From patchwork Thu Oct 8 07:54:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: yulei zhang X-Patchwork-Id: 11822385 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 276E513B2 for ; Thu, 8 Oct 2020 07:55:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0373C21897 for ; Thu, 8 Oct 2020 07:55:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fngZ4V7u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729098AbgJHHzq (ORCPT ); Thu, 8 Oct 2020 03:55:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729040AbgJHHzm (ORCPT ); Thu, 8 Oct 2020 03:55:42 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5382C0613D7; Thu, 8 Oct 2020 00:55:27 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id g10so3317316pfc.8; Thu, 08 Oct 2020 00:55:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=rgl0RB6gKY0poqmey3m0fH+Fzjy9yKEsxNNtoKcaNdI=; b=fngZ4V7uI0g9A6oGR8TT184yksleNQiusVTwWIjxfwwoKMU1wm78uDgw4GhFCinpLT +5h7GvXwXYZ/tSqURQ2Tq28OTn9cZdYpbuc9i/+5QfFNfKDql8jLuOJvp3pZMqzzSpoq JkVRBPdFlpg9p5p4nO8u2r6ghJvAjYSFs0VzTnFqWT3Qklsxq3dHrx1QJOD/FqOKir/8 c390Pqs5yl9bpYxI3jAZA1NmbAB5FRlB6FYY0jt/dbirBkws2o2k9Jnx+xEXda7bDKi5 lxSdolQfWzRLtbR+EYOMZUQ3G0mV1QvhE3zsSPnWXDu70Oqzf2AfwS6qh6JW6y4MgiHh W2fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=rgl0RB6gKY0poqmey3m0fH+Fzjy9yKEsxNNtoKcaNdI=; b=IZpNoWgh+u7LvNhjZjxuf9BNmBooDMYkoC5hxF4crnpKMHjQZdcUfKtw0vbuNnLYM1 HBCX9kuxR1kNk7Jd2/OEctRfbM1dBglZuzsHKH790wwaGNgFfEzJqjlV9/YX4Ig20r8V oK+R+YtKlkT5FEsrC/MHx+L6Gm0Fab1mZt3zKU74LtgAC1YWrGOQ7iaMTmGtu+xleRQL ZmpPA4eDDdhHz646ExoxhfXRcv96cg6+E5gZxbe2VMUGWvL99VrIBv3Z59nz0Odhvau7 jkhF+Grr3qi8M7bfrsokIjElr68tjVir6KwkUr6MEq/N+8X4JKNTqVZBtFmGJXK5PCO3 doqw== X-Gm-Message-State: AOAM533RlCSC6Rly6NeFLM7/tuWUJu2AR8JkUrzwhrmO5dSyIN3xzbDt pba/q7PNGOo4dAwbwc/xHR602ix3zQ+NXA== X-Google-Smtp-Source: ABdhPJw6ynUy5YDxI8vIljMLF5r1pNoOsWb1QWSg0/UqQKFCKO4W8P/RsEsn26/IjH6bTFmivX+QQA== X-Received: by 2002:a17:90b:f8b:: with SMTP id ft11mr6844289pjb.8.1602143727295; Thu, 08 Oct 2020 00:55:27 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.61]) by smtp.gmail.com with ESMTPSA id k206sm6777106pfd.126.2020.10.08.00.55.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Oct 2020 00:55:26 -0700 (PDT) From: yulei.kernel@gmail.com X-Google-Original-From: yuleixzhang@tencent.com To: akpm@linux-foundation.org, naoya.horiguchi@nec.com, viro@zeniv.linux.org.uk, pbonzini@redhat.com Cc: linux-fsdevel@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, xiaoguangrong.eric@gmail.com, kernellwp@gmail.com, lihaiwei.kernel@gmail.com, Yulei Zhang , Chen Zhuo Subject: [PATCH 23/35] kvm, x86: introduce VM_DMEM Date: Thu, 8 Oct 2020 15:54:13 +0800 Message-Id: <3c8fc6f37abe66c13348c9af2eacee04d4dfaa72.1602093760.git.yuleixzhang@tencent.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Yulei Zhang Currently dmemfs do not support memory readonly, so change_protection() will be disabled for dmemfs vma. Since vma->vm_flags could be changed to new flag in mprotect_fixup(), so we introduce a new vma flag VM_DMEM and check this flag in mprotect_fixup() to avoid changing vma->vm_flags. We also check it in vma_to_resize() to disable mremap() for dmemfs vma. Signed-off-by: Chen Zhuo Signed-off-by: Yulei Zhang --- fs/dmemfs/inode.c | 2 +- include/linux/mm.h | 7 +++++++ mm/mprotect.c | 5 ++++- mm/mremap.c | 3 +++ 4 files changed, 15 insertions(+), 2 deletions(-) diff --git a/fs/dmemfs/inode.c b/fs/dmemfs/inode.c index e37498c00497..b3e394f33b42 100644 --- a/fs/dmemfs/inode.c +++ b/fs/dmemfs/inode.c @@ -510,7 +510,7 @@ int dmemfs_file_mmap(struct file *file, struct vm_area_struct *vma) if (!(vma->vm_flags & VM_SHARED)) return -EINVAL; - vma->vm_flags |= VM_PFNMAP; + vma->vm_flags |= VM_PFNMAP | VM_DMEM | VM_IO; file_accessed(file); vma->vm_ops = &dmemfs_vm_ops; diff --git a/include/linux/mm.h b/include/linux/mm.h index ca6e6a81576b..7b1e574d2387 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -309,6 +309,8 @@ extern unsigned int kobjsize(const void *objp); #define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4) #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */ +#define VM_DMEM BIT(38) /* Dmem page VM */ + #ifdef CONFIG_ARCH_HAS_PKEYS # define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0 # define VM_PKEY_BIT0 VM_HIGH_ARCH_0 /* A protection key is a 4-bit value */ @@ -656,6 +658,11 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma) return vma->vm_flags & VM_ACCESS_FLAGS; } +static inline bool vma_is_dmem(struct vm_area_struct *vma) +{ + return !!(vma->vm_flags & VM_DMEM); +} + #ifdef CONFIG_SHMEM /* * The vma_is_shmem is not inline because it is used only by slow diff --git a/mm/mprotect.c b/mm/mprotect.c index ce8b8a5eacbb..36f885cbbb30 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -236,7 +236,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, * for all the checks. */ if (!is_swap_pmd(*pmd) && !pmd_devmap(*pmd) && - pmd_none_or_clear_bad_unless_trans_huge(pmd)) + pmd_none_or_clear_bad_unless_trans_huge(pmd) && !pmd_special(*pmd)) goto next; /* invoke the mmu notifier if the pmd is populated */ @@ -412,6 +412,9 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, return 0; } + if (vma_is_dmem(vma)) + return -EINVAL; + /* * Do PROT_NONE PFN permission checks here when we can still * bail out without undoing a lot of state. This is a rather diff --git a/mm/mremap.c b/mm/mremap.c index 138abbae4f75..598e68174e24 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -482,6 +482,9 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr, if (!vma || vma->vm_start > addr) return ERR_PTR(-EFAULT); + if (vma_is_dmem(vma)) + return ERR_PTR(-EINVAL); + /* * !old_len is a special case where an attempt is made to 'duplicate' * a mapping. This makes no sense for private mappings as it will