[Mesa-dev] [PATCH 2/2] egl/drm: Fix misused x and y offsets on swrast_get_image()

[Gwan-gyeong Mun]

It fixes misused x and y offsets on the calculation of the memory copy regions.
And it adds limits of the height and the width on the copy region.

Signed-off-by: Mun Gwan-gyeong <elongbug at gmail.com>
---
 src/egl/drivers/dri2/platform_drm.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/egl/drivers/dri2/platform_drm.c b/src/egl/drivers/dri2/platform_drm.c
index 36e9c74a56..d2fefad83b 100644
--- a/src/egl/drivers/dri2/platform_drm.c
+++ b/src/egl/drivers/dri2/platform_drm.c
@@ -575,6 +575,9 @@ swrast_get_image(__DRIdrawable *driDrawable,
    struct dri2_egl_surface *dri2_surf = loaderPrivate;
    int internal_stride, stride;
    struct gbm_dri_bo *bo;
+   int x_offset = x * 4;
+   int copy_width = width * 4;
+   char *src, *dst;
 
    if (get_swrast_front_bo(dri2_surf) < 0)
       return;
@@ -584,11 +587,21 @@ swrast_get_image(__DRIdrawable *driDrawable,
       return;
 
    internal_stride = bo->base.stride;
-   stride = width * 4;
+   stride = copy_width;
+
+   if (height > dri2_surf->base.Height - y)
+      height = dri2_surf->base.Height - y;
+
+   if (copy_width > internal_stride - x_offset)
+      copy_width = internal_stride - x_offset;
+
+   dst = data;
+   src = bo->map + x_offset + (y * internal_stride);
 
    for (int i = 0; i < height; i++) {
-      memcpy(data + i * stride,
-             bo->map + (x + i) * internal_stride + y, stride);
+      memcpy(dst, src, copy_width);
+      dst += stride;
+      src += internal_stride;
    }
 
    gbm_dri_bo_unmap_dumb(bo);
-- 
2.13.3