From 402096cb5b7d9ae9c69b851f5ec6289d249a9ed5 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Fri, 30 Aug 2019 11:14:23 -0500 Subject: dmaengine: stm32-dma: Use struct_size() helper 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 stm32_dma_desc { ... struct stm32_dma_sg_req sg_req[]; }; 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 function: static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs) { return kzalloc(sizeof(struct stm32_dma_desc) + sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT); } with: kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20190830161423.GA3483@embeddedor Signed-off-by: Vinod Koul --- drivers/dma/stm32-dma.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index e4cbe38d1b83..5989b0893521 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -243,12 +243,6 @@ static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val) writel_relaxed(val, dmadev->base + reg); } -static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs) -{ - return kzalloc(sizeof(struct stm32_dma_desc) + - sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT); -} - static int stm32_dma_get_width(struct stm32_dma_chan *chan, enum dma_slave_buswidth width) { @@ -853,7 +847,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg( return NULL; } - desc = stm32_dma_alloc_desc(sg_len); + desc = kzalloc(struct_size(desc, sg_req, sg_len), GFP_NOWAIT); if (!desc) return NULL; @@ -954,7 +948,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic( num_periods = buf_len / period_len; - desc = stm32_dma_alloc_desc(num_periods); + desc = kzalloc(struct_size(desc, sg_req, num_periods), GFP_NOWAIT); if (!desc) return NULL; @@ -989,7 +983,7 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy( int i; num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS); - desc = stm32_dma_alloc_desc(num_sgs); + desc = kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT); if (!desc) return NULL; -- cgit v1.2.3-59-g8ed1b