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 F273A3F8881; Tue, 9 Jun 2026 10:57:19 +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=1781002641; cv=none; b=MMON/1Aqr1XJMMmbN+1b+VdwDKOfJzL1jAlFZX20OAmlud+Hbw2MZ61jokx59n4msgFicQO0Ah66KHPSl5P8UwbSTheMtgXrGUoRq/pzLduDwn6uWcvbO7yqW+WLVDxAidfv5AEAzK6NCP+MDuRIHWTnIol22h4k2vjbC0pLVMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781002641; c=relaxed/simple; bh=4q+m/q/9D0qk1AYIowkmaI4NFqQWTn3bCYXkUMG87eg=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=skY6QrQSvw4qn/E2DReK13IumJZ44vtzd1YmsnejOt0vusWwHefY2U6jP0UQcHcI2BRHBaZthRarpGQEiE4BMp2l7SypuBg04yVDBxLtOMyQXvWvm7u4hBX6ML6rSWpWvizPBOp+dYPA+oxIQ4dwy4/OLTfwgjTnL5vLXIDHsYU= 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=M+Wh8aO7; 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="M+Wh8aO7" 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:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-Id:Date:Subject:From:Reply-To:Content-ID: Content-Description:In-Reply-To:References; bh=NUw1no3vQFX9EOgXz+vtElmwkxf14VIbO+M2GscH20c=; b=M+Wh8aO7KjNIpVrFdfYe2R+Q5+ 8pqjwVB/Lbnlj1UbRqsrjN1o45LzWlzPhkQ+E8pg+YzOBWYqa87cxCw38kdhKJmWkpapKAwjcMmt4 osg2G+PTi9g4m0LC9epOd77n8V8QF5nGxF8wkRv5pWVrsfeckeIS1x1ggkwxLodMqJMlKMecrDfbt 2F5FNCAPDTuriAdt6uZ2rG1u09UlDOxe3Vp7Vd4UcquVdzADCPLD0za1FQ0yLCUtfJDkaGD3oZDLI fm9n1w3EjdEz/hSLaznulIbgX+6pD614atkoaahOxuFiYDI6ptnN86NOEXsn1tE0OJqzLZCjQTO0N VlARR/Vg==; 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 1wWu8q-008Lt8-2S; Tue, 09 Jun 2026 10:57:09 +0000 From: Breno Leitao Subject: [PATCH v9 0/6] mm/memory-failure: add panic option for unrecoverable pages Date: Tue, 09 Jun 2026 03:56:54 -0700 Message-Id: <20260609-ecc_panic-v9-0-432a74002e74@debian.org> 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: 8bit X-B4-Tracking: v=1; b=H4sIAHbxJ2oC/23QyWrDQAwG4Fcxc46KpFmTU9+jlDJrMj04wU5NS /C7F7uHjHGPAn2/locY81DzKE7dQwx5qmO99uLUHQ+diBffnzPUJE6dYGSDkiXkGD9uvq8RVFZ WBifR2SgOnbgNudTvNevt/a8ev8JnjvclYOm41PF+HX7WYRMtff/lTgQIlj0dmSybqF9TDtX3L 9fhLJbgiRsqqaUMCMesMGExqli/o/JJFW2mSkCgFEPgQhyi2lHVUt1SBQickK0trhikHdUNZdV SDQhe6qKCRsU67qh5Uk2bW82ysJNIHLxNKuyobenmVgsIIXPW1mVDaf8m11C2LXXrhz3G4smEg Bs6z/MvOdJnXFICAAA= X-Change-ID: 20260323-ecc_panic-4e473b83087c 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=9278; i=leitao@debian.org; h=from:subject:message-id; bh=4q+m/q/9D0qk1AYIowkmaI4NFqQWTn3bCYXkUMG87eg=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqJ/F+do7Ut+FBaddOPG1+2qVEDpcVf8ikfWZbA 7qewc7PmmaJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaifxfgAKCRA1o5Of/Hh3 ba/ZD/0YWvdiczpAWmvI6ykiRuMzvIr3wTG4PKKiC1VMAplKfaIlQwVeuLVjJssclzNO9cgITHe 1D3Kgtla/irdCqhN7/1vywoUHyxD5Kmq+ViPyJpckeeQA2vck4NeXMakolv6hYLuHBew+yUsV4V 0aqliEXX0aKG0CYTiJSNrOMhyaCBB2B0pZ4UtyjCrmKDbx7U5C3q65HIBfkdUGmxxSGHL+xrkpq XZcshhtNTOOnQmMIjuP3jUM9bvz0a8nb2LwDC1lhg+/eHoSuDZIdEOUWtK9T6EVuqyl4s8X1zsr H6dfb+nafbXc6vDu9u0BC4aky6EXIufdkoVcIOfmBu/X4wSivucoWrIA6nU/XwTREHO2DqywUct qYlLVrPC4LqNyil8bJ7jXeV7AgGElF0adr+td/2lIKP5T9BsNZfS7Px3dyb5qXFe2cnCFlHr5mn tQUvvWKcPmVw700SiPYKNB1JeHR42j3293/qof5+TPD0qIXumNMZwMzOx1p/i/zYg7kA5Sp5r7U y1KW2vQGJKE7s0Bn+RHMJivnHyKv2jZci1P4mZuvLySNzlP2HcgaJWj5xSiY1xXlyUnT68LmoDa ppk1wkudwX7t9s4SFbBPd2zcFmf1LL9iIpNfKBYWj/0c2LoAUPTTLJxHFjizxjzZe+KIZQOqxu/ uAECt8H4sHQyxhw== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao A multi-bit ECC error on a kernel-owned page that the memory failure handler cannot recover is currently swallowed: PG_hwpoison is set, the event is logged, and the kernel keeps running. The corrupted memory remains accessible to the kernel and either drives silent data corruption or surfaces seconds-to-minutes later as an apparently unrelated crash. In a large fleet that delayed, unattributable crash turns into significant engineering effort to root-cause; in a kdump configuration, by the time the crash happens the original error context (faulting PFN, MCE/GHES record, page state) is long gone. This series adds an opt-in sysctl, vm.panic_on_unrecoverable_memory_failure, that converts an unrecoverable kernel-page hwpoison event into an immediate panic with a clean dmesg/vmcore that still contains the original failure context. The default is disabled so existing workloads see no change. There is a selftest that test different cases, and I tested it using the following variants: ┌─────────┬──────────┬───────────────────────────────────────────────────────────┐ │ Variant │ PFN │ Result │ ├─────────┼──────────┼───────────────────────────────────────────────────────────┤ │ rodata │ 0x2600 │ Panic with "Memory failure: 0x2600: unrecoverable page" │ ├─────────┼──────────┼───────────────────────────────────────────────────────────┤ │ slab │ 0x100032 │ Panic with "Memory failure: 0x100032: unrecoverable page" │ ├─────────┼──────────┼───────────────────────────────────────────────────────────┤ │ pgtable │ 0x100000 │ Panic with "Memory failure: 0x100000: unrecoverable page" │ └─────────┴──────────┴───────────────────────────────────────────────────────────┘ Each one shows the same call trace, exactly the path the series builds: hard_offline_page_store → memory_failure → action_result → panic("Memory failure: %#lx: unrecoverable page") Signed-off-by: Breno Leitao --- Changes in v9: - HWPoisonKernelOwned(): wrap the head-page checks in a compound_head() recheck loop so a concurrent split or compound free cannot leave us trusting a stale view (Miaohe, Lance, David). - selftest: drop the gawk-only strtonum() in hwpoison-panic.sh; do the hex parsing with a small index()-based helper so the test no longer spuriously skips itself on mawk-based distros (Sashiko). - selftest: move hwpoison-panic.sh from TEST_FILES to TEST_PROGS_EXTENDED so the script is installed executable rather than as a non-executable data file (Sashiko). - Link to v8: https://patch.msgid.link/20260527-ecc_panic-v8-0-9ea0cfa16bb0@debian.org Changes in v8: - Commit message rewording (David) - Add HWPoisonKernelOwned() helper (Lance) - Removed patch "mm/memory-failure: short-circuit PG_reserved before get_hwpoison_page()" - Broaden the selftest (Lance) - Link to v7: https://patch.msgid.link/20260513-ecc_panic-v7-0-be2e578e61da@debian.org Changes in v7: - Move the PG_reserved / unhandlable-kernel-page classification into get_any_page() and surface it via -ENOTRECOVERABLE, per David Hildenbrand's and Lance Yang's review of v6. This drops the is_reserved snapshot in memory_failure() and the mf_get_page_status enum / out-parameter introduced in v6. - Restructure the post-call branch in memory_failure() as a switch over the get_hwpoison_page() return code (David). - Drop the "reserved" qualifier from the MF_MSG_KERNEL label and the matching tracepoint string; the enum now covers both PG_reserved pages and other unhandlable kernel pages. - Squash the former patches 1/4 ("MF_MSG_KERNEL for reserved pages") and 2/4 ("classify get_any_page() failures by reason") into a single classification patch; the series is now 3 patches. - Simplify panic_on_unrecoverable_mf() to a single return statement (David). - Link to v6: https://patch.msgid.link/20260511-ecc_panic-v6-0-183012ba7d4b@debian.org Changes in v6: - Dropped the selftest given the value was not clear - Get the status of the failure from get_any_page() - Small nits from different people/AIs. - Link to v5: https://patch.msgid.link/20260424-ecc_panic-v5-0-a35f4b50425c@debian.org Changes in v5: - Add vm.panic_on_unrecoverable_memory_failure sysctl to panic on unrecoverable kernel page hwpoison events (reserved pages, refcount-0 non-buddy pages, unknown state), with a recheck to avoid racing with concurrent buddy allocations. (Miaohe) - Distinguish reserved pages as MF_MSG_KERNEL in memory_failure(), document the new sysctl in Documentation/admin-guide/sysctl/vm.rst, and add a selftest verifying SIGBUS recovery on userspace pages still works when the sysctl is enabled. (Miaohe) - Added a selftest - Link to v4: https://patch.msgid.link/20260415-ecc_panic-v4-0-2d0277f8f601@debian.org Changes in v4: - Drop CONFIG_BOOTPARAM_MEMORY_FAILURE_PANIC kernel configuration option. - Split the reserved page classification (MF_MSG_KERNEL) into its own patch, separate from the panic mechanism. - Document why the buddy allocator TOCTOU race (between get_hwpoison_page() and is_free_buddy_page()) cannot cause false positives: PG_hwpoison is set beforehand and check_new_page() in the page allocator rejects hwpoisoned pages. - Document the narrow LRU isolation race window for MF_MSG_UNKNOWN and its mitigation via identify_page_state()'s two-pass design. - Explicitly document why MF_MSG_GET_HWPOISON is excluded from the panic conditions (shared path with transient races and non-reserved kernel memory). - Link to v3: https://patch.msgid.link/20260413-ecc_panic-v3-0-1dcbb2f12bc4@debian.org Changes in v3: - Rename is_unrecoverable_memory_failure() to panic_on_unrecoverable_mf() as suggested by maintainer. - Add CONFIG_BOOTPARAM_MEMORY_FAILURE_PANIC kernel configuration option, similar to CONFIG_BOOTPARAM_HARDLOCKUP_PANIC. - Add documentation for the sysctl and CONFIG option. - Add code comments documenting the panic condition design rationale and how the retry mechanism mitigates false positives from buddy allocator races. - Link to v2: https://patch.msgid.link/20260331-ecc_panic-v2-0-9e40d0f64f7a@debian.org Changes in v2: - Panic on MF_MSG_KERNEL, MF_MSG_KERNEL_HIGH_ORDER and MF_MSG_UNKNOWN instead of MF_MSG_GET_HWPOISON. - Report MF_MSG_KERNEL for reserved pages when get_hwpoison_page() fails instead of MF_MSG_GET_HWPOISON. - Link to v1: https://patch.msgid.link/20260323-ecc_panic-v1-0-72a1921726c5@debian.org To: Miaohe Lin To: Naoya Horiguchi To: Andrew Morton To: Steven Rostedt To: Masami Hiramatsu To: Mathieu Desnoyers To: Jonathan Corbet To: Shuah Khan To: David Hildenbrand To: Lorenzo Stoakes To: "Liam R. Howlett" To: Vlastimil Babka To: Mike Rapoport To: Suren Baghdasaryan To: Michal Hocko To: Shuah Khan Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kselftest@vger.kernel.org --- Breno Leitao (6): mm/memory-failure: drop dead error_states[] entry for reserved pages mm/memory-failure: surface unhandlable kernel pages as -ENOTRECOVERABLE mm/memory-failure: report MF_MSG_KERNEL for unrecoverable kernel pages mm/memory-failure: add panic option for unrecoverable pages Documentation: document panic_on_unrecoverable_memory_failure sysctl selftests/mm: add hwpoison-panic destructive test Documentation/admin-guide/sysctl/vm.rst | 85 +++++++++++ mm/memory-failure.c | 114 ++++++++++++--- tools/testing/selftests/mm/Makefile | 4 + tools/testing/selftests/mm/hwpoison-panic.sh | 208 +++++++++++++++++++++++++++ 4 files changed, 393 insertions(+), 18 deletions(-) --- base-commit: e7e28506af98ce4e1059e5ec59334b335c00a246 change-id: 20260323-ecc_panic-4e473b83087c Best regards, -- Breno Leitao