From: "Gustavo A. R. Silva" Subject: [PATCH] mISDN: hfcsusb: Use struct_size() in kzalloc() Date: Tue, 8 Jan 2019 15:27:05 -0600 Message-ID: <20190108212705.GA8470@embeddedor> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" To: Karsten Keil Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.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 = kzalloc(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 = kzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/isdn/hardware/mISDN/hfcsusb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c index 6d05946b445e..124ff530da82 100644 --- a/drivers/isdn/hardware/mISDN/hfcsusb.c +++ b/drivers/isdn/hardware/mISDN/hfcsusb.c @@ -262,8 +262,7 @@ hfcsusb_ph_info(struct hfcsusb *hw) struct dchannel *dch = &hw->dch; int i; - phi = kzalloc(sizeof(struct ph_info) + - dch->dev.nrbchan * sizeof(struct ph_info_ch), GFP_ATOMIC); + phi = kzalloc(struct_size(phi, bch, dch->dev.nrbchan), GFP_ATOMIC); phi->dch.ch.protocol = hw->protocol; phi->dch.ch.Flags = dch->Flags; phi->dch.state = dch->state; -- 2.20.1