From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224O2zSgdyHSWGpE2lcV5Rlb/YS4TOKqp5EIgWZX1N/0yMbTnQBayMUx5G+b8aOuwPmCwMax ARC-Seal: i=1; a=rsa-sha256; t=1519676581; cv=none; d=google.com; s=arc-20160816; b=mMv6t3wgq/uASsv4iW4BnlOC5IdXDPC/cyBNyCC4gtMTbGeM/rU0b5GawXoLddb9ee ggakv3krpEXH5Uu19sQpcN049NWuFwkHACsWH/dlPXv7Ns78N0k7MnXjnmaPnSb2LOuw p9ESnwjh2b1q4L/9Ga7oRF6Na3//iRTepVFQ9gb4oNRPSHMrj8xzsLAf2PuC9VEgyDEo NMZfcpFM2wyMKhutk5RFVdLk+c3xAILh98SDwkbkOYOJ1vL72TwZFjV+9shhAj9uEbUe PqAQiD75AVz3A78rHR1Cy59y3uabpI3qhhFZIxJkFq5bVG2+nbkf/SRy6E2GIEfnEaAn JV0A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=Vt2pagSk4OTx2a40ROa+IZn/42UuAt/x/wwGTy7rAkY=; b=lY4tceTw1tQyBvnB2YvZn5Jyqbwz30fVXF/T68pPCDD2Ei0NDvgJLo6pzDYEssw2Fo Csu26xrlYbI6LSCdWSntM6lDQOWKsSyUU6CkOOF3I2wUwrbwsoCL3/SGpKHrFsTxR2c/ LqJwr5ZFdqRN0RKaluHZqIx+p3UnVyxUj4n9cuB7XTbHDyrUuRUz1E54TNbSzJE/eBYa LIlWDJj7hlGarSir/Al/GWEVElk+HTrPLIG8ZT0QrMdMGElIT8GWbWxymR9A/hcNVg2U gQ0vGlKkf6CWovmBPE4pRMlHolZC4ceIapWP45ik/6vEi76jZl/gSzHrEo2TOm2ghgeE fXIg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 83.175.124.243 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 83.175.124.243 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Williams , Jan Kara , Inki Dae , Seung-Woo Kim , Joonyoung Shim , Kyungmin Park , Mauro Carvalho Chehab , Mel Gorman , Vlastimil Babka , Christoph Hellwig , Doug Ledford , Hal Rosenstock , Jason Gunthorpe , Jeff Moyer , Ross Zwisler , Sean Hefty , Andrew Morton , Linus Torvalds Subject: [PATCH 4.9 38/39] mm: fail get_vaddr_frames() for filesystem-dax mappings Date: Mon, 26 Feb 2018 21:20:59 +0100 Message-Id: <20180226201645.332724931@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180226201643.660109883@linuxfoundation.org> References: <20180226201643.660109883@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593496390854252085?= X-GMAIL-MSGID: =?utf-8?q?1593496390854252085?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams commit b7f0554a56f21fb3e636a627450a9add030889be upstream. Until there is a solution to the dma-to-dax vs truncate problem it is not safe to allow V4L2, Exynos, and other frame vector users to create long standing / irrevocable memory registrations against filesytem-dax vmas. [dan.j.williams@intel.com: add comment for vma_is_fsdax() check in get_vaddr_frames(), per Jan] Link: http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.stgit@dwillia2-desk3.amr.corp.intel.com Link: http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Dan Williams Reviewed-by: Jan Kara Cc: Inki Dae Cc: Seung-Woo Kim Cc: Joonyoung Shim Cc: Kyungmin Park Cc: Mauro Carvalho Chehab Cc: Mel Gorman Cc: Vlastimil Babka Cc: Christoph Hellwig Cc: Doug Ledford Cc: Hal Rosenstock Cc: Jason Gunthorpe Cc: Jeff Moyer Cc: Ross Zwisler Cc: Sean Hefty Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/frame_vector.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -52,6 +52,18 @@ int get_vaddr_frames(unsigned long start ret = -EFAULT; goto out; } + + /* + * While get_vaddr_frames() could be used for transient (kernel + * controlled lifetime) pinning of memory pages all current + * users establish long term (userspace controlled lifetime) + * page pinning. Treat get_vaddr_frames() like + * get_user_pages_longterm() and disallow it for filesystem-dax + * mappings. + */ + if (vma_is_fsdax(vma)) + return -EOPNOTSUPP; + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { vec->got_ref = true; vec->is_pfns = false;