From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] qxl: Use struct_size() in kzalloc() Date: Tue, 8 Jan 2019 10:21:52 -0600 Message-ID: <20190108162152.GA25361@embeddedor> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Dave Airlie , Gerd Hoffmann , David Airlie , Daniel Vetter Cc: virtualization@lists.linux-foundation.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: dri-devel@lists.freedesktop.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/gpu/drm/qxl/qxl_display.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c index ce0b9c40fc21..c8642712412e 100644 --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -48,8 +48,8 @@ static int qxl_alloc_client_monitors_config(struct qxl_device *qdev, } if (!qdev->client_monitors_config) { qdev->client_monitors_config = kzalloc( - sizeof(struct qxl_monitors_config) + - sizeof(struct qxl_head) * count, GFP_KERNEL); + struct_size(qdev->client_monitors_config, + heads, count), GFP_KERNEL); if (!qdev->client_monitors_config) return -ENOMEM; } -- 2.20.1