kernel/linux.git/samples/bpf/Makefile, branch v5.10.7

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

samples/bpf: Add new sample xsk_fwd.c

2020-08-31T19:17:55+00:00

This sample code illustrates the packet forwarding between multiple AF_XDP sockets in multi-threading environment. All the threads and sockets are sharing a common buffer pool, with each socket having its own private buffer cache. The sockets are created with the xsk_socket__create_shared() function, which allows multiple AF_XDP sockets to share the same UMEM object. Example 1: Single thread handling two sockets. Packets received from socket A (on top of interface IFA, queue QA) are forwarded to socket B (on top of interface IFB, queue QB) and vice-versa. The thread is affinitized to CPU core C: ./xsk_fwd -i IFA -q QA -i IFB -q QB -c C Example 2: Two threads, each handling two sockets. Packets from socket A are sent to socket B (by thread X), packets from socket B are sent to socket A (by thread X); packets from socket C are sent to socket D (by thread Y), packets from socket D are sent to socket C (by thread Y). The two threads are bound to CPU cores CX and CY: ./xdp_fwd -i IFA -q QA -i IFB -q QB -i IFC -q QC -i IFD -q QD -c CX -c CY Signed-off-by: Cristian Dumitrescu Signed-off-by: Daniel Borkmann Acked-by: Björn Töpel Link: https://lore.kernel.org/bpf/1598603189-32145-15-git-send-email-magnus.karlsson@intel.com

samples: bpf: Refactor tracepoint tracing programs with libbpf

2020-08-25T03:59:35+00:00

For the problem of increasing fragmentation of the bpf loader programs, instead of using bpf_loader.o, which is used in samples/bpf, this commit refactors the existing tracepoint tracing programs with libbbpf bpf loader. - Adding a tracepoint event and attaching a bpf program to it was done through bpf_program_attach(). - Instead of using the existing BPF MAP definition, MAP definition has been refactored with the new BTF-defined MAP format. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200823085334.9413-4-danieltimlee@gmail.com

samples: bpf: Refactor kprobe tracing programs with libbpf

2020-08-25T03:59:35+00:00

For the problem of increasing fragmentation of the bpf loader programs, instead of using bpf_loader.o, which is used in samples/bpf, this commit refactors the existing kprobe tracing programs with libbbpf bpf loader. - For kprobe events pointing to system calls, the SYSCALL() macro in trace_common.h was used. - Adding a kprobe event and attaching a bpf program to it was done through bpf_program_attach(). - Instead of using the existing BPF MAP definition, MAP definition has been refactored with the new BTF-defined MAP format. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200823085334.9413-3-danieltimlee@gmail.com

samples: bpf: Cleanup bpf_load.o from Makefile

2020-08-25T03:59:35+00:00

Since commit cc7f641d637b ("samples: bpf: Refactor BPF map performance test with libbpf") has ommited the removal of bpf_load.o from Makefile, this commit removes the bpf_load.o rule for targets where bpf_load.o is not used. Fixes: cc7f641d637b ("samples: bpf: Refactor BPF map performance test with libbpf") Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200823085334.9413-2-danieltimlee@gmail.com

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