Commit 25b21cb2 authored by Kirill Korotaev's avatar Kirill Korotaev Committed by Linus Torvalds
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[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: default avatarPavel Emelianov <xemul@openvz.org>
Signed-off-by: default avatarKirill Korotaev <dev@openvz.org>
Signed-off-by: default avatarCedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c0b2fc31
......@@ -74,6 +74,7 @@ extern struct nsproxy init_nsproxy;
.count = ATOMIC_INIT(1), \
.nslock = SPIN_LOCK_UNLOCKED, \
.uts_ns = &init_uts_ns, \
.ipc_ns = &init_ipc_ns, \
.namespace = NULL, \
}
......
......@@ -2,6 +2,7 @@
#define _LINUX_IPC_H
#include <linux/types.h>
#include <linux/kref.h>
#define IPC_PRIVATE ((__kernel_key_t) 0)
......@@ -68,6 +69,41 @@ struct kern_ipc_perm
void *security;
};
struct ipc_ids;
struct ipc_namespace {
struct kref kref;
struct ipc_ids *ids[3];
int sem_ctls[4];
int used_sems;
int msg_ctlmax;
int msg_ctlmnb;
int msg_ctlmni;
size_t shm_ctlmax;
size_t shm_ctlall;
int shm_ctlmni;
int shm_tot;
};
extern struct ipc_namespace init_ipc_ns;
extern void free_ipc_ns(struct kref *kref);
extern int copy_ipcs(unsigned long flags, struct task_struct *tsk);
extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns);
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
if (ns)
kref_get(&ns->kref);
return ns;
}
static inline void put_ipc_ns(struct ipc_namespace *ns)
{
kref_put(&ns->kref, free_ipc_ns);
}
#endif /* __KERNEL__ */
#endif /* _LINUX_IPC_H */
......
......@@ -6,6 +6,7 @@
struct namespace;
struct uts_namespace;
struct ipc_namespace;
/*
* A structure to contain pointers to all per-process
......@@ -23,6 +24,7 @@ struct nsproxy {
atomic_t count;
spinlock_t nslock;
struct uts_namespace *uts_ns;
struct ipc_namespace *ipc_ns;
struct namespace *namespace;
};
extern struct nsproxy init_nsproxy;
......
......@@ -25,6 +25,7 @@
#define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
#define CLONE_STOPPED 0x02000000 /* Start in stopped state */
#define CLONE_NEWUTS 0x04000000 /* New utsname group? */
#define CLONE_NEWIPC 0x08000000 /* New ipcs */
/*
* Scheduling policies
......
......@@ -115,6 +115,15 @@ config SYSVIPC
section 6.4 of the Linux Programmer's Guide, available from
<http://www.tldp.org/guides.html>.
config IPC_NS
bool "IPC Namespaces"
depends on SYSVIPC
default n
help
Support ipc namespaces. This allows containers, i.e. virtual
environments, to use ipc namespaces to provide different ipc
objects for different servers. If unsure, say N.
config POSIX_MQUEUE
bool "POSIX Message Queues"
depends on NET && EXPERIMENTAL
......
......@@ -1608,13 +1608,15 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
struct sem_undo_list *new_ulist = NULL;
struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL;
struct uts_namespace *uts, *new_uts = NULL;
struct ipc_namespace *ipc, *new_ipc = NULL;
check_unshare_flags(&unshare_flags);
/* Return -EINVAL for all unsupported flags */
err = -EINVAL;
if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|CLONE_NEWUTS))
CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
CLONE_NEWUTS|CLONE_NEWIPC))
goto bad_unshare_out;
if ((err = unshare_thread(unshare_flags)))
......@@ -1633,18 +1635,20 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
goto bad_unshare_cleanup_fd;
if ((err = unshare_utsname(unshare_flags, &new_uts)))
goto bad_unshare_cleanup_semundo;
if ((err = unshare_ipcs(unshare_flags, &new_ipc)))
goto bad_unshare_cleanup_uts;
if (new_ns || new_uts) {
if (new_ns || new_uts || new_ipc) {
old_nsproxy = current->nsproxy;
new_nsproxy = dup_namespaces(old_nsproxy);
if (!new_nsproxy) {
err = -ENOMEM;
goto bad_unshare_cleanup_uts;
goto bad_unshare_cleanup_ipc;
}
}
if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist ||
new_uts) {
new_uts || new_ipc) {
task_lock(current);
......@@ -1692,12 +1696,22 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
new_uts = uts;
}
if (new_ipc) {
ipc = current->nsproxy->ipc_ns;
current->nsproxy->ipc_ns = new_ipc;
new_ipc = ipc;
}
task_unlock(current);
}
if (new_nsproxy)
put_nsproxy(new_nsproxy);
bad_unshare_cleanup_ipc:
if (new_ipc)
put_ipc_ns(new_ipc);
bad_unshare_cleanup_uts:
if (new_uts)
put_uts_ns(new_uts);
......
......@@ -7,6 +7,10 @@
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
* Jun 2006 - namespaces support
* OpenVZ, SWsoft Inc.
* Pavel Emelianov <xemul@openvz.org>
*/
#include <linux/module.h>
......@@ -62,6 +66,8 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig)
get_namespace(ns->namespace);
if (ns->uts_ns)
get_uts_ns(ns->uts_ns);
if (ns->ipc_ns)
get_ipc_ns(ns->ipc_ns);
}
return ns;
......@@ -82,7 +88,7 @@ int copy_namespaces(int flags, struct task_struct *tsk)
get_nsproxy(old_ns);
if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS)))
if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
return 0;
new_ns = clone_namespaces(old_ns);
......@@ -94,24 +100,31 @@ int copy_namespaces(int flags, struct task_struct *tsk)
tsk->nsproxy = new_ns;
err = copy_namespace(flags, tsk);
if (err) {
tsk->nsproxy = old_ns;
put_nsproxy(new_ns);
goto out;
}
if (err)
goto out_ns;
err = copy_utsname(flags, tsk);
if (err) {
if (new_ns->namespace)
put_namespace(new_ns->namespace);
tsk->nsproxy = old_ns;
put_nsproxy(new_ns);
goto out;
}
if (err)
goto out_uts;
err = copy_ipcs(flags, tsk);
if (err)
goto out_ipc;
out:
put_nsproxy(old_ns);
return err;
out_ipc:
if (new_ns->uts_ns)
put_uts_ns(new_ns->uts_ns);
out_uts:
if (new_ns->namespace)
put_namespace(new_ns->namespace);
out_ns:
tsk->nsproxy = old_ns;
put_nsproxy(new_ns);
goto out;
}
void free_nsproxy(struct nsproxy *ns)
......@@ -120,5 +133,7 @@ void free_nsproxy(struct nsproxy *ns)
put_namespace(ns->namespace);
if (ns->uts_ns)
put_uts_ns(ns->uts_ns);
if (ns->ipc_ns)
put_ipc_ns(ns->ipc_ns);
kfree(ns);
}
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