Re: [Intel-gfx] [PATCH v12 07/10] drm: Handle aspect ratio info in legacy modeset path

[Nautiyal, Ankit K]

On 4/27/2018 7:24 PM, Ville Syrjälä wrote:

On Fri, Apr 27, 2018 at 05:44:53PM +0530, Nautiyal, Ankit K wrote:

From: Ankit Nautiyal 

If the user-space does not support aspect-ratio, and requests for a
modeset with mode having aspect ratio bits set, then the given
user-mode must be rejected. Secondly, while preparing a user-mode from
kernel mode, the aspect-ratio info must not be given, if aspect-ratio
is not supported by the user.

This patch:
1. rejects the modes with aspect-ratio info, during modeset, if the
user does not support aspect ratio.
2. does not load the aspect-ratio info in user-mode structure, if
aspect ratio is not supported.
3. adds helper functions for determining if aspect-ratio is expected
in user-mode and for allowing/disallowing the aspect-ratio, if its
not expected.

Signed-off-by: Ankit Nautiyal 

V3: Addressed review comments from Ville:
 Do not corrupt the current crtc state by updating aspect-ratio on
 the fly.
V4: rebase
V5: As suggested by Ville, rejected the modeset calls for modes with
 aspect ratio, if the user does not set aspect-ratio cap.
V6: Used the helper functions for determining if aspect-ratio is
 expected in the user-mode.
V7: rebase
V8: rebase
V9: rebase
v10: Modified the commit-message
v11: rebase
v12: Merged the patch for adding aspect-ratio helper functions
  with this patch.
---
  drivers/gpu/drm/drm_crtc.c  |  8 
  drivers/gpu/drm/drm_modes.c | 45 +
  include/drm/drm_modes.h |  4 
  3 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index a231dd5..98323f4 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -449,6 +449,7 @@ int drm_mode_getcrtc(struct drm_device *dev,
   crtc_resp->mode_valid = 0;
   }
   }
+ drm_mode_filter_aspect_ratio_flags(file_priv, _resp->mode);
   drm_modeset_unlock(>mutex);

   return 0;
@@ -628,6 +629,13 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
   ret = -ENOMEM;
   goto out;
   }
+ if (!drm_mode_aspect_ratio_allowed(file_priv,
+_req->mode)) {
+ DRM_DEBUG_KMS("Unexpected aspect-ratio flag bits\n");
+ ret = -EINVAL;
+ goto out;
+ }
+

   ret = drm_mode_convert_umode(dev, mode, _req->mode);
   if (ret) {
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index c395a24..d6f68c8 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1759,3 +1759,48 @@ bool drm_mode_is_420(const struct drm_display_info 
*display,
   drm_mode_is_420_also(display, mode);
  }
  EXPORT_SYMBOL(drm_mode_is_420);
+
+/**
+ * drm_mode_aspect_ratio_allowed - checks if the aspect-ratio information
+ * is expected from the user-mode.
+ *
+ * If the user has set aspect-ratio cap, then the flag of the user-mode is
+ * allowed to contain aspect-ratio value.
+ * If the user does not set aspect-ratio cap, then the only value allowed in 
the
+ * flags bits is aspect-ratio NONE.
+ *
+ * @file_priv: file private structure to get the user capabilities
+ * @umode: drm_mode_modeinfo struct, whose flag carry the aspect ratio
+ * information.
+ *
+ * Returns:
+ * true if the aspect-ratio info is allowed in the user-mode flags.
+ * false, otherwise.
+ */
+bool
+drm_mode_aspect_ratio_allowed(const struct drm_file *file_priv,
+   struct drm_mode_modeinfo *umode)
+{
+ return file_priv->aspect_ratio_allowed || (umode->flags &
+ DRM_MODE_FLAG_PIC_AR_MASK) == DRM_MODE_FLAG_PIC_AR_NONE;

Still looks funny.


Alright. Let me change it to:
  if (file_priv->aspect_ratio_allowed ||
(umode->flags & DRM_MODE_FLAG_PIC_AR_MASK) == 
DRM_MODE_FLAG_PIC_AR_NONE)

return true;
return false;


+}
+
+/**
+ * drm_mode_filter_aspect_ratio_flags - filters the aspect-ratio bits in the
+ * user-mode flags.
+ *
+ * Checks if the aspect-ratio information is allowed. Resets the aspect-ratio
+ * bits in the user-mode flags, if aspect-ratio info is not allowed.
+ *
+ * @file_priv: file private structure to get the user capabilities.
+ * @umode: drm_mode_modeinfo struct, whose flags' aspect-ratio bits needs to
+ * be filtered.
+ *
+ */
+void
+drm_mode_filter_aspect_ratio_flags(const struct drm_file *file_priv,
+struct drm_mode_modeinfo *umode)
+{
+ if (!drm_mode_aspect_ratio_allowed(file_priv, umode))
+ umode->flags &= ~DRM_MODE_FLAG_PIC_AR_MASK;
+}
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 2f78b7e..e0b060d 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -461,6 +461,10 @@ bool 

Re: [Intel-gfx] [PATCH v12 07/10] drm: Handle aspect ratio info in legacy modeset path

[Ville Syrjälä]

On Fri, Apr 27, 2018 at 05:44:53PM +0530, Nautiyal, Ankit K wrote:
> From: Ankit Nautiyal 
> 
> If the user-space does not support aspect-ratio, and requests for a
> modeset with mode having aspect ratio bits set, then the given
> user-mode must be rejected. Secondly, while preparing a user-mode from
> kernel mode, the aspect-ratio info must not be given, if aspect-ratio
> is not supported by the user.
> 
> This patch:
> 1. rejects the modes with aspect-ratio info, during modeset, if the
>user does not support aspect ratio.
> 2. does not load the aspect-ratio info in user-mode structure, if
>aspect ratio is not supported.
> 3. adds helper functions for determining if aspect-ratio is expected
>in user-mode and for allowing/disallowing the aspect-ratio, if its
>not expected.
> 
> Signed-off-by: Ankit Nautiyal 
> 
> V3: Addressed review comments from Ville:
> Do not corrupt the current crtc state by updating aspect-ratio on
> the fly.
> V4: rebase
> V5: As suggested by Ville, rejected the modeset calls for modes with
> aspect ratio, if the user does not set aspect-ratio cap.
> V6: Used the helper functions for determining if aspect-ratio is
> expected in the user-mode.
> V7: rebase
> V8: rebase
> V9: rebase
> v10: Modified the commit-message
> v11: rebase
> v12: Merged the patch for adding aspect-ratio helper functions
>  with this patch.
> ---
>  drivers/gpu/drm/drm_crtc.c  |  8 
>  drivers/gpu/drm/drm_modes.c | 45 
> +
>  include/drm/drm_modes.h |  4 
>  3 files changed, 57 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index a231dd5..98323f4 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -449,6 +449,7 @@ int drm_mode_getcrtc(struct drm_device *dev,
>   crtc_resp->mode_valid = 0;
>   }
>   }
> + drm_mode_filter_aspect_ratio_flags(file_priv, _resp->mode);
>   drm_modeset_unlock(>mutex);
>  
>   return 0;
> @@ -628,6 +629,13 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
>   ret = -ENOMEM;
>   goto out;
>   }
> + if (!drm_mode_aspect_ratio_allowed(file_priv,
> +_req->mode)) {
> + DRM_DEBUG_KMS("Unexpected aspect-ratio flag bits\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
>  
>   ret = drm_mode_convert_umode(dev, mode, _req->mode);
>   if (ret) {
> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> index c395a24..d6f68c8 100644
> --- a/drivers/gpu/drm/drm_modes.c
> +++ b/drivers/gpu/drm/drm_modes.c
> @@ -1759,3 +1759,48 @@ bool drm_mode_is_420(const struct drm_display_info 
> *display,
>   drm_mode_is_420_also(display, mode);
>  }
>  EXPORT_SYMBOL(drm_mode_is_420);
> +
> +/**
> + * drm_mode_aspect_ratio_allowed - checks if the aspect-ratio information
> + * is expected from the user-mode.
> + *
> + * If the user has set aspect-ratio cap, then the flag of the user-mode is
> + * allowed to contain aspect-ratio value.
> + * If the user does not set aspect-ratio cap, then the only value allowed in 
> the
> + * flags bits is aspect-ratio NONE.
> + *
> + * @file_priv: file private structure to get the user capabilities
> + * @umode: drm_mode_modeinfo struct, whose flag carry the aspect ratio
> + * information.
> + *
> + * Returns:
> + * true if the aspect-ratio info is allowed in the user-mode flags.
> + * false, otherwise.
> + */
> +bool
> +drm_mode_aspect_ratio_allowed(const struct drm_file *file_priv,
> +   struct drm_mode_modeinfo *umode)
> +{
> + return file_priv->aspect_ratio_allowed || (umode->flags &
> + DRM_MODE_FLAG_PIC_AR_MASK) == DRM_MODE_FLAG_PIC_AR_NONE;

Still looks funny.

> +}
> +
> +/**
> + * drm_mode_filter_aspect_ratio_flags - filters the aspect-ratio bits in the
> + * user-mode flags.
> + *
> + * Checks if the aspect-ratio information is allowed. Resets the aspect-ratio
> + * bits in the user-mode flags, if aspect-ratio info is not allowed.
> + *
> + * @file_priv: file private structure to get the user capabilities.
> + * @umode: drm_mode_modeinfo struct, whose flags' aspect-ratio bits needs to
> + * be filtered.
> + *
> + */
> +void
> +drm_mode_filter_aspect_ratio_flags(const struct drm_file *file_priv,
> +struct drm_mode_modeinfo *umode)
> +{
> + if (!drm_mode_aspect_ratio_allowed(file_priv, umode))
> + umode->flags &= ~DRM_MODE_FLAG_PIC_AR_MASK;
> +}
> diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
> index 2f78b7e..e0b060d 100644
> --- a/include/drm/drm_modes.h
> +++ b/include/drm/drm_modes.h
> @@ -461,6 +461,10 @@ bool drm_mode_is_420_also(const struct