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 2FD784A2A75 for ; Sun, 18 Oct 2026 22:11:06 +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=1792361468; cv=none; b=Zr3wkoxAR1Jhz/tAlpN87+CjVvyeckAaM4SZYndwTHXjwkQVOZdUKmfjbV3Jw8l5lWZ6WcGoeqSMd1lzgoYScP8KmBAC8D3bhgsv8kTupeqp9VsKigsVo0JUhQpTX2LlHiGoTlBpvTtFZJQspCS08TaCZGUW6rW+4VmYJ/gGPj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792361468; c=relaxed/simple; bh=lqy47y+3NndPVo2AbjqJho7REs02UH9Vw/QD0ptG2Xc=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=lEuUsRrAwWd2hEKzrxhWK8cfkVSr/2rpn4niHl8zqyL4RBHi7LSsc7m3TYhJEB1jtFIDTrrP6mjpSoiGc6eM74uRRNn23wt6AJtyEGd3n2sTBqYpnx44sFEFDTpgW8T4h7FHukqQhv80RfeLFtQKdth2qKDy+nqOXmMtFDPDZGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G36YZRXC; 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="G36YZRXC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 896B41F000C4; Sun, 18 Oct 2026 22:11:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792361466; bh=Og2EJsxxAc5npVZpLxXfEFaB4KJhNSzXqile489hobU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=G36YZRXC/OTU73bwidpCd7iMYyBCjwB4nMI5dHa9raADe6QInW8Wvv7D49l9rjclC kmVh9EOVY/n7HOYeUzsWYtBg4UdIlyIVJaUi8VRQZ3wxmiV/oKmIeX1aUmHVOPcwvF DpH0vuTTSD/iS9TcXeC0YH768wXDoReRd1b0nim/AlmK5635zVpr+tCooybkC76fQ3 Wp+r6lb3xha1lBaA60L48NHd6XSxPPaok0ePQLJzGICyTeTCUG2Kn2i7/xWiumzVK0 /fcOM9TVP1o9cwLsU2gllYXBtHWEWCwN4DBWOTL0Z4pCl/xBBwN0tcSj6lLRFA/Qp0 /tqwHpyLSyq5Q== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH] mm/damon/core: filter out damos address filter-split failed region Reply-To: sashiko-reviews@lists.linux.dev To: "SJ Park" Cc: "Andrew Morton" , damon@lists.linux.dev, linux-mm@kvack.org In-Reply-To: <20261018220253.158238-1-sj@kernel.org> References: <20261018220253.158238-1-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 18 Oct 2026 22:11:06 +0000 Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: 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_filte= r_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, > =20 > static bool damos_filter_match(struct damon_ctx *ctx, struct damon_targe= t *t, > struct damon_region *r, struct damos_filter *filter, > - unsigned long min_region_sz) > + unsigned long min_region_sz, int *err) > { > bool matched =3D false; > struct damon_target *ti; > int target_idx =3D 0; > unsigned long start, end, wsum; > =20 > + *err =3D 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 *ct= x, struct damon_target *t, > break; > } > /* start inside the range */ > - damon_split_region_at(t, r, end - r->ar.start); > + *err =3D damon_split_region_at(t, r, end - r->ar.start); > + if (*err) > + return false; > matched =3D 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 =3D 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 =3D=3D true and filter->allow =3D=3D false with s->core_filters_default_reject =3D=3D false, or filter->matching =3D=3D fal= se and filter->allow =3D=3D true), kdamond_apply_schemes() -> damos_apply_scheme()= -> damos_core_filter_out() sees err =3D=3D 0, does not reject r, and proceeds = to call c->ops.apply_scheme() on the entire unsplit region including the excluded address range. [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261018220253.1582= 38-1-sj@kernel.org?part=3D1