From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5511D3074AA; Wed, 13 Aug 2025 17:02:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755104547; cv=none; b=jS8ASk4d9ue9fQVXXpBFWPzgQpQrFxTcpzSkCP4Vsyq2MD2sdD57jy4/7OtGf/UzLodvrqj8QwrHEqPWvJJbgdoz6O6t2Ys6guf7ZjD2BmtI/vUW4xMktGawtco1w2L2KlxlskEJka+5OHuy0nAktBRUmreUEduaCv6pEjN2gus= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755104547; c=relaxed/simple; bh=pxPFIqlcVAMG5sLiG3JCncN+PKieiRwzMe/d3NJAQGs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=R5G6r0uaFIQ6+XiUBBKhsDmPo29IPyTz2Rjvd7HId21uJvc3qoW7FhWHOqirJckM9G/aulCGacoG38pzk4FpV18CyJqg4NJBakXCDZUfUliQH8kyF6uLe9QUHuU3sip6J/sBRx4UnnHLp2nlCclF4ERVtTmMmLeky99SWgNM3YU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ek1oiK1X; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ek1oiK1X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B17D2C4CEF8; Wed, 13 Aug 2025 17:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755104546; bh=pxPFIqlcVAMG5sLiG3JCncN+PKieiRwzMe/d3NJAQGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ek1oiK1XjXTi0SESN0AUPvtcaMoHxYRtyyZaq295L01XSarSLm92n3YPf5vxwipsw KGqabxNl58laYyM/23faOZSmlQluwCUO5e/WArOUQgverIDf10+X0FpW3M2FCWhaJG i5OazMp25tk4QUOzpzvlwS1cHO/JP/DUEAPjdl5Zck0wPnvFYZL5B67T66uEkrRSDN FTv9BU3mOnVhEhbUvwwOg6L7f8kLZhkrd4OkaIQfoavKlcq10q/xPm8jtE+Jo66HQG BVOaYz2N9jsxARJZQX373m4zG5Q7YKcyFQYLPe0s7az+NAe8cIda9dT+k0WOFNV82/ VjnbRziy0istg== From: SeongJae Park To: Quanmin Yan Cc: SeongJae Park , akpm@linux-foundation.org, damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, wangkefeng.wang@huawei.com, zuoze1@huawei.com Subject: Re: [RFC PATCH -next 13/16] mm/damon/sysfs: ensure valid addr_unit setting in damon_sysfs_apply_inputs() Date: Wed, 13 Aug 2025 10:02:24 -0700 Message-Id: <20250813170224.6128-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250813050706.1564229-14-yanquanmin1@huawei.com> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 13 Aug 2025 13:07:03 +0800 Quanmin Yan wrote: > By calling damon_sysfs_turn_damon_on(), the execution of damon_commit_ctx() > can be bypassed. Therefore, it is necessary to prevent ctx->addr_unit from > being set to 0 in damon_sysfs_apply_inputs() and update min_region to avoid > potential issues. Nice catch! > > Signed-off-by: Quanmin Yan > --- > mm/damon/sysfs.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c > index bea782b0a711..122824776c1d 100644 > --- a/mm/damon/sysfs.c > +++ b/mm/damon/sysfs.c > @@ -1422,7 +1422,8 @@ static int damon_sysfs_apply_inputs(struct damon_ctx *ctx, > err = damon_select_ops(ctx, sys_ctx->ops_id); > if (err) > return err; > - ctx->addr_unit = sys_ctx->addr_unit; > + ctx->addr_unit = sys_ctx->addr_unit ? : 1; So this is fixing a bug of the seventh patch ("mm/damon/sysfs: implement addr_unit file under context dir") of this series, right? It is better to not add a broken patch, and then fixing it in the same series. Let's squash the fix of the problem into the patch. Don't forget adding your Signed-off-by on the patch. Also, since sys_ctx->addr_unit is initialized as 1, the value being zero is user's wrong input. Let's return -EINVAL instead of making it silently success. > + ctx->min_region = max(DAMON_MIN_REGION / ctx->addr_unit, 1); Seems this is a fix of an issue in the 12th patch ("mm/damon: add damon_ctx->min_region and damon_target->min_region") of this series? Let's fix it on the patch. > err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs); > if (err) > return err; > -- > 2.34.1 Thanks, SJ