From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EC2BCCCA490 for ; Sun, 18 Oct 2026 22:13:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9481B6B00B1; Sun, 18 Oct 2026 18:13:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 91F856B00B2; Sun, 18 Oct 2026 18:13:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 835426B00B3; Sun, 18 Oct 2026 18:13:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 5A28C6B00B1 for ; Sun, 18 Oct 2026 18:13:45 -0400 (EDT) Received: from smtpin22.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id B9CB9A81BC for ; Sun, 18 Oct 2026 22:13:44 +0000 (UTC) X-FDA: 85337149968.22.33B35EA Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf17.hostedemail.com (Postfix) with ESMTP id B59C940009 for ; Sun, 18 Oct 2026 22:13:40 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=HuASiBCM; spf=pass (imf17.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1792361620; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=g1ox3F3vY0udjg1jNOYHLcMDmNuqPu327im69Kd+WlU=; b=C86/4Dw+NLmYK7IWrHyDGoUb3iROjh+Mjdg8dScx45Lpafuo+Qc7wNnVWeSdSGvXg4jb8D tjaKTt3rllwor2EtsjW+wYH3w/C38aRISvkAvb6o9Wy/VlzPuCayXg+ZMzLMYiW8cwSwV9 8Pv+QsgcwKd3lhSAkfra2yNPDgYeyyM= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1792361620; b=XWCqb1xOc+xv3fAMwCTrCVSSsLvyi6PrxOWluY5mOQsYJN0LfQb1d/rNhHgxzZcfTauWGa SVNmWFchGVElTf0HNeD82KzQTjAXeGAAOOZjWQzG1FAE1frAy+bLG6zTgf9hfgeF107xv3 7Q9nPMtkI0ri09LqmC7jMCCmSCFTZ+c= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=HuASiBCM; spf=pass (imf17.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 2665960DA0; Sun, 18 Oct 2026 22:13:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 962B51F000C4; Sun, 18 Oct 2026 22:13:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792361619; bh=g1ox3F3vY0udjg1jNOYHLcMDmNuqPu327im69Kd+WlU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HuASiBCMB0bQyh2+ueLSuaAWt4A9220/zXe5IvoBS28/Um4p6RspWEEGZpYxWlmFt sOYWpsVy8xFQJBLtNCcT30hy0XUR9Vhsglho5WLN2WZJ5t4q6suaE9qX0rdh9hT6a7 +pk3zMBr2mHYlZ9qUePVgmsC9PKDXQuF4aG5t0xMtBsSlPB8hJGFPTuMkQK3tb2vQo n0r6k+bLe1r4w6wwb+GqirnMOs3nefIbvDIta+LMTsURKA+nPGNhdxFIpcFL9oLnx8 XclIush3QgtCvi16GI1IEcHyoky0lRZ46P+h4VAotzFIcxfXldZ/Fc/lFVSvmD5C4b 32+YB4CZpLTLA== From: SJ Park To: sashiko-bot@kernel.org Cc: SJ Park , "Andrew Morton" , damon@lists.linux.dev, linux-mm@kvack.org Subject: Re: [RFC PATCH] mm/damon/core: filter out damos address filter-split failed region Date: Sun, 18 Oct 2026 15:13:31 -0700 Message-ID: <20261018221332.158824-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Stat-Signature: qer9w9oqyu3875qrikxthx6mbtd17jrb X-Rspam-User: X-Rspamd-Queue-Id: B59C940009 X-Rspamd-Server: rspam10 X-HE-Tag: 1792361620-69293 X-HE-Meta: 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 KWCtAJOW 8KqSOYaCyhrIb6sBt+AewpiMB7m3XlQIGCnX1QJvSixEysldGdiE1jbjqnGcVICa5/HYic9LlD3ocd/UL+m//9nP3PNQNAfT2E2jcR2vl0uiQo/V5IqMX7XvkQZoYF/9CBEqjIzgBi8lu8kAhISE5aiT6ek1SPrF54V8UwOZADRjQ6ukhfYVHgnrRdL+zBG1l8jmkiBuP8nCocc0BaKZHUD0H5rVeDmVihJHMha0WdwbU1xDNamqhtXvm4oXYoogbgFI2UhQGfW0oNGF/bNvlORtIv6zwBeNTn12usat40Ti/TdOanMGRBdJ9cLlWHRxosYNZ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, 18 Oct 2026 22:11:06 +0000 sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: > - [Medium] mm/damon: unchecked damon_split_region_at() error in damos_filter_match() > -- > > commit 881e287348e01011e3ec5442e7deb6f9c112db9c > Author: SJ Park > > mm/damon/core: filter out damos address filter-split failed region > > This commit updates damos_filter_match() and damos_core_filter_out() to > propagate errors from damon_split_region_at() and filter out the region if > splitting fails during DAMOS_FILTER_TYPE_ADDR evaluation. > > > diff --git a/mm/damon/core.c b/mm/damon/core.c > > index b63e60ef89901..4d34587387456 100644 > > --- a/mm/damon/core.c > > +++ b/mm/damon/core.c > > @@ -2551,13 +2551,14 @@ static void damos_update_stat(struct damos *s, > > > > static bool damos_filter_match(struct damon_ctx *ctx, struct damon_target *t, > > struct damon_region *r, struct damos_filter *filter, > > - unsigned long min_region_sz) > > + unsigned long min_region_sz, int *err) > > { > > bool matched = false; > > struct damon_target *ti; > > int target_idx = 0; > > unsigned long start, end, wsum; > > > > + *err = 0; > > switch (filter->type) { > > case DAMOS_FILTER_TYPE_TARGET: > > damon_for_each_target(ti, ctx) { > > @@ -2588,7 +2589,9 @@ static bool damos_filter_match(struct damon_ctx *ctx, struct damon_target *t, > > break; > > } > > /* start inside the range */ > > - damon_split_region_at(t, r, end - r->ar.start); > > + *err = damon_split_region_at(t, r, end - r->ar.start); > > + if (*err) > > + return false; > > matched = true; > > break; > > [Severity: Medium] > Should the earlier damon_split_region_at() call in damos_filter_match() > when r->ar.start < start also propagate its return value via *err? > > mm/damon/core.c:damos_filter_match() { > case DAMOS_FILTER_TYPE_ADDR: > ... > /* start before the range and overlap */ > if (r->ar.start < start) { > damon_split_region_at(t, r, start - r->ar.start); > matched = false; > break; > } > } > > When a region starts before the filter range and overlaps it (r->ar.start < > start and r->ar.end > start), if damon_split_region_at(t, r, start - > r->ar.start) fails with -ENOMEM, r remains unsplit across [r->ar.start, > r->ar.end) while matched is set to false and *err remains 0. > > If the filter is configured to exclude [start, end) (for example, > filter->matching == true and filter->allow == false with > s->core_filters_default_reject == false, or filter->matching == false and > filter->allow == true), kdamond_apply_schemes() -> damos_apply_scheme() -> > damos_core_filter_out() sees err == 0, does not reject r, and proceeds to > call c->ops.apply_scheme() on the entire unsplit region including the > excluded address range. Good catch. I will fix this in the next revision. > > [ ... ] > > -- > Sashiko AI review ยท https://sashiko.dev/#/patchset/20261018220253.158238-1-sj@kernel.org?part=1 Thanks, SJ