X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fdup3.c;h=2f87da61678255172208d357485048c8edd7d555;hb=86fd2114ac3940e03a02e99658c8df88aed8a235;hp=b9fb341f3b3fe94df45233ef6a0fee21b6a9d8cc;hpb=c246263698fcd636f1333b0d12c80d7ed581e980;p=pspp

diff --git a/lib/dup3.c b/lib/dup3.c
index b9fb341f3b..2f87da6167 100644
--- a/lib/dup3.c
+++ b/lib/dup3.c
@@ -1,5 +1,5 @@
 /* Copy a file descriptor, applying specific flags.
-   Copyright (C) 2009 Free Software Foundation, Inc.
+   Copyright (C) 2009-2011 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -29,6 +29,8 @@
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 /* Native Woe32 API.  */
 
+# include <string.h>
+
 /* Get declarations of the Win32 API functions.  */
 # define WIN32_LEAN_AND_MEAN
 # include <windows.h>
@@ -36,19 +38,36 @@
 /* Upper bound on getdtablesize().  See lib/getdtablesize.c.  */
 # define OPEN_MAX_MAX 0x10000
 
-#else
-/* Unix API.  */
-
-# ifndef O_CLOEXEC
-#  define O_CLOEXEC 0
-# endif
-
 #endif
 
 int
 dup3 (int oldfd, int newfd, int flags)
 {
-  if (oldfd < 0 || newfd < 0 || newfd >= getdtablesize ())
+#if HAVE_DUP3
+# undef dup3
+  /* Try the system call first, if it exists.  (We may be running with a glibc
+     that has the function but with an older kernel that lacks it.)  */
+  {
+    /* Cache the information whether the system call really exists.  */
+    static int have_dup3_really; /* 0 = unknown, 1 = yes, -1 = no */
+    if (have_dup3_really >= 0)
+      {
+        int result = dup3 (oldfd, newfd, flags);
+        if (!(result < 0 && errno == ENOSYS))
+          {
+            have_dup3_really = 1;
+# if REPLACE_FCHDIR
+            if (0 <= result)
+              result = _gl_register_dup (oldfd, newfd);
+# endif
+            return result;
+          }
+        have_dup3_really = -1;
+      }
+  }
+#endif
+
+  if (newfd < 0 || newfd >= getdtablesize () || fcntl (oldfd, F_GETFD) == -1)
     {
       errno = EBADF;
       return -1;
@@ -69,126 +88,23 @@ dup3 (int oldfd, int newfd, int flags)
       return -1;
     }
 
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-/* Native Woe32 API.  */
-
   if (flags & O_CLOEXEC)
     {
-      /* Neither dup() nor dup2() can create a file descriptor with
-	 O_CLOEXEC = O_NOINHERIT set.  We need to use the low-level function
-	 _open_osfhandle for this.  Iterate until all file descriptors less
-	 than newfd are filled up.  */
-      HANDLE curr_process = GetCurrentProcess ();
-      HANDLE old_handle = (HANDLE) _get_osfhandle (oldfd);
-      unsigned char fds_to_close[OPEN_MAX_MAX / CHAR_BIT];
-      unsigned int fds_to_close_bound = 0;
       int result;
-
-      if (old_handle == INVALID_HANDLE_VALUE)
-	{
-	  /* oldfd is not open, or is an unassigned standard file
-	     descriptor.  */
-	  errno = EBADF;
-	  return -1;
-	}
-
       close (newfd);
-
-      for (;;)
-	{
-	  HANDLE new_handle;
-	  int duplicated_fd;
-	  unsigned int index;
-
-	  if (!DuplicateHandle (curr_process,	      /* SourceProcessHandle */
-				old_handle,	      /* SourceHandle */
-				curr_process,	      /* TargetProcessHandle */
-				(PHANDLE) &new_handle, /* TargetHandle */
-				(DWORD) 0,	      /* DesiredAccess */
-				FALSE,		      /* InheritHandle */
-				DUPLICATE_SAME_ACCESS)) /* Options */
-	    {
-	      errno = EBADF; /* arbitrary */
-	      result = -1;
-	      break;
-	    }
-	  duplicated_fd = _open_osfhandle ((long) new_handle, flags);
-	  if (duplicated_fd < 0)
-	    {
-	      CloseHandle (new_handle);
-	      result = -1;
-	      break;
-	    }
-	  if (duplicated_fd > newfd)
-	    /* Shouldn't happen, since newfd is still closed.  */
-	    abort ();
-	  if (duplicated_fd == newfd)
-	    {
-	      result = newfd;
-	      break;
-	    }
-
-	  /* Set the bit duplicated_fd in fds_to_close[].  */
-	  index = (unsigned int) duplicated_fd / CHAR_BIT;
-	  if (index >= fds_to_close_bound)
-	    {
-	      if (index >= sizeof (fds_to_close))
-		/* Need to increase OPEN_MAX_MAX.  */
-		abort ();
-	      memset (fds_to_close + fds_to_close_bound, '\0',
-		      index + 1 - fds_to_close_bound);
-	      fds_to_close_bound = index + 1;
-	    }
-	  fds_to_close[index] |= 1 << ((unsigned int) duplicated_fd % CHAR_BIT);
-	}
-
-      /* Close the previous fds that turned out to be too small.  */
-      {
-	int saved_errno = errno;
-	unsigned int duplicated_fd;
-
-	for (duplicated_fd = 0;
-	     duplicated_fd < fds_to_close_bound * CHAR_BIT;
-	     duplicated_fd++)
-	  if ((fds_to_close[duplicated_fd / CHAR_BIT]
-	       >> (duplicated_fd % CHAR_BIT))
-	      & 1)
-	    close (duplicated_fd);
-
-	errno = saved_errno;
-      }
-
-      return result;
+      result = fcntl (oldfd, F_DUPFD_CLOEXEC, newfd);
+      if (newfd < result)
+        {
+          close (result);
+          errno = EIO;
+          result = -1;
+        }
+      if (result < 0)
+        return -1;
     }
-
-  if (dup2 (oldfd, newfd) < 0)
-    return -1;
-
-#else
-/* Unix API.  */
-
-  if (dup2 (oldfd, newfd) < 0)
+  else if (dup2 (oldfd, newfd) < 0)
     return -1;
 
-  /* POSIX <http://www.opengroup.org/onlinepubs/9699919799/functions/dup.html>
-     says that initially, the FD_CLOEXEC flag is cleared on newfd.  */
-
-  if (flags & O_CLOEXEC)
-    {
-      int fcntl_flags;
-
-      if ((fcntl_flags = fcntl (newfd, F_GETFD, 0)) < 0
-	  || fcntl (newfd, F_SETFD, fcntl_flags | FD_CLOEXEC) == -1)
-	{
-	  int saved_errno = errno;
-	  close (newfd);
-	  errno = saved_errno;
-	  return -1;
-	}
-    }
-
-#endif
-
 #if O_BINARY
   if (flags & O_BINARY)
     setmode (newfd, O_BINARY);