xorg-x11-server/u_render-Don-t-generate-invalid-pixman-format-when-using-a-24bpp-framebuffer-with-a-32bit-depth-visual.patch

From patchwork Fri Jun  6 04:36:59 2014
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Subject: render: Don't generate invalid pixman format when using a 24bpp
 framebuffer with a 32bit depth visual.
From: Robert Ancell <robert.ancell@canonical.com>
X-Patchwork-Id: 27240
Message-Id: <1402029419-6400-1-git-send-email-robert.ancell@canonical.com>
To: xorg-devel@lists.x.org
Cc: Robert Ancell <robert.ancell@canonical.com>
Date: Fri,  6 Jun 2014 16:36:59 +1200

When using the fb backend at 24bpp it allows a visual with 32 bit depth.
This would cause RENDER to try and create an invalid pixman buffer and hit the
following assertion when trying to render to it:

---
 render/picture.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/render/picture.c
+++ b/render/picture.c
@@ -762,6 +762,7 @@ CreatePicture(Picture pid,
 {
     PicturePtr pPicture;
     PictureScreenPtr ps = GetPictureScreen(pDrawable->pScreen);
+    int bpp;
 
     pPicture = dixAllocateScreenObjectWithPrivates(pDrawable->pScreen,
                                                    PictureRec, PRIVATE_PICTURE);
@@ -773,7 +774,10 @@ CreatePicture(Picture pid,
     pPicture->id = pid;
     pPicture->pDrawable = pDrawable;
     pPicture->pFormat = pFormat;
-    pPicture->format = pFormat->format | (pDrawable->bitsPerPixel << 24);
+    bpp = pDrawable->bitsPerPixel;
+    if (bpp < pFormat->depth)
+        bpp = BitsPerPixel (pFormat->depth);
+    pPicture->format = pFormat->format | (bpp << 24);
 
     /* security creation/labeling check */
     *error = XaceHook(XACE_RESOURCE_ACCESS, client, pid, PictureType, pPicture,