forked from mirrors/linux
		
	 d6c494e8ee
			
		
	
	
		d6c494e8ee
		
	
	
	
	
		
			
			find_timens_vvar_page() is not architecture-specific, as can be seen from how all five per-architecture versions of it are the same. (arm64, powerpc and riscv are exactly the same; x86 and s390 have two characters difference inside a comment, less blank lines, and mark the !CONFIG_TIME_NS version as inline.) Refactor the five copies into a central copy in kernel/time/namespace.c. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20221130115320.2918447-1-jannh@google.com
		
			
				
	
	
		
			166 lines
		
	
	
	
		
			4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			166 lines
		
	
	
	
		
			4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
 | |
| #ifndef _LINUX_TIMENS_H
 | |
| #define _LINUX_TIMENS_H
 | |
| 
 | |
| 
 | |
| #include <linux/sched.h>
 | |
| #include <linux/nsproxy.h>
 | |
| #include <linux/ns_common.h>
 | |
| #include <linux/err.h>
 | |
| 
 | |
| struct user_namespace;
 | |
| extern struct user_namespace init_user_ns;
 | |
| 
 | |
| struct timens_offsets {
 | |
| 	struct timespec64 monotonic;
 | |
| 	struct timespec64 boottime;
 | |
| };
 | |
| 
 | |
| struct time_namespace {
 | |
| 	struct user_namespace	*user_ns;
 | |
| 	struct ucounts		*ucounts;
 | |
| 	struct ns_common	ns;
 | |
| 	struct timens_offsets	offsets;
 | |
| 	struct page		*vvar_page;
 | |
| 	/* If set prevents changing offsets after any task joined namespace. */
 | |
| 	bool			frozen_offsets;
 | |
| } __randomize_layout;
 | |
| 
 | |
| extern struct time_namespace init_time_ns;
 | |
| 
 | |
| #ifdef CONFIG_TIME_NS
 | |
| extern int vdso_join_timens(struct task_struct *task,
 | |
| 			    struct time_namespace *ns);
 | |
| extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
 | |
| 
 | |
| static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
 | |
| {
 | |
| 	refcount_inc(&ns->ns.count);
 | |
| 	return ns;
 | |
| }
 | |
| 
 | |
| struct time_namespace *copy_time_ns(unsigned long flags,
 | |
| 				    struct user_namespace *user_ns,
 | |
| 				    struct time_namespace *old_ns);
 | |
| void free_time_ns(struct time_namespace *ns);
 | |
| void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
 | |
| struct vdso_data *arch_get_vdso_data(void *vvar_page);
 | |
| struct page *find_timens_vvar_page(struct vm_area_struct *vma);
 | |
| 
 | |
| static inline void put_time_ns(struct time_namespace *ns)
 | |
| {
 | |
| 	if (refcount_dec_and_test(&ns->ns.count))
 | |
| 		free_time_ns(ns);
 | |
| }
 | |
| 
 | |
| void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
 | |
| 
 | |
| struct proc_timens_offset {
 | |
| 	int			clockid;
 | |
| 	struct timespec64	val;
 | |
| };
 | |
| 
 | |
| int proc_timens_set_offset(struct file *file, struct task_struct *p,
 | |
| 			   struct proc_timens_offset *offsets, int n);
 | |
| 
 | |
| static inline void timens_add_monotonic(struct timespec64 *ts)
 | |
| {
 | |
| 	struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
 | |
| 
 | |
| 	*ts = timespec64_add(*ts, ns_offsets->monotonic);
 | |
| }
 | |
| 
 | |
| static inline void timens_add_boottime(struct timespec64 *ts)
 | |
| {
 | |
| 	struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
 | |
| 
 | |
| 	*ts = timespec64_add(*ts, ns_offsets->boottime);
 | |
| }
 | |
| 
 | |
| static inline u64 timens_add_boottime_ns(u64 nsec)
 | |
| {
 | |
| 	struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
 | |
| 
 | |
| 	return nsec + timespec64_to_ns(&ns_offsets->boottime);
 | |
| }
 | |
| 
 | |
| static inline void timens_sub_boottime(struct timespec64 *ts)
 | |
| {
 | |
| 	struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
 | |
| 
 | |
| 	*ts = timespec64_sub(*ts, ns_offsets->boottime);
 | |
| }
 | |
| 
 | |
| ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
 | |
| 				struct timens_offsets *offsets);
 | |
| 
 | |
| static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
 | |
| {
 | |
| 	struct time_namespace *ns = current->nsproxy->time_ns;
 | |
| 
 | |
| 	if (likely(ns == &init_time_ns))
 | |
| 		return tim;
 | |
| 
 | |
| 	return do_timens_ktime_to_host(clockid, tim, &ns->offsets);
 | |
| }
 | |
| 
 | |
| #else
 | |
| static inline int vdso_join_timens(struct task_struct *task,
 | |
| 				   struct time_namespace *ns)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static inline void timens_commit(struct task_struct *tsk,
 | |
| 				 struct time_namespace *ns)
 | |
| {
 | |
| }
 | |
| 
 | |
| static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
 | |
| {
 | |
| 	return NULL;
 | |
| }
 | |
| 
 | |
| static inline void put_time_ns(struct time_namespace *ns)
 | |
| {
 | |
| }
 | |
| 
 | |
| static inline
 | |
| struct time_namespace *copy_time_ns(unsigned long flags,
 | |
| 				    struct user_namespace *user_ns,
 | |
| 				    struct time_namespace *old_ns)
 | |
| {
 | |
| 	if (flags & CLONE_NEWTIME)
 | |
| 		return ERR_PTR(-EINVAL);
 | |
| 
 | |
| 	return old_ns;
 | |
| }
 | |
| 
 | |
| static inline void timens_on_fork(struct nsproxy *nsproxy,
 | |
| 				 struct task_struct *tsk)
 | |
| {
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
 | |
| {
 | |
| 	return NULL;
 | |
| }
 | |
| 
 | |
| static inline void timens_add_monotonic(struct timespec64 *ts) { }
 | |
| static inline void timens_add_boottime(struct timespec64 *ts) { }
 | |
| 
 | |
| static inline u64 timens_add_boottime_ns(u64 nsec)
 | |
| {
 | |
| 	return nsec;
 | |
| }
 | |
| 
 | |
| static inline void timens_sub_boottime(struct timespec64 *ts) { }
 | |
| 
 | |
| static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
 | |
| {
 | |
| 	return tim;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #endif /* _LINUX_TIMENS_H */
 |