commit f512634ddef242ef0ff025ddeba64ce51035040f
Author: Joseph Myers <josmyers@redhat.com>
Date:   Thu Sep 5 11:15:29 2024 +0000

    Clear flags2 flags set from mode in freopen (bug 32134)
    
    As reported in bug 32134, freopen does not clear the flags set in
    fp->_flags2 by the "e", "m" or "c" mode characters.  Clear these so
    that they can be set or not as appropriate from the mode string passed
    to freopen.  The relevant test for "e" in tst-freopen2-main.c is
    enabled accordingly; "c" is expected to be covered in a separately
    written test (and while tst-freopen2-main.c does include transitions
    to and from "m", that's not really a semantic flag intended to result
    in behaving in an observably different way).
    
    Tested for x86_64.

diff --git a/libio/freopen.c b/libio/freopen.c
index c947a5aecfde3c80..bed034d89441f200 100644
--- a/libio/freopen.c
+++ b/libio/freopen.c
@@ -63,6 +63,9 @@ freopen (const char *filename, const char *mode, FILE *fp)
 	 up here. */
       _IO_old_file_close_it (fp);
       _IO_JUMPS_FUNC_UPDATE (fp, &_IO_old_file_jumps);
+      fp->_flags2 &= ~(_IO_FLAGS2_MMAP
+		       | _IO_FLAGS2_NOTCANCEL
+		       | _IO_FLAGS2_CLOEXEC);
       result = _IO_old_file_fopen (fp, gfilename, mode);
     }
   else
@@ -72,6 +75,9 @@ freopen (const char *filename, const char *mode, FILE *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;
+      fp->_flags2 &= ~(_IO_FLAGS2_MMAP
+		       | _IO_FLAGS2_NOTCANCEL
+		       | _IO_FLAGS2_CLOEXEC);
       result = _IO_file_fopen (fp, gfilename, mode, 1);
       if (result != NULL)
 	result = __fopen_maybe_mmap (result);
diff --git a/libio/freopen64.c b/libio/freopen64.c
index fb02c201bd83c401..9a314c65c1d8a5a4 100644
--- a/libio/freopen64.c
+++ b/libio/freopen64.c
@@ -56,6 +56,9 @@ freopen64 (const char *filename, const char *mode, FILE *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;
+  fp->_flags2 &= ~(_IO_FLAGS2_MMAP
+		   | _IO_FLAGS2_NOTCANCEL
+		   | _IO_FLAGS2_CLOEXEC);
   result = _IO_file_fopen (fp, gfilename, mode, 0);
   fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
   if (result != NULL)
diff --git a/stdio-common/tst-freopen2-main.c b/stdio-common/tst-freopen2-main.c
index 22b21afebf709563..5dad41c76b02e6de 100644
--- a/stdio-common/tst-freopen2-main.c
+++ b/stdio-common/tst-freopen2-main.c
@@ -308,9 +308,7 @@ do_test (void)
   TEST_VERIFY_EXIT (fp != NULL);
   ret = fcntl (fileno (fp), F_GETFD);
   TEST_VERIFY (ret != -1);
-#if 0 /* Fails to clear FD_CLOEXEC (bug 32134).  */
   TEST_COMPARE (ret & FD_CLOEXEC, 0);
-#endif
   TEST_COMPARE_FILE_STRING (fp, "plustomore");
   xfclose (fp);
   END_TEST;