From e415b469b33ba328765e39fd62edcd28f30d9c3c Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Wed, 7 Jan 2015 22:33:58 -0500
Subject: [PATCH] Reject ANALYZE commands during VACUUM FULL or another
ANALYZE.
vacuum()'s static variable handling makes it non-reentrant; an ensuing
null pointer deference crashed the backend. Back-patch to 9.0 (all
supported versions).
---
src/backend/commands/vacuum.c | 14 ++++++++++++--
src/test/regress/expected/vacuum.out | 14 +++++++++++++-
src/test/regress/sql/vacuum.sql | 9 ++++++++-
3 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a787e8071fe..2f3f79d87d3 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -105,6 +105,7 @@ vacuum(VacuumStmt *vacstmt, Oid relid, bool do_toast,
volatile bool in_outer_xact,
use_own_xacts;
List *relations;
+ static bool in_vacuum = false;
/* sanity checks on options */
Assert(vacstmt->options & (VACOPT_VACUUM | VACOPT_ANALYZE));
@@ -130,6 +131,14 @@ vacuum(VacuumStmt *vacstmt, Oid relid, bool do_toast,
else
in_outer_xact = IsInTransactionChain(isTopLevel);
+ /*
+ * Due to static variables vac_context, anl_context and vac_strategy,
+ * vacuum() is not reentrant. This matters when VACUUM FULL or ANALYZE
+ * calls a hostile index expression that itself calls ANALYZE.
+ */
+ if (in_vacuum)
+ elog(ERROR, "%s cannot be executed from VACUUM or ANALYZE", stmttype);
+
/*
* Send info about dead objects to the statistics collector, unless we are
* in autovacuum --- autovacuum.c does this for itself.
@@ -222,6 +231,7 @@ vacuum(VacuumStmt *vacstmt, Oid relid, bool do_toast,
{
ListCell *cur;
+ in_vacuum = true;
VacuumCostActive = (VacuumCostDelay > 0);
VacuumCostBalance = 0;
VacuumPageHit = 0;
@@ -266,13 +276,13 @@ vacuum(VacuumStmt *vacstmt, Oid relid, bool do_toast,
}
PG_CATCH();
{
- /* Make sure cost accounting is turned off after error */
+ in_vacuum = false;
VacuumCostActive = false;
PG_RE_THROW();
}
PG_END_TRY();
- /* Turn off vacuum cost accounting */
+ in_vacuum = false;
VacuumCostActive = false;
/*
diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out
index 190043c2558..4f2f5e228f4 100644
--- a/src/test/regress/expected/vacuum.out
+++ b/src/test/regress/expected/vacuum.out
@@ -60,12 +60,24 @@ VACUUM (FULL, FREEZE) vactst;
VACUUM (ANALYZE, FULL) vactst;
CREATE TABLE vaccluster (i INT PRIMARY KEY);
ALTER TABLE vaccluster CLUSTER ON vaccluster_pkey;
-INSERT INTO vaccluster SELECT * FROM vactst;
CLUSTER vaccluster;
+CREATE FUNCTION do_analyze() RETURNS VOID VOLATILE LANGUAGE SQL
+ AS 'ANALYZE pg_am';
+CREATE FUNCTION wrap_do_analyze(c INT) RETURNS INT IMMUTABLE LANGUAGE SQL
+ AS 'SELECT $1 FROM do_analyze()';
+CREATE INDEX ON vactst(wrap_do_analyze(i));
+INSERT INTO vactst VALUES (1), (2);
+ANALYZE vactst;
+ERROR: ANALYZE cannot be executed from VACUUM or ANALYZE
+CONTEXT: SQL function "do_analyze" statement 1
+SQL function "wrap_do_analyze" statement 1
VACUUM FULL pg_am;
VACUUM FULL pg_class;
VACUUM FULL pg_database;
VACUUM FULL vaccluster;
VACUUM FULL vactst;
+ERROR: ANALYZE cannot be executed from VACUUM or ANALYZE
+CONTEXT: SQL function "do_analyze" statement 1
+SQL function "wrap_do_analyze" statement 1
DROP TABLE vaccluster;
DROP TABLE vactst;
diff --git a/src/test/regress/sql/vacuum.sql b/src/test/regress/sql/vacuum.sql
index 30551ad1f27..4b624fe379e 100644
--- a/src/test/regress/sql/vacuum.sql
+++ b/src/test/regress/sql/vacuum.sql
@@ -44,9 +44,16 @@ VACUUM (ANALYZE, FULL) vactst;
CREATE TABLE vaccluster (i INT PRIMARY KEY);
ALTER TABLE vaccluster CLUSTER ON vaccluster_pkey;
-INSERT INTO vaccluster SELECT * FROM vactst;
CLUSTER vaccluster;
+CREATE FUNCTION do_analyze() RETURNS VOID VOLATILE LANGUAGE SQL
+ AS 'ANALYZE pg_am';
+CREATE FUNCTION wrap_do_analyze(c INT) RETURNS INT IMMUTABLE LANGUAGE SQL
+ AS 'SELECT $1 FROM do_analyze()';
+CREATE INDEX ON vactst(wrap_do_analyze(i));
+INSERT INTO vactst VALUES (1), (2);
+ANALYZE vactst;
+
VACUUM FULL pg_am;
VACUUM FULL pg_class;
VACUUM FULL pg_database;
--
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