From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] drm/nouveau/nvif/mmu: Use struct_size() helper Date: Wed, 7 Aug 2019 10:50:02 -0500 Message-ID: <20190807155002.GA25502@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: Ben Skeggs , David Airlie , Daniel Vetter Cc: dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-Id: nouveau.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 nvif_mmu_kind_v0 { ... __u8 data[]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*kind) + sizeof(*kind->data) * mmu->kind_nr with: struct_size(kind, data, mmu->kind_nr) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/nouveau/nvif/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/nvif/mmu.c b/drivers/gpu/drm/nouveau/nvif/mmu.c index ae08a1ca8044..5641bda2046d 100644 --- a/drivers/gpu/drm/nouveau/nvif/mmu.c +++ b/drivers/gpu/drm/nouveau/nvif/mmu.c @@ -110,7 +110,7 @@ nvif_mmu_init(struct nvif_object *parent, s32 oclass, struct nvif_mmu *mmu) if (mmu->kind_nr) { struct nvif_mmu_kind_v0 *kind; - u32 argc = sizeof(*kind) + sizeof(*kind->data) * mmu->kind_nr; + size_t argc = struct_size(kind, data, mmu->kind_nr); if (ret = -ENOMEM, !(kind = kmalloc(argc, GFP_KERNEL))) goto done; -- 2.22.0