From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (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 E5A1019B5BC for ; Tue, 18 Jun 2024 03:20:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718680823; cv=none; b=sosYcP30+l7QVkRWhUC5pTzfcBtRkaY4aE+qE4SotmF8SBpe53ZQNUm3/3REVhz1phs4YrjleW7dOaj1afKxA77962f/UnptMI6kWj9YZdc2HDeG7Xb8MQ9hszpOKJY29UijSokcj7WDde6ZkYgIT6DVfARGEihXdpmw3ErmaSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718680823; c=relaxed/simple; bh=lp4hNuK2bQ6QkZJoBgwp3RYljscVUJDjF0uZhqD/E0Q=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=DfqO1WIr/iMN2FmFqsGB6LpL4cTENzwolRxLbNTsWDMV3o8WR/aOqnMSxCJ35jXZD39gIHtJe5pFxMBH/mRqccCv1v60flItfhxtvAy+iFva2oTvGm3Tiiks7cPnaqviZzpRMlEo9vnFmUYktW9JlBuueZjYi2YDDf32koYKbrY= 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=45.249.212.191 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 szxga05-in.huawei.com (SkyGuard) with ESMTP id 4W3Blq3sRHz1HDWx; Tue, 18 Jun 2024 11:18:15 +0800 (CST) Received: from canpemm500002.china.huawei.com (unknown [7.192.104.244]) by mail.maildlp.com (Postfix) with ESMTPS id CF7AC140123; Tue, 18 Jun 2024 11:20:16 +0800 (CST) Received: from huawei.com (10.173.127.72) 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 15.1.2507.39; Tue, 18 Jun 2024 11:20:16 +0800 From: Miaohe Lin To: CC: Miaohe Lin , David Hildenbrand , Yang Shi , Oscar Salvador , Anshuman Khandual , Naoya Horiguchi , Xu Yu , Andrew Morton Subject: [PATCH 6.9.y] mm/huge_memory: don't unpoison huge_zero_folio Date: Tue, 18 Jun 2024 11:16:24 +0800 Message-ID: <20240618031624.2277227-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <2024061356-victory-clothes-c151@gregkh> References: <2024061356-victory-clothes-c151@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500002.china.huawei.com (7.192.104.244) 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-dirty #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:0000000000000000 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:0000000000000000 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 unexpectedly as it appears like a successfully hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 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. Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@huawei.com Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") Signed-off-by: Miaohe Lin Acked-by: David Hildenbrand Reviewed-by: Yang Shi Reviewed-by: Oscar Salvador Reviewed-by: Anshuman Khandual Cc: Naoya Horiguchi Cc: Xu Yu Cc: Signed-off-by: Andrew Morton (cherry picked from commit fe6f86f4b40855a130a19aa589f9ba7f650423f4) Signed-off-by: Miaohe Lin --- mm/memory-failure.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 18da1c2b08c3..7751bd78fbcb 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2550,6 +2550,13 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } + if (is_huge_zero_page(&folio->page)) { + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", + pfn, &unpoison_rs); + ret = -EOPNOTSUPP; + goto unlock_mutex; + } + if (!PageHWPoison(p)) { unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n", pfn, &unpoison_rs); -- 2.33.0