From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751738AbcGTEUy (ORCPT ); Wed, 20 Jul 2016 00:20:54 -0400 Received: from alt22.smtp-out.videotron.ca ([70.80.0.73]:37917 "EHLO alt22.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751400AbcGTEUs (ORCPT ); Wed, 20 Jul 2016 00:20:48 -0400 X-Authority-Analysis: v=2.1 cv=QfzGxpvv c=1 sm=1 tr=0 a=keA3yYpnlypCNW5BNWqu+w==:117 a=keA3yYpnlypCNW5BNWqu+w==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=cAmyUtKerLwA:10 a=KKAkSRfTAAAA:8 a=wXFPGMgaMj5dZSrfe8YA:9 a=cvBusfyB2V15izCimMoJ:22 From: Nicolas Pitre To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexander Viro , David Howells , Greg Ungerer Subject: [PATCH v3 00/12] allow BFLT executables on systems with a MMU Date: Wed, 20 Jul 2016 00:20:12 -0400 Message-Id: <1468988424-32671-1-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 X-CMAE-Envelope: MS4wfPWGNZha1PY+ll+oEO/MF4UgVLh5dSsv24JDN8CjkpDK7HZzAVZo0hHQ2vsBYHtds9ae63IEohIxpyseQFFyQqDWwLsFndIPcebPjjwQN2P4x/P2SABX 7qjegsEaF5v4SER50+HJvoP8/SBoNDhOO0LRFCvdplYg3f9qlA0qgrSS0xfKlHnHgPW899iAWYy4gWtEXMbEXkghDcP1coTipUeJyBDC3fvkeAunNbTZfU/v fIsSOx/zo+Rdotct2AsvsPtz5pe6m8mAhtqkXyv4mk18hR7tY1no6V6B3rUkjJZwz29qud14sjmXq24XMxv4gQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series provides the necessary changes to allow "flat" executable binaries meant for no-MMU systems to actually run on systems with a MMU. This can also be found in the following git repo: git://git.linaro.org/people/nicolas.pitre/linux binfmt_flat_with_mmu *Why?* Because developing and testing natively on a large system with lots of RAM makes it so much more convenient to use all the existing profiling tools and debugging facilities that a kernel with lots of RAM can give. And incidentally, those systems with lots of RAM all have a MMU. *Why not use elf_fdpic?* The flat executable format is simple with very small footprint overhead, either in the executables themselves or kernel support. This makes the flat format more suitable than elf_fdpic for very small single-user-app embedded systems. And while elf_fdpic binaries can run on MMU systems, flat binaries still couldn't, which just felt wrong. So here it is. The no-MMU support should remain unaffected, confirmed by Greg Ungerer. Tested on ARM with MMU only with a busybox build. Please consider for merging. Changes since v2: - Added protection against a corrupted header that could have caused nasty overflows etc. Suggested by Alan Cox. - printk() modernization. Suggested by Greg Ungerer / Geert Uytterhoeven. - Added Greg Ungerer's reviewed-by tag. Changes since v1: - Removed SuperH and Xtensa from the Kconfig rule as they fail to build due to lack of get/put_unaligned_user(). - Clarified some commit logs a bit. diffstat: arch/arm/include/asm/flat.h | 5 +- arch/m68k/include/asm/flat.h | 5 +- fs/Kconfig.binfmt | 3 +- fs/binfmt_elf_fdpic.c | 38 +--- fs/binfmt_flat.c | 453 +++++++++++++++++++++---------------- fs/exec.c | 33 +++ include/linux/binfmts.h | 2 + 7 files changed, 306 insertions(+), 233 deletions(-)