OpenCloudOS-Kernel/include/linux/proc_ns.h

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/*
* procfs namespace bits
*/
#ifndef _LINUX_PROC_NS_H
#define _LINUX_PROC_NS_H
#include <linux/ns_common.h>
struct pid_namespace;
struct nsproxy;
struct path;
struct task_struct;
struct inode;
struct proc_ns_operations {
const char *name;
ns: allow ns_entries to have custom symlink content Patch series "Expose task pid_ns_for_children to userspace". pid_ns_for_children set by a task is known only to the task itself, and it's impossible to identify it from outside. It's a big problem for checkpoint/restore software like CRIU, because it can't correctly handle tasks, that do setns(CLONE_NEWPID) in proccess of their work. If they have a custom pid_ns_for_children before dump, they must have the same ns after restore. Otherwise, restored task bumped into enviroment it does not expect. This patchset solves the problem. It exposes pid_ns_for_children to ns directory in standard way with the name "pid_for_children": ~# ls /proc/5531/ns -l | grep pid lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid -> pid:[4026531836] lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid_for_children -> pid:[4026532286] This patch (of 2): Make possible to have link content prefix yyy different from the link name xxx: $ readlink /proc/[pid]/ns/xxx yyy:[4026531838] This will be used in next patch. Link: http://lkml.kernel.org/r/149201120318.6007.7362655181033883000.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Serge Hallyn <serge@hallyn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-09 06:56:38 +08:00
const char *real_ns_name;
int type;
struct ns_common *(*get)(struct task_struct *task);
void (*put)(struct ns_common *ns);
int (*install)(struct nsproxy *nsproxy, struct ns_common *ns);
struct user_namespace *(*owner)(struct ns_common *ns);
struct ns_common *(*get_parent)(struct ns_common *ns);
};
extern const struct proc_ns_operations netns_operations;
extern const struct proc_ns_operations utsns_operations;
extern const struct proc_ns_operations ipcns_operations;
extern const struct proc_ns_operations pidns_operations;
extern const struct proc_ns_operations pidns_for_children_operations;
extern const struct proc_ns_operations userns_operations;
extern const struct proc_ns_operations mntns_operations;
extern const struct proc_ns_operations cgroupns_operations;
/*
* We always define these enumerators
*/
enum {
PROC_ROOT_INO = 1,
PROC_IPC_INIT_INO = 0xEFFFFFFFU,
PROC_UTS_INIT_INO = 0xEFFFFFFEU,
PROC_USER_INIT_INO = 0xEFFFFFFDU,
PROC_PID_INIT_INO = 0xEFFFFFFCU,
PROC_CGROUP_INIT_INO = 0xEFFFFFFBU,
};
#ifdef CONFIG_PROC_FS
extern int pid_ns_prepare_proc(struct pid_namespace *ns);
extern void pid_ns_release_proc(struct pid_namespace *ns);
extern int proc_alloc_inum(unsigned int *pino);
extern void proc_free_inum(unsigned int inum);
#else /* CONFIG_PROC_FS */
static inline int pid_ns_prepare_proc(struct pid_namespace *ns) { return 0; }
static inline void pid_ns_release_proc(struct pid_namespace *ns) {}
static inline int proc_alloc_inum(unsigned int *inum)
{
*inum = 1;
return 0;
}
static inline void proc_free_inum(unsigned int inum) {}
#endif /* CONFIG_PROC_FS */
static inline int ns_alloc_inum(struct ns_common *ns)
{
atomic_long_set(&ns->stashed, 0);
return proc_alloc_inum(&ns->inum);
}
#define ns_free_inum(ns) proc_free_inum((ns)->inum)
extern struct file *proc_ns_fget(int fd);
#define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
extern void *ns_get_path(struct path *path, struct task_struct *task,
const struct proc_ns_operations *ns_ops);
extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
const struct proc_ns_operations *ns_ops);
extern void nsfs_init(void);
#endif /* _LINUX_PROC_NS_H */