From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7CC01F34C49 for ; Mon, 13 Apr 2026 13:27:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4C1516B008A; Mon, 13 Apr 2026 09:27:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 48C9A6B0095; Mon, 13 Apr 2026 09:27:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 306FD6B0096; Mon, 13 Apr 2026 09:27:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 0F2036B0092 for ; Mon, 13 Apr 2026 09:27:06 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id ACABF56241 for ; Mon, 13 Apr 2026 13:27:05 +0000 (UTC) X-FDA: 84653608410.16.1FFF39C Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) by imf18.hostedemail.com (Postfix) with ESMTP id D77551C0007 for ; Mon, 13 Apr 2026 13:27:03 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=debian.org header.s=smtpauto.stravinsky header.b=SegWXM+3 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1776086824; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Ts5NH0xUvZdmVlkgq9z2yi5cSaxNAbH4JcbwnyOwfPI=; b=qjtlQWzhHXM+3iZRqCEG0/ARZfkkgih8WZU0Yfntc2UuIK1p09XJAyVe54ea8Zh7hBes6y Lr6vztYY0gsiE7/X0+WFdLJ8KpzhdR6GKm29Wy4p1IC8/FfppjxB1NeHJAI5YKbAg+i2Xl g9x1QGse55eXUO3sT3/Y44fubE1qNxo= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=debian.org header.s=smtpauto.stravinsky header.b=SegWXM+3; spf=none (imf18.hostedemail.com: domain of leitao@debian.org has no SPF policy when checking 82.195.75.108) smtp.mailfrom=leitao@debian.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1776086824; a=rsa-sha256; cv=none; b=JuzvETOWYEpGjjpQjkTrwMo4S5G9DYO2uinK5C/XM7VLNB5OKJ8vsm+HPMRoQY7jTotPwt JKmT2Sne5xcaS//sISSNMGJxK8ccs46RZfnQh8+Aw3OWxw8atfikZMkxSTXFCdLHcbyG7o NRb1lkfLPeYZCJRTJV3iP7vbLXPGETg= 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=Ts5NH0xUvZdmVlkgq9z2yi5cSaxNAbH4JcbwnyOwfPI=; b=SegWXM+33+iQB4lzbciiQtJfqE y9zWi3WdYV5DpEeTro/sk84OUYQNQVXiNyWsbRLqt2/N/CcK9paVcPJMRqKbsthaKoz/3+sb9beNI 32BB5VuwvDNg5IYdhiB8D4GkP6b0PVIVf9kgcd6j2pdv3fhtNe2llJUC/6GN7RNCqkimqw2o/+OeO NKNCv7SIBZFbG4myyCZ+8dlwRID4SOHvnyI/s6P5IIpZ5dIjaQ6vtfYmLu3p/zCz8QvhgJkLoeZ26 KAkWfydAemXmFix9QXWrfWTCDPRnQZPYlEXq2vOUFVXsCPo8VrviOsUf/V66pCLP6SgF1rjhYamtx Gh5qEKDQ==; 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 1wCHJQ-00CKEQ-2C; Mon, 13 Apr 2026 13:26:48 +0000 From: Breno Leitao Date: Mon, 13 Apr 2026 06:26:33 -0700 Subject: [PATCH v3 1/3] mm/memory-failure: report MF_MSG_KERNEL for reserved pages MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260413-ecc_panic-v3-1-1dcbb2f12bc4@debian.org> References: <20260413-ecc_panic-v3-0-1dcbb2f12bc4@debian.org> In-Reply-To: <20260413-ecc_panic-v3-0-1dcbb2f12bc4@debian.org> To: Miaohe Lin , Naoya Horiguchi , Andrew Morton , Jonathan Corbet , Shuah Khan , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Breno Leitao , kernel-team@meta.com X-Mailer: b4 0.16-dev-453a6 X-Developer-Signature: v=1; a=openpgp-sha256; l=3839; i=leitao@debian.org; h=from:subject:message-id; bh=5kticVozScC6u8qmLk9+hhZd71yiocm3BKCHqXfpTvc=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBp3O8OGjMhJ00sPwi1tkdTGacpr0NdoWmXFCwqB fETGcica/uJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCadzvDgAKCRA1o5Of/Hh3 bTMOEACDVZS/51etxbpUL7Fkz6ajXdmMgOGgxmuNv7buSOZbViDuCi1ds2F/1rXwxwpxHG83XA3 KYdFSDzqS9bqK17+lFSC4W7hfOXqLUID2NYoVCuvKScI1sk6JL9UHn8Q8mQFh7ohtfQgnYRJd/p VSDvW4wpIgX8+UavBQCvtRr5QIaH2zAhJD6DD6OUBQyn8/l4LSFOfVZHtEiCkOJO2xB8HrHDtM1 UHQMlsndcKtDtErSj1OJlbqmy19xM/jD2HOf9zWN4RsGGOgz97uhbFYRHzb1ZgKdPagi+4Wm3v1 R4SYPz6OHHtb+orElndz4KXEwwozJA5N8Msh+7efgPPho7Jpxxl789+XZVNVEiXfpOzqMSRVZD3 DdnbIlV4hNrspnEz4iBuzVy9p5xJxn4yPSi4fmudxWGxon8iLyvzYdwGDhXi8kW5xzRvAh03Gry pttT2Vl7BcM81su4p1IOFRkj/WrBpcdWJOXhy4yzxkbHIEwYIHNldDBO5QRiRvm7zcGmY0R024/ 70ETzBG98+7b2FHdnFxlg7HzcOw9SRPCfF+ODwTOYVoEn0twZKFTT1GOqqLlvVKEcPVAlloxV/G OJfI0egBuyqFiBQIx8+pdyhjLqBKL/oY3hldDPmapM2IONXLZpO1kjwarMk4T8KCFQKbhTf58Sv ET1F4s/x9fIsJGg== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao X-Rspam-User: X-Stat-Signature: qhh9urkunao1bd61beiaj5h1r48fogts X-Rspamd-Queue-Id: D77551C0007 X-Rspamd-Server: rspam09 X-HE-Tag: 1776086823-351862 X-HE-Meta: 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 Zan6xhiO cEybyu7EWUF0BP8aJXAOczA4MP2UNN5n2a6L2mXxOsnYVbNt5wmqSDBADoijtSTlEKiuBeSc6mqZhz5YP7+K32ogKXgwTNmqQSgn/GUSWgHDKlbTJKTun0vY6yiJbC5bJvRgQsisPaHqHkdu6pC46uyEeTCqvVJBzRlmVS72ZSSadyIYBdfDeDtCs+MYrjkC0VqbAPvVS0Usq1SVDtCm3Mxh9+yyr6nxbhn6a+ZSg8/20VoA73Gyztd89dVUQMMh7krVOLd0hqud0uUpDvjDRdTBVGg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: When get_hwpoison_page() returns a negative value, distinguish reserved pages from other failure cases by reporting MF_MSG_KERNEL instead of MF_MSG_GET_HWPOISON. Reserved pages belong to the kernel and should be classified accordingly for proper handling by the panic_on_unrecoverable_memory_failure mechanism. Signed-off-by: Breno Leitao --- mm/memory-failure.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index ee42d43613097..852c595aff108 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, } }; @@ -1281,6 +1292,35 @@ static void update_per_node_mf_stats(unsigned long pfn, ++mf_stats->total; } +/* + * Determine whether to panic on an unrecoverable memory failure. + * + * Design rationale: This design opts for immediate panic on kernel memory + * failures, capturing clean crashes other than random crashes on MF_IGNORED pages + * + * This panics on three categories of failures: + * - MF_MSG_KERNEL: Reserved pages that cannot be recovered + * - MF_MSG_KERNEL_HIGH_ORDER: High-order kernel pages that cannot be recovered + * - MF_MSG_UNKNOWN: Pages with unknown state that cannot be classified as recoverable + * - and the page is not being recovered (result = MF_IGNORED) + * + * Note: Transient races are mitigated by memory_failure()'s retry mechanism. + * When a buddy allocator race is detected (take_page_off_buddy() fails), the + * code clears PageHWPoison and retries the entire memory_failure() flow, + * allowing pages to be properly reclassified with updated flags. This ensures + * that false posiotives are not misclassified as unrecoverable. + * + */ +static bool panic_on_unrecoverable_mf(enum mf_action_page_type type, + enum mf_result result) +{ + return sysctl_panic_on_unrecoverable_mf && + result == MF_IGNORED && + (type == MF_MSG_KERNEL || + type == MF_MSG_KERNEL_HIGH_ORDER || + type == MF_MSG_UNKNOWN); +} + /* * "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(). @@ -1298,6 +1338,9 @@ 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; } @@ -2432,7 +2475,11 @@ int memory_failure(unsigned long pfn, int flags) } goto unlock_mutex; } else if (res < 0) { - res = action_result(pfn, MF_MSG_GET_HWPOISON, MF_IGNORED); + if (PageReserved(p)) + res = action_result(pfn, MF_MSG_KERNEL, MF_IGNORED); + else + res = action_result(pfn, MF_MSG_GET_HWPOISON, + MF_IGNORED); goto unlock_mutex; } -- 2.52.0