linux/tools/lib/bpf
Andrii Nakryiko 697f104db8 libbpf: Support custom SEC() handlers
Allow registering and unregistering custom handlers for BPF program.
This allows user applications and libraries to plug into libbpf's
declarative SEC() definition handling logic. This allows to offload
complex and intricate custom logic into external libraries, but still
provide a great user experience.

One such example is USDT handling library, which has a lot of code and
complexity which doesn't make sense to put into libbpf directly, but it
would be really great for users to be able to specify BPF programs with
something like SEC("usdt/<path-to-binary>:<usdt_provider>:<usdt_name>")
and have correct BPF program type set (BPF_PROGRAM_TYPE_KPROBE, as it is
uprobe) and even support BPF skeleton's auto-attach logic.

In some cases, it might be even good idea to override libbpf's default
handling, like for SEC("perf_event") programs. With custom library, it's
possible to extend logic to support specifying perf event specification
right there in SEC() definition without burdening libbpf with lots of
custom logic or extra library dependecies (e.g., libpfm4). With current
patch it's possible to override libbpf's SEC("perf_event") handling and
specify a completely custom ones.

Further, it's possible to specify a generic fallback handling for any
SEC() that doesn't match any other custom or standard libbpf handlers.
This allows to accommodate whatever legacy use cases there might be, if
necessary.

See doc comments for libbpf_register_prog_handler() and
libbpf_unregister_prog_handler() for detailed semantics.

This patch also bumps libbpf development version to v0.8 and adds new
APIs there.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220305010129.1549719-3-andrii@kernel.org
2022-03-05 09:38:15 -08:00
..
.gitignore libbpf: Make libbpf_version.h non-auto-generated 2021-09-13 15:36:47 -07:00
bpf_core_read.h libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED() 2021-10-25 20:39:41 -07:00
bpf_endian.h
bpf_gen_internal.h Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-10 15:56:13 -08:00
bpf_helpers.h libbpf: deprecate legacy BPF map definitions 2022-01-20 21:19:05 -08:00
bpf_prog_linfo.c libbpf: Streamline error reporting for high-level APIs 2021-05-25 17:32:35 -07:00
bpf_tracing.h libbpf: Add BPF_KPROBE_SYSCALL macro 2022-02-08 21:45:02 -08:00
bpf.c libbpf: Rename bpf_prog_attach_xattr() to bpf_prog_attach_opts() 2022-01-12 17:01:37 -08:00
bpf.h libbpf: Deprecate bpf_prog_test_run_xattr and bpf_prog_test_run 2022-02-02 22:31:18 -08:00
btf_dump.c libbpf: Skip forward declaration when counting duplicated type names 2022-03-01 13:40:57 +01:00
btf.c libbpf: Improve btf__add_btf() with an additional hashmap for strings. 2022-01-19 10:57:27 -08:00
btf.h libbpf: Deprecate forgotten btf__get_map_kv_tids() 2022-02-04 01:07:16 +01:00
Build libbpf: Split CO-RE logic into relo_core.c. 2021-07-26 12:29:14 -07:00
gen_loader.c libbpf: Prepare light skeleton for the kernel. 2022-02-10 23:31:51 +01:00
hashmap.c libbpf: Use IS_ERR_OR_NULL() in hashmap__free() 2022-01-12 17:01:36 -08:00
hashmap.h libbpf, hashmap: Fix undefined behavior in hash_bits 2020-11-02 23:33:51 +01:00
libbpf_common.h libbpf: Deprecate bpf_prog_load_xattr() API 2021-12-02 15:23:41 -08:00
libbpf_errno.c libbpf: Streamline error reporting for high-level APIs 2021-05-25 17:32:35 -07:00
libbpf_internal.h libbpf: Expose bpf_core_{add,free}_cands() to bpftool 2022-02-16 10:05:45 -08:00
libbpf_legacy.h libbpf: hide and discourage inconsistently named getters 2022-01-25 17:59:06 -08:00
libbpf_probes.c libbpf: Improve LINUX_VERSION_CODE detection 2021-12-28 19:20:31 -08:00
libbpf_version.h libbpf: Support custom SEC() handlers 2022-03-05 09:38:15 -08:00
libbpf.c libbpf: Support custom SEC() handlers 2022-03-05 09:38:15 -08:00
libbpf.h libbpf: Support custom SEC() handlers 2022-03-05 09:38:15 -08:00
libbpf.map libbpf: Support custom SEC() handlers 2022-03-05 09:38:15 -08:00
libbpf.pc.template
linker.c libbpf: Fix using invalidated memory in bpf_linker 2021-11-26 00:15:03 +01:00
Makefile libbpf: Fix build issue with llvm-readelf 2022-02-04 18:22:56 -08:00
netlink.c libbpf: Fix memleak in libbpf_netlink_recv() 2022-02-17 16:09:07 +01:00
nlattr.c libbpf: Switch to void * casting in netlink helpers 2021-06-22 17:04:02 +02:00
nlattr.h libbpf: Switch to void * casting in netlink helpers 2021-06-22 17:04:02 +02:00
relo_core.c libbpf: Split bpf_core_apply_relo() 2022-02-16 10:05:42 -08:00
relo_core.h libbpf: Split bpf_core_apply_relo() 2022-02-16 10:05:42 -08:00
ringbuf.c libbpf: Streamline error reporting for high-level APIs 2021-05-25 17:32:35 -07:00
skel_internal.h libbpf: Prepare light skeleton for the kernel. 2022-02-10 23:31:51 +01:00
str_error.c
str_error.h
strset.c libbpf: Fix memory leak in strset 2021-10-01 22:54:38 +02:00
strset.h libbpf: Extract internal set-of-strings datastructure APIs 2021-03-18 16:14:22 -07:00
xsk.c libbpf: Add sane strncpy alternative and use it internally 2021-12-14 15:47:56 +01:00
xsk.h libbpf: Deprecate AF_XDP support 2021-11-01 18:12:44 -07:00