From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755962AbdCXJai (ORCPT ); Fri, 24 Mar 2017 05:30:38 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36054 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753776AbdCXJaY (ORCPT ); Fri, 24 Mar 2017 05:30:24 -0400 Date: Fri, 24 Mar 2017 12:30:19 +0300 From: "Kirill A. Shutemov" To: "Aneesh Kumar K.V" Cc: "Kirill A. Shutemov" , Linus Torvalds , Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , Arnd Bergmann , "H. Peter Anvin" , Andi Kleen , Dave Hansen , Andy Lutomirski , Michal Hocko , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 26/26] x86/mm: allow to have userspace mappings above 47-bits Message-ID: <20170324093019.ts7sljfg32kpajd2@node.shutemov.name> References: <20170313055020.69655-1-kirill.shutemov@linux.intel.com> <20170313055020.69655-27-kirill.shutemov@linux.intel.com> <8760j4sfcz.fsf@skywalker.in.ibm.com> <20170324090408.xsj7othssj547w5k@node.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170306 (1.8.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 24, 2017 at 02:44:10PM +0530, Aneesh Kumar K.V wrote: > > > On Friday 24 March 2017 02:34 PM, Kirill A. Shutemov wrote: > > On Mon, Mar 20, 2017 at 10:40:20AM +0530, Aneesh Kumar K.V wrote: > > > "Kirill A. Shutemov" writes: > > > @@ -168,6 +182,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, > > > > unsigned long addr = addr0; > > > > struct vm_unmapped_area_info info; > > > > > > > > + addr = mpx_unmapped_area_check(addr, len, flags); > > > > + if (IS_ERR_VALUE(addr)) > > > > + return addr; > > > > + > > > > /* requested length too big for entire address space */ > > > > if (len > TASK_SIZE) > > > > return -ENOMEM; > > > > @@ -192,6 +210,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, > > > > info.length = len; > > > > info.low_limit = PAGE_SIZE; > > > > info.high_limit = mm->mmap_base; > > > > + > > > > + /* > > > > + * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area > > > > + * in the full address space. > > > > + */ > > > > + if (addr > DEFAULT_MAP_WINDOW) > > > > + info.high_limit += TASK_SIZE - DEFAULT_MAP_WINDOW; > > > > + > > > > > > Is this ok for 32 bit application ? > > > > DEFAULT_MAP_WINDOW is equal to TASK_SIZE on 32-bit, so it's nop and will > > be compile out. > > > > That is not about CONFIG_X86_32 but about 32 bit application on a 64 bit > kernel. I guess we will never find addr > DEFAULT_MAP_WINDOW with > a 32 bit app ? I have local change to avoid this within 32-bit syscall, but I'll need to recheck everthing. -- Kirill A. Shutemov From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 120EB6B0333 for ; Fri, 24 Mar 2017 05:30:26 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id y90so6389711wrb.1 for ; Fri, 24 Mar 2017 02:30:26 -0700 (PDT) Received: from mail-wm0-x244.google.com (mail-wm0-x244.google.com. [2a00:1450:400c:c09::244]) by mx.google.com with ESMTPS id n107si2346966wrb.4.2017.03.24.02.30.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Mar 2017 02:30:21 -0700 (PDT) Received: by mail-wm0-x244.google.com with SMTP id u132so2028470wmg.1 for ; Fri, 24 Mar 2017 02:30:21 -0700 (PDT) Date: Fri, 24 Mar 2017 12:30:19 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH 26/26] x86/mm: allow to have userspace mappings above 47-bits Message-ID: <20170324093019.ts7sljfg32kpajd2@node.shutemov.name> References: <20170313055020.69655-1-kirill.shutemov@linux.intel.com> <20170313055020.69655-27-kirill.shutemov@linux.intel.com> <8760j4sfcz.fsf@skywalker.in.ibm.com> <20170324090408.xsj7othssj547w5k@node.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: "Kirill A. Shutemov" , Linus Torvalds , Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , Arnd Bergmann , "H. Peter Anvin" , Andi Kleen , Dave Hansen , Andy Lutomirski , Michal Hocko , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Fri, Mar 24, 2017 at 02:44:10PM +0530, Aneesh Kumar K.V wrote: > > > On Friday 24 March 2017 02:34 PM, Kirill A. Shutemov wrote: > > On Mon, Mar 20, 2017 at 10:40:20AM +0530, Aneesh Kumar K.V wrote: > > > "Kirill A. Shutemov" writes: > > > @@ -168,6 +182,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, > > > > unsigned long addr = addr0; > > > > struct vm_unmapped_area_info info; > > > > > > > > + addr = mpx_unmapped_area_check(addr, len, flags); > > > > + if (IS_ERR_VALUE(addr)) > > > > + return addr; > > > > + > > > > /* requested length too big for entire address space */ > > > > if (len > TASK_SIZE) > > > > return -ENOMEM; > > > > @@ -192,6 +210,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, > > > > info.length = len; > > > > info.low_limit = PAGE_SIZE; > > > > info.high_limit = mm->mmap_base; > > > > + > > > > + /* > > > > + * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area > > > > + * in the full address space. > > > > + */ > > > > + if (addr > DEFAULT_MAP_WINDOW) > > > > + info.high_limit += TASK_SIZE - DEFAULT_MAP_WINDOW; > > > > + > > > > > > Is this ok for 32 bit application ? > > > > DEFAULT_MAP_WINDOW is equal to TASK_SIZE on 32-bit, so it's nop and will > > be compile out. > > > > That is not about CONFIG_X86_32 but about 32 bit application on a 64 bit > kernel. I guess we will never find addr > DEFAULT_MAP_WINDOW with > a 32 bit app ? I have local change to avoid this within 32-bit syscall, but I'll need to recheck everthing. -- 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