From patchwork Wed Mar 17 19:13:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Geffon X-Patchwork-Id: 12146907 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 A26BFC433E0 for ; Wed, 17 Mar 2021 19:39:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 190D164EEC for ; Wed, 17 Mar 2021 19:39:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 190D164EEC 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 6C2BB6B006E; Wed, 17 Mar 2021 15:39:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 69C9D6B0070; Wed, 17 Mar 2021 15:39:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 53B406B0071; Wed, 17 Mar 2021 15:39:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0212.hostedemail.com [216.40.44.212]) by kanga.kvack.org (Postfix) with ESMTP id ED7156B006E for ; Wed, 17 Mar 2021 15:39:14 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4ED30180AD817 for ; Wed, 17 Mar 2021 19:39:14 +0000 (UTC) X-FDA: 77930379828.03.D8389CD Received: from mail-qv1-f74.google.com (mail-qv1-f74.google.com [209.85.219.74]) by imf02.hostedemail.com (Postfix) with ESMTP id 4EBE5402E475 for ; Wed, 17 Mar 2021 19:13:42 +0000 (UTC) Received: by mail-qv1-f74.google.com with SMTP id n1so28315469qvi.4 for ; Wed, 17 Mar 2021 12:13:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=vXuIw2r0KUths+dHDGslenhj94hjKPvWBq4rQwLj4o0=; b=vTiA3fHbv6U+fwsYlMXPFTMtzhTMXvkDESZyUN5z3abXBl83IpebxQk0tn/4N0Eqfk J/1oiRtAPkgxAetDq3sgkiSOqaE8EDyGM7R1FmbNnKll3WeQVCVzxuWL6mR0yIAga4Ck dKlb/YTwVhVei5UjQ+TH2DyHwM+r9wa17lvMFLU1AmDoB3MkrNRvRNiHcA3JtA4Xd/Bm IcO46vwWOQGjLptxQTLsoEziY/WRHi6NuhFNiSk5DQxPFp3JZUyoo5G5k8kaYVXe0hox Gp1CHZnuzS6HZ8ZXOWCcaFWOm8+z1AlNcMQ1gIUOYLLjVbejw1oqdXEJ8USpu8/snnE7 po1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=vXuIw2r0KUths+dHDGslenhj94hjKPvWBq4rQwLj4o0=; b=Pg3R8XU9ZB03mKW3aFIM+pgjWO58TjZ0Q1ZumHQS8BTasNIJuzojM1u3vANLTe9U0X RyuG0ihTe4hPwA/Pk/rGtYfHL2GWymVey4z4qFwAiPtDkcgI+q+8+u7VBz0f3KK204BS rTgo82SgtRpEKyO+LkEZbX8WWUkqb/df8ceNQWQCaXzqBTRxHgVw6r1mjmr5aIv/PFls DuxjN7mdc91qN6iAZaVR1fZTZMqHdZX9ONixNJu8MUHpn7vrxOp9rVn6brpDgMH3dPC1 luQXyb/12xqXBxnZi2RKj6f3m8Fo+hpO65eh6AihIyH8u8DZBYAJG/vHTmk+nmvKwbjE hWHA== X-Gm-Message-State: AOAM5313BzDOS74JYM0BRcolcJjQL8JsRu3Od/zkZeSAPrrPhcPAQSXu 1rwCGb5u92b4qPAy15/HjqnqrmoPji4r X-Google-Smtp-Source: ABdhPJzN/koKc7ECpfZRve3vcimXug/j+r6R3c5wMYiU4dPi+khV8lqZ0DEpfirn8y64cPtkqDkTIZQ8c4NX X-Received: from bg.sfo.corp.google.com ([2620:15c:8:10:8c6a:2e6f:ed81:d930]) (user=bgeffon job=sendgmr) by 2002:ad4:4c4c:: with SMTP id cs12mr630569qvb.35.1616008421589; Wed, 17 Mar 2021 12:13:41 -0700 (PDT) Date: Wed, 17 Mar 2021 12:13:34 -0700 In-Reply-To: <20210317191334.564944-1-bgeffon@google.com> Message-Id: <20210317191334.564944-2-bgeffon@google.com> Mime-Version: 1.0 References: <20210303175235.3308220-1-bgeffon@google.com> <20210317191334.564944-1-bgeffon@google.com> X-Mailer: git-send-email 2.31.0.rc2.261.g7f71774620-goog Subject: [PATCH v2 2/2] Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio" From: Brian Geffon To: Andrew Morton Cc: Axel Rasmussen , Lokesh Gidra , Mike Rapoport , Peter Xu , Hugh Dickins , "Michael S . Tsirkin" , Brian Geffon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andy Lutomirski , Vlastimil Babka , Andrea Arcangeli , Sonny Rao , Minchan Kim , "Kirill A . Shutemov" , Dmitry Safonov X-Stat-Signature: skx46d7r6a5r3inwzm8u45sm7e3zn47q X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 4EBE5402E475 Received-SPF: none (flex--bgeffon.bounces.google.com>: No applicable sender policy available) receiver=imf02; identity=mailfrom; envelope-from="<35VRSYAcKCOADIGHHQPIQQING.EQONKPWZ-OOMXCEM.QTI@flex--bgeffon.bounces.google.com>"; helo=mail-qv1-f74.google.com; client-ip=209.85.219.74 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616008422-989120 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: This reverts commit cd544fd1dc9293c6702fab6effa63dac1cc67e99. As discussed in [1] this commit was a no-op because the mapping type was checked in vma_to_resize before move_vma is ever called. This meant that vm_ops->mremap() would never be called on such mappings. Furthermore, we've since expanded support of MREMAP_DONTUNMAP to non-anonymous mappings, and these special mappings are still protected by the existing check of !VM_DONTEXPAND and !VM_PFNMAP which will result in a -EFAULT. 1. https://lkml.org/lkml/2020/12/28/2340 Signed-off-by: Brian Geffon --- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 2 +- fs/aio.c | 5 +---- include/linux/mm.h | 2 +- mm/mmap.c | 6 +----- mm/mremap.c | 2 +- 5 files changed, 5 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index e916646adc69..0daf2f1cf7a8 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -1458,7 +1458,7 @@ static int pseudo_lock_dev_release(struct inode *inode, struct file *filp) return 0; } -static int pseudo_lock_dev_mremap(struct vm_area_struct *area, unsigned long flags) +static int pseudo_lock_dev_mremap(struct vm_area_struct *area) { /* Not supported */ return -EINVAL; diff --git a/fs/aio.c b/fs/aio.c index 1f32da13d39e..76ce0cc3ee4e 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -323,16 +323,13 @@ static void aio_free_ring(struct kioctx *ctx) } } -static int aio_ring_mremap(struct vm_area_struct *vma, unsigned long flags) +static int aio_ring_mremap(struct vm_area_struct *vma) { struct file *file = vma->vm_file; struct mm_struct *mm = vma->vm_mm; struct kioctx_table *table; int i, res = -EINVAL; - if (flags & MREMAP_DONTUNMAP) - return -EINVAL; - spin_lock(&mm->ioctx_lock); rcu_read_lock(); table = rcu_dereference(mm->ioctx_table); diff --git a/include/linux/mm.h b/include/linux/mm.h index 77e64e3eac80..8c3729eb3e38 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -570,7 +570,7 @@ struct vm_operations_struct { void (*close)(struct vm_area_struct * area); /* Called any time before splitting to check if it's allowed */ int (*may_split)(struct vm_area_struct *area, unsigned long addr); - int (*mremap)(struct vm_area_struct *area, unsigned long flags); + int (*mremap)(struct vm_area_struct *area); /* * Called by mprotect() to make driver-specific permission * checks before mprotect() is finalised. The VMA must not diff --git a/mm/mmap.c b/mm/mmap.c index 3f287599a7a3..9d7651e4e1fe 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3403,14 +3403,10 @@ static const char *special_mapping_name(struct vm_area_struct *vma) return ((struct vm_special_mapping *)vma->vm_private_data)->name; } -static int special_mapping_mremap(struct vm_area_struct *new_vma, - unsigned long flags) +static int special_mapping_mremap(struct vm_area_struct *new_vma) { struct vm_special_mapping *sm = new_vma->vm_private_data; - if (flags & MREMAP_DONTUNMAP) - return -EINVAL; - if (WARN_ON_ONCE(current->mm != new_vma->vm_mm)) return -EFAULT; diff --git a/mm/mremap.c b/mm/mremap.c index 2c57dc4bc8b6..b1f7bc43ece9 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -545,7 +545,7 @@ static unsigned long move_vma(struct vm_area_struct *vma, if (moved_len < old_len) { err = -ENOMEM; } else if (vma->vm_ops && vma->vm_ops->mremap) { - err = vma->vm_ops->mremap(new_vma, flags); + err = vma->vm_ops->mremap(new_vma); } if (unlikely(err)) {