linux/kernel/bpf
Martin KaFai Lau a26ca7c982 bpf: btf: Add pretty print support to the basic arraymap
This patch adds pretty print support to the basic arraymap.
Support for other bpf maps can be added later.

This patch adds new attrs to the BPF_MAP_CREATE command to allow
specifying the btf_fd, btf_key_id and btf_value_id.  The
BPF_MAP_CREATE can then associate the btf to the map if
the creating map supports BTF.

A BTF supported map needs to implement two new map ops,
map_seq_show_elem() and map_check_btf().  This patch has
implemented these new map ops for the basic arraymap.

It also adds file_operations, bpffs_map_fops, to the pinned
map such that the pinned map can be opened and read.
After that, the user has an intuitive way to do
"cat bpffs/pathto/a-pinned-map" instead of getting
an error.

bpffs_map_fops should not be extended further to support
other operations.  Other operations (e.g. write/key-lookup...)
should be realized by the userspace tools (e.g. bpftool) through
the BPF_OBJ_GET_INFO_BY_FD, map's lookup/update interface...etc.
Follow up patches will allow the userspace to obtain
the BTF from a map-fd.

Here is a sample output when reading a pinned arraymap
with the following map's value:

struct map_value {
	int count_a;
	int count_b;
};

cat /sys/fs/bpf/pinned_array_map:

0: {1,2}
1: {3,4}
2: {5,6}
...

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-19 21:46:25 +02:00
..
Makefile bpf: btf: Introduce BPF Type Format (BTF) 2018-04-19 21:46:24 +02:00
arraymap.c bpf: btf: Add pretty print support to the basic arraymap 2018-04-19 21:46:25 +02:00
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: Add BPF_OBJ_GET_INFO_BY_FD support to BTF fd 2018-04-19 21:46:25 +02:00
cgroup.c bpf: Hooks for sys_bind 2018-03-31 02:15:18 +02:00
core.c bpf: fix bpf_prog_array_copy_to_user warning from perf event prog query 2018-02-14 08:59:37 -08:00
cpumap.c xdp: transition into using xdp_frame for return API 2018-04-17 10:50:29 -04:00
devmap.c bpf: add helper for copying attrs to struct bpf_map 2018-01-14 23:36:29 +01:00
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 helper for copying attrs to struct bpf_map 2018-01-14 23:36:29 +01:00
helpers.c bpf: rename ARG_PTR_TO_STACK 2017-01-09 16:56:27 -05:00
inode.c bpf: btf: Add pretty print support to the basic arraymap 2018-04-19 21:46:25 +02:00
lpm_trie.c bpf: fix rcu lockdep warning for lpm_trie map_free callback 2018-02-22 21:29:12 +01:00
map_in_map.c bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
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: offload: report device information about offloaded maps 2018-01-18 22:54:25 +01:00
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
sockmap.c bpf: sockmap, duplicates release calls may NULL sk_prot 2018-04-04 11:04:31 +02:00
stackmap.c bpf: extend stackmap to save binary_build_id+offset instead of address 2018-03-15 01:09:28 +01:00
syscall.c bpf: btf: Add pretty print support to the basic arraymap 2018-04-19 21:46:25 +02:00
tnum.c bpf/verifier: track signed and unsigned min/max values 2017-08-08 17:51:34 -07:00
verifier.c bpf: Hooks for sys_bind 2018-03-31 02:15:18 +02:00