linux/include
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
..
acpi xen: fixes for 4.17-rc1 2018-04-12 11:04:35 -07:00
asm-generic asm-generic fixes for v4.17-rc1 2018-04-12 09:15:48 -07:00
clocksource
crypto
drm
dt-bindings
keys
kvm
linux bpf: btf: Add pretty print support to the basic arraymap 2018-04-19 21:46:25 +02:00
math-emu
media
memory
misc
net vxlan: add ttl inherit support 2018-04-17 13:53:13 -04:00
pcmcia
ras
rdma
scsi
soc
sound
target
trace net: Remove unused tcp_set_state tracepoint 2018-04-16 19:02:15 -04:00
uapi bpf: btf: Add pretty print support to the basic arraymap 2018-04-19 21:46:25 +02:00
video
xen