From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by kanga.kvack.org (Postfix) with ESMTP id A88F36B025C for ; Thu, 23 Jul 2015 17:09:01 -0400 (EDT) Received: by wibxm9 with SMTP id xm9so1746974wib.1 for ; Thu, 23 Jul 2015 14:09:01 -0700 (PDT) Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com. [209.85.212.174]) by mx.google.com with ESMTPS id iv2si10730792wjb.141.2015.07.23.14.08.59 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 23 Jul 2015 14:09:00 -0700 (PDT) Received: by wibxm9 with SMTP id xm9so1746224wib.1 for ; Thu, 23 Jul 2015 14:08:59 -0700 (PDT) Date: Fri, 24 Jul 2015 00:08:56 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCHv2 2/6] x86, mpx: do not set ->vm_ops on mpx VMAs Message-ID: <20150723210856.GA26354@node.dhcp.inet.fi> References: <1437133993-91885-1-git-send-email-kirill.shutemov@linux.intel.com> <1437133993-91885-3-git-send-email-kirill.shutemov@linux.intel.com> <20150723135911.af81b6a685f5b779ca66f3c3@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150723135911.af81b6a685f5b779ca66f3c3@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: "Kirill A. Shutemov" , Oleg Nesterov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Thomas Gleixner , Ingo Molnar On Thu, Jul 23, 2015 at 01:59:11PM -0700, Andrew Morton wrote: > On Fri, 17 Jul 2015 14:53:09 +0300 "Kirill A. Shutemov" wrote: > > > MPX setups private anonymous mapping, but uses vma->vm_ops too. > > This can confuse core VM, as it relies on vm->vm_ops to distinguish > > file VMAs from anonymous. > > > > As result we will get SIGBUS, because handle_pte_fault() thinks it's > > file VMA without vm_ops->fault and it doesn't know how to handle the > > situation properly. > > > > Let's fix that by not setting ->vm_ops. > > > > We don't really need ->vm_ops here: MPX VMA can be detected with VM_MPX > > flag. And vma_merge() will not merge MPX VMA with non-MPX VMA, because > > ->vm_flags won't match. > > > > The only thing left is name of VMA. I'm not sure if it's part of ABI, or > > we can just drop it. The patch keep it by providing arch_vma_name() on x86. > > > > Build tested only. > > mpx.c has changed. > > arch/x86/mm/mpx.c: In function 'try_unmap_single_bt': > arch/x86/mm/mpx.c:930: error: implicit declaration of function 'is_mpx_vma' > > I'll drop this patch and see what happens. Ingo has applied an updated version to x86/urgent: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?h=x86/urgent&id=a89652769470d12cd484ee3d3f7bde0742be8d96 -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org