Date: Fri, 10 Jan 2020 15:38:07 -0500
From: Stephen Frost <sfrost@snowman.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter <pmc@citylink.dinoex.sub.org>, pgsql-hackers@lists.postgresql.org
Subject: Re: 12.1 not useable: clientlib fails after a dozen queries (GSSAPI
 ?)
Message-ID: <20200110203807.GC3195@tamriel.snowman.net>
References: <20200109181822.GA74698@gate.oper.dinoex.org>
 <7042.1578595681@sss.pgh.pa.us>
 <20200109205319.GA85142@gate.oper.dinoex.org>
 <15232.1578605504@sss.pgh.pa.us>
 <20200110022342.GA92515@gate.oper.dinoex.org>
 <12348.1578679149@sss.pgh.pa.us>
 <16362.1578684322@sss.pgh.pa.us>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="iK81oC7B6hkgNW1o"
Content-Disposition: inline
In-Reply-To: <16362.1578684322@sss.pgh.pa.us>
User-Agent: Mutt/1.5.24 (2015-08-30)
Precedence: bulk


--iK81oC7B6hkgNW1o
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Greetings,

* Tom Lane (tgl@sss.pgh.pa.us) wrote:
> I wrote:
> > I haven't run it further to ground than that, but there's definitely
> > something fishy here.  Based on just these results one would be hard
> > pressed to say if it's our bug or FreeBSD's, but your report that you
> > don't see the failure with PG 11 makes it sound like our problem.
>=20
> Ah, I have it: whoever wrote pg_GSS_read() failed to pay attention
> to the fact that setting errno is a critical part of its API.
> Sometimes it returns -1 while leaving errno in a state that causes
> pqReadData to draw the wrong conclusions.  In particular that can
> happen when it reads an incomplete packet, and that's very timing
> dependent, which is why this is so ticklish to reproduce.

Ah-hah.  Not sure if that was Robbie or myself (probably me, really,
since I rewrote a great deal of that code).  I agree that the regression
tests don't test with very much data, but I tested pushing quite a bit
of data through and didn't see any issues with my testing.  Apparently I
was getting pretty lucky. :/

> I'll have a patch in a little while.

That's fantastic, thanks!

Stephen

--iK81oC7B6hkgNW1o
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iQIcBAEBCgAGBQJeGOCvAAoJEO1sijiDR2RV2bgP/RjQqDLKSPmUBxiF07t7ChPf
cAwMPl6TFolrkXzwDmoUb8EE0AHC1OkA3O23pPwDE6FK2Bl+jAVmTPaaIaJwasDu
bCu6l0JSy7mwQhMj99Qd7THV6+8ZITCsshjJaqdmrttLzS/FzeToq4D1IKUA2qx6
Rn/PrKeWwxRq+6jRpAV+p99ARpWNqxGkfzOuGLYgPLWBL2IdRvAd0cuxVatUsKHs
oiw7MdGoUu/lSB2a2LoVnLHvyvAi+9im5dfhjc+6QlYHBjB6Hv5fN79gHw1Xn2wd
Mfionl9t+GNEFoFjhU/K4TH8EBUOLb9hLhnC38xqErYT+T4O7ujX20pXR3NoIY+n
v63jcRWUCsKbAGL7uPlxdSfEViEq2UJq+c2HVbFMhaT0cQy8peum/R1bEIqCewua
WW3+hwlBKwQXo4vfohib7ZVrsk574U6U/+eB3svl0oLILok+Qi99DPOCLjrMfZYZ
0FK7NAFeuxk/4y+FsaZ15O4h/xc8tF+x6oiq9Ao49uvRjWjOvBrolKsAiuYRWnEi
SR8pDijbN6zv4X5EKtfIYucQrzP3EJ9naV3vBtuaX6XFbLyMq7y1nnBTx0J9dp2s
BXTANkan98owTGQWeqy/l/R3Dn+xxYG7huIjoh2w0As49OGMVaMyW+p/6CdvZOiV
mhZy4xRVbP3q54zS6F8z
=yFJn
-----END PGP SIGNATURE-----

--iK81oC7B6hkgNW1o--