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76c12881a3
So far setns() was missing time namespace support. This was partially due to it simply not being implemented but also because vdso_join_timens() could still fail which made switching to multiple namespaces atomically problematic. This is now fixed so support CLONE_NEWTIME with setns() Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Andrei Vagin <avagin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200706154912.3248030-4-christian.brauner@ubuntu.com
139 lines
3.3 KiB
C
139 lines
3.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_TIMENS_H
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#define _LINUX_TIMENS_H
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#include <linux/sched.h>
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#include <linux/kref.h>
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#include <linux/nsproxy.h>
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#include <linux/ns_common.h>
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#include <linux/err.h>
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struct user_namespace;
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extern struct user_namespace init_user_ns;
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struct timens_offsets {
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struct timespec64 monotonic;
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struct timespec64 boottime;
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};
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struct time_namespace {
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struct kref kref;
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struct user_namespace *user_ns;
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struct ucounts *ucounts;
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struct ns_common ns;
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struct timens_offsets offsets;
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struct page *vvar_page;
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/* If set prevents changing offsets after any task joined namespace. */
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bool frozen_offsets;
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} __randomize_layout;
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extern struct time_namespace init_time_ns;
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#ifdef CONFIG_TIME_NS
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extern int vdso_join_timens(struct task_struct *task,
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struct time_namespace *ns);
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extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
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static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
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{
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kref_get(&ns->kref);
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return ns;
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}
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struct time_namespace *copy_time_ns(unsigned long flags,
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struct user_namespace *user_ns,
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struct time_namespace *old_ns);
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void free_time_ns(struct kref *kref);
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int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
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struct vdso_data *arch_get_vdso_data(void *vvar_page);
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static inline void put_time_ns(struct time_namespace *ns)
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{
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kref_put(&ns->kref, free_time_ns);
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}
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void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
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struct proc_timens_offset {
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int clockid;
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struct timespec64 val;
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};
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int proc_timens_set_offset(struct file *file, struct task_struct *p,
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struct proc_timens_offset *offsets, int n);
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static inline void timens_add_monotonic(struct timespec64 *ts)
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{
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struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
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*ts = timespec64_add(*ts, ns_offsets->monotonic);
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}
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static inline void timens_add_boottime(struct timespec64 *ts)
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{
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struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
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*ts = timespec64_add(*ts, ns_offsets->boottime);
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}
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ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
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struct timens_offsets *offsets);
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static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
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{
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struct time_namespace *ns = current->nsproxy->time_ns;
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if (likely(ns == &init_time_ns))
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return tim;
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return do_timens_ktime_to_host(clockid, tim, &ns->offsets);
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}
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#else
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static inline int vdso_join_timens(struct task_struct *task,
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struct time_namespace *ns)
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{
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return 0;
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}
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static inline void timens_commit(struct task_struct *tsk,
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struct time_namespace *ns)
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{
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}
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static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
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{
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return NULL;
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}
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static inline void put_time_ns(struct time_namespace *ns)
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{
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}
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static inline
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struct time_namespace *copy_time_ns(unsigned long flags,
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struct user_namespace *user_ns,
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struct time_namespace *old_ns)
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{
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if (flags & CLONE_NEWTIME)
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return ERR_PTR(-EINVAL);
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return old_ns;
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}
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static inline int timens_on_fork(struct nsproxy *nsproxy,
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struct task_struct *tsk)
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{
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return 0;
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}
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static inline void timens_add_monotonic(struct timespec64 *ts) { }
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static inline void timens_add_boottime(struct timespec64 *ts) { }
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static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
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{
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return tim;
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}
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#endif
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#endif /* _LINUX_TIMENS_H */
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