nptl/tst-cancel25 needs to be an internal test

[thirdparty/glibc.git] / libio / freopen64.c

diff --git a/libio/freopen64.c b/libio/freopen64.c
index 7e1beeff33bca3822a2c4e1258796baff53137e2..3c596894c3cbaeeae354536e87c2d9bf7b3c24e9 100644 (file)
--- a/libio/freopen64.c
+++ b/libio/freopen64.c
@@ -1,5 +1,4 @@
-/* Copyright (C) 1993,1995,1996,1997,1998,2000,2001,2002, 2003, 2008, 2011
-   Free Software Foundation, Inc.
+/* Copyright (C) 1993-2019 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
@@ -14,7 +13,7 @@
 
    You should have received a copy of the GNU Lesser General Public
    License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.
+   <https://www.gnu.org/licenses/>.
 
    As a special exception, if you link the code in this file with
    files compiled with a GNU compiler to produce an executable,
@@ -25,35 +24,39 @@
    This exception applies to code released by its copyright holders
    in files containing the exception.  */
 
-#include "libioP.h"
-#include "stdio.h"
+#include <stdio.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <libioP.h>
 #include <fd_to_filename.h>
 
 FILE *
-freopen64 (filename, mode, fp)
-     const char* filename;
-     const char* mode;
-     FILE *fp;
+freopen64 (const char *filename, const char *mode, FILE *fp)
 {
-#ifdef _G_OPEN64
-  FILE *result;
+  FILE *result = NULL;
+  char fdfilename[FD_TO_FILENAME_SIZE];
+
   CHECK_FILE (fp, NULL);
-  if (!(fp->_flags & _IO_IS_FILEBUF))
-    return NULL;
+
   _IO_acquire_lock (fp);
+  /* First flush the stream (failure should be ignored).  */
+  _IO_SYNC (fp);
+
+  if (!(fp->_flags & _IO_IS_FILEBUF))
+    goto end;
+
   int fd = _IO_fileno (fp);
-  const char *gfilename = (filename == NULL && fd >= 0
-                          ? fd_to_filename (fd) : filename);
+  const char *gfilename
+    = filename != NULL ? filename : fd_to_filename (fd, fdfilename);
+
   fp->_flags2 |= _IO_FLAGS2_NOCLOSE;
-  INTUSE(_IO_file_close_it) (fp);
-  _IO_JUMPS ((struct _IO_FILE_plus *) fp) = &_IO_file_jumps;
+  _IO_file_close_it (fp);
+  _IO_JUMPS_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, gfilename, mode, 0);
+  result = _IO_file_fopen (fp, gfilename, mode, 0);
   fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
   if (result != NULL)
     result = __fopen_maybe_mmap (result);
@@ -62,46 +65,31 @@ freopen64 (filename, mode, fp)
       /* unbound stream orientation */
       result->_mode = 0;
 
-      if (fd != -1)
+      if (fd != -1 && _IO_fileno (result) != fd)
        {
-#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)
+         /* At this point we have both file descriptors already allocated,
+            so __dup3 will not fail with EBADF, EINVAL, or EMFILE.  But
+            we still need to check for EINVAL and, due Linux internal
+            implementation, EBUSY.  It is because on how it internally opens
+            the file by splitting the buffer allocation operation and VFS
+            opening (a dup operation may run when a file is still pending
+            'install' on VFS).  */
+         if (__dup3 (_IO_fileno (result), fd,
+                     (result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
+                     ? O_CLOEXEC : 0) == -1)
            {
-             if (errno == ENOSYS)
-               __have_dup3 = -1;
-
-             __dup2 (_IO_fileno (result), fd);
-             if ((result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0)
-               __fcntl (fd, F_SETFD, FD_CLOEXEC);
+             _IO_file_close_it (result);
+             result = NULL;
+             goto end;
            }
-#endif
          __close (_IO_fileno (result));
          _IO_fileno (result) = fd;
        }
     }
   else if (fd != -1)
     __close (fd);
-  if (filename == NULL)
-    free ((char *) gfilename);
+
+end:
   _IO_release_lock (fp);
   return result;
-#else
-  __set_errno (ENOSYS);
-  return NULL;
-#endif
 }