Re: pgsql: Implementation of subscripting for jsonb

Alexander Korotkov <aekorotkov@gmail.com>

From: Alexander Korotkov <aekorotkov@gmail.com>

To: Tom Lane <tgl@sss.pgh.pa.us>

Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Alexander Korotkov <akorotkov@postgresql.org>, pgsql-committers <pgsql-committers@lists.postgresql.org>

Date: 2021-02-01T12:41:59Z

Lists: pgsql-hackers

Attachments

pg_comp_crc32c_sse42_no_sanitize_alignment.patch (application/octet-stream) patch

On Mon, Feb 1, 2021 at 10:06 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Heikki Linnakangas <hlinnaka@iki.fi> writes:
> > On 31/01/2021 22:54, Alexander Korotkov wrote:
> >> Implementation of subscripting for jsonb
>
> > The Itanium and sparc64 buildfarm members didn't like this, and are
> > crashing at "select ('123'::jsonb)['a'];". Unaligned memory access, perhaps?
>
> I think I just identified the cause.

Thanks again for fixing this.

BTW, I managed to reproduce the issue by compiling with CFLAGS="-O0
-fsanitize=alignment -fsanitize-trap=alignment" and the patch
attached.

I can propose the following to catch such issues earlier.  We could
finish (wrap attribute with macro and apply it to other places with
misalignment access if any) and apply the attached patch and make
commitfest.cputube.org check patches with CFLAGS="-O0
-fsanitize=alignment -fsanitize-trap=alignment".  What do you think?

------
Regards,
Alexander Korotkov

Commits

pg_attribute_no_sanitize_alignment() macro
- cc7ea0717b12 9.6.22 landed
- c86eae39ce1e 13.3 landed
- c3dc311ffd64 12.7 landed
- 22001684623b 11.12 landed
- 02e7da01a436 10.17 landed
- 993bdb9f935a 14.0 landed
Tweak compiler version cutoff for no_sanitize("alignment") support.
- ad2ad698ac16 14.0 landed
Implementation of subscripting for jsonb
- 676887a3b0b8 14.0 cited