diff options
Diffstat (limited to 'kernel/hrtimer.c')
| -rw-r--r-- | kernel/hrtimer.c | 53 |
1 files changed, 40 insertions, 13 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index c21ca6bfaa6..b2b2c2b0a49 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -277,6 +277,30 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) } EXPORT_SYMBOL_GPL(ktime_add_ns); + +/** + * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable + * @kt: minuend + * @nsec: the scalar nsec value to subtract + * + * Returns the subtraction of @nsec from @kt in ktime_t format + */ +ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) +{ + ktime_t tmp; + + if (likely(nsec < NSEC_PER_SEC)) { + tmp.tv64 = nsec; + } else { + unsigned long rem = do_div(nsec, NSEC_PER_SEC); + + tmp = ktime_set((long)nsec, rem); + } + + return ktime_sub(kt, tmp); +} + +EXPORT_SYMBOL_GPL(ktime_sub_ns); # endif /* !CONFIG_KTIME_SCALAR */ /* @@ -1262,8 +1286,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod long __sched hrtimer_nanosleep_restart(struct restart_block *restart) { struct hrtimer_sleeper t; - struct timespec __user *rmtp; - struct timespec tu; + struct timespec *rmtp; ktime_t time; restart->fn = do_no_restart_syscall; @@ -1274,14 +1297,12 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) if (do_nanosleep(&t, HRTIMER_MODE_ABS)) return 0; - rmtp = (struct timespec __user *) restart->arg1; + rmtp = (struct timespec *)restart->arg1; if (rmtp) { time = ktime_sub(t.timer.expires, t.timer.base->get_time()); if (time.tv64 <= 0) return 0; - tu = ktime_to_timespec(time); - if (copy_to_user(rmtp, &tu, sizeof(tu))) - return -EFAULT; + *rmtp = ktime_to_timespec(time); } restart->fn = hrtimer_nanosleep_restart; @@ -1290,12 +1311,11 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) return -ERESTART_RESTARTBLOCK; } -long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, +long hrtimer_nanosleep(struct timespec *rqtp, struct timespec *rmtp, const enum hrtimer_mode mode, const clockid_t clockid) { struct restart_block *restart; struct hrtimer_sleeper t; - struct timespec tu; ktime_t rem; hrtimer_init(&t.timer, clockid, mode); @@ -1311,9 +1331,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, rem = ktime_sub(t.timer.expires, t.timer.base->get_time()); if (rem.tv64 <= 0) return 0; - tu = ktime_to_timespec(rem); - if (copy_to_user(rmtp, &tu, sizeof(tu))) - return -EFAULT; + *rmtp = ktime_to_timespec(rem); } restart = ¤t_thread_info()->restart_block; @@ -1329,7 +1347,8 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) { - struct timespec tu; + struct timespec tu, rmt; + int ret; if (copy_from_user(&tu, rqtp, sizeof(tu))) return -EFAULT; @@ -1337,7 +1356,15 @@ sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) if (!timespec_valid(&tu)) return -EINVAL; - return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); + ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL, + CLOCK_MONOTONIC); + + if (ret && rmtp) { + if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) + return -EFAULT; + } + + return ret; } /* |