From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 03292437465; Mon, 13 Jul 2026 13:58:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783951128; cv=none; b=Q3ufc94JJZdi3ITXqRrEFK+N9OC8XM3TifoTpZWIZoEkQfxHRwfpNDmAsGKIFegqtJtmm82IzlVn6LVkS2IjQ+PHsGrKOalS5EK9Mmez0pfNY8rU0ZlPg4OzZaJ6F1D1m/sQZGvgZOonBuLXtVTf2K93RfyV/meDTHF4hGZU7qI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783951128; c=relaxed/simple; bh=NMKcm1pkCs64lfIHYa2THibb8WzHVI8aMRYFrV5tuv8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=c3gr9jE+00ENba2MuQL2IktcD7lu0GjIOyFphrELgsR9lSoY3I/j1ObITTh1uRYPWDHjY47ebruGVGiiBPSq+8BwFJLPmI2O/LYsqr7/BSknEsGak3FiVSFmkE83+FMF+X0vYcrgPgTFp8+9QUyMKlkE+tWWHiRNsCeuddtqxyY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y5R975aO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Y5R975aO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60A171F00A3A; Mon, 13 Jul 2026 13:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783951125; bh=kw48eNAzxFRXO6yZLVXQ5NvQIurCQHZvh9V8CBG541c=; h=From:To:Cc:Subject:Date; b=Y5R975aOCRLNoN4CCClsQVWkZ2zFMRMZznKjqildidyehZoUelNcs6ATVc3mjonKW A18YnBR5cIur/f3whvlhNNuah1hRPblBSy1hd3uqGawgTIQFjpK+WXqn/lFZmdHfA2 hZEcSj/xhioRp4fTT47PJGTQHhCt1xIcGj91Jo1AhY21n675b+mlSokY3/0KnQNC1i PlifB5A1j0TlHIPDT47wu/8VYo+584fQQ68909KnlC4UIHGc5BQ06b41eVdHz1xi7b E7s5eufe1vv68EP5xHYuv3576UvvEuz4n1x4kIaCmpuFtoH7tt5JQutxxgYLpKfgCO BRMhdprJ47juw== From: SJ Park To: Cc: SJ Park , stable@vger.kernel.org, Andrew Morton , Brendan Higgins , David Gow , Fernand Sieber , Leonard Foerster , SeongJae Park , Shakeel Butt , damon@lists.linux.dev, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1.2 0/5] mm/damon: unurgent fixes for infinite loop, NULL de-ref and races Date: Mon, 13 Jul 2026 06:58:31 -0700 Message-ID: <20260713135838.32730-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sashiko found a few issues in DAMON that could cause infinite loop, NULL dereference and monitoring results degradation. The first two sounds scary but the infinite loop happens only under unreasonable user setup. The NULL dereference is only in a unit test. Monitoring results degradation is trivial since it is only best-effort, and those happens from only unlikely races. Still those are bugs that better to fix if possible. Fix those. Changes from RFC v1.1 - RFC v1.1: https://lore.kernel.org/20260712170328.91144-1-sj@kernel.org - Remove same_target param from __damon_va_check_access(). Changes from RFC - RFC: https://lore.kernel.org/20260711180409.82093-1-sj@kernel.org - Rebase to mm-new. SJ Park (5): mm/damon/core: avoid infinite kdamond_merge_regions() internal loop mm/damon/tests/core-kunit: catch test failure in test_merge_regions_of() mm/damon/vaddr: drop last same folio access check optimization mm/damon/paddr: drop last same folio access check reuse optimization mm/damon/sysfs: read ops_id only once mm/damon/core.c | 13 +++++++++---- mm/damon/paddr.c | 20 ++++---------------- mm/damon/sysfs.c | 6 ++++-- mm/damon/tests/core-kunit.h | 3 +++ mm/damon/vaddr.c | 33 ++++++--------------------------- 5 files changed, 26 insertions(+), 49 deletions(-) base-commit: 9d192aa422c3f9c503a40e5eb98093df671accf8 -- 2.47.3