The issue here is that __ctype_b() is actually gone for __ctype_b_loc() because Red Hat uses a new locale model. However, in libc.so, __ctype_b is still exported as compatibility symbol;
arm-linux-gcc --version
arm-linux-gcc (GCC) 3.2.3
Copyright (C) 2002 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
gcc --version
gcc (GCC) 3.4.3
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.