Martin KaFai Lau bcc6b1b7eb bpf: Add hash of maps support ... This patch adds hash of maps support (hashmap->bpf_map). BPF_MAP_TYPE_HASH_OF_MAPS is added. A map-in-map contains a pointer to another map and lets call this pointer 'inner_map_ptr'. Notes on deleting inner_map_ptr from a hash map: 1. For BPF_F_NO_PREALLOC map-in-map, when deleting an inner_map_ptr, the htab_elem itself will go through a rcu grace period and the inner_map_ptr resides in the htab_elem. 2. For pre-allocated htab_elem (!BPF_F_NO_PREALLOC), when deleting an inner_map_ptr, the htab_elem may get reused immediately. This situation is similar to the existing prealloc-ated use cases. However, the bpf_map_fd_put_ptr() calls bpf_map_put() which calls inner_map->ops->map_free(inner_map) which will go through a rcu grace period (i.e. all bpf_map's map_free currently goes through a rcu grace period). Hence, the inner_map_ptr is still safe for the rcu reader side. This patch also includes BPF_MAP_TYPE_HASH_OF_MAPS to the check_map_prealloc() in the verifier. preallocation is a must for BPF_PROG_TYPE_PERF_EVENT. Hence, even we don't expect heavy updates to map-in-map, enforcing BPF_F_NO_PREALLOC for map-in-map is impossible without disallowing BPF_PROG_TYPE_PERF_EVENT from using map-in-map first. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>		2017-03-22 15:45:45 -07:00
..
arraymap.c	bpf: Add array of maps support	2017-03-22 15:45:45 -07:00
bpf_lru_list.c	bpf: Make unnecessarily global functions static	2017-01-10 21:00:59 -05:00
bpf_lru_list.h	bpf: Add percpu LRU list	2016-11-15 11:50:20 -05:00
cgroup.c	bpf: introduce BPF_F_ALLOW_OVERRIDE flag	2017-02-12 21:52:19 -05:00
core.c	bpf: make jited programs visible in traces	2017-02-17 13:40:05 -05:00
hashtab.c	bpf: Add hash of maps support	2017-03-22 15:45:45 -07:00
helpers.c	bpf: rename ARG_PTR_TO_STACK	2017-01-09 16:56:27 -05:00
inode.c	bpf: add initial bpf tracepoints	2017-01-25 13:17:47 -05:00
lpm_trie.c	bpf: add get_next_key callback to LPM map	2017-03-05 17:55:29 -08:00
Makefile	bpf: Add array of maps support	2017-03-22 15:45:45 -07:00
map_in_map.c	bpf: Add array of maps support	2017-03-22 15:45:45 -07:00
map_in_map.h	bpf: Add array of maps support	2017-03-22 15:45:45 -07:00
percpu_freelist.c	bpf: introduce percpu_freelist	2016-03-08 15:28:31 -05:00
percpu_freelist.h	bpf: introduce percpu_freelist	2016-03-08 15:28:31 -05:00
stackmap.c	bpf: mark all registered map/prog types as __ro_after_init	2017-02-17 13:40:04 -05:00
syscall.c	bpf: Add hash of maps support	2017-03-22 15:45:45 -07:00
verifier.c	bpf: Add hash of maps support	2017-03-22 15:45:45 -07:00