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 941DE3242A9; Wed, 27 May 2026 14:06:35 +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=1779890798; cv=none; b=YXt2YtXeZTNXHSNfYBoFMYtK1xEbF38r5GF1nUT45/Ha5vs5pYdP8C5OLNngOWhNzR9gGldOBLeZHNKiEUMMDsbAQ+x0t+9RE3+lh6qKRtOwQGvEwGQGnr2B9ATZuQZqpimMXYPmblbUMFdfxdym1EV/AjMzvulsFAcg5c2C3zY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779890798; c=relaxed/simple; bh=2jCKYTQjoKuxxT2ozar3gAihqc+gFK+1/JJPsrGwdlY=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=teC6Cdo8NtMtHCzuFKZw3XwlH6r188VsGgZNmv/NlOmk4MolCgL8vu46pZDJ+sVKW9XDW0Ddyn7wnwfrtfbasIrSvSDxLjXxr/f6NhsJ8Db47FUmj9OEYmC9R+ABmvTlKiL78ZYUkMfRvieXfQb4lp02eUB88vqO67Sz4eQzF58= 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=C77Rwbr0; 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="C77Rwbr0" 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=kMARWeKKUnu5AW49H0a/tY2hHiXSjf7x6sDlYFbA0no=; b=C77Rwbr037HBrCPXLJGFa+WDPT 9EwbR83ut5Hui0/kA13sm2MT/I/RcHKS8I8IeDzmAmexUl6s60YOHfmKBNS5YaVfQNFcMbVxQ2GtZ L76qZjTV4bR8a6Ttd852S4CzUfNb+dSztgtNC/Vwi+chw0eM1FL93k1RzEpSH8vAjU37It4Chcfae tC8aLk/gtct8uIc0yM02eX+p2Y0786Q9MuZgMrSyfxKPQ2EtNiYk9JKBCvFTrYNHgnsppzgaiqajR A4HxKb+Go2LgR0yeAHmSn4RoNgNzeDvgQ8p1LYlIY2wSpKsTwzkVE0NLkBH+PbYUUWJ4zzjqHLYru Me3edNvw==; 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 1wSEts-003DSa-2P; Wed, 27 May 2026 14:06:26 +0000 From: Breno Leitao Subject: [PATCH v8 0/6] mm/memory-failure: add panic option for unrecoverable pages Date: Wed, 27 May 2026 07:06:13 -0700 Message-Id: <20260527-ecc_panic-v8-0-9ea0cfa16bb0@debian.org> 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: 8bit X-B4-Tracking: v=1; b=H4sIAFX6FmoC/23QyWrDMBAG4FcxOmfKaLTGp75HKUXLKFEPdrBT0 xLy7sXpITLucWC+f5abmHmqPIu+u4mJlzrXcRB95w+dSOcwnBhqFn0nCMmiIgWc0sclDDWBZu1 U9Aq9S+LQicvEpX4/st7e/+r5K35yuq4Ba8e5ztdx+nkMW+Ta91/uIgHBUZBHko5sMq+ZYw3Dy zidxBq8UEOVbCkBwpE1ZixWFxd2VD2plpupChBkTjFSkRST3lHdUtNSDQiUkZwrvliUO2oaSrq lBhCCMkVHg5pM2lH7pEZubrXrwl6hpBhc1nFHXUs3tzpAiExsnGcr8/ZN9/v9FzUJaq4XAgAA 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 , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , "Liam R. Howlett" , "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, Lance Yang X-Mailer: b4 0.16-dev-d5d98 X-Developer-Signature: v=1; a=openpgp-sha256; l=8604; i=leitao@debian.org; h=from:subject:message-id; bh=2jCKYTQjoKuxxT2ozar3gAihqc+gFK+1/JJPsrGwdlY=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqFvpbglPkMusQgxkazyuCvti8qWt9bG/4PfTrp RSqR5ICdNaJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCahb6WwAKCRA1o5Of/Hh3 baMUD/9gwdHPys6imhPmurHFc/W3OtkS1wf6kvREznCJqeTA6jqwKCBChTbWFmPZ1BjBlAzhVK2 fBlYDm0Ast271fYcq9j2pczdE0eJGsQjT4qiuhgPvmjBFb0D5YECz47fgVJkQH+wU8dtSK1r9KD ENVj/M5otrDy81tn9SE82BGhd7nIZsZb7aM+GRPLyvZyi9kVvR4rstd5HRRadzn68GnFCtDB93l VdTe9ImE2PatUhoJa4jKr4umVy4hvNW7oADNYFmqxoYQhY4V9nGmdG+TEMEmxw3smwGZW60yUrI v7QIeVMwTUTFIRTzvTDBFzrbXl5FWV0UDPtjCJA/x29OPdYTgXfCuPlYLAcjsxvfFwjo5Ic3Tn0 Zg6pCMqbK1KtBuHEfOslgIxYVgDCJzztBeu/BtkantgV52ijn4s9OinEEKCmSMM9hWx98zD0jXi 8GqkWMv+wZrpSgsSh1WS5t3QJj0dlGDtaaeBd+rNJenQS952H1oYHoXdwpu5R7j/uij4zav1FWv 29/QgcUoK0G0sd5n60o4qGGL2OSwBdSB1rqzJGgixujOyVkoBzRWXx0AzCJHS0snHB/FHXI0SXc aJWjSodLQmkBmZVaeWVzy1IFjy2qWM47uJCLSGRYu5mcI7+690EDOtv0Ao1pCvx5891pWCMPTN0 XEJIGMhWm0unMrg== 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 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 | 96 ++++++++++--- tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/hwpoison-panic.sh | 193 +++++++++++++++++++++++++++ 4 files changed, 357 insertions(+), 18 deletions(-) --- base-commit: e7e28506af98ce4e1059e5ec59334b335c00a246 change-id: 20260323-ecc_panic-4e473b83087c Best regards, -- Breno Leitao