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From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	James Clark <james.clark@linaro.org>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Clark Williams <williams@redhat.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	sashiko-bot <sashiko-bot@kernel.org>,
	David Ahern <dsahern@gmail.com>,
	"Claude Opus 4.6" <noreply@anthropic.com>
Subject: [PATCH 8/9] perf sched: Use thread__put() in free_idle_threads()
Date: Fri,  5 Jun 2026 20:38:36 -0300	[thread overview]
Message-ID: <20260605233837.1773732-9-acme@kernel.org> (raw)
In-Reply-To: <20260605233837.1773732-1-acme@kernel.org>

From: Arnaldo Carvalho de Melo <acme@redhat.com>

free_idle_threads() calls thread__delete() directly instead of
thread__put(), bypassing the reference counting lifecycle.  Under
REFCNT_CHECKING builds, this leaks the pointer handle since
thread__delete() frees the object without going through the refcount
wrapper.

The idle threads are created via thread__new() (refcount=1) in
get_idle_thread().  Callers get additional references via thread__get()
which they release with thread__put().  free_idle_threads() drops the
base reference — thread__put() is the correct call, matching the
thread__new() acquisition.

Fixes: 49394a2a24c7 ("perf sched timehist: Introduce timehist command")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Assisted-by: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-sched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index c0cd3cbb602aa4c0..732c65008a8a5240 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -2481,7 +2481,7 @@ static void free_idle_threads(void)
 			if (itr)
 				thread__put(itr->last_thread);
 
-			thread__delete(idle);
+			thread__put(idle);
 		}
 	}
 
-- 
2.54.0


  parent reply	other threads:[~2026-06-05 23:39 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-05 23:38 [PATCHES v2 0/9] perf tools: Fix OOB writes, refcount bugs, and BUG_ON in mmap/stat/c2c/sched Arnaldo Carvalho de Melo
2026-06-05 23:38 ` [PATCH 1/9] perf mmap: Guard cpu__get_node() return in aio_bind() Arnaldo Carvalho de Melo
2026-06-05 23:56   ` sashiko-bot
2026-06-05 23:38 ` [PATCH 2/9] perf stat: Bounds-check CPU index in topology aggregation callbacks Arnaldo Carvalho de Melo
2026-06-05 23:55   ` sashiko-bot
2026-06-05 23:38 ` [PATCH 3/9] perf c2c: Bounds-check CPU and node IDs before bitmap and array access Arnaldo Carvalho de Melo
2026-06-05 23:54   ` sashiko-bot
2026-06-05 23:38 ` [PATCH 4/9] perf c2c: Bounds-check CPU IDs in setup_nodes() topology loop Arnaldo Carvalho de Melo
2026-06-05 23:38 ` [PATCH 5/9] perf sched: Clean up idle_threads entry on init failure Arnaldo Carvalho de Melo
2026-06-05 23:56   ` sashiko-bot
2026-06-05 23:38 ` [PATCH 6/9] perf sched: Use is_idle_sample() for idle thread runtime cast guard Arnaldo Carvalho de Melo
2026-06-05 23:38 ` [PATCH 7/9] perf sched: Fix thread reference leak in idle hist processing Arnaldo Carvalho de Melo
2026-06-05 23:56   ` sashiko-bot
2026-06-05 23:38 ` Arnaldo Carvalho de Melo [this message]
2026-06-05 23:38 ` [PATCH 9/9] perf sched: Replace BUG_ON and add NULL checks in replay event helpers Arnaldo Carvalho de Melo

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