open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix incorrect logic in plpgsql for cleanup after evaluation of non-simple

Browse Source 
expressions.  We need to deal with this when handling subscripts in an array
assignment, and also when catching an exception.  In an Assert-enabled build
these omissions led to Assert failures, but I think in a normal build the
only consequence would be short-term memory leakage; which may explain why
this wasn't reported from the field long ago.

Back-patch to all supported versions.  7.4 doesn't have exceptions, but
otherwise these bugs go all the way back.

Heikki Linnakangas and Tom Lane
REL8_4_STABLE
Tom Lane 16 years ago
parent 4e49ea084e
commit 63c232b505
3 changed files with 123 additions and 3 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 43
      src/pl/plpgsql/src/pl_exec.c
  2. 43
      src/test/regress/expected/plpgsql.out
  3. 40
      src/test/regress/sql/plpgsql.sql

43
src/pl/plpgsql/src/pl_exec.c
Unescape View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.244.2.6 2010/07/05 09:27:24 heikki Exp $
* $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.244.2.7 2010/08/09 18:50:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1076,6 +1076,9 @@ exec_stmt_block(PLpgSQL_execstate *estate, PLpgSQL_stmt_block *block)
*/
SPI_restore_connection();
/* Must clean up the econtext too */
exec_eval_cleanup(estate);
/* Look for a matching exception handler */
foreach(e, block->exceptions->exc_list)
{
@ -2636,6 +2639,9 @@ plpgsql_estate_setup(PLpgSQL_execstate *estate,
*
* NB: the result of the evaluation is no longer valid after this is done,
* unless it is a pass-by-value datatype.
*
* NB: if you change this code, see also the hacks in exec_assign_value's
* PLPGSQL_DTYPE_ARRAYELEM case.
* ----------
*/
static void
@ -3443,6 +3449,10 @@ exec_assign_expr(PLpgSQL_execstate *estate, PLpgSQL_datum *target,
/* ----------
* exec_assign_value Put a value into a target field
*
* Note: in some code paths, this may leak memory in the eval_econtext;
* we assume that will be cleaned up later by exec_eval_cleanup. We cannot
* call exec_eval_cleanup here for fear of destroying the input Datum value.
* ----------
*/
static void
@ -3693,6 +3703,9 @@ exec_assign_value(PLpgSQL_execstate *estate,
case PLPGSQL_DTYPE_ARRAYELEM:
{
/*
* Target is an element of an array
*/
int nsubscripts;
int i;
PLpgSQL_expr *subscripts[MAXDIM];
@ -3708,10 +3721,19 @@ exec_assign_value(PLpgSQL_execstate *estate,
coerced_value;
ArrayType *oldarrayval;
ArrayType *newarrayval;
SPITupleTable *save_eval_tuptable;
/*
* We need to do subscript evaluation, which might require
* evaluating general expressions; and the caller might have
* done that too in order to prepare the input Datum. We
* have to save and restore the caller's SPI_execute result,
* if any.
*/
save_eval_tuptable = estate->eval_tuptable;
estate->eval_tuptable = NULL;
/*
* Target is an element of an array
*
* To handle constructs like x[1][2] := something, we have to
* be prepared to deal with a chain of arrayelem datums. Chase
* back to find the base array datum, and save the subscript
@ -3765,8 +3787,23 @@ exec_assign_value(PLpgSQL_execstate *estate,
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array subscript in assignment must not be null")));
/*
* Clean up in case the subscript expression wasn't simple.
* We can't do exec_eval_cleanup, but we can do this much
* (which is safe because the integer subscript value is
* surely pass-by-value), and we must do it in case the
* next subscript expression isn't simple either.
*/
if (estate->eval_tuptable != NULL)
SPI_freetuptable(estate->eval_tuptable);
estate->eval_tuptable = NULL;
}
/* Now we can restore caller's SPI_execute result if any. */
Assert(estate->eval_tuptable == NULL);
estate->eval_tuptable = save_eval_tuptable;
/* Coerce source value to match array element type. */
coerced_value = exec_simple_cast_value(value,
valtype,

43
src/test/regress/expected/plpgsql.out
Unescape View File

@ -3737,6 +3737,49 @@ SELECT * FROM leaker_1(true);
DROP FUNCTION leaker_1(bool);
DROP FUNCTION leaker_2(bool);
-- Test for appropriate cleanup of non-simple expression evaluations
-- (bug in all versions prior to August 2010)
CREATE FUNCTION nonsimple_expr_test() RETURNS text[] AS $$
DECLARE
arr text[];
lr text;
i integer;
BEGIN
arr := array[array['foo','bar'], array['baz', 'quux']];
lr := 'fool';
i := 1;
-- use sub-SELECTs to make expressions non-simple
arr[(SELECT i)][(SELECT i+1)] := (SELECT lr);
RETURN arr;
END;
$$ LANGUAGE plpgsql;
SELECT nonsimple_expr_test();
nonsimple_expr_test
-------------------------
{{foo,fool},{baz,quux}}
(1 row)
DROP FUNCTION nonsimple_expr_test();
CREATE FUNCTION nonsimple_expr_test() RETURNS integer AS $$
declare
i integer NOT NULL := 0;
begin
begin
i := (SELECT NULL::integer); -- should throw error
exception
WHEN OTHERS THEN
i := (SELECT 1::integer);
end;
return i;
end;
$$ LANGUAGE plpgsql;
SELECT nonsimple_expr_test();
nonsimple_expr_test
---------------------
1
(1 row)
DROP FUNCTION nonsimple_expr_test();
-- Test handling of string literals.
set standard_conforming_strings = off;
create or replace function strtest() returns text as $$

40
src/test/regress/sql/plpgsql.sql
Unescape View File

@ -3006,6 +3006,46 @@ SELECT * FROM leaker_1(true);
DROP FUNCTION leaker_1(bool);
DROP FUNCTION leaker_2(bool);
-- Test for appropriate cleanup of non-simple expression evaluations
-- (bug in all versions prior to August 2010)
CREATE FUNCTION nonsimple_expr_test() RETURNS text[] AS $$
DECLARE
arr text[];
lr text;
i integer;
BEGIN
arr := array[array['foo','bar'], array['baz', 'quux']];
lr := 'fool';
i := 1;
-- use sub-SELECTs to make expressions non-simple
arr[(SELECT i)][(SELECT i+1)] := (SELECT lr);
RETURN arr;
END;
$$ LANGUAGE plpgsql;
SELECT nonsimple_expr_test();
DROP FUNCTION nonsimple_expr_test();
CREATE FUNCTION nonsimple_expr_test() RETURNS integer AS $$
declare
i integer NOT NULL := 0;
begin
begin
i := (SELECT NULL::integer); -- should throw error
exception
WHEN OTHERS THEN
i := (SELECT 1::integer);
end;
return i;
end;
$$ LANGUAGE plpgsql;
SELECT nonsimple_expr_test();
DROP FUNCTION nonsimple_expr_test();
-- Test handling of string literals.
set standard_conforming_strings = off;

Write Preview
Loading…
Cancel
Save