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()
Cc: Thomas Gleixner <[email protected]> Cc: Michael Kerrisk <[email protected]> Cc: Serge Hallyn <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Andrei Vagin <[email protected]> Signed-off-by: Christian Brauner <[email protected]> --- include/linux/time_namespace.h | 6 ++++++ kernel/nsproxy.c | 21 +++++++++++++++++++-- kernel/time/namespace.c | 5 +---- 3 files changed, 26 insertions(+), 6 deletions(-) diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 4d1768c6f836..d308a3812f79 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -33,6 +33,7 @@ extern struct time_namespace init_time_ns; #ifdef CONFIG_TIME_NS extern void 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) { @@ -95,6 +96,11 @@ static inline void vdso_join_timens(struct task_struct *task, { } +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; diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index b03df67621d0..f12231c41b69 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -262,8 +262,8 @@ void exit_task_namespaces(struct task_struct *p) static int check_setns_flags(unsigned long flags) { if (!flags || (flags & ~(CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWNET | CLONE_NEWUSER | CLONE_NEWPID | - CLONE_NEWCGROUP))) + CLONE_NEWNET | CLONE_NEWTIME | CLONE_NEWUSER | + CLONE_NEWPID | CLONE_NEWCGROUP))) return -EINVAL; #ifndef CONFIG_USER_NS @@ -290,6 +290,10 @@ static int check_setns_flags(unsigned long flags) if (flags & CLONE_NEWNET) return -EINVAL; #endif +#ifndef CONFIG_TIME_NS + if (flags & CLONE_NEWTIME) + return -EINVAL; +#endif return 0; } @@ -464,6 +468,14 @@ static int validate_nsset(struct nsset *nsset, struct pid *pid) } #endif +#ifdef CONFIG_TIME_NS + if (flags & CLONE_NEWTIME) { + ret = validate_ns(nsset, &nsp->time_ns->ns); + if (ret) + goto out; + } +#endif + out: if (pid_ns) put_pid_ns(pid_ns); @@ -507,6 +519,11 @@ static void commit_nsset(struct nsset *nsset) exit_sem(me); #endif +#ifdef CONFIG_TIME_NS + if (flags & CLONE_NEWTIME) + timens_commit(me, nsset->nsproxy->time_ns); +#endif + /* transfer ownership */ switch_task_namespaces(me, nsset->nsproxy); nsset->nsproxy = NULL; diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index aa7b90aac2a7..afc65e6be33e 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -280,7 +280,7 @@ static void timens_put(struct ns_common *ns) put_time_ns(to_time_ns(ns)); } -static void timens_commit(struct task_struct *tsk, struct time_namespace *ns) +void timens_commit(struct task_struct *tsk, struct time_namespace *ns) { timens_set_vvar_page(tsk, ns); vdso_join_timens(tsk, ns); @@ -298,9 +298,6 @@ static int timens_install(struct nsset *nsset, struct ns_common *new) !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; - - timens_commit(current, ns); - get_time_ns(ns); put_time_ns(nsproxy->time_ns); nsproxy->time_ns = ns; -- 2.27.0
