From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 732B627603C for ; Mon, 27 Apr 2026 10:06:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777284380; cv=none; b=PZJWCbZwXwLu5xgxVmkPD48vamaRarLzYy8NaOXf/fjBUpClWTBFtvUvLlnHCeSOVVDYe4+G+fvbaTN8oSrpwXg1+Y9OWwi1bXYFAaj1jIQsrBYB7ckAJVh8lFvIH49U/WRmlw0vwrP9Hgi4+wFnBwzMdtAG/YCzBQPmhEiCMAA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777284380; c=relaxed/simple; bh=NMIY67YYgduidE+T/urpPwMt1nNkWqtfRqW8wr9e7pw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=swYiM6R8jj8bK18YCYF5DYVlpKh8oq6/kTxtcM+rxqfZNaIdPqGBwHCsqcH4Jk5Yn5YlSIB576ZN+nhXpVh3YhRwr5lo73Z7mxUwUQLc6E3ExQier1pfXr3My6nPIKOwJr5RLTBP9D59yvMR9jDEufkTt5JSe3pNfsuHNzZ442w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Y0W17+Qx; arc=none smtp.client-ip=91.218.175.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Y0W17+Qx" 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=1777284376; 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=WkQaonlSbia/a4KAdQJshQwfTS6rg6fLOV9FgvKBtm8=; b=Y0W17+QxsNNB0QMvzmIIcqr/EMlrVgl8BGBkmO8G2jcoA5XkKxT5cSEgMXqQ4e+JznbEFl jbkVMJeXK1GNblfHEUtOwwEOzWslqQ7Jr9gR5AYWwLLAkCS0ywgmPc1KKWm986IaTEaEC9 blU0yhyUciA5wc+Nbee8kQ6tYyyB/TQ= From: Usama Arif To: Andrew Morton , david@kernel.org, chrisl@kernel.org, kasong@tencent.com, ljs@kernel.org, ziy@nvidia.com Cc: bhe@redhat.com, willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, alex@ghiti.fr, kas@kernel.org, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, kernel-team@meta.com, Usama Arif Subject: [PATCH 03/13] fs/proc: use softleaf_has_pfn() in pagemap PMD walker Date: Mon, 27 Apr 2026 03:01:52 -0700 Message-ID: <20260427100553.2754667-4-usama.arif@linux.dev> In-Reply-To: <20260427100553.2754667-1-usama.arif@linux.dev> References: <20260427100553.2754667-1-usama.arif@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT pagemap_pmd_range_thp() assumes that every non-present PMD is a migration entry and unconditionally calls softleaf_to_page(). This will crash on any non-present PMD type that does not encode a PFN, such as the upcoming PMD-level swap entries. Guard the page lookup with softleaf_has_pfn(), matching how pte_to_pagemap_entry() already handles non-present PTEs. Signed-off-by: Usama Arif --- fs/proc/task_mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 751b9ba160fb..6d9f43881e62 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2042,8 +2042,8 @@ static int pagemap_pmd_range_thp(pmd_t *pmdp, unsigned long addr, flags |= PM_SOFT_DIRTY; if (pmd_swp_uffd_wp(pmd)) flags |= PM_UFFD_WP; - VM_WARN_ON_ONCE(!pmd_is_migration_entry(pmd)); - page = softleaf_to_page(entry); + if (softleaf_has_pfn(entry)) + page = softleaf_to_page(entry); } if (page) { -- 2.52.0