From patchwork Fri Apr 26 23:22:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Amit X-Patchwork-Id: 10920037 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 673DB912 for ; Sat, 27 Apr 2019 06:44:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 58CFA28E6B for ; Sat, 27 Apr 2019 06:44:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 48DCF28E7B; Sat, 27 Apr 2019 06:44:41 +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=-3.8 required=2.0 tests=BAYES_00,DATE_IN_PAST_06_12, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,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 61F6528E6B for ; Sat, 27 Apr 2019 06:44:40 +0000 (UTC) Received: (qmail 3249 invoked by uid 550); 27 Apr 2019 06:43:25 -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 Received: (qmail 3129 invoked from network); 27 Apr 2019 06:43:24 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=PqX9u33LMatWrF2rdzOLAo8PTOZ3S7r/OUOEdwJc/wY=; b=dLUUcPucbWSjI0KF0GYdfa3//vc9Trf9GNL1Jxgol/lAzL/Qif+nwieAhan1enOtj9 IEvF0toGPmi5evSU5LGqWY70kCiO3p7KKseN+96U+aK7PFiGt1LmM5YwgAU+lA6dRruQ txGFF06hrpSSsexZDBeyJTD8iZpafmkscb7dw3FJPuVKduR/83ccqIn9U64Bhl7mXai2 QvPXBsrBhxIENhDIjXt5l8fioHpUH4RBLdAlGLQjejsyatNlX3PJPjeZX8AdLYgJMv+s txk3ENcm6pNvFPMHYkZ9djMndR8b2wvyhfIPdTbE4Wq/3iIH/ChGjSPLA1uzJUN9rbuN 8qpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=PqX9u33LMatWrF2rdzOLAo8PTOZ3S7r/OUOEdwJc/wY=; b=D/S0UEAOToJjcb6o1vigYzKTlZnW6X+Ik06WYnIEdkX+TF2k5/nExwke2ReJ9yP8Jn kCcsUw/2YyJbePCmjBiJSbZJ+03FM0pxloeGfaoQYGsN6mcaJE3u0P22M6yae0ct++gN GsvxvPZJ9xE+TYkkSl0eqHkKBTw81GwFQsWh/bNPcUlppGixInQmhtxlYgDUQ46uyefw FE4BQX/mQmNf3JukyKURq6G4WpEewJr02kMNf6nOLCsnc7wc9BfY3E3LNv9UpBfohzEh fXp4rI9T8o4E402XGIa3fP6R+eCVpFe18HqVr66sqNk//UWDRrBeFZYrI0ekvPxe1gkp Gk9Q== X-Gm-Message-State: APjAAAUY78vJNEzrwryP/2mS6adCyYx1LmewcSKZvv0rMLmmYGXYVAU5 XHin2FEM92yrLcSwwuIxmfk= X-Google-Smtp-Source: APXvYqwtiOYLXN6z+omvr9q5XmanCyE26RTxB/9RLJMeynpzcv4zb2Q6alFcE2kD+WU/ILJ0eVx92Q== X-Received: by 2002:aa7:920b:: with SMTP id 11mr49825084pfo.3.1556347392003; Fri, 26 Apr 2019 23:43:12 -0700 (PDT) From: nadav.amit@gmail.com To: Peter Zijlstra , Borislav Petkov , Andy Lutomirski , Ingo Molnar Cc: linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, Thomas Gleixner , Nadav Amit , Dave Hansen , 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, Rick Edgecombe , Nadav Amit , Kees Cook , Dave Hansen Subject: [PATCH v6 06/24] fork: Provide a function for copying init_mm Date: Fri, 26 Apr 2019 16:22:45 -0700 Message-Id: <20190426232303.28381-7-nadav.amit@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190426232303.28381-1-nadav.amit@gmail.com> References: <20190426232303.28381-1-nadav.amit@gmail.com> X-Virus-Scanned: ClamAV using ClamSMTP 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 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. *