From: David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>
To: Luca Weiss <luca-IfPCFPJWly+lVyrhU4qvOw@public.gmane.org>
Cc: devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] Fix Python crash on getprop deallocation
Date: Sun, 26 Dec 2021 15:46:13 +1100 [thread overview]
Message-ID: <YcfzlVfFMqJtGFzK@yekko> (raw)
In-Reply-To: <5777466.lOV4Wx5bFT@g550jk>
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On Sat, Dec 25, 2021 at 11:25:51AM +0100, Luca Weiss wrote:
> Hi David,
>
> On Samstag, 25. Dezember 2021 07:29:58 CET David Gibson wrote:
> > On Fri, Dec 24, 2021 at 11:28:12AM +0100, Luca Weiss wrote:
> > > Fatal Python error: none_dealloc: deallocating None
> > > Python runtime state: finalizing (tstate=0x000055c9bac70920)
> > >
> > > Current thread 0x00007fbe34e47740 (most recent call first):
> > > <no Python frame>
> > >
> > > Aborted (core dumped)
> > >
> > > This is caused by a missing Py_INCREF on the returned Py_None, as
> > > demonstrated e.g. in https://github.com/mythosil/swig-python-incref or
> > > described at https://edcjones.tripod.com/refcount.html ("Remember to
> > > INCREF Py_None!")
> > >
> > > A PoC for triggering this crash is uploaded to
> > > https://github.com/z3ntu/pylibfdt-crash .
> > > With this patch applied to pylibfdt the crash does not happen.
> >
> > Any chance you could rework your testcase into the libfdt testsuite
> > (make check)?
> >
>
> To be completely honest I don't exactly understand why this crash is
> happening. If you reduce the iteration count in my PoC from the "10" I used to
> just 1 or 2, then the crash doesn't happen. But I don't have any insights into
> how Python actually allocates and deallocates things internally, as this crash
> happens during dellocation when Python exits and after the supplied code is
> already run.
Ok, fair enough. Applied to main branch.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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prev parent reply other threads:[~2021-12-26 4:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-24 10:28 [PATCH] Fix Python crash on getprop deallocation Luca Weiss
[not found] ` <20211224102811.70695-1-luca-IfPCFPJWly+lVyrhU4qvOw@public.gmane.org>
2021-12-24 13:17 ` Simon Glass
[not found] ` <CAPnjgZ227FLO_UYqsq44dQwOYqa+vXuu5BGgmjoCThHnTGS5FA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2021-12-25 6:30 ` David Gibson
2021-12-25 6:29 ` David Gibson
2021-12-25 10:25 ` Luca Weiss
2021-12-26 4:46 ` David Gibson [this message]
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