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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 A3664C433DF for ; Mon, 6 Jul 2020 15:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8666320720 for ; Mon, 6 Jul 2020 15:49:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729297AbgGFPt2 (ORCPT ); Mon, 6 Jul 2020 11:49:28 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:60985 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729476AbgGFPtY (ORCPT ); Mon, 6 Jul 2020 11:49:24 -0400 Received: from ip5f5af08c.dynamic.kabel-deutschland.de ([95.90.240.140] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jsTMv-0005O9-JL; Mon, 06 Jul 2020 15:49:21 +0000 From: Christian Brauner To: linux-kernel@vger.kernel.org Cc: Andrei Vagin , linux-arm-kernel@lists.infradead.org, x86@kernel.org, Will Deacon , Vincenzo Frascino , Thomas Gleixner , Serge Hallyn , Michael Kerrisk , Andy Lutomirski , Catalin Marinas , Mark Rutland , Dmitry Safonov , Christian Brauner Subject: [PATCH v2 3/4] nsproxy: support CLONE_NEWTIME with setns() Date: Mon, 6 Jul 2020 17:49:11 +0200 Message-Id: <20200706154912.3248030-4-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200706154912.3248030-1-christian.brauner@ubuntu.com> References: <20200706154912.3248030-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org So far setns() was missing time namespace support. This was partially due to it simply not being implemented but also because vdso_join_timens() could still fail which made switching to multiple namespaces atomically problematic. This is now fixed so support CLONE_NEWTIME with setns() Signed-off-by: Christian Brauner Reviewed-by: Andrei Vagin Cc: Thomas Gleixner Cc: Michael Kerrisk Cc: Serge Hallyn Cc: Dmitry Safonov Link: https://lore.kernel.org/r/20200619153559.724863-4-christian.brauner@ubuntu.com --- include/linux/time_namespace.h | 6 ++++++ kernel/nsproxy.c | 21 +++++++++++++++++++-- kernel/time/namespace.c | 5 +---- 3 files changed, 26 insertions(+), 6 deletions(-) diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 824d54e057eb..5b6031385db0 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -33,6 +33,7 @@ extern struct time_namespace init_time_ns; #ifdef CONFIG_TIME_NS extern int vdso_join_timens(struct task_struct *task, struct time_namespace *ns); +extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns); static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { @@ -96,6 +97,11 @@ static inline int vdso_join_timens(struct task_struct *task, return 0; } +static inline void timens_commit(struct task_struct *tsk, + struct time_namespace *ns) +{ +} + static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { return NULL; diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index cd356630a311..12dd41b39a7f 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -262,8 +262,8 @@ void exit_task_namespaces(struct task_struct *p) static int check_setns_flags(unsigned long flags) { if (!flags || (flags & ~(CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWNET | CLONE_NEWUSER | CLONE_NEWPID | - CLONE_NEWCGROUP))) + CLONE_NEWNET | CLONE_NEWTIME | CLONE_NEWUSER | + CLONE_NEWPID | CLONE_NEWCGROUP))) return -EINVAL; #ifndef CONFIG_USER_NS @@ -290,6 +290,10 @@ static int check_setns_flags(unsigned long flags) if (flags & CLONE_NEWNET) return -EINVAL; #endif +#ifndef CONFIG_TIME_NS + if (flags & CLONE_NEWTIME) + return -EINVAL; +#endif return 0; } @@ -464,6 +468,14 @@ static int validate_nsset(struct nsset *nsset, struct pid *pid) } #endif +#ifdef CONFIG_TIME_NS + if (flags & CLONE_NEWTIME) { + ret = validate_ns(nsset, &nsp->time_ns->ns); + if (ret) + goto out; + } +#endif + out: if (pid_ns) put_pid_ns(pid_ns); @@ -507,6 +519,11 @@ static void commit_nsset(struct nsset *nsset) exit_sem(me); #endif +#ifdef CONFIG_TIME_NS + if (flags & CLONE_NEWTIME) + timens_commit(me, nsset->nsproxy->time_ns); +#endif + /* transfer ownership */ switch_task_namespaces(me, nsset->nsproxy); nsset->nsproxy = NULL; diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index aa7b90aac2a7..afc65e6be33e 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -280,7 +280,7 @@ static void timens_put(struct ns_common *ns) put_time_ns(to_time_ns(ns)); } -static void timens_commit(struct task_struct *tsk, struct time_namespace *ns) +void timens_commit(struct task_struct *tsk, struct time_namespace *ns) { timens_set_vvar_page(tsk, ns); vdso_join_timens(tsk, ns); @@ -298,9 +298,6 @@ static int timens_install(struct nsset *nsset, struct ns_common *new) !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; - - timens_commit(current, ns); - get_time_ns(ns); put_time_ns(nsproxy->time_ns); nsproxy->time_ns = ns; -- 2.27.0