From: Erick Archer <erick.archer@gmx.com>
To: Yong Wu <yong.wu@mediatek.com>, Joerg Roedel <joro@8bytes.org>,
Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
Kees Cook <keescook@chromium.org>
Cc: Erick Archer <erick.archer@gmx.com>,
iommu@lists.linux.dev, linux-mediatek@lists.infradead.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] iommu/mtk_iommu: Use devm_kcalloc() instead of devm_kzalloc()
Date: Sun, 11 Feb 2024 19:22:50 +0100 [thread overview]
Message-ID: <20240211182250.12656-1-erick.archer@gmx.com> (raw)
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 [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2]
Signed-off-by: Erick Archer <erick.archer@gmx.com>
---
drivers/iommu/mtk_iommu.c | 2 +-
drivers/iommu/mtk_iommu_v1.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 7abe9e85a570..9aae6eb604b1 100644
--- 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 25b41222abae..45cd845d153f 100644
--- 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);
--
2.25.1
next reply other threads:[~2024-02-11 18:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-11 18:22 Erick Archer [this message]
2024-02-12 8:49 ` [PATCH] iommu/mtk_iommu: Use devm_kcalloc() instead of devm_kzalloc() AngeloGioacchino Del Regno
2024-02-12 15:50 ` Matthias Brugger
2024-02-12 20:41 ` Gustavo A. R. Silva
2024-02-16 14:18 ` Joerg Roedel
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