From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Date: Mon, 19 Aug 2019 14:10:01 +0000 Subject: Re: [PATCH] video: fbdev/mmp/core: Use struct_size() in kzalloc() Message-Id: List-Id: References: <20190807161312.GA26835@embeddedor> In-Reply-To: <20190807161312.GA26835@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Gustavo A. R. Silva" Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org On 8/7/19 6:13 PM, 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 mmp_path { > ... > struct mmp_overlay overlays[0]; > }; > > size = sizeof(struct mmp_path) + count * sizeof(struct mmp_overlay); > 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: > > instance = kzalloc(struct_size(instance, overlays, count), GFP_KERNEL) > > Notice that, in this case, variable size is not necessary, hence it > is removed. > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva Patch queued for v5.4, thanks. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics