Horton

Re: BUG #15121: Multiple UBSAN errors

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Martin Liška <marxin.liska@gmail.com>, pgsql-bugs@lists.postgresql.org
Date: 2018-03-19T18:27:05Z
Lists: pgsql-bugs 
On 2018-03-19 14:20:33 -0400, Tom Lane wrote:
> I tried -O3 with gcc 7.3.1 (Fedora 26), and that passes check-world
> just fine.  Then I tried -O3 with gcc 8.0.1 (prerelease Fedora 28),
> and indeed that's got some problems.

> Note that 1-D and 2-D arrays print fine, it's only 3-D or deeper
> that print wrong.  Very odd.  Maybe it's bad code on our part,
> but I think the odds are at least as good that it's a new gcc bug.

Might be worth trying with a new clang, I think it's been a bit ahead on
the quality of the ubsan (et al) integration quality.

Greetings,

Andres Freund

Commits

  1. Don't read fields of a misaligned ExpandedObjectHeader or AnyArrayType.

  2. Doc: note that statement-level view triggers require an INSTEAD OF trigger.