[a1369209993]

> Otherwise what would malloc return, besides void*

IIRC, historically void* didn't exist, and it used char*. It added void as a unit type, and absent historical baggage could add... let's call it "noreturn" as a bottom type:

  #define NULL ((noreturn*)0)
  noreturn* malloc(size_t);
  void free(void*);
  noreturn exit(int); // never returns
  int main() {
    // where (T)... is any expression of type T
    void x = (T)...; // throw away the value
    T y = (noreturn)...; // a nonterminating expression
    void* p = (T*)...; // pointers convertible *to* void*
    T* q = (noreturn*)...; // pointers convertible *from* noreturn*
    *(noreturn*)...; // notionally, this should always fault
    *(void*)...; // read zero bytes, so always fine
    }