stub command allows you stub out functions, optionally specifying the
gef➤ stub [-h] [-r RETVAL] [LOCATION]
LOCATION indicates the address of the function to bypass. If not
specified, gef will consider the instruction at the program counter to be the
start of the function.
-r RETVAL is provided, gef will set the return value to the provided
value. Otherwise it will set the return value to 0.
For example, it is trivial to bypass
fork() calls. Since the return value is
set to 0, it will in fact drop us into the "child" process. It must be noted
that this is a different behaviour from the classic
child since here we do not spawn a new process, we only trick the parent
process into thinking it has become the child.