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 X-Spam-Level: X-Spam-Status: No, score=-14.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36956C28CBC for ; Wed, 6 May 2020 17:32:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ED85720CC7 for ; Wed, 6 May 2020 17:32:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="gU8Xg+y9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED85720CC7 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9F6C58E0005; Wed, 6 May 2020 13:32:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9A86E8E0003; Wed, 6 May 2020 13:32:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8BD698E0005; Wed, 6 May 2020 13:32:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0084.hostedemail.com [216.40.44.84]) by kanga.kvack.org (Postfix) with ESMTP id 761C08E0003 for ; Wed, 6 May 2020 13:32:56 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 287EC3A97 for ; Wed, 6 May 2020 17:32:56 +0000 (UTC) X-FDA: 76786989552.19.kitty42_36b3a76393a09 X-HE-Tag: kitty42_36b3a76393a09 X-Filterd-Recvd-Size: 4806 Received: from mail-ed1-f68.google.com (mail-ed1-f68.google.com [209.85.208.68]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Wed, 6 May 2020 17:32:55 +0000 (UTC) Received: by mail-ed1-f68.google.com with SMTP id k22so2699967eds.6 for ; Wed, 06 May 2020 10:32:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zINnKrADJ456wEG+eExotg4mZm+1AAItrQjk1QMDkRw=; b=gU8Xg+y94kUk/jJIxbbaNYMn4rphbC4fBnewawj1Uh/frMvnwP7mLkSJpsbqZmnsg0 dy0V++iiQf7VFwxKL8e4ZMwSo/ZVZtqDaZM/ACqSLASsNUwmiLgHErctdGmSUYPtROyE 0XFlBPlZZnopz7Ar9VUqla93WH7yAvMdnSlgiq8m7kgKrUDEyOcWQCDakebeXhePjTl3 7f4Sd9Q/s79BGA5MkzfBUc1QFR+hOp4j32DrpmCG0opc52MYma1Rz6VLQ71R8PqEuK9f 3IH0431rnvHokYkc5P7f0fnmSwzqr6/uYVPAk0sEJJl/zFtsUXKnEc+HRQ8kPUuztXv3 POPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zINnKrADJ456wEG+eExotg4mZm+1AAItrQjk1QMDkRw=; b=jMRtuuLFkkdwvKpuvrYmZ5O8J8NMS3GhZGZybQZRzdfnZ6gkFC095198UIWfV9THzz MrQHKoWWnLzXmUvPTMSScrmd1Bw6IQSGhs/DgMxD1/KfbTACatK/90fYnN5jraG37uh+ 2yVJRoGB4fhHHJh6ieJmNpQ1+HQzPR2qMcDTUNmXBXcwieq+iVdQkL2GUV/rU6uC8Svy n/AYgUj2Zbub/fDZ5N1qR5Mom792HkqDLpfMwo+sQ2Kgq0BdQOerqazemcfwhpJwTG3b E86wC470mQJYQeoKSQU7r2yXqnpOGqTmBQZBYUIBBBoBftGUhohfRhVw61Dm3cwn4rx+ qaVQ== X-Gm-Message-State: AGi0PubmPwquScTOTb4WGso3rpsBmnOLPSxT/DYw3N6f6Vojl8eFjMG+ 8FkKXmT1B6p4Rx+LQjnsNW2vpsVZE4LesPL6BfsNHQ== X-Google-Smtp-Source: APiQypJRjLXomMpn1XVcFOW8Zv8LVVjTey/4sLxDYEh8dNjtfEU+SBnFiqdM5Xz7Nz2pyENEky70nKqDHLseidxPiUk= X-Received: by 2002:a50:fb92:: with SMTP id e18mr7868188edq.177.1588786374285; Wed, 06 May 2020 10:32:54 -0700 (PDT) MIME-Version: 1.0 References: <20200506172158.218366-1-bgeffon@google.com> In-Reply-To: From: Brian Geffon Date: Wed, 6 May 2020 10:32:18 -0700 Message-ID: Subject: Re: [PATCH] userfaultfd: fix remap event with MREMAP_DONTUNMAP. To: Joel Fernandes Cc: Andrew Morton , "Michael S . Tsirkin" , LKML , linux-mm , Andrea Arcangeli , Sonny Rao , Minchan Kim , "Kirill A . Shutemov" Content-Type: text/plain; charset="UTF-8" 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: It hasn't landed in a stable kernel yet, 5.7 is rc4 so I don't think it needs to cc stable, right? Andrew, I'd be happy to mail a new patch if necessary, otherwise here is the fixes: Fixes: e346b38 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()") Brian On Wed, May 6, 2020 at 10:28 AM Joel Fernandes wrote: > > On Wed, May 6, 2020 at 1:22 PM Brian Geffon wrote: > > > > A user is not required to set a new address when using > > MREMAP_DONTUNMAP as it can be used without MREMAP_FIXED. > > When doing so the remap event will use new_addr which may not > > have been set and we didn't propagate it back other then > > in the return value of remap_to. > > > > Because ret is always the new address it's probably more > > correct to use it rather than new_addr on the remap_event_complete > > call, and it resolves this bug. > > > > Does it need Fixes: tag, and CC to stable? Going into a stable kernel > will mean the stable kernel merges into ChromeOS also gets it. > > thanks, > > - Joel > > > Signed-off-by: Brian Geffon > > --- > > mm/mremap.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/mm/mremap.c b/mm/mremap.c > > index c881abeba0bf..6aa6ea605068 100644 > > --- a/mm/mremap.c > > +++ b/mm/mremap.c > > @@ -794,7 +794,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, > > if (locked && new_len > old_len) > > mm_populate(new_addr + old_len, new_len - old_len); > > userfaultfd_unmap_complete(mm, &uf_unmap_early); > > - mremap_userfaultfd_complete(&uf, addr, new_addr, old_len); > > + mremap_userfaultfd_complete(&uf, addr, ret, old_len); > > userfaultfd_unmap_complete(mm, &uf_unmap); > > return ret; > > } > > -- > > 2.26.2.526.g744177e7f7-goog > >