From: Andrei Vagin <[email protected]> Make timerfd respect timens offsets. Provide two helpers timens_clock_to_host() timens_clock_from_host() that are useful to wire up timens to different kernel subsystems. Following patches will use timens_clock_from_host(), added here for completeness.
Signed-off-by: Andrei Vagin <[email protected]> Co-developed-by: Dmitry Safonov <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> --- fs/timerfd.c | 16 +++++++++++----- include/linux/time_namespace.h | 11 +++++++++++ kernel/time_namespace.c | 39 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 61 insertions(+), 5 deletions(-) diff --git a/fs/timerfd.c b/fs/timerfd.c index d69ad801eb80..001ab7a0fd8b 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -26,6 +26,7 @@ #include <linux/syscalls.h> #include <linux/compat.h> #include <linux/rcupdate.h> +#include <linux/time_namespace.h> struct timerfd_ctx { union { @@ -433,22 +434,27 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags) } static int do_timerfd_settime(int ufd, int flags, - const struct itimerspec64 *new, + struct itimerspec64 *new, struct itimerspec64 *old) { struct fd f; struct timerfd_ctx *ctx; int ret; - if ((flags & ~TFD_SETTIME_FLAGS) || - !itimerspec64_valid(new)) - return -EINVAL; - ret = timerfd_fget(ufd, &f); if (ret) return ret; ctx = f.file->private_data; + if (flags & TFD_TIMER_ABSTIME) + timens_clock_to_host(ctx->clockid, &new->it_value); + + if ((flags & ~TFD_SETTIME_FLAGS) || + !itimerspec64_valid(new)) { + fdput(f); + return -EINVAL; + } + if (isalarm(ctx) && !capable(CAP_WAKE_ALARM)) { fdput(f); return -EPERM; diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 4960c54f1b33..910711d1c39d 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -38,6 +38,9 @@ static inline void put_time_ns(struct time_namespace *ns) kref_put(&ns->kref, free_time_ns); } +void timens_clock_to_host(int clockid, struct timespec64 *val); +void timens_clock_from_host(int clockid, struct timespec64 *val); + #else static inline void get_time_ns(struct time_namespace *ns) { @@ -56,6 +59,14 @@ static inline struct time_namespace *copy_time_ns(unsigned long flags, return old_ns; } +static inline void timens_clock_to_host(int clockid, struct timespec64 *val) +{ +} + +static inline void timens_clock_from_host(int clockid, struct timespec64 *val) +{ +} + #endif #endif /* _LINUX_TIMENS_H */ diff --git a/kernel/time_namespace.c b/kernel/time_namespace.c index a985529754b4..f96871cb8124 100644 --- a/kernel/time_namespace.c +++ b/kernel/time_namespace.c @@ -154,6 +154,45 @@ static struct user_namespace *timens_owner(struct ns_common *ns) return to_time_ns(ns)->user_ns; } +static void clock_timens_fixup(int clockid, struct timespec64 *val, bool to_ns) +{ + struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets; + struct timespec64 *offsets = NULL; + + if (!ns_offsets) + return; + + if (val->tv_sec == 0 && val->tv_nsec == 0) + return; + + switch (clockid) { + case CLOCK_MONOTONIC: + offsets = &ns_offsets->monotonic_time_offset; + break; + case CLOCK_BOOTTIME: + offsets = &ns_offsets->monotonic_boottime_offset; + break; + } + + if (!offsets) + return; + + if (to_ns) + *val = timespec64_add(*val, *offsets); + else + *val = timespec64_sub(*val, *offsets); +} + +void timens_clock_to_host(int clockid, struct timespec64 *val) +{ + clock_timens_fixup(clockid, val, false); +} + +void timens_clock_from_host(int clockid, struct timespec64 *val) +{ + clock_timens_fixup(clockid, val, true); +} + const struct proc_ns_operations timens_operations = { .name = "time", .type = CLONE_NEWTIME, -- 2.13.6
