From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 035B93FBEAB; Tue, 9 Jun 2026 10:57:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781002657; cv=none; b=bL4KEqKz2ebavX/jVmCKK0wSA1ZEo00QEw1l5691Haw5iGrhgbJzfH3VPWFhZV499vzNx0mW/up9yN/8illpp4Ct0IlFVstFzjCxhyynnLUcXG58di5biIrm2yHfqh6HDzyt4mKgN/qXS9WtJAGSZFaeUOJt+tinWWc0h9bSXFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781002657; c=relaxed/simple; bh=pptrxwgjoBdTEzfy0Zc6OZLCiUUl50m92rZCrLci1Ug=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=K4CRCU+qpzhGjTKXdBfDoGzOqzaU1JfxCXnUZihNJwNASySjyjbP6dUYjQCAFXVRq8nggqEdYkCi66dceaOx3OS8kajrYt8CmOO8ACjOpjO2CBH/NqlcmzUJF/HKD60LtVwQj51ml3v7XkXb/mJxAzLH9PBWOOIrN0F40/Z86ZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=PPguWdWz; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="PPguWdWz" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:In-Reply-To:References: Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description; bh=BtvYFqoloPPtAp1pIQqyXcufUFMrAyAb/WE85RRt7eI=; b=PPguWdWz7YUz61OS+TRNLJgm6N 1aYxKyk2lPR2q4ICiU3HYfikJz1uv70/ogItEDn9gmsp+Oat4KqxF/NqEoAteLwN4GUMqOvDTYG1C w/w0kWaqhxYBKUiejwGfXJ04DM7P5xPHR1qRyfJEFEzIoGxWkX6gEL09fjIQWs4sRdQpnub5bXEg3 nZKWjrXdXI6Lihmj+S37+MSZbzq23Ih9z8c69msxUwjzUpDEy4NjhXZhuHjqB3mGkPEW2vczxI+Fu orXfRXPzQa8W7yq3DVfGLbKK3as3qZ9DWFB7iDp1ABfNScx0pnop689ILvS2RxYDVbBe6Acg1mlON wvKfwVgQ==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wWu9E-008Ltr-0F; Tue, 09 Jun 2026 10:57:32 +0000 From: Breno Leitao Date: Tue, 09 Jun 2026 03:56:58 -0700 Subject: [PATCH v9 4/6] mm/memory-failure: add panic option for unrecoverable pages Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260609-ecc_panic-v9-4-432a74002e74@debian.org> References: <20260609-ecc_panic-v9-0-432a74002e74@debian.org> In-Reply-To: <20260609-ecc_panic-v9-0-432a74002e74@debian.org> To: Miaohe Lin , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Naoya Horiguchi , Jonathan Corbet , Shuah Khan , "Liam R. Howlett" , lance.yang@linux.dev, Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , "Liam R. Howlett" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Breno Leitao , linux-trace-kernel@vger.kernel.org, kernel-team@meta.com X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=3152; i=leitao@debian.org; h=from:subject:message-id; bh=pptrxwgjoBdTEzfy0Zc6OZLCiUUl50m92rZCrLci1Ug=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqJ/F/uyEq1JIbPVqIFYZev6obTOmTvOQvfMd3s zL4LNHIrhOJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaifxfwAKCRA1o5Of/Hh3 bQCJD/9DiZd5c3g/931cj1m5gW6orYI3GnfV9eUGkKD0VFG3Jz7S+pA6eCWImC6gc2AVh6hhX63 p4KROpQub0l5Dhc2jNMdjr+jfYqmykBfADbdWk5RWZ/Z3mYPCQeDmFM8aA8fKE+Keoingbv5uAn +rL2SRe2YrBIGE11QHluVBU+B7EgRV8bWn/UDhwjMIjE63XA8ZmEbg2NUWdNyqqs0cOTRzgAntu AixH87/fyd7qfLrAtat670Lw52FvxGSiUJ6GVGS2WQH0z0qVQ6kjZvsH5/nA/Mkgoiccs6HISK1 IOei3GNsPLiEyxfZzUM1Jtp9u5xqr+MO4aclGMI+BAuP6SQV4Y14Fo8yNpl7SvnMxry7gM1eBK9 UlwNX0d+thLKRbqiv+o58OK82lVbKeHPNZ4TyH6fvHY/kbmyvU5oUwXoD7lLhXFg7Wrj7dN2UJO UhV9m4jx/DpmKu9zaGeYK/ffepGvKN1gh6GKU4kxdzXVs7O28j6YAC4BKLvob3V7WQ7+xd1455f Vupd5VI4DZWurmPRFQnookUOXJshHRiH9ADMHn2x7asuaRAOF2hVVNr0y9+rK05uFzD49ckvxjK Br6PEI94VQa0oA15IGfFrrKwVn6rAoAHFDy7v0HR9fyDUsGNDhRKCkMfgADwO6/QnSqLfTc6tVm 07+h3LVb5zfyi4g== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao Add a sysctl panic_on_unrecoverable_memory_failure (disabled by default) that triggers a kernel panic when memory_failure() encounters pages that cannot be recovered. This provides a clean crash with useful debug information rather than allowing silent data corruption or a delayed crash at an unrelated code path. Panic eligibility is intentionally narrow: only MF_MSG_KERNEL with result == MF_IGNORED panics. After the previous patch, MF_MSG_KERNEL covers PG_reserved pages and the kernel-owned pages promoted from get_hwpoison_page() via -ENOTRECOVERABLE (slab, page tables, large-kmalloc). All other action types are excluded: - MF_MSG_GET_HWPOISON and MF_MSG_KERNEL_HIGH_ORDER can be reached by transient refcount races with the page allocator (an in-flight buddy allocation has refcount 0 and is no longer on the buddy free list, briefly), and panicking on them would risk killing the box for what is actually a recoverable userspace page. - MF_MSG_UNKNOWN means identify_page_state() could not classify the page; that is precisely the wrong basis for a panic decision. Signed-off-by: Breno Leitao --- mm/memory-failure.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 35f2b5d89fbe..a8b466a48b02 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -74,6 +74,8 @@ static int sysctl_memory_failure_recovery __read_mostly = 1; static int sysctl_enable_soft_offline __read_mostly = 1; +static int sysctl_panic_on_unrecoverable_mf __read_mostly; + atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0); static bool hw_memory_failure __read_mostly = false; @@ -155,6 +157,15 @@ static const struct ctl_table memory_failure_table[] = { .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE, + }, + { + .procname = "panic_on_unrecoverable_memory_failure", + .data = &sysctl_panic_on_unrecoverable_mf, + .maxlen = sizeof(sysctl_panic_on_unrecoverable_mf), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, } }; @@ -1255,6 +1266,15 @@ static void update_per_node_mf_stats(unsigned long pfn, ++mf_stats->total; } +static bool panic_on_unrecoverable_mf(enum mf_action_page_type type, + enum mf_result result) +{ + if (!sysctl_panic_on_unrecoverable_mf) + return false; + + return type == MF_MSG_KERNEL && result == MF_IGNORED; +} + /* * "Dirty/Clean" indication is not 100% accurate due to the possibility of * setting PG_dirty outside page lock. See also comment above set_page_dirty(). @@ -1272,6 +1292,9 @@ static int action_result(unsigned long pfn, enum mf_action_page_type type, pr_err("%#lx: recovery action for %s: %s\n", pfn, action_page_types[type], action_name[result]); + if (panic_on_unrecoverable_mf(type, result)) + panic("Memory failure: %#lx: unrecoverable page", pfn); + return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY; } -- 2.53.0-Meta