Description of problem:

$ cat foo.c
#define _XOPEN_SOURCE 600
#define _FILE_OFFSET_BITS 64
#include <unistd.h>
$ gcc -D_FORTIFY_SOURCE=2 -O2 -c foo.c
In file included from /usr/include/unistd.h:1052,
                 from foo.c:3:
/usr/include/bits/unistd.h:55: error: conflicting types for âpreadâ
/usr/include/unistd.h:341: error: previous declaration of âpreadâ was here

 
Version-Release number of selected component (if applicable):
glibc-2.3.4-15

Additional info:
Maybe just s/__off_t/__off64_t/ on bits/unistd.h line 54