Commit 57d5f66b authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Linus Torvalds
Browse files

pidns: Place under CONFIG_EXPERIMENTAL 



This is my trivial patch to swat innumerable little bugs with a single
blow.

After some intensive review (my apologies for not having gotten to this
sooner) what we have looks like a good base to build on with the current
pid namespace code but it is not complete, and it is still much to simple
to find issues where the kernel does the wrong thing outside of the initial
pid namespace.

Until the dust settles and we are certain we have the ABI and the
implementation is as correct as humanly possible let's keep process ID
namespaces behind CONFIG_EXPERIMENTAL.

Allowing us the option of fixing any ABI or other bugs we find as long as
they are minor.

Allowing users of the kernel to avoid those bugs simply by ensuring their
kernel does not have support for multiple pid namespaces.

[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kir Kolyshkin <kir@swsoft.com>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 42614fcd

include/linux/pid_namespace.h

+23 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ struct pid_namespace { 


extern struct pid_namespace init_pid_ns;



#ifdef CONFIG_PID_NS

static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)

{

	if (ns != &init_pid_ns)
@@ -45,6 +46,28 @@ static inline void put_pid_ns(struct pid_namespace *ns) 
		kref_put(&ns->kref, free_pid_ns);

}



#else /* !CONFIG_PID_NS */

#include <linux/err.h>



static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)

{

	return ns;

}



static inline struct pid_namespace *

copy_pid_ns(unsigned long flags, struct pid_namespace *ns)

{

	if (flags & CLONE_NEWPID)

		ns = ERR_PTR(-EINVAL);

	return ns;

}



static inline void put_pid_ns(struct pid_namespace *ns)

{

}



#endif /* CONFIG_PID_NS */



static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)

{

	return tsk->nsproxy->pid_ns;

init/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -215,6 +215,18 @@ config USER_NS 
	  vservers, to use user namespaces to provide different

	  user info for different servers.  If unsure, say N.



config PID_NS

	bool "PID Namespaces (EXPERIMENTAL)"

	default n

	depends on EXPERIMENTAL

	help

	  Suport process id namespaces.  This allows having multiple

	  process with the same pid as long as they are in different

	  pid namespaces.  This is a building block of containers.



	  Unless you want to work with an experimental feature

	  say N here.



config AUDIT

	bool "Auditing support"

	depends on NET

kernel/pid.c

+2 −0
Original line number Diff line number Diff line
@@ -537,6 +537,7 @@ err_alloc: 
	return NULL;

}



#ifdef CONFIG_PID_NS

static struct pid_namespace *create_pid_namespace(int level)

{

	struct pid_namespace *ns;
@@ -621,6 +622,7 @@ void free_pid_ns(struct kref *kref) 
	if (parent != NULL)

		put_pid_ns(parent);

}

#endif /* CONFIG_PID_NS */



void zap_pid_ns_processes(struct pid_namespace *pid_ns)

{

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