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2022-12-29samples/bpf: Change _kern suffix to .bpf with syscall tracing programDaniel T. Lee
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 ↵Daniel T. Lee
program 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. Lee
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
2022-11-04samples/bpf: Fix tracex2 error: No such file or directoryRong Tao
since commit c504e5c2f964("net: skb: introduce kfree_skb_reason()") kfree_skb() is replaced by kfree_skb_reason() and kfree_skb() is set to the inline function. So, we replace kprobe/kfree_skb with kprobe/kfree_skb_reason to solve the tracex2 error. $ cd samples/bpf $ sudo ./tracex2 libbpf: prog 'bpf_prog2': failed to create kprobe 'kfree_skb+0x0' perf event: No such file or directory ERROR: bpf_program__attach failed Signed-off-by: Rong Tao <rongtao@cestc.cn> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/tencent_0F0DAE84C0B3C42E0B550E5E9F47A9114D09@qq.com
2020-05-19samples, bpf: Refactor kprobe, tail call kern progs map definitionDaniel T. Lee
Because the previous two commit replaced the bpf_load implementation of the user program with libbpf, the corresponding kernel program's MAP definition can be replaced with new BTF-defined map syntax. This commit only updates the samples which uses libbpf API for loading bpf program not with bpf_load. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200516040608.1377876-6-danieltimlee@gmail.com
2020-05-19samples, bpf: Refactor kprobe tracing user progs with libbpfDaniel T. Lee
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 <danieltimlee@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com
2020-01-20samples/bpf: Use consistent include paths for libbpfToke Høiland-Jørgensen
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
2019-10-08selftests/bpf: Split off tracing-only helpers into bpf_tracing.hAndrii Nakryiko
Split-off PT_REGS-related helpers into bpf_tracing.h header. Adjust selftests and samples to include it where necessary. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20191008175942.1769476-5-andriin@fb.com
2016-04-14bpf, samples: don't zero data when not neededDaniel Borkmann
Remove the zero initialization in the sample programs where appropriate. Note that this is an optimization which is now possible, old programs still doing the zero initialization are just fine as well. Also, make sure we don't have padding issues when we don't memset() the entire struct anymore. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-06samples/bpf: Enable powerpc supportNaveen N. Rao
Add the necessary definitions for building bpf samples on ppc. Since ppc doesn't store function return address on the stack, modify how PT_REGS_RET() and PT_REGS_FP() work. Also, introduce PT_REGS_IP() to access the instruction pointer. Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06samples/bpf: update tracex[23] examples to use per-cpu mapsAlexei Starovoitov
Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-08samples: bpf: enable trace samples for s390xMichael Holzheu
The trace bpf samples do not compile on s390x because they use x86 specific fields from the "pt_regs" structure. Fix this and access the fields via new PT_REGS macros. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-15bpf: introduce current->pid, tgid, uid, gid, comm accessorsAlexei Starovoitov
eBPF programs attached to kprobes need to filter based on current->pid, uid and other fields, so introduce helper functions: u64 bpf_get_current_pid_tgid(void) Return: current->tgid << 32 | current->pid u64 bpf_get_current_uid_gid(void) Return: current_gid << 32 | current_uid bpf_get_current_comm(char *buf, int size_of_buf) stores current->comm into buf They can be used from the programs attached to TC as well to classify packets based on current task fields. Update tracex2 example to print histogram of write syscalls for each process instead of aggregated for all. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-02samples/bpf: Add counting example for kfree_skb() function calls and the ↵Alexei Starovoitov
write() syscall this example has two probes in one C file that attach to different kprove events and use two different maps. 1st probe is x64 specific equivalent of dropmon. It attaches to kfree_skb, retrevies 'ip' address of kfree_skb() caller and counts number of packet drops at that 'ip' address. User space prints 'location - count' map every second. 2nd probe attaches to kprobe:sys_write and computes a histogram of different write sizes Usage: $ sudo tracex2 location 0xffffffff81695995 count 1 location 0xffffffff816d0da9 count 2 location 0xffffffff81695995 count 2 location 0xffffffff816d0da9 count 2 location 0xffffffff81695995 count 3 location 0xffffffff816d0da9 count 2 557145+0 records in 557145+0 records out 285258240 bytes (285 MB) copied, 1.02379 s, 279 MB/s syscall write() stats byte_size : count distribution 1 -> 1 : 3 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 2 | | 32 -> 63 : 3 | | 64 -> 127 : 1 | | 128 -> 255 : 1 | | 256 -> 511 : 0 | | 512 -> 1023 : 1118968 |************************************* | Ctrl-C at any time. Kernel will auto cleanup maps and programs $ addr2line -ape ./bld_x64/vmlinux 0xffffffff81695995 0xffffffff816d0da9 0xffffffff81695995: ./bld_x64/../net/ipv4/icmp.c:1038 0xffffffff816d0da9: ./bld_x64/../net/unix/af_unix.c:1231 Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1427312966-8434-8-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>