diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2019-05-14 01:18:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-25 18:25:37 +0200 |
| commit | 9f2292309de82d53b03123e7991912150a8016d4 (patch) | |
| tree | 6962bc7e540cd54356bfbcd840d3c42c57da52d9 /kernel/bpf | |
| parent | ff8af90d5604cadf2dcdd6e952a745f92d7eafe9 (diff) | |
bpf: add map_lookup_elem_sys_only for lookups from syscall side
commit c6110222c6f49ea68169f353565eb865488a8619 upstream.
Add a callback map_lookup_elem_sys_only() that map implementations
could use over map_lookup_elem() from system call side in case the
map implementation needs to handle the latter differently than from
the BPF data path. If map_lookup_elem_sys_only() is set, this will
be preferred pick for map lookups out of user space. This hook is
used in a follow-up fix for LRU map, but once development window
opens, we can convert other map types from map_lookup_elem() (here,
the one called upon BPF_MAP_LOOKUP_ELEM cmd is meant) over to use
the callback to simplify and clean up the latter.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/syscall.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 5c9deed4524e..2d828d346982 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -493,7 +493,10 @@ static int map_lookup_elem(union bpf_attr *attr) err = bpf_fd_htab_map_lookup_elem(map, key, value); } else { rcu_read_lock(); - ptr = map->ops->map_lookup_elem(map, key); + if (map->ops->map_lookup_elem_sys_only) + ptr = map->ops->map_lookup_elem_sys_only(map, key); + else + ptr = map->ops->map_lookup_elem(map, key); if (ptr) memcpy(value, ptr, value_size); rcu_read_unlock(); |