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 18:23:48 +0200 |
commit | 2bb3c5470aaf0c84229359d5ae9cb0582fa015b5 (patch) | |
tree | 4ca1670b1257246bbb8527c6ab83971dffceaf51 /kernel/bpf | |
parent | 3ded3aaa4aa84125812d45526c31ac575ef18851 (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 cc40b8be1171..ede82382dd32 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -721,7 +721,10 @@ static int map_lookup_elem(union bpf_attr *attr) err = bpf_fd_reuseport_array_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(); |