kernel/tools/lib/bpf/libbpf.h, branch linux-5.11.y

libbpf: Add explicit padding to bpf_xdp_set_link_opts

2021-05-14T08:50:00Z

[ Upstream commit dde7b3f5f2f458297aeccfd4783e53ab8ca046db ] Adding such anonymous padding fixes the issue with uninitialized portions of bpf_xdp_set_link_opts when using LIBBPF_DECLARE_OPTS macro with inline field initialization: DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1); When such code is compiled in debug mode, compiler is generating code that leaves padding bytes uninitialized, which triggers error inside libbpf APIs that do strict zero initialization checks for OPTS structs. Adding anonymous padding field fixes the issue. Fixes: bd5ca3ef93cd ("libbpf: Add function to set link XDP fd while specifying old program") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@kernel.org Signed-off-by: Sasha Levin

libbpf: Expose libbpf ring_buffer epoll_fd

2020-12-14T18:04:55Z

This provides a convenient perf ringbuf -> libbpf ringbuf migration path for users of external polling systems. It is analogous to perf_buffer__epoll_fd. Signed-off-by: Brendan Jackman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201214113812.305274-1-jackmanb@google.com

libbpf: Add support for freplace attachment in bpf_link_create

2020-09-29T20:09:24Z

This adds support for supplying a target btf ID for the bpf_link_create() operation, and adds a new bpf_program__attach_freplace() high-level API for attaching freplace functions with a target. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/160138355387.48470.18026176785351166890.stgit@toke.dk

libbpf: Deprecate notion of BPF program "title" in favor of "section name"

2020-09-04T00:14:40Z

BPF program title is ambigious and misleading term. It is ELF section name, so let's just call it that and deprecate bpf_program__title() API in favor of bpf_program__section_name(). Additionally, using bpf_object__find_program_by_title() is now inherently dangerous and ambiguous, as multiple BPF program can have the same section name. So deprecate this API as well and recommend to switch to non-ambiguous bpf_object__find_program_by_name(). Internally, clean up usage and mis-usage of BPF program section name for denoting BPF program name. Shorten the field name to prog->sec_name to be consistent with all other prog->sec_* variables. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200903203542.15944-11-andriin@fb.com

libbpf: Add perf_buffer APIs for better integration with outside epoll loop

2020-08-21T21:26:55Z

Add a set of APIs to perf_buffer manage to allow applications to integrate perf buffer polling into existing epoll-based infrastructure. One example is applications using libevent already and wanting to plug perf_buffer polling, instead of relying on perf_buffer__poll() and waste an extra thread to do it. But perf_buffer is still extremely useful to set up and consume perf buffer rings even for such use cases. So to accomodate such new use cases, add three new APIs: - perf_buffer__buffer_cnt() returns number of per-CPU buffers maintained by given instance of perf_buffer manager; - perf_buffer__buffer_fd() returns FD of perf_event corresponding to a specified per-CPU buffer; this FD is then polled independently; - perf_buffer__consume_buffer() consumes data from single per-CPU buffer, identified by its slot index. To support a simpler, but less efficient, way to integrate perf_buffer into external polling logic, also expose underlying epoll FD through perf_buffer__epoll_fd() API. It will need to be followed by perf_buffer__poll(), wasting extra syscall, or perf_buffer__consume(), wasting CPU to iterate buffers with no data. But could be simpler and more convenient for some cases. These APIs allow for great flexiblity, but do not sacrifice general usability of perf_buffer. Also exercise and check new APIs in perf_buffer selftest. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Reviewed-by: Alan Maguire Link: https://lore.kernel.org/bpf/20200821165927.849538-1-andriin@fb.com

tools/bpf: Support new uapi for map element bpf iterator

2020-08-06T23:39:14Z

Previous commit adjusted kernel uapi for map element bpf iterator. This patch adjusted libbpf API due to uapi change. bpftool and bpf_iter selftests are also changed accordingly. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200805055058.1457623-1-yhs@fb.com

libbpf: Add bpf_link detach APIs

2020-08-02T03:38:28Z

Add low-level bpf_link_detach() API. Also add higher-level bpf_link__detach() one. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200731182830.286260-3-andriin@fb.com

libbpf: Add support for BPF XDP link

2020-07-26T03:37:02Z

Sync UAPI header and add support for using bpf_link-based XDP attachment. Make xdp/ prog type set expected attach type. Kernel didn't enforce attach_type for XDP programs before, so there is no backwards compatiblity issues there. Also fix section_names selftest to recognize that xdp prog types now have expected attach type. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200722064603.3350758-8-andriin@fb.com

tools/libbpf: Add support for bpf map element iterator

2020-07-26T03:16:33Z

Add map_fd to bpf_iter_attach_opts and flags to bpf_link_create_opts. Later on, bpftool or selftest will be able to create a bpf map element iterator by passing map_fd to the kernel during link creation time. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200723184117.590673-1-yhs@fb.com

libbpf: Add support for SK_LOOKUP program type

2020-07-18T03:18:17Z

Make libbpf aware of the newly added program type, and assign it a section name. Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200717103536.397595-13-jakub@cloudflare.com