From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 6C50525A2CD for ; Fri, 12 Sep 2025 07:57:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757663856; cv=none; b=X41ogg9DPlNaY2n4L6DvHtI/cF8NSNab0UZkNdTiKPvmn1/TCvo5mcbl47uMiuDhLfRqGXsd+tV4tYB7LQnw+wDS4GOvQnbRzTkpVVYcJr8f9SyKDup7hXVquo+cDn2j4V7vom2q54Yr32NbPF8J7X6YjT7A0ug3wTRUquLVTMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757663856; c=relaxed/simple; bh=5u0szFnsmz3jOdzApEVIbycNY2Ant7XU0MZjL/xAevo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fXQvlhg+8VkLa6p6CPYO97ZwdGLkvJZ39wIuBLs5I9hI+VB55igksnLe8RJw1xP9+QDCw+NcrfMIdqEozHS+XTym7QDFJ1mapvP9vgqI44aFiheBTSbNsTzAfRTouhX1jn9tDdR83A5hGdxoHDSVd9O1GrFaOQzzm1UxZC3egWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YZsnxfOD; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YZsnxfOD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757663853; 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:autocrypt:autocrypt; bh=r+PqVYBDLbo+GI2XNIjczAPm5r0PaP1XGtlnWHDNHZk=; b=YZsnxfODrcqQHFT3QrKNrDeJcfGHC85vx3t1KKXbuJTSugN3KrKdgD4fHMiPDYpRJZJIRI Uzz87777EmeASGTap9L9mo42CrC7lKoozp4S5OgQusQRUdFY9BAz2k0mvSE8ejdGovbvuy moP614TGWpOjlaE/6qJTOEj7oPX+3/E= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-665-AogXbJW-NsOcGIQ2PGG2cQ-1; Fri, 12 Sep 2025 03:57:31 -0400 X-MC-Unique: AogXbJW-NsOcGIQ2PGG2cQ-1 X-Mimecast-MFC-AGG-ID: AogXbJW-NsOcGIQ2PGG2cQ_1757663851 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-3e04ea95c6cso738811f8f.1 for ; Fri, 12 Sep 2025 00:57:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757663850; x=1758268650; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=r+PqVYBDLbo+GI2XNIjczAPm5r0PaP1XGtlnWHDNHZk=; b=C2CC2ObtEeEihwrfQdN36Ou47eeu9H7N0KAg30jgO5TgZt8DOxkmtefxFy1R93b1Ux aH8YuDhN+5B0Kjk8xu5PQ1pN6zEDEJU/N39mtLePoMj6q0f2Cag/sAoytr1LkQGXJMxI BRG/0+dEBzBL/170EiiknFjB/obhRkwCzvlHINBTdq7CaUB7nyrkgc+pxy3dzHXLjm4i lKYcO+3LZJwQD94y+l6ad7tztj4XdY7BNJZPW0SsCB2edlmLd3ltyRl8Itlbuvy2ZQa+ N21j4qVBchWKyyFOQWc3FgLcj3HYuyNvetXlMvg0XITRsL3ASnLYK/Sp2NJ21c/q3L2l joVA== X-Forwarded-Encrypted: i=1; AJvYcCXU+yc2nnLR6gEuZk5I/mqxVUfWPNiGSdWVZLKtWpd4aydm48iI2ZArhz7ScnYrCDdq9GuW3uZkmgzu7AM=@vger.kernel.org X-Gm-Message-State: AOJu0Yy+IYzR3m91QJCG21BUmRxfIG3QpE87DZ8UuLMEwsv9q6OIthUt lz3OJSR1HGRRqX9Va5QSgjRzlDOTEPC2Ca8bG/8/Zd0ROtHz6gWd24abszAlx6PJrNjZzVUdTSg gs+AKLSZH+7MWZPb4mdyLxNNoBYRcaDpOU/NTfzocS+H+5F2FmmwKBM2XZNuqNMmhKA== X-Gm-Gg: ASbGncvOzA8KBZ2TcWxauUnLUTHFh23+IjPdvrEQtXpyY5yQ19ZNpNWkQz7UyKm5CDR MyhLFRoIZbcMXX1PfE2TjfB5RBKOm4abgPQiAhkRNmiJy7MiYQ+MGervExXIbYy2kP3dkl5W3vD WXFQl9XyQ+2qdYleA41Y3S1/yPIwXhXze5nwmrxQ4O3GMe0hP4YSpEpXe/91V4KFyG24R5UQNop Zd38GPip90eMCQYvj0eNL8r9LFz8aIa4c+TMIUm+fwCs2B559o9uXq7tX3gfZDPJaSpbAKzUltQ mrK1+yH5oX1S3m87IIQXxznu3PME3T6jP643OrHFszHShAhvGUUs9wPAz7DilS0hy0+vYCYA07v Gy2MQHgjJ9EltRa3+H5fwhkh4oVF4EyEwTvD0bBpLsL4IWI013iTtsQMNzEKBxRucIso= X-Received: by 2002:a05:6000:1acb:b0:3e5:d2f1:403d with SMTP id ffacd0b85a97d-3e7659e981fmr1992698f8f.36.1757663850561; Fri, 12 Sep 2025 00:57:30 -0700 (PDT) X-Google-Smtp-Source: AGHT+IF5jTihNZ8u71EpurEXi9WIL859gU0373T54vnlvHENg3fNIgXreHhMHhAU/LbYZT2vWSOlPw== X-Received: by 2002:a05:6000:1acb:b0:3e5:d2f1:403d with SMTP id ffacd0b85a97d-3e7659e981fmr1992669f8f.36.1757663850093; Fri, 12 Sep 2025 00:57:30 -0700 (PDT) Received: from ?IPV6:2003:d8:2f20:da00:b70a:d502:3b51:1f2d? (p200300d82f20da00b70ad5023b511f2d.dip0.t-ipconnect.de. [2003:d8:2f20:da00:b70a:d502:3b51:1f2d]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3e7607e1400sm5516947f8f.55.2025.09.12.00.57.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 12 Sep 2025 00:57:29 -0700 (PDT) Message-ID: Date: Fri, 12 Sep 2025 09:57:28 +0200 Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: boot failure because of inaccurate page_pool_page_is_pp() on 32-bit kernels To: Helge Deller , =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vu?= =?UTF-8?Q?sen?= , Linux Kernel Development , Linux Memory Management List , linux-parisc Cc: Christoph Biedl , Helge Deller , Byungchul Park References: <5a004aef-9df1-4126-b167-1aae27d4240d@gmx.de> <1756327287@msgid.manchmal.in-ulm.de> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 12.09.25 00:12, Helge Deller wrote: > As reported earlier in this mail thread, all 32-bit Linux kernels since v6.16 > fail to boot on the parisc architecture like this: > > BUG: Bad page state in process swapper pfn:000f7 > page: refcount:0 mapcount:0 mapping:00000000 index:0x0 pfn:0xf7 > flags: 0x0(zone=0) > raw: 00000000 118022c0 118022c0 00000000 00000000 00000000 ffffffff 00000000 > raw: 00000000 > page dumped because: page_pool leak > Modules linked in: > CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.15.0-rc1-32bit+ #2730 NONE > Hardware name: 9000/778/B160L > Backtrace: > [<106ece88>] bad_page+0x14c/0x17c > [<10406c50>] free_page_is_bad.part.0+0xd4/0xec > [<106ed180>] free_page_is_bad+0x80/0x88 > [<106ef05c>] __free_pages_ok+0x374/0x508 > [<1011d34c>] __free_pages_core+0x1f0/0x218 > [<1011a2f0>] memblock_free_pages+0x68/0x94 > [<10120324>] memblock_free_all+0x26c/0x310 > [<1011a4d8>] mm_core_init+0x18c/0x208 > [<10100e88>] start_kernel+0x4ec/0x7a0 > [<101054d0>] start_parisc+0xb4/0xc4 > > git bisecting leads to this patch which triggers the crash: > > commit ee62ce7a1d909ccba0399680a03c2dee83bcae95 > Author: Toke Høiland-Jørgensen > Date: Wed Apr 9 12:41:37 2025 +0200 > page_pool: Track DMA-mapped pages and unmap them when destroying the pool > > It turns out that the patch itself isn't wrong. > > But it's the culprit which leads to the kernel bug since it modifies > PP_MAGIC_MASK for 32-bit kernels from: > > -#define PP_MAGIC_MASK ~0x3UL > +#define PP_MAGIC_MASK ~(PP_DMA_INDEX_MASK | 0x3UL) > > Function page_pool_page_is_pp() needs to unambiguously identify page pool > pages (using PP_MAGIC_MASK), but since the patch now reduced the valid bits to > check in PP_MAGIC_MASK from 0xFFFFFFFC to 0xc000007c, the remaining bits are > not sufficient to unambiguously identify such pages any longer. > > Because of that, page_pool_page_is_pp() sometimes wrongly reports pages as > page pool pages and as such triggers the kernel BUG as it believes it found a > page pool leak. > > IMHO this is a generic 32-bit kernel issue, not just affecting parisc. > > Do you see any options other than: > a) revert the patch (ee62ce7a1d90), or: > b) return false in page_pool_page_is_pp() when !defined(CONFIG_64BIT), > which means to effectively disable the page pool page test on 32bit > machines We should have a change coming soon that would use a page type and fix it as well I think. https://lkml.kernel.org/r/20250728052742.81294-1-byungchul@sk.com Until then, the easiest fix would be indeed to go with b). But maybe the page type thing could be backported? -- Cheers David / dhildenb