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=-12.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 99A23C43219 for ; Tue, 30 Apr 2019 11:19:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6264520835 for ; Tue, 30 Apr 2019 11:19:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="MytLcW5D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727613AbfD3LTP (ORCPT ); Tue, 30 Apr 2019 07:19:15 -0400 Received: from terminus.zytor.com ([198.137.202.136]:39505 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726648AbfD3LTO (ORCPT ); Tue, 30 Apr 2019 07:19:14 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x3UBIeWP1347157 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 30 Apr 2019 04:18:40 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x3UBIeWP1347157 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019041745; t=1556623122; bh=ZhGa5Rw2An+g9Pm5bMaZJRBKLbUWU/FVeTI2VZxezKQ=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=MytLcW5D5rC54iKa5hv8XWJ21/xogRmGGierAS8SWy8Fp6CDz+kkTEtbhujPGefJw 3rfxgycUOK3aIuSb+fTpgdFCOXboCHSb4/Nnn+qO/VExDNDKXzSmg7MjlsTDvqNqJw s2Q8eCh+rT//3EdhYwjC6bB3hEa7BTdGPHkkjANdp3QbwHWuFsXgYHoTVyrzccO+UM 4bxOfzIDeM4sDRSKzAUmVsXIa63bjrDtqVCmP0Q/3mGVmn/dTBYa8yLRjsi7vcLLVU yZpeeSLPiMMBvCGRGDTnyzJib/5N+MzwiirQ/jwBJFN3hhBwtbllqT454YRl3sNSwG blhl0j03QEyLQ== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x3UBIe5w1347154; Tue, 30 Apr 2019 04:18:40 -0700 Date: Tue, 30 Apr 2019 04:18:40 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Nadav Amit Message-ID: Cc: peterz@infradead.org, luto@kernel.org, mhiramat@kernel.org, kristen@linux.intel.com, linux-kernel@vger.kernel.org, hpa@zytor.com, deneen.t.dock@intel.com, namit@vmware.com, tglx@linutronix.de, torvalds@linux-foundation.org, dave.hansen@intel.com, mingo@kernel.org, linux_dti@icloud.com, kernel-hardening@lists.openwall.com, will.deacon@arm.com, rick.p.edgecombe@intel.com, riel@surriel.com, keescook@chromium.org, akpm@linux-foundation.org, bp@alien8.de, ard.biesheuvel@linaro.org Reply-To: rick.p.edgecombe@intel.com, will.deacon@arm.com, riel@surriel.com, akpm@linux-foundation.org, bp@alien8.de, keescook@chromium.org, ard.biesheuvel@linaro.org, dave.hansen@intel.com, linux_dti@icloud.com, mingo@kernel.org, kernel-hardening@lists.openwall.com, linux-kernel@vger.kernel.org, hpa@zytor.com, deneen.t.dock@intel.com, namit@vmware.com, tglx@linutronix.de, torvalds@linux-foundation.org, peterz@infradead.org, luto@kernel.org, mhiramat@kernel.org, kristen@linux.intel.com In-Reply-To: <20190426001143.4983-6-namit@vmware.com> References: <20190426001143.4983-6-namit@vmware.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] fork: Provide a function for copying init_mm Git-Commit-ID: 13585fa0668c724efab9635aaeef6ec390217415 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 13585fa0668c724efab9635aaeef6ec390217415 Gitweb: https://git.kernel.org/tip/13585fa0668c724efab9635aaeef6ec390217415 Author: Nadav Amit AuthorDate: Thu, 25 Apr 2019 17:11:25 -0700 Committer: Ingo Molnar CommitDate: Tue, 30 Apr 2019 12:37:51 +0200 fork: Provide a function for copying init_mm Provide a function for copying init_mm. This function will be later used for setting a temporary mm. Tested-by: Masami Hiramatsu Signed-off-by: Nadav Amit Signed-off-by: Rick Edgecombe Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Masami Hiramatsu Cc: Cc: Cc: Cc: Cc: Cc: Cc: Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Rik van Riel Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190426001143.4983-6-namit@vmware.com Signed-off-by: Ingo Molnar --- 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 2e97a2227045..f1227f2c38a4 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 44fba5e5e916..fbe9dfcd8680 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. *