From: Andrei Vagin <[email protected]> Make timerfd respect timens offsets. Provide a helper timens_ktime_to_host() that is useful to wire up timens to different kernel subsystems.
Signed-off-by: Andrei Vagin <[email protected]> Co-developed-by: Dmitry Safonov <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> --- fs/timerfd.c | 8 +++++-- include/linux/hrtimer.h | 1 + include/linux/time_namespace.h | 40 ++++++++++++++++++++++++++++++++++ kernel/time/hrtimer.c | 3 +++ 4 files changed, 50 insertions(+), 2 deletions(-) diff --git a/fs/timerfd.c b/fs/timerfd.c index 6a6fc8aa1de7..a55ade09eee1 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 { @@ -179,6 +180,8 @@ static int timerfd_setup(struct timerfd_ctx *ctx, int flags, htmode = (flags & TFD_TIMER_ABSTIME) ? HRTIMER_MODE_ABS: HRTIMER_MODE_REL; + htmode |= HRTIMER_MODE_NS; + texp = timespec64_to_ktime(ktmr->it_value); ctx->expired = 0; ctx->ticks = 0; @@ -197,9 +200,10 @@ static int timerfd_setup(struct timerfd_ctx *ctx, int flags, if (texp != 0) { if (isalarm(ctx)) { - if (flags & TFD_TIMER_ABSTIME) + if (flags & TFD_TIMER_ABSTIME) { + texp = timens_ktime_to_host(clockid, texp); alarm_start(&ctx->t.alarm, texp); - else + } else alarm_start_relative(&ctx->t.alarm, texp); } else { hrtimer_start(&ctx->t.tmr, texp, htmode); diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 2e8957eac4d4..4b9c89c797ee 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -38,6 +38,7 @@ enum hrtimer_mode { HRTIMER_MODE_REL = 0x01, HRTIMER_MODE_PINNED = 0x02, HRTIMER_MODE_SOFT = 0x04, + HRTIMER_MODE_NS = 0x08, HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED, HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED, diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 5f0da6858b10..988414f7f791 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -56,6 +56,41 @@ static inline void timens_add_boottime(struct timespec64 *ts) *ts = timespec64_add(*ts, ns_offsets->monotonic_boottime_offset); } +static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) +{ + struct timens_offsets *ns_offsets = current->nsproxy->time_ns->offsets; + struct timespec64 *offset; + ktime_t koff; + + if (!ns_offsets) + return tim; + + switch (clockid) { + case CLOCK_MONOTONIC: + case CLOCK_MONOTONIC_RAW: + case CLOCK_MONOTONIC_COARSE: + offset = &ns_offsets->monotonic_time_offset; + break; + case CLOCK_BOOTTIME: + case CLOCK_BOOTTIME_ALARM: + offset = &ns_offsets->monotonic_boottime_offset; + break; + default: + return tim; + } + + koff = timespec64_to_ktime(*offset); + if (tim < koff) + tim = 0; + else if (KTIME_MAX - tim < -koff) + tim = KTIME_MAX; + else + tim = ktime_sub(tim, koff); + + return tim; +} + + #else static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { @@ -82,6 +117,11 @@ static inline int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *ts static inline void timens_add_monotonic(struct timespec64 *ts) {} static inline void timens_add_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 */ diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 41dfff23c1f9..484a0efec1df 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -42,6 +42,7 @@ #include <linux/timer.h> #include <linux/freezer.h> #include <linux/compat.h> +#include <linux/time_namespace.h> #include <linux/uaccess.h> @@ -1069,6 +1070,8 @@ static int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, if (mode & HRTIMER_MODE_REL) tim = ktime_add_safe(tim, base->get_time()); + else if (mode & HRTIMER_MODE_NS) + tim = timens_ktime_to_host(base->clockid, tim); tim = hrtimer_update_lowres(timer, tim, mode); -- 2.21.0
