[v7,00/15] libtracefs dynamic events support

Message

Tzvetomir Stoyanov (VMware) Nov. 15, 2021, 10:45 a.m. UTC

The libtracefs logic that works with ftrace dynamic events is unified
and capsulated into a new set of dynamic events APIs. This change makes
the code more consistent and reusable. Also, adding future libtracefs
support for uprobes and eprobes dynamic events is simplified.
The existing library APIs for kprobes and synthetic events are
reimplemented using the new dynamic events helpers.

This patch sets depends on "[PATCH v2 0/4] Modifications of some 'hist' APIs":
 https://lore.kernel.org/linux-trace-devel/[e-mail]/

Suggested-by: Yordan Karadzhov (VMware) <[e-mail]>

v7 changes:
 - Introduced new eprobe API.
 - Changed allocation of a new dynamic event, to use old ftrace interface
   files by default without a check if they exist. That change allows to
   allocate a dynamic event even if the caller have no ftrace permissions.

v6 changes:
 - Removed "instance" parameter from synthetic event APIs, default instance
   is used.
 - Fixed "make doc_clean" to not remove the sources of sqlhist man page.
 - Coding style fixes.

v5 changes:
 - Improved parsing of dynamic events files - added ' \t' as delimiter.
 - Added TRACEFS_DYNEVENT_UNKNOWN in dynamic events enum, which is used as
   error return by the APIsi.
 - Renamed and moved tracefs_kprobe_info() to tracefs_dynevent_info(), as
   the API is more generic and not kprobe specific.
 - Added unit tests for synthetic events APIs.
 - Fixed bugs in synthetic events APIs, related to dynamic events.
 - Coding style fixes.
 - Man pages clean ups.

v4 changes:
 - Redefined the dynamic events enum, so the items can be used in a bitmask.
 - Reimplement the logic for parsing dynamic event strings from ftrace files.
 - Coding style fixes.
 - Added more comments.

v3 changes:
 - Exposed dynamic events API as official tracefs APIs.
 - Removed kprobe specific APIs, that duplicate corresponding dynamic events
   APIs.
 - Updated unit tests and man pages with the new dynamic events APIs.
 - Fixed typos, found by Yordan. 

v2 changes:
 - Removed triple pointer from the APIs.
 - Reimplement dynamic events parsing using strtok_r instead of strchr.
 - Coding style fixes.

Tzvetomir Stoyanov (VMware) (15):
  libtracefs: New APIs for dynamic events
  libtracefs: New APIs for kprobe allocation
  libtracefs: Remove redundant kprobes APIs
  libtracefs: Reimplement kprobe raw APIs
  libtracefs: Extend kprobes unit test
  libtracefs: Rename tracefs_synth_init API
  libtracefs: Use the internal dynamic events API when creating
    synthetic events
  libtracefs: Remove instance parameter from synthetic events APIs
  libtracefs: Add unit test for synthetic events
  libtracefs: Update kprobes man pages
  libtracefs: Document dynamic events APIs
  libtracefs: Do not clean sqlhist man page source
  libtracefs: Introduce eprobe API
  libtracefs: Add utest for event probes
  libtracefs: Document eprobe API

 Documentation/Makefile                 |   3 +-
 Documentation/libtracefs-dynevents.txt | 264 +++++++++
 Documentation/libtracefs-eprobes.txt   | 189 +++++++
 Documentation/libtracefs-kprobes.txt   |  94 ++--
 Documentation/libtracefs-sql.txt       |   4 +-
 Documentation/libtracefs-synth.txt     |  26 +-
 Documentation/libtracefs-synth2.txt    |  40 +-
 Documentation/libtracefs.txt           |  20 +
 include/tracefs-local.h                |  18 +
 include/tracefs.h                      |  68 ++-
 src/Makefile                           |   2 +
 src/tracefs-dynevents.c                | 709 +++++++++++++++++++++++++
 src/tracefs-eprobes.c                  |  56 ++
 src/tracefs-hist.c                     | 163 +++---
 src/tracefs-kprobes.c                  | 508 ++++--------------
 src/tracefs-sqlhist.c                  |   6 +-
 utest/tracefs-utest.c                  | 592 +++++++++++++++------
 17 files changed, 1980 insertions(+), 782 deletions(-)
 create mode 100644 Documentation/libtracefs-dynevents.txt
 create mode 100644 Documentation/libtracefs-eprobes.txt
 create mode 100644 src/tracefs-dynevents.c
 create mode 100644 src/tracefs-eprobes.c