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]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC9C7C77B73 for ; Mon, 22 May 2023 12:25:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6E861900004; Mon, 22 May 2023 08:25:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6988A900003; Mon, 22 May 2023 08:25:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 560C1900004; Mon, 22 May 2023 08:25:06 -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 49BCC900003 for ; Mon, 22 May 2023 08:25:06 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 0FCFAADA9D for ; Mon, 22 May 2023 12:25:06 +0000 (UTC) X-FDA: 80817810612.07.D0CA53F Received: from out-21.mta1.migadu.com (out-21.mta1.migadu.com [95.215.58.21]) by imf05.hostedemail.com (Postfix) with ESMTP id 294B210000B for ; Mon, 22 May 2023 12:25:02 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=jE9wkVE1; spf=pass (imf05.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.21 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1684758303; a=rsa-sha256; cv=none; b=QVwohGOj+wnmsCsz67WZJhdenc5sLcehbD/jqd+IVz0VdHCsd7dxvZIPWNrHbXMnJd304I xfa4qFOk3ZLgCuPmDRu27INKxUtaByOj9FSUhnUY1KAwaE0+++S7YBWKaaP14oMpVW1cNL QwQ5nIru2Tv+rvY87tH/YHopGdOzi80= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=jE9wkVE1; spf=pass (imf05.hostedemail.com: domain of qi.zheng@linux.dev designates 95.215.58.21 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1684758303; 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=r1IveFjFr/0G5nfPmQ1aYDtWSC7eo753hQs8Co832NI=; b=F1AQhql1Hi4k1RRluCb4l58l0AlbECcqibROG/zWK9N0NkPCtTtl0iHmAhUeXeWoXPt8hT GOFoOs70CLrcTmeCjaVn/+q3LZj2R9svkDS198NXk97zoWBl45yiPryou1umBT3VJlFMiv 79y/TiqUzoS7Wv6nDqTJ5vufNlSmNtU= Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1684758301; h=from:from: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; bh=r1IveFjFr/0G5nfPmQ1aYDtWSC7eo753hQs8Co832NI=; b=jE9wkVE1qhHuRF/ah9JoCOIcSKA1B5FaHdoFa8smx3qZO2ktUEzWV+AR/VczQifC9+sOee TiXSanP8l15OrBvvOE0EBtkNnPiIQtpkyn/FTyvbZf9T+d9sb+mV5vS1dEQ4wTiFdAyfoU ejXCpsZ0kjD0eVff0b56qxa/xQAqsJg= Date: Mon, 22 May 2023 20:24:45 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 17/31] mm/various: give up if pte_offset_map[_lock]() fails Content-Language: en-US To: Hugh Dickins , Andrew Morton Cc: Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Yang Shi , Mel Gorman , Peter Xu , Peter Zijlstra , Will Deacon , Yu Zhao , Alistair Popple , Ralph Campbell , Ira Weiny , Steven Price , SeongJae Park , Naoya Horiguchi , Christophe Leroy , Zack Rusin , Jason Gunthorpe , Axel Rasmussen , Anshuman Khandual , Pasha Tatashin , Miaohe Lin , Minchan Kim , Christoph Hellwig , Song Liu , Thomas Hellstrom , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <68a97fbe-5c1e-7ac6-72c-7b9c6290b370@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 294B210000B X-Stat-Signature: mpc91mh5hr4c3su6t88pu6b153id9bu3 X-Rspam-User: X-HE-Tag: 1684758302-755737 X-HE-Meta: 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 5ff9Z9oA ZN6BZGYHv21DExIhwF9ppzREGN6embYlAr15fpvjgC9I79LDma5lteqaPK3Q9YeUcL2OSPtk311Nwor0frP9ez5aeMcKLjI+S14qrEuA7PKxDZt9Yq/wWbVWMOCjq3Z8U1loM0KIQJlH/rvKsDaBSVH9nspPGoVc/Rk/u 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: On 2023/5/22 13:10, Hugh Dickins wrote: > Following the examples of nearby code, various functions can just give > up if pte_offset_map() or pte_offset_map_lock() fails. And there's no > need for a preliminary pmd_trans_unstable() or other such check, since > such cases are now safely handled inside. > > Signed-off-by: Hugh Dickins > --- > mm/gup.c | 9 ++++++--- > mm/ksm.c | 7 ++++--- > mm/memcontrol.c | 8 ++++---- > mm/memory-failure.c | 8 +++++--- > mm/migrate.c | 3 +++ > mm/swap_state.c | 3 +++ > 6 files changed, 25 insertions(+), 13 deletions(-) > [...] > diff --git a/mm/migrate.c b/mm/migrate.c > index 3ecb7a40075f..308a56f0b156 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -305,6 +305,9 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, > swp_entry_t entry; > > ptep = pte_offset_map_lock(mm, pmd, address, &ptl); > + if (!ptep) > + return; Maybe we should return false and let the caller handle the failure. > + > pte = *ptep; > pte_unmap(ptep); > > diff --git a/mm/swap_state.c b/mm/swap_state.c > index b76a65ac28b3..db2ec85ef332 100644 > --- a/mm/swap_state.c > +++ b/mm/swap_state.c > @@ -734,6 +734,9 @@ static void swap_ra_info(struct vm_fault *vmf, > > /* Copy the PTEs because the page table may be unmapped */ > orig_pte = pte = pte_offset_map(vmf->pmd, faddr); > + if (!pte) > + return; Ditto? > + > if (fpfn == pfn + 1) { > lpfn = fpfn; > rpfn = fpfn + win; -- Thanks, Qi