lwn.git/tools/lib/bpf/bpf.c, branch docs-5.13

libbpf: Support attachment of BPF tracing programs to kernel modules

2020-12-04T01:38:21+00:00

Teach libbpf to search for BTF types in kernel modules for tracing BPF programs. This allows attachment of raw_tp/fentry/fexit/fmod_ret/etc BPF program types to tracepoints and functions in kernel modules. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201203204634.1325171-13-andrii@kernel.org

libbpf: Factor out low-level BPF program loading helper

2020-12-04T01:38:21+00:00

Refactor low-level API for BPF program loading to not rely on public API types. This allows painless extension without constant efforts to cleverly not break backwards compatibility. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201203204634.1325171-12-andrii@kernel.org

libbpf: Cap retries in sys_bpf_prog_load

2020-12-03T20:01:18+00:00

I've seen a situation, where a process that's under pprof constantly generates SIGPROF which prevents program loading indefinitely. The right thing to do probably is to disable signals in the upper layers while loading, but it still would be nice to get some error from libbpf instead of an endless loop. Let's add some small retry limit to the program loading: try loading the program 5 (arbitrary) times and give up. v2: * 10 -> 5 retires (Andrii Nakryiko) Signed-off-by: Stanislav Fomichev Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201202231332.3923644-1-sdf@google.com

libbpf: Add support for freplace attachment in bpf_link_create

2020-09-29T20:09:24+00:00

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: Remove assumption of single contiguous memory for BTF data

2020-09-29T00:27:31+00:00

Refactor internals of struct btf to remove assumptions that BTF header, type data, and string data are layed out contiguously in a memory in a single memory allocation. Now we have three separate pointers pointing to the start of each respective are: header, types, strings. In the next patches, these pointers will be re-assigned to point to independently allocated memory areas, if BTF needs to be modified. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200926011357.2366158-3-andriin@fb.com

libbpf: Support test run of raw tracepoint programs

2020-09-28T19:52:36+00:00

Add bpf_prog_test_run_opts() with support of new fields in bpf_attr.test, namely, flags and cpu. Also extend _opts operations to support outputs via opts. Signed-off-by: Song Liu Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200925205432.1777-3-songliubraving@fb.com

libbpf: Add BPF_PROG_BIND_MAP syscall and use it on .rodata section

2020-09-16T01:28:27+00:00

The patch adds a simple wrapper bpf_prog_bind_map around the syscall. When the libbpf tries to load a program, it will probe the kernel for the support of this syscall and unconditionally bind .rodata section to the program. Signed-off-by: YiFei Zhu Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Cc: YiFei Zhu Link: https://lore.kernel.org/bpf/20200915234543.3220146-4-sdf@google.com

libbpf: Centralize poisoning and poison reallocarray()

2020-08-19T01:38:25+00:00

Most of libbpf source files already include libbpf_internal.h, so it's a good place to centralize identifier poisoning. So move kernel integer type poisoning there. And also add reallocarray to a poison list to prevent accidental use of it. libbpf_reallocarray() should be used universally instead. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200819013607.3607269-4-andriin@fb.com

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

2020-08-06T23:39:14+00:00

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

2020-08-02T03:38:28+00:00

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