[PATCH 3/3] virGlobalInit: Make glib init its own global state

[Daniel P. Berrangé]

On Thu, Jun 22, 2023 at 11:10:25AM +0200, Michal Privoznik wrote:
> On Wed, Jun 21, 2023 at 5:30 PM Daniel P. Berrangé <berrange at redhat.com> wrote:
> >
> > On Wed, Jun 21, 2023 at 04:09:11PM +0200, Michal Privoznik wrote:
> > > This should not be needed, but here's what's happening:
> > > virStrToLong_*() family of functions was switched from strtol*()
> > > to g_ascii_strtol*() in order to handle corner cases on Windows
> > > (most notably parsing hex numbers with base=0) - see
> > > v9.4.0-61-g2ed41d7cd9. But what we did not realize back then, is
> > > the fact that g_ascii_strtol*() family has their own global lock
> > > rendering virStrToLong_*() function unsafe between fork() +
> > > exec(). Worse, if one of the threads has to wait for the lock (or
> > > on its corresponding condition), then errno is mangled and
> > > g_ascii_strtol*() signals an error, even though there's no error.
> > >
> > > Read more here:
> > >
> > >   https://gitlab.gnome.org/GNOME/glib/-/issues/3034
> > >
> > > Nevertheless, if we make glib init the g_ascii_strtol*() global
> > > state (by calling one function from g_ascii_strtol*() family),
> > > then there shouldn't be any congestion on the lock and thus no
> > > errno mangling.
> > >
> > > Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> > > ---
> > >  src/libvirt.c | 8 ++++++++
> > >  1 file changed, 8 insertions(+)
> >
> > Reviewed-by: Daniel P. Berrangé <berrange at redhat.com>
> 
> Thanks, let me push this one, as it fixes both problems (daedlock and
> string parse problem) and work on the other two next week as I'm going
> AFK for the rest of the week. Jirka plans to freeze on Tuesday next
> week but after this patch, close_range()/closefrom() is not that
> critical.

Sure, sounds fine to me.

With regards,
Daniel
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