Date: Tue, 9 Nov 2021 06:40:21 -0800
From: Noah Misch <noah@leadboat.com>
To: Semab Tariq <semab.tariq@enterprisedb.com>
Cc: Thomas Munro <thomas.munro@gmail.com>,
	Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>,
	Robert Haas <robertmhaas@gmail.com>,
	Andrey Borodin <x4mmm@yandex-team.ru>,
	Andres Freund <andres@anarazel.de>, CM Team <cm@enterprisedb.com>,
	PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>,
	Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>,
	Peter Geoghegan <pg@bowt.ie>
Subject: Re: CREATE INDEX CONCURRENTLY does not index prepared xact's data
Message-ID: <20211109144021.GD940092@rfd.leadboat.com>
References: 
 <CABimMB6HFAu3fRn3sD0EKU=Hhz5fxQNixrhB__8Wk-p7v5zExg@mail.gmail.com>
 <20211105112236.GA711250@rfd.leadboat.com>
 <20211106230846.GA790288@rfd.leadboat.com>
 <CABimMB4dQXvhB2Ja93BAWJzpM89RDzF-vdpM+=s4W7EbN+jKDw@mail.gmail.com>
 <20211107232202.GA882747@rfd.leadboat.com>
 <CABimMB5S-+-B5yU3g37qOg3b6+VqKKHygf0DUpG2J3WH=rd+Qg@mail.gmail.com>
 <20211108070950.GB882747@rfd.leadboat.com>
 <CABimMB4Z_qfkNrbYGXp=+oO6WPdGkVm35s9Zm+0r8gVxz_=sog@mail.gmail.com>
 <20211108144639.GA919568@rfd.leadboat.com>
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On Tue, Nov 09, 2021 at 11:55:57AM +0500, Semab Tariq wrote:
> On Mon, Nov 8, 2021 at 7:46 PM Noah Misch <noah@leadboat.com> wrote:
> > On Mon, Nov 08, 2021 at 02:09:15PM +0500, Semab Tariq wrote:
> > > On Mon, Nov 8, 2021 at 12:09 PM Noah Misch <noah@leadboat.com> wrote:
> > > > This postgres binary apparently contains an explicit branch to
> > > > 0x3fffffffff3fdc30, which is not an address reasonably expected to contain
> > > > code.  (It's not a known heap, a known stack, or a CODE section from the
> > > > binary file.)  This probably confirms a toolchain bug.
> > > >
> > > > Would you do "git checkout 166f943" in the source directory you've been
> > > > testing, then rerun the test and post the compressed
> > > > tmp_check/log directory?

> PFA tmp_check.tar.bz2

Excellent.  No crash, and the only difference in equalTupleDescs() code
generation is the branch destination addresses.  At commit 70bef49, gharial's
toolchain generates the invalid branch destination:

$ diff -U0 <(cut -b47- disasm/70bef49/equalTupleDescs) <(cut -b47- disasm/166f943/equalTupleDescs)
--- /dev/fd/63  2021-11-09 06:11:20.927444437 -0800
+++ /dev/fd/62  2021-11-09 06:11:20.926444428 -0800
@@ -100 +100 @@
-      br.call.sptk.many rp=0x40000000003cdc20
+      br.call.sptk.many rp=0x40000000003cde20
@@ -658 +658 @@
-      br.call.sptk.many rp=0x40000000003cdc20
+      br.call.sptk.many rp=0x40000000003cde20
@@ -817 +817 @@
-             br.call.sptk.many rp=0x3fffffffff3fdc30
+             br.call.sptk.many rp=0x4000000000400c30
@@ -949 +949 @@
-             br.call.sptk.many rp=0x40000000003cdc20
+             br.call.sptk.many rp=0x40000000003cde20
@@ -970 +970 @@
-             br.call.sptk.many rp=0x40000000003cdc20
+             br.call.sptk.many rp=0x40000000003cde20

Since "git diff 70bef49 166f943" contains nothing that correlates with such a
change, I'm concluding that this is a bug in gharial's toolchain.

It looks like gharial's automatic buildfarm runs have been paused for nine
days.  Feel free to unpause it.  Also, I recommend using the buildfarm client
setnotes.pl to add a note like 'Rare signal 11 from toolchain bug'.  Months or
years pass between these events.  Here are all gharial "signal 11" failures,
likely some of which have other causes:

 sysname │      snapshot       │    branch     │                                            bfurl                                            
─────────┼─────────────────────┼───────────────┼─────────────────────────────────────────────────────────────────────────────────────────────
 gharial │ 2018-04-10 00:32:08 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2018-04-10%2000%3A32%3A08
 gharial │ 2019-03-08 01:30:45 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-03-08%2001%3A30%3A45
 gharial │ 2019-03-08 08:55:31 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-03-08%2008%3A55%3A31
 gharial │ 2019-03-08 19:55:38 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-03-08%2019%3A55%3A38
 gharial │ 2019-08-20 09:57:27 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-20%2009%3A57%3A27
 gharial │ 2019-08-21 08:04:58 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-21%2008%3A04%3A58
 gharial │ 2019-08-22 00:37:03 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-22%2000%3A37%3A03
 gharial │ 2019-08-22 12:42:02 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-22%2012%3A42%3A02
 gharial │ 2019-08-24 18:43:52 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-24%2018%3A43%3A52
 gharial │ 2019-08-25 11:14:36 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-25%2011%3A14%3A36
 gharial │ 2019-08-25 18:44:04 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-25%2018%3A44%3A04
 gharial │ 2019-08-26 08:47:19 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-26%2008%3A47%3A19
 gharial │ 2019-08-26 22:30:23 │ REL_12_STABLE │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2019-08-26%2022%3A30%3A23
 gharial │ 2021-04-08 03:21:42 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2021-04-08%2003%3A21%3A42
 gharial │ 2021-04-09 06:40:31 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2021-04-09%2006%3A40%3A31
 gharial │ 2021-10-24 16:19:05 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2021-10-24%2016%3A19%3A05
 gharial │ 2021-10-24 20:38:39 │ HEAD          │ http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2021-10-24%2020%3A38%3A39
(17 rows)