y2038: Convert aio_suspend to support 64 bit timeazanella/futex-refactor

The aio_suspend function has been converted to support 64 bit time.
In the __aio_suspend_common64() function not all occurrences of struct
timespec, clock_gettime() and pthread_cond_timedwait() have been replaced
with their 64 bit counterparts, as i686-gnu port (HURD) don't #define
DONT_NEED_AIO_MISC_COND and requires them (as it is not yet supporting 64
bit time for being Y2038 safe).

This change uses:
- New __futex_reltimed_wait64 (instead of futex_reltimed_wait)
- New __futex_reltimed_wait_cancellable64
	(instead of futex_reltimed_wait_cancellable)
    from ./sysdeps/nptl/futex-helpers.h

The aio_suspend() accepts relative timeout.

The __aio_suspend() is supposed to be run on ports with __TIMESIZE !=64 and
__WORDSIZE==32. It internally utilizes __aio_suspend_time64() and hence the
conversion from 32 bit struct timespec to 64 bit one is required.

For ports supporting 64 bit time the __aio_suspend_time64() will be used
either via alias (to __aio_suspend when __TIMESIZE==64) or redirection
(when -D_TIME_BITS=64 is passed).

Build tests:
./src/scripts/build-many-glibcs.py glibcs

---
Changes for v2:
- Add missing -EOVERFLOW error handling for __futex_reltimed_wait64 and
  _futex_reltimed_wait_cancelable64

Changes for v3:
- Remove "__" prefix from futex_reltimed_wait64 and
  futex_reltimed_wait_cancellable64

- Remove some code, as HURD is not defining DONT_NEED_AIO_MISC_COND
  (i.e. Linux ports are defining it) and add in-code explanation why
  the code is NOT converted to support 64 bit time.

- Rewrite the commit message

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

4 files changed, 46 insertions, 31 deletions

diff --git a/sysdeps/nptl/aio_misc.h b/sysdeps/nptl/aio_misc.h
index 3f195f4794..dd8d99e5d6 100644
--- a/sysdeps/nptl/aio_misc.h
+++ b/sysdeps/nptl/aio_misc.h
@@ -45,11 +45,12 @@
 	do								      \
 	  {								      \
 	    if (cancel)							      \
-	      status = futex_reltimed_wait_cancelable (			      \
-		(unsigned int *) futexaddr, oldval, timeout, FUTEX_PRIVATE);  \
+	      status = __futex_abstimed_wait_cancelable64 (		      \
+		(unsigned int *) futexaddr, oldval, CLOCK_MONOTONIC, timeout, \
+		FUTEX_PRIVATE);						      \
 	    else							      \
-	      status = futex_reltimed_wait ((unsigned int *) futexaddr,	      \
-		oldval, timeout, FUTEX_PRIVATE);	      		      \
+	      status = __futex_abstimed_wait64 ((unsigned int *) futexaddr,   \
+		oldval, CLOCK_REALTIME, timeout, FUTEX_PRIVATE); 	      \
 	    if (status != EAGAIN)					      \
 	      break;							      \
 									      \
diff --git a/sysdeps/nptl/futex-internal.c b/sysdeps/nptl/futex-internal.c
index 11031cc46a..22ef312c2a 100644
--- a/sysdeps/nptl/futex-internal.c
+++ b/sysdeps/nptl/futex-internal.c
@@ -112,6 +112,7 @@ __futex_abstimed_wait64 (unsigned int* futex_word, unsigned int expected,
   return __futex_abstimed_wait_common64 (futex_word, expected, clockid,
                                          abstime, private, false);
 }
+libpthread_hidden_def (__futex_abstimed_wait64)
 
 int
 __futex_abstimed_wait_cancelable64 (unsigned int* futex_word,
@@ -122,3 +123,4 @@ __futex_abstimed_wait_cancelable64 (unsigned int* futex_word,
   return __futex_abstimed_wait_common64 (futex_word, expected, clockid,
                                          abstime, private, true);
 }
+libpthread_hidden_def (__futex_abstimed_wait_cancelable64)
diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h
index 632051278b..2619f59f07 100644
--- a/sysdeps/nptl/futex-internal.h
+++ b/sysdeps/nptl/futex-internal.h
@@ -409,13 +409,15 @@ int
 __futex_abstimed_wait_cancelable64 (unsigned int* futex_word,
                                     unsigned int expected, clockid_t clockid,
                                     const struct __timespec64* abstime,
-                                    int private) attribute_hidden;
+                                    int private);
+libpthread_hidden_proto (__futex_abstimed_wait_cancelable64);
 
 int
 __futex_abstimed_wait64 (unsigned int* futex_word, unsigned int expected,
                          clockid_t clockid,
                          const struct __timespec64* abstime,
-                         int private) attribute_hidden;
+                         int private);
+libpthread_hidden_proto (__futex_abstimed_wait64);
 
 
 static __always_inline int
diff --git a/sysdeps/pthread/aio_suspend.c b/sysdeps/pthread/aio_suspend.c
index ad03f13558..32032a4f44 100644
--- a/sysdeps/pthread/aio_suspend.c
+++ b/sysdeps/pthread/aio_suspend.c
@@ -94,7 +94,7 @@ cleanup (void *arg)
 #ifdef DONT_NEED_AIO_MISC_COND
 static int
 __attribute__ ((noinline))
-do_aio_misc_wait (unsigned int *cntr, const struct timespec *timeout)
+do_aio_misc_wait (unsigned int *cntr, const struct __timespec64 *timeout)
 {
   int result = 0;
 
@@ -105,8 +105,8 @@ do_aio_misc_wait (unsigned int *cntr, const struct timespec *timeout)
 #endif
 
 int
-aio_suspend (const struct aiocb *const list[], int nent,
-	     const struct timespec *timeout)
+__aio_suspend_time64 (const struct aiocb *const list[], int nent,
+		      const struct __timespec64 *timeout)
 {
   if (__glibc_unlikely (nent < 0))
     {
@@ -157,6 +157,18 @@ aio_suspend (const struct aiocb *const list[], int nent,
 	  break;
       }
 
+  struct __timespec64 ts;
+  if (timeout != NULL)
+    {
+      __clock_gettime64 (CLOCK_MONOTONIC, &ts);
+      ts.tv_sec += timeout->tv_sec;
+      ts.tv_nsec += timeout->tv_nsec;
+      if (ts.tv_nsec >= 1000000000)
+	{
+	  ts.tv_nsec -= 1000000000;
+	  ts.tv_sec++;
+	}
+    }
 
   /* Only if none of the entries is NULL or finished to be wait.  */
   if (cnt == nent && any)
@@ -175,29 +187,11 @@ aio_suspend (const struct aiocb *const list[], int nent,
       pthread_cleanup_push (cleanup, &clparam);
 
 #ifdef DONT_NEED_AIO_MISC_COND
-      result = do_aio_misc_wait (&cntr, timeout);
+      result = do_aio_misc_wait (&cntr, timeout == NULL ? NULL : &ts);
 #else
-      if (timeout == NULL)
-	result = pthread_cond_wait (&cond, &__aio_requests_mutex);
-      else
-	{
-	  /* We have to convert the relative timeout value into an
-	     absolute time value with pthread_cond_timedwait expects.  */
-	  struct timespec now;
-	  struct timespec abstime;
-
-	  __clock_gettime (CLOCK_REALTIME, &now);
-	  abstime.tv_nsec = timeout->tv_nsec + now.tv_nsec;
-	  abstime.tv_sec = timeout->tv_sec + now.tv_sec;
-	  if (abstime.tv_nsec >= 1000000000)
-	    {
-	      abstime.tv_nsec -= 1000000000;
-	      abstime.tv_sec += 1;
-	    }
-
-	  result = pthread_cond_timedwait (&cond, &__aio_requests_mutex,
-					   &abstime);
-	}
+      struct timespec ts32 = valid_timespec64_to_timespec (ts);
+      result = pthread_cond_timedwait (&cond, &__aio_requests_mutex,
+				       timeout == NULL ? NULL : &ts32);
 #endif
 
       pthread_cleanup_pop (0);
@@ -250,4 +244,20 @@ aio_suspend (const struct aiocb *const list[], int nent,
   return result;
 }
 
+#if __TIMESIZE != 64
+librt_hidden_def (__aio_suspend_time64)
+
+int
+__aio_suspend (const struct aiocb *const list[], int nent,
+               const struct timespec *timeout)
+{
+  struct __timespec64 ts64;
+
+  if (timeout != NULL)
+    ts64 = valid_timespec_to_timespec64 (*timeout);
+
+  return __aio_suspend_time64 (list, nent, timeout != NULL ? &ts64 : NULL);
+}
+#endif
+weak_alias (__aio_suspend, aio_suspend)
 weak_alias (aio_suspend, aio_suspend64)