On 1/15/19 3:49 PM, Chuck Lever wrote:
On Jan 15, 2019, at 4:11 PM, Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> 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 foo { int stuff; struct boo entry[]; }; instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Thank you, Chuck. -- Gustavo
--- net/sunrpc/xprtrdma/svc_rdma_rw.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c index dc1951759a8e..cad37c2122ab 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c @@ -64,8 +64,7 @@ svc_rdma_get_rw_ctxt(struct svcxprt_rdma *rdma, unsigned int sges) spin_unlock(&rdma->sc_rw_ctxt_lock); } else { spin_unlock(&rdma->sc_rw_ctxt_lock); - ctxt = kmalloc(sizeof(*ctxt) + - SG_CHUNK_SIZE * sizeof(struct scatterlist), + ctxt = kmalloc(struct_size(ctxt, rw_first_sgl, SG_CHUNK_SIZE), GFP_KERNEL); if (!ctxt) goto out; -- 2.20.1-- Chuck Lever
