lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 20 Aug 2020 10:02:15 +0200 From: Jesper Dangaard Brouer <brouer@...hat.com> To: Lorenzo Bianconi <lorenzo@...nel.org> Cc: netdev@...r.kernel.org, bpf@...r.kernel.org, davem@...emloft.net, lorenzo.bianconi@...hat.com, echaudro@...hat.com, sameehj@...zon.com, kuba@...nel.org, brouer@...hat.com Subject: Re: [PATCH net-next 3/6] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer On Wed, 19 Aug 2020 15:13:48 +0200 Lorenzo Bianconi <lorenzo@...nel.org> wrote: > Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and > XDP remote drivers if this is a "non-linear" XDP buffer > > Signed-off-by: Lorenzo Bianconi <lorenzo@...nel.org> > --- > drivers/net/ethernet/marvell/mvneta.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c > index 832bbb8b05c8..36a3defa63fa 100644 > --- a/drivers/net/ethernet/marvell/mvneta.c > +++ b/drivers/net/ethernet/marvell/mvneta.c > @@ -2170,11 +2170,14 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, > struct bpf_prog *prog, struct xdp_buff *xdp, > u32 frame_sz, struct mvneta_stats *stats) > { > + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); > unsigned int len, data_len, sync; > u32 ret, act; > > len = xdp->data_end - xdp->data_hard_start - pp->rx_offset_correction; > data_len = xdp->data_end - xdp->data; > + > + xdp->mb = !!sinfo->nr_frags; > act = bpf_prog_run_xdp(prog, xdp); Reading the memory sinfo->nr_frags could be a performance issue for our baseline case of no-multi-buffer. As you are reading a cache-line that you don't need to (and driver have not touch yet). -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
Powered by blists - more mailing lists