[PATCH v5 0/8] perf trace: Augment enum arguments with BTF

[Howard Chu <howardchu95@gmail.com>]

Changes in v5:

- Use hardcoded landlock structs and macros for landlock.c workload to
make this build in older systems.

Changes in v4:

- Fix landlock workload's build error.

Changes in v3:

- Add trace__btf_scnprintf() helper function
- Remove is_enum memeber in struct syscall_arg_fmt, replace it with 
btf_is_enum()
- Add syscall_arg_fmt__cache_btf_enum() to cache btf_type only
- Resolve NO_LIBBPF=1 build error
- Skip BTF augmentation test if landlock_add_rule syscall and LIBBPF are not
available
- Rename landlock.c workload, add a comment to landlock.c workload
- Change the way of skipping 'enum ' prefix
- Add type_name member to struct syscall_arg

Changes in v2:

- Add trace_btf_enum regression test, and landlock workload

v1:

In this patch, BTF is used to turn enum value to the corresponding
enum variable name. There is only one system call that uses enum value
as its argument, that is `landlock_add_rule()`.

Enum arguments of non-syscall tracepoints can also be augmented, for
instance timer:hrtimer_start and timer:hrtimer_init's 'mode' argument.


Arnaldo Carvalho de Melo (2):
  perf trace: Introduce trace__btf_scnprintf()
  perf trace: Remove arg_fmt->is_enum, we can get that from the BTF type

Howard Chu (6):
  perf trace: Fix iteration of syscall ids in syscalltbl->entries
  perf trace: BTF-based enum pretty printing for syscall args
  perf trace: Augment non-syscall tracepoints with enum arguments with
    BTF
  perf trace: Filter enum arguments with enum names
  perf test: Add landlock workload
  perf test trace_btf_enum: Add regression test for the BTF augmentation
    of enums in 'perf trace'

 tools/perf/builtin-trace.c               | 229 ++++++++++++++++++++---
 tools/perf/tests/builtin-test.c          |   1 +
 tools/perf/tests/shell/trace_btf_enum.sh |  61 ++++++
 tools/perf/tests/tests.h                 |   1 +
 tools/perf/tests/workloads/Build         |   2 +
 tools/perf/tests/workloads/landlock.c    |  66 +++++++
 tools/perf/trace/beauty/beauty.h         |   1 +
 tools/perf/util/syscalltbl.c             |   7 +
 tools/perf/util/syscalltbl.h             |   1 +
 9 files changed, 345 insertions(+), 24 deletions(-)
 create mode 100755 tools/perf/tests/shell/trace_btf_enum.sh
 create mode 100644 tools/perf/tests/workloads/landlock.c

-- 
2.45.2