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 DCFA8C43458 for ; Fri, 10 Jul 2026 10:56:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C293A6B00A1; Fri, 10 Jul 2026 06:56:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BDA2B6B00A3; Fri, 10 Jul 2026 06:56:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B17456B00A4; Fri, 10 Jul 2026 06:56:32 -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 969886B00A1 for ; Fri, 10 Jul 2026 06:56:32 -0400 (EDT) Received: from smtpin13.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 22A8B140384 for ; Fri, 10 Jul 2026 10:56:32 +0000 (UTC) X-FDA: 84972563424.13.96A6349 Received: from out-176.mta1.migadu.com (out-176.mta1.migadu.com [95.215.58.176]) by imf01.hostedemail.com (Postfix) with ESMTP id 635AF40008 for ; Fri, 10 Jul 2026 10:56:30 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=bmuMWEqB; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf01.hostedemail.com: domain of usama.arif@linux.dev designates 95.215.58.176 as permitted sender) smtp.mailfrom=usama.arif@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783680990; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=wJFhjNRrGWhFd4/UKA3CK1oa3jEQdlfP2tw+6VJV9xw=; b=psoxOHitTgCWyXRDuJ4LahocwVqWSYWwml0etfhVjz8czWMSN+8ZNf+pzmwLm9lzSG5AK0 tpKNP2rGrYmNmINXY5LzJHdCQlLlyVpPgCX7mt0bmkkONRSn6YJh27VRomNoo2fLtQCHzX a71PUxqnndxVJCbudO4mSS1q4sBLXPo= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=bmuMWEqB; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf01.hostedemail.com: domain of usama.arif@linux.dev designates 95.215.58.176 as permitted sender) smtp.mailfrom=usama.arif@linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783680990; b=NgweGSHad21ToaDAkYlH2ouM+6LFySqW1Qxs8hWtjRL//EtOmZG3WKg2YHfq8LfDSWMDif Q3r5i8z90kuDGRCrtNKBIKyd92jsuwWRAeCUPsAyZ2ZAZg5hZivWqouMtLbqATEed/0bfT AIfcJjukaYg3OwMYGnN34mKrcvMb+A8= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783680989; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wJFhjNRrGWhFd4/UKA3CK1oa3jEQdlfP2tw+6VJV9xw=; b=bmuMWEqByFKDrkHgq9LDQ6o45YZlph9ybTzEW8i06SsYucuVvujsPEGBhDUpbjqtdhsKfL jhwH5WR8sqYPFgztSmKHzp0vKZBjKMZpxrZHRBlZp3njKcJL/ax8+eKpsEOYAEIe0qumbn AFi3rsYxug8QgbCe+Ffc0PToTIGkSeM= From: Usama Arif To: Andrew Morton , apopple@nvidia.com, balbirs@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, david@kernel.org, dev.jain@arm.com, gourry@gourry.net, jannh@google.com, joshua.hahnjy@gmail.com, lance.yang@linux.dev, liam@infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, matthew.brost@intel.com, npache@redhat.com, rakie.kim@sk.com, ryan.roberts@arm.com, usama.arif@linux.dev, vbabka@kernel.org, ying.huang@linux.alibaba.com, ziy@nvidia.com, shakeel.butt@linux.dev, hannes@cmpxchg.org Cc: sashiko-bot , stable@vger.kernel.org Subject: [PATCH v3 1/3] mm/mempolicy: skip non-present PMDs when queueing folios Date: Fri, 10 Jul 2026 03:55:21 -0700 Message-ID: <20260710105557.1987433-2-usama.arif@linux.dev> In-Reply-To: <20260710105557.1987433-1-usama.arif@linux.dev> References: <20260710105557.1987433-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 635AF40008 X-Stat-Signature: rhj37auczseswbi7hkade3hgdoy4gbiy X-Rspam-User: X-HE-Tag: 1783680990-424704 X-HE-Meta: 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 UZ9CyWoO XIZAqtV/hUuiWBFKQwzFJHA0zGPUhjg5bb2Z/nHKLJiO6iPNfYsJTBTf8aD2a8XQ8QQZBw+4AtOqgrgR05GcAU9q83w+WWJDMHcKGqUhSk7GvZyfh5biEmFYbKY1xvXgGrGVGWk/2D1GuVUDzB6bS8MoW46Fns1tVyL0vMUBjrMqHcBbRtJr96TFRurkN8VLWm/8vDEFFjccdht3NDRavVbfHNTAPdi9Sy5jCWB4v5ukV5YtNT1DtfQamJB8EhfQWc8/RoWJlGCz8HfjWmO/aBMbfX7M1aSm6d4ZMiyef9Asy9aw9WcxN8nl1Bvy5tXbzd07t1L0yCxbv5uaw62q1I3VVvq6VuNbH6rQMRTPYtS1bdz0nsZGanhaBSsSxEmirRKdHRhBxsTenoBYXx+wVPcf9xA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: queue_folios_pmd() is called under pmd_trans_huge_lock(), whose pmd_is_huge() check returns true for any non-present, non-none PMD softleaf. Passing such a PMD to pmd_folio() treats the softleaf encoding as a hardware PFN and can return a bogus folio pointer. Mirror queue_folios_pte_range(): handle non-present entries before looking up a folio. Keep migration entries counted as failures, but skip other non-present PMDs such as device-private entries. Potential trigger: an HMM-based GPU driver migrates an anonymous THP folio to device memory via migrate_vma_pages(), leaving a device-private PMD. Userspace then calls mbind(), migrate_pages() or set_mempolicy_home_node() on that range. Reported-by: sashiko-bot Link: https://sashiko.dev/#/patchset/20260703173903.3789516-1-usama.arif%40linux.dev?part=6 Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations") Cc: Reviewed-by: Joshua Hahn Reviewed-by: Zi Yan Acked-by: David Hildenbrand (Arm) Signed-off-by: Usama Arif --- mm/mempolicy.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 914f81863db5..69a00a324ef5 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -654,12 +654,14 @@ static void queue_folios_pmd(pmd_t *pmd, struct mm_walk *walk) { struct folio *folio; struct queue_pages *qp = walk->private; + pmd_t pmdval = pmdp_get(pmd); - if (unlikely(pmd_is_migration_entry(*pmd))) { - qp->nr_failed++; + if (unlikely(!pmd_present(pmdval))) { + if (pmd_is_migration_entry(pmdval)) + qp->nr_failed++; return; } - folio = pmd_folio(*pmd); + folio = pmd_folio(pmdval); if (is_huge_zero_folio(folio)) { walk->action = ACTION_CONTINUE; return; -- 2.53.0-Meta