From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] staging: mt7621-dma: Use struct_size() in devm_kzalloc() Date: Fri, 4 Jan 2019 15:30:47 -0600 Message-ID: <20190104213047.GA19391@embeddedor> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Greg Kroah-Hartman , Matthias Brugger Cc: devel@driverdev.osuosl.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: linux-mediatek@lists.infradead.org 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 foo { int stuff; void *entry[]; }; instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/staging/mt7621-dma/ralink-gdma.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/staging/mt7621-dma/ralink-gdma.c b/drivers/staging/mt7621-dma/ralink-gdma.c index 792a63bd55d4..d78042eba6dd 100644 --- a/drivers/staging/mt7621-dma/ralink-gdma.c +++ b/drivers/staging/mt7621-dma/ralink-gdma.c @@ -821,9 +821,9 @@ static int gdma_dma_probe(struct platform_device *pdev) return -EINVAL; data = (struct gdma_data *) match->data; - dma_dev = devm_kzalloc(&pdev->dev, sizeof(*dma_dev) + - (sizeof(struct gdma_dmaengine_chan) * data->chancnt), - GFP_KERNEL); + dma_dev = devm_kzalloc(&pdev->dev, + struct_size(dma_dev, chan, data->chancnt), + GFP_KERNEL); if (!dma_dev) { dev_err(&pdev->dev, "alloc dma device failed\n"); return -EINVAL; -- 2.20.1