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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 0DF12C282CB for ; Wed, 6 Feb 2019 00:12:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3BB5217F9 for ; Wed, 6 Feb 2019 00:12:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="k7cMgRR5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730004AbfBFAMj (ORCPT ); Tue, 5 Feb 2019 19:12:39 -0500 Received: from mail-ed1-f68.google.com ([209.85.208.68]:45745 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729232AbfBFALn (ORCPT ); Tue, 5 Feb 2019 19:11:43 -0500 Received: by mail-ed1-f68.google.com with SMTP id t6so3213344edw.12 for ; Tue, 05 Feb 2019 16:11:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Cvq3ho7ev4E3iI9XxeFOmqSWdHYslt3os8SFMFZoq+0=; b=k7cMgRR5z7R7xvCZ+cySSXExVHDch3yGE0nGs2TORoqzan5r0/FLz1lmRxdMmnNiJQ 9daWdr44SJgWxlSG5hxsqcu4QXPnwl/i3CbvnIw2JdIBL5W8wugu15SZ8//TN3cteo+N yAQA3amIQICubQzG87kRE/Lu4eHxDowFDjofWGYIM8k/cQ1SBbPJSj+0rYDu12vxRvtB vDzwKDr0SOOuFCSMjMbiS6Ou/aQaJ2GvRxhoGSRfVbLJgFUVDExW4LsZGTiYAwwTMpQ/ B8VkbcrlL2JuUnmwNGhLU3MmYgs1oWbBIu8i0pjjKEP1qE9Qodb9GFDe263QVcQbp3ES CDxw== 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:mime-version:content-transfer-encoding; bh=Cvq3ho7ev4E3iI9XxeFOmqSWdHYslt3os8SFMFZoq+0=; b=huMqqG6iX8MeYQ0H2klRrndxQUOLZUeEYXPYt8+5whUMrbyMaNPbhkLeM4woSC2PL1 rainpTia1yDT0Zv7Xw9onqYTCXErisONviD5ovFUI8v2tSZJvao4GCciJs4Uwwi6/cJ2 ibFHm00yGsAa1BnC1F9nGxrKz/eVTaQgqriEyIEAzFGaOv9Dy6gVy5kJToQcR2maI5uv OmWzC0DI5j6fhPbGobAraXCcengY9FjXYA+tJRvwfGnEfa736npbL+PSRvsl5gxbP7mm F5dEurVe6+fYUwww8HVX3qFUttR3tBNjGoaCwQXZTENcobqZd/J1ZDLSVDgoayFnZtqW dOBg== X-Gm-Message-State: AHQUAuY0JUa4Y6XrhEEOYomoqsSiTdu8Kt5bWPIZgzpFbh3kDkkYf3N5 RcP5SMO3o516rBRkKteCYN23gzxreOU= X-Google-Smtp-Source: AHgI3IbmoDbLFz7lGbxJZ/ochE7wPIpnbme1XBz+ufeWnrIZyOCUHS0Vh+YPQcevaIO0Q1ft8fOdug== X-Received: by 2002:a50:9291:: with SMTP id k17mr5955796eda.243.1549411900397; Tue, 05 Feb 2019 16:11:40 -0800 (PST) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id p30sm5489594eda.68.2019.02.05.16.11.39 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 05 Feb 2019 16:11:39 -0800 (PST) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Andrei Vagin , Dmitry Safonov , Adrian Reber , Andrei Vagin , Andy Lutomirski , Andy Tucker , Arnd Bergmann , Christian Brauner , Cyrill Gorcunov , Dmitry Safonov <0x7f454c46@gmail.com>, "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Jeff Dike , Oleg Nesterov , Pavel Emelyanov , Shuah Khan , Thomas Gleixner , containers@lists.linux-foundation.org, criu@openvz.org, linux-api@vger.kernel.org, x86@kernel.org Subject: [PATCH 23/32] timens/fs/proc: Introduce /proc/pid/timens_offsets Date: Wed, 6 Feb 2019 00:10:57 +0000 Message-Id: <20190206001107.16488-24-dima@arista.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190206001107.16488-1-dima@arista.com> References: <20190206001107.16488-1-dima@arista.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 From: Andrei Vagin API to set time namespace offsets for children processes, i.e.: echo "clockid off_ses off_nsec" > /proc/self/timens_offsets Signed-off-by: Andrei Vagin Signed-off-by: Dmitry Safonov --- fs/proc/base.c | 101 +++++++++++++++++++++++++++++++++ include/linux/time_namespace.h | 10 ++++ kernel/time_namespace.c | 71 +++++++++++++++++++++++ 3 files changed, 182 insertions(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index 633a63462573..1ba31050dcb5 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -94,6 +94,7 @@ #include #include #include +#include #include #include "internal.h" #include "fd.h" @@ -1520,6 +1521,103 @@ static const struct file_operations proc_pid_sched_autogroup_operations = { #endif /* CONFIG_SCHED_AUTOGROUP */ +#ifdef CONFIG_TIME_NS +static int timens_offsets_show(struct seq_file *m, void *v) +{ + struct inode *inode = m->private; + struct task_struct *p; + + p = get_proc_task(inode); + if (!p) + return -ESRCH; + proc_timens_show_offsets(p, m); + + put_task_struct(p); + + return 0; +} + +static ssize_t +timens_offsets_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct inode *inode = file_inode(file); + struct proc_timens_offset offsets[2]; + char *kbuf = NULL, *pos, *next_line; + struct task_struct *p; + int ret, noffsets; + + /* Only allow < page size writes at the beginning of the file */ + if ((*ppos != 0) || (count >= PAGE_SIZE)) + return -EINVAL; + + /* Slurp in the user data */ + kbuf = memdup_user_nul(buf, count); + if (IS_ERR(kbuf)) + return PTR_ERR(kbuf); + + /* Parse the user data */ + ret = -EINVAL; + noffsets = 0; + pos = kbuf; + for (; pos; pos = next_line) { + struct proc_timens_offset *off = &offsets[noffsets]; + int err; + + /* Find the end of line and ensure I don't look past it */ + next_line = strchr(pos, '\n'); + if (next_line) { + *next_line = '\0'; + next_line++; + if (*next_line == '\0') + next_line = NULL; + } + + err = sscanf(pos, "%u %lld %lu", &off->clockid, + &off->val.tv_sec, &off->val.tv_nsec); + if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC) + goto out; + if (noffsets++ == ARRAY_SIZE(offsets)) + break; + } + + ret = -ESRCH; + p = get_proc_task(inode); + if (!p) + goto out; + ret = proc_timens_set_offset(p, offsets, noffsets); + put_task_struct(p); + if (ret) + goto out; + + ret = count; +out: + kfree(kbuf); + return ret; +} + +static int timens_offsets_open(struct inode *inode, struct file *filp) +{ + int ret; + + ret = single_open(filp, timens_offsets_show, NULL); + if (!ret) { + struct seq_file *m = filp->private_data; + + m->private = inode; + } + return ret; +} + +static const struct file_operations proc_timens_offsets_operations = { + .open = timens_offsets_open, + .read = seq_read, + .write = timens_offsets_write, + .llseek = seq_lseek, + .release = single_release, +}; +#endif /* CONFIG_TIME_NS */ + static ssize_t comm_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) { @@ -2953,6 +3051,9 @@ static const struct pid_entry tgid_base_stuff[] = { #endif #ifdef CONFIG_SCHED_AUTOGROUP REG("autogroup", S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations), +#endif +#ifdef CONFIG_TIME_NS + REG("timens_offsets", S_IRUGO|S_IWUSR, proc_timens_offsets_operations), #endif REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations), #ifdef CONFIG_HAVE_ARCH_TRACEHOOK diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index f1807d7f524d..c9ba7366b3d6 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -41,6 +41,16 @@ static inline void put_time_ns(struct time_namespace *ns) } +extern void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m); + +struct proc_timens_offset { + int clockid; + struct timespec64 val; +}; + +extern int proc_timens_set_offset(struct task_struct *p, + struct proc_timens_offset *offsets, int n); + extern void timens_clock_to_host(int clockid, struct timespec64 *val); extern void timens_clock_from_host(int clockid, struct timespec64 *val); diff --git a/kernel/time_namespace.c b/kernel/time_namespace.c index 1d1d1c023ec1..6e2e6629e1ba 100644 --- a/kernel/time_namespace.c +++ b/kernel/time_namespace.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -202,6 +203,76 @@ static struct user_namespace *timens_owner(struct ns_common *ns) return to_time_ns(ns)->user_ns; } +static void show_offset(struct seq_file *m, int clockid, struct timespec64 *ts) +{ + seq_printf(m, "%d %lld %ld\n", clockid, ts->tv_sec, ts->tv_nsec); +} + +void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m) +{ + struct ns_common *ns; + struct time_namespace *time_ns; + struct timens_offsets *ns_offsets; + + ns = timens_for_children_get(p); + if (!ns) + return; + time_ns = to_time_ns(ns); + + if (!time_ns->offsets) { + put_time_ns(time_ns); + return; + } + ns_offsets = time_ns->offsets; + + show_offset(m, CLOCK_MONOTONIC, &ns_offsets->monotonic_time_offset); + show_offset(m, CLOCK_BOOTTIME, &ns_offsets->monotonic_boottime_offset); + put_time_ns(time_ns); +} + +int proc_timens_set_offset(struct task_struct *p, + struct proc_timens_offset *offsets, int noffsets) +{ + struct ns_common *ns; + struct time_namespace *time_ns; + struct timens_offsets *ns_offsets; + int i, err; + + ns = timens_for_children_get(p); + if (!ns) + return -ESRCH; + time_ns = to_time_ns(ns); + + if (!time_ns->offsets || time_ns->initialized || + !ns_capable(time_ns->user_ns, CAP_SYS_TIME)) { + put_time_ns(time_ns); + return -EPERM; + } + ns_offsets = time_ns->offsets; + + err = -EINVAL; + for (i = 0; i < noffsets; i++) { + struct proc_timens_offset *off = &offsets[i]; + + switch (off->clockid) { + case CLOCK_MONOTONIC: + ns_offsets->monotonic_time_offset = off->val; + break; + case CLOCK_BOOTTIME: + ns_offsets->monotonic_boottime_offset = off->val; + break; + default: + goto out; + } + } + + err = 0; +out: + put_time_ns(time_ns); + + return err; +} + static void clock_timens_fixup(int clockid, struct timespec64 *val, bool to_ns) { struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets; -- 2.20.1