Fix a few problems in fopen and freopen

fopen should set the FD_CLOEXEC flag if requested evenif the kernel does
not support an aotmic operation.

freopen should reuse the file descriptor for the stream.  This is
especially important for calls to change the standard streams (stin,
stdout, stderr).

5 files changed, 121 insertions, 37 deletions

diff --git a/libio/fileops.c b/libio/fileops.c
index 343afa6..2b696ab 100644
--- a/libio/fileops.c
+++ b/libio/fileops.c
@@ -180,7 +180,8 @@ _IO_new_file_close_it (fp)
 
   INTUSE(_IO_unsave_markers) (fp);
 
-  int close_status = _IO_SYSCLOSE (fp);
+  int close_status = ((fp->_flags2 & _IO_FLAGS2_NOCLOSE) == 0
+		      ? _IO_SYSCLOSE (fp) : 0);
 
   /* Free buffer. */
 #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
@@ -328,11 +329,12 @@ _IO_new_file_fopen (fp, filename, mode, is32not64)
 	case 'c':
 	  fp->_flags2 |= _IO_FLAGS2_NOTCANCEL;
 	  continue;
-#ifdef O_CLOEXEC
 	case 'e':
+#ifdef O_CLOEXEC
 	  oflags |= O_CLOEXEC;
-	  continue;
 #endif
+	  fp->_flags2 |= _IO_FLAGS2_CLOEXEC;
+	  continue;
 	default:
 	  /* Ignore.  */
 	  continue;
@@ -343,6 +345,18 @@ _IO_new_file_fopen (fp, filename, mode, is32not64)
   result = _IO_file_open (fp, filename, omode|oflags, oprot, read_write,
 			  is32not64);
 
+#ifndef __ASSUME_O_CLOEXEC
+  if ((fp->_flags2 & _IO_FLAGS2_CLOEXEC) != 0 && __have_o_cloexec <= 0)
+    {
+      if (__have_o_cloexec == 0)
+	{
+	  int flags = __fcntl (fd, F_GETFD);
+	  __have_o_cloexec = (flags & FD_CLOEXEC) == 0 ? -1 : 1;
+	}
+      if (__have_o_cloexec < 0)
+	__fcntl (fd, F_SETFD, FD_CLOEXEC);
+    }
+#endif
 
 #ifdef _LIBC
   if (result != NULL)
diff --git a/libio/freopen.c b/libio/freopen.c
index d80815f..20eda9d 100644
--- a/libio/freopen.c
+++ b/libio/freopen.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993,95,96,97,98,2000,2001,2002,2003,2008
+/* Copyright (C) 1993,95,96,97,98,2000,2001,2002,2003,2008,2011
 	Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -28,7 +28,9 @@
 
 #include "libioP.h"
 #include "stdio.h"
+#include <fcntl.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include <shlib-compat.h>
 #include <fd_to_filename.h>
@@ -40,17 +42,14 @@ freopen (filename, mode, fp)
      FILE* fp;
 {
   FILE *result;
-  int fd = -1;
   CHECK_FILE (fp, NULL);
   if (!(fp->_flags & _IO_IS_FILEBUF))
     return NULL;
   _IO_acquire_lock (fp);
-  if (filename == NULL && _IO_fileno (fp) >= 0)
-    {
-      fd = __dup (_IO_fileno (fp));
-      if (fd != -1)
-	filename = fd_to_filename (fd);
-    }
+  int fd = _IO_fileno (fp);
+  const char *gfilename = (filename == NULL && fd >= 0
+			   ? fd_to_filename (fd) : filename);
+  fp->_flags2 |= _IO_FLAGS2_NOCLOSE;
 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
   if (&_IO_stdin_used == NULL)
     {
@@ -61,7 +60,7 @@ freopen (filename, mode, fp)
 	 up here. */
       _IO_old_file_close_it (fp);
       _IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_old_file_jumps;
-      result = _IO_old_file_fopen (fp, filename, mode);
+      result = _IO_old_file_fopen (fp, gfilename, mode);
     }
   else
 #endif
@@ -70,18 +69,53 @@ freopen (filename, mode, fp)
       _IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
       if (_IO_vtable_offset (fp) == 0 && fp->_wide_data != NULL)
 	fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
-      result = INTUSE(_IO_file_fopen) (fp, filename, mode, 1);
+      result = INTUSE(_IO_file_fopen) (fp, gfilename, mode, 1);
       if (result != NULL)
 	result = __fopen_maybe_mmap (result);
     }
+  fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
   if (result != NULL)
-    /* unbound stream orientation */
-    result->_mode = 0;
-  if (fd != -1)
     {
-      __close (fd);
-      free ((char *) filename);
+      /* unbound stream orientation */
+      result->_mode = 0;
+
+      if (fd != -1)
+	{
+#ifdef O_CLOEXEC
+# ifndef __ASSUME_DUP3
+	  int newfd;
+	  if (__have_dup3 < 0)
+	    newfd = -1;
+	  else
+	    newfd =
+# endif
+	      dup3 (_IO_fileno (result), fd,
+		    (result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
+		    ? O_CLOEXEC : 0);
+#else
+# define newfd 1
+#endif
+
+#ifndef __ASSUME_DUP3
+	  if (newfd < 0)
+	    {
+	      if (errno == ENOSYS)
+		__have_dup3 = -1;
+
+	      dup2 (_IO_fileno (result), fd);
+	      if ((result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0)
+		__fcntl (fd, F_SETFD, FD_CLOEXEC);
+	    }
+#endif
+	  __close (_IO_fileno (result));
+	  _IO_fileno (result) = fd;
+	}
     }
+  else if (fd != -1)
+    __close (fd);
+  if (filename == NULL)
+    free ((char *) gfilename);
+
   _IO_release_lock (fp);
   return result;
 }
diff --git a/libio/freopen64.c b/libio/freopen64.c
index 2dad6d7..99045c6 100644
--- a/libio/freopen64.c
+++ b/libio/freopen64.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993,1995,1996,1997,1998,2000,2001,2002, 2003, 2008
+/* Copyright (C) 1993,1995,1996,1997,1998,2000,2001,2002, 2003, 2008, 2011
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -28,7 +28,9 @@
 
 #include "libioP.h"
 #include "stdio.h"
+#include <fcntl.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include <fd_to_filename.h>
 
@@ -40,32 +42,63 @@ freopen64 (filename, mode, fp)
 {
 #ifdef _G_OPEN64
   FILE *result;
-  int fd = -1;
   CHECK_FILE (fp, NULL);
   if (!(fp->_flags & _IO_IS_FILEBUF))
     return NULL;
   _IO_acquire_lock (fp);
-  if (filename == NULL && _IO_fileno (fp) >= 0)
-    {
-      fd = __dup (_IO_fileno (fp));
-      if (fd != -1)
-	filename = fd_to_filename (fd);
-    }
+  int fd = _IO_fileno (fp);
+  const char *gfilename = (filename == NULL && fd >= 0
+			   ? fd_to_filename (fd) : filename);
+  fp->_flags2 |= _IO_FLAGS2_NOCLOSE;
   INTUSE(_IO_file_close_it) (fp);
   _IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
   if (_IO_vtable_offset (fp) == 0 && fp->_wide_data != NULL)
     fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
-  result = INTUSE(_IO_file_fopen) (fp, filename, mode, 0);
+  result = INTUSE(_IO_file_fopen) (fp, gfilename, mode, 0);
+  fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
   if (result != NULL)
     result = __fopen_maybe_mmap (result);
   if (result != NULL)
-    /* unbound stream orientation */
-    result->_mode = 0;
-  if (fd != -1)
     {
-      __close (fd);
-      free ((char *) filename);
+      /* unbound stream orientation */
+      result->_mode = 0;
+
+      if (fd != -1)
+	{
+#ifdef O_CLOEXEC
+# ifndef __ASSUME_DUP3
+	  int newfd;
+	  if (__have_dup3 < 0)
+	    newfd = -1;
+	  else
+	    newfd =
+# endif
+	      dup3 (_IO_fileno (result), fd,
+		    (result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
+		    ? O_CLOEXEC : 0);
+#else
+# define newfd 1
+#endif
+
+#ifndef __ASSUME_DUP3
+	  if (newfd < 0)
+	    {
+	      if (errno == ENOSYS)
+		__have_dup3 = -1;
+
+	      dup2 (_IO_fileno (result), fd);
+	      if ((result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0)
+		__fcntl (fd, F_SETFD, FD_CLOEXEC);
+	    }
+#endif
+	  __close (_IO_fileno (result));
+	  _IO_fileno (result) = fd;
+	}
     }
+  else if (fd != -1)
+    __close (fd);
+  if (filename == NULL)
+    free ((char *) gfilename);
   _IO_release_lock (fp);
   return result;
 #else
diff --git a/libio/libio.h b/libio/libio.h
index 3c9f2bd..bebc112 100644
--- a/libio/libio.h
+++ b/libio/libio.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991-1995,1997-2006,2007,2009 Free Software Foundation, Inc.
+/* Copyright (C) 1991-1995,1997-2006,2007,2009,2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Written by Per Bothner <bothner@cygnus.com>.
 
@@ -145,6 +145,8 @@
 #define _IO_FLAGS2_USER_WBUF 8
 #ifdef _LIBC
 # define _IO_FLAGS2_SCANF_STD 16
+# define _IO_FLAGS2_NOCLOSE 32
+# define _IO_FLAGS2_CLOEXEC 64
 #endif
 
 /* These are "formatting flags" matching the iostream fmtflags enum values. */
diff --git a/libio/oldfileops.c b/libio/oldfileops.c
index be99a25..3e3daa8 100644
--- a/libio/oldfileops.c
+++ b/libio/oldfileops.c
@@ -155,7 +155,8 @@ _IO_old_file_close_it (fp)
 
   INTUSE(_IO_unsave_markers) (fp);
 
-  close_status = _IO_SYSCLOSE (fp);
+  close_status = ((fp->_flags2 & _IO_FLAGS2_NOCLOSE) == 0
+		  ? _IO_SYSCLOSE (fp) : 0);
 
   /* Free buffer. */
   INTUSE(_IO_setb) (fp, NULL, NULL, 0);
@@ -676,7 +677,7 @@ _IO_old_file_write (f, data, n)
 	{
 	  f->_flags |= _IO_ERR_SEEN;
 	  break;
-        }
+	}
       to_do -= count;
       data = (void *) ((char *) data + count);
     }
@@ -763,12 +764,12 @@ _IO_old_file_xsputn (f, data, n)
       do_write = to_do - (block_size >= 128 ? to_do % block_size : 0);
 
       if (do_write)
-        {
+	{
 	  count = old_do_write (f, s, do_write);
 	  to_do -= count;
 	  if (count < do_write)
 	    return n - to_do;
-        }
+	}
 
       /* Now write out the remainder.  Normally, this will fit in the
 	 buffer, but it's somewhat messier for line-buffered files,