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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B0F69C46467 for ; Sat, 14 Jan 2023 16:11:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:Subject:From:References:Cc:To: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2e879ekDlahf8lw5y+Dan4q//ln4fRs2r1wZuyCUx7M=; b=1MTBp01gr20/tS UXleJeDv+qhlZrJNlR82xItLfLAS2ZU+OfYsi8agX6A7al34AkNyuJtQcyU5FeFkDx+OFdV0bDOw9 YpzpggNUjg9XtRS1FyF+ZnEc2/0DJfK9hVbFEYimP+fEhFAk7ZHMRYwCnE8LJtnWokOF4gh+wyqk1 c/n+n3vBWPQ7D0fzt5c5j36NV33IXrP0PbZcHy2UCtGPM6Cj84NX37AzJqscBC5QIDhB6g1wEu1Yr 9RG40QcB4Juzn+0h5B4byIms6Xuq87YfrhSt1Sq5SrSWa8GihrrmDz0wwb+BJ+iEsppbQkgBVqb+l f5I7WYOSJgQlysLAWMCQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGj6W-006AwE-T9; Sat, 14 Jan 2023 16:10:01 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGj6S-006AuY-Dl for linux-arm-kernel@lists.infradead.org; Sat, 14 Jan 2023 16:09:58 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673712595; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Q3R4pvBr6dG+A0u3o+nBNguX6qX9S+oXSEacD+sP77s=; b=RYgsdZXkGI1f/95E0Bt12LQTW7+y1Cp31FI+IKA8rNsaxR8YRiQ1lb33rMgOBQxZ6p2mxB 4X/dkZu6t8wOJjuCifo3GAe71EM2/IgwbdYp04hwcxbFC9VzFRloVa1HqcimOqKg06VhSt 3fJcvqNlHqPTxQG4qtjQt2YImiggJbQ= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-52-r0cjZO9KMgS0WER-vRGOsA-1; Sat, 14 Jan 2023 11:09:39 -0500 X-MC-Unique: r0cjZO9KMgS0WER-vRGOsA-1 Received: by mail-wm1-f69.google.com with SMTP id bd6-20020a05600c1f0600b003d96f7f2396so16008096wmb.3 for ; Sat, 14 Jan 2023 08:09:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:subject:organization:from :references:cc:to:content-language:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Q3R4pvBr6dG+A0u3o+nBNguX6qX9S+oXSEacD+sP77s=; b=byILu7f6inxyf2o9nI2Q7cSkdn/xd2qZizLpfPWaq9Z20KNX6yOYU9682lWkAw3psX nLQPSDNWpGnNDOpu6T1gCT1wOBjrpwrv3z45adKbe5Bqq6X4QhpyuUvp1KPhouGOfuO2 n79c+ecJGFUqTJvKnyblvh/4xrML0lHr4M7Gh656zruvm2L8N9gUKBRdfPHr23s86As/ mlOXePXeDZUL38tP/s4mTDmUCemMwx85LtK+fe6E4psIVlE426Oocs+nbR0uFpg6GrW3 Xsd4MHhgaY6b3j5EBI9AdYDprG/33prQrEit2iQnvez+bAA8WoNSlYeiBPNolA9mFRtP vewQ== X-Gm-Message-State: AFqh2kqpiZf/3prNuRIeLMPhP8yDzVadbsCwB248BsJdO/wqQ4uvZ/6b XuDb5zDkeNurSN6zsg3ZUfWIhvdJ+Sd+T8DeDBJeN5QSqtpQCgJPPE26nGyVADF9+ZeUjfuoKBh uAH6QRb3NxsWmfA8pYQoeMkviCuz3TqwJy+E= X-Received: by 2002:a05:600c:348b:b0:3d1:f16b:30e6 with SMTP id a11-20020a05600c348b00b003d1f16b30e6mr62422458wmq.28.1673712578319; Sat, 14 Jan 2023 08:09:38 -0800 (PST) X-Google-Smtp-Source: AMrXdXtvXECQ77f+OwG9Mdcw6TdAWlLhcG76s2TeMh5Hr9A1VofwYXs3lPZWG9daADyc7xNo4jh7zQ== X-Received: by 2002:a05:600c:348b:b0:3d1:f16b:30e6 with SMTP id a11-20020a05600c348b00b003d1f16b30e6mr62422426wmq.28.1673712578037; Sat, 14 Jan 2023 08:09:38 -0800 (PST) Received: from ?IPV6:2003:cb:c71c:9800:fa4a:c1fc:a860:85af? (p200300cbc71c9800fa4ac1fca86085af.dip0.t-ipconnect.de. [2003:cb:c71c:9800:fa4a:c1fc:a860:85af]) by smtp.gmail.com with ESMTPSA id q18-20020adfdfd2000000b002bdc129c8f6sm10260315wrn.43.2023.01.14.08.09.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 14 Jan 2023 08:09:37 -0800 (PST) Message-ID: <6aaad548-cf48-77fa-9d6c-db83d724b2eb@redhat.com> Date: Sat, 14 Jan 2023 17:09:35 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Hugh Dickins , John Hubbard , Jason Gunthorpe , Mike Rapoport , Yang Shi , Vlastimil Babka , Nadav Amit , Andrea Arcangeli , Peter Xu , linux-mm@kvack.org, x86@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org References: <20230113171026.582290-1-david@redhat.com> <20230113171026.582290-2-david@redhat.com> From: David Hildenbrand Organization: Red Hat Subject: Re: [PATCH mm-unstable v1 01/26] mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks In-Reply-To: <20230113171026.582290-2-david@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230114_080956_547614_2B77E212 X-CRM114-Status: GOOD ( 20.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 13.01.23 18:10, David Hildenbrand wrote: > We want to implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures. > Let's extend our sanity checks, especially testing that our PTE bit > does not affect: > * is_swap_pte() -> pte_present() and pte_none() > * the swap entry + type > * pte_swp_soft_dirty() > > Especially, the pfn_pte() is dodgy when the swap PTE layout differs > heavily from ordinary PTEs. Let's properly construct a swap PTE from > swap type+offset. > > Signed-off-by: David Hildenbrand > --- The following fixup for !CONFIG_SWAP on top, which makes it compile for me and passes when booting on x86_64 with CONFIG_DEBUG_VM_PGTABLE: ... [ 0.347112] Loaded X.509 cert 'Build time autogenerated kernel key: ee6afc0578f6475656fec8a4f9d02832' [ 0.350112] debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page table helpers [ 0.351217] page_owner is disabled ... From 6a6162e8af62a4b3f7b9d823fdfae86de3f34a9d Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Sat, 14 Jan 2023 16:47:12 +0100 Subject: [PATCH] fixup: mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks generic_max_swapfile_size() is only available with CONFIG_SWAP -- which makes sense, because without SWAP there are no swap files. Let's simply probe manually which bits we can obtain after storing them in a PTE, and properly call it "max swap offset", which is more generic for a swap entry. Reported-by: kernel test robot Signed-off-by: David Hildenbrand --- mm/debug_vm_pgtable.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 3da0cc380c35..af59cc7bd307 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -810,15 +810,17 @@ static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args) { - unsigned long max_swapfile_size = generic_max_swapfile_size(); + unsigned long max_swap_offset; swp_entry_t entry, entry2; pte_t pte; pr_debug("Validating PTE swap exclusive\n"); + /* See generic_max_swapfile_size(): probe the maximum offset */ + max_swap_offset = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0, ~0UL)))); + /* Create a swp entry with all possible bits set */ - entry = swp_entry((1 << MAX_SWAPFILES_SHIFT) - 1, - max_swapfile_size - 1); + entry = swp_entry((1 << MAX_SWAPFILES_SHIFT) - 1, max_swap_offset); pte = swp_entry_to_pte(entry); WARN_ON(pte_swp_exclusive(pte)); -- 2.39.0 -- Thanks, David / dhildenb _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel