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 A576A40F8C4; Tue, 30 Jun 2026 12:46:45 +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=1782823607; cv=none; b=l3KHyRA/XVoRa8fT+F3wAHiIT5033Sq4SKCSCyE0NM7by1lyIal6dFbCacaaxgi+1USsn6FjVtM9gmKvQ66IGXx7LP090ucCWbVuoO/bI1AooOUp7UXlLXnV+Yg+FFTvY06yKUZsnot/Z8im6ffQqEXXbJmHyMY2qddFPSF0nNE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782823607; c=relaxed/simple; bh=rzlmeFMvKoMLceiaLrM0kWBbYhUIPGoUIe6rGm5ZwiQ=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=sOsMFDzFhriM4VHUfSQBnYGzlCsSS4pjsi4uBpKmLy+VRILR1272ZarbSBhI+4vmt4THd5BbDTZ1zFurWOeIeNBuZANO1HTODtBfw0IDNOgGh4+KlTjXRvc+cW4rseiFTJacvYnTfP8EGxnA1wXEVqhVSLuc+TurP7nxVlzwCec= 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=BWQLB8jU; 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="BWQLB8jU" 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=Qh4NiYPbRruC4mvjxUzpupWki3z36d7XvZrwd3TdvC4=; b=BWQLB8jU6mcNh1heXB/lqQklx4 s+07onfRthNaz50wY8ifyU7opExoLJIdyGoRUAqFDdoEJOib/cdAGDcy8AlDp9fmsS1xKFx3KK8Zb 9ZynezgLH+gNqaO65ayOBcQo1XtJvc5puL2PS5V9fcZHYLXbHb3+9B7MZXQxRpk/WATuJjF4bT1IM bYY+8+bEfpMvDnybVPlTpMbsEDdZ7W7DCyh4OKby8yFpER+cVl/pOQxaNLbXBqD933nhNenr33aPk iXaPMpCWij3qkJgq9LxOj1uQ1+NkJSf8pOlXHiet0wb2THbBea1nty9g/jz4Suy7XWy+vTmaElIwz Kt0EGmYw==; 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 1weXrA-0074bC-0V; Tue, 30 Jun 2026 12:46:29 +0000 From: Breno Leitao Subject: [PATCH v10 0/6] mm/memory-failure: add panic option for unrecoverable pages Date: Tue, 30 Jun 2026 05:46:03 -0700 Message-Id: <20260630-ecc_panic-v10-0-c6ed5b62eea2@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=H4sIAIu6Q2oC/23SS2oDMQwG4KsMXkdFkp+TVe9RSvEzcRdJmEmHl pC7l0kX8eAuDfp+WUI3Meep5lnsh5uY8lLnej6J/UC4G0Q8+tMhQ01iPwhGNihZQo7x4+JPNYL KysrgJDobxW4QlymX+v0Ie3v/e89f4TPH6xqwVhzrfD1PP49uC611/+UuBAiWPY1Mlk3UrymH6 k8v5+kg1uCFGyqppQwIY1aYsBhVrO+ofFJFm64SECjFELgQh6g6qlqqW6oAgROytcUVg9RR3VB WLdWA4KUuKmhUrGNHzZNq2sxq1g87icTB26RCR21LN7NaQAiZs7YuG0r9mlxD2bbUPTbsMRZPJ gTs6PikBseWjoCgJHurEDnbfsOEjWWzuQkEBJN8DM4nZJU2+H6//wKFSZUnywIAAA== 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=9452; i=leitao@debian.org; h=from:subject:message-id; bh=rzlmeFMvKoMLceiaLrM0kWBbYhUIPGoUIe6rGm5ZwiQ=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqQ7qcJMsLrQMFVu0gEasMRTudO2rYviwaZ2bCj DAp2LspyJeJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCakO6nAAKCRA1o5Of/Hh3 bdg2D/9vJwL8x5oEhRZMdlefW2IZJ6ulKZudvqfPju4Qy6uTsXeMJzGvqoK2NyLbohCn/5IEhzP ah0yHQVZCjhFX4qtdU8MQ9SbvCDUP3PMYYXb+zH1G2NdtGDF4F5q2gOmiTV3taQMF17y8hjMJqv hZ/2QC1wk3YFIo3OWhK0RbyIzpf8Kz8nuhBuAph6qJMqmakta85mmHLjmqttDde0MbSEoSxX0eF 64VLj3lcUaZBa8OI7Qv+73Os0X0JuPgO9F5zv0/1xN3JCMjaXa5FHdFMdsnosVoSA7vmeDi0zZ5 Mu1dkoPU+WVWI07SOt3IrcAmlGJ17ItESrsgaTEiPSfhP4v44kZ4yViiDPs9QReLbXwZXGL0xT0 LRlq+s5py+UR/hne/rehx1o+lW43hITmKuE90OS7rd5G+Z0Pao6F/94xZHddgOPTP/OPmSZfGoT KuN9ebW4McP/lVSKp5n0tQTviVtMRUsv5jV6DHbZaI+OjIfu7SZKM1X2SRPK3Umkl4tLLIyp3Mc xiXpMw8Dl0wcUbwQw3pnhkdhGO3D0R8SDOOmWzYBIEBASrFw0ZLf9MfWQSv3ffamA6Cn4N+cb3W ENU42rWwbRP4v8DF0AcUm3fBEfc99LmCPIjg/2/f9+ynwuffVEtb8Kaw/3mTT+MRaWJSiKpSxM3 OfdOCKNvSV9YOVA== 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 v10: - Reuse kselftest declarations - Residual race harmless documentation - Link to v9: https://lore.kernel.org/r/20260609-ecc_panic-v9-0-432a74002e74@debian.org 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 | 80 +++++++++ mm/memory-failure.c | 106 +++++++++-- tools/testing/selftests/mm/Makefile | 4 + tools/testing/selftests/mm/hwpoison-panic.sh | 255 +++++++++++++++++++++++++++ 4 files changed, 427 insertions(+), 18 deletions(-) --- base-commit: 30ffa8de54e5cc80d93fd211ca134d1764a7011f change-id: 20260323-ecc_panic-4e473b83087c Best regards, -- Breno Leitao