kernel/linux.git/samples/bpf/Makefile, branch linux-5.9.y

samples: bpf: Refactor BPF map in map test with libbpf

2020-07-07T23:33:10+00:00

From commit 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support"), a way to define internal map in BTF-defined map has been added. Instead of using previous 'inner_map_idx' definition, the structure to be used for the inner map can be directly defined using array directive. __array(values, struct inner_map) This commit refactors map in map test program with libbpf by explicitly defining inner map with BTF-defined format. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200707184855.30968-3-danieltimlee@gmail.com

samples, bpf: Refactor tail call user progs with libbpf

2020-05-19T15:12:56+00:00

BPF tail call uses the BPF_MAP_TYPE_PROG_ARRAY type map for calling into other BPF programs and this PROG_ARRAY should be filled prior to use. Currently, samples with the PROG_ARRAY type MAP fill this program array with bpf_load. For bpf_load to fill this map, kernel BPF program must specify the section with specific format of / (e.g. SEC("socket/0")) But by using libbpf instead of bpf_load, user program can specify which programs should be added to PROG_ARRAY. The advantage of this approach is that you can selectively add only the programs you want, rather than adding all of them to PROG_ARRAY, and it's much more intuitive than the traditional approach. This commit refactors user programs with the PROG_ARRAY type MAP with libbpf instead of using bpf_load. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-4-danieltimlee@gmail.com

samples, bpf: Refactor kprobe tracing user progs with libbpf

2020-05-19T15:12:53+00:00

Currently, the kprobe BPF program attachment method for bpf_load is quite old. The implementation of bpf_load "directly" controls and manages(create, delete) the kprobe events of DEBUGFS. On the other hand, using using the libbpf automatically manages the kprobe event. (under bpf_link interface) By calling bpf_program__attach(_kprobe) in libbpf, the corresponding kprobe is created and the BPF program will be attached to this kprobe. To remove this, by simply invoking bpf_link__destroy will clean up the event. This commit refactors kprobe tracing programs (tracex{1~7}_user.c) with libbpf using bpf_link interface and bpf_program__attach. tracex2_kern.c, which tracks system calls (sys_*), has been modified to append prefix depending on architecture. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com

samples, bpf: Refactor perf_event user program with libbpf bpf_link

2020-03-23T21:27:57+00:00

The bpf_program__attach of libbpf(using bpf_link) is much more intuitive than the previous method using ioctl. bpf_program__attach_perf_event manages the enable of perf_event and attach of BPF programs to it, so there's no neeed to do this directly with ioctl. In addition, bpf_link provides consistency in the use of API because it allows disable (detach, destroy) for multiple events to be treated as one bpf_link__destroy. Also, bpf_link__destroy manages the close() of perf_event fd. This commit refactors samples that attach the bpf program to perf_event by using libbbpf instead of ioctl. Also the bpf_load in the samples were removed and migrated to use libbbpf API. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200321100424.1593964-3-danieltimlee@gmail.com

samples, bpf: Move read_trace_pipe to trace_helpers

2020-03-23T21:27:51+00:00

To reduce the reliance of trace samples (trace*_user) on bpf_load, move read_trace_pipe to trace_helpers. By moving this bpf_loader helper elsewhere, trace functions can be easily migrated to libbbpf. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200321100424.1593964-2-danieltimlee@gmail.com

kbuild: rename hostprogs-y/always to hostprogs/always-y

2020-02-03T16:53:07+00:00

In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada

samples/bpf: Use consistent include paths for libbpf

2020-01-21T00:37:45+00:00

Fix all files in samples/bpf to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Acked-by: Jesper Dangaard Brouer Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk

samples/bpf: Don't try to remove user's homedir on clean

2020-01-21T00:37:45+00:00

The 'clean' rule in the samples/bpf Makefile tries to remove backup files (ending in ~). However, if no such files exist, it will instead try to remove the user's home directory. While the attempt is mostly harmless, it does lead to a somewhat scary warning like this: rm: cannot remove '~': Is a directory Fix this by using find instead of shell expansion to locate any actual backup files that need to be removed. Fixes: b62a796c109c ("samples/bpf: allow make to be run from samples/bpf/ directory") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/157952560126.1683545.7273054725976032511.stgit@toke.dk

samples/bpf: Set -fno-stack-protector when building BPF programs

2019-12-16T15:03:12+00:00

It seems Clang can in some cases turn on stack protection by default, which doesn't work with BPF. This was reported once before[0], but it seems the flag to explicitly turn off the stack protector wasn't added to the Makefile, so do that now. The symptom of this is compile errors like the following: error: :0:0: in function bpf_prog1 i32 (%struct.__sk_buff*): A call to built-in function '__stack_chk_fail' is not supported. [0] https://www.spinics.net/lists/netdev/msg556400.html Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191216103819.359535-1-toke@redhat.com

samples/bpf: Add missing -lz to TPROGS_LDLIBS

2019-12-16T14:58:10+00:00

Since libbpf now links against zlib, this needs to be included in the linker invocation for the userspace programs in samples/bpf that link statically against libbpf. Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Tested-by: Björn Töpel Link: https://lore.kernel.org/bpf/20191216102405.353834-1-toke@redhat.com