nfp: bpf: record offload neutral maps in the driver

For asynchronous events originating from the device, like perf event
output, we need to be able to make sure that objects being referred
to by the FW message are valid on the host.  FW events can get queued
and reordered.  Even if we had a FW message "barrier" we should still
protect ourselves from bogus FW output.

Add a reverse-mapping hash table and record in it all raw map pointers
FW may refer to.  Only record neutral maps, i.e. perf event arrays.
These are currently the only objects FW can refer to.  Use RCU protection
on the read side, update side is under RTNL.

Since program vs map destruction order is slightly painful for offload
simply take an extra reference on all the recorded maps to make sure
they don't disappear.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Jakub Kicinski 2018-05-03 18:37:09 -07:00 committed by Daniel Borkmann
parent 0cd3cbed3c
commit 630a4d3874
5 changed files with 168 additions and 6 deletions

View file

@ -282,6 +282,7 @@ void bpf_map_put(struct bpf_map *map)
{
__bpf_map_put(map, true);
}
EXPORT_SYMBOL_GPL(bpf_map_put);
void bpf_map_put_with_uref(struct bpf_map *map)
{
@ -543,6 +544,7 @@ struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
atomic_inc(&map->usercnt);
return map;
}
EXPORT_SYMBOL_GPL(bpf_map_inc);
struct bpf_map *bpf_map_get_with_uref(u32 ufd)
{