From c488dd2048662f35c56d002379221edf1a2a9404 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Mon, 8 May 2017 21:59:24 +0300 Subject: [PATCH] drm: omapdrm: Take GEM object reference when exporting dmabuf To ensure that neither the GEM object nor the DRM device goes away while a GEM object exported through dma-buf is still accessible, references must be taken to both the GEM object and the DRM device at export time. The dma-buf release handler already releases the GEM object, but the export handler doesn't take a corresponding reference, which results in a refcount underflow. Fix this by replacing the custom implementation by drm_gem_dmabuf_export() and drm_gem_dmabuf_release() that handle reference counting for us. Fixes: 6ad11bc3a0b8 ("staging: drm/omap: dmabuf/prime support") Signed-off-by: Laurent Pinchart --- drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c index 6ab6f52..863a881 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c +++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c @@ -72,16 +72,6 @@ static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, kfree(sg); } -static void omap_gem_dmabuf_release(struct dma_buf *buffer) -{ - struct drm_gem_object *obj = buffer->priv; - /* release reference that was taken when dmabuf was exported - * in omap_gem_prime_set().. - */ - drm_gem_object_unreference_unlocked(obj); -} - - static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer, enum dma_data_direction dir) { @@ -157,7 +147,7 @@ static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, static struct dma_buf_ops omap_dmabuf_ops = { .map_dma_buf = omap_gem_map_dma_buf, .unmap_dma_buf = omap_gem_unmap_dma_buf, - .release = omap_gem_dmabuf_release, + .release = drm_gem_dmabuf_release, .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access, .end_cpu_access = omap_gem_dmabuf_end_cpu_access, .map_atomic = omap_gem_dmabuf_kmap_atomic, @@ -177,7 +167,7 @@ struct dma_buf *omap_gem_prime_export(struct drm_device *dev, exp_info.flags = flags; exp_info.priv = obj; - return dma_buf_export(&exp_info); + return drm_gem_dmabuf_export(dev, &exp_info); } /* ----------------------------------------------------------------------------- -- 2.7.4