From patchwork Wed Jul 20 19:22:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 72470 Delivered-To: patch@linaro.org Received: by 10.140.29.52 with SMTP id a49csp43902qga; Wed, 20 Jul 2016 12:23:48 -0700 (PDT) X-Received: by 10.66.189.199 with SMTP id gk7mr78124699pac.158.1469042627845; Wed, 20 Jul 2016 12:23:47 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o18si4858995pag.285.2016.07.20.12.23.47; Wed, 20 Jul 2016 12:23:47 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755183AbcGTTXe (ORCPT + 29 others); Wed, 20 Jul 2016 15:23:34 -0400 Received: from alt32.smtp-out.videotron.ca ([24.53.0.21]:6712 "EHLO alt32.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754739AbcGTTWu (ORCPT ); Wed, 20 Jul 2016 15:22:50 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id Px4xbSuz1YOXTPx4ybDLKx; Wed, 20 Jul 2016 15:22:48 -0400 X-Authority-Analysis: v=2.1 cv=Gfm35VjL 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=tBb2bbeoAAAA:8 a=R5CuANmm5DveqMR5uOoA:9 a=cvBusfyB2V15izCimMoJ:22 a=Oj-tNtZlA1e06AYgeCfH:22 Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id 079F42DA069E; Wed, 20 Jul 2016 15:22:46 -0400 (EDT) From: Nicolas Pitre To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexander Viro , David Howells , Greg Ungerer Subject: [PATCH v4 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors Date: Wed, 20 Jul 2016 15:22:39 -0400 Message-Id: <1469042561-7360-11-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org> References: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfIEkx2lqpLUL0yWfyNLRfTp6Xvt4KdjpFLkNtvVYclvB3Zwc2z4sVGU09FtvXF8W5whvpp9dT8bCMkRSxwq18+3f5zADKf6A+1DW5AWbE9WEJVDGDfFu 2X+6oIt/b6+z7K+dNHY/hCB3YLxwnpgN11r1nFdRUqsUGfl0egFHbYKaJcmYsQwGtwirm28Ictv5JFGI3/VoCduemMqx0QMH3JEEn2OEAAErheQXUylE2Ru/ nHibSCVpBTBlg/98EmrEeocWEk//whQAC0MpwlQg1FXMCgTZzjEzFCc7fMUcmfPZB6FXkAFAGVWYzbKoml6Ceg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is needed on systems with a MMU. This also gets rid of the strangest C code I've seen lateli i.e. an integer indexed with a pointer value within square brackets. That really looked backwards. Signed-off-by: Nicolas Pitre Reviewed-by: Greg Ungerer --- fs/binfmt_flat.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) -- 2.7.4 diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 92c1530a2c..aa7971ce6a 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -894,12 +894,19 @@ static int load_flat_binary(struct linux_binprm *bprm) return res; /* Update data segment pointers for all libraries */ - for (i = 0; i < MAX_SHARED_LIBS; i++) - if (libinfo.lib_list[i].loaded) - for (j = 0; j < MAX_SHARED_LIBS; j++) - (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = - (libinfo.lib_list[j].loaded) ? - libinfo.lib_list[j].start_data : UNLOADED_LIB; + for (i = 0; i < MAX_SHARED_LIBS; i++) { + if (!libinfo.lib_list[i].loaded) + continue; + for (j = 0; j < MAX_SHARED_LIBS; j++) { + unsigned long val = libinfo.lib_list[j].loaded ? + libinfo.lib_list[j].start_data : UNLOADED_LIB; + unsigned long __user *p = (unsigned long __user *) + libinfo.lib_list[i].start_data; + p -= j + 1; + if (put_user(val, p)) + return -EFAULT; + } + } install_exec_creds(bprm);