RFR(s): 8223777: In posix_spawn mode, failing to exec() jspawnhelper does not result in an error

Thomas Stüfe thomas.stuefe at gmail.com
Tue May 14 09:36:47 UTC 2019

Neat idea!

But this incurs costs for this pipe communication on every spawn. What do
the others think?

Cheers, Thomas

On Tue, May 14, 2019 at 10:22 AM Florian Weimer <fweimer at redhat.com> wrote:

> * Thomas Stüfe:
> > This is impossible to fix completely - see Martin's comment about the
> > impossibility to foresee whether an exec() will succeed without actually
> > exec()ing. But at least we can test the execute permissions on the
> > jspawnhelper. Which this fix does. This fixes Ubuntu 16.4 (Now, I get an
> > IOException if jspawnhelper is not executable).
> I think jspawnhelper could write something to the pipe to show that it
> has started.  If you never get that notification, you know that
> jspawnhelper hasn't run, even if posix_spawn has succeeded.
> (This fix will also help qemu-user and WSL, which implement vfork as
> fork and interfere with the internal error reporting from posix_spawn.)
> Thanks,
> Florian

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