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=1792971011; b=jop9PTjJtOvSK5x9/TBGinaUAsITtuN+R42jziJ5oBkN07ZzeJ0qdzD7b8BjNdkjFPx1 kKi8Vv7PpY91E6Dca7RCxYnyHxdlWQbcYMweeHa5aBxRgF9tkzUFItDD/E8V+BBUaVpK9 eb1KLXT2crNJv+ZcMNtVuGRg+O2hpnhCxFRjzxkZ7kCanwn26+JPSeNLWtaRDGm5zmwF9 9rivdp4As3xx+uZ9M/dS6rFOV2rST6pB7k38oazZthq107JYK5XUdi7DfBBPDoG/mBAGz Kcl5JyK7fMARErtdY1Sn/T9EApK70eg9Oi0HRVFqrglgB7si52YgtC3KCTYN+SrJ4cw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792971011; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=IgHIB6FOcL0bCiYPaegMhdluu/k3cOQL1TguKu3CfbA=; b=dH4ejUbrHNUev0ZRrfGBUeDn6VaU4ejrR+DP7X0m9kk5JdG8v8Qd3HabcCY9Vv1Nbzes zhj2BH/5E0AxN9CYzMrxT2fY7q7n7s4gBnDDWAHm5Px1GidbKyp+6BJzY9lMIeku3Ti6E iYwOh1nhDK0j+ywc54dbQ50IZCfVrwYkeRduaMLv2iGAlh58Lon9V4xc78X26PcIHLbiD DMlweBL4UxFMfROV50Nh6MdDEFDLCP5PdbwatkgPJLtRgcMkCHBdVaP4d+NuJ8tOOk8yW EMJElnnS3g9aabbIDKsOTOVPTNjmYx9LVfANEGqOfakZfEiTlsYBp5yeLojPe34sCvA== 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=RsKPsTZX; 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 6CCA1606A31A; Sun, 25 Oct 2026 23:30:11 +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=RsKPsTZX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 452381F031E3; Sun, 25 Oct 2026 23:30:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792971011; bh=IgHIB6FOcL0bCiYPaegMhdluu/k3cOQL1TguKu3CfbA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RsKPsTZXjG3XXKmYD9MfedxVJxvR1k+Bngrc8JlS7vFSfL05vAecigviHGlboP0fh bWrvygLpdpuSlX1T4yW5JHZGUSn0nQm+uM+nxqdvo/AiyTLhOGoSpm+e/wI4VCUuOy 4J5+Plg/tB9Dr4QM8orhdzhNlkNS7FJ4BVrfPY2o1lslo7xZgWlpw+c5V9NQGD5DX2 JzjDJVqks/pk10gpOSQRNW3APUEx9JqBnkVPRKNEsx+uLTGI7iiYghuLaOL6OWHdTr 3x9uaxDSLSwfIzAVjLyfkCnjMWMBepRrweTG5+/4ccYJZNwaQM2FNiHIWNym7IWLuM BjVrNu3BTHMLQ== From: Sasha Levin To: SJ Park Cc: Sasha Levin , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Subject: Re: [RFC PATCH 7.3.y] mm/damon/core: error damos_commit_quota_goal() for zero target_value Date: Sun, 25 Oct 2026 19:29:57 -0400 Message-ID: <2026-10-25-1-daily-reply-0011-damon-zero-target-value-decline@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261025171526.157414-1-sj@kernel.org> References: <20261025171526.157414-1-sj@kernel.org> 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 > Notes for stable kernel porting. The upstream commit doesn't have > Fixes: and therefore not ported to stable kernels. It turned out it > fixes commit 8b549a4fd3c5 ("mm/damon/sysfs-schemes: commit damos quota > goals user input to DAMOS") which was merged into v6.8. The user impact > is a race condition that can result in divide-by-zero. Hence backport. The older trees don't need this one. The callers in 7.2, 6.18 and 6.12 already reject a zero target_value (7.2 also has 06befa61c427 ("mm/damon/lru_sort: error out for >10000 active_mem_bp") and a16fd3ad9d89 ("samples/damon/mtier: error out for zero quota goal target values")), the commit has no Fixes: or Cc: stable, and it is patch 1/3 of a series whose patches 2 and 3 remove those caller-side checks. -- Thanks, Sasha