[PATCH v5 v5 0/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit

["Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com>]

This series extends fprobe dynamic events to accept a comma-separated list of
symbols and explicit/suffixes.

Currently, fprobe only supports a single symbol (or wildcard) per event. This
series allow users to specify a comma-separated list of symbols, including
exclusions, and to select entry/exit explicitly using /

Examples:
- f:[GRP/][EVENT] func1,func2,func3
- f:[GRP/][EVENT] func1,!func2,func3 (exclude with '!')

Logic changes:
- Refactor parsing logic into parse_fprobe_spec()
- Support comma-separated lists and '!' exclusions
- Add / suffixes for explicit entry/exit selection
- Preserve legacy single-symbol behavior (single symbols still accept %return)
- Disable BTF-based signature lookup when list/wildcard is used, since one
  function signature cannot apply to multiple functions
- Reject mixed legacy/new syntax where applicable (e.g. list + %return)
- Update tracefs/README and fprobe documentation
- Add ftrace selftests covering accepted list syntax cases

*Patch order is adjusted: code first, then docs, then selftest

Changes in v5:
- Reordered patches (code->docs->selftests) as suggested
- Addressed review feedback on README help text to show both legacy and list
  syntaxes
- Added missing traceprobe error IDs used by the new validation and fixed
  parsing/bracing issues found by automated builds
- Removed the dedicated list_mode field and infer list behavior from presence of
  filter/nofilter and keep struct trace_probe as the last member
- Link to v4: https://lore.kernel.org/linux-trace-kernel/20251127151218.4763b25c751bb2aac4b1ee36@kernel.org/

I am not fully confident the runtime testing coverage that I did is sufficient
across configs/architectures, so additional verification would be appreciated.

Best regards,
Ryan Chung


Seokwoo Chung (Ryan) (3):
  docs: tracing/fprobe: Document list filters and :entry/:exit
  tracing/fprobe: Support comma-separated symbols and :entry/:exit
  selftests/ftrace: Add accept cases for fprobe list syntax

 Documentation/trace/fprobetrace.rst           |  17 +-
 kernel/trace/trace.c                          |   3 +-
 kernel/trace/trace_fprobe.c                   | 209 ++++++++++++++----
 .../ftrace/test.d/dynevent/fprobe_list.tc     |  92 ++++++++
 4 files changed, 269 insertions(+), 52 deletions(-)
 create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc

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2.43.0