kernel/linux.git/tools/lib/bpf/libbpf.h, branch v6.4.3

libbpf: Ensure print callback usage is thread-safe

2023-03-27T18:33:43+00:00

This patch prevents races on the print function pointer, allowing the libbpf_set_print() function to become thread-safe. Signed-off-by: JP Kobryn Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230325010845.46000-1-inwardvessel@gmail.com

libbpf: Update a bpf_link with another struct_ops.

2023-03-23T05:53:02+00:00

Introduce bpf_link__update_map(), which allows to atomically update underlying struct_ops implementation for given struct_ops BPF link. Also add old_map_fd to struct bpf_link_update_opts to handle BPF_F_REPLACE feature. Signed-off-by: Kui-Feng Lee Link: https://lore.kernel.org/r/20230323032405.3735486-7-kuifeng@meta.com Signed-off-by: Martin KaFai Lau

libbpf: Add support to set kprobe/uprobe attach mode

2023-03-06T17:38:04+00:00

By default, libbpf will attach the kprobe/uprobe BPF program in the latest mode that supported by kernel. In this patch, we add the support to let users manually attach kprobe/uprobe in legacy or perf mode. There are 3 mode that supported by the kernel to attach kprobe/uprobe: LEGACY: create perf event in legacy way and don't use bpf_link PERF: create perf event with perf_event_open() and don't use bpf_link Signed-off-by: Menglong Dong Signed-off-by: Andrii Nakryiko Reviewed-by: Biao Jiang Link: create perf event with perf_event_open() and use bpf_link Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com/ Link: https://lore.kernel.org/bpf/20230306064833.7932-2-imagedong@tencent.com Users now can manually choose the mode with bpf_program__attach_uprobe_opts()/bpf_program__attach_kprobe_opts().

libbpf: Add sample_period to creation options

2023-02-08T23:27:39+00:00

Add option to set when the perf buffer should wake up, by default the perf buffer becomes signaled for every event that is being pushed to it. In case of a high throughput of events it will be more efficient to wake up only once you have X events ready to be read. So your application can wakeup once and drain the entire perf buffer. Signed-off-by: Jon Doron Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230207081916.3398417-1-arilou@gmail.com

libbpf: add API to get XDP/XSK supported features

2023-02-03T04:48:24+00:00

Extend bpf_xdp_query routine in order to get XDP/XSK supported features of netdev over route netlink interface. Extend libbpf netlink implementation in order to support netlink_generic protocol. Co-developed-by: Kumar Kartikeya Dwivedi Signed-off-by: Kumar Kartikeya Dwivedi Co-developed-by: Marek Majtyka Signed-off-by: Marek Majtyka Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/a72609ef4f0de7fee5376c40dbf54ad7f13bfb8d.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Add documentation to map pinning API functions

2023-01-27T22:03:19+00:00

This adds documentation for the following API functions: - bpf_map__set_pin_path() - bpf_map__pin_path() - bpf_map__is_pinned() - bpf_map__pin() - bpf_map__unpin() - bpf_object__pin_maps() - bpf_object__unpin_maps() Signed-off-by: Grant Seltzer Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230126024225.520685-1-grantseltzer@gmail.com

libbpf: Fix malformed documentation formatting

2023-01-27T22:02:03+00:00

This fixes the doxygen format documentation above the user_ring_buffer__* APIs. There has to be a newline before the @brief, otherwise doxygen won't render them for libbpf.readthedocs.org. Signed-off-by: Grant Seltzer Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230126024749.522278-1-grantseltzer@gmail.com

libbpf: Added the description of some API functions

2022-12-29T22:32:20+00:00

Currently, many API functions are not described in the document. Add add API description of the following four API functions: - libbpf_set_print; - bpf_object__open; - bpf_object__load; - bpf_object__close. Signed-off-by: Xin Liu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221224112058.12038-1-liuxin350@huawei.com

libbpf: restore memory layout of bpf_object_open_opts

2022-09-23T23:19:37+00:00

When attach_prog_fd field was removed in libbpf 1.0 and replaced with `long: 0` placeholder, it actually shifted all the subsequent fields by 8 byte. This is due to `long: 0` promising to adjust next field's offset to long-aligned offset. But in this case we were already long-aligned as pin_root_path is a pointer. So `long: 0` had no effect, and thus didn't feel the gap created by removed attach_prog_fd. Non-zero bitfield should have been used instead. I validated using pahole. Originally kconfig field was at offset 40. With `long: 0` it's at offset 32, which is wrong. With this change it's back at offset 40. While technically libbpf 1.0 is allowed to break backwards compatibility and applications should have been recompiled against libbpf 1.0 headers, but given how trivial it is to preserve memory layout, let's fix this. Reported-by: Grant Seltzer Richman Fixes: 146bf811f5ac ("libbpf: remove most other deprecated high-level APIs") Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220923230559.666608-1-andrii@kernel.org Signed-off-by: Martin KaFai Lau

bpf: Add libbpf logic for user-space ring buffer

2022-09-21T23:25:03+00:00

Now that all of the logic is in place in the kernel to support user-space produced ring buffers, we can add the user-space logic to libbpf. This patch therefore adds the following public symbols to libbpf: struct user_ring_buffer * user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, __u32 size, int timeout_ms); void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); void user_ring_buffer__discard(struct user_ring_buffer *rb, void user_ring_buffer__free(struct user_ring_buffer *rb); A user-space producer must first create a struct user_ring_buffer * object with user_ring_buffer__new(), and can then reserve samples in the ring buffer using one of the following two symbols: void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, __u32 size, int timeout_ms); With user_ring_buffer__reserve(), a pointer to a 'size' region of the ring buffer will be returned if sufficient space is available in the buffer. user_ring_buffer__reserve_blocking() provides similar semantics, but will block for up to 'timeout_ms' in epoll_wait if there is insufficient space in the buffer. This function has the guarantee from the kernel that it will receive at least one event-notification per invocation to bpf_ringbuf_drain(), provided that at least one sample is drained, and the BPF program did not pass the BPF_RB_NO_WAKEUP flag to bpf_ringbuf_drain(). Once a sample is reserved, it must either be committed to the ring buffer with user_ring_buffer__submit(), or discarded with user_ring_buffer__discard(). Signed-off-by: David Vernet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220920000100.477320-4-void@manifault.com