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2e4913e025
Wire up libbpf USDT support APIs without yet implementing all the
nitty-gritty details of USDT discovery, spec parsing, and BPF map
initialization.
User-visible user-space API is simple and is conceptually very similar
to uprobe API.
bpf_program__attach_usdt() API allows to programmatically attach given
BPF program to a USDT, specified through binary path (executable or
shared lib), USDT provider and name. Also, just like in uprobe case, PID
filter is specified (0 - self, -1 - any process, or specific PID).
Optionally, USDT cookie value can be specified. Such single API
invocation will try to discover given USDT in specified binary and will
use (potentially many) BPF uprobes to attach this program in correct
locations.
Just like any bpf_program__attach_xxx() APIs, bpf_link is returned that
represents this attachment. It is a virtual BPF link that doesn't have
direct kernel object, as it can consist of multiple underlying BPF
uprobe links. As such, attachment is not atomic operation and there can
be brief moment when some USDT call sites are attached while others are
still in the process of attaching. This should be taken into
consideration by user. But bpf_program__attach_usdt() guarantees that
in the case of success all USDT call sites are successfully attached, or
all the successfuly attachments will be detached as soon as some USDT
call sites failed to be attached. So, in theory, there could be cases of
failed bpf_program__attach_usdt() call which did trigger few USDT
program invocations. This is unavoidable due to multi-uprobe nature of
USDT and has to be handled by user, if it's important to create an
illusion of atomicity.
USDT BPF programs themselves are marked in BPF source code as either
SEC("usdt"), in which case they won't be auto-attached through
skeleton's <skel>__attach() method, or it can have a full definition,
which follows the spirit of fully-specified uprobes:
SEC("usdt/<path>:<provider>:<name>"). In the latter case skeleton's
attach method will attempt auto-attachment. Similarly, generic
bpf_program__attach() will have enought information to go off of for
parameterless attachment.
USDT BPF programs are actually uprobes, and as such for kernel they are
marked as BPF_PROG_TYPE_KPROBE.
Another part of this patch is USDT-related feature probing:
- BPF cookie support detection from user-space;
- detection of kernel support for auto-refcounting of USDT semaphore.
The latter is optional. If kernel doesn't support such feature and USDT
doesn't rely on USDT semaphores, no error is returned. But if libbpf
detects that USDT requires setting semaphores and kernel doesn't support
this, libbpf errors out with explicit pr_warn() message. Libbpf doesn't
support poking process's memory directly to increment semaphore value,
like BCC does on legacy kernels, due to inherent raciness and danger of
such process memory manipulation. Libbpf let's kernel take care of this
properly or gives up.
Logistically, all the extra USDT-related infrastructure of libbpf is put
into a separate usdt.c file and abstracted behind struct usdt_manager.
Each bpf_object has lazily-initialized usdt_manager pointer, which is
only instantiated if USDT programs are attempted to be attached. Closing
BPF object frees up usdt_manager resources. usdt_manager keeps track of
USDT spec ID assignment and few other small things.
Subsequent patches will fill out remaining missing pieces of USDT
initialization and setup logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-3-andrii@kernel.org
452 lines
9.7 KiB
Plaintext
452 lines
9.7 KiB
Plaintext
LIBBPF_0.0.1 {
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global:
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bpf_btf_get_fd_by_id;
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bpf_create_map;
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bpf_create_map_in_map;
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bpf_create_map_in_map_node;
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bpf_create_map_name;
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bpf_create_map_node;
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bpf_create_map_xattr;
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bpf_load_btf;
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bpf_load_program;
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bpf_load_program_xattr;
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bpf_map__btf_key_type_id;
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bpf_map__btf_value_type_id;
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bpf_map__def;
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bpf_map__fd;
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bpf_map__is_offload_neutral;
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bpf_map__name;
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bpf_map__next;
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bpf_map__pin;
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bpf_map__prev;
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bpf_map__priv;
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bpf_map__reuse_fd;
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bpf_map__set_ifindex;
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bpf_map__set_inner_map_fd;
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bpf_map__set_priv;
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bpf_map__unpin;
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bpf_map_delete_elem;
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bpf_map_get_fd_by_id;
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bpf_map_get_next_id;
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bpf_map_get_next_key;
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bpf_map_lookup_and_delete_elem;
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bpf_map_lookup_elem;
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bpf_map_update_elem;
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bpf_obj_get;
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bpf_obj_get_info_by_fd;
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bpf_obj_pin;
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bpf_object__btf_fd;
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bpf_object__close;
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bpf_object__find_map_by_name;
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bpf_object__find_map_by_offset;
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bpf_object__find_program_by_title;
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bpf_object__kversion;
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bpf_object__load;
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bpf_object__name;
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bpf_object__next;
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bpf_object__open;
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bpf_object__open_buffer;
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bpf_object__open_xattr;
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bpf_object__pin;
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bpf_object__pin_maps;
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bpf_object__pin_programs;
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bpf_object__priv;
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bpf_object__set_priv;
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bpf_object__unload;
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bpf_object__unpin_maps;
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bpf_object__unpin_programs;
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bpf_perf_event_read_simple;
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bpf_prog_attach;
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bpf_prog_detach;
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bpf_prog_detach2;
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bpf_prog_get_fd_by_id;
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bpf_prog_get_next_id;
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bpf_prog_load;
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bpf_prog_load_xattr;
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bpf_prog_query;
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bpf_prog_test_run;
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bpf_prog_test_run_xattr;
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bpf_program__fd;
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bpf_program__is_kprobe;
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bpf_program__is_perf_event;
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bpf_program__is_raw_tracepoint;
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bpf_program__is_sched_act;
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bpf_program__is_sched_cls;
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bpf_program__is_socket_filter;
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bpf_program__is_tracepoint;
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bpf_program__is_xdp;
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bpf_program__load;
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bpf_program__next;
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bpf_program__nth_fd;
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bpf_program__pin;
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bpf_program__pin_instance;
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bpf_program__prev;
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bpf_program__priv;
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bpf_program__set_expected_attach_type;
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bpf_program__set_ifindex;
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bpf_program__set_kprobe;
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bpf_program__set_perf_event;
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bpf_program__set_prep;
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bpf_program__set_priv;
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bpf_program__set_raw_tracepoint;
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bpf_program__set_sched_act;
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bpf_program__set_sched_cls;
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bpf_program__set_socket_filter;
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bpf_program__set_tracepoint;
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bpf_program__set_type;
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bpf_program__set_xdp;
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bpf_program__title;
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bpf_program__unload;
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bpf_program__unpin;
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bpf_program__unpin_instance;
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bpf_prog_linfo__free;
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bpf_prog_linfo__new;
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bpf_prog_linfo__lfind_addr_func;
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bpf_prog_linfo__lfind;
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bpf_raw_tracepoint_open;
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bpf_set_link_xdp_fd;
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bpf_task_fd_query;
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bpf_verify_program;
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btf__fd;
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btf__find_by_name;
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btf__free;
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btf__get_from_id;
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btf__name_by_offset;
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btf__new;
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btf__resolve_size;
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btf__resolve_type;
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btf__type_by_id;
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libbpf_attach_type_by_name;
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libbpf_get_error;
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libbpf_prog_type_by_name;
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libbpf_set_print;
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libbpf_strerror;
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local:
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*;
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};
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LIBBPF_0.0.2 {
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global:
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bpf_probe_helper;
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bpf_probe_map_type;
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bpf_probe_prog_type;
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bpf_map__resize;
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bpf_map_lookup_elem_flags;
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bpf_object__btf;
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bpf_object__find_map_fd_by_name;
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bpf_get_link_xdp_id;
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btf__dedup;
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btf__get_map_kv_tids;
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btf__get_nr_types;
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btf__get_raw_data;
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btf__load;
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btf_ext__free;
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btf_ext__func_info_rec_size;
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btf_ext__get_raw_data;
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btf_ext__line_info_rec_size;
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btf_ext__new;
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btf_ext__reloc_func_info;
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btf_ext__reloc_line_info;
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xsk_umem__create;
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xsk_socket__create;
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xsk_umem__delete;
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xsk_socket__delete;
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xsk_umem__fd;
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xsk_socket__fd;
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bpf_program__get_prog_info_linear;
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bpf_program__bpil_addr_to_offs;
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bpf_program__bpil_offs_to_addr;
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} LIBBPF_0.0.1;
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LIBBPF_0.0.3 {
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global:
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bpf_map__is_internal;
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bpf_map_freeze;
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btf__finalize_data;
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} LIBBPF_0.0.2;
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LIBBPF_0.0.4 {
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global:
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bpf_link__destroy;
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bpf_object__load_xattr;
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bpf_program__attach_kprobe;
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bpf_program__attach_perf_event;
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bpf_program__attach_raw_tracepoint;
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bpf_program__attach_tracepoint;
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bpf_program__attach_uprobe;
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btf_dump__dump_type;
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btf_dump__free;
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btf_dump__new;
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btf__parse_elf;
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libbpf_num_possible_cpus;
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perf_buffer__free;
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perf_buffer__new;
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perf_buffer__new_raw;
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perf_buffer__poll;
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xsk_umem__create;
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} LIBBPF_0.0.3;
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LIBBPF_0.0.5 {
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global:
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bpf_btf_get_next_id;
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} LIBBPF_0.0.4;
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LIBBPF_0.0.6 {
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global:
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bpf_get_link_xdp_info;
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bpf_map__get_pin_path;
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bpf_map__is_pinned;
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bpf_map__set_pin_path;
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bpf_object__open_file;
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bpf_object__open_mem;
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bpf_program__attach_trace;
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bpf_program__get_expected_attach_type;
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bpf_program__get_type;
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bpf_program__is_tracing;
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bpf_program__set_tracing;
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bpf_program__size;
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btf__find_by_name_kind;
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libbpf_find_vmlinux_btf_id;
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} LIBBPF_0.0.5;
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LIBBPF_0.0.7 {
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global:
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btf_dump__emit_type_decl;
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bpf_link__disconnect;
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bpf_map__attach_struct_ops;
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bpf_map_delete_batch;
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bpf_map_lookup_and_delete_batch;
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bpf_map_lookup_batch;
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bpf_map_update_batch;
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bpf_object__find_program_by_name;
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bpf_object__attach_skeleton;
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bpf_object__destroy_skeleton;
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bpf_object__detach_skeleton;
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bpf_object__load_skeleton;
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bpf_object__open_skeleton;
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bpf_probe_large_insn_limit;
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bpf_prog_attach_xattr;
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bpf_program__attach;
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bpf_program__name;
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bpf_program__is_extension;
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bpf_program__is_struct_ops;
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bpf_program__set_extension;
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bpf_program__set_struct_ops;
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btf__align_of;
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libbpf_find_kernel_btf;
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} LIBBPF_0.0.6;
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LIBBPF_0.0.8 {
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global:
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bpf_link__fd;
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bpf_link__open;
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bpf_link__pin;
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bpf_link__pin_path;
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bpf_link__unpin;
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bpf_link__update_program;
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bpf_link_create;
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bpf_link_update;
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bpf_map__set_initial_value;
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bpf_prog_attach_opts;
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bpf_program__attach_cgroup;
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bpf_program__attach_lsm;
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bpf_program__is_lsm;
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bpf_program__set_attach_target;
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bpf_program__set_lsm;
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bpf_set_link_xdp_fd_opts;
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} LIBBPF_0.0.7;
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LIBBPF_0.0.9 {
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global:
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bpf_enable_stats;
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bpf_iter_create;
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bpf_link_get_fd_by_id;
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bpf_link_get_next_id;
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bpf_program__attach_iter;
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bpf_program__attach_netns;
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perf_buffer__consume;
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ring_buffer__add;
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ring_buffer__consume;
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ring_buffer__free;
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ring_buffer__new;
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ring_buffer__poll;
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} LIBBPF_0.0.8;
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LIBBPF_0.1.0 {
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global:
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bpf_link__detach;
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bpf_link_detach;
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bpf_map__ifindex;
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bpf_map__key_size;
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bpf_map__map_flags;
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bpf_map__max_entries;
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bpf_map__numa_node;
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bpf_map__set_key_size;
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bpf_map__set_map_flags;
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bpf_map__set_max_entries;
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bpf_map__set_numa_node;
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bpf_map__set_type;
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bpf_map__set_value_size;
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bpf_map__type;
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bpf_map__value_size;
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bpf_program__attach_xdp;
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bpf_program__autoload;
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bpf_program__is_sk_lookup;
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bpf_program__set_autoload;
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bpf_program__set_sk_lookup;
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btf__parse;
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btf__parse_raw;
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btf__pointer_size;
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btf__set_fd;
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btf__set_pointer_size;
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} LIBBPF_0.0.9;
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LIBBPF_0.2.0 {
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global:
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bpf_prog_bind_map;
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bpf_prog_test_run_opts;
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bpf_program__attach_freplace;
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bpf_program__section_name;
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btf__add_array;
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btf__add_const;
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btf__add_enum;
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btf__add_enum_value;
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btf__add_datasec;
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btf__add_datasec_var_info;
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btf__add_field;
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btf__add_func;
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btf__add_func_param;
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btf__add_func_proto;
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btf__add_fwd;
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btf__add_int;
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btf__add_ptr;
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btf__add_restrict;
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btf__add_str;
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btf__add_struct;
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btf__add_typedef;
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btf__add_union;
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btf__add_var;
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btf__add_volatile;
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btf__endianness;
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btf__find_str;
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btf__new_empty;
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btf__set_endianness;
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btf__str_by_offset;
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perf_buffer__buffer_cnt;
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perf_buffer__buffer_fd;
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perf_buffer__epoll_fd;
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perf_buffer__consume_buffer;
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xsk_socket__create_shared;
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} LIBBPF_0.1.0;
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LIBBPF_0.3.0 {
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global:
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btf__base_btf;
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btf__parse_elf_split;
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btf__parse_raw_split;
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btf__parse_split;
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btf__new_empty_split;
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btf__new_split;
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ring_buffer__epoll_fd;
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xsk_setup_xdp_prog;
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xsk_socket__update_xskmap;
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} LIBBPF_0.2.0;
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LIBBPF_0.4.0 {
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global:
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btf__add_float;
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btf__add_type;
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bpf_linker__add_file;
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bpf_linker__finalize;
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bpf_linker__free;
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bpf_linker__new;
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bpf_map__inner_map;
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bpf_object__set_kversion;
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bpf_tc_attach;
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bpf_tc_detach;
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bpf_tc_hook_create;
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bpf_tc_hook_destroy;
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bpf_tc_query;
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} LIBBPF_0.3.0;
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LIBBPF_0.5.0 {
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global:
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bpf_map__initial_value;
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bpf_map__pin_path;
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bpf_map_lookup_and_delete_elem_flags;
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bpf_program__attach_kprobe_opts;
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bpf_program__attach_perf_event_opts;
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bpf_program__attach_tracepoint_opts;
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bpf_program__attach_uprobe_opts;
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bpf_object__gen_loader;
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btf__load_from_kernel_by_id;
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btf__load_from_kernel_by_id_split;
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btf__load_into_kernel;
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btf__load_module_btf;
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btf__load_vmlinux_btf;
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btf_dump__dump_type_data;
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libbpf_set_strict_mode;
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} LIBBPF_0.4.0;
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LIBBPF_0.6.0 {
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global:
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bpf_map__map_extra;
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bpf_map__set_map_extra;
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bpf_map_create;
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bpf_object__next_map;
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bpf_object__next_program;
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bpf_object__prev_map;
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bpf_object__prev_program;
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bpf_prog_load_deprecated;
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bpf_prog_load;
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bpf_program__flags;
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bpf_program__insn_cnt;
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bpf_program__insns;
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bpf_program__set_flags;
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btf__add_btf;
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btf__add_decl_tag;
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btf__add_type_tag;
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btf__dedup;
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btf__dedup_deprecated;
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btf__raw_data;
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btf__type_cnt;
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btf_dump__new;
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btf_dump__new_deprecated;
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libbpf_major_version;
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libbpf_minor_version;
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libbpf_version_string;
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perf_buffer__new;
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perf_buffer__new_deprecated;
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perf_buffer__new_raw;
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perf_buffer__new_raw_deprecated;
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} LIBBPF_0.5.0;
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LIBBPF_0.7.0 {
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global:
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bpf_btf_load;
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bpf_program__expected_attach_type;
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bpf_program__log_buf;
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bpf_program__log_level;
|
|
bpf_program__set_log_buf;
|
|
bpf_program__set_log_level;
|
|
bpf_program__type;
|
|
bpf_xdp_attach;
|
|
bpf_xdp_detach;
|
|
bpf_xdp_query;
|
|
bpf_xdp_query_id;
|
|
libbpf_probe_bpf_helper;
|
|
libbpf_probe_bpf_map_type;
|
|
libbpf_probe_bpf_prog_type;
|
|
libbpf_set_memlock_rlim_max;
|
|
} LIBBPF_0.6.0;
|
|
|
|
LIBBPF_0.8.0 {
|
|
global:
|
|
bpf_object__destroy_subskeleton;
|
|
bpf_object__open_subskeleton;
|
|
bpf_program__attach_usdt;
|
|
libbpf_register_prog_handler;
|
|
libbpf_unregister_prog_handler;
|
|
bpf_program__attach_kprobe_multi_opts;
|
|
} LIBBPF_0.7.0;
|