linux/kernel/bpf
Mauricio Vasquez B f1a2e44a3a bpf: add queue and stack maps
Queue/stack maps implement a FIFO/LIFO data storage for ebpf programs.
These maps support peek, pop and push operations that are exposed to eBPF
programs through the new bpf_map[peek/pop/push] helpers.  Those operations
are exposed to userspace applications through the already existing
syscalls in the following way:

BPF_MAP_LOOKUP_ELEM            -> peek
BPF_MAP_LOOKUP_AND_DELETE_ELEM -> pop
BPF_MAP_UPDATE_ELEM            -> push

Queue/stack maps are implemented using a buffer, tail and head indexes,
hence BPF_F_NO_PREALLOC is not supported.

As opposite to other maps, queue and stack do not use RCU for protecting
maps values, the bpf_map[peek/pop] have a ARG_PTR_TO_UNINIT_MAP_VALUE
argument that is a pointer to a memory zone where to save the value of a
map.  Basically the same as ARG_PTR_TO_UNINIT_MEM, but the size has not
be passed as an extra argument.

Our main motivation for implementing queue/stack maps was to keep track
of a pool of elements, like network ports in a SNAT, however we forsee
other use cases, like for exampling saving last N kernel events in a map
and then analysing from userspace.

Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-19 13:24:31 -07:00
..
arraymap.c bpf: return EOPNOTSUPP when map lookup isn't supported 2018-10-09 21:52:20 -07:00
bpf_lru_list.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
bpf_lru_list.h bpf: Only set node->ref = 1 if it has not been set 2017-09-01 09:57:39 -07:00
btf.c bpf: btf: Fix a missing check bug 2018-10-09 21:42:51 -07:00
cgroup.c bpf: extend cgroup bpf core to allow multiple cgroup storage types 2018-10-01 16:18:32 +02:00
core.c bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
cpumap.c bpf: fix redirect to map under tail calls 2018-08-17 15:56:23 -07:00
devmap.c bpf: fix redirect to map under tail calls 2018-08-17 15:56:23 -07:00
disasm.c bpf: Remove struct bpf_verifier_env argument from print_bpf_insn 2018-03-23 17:38:57 +01:00
disasm.h bpf: Remove struct bpf_verifier_env argument from print_bpf_insn 2018-03-23 17:38:57 +01:00
hashtab.c bpf: add bpffs pretty print for percpu arraymap/hash/lru_hash 2018-08-30 14:03:53 +02:00
helpers.c bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
inode.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
local_storage.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-10-08 23:42:44 -07:00
lpm_trie.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
Makefile bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
map_in_map.c bpf: don't allow create maps of per-cpu cgroup local storages 2018-10-01 16:18:33 +02:00
map_in_map.h bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
offload.c bpf: add verifier callback to get stack usage info for offloaded progs 2018-10-08 10:24:12 +02:00
percpu_freelist.c bpf: fix lockdep splat 2017-11-15 19:46:32 +09:00
percpu_freelist.h bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
queue_stack_maps.c bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
reuseport_array.c bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY 2018-08-11 01:58:46 +02:00
stackmap.c bpf: rename stack trace map operations 2018-10-19 13:24:30 -07:00
syscall.c bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
tnum.c bpf/verifier: improve register value range tracking with ARSH 2018-04-29 08:45:53 -07:00
verifier.c bpf: add queue and stack maps 2018-10-19 13:24:31 -07:00
xskmap.c bpf: return EOPNOTSUPP when map lookup isn't supported 2018-10-09 21:52:20 -07:00