Re: pgcrypto: remove useless px_memset() and BF_ASM - Mailing list pgsql-hackers

From Daniel Gustafsson
Subject Re: pgcrypto: remove useless px_memset() and BF_ASM
Date
Msg-id 9B96C179-32FA-4715-BC26-4E31D9EFF3A2@yesql.se
Whole thread Raw
In response to pgcrypto: remove useless px_memset() and BF_ASM  (Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>)
List pgsql-hackers
> On 9 Apr 2026, at 13:51, Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> wrote:

> In the thread about centralised architecture detection, I noticed that
> the BF_ASM macro in crypt-blowfish.c has never been defined to anything
> but 0, and the _BF_body_r() function it would call has never existed, so
> that can be got rid of.

Agreed.  I didn't do enough archaeology to figure out what upstream has/had or
why it was removed, but it's been dead for 25 odd years so it's about time to
remove.

> While investigating at that, I also noticed that px_memset(), which has
> the comment /* memset that must not be optimized away */, is only ever
> called with zero for the value, which could be better written with
> explicit_bzero() now that we have that.

One could imagine various tricks for rewriting px_memset to explicit_bzero in
order to reduce the churn, but since this code is very rarely backpatched into
it's not a big problem IMHO.

I'll have another look with fresh eyes once back in the office.

--
Daniel Gustafsson




pgsql-hackers by date:

Previous
From: SATYANARAYANA NARLAPURAM
Date:
Subject: Bug: var_is_nonnullable() gives wrong results for old/new in RETURNING
Next
From: Yogesh Sharma
Date:
Subject: Re: Logging parallel worker draught