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2022-12-29samples/bpf: Change _kern suffix to .bpf with syscall tracing programDaniel T. Lee1-29/+0
Currently old compile rule (CLANG-bpf) doesn't contains VMLINUX_H define flag which is essential for the bpf program that includes "vmlinux.h". Also old compile rule doesn't directly specify the compile target as bpf, instead it uses bunch of extra options with clang followed by long chain of commands. (e.g. clang | opt | llvm-dis | llc) In Makefile, there is already new compile rule which is more simple and neat. And it also has -D__VMLINUX_H__ option. By just changing the _kern suffix to .bpf will inherit the benefit of the new CLANG-BPF compile target. Also, this commit adds dummy gnu/stub.h to the samples/bpf directory. As commit 1c2dd16add7e ("selftests/bpf: get rid of -D__x86_64__") noted, compiling with 'clang -target bpf' will raise an error with stubs.h unless workaround (-D__x86_64) is used. This commit solves this problem by adding dummy stub.h to make /usr/include/features.h to follow the expected path as the same way selftests/bpf dealt with. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221224071527.2292-4-danieltimlee@gmail.com
2022-12-29samples/bpf: Use vmlinux.h instead of implicit headers in syscall tracing programDaniel T. Lee1-2/+1
This commit applies vmlinux.h to syscall tracing program. This change allows the bpf program to refer to the internal structure as a single "vmlinux.h" instead of including each header referenced by the bpf program. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221224071527.2292-3-danieltimlee@gmail.com
2022-12-29samples/bpf: Use kyscall instead of kprobe in syscall tracing programDaniel T. Lee1-2/+1
Syscall tracing using kprobe is quite unstable. Since it uses the exact name of the kernel function, the program might broke due to the rename of a function. The problem can also be caused by a changes in the arguments of the function to which the kprobe connects. In this commit, ksyscall is used instead of kprobe. By using ksyscall, libbpf will detect the appropriate kernel function name. (e.g. sys_write -> __s390_sys_write). This eliminates the need to worry about which wrapper function to attach in order to parse arguments. In addition, ksyscall provides more fine method with attaching system call, the coarse SYSCALL helper at trace_common.h can be removed. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221224071527.2292-2-danieltimlee@gmail.com
2020-08-24samples: bpf: Refactor kprobe tracing programs with libbpfDaniel T. Lee1-7/+8
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 <danieltimlee@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200823085334.9413-3-danieltimlee@gmail.com
2020-01-20samples/bpf: Use consistent include paths for libbpfToke Høiland-Jørgensen1-1/+1
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 <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2016-04-28samples/bpf: fix trace_output exampleAlexei Starovoitov1-1/+0
llvm cannot always recognize memset as builtin function and optimize it away, so just delete it. It was a leftover from testing of bpf_perf_event_output() with large data structures. Fixes: 39111695b1b8 ("samples: bpf: add bpf_perf_event_output example") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-22samples: bpf: add bpf_perf_event_output exampleAlexei Starovoitov1-0/+31
Performance test and example of bpf_perf_event_output(). kprobe is attached to sys_write() and trivial bpf program streams pid+cookie into userspace via PERF_COUNT_SW_BPF_OUTPUT event. Usage: $ sudo ./bld_x64/samples/bpf/trace_output recv 2968913 events per sec Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>