• Joe Stringer's avatar
    samples/bpf: Switch over to libbpf · 43371c83
    Joe Stringer authored
    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: default avatarJoe Stringer <joe@ovn.org>
    Tested-by: default avatarArnaldo 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    43371c83
sock_example.c 2.83 KB