(JP) textタイプのカラムにNULL値を含むテーブルの検索でSIGSEGV

[taiki-k]

textタイプのカラムにNULL値を含むテーブルを検索したところ、Segmentation Faultが発生しました。

• バックトレース

#0  0x00007f593f8f972d in do_insert_tuple (tc_head=0x7f5937682018, tc_node=0x7f5937682278, tuple=0x254ec98) at tcache.c:2003
#1  0x00007f593f8fa454 in tcache_insert_tuple (tc_head=0x7f5937682018, tc_node=0x7f5937682278, tuple=0x254ec98) at tcache.c:2090
#2  0x00007f593f8fa76a in tcache_build_main (tc_scan=0x2562188) at tcache.c:2170
#3  0x00007f593f8fac34 in tcache_scan_next (tc_scan=0x2562188) at tcache.c:2302
#4  0x00007f593f90262b in pgstrom_load_gpuscan (gss=0x2560e98) at gpuscan.c:874
#5  0x00007f593f90363e in gpuscan_fetch_tuple (node=0x2560e98) at gpuscan.c:1175
#6  0x00007f593f903c80 in gpuscan_exec (node=0x2560e98) at gpuscan.c:1331
#7  0x00000000006807e7 in ExecCustomPlan (cpstate=0x2560e98) at nodeCustom.c:37
#8  0x00000000006684b5 in ExecProcNode (node=0x2560e98) at execProcnode.c:453
#9  0x000000000067dab4 in agg_retrieve_direct (aggstate=0x2560700) at nodeAgg.c:1164
#10 0x000000000067d9cb in ExecAgg (node=0x2560700) at nodeAgg.c:1117
#11 0x0000000000668548 in ExecProcNode (node=0x2560700) at execProcnode.c:487
#12 0x0000000000665efe in ExecutePlan (estate=0x25605e8, planstate=0x2560700, operation=CMD_SELECT, sendTuples=1 '\001',
    numberTuples=0, direction=ForwardScanDirection, dest=0x24c8590) at execMain.c:1475
#13 0x0000000000663da8 in standard_ExecutorRun (queryDesc=0x2553d18, direction=ForwardScanDirection, count=0) at execMain.c:308
#14 0x0000000000663beb in ExecutorRun (queryDesc=0x2553d18, direction=ForwardScanDirection, count=0) at execMain.c:256
#15 0x00000000007f964e in PortalRunSelect (portal=0x25781b8, forward=1 '\001', count=0, dest=0x24c8590) at pquery.c:946
#16 0x00000000007f9275 in PortalRun (portal=0x25781b8, count=9223372036854775807, isTopLevel=1 '\001', dest=0x24c8590,
    altdest=0x24c8590, completionTag=0x7fffb2d12eb0 "") at pquery.c:790
#17 0x00000000007f29e2 in exec_simple_query (query_string=0x2510778 "select count(*) from text_test_null where str like 'A%';")
    at postgres.c:1045
#18 0x00000000007f7162 in PostgresMain (argc=1, argv=0x24a45c8, dbname=0x24a4428 "pgstrom_test", username=0x24a4408 "tkondo")
    at postgres.c:4004
#19 0x000000000076e18a in BackendRun (port=0x24cc2f0) at postmaster.c:4104
#20 0x000000000076d840 in BackendStartup (port=0x24cc2f0) at postmaster.c:3778
#21 0x0000000000769bfe in ServerLoop () at postmaster.c:1569
#22 0x0000000000769251 in PostmasterMain (argc=1, argv=0x24a33c0) at postmaster.c:1222
#23 0x00000000006b8aee in main (argc=1, argv=0x24a33c0) at main.c:223

• 対象のテーブル

pgstrom_test=# \d text_test_null
 Table "public.text_test_null"
 Column |   Type   | Modifiers
--------+----------+-----------
 id     | integer  |
 len    | smallint |
 str    | text     |

• 実行したSQL

select count(*) from text_test_null where str like 'A%';

[kaigai]

do_insert_tuple() 関数で、NULLフィールドのテストをしていませんでした。
最新版で修正しています。

なお、like関数はPG-Stromで実装されていませんので、キャッシュ上を
スキャンしてCPUで処理を行います…。

[taiki-k]

最新版で再現確認したところ、別の場所でSEGVしました。

• バックトレース

#0  0x0000003cdbc89cf8 in memcpy () from /lib64/libc.so.6
#1  0x00007fbb93d108cc in tcache_copy_cs_varlena (tcs_dst=0x7fbb83bd8018, base_dst=0, tcs_src=0x7fbb89bd8018, base_src=262017,
    attidx=0, nitems=127) at tcache.c:1189
#2  0x00007fbb93d120e3 in tcache_split_tcnode (tc_head=0x7fbb8ba9c018, tc_node_old=0x7fbb8ba9c318) at tcache.c:1631
#3  0x00007fbb93d1466b in tcache_insert_tuple (tc_head=0x7fbb8ba9c018, tc_node=0x7fbb8ba9c318, tuple=0x2934dd8) at tcache.c:2142
#4  0x00007fbb93d145db in tcache_insert_tuple (tc_head=0x7fbb8ba9c018, tc_node=0x7fbb8ba9c2c8, tuple=0x2934dd8) at tcache.c:2126
#5  0x00007fbb93d14775 in tcache_build_main (tc_scan=0x29267f8) at tcache.c:2173
#6  0x00007fbb93d14c3f in tcache_scan_next (tc_scan=0x29267f8) at tcache.c:2305
#7  0x00007fbb93d1c65c in pgstrom_load_gpuscan (gss=0x2925528) at gpuscan.c:880
#8  0x00007fbb93d1d66f in gpuscan_fetch_tuple (node=0x2925528) at gpuscan.c:1181
#9  0x00007fbb93d1dcb1 in gpuscan_exec (node=0x2925528) at gpuscan.c:1337
#10 0x00000000006807e7 in ExecCustomPlan (cpstate=0x2925528) at nodeCustom.c:37
#11 0x00000000006684b5 in ExecProcNode (node=0x2925528) at execProcnode.c:453
#12 0x000000000067dab4 in agg_retrieve_direct (aggstate=0x2924d90) at nodeAgg.c:1164
#13 0x000000000067d9cb in ExecAgg (node=0x2924d90) at nodeAgg.c:1117
#14 0x0000000000668548 in ExecProcNode (node=0x2924d90) at execProcnode.c:487
#15 0x0000000000665efe in ExecutePlan (estate=0x2924c78, planstate=0x2924d90, operation=CMD_SELECT, sendTuples=1 '\001',
    numberTuples=0, direction=ForwardScanDirection, dest=0x288cb80) at execMain.c:1475
#16 0x0000000000663da8 in standard_ExecutorRun (queryDesc=0x2898d08, direction=ForwardScanDirection, count=0) at execMain.c:308
#17 0x0000000000663beb in ExecutorRun (queryDesc=0x2898d08, direction=ForwardScanDirection, count=0) at execMain.c:256
#18 0x00000000007f964e in PortalRunSelect (portal=0x2922c68, forward=1 '\001', count=0, dest=0x288cb80) at pquery.c:946
#19 0x00000000007f9275 in PortalRun (portal=0x2922c68, count=9223372036854775807, isTopLevel=1 '\001', dest=0x288cb80,
    altdest=0x288cb80, completionTag=0x7fff8679fc20 "") at pquery.c:790
#20 0x00000000007f29e2 in exec_simple_query (query_string=0x28de778 "select count(*) from text_test_null where str like 'A%';")
    at postgres.c:1045
#21 0x00000000007f7162 in PostgresMain (argc=1, argv=0x28725c8, dbname=0x2872428 "pgstrom_test", username=0x2872408 "tkondo")
    at postgres.c:4004
#22 0x000000000076e18a in BackendRun (port=0x289a2f0) at postmaster.c:4104
#23 0x000000000076d840 in BackendStartup (port=0x289a2f0) at postmaster.c:3778
#24 0x0000000000769bfe in ServerLoop () at postmaster.c:1569
#25 0x0000000000769251 in PostmasterMain (argc=1, argv=0x28713c0) at postmaster.c:1222
#26 0x00000000006b8aee in main (argc=1, argv=0x28713c0) at main.c:223

[taiki-k]

最新版で再現確認し、再現しないことを確認しました。
修正されたと判断します。