drm/i915/kvmgt: Use struct_size() helper (cd3e0583) · Commits · 戴 / test

Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes, in particular in the context in which this code is being used. So, replace the following form: sizeof(*sparse) + (nr_areas * sizeof(*sparse->areas) with: struct_size(sparse, areas, sparse->nr_areas) and so on... Also, notice that variable size is unnecessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by:

Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by:

Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/kvmgt.c

+5 −7

Original line number	Diff line number	Diff line
		@@ -1306,7 +1306,6 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
		unsigned int i;
		int ret;
		struct vfio_region_info_cap_sparse_mmap *sparse = NULL;
		size_t size;
		int nr_areas = 1;
		int cap_type_id;

		@@ -1349,9 +1348,8 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
		VFIO_REGION_INFO_FLAG_WRITE;
		info.size = gvt_aperture_sz(vgpu->gvt);

		size = sizeof(*sparse) +
		(nr_areas * sizeof(*sparse->areas));
		sparse = kzalloc(size, GFP_KERNEL);
		sparse = kzalloc(struct_size(sparse, areas, nr_areas),
		GFP_KERNEL);
		if (!sparse)
		return -ENOMEM;

		@@ -1416,9 +1414,9 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
		switch (cap_type_id) {
		case VFIO_REGION_INFO_CAP_SPARSE_MMAP:
		ret = vfio_info_add_capability(&caps,
		&sparse->header, sizeof(*sparse) +
		(sparse->nr_areas *
		sizeof(*sparse->areas)));
		&sparse->header,
		struct_size(sparse, areas,
		sparse->nr_areas));
		if (ret) {
		kfree(sparse);
		return ret;

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