linux: Add time64 pselect support

The syscall __NR_pselect6_time64 (32-bit) or __NR_pselect6 (64-bit)
is used as default.  For architectures with __ASSUME_TIME64_SYSCALLS
the 32-bit fallback uses __NR_pselec6.

To accomodate microblaze missing pselect6 support on kernel older
than 3.15 the fallback is moved to its own function to the microblaze
specific implementation can override it.

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).

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

include/sys/select.h

@@ -3,6 +3,22 @@
 
 #ifndef _ISOMAC
 /* Now define the internal interfaces.  */
+# if __TIMESIZE == 64
+#  define __pselect64 __pselect
+#else
+# include <struct___timespec64.h>
+extern int __pselect64 (int __nfds, fd_set *__readfds,
+			fd_set *__writefds, fd_set *__exceptfds,
+			const struct __timespec64 *__timeout,
+			const __sigset_t *__sigmask);
+libc_hidden_proto (__pselect64)
+
+extern int __pselect32 (int __nfds, fd_set *__readfds,
+			fd_set *__writefds, fd_set *__exceptfds,
+			const struct __timespec64 *__timeout,
+			const __sigset_t *__sigmask)
+  attribute_hidden;
+#endif
 extern int __pselect (int __nfds, fd_set *__readfds,
 		      fd_set *__writefds, fd_set *__exceptfds,
 		      const struct timespec *__timeout,

sysdeps/unix/sysv/linux/Makefile

@@ -61,7 +61,7 @@ sysdep_routines += adjtimex clone umount umount2 readahead sysctl \
 		   open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get \
 		   timerfd_gettime timerfd_settime prctl \
 		   process_vm_readv process_vm_writev clock_adjtime \
-		   time64-support
+		   time64-support pselect32
 
 CFLAGS-gethostid.c = -fexceptions
 CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables

sysdeps/unix/sysv/linux/microblaze/pselect32.c

@@ -23,38 +23,27 @@
 #include <sysdep-cancel.h>
 
 #ifndef __ASSUME_PSELECT
-# define __pselect __pselect_syscall
-#endif
-
-/* If pselect is supported, just use the Linux generic implementation.  */
-#include <sysdeps/unix/sysv/linux/pselect.c>
-
-#ifndef __ASSUME_PSELECT
-# undef __pselect
 int
-__pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+__pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
-	   const struct timespec *timeout, const sigset_t *sigmask)
+	     fd_set *exceptfds, const struct __timespec64 *timeout,
+	     const sigset_t *sigmask)
 {
-  int ret = __pselect_syscall (nfds, readfds, writefds, exceptfds, timeout,
-			       sigmask);
-  if (ret >= 0 || errno != ENOSYS)
-    return ret;
-
   /* The fallback uses 'select' which shows the race condition regarding
      signal mask set/restore, requires two additional syscalls, and has
      a worse timeout precision (microseconds instead of nanoseconds).  */
 
-  struct timeval tval, *ptval = NULL;
+  struct timeval tv32, *ptv32 = NULL;
   if (timeout != NULL)
     {
-      if (! valid_nanoseconds (timeout->tv_nsec))
+      if (! in_time_t_range (timeout->tv_sec)
+	  || ! valid_nanoseconds (timeout->tv_nsec))
 	{
 	  __set_errno (EINVAL);
 	  return -1;
 	}
 
-      TIMESPEC_TO_TIMEVAL (&tval, timeout);
+      tv32 = valid_timespec64_to_timeval (*timeout);
-      ptval = &tval;
+      ptv32 = &tv32;
     }
 
   sigset_t savemask;
@@ -62,12 +51,11 @@ __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
     __sigprocmask (SIG_SETMASK, sigmask, &savemask);
 
   /* select itself is a cancellation entrypoint.  */
-  ret = __select (nfds, readfds, writefds, exceptfds, ptval);
+  int ret = __select (nfds, readfds, writefds, exceptfds, ptv32);
 
   if (sigmask != NULL)
     __sigprocmask (SIG_SETMASK, &savemask, NULL);
 
   return ret;
 }
-weak_alias (__pselect, pselect)
+#endif /* __ASSUME_PSELECT  */
-#endif

sysdeps/unix/sysv/linux/pselect.c

@@ -18,14 +18,15 @@
 
 #include <sys/select.h>
 #include <sysdep-cancel.h>
+#include <time64-support.h>
 
 int
-__pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+__pselect64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
-	   const struct timespec *timeout, const sigset_t *sigmask)
+	     const struct __timespec64 *timeout, const sigset_t *sigmask)
 {
   /* The Linux kernel can in some situations update the timeout value.
      We do not want that so use a local variable.  */
-  struct timespec tval;
+  struct __timespec64 tval;
   if (timeout != NULL)
     {
       tval = *timeout;
@@ -36,18 +37,46 @@ __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
      we can only pass in 6 directly.  If there is an architecture with
      support for more parameters a new version of this file needs to
      be created.  */
-  struct
-  {
-    __syscall_ulong_t ss;
-    __syscall_ulong_t ss_len;
-  } data;
 
-  data.ss = (__syscall_ulong_t) (uintptr_t) sigmask;
+#ifndef __NR_pselect6_time64
-  data.ss_len = __NSIG_BYTES;
+# define __NR_pselect6_time64 __NR_pselect6
+#endif
+  int r;
+  if (supports_time64 ())
+    {
+      r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
+			  timeout,
+			  ((__syscall_ulong_t[]){ (uintptr_t) sigmask,
+						  __NSIG_BYTES }));
+      if (r == 0 || errno != ENOSYS)
+	return r;
 
-  return SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds,
+      mark_time64_unsupported ();
-                         timeout, &data);
+    }
+
+#ifndef __ASSUME_TIME64_SYSCALLS
+  r = __pselect32 (nfds, readfds, writefds, exceptfds, timeout, sigmask);
+#endif
+  return r;
 }
+
+#if __TIMESIZE != 64
+libc_hidden_def (__pselect64)
+
+int
+__pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	   const struct timespec *timeout, const sigset_t *sigmask)
+{
+  struct __timespec64 ts64, *pts64 = NULL;
+  if (timeout != NULL)
+    {
+      ts64 = valid_timespec_to_timespec64 (*timeout);
+      pts64 = &ts64;
+    }
+  return __pselect64 (nfds, readfds, writefds, exceptfds, pts64, sigmask);
+}
+#endif
+
 #ifndef __pselect
 weak_alias (__pselect, pselect)
 #endif

sysdeps/unix/sysv/linux/pselect32.c

@@ -0,0 +1,47 @@
+/* Synchronous I/O multiplexing.  Linux 32-bit time fallback.
+   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; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/select.h>
+#include <sysdep-cancel.h>
+
+#ifndef __ASSUME_TIME64_SYSCALLS
+
+int
+__pselect32 (int nfds, fd_set *readfds, fd_set *writefds,
+	     fd_set *exceptfds, const struct __timespec64 *timeout,
+	     const sigset_t *sigmask)
+{
+  struct timespec ts32, *pts32 = NULL;
+  if (timeout != NULL)
+    {
+      if (! in_time_t_range (timeout->tv_sec))
+	{
+	  __set_errno (EINVAL);
+	  return -1;
+	}
+
+      ts32 = valid_timespec64_to_timespec (*timeout);
+      pts32 = &ts32;
+    }
+
+  return SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds,
+			 pts32,
+			 ((__syscall_ulong_t[]){ (uintptr_t) sigmask,
+						 __NSIG_BYTES }));
+}
+#endif