Undefined reference when I call a function in ARM from C

.extern tratar_excepcion

.global exception_data_abort

exception_data_abort:
mov r0, #1
b tratar_excepcion

In the first file what I do is to clear the function in assembler that is going to deal with the interruption and what it is going to do, it is going to move a 1 to a record and then it will jump to a function in c.

void exception_data_abort(void);
void configurar_interrupciones() {
pISR_DABORT = (unsigned) exception_data_abort;
}

void tratar_excepcion(int tipo){
D8Led_symbol(tipo);
while(1);
 }

In the second file, I assign to the ABORT interrupt the function defined above so that when an interruption of that type occurs, that instruction is executed.

When I compile it gives me a bug of undefined reference to 'exception_data_abort'

And I do not know why.