mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 23:53:55 +08:00
98f842e675
Assign a unique proc inode to each namespace, and use that inode number to ensure we only allocate at most one proc inode for every namespace in proc. A single proc inode per namespace allows userspace to test to see if two processes are in the same namespace. This has been a long requested feature and only blocked because a naive implementation would put the id in a global space and would ultimately require having a namespace for the names of namespaces, making migration and certain virtualization tricks impossible. We still don't have per superblock inode numbers for proc, which appears necessary for application unaware checkpoint/restart and migrations (if the application is using namespace file descriptors) but that is now allowd by the design if it becomes important. I have preallocated the ipc and uts initial proc inode numbers so their structures can be statically initialized. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
84 lines
1.6 KiB
C
84 lines
1.6 KiB
C
#ifndef _LINUX_UTSNAME_H
|
|
#define _LINUX_UTSNAME_H
|
|
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/kref.h>
|
|
#include <linux/nsproxy.h>
|
|
#include <linux/err.h>
|
|
#include <uapi/linux/utsname.h>
|
|
|
|
enum uts_proc {
|
|
UTS_PROC_OSTYPE,
|
|
UTS_PROC_OSRELEASE,
|
|
UTS_PROC_VERSION,
|
|
UTS_PROC_HOSTNAME,
|
|
UTS_PROC_DOMAINNAME,
|
|
};
|
|
|
|
struct user_namespace;
|
|
extern struct user_namespace init_user_ns;
|
|
|
|
struct uts_namespace {
|
|
struct kref kref;
|
|
struct new_utsname name;
|
|
struct user_namespace *user_ns;
|
|
unsigned int proc_inum;
|
|
};
|
|
extern struct uts_namespace init_uts_ns;
|
|
|
|
#ifdef CONFIG_UTS_NS
|
|
static inline void get_uts_ns(struct uts_namespace *ns)
|
|
{
|
|
kref_get(&ns->kref);
|
|
}
|
|
|
|
extern struct uts_namespace *copy_utsname(unsigned long flags,
|
|
struct user_namespace *user_ns, struct uts_namespace *old_ns);
|
|
extern void free_uts_ns(struct kref *kref);
|
|
|
|
static inline void put_uts_ns(struct uts_namespace *ns)
|
|
{
|
|
kref_put(&ns->kref, free_uts_ns);
|
|
}
|
|
#else
|
|
static inline void get_uts_ns(struct uts_namespace *ns)
|
|
{
|
|
}
|
|
|
|
static inline void put_uts_ns(struct uts_namespace *ns)
|
|
{
|
|
}
|
|
|
|
static inline struct uts_namespace *copy_utsname(unsigned long flags,
|
|
struct user_namespace *user_ns, struct uts_namespace *old_ns)
|
|
{
|
|
if (flags & CLONE_NEWUTS)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return old_ns;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_PROC_SYSCTL
|
|
extern void uts_proc_notify(enum uts_proc proc);
|
|
#else
|
|
static inline void uts_proc_notify(enum uts_proc proc)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static inline struct new_utsname *utsname(void)
|
|
{
|
|
return ¤t->nsproxy->uts_ns->name;
|
|
}
|
|
|
|
static inline struct new_utsname *init_utsname(void)
|
|
{
|
|
return &init_uts_ns.name;
|
|
}
|
|
|
|
extern struct rw_semaphore uts_sem;
|
|
|
|
#endif /* _LINUX_UTSNAME_H */
|