summaryrefslogtreecommitdiff
path: root/samples/bpf/README.rst
AgeCommit message (Collapse)Author
2016-12-20samples/bpf: Switch over to libbpfJoe Stringer
Now that libbpf under tools/lib/bpf/* is synced with the version from samples/bpf, we can get rid most of the libbpf library here. Committer notes: Built it in a docker fedora rawhide container and ran it in the f25 host, seems to work just like it did before this patch, i.e. the switch to tools/lib/bpf/ doesn't seem to have introduced problems and Joe said he tested it with all the entries in samples/bpf/ and other code he found: [root@f5065a7d6272 linux]# make -j4 O=/tmp/build/linux headers_install <SNIP> [root@f5065a7d6272 linux]# rm -rf /tmp/build/linux/samples/bpf/ [root@f5065a7d6272 linux]# make -j4 O=/tmp/build/linux samples/bpf/ make[1]: Entering directory '/tmp/build/linux' CHK include/config/kernel.release HOSTCC scripts/basic/fixdep GEN ./Makefile CHK include/generated/uapi/linux/version.h Using /git/linux as source for kernel CHK include/generated/utsrelease.h HOSTCC scripts/basic/bin2c HOSTCC arch/x86/tools/relocs_32.o HOSTCC arch/x86/tools/relocs_64.o LD samples/bpf/built-in.o <SNIP> HOSTCC samples/bpf/fds_example.o HOSTCC samples/bpf/sockex1_user.o /git/linux/samples/bpf/fds_example.c: In function 'bpf_prog_create': /git/linux/samples/bpf/fds_example.c:63:6: warning: passing argument 2 of 'bpf_load_program' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] insns, insns_cnt, "GPL", 0, ^~~~~ In file included from /git/linux/samples/bpf/libbpf.h:5:0, from /git/linux/samples/bpf/bpf_load.h:4, from /git/linux/samples/bpf/fds_example.c:15: /git/linux/tools/lib/bpf/bpf.h:31:5: note: expected 'struct bpf_insn *' but argument is of type 'const struct bpf_insn *' int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, ^~~~~~~~~~~~~~~~ HOSTCC samples/bpf/sockex2_user.o <SNIP> HOSTCC samples/bpf/xdp_tx_iptunnel_user.o clang -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/6.2.1/include -I/git/linux/arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated -I/git/linux/include -I./include -I/git/linux/arch/x86/include/uapi -I/git/linux/include/uapi -I./include/generated/uapi -include /git/linux/include/linux/kconfig.h \ -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \ -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \ -O2 -emit-llvm -c /git/linux/samples/bpf/sockex1_kern.c -o -| llc -march=bpf -filetype=obj -o samples/bpf/sockex1_kern.o HOSTLD samples/bpf/tc_l2_redirect <SNIP> HOSTLD samples/bpf/lwt_len_hist HOSTLD samples/bpf/xdp_tx_iptunnel make[1]: Leaving directory '/tmp/build/linux' [root@f5065a7d6272 linux]# And then, in the host: [root@jouet bpf]# mount | grep "docker.*devicemapper\/" /dev/mapper/docker-253:0-1705076-9bd8aa1e0af33adce89ff42090847868ca676932878942be53941a06ec5923f9 on /var/lib/docker/devicemapper/mnt/9bd8aa1e0af33adce89ff42090847868ca676932878942be53941a06ec5923f9 type xfs (rw,relatime,context="system_u:object_r:container_file_t:s0:c73,c276",nouuid,attr2,inode64,sunit=1024,swidth=1024,noquota) [root@jouet bpf]# cd /var/lib/docker/devicemapper/mnt/9bd8aa1e0af33adce89ff42090847868ca676932878942be53941a06ec5923f9/rootfs/tmp/build/linux/samples/bpf/ [root@jouet bpf]# file offwaketime offwaketime: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=f423d171e0487b2f802b6a792657f0f3c8f6d155, not stripped [root@jouet bpf]# readelf -SW offwaketime offwaketime offwaketime_kern.o offwaketime_user.o [root@jouet bpf]# readelf -SW offwaketime_kern.o There are 11 section headers, starting at offset 0x700: Section Headers: [Nr] Name Type Address Off Size ES Flg Lk Inf Al [ 0] NULL 0000000000000000 000000 000000 00 0 0 0 [ 1] .strtab STRTAB 0000000000000000 000658 0000a8 00 0 0 1 [ 2] .text PROGBITS 0000000000000000 000040 000000 00 AX 0 0 4 [ 3] kprobe/try_to_wake_up PROGBITS 0000000000000000 000040 0000d8 00 AX 0 0 8 [ 4] .relkprobe/try_to_wake_up REL 0000000000000000 0005a8 000020 10 10 3 8 [ 5] tracepoint/sched/sched_switch PROGBITS 0000000000000000 000118 000318 00 AX 0 0 8 [ 6] .reltracepoint/sched/sched_switch REL 0000000000000000 0005c8 000090 10 10 5 8 [ 7] maps PROGBITS 0000000000000000 000430 000050 00 WA 0 0 4 [ 8] license PROGBITS 0000000000000000 000480 000004 00 WA 0 0 1 [ 9] version PROGBITS 0000000000000000 000484 000004 00 WA 0 0 4 [10] .symtab SYMTAB 0000000000000000 000488 000120 18 1 4 8 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific) [root@jouet bpf]# ./offwaketime | head -3 qemu-system-x86;entry_SYSCALL_64_fastpath;sys_ppoll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;local_apic_timer_interrupt;smp_apic_timer_interrupt;__irqentry_text_start;cpuidle_enter_state;cpuidle_enter;call_cpuidle;cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;x86_64_start_kernel;start_cpu;;swapper/0 4 firefox;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;pollwake;__wake_up_common;__wake_up_sync_key;pipe_write;__vfs_write;vfs_write;sys_write;entry_SYSCALL_64_fastpath;;Timer 1 swapper/2;start_cpu;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 61 [root@jouet bpf]# Signed-off-by: Joe Stringer <joe@ovn.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Cc: netdev@vger.kernel.org Link: https://github.com/joestringer/linux/commit/5c40f54a52b1f437123c81e21873f4b4b1f9bd55.patch Link: http://lkml.kernel.org/n/tip-xr8twtx7sjh5821g8qw47yxk@git.kernel.org [ Use -I$(srctree)/tools/lib/ to support out of source code tree builds, as noticed by Wang Nan ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-29samples/bpf: like LLC also verify and allow redefining CLANG commandJesper Dangaard Brouer
Users are likely to manually compile both LLVM 'llc' and 'clang' tools. Thus, also allow redefining CLANG and verify command exist. Makefile implementation wise, the target that verify the command have been generalized. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-29samples/bpf: allow make to be run from samples/bpf/ directoryJesper Dangaard Brouer
It is not intuitive that 'make' must be run from the top level directory with argument "samples/bpf/" to compile these eBPF samples. Introduce a kbuild make file trick that allow make to be run from the "samples/bpf/" directory itself. It basically change to the top level directory and call "make samples/bpf/" with the "/" slash after the directory name. Also add a clean target that only cleans this directory, by taking advantage of the kbuild external module setting M=$PWD. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-29samples/bpf: add a README file to get users startedJesper Dangaard Brouer
Getting started with using examples in samples/bpf/ is not straightforward. There are several dependencies, and specific versions of these dependencies. Just compiling the example tool is also slightly obscure, e.g. one need to call make like: make samples/bpf/ Do notice the "/" slash after the directory name. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-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>