From 65f8f9a1c1db831e5159e3e3e50912d1f214cd0c Mon Sep 17 00:00:00 2001 From: Richard Cochran Date: Wed, 31 Oct 2012 06:27:25 +0000 Subject: time: remove the timecompare code. This patch removes the timecompare code from the kernel. The top five reasons to do this are: 1. There are no more users of this code. 2. The original idea was a bit weak. 3. The original author has disappeared. 4. The code was not general purpose but tuned to a particular hardware, 5. There are better ways to accomplish clock synchronization. Signed-off-by: Richard Cochran Acked-by: John Stultz Tested-by: Bob Liu Signed-off-by: David S. Miller --- kernel/time/Makefile | 2 +- kernel/time/timecompare.c | 193 ---------------------------------------------- 2 files changed, 1 insertion(+), 194 deletions(-) delete mode 100644 kernel/time/timecompare.c (limited to 'kernel') diff --git a/kernel/time/Makefile b/kernel/time/Makefile index e2fd74b8e8c2..ff7d9d2ab504 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -1,4 +1,4 @@ -obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o +obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o obj-y += timeconv.o posix-clock.o alarmtimer.o obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c deleted file mode 100644 index a9ae369925ce..000000000000 --- a/kernel/time/timecompare.c +++ /dev/null @@ -1,193 +0,0 @@ -/* - * Copyright (C) 2009 Intel Corporation. - * Author: Patrick Ohly - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ - -#include -#include -#include -#include -#include - -/* - * fixed point arithmetic scale factor for skew - * - * Usually one would measure skew in ppb (parts per billion, 1e9), but - * using a factor of 2 simplifies the math. - */ -#define TIMECOMPARE_SKEW_RESOLUTION (((s64)1)<<30) - -ktime_t timecompare_transform(struct timecompare *sync, - u64 source_tstamp) -{ - u64 nsec; - - nsec = source_tstamp + sync->offset; - nsec += (s64)(source_tstamp - sync->last_update) * sync->skew / - TIMECOMPARE_SKEW_RESOLUTION; - - return ns_to_ktime(nsec); -} -EXPORT_SYMBOL_GPL(timecompare_transform); - -int timecompare_offset(struct timecompare *sync, - s64 *offset, - u64 *source_tstamp) -{ - u64 start_source = 0, end_source = 0; - struct { - s64 offset; - s64 duration_target; - } buffer[10], sample, *samples; - int counter = 0, i; - int used; - int index; - int num_samples = sync->num_samples; - - if (num_samples > ARRAY_SIZE(buffer)) { - samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC); - if (!samples) { - samples = buffer; - num_samples = ARRAY_SIZE(buffer); - } - } else { - samples = buffer; - } - - /* run until we have enough valid samples, but do not try forever */ - i = 0; - counter = 0; - while (1) { - u64 ts; - ktime_t start, end; - - start = sync->target(); - ts = timecounter_read(sync->source); - end = sync->target(); - - if (!i) - start_source = ts; - - /* ignore negative durations */ - sample.duration_target = ktime_to_ns(ktime_sub(end, start)); - if (sample.duration_target >= 0) { - /* - * assume symetric delay to and from source: - * average target time corresponds to measured - * source time - */ - sample.offset = - (ktime_to_ns(end) + ktime_to_ns(start)) / 2 - - ts; - - /* simple insertion sort based on duration */ - index = counter - 1; - while (index >= 0) { - if (samples[index].duration_target < - sample.duration_target) - break; - samples[index + 1] = samples[index]; - index--; - } - samples[index + 1] = sample; - counter++; - } - - i++; - if (counter >= num_samples || i >= 100000) { - end_source = ts; - break; - } - } - - *source_tstamp = (end_source + start_source) / 2; - - /* remove outliers by only using 75% of the samples */ - used = counter * 3 / 4; - if (!used) - used = counter; - if (used) { - /* calculate average */ - s64 off = 0; - for (index = 0; index < used; index++) - off += samples[index].offset; - *offset = div_s64(off, used); - } - - if (samples && samples != buffer) - kfree(samples); - - return used; -} -EXPORT_SYMBOL_GPL(timecompare_offset); - -void __timecompare_update(struct timecompare *sync, - u64 source_tstamp) -{ - s64 offset; - u64 average_time; - - if (!timecompare_offset(sync, &offset, &average_time)) - return; - - if (!sync->last_update) { - sync->last_update = average_time; - sync->offset = offset; - sync->skew = 0; - } else { - s64 delta_nsec = average_time - sync->last_update; - - /* avoid division by negative or small deltas */ - if (delta_nsec >= 10000) { - s64 delta_offset_nsec = offset - sync->offset; - s64 skew; /* delta_offset_nsec * - TIMECOMPARE_SKEW_RESOLUTION / - delta_nsec */ - u64 divisor; - - /* div_s64() is limited to 32 bit divisor */ - skew = delta_offset_nsec * TIMECOMPARE_SKEW_RESOLUTION; - divisor = delta_nsec; - while (unlikely(divisor >= ((s64)1) << 32)) { - /* divide both by 2; beware, right shift - of negative value has undefined - behavior and can only be used for - the positive divisor */ - skew = div_s64(skew, 2); - divisor >>= 1; - } - skew = div_s64(skew, divisor); - - /* - * Calculate new overall skew as 4/16 the - * old value and 12/16 the new one. This is - * a rather arbitrary tradeoff between - * only using the latest measurement (0/16 and - * 16/16) and even more weight on past measurements. - */ -#define TIMECOMPARE_NEW_SKEW_PER_16 12 - sync->skew = - div_s64((16 - TIMECOMPARE_NEW_SKEW_PER_16) * - sync->skew + - TIMECOMPARE_NEW_SKEW_PER_16 * skew, - 16); - sync->last_update = average_time; - sync->offset = offset; - } - } -} -EXPORT_SYMBOL_GPL(__timecompare_update); -- cgit v1.2.3-71-gd317 From d328b836823cd4a76611a45f52e208f8ce3d75d7 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 16 Nov 2012 03:02:57 +0000 Subject: userns: make each net (net_ns) belong to a user_ns The user namespace which creates a new network namespace owns that namespace and all resources created in it. This way we can target capability checks for privileged operations against network resources to the user_ns which created the network namespace in which the resource lives. Privilege to the user namespace which owns the network namespace, or any parent user namespace thereof, provides the same privilege to the network resource. This patch is reworked from a version originally by Serge E. Hallyn Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- include/net/net_namespace.h | 9 +++++++-- kernel/nsproxy.c | 2 +- net/core/net_namespace.c | 16 ++++++++++++---- 3 files changed, 20 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 32dcb6085ebe..c5a43f56b796 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -23,6 +23,7 @@ #endif #include +struct user_namespace; struct proc_dir_entry; struct net_device; struct sock; @@ -53,6 +54,8 @@ struct net { struct list_head cleanup_list; /* namespaces on death row */ struct list_head exit_list; /* Use only net_mutex */ + struct user_namespace *user_ns; /* Owning user namespace */ + struct proc_dir_entry *proc_net; struct proc_dir_entry *proc_net_stat; @@ -127,12 +130,14 @@ struct net { extern struct net init_net; #ifdef CONFIG_NET_NS -extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns); +extern struct net *copy_net_ns(unsigned long flags, + struct user_namespace *user_ns, struct net *old_net); #else /* CONFIG_NET_NS */ #include #include -static inline struct net *copy_net_ns(unsigned long flags, struct net *old_net) +static inline struct net *copy_net_ns(unsigned long flags, + struct user_namespace *user_ns, struct net *old_net) { if (flags & CLONE_NEWNET) return ERR_PTR(-EINVAL); diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index b576f7f14bc6..7e1c3de1ce45 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -90,7 +90,7 @@ static struct nsproxy *create_new_namespaces(unsigned long flags, goto out_pid; } - new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns); + new_nsp->net_ns = copy_net_ns(flags, task_cred_xxx(tsk, user_ns), tsk->nsproxy->net_ns); if (IS_ERR(new_nsp->net_ns)) { err = PTR_ERR(new_nsp->net_ns); goto out_net; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 2c1c59091685..6456439cbbd9 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -145,7 +146,7 @@ static void ops_free_list(const struct pernet_operations *ops, /* * setup_net runs the initializers for the network namespace object. */ -static __net_init int setup_net(struct net *net) +static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) { /* Must be called with net_mutex held */ const struct pernet_operations *ops, *saved_ops; @@ -155,6 +156,7 @@ static __net_init int setup_net(struct net *net) atomic_set(&net->count, 1); atomic_set(&net->passive, 1); net->dev_base_seq = 1; + net->user_ns = user_ns; #ifdef NETNS_REFCNT_DEBUG atomic_set(&net->use_count, 0); @@ -232,7 +234,8 @@ void net_drop_ns(void *p) net_free(ns); } -struct net *copy_net_ns(unsigned long flags, struct net *old_net) +struct net *copy_net_ns(unsigned long flags, + struct user_namespace *user_ns, struct net *old_net) { struct net *net; int rv; @@ -243,8 +246,11 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net) net = net_alloc(); if (!net) return ERR_PTR(-ENOMEM); + + get_user_ns(user_ns); + mutex_lock(&net_mutex); - rv = setup_net(net); + rv = setup_net(net, user_ns); if (rv == 0) { rtnl_lock(); list_add_tail_rcu(&net->list, &net_namespace_list); @@ -252,6 +258,7 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net) } mutex_unlock(&net_mutex); if (rv < 0) { + put_user_ns(user_ns); net_drop_ns(net); return ERR_PTR(rv); } @@ -308,6 +315,7 @@ static void cleanup_net(struct work_struct *work) /* Finally it is safe to free my network namespace structure */ list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { list_del_init(&net->exit_list); + put_user_ns(net->user_ns); net_drop_ns(net); } } @@ -395,7 +403,7 @@ static int __init net_ns_init(void) rcu_assign_pointer(init_net.gen, ng); mutex_lock(&net_mutex); - if (setup_net(&init_net)) + if (setup_net(&init_net, &init_user_ns)) panic("Could not setup the initial network namespace"); rtnl_lock(); -- cgit v1.2.3-71-gd317