoine <peter.antoine at intel.com>


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