From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 908DB6B025F for ; Mon, 14 Aug 2017 12:26:58 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id x64so14507178wmg.11 for ; Mon, 14 Aug 2017 09:26:58 -0700 (PDT) Received: from mail-wm0-x243.google.com (mail-wm0-x243.google.com. [2a00:1450:400c:c09::243]) by mx.google.com with ESMTPS id z44si6840622ede.201.2017.08.14.09.26.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Aug 2017 09:26:57 -0700 (PDT) Received: by mail-wm0-x243.google.com with SMTP id d40so14998920wma.3 for ; Mon, 14 Aug 2017 09:26:57 -0700 (PDT) Date: Mon, 14 Aug 2017 19:26:55 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH] x86/mm: Fix personality(ADDR_NO_RANDOMIZE) Message-ID: <20170814162655.5famb4r5e5epevhq@node.shutemov.name> References: <20170814155719.74839-1-kirill.shutemov@linux.intel.com> <20170814161347.GO2005@uranus.lan> <20170814162002.GA9559@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170814162002.GA9559@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Oleg Nesterov Cc: Cyrill Gorcunov , "Kirill A. Shutemov" , Linus Torvalds , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andrew Morton , Andy Lutomirski , Dmitry Safonov , Borislav Petkov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable On Mon, Aug 14, 2017 at 06:20:02PM +0200, Oleg Nesterov wrote: > On 08/14, Cyrill Gorcunov wrote: > > > > On Mon, Aug 14, 2017 at 06:57:19PM +0300, Kirill A. Shutemov wrote: > > > In v4.12, during rework of infrastructure around mmap_base, disable-ASLR > > > personality flag got accidentally broken. > > > > > > Let's make it work again. > > > > > > Signed-off-by: Kirill A. Shutemov > > > Fixes: 1b028f784e8c ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()") > > > Cc: stable [4.12+] > > > --- > > > arch/x86/mm/mmap.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c > > > index 229d04a83f85..779bdbe5e424 100644 > > > --- a/arch/x86/mm/mmap.c > > > +++ b/arch/x86/mm/mmap.c > > > @@ -127,6 +127,8 @@ static unsigned long mmap_legacy_base(unsigned long rnd, > > > static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base, > > > unsigned long random_factor, unsigned long task_size) > > > { > > > + if (!(current->flags & PF_RANDOMIZE)) > > > + random_factor = 0; > > > *legacy_base = mmap_legacy_base(random_factor, task_size); > > > if (mmap_is_legacy()) > > > *base = *legacy_base; > > > > Didn't Oleg's patch does the same? > > > > https://patchwork.kernel.org/patch/9832697/ > > at first glance yes, thanks Cyrill. And note that we do not need another > PF_RANDOMIZE check. > > > for some reason it's not yet merged. > > because nobody cares ;) Well, I do. :) It took me few days to track down where huge variablity in micro benchmark results comes from. :/ -- 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