From patchwork Tue Jun 18 04:46:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vaibhav Jain X-Patchwork-Id: 1117624 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45SbDP3dw2z9s5c for ; Tue, 18 Jun 2019 14:47:49 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45SbDP2m94zDqbG for ; Tue, 18 Jun 2019 14:47:49 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=vaibhav@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45SbBt3mXRzDqVv for ; Tue, 18 Jun 2019 14:46:24 +1000 (AEST) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5I4htaB135823 for ; Tue, 18 Jun 2019 00:46:21 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2t6r1jt53p-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 18 Jun 2019 00:46:21 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 18 Jun 2019 05:46:18 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5I4kHci35586322 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 18 Jun 2019 04:46:17 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 30AA0A4065; Tue, 18 Jun 2019 04:46:17 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A59C0A4054; Tue, 18 Jun 2019 04:46:15 +0000 (GMT) Received: from vajain21.in.ibm.com (unknown [9.109.195.188]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 18 Jun 2019 04:46:15 +0000 (GMT) From: Vaibhav Jain To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/mm: Ensure Huge-page memory is free before allocation Date: Tue, 18 Jun 2019 10:16:09 +0530 X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19061804-0020-0000-0000-0000034AFEB0 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19061804-0021-0000-0000-0000219E4947 Message-Id: <20190618044609.19997-1-vaibhav@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-06-18_02:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=925 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906180037 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hari Bathini , Vaibhav Jain , Mahesh J Salgaonkar , "Aneesh Kumar K.V" Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" We recently discovered an bug where physical memory meant for allocation of Huge-pages was inadvertently allocated by another component during early boot. The behavior of memblock_reserve() where it wont indicate whether an existing reserved block overlaps with the requested reservation only makes such bugs hard to investigate. Hence this patch proposes adding a memblock reservation check in htab_dt_scan_hugepage_blocks() just before call to memblock_reserve() to ensure that the physical memory thats being reserved for is not already reserved by someone else. In case this happens we panic the the kernel to ensure that user of this huge-page doesn't accidentally stomp on memory allocated to someone else. Signed-off-by: Vaibhav Jain --- arch/powerpc/mm/book3s64/hash_utils.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 28ced26f2a00..a05be3adb8c9 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -516,6 +516,11 @@ static int __init htab_dt_scan_hugepage_blocks(unsigned long node, printk(KERN_INFO "Huge page(16GB) memory: " "addr = 0x%lX size = 0x%lX pages = %d\n", phys_addr, block_size, expected_pages); + + /* Ensure no one else has reserved memory for huge pages before */ + BUG_ON(memblock_is_region_reserved(phys_addr, + block_size * expected_pages)); + if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) { memblock_reserve(phys_addr, block_size * expected_pages); pseries_add_gpage(phys_addr, block_size, expected_pages);