| Message ID | 20190107170631.GA32119@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | dmaengine: tegra210-adma: Use struct_size() in devm_kzalloc() | expand |
On 07-01-19, 11:06, Gustavo A. R. Silva wrote: > 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. Applied, thanks
diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c index b26256f23d67..5ec0dd97b397 100644 --- a/drivers/dma/tegra210-adma.c +++ b/drivers/dma/tegra210-adma.c @@ -678,8 +678,9 @@ static int tegra_adma_probe(struct platform_device *pdev) return -ENODEV; } - tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels * - sizeof(struct tegra_adma_chan), GFP_KERNEL); + tdma = devm_kzalloc(&pdev->dev, + struct_size(tdma, channels, cdata->nr_channels), + GFP_KERNEL); if (!tdma) return -ENOMEM;
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 <gustavo@embeddedor.com> --- drivers/dma/tegra210-adma.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)