[RFC PATCH v4 00/29] perf tools: filtering events using eBPF programs

[Wang Nan]

This is the 4th version of patch series which tries to introduce eBPF
programs to perf. Based on v4.1-rc3. This patch series improves
'perf record', enables commands like

 # perf record --event bpf-file.o sleep 1

to select events defined in bpf-file.o and filter those events using
bpf programs inside it.

Different from previous (perf tools: introduce 'perf bpf' command to
load eBPF programs.) version, the 4th version drops 'perf bpf'
subcommand, merges event filtering use case directly into 'perf
record'.

Other improvments including:

 1. Simply return an error if byte ordering mismatch, instead of trying
    to correct it.

 2. Introduce zfree() and zclose() to free memory and close file to
    ensure the pointers are set to NULL and fd set to -1.

 3. Use OO style naming. For example, bpf_object__open() instead of
    bpf_open_object() in v3.

 4. libbpf use linked list to link all bpf_object together. Caller
    doesn't need to store pointers of bpf_object and bpf_program.

 5. Doesn't treat 'config' section specially.

 6. Remove 'atexit' hook.

 7. Bugfix: if multiple perf events are created for one kprobe event,
    only the first try to hook eBPF program can success. Other try
    returns EEXIST. Such error should be ignored.

 8. Coding style, makefile and license correction.

Patch 1/29 - 4/29 are preparations, moves some headers from perf
    internal include directory to tools/include. libbpf will use them.

Patch 5/29 - 22/29 introduces libbpf. The design principle is similar
    to v3, except that allow caller iterate over objects using macro.

Patch 23/29 - 29/29 improve 'perf record' subcommand. In patch 24,
    event parsing syntax is improved to accept strings like
    './bpf-file.o' and 'bpf-object.bpf' to be passed by '--event'.

To make it work, following acked patches should be cherry-picked before
applying this series:

 tools: Change FEATURE_TESTS and FEATURE_DISPLAY to weak binding
 perf tools: Set vmlinux_path__nr_entries to 0 in vmlinux_path__exit
 perf/events/core: fix race in bpf program unregister

Wang Nan (29):
  tools: Add __aligned_u64 to types.h
  perf tools: Move linux/kernel.h to tools/include
  perf tools: Move linux/{list.h,poison.h} to tools/include
  bpf tools: Introduce 'bpf' library to tools
  bpf tools: Allow caller to set printing function
  bpf tools: Open eBPF object file and do basic validation
  bpf tools: Check endianess and make libbpf fail early
  bpf tools: Iterate over ELF sections to collect information
  bpf tools: Collect version and license from ELF sections
  bpf tools: Collect map definitions from 'maps' section
  bpf tools: Collect symbol table from SHT_SYMTAB section
  bpf tools: Collect eBPF programs from their own sections
  bpf tools: Collect relocation sections from SHT_REL sections
  bpf tools: Record map accessing instructions for each program
  bpf tools: Add bpf.c/h for common bpf operations
  bpf tools: Create eBPF maps defined in an object file
  bpf tools: Relocate eBPF programs
  bpf tools: Introduce bpf_load_program() to bpf.c
  bpf tools: Load eBPF programs in object files into kernel
  bpf tools: Introduce accessors for struct bpf_program
  bpf tools: Introduce accessors for struct bpf_object
  bpf tools: Link all bpf objects onto a list
  perf tools: Make perf depend on libbpf
  perf record: Enable passing bpf object file to --event
  perf tools: Parse probe points of eBPF programs during preparation
  perf record: Probe at kprobe points
  perf record: Load all eBPF object into kernel
  perf tools: Add bpf_fd field to evsel and config it
  perf tools: Attach eBPF program to perf event

 tools/{perf/util => }/include/linux/kernel.h |   0
 tools/{perf/util => }/include/linux/list.h   |   6 +-
 tools/include/linux/poison.h                 |   1 +
 tools/include/linux/types.h                  |   5 +
 tools/lib/bpf/.gitignore                     |   2 +
 tools/lib/bpf/Build                          |   1 +
 tools/lib/bpf/Makefile                       | 190 ++++++
 tools/lib/bpf/bpf.c                          |  90 +++
 tools/lib/bpf/bpf.h                          |  23 +
 tools/lib/bpf/libbpf.c                       | 969 +++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h                       |  75 +++
 tools/perf/Makefile.perf                     |  19 +-
 tools/perf/builtin-record.c                  |  32 +
 tools/perf/util/Build                        |   1 +
 tools/perf/util/bpf-loader.c                 | 284 ++++++++
 tools/perf/util/bpf-loader.h                 |  32 +
 tools/perf/util/debug.c                      |   5 +
 tools/perf/util/debug.h                      |   1 +
 tools/perf/util/evlist.c                     |  32 +
 tools/perf/util/evlist.h                     |   1 +
 tools/perf/util/evsel.c                      |  17 +
 tools/perf/util/evsel.h                      |   1 +
 tools/perf/util/include/linux/poison.h       |   1 -
 tools/perf/util/parse-events.c               |  16 +
 tools/perf/util/parse-events.h               |   2 +
 tools/perf/util/parse-events.l               |   5 +-
 tools/perf/util/parse-events.y               |  18 +-
 27 files changed, 1822 insertions(+), 7 deletions(-)
 rename tools/{perf/util => }/include/linux/kernel.h (100%)
 rename tools/{perf/util => }/include/linux/list.h (90%)
 create mode 100644 tools/include/linux/poison.h
 create mode 100644 tools/lib/bpf/.gitignore
 create mode 100644 tools/lib/bpf/Build
 create mode 100644 tools/lib/bpf/Makefile
 create mode 100644 tools/lib/bpf/bpf.c
 create mode 100644 tools/lib/bpf/bpf.h
 create mode 100644 tools/lib/bpf/libbpf.c
 create mode 100644 tools/lib/bpf/libbpf.h
 create mode 100644 tools/perf/util/bpf-loader.c
 create mode 100644 tools/perf/util/bpf-loader.h
 delete mode 100644 tools/perf/util/include/linux/poison.h

-- 
1.8.3.4

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