2019-06-01 16:08:55 +08:00
|
|
|
// SPDX-License-Identifier: GPL-2.0-only
|
2006-10-02 17:18:06 +08:00
|
|
|
/*
|
|
|
|
|
* Copyright (C) 2006 IBM Corporation
|
|
|
|
|
*
|
|
|
|
|
* Author: Serge Hallyn <serue@us.ibm.com>
|
|
|
|
|
*
|
2006-10-02 17:18:19 +08:00
|
|
|
* Jun 2006 - namespaces support
|
|
|
|
|
* OpenVZ, SWsoft Inc.
|
|
|
|
|
* Pavel Emelianov <xemul@openvz.org>
|
2006-10-02 17:18:06 +08:00
|
|
|
*/
|
|
|
|
|
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
|
|
|
#include <linux/slab.h>
|
2011-05-24 02:51:41 +08:00
|
|
|
#include <linux/export.h>
|
2006-10-02 17:18:06 +08:00
|
|
|
#include <linux/nsproxy.h>
|
2006-10-02 17:18:07 +08:00
|
|
|
#include <linux/init_task.h>
|
2006-12-08 18:37:56 +08:00
|
|
|
#include <linux/mnt_namespace.h>
|
2006-10-02 17:18:14 +08:00
|
|
|
#include <linux/utsname.h>
|
2006-12-08 18:37:59 +08:00
|
|
|
#include <linux/pid_namespace.h>
|
2007-09-27 13:04:26 +08:00
|
|
|
#include <net/net_namespace.h>
|
2008-02-08 20:18:22 +08:00
|
|
|
#include <linux/ipc_namespace.h>
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
#include <linux/time_namespace.h>
|
2013-04-12 08:50:06 +08:00
|
|
|
#include <linux/proc_ns.h>
|
2010-03-08 09:48:52 +08:00
|
|
|
#include <linux/file.h>
|
|
|
|
|
#include <linux/syscalls.h>
|
2016-01-29 16:54:06 +08:00
|
|
|
#include <linux/cgroup.h>
|
2017-03-08 04:41:36 +08:00
|
|
|
#include <linux/perf_event.h>
|
2006-10-02 17:18:07 +08:00
|
|
|
|
2007-07-16 14:41:07 +08:00
|
|
|
static struct kmem_cache *nsproxy_cachep;
|
|
|
|
|
|
2010-03-11 07:23:10 +08:00
|
|
|
struct nsproxy init_nsproxy = {
|
2013-08-23 02:39:16 +08:00
|
|
|
.count = ATOMIC_INIT(1),
|
|
|
|
|
.uts_ns = &init_uts_ns,
|
2010-03-11 07:23:10 +08:00
|
|
|
#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
|
2013-08-23 02:39:16 +08:00
|
|
|
.ipc_ns = &init_ipc_ns,
|
2010-03-11 07:23:10 +08:00
|
|
|
#endif
|
2013-08-23 02:39:16 +08:00
|
|
|
.mnt_ns = NULL,
|
|
|
|
|
.pid_ns_for_children = &init_pid_ns,
|
2010-03-11 07:23:10 +08:00
|
|
|
#ifdef CONFIG_NET
|
2013-08-23 02:39:16 +08:00
|
|
|
.net_ns = &init_net,
|
2010-03-11 07:23:10 +08:00
|
|
|
#endif
|
2016-01-29 16:54:06 +08:00
|
|
|
#ifdef CONFIG_CGROUPS
|
|
|
|
|
.cgroup_ns = &init_cgroup_ns,
|
|
|
|
|
#endif
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
#ifdef CONFIG_TIME_NS
|
|
|
|
|
.time_ns = &init_time_ns,
|
|
|
|
|
.time_ns_for_children = &init_time_ns,
|
|
|
|
|
#endif
|
2010-03-11 07:23:10 +08:00
|
|
|
};
|
2006-10-02 17:18:06 +08:00
|
|
|
|
2009-06-18 07:27:56 +08:00
|
|
|
static inline struct nsproxy *create_nsproxy(void)
|
2006-10-02 17:18:06 +08:00
|
|
|
{
|
2009-06-18 07:27:56 +08:00
|
|
|
struct nsproxy *nsproxy;
|
2006-10-02 17:18:06 +08:00
|
|
|
|
2009-06-18 07:27:56 +08:00
|
|
|
nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
|
|
|
|
|
if (nsproxy)
|
|
|
|
|
atomic_set(&nsproxy->count, 1);
|
|
|
|
|
return nsproxy;
|
2006-10-02 17:18:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
2007-05-08 15:25:21 +08:00
|
|
|
* Create new nsproxy and all of its the associated namespaces.
|
|
|
|
|
* Return the newly created nsproxy. Do not attach this to the task,
|
|
|
|
|
* leave it to the caller to do proper locking and attach it to task.
|
2006-10-02 17:18:06 +08:00
|
|
|
*/
|
2007-07-16 14:41:15 +08:00
|
|
|
static struct nsproxy *create_new_namespaces(unsigned long flags,
|
2012-07-26 19:02:49 +08:00
|
|
|
struct task_struct *tsk, struct user_namespace *user_ns,
|
|
|
|
|
struct fs_struct *new_fs)
|
2006-10-02 17:18:06 +08:00
|
|
|
{
|
2007-05-08 15:25:21 +08:00
|
|
|
struct nsproxy *new_nsp;
|
2007-07-16 14:41:06 +08:00
|
|
|
int err;
|
2006-10-02 17:18:06 +08:00
|
|
|
|
2009-06-18 07:27:56 +08:00
|
|
|
new_nsp = create_nsproxy();
|
2007-05-08 15:25:21 +08:00
|
|
|
if (!new_nsp)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
2006-10-02 17:18:08 +08:00
|
|
|
|
2012-07-26 19:02:49 +08:00
|
|
|
new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs);
|
2007-07-16 14:41:06 +08:00
|
|
|
if (IS_ERR(new_nsp->mnt_ns)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->mnt_ns);
|
2007-05-08 15:25:21 +08:00
|
|
|
goto out_ns;
|
2007-07-16 14:41:06 +08:00
|
|
|
}
|
2007-05-08 15:25:21 +08:00
|
|
|
|
2012-07-26 19:02:49 +08:00
|
|
|
new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns);
|
2007-07-16 14:41:06 +08:00
|
|
|
if (IS_ERR(new_nsp->uts_ns)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->uts_ns);
|
2007-05-08 15:25:21 +08:00
|
|
|
goto out_uts;
|
2007-07-16 14:41:06 +08:00
|
|
|
}
|
2007-05-08 15:25:21 +08:00
|
|
|
|
2012-07-26 19:02:49 +08:00
|
|
|
new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns);
|
2007-07-16 14:41:06 +08:00
|
|
|
if (IS_ERR(new_nsp->ipc_ns)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->ipc_ns);
|
2007-05-08 15:25:21 +08:00
|
|
|
goto out_ipc;
|
2007-07-16 14:41:06 +08:00
|
|
|
}
|
2007-05-08 15:25:21 +08:00
|
|
|
|
2013-08-23 02:39:16 +08:00
|
|
|
new_nsp->pid_ns_for_children =
|
|
|
|
|
copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
|
|
|
|
|
if (IS_ERR(new_nsp->pid_ns_for_children)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->pid_ns_for_children);
|
2007-05-08 15:25:21 +08:00
|
|
|
goto out_pid;
|
2007-07-16 14:41:06 +08:00
|
|
|
}
|
2007-05-08 15:25:21 +08:00
|
|
|
|
2016-01-29 16:54:06 +08:00
|
|
|
new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns,
|
|
|
|
|
tsk->nsproxy->cgroup_ns);
|
|
|
|
|
if (IS_ERR(new_nsp->cgroup_ns)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->cgroup_ns);
|
|
|
|
|
goto out_cgroup;
|
|
|
|
|
}
|
|
|
|
|
|
2012-07-26 19:02:49 +08:00
|
|
|
new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns);
|
2007-09-27 13:04:26 +08:00
|
|
|
if (IS_ERR(new_nsp->net_ns)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->net_ns);
|
|
|
|
|
goto out_net;
|
|
|
|
|
}
|
|
|
|
|
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
new_nsp->time_ns_for_children = copy_time_ns(flags, user_ns,
|
|
|
|
|
tsk->nsproxy->time_ns_for_children);
|
|
|
|
|
if (IS_ERR(new_nsp->time_ns_for_children)) {
|
|
|
|
|
err = PTR_ERR(new_nsp->time_ns_for_children);
|
|
|
|
|
goto out_time;
|
|
|
|
|
}
|
|
|
|
|
new_nsp->time_ns = get_time_ns(tsk->nsproxy->time_ns);
|
|
|
|
|
|
2007-05-08 15:25:21 +08:00
|
|
|
return new_nsp;
|
|
|
|
|
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
out_time:
|
|
|
|
|
put_net(new_nsp->net_ns);
|
2007-09-27 13:04:26 +08:00
|
|
|
out_net:
|
2016-01-29 16:54:06 +08:00
|
|
|
put_cgroup_ns(new_nsp->cgroup_ns);
|
|
|
|
|
out_cgroup:
|
2013-08-23 02:39:16 +08:00
|
|
|
if (new_nsp->pid_ns_for_children)
|
|
|
|
|
put_pid_ns(new_nsp->pid_ns_for_children);
|
2007-05-08 15:25:21 +08:00
|
|
|
out_pid:
|
|
|
|
|
if (new_nsp->ipc_ns)
|
|
|
|
|
put_ipc_ns(new_nsp->ipc_ns);
|
|
|
|
|
out_ipc:
|
|
|
|
|
if (new_nsp->uts_ns)
|
|
|
|
|
put_uts_ns(new_nsp->uts_ns);
|
|
|
|
|
out_uts:
|
|
|
|
|
if (new_nsp->mnt_ns)
|
|
|
|
|
put_mnt_ns(new_nsp->mnt_ns);
|
|
|
|
|
out_ns:
|
2007-07-16 14:41:07 +08:00
|
|
|
kmem_cache_free(nsproxy_cachep, new_nsp);
|
2007-07-16 14:41:06 +08:00
|
|
|
return ERR_PTR(err);
|
2006-10-02 17:18:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* called from clone. This now handles copy for nsproxy and all
|
|
|
|
|
* namespaces therein.
|
|
|
|
|
*/
|
2007-07-16 14:41:15 +08:00
|
|
|
int copy_namespaces(unsigned long flags, struct task_struct *tsk)
|
2006-10-02 17:18:06 +08:00
|
|
|
{
|
|
|
|
|
struct nsproxy *old_ns = tsk->nsproxy;
|
2012-07-26 15:50:47 +08:00
|
|
|
struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
|
2006-10-02 17:18:08 +08:00
|
|
|
struct nsproxy *new_ns;
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
int ret;
|
2006-10-02 17:18:06 +08:00
|
|
|
|
2013-03-10 08:15:23 +08:00
|
|
|
if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
|
2016-01-29 16:54:06 +08:00
|
|
|
CLONE_NEWPID | CLONE_NEWNET |
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
CLONE_NEWCGROUP | CLONE_NEWTIME)))) {
|
|
|
|
|
if (likely(old_ns->time_ns_for_children == old_ns->time_ns)) {
|
|
|
|
|
get_nsproxy(old_ns);
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
} else if (!ns_capable(user_ns, CAP_SYS_ADMIN))
|
2013-03-10 08:15:23 +08:00
|
|
|
return -EPERM;
|
|
|
|
|
|
2008-04-29 16:01:00 +08:00
|
|
|
/*
|
|
|
|
|
* CLONE_NEWIPC must detach from the undolist: after switching
|
|
|
|
|
* to a new ipc namespace, the semaphore arrays from the old
|
|
|
|
|
* namespace are unreachable. In clone parlance, CLONE_SYSVSEM
|
|
|
|
|
* means share undolist with parent, so we must forbid using
|
|
|
|
|
* it along with CLONE_NEWIPC.
|
|
|
|
|
*/
|
2013-02-28 02:32:09 +08:00
|
|
|
if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) ==
|
2013-03-10 08:15:23 +08:00
|
|
|
(CLONE_NEWIPC | CLONE_SYSVSEM))
|
|
|
|
|
return -EINVAL;
|
2008-04-29 16:01:00 +08:00
|
|
|
|
2013-02-22 08:44:21 +08:00
|
|
|
new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
|
2013-03-10 08:15:23 +08:00
|
|
|
if (IS_ERR(new_ns))
|
|
|
|
|
return PTR_ERR(new_ns);
|
2006-12-08 18:37:59 +08:00
|
|
|
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
ret = timens_on_fork(new_ns, tsk);
|
|
|
|
|
if (ret) {
|
|
|
|
|
free_nsproxy(new_ns);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2007-05-08 15:25:21 +08:00
|
|
|
tsk->nsproxy = new_ns;
|
2013-03-10 08:15:23 +08:00
|
|
|
return 0;
|
2006-10-02 17:18:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void free_nsproxy(struct nsproxy *ns)
|
|
|
|
|
{
|
2006-12-08 18:37:59 +08:00
|
|
|
if (ns->mnt_ns)
|
|
|
|
|
put_mnt_ns(ns->mnt_ns);
|
|
|
|
|
if (ns->uts_ns)
|
|
|
|
|
put_uts_ns(ns->uts_ns);
|
|
|
|
|
if (ns->ipc_ns)
|
|
|
|
|
put_ipc_ns(ns->ipc_ns);
|
2013-08-23 02:39:16 +08:00
|
|
|
if (ns->pid_ns_for_children)
|
|
|
|
|
put_pid_ns(ns->pid_ns_for_children);
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
if (ns->time_ns)
|
|
|
|
|
put_time_ns(ns->time_ns);
|
|
|
|
|
if (ns->time_ns_for_children)
|
|
|
|
|
put_time_ns(ns->time_ns_for_children);
|
2016-01-29 16:54:06 +08:00
|
|
|
put_cgroup_ns(ns->cgroup_ns);
|
2007-09-27 13:04:26 +08:00
|
|
|
put_net(ns->net_ns);
|
2007-07-16 14:41:07 +08:00
|
|
|
kmem_cache_free(nsproxy_cachep, ns);
|
2006-10-02 17:18:06 +08:00
|
|
|
}
|
2007-05-08 15:25:21 +08:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Called from unshare. Unshare all the namespaces part of nsproxy.
|
2007-06-24 08:16:25 +08:00
|
|
|
* On success, returns the new nsproxy.
|
2007-05-08 15:25:21 +08:00
|
|
|
*/
|
|
|
|
|
int unshare_nsproxy_namespaces(unsigned long unshare_flags,
|
2012-07-26 20:15:35 +08:00
|
|
|
struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs)
|
2007-05-08 15:25:21 +08:00
|
|
|
{
|
2012-07-26 19:02:49 +08:00
|
|
|
struct user_namespace *user_ns;
|
2007-05-08 15:25:21 +08:00
|
|
|
int err = 0;
|
|
|
|
|
|
2007-07-16 14:41:01 +08:00
|
|
|
if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
|
ns: Introduce Time Namespace
Time Namespace isolates clock values.
The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.
CLOCK_REALTIME
System-wide clock that measures real (i.e., wall-clock) time.
CLOCK_MONOTONIC
Clock that cannot be set and represents monotonic time since
some unspecified starting point.
CLOCK_BOOTTIME
Identical to CLOCK_MONOTONIC, except it also includes any time
that the system is suspended.
For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.
But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.
A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.
This scheme allows setting clock offsets for a namespace, before any
processes appear in it.
All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.
[ tglx: Adjusted paragraph about clone3() to reality and massaged the
changelog a bit. ]
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2019-11-12 09:26:52 +08:00
|
|
|
CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP |
|
|
|
|
|
CLONE_NEWTIME)))
|
2007-05-08 15:25:21 +08:00
|
|
|
return 0;
|
|
|
|
|
|
2012-07-26 20:15:35 +08:00
|
|
|
user_ns = new_cred ? new_cred->user_ns : current_user_ns();
|
|
|
|
|
if (!ns_capable(user_ns, CAP_SYS_ADMIN))
|
2007-05-08 15:25:21 +08:00
|
|
|
return -EPERM;
|
|
|
|
|
|
2012-07-26 19:02:49 +08:00
|
|
|
*new_nsp = create_new_namespaces(unshare_flags, current, user_ns,
|
2012-07-26 20:15:35 +08:00
|
|
|
new_fs ? new_fs : current->fs);
|
2007-10-19 14:39:45 +08:00
|
|
|
if (IS_ERR(*new_nsp)) {
|
2007-05-08 15:25:21 +08:00
|
|
|
err = PTR_ERR(*new_nsp);
|
2007-10-19 14:39:45 +08:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
out:
|
2007-05-08 15:25:21 +08:00
|
|
|
return err;
|
|
|
|
|
}
|
2007-07-16 14:41:07 +08:00
|
|
|
|
2007-10-19 14:39:54 +08:00
|
|
|
void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
|
|
|
|
|
{
|
|
|
|
|
struct nsproxy *ns;
|
|
|
|
|
|
|
|
|
|
might_sleep();
|
|
|
|
|
|
2014-02-04 11:13:49 +08:00
|
|
|
task_lock(p);
|
2007-10-19 14:39:54 +08:00
|
|
|
ns = p->nsproxy;
|
2014-02-04 11:13:49 +08:00
|
|
|
p->nsproxy = new;
|
|
|
|
|
task_unlock(p);
|
2007-10-19 14:39:54 +08:00
|
|
|
|
2014-02-04 11:13:49 +08:00
|
|
|
if (ns && atomic_dec_and_test(&ns->count))
|
2007-10-19 14:39:54 +08:00
|
|
|
free_nsproxy(ns);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void exit_task_namespaces(struct task_struct *p)
|
|
|
|
|
{
|
|
|
|
|
switch_task_namespaces(p, NULL);
|
|
|
|
|
}
|
|
|
|
|
|
2010-03-08 09:48:52 +08:00
|
|
|
SYSCALL_DEFINE2(setns, int, fd, int, nstype)
|
|
|
|
|
{
|
|
|
|
|
struct task_struct *tsk = current;
|
|
|
|
|
struct nsproxy *new_nsproxy;
|
|
|
|
|
struct file *file;
|
2014-11-01 14:32:53 +08:00
|
|
|
struct ns_common *ns;
|
2010-03-08 09:48:52 +08:00
|
|
|
int err;
|
|
|
|
|
|
|
|
|
|
file = proc_ns_fget(fd);
|
|
|
|
|
if (IS_ERR(file))
|
|
|
|
|
return PTR_ERR(file);
|
|
|
|
|
|
|
|
|
|
err = -EINVAL;
|
2014-11-01 15:13:17 +08:00
|
|
|
ns = get_proc_ns(file_inode(file));
|
2014-11-01 14:32:53 +08:00
|
|
|
if (nstype && (ns->ops->type != nstype))
|
2010-03-08 09:48:52 +08:00
|
|
|
goto out;
|
|
|
|
|
|
2012-07-26 19:02:49 +08:00
|
|
|
new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
|
2010-03-08 09:48:52 +08:00
|
|
|
if (IS_ERR(new_nsproxy)) {
|
|
|
|
|
err = PTR_ERR(new_nsproxy);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2014-11-01 14:32:53 +08:00
|
|
|
err = ns->ops->install(new_nsproxy, ns);
|
2010-03-08 09:48:52 +08:00
|
|
|
if (err) {
|
|
|
|
|
free_nsproxy(new_nsproxy);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
switch_task_namespaces(tsk, new_nsproxy);
|
2017-03-08 04:41:36 +08:00
|
|
|
|
|
|
|
|
perf_event_namespaces(tsk);
|
2010-03-08 09:48:52 +08:00
|
|
|
out:
|
|
|
|
|
fput(file);
|
|
|
|
|
return err;
|
|
|
|
|
}
|
|
|
|
|
|
2011-06-29 03:41:10 +08:00
|
|
|
int __init nsproxy_cache_init(void)
|
2007-07-16 14:41:07 +08:00
|
|
|
{
|
2007-10-17 14:30:11 +08:00
|
|
|
nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
|
2007-07-16 14:41:07 +08:00
|
|
|
return 0;
|
|
|
|
|
}
|