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From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Vinod Koul <vkoul@kernel.org>, Dan Williams <dan.j.williams@intel.com>
Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] ioat/dca: Use struct_size() helper
Date: Wed, 28 Aug 2019 13:40:15 -0500
Message-ID: <20190828184015.GA4273@embeddedor> (raw)

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct ioat_dca_priv {
	...
        struct ioat_dca_slot     req_slots[0];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(*ioatdca) + (sizeof(struct ioat_dca_slot) * slots)

with:

struct_size(ioatdca, req_slots, slots)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/dma/ioat/dca.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/ioat/dca.c b/drivers/dma/ioat/dca.c
index 70fd8454d002..be61c32a876f 100644
--- a/drivers/dma/ioat/dca.c
+++ b/drivers/dma/ioat/dca.c
@@ -286,8 +286,7 @@ struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
 		return NULL;
 
 	dca = alloc_dca_provider(&ioat_dca_ops,
-				 sizeof(*ioatdca)
-				      + (sizeof(struct ioat_dca_slot) * slots));
+				 struct_size(ioatdca, req_slots, slots));
 	if (!dca)
 		return NULL;
 
-- 
2.23.0


             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-28 18:40 Gustavo A. R. Silva [this message]
2019-08-28 19:38 ` Dave Jiang
2019-09-04  4:48 ` Vinod Koul

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