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12d9466d8b
Refactor internals of libbpf to allow adding custom SEC() handling logic easily from outside of libbpf. To that effect, each SEC()-handling registration sets mandatory program type/expected attach type for a given prefix and can provide three callbacks called at different points of BPF program lifetime: - init callback for right after bpf_program is initialized and prog_type/expected_attach_type is set. This happens during bpf_object__open() step, close to the very end of constructing bpf_object, so all the libbpf APIs for querying and updating bpf_program properties should be available; - pre-load callback is called right before BPF_PROG_LOAD command is called in the kernel. This callbacks has ability to set both bpf_program properties, as well as program load attributes, overriding and augmenting the standard libbpf handling of them; - optional auto-attach callback, which makes a given SEC() handler support auto-attachment of a BPF program through bpf_program__attach() API and/or BPF skeletons <skel>__attach() method. Each callbacks gets a `long cookie` parameter passed in, which is specified during SEC() handling. This can be used by callbacks to lookup whatever additional information is necessary. This is not yet completely ready to be exposed to the outside world, mainly due to non-public nature of struct bpf_prog_load_params. Instead of making it part of public API, we'll wait until the planned low-level libbpf API improvements for BPF_PROG_LOAD and other typical bpf() syscall APIs, at which point we'll have a public, probably OPTS-based, way to fully specify BPF program load parameters, which will be used as an interface for custom pre-load callbacks. But this change itself is already a good first step to unify the BPF program hanling logic even within the libbpf itself. As one example, all the extra per-program type handling (sleepable bit, attach_btf_id resolution, unsetting optional expected attach type) is now more obvious and is gathered in one place. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20210928161946.2512801-6-andrii@kernel.org |
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| .. | ||
| .gitignore | ||
| bpf.c | ||
| bpf.h | ||
| bpf_core_read.h | ||
| bpf_endian.h | ||
| bpf_gen_internal.h | ||
| bpf_helpers.h | ||
| bpf_prog_linfo.c | ||
| bpf_tracing.h | ||
| btf.c | ||
| btf.h | ||
| btf_dump.c | ||
| Build | ||
| gen_loader.c | ||
| hashmap.c | ||
| hashmap.h | ||
| libbpf.c | ||
| libbpf.h | ||
| libbpf.map | ||
| libbpf.pc.template | ||
| libbpf_common.h | ||
| libbpf_errno.c | ||
| libbpf_internal.h | ||
| libbpf_legacy.h | ||
| libbpf_probes.c | ||
| libbpf_version.h | ||
| linker.c | ||
| Makefile | ||
| netlink.c | ||
| nlattr.c | ||
| nlattr.h | ||
| relo_core.c | ||
| relo_core.h | ||
| ringbuf.c | ||
| skel_internal.h | ||
| str_error.c | ||
| str_error.h | ||
| strset.c | ||
| strset.h | ||
| xsk.c | ||
| xsk.h | ||