From patchwork Tue Aug 27 05:36:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alastair D'Silva X-Patchwork-Id: 11116051 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D6857174A for ; Tue, 27 Aug 2019 05:37:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A90DF217F5 for ; Tue, 27 Aug 2019 05:37:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A90DF217F5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=au1.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9792E6B000C; Tue, 27 Aug 2019 01:37:25 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8D9756B000D; Tue, 27 Aug 2019 01:37:25 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7EF2C6B000E; Tue, 27 Aug 2019 01:37:25 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0236.hostedemail.com [216.40.44.236]) by kanga.kvack.org (Postfix) with ESMTP id 5A3716B000C for ; Tue, 27 Aug 2019 01:37:25 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 0F426180AD802 for ; Tue, 27 Aug 2019 05:37:25 +0000 (UTC) X-FDA: 75867100050.24.title65_23977704ba459 X-Spam-Summary: 2,0,0,1dabf350ad8b9c55,d41d8cd98f00b204,alastair@au1.ibm.com,:alastair@d-silva.org:akpm@linux-foundation.org:osalvador@suse.de:mhocko@suse.com:rppt@linux.ibm.com:dan.j.williams@intel.com:richardw.yang@linux.intel.com:david@redhat.com:cai@lca.pw::linux-kernel@vger.kernel.org,RULES_HIT:41:355:379:541:800:960:968:973:988:989:1260:1261:1311:1314:1345:1359:1431:1437:1515:1535:1541:1711:1730:1747:1777:1792:2198:2199:2393:2559:2562:3138:3139:3140:3141:3142:3353:3865:3867:3870:3872:4321:5007:6261:7576:8957:10004:11026:11473:11658:11914:12043:12114:12296:12297:12438:12517:12519:12555:12679:12895:13069:13255:13311:13357:13894:14181:14384:14394:14721:21080:21451:21627:30054:30070,0,RBL:148.163.158.5:@au1.ibm.com:.lbl8.mailshell.net-62.2.0.100 64.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: title65_23977704ba459 X-Filterd-Recvd-Size: 5654 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Tue, 27 Aug 2019 05:37:24 +0000 (UTC) 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 x7R5W82I054693 for ; Tue, 27 Aug 2019 01:37:23 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2umxesr3at-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 27 Aug 2019 01:37:23 -0400 Received: from localhost by e06smtp04.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, 27 Aug 2019 06:37:18 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7R5bH8j48955528 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 27 Aug 2019 05:37:17 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2D6814C046; Tue, 27 Aug 2019 05:37:17 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CF0AF4C04A; Tue, 27 Aug 2019 05:37:16 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 27 Aug 2019 05:37:16 +0000 (GMT) Received: from adsilva.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id A2235A0300; Tue, 27 Aug 2019 15:37:15 +1000 (AEST) From: "Alastair D'Silva" To: alastair@d-silva.org Cc: Andrew Morton , Oscar Salvador , Michal Hocko , Mike Rapoport , Dan Williams , Wei Yang , David Hildenbrand , Qian Cai , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] mm: don't hide potentially null memmap pointer in sparse_remove_section Date: Tue, 27 Aug 2019 15:36:55 +1000 X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190827053656.32191-1-alastair@au1.ibm.com> References: <20190827053656.32191-1-alastair@au1.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19082705-0016-0000-0000-000002A35CF4 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19082705-0017-0000-0000-00003303A5D6 Message-Id: <20190827053656.32191-3-alastair@au1.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-26_08:,, 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=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=835 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908270062 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Alastair D'Silva By adding offset to memmap before passing it in to clear_hwpoisoned_pages, we hide a theoretically null memmap from the null check inside clear_hwpoisoned_pages. This patch passes the offset to clear_hwpoisoned_pages instead, allowing memmap to successfully perform it's null check. Signed-off-by: Alastair D'Silva --- mm/sparse.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/sparse.c b/mm/sparse.c index e41917a7e844..3ff84e627e58 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -882,7 +882,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, } #ifdef CONFIG_MEMORY_FAILURE -static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) +static void clear_hwpoisoned_pages(struct page *memmap, int start, int count) { int i; @@ -898,7 +898,7 @@ static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) if (atomic_long_read(&num_poisoned_pages) == 0) return; - for (i = 0; i < nr_pages; i++) { + for (i = start; i < start + count; i++) { if (PageHWPoison(&memmap[i])) { num_poisoned_pages_dec(); ClearPageHWPoison(&memmap[i]); @@ -906,7 +906,8 @@ static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) } } #else -static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) +static inline void clear_hwpoisoned_pages(struct page *memmap, int start, + int count) { } #endif @@ -915,7 +916,7 @@ void sparse_remove_section(struct mem_section *ms, unsigned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap) { - clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset, + clear_hwpoisoned_pages(pfn_to_page(pfn), map_offset, nr_pages - map_offset); section_deactivate(pfn, nr_pages, altmap); }