database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-05-05 09:19:17 +03:00
Code

Add an Assert that enum_cmp_internal() gets passed an FmgrInfo pointer.

Browse Source 
If someone were to try to call one of the enum comparison functions
using DirectFunctionCallN, it would very likely seem to work, because
only in unusual cases does enum_cmp_internal() need to access the
typcache.  But once such a case occurred, code like that would crash
with a null pointer dereference.  To make an oversight of that sort
less likely to escape detection, add a non-bypassable Assert that
fcinfo->flinfo isn't NULL.

Discussion: https://postgr.es/m/25226.1487900067@sss.pgh.pa.us
This commit is contained in:
Tom Lane 2017-02-23 22:08:10 -05:00
parent c29aff959d
commit 6d493e1a01
1 changed files with 10 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/backend/utils/adt/enum.c
View File

@ -263,6 +263,15 @@ enum_cmp_internal(Oid arg1, Oid arg2, FunctionCallInfo fcinfo)
{
TypeCacheEntry *tcache;
/*
* We don't need the typcache except in the hopefully-uncommon case that
* one or both Oids are odd. This means that cursory testing of code that
* fails to pass flinfo to an enum comparison function might not disclose
* the oversight. To make such errors more obvious, Assert that we have a
* place to cache even when we take a fast-path exit.
*/
Assert(fcinfo->flinfo != NULL);
/* Equal OIDs are equal no matter what */
if (arg1 == arg2)
return 0;
@ -381,12 +390,7 @@ enum_cmp(PG_FUNCTION_ARGS)
Oid a = PG_GETARG_OID(0);
Oid b = PG_GETARG_OID(1);
if (a == b)
PG_RETURN_INT32(0);
else if (enum_cmp_internal(a, b, fcinfo) > 0)
PG_RETURN_INT32(1);
else
PG_RETURN_INT32(-1);
PG_RETURN_INT32(enum_cmp_internal(a, b, fcinfo));
}
/* Enum programming support functions */