Re: Improper use about DatumGetInt32

Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Ashutosh Bapat <ashutosh.bapat@2ndquadrant.com>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, "Hou, Zhijie" <houzj.fnst@cn.fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-11-27T12:37:26Z
Lists: pgsql-hackers
On Thu, Nov 26, 2020 at 9:57 PM Peter Eisentraut <
peter.eisentraut@enterprisedb.com> wrote:

> On 2020-11-26 14:27, Alvaro Herrera wrote:
> > On 2020-Nov-26, Peter Eisentraut wrote:
> >
> >> The point of the patch is to have the range check somewhere.  If you
> just
> >> cast it, then you won't notice out of range arguments.  Note that other
> >> contrib modules that take block numbers work the same way.
> >
> > I'm not saying not to do that; just saying we should not propagate it to
> > places that don't need it.  get_raw_page gets its page number from
> > PG_GETARG_INT64(), and the range check should be there.  But then it
> > calls get_raw_page_internal, and it could pass a BlockNumber -- there's
> > no need to pass an int64.  So get_raw_page_internal does not need a
> > range check.
>
> Yeah, I had it like that for a moment, but then you need to duplicate
> the check in get_raw_page() and get_raw_page_fork().  I figured since
> get_raw_page_internal() does all the other argument checking also, it
> seems sensible to put the block range check there too.  But it's not a
> big deal either way.
>

FWIW, my 2c. Though I agree with both sides, I
prefer get_raw_page_internal() accepting BlockNumber, since that's what it
deals with and not the entire int8.

--
Best Wishes,
Ashutosh

Commits

  1. pageinspect: Change block number arguments to bigint

  2. tablefunc: Reject negative number of tuples passed to normal_rand()

  3. Use PG_GETARG_TRANSACTIONID where appropriate