Usage of these apis and their compat versions makes the syscalls: timer_settime and timer_gettime and their compat implementations simpler.
This patch also serves as a preparatory patch for changing syscalls to use new time_t data types to support the y2038 effort by isolating the processing of user pointers through these apis.
Signed-off-by: Deepa Dinamani deepa.kernel@gmail.com --- kernel/time/posix-timers.c | 138 +++++++++++++++++++++++++++------------------ 1 file changed, 84 insertions(+), 54 deletions(-)
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 58ed4e759485..c642c6a959ff 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -690,32 +690,54 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) } }
+/* common set of checks before we invoke timer_gettime and + * timer_settime apis. + */ +static int common_prep_timer(const struct k_clock **kc_ptr, + struct k_itimer **timr_ptr, + timer_t timer_id, + long *flags, + struct itimerspec64 *it) +{ + int error = 0; + const struct k_clock *kc; + struct k_itimer *timr; + + if (it && !itimerspec64_valid(it)) + return -EINVAL; + + *timr_ptr = timr = lock_timer(timer_id, flags); + if (!timr) + return -EINVAL; + + *kc_ptr = kc = timr->kclock; + + if (WARN_ON_ONCE(!kc || !kc->timer_set)) + error = -EINVAL; + + return error; +} + /* Get the time remaining on a POSIX.1b interval timer. */ SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, struct itimerspec __user *, setting) { - struct itimerspec64 cur_setting64; - struct itimerspec cur_setting; + struct itimerspec64 cur_setting; struct k_itimer *timr; const struct k_clock *kc; unsigned long flags; int ret = 0;
- timr = lock_timer(timer_id, &flags); - if (!timr) - return -EINVAL; - - memset(&cur_setting64, 0, sizeof(cur_setting64)); - kc = timr->kclock; - if (WARN_ON_ONCE(!kc || !kc->timer_get)) - ret = -EINVAL; + memset(&cur_setting, 0, sizeof(cur_setting)); + ret = common_prep_timer(&kc, &timr, timer_id, &flags, NULL); + if (ret) + return ret; else - kc->timer_get(timr, &cur_setting64); + kc->timer_get(timr, &cur_setting);
unlock_timer(timr, flags);
- cur_setting = itimerspec64_to_itimerspec(&cur_setting64); - if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting))) + if (!ret && put_itimerspec64(&cur_setting, setting)) return -EFAULT;
return ret; @@ -813,9 +835,8 @@ SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, const struct itimerspec __user *, new_setting, struct itimerspec __user *, old_setting) { - struct itimerspec64 new_spec64, old_spec64; - struct itimerspec64 *rtn = old_setting ? &old_spec64 : NULL; - struct itimerspec new_spec, old_spec; + struct itimerspec64 new_spec, old_spec; + struct itimerspec64 *rtn = old_setting ? &old_spec : NULL; struct k_itimer *timr; unsigned long flag; const struct k_clock *kc; @@ -824,23 +845,15 @@ SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, if (!new_setting) return -EINVAL;
- if (copy_from_user(&new_spec, new_setting, sizeof (new_spec))) - return -EFAULT; - new_spec64 = itimerspec_to_itimerspec64(&new_spec); + error = get_itimerspec64(&new_spec, new_setting); + if (error) + return error;
- if (!timespec64_valid(&new_spec64.it_interval) || - !timespec64_valid(&new_spec64.it_value)) - return -EINVAL; retry: - timr = lock_timer(timer_id, &flag); - if (!timr) - return -EINVAL; + error = common_prep_timer(&kc, &timr, timer_id, &flag, &new_spec);
- kc = timr->kclock; - if (WARN_ON_ONCE(!kc || !kc->timer_set)) - error = -EINVAL; - else - error = kc->timer_set(timr, flags, &new_spec64, rtn); + if (!error) + error = kc->timer_set(timr, flags, &new_spec, rtn);
unlock_timer(timr, flag); if (error == TIMER_RETRY) { @@ -848,9 +861,8 @@ SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, goto retry; }
- old_spec = itimerspec64_to_itimerspec(&old_spec64); if (old_setting && !error && - copy_to_user(old_setting, &old_spec, sizeof (old_spec))) + put_itimerspec64(&old_spec, old_setting)) error = -EFAULT;
return error; @@ -1220,21 +1232,33 @@ COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, struct compat_itimerspec __user *, new, struct compat_itimerspec __user *, old) { + struct itimerspec64 newts, oldts; + struct itimerspec64 *rtn = old ? &oldts : NULL; + struct k_itimer *timr; + unsigned long flag; + const struct k_clock *kc; long err; - mm_segment_t oldfs; - struct itimerspec newts, oldts;
if (!new) return -EINVAL; - if (get_compat_itimerspec(&newts, new)) - return -EFAULT; - oldfs = get_fs(); - set_fs(KERNEL_DS); - err = sys_timer_settime(timer_id, flags, - (struct itimerspec __user *) &newts, - (struct itimerspec __user *) &oldts); - set_fs(oldfs); - if (!err && old && put_compat_itimerspec(old, &oldts)) + err = get_compat_itimerspec64(&newts, new); + if (err) + return err; + +retry: + + err = common_prep_timer(&kc, &timr, timer_id, &flag, &newts); + + if (!err) + err = kc->timer_set(timr, flags, &newts, rtn); + + unlock_timer(timr, flag); + if (err == TIMER_RETRY) { + rtn = NULL; // We already got the old time... + goto retry; + } + + if (!err && old && put_compat_itimerspec64(&oldts, old)) return -EFAULT; return err; } @@ -1242,18 +1266,24 @@ COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, struct compat_itimerspec __user *, setting) { - long err; - mm_segment_t oldfs; - struct itimerspec ts; - - oldfs = get_fs(); - set_fs(KERNEL_DS); - err = sys_timer_gettime(timer_id, - (struct itimerspec __user *) &ts); - set_fs(oldfs); - if (!err && put_compat_itimerspec(setting, &ts)) + struct itimerspec64 ts; + struct k_itimer *timr; + const struct k_clock *kc; + unsigned long flags; + int ret = 0; + + memset(&ts, 0, sizeof(ts)); + ret = common_prep_timer(&kc, &timr, timer_id, &flags, NULL); + if (ret) + return ret; + + kc->timer_get(timr, &ts); + + unlock_timer(timr, flags); + + if (!ret && put_compat_itimerspec64(&ts, setting)) return -EFAULT; - return err; + return ret; }
COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,