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 B8E42387361; Fri, 26 Jun 2026 15:34:03 +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=1782488045; cv=none; b=i58L1QIHsZxqt2hX54dEUhsHLSLf0lH6fDcQ7HTKob7nxjtQbSR4LgVpGUKAC86Qw/biHfHVEW1BkriAjYljtD0qBEDzNeumOJUw2+Ut7lGWDaYrk61wrT7SysiwtA0aQouHPSUIJwGg7iVwmswiHYxaNzaX06dG0IjIIwGD10s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782488045; c=relaxed/simple; bh=qqg1VFQgG3N6sRDY3kMkDgN5t+H1A3GPVMupI+jkNNM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bsd0sgOgkFwb55vhMSJKyWbV2v6HFIRPBEcwLgAmtJd11ON+4oXkE5N0pQUzMyTwE/xK8XwEd3UGWbHVgrB7gIU5Xi+7QYPFFuYFzB6Nfl1avmif9YJe9LkBZJH/K2CfXFqYzsw0q4MknPxn3HV8M78arwnaKJ0lce6hYOrujxc= 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=XpIy72Re; 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="XpIy72Re" 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=ZyfgFwlQERVjmxPNgC+88+drKDA3XcfRT7Olyh7E52k=; b=XpIy72Rec580X88Z8TOB/5sFAP WTh9Q8Uj7N1g9gKSzMBlz4oR9dA2sq7h2HiykDDnNjurycRXNrTMskJzUY5IREqBaHNYs03VhtMqf KsgOha6b1uah94cC+RS6i6iqeWfG8OoxvGgmhNupBj5h/8wmIzWC4liSyk6nAwTx7pYuNYBRhSivQ cPsxy4PNEd4aEY34vKGJjx4oWGFWlpgkLp23jPbd/dG9pS2SHCRFBv5TNstGoOMtdsFaDJSJangTT uMD1JpXv4yW28aDzWv7GfohtWKcQ+G5yUQQX3EavPzqWd+1DVb4+PhMlOyD7SJnKdnFpZMH5XJs5u GDSabWYw==; 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 1wd8Yz-0044E3-2T; Fri, 26 Jun 2026 15:33:54 +0000 From: Breno Leitao Date: Fri, 26 Jun 2026 08:33:18 -0700 Subject: [PATCH v10 4/6] mm/memory-failure: add panic option for unrecoverable pages Precedence: bulk X-Mailing-List: linux-trace-kernel@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: <20260626-ecc_panic-v10-4-6dacb8ad024d@debian.org> References: <20260626-ecc_panic-v10-0-6dacb8ad024d@debian.org> In-Reply-To: <20260626-ecc_panic-v10-0-6dacb8ad024d@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=3199; i=leitao@debian.org; h=from:subject:message-id; bh=qqg1VFQgG3N6sRDY3kMkDgN5t+H1A3GPVMupI+jkNNM=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqPpvFfXSAss0UBGCQbv2RZto5oeldCmxwzsWwI cKDQxvqqhCJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaj6bxQAKCRA1o5Of/Hh3 bVHzD/4jF0IpI50h7hCvhTrOwq6Hr6ijwDMoT/efaHXUMZQHWKAR3tZYPbzxwcDcyMequxzG2nM KL607E6MILB95hmVEAf31A/MZNaZADRYkJwjZOvljFWhYKPuIYrGPB7QS0m0qveGGmf0iV0cHm/ MYpCfj9D21IMOWqtbzM59bP94NkFzBnadRrjWBECnJpq9D5Qpbf8AoiksVEUOz3MgKyRDV7F/Y0 UNHXpEPa7wLRnilHctaWaB+oW0+IT2+MEhzqKYbYLvaPcET6ea5FncvAqi4+DdFs//hucxcVRMD IsKWm+yrS7CcZu4A+pkQj4vuadOnAo8/RgBa9383SqcH3wo8dQ63cXyH4PamSZfA7gGoICC0s5A L247KYNYSYhCconARaRBmCSS1LsbkUKPeFHIchLB7206y5EznWsEtGEjKx/E9JFiTNhsYBhrB64 lmmOBuBkfWotscwDNx60Cs3cbNWsm8IhTmRrcsELGmf0C3AW1/PRUoTGDOjUm24WhKt2Iw+y4Zu GBlkNlLy3aqhvOyyUFYDr9kpMosyOrDGQgrm5bf10VmXpaSPqkHVJ59GyWKqxT0cP+FzQ6vNHMI uNAf839LmVWJp81gpQ2QZr3AuslDyjRUtIgNA5WovvgHtJGDJ8zEMhRk8bMAUQFcij/ISGrtH6x r1TTGLD8+bv8Sww== 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. Acked-by: Miaohe Lin 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 8e2aa2fafc14e..611160c98c6f6 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