y2038: linux: Provide __sched_rr_get_interval64 implementation

This patch replaces auto generated wrapper (as described in
sysdeps/unix/sysv/linux/syscalls.list) for sched_rr_get_interval with one which
adds extra support for reading 64 bit time values on machines with
__TIMESIZE != 64.
There is no functional change for architectures already supporting 64 bit
time ABI.

The sched_rr_get_interval declaration in ./include/sched.h is not followed by
corresponding libc_hidden_proto(), so it has been assumed that newly introduced
syscall wrapper doesn't require libc_hidden_def() (which has been added by
template used with auto generation script).

Moreover, the code for building sched_rr_gi.c file is already placed in
./posix/Makefiles, so there was no need to add it elsewhere.

Performed tests and validation are the same as for timer_gettime() conversion
(sysdeps/unix/sysv/linux/timer_gettime.c).

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

include/time.h

@@ -203,6 +203,13 @@ libc_hidden_proto (__timer_settime64);
 libc_hidden_proto (__timerfd_settime64);
 #endif
 
+#if __TIMESIZE == 64
+# define __sched_rr_get_interval64 __sched_rr_get_interval
+#else
+extern int __sched_rr_get_interval64 (pid_t pid, struct __timespec64 *tp);
+libc_hidden_proto (__sched_rr_get_interval64);
+#endif
+
 /* Compute the `struct tm' representation of T,
    offset OFFSET seconds east of UTC,
    and store year, yday, mon, mday, wday, hour, min, sec into *TP.

sysdeps/unix/sysv/linux/sched_rr_gi.c

@@ -0,0 +1,73 @@
+/* sched_rr_get_interval -- get the scheduler's SCHED_RR policy time interval.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sysdep.h>
+#include <kernel-features.h>
+
+int
+__sched_rr_get_interval64 (pid_t pid, struct __timespec64 *tp)
+{
+#ifdef __ASSUME_TIME64_SYSCALLS
+# ifndef __NR_sched_rr_get_interval_time64
+#  define __NR_sched_rr_get_interval_time64 __NR_sched_rr_get_interval
+# endif
+  return INLINE_SYSCALL_CALL (sched_rr_get_interval_time64, pid, tp);
+#else
+# ifdef __NR_sched_rr_get_interval_time64
+  int ret = INLINE_SYSCALL_CALL (sched_rr_get_interval_time64, pid, tp);
+  if (ret == 0 || errno != ENOSYS)
+    return ret;
+# endif
+  struct timespec tp32;
+  int retval = INLINE_SYSCALL_CALL (sched_rr_get_interval, pid, &tp32);
+  if (retval == 0)
+    *tp = valid_timespec_to_timespec64 (tp32);
+
+  return retval;
+#endif
+}
+
+#if __TIMESIZE != 64
+libc_hidden_def (__sched_rr_get_interval64)
+
+int
+__sched_rr_get_interval (pid_t pid, struct timespec *tp)
+{
+  int ret;
+  struct __timespec64 tp64;
+
+  ret = __sched_rr_get_interval64 (pid, &tp64);
+
+  if (ret == 0)
+    {
+      if (! in_time_t_range (tp64.tv_sec))
+        {
+          __set_errno (EOVERFLOW);
+          return -1;
+        }
+
+      *tp = valid_timespec64_to_timespec (tp64);
+    }
+
+  return ret;
+}
+#endif
+strong_alias (__sched_rr_get_interval, sched_rr_get_interval)

sysdeps/unix/sysv/linux/syscalls.list

@@ -51,7 +51,6 @@ sched_getp	-	sched_getparam	i:ip	__sched_getparam	sched_getparam
 sched_gets	-	sched_getscheduler	i:i	__sched_getscheduler	sched_getscheduler
 sched_primax	-	sched_get_priority_max	i:i	__sched_get_priority_max	sched_get_priority_max
 sched_primin	-	sched_get_priority_min	i:i	__sched_get_priority_min	sched_get_priority_min
-sched_rr_gi	-	sched_rr_get_interval	i:ip	__sched_rr_get_interval	sched_rr_get_interval
 sched_setp	-	sched_setparam	i:ip	__sched_setparam	sched_setparam
 sched_sets	-	sched_setscheduler	i:iip	__sched_setscheduler	sched_setscheduler
 sched_yield	-	sched_yield	i:	__sched_yield	sched_yield