From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb0-f198.google.com (mail-yb0-f198.google.com [209.85.213.198]) by kanga.kvack.org (Postfix) with ESMTP id B3A416B0006 for ; Tue, 27 Mar 2018 18:17:20 -0400 (EDT) Received: by mail-yb0-f198.google.com with SMTP id i16-v6so204390ybk.21 for ; Tue, 27 Mar 2018 15:17:20 -0700 (PDT) Received: from imap.thunk.org (imap.thunk.org. [2600:3c02::f03c:91ff:fe96:be03]) by mx.google.com with ESMTPS id b125si484925ywf.609.2018.03.27.15.17.19 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 27 Mar 2018 15:17:19 -0700 (PDT) Date: Tue, 27 Mar 2018 18:16:35 -0400 From: "Theodore Y. Ts'o" Subject: Re: [RFC PATCH v2 0/2] Randomization of address chosen by mmap. Message-ID: <20180327221635.GA3790@thunk.org> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0549F29C-12FC-4401-9E85-A430BC11DA78@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ilya Smith 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 Tue, Mar 27, 2018 at 04:51:08PM +0300, Ilya Smith wrote: > > /dev/[u]random is not sufficient? > > Using /dev/[u]random makes 3 syscalls - open, read, close. This is a performance > issue. 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. > > Well, I am pretty sure userspace can implement proper free ranges > > trackinga?| > > I think we need to know what libc developers will say on implementing ASLR in > user-mode. I am pretty sure they will say a??nethera?? or a??some-daya??. And problem > of ASLR will stay forever. Why can't you send patches to the libc developers? Regards, - Ted