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 55719C43458 for ; Tue, 7 Jul 2026 13:53:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 426776B00C7; Tue, 7 Jul 2026 09:53:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D6F36B00C9; Tue, 7 Jul 2026 09:53:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 29EF06B00CA; Tue, 7 Jul 2026 09:53:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id EDE2C6B00C7 for ; Tue, 7 Jul 2026 09:53:33 -0400 (EDT) Received: from smtpin23.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 788824041F for ; Tue, 7 Jul 2026 13:53:33 +0000 (UTC) X-FDA: 84962123106.23.4417631 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) by imf04.hostedemail.com (Postfix) with ESMTP id E464F4000C for ; Tue, 7 Jul 2026 13:53:31 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=bOEfrOOd; spf=pass (imf04.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.180 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=1783432412; b=w5ObouU4WHeJ7EnQUF8NV87yrj6VALIwv88aPqAB32B5SF5WZ5H9er9ztT8dCvBOkrpG1n Zh236TvuGoem9zlrKKK7gQ11RSKU7VwEuzFjIkE9/rzq0pA+JHAqgP/B47DI+BmdAZiwTY pj5TemnJ696laBzHvTjfphr7EaDYCvY= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=bOEfrOOd; spf=pass (imf04.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.180 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=1783432412; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=quqW7QPkkOmuZBsVPZ6/a3v09/W0iGtXtzNekQUkyPQ=; b=IN36mrv3UiJ18mZiBNTJ9lSGv+86HT5NkN/yltNBlwekvxzbOrIpoaJSvAAn5xIKAgc7H0 UZpuBtpcCrOP/pg5o1pqS5rWYyeEFJgRV2aXpawJsrH/Ua2XOyZWCJepFen1hH04w/ZlC+ ruQTAR/9+N2FF9q/13UXyo9JUsHRaBs= 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=1783432410; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=quqW7QPkkOmuZBsVPZ6/a3v09/W0iGtXtzNekQUkyPQ=; b=bOEfrOOdGuOrim4uKpsIvxxBxZIz2xNb0Lp6GVAkmYdPwWkfmxFv6q82lsGngNwTn0Uhtp 0PC09+w0Q0nUSEvYgcdT5eDKB6MtOIP+K18zkmp6Oz768mkISYkUXPW/EEug62fjQXhSqm oitahOP5nju9IzBuRypc8sqyu+1TQZg= From: Usama Arif To: Andrew Morton , apopple@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 Subject: [PATCH 3/3] mm/huge_memory: skip device-private PMDs in madvise_free_huge_pmd Date: Tue, 7 Jul 2026 06:45:09 -0700 Message-ID: <20260707135255.292870-4-usama.arif@linux.dev> In-Reply-To: <20260707135255.292870-1-usama.arif@linux.dev> References: <20260707135255.292870-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E464F4000C X-Stat-Signature: 3gtyach748c1bk3xm6wyb7m46eusomo9 X-HE-Tag: 1783432411-331580 X-HE-Meta: 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 DDQWgB2P 7WiXlZJX+jkXPB8ta/Vr8PZwRZkkdizi5eQTnQXFiXGqD+vW70Ie4mfV4yqMKEW8/Kw5dilIOYMQvVSiPE7d4rPECrRIPHWphCiDYwODCdBQK1rG+pwI8GCVVTisiYfiyhHIFmV+o1xhLQAiahl0I7+31icS7sVCqIZdiv91nv878lLjse27mkM9JTwTnVPI5PX9MvqN/NgSg4ZQrw+EPchArQFraoyzhioqvFNsrMWJ5NpcdyftSnAx4ftDjspFuyPWPVJ24fJSO5AWkmkqMbIhS62kg6vuh1PkO4XhivmGG/yWZNzarkTmw+K8srFSfdRy6jaw19A51FUKqVikJfR6Ufa6GGojUgyViW5WvZLTC4HIiiqYIa4AQXg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: madvise_free_pte_range() checks pmd_trans_huge(*pmd) unlocked, then madvise_free_huge_pmd() takes pmd_trans_huge_lock(). pmd_is_huge() returns true for a device-private PMD, so orig_pmd can be device-private and hit the VM_BUG_ON() on the !pmd_present() branch. Potential trigger: an HMM-based GPU driver races with madvise(MADV_FREE): migrate_vma_pages() flips the PMD to a device-private entry between the caller's pmd_trans_huge() check and the callee's pmd_trans_huge_lock(). Skip device-private PMDs after taking the lock, before the !pmd_present() check. Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations") Signed-off-by: Usama Arif --- mm/huge_memory.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c0892cc533a9..cfce9f31b30e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2296,6 +2296,9 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, if (is_huge_zero_pmd(orig_pmd)) goto out; + if (pmd_is_device_private_entry(orig_pmd)) + goto out; + if (unlikely(!pmd_present(orig_pmd))) { VM_BUG_ON(thp_migration_supported() && !pmd_is_migration_entry(orig_pmd)); -- 2.53.0-Meta