Re: Plproxy with returns table() make PG segfault - Mailing list pgsql-general

On 11/15/2012 08:40 PM, Cédric Villemain wrote:
> top post: this looks like a plproxy bug (no ?), I've added Marko in CC.

Yes, it is, i think …


>
>
>> I've a segfault on a PostgreSQL 9.1 cluster, with a plproxy function
>> call. Both PostgreSQL and plproxy are up to date. I use SQL/MED in that
>> specific case, but it's the same without. I reproduced the following
>> scenario on a few clusters, with or without streaming replication.
>>
>> On a given cluster, I created this function (very stupid, I know) (note
>> the « returns table () » ) :
>>
>> p0=# create function testtoto( id int)
>> returns table(id int, t text)
>> language sql
>> as $$
>> select * from (values(1, 'test'),(2, 'toto') )as toto;
>> $$;
>> p0=# \df testtoto
>> List of functions
>> Schema | Name | Result data type | Argument data types | Type
>> --------+----------+---------------------------+---------------------+-----
>> --- public | testtoto | TABLE(id integer, t text) | id integer | normal (1
>> row)
>>
>>
>> And I use it on another cluster, by doing this :
>>
>> test=# CREATE SERVER test FOREIGN DATA WRAPPER plproxy
>> options( connection_lifetime '200',p0 'host=localhost port=5433
>> dbname=p0 user=postgres');
>> CREATE USER MAPPING FOR postgres SERVER test OPTIONS (user 'postgres');
>>
>> -- this function returns setof record
>>
>> test=# CREATE OR REPLACE FUNCTION test(IN _account_id integer, OUT id
>> integer, OUT t text )
>> RETURNS setof record
>> LANGUAGE plproxy
>> AS $function$
>> CLUSTER 'test';
>> TARGET testtoto;
>> $function$;
>>
>> -- this on returns TABLE()
>>
>> test=# CREATE OR REPLACE FUNCTION test2(IN _account_id integer)
>> returns TABLE( id integer, t text )
>> LANGUAGE plproxyAS $function$
>> CLUSTER 'test';
>> TARGET testtoto;
>> $function$;
>>
>> When I call test(), everything is OK :
>>
>> test=# select * from test(1);
>> id | t
>> ----+------
>> 1 | test
>> 2 | toto
>> (2 rows)
>>
>> But when I call test2(1) :
>>
>> test=# select pg_backend_pid();
>> pg_backend_pid
>> ----------------
>> 25330
>> (1 row)
>> test=# select * from test2(1);
>> The connection to the server was lost. Attempting reset: Failed.
>> !>
>>
>> Badaboum !
>>
>> And the log reads :
>>
>> 2012-11-15 18:07:55 CET LOG: server process (PID 25330) was terminated
>> by signal 11: Segmentation fault
>> 2012-11-15 18:07:55 CET LOG: terminating any other active server processes
>> 2012-11-15 18:07:55 CET WARNING: terminating connection because of crash
>> of another server process
>> 2012-11-15 18:07:55 CET DETAIL: The postmaster has commanded this server
>> process to roll back the current transaction and exit, because another
>> server process exited abnormally and possibly corrupted shared memory.
>> 2012-11-15 18:07:55 CET HINT: In a moment you should be able to
>> reconnect to the database and repeat your command.
>>
>> …
>>
>> When I try to debug the session, I get this trace :
>>
>> (gdb)
>> Run till exit from #0 PostgresMain (argc=<optimized out>,
>> argv=<optimized out>, username=<optimized out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/tcop/postgres.c:3932
>>
>> Program received signal SIGSEGV, Segmentation fault.
>> pg_detoast_datum_packed (datum=0x800000000) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/utils/fmgr/fmgr.c:2272
>> 2272 if (VARATT_IS_COMPRESSED(datum) || VARATT_IS_EXTERNAL(datum))
>> (gdb) bt
>> #0 pg_detoast_datum_packed (datum=0x800000000) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/utils/fmgr/fmgr.c:2272
>> #1 0x00007f26ea7c0040 in text_to_cstring (t=0x800000000) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/utils/adt/varlena.c:135
>> #2 0x00007f26ea80a8c6 in FunctionCall1Coll (flinfo=0x7f26eb7fa2b8,
>> collation=0, arg1=34359738368) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/utils/fmgr/fmgr.c:1300
>> #3 0x00007f26ea80ba2d in OutputFunctionCall (flinfo=0x7f26eb7fa2b8,
>> val=34359738368) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/utils/fmgr/fmgr.c:1953
>> #4 0x00007f26611c2577 in plproxy_send_type () from
>> /usr/lib/postgresql/9.1/lib/plproxy.so
>> #5 0x00007f26611bfe66 in plproxy_exec () from
>> /usr/lib/postgresql/9.1/lib/plproxy.so
>> #6 0x00007f26611c1634 in ?? () from /usr/lib/postgresql/9.1/lib/plproxy.so
>> #7 0x00007f26611c1865 in plproxy_call_handler () from
>> /usr/lib/postgresql/9.1/lib/plproxy.so
>> #8 0x00007f26ea677985 in ExecMakeTableFunctionResult
>> (funcexpr=0x7f26eb7e9020, econtext=0x7f26eb7e7ff0,
>> expectedDesc=<optimized out>, randomAccess=<optimized out>)
>> at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/execQual.c:2146
>> #9 0x00007f26ea688471 in FunctionNext (node=0x7f26eb7e7ee0) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/nodeFunctionsca
>> n.c:66 #10 0x00007f26ea678657 in ExecScanFetch (recheckMtd=<optimized out>,
>> accessMtd=<optimized out>, node=<optimized out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/execScan.c:82
>> #11 ExecScan (node=0x7f26eb7e7ee0, accessMtd=<optimized out>,
>> recheckMtd=<optimized out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/execScan.c:132
>> #12 0x00007f26ea670da8 in ExecProcNode (node=0x7f26eb7e7ee0) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/execProcnode.c:
>> 416 #13 0x00007f26ea66fbf2 in ExecutePlan (dest=<optimized out>,
>> direction=<optimized out>, numberTuples=<optimized out>,
>> sendTuples=<optimized out>, operation=<optimized out>,
>> planstate=<optimized out>, estate=<optimized out>)
>> at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/execMain.c:1440
>> #14 standard_ExecutorRun (queryDesc=0x7f26eb7a1790,
>> direction=NoMovementScanDirection, count=0) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/executor/execMain.c:314
>> #15 0x00007f26ea7461d7 in PortalRunSelect (portal=0x7f26eb7dbd90,
>> forward=<optimized out>, count=0, dest=0x7f26eb6d87a0) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/tcop/pquery.c:943
>> #16 0x00007f26ea747640 in PortalRun (portal=<optimized out>,
>> count=<optimized out>, isTopLevel=<optimized out>, dest=<optimized out>,
>> altdest=<optimized out>, completionTag=<optimized out>)
>> at /opt/src/postgresql-9.1-9.1.6/build/../src/backend/tcop/pquery.c:787
>> #17 0x00007f26ea7438a3 in exec_simple_query (query_string=<optimized
>> out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/tcop/postgres.c:1020
>> #18 0x00007f26ea744965 in PostgresMain (argc=<optimized out>,
>> argv=<optimized out>, username=<optimized out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/tcop/postgres.c:3968
>> #19 0x00007f26ea702da3 in BackendRun (port=<optimized out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/postmaster/postmaster.c:
>> 3617 #20 BackendStartup (port=<optimized out>) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/postmaster/postmaster.c:
>> 3302 #21 ServerLoop () at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/postmaster/postmaster.c:
>> 1466 #22 0x00007f26ea705861 in PostmasterMain (argc=-345045536,
>> argv=0x7f26eb6cb200) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/postmaster/postmaster.c:
>> 1127 #23 0x00007f26ea6a3dc3 in main (argc=5, argv=0x7f26eb6cb1e0) at
>> /opt/src/postgresql-9.1-9.1.6/build/../src/backend/main/main.c:199
>> (gdb) quit
>>
>>
>> We can see here that "return setof record" works fine, but "return
>> table()" crashes.
>>
>> Even if we can use the first syntax, I don't think we can accept that.
>


--
Sébastien Lardière
PostgreSQL DBA Team Manager
Hi-Media
0228082071 / 0626595833