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 AB2B025F98A; Thu, 3 Sep 2026 01:03:42 +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=1788397423; cv=none; b=J6uRsb0CqVQxq5TKBvOPNcG8NYTaGRvS9hvATBeEzRnTdSXU4Le5aLDGFVrCrafBlT9nEQcLGZbPSxpyB6ycopZdbMRoxnsHAeeXsRtnl+K9KdqGhFHMr8csbspd9olGGm88Yi6KYyMmTixSNlkdKq6F503wH0o7uDa8JXeEmxA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788397423; c=relaxed/simple; bh=r4iZrzj5qL7LAWTz63717Wz1x4MBKJBWzcg3SftZdDM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LakKKwCYrTkjyAPOQVOSvxYEjczEF0Or9rSRXQMz3Lz1KrLXhuWgmKtlLnQmtu61d+798nZ3iWMvPwCE1NGSD+dcyhL9yIGP6NXKZEwWb11FssRGxlkTKb2xxx8APMZ44EYhbIxkC3Z09s7y4JkEpCijbmQ1hjpgP0KDCqN85JE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h+egqciW; 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="h+egqciW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CA4E1F000E9; Thu, 3 Sep 2026 01:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788397422; bh=0ONhJWY5DgYVDUUnZ1xlMrMEr8Cx+Nb9XbB8pDmxhHk=; h=From:To:Cc:Subject:Date; b=h+egqciWGoWX9TsIcJAj9E+10Dduu+fOKklXNcGnDE5p+hMmzylMqGVmO/W0UphWf s1E32GSyGpmBAB7BLCrKZV78GOKerAxxT/3WeOs+3ZtrVuZ56fDECMNnlOKZpYz+E7 uLxleOlms2+ZVfDvUibwFZjCTKxocsA6cjKW7P4kjfZFL0bJAf0ZWQnmROD49Yxjio iLWVAFWUsxxeuku2PW03E8jr6oMq4uGjfOpHre4540vpwLV0M9PO3yziFEW3oG1Dqo TUO1Z4KhV1cdMi6wP6oIrDVIiWsfE2WJtE/6Xd6pXtkWYO4ZSfnqduMTHi4UrL4Iza gEYyAQ5DXzwTg== From: SJ Park To: Andrew Morton Cc: SJ Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 0/4] mm/damon: allow NULL or unstarted damon_ctx parameter for damon_call() Date: Wed, 2 Sep 2026 18:03:29 -0700 Message-ID: <20260903010334.93622-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Callers of damon_call() should validate the damon_ctx object parameter. If it is NULL or never damon_start()-ed object, damon_call() could dereference the NULL pointer or indefinitely hang. Ensuring all callers doing the validation correctly has turned out to be difficult. Handle the corner cases inside the core layer and remove callers' validations. Patches 1 and 2 respectively allow passing NULL and not yet damon_start()-ed ctx parameter to damon_call(). Patches 3 and 4 remove the callers side validations in DMON_RECLAIM and DASMON_LRU_SORT, respectively. Changes from RFC - RFC: https://lore.kernel.org/20260813035001.97364-1-sj@kernel.org - Drop RFC tag. - Rebase to lates mm-new. SJ Park (4): mm/damon/core: handle NULL ctx parameter in damon_call() mm/damon/core: set ctx->call_controls_obsolete in damon_new_ctx() mm/damon/reclaim: remove unnecessary damon_call() param validation mm/damon/lru_sort: remove unnecessary damon_call() param validation mm/damon/core.c | 7 +++---- mm/damon/lru_sort.c | 8 -------- mm/damon/reclaim.c | 8 -------- 3 files changed, 3 insertions(+), 20 deletions(-) base-commit: 7fe9a8a366a72a631bcb23c2b108669ab182f2f2 -- 2.47.3