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 AF3B4C43458 for ; Wed, 8 Jul 2026 12:20:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6A3A46B008C; Wed, 8 Jul 2026 08:20:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 62D466B0095; Wed, 8 Jul 2026 08:20:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4F5036B0096; Wed, 8 Jul 2026 08:20:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 2513E6B008C for ; Wed, 8 Jul 2026 08:20:56 -0400 (EDT) Received: from smtpin13.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id A1786120113 for ; Wed, 8 Jul 2026 12:20:55 +0000 (UTC) X-FDA: 84965518470.13.D6951BF Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) by imf28.hostedemail.com (Postfix) with ESMTP id DF398C0006 for ; Wed, 8 Jul 2026 12:20:53 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=klKLKaKp; spf=pass (imf28.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.182 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783513254; 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=pLR4NTdd81YwHMva27KFRdPfSNha1yNVphS6scVIA8Y=; b=OSpBkB+kbeCmAIYQAowOJUN//j/EAPKDoXOzUwMiYlte+qEb4pv13F6icOwSXyRkMGmRwE HHsd2pEzlT3H3BVXR2e7O6JnL+Vn/PTMYdQp9J9Y64BQxoekFZu2KtCOFnP205mP2VuS/f 5MXs8Al9Sd7TwdPP/zrZ7Yx9Y7z++7U= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=klKLKaKp; spf=pass (imf28.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.182 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783513254; b=2truHtD7WN68eJjPJn9sNUUVNZ7JqvDYU8XUovIoYjLCJVUKlC/VH6E3ixOppqV1boY4/e 1Y1FxLqmtaVg4ALAMn5HRZsKWzbKmgFtFPJn6HhJkHQ7f2vHdLUkgwWBkgvOxc6z+ImdHx tupJqKlNscyJi9+gheIgH2RmCGDJ7zo= 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=1783513252; 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=pLR4NTdd81YwHMva27KFRdPfSNha1yNVphS6scVIA8Y=; b=klKLKaKplweSEQGqTSBhvVQKqIE/wZDOFqmqFojo/YESsUhqb8YNMex/lxIBX+G7/lD9SD W+K/4Kz5m9z+IKgKIIJx+u11F0X5XEv5iPIIfBDd64Z0U01DH7+k0MRgMmT21SDLSipEYD TTmx4fKshMqLGdALX4PfGjY6QRogNLU= 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 v2 1/3] mm/mempolicy: skip non-present PMDs when queueing folios Date: Wed, 8 Jul 2026 05:20:07 -0700 Message-ID: <20260708122040.861335-2-usama.arif@linux.dev> In-Reply-To: <20260708122040.861335-1-usama.arif@linux.dev> References: <20260708122040.861335-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: DF398C0006 X-Stat-Signature: f39soq9sprat1snczupbb5ufos6idw3c X-HE-Tag: 1783513253-295474 X-HE-Meta: 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 4hqyB8HH VoED1iEGn4fl9Z5A9P45H+GNoVE/Zxa/pV2+xR3kLHvwDIUB3iECfcmmVdI6PnWtmgF8jWuoblcbJrceTu5EBb00hDWCqPmVwmuO3NhMoaII1doRBX0Hk1HRjpBb355bFboFx2nit2G31ZyxXh017nLTwTAV+xROdSz4IzGeVnokdYYz174dfM4LW7AwWnDcJUiHJHxyVntCBYKh/+CoAA8+eQOuZPlkrkBV7w6fXPpyBz9u4VVfLrwSre+7f2//uzwm1UTnPDLC1v94asEkqnyVl54eSZCCbdoJ24UtWuNfDO1f1c5y9L3kiqf/6p8O1+gyLvBZBAHGPjApW0SbQwtC//eyaSsqSQJJEsWSwpz8vFhWBxY/dRZszjwVIdlYU+Xn/ 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 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..4785b55c02da 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 = *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