Horton

Re: PostgreSQL crashes with SIGSEGV

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Aleksandr Parfenov <a.parfenov@postgrespro.ru>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2018-03-27T03:40:51Z
Lists: pgsql-bugs, pgsql-hackers 
On Mon, Mar 26, 2018 at 5:14 AM, Kyotaro HORIGUCHI
<horiguchi.kyotaro@lab.ntt.co.jp> wrote:
>> Attached patches do it that way. I'm happy with what I came up with,
>> which is a lot simpler than my first approach. The extra copying seems
>> likely to be well worth it, since it is fairly isolated in practice,
>> especially on 9.6. There is no extra copying from v10+, since they
>> don't need the first fix at all.

> If no one objects, I'll mark this as Ready for Commit in a couple
> of days.

Thank you for the review, Horiguchi-san. It's hard to decide how
important each goal is when coming up with a back-patchable fix like
this. When the goals are somewhat in competition with each other, a
second or a third opinion is particularly appreciated.

-- 
Peter Geoghegan

Commits

  1. Fix actual and potential double-frees around tuplesort usage.

  2. Allow the built-in ordered-set aggregates to share transition state.

  3. Avoid integer overflow while sifting-up a heap in tuplesort.c.

  4. Allow avoiding tuple copy within tuplesort_gettupleslot().

  5. Remove should_free arguments to tuplesort routines.

  6. Fix use-after-free around DISTINCT transition function calls.

  7. Reuse abbreviated keys in ordered [set] aggregates.