[PATCH v4 06/25] time/posix-timers:Introduce {get,put}_timespec and {get,put}_itimerspec

[Baolin Wang <baolin.wang@linaro.org>]

These are new helper functions that convert between a user timespec/
itimerspec and a kernel timespec64/itimerspec64 structure.

These macros can change the types underneath from both ends and it
will work efficiently on both 32-bit and 64-bit that can avoid the
CONFIG_64BIT macro in syscall functions, and also it can make the
syscall functions more simple.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 kernel/time/posix-timers.c |   29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 31ea01f..96efe1d 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -147,6 +147,35 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);
 	__timr;								   \
 })
 
+#define __get_timespec(kts, uts) \
+	(__get_user((kts)->tv_sec, &(uts)->tv_sec) || \
+	__get_user((kts)->tv_nsec, &(uts)->tv_nsec))
+
+#define __put_timespec(kts, uts) \
+	(__put_user((kts)->tv_sec, &(uts)->tv_sec) || \
+	__put_user((kts)->tv_nsec, &(uts)->tv_nsec))
+
+#define get_timespec(kts, uts) \
+	((access_ok(VERIFY_READ, (uts), sizeof(*(uts))) || \
+	__get_timespec((kts), (uts))) ? \
+	-EFAULT : 0)
+
+#define put_timespec(kts, uts) \
+	((access_ok(VERIFY_WRITE, (uts), sizeof(*(uts))) || \
+	__put_timespec((kts), (uts))) ? \
+	-EFAULT : 0)
+
+#define get_itimerspec(kit, uit) \
+	((access_ok(VERIFY_READ, (uit), sizeof(*(uit))) || \
+	__get_timespec(&(kit)->it_interval, &(uit)->it_interval) || \
+	__get_timespec(&(kit)->it_value, &(uit)->it_value)))
+
+#define put_itimerspec(kit, uit) \
+	((access_ok(VERIFY_WRITE, (uit), sizeof(*(uit))) || \
+	__put_timespec(&(kit)->it_interval, &(uit)->it_interval) || \
+	__put_timespec(&(kit)->it_value, &(uit)->it_value)) ? \
+	-EFAULT : 0)
+
 static int hash(struct signal_struct *sig, unsigned int nr)
 {
 	return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable));
-- 
1.7.9.5