From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Subject: Re: [PATCH] net/mlx5: IPSec, fix 64-bit division correctly Date: Mon, 10 Jul 2017 08:45:43 -0700 Message-ID: <1499701543.5468.11.camel@perches.com> References: <20170710093842.2921914-1-arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Ilan Tayari , Arnd Bergmann , Saeed Mahameed Cc: Matan Barak , Leon Romanovsky , Yossi Kuperman , Yevgeny Kliteynik , Boris Pismenny , "netdev@vger.kernel.org" , "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: linux-rdma@vger.kernel.org On Mon, 2017-07-10 at 10:24 +0000, Ilan Tayari wrote: > > -----Original Message----- > > From: Arnd Bergmann [mailto:arnd@arndb.de] > > Subject: [PATCH] net/mlx5: IPSec, fix 64-bit division correctly > > > > The new IPSec offload code introduced a build error: > > > > drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.o: In function > > `mlx5e_ipsec_build_inverse_table': > > ipsec_rxtx.c:(.text+0x556): undefined reference > > > > Another patch was added on top to fix the build error, but > > that introduced a new bug, as we now use the remainder of > > the division rather than the result. Is it possible to return noise in mlx5e_ipsec_mss_inv ? What clamps skb_shinfo(skb)->gso_size to MAX_LSO (the size of inverse_table)? #define MAX_LSO_MSS 2048 static __be16 mlx5e_ipsec_inverse_table[MAX_LSO_MSS]; static inline __be16 mlx5e_ipsec_mss_inv(struct sk_buff *skb) { return mlx5e_ipsec_inverse_table[skb_shinfo(skb)->gso_size]; }