From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792946900; b=fjmnxZ5zrrt7aBlWLtFAUBfCr25Bb0q9gKJqJOXGjn0D6hWCMh9AodIOiVs+0lPF2pg4 Umkf6X1MdND1z7p6hYP8DM3PzDE0x76+/MLQrgXIUF4f/x84c6rNIYJAi1/OQLTO4MI0F IF9+Hs5F01chqQT1KcXCg1hqg5byPQOp0zJTeZ0rD7ZdAAymVPdWnHZTeJwxTIA1Rwy7q e5ETJvTLd1ppCHOeGHETC43JRstzm9ECwhkbL+i+8Fe58hvtEXYm3X5yUub1/H1maz9Jd appmg3G60PxBwgXUNLePpNSofReQcGseWwJL7DODS4oMh1QkmyO1wWlHbDob+9T9f0w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792946900; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Transfer-Encoding; bh=Q80p5MCUlafYdcYjwuOtEqPOJb6ACREJHt1LW8otA0U=; b=BIR2UBVbsuzGLwnCZdpNA0eY+s/in87qI7ohO0DFYubX58RnS32EB0VoDpG7pPNjZwY2 DfBQj6YP+t5f1VIWC72s/5E8w9H40f2Im98MLhKaPjqOPLEksTXzU+hYmd7/Xgw5EHqN9 YRM6NH4m5f55B8CIHucl/2WzzNul0Cfy1vym6O94cELRyNMv6hOQDlolpXE5MsaGskvr0 qzCZJF8aAN58juiOROwBxc7j70mxuHxpUed8gxviUR7MkejL06/APgqsiUzUxDgIMP31c pkToWNjD9il5KonvhW5KWERb93VM9iI3eL3j7Q73D42wf4OTp42gajXtiK6JAIMykZQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BE59L+tX; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5934F606A31A; Sun, 25 Oct 2026 16:48:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BE59L+tX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95F6E1F01825; Sun, 25 Oct 2026 16:48:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792946899; bh=Q80p5MCUlafYdcYjwuOtEqPOJb6ACREJHt1LW8otA0U=; h=From:To:Cc:Subject:Date; b=BE59L+tXgKsr6xmG/v2ova9IBI5Ez0pYWp5yRRfHpJgTtL9+iX+yTdY7eS/Xfk/w3 jLfAWkaugebck40qc3kL1tzD462m8fb9d9PbCdA/lv8PyLcTzF89tARN3sj0FKPrwM nYiwCeVa5orPCVQfJE0AWBT8xENUJk7d0b0LZDlN6868enbv5i7EQvD2PCzSyEEEjf tO23WIIWmat/Dfb7et2QEjrCRjPBBxdOjMDHEzsgnkd7iaRdkq9KWinnBkGXn0X8+c gaD4QRhwd95iFVVHPgRE4ud8rrqPSCMadF1j0/kIQLo3UHmS43f1Hf44zdJZ1hYX0u wZI+FrfvFOGHg== From: SJ Park To: Andrew Morton Cc: SJ Park , stable@vger.kernel.org, Fernand Sieber , Jiayuan Chen , SeongJae Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 0/3] mm/damon: fix three race bugs in sysfs and core Date: Sun, 25 Oct 2026 09:48:03 -0700 Message-ID: <20261025164808.152048-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit There are three race condition bugs in DAMON sysfs interface and the core layer. User impacts are not critical but better to fix sooner than later. Patch 1 fixes a toctou bug in DAMON sysfs interface that can mess up DAMOS auto-tuning. Patches 2 and 3 move static variables that can be wrongly shared with multiple kdamonds and therefore make DAMON monitoring results be a little more indeterministic. Note for Andrew. These are not urgent but better to take the hotfix track in my humble opinion. Changes from RFC - RFC: https://lore.kernel.org/20261024193351.87130-1-sj@kernel.org - Rebase to latest mm-new. - Drop RFC tag. SJ Park (3): mm/damon/sysfs-schemes: hold damon_sysfs_lock in target_metric_store() mm/damon/core: move static variable last_nr_regions to damon_ctx mm/damon/core: move static variable rotation to damon_ctx include/linux/damon.h | 10 ++++++++++ mm/damon/core.c | 10 +++++----- mm/damon/sysfs-schemes.c | 3 +++ 3 files changed, 18 insertions(+), 5 deletions(-) base-commit: 34b81edd2a3300a88493222637ea010223c00ecd -- 2.47.3