15 May, 2020

1 commit

  • GCC 10 is very strict about symbol clash, and lwt_len_hist_user contains
    a symbol which clashes with libbpf:

    /usr/bin/ld: samples/bpf/lwt_len_hist_user.o:(.bss+0x0): multiple definition of `bpf_log_buf'; samples/bpf/bpf_load.o:(.bss+0x8c0): first defined here
    collect2: error: ld returned 1 exit status

    bpf_log_buf here seems to be a leftover, so removing it.

    Signed-off-by: Matteo Croce
    Signed-off-by: Alexei Starovoitov
    Acked-by: Yonghong Song
    Link: https://lore.kernel.org/bpf/20200511113234.80722-1-mcroce@redhat.com

    Matteo Croce
     

15 May, 2018

1 commit


02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

16 Dec, 2016

1 commit

  • Switch all of the sample code to use the function names from
    tools/lib/bpf so that they're consistent with that, and to declare their
    own log buffers. This allow the next commit to be purely devoted to
    getting rid of the duplicate library in samples/bpf.

    Committer notes:

    Testing it:

    On a fedora rawhide container, with clang/llvm 3.9, sharing the host
    linux kernel git tree:

    # make O=/tmp/build/linux/ headers_install
    # make O=/tmp/build/linux -C samples/bpf/

    Since I forgot to make it privileged, just tested it outside the
    container, using what it generated:

    # uname -a
    Linux jouet 4.9.0-rc8+ #1 SMP Mon Dec 12 11:20:49 BRT 2016 x86_64 x86_64 x86_64 GNU/Linux
    # cd /var/lib/docker/devicemapper/mnt/c43e09a53ff56c86a07baf79847f00e2cc2a17a1e2220e1adbf8cbc62734feda/rootfs/tmp/build/linux/samples/bpf/
    # ls -la offwaketime
    -rwxr-xr-x. 1 root root 24200 Dec 15 12:19 offwaketime
    # 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]=c940d3f127d5e66cdd680e42d885cb0b64f8a0e4, not stripped
    # readelf -SW offwaketime_kern.o | grep PROGBITS
    [ 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
    [ 5] tracepoint/sched/sched_switch PROGBITS 0000000000000000 000118 000318 00 AX 0 0 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
    # ./offwaketime | head -5
    swapper/1;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 106
    CPU 0/KVM;entry_SYSCALL_64_fastpath;sys_ioctl;do_vfs_ioctl;kvm_vcpu_ioctl;kvm_arch_vcpu_ioctl_run;kvm_vcpu_block;schedule;__schedule;-;try_to_wake_up;swake_up_locked;swake_up;apic_timer_expired;apic_timer_fn;__hrtimer_run_queues;hrtimer_interrupt;local_apic_timer_interrupt;smp_apic_timer_interrupt;__irqentry_text_start;cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary;;swapper/3 2
    Compositor;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;futex_requeue;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;SoftwareVsyncTh 5
    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 13
    JS Helper;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;firefox 2
    #

    Signed-off-by: Joe Stringer
    Tested-by: Arnaldo Carvalho de Melo
    Cc: Alexei Starovoitov
    Cc: Daniel Borkmann
    Cc: Wang Nan
    Cc: netdev@vger.kernel.org
    Link: http://lkml.kernel.org/r/20161214224342.12858-2-joe@ovn.org
    Signed-off-by: Arnaldo Carvalho de Melo

    Joe Stringer
     

02 Dec, 2016

1 commit

  • Adds a series of tests to verify the functionality of attaching
    BPF programs at LWT hooks.

    Also adds a sample which collects a histogram of packet sizes which
    pass through an LWT hook.

    $ ./lwt_len_hist.sh
    Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family AF_UNSPEC
    MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.253.2 () port 0 AF_INET : demo
    Recv Send Send
    Socket Socket Message Elapsed
    Size Size Size Time Throughput
    bytes bytes bytes secs. 10^6bits/sec

    87380 16384 16384 10.00 39857.69
    1 -> 1 : 0 | |
    2 -> 3 : 0 | |
    4 -> 7 : 0 | |
    8 -> 15 : 0 | |
    16 -> 31 : 0 | |
    32 -> 63 : 22 | |
    64 -> 127 : 98 | |
    128 -> 255 : 213 | |
    256 -> 511 : 1444251 |******** |
    512 -> 1023 : 660610 |*** |
    1024 -> 2047 : 535241 |** |
    2048 -> 4095 : 19 | |
    4096 -> 8191 : 180 | |
    8192 -> 16383 : 5578023 |************************************* |
    16384 -> 32767 : 632099 |*** |
    32768 -> 65535 : 6575 | |

    Signed-off-by: Thomas Graf
    Acked-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Thomas Graf