From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f72.google.com (mail-lf0-f72.google.com [209.85.215.72]) by kanga.kvack.org (Postfix) with ESMTP id B94606B0011 for ; Wed, 28 Mar 2018 14:48:26 -0400 (EDT) Received: by mail-lf0-f72.google.com with SMTP id m16-v6so1022383lfc.0 for ; Wed, 28 Mar 2018 11:48:26 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id e19sor1124779ljj.82.2018.03.28.11.48.25 for (Google Transport Security); Wed, 28 Mar 2018 11:48:25 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.2 \(3445.5.20\)) Subject: Re: [RFC PATCH v2 0/2] Randomization of address chosen by mmap. From: Ilya Smith In-Reply-To: <20180327221635.GA3790@thunk.org> Date: Wed, 28 Mar 2018 21:48:22 +0300 Content-Transfer-Encoding: quoted-printable Message-Id: References: <1521736598-12812-1-git-send-email-blackzert@gmail.com> <20180323124806.GA5624@bombadil.infradead.org> <651E0DB6-4507-4DA1-AD46-9C26ED9792A8@gmail.com> <20180326084650.GC5652@dhcp22.suse.cz> <01A133F4-27DF-4AE2-80D6-B0368BF758CD@gmail.com> <20180327072432.GY5652@dhcp22.suse.cz> <0549F29C-12FC-4401-9E85-A430BC11DA78@gmail.com> <20180327221635.GA3790@thunk.org> Sender: owner-linux-mm@kvack.org List-ID: To: "Theodore Y. Ts'o" Cc: Michal Hocko , Matthew Wilcox , rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@synopsys.com, linux@armlinux.org.uk, tony.luck@intel.com, fenghua.yu@intel.com, ralf@linux-mips.org, jejb@parisc-linux.org, Helge Deller , benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, nyc@holomorphy.com, viro@zeniv.linux.org.uk, arnd@arndb.de, gregkh@linuxfoundation.org, deepa.kernel@gmail.com, Hugh Dickins , kstewart@linuxfoundation.org, pombredanne@nexb.com, Andrew Morton , steve.capper@arm.com, punit.agrawal@arm.com, aneesh.kumar@linux.vnet.ibm.com, npiggin@gmail.com, Kees Cook , bhsharma@redhat.com, riel@redhat.com, nitin.m.gupta@oracle.com, "Kirill A. Shutemov" , Dan Williams , Jan Kara , ross.zwisler@linux.intel.com, Jerome Glisse , Andrea Arcangeli , Oleg Nesterov , linux-alpha@vger.kernel.org, LKML , linux-snps-arc@lists.infradead.org, linux-ia64@vger.kernel.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Linux-MM > On 28 Mar 2018, at 01:16, Theodore Y. Ts'o wrote: >=20 > On Tue, Mar 27, 2018 at 04:51:08PM +0300, Ilya Smith wrote: >>> /dev/[u]random is not sufficient? >>=20 >> Using /dev/[u]random makes 3 syscalls - open, read, close. This is a = performance >> issue. >=20 > You may want to take a look at the getrandom(2) system call, which is > the recommended way getting secure random numbers from the kernel. >=20 >>> Well, I am pretty sure userspace can implement proper free ranges >>> tracking=E2=80=A6 >>=20 >> I think we need to know what libc developers will say on implementing = ASLR in=20 >> user-mode. I am pretty sure they will say =E2=80=98nether=E2=80=99 or = =E2=80=98some-day=E2=80=99. And problem=20 >> of ASLR will stay forever. >=20 > Why can't you send patches to the libc developers? >=20 > Regards, >=20 > - Ted I still believe the issue is on kernel side, not in library. Best regards, Ilya