[glibc/azanella/pselect-time64] Move generic pselect to microblaze

[Adhemerval Zanella <azanella at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=1ed2a584a63620ad1aef822a756d0335111ec6c8

commit 1ed2a584a63620ad1aef822a756d0335111ec6c8
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue Nov 12 11:39:06 2019 -0300

    Move generic pselect to microblaze
    
    The generic pselect has the very specific race condition that motived
    the creation of the syscall, no atomicity in signal mask set/reset
    prior issuing the select operation).  Using it as generic
    implementation or either as fallback is counterproductive since the
    resulting implementation will have the inherent flaw the symbol
    semantic aims to fix.
    
    Also, only microblaze uses as fallback when used on kernel prior 3.15.
    
    This patch moves the generic implementation to a microblaze specific
    implementation, sets the generic internal as a ENOSYS, and cleanups
    the Linux generic implementation.
    
    Also, the microblaze generic implementation first try to issue
    pselect instead of use the fallback (since it is expect that if
    the microblaze usage does rely on pselect, a sufficient updated
    kernel will be used).
    
    Checked with a build against i686-linux-gnu (smoke test) and
    microblaze-linux-gnu.

Diff:
---
 misc/pselect.c                               | 41 ++-------------
 sysdeps/unix/sysv/linux/microblaze/pselect.c | 79 ++++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/pselect.c            | 31 ++---------
 3 files changed, 85 insertions(+), 66 deletions(-)

diff --git a/misc/pselect.c b/misc/pselect.c
index 76ded85..7296b6e 100644
--- a/misc/pselect.c
+++ b/misc/pselect.c
@@ -34,43 +34,8 @@ int
 __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	   const struct timespec *timeout, const sigset_t *sigmask)
 {
-  struct timeval tval;
-  int retval;
-  sigset_t savemask;
-
-  /* Change nanosecond number to microseconds.  This might mean losing
-     precision and therefore the `pselect` should be available.  But
-     for now it is hardly found.  */
-  if (timeout != NULL)
-    {
-      /* Catch bugs which would be hidden by the TIMESPEC_TO_TIMEVAL
-	 computations.  The division by 1000 truncates values.  */
-      if (__glibc_unlikely (timeout->tv_nsec < 0))
-	{
-	  __set_errno (EINVAL);
-	  return -1;
-	}
-
-      TIMESPEC_TO_TIMEVAL (&tval, timeout);
-    }
-
-  /* The setting and restoring of the signal mask and the select call
-     should be an atomic operation.  This can't be done without kernel
-     help.  */
-  if (sigmask != NULL)
-    __sigprocmask (SIG_SETMASK, sigmask, &savemask);
-
-  /* Note the pselect() is a cancellation point.  But since we call
-     select() which itself is a cancellation point we do not have
-     to do anything here.  */
-  retval = __select (nfds, readfds, writefds, exceptfds,
-		     timeout != NULL ? &tval : NULL);
-
-  if (sigmask != NULL)
-    __sigprocmask (SIG_SETMASK, &savemask, NULL);
-
-  return retval;
+  __set_errno (ENOSYS);
+  return -1;
 }
-#ifndef __pselect
 weak_alias (__pselect, pselect)
-#endif
+stub_warning (pselect)
diff --git a/sysdeps/unix/sysv/linux/microblaze/pselect.c b/sysdeps/unix/sysv/linux/microblaze/pselect.c
new file mode 100644
index 0000000..f426e88
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/microblaze/pselect.c
@@ -0,0 +1,79 @@
+/* Copyright (C) 1996-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+   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 <errno.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/poll.h>
+#include <sysdep-cancel.h>
+
+#define __pselect __pselect_syscall
+#include <sysdeps/unix/sysv/linux/pselect.c>
+#undef __pselect
+
+/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
+   readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
+   (if not NULL) for exceptional conditions.  If TIMEOUT is not NULL, time out
+   after waiting the interval specified therein.  Additionally set the sigmask
+   SIGMASK for this call.  Returns the number of ready descriptors, or -1 for
+   errors.  */
+int
+__pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	   const struct timespec *timeout, const sigset_t *sigmask)
+{
+  int ret = __pselect_syscall (nfds, readfds, writefds, exceptfds, timeout,
+			       sigmask);
+  if (ret < 0 && errno != ENOSYS)
+    return ret;
+
+  /* Change nanosecond number to microseconds.  This might mean losing
+     precision and therefore the `pselect` should be available.  But
+     for now it is hardly found.  */
+  struct timeval tval;
+  if (timeout != NULL)
+    {
+      /* Catch bugs which would be hidden by the TIMESPEC_TO_TIMEVAL
+	 computations.  The division by 1000 truncates values.  */
+      if (! valid_nanoseconds (timeout->tv_nsec))
+	{
+	  __set_errno (EINVAL);
+	  return -1;
+	}
+
+      TIMESPEC_TO_TIMEVAL (&tval, timeout);
+    }
+
+  /* The setting and restoring of the signal mask and the select call
+     should be an atomic operation.  This can't be done without kernel
+     help.  */
+  sigset_t savemask;
+  if (sigmask != NULL)
+    __sigprocmask (SIG_SETMASK, sigmask, &savemask);
+
+  /* Note the pselect() is a cancellation point.  But since we call
+     select() which itself is a cancellation point we do not have
+     to do anything here.  */
+  ret = __select (nfds, readfds, writefds, exceptfds,
+		  timeout != NULL ? &tval : NULL);
+
+  if (sigmask != NULL)
+    __sigprocmask (SIG_SETMASK, &savemask, NULL);
+
+  return ret;
+}
+weak_alias (__pselect, pselect)
diff --git a/sysdeps/unix/sysv/linux/pselect.c b/sysdeps/unix/sysv/linux/pselect.c
index acda3e0..77a5179 100644
--- a/sysdeps/unix/sysv/linux/pselect.c
+++ b/sysdeps/unix/sysv/linux/pselect.c
@@ -23,16 +23,6 @@
 #include <kernel-features.h>
 #include <sysdep-cancel.h>
 
-
-#ifdef __NR_pselect6
-# ifndef __ASSUME_PSELECT
-static int __generic_pselect (int nfds, fd_set *readfds, fd_set *writefds,
-			      fd_set *exceptfds,
-			      const struct timespec *timeout,
-			      const sigset_t *sigmask);
-# endif
-
-
 int
 __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	   const struct timespec *timeout, const sigset_t *sigmask)
@@ -59,24 +49,9 @@ __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
   data.ss = (__syscall_ulong_t) (uintptr_t) sigmask;
   data.ss_len = _NSIG / 8;
 
-  int result = SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds,
-                               timeout, &data);
-
-# ifndef __ASSUME_PSELECT
-  if (result == -1 && errno == ENOSYS)
-    result = __generic_pselect (nfds, readfds, writefds, exceptfds, timeout,
-				sigmask);
-# endif
-
-  return result;
+  return SYSCALL_CANCEL (pselect6, nfds, readfds, writefds, exceptfds,
+                         timeout, &data);
 }
+#ifndef __pselect
 weak_alias (__pselect, pselect)
-
-# ifndef __ASSUME_PSELECT
-#  define __pselect static __generic_pselect
-# endif
-#endif
-
-#ifndef __ASSUME_PSELECT
-# include <misc/pselect.c>
 #endif