Commit Graph

8 Commits

Author SHA1 Message Date
Daniel T. Lee
f0c328f8af samples: bpf: Refactor tracepoint tracing programs with libbpf
For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing tracepoint tracing programs with libbbpf
bpf loader.

    - Adding a tracepoint event and attaching a bpf program to it was done
    through bpf_program_attach().
    - Instead of using the existing BPF MAP definition, MAP definition
    has been refactored with the new BTF-defined MAP format.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200823085334.9413-4-danieltimlee@gmail.com
2020-08-24 20:59:35 -07:00
Ilya Leoshkevich
e4d9c23207 samples/bpf, selftests/bpf: Use bpf_probe_read_kernel
A handful of samples and selftests fail to build on s390, because
after commit 0ebeea8ca8 ("bpf: Restrict bpf_probe_read{, str}()
only to archs where they work") bpf_probe_read is not available
anymore.

Fix by using bpf_probe_read_kernel.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720114806.88823-1-iii@linux.ibm.com
2020-07-21 13:26:26 -07:00
Yonghong Song
03421a92f5 samples/bpf: Remove compiler warnings
Commit 5fbc220862 ("tools/libpf: Add offsetof/container_of macro
in bpf_helpers.h") added macros offsetof/container_of to
bpf_helpers.h. Unfortunately, it caused compilation warnings
below for a few samples/bpf programs:
  In file included from /data/users/yhs/work/net-next/samples/bpf/sockex2_kern.c:4:
  In file included from /data/users/yhs/work/net-next/include/uapi/linux/in.h:24:
  In file included from /data/users/yhs/work/net-next/include/linux/socket.h:8:
  In file included from /data/users/yhs/work/net-next/include/linux/uio.h:8:
  /data/users/yhs/work/net-next/include/linux/kernel.h:992:9: warning: 'container_of' macro redefined [-Wmacro-redefined]
          ^
  /data/users/yhs/work/net-next/tools/lib/bpf/bpf_helpers.h:46:9: note: previous definition is here
          ^
  1 warning generated.
    CLANG-bpf  samples/bpf/sockex3_kern.o

In all these cases, bpf_helpers.h is included first, followed by other
standard headers. The macro container_of is defined unconditionally
in kernel.h, causing the compiler warning.

The fix is to move bpf_helpers.h after standard headers.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513180223.2949987-1-yhs@fb.com
2020-05-13 12:30:50 -07:00
Toke Høiland-Jørgensen
7cf245a37e samples/bpf: Use consistent include paths for libbpf
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: 6910d7d386 ("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
2020-01-20 16:37:45 -08:00
Andrii Nakryiko
3ac4dbe3dd selftests/bpf: Split off tracing-only helpers into bpf_tracing.h
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
2019-10-08 23:16:03 +02:00
Daniel Borkmann
02413cabd6 bpf, samples: don't zero data when not needed
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>
2016-04-14 21:40:42 -04:00
Alexei Starovoitov
3c9b16448c samples/bpf: tracepoint example
modify offwaketime to work with sched/sched_switch tracepoint
instead of kprobe into finish_task_switch

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 21:04:27 -04:00
Alexei Starovoitov
a6ffe7b9df samples/bpf: offwaketime example
This is simplified version of Brendan Gregg's offwaketime:
This program shows kernel stack traces and task names that were blocked and
"off-CPU", along with the stack traces and task names for the threads that woke
them, and the total elapsed time from when they blocked to when they were woken
up. The combined stacks, task names, and total time is summarized in kernel
context for efficiency.

Example:
$ sudo ./offwaketime | flamegraph.pl > demo.svg
Open demo.svg in the browser as FlameGraph visualization.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-20 00:21:44 -05:00