It's important to understand that functions like execve(), which are used to spawn processes, are upstream dependencies of dynamic memory functions like malloc(

It's important to understand that functions like execve(), which are used to spawn processes, are upstream dependencies of dynamic memory functions like malloc(). It's hairy to have low-level functions in your system depend on other functions that are higher level than them. For instance I've been in situations where malloc() failed and the LLVM libcxx abort handler depends on malloc(). POSIX also defines execve() as being asynchronous signal safe, which means it isn't allowed to do things like acquire a mutex (which is necessary to allocate unbounded dynamic memory).