opensourcemirror
/
postgresql
mirror of git://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Releases Wiki Activity

EXPLAIN VERBOSE had a very high probability of triggering 

a backend core dump, because it was concatenating a potentially long
string onto another string that didn't necessarily have enough room.
Shame, shame.
This commit is contained in:
Tom Lane 1998-11-08 19:38:34 +00:00
parent 8f5ff4cf1c
commit 39792e5b01
1 changed files with 34 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
src/backend/commands/explain.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.25 1998/10/21 16:21:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.26 1998/11/08 19:38:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -38,6 +38,7 @@ typedef struct ExplainState
} ExplainState;
static char *Explain_PlanToString(Plan *plan, ExplainState *es);
static void printLongNotice(const char * header, const char * message);
static void ExplainOneQuery(Query *query, bool verbose, CommandDest dest);
@ -87,11 +88,9 @@ ExplainQuery(Query *query, bool verbose, CommandDest dest)
static void
ExplainOneQuery(Query *query, bool verbose, CommandDest dest)
{
char *s = NULL,
*s2;
char *s;
Plan *plan;
ExplainState *es;
int len;
/* plan the queries (XXX we've ignored rewrite!!) */
plan = planner(query);
@ -111,30 +110,25 @@ ExplainOneQuery(Query *query, bool verbose, CommandDest dest)
es->rtable = query->rtable;
if (es->printNodes)
s = nodeToString(plan);
if (es->printCost)
{
s2 = Explain_PlanToString(plan, es);
if (s == NULL)
s = s2;
else
s = nodeToString(plan);
if (s)
{
strcat(s, "\n\n");
strcat(s, s2);
printLongNotice("QUERY DUMP:\n\n", s);
pfree(s);
}
}
/* output the plan */
len = strlen(s);
elog(NOTICE, "QUERY PLAN:\n\n%.*s", ELOG_MAXLEN - 64, s);
len -= ELOG_MAXLEN - 64;
while (len > 0)
if (es->printCost)
{
s += ELOG_MAXLEN - 64;
elog(NOTICE, "%.*s", ELOG_MAXLEN - 64, s);
len -= ELOG_MAXLEN - 64;
s = Explain_PlanToString(plan, es);
if (s)
{
printLongNotice("QUERY PLAN:\n\n", s);
pfree(s);
}
}
if (es->printNodes)
pprint(plan); /* display in postmaster log file */
@ -361,3 +355,22 @@ Explain_PlanToString(Plan *plan, ExplainState *es)
return s;
}
/*
* Print a message that might exceed the size of the elog message buffer.
* This is a crock ... there shouldn't be an upper limit to what you can elog().
*/
static void
printLongNotice(const char * header, const char * message)
{
int len = strlen(message);
elog(NOTICE, "%.20s%.*s", header, ELOG_MAXLEN - 64, message);
len -= ELOG_MAXLEN - 64;
while (len > 0)
{
message += ELOG_MAXLEN - 64;
elog(NOTICE, "%.*s", ELOG_MAXLEN - 64, message);
len -= ELOG_MAXLEN - 64;
}
}