57d5f66b86
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: Eric 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
83 lines
1.7 KiB
C
83 lines
1.7 KiB
C
#ifndef _LINUX_PID_NS_H
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#define _LINUX_PID_NS_H
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/threads.h>
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#include <linux/nsproxy.h>
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#include <linux/kref.h>
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struct pidmap {
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atomic_t nr_free;
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void *page;
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};
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#define PIDMAP_ENTRIES ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
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struct pid_namespace {
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struct kref kref;
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struct pidmap pidmap[PIDMAP_ENTRIES];
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int last_pid;
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struct task_struct *child_reaper;
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struct kmem_cache *pid_cachep;
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int level;
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struct pid_namespace *parent;
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#ifdef CONFIG_PROC_FS
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struct vfsmount *proc_mnt;
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#endif
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};
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extern struct pid_namespace init_pid_ns;
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#ifdef CONFIG_PID_NS
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static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
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{
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if (ns != &init_pid_ns)
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kref_get(&ns->kref);
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return ns;
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}
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extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
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extern void free_pid_ns(struct kref *kref);
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static inline void put_pid_ns(struct pid_namespace *ns)
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{
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if (ns != &init_pid_ns)
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kref_put(&ns->kref, free_pid_ns);
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}
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#else /* !CONFIG_PID_NS */
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#include <linux/err.h>
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static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
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{
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return ns;
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}
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static inline struct pid_namespace *
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copy_pid_ns(unsigned long flags, struct pid_namespace *ns)
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{
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if (flags & CLONE_NEWPID)
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ns = ERR_PTR(-EINVAL);
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return ns;
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}
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static inline void put_pid_ns(struct pid_namespace *ns)
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{
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}
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#endif /* CONFIG_PID_NS */
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static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
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{
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return tsk->nsproxy->pid_ns;
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}
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static inline struct task_struct *task_child_reaper(struct task_struct *tsk)
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{
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BUG_ON(tsk != current);
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return tsk->nsproxy->pid_ns->child_reaper;
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}
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#endif /* _LINUX_PID_NS_H */
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