[v4,perf,bpf,00/15] perf annotation of BPF programs

Changes v3 to v4:
1. Incorporate feedbacks from Jiri and Namhyung;
2. Fixed compilation error with different feature-disassembler-four-args;
3. Split some patches to smaller patches;
4. Improved error handleing in symbol__disassemble_bpf();
5. Made side band thread more generic;
6. Added comments as suggested.

Changes v2 to v3:
1. Remove unnecessary include in header files;
2. Improved error handling;
3. Better naming of functions, variables, etc.;
4. Enable bpf events by default for perf-top.

Changes v1 to v2:
1. Fix compilation error with different feature-disassembler-four-args;
2. Fix a segfault in perf-record;
3. Split patches 5/9 and 6/9 so that perf_env changes and perf.data changes
   are in separate patches.

This series enables annotation of BPF programs in perf.

perf tool gathers information via sys_bpf and (optionally) stores them in
perf.data as headers.

Patch 1/15 fixes a minor issue in kernel;
Patch 2/15 to 4/15 introduce new helper functions and use them in perf and
     bpftool;
Patch 5/15 to 9/15 saves information of bpf program in perf_env;
Patch 10/15 adds --bpf-event options to perf-top;
Patch 11/15 to 13/15 enables annotation of bpf progs based on information
     gathered in 5/15 to 9/15;
Patch 14/15 introduces side band polling thread that gathers information
     for special kernel events during perf-record or perf-top.
Patch 15/15 handles information of short living BPF program using the new
     side band polling thread.

Commands tested during developments are perf-top, perf-record, perf-report,
and perf-annotate.

===================== Note on patch dependency  ========================
This set has dependency in both bpf-next tree and tip/perf/core. Current
version is developed on bpf-next tree with the following commits
cherry-picked from tip/perf/core:

(from 1/10 to 10/10)
commit 76193a94522f ("perf, bpf: Introduce PERF_RECORD_KSYMBOL")
commit d764ac646491 ("tools headers uapi: Sync tools/include/uapi/linux/perf_event.h")
commit 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
commit df063c83aa2c ("tools headers uapi: Sync tools/include/uapi/linux/perf_event.h")
commit 9aa0bfa370b2 ("perf tools: Handle PERF_RECORD_KSYMBOL")
commit 45178a928a4b ("perf tools: Handle PERF_RECORD_BPF_EVENT")
commit 7b612e291a5a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs")
commit a40b95bcd30c ("perf top: Synthesize BPF events for pre-existing loaded BPF programs")
commit 6934058d9fb6 ("bpf: Add module name [bpf] to ksymbols for bpf programs")
commit 811184fb6977 ("perf bpf: Fix synthesized PERF_RECORD_KSYMBOL/BPF_EVENT")
========================================================================

This set is also available at:

https://github.com/liu-song-6/linux/tree/bpf-annotation

Thanks!!

Song Liu (15):
  perf, bpf: consider events with attr.bpf_event as side-band events
  bpf: libbpf: introduce bpf_program__get_prog_info_linear()
  bpf: bpftool: use bpf_program__get_prog_info_linear() in
    prog.c:do_dump()
  perf, bpf: synthesize bpf events with
    bpf_program__get_prog_info_linear()
  perf: change prototype of perf_event__synthesize_bpf_events()
  perf, bpf: save bpf_prog_info in a rbtree in perf_env
  perf, bpf: save bpf_prog_info information as headers to perf.data
  perf, bpf: save btf in a rbtree in perf_env
  perf, bpf: save btf information as headers to perf.data
  perf-top: add option --no-bpf-event
  perf: add -lopcodes to feature-libbfd
  perf, bpf: enable annotation of bpf program
  perf, bpf: process PERF_BPF_EVENT_PROG_LOAD for annotation
  perf: introduce side band thread
  perf, bpf: save information about short living bpf programs

 kernel/events/core.c         |   3 +-
 tools/bpf/bpftool/prog.c     | 266 +++++++------------------------
 tools/build/Makefile.feature |   6 +-
 tools/lib/bpf/libbpf.c       | 251 +++++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h       |  63 ++++++++
 tools/lib/bpf/libbpf.map     |   3 +
 tools/perf/Makefile.config   |   6 +-
 tools/perf/builtin-record.c  |  12 +-
 tools/perf/builtin-top.c     |  15 +-
 tools/perf/util/annotate.c   | 149 ++++++++++++++++-
 tools/perf/util/bpf-event.c  | 301 +++++++++++++++++++++++++----------
 tools/perf/util/bpf-event.h  |  36 ++++-
 tools/perf/util/dso.c        |   1 +
 tools/perf/util/dso.h        |  33 ++--
 tools/perf/util/env.c        | 150 +++++++++++++++++
 tools/perf/util/env.h        |  21 +++
 tools/perf/util/evlist.c     | 105 ++++++++++++
 tools/perf/util/evlist.h     |  13 ++
 tools/perf/util/header.c     | 256 ++++++++++++++++++++++++++++-
 tools/perf/util/header.h     |   2 +
 tools/perf/util/symbol.c     |   1 +
 tools/perf/util/top.h        |   1 +
 tools/perf/util/util.c       |  10 ++
 tools/perf/util/util.h       |   2 +
 24 files changed, 1389 insertions(+), 317 deletions(-)

--
2.17.1