Re: [PATCH v2 0/5] ftrace: Fix fprobe with function graph accounting

On Wed, Feb 19, 2025 at 05:04:36PM -0500, Steven Rostedt wrote:

Heiko Carstens reported[1] a bug when running the ftrace selftests.
After running them, he noticed that the enabled_functions file had
all functions enabled in it. That means something was registered to
ftrace that shouldn't be.

The issue was with the accounting of the new fprobe logic which was
built on top of the function graph infrastructure. Patch 3 of this
series is the fix for that bug, but while debugging that, 3 other
accounting bugs were discovered.

...

Steven Rostedt (5):
      ftrace: Fix accounting of adding subops to a manager ops
      ftrace: Do not add duplicate entries in subops manager ops
      fprobe: Always unregister fgraph function from ops
      fprobe: Fix accounting of when to unregister from function graph
      selftests/ftrace: Update fprobe test to check enabled_functions file

----
 kernel/trace/fprobe.c                              | 12 ++---
 kernel/trace/ftrace.c                              | 33 +++++++++----
 .../ftrace/test.d/dynevent/add_remove_fprobe.tc    | 54 ++++++++++++++++++++++
 3 files changed, 82 insertions(+), 17 deletions(-)

FWIW, I can confirm that this fixes the bug I reported.
Feel free to add

Tested-by: Heiko Carstens <hca@linux.ibm.com>