2 ms·

I think you mean between vfork and exec. The Linux manpage says: Standard description (From POSIX.1) The vfork() function has the same effect as fork(2), exce

I think you mean between vfork and exec. The Linux manpage says: Standard description (From POSIX.1) The vfork() function has the same effect as fork(2), except that the behavior is undefined if the process created by vfork() either modifies any data other than a variable of type pid_t used to store the return value from vfork(), or returns from the function in which vfork() was called, or calls any other function before successfully calling _exit(2) or one of the exec(3) family of functions.

jart 5y ago
Note that modern POSIX recommends just calling fork() because "[vfork] was previously under-specified". The glibc man pages shouldn't say undefined since that's too strong a word. There is so much you can actually do in practice during vfork(). Pretty much all system calls are just as safe. It's mostly a question of whether or not your userspace libraries might clobber some global, due to how vfork puts the process in a state where implementation details that are normally private become part of the public surface area of these apis, and not many library authors are disposed to offer those kinds of assurances.