kernel/linux.git/samples/bpf/Makefile, branch linux-5.11.y

samples/bpf: Sample application for eBPF load and socket creation split

2020-12-03T18:37:59+00:00

Introduce a sample program to demonstrate the control and data plane split. For the control plane part a new program called xdpsock_ctrl_proc is introduced. For the data plane part, some code was added to xdpsock_user.c to act as the data plane entity. Application xdpsock_ctrl_proc works as control entity with sudo privileges (CAP_SYS_ADMIN and CAP_NET_ADMIN are sufficient) and the extended xdpsock as data plane entity with CAP_NET_RAW capability only. Usage example: sudo ./samples/bpf/xdpsock_ctrl_proc -i sudo ./samples/bpf/xdpsock -i -q -n -N -l -R Signed-off-by: Mariusz Dudek Signed-off-by: Alexei Starovoitov Acked-by: Magnus Karlsson Link: https://lore.kernel.org/bpf/20201203090546.11976-3-mariuszx.dudek@intel.com

samples: bpf: Remove bpf_load loader completely

2020-11-27T03:33:36+00:00

Numerous refactoring that rewrites BPF programs written with bpf_load to use the libbpf loader was finally completed, resulting in BPF programs using bpf_load within the kernel being completely no longer present. This commit removes bpf_load, an outdated bpf loader that is difficult to keep up with the latest kernel BPF and causes confusion. Also, this commit removes the unused trace_helper and bpf_load from samples/bpf target objects from Makefile. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Acked-by: Jesper Dangaard Brouer Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-8-danieltimlee@gmail.com

samples: bpf: Refactor test_overhead program with libbpf

2020-11-27T03:33:36+00:00

This commit refactors the existing program with libbpf bpf loader. Since the kprobe, tracepoint and raw_tracepoint bpf program can be attached with single bpf_program__attach() interface, so the corresponding function of libbpf is used here. Rather than specifying the number of cpus inside the code, this commit uses the number of available cpus with _SC_NPROCESSORS_ONLN. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-6-danieltimlee@gmail.com

samples: bpf: Refactor ibumad program with libbpf

2020-11-27T03:33:36+00:00

This commit refactors the existing ibumad program with libbpf bpf loader. Attach/detach of Tracepoint bpf programs has been managed with the generic bpf_program__attach() and bpf_link__destroy() from the libbpf. Also, instead of using the previous BPF MAP definition, this commit refactors ibumad MAP definition with the new BTF-defined MAP format. To verify that this bpf program works without an infiniband device, try loading ib_umad kernel module and test the program as follows: # modprobe ib_umad # ./ibumad Moreover, TRACE_HELPERS has been removed from the Makefile since it is not used on this program. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-5-danieltimlee@gmail.com

samples: bpf: Refactor task_fd_query program with libbpf

2020-11-27T03:33:35+00:00

This commit refactors the existing kprobe program with libbpf bpf loader. To attach bpf program, this uses generic bpf_program__attach() approach rather than using bpf_load's load_bpf_file(). To attach bpf to perf_event, instead of using previous ioctl method, this commit uses bpf_program__attach_perf_event since it manages the enable of perf_event and attach of BPF programs to it, which is much more intuitive way to achieve. Also, explicit close(fd) has been removed since event will be closed inside bpf_link__destroy() automatically. Furthermore, to prevent conflict of same named uprobe events, O_TRUNC flag has been used to clear 'uprobe_events' interface. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-4-danieltimlee@gmail.com

samples: bpf: Refactor test_cgrp2_sock2 program with libbpf

2020-11-27T03:33:35+00:00

This commit refactors the existing cgroup program with libbpf bpf loader. The original test_cgrp2_sock2 has keeped the bpf program attached to the cgroup hierarchy even after the exit of user program. To implement the same functionality with libbpf, this commit uses the BPF_LINK_PINNING to pin the link attachment even after it is closed. Since this uses LINK instead of ATTACH, detach of bpf program from cgroup with 'test_cgrp2_sock' is not used anymore. The code to mount the bpf was added to the .sh file in case the bpff was not mounted on /sys/fs/bpf. Additionally, to fix the problem that shell script cannot find the binary object from the current path, relative path './' has been added in front of binary. Fixes: 554ae6e792ef3 ("samples/bpf: add userspace example for prohibiting sockets") Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-3-danieltimlee@gmail.com

samples: bpf: Refactor hbm program with libbpf

2020-11-27T03:33:35+00:00

This commit refactors the existing cgroup programs with libbpf bpf loader. Since bpf_program__attach doesn't support cgroup program attachment, this explicitly attaches cgroup bpf program with bpf_program__attach_cgroup(bpf_prog, cg1). Also, to change attach_type of bpf program, this uses libbpf's bpf_program__set_expected_attach_type helper to switch EGRESS to INGRESS. To keep bpf program attached to the cgroup hierarchy even after the exit, this commit uses the BPF_LINK_PINNING to pin the link attachment even after it is closed. Besides, this program was broken due to the typo of BPF MAP definition. But this commit solves the problem by fixing this from 'queue_stats' map struct hvm_queue_stats -> hbm_queue_stats. Fixes: 36b5d471135c ("selftests/bpf: samples/bpf: Split off legacy stuff from bpf_helpers.h") Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-2-danieltimlee@gmail.com

samples: bpf: Replace attach_tracepoint() to attach() in xdp_redirect_cpu

2020-10-11T19:14:36+00:00

>From commit d7a18ea7e8b6 ("libbpf: Add generic bpf_program__attach()"), for some BPF programs, it is now possible to attach BPF programs with __attach() instead of explicitly calling __attach_(). This commit refactors the __attach_tracepoint() with libbpf's generic __attach() method. In addition, this refactors the logic of setting the map FD to simplify the code. Also, the missing removal of bpf_load.o in Makefile has been fixed. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201010181734.1109-3-danieltimlee@gmail.com

samples: bpf: Refactor xdp_monitor with libbpf

2020-10-11T19:14:36+00:00

To avoid confusion caused by the increasing fragmentation of the BPF Loader program, this commit would like to change to the libbpf loader instead of using the bpf_load. Thanks to libbpf's bpf_link interface, managing the tracepoint BPF program is much easier. bpf_program__attach_tracepoint manages the enable of tracepoint event and attach of BPF programs to it with a single interface bpf_link, so there is no need to manage event_fd and prog_fd separately. This commit refactors xdp_monitor with using this libbpf API, and the bpf_load is removed and migrated to libbpf. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201010181734.1109-2-danieltimlee@gmail.com

samples/bpf: Change Makefile to cope with latest llvm

2020-10-06T18:45:03+00:00

With latest llvm trunk, bpf programs under samples/bpf directory, if using CORE, may experience the following errors: LLVM ERROR: Cannot select: intrinsic %llvm.preserve.struct.access.index PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace. Stack dump: 0. Program arguments: llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o 1. Running pass 'Function Pass Manager' on module ''. 2. Running pass 'BPF DAG->DAG Pattern Instruction Selection' on function '@bpf_prog1' #0 0x000000000183c26c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x183c26c) ... #7 0x00000000017c375e (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x17c375e) #8 0x00000000016a75c5 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16a75c5) #9 0x00000000016ab4f8 llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*, unsigned int) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16ab4f8) ... Aborted (core dumped) | llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o The reason is due to llvm change https://reviews.llvm.org/D87153 where the CORE relocation global generation is moved from the beginning of target dependent optimization (llc) to the beginning of target independent optimization (opt). Since samples/bpf programs did not use vmlinux.h and its clang compilation uses native architecture, we need to adjust arch triple at opt level to do CORE relocation global generation properly. Otherwise, the above error will appear. This patch fixed the issue by introduce opt and llvm-dis to compilation chain, which will do proper CORE relocation global generation as well as O2 level optimization. Tested with llvm10, llvm11 and trunk/llvm12. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201006043427.1891742-1-yhs@fb.com