On Tue, Jan 15, 2019 at 04:49:16PM -0500, Chuck Lever wrote:
> 
> 
> On Jan 15, 2019, at 4:11 PM, Gustavo A. R. Silva <gust...@embeddedor.com> 
> 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 <gust...@embeddedor.com>
> 
> Reviewed-by: Chuck Lever <chuck.le...@oracle.com>

Thanks, applying for 5.1.--b.

> 
> 
> > ---
> > 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
> 
> 

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