Eric Lee / smarc-fsl-linux-kernel

19 May, 2020

2 commits

  • 59929cd1f   samples, bpf: Refactor kprobe, tail call kern progs map definition ... Browse Code »

    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
    Signed-off-by: Daniel Borkmann
    Acked-by: Yonghong Song
    Link: https://lore.kernel.org/bpf/20200516040608.1377876-6-danieltimlee@gmail.com

    Daniel T. Lee
     
  • 63841bc08   samples, bpf: Refactor kprobe tracing user progs with libbpf ... Browse Code »

    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
    Signed-off-by: Daniel Borkmann
    Acked-by: Yonghong Song
    Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com

    Daniel T. Lee
     

21 Jan, 2020

1 commit

  • 7cf245a37   samples/bpf: Use consistent include paths for libbpf ... Browse Code »

    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
    Signed-off-by: Alexei Starovoitov
    Acked-by: Jesper Dangaard Brouer
    Acked-by: Andrii Nakryiko
    Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk

    Toke Høiland-Jørgensen
     

09 Oct, 2019

1 commit

15 Apr, 2016

1 commit

  • 02413cabd   bpf, samples: don't zero data when not needed ... Browse Code »

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

    Daniel Borkmann
     

07 Apr, 2016

1 commit

  • 138d6153a   samples/bpf: Enable powerpc support ... Browse Code »

    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
    Cc: Daniel Borkmann
    Cc: David S. Miller
    Cc: Ananth N Mavinakayanahalli
    Cc: Michael Ellerman
    Signed-off-by: Naveen N. Rao
    Acked-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Naveen N. Rao
     

06 Feb, 2016

1 commit

09 Jul, 2015

1 commit

16 Jun, 2015

1 commit

  • ffeedafbf   bpf: introduce current->pid, tgid, uid, gid, comm accessors ... Browse Code »

    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
    Signed-off-by: David S. Miller

    Alexei Starovoitov
     

02 Apr, 2015

1 commit

  • d822a1926   samples/bpf: Add counting example for kfree_skb() function calls and the write() syscall ... Browse Code »

    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
    Cc: Arnaldo Carvalho de Melo
    Cc: Arnaldo Carvalho de Melo
    Cc: Daniel Borkmann
    Cc: David S. Miller
    Cc: Jiri Olsa
    Cc: Linus Torvalds
    Cc: Masami Hiramatsu
    Cc: Namhyung Kim
    Cc: Peter Zijlstra
    Cc: Peter Zijlstra
    Cc: Steven Rostedt
    Link: http://lkml.kernel.org/r/1427312966-8434-8-git-send-email-ast@plumgrid.com
    Signed-off-by: Ingo Molnar

    Alexei Starovoitov