iommu/mtk_iommu: Use devm_kcalloc() instead of devm_kzalloc()

This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1].

Here the multiplication is obviously safe because MTK_PROTECT_PA_ALIGN
is defined as a literal value of 256 or 128.

For the "mtk_iommu.c" file: 256
For the "mtk_iommu_v1.c" file: 128

However, using devm_kcalloc() is more appropriate [2] and improves
readability. This patch has no effect on runtime behavior.

Link: https://github.com/KSPP/linux/issues/162
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Erick Archer <erick.archer@gmx.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20240211182250.12656-1-erick.archer@gmx.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 7abe9e85a570632a74080ba275b44e14882d6cec..9aae6eb604b16439a6ee56e2db5a2caaad6d88c8 100644 (file)
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -1264,7 +1264,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
        data->plat_data = of_device_get_match_data(dev);
 
        /* Protect memory. HW will access here while translation fault.*/
-       protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2, GFP_KERNEL);
+       protect = devm_kcalloc(dev, 2, MTK_PROTECT_PA_ALIGN, GFP_KERNEL);
        if (!protect)
                return -ENOMEM;
        data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);

diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 25b41222abaec109b4c87a8feba380401ad61a69..45cd845d153f8025ff0c3b35f0e41cbe12a7a2cc 100644 (file)
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -621,8 +621,8 @@ static int mtk_iommu_v1_probe(struct platform_device *pdev)
        data->dev = dev;
 
        /* Protect memory. HW will access here while translation fault.*/
-       protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2,
-                       GFP_KERNEL | GFP_DMA);
+       protect = devm_kcalloc(dev, 2, MTK_PROTECT_PA_ALIGN,
+                              GFP_KERNEL | GFP_DMA);
        if (!protect)
                return -ENOMEM;
        data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);