Horton

Re: Improper use about DatumGetInt32

Peter Eisentraut <peter.eisentraut@enterprisedb.com>

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From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
To: Michael Paquier <michael@paquier.xyz>, Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, 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: 2021-01-08T09:21:15Z
Lists: pgsql-hackers 
On 2020-12-25 08:45, Michael Paquier wrote:
>> If we really think that we ought to differentiate, then we could do what
>> pg_stat_statement does, and have a separate C function that's called
>> with the obsolete signature (pg_stat_statements_1_8 et al).
> With the 1.8 flavor, it is possible to pass down a negative number
> and it may not fail depending on the number of blocks of the relation,
> so I think that you had better have a compatibility layer if a user
> has the new binaries but is still on 1.8.  And that's surely a safe
> move.

I think on 64-bit systems it's actually safe, but on 32-bit systems 
(with USE_FLOAT8_BYVAL), if you use the new binaries with the old 
SQL-level definitions, you'd get the int4 that is passed in interpreted 
as a pointer, which would lead to very bad things.  So I think we need 
to create new functions with a different C symbol.  I'll work on that.

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