linux/tools/lib/bpf/libbpf.map
Andrey Ignatov 1a11a4c74f libbpf: Introduce bpf_map__resize
Add bpf_map__resize() to change max_entries for a map.

Quite often necessary map size is unknown at compile time and can be
calculated only at run time.

Currently the following approach is used to do so:
* bpf_object__open_buffer() to open Elf file from a buffer;
* bpf_object__find_map_by_name() to find relevant map;
* bpf_map__def() to get map attributes and create struct
  bpf_create_map_attr from them;
* update max_entries in bpf_create_map_attr;
* bpf_create_map_xattr() to create new map with updated max_entries;
* bpf_map__reuse_fd() to replace the map in bpf_object with newly
  created one.

And after all this bpf_object can finally be loaded. The map will have
new size.

It 1) is quite a lot of steps; 2) doesn't take BTF into account.

For "2)" even more steps should be made and some of them require changes
to libbpf (e.g. to get struct btf * from bpf_object).

Instead the whole problem can be solved by introducing simple
bpf_map__resize() API that checks the map and sets new max_entries if
the map is not loaded yet.

So the new steps are:
* bpf_object__open_buffer() to open Elf file from a buffer;
* bpf_object__find_map_by_name() to find relevant map;
* bpf_map__resize() to update max_entries.

That's much simpler and works with BTF.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-15 15:20:42 +01:00

149 lines
3.3 KiB
Text

LIBBPF_0.0.1 {
global:
bpf_btf_get_fd_by_id;
bpf_create_map;
bpf_create_map_in_map;
bpf_create_map_in_map_node;
bpf_create_map_name;
bpf_create_map_node;
bpf_create_map_xattr;
bpf_load_btf;
bpf_load_program;
bpf_load_program_xattr;
bpf_map__btf_key_type_id;
bpf_map__btf_value_type_id;
bpf_map__def;
bpf_map__fd;
bpf_map__is_offload_neutral;
bpf_map__name;
bpf_map__next;
bpf_map__pin;
bpf_map__prev;
bpf_map__priv;
bpf_map__reuse_fd;
bpf_map__set_ifindex;
bpf_map__set_inner_map_fd;
bpf_map__set_priv;
bpf_map__unpin;
bpf_map_delete_elem;
bpf_map_get_fd_by_id;
bpf_map_get_next_id;
bpf_map_get_next_key;
bpf_map_lookup_and_delete_elem;
bpf_map_lookup_elem;
bpf_map_update_elem;
bpf_obj_get;
bpf_obj_get_info_by_fd;
bpf_obj_pin;
bpf_object__btf_fd;
bpf_object__close;
bpf_object__find_map_by_name;
bpf_object__find_map_by_offset;
bpf_object__find_program_by_title;
bpf_object__kversion;
bpf_object__load;
bpf_object__name;
bpf_object__next;
bpf_object__open;
bpf_object__open_buffer;
bpf_object__open_xattr;
bpf_object__pin;
bpf_object__pin_maps;
bpf_object__pin_programs;
bpf_object__priv;
bpf_object__set_priv;
bpf_object__unload;
bpf_object__unpin_maps;
bpf_object__unpin_programs;
bpf_perf_event_read_simple;
bpf_prog_attach;
bpf_prog_detach;
bpf_prog_detach2;
bpf_prog_get_fd_by_id;
bpf_prog_get_next_id;
bpf_prog_load;
bpf_prog_load_xattr;
bpf_prog_query;
bpf_prog_test_run;
bpf_prog_test_run_xattr;
bpf_program__fd;
bpf_program__is_kprobe;
bpf_program__is_perf_event;
bpf_program__is_raw_tracepoint;
bpf_program__is_sched_act;
bpf_program__is_sched_cls;
bpf_program__is_socket_filter;
bpf_program__is_tracepoint;
bpf_program__is_xdp;
bpf_program__load;
bpf_program__next;
bpf_program__nth_fd;
bpf_program__pin;
bpf_program__pin_instance;
bpf_program__prev;
bpf_program__priv;
bpf_program__set_expected_attach_type;
bpf_program__set_ifindex;
bpf_program__set_kprobe;
bpf_program__set_perf_event;
bpf_program__set_prep;
bpf_program__set_priv;
bpf_program__set_raw_tracepoint;
bpf_program__set_sched_act;
bpf_program__set_sched_cls;
bpf_program__set_socket_filter;
bpf_program__set_tracepoint;
bpf_program__set_type;
bpf_program__set_xdp;
bpf_program__title;
bpf_program__unload;
bpf_program__unpin;
bpf_program__unpin_instance;
bpf_prog_linfo__free;
bpf_prog_linfo__new;
bpf_prog_linfo__lfind_addr_func;
bpf_prog_linfo__lfind;
bpf_raw_tracepoint_open;
bpf_set_link_xdp_fd;
bpf_task_fd_query;
bpf_verify_program;
btf__fd;
btf__find_by_name;
btf__free;
btf__get_from_id;
btf__name_by_offset;
btf__new;
btf__resolve_size;
btf__resolve_type;
btf__type_by_id;
libbpf_attach_type_by_name;
libbpf_get_error;
libbpf_prog_type_by_name;
libbpf_set_print;
libbpf_strerror;
local:
*;
};
LIBBPF_0.0.2 {
global:
bpf_probe_helper;
bpf_probe_map_type;
bpf_probe_prog_type;
bpf_map__resize;
bpf_map_lookup_elem_flags;
bpf_object__find_map_fd_by_name;
bpf_get_link_xdp_id;
btf__dedup;
btf__get_map_kv_tids;
btf__get_nr_types;
btf__get_raw_data;
btf__load;
btf_ext__free;
btf_ext__func_info_rec_size;
btf_ext__get_raw_data;
btf_ext__line_info_rec_size;
btf_ext__new;
btf_ext__reloc_func_info;
btf_ext__reloc_line_info;
} LIBBPF_0.0.1;