[PATCH v3 0/8] perf trace: Augment enum arguments with BTF

Howard Chu
2024-06-24T18:12:08Z

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.

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

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 | 1 +
tools/perf/tests/workloads/landlock.c | 39 ++++
tools/perf/trace/beauty/beauty.h | 1 +
tools/perf/util/syscalltbl.c | 7 +
tools/perf/util/syscalltbl.h | 1 +
9 files changed, 317 insertions(+), 24 deletions(-)
create mode 100755 tools/perf/tests/shell/trace_btf_enum.sh
create mode 100644 tools/perf/tests/workloads/landlock.c

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2.45.2