From e291fa1237a74dc4692995a4a598d4818a747191 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Wed, 3 Apr 2019 15:50:43 -0500 Subject: staging: ralink-gdma: Use struct_size() in kzalloc() 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; struct boo entry[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = kzalloc(size, GFP_KERNEL) Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: size = struct_size(instance, entry, count); or instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL) Based on the above, replace gdma_dma_alloc_desc() with kzalloc() and use the new struct_size() helper. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Greg Kroah-Hartman --- drivers/staging/ralink-gdma/ralink-gdma.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'drivers/staging/ralink-gdma/ralink-gdma.c') diff --git a/drivers/staging/ralink-gdma/ralink-gdma.c b/drivers/staging/ralink-gdma/ralink-gdma.c index d12ecdc01e61..de3e357b2640 100644 --- a/drivers/staging/ralink-gdma/ralink-gdma.c +++ b/drivers/staging/ralink-gdma/ralink-gdma.c @@ -164,12 +164,6 @@ static inline void gdma_dma_write(struct gdma_dma_dev *dma_dev, writel(val, dma_dev->base + reg); } -static struct gdma_dma_desc *gdma_dma_alloc_desc(unsigned int num_sgs) -{ - return kzalloc(sizeof(struct gdma_dma_desc) + - sizeof(struct gdma_dma_sg) * num_sgs, GFP_ATOMIC); -} - static enum gdma_dma_transfer_size gdma_dma_maxburst(u32 maxburst) { if (maxburst < 2) @@ -526,7 +520,7 @@ static struct dma_async_tx_descriptor *gdma_dma_prep_slave_sg( struct scatterlist *sg; unsigned int i; - desc = gdma_dma_alloc_desc(sg_len); + desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); if (!desc) { dev_err(c->device->dev, "alloc sg decs error\n"); return NULL; @@ -581,7 +575,7 @@ static struct dma_async_tx_descriptor *gdma_dma_prep_dma_memcpy( xfer_count = GDMA_REG_CTRL0_TX_MASK; num_periods = DIV_ROUND_UP(len, xfer_count); - desc = gdma_dma_alloc_desc(num_periods); + desc = kzalloc(struct_size(desc, sg, num_periods), GFP_ATOMIC); if (!desc) { dev_err(c->device->dev, "alloc memcpy decs error\n"); return NULL; @@ -626,7 +620,7 @@ static struct dma_async_tx_descriptor *gdma_dma_prep_dma_cyclic( } num_periods = buf_len / period_len; - desc = gdma_dma_alloc_desc(num_periods); + desc = kzalloc(struct_size(desc, sg, num_periods), GFP_ATOMIC); if (!desc) { dev_err(c->device->dev, "alloc cyclic decs error\n"); return NULL; -- cgit v1.2.3