From: Eugene Mavick via B4 Relay <devnull+m.mavick.dev@kernel.org>
To: Will Deacon <will@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Boqun Feng <boqun@kernel.org>,
Mark Rutland <mark.rutland@arm.com>, Gary Guo <gary@garyguo.net>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@gentwo.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-mm@kvack.org, Eugene Mavick <m@mavick.dev>
Subject: [PATCH 0/4] tracing: add ref_trace_final_put tracing
Date: Sun, 05 Jul 2026 09:20:50 +0800 [thread overview]
Message-ID: <20260705-refcount-final-put-trace-v1-0-0ae936edb750@mavick.dev> (raw)
When debugging use-after-free(UAF) bugs, knowing when the object reaches
0 references and enters final release can significantly aide the
debugging process.
There is currently no universal way to trace this information.
This patches traces the final puts in the most widely used refcounting
implementations, refcount_t(and thus kref which uses it), and
percpu-ref.
The tracepoint records three fields:
- caller: function that called the refcounting
function(refcount_sub_and_test, percpu_ref_put_many)
- fn: refcounting function(eg refcount_sub_and_test)
- obj: refcount object(struct percpu_ref, refcount_t)
Signed-off-by: Eugene Mavick <m@mavick.dev>
---
Eugene Mavick (4):
tracing: add ref_trace_final_put tracepoint
refcount: add ref_trace_final_put tracepoint
percpu-refcount: add ref_trace_final_put trace
kunit: add test for ref_trace_final_put
MAINTAINERS | 3 +
include/linux/percpu-refcount.h | 5 +-
include/linux/ref_trace.h | 26 ++++++++
include/linux/refcount.h | 2 +
include/trace/events/ref_trace.h | 46 +++++++++++++
lib/Kconfig | 10 +++
lib/Makefile | 2 +
lib/ref_trace.c | 12 ++++
lib/tests/Makefile | 1 +
lib/tests/ref_trace_kunit.c | 138 +++++++++++++++++++++++++++++++++++++++
10 files changed, 244 insertions(+), 1 deletion(-)
---
base-commit: df685633c3dbc67441cc86f1c3fee58de4652ba2
change-id: 20260624-refcount-final-put-trace-49bd7c39bd5a
Best regards,
--
Eugene Mavick <m@mavick.dev>
next reply other threads:[~2026-07-05 1:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-05 1:20 Eugene Mavick via B4 Relay [this message]
2026-07-05 1:20 ` [PATCH 1/4] tracing: add ref_trace_final_put tracepoint Eugene Mavick via B4 Relay
2026-07-05 1:20 ` [PATCH 2/4] refcount: " Eugene Mavick via B4 Relay
2026-07-06 10:07 ` Usama Arif
2026-07-05 1:20 ` [PATCH 3/4] percpu-refcount: add ref_trace_final_put trace Eugene Mavick via B4 Relay
2026-07-05 1:20 ` [PATCH 4/4] kunit: add test for ref_trace_final_put Eugene Mavick via B4 Relay
-- strict thread matches above, loose matches on Subject: below --
2026-07-05 0:36 [PATCH 0/4] tracing: add ref_trace_final_put tracing Eugene Mavick
2026-07-04 23:19 Eugene Mavick
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