drm/exynos: iommu: move dma_params configuration code to separate functions

Move code for managing DMA max segment size parameter to separate
functions. This patch also replaces devm_kzalloc() with kzalloc() and
adds proper kfree call. devm_kzalloc() cannot be used for dma_params
structure, because it will be freed on driver remove not on device
release. This means in case of Exynos DRM being compiled as module and
loaded 2 times, a user-after-free issue will happen.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
This commit is contained in:
Marek Szyprowski 2016-06-17 09:54:23 +02:00 committed by Inki Dae
parent 5dd0775e50
commit f7c72773de
1 changed files with 22 additions and 6 deletions

View File

@ -21,6 +21,23 @@
#include "exynos_drm_drv.h"
#include "exynos_drm_iommu.h"
static inline int configure_dma_max_seg_size(struct device *dev)
{
if (!dev->dma_parms)
dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
if (!dev->dma_parms)
return -ENOMEM;
dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
return 0;
}
static inline void clear_dma_max_seg_size(struct device *dev)
{
kfree(dev->dma_parms);
dev->dma_parms = NULL;
}
/*
* drm_create_iommu_mapping - create a mapping structure
*
@ -80,13 +97,10 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
if (!priv->mapping)
return 0;
subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
sizeof(*subdrv_dev->dma_parms),
GFP_KERNEL);
if (!subdrv_dev->dma_parms)
return -ENOMEM;
dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
ret = configure_dma_max_seg_size(subdrv_dev);
if (ret)
return ret;
if (subdrv_dev->archdata.mapping)
arm_iommu_detach_device(subdrv_dev);
@ -94,6 +108,7 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
ret = arm_iommu_attach_device(subdrv_dev, priv->mapping);
if (ret < 0) {
DRM_DEBUG_KMS("failed iommu attach.\n");
clear_dma_max_seg_size(subdrv_dev);
return ret;
}
@ -119,4 +134,5 @@ void drm_iommu_detach_device(struct drm_device *drm_dev,
return;
arm_iommu_detach_device(subdrv_dev);
clear_dma_max_seg_size(subdrv_dev);
}