linux/tools/lib/bpf/libbpf.map, branch v5.3

libbpf: add perf buffer API

2019-07-08T13:35:43Z

BPF_MAP_TYPE_PERF_EVENT_ARRAY map is often used to send data from BPF program to user space for additional processing. libbpf already has very low-level API to read single CPU perf buffer, bpf_perf_event_read_simple(), but it's hard to use and requires a lot of code to set everything up. This patch adds perf_buffer abstraction on top of it, abstracting setting up and polling per-CPU logic into simple and convenient API, similar to what BCC provides. perf_buffer__new() sets up per-CPU ring buffers and updates corresponding BPF map entries. It accepts two user-provided callbacks: one for handling raw samples and one for get notifications of lost samples due to buffer overflow. perf_buffer__new_raw() is similar, but provides more control over how perf events are set up (by accepting user-provided perf_event_attr), how they are handled (perf_event_header pointer is passed directly to user-provided callback), and on which CPUs ring buffers are created (it's possible to provide a list of CPUs and corresponding map keys to update). This API allows advanced users fuller control. perf_buffer__poll() is used to fetch ring buffer data across all CPUs, utilizing epoll instance. perf_buffer__free() does corresponding clean up and unsets FDs from BPF map. All APIs are not thread-safe. User should ensure proper locking/coordination if used in multi-threaded set up. Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann

libbpf: add raw tracepoint attach API

2019-07-05T20:37:30Z

Add a wrapper utilizing bpf_link "infrastructure" to allow attaching BPF programs to raw tracepoints. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

libbpf: add tracepoint attach API

2019-07-05T20:37:30Z

Allow attaching BPF programs to kernel tracepoint BPF hooks specified by category and name. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

libbpf: add kprobe/uprobe attach API

2019-07-05T20:37:30Z

Add ability to attach to kernel and user probes and retprobes. Implementation depends on perf event support for kprobes/uprobes. Signed-off-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

libbpf: add ability to attach/detach BPF program to perf event

2019-07-05T20:37:30Z

bpf_program__attach_perf_event allows to attach BPF program to existing perf event hook, providing most generic and most low-level way to attach BPF programs. It returns struct bpf_link, which should be passed to bpf_link__destroy to detach and free resources, associated with a link. Signed-off-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

libbpf: introduce concept of bpf_link

2019-07-05T20:37:30Z

bpf_link is an abstraction of an association of a BPF program and one of many possible BPF attachment points (hooks). This allows to have uniform interface for detaching BPF programs regardless of the nature of link and how it was created. Details of creation and setting up of a specific bpf_link is handled by corresponding attachment methods (bpf_program__attach_xxx) added in subsequent commits. Once successfully created, bpf_link has to be eventually destroyed with bpf_link__destroy(), at which point BPF program is disassociated from a hook and all the relevant resources are freed. Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

bpf: add a new API libbpf_num_possible_cpus()

2019-06-11T08:36:02Z

Adding a new API libbpf_num_possible_cpus() that helps user with per-CPU map operations. Signed-off-by: Hechao Li Signed-off-by: Daniel Borkmann

libbpf: add bpf_object__load_xattr() API function to pass log_level

2019-05-28T09:03:26Z

libbpf was recently made aware of the log_level attribute for programs, used to specify the level of information expected to be dumped by the verifier. Function bpf_prog_load_xattr() got support for this log_level parameter. But some applications using libbpf rely on another function to load programs, bpf_object__load(), which does accept any parameter for log level. Create an API function based on bpf_object__load(), but accepting an "attr" object as a parameter. Then add a log_level field to that object, so that applications calling the new bpf_object__load_xattr() can pick the desired log level. v3: - Rewrite commit log. v2: - We are in a new cycle, bump libbpf extraversion number. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann

libbpf: add btf_dump API for BTF-to-C conversion

2019-05-24T21:05:58Z

BTF contains enough type information to allow generating valid compilable C header w/ correct layout of structs/unions and all the typedef/enum definitions. This patch adds a new "object" - btf_dump to facilitate dumping BTF as valid C. btf_dump__dump_type() is the main API which takes care of dumping out (through user-provided printf-like callback function) C definitions for given type ID and it's required dependencies. This allows for not just dumping out entirety of BTF types, but also selective filtering based on user-provided criterias w/ minimal set of dependent types. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov

libbpf: add btf__parse_elf API to load .BTF and .BTF.ext

2019-05-24T21:05:57Z

Loading BTF and BTF.ext from ELF file is a common need. Instead of requiring every user to re-implement it, let's provide this API from libbpf itself. It's mostly copy/paste from `bpftool btf dump` implementation, which will be switched to libbpf's version in next patch. btf__parse_elf allows to load BTF and optionally BTF.ext. This is also useful for tests that need to load/work with BTF, loaded from test ELF files. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov