From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id 20563440CD7 for ; Thu, 9 Nov 2017 10:38:55 -0500 (EST) Received: by mail-wr0-f197.google.com with SMTP id u97so3410410wrc.3 for ; Thu, 09 Nov 2017 07:38:55 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id n8si5661834edi.99.2017.11.09.07.38.53 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 09 Nov 2017 07:38:53 -0800 (PST) Date: Thu, 9 Nov 2017 16:38:51 +0100 From: Michal Hocko Subject: Re: [PATCH] x86/mm: Fix ELF_ET_DYN_BASE for 5-level paging Message-ID: <20171109153851.xvgmfnbkoxj64jm6@dhcp22.suse.cz> References: <20171107103804.47341-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171107103804.47341-1-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Ingo Molnar , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kees Cook , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , Nicholas Piggin On Tue 07-11-17 13:38:04, Kirill A. Shutemov wrote: > On machines with 5-level paging we don't want to allocate mapping above > 47-bit unless user explicitly asked for it. See b569bab78d8d ("x86/mm: > Prepare to expose larger address space to userspace") for details. > > c715b72c1ba4 ("mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base > changes") broke the behaviour. After the commit elf binary and heap got > mapped above 47-bits. > > Let's fix this. > > Signed-off-by: Kirill A. Shutemov > Fixes: c715b72c1ba4 ("mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes") > Cc: Kees Cook > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: Thomas Gleixner > Cc: Nicholas Piggin FWIW Acked-by: Michal Hocko > --- > arch/x86/include/asm/elf.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h > index c1a125e47ff3..3a091cea36c5 100644 > --- a/arch/x86/include/asm/elf.h > +++ b/arch/x86/include/asm/elf.h > @@ -253,7 +253,7 @@ extern int force_personality32; > * space open for things that want to use the area for 32-bit pointers. > */ > #define ELF_ET_DYN_BASE (mmap_is_ia32() ? 0x000400000UL : \ > - (TASK_SIZE / 3 * 2)) > + (DEFAULT_MAP_WINDOW / 3 * 2)) > > /* This yields a mask that user programs can use to figure out what > instruction set this CPU supports. This could be done in user space, > -- > 2.14.2 -- Michal Hocko SUSE Labs -- 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