Re: [RFC PATCH 2/6] bpf: add BPF_MAP_DUMP command to access more than one entry per call

From: Jakub Kicinski
Date: Mon Jun 24 2019 - 20:14:27 EST


On Mon, 24 Jun 2019 16:35:05 -0700, Brian Vazquez wrote:
> On Mon, Jun 24, 2019 at 3:46 PM Jakub Kicinski wrote:
> > On Fri, 21 Jun 2019 16:16:46 -0700, Brian Vazquez wrote:
> > > @@ -385,6 +386,14 @@ union bpf_attr {
> > > __u64 flags;
> > > };
> > >
> > > + struct { /* struct used by BPF_MAP_DUMP command */
> > > + __u32 map_fd;
> >
> > There is a hole here, perhaps flags don't have to be 64 bit?
> The command implementation is wrapping BPF_MAP_*_ELEM commands, I
> would expect this one to handle the same flags which are 64 bit.
> Note that there's a hole in the anonymous structure used by the other
> commands too:
> struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
> __u32 map_fd;
> __aligned_u64 key;
> union {
> __aligned_u64 value;
> __aligned_u64 next_key;
> };
> __u64 flags;
> };

Ah, okay.