From patchwork Tue Apr 30 11:18:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: tip-bot for Kobe Wu X-Patchwork-Id: 10923313 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B80D814B6 for ; Tue, 30 Apr 2019 11:30:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A5BE528AA5 for ; Tue, 30 Apr 2019 11:30:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A09F28AA8; Tue, 30 Apr 2019 11:30:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.0 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 0F06228AA5 for ; Tue, 30 Apr 2019 11:30:44 +0000 (UTC) Received: (qmail 21924 invoked by uid 550); 30 Apr 2019 11:30:14 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Delivered-To: moderator for kernel-hardening@lists.openwall.com Received: (qmail 12109 invoked from network); 30 Apr 2019 11:19:12 -0000 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== Date: Tue, 30 Apr 2019 04:18:40 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f Sender: tip tree robot 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 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-Disposition: inline X-Virus-Scanned: ClamAV using ClamSMTP 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. *