From nobody Tue Feb 10 23:53:04 2026 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (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 EE9663D0D9 for ; Wed, 15 May 2024 02:39:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715740754; cv=none; b=kDvc6w3G1VuS8Y5VqSYxEM6w/6D685/dyec4UUvkzPm60HR9wtfvg90dFa7GezImVdHes1qTd0GmOfT4iTgfC9wfGsoXD/xNwNqRiTl3oWjv2cONx5Djpd+wAMng+X/uk8TWHhYuNdFazVGBPQsqSAJVSpXaKU1UvSEzw7gS2Lo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715740754; c=relaxed/simple; bh=5iSS9sXfbHYU0cpJ/xFgcqmUkP2JVSCYu+CyTFpzZkA=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=OmqNwqobsLR3jt60RiarPRatGhieUukajpHkOVZ8Dxi3KdjXQIaJmvYkOUVoJRUr8afHX6fRl9zbXqUq9vsDU8e/umee9bLadrCI4z4PhQ++q3juNfBHHO/rGv8GvX5RSQDtMVfxmX7Rfu/udh9ddrInzbZyMmURgahF7c3QAa0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4VfHR24Qq6z1ynTf; Wed, 15 May 2024 10:36:14 +0800 (CST) Received: from canpemm500002.china.huawei.com (unknown [7.192.104.244]) by mail.maildlp.com (Postfix) with ESMTPS id 3D8BF140154; Wed, 15 May 2024 10:39:08 +0800 (CST) Received: from huawei.com (10.173.135.154) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Wed, 15 May 2024 10:39:07 +0800 From: Miaohe Lin To: CC: , , , , , , Subject: [PATCH v2] mm/huge_memory: don't unpoison huge_zero_folio Date: Wed, 15 May 2024 10:36:07 +0800 Message-ID: <20240515023607.870022-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.33.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500002.china.huawei.com (7.192.104.244) Content-Type: text/plain; charset="utf-8" When I did memory failure tests recently, below panic occurs: kernel BUG at include/linux/mm.h:1135! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-di= rty #14 RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:00000000000000= 00 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 Call Trace: do_shrink_slab+0x14f/0x6a0 shrink_slab+0xca/0x8c0 shrink_node+0x2d0/0x7d0 balance_pgdat+0x33a/0x720 kswapd+0x1f3/0x410 kthread+0xd5/0x100 ret_from_fork+0x2f/0x50 ret_from_fork_asm+0x1a/0x30 Modules linked in: mce_inject hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:00000000000000= 00 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 The root cause is that HWPoison flag will be set for huge_zero_folio without increasing the folio refcnt. But then unpoison_memory() will decrease the folio refcnt unexpectly as it appears like a successfully hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) =3D=3D 0) when releasing huge_zero_folio. Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. We're not prepared to unpoison huge_zero_folio yet. Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_z= ero_page") Signed-off-by: Miaohe Lin Cc: Acked-by: David Hildenbrand Reviewed-by: Oscar Salvador Reviewed-by: Yang Shi --- v2: Change to simply check for the huge zero page. Thanks. --- mm/memory-failure.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 16ada4fb02b7..68bc8d7ff53d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2558,6 +2558,12 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } =20 + if (is_huge_zero_folio(folio)) { + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", + pfn, &unpoison_rs); + goto unlock_mutex; + } + if (folio_test_slab(folio) || folio_test_pgtable(folio) || folio_test_reserved(folio) || folio_test_offline(folio)) goto unlock_mutex; --=20 2.33.0