[PATCH 2/6] drm/i915: Check framebuffer stride more thoroughly

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Make sure the the framebuffer stride is smaller than the maximum
accepted by any plane.

Also when using a tiled memory make sure the object stride matches
the framebuffer stride.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 7cf639c..8fea475 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6643,6 +6643,17 @@ static const struct drm_framebuffer_funcs intel_fb_funcs = {
 	.create_handle = intel_user_framebuffer_create_handle,
 };
 
+static unsigned int intel_max_fb_stride(const struct drm_device *dev)
+{
+	/* FIXME: BSpec for pre-Gen5 is a bit unclear on stride limits */
+	if (INTEL_INFO(dev)->gen <= 3)
+		return 8192;
+	else if (INTEL_INFO(dev)->gen <= 4)
+		return 16384;
+	else
+		return 32768;
+}
+
 int intel_framebuffer_init(struct drm_device *dev,
 			   struct intel_framebuffer *intel_fb,
 			   struct drm_mode_fb_cmd2 *mode_cmd,
@@ -6656,6 +6667,13 @@ int intel_framebuffer_init(struct drm_device *dev,
 	if (mode_cmd->pitches[0] & 63)
 		return -EINVAL;
 
+	if (mode_cmd->pitches[0] > intel_max_fb_stride(dev))
+		return -EINVAL;
+
+	if (obj->tiling_mode != I915_TILING_NONE &&
+	    mode_cmd->pitches[0] != obj->stride)
+		return -EINVAL;
+
 	/* Reject formats not supported by any plane early. */
 	switch (mode_cmd->pixel_format) {
 	case DRM_FORMAT_C8:
-- 
1.7.3.4