Re: Looking at "int vforked" in signal handler is racy

Denys Vlasenko <[email protected]> Sat, 9 Aug 2025 15:42:13 +0200

Newsgroups	org.kernel.vger.dash
Message-ID	<[email protected]>

> I see this solution:
> 
> vfork_parent_pid = getpid();
> have_vfork_sibling = 1;
> pid = vfork();
> if (!pid) { child ops; NORETURN; }
> have_vfork_sibling = 0;
> 
> void
> onsig(int signo)
> {
>          if (after_vfork && getpid() != vfork_parent_pid)
                ^^^^^^^^^^^s/after_vfork/have_vfork_sibling/

>                  /* We are vfork child, DO NOT MODIFY ANY VARIABLES! */
>                  return;