[RFC v2 05/20] sysdeps/nanosleep: Use clock_nanosleep_time64 if avaliable

[Alistair Francis]

The nanosleep syscall is not supported on newer 32-bit platforms (such
as RV32). To fix this issue let's use clock_nanosleep_time64 if it is
avaliable.

Let's use CLOCK_REALTIME when calling clock_nanosleep_time64 as the
Linux specification says:
  "POSIX.1 specifies that nanosleep() should measure time against the
   CLOCK_REALTIME clock. However, Linux measures the time using the
   CLOCK_MONOTONIC clock. This probably does not matter, since the POSIX.1
   specification for clock_settime(2) says that discontinuous changes in
   CLOCK_REALTIME should not affect nanosleep()"

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 ChangeLog                                    |  6 ++++++
 nptl/thrd_sleep.c                            | 19 ++++++++++++++++++-
 sysdeps/unix/sysv/linux/nanosleep.c          | 12 ++++++++++++
 sysdeps/unix/sysv/linux/nanosleep_nocancel.c | 11 +++++++++++
 4 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 05291d7825..b90c5ab60c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2019-06-21  Alistair Francis  <alistair.francis@wdc.com>
+
+	* nptl/thrd_sleep.c: Use clock_nanosleep_time64 instead of nanosleep.
+	* sysdeps/unix/sysv/linux/nanosleep.c: Likewise.
+	* sysdeps/unix/sysv/linux/nanosleep_nocancel.c: Likewise.
+
 2019-06-20  Dmitry V. Levin  <ldv@altlinux.org>
 	    Florian Weimer  <fweimer@redhat.com>
 
diff --git a/nptl/thrd_sleep.c b/nptl/thrd_sleep.c
index 07a51808df..09f8c7159f 100644
--- a/nptl/thrd_sleep.c
+++ b/nptl/thrd_sleep.c
@@ -25,7 +25,24 @@ int
 thrd_sleep (const struct timespec* time_point, struct timespec* remaining)
 {
   INTERNAL_SYSCALL_DECL (err);
-  int ret = INTERNAL_SYSCALL_CANCEL (nanosleep, err, time_point, remaining);
+  int ret;
+
+#ifdef __ASSUME_TIME64_SYSCALLS
+  ret = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err,
+                                 CLOCK_REALTIME, 0, time_point, remaining);
+#else
+# ifdef __NR_clock_nanosleep_time64
+  long int ret_64 = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err,
+                                             CLOCK_REALTIME, 0, time_point, remaining);
+  if (ret_64 == 0 || errno != ENOSYS) {
+    ret = ret_64;
+  } else {
+    ret = INTERNAL_SYSCALL_CANCEL (nanosleep, err, time_point, remaining);
+  }
+# else
+  ret = INTERNAL_SYSCALL_CANCEL (nanosleep, err, time_point, remaining);
+# endif
+#endif
   if (INTERNAL_SYSCALL_ERROR_P (ret, err))
     {
       /* C11 states thrd_sleep function returns -1 if it has been interrupted
diff --git a/sysdeps/unix/sysv/linux/nanosleep.c b/sysdeps/unix/sysv/linux/nanosleep.c
index f14ae565af..c2d6e2f766 100644
--- a/sysdeps/unix/sysv/linux/nanosleep.c
+++ b/sysdeps/unix/sysv/linux/nanosleep.c
@@ -25,7 +25,19 @@ int
 __nanosleep (const struct timespec *requested_time,
 	     struct timespec *remaining)
 {
+
+#ifdef __ASSUME_TIME64_SYSCALLS
+  return SYSCALL_CANCEL (clock_nanosleep_time64, CLOCK_REALTIME, 0,
+                         requested_time, remaining);
+#else
+# ifdef __NR_clock_nanosleep_time64
+  long int ret = SYSCALL_CANCEL (clock_nanosleep_time64, CLOCK_REALTIME, 0,
+                                 requested_time, remaining);
+  if (ret == 0 || errno != ENOSYS)
+    return ret;
+# endif
   return SYSCALL_CANCEL (nanosleep, requested_time, remaining);
+#endif
 }
 hidden_def (__nanosleep)
 weak_alias (__nanosleep, nanosleep)
diff --git a/sysdeps/unix/sysv/linux/nanosleep_nocancel.c b/sysdeps/unix/sysv/linux/nanosleep_nocancel.c
index 122ba627ff..f411a1c6c2 100644
--- a/sysdeps/unix/sysv/linux/nanosleep_nocancel.c
+++ b/sysdeps/unix/sysv/linux/nanosleep_nocancel.c
@@ -24,6 +24,17 @@ int
 __nanosleep_nocancel (const struct timespec *requested_time,
 		      struct timespec *remaining)
 {
+#ifdef __ASSUME_TIME64_SYSCALLS
+  return INLINE_SYSCALL_CALL (clock_nanosleep_time64, CLOCK_REALTIME, 0,
+                         requested_time, remaining);
+#else
+# ifdef __NR_clock_nanosleep_time64
+  long int ret = INLINE_SYSCALL_CALL (clock_nanosleep_time64, CLOCK_REALTIME, 0,
+                                 requested_time, remaining);
+  if (ret == 0 || errno != ENOSYS)
+    return ret;
+# endif
   return INLINE_SYSCALL_CALL (nanosleep, requested_time, remaining);
+#endif
 }
 hidden_def (__nanosleep_nocancel)
-- 
2.22.0