database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-27 23:21:58 +03:00
Code Activity

Replace max_expr_depth parameter with a max_stack_depth parameter that

Browse Source 
is measured in kilobytes and checked against actual physical execution
stack depth, as per my proposal of 30-Dec.  This gives us a fairly
bulletproof defense against crashing due to runaway recursive functions.
This commit is contained in:
Tom Lane
2004-03-24 22:40:29 +00:00
parent a09b9a36d3
commit 8899a2aba9
13 changed files with 157 additions and 79 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
src/backend/parser/parse_expr.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.166 2004/03/17 20:48:42 tgl Exp $
* $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.167 2004/03/24 22:40:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -35,9 +35,6 @@
#include "utils/syscache.h"
int max_expr_depth = DEFAULT_MAX_EXPR_DEPTH;
static int expr_depth_counter = 0;
bool Transform_null_equals = false;
static Node *typecast_expression(ParseState *pstate, Node *expr,
@ -47,19 +44,6 @@ static Node *transformIndirection(ParseState *pstate, Node *basenode,
List *indirection);
/*
* Initialize for parsing a new query.
*
* We reset the expression depth counter here, in case it was left nonzero
* due to ereport()'ing out of the last parsing operation.
*/
void
parse_expr_init(void)
{
expr_depth_counter = 0;
}
/*
* transformExpr -
* Analyze and transform expressions. Type checking and type casting is
@ -92,20 +76,8 @@ transformExpr(ParseState *pstate, Node *expr)
if (expr == NULL)
return NULL;
/*
* Guard against an overly complex expression leading to coredump due
* to stack overflow here, or in later recursive routines that
* traverse expression trees. Note that this is very unlikely to
* happen except with pathological queries; but we don't want someone
* to be able to crash the backend quite that easily...
*/
if (++expr_depth_counter > max_expr_depth)
ereport(ERROR,
(errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
errmsg("expression too complex"),
errdetail("Nesting depth exceeds maximum expression depth %d.",
max_expr_depth),
errhint("Increase the configuration parameter \"max_expr_depth\".")));
/* Guard against stack overflow due to overly complex expressions */
check_stack_depth();
switch (nodeTag(expr))
{
@ -938,8 +910,6 @@ transformExpr(ParseState *pstate, Node *expr)
break;
}
expr_depth_counter--;
return result;
}