From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752561AbcF1UXQ (ORCPT ); Tue, 28 Jun 2016 16:23:16 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36477 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752119AbcF1UXO (ORCPT ); Tue, 28 Jun 2016 16:23:14 -0400 Date: Tue, 28 Jun 2016 22:29:41 +0200 From: Emese Revfy To: Mathias Krause Cc: kernel-hardening@lists.openwall.com, pageexec@freemail.hu, spender@grsecurity.net, mmarek@suse.com, keescook@chromium.org, linux-kernel@vger.kernel.org, yamada.masahiro@socionext.com, linux-kbuild@vger.kernel.org, linux@armlinux.org.uk, catalin.marinas@arm.com, linux@rasmusvillemoes.dk, david.brown@linaro.org, benh@kernel.crashing.org, tglx@linutronix.de, akpm@linux-foundation.org, jlayton@poochiereds.net, arnd@arndb.de Subject: Re: [PATCH v1 0/2] Introduce the initify gcc plugin Message-Id: <20160628222941.3f76a4a09767c0134a03a70b@gmail.com> In-Reply-To: <20160628170022.GH22554@ld-linux.so> References: <20160628133407.10c2ea1ecd194e8085e84c5a@gmail.com> <20160628170022.GH22554@ld-linux.so> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Jun 2016 19:00:22 +0200 Mathias Krause wrote: > > section vanilla vanilla + initify change > > ----------------------------------------------------------------------- > > .rodata 39059688 (0x25400e8) 38527210 (0x24be0ea) -532478 > > .data 45744128 (0x2ba0000) 45404160 (0x2b4d000) -339968 > > .init.data 1361144 (0x14c4f8) 1674200 (0x198bd8) +313056 > > .text 77615128 (0x4a05018) 77576664 (0x49fb9d8) -38464 > > .init.text 1108455 (0x10e9e7) 1137618 (0x115bd2) +29163 > > You should probably provide numbers for .init.rodata.str, .exit.rodata.str > and .exit.text as well. Otherwise this delta calculation suggests a rather > gigantic image size reduction which is probably not the case ;) init.rodata.str is an input section that merges into the INIT_DATA output section. I didn't make statistics for exit* yet because I have a problem with that (I asked for help in a previous e-mail). > Also a comparison of the final kernel image size would be nice to see if I no longer have the vmlinux images but I saved away the readelf outputs, here's the PT_LOAD size data: FileSiz (vanilla) FileSiz (vanilla+initify) change ----------------------------------------------------------------------- 00 119189504 (0x71ab000) 118657024 (0x7129000) -532480 01 45838336 (0x2bb7000) 45498368 (0x2b64000) -339968 03 2830336 (0x2b3000) 3198976 (0x30d000) +368640 00 .text .text.exit .text.startup .notes __ex_table .rodata __bug_table .pci_fixup .builtin_fw .tracedata __ksymtab __ksymtab_gpl __ksymtab_strings __init_rodata __param __modver 01 .data .fini_array .vvar 03 .init.text .altinstr_aux .init.data .x86_cpu_dev.init .parainstructions .altinstructions .altinstr_replacement .iommu_table .apicdrivers .exit.text .exit.data .smp_locks .bss .brk I think the smaller .data section is wrong, so I'll look into it. -- Emese