From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2384F3A48ED; Mon, 1 Jun 2026 13:24:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780320260; cv=none; b=jpBis33oGMxNOaM9098Ug6OWDBc6lNWOVAYuBaV6ISAYlS3KTAkhuMV0ZpY9mouQ6Ui2HDL0UVkR838tUb6LG3TAcZIohKtt+t2HN5zA38kyD7TjLLz2wDGSbztAFBWCPiE3PS49B9fekonKA+R2m2YzUd7wrqUXceCfZxYqup4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780320260; c=relaxed/simple; bh=IbiceRXvZkXi/7BRAAuln6FFbYCO1o0615V8tzKEuqQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LnAhnWivKlHbyd+x8nTUglLyJCQXC5baJ5Llpj54xM8eBeVtn6z8BUvnmcNiQ3Om1tKRAg1FH4PYfP/8/lBILVU7vWMwBZcq328/aeeNX228CHbX2hC4wdP9MMkHaO5mI+aPPfs4lVj0cgP0z48KtKxueStRlUm2YJKeCX5kak8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aHTWbVtK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aHTWbVtK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B419F1F00893; Mon, 1 Jun 2026 13:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780320259; bh=4xj0Qmb3PGvR9vYXLCTRMNng9IbwfFzut9XpsoiGbGg=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=aHTWbVtKn7f+LNNNpRHoDFO9RRSGdRMNh+r/lcwYlL4Kpb96gJTSUYUalNPuCsI83 Xnddj/uOXCZ7MmgKTAa5furNrlqlZIsJBIaqJp64H1FKDFpBGnc86eNbGnHk/kMtUb aLxbEunIY1/JuAIvCeJ4iYSUnYlJ2d3GcUYBNh7lfvgUHc5JyunfmPzbpru9L1Tg7D DCtaTk3iZ7N51uQrnxKjPJuEWtcWV8BKb2JzGRGRT29OMVksUbgemQidyKWGcmlXDG L9j4zrUaeYrIrIr8eS2RkkZtpF0OUUxDZyQIfz3ar4tAM0QRy/3jh+C+g69I4GqTc3 JybqLRPxBDJhg== Message-ID: Date: Mon, 1 Jun 2026 15:24:11 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 3/6] mm/memory-failure: report MF_MSG_KERNEL for unrecoverable kernel pages To: Breno Leitao , Miaohe Lin , Andrew Morton , Lorenzo Stoakes , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Naoya Horiguchi , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , "Liam R. Howlett" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-trace-kernel@vger.kernel.org, kernel-team@meta.com References: <20260527-ecc_panic-v8-0-9ea0cfa16bb0@debian.org> <20260527-ecc_panic-v8-3-9ea0cfa16bb0@debian.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+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: <20260527-ecc_panic-v8-3-9ea0cfa16bb0@debian.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/27/26 16:06, Breno Leitao wrote: > The previous patch teaches get_any_page() to return -ENOTRECOVERABLE > for stable unhandlable kernel pages (PG_reserved, slab, page tables, > large-kmalloc). memory_failure() still folds every negative return > into MF_MSG_GET_HWPOISON, so callers that want to react to the > unrecoverable cases (a panic option, smarter logging) cannot tell > them apart from transient page-allocator races. > > Turn the post-call branch into a switch over the get_hwpoison_page() > return code: map -ENOTRECOVERABLE to MF_MSG_KERNEL and any other > negative return to MF_MSG_GET_HWPOISON. case 0 keeps the existing > free-buddy / kernel-high-order handling and case 1 falls through to > the rest of memory_failure() unchanged. > > The MF_MSG_KERNEL label and tracepoint string are kept as > "reserved kernel page" to avoid breaking userspace tools that match > on those literals; the enum value still adequately tags the failure > even though it now also covers slab, page tables and large-kmalloc > pages. > > Suggested-by: David Hildenbrand > Signed-off-by: Breno Leitao > --- > mm/memory-failure.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 8f63bdfeff8f..14c0a958638c 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -2426,7 +2426,8 @@ int memory_failure(unsigned long pfn, int flags) > * that may make page_ref_freeze()/page_ref_unfreeze() mismatch. > */ > res = get_hwpoison_page(p, flags); > - if (!res) { > + switch (res) { > + case 0: > if (is_free_buddy_page(p)) { > if (take_page_off_buddy(p)) { > page_ref_inc(p); > @@ -2445,7 +2446,19 @@ int memory_failure(unsigned long pfn, int flags) > res = action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); > } > goto unlock_mutex; > - } else if (res < 0) { > + case 1: > + /* Got a refcount on a handlable page. */ > + break; > + case -ENOTRECOVERABLE: > + /* > + * Stable unhandlable kernel-owned page (PG_reserved, > + * slab, page tables, large-kmalloc). > + * No recovery possible. > + */ > + res = action_result(pfn, MF_MSG_KERNEL, MF_IGNORED); > + goto unlock_mutex; > + default: > + /* Transient lifecycle race with the page allocator. */ > res = action_result(pfn, MF_MSG_GET_HWPOISON, MF_IGNORED); > goto unlock_mutex; > } > Acked-by: David Hildenbrand (Arm) -- Cheers, David