| Message ID | 1533283098-2397-5-git-send-email-makita.toshiaki@lab.ntt.co.jp |
|---|---|
| State | Accepted, archived |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | veth: Driver XDP | expand |
On Fri, 3 Aug 2018 16:58:12 +0900 Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> wrote: > xdp_frame has kernel pointers which should not be readable from bpf > programs. When we want to reuse xdp_frame region but it may be read by > bpf programs later, we can use this helper to clear kernel pointers. > This is more efficient than calling memset() for the entire struct. > > Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> After this patch is applied, I will take care of updating cpumap in a similar way. Thanks.
diff --git a/include/net/xdp.h b/include/net/xdp.h index fcb033f..76b9525 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -84,6 +84,13 @@ struct xdp_frame { struct net_device *dev_rx; /* used by cpumap */ }; +/* Clear kernel pointers in xdp_frame */ +static inline void xdp_scrub_frame(struct xdp_frame *frame) +{ + frame->data = NULL; + frame->dev_rx = NULL; +} + /* Convert xdp_buff to xdp_frame */ static inline struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
xdp_frame has kernel pointers which should not be readable from bpf programs. When we want to reuse xdp_frame region but it may be read by bpf programs later, we can use this helper to clear kernel pointers. This is more efficient than calling memset() for the entire struct. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> --- include/net/xdp.h | 7 +++++++ 1 file changed, 7 insertions(+)