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=1792870439; b=xAzssHrprEnT6X+eTkhn0tdWykJ5UFOsSufSXs8Y4oaJno0EJZNi+/tygEVSN9xCyeXu FlSiZTmq+C1OxlZ4fTX4f7/3XFMxYgg7fgB84KQSSAP0y2b08BrO1ZAjDxTqv+a8HOQ7Q YZFzc7CTXJx6jSXVwmGPssW7waVWUku8Uq3uzan7fETS50sWkMCarEUN6WsVbWgpvTLAW hl/xic9o/5ruLAU7DBefZkkJGDsFOAzkx7w4UkyXu/UuUlMpO9S64jYTwPiGQAxSSQ4th RCeDBX4T2hyLh7Gvwf4t+/tgF0ZPYu906OhbRvPqXWdmfpEYhXf1Q6l7pdNwTZwyeKQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792870439; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Transfer-Encoding; bh=B+9LPpeyWJrESAgg+ZQjlbIQ+zZneFd2FYznRyvKzQ8=; b=aHk3Cmdl+wjBSVE44ar/2+MCAj6KdTpHwYyPimroNiRLAtaj/IeA3j0Vg5VA8PjRDrCg aXKGup+K3b1OQiPVPqhgP9cM1BHceJp3meHMbccl52RRgDS99ntXW/N3TK0kgSDIzLR1f Ii16UrEzNSqqk3gOoHmmR5fOSodszCOS8VGqnNWUMT+iZufenxdyfTAMLrLgFChvnl4+a oVIilYh3oBaI7ACuDmUeFS3ooQAkUl0NSLeL9njit3IdzA2KFi3unVPvEMp8wFvoQgUT9 8LpjihQESDLsVe2ZHr0WslFXPz4sTms8dVgeh++/C4ewgEbyOFeGAFO1yBrFVVfLqsw== 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="i/aG3jxE"; 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 88179606A31A; Sat, 24 Oct 2026 19:33:59 +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=i/aG3jxE Received: by smtp.kernel.org (Postfix) with ESMTPSA id C15F01F01825; Sat, 24 Oct 2026 19:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792870439; bh=B+9LPpeyWJrESAgg+ZQjlbIQ+zZneFd2FYznRyvKzQ8=; h=From:To:Cc:Subject:Date; b=i/aG3jxEddkj7xtQ9f3WYVMpUdNeqlPxwj4ciVD5BchuvceGln2DXw8sx1RReEiFR yUVmEz/gLrY0iuGzOCzT4ZOJT0370ye3AB8krrxnKd1wmKG1YW4DrpbEPlesZhv3gf y5buFfvDheBg474TrlT/ICDVbdESfWutV7RXpmfqvU1t/wAp+HSLivn9EOu7N+z0S1 ABLrHwhEMrzZLab5gnwJDJ6x81N/vjKB0x6VwpDFANxz0cRUq32O4u92UzI5ARUJ8a Yp/czdUdLef0U0qPRlP+nfgwhdj3z14nxxu1b8/M4Gugutxah8A+1MBS8RxE0UYQ4e AbWFYk7IdHHKQ== From: SJ Park To: Cc: SJ Park , stable@vger.kernel.org, Andrew Morton , Fernand Sieber , Jiayuan Chen , SeongJae Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 0/3] mm/damon: fix three race bugs in sysfs and core Date: Sat, 24 Oct 2026 12:33:46 -0700 Message-ID: <20261024193351.87130-1-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. 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: f390255d9de653f4e7a9bae8c9a5ad881ad25a87 -- 2.47.3