From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753389AbaIXRvL (ORCPT ); Wed, 24 Sep 2014 13:51:11 -0400 Received: from smtp1-g21.free.fr ([212.27.42.1]:23819 "EHLO smtp1-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbaIXRvJ (ORCPT ); Wed, 24 Sep 2014 13:51:09 -0400 From: Yann Droneaud To: Al Viro , Andrew Morton Cc: linux-kernel@vger.kernel.org, Yann Droneaud , linux-fsdevel@vger.kernel.org Subject: [PATCHv8 6/6] file: remove get_unused_fd() macro Date: Wed, 24 Sep 2014 15:11:11 +0200 Message-Id: <28ff601c10cc16940919c0c45dc47f73c870c16b.1411562410.git.ydroneaud@opteya.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Macro get_unused_fd() is used to allocate a file descriptor with default flags. Those default flags (0) don't enable close-on-exec. This can be seen as an unsafe default: in most case close-on-exec should be enabled to not leak file descriptor across exec(). It would be better to have a "safer" default set of flags, eg. O_CLOEXEC must be used to enable close-on-exec. Instead this patch removes get_unused_fd() so that out of tree modules won't be affect by a runtime behavor change which might introduce other kind of bugs: it's better to catch the change at build time, making it easier to fix. Removing the macro will also promote use of get_unused_fd_flags() (or anon_inode_getfd()) with flags provided by userspace. Or, if flags cannot be given by userspace, with flags set to O_CLOEXEC by default. Link: http://lkml.kernel.org/r/cover.1411562410.git.ydroneaud@opteya.com Cc: Al Viro Cc: Andrew Morton Signed-off-by: Yann Droneaud --- include/linux/file.h | 1 - 1 file changed, 1 deletion(-) diff --git a/include/linux/file.h b/include/linux/file.h index 4d69123377a2..f87d30882a24 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -66,7 +66,6 @@ extern void set_close_on_exec(unsigned int fd, int flag); extern bool get_close_on_exec(unsigned int fd); extern void put_filp(struct file *); extern int get_unused_fd_flags(unsigned flags); -#define get_unused_fd() get_unused_fd_flags(0) extern void put_unused_fd(unsigned int fd); extern void fd_install(unsigned int fd, struct file *file); -- 1.9.3