From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from alt32.smtp-out.videotron.ca ([24.53.0.21]:45560 "EHLO alt32.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754731AbcGTTWu (ORCPT ); Wed, 20 Jul 2016 15:22:50 -0400 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> In-Reply-To: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org> References: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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(-) 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); -- 2.7.4