From 28c41efd08bf97fc64f75304035ee3943995b68e Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Mon, 3 Aug 2020 13:17:00 +0300 Subject: time: Use generic ns_common::count Switch over time namespaces to use the newly introduced common lifetime counter. Currently every namespace type has its own lifetime counter which is stored in the specific namespace struct. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This introduces a common lifetime counter into struct ns_common. The ns_common struct encompasses information that all namespaces share. That should include the lifetime counter since its common for all of them. It also allows us to unify the type of the counters across all namespaces. Most of them use refcount_t but one uses atomic_t and at least one uses kref. Especially the last one doesn't make much sense since it's just a wrapper around refcount_t since 2016 and actually complicates cleanup operations by having to use container_of() to cast the correct namespace struct out of struct ns_common. Having the lifetime counter for the namespaces in one place reduces maintenance cost. Not just because after switching all namespaces over we will have removed more code than we added but also because the logic is more easily understandable and we indicate to the user that the basic lifetime requirements for all namespaces are currently identical. Signed-off-by: Kirill Tkhai Reviewed-by: Kees Cook Acked-by: Christian Brauner Link: https://lore.kernel.org/r/159644982033.604812.9406853013011123238.stgit@localhost.localdomain Signed-off-by: Christian Brauner --- include/linux/time_namespace.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'include/linux/time_namespace.h') diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 5b6031385db0..a51ffc089219 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -4,7 +4,6 @@ #include -#include #include #include #include @@ -18,7 +17,6 @@ struct timens_offsets { }; struct time_namespace { - struct kref kref; struct user_namespace *user_ns; struct ucounts *ucounts; struct ns_common ns; @@ -37,20 +35,21 @@ extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns); static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { - kref_get(&ns->kref); + 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 kref *kref); +void free_time_ns(struct time_namespace *ns); int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk); struct vdso_data *arch_get_vdso_data(void *vvar_page); static inline void put_time_ns(struct time_namespace *ns) { - kref_put(&ns->kref, free_time_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); -- cgit From 31909e3330c8d65e9a928d40833ebd5feb4f64e6 Mon Sep 17 00:00:00 2001 From: Michael Weiß Date: Tue, 27 Oct 2020 21:42:56 +0100 Subject: timens: additional helper functions for boottime offset handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Provide functions for time_namespace to subtract the boottime offset from a timespec64 as well as to apply the boottime offset to u64 types in nanoseconds. Signed-off-by: Michael Weiß Reviewed-by: Andrei Vagin Acked-by: Thomas Gleixner Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20201027204258.7869-2-michael.weiss@aisec.fraunhofer.de --- include/linux/time_namespace.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/linux/time_namespace.h') diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 5b6031385db0..68770ac9ba89 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -77,6 +77,20 @@ static inline void timens_add_boottime(struct timespec64 *ts) *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); @@ -130,6 +144,14 @@ static inline int timens_on_fork(struct nsproxy *nsproxy, 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; -- cgit From 5c62634fc65101d350cbd47722fb76f02693059d Mon Sep 17 00:00:00 2001 From: Hui Su Date: Wed, 18 Nov 2020 00:17:50 +0800 Subject: namespace: make timens_on_fork() return nothing timens_on_fork() always return 0, and maybe not need to judge the return value in copy_namespaces(). So make timens_on_fork() return nothing and do not judge its return val in copy_namespaces(). Signed-off-by: Hui Su Link: https://lore.kernel.org/r/20201117161750.GA45121@rlk Signed-off-by: Christian Brauner --- include/linux/time_namespace.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux/time_namespace.h') diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 68770ac9ba89..30312166e70a 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -45,7 +45,7 @@ struct time_namespace *copy_time_ns(unsigned long flags, struct user_namespace *user_ns, struct time_namespace *old_ns); void free_time_ns(struct kref *kref); -int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk); +void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk); struct vdso_data *arch_get_vdso_data(void *vvar_page); static inline void put_time_ns(struct time_namespace *ns) @@ -136,10 +136,10 @@ struct time_namespace *copy_time_ns(unsigned long flags, return old_ns; } -static inline int timens_on_fork(struct nsproxy *nsproxy, +static inline void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk) { - return 0; + return; } static inline void timens_add_monotonic(struct timespec64 *ts) { } -- cgit