Commit graph

30 commits

Author SHA1 Message Date
Christian Brauner
f2a8d52e0a
nsproxy: add struct nsset
Add a simple struct nsset. It holds all necessary pieces to switch to a new
set of namespaces without leaving a task in a half-switched state which we
will make use of in the next patch. This patch switches the existing setns
logic over without causing a change in setns() behavior. This brings
setns() closer to how unshare() works(). The prepare_ns() function is
responsible to prepare all necessary information. This has two reasons.
First it minimizes dependencies between individual namespaces, i.e. all
install handler can expect that all fields are properly initialized
independent in what order they are called in. Second, this makes the code
easier to maintain and easier to follow if it needs to be changed.

The prepare_ns() helper will only be switched over to use a flags argument
in the next patch. Here it will still use nstype as a simple integer
argument which was argued would be clearer. I'm not particularly
opinionated about this if it really helps or not. The struct nsset itself
already contains the flags field since its name already indicates that it
can contain information required by different namespaces. None of this
should have functional consequences.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Jann Horn <jannh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20200505140432.181565-2-christian.brauner@ubuntu.com
2020-05-09 13:57:12 +02:00
Andrei Vagin
769071ac9f 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
2020-01-14 12:20:48 +01:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Aditya Kali
a79a908fd2 cgroup: introduce cgroup namespaces
Introduce the ability to create new cgroup namespace. The newly created
cgroup namespace remembers the cgroup of the process at the point
of creation of the cgroup namespace (referred as cgroupns-root).
The main purpose of cgroup namespace is to virtualize the contents
of /proc/self/cgroup file. Processes inside a cgroup namespace
are only able to see paths relative to their namespace root
(unless they are moved outside of their cgroupns-root, at which point
 they will see a relative path from their cgroupns-root).
For a correctly setup container this enables container-tools
(like libcontainer, lxc, lmctfy, etc.) to create completely virtualized
containers without leaking system level cgroup hierarchy to the task.
This patch only implements the 'unshare' part of the cgroupns.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-16 13:04:58 -05:00
Eric W. Biederman
728dba3a39 namespaces: Use task_lock and not rcu to protect nsproxy
The synchronous syncrhonize_rcu in switch_task_namespaces makes setns
a sufficiently expensive system call that people have complained.

Upon inspect nsproxy no longer needs rcu protection for remote reads.
remote reads are rare.  So optimize for same process reads and write
by switching using rask_lock instead.

This yields a simpler to understand lock, and a faster setns system call.

In particular this fixes a performance regression observed
by Rafael David Tinoco <rafael.tinoco@canonical.com>.

This is effectively a revert of Pavel Emelyanov's commit
cf7b708c8d Make access to task's nsproxy lighter
from 2007.  The race this originialy fixed no longer exists as
do_notify_parent uses task_active_pid_ns(parent) instead of
parent->nsproxy.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-07-29 18:08:50 -07:00
Andy Lutomirski
c2b1df2eb4 Rename nsproxy.pid_ns to nsproxy.pid_ns_for_children
nsproxy.pid_ns is *not* the task's pid namespace.  The name should clarify
that.

This makes it more obvious that setns on a pid namespace is weird --
it won't change the pid namespace shown in procfs.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-27 13:52:52 -04:00
Eric W. Biederman
b2e0d98705 userns: Implement unshare of the user namespace
- Add CLONE_THREAD to the unshare flags if CLONE_NEWUSER is selected
  As changing user namespaces is only valid if all there is only
  a single thread.
- Restore the code to add CLONE_VM if CLONE_THREAD is selected and
  the code to addCLONE_SIGHAND if CLONE_VM is selected.
  Making the constraints in the code clear.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-11-20 04:18:14 -08:00
Al Viro
6657719390 make sure that nsproxy_cache is initialized early enough
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:07 -04:00
Daniel Lezcano
a77aea9201 cgroup: remove the ns_cgroup
The ns_cgroup is an annoying cgroup at the namespace / cgroup frontier and
leads to some problems:

  * cgroup creation is out-of-control
  * cgroup name can conflict when pids are looping
  * it is not possible to have a single process handling a lot of
    namespaces without falling in a exponential creation time
  * we may want to create a namespace without creating a cgroup

  The ns_cgroup was replaced by a compatibility flag 'clone_children',
  where a newly created cgroup will copy the parent cgroup values.
  The userspace has to manually create a cgroup and add a task to
  the 'tasks' file.

This patch removes the ns_cgroup as suggested in the following thread:

https://lists.linux-foundation.org/pipermail/containers/2009-June/018616.html

The 'cgroup_clone' function is removed because it is no longer used.

This is a userspace-visible change.  Commit 45531757b4 ("cgroup: notify
ns_cgroup deprecated") (merged into 2.6.27) caused the kernel to emit a
printk warning users that the feature is planned for removal.  Since that
time we have heard from XXX users who were affected by this.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:34 -07:00
Al Viro
5ad4e53bd5 Get rid of indirect include of fs_struct.h
Don't pull it in sched.h; very few files actually need it and those
can include directly.  sched.h itself only needs forward declaration
of struct fs_struct;

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:27 -04:00
Serge Hallyn
18b6e0414e User namespaces: set of cleanups (v2)
The user_ns is moved from nsproxy to user_struct, so that a struct
cred by itself is sufficient to determine access (which it otherwise
would not be).  Corresponding ecryptfs fixes (by David Howells) are
here as well.

Fix refcounting.  The following rules now apply:
        1. The task pins the user struct.
        2. The user struct pins its user namespace.
        3. The user namespace pins the struct user which created it.

User namespaces are cloned during copy_creds().  Unsharing a new user_ns
is no longer possible.  (We could re-add that, but it'll cause code
duplication and doesn't seem useful if PAM doesn't need to clone user
namespaces).

When a user namespace is created, its first user (uid 0) gets empty
keyrings and a clean group_info.

This incorporates a previous patch by David Howells.  Here
is his original patch description:

>I suggest adding the attached incremental patch.  It makes the following
>changes:
>
> (1) Provides a current_user_ns() macro to wrap accesses to current's user
>     namespace.
>
> (2) Fixes eCryptFS.
>
> (3) Renames create_new_userns() to create_user_ns() to be more consistent
>     with the other associated functions and because the 'new' in the name is
>     superfluous.
>
> (4) Moves the argument and permission checks made for CLONE_NEWUSER to the
>     beginning of do_fork() so that they're done prior to making any attempts
>     at allocation.
>
> (5) Calls create_user_ns() after prepare_creds(), and gives it the new creds
>     to fill in rather than have it return the new root user.  I don't imagine
>     the new root user being used for anything other than filling in a cred
>     struct.
>
>     This also permits me to get rid of a get_uid() and a free_uid(), as the
>     reference the creds were holding on the old user_struct can just be
>     transferred to the new namespace's creator pointer.
>
> (6) Makes create_user_ns() reset the UIDs and GIDs of the creds under
>     preparation rather than doing it in copy_creds().
>
>David

>Signed-off-by: David Howells <dhowells@redhat.com>

Changelog:
	Oct 20: integrate dhowells comments
		1. leave thread_keyring alone
		2. use current_user_ns() in set_user()

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
2008-11-24 18:57:41 -05:00
Serge E. Hallyn
e885dcde75 cgroup_clone: use pid of newly created task for new cgroup
cgroup_clone creates a new cgroup with the pid of the task.  This works
correctly for unshare, but for clone cgroup_clone is called from
copy_namespaces inside copy_process, which happens before the new pid is
created.  As a result, the new cgroup was created with current's pid.
This patch:

	1. Moves the call inside copy_process to after the new pid
	   is created
	2. Passes the struct pid into ns_cgroup_clone (as it is not
	   yet attached to the task)
	3. Passes a name from ns_cgroup_clone() into cgroup_clone()
	   so as to keep cgroup_clone() itself simpler
	4. Uses pid_vnr() to get the process id value, so that the
	   pid used to name the new cgroup is always the pid as it
	   would be known to the task which did the cloning or
	   unsharing.  I think that is the most intuitive thing to
	   do.  This way, task t1 does clone(CLONE_NEWPID) to get
	   t2, which does clone(CLONE_NEWPID) to get t3, then the
	   cgroup for t3 will be named for the pid by which t2 knows
	   t3.

(Thanks to Dan Smith for finding the main bug)

Changelog:
	June 11: Incorporate Paul Menage's feedback:  don't pass
	         NULL to ns_cgroup_clone from unshare, and reduce
		 patch size by using 'nodename' in cgroup_clone.
	June 10: Original version

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge Hallyn <serge@us.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Tested-by: Dan Smith <danms@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:37 -07:00
Pavel Emelyanov
cf7b708c8d Make access to task's nsproxy lighter
When someone wants to deal with some other taks's namespaces it has to lock
the task and then to get the desired namespace if the one exists.  This is
slow on read-only paths and may be impossible in some cases.

E.g.  Oleg recently noticed a race between unshare() and the (sent for
review in cgroups) pid namespaces - when the task notifies the parent it
has to know the parent's namespace, but taking the task_lock() is
impossible there - the code is under write locked tasklist lock.

On the other hand switching the namespace on task (daemonize) and releasing
the namespace (after the last task exit) is rather rare operation and we
can sacrifice its speed to solve the issues above.

The access to other task namespaces is proposed to be performed
like this:

     rcu_read_lock();
     nsproxy = task_nsproxy(tsk);
     if (nsproxy != NULL) {
             / *
               * work with the namespaces here
               * e.g. get the reference on one of them
               * /
     } / *
         * NULL task_nsproxy() means that this task is
         * almost dead (zombie)
         * /
     rcu_read_unlock();

This patch has passed the review by Eric and Oleg :) and,
of course, tested.

[clg@fr.ibm.com: fix unshare()]
[ebiederm@xmission.com: Update get_net_ns_by_pid]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:37 -07:00
Serge E. Hallyn
858d72ead4 cgroups: implement namespace tracking subsystem
When a task enters a new namespace via a clone() or unshare(), a new cgroup
is created and the task moves into it.

This version names cgroups which are automatically created using
cgroup_clone() as "node_<pid>" where pid is the pid of the unsharing or
cloned process.  (Thanks Pavel for the idea) This is safe because if the
process unshares again, it will create

	/cgroups/(...)/node_<pid>/node_<pid>

The only possibilities (AFAICT) for a -EEXIST on unshare are

	1. pid wraparound
	2. a process fails an unshare, then tries again.

Case 1 is unlikely enough that I ignore it (at least for now).  In case 2, the
node_<pid> will be empty and can be rmdir'ed to make the subsequent unshare()
succeed.

Changelog:
	Name cloned cgroups as "node_<pid>".

[clg@fr.ibm.com: fix order of cgroup subsystems in init/Kconfig]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:37 -07:00
Pavel Emelyanov
1efd24fa05 Remove unused member from nsproxy
The nslock spinlock is not used in the kernel at all.  Remove it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:59 -07:00
Eric W. Biederman
772698f636 [NET]: Add a network namespace parameter to tasks
This is the network namespace from which all which all sockets
and anything else under user control ultimately get their network
namespace parameters.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:04 -07:00
Eric W. Biederman
213dd266d4 namespace: ensure clone_flags are always stored in an unsigned long
While working on unshare support for the network namespace I noticed we
were putting clone flags in an int.  Which is weird because the syscall
uses unsigned long and we at least need an unsigned to properly hold all of
the unshare flags.

So to make the code consistent, this patch updates the code to use
unsigned long instead of int for the clone flags in those places
where we get it wrong today.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:48 -07:00
Cedric Le Goater
acce292c82 user namespace: add the framework
Basically, it will allow a process to unshare its user_struct table,
resetting at the same time its own user_struct and all the associated
accounting.

A new root user (uid == 0) is added to the user namespace upon creation.
Such root users have full privileges and it seems that theses privileges
should be controlled through some means (process capabilities ?)

The unshare is not included in this patch.

Changes since [try #4]:
	- Updated get_user_ns and put_user_ns to accept NULL, and
	  get_user_ns to return the namespace.

Changes since [try #3]:
	- moved struct user_namespace to files user_namespace.{c,h}

Changes since [try #2]:
	- removed struct user_namespace* argument from find_user()

Changes since [try #1]:
	- removed struct user_namespace* argument from find_user()
	- added a root_user per user namespace

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:47 -07:00
Badari Pulavarty
e3222c4ecc Merge sys_clone()/sys_unshare() nsproxy and namespace handling
sys_clone() and sys_unshare() both makes copies of nsproxy and its associated
namespaces.  But they have different code paths.

This patch merges all the nsproxy and its associated namespace copy/clone
handling (as much as possible).  Posted on container list earlier for
feedback.

- Create a new nsproxy and its associated namespaces and pass it back to
  caller to attach it to right process.

- Changed all copy_*_ns() routines to return a new copy of namespace
  instead of attaching it to task->nsproxy.

- Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines.

- Removed unnessary !ns checks from copy_*_ns() and added BUG_ON()
  just incase.

- Get rid of all individual unshare_*_ns() routines and make use of
  copy_*_ns() instead.

[akpm@osdl.org: cleanups, warning fix]
[clg@fr.ibm.com: remove dup_namespaces() declaration]
[serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval]
[akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n]
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <containers@lists.osdl.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:00 -07:00
Linus Torvalds
444f378b23 Revert "[PATCH] namespaces: fix exit race by splitting exit"
This reverts commit 7a238fcba0 in
preparation for a better and simpler fix proposed by Eric Biederman
(and fixed up by Serge Hallyn)

Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-30 13:35:18 -08:00
Serge E. Hallyn
7a238fcba0 [PATCH] namespaces: fix exit race by splitting exit
Fix exit race by splitting the nsproxy putting into two pieces.  First
piece reduces the nsproxy refcount.  If we dropped the last reference, then
it puts the mnt_ns, and returns the nsproxy as a hint to the caller.  Else
it returns NULL.  The second piece of exiting task namespaces sets
tsk->nsproxy to NULL, and drops the references to other namespaces and
frees the nsproxy only if an nsproxy was passed in.

A little awkward and should probably be reworked, but hopefully it fixes
the NFS oops.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Daniel Hokka Zakrisson <daniel@hozac.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-30 08:26:44 -08:00
Eric W. Biederman
5f8442edfb [PATCH] Revert "[PATCH] identifier to nsproxy"
This reverts commit 373beb35cd.

No one is using this identifier yet.  The purpose of this identifier is to
export nsproxy to user space which is wrong.  nsproxy is an internal
implementation optimization, which should keep our fork times from getting
slower as we increase the number of global namespaces you don't have to
share.

Adding a global identifier like this is inappropriate because it makes
namespaces inherently non-recursive, greatly limiting what we can do with
them in the future.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13 09:05:47 -08:00
Cedric Le Goater
9a575a92db [PATCH] to nsproxy
Add the pid namespace framework to the nsproxy object.  The copy of the pid
namespace only increases the refcount on the global pid namespace,
init_pid_ns, and unshare is not implemented.

There is no configuration option to activate or deactivate this feature
because this not relevant for the moment.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:52 -08:00
Cedric Le Goater
373beb35cd [PATCH] identifier to nsproxy
Add an identifier to nsproxy.  The default init_ns_proxy has identifier 0 and
allocated nsproxies are given -1.

This identifier will be used by a new syscall sys_bind_ns.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:52 -08:00
Kirill Korotaev
6b3286ed11 [PATCH] rename struct namespace to struct mnt_namespace
Rename 'struct namespace' to 'struct mnt_namespace' to avoid confusion with
other namespaces being developped for the containers : pid, uts, ipc, etc.
'namespace' variables and attributes are also renamed to 'mnt_ns'

Signed-off-by: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:51 -08:00
Vasily Tarasov
701e054e0c [PATCH] mounstats NULL pointer dereference
OpenVZ developers team has encountered the following problem in 2.6.19-rc6
kernel. After some seconds of running script

while [[ 1 ]]
do
	find  /proc -name mountstats | xargs cat
done

this Oops appears:

BUG: unable to handle kernel NULL pointer dereference at virtual address
00000010
 printing eip:
c01a6b70
*pde = 00000000
Oops: 0000 [#1]
SMP
Modules linked in: xt_length ipt_ttl xt_tcpmss ipt_TCPMSS iptable_mangle
iptable_filter xt_multiport xt_limit ipt_tos ipt_REJECT ip_tables x_tables
parport_pc lp parport sunrpc af_packet thermal processor fan button battery
asus_acpi ac ohci_hcd ehci_hcd usbcore i2c_nforce2 i2c_core tg3 floppy
pata_amd
ide_cd cdrom sata_nv libata
CPU:    1
EIP:    0060:[<c01a6b70>]    Not tainted VLI
EFLAGS: 00010246   (2.6.19-rc6 #2)
EIP is at mountstats_open+0x70/0xf0
eax: 00000000   ebx: e6247030   ecx: e62470f8   edx: 00000000
esi: 00000000   edi: c01a6b00   ebp: c33b83c0   esp: f4105eb4
ds: 007b   es: 007b   ss: 0068
Process cat (pid: 6044, ti=f4105000 task=f4104a70 task.ti=f4105000)
Stack: c33b83c0 c04ee940 f46a4a80 c33b83c0 e4df31b4 c01a6b00 f4105000 c0169231
       e4df31b4 c33b83c0 c33b83c0 f4105f20 00000003 f4105000 c0169445 f2503cf0
       f7f8c4c0 00008000 c33b83c0 00000000 00008000 c0169350 f4105f20 00008000
Call Trace:
 [<c01a6b00>] mountstats_open+0x0/0xf0
 [<c0169231>] __dentry_open+0x181/0x250
 [<c0169445>] nameidata_to_filp+0x35/0x50
 [<c0169350>] do_filp_open+0x50/0x60
 [<c01873d6>] seq_read+0xc6/0x300
 [<c0169511>] get_unused_fd+0x31/0xc0
 [<c01696d3>] do_sys_open+0x63/0x110
 [<c01697a7>] sys_open+0x27/0x30
 [<c01030bd>] sysenter_past_esp+0x56/0x79
 =======================
Code: 45 74 8b 54 24 20 89 44 24 08 8b 42 f0 31 d2 e8 47 cb f8 ff 85 c0 89 c3
74 51 8d 80 a0 04 00 00 e8 46 06 2c 00 8b 83 48 04 00 00 <8b> 78 10 85 ff 74
03
f0 ff 07 b0 01 86 83 a0 04 00 00 f0 ff 4b
EIP: [<c01a6b70>] mountstats_open+0x70/0xf0 SS:ESP 0068:f4105eb4

The problem is that task->nsproxy can be equal NULL for some time during
task exit. This patch fixes the BUG.

Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-25 13:28:33 -08:00
Kirill Korotaev
25b21cb2f6 [PATCH] IPC namespace core
This patch set allows to unshare IPCs and have a private set of IPC objects
(sem, shm, msg) inside namespace.  Basically, it is another building block of
containers functionality.

This patch implements core IPC namespace changes:
- ipc_namespace structure
- new config option CONFIG_IPC_NS
- adds CLONE_NEWIPC flag
- unshare support

[clg@fr.ibm.com: small fix for unshare of ipc namespace]
[akpm@osdl.org: build fix]
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:22 -07:00
Serge E. Hallyn
4865ecf131 [PATCH] namespaces: utsname: implement utsname namespaces
This patch defines the uts namespace and some manipulators.
Adds the uts namespace to task_struct, and initializes a
system-wide init namespace.

It leaves a #define for system_utsname so sysctl will compile.
This define will be removed in a separate patch.

[akpm@osdl.org: build fix, cleanup]
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:21 -07:00
Serge E. Hallyn
1651e14e28 [PATCH] namespaces: incorporate fs namespace into nsproxy
This moves the mount namespace into the nsproxy.  The mount namespace count
now refers to the number of nsproxies point to it, rather than the number of
tasks.  As a result, the unshare_namespace() function in kernel/fork.c no
longer checks whether it is being shared.

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:20 -07:00
Serge E. Hallyn
ab516013ad [PATCH] namespaces: add nsproxy
This patch adds a nsproxy structure to the task struct.  Later patches will
move the fs namespace pointer into this structure, and introduce a new utsname
namespace into the nsproxy.

The vserver and openvz functionality, then, would be implemented in large part
by virtualizing/isolating more and more resources into namespaces, each
contained in the nsproxy.

[akpm@osdl.org: build fix]
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:20 -07:00