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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DBDA7EB64DD for ; Thu, 27 Jul 2023 23:50:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229664AbjG0Xue (ORCPT ); Thu, 27 Jul 2023 19:50:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229600AbjG0Xue (ORCPT ); Thu, 27 Jul 2023 19:50:34 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B25630F7; Thu, 27 Jul 2023 16:50:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=xkFsN0nLFndawtL4141L8X/JoZGbeREgGfgGd37885M=; b=Wg+GAAwUWeNRD75anK4VxNzaDo X2K8CQfGrt295ANJO9MWD0yKUmm9oNYH7OHJUwQWtmMqWEb+jHwUs1s7HqYVBcc+0KRh2NutXPRYm jfQnPEMeMZ63/IJLfMW83F/71lAtSU0C+I8ur0fwD7ItFB01Tifqk4Vo4eGj2mV/wnnwG5pKEmGaw +5v2XHg6xAHTRXHt1oX+RaQBRJV6sl18/QBCLXKPlfHVDzO+xtAO2czHNs+e6awlVwcdDlfJsALq4 /M35/NoVH+Wjd2A9uTPjy7yrtt/BOvs7om4/ql2HC8ZJMWkb1lvNL8OyCjtUHXL7Zm0wA5X3CNk25 cgaVlayA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qPAkX-007ylq-Qh; Thu, 27 Jul 2023 23:50:29 +0000 Date: Fri, 28 Jul 2023 00:50:29 +0100 From: Matthew Wilcox To: Suren Baghdasaryan Cc: Stephen Rothwell , Andrew Morton , Jann Horn , Linus Torvalds , Linux Kernel Mailing List , Linux Next Mailing List Subject: Re: linux-next: manual merge of the mm tree with Linus' tree Message-ID: References: <20230728091849.7f32259d@canb.auug.org.au> <20230728092915.732d4115@canb.auug.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Thu, Jul 27, 2023 at 04:40:20PM -0700, Suren Baghdasaryan wrote: > On Thu, Jul 27, 2023 at 4:29 PM Stephen Rothwell wrote: > > > > Hi all, > > > > On Fri, 28 Jul 2023 09:18:49 +1000 Stephen Rothwell wrote: > > > > > > Today's linux-next merge of the mm tree got a conflict in: > > > > > > mm/memory.c > > > > > > between commit: > > > > > > 657b5146955e ("mm: lock_vma_under_rcu() must check vma->anon_vma under vma lock") > > > > > > from Linus' tree and commits: > > > > > > 69f6bbd1317f ("mm: handle userfaults under VMA lock") > > > a3bdf38e85aa ("mm: allow per-VMA locks on file-backed VMAs") > > > > > > from the mm tree. > > > > > > I fixed it up (I think, please check - see below) and can carry the fix > > > as necessary. This is now fixed as far as linux-next is concerned, but > > > any non trivial conflicts should be mentioned to your upstream > > > maintainer when your tree is submitted for merging. You may also want > > > to consider cooperating with the maintainer of the conflicting tree to > > > minimise any particularly complex conflicts. > > > > > > -- > > > Cheers, > > > Stephen Rothwell > > > > > > diff --cc mm/memory.c > > > index ca632b58f792,271982fab2b8..000000000000 > > > --- a/mm/memory.c > > > +++ b/mm/memory.c > > > @@@ -5392,32 -5597,18 +5597,21 @@@ retry > > > if (!vma) > > > goto inval; > > > > > > - /* Only anonymous and tcp vmas are supported for now */ > > > - if (!vma_is_anonymous(vma) && !vma_is_tcp(vma)) > > > - /* find_mergeable_anon_vma uses adjacent vmas which are not locked */ > > > - if (vma_is_anonymous(vma) && !vma->anon_vma) > > > -- goto inval; > > > -- > > > if (!vma_start_read(vma)) > > > goto inval; > > > > > > + /* > > > + * find_mergeable_anon_vma uses adjacent vmas which are not locked. > > > + * This check must happen after vma_start_read(); otherwise, a > > > + * concurrent mremap() with MREMAP_DONTUNMAP could dissociate the VMA > > > + * from its anon_vma. > > > + */ > > > - if (unlikely(!vma->anon_vma && !vma_is_tcp(vma))) > > > - goto inval_end_read; > > > - > > > - /* > > > - * Due to the possibility of userfault handler dropping mmap_lock, avoid > > > - * it for now and fall back to page fault handling under mmap_lock. > > > - */ > > > - if (userfaultfd_armed(vma)) > > > ++ if (unlikely(vma_is_anonymous(vma) && !vma_is_tcp(vma))) > > Is the above extra '+' what compiler complains about? > Patches from Linus' tree remove some code from that function, so > applying them first should simplify the merge. I see you're unfamiliar with the output of git diff --cc ...