From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24F93C00319 for ; Thu, 21 Feb 2019 23:52:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0D0B2084D for ; Thu, 21 Feb 2019 23:52:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726647AbfBUXwh (ORCPT ); Thu, 21 Feb 2019 18:52:37 -0500 Received: from mga14.intel.com ([192.55.52.115]:3143 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726881AbfBUXu5 (ORCPT ); Thu, 21 Feb 2019 18:50:57 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Feb 2019 15:50:56 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,397,1544515200"; d="scan'208";a="322394821" Received: from linksys13920.jf.intel.com (HELO rpedgeco-DESK5.jf.intel.com) ([10.54.75.11]) by fmsmga005.fm.intel.com with ESMTP; 21 Feb 2019 15:50:55 -0800 From: Rick Edgecombe To: Andy Lutomirski , Ingo Molnar Cc: linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, Thomas Gleixner , Borislav Petkov , Nadav Amit , Dave Hansen , Peter Zijlstra , linux_dti@icloud.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, akpm@linux-foundation.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, will.deacon@arm.com, ard.biesheuvel@linaro.org, kristen@linux.intel.com, deneen.t.dock@intel.com, Nadav Amit , Kees Cook , Dave Hansen , Rick Edgecombe Subject: [PATCH v3 04/20] fork: Provide a function for copying init_mm Date: Thu, 21 Feb 2019 15:44:35 -0800 Message-Id: <20190221234451.17632-5-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190221234451.17632-1-rick.p.edgecombe@intel.com> References: <20190221234451.17632-1-rick.p.edgecombe@intel.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Nadav Amit Provide a function for copying init_mm. This function will be later used for setting a temporary mm. Cc: Andy Lutomirski Cc: Kees Cook Cc: Dave Hansen Acked-by: Peter Zijlstra (Intel) Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Nadav Amit Signed-off-by: Rick Edgecombe --- include/linux/sched/task.h | 1 + kernel/fork.c | 24 ++++++++++++++++++------ 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 44c6f15800ff..c5a00a7b3beb 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -76,6 +76,7 @@ extern void exit_itimers(struct signal_struct *); extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long); extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *); struct task_struct *fork_idle(int); +struct mm_struct *copy_init_mm(void); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); diff --git a/kernel/fork.c b/kernel/fork.c index b69248e6f0e0..1b43753c1884 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1299,13 +1299,20 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) complete_vfork_done(tsk); } -/* - * Allocate a new mm structure and copy contents from the - * mm structure of the passed in task structure. +/** + * dup_mm() - duplicates an existing mm structure + * @tsk: the task_struct with which the new mm will be associated. + * @oldmm: the mm to duplicate. + * + * Allocates a new mm structure and duplicates the provided @oldmm structure + * content into it. + * + * Return: the duplicated mm or NULL on failure. */ -static struct mm_struct *dup_mm(struct task_struct *tsk) +static struct mm_struct *dup_mm(struct task_struct *tsk, + struct mm_struct *oldmm) { - struct mm_struct *mm, *oldmm = current->mm; + struct mm_struct *mm; int err; mm = allocate_mm(); @@ -1372,7 +1379,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk) } retval = -ENOMEM; - mm = dup_mm(tsk); + mm = dup_mm(tsk, current->mm); if (!mm) goto fail_nomem; @@ -2187,6 +2194,11 @@ struct task_struct *fork_idle(int cpu) return task; } +struct mm_struct *copy_init_mm(void) +{ + return dup_mm(NULL, &init_mm); +} + /* * Ok, this is the main fork-routine. * -- 2.17.1