From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 9 Jan 2019 11:35:41 -0600 From: "Gustavo A. R. Silva" Subject: [PATCH] s390/hypfs: Use struct_size() in kzalloc() Message-ID: <20190109173541.GA16953@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Martin Schwidefsky , Heiko Carstens Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-ID: 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 --- arch/s390/hypfs/hypfs_diag0c.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/s390/hypfs/hypfs_diag0c.c b/arch/s390/hypfs/hypfs_diag0c.c index cebf05150cc1..9c398bf0ddc6 100644 --- a/arch/s390/hypfs/hypfs_diag0c.c +++ b/arch/s390/hypfs/hypfs_diag0c.c @@ -54,8 +54,7 @@ static void *diag0c_store(unsigned int *count) if (!cpu_vec) goto fail_put_online_cpus; /* Note: Diag 0c needs 8 byte alignment and real storage */ - diag0c_data = kzalloc(sizeof(struct hypfs_diag0c_hdr) + - cpu_count * sizeof(struct hypfs_diag0c_entry), + diag0c_data = kzalloc(struct_size(diag0c_data, entry, cpu_count), GFP_KERNEL | GFP_DMA); if (!diag0c_data) goto fail_kfree_cpu_vec; -- 2.20.1