On Linux, the symbols in glibc are marked as "weak"---that is, if the symbol "malloc" isn't found in another object file, then the one in glibc is used. It's t

On Linux, the symbols in glibc are marked as "weak"---that is, if the symbol "malloc" isn't found in another object file, then the one in glibc is used. It's that way so that users can override system provided functions (non-"weak" symbols that are duplicated are considered an error).