segfault on rollback - Mailing list pgsql-hackers

Hello -hackers,

I recently have seen the segfault with Postgres 8.1.4.

The situation in which the segfault occur is quite complicated (a lot of
commands in one transaction from JDBC), but Here I show the gdb core dump of
it. From looking in my application, it seems that the core dump occurs when
the application issue the ROLLBACK command in the end of large transaction.
(when I do Connection.rollback() from JDBC)

Also I must notice that the segfault only occur if
log_min_duration_statement is set to 0

if it is set to -1, the segfault do not occur.

Also I must say that I specially removed all the C functions calls from the
transaction, to be sure that I'm not corrupting the memory myself.


Program received signal SIGSEGV, Segmentation fault.
0xb7dbd6db in strlen () from /lib/tls/libc.so.6
(gdb) bt
#0  0xb7dbd6db in strlen () from /lib/tls/libc.so.6
#1  0xb7d91ef1 in vfprintf () from /lib/tls/libc.so.6
#2  0xb7db0700 in vsnprintf () from /lib/tls/libc.so.6
#3  0x08179c47 in appendStringInfoVA (str=0xbfd639f0,    fmt=0x83d43c0 "duration: %ld.%03ld ms  statement: %sEXECUTE %s
[PREPARE:  %s]", args=0xbfd63a24 "Y") at stringinfo.c:125 
#4  0x08290471 in errmsg (    fmt=0x834b0c0 "duration: %ld.%03ld ms  statement: %sEXECUTE %s  [PREPARE:  %s]") at
elog.c:647
#5  0x08202bd2 in exec_execute_message (portal_name=0x8421a6c "", max_rows=1)    at postgres.c:1825
#6  0x0820498a in PostgresMain (argc=4, argv=0x83d2754,    username=0x83d2658 "cas_user_tmp") at postgres.c:3268
#7  0x081d3528 in BackendRun (port=0x83eaed0) at postmaster.c:2856
#8  0x081d2b3f in BackendStartup (port=0x83eaed0) at postmaster.c:2500
#9  0x081d0bc9 in ServerLoop () at postmaster.c:1230
#10 0x081d0474 in PostmasterMain (argc=1, argv=0x83bb000) at postmaster.c:941
#11 0x081821d8 in main (argc=1, argv=0x83bb000) at main.c:265

(gdb) bt full
#0  0xb7dbd6db in strlen () from /lib/tls/libc.so.6
No symbol table info available.
#1  0xb7d91ef1 in vfprintf () from /lib/tls/libc.so.6
No symbol table info available.
#2  0xb7db0700 in vsnprintf () from /lib/tls/libc.so.6
No symbol table info available.
#3  0x08179c47 in appendStringInfoVA (str=0xbfd639f0,    fmt=0x83d43c0 "duration: %ld.%03ld ms  statement: %sEXECUTE %s
[PREPARE:  %s]", args=0xbfd63a24 "Y") at stringinfo.c:125        avail = 255        nprinted = 256 
#4  0x08290471 in errmsg (    fmt=0x834b0c0 "duration: %ld.%03ld ms  statement: %sEXECUTE %s  [PREPARE:  %s]") at
elog.c:647       args = 0xbfd63a24 "Y"        success = -65 '©'        fmtbuf = 0x83d43c0 "duration: %ld.%03ld ms
statement:%sEXECUTE %s  [PREPARE:  %s]"        buf = {  data = 0x83d42b4 "duration: 89.073 ms  statement: EXECUTE
<unnamed> [PREPARE:  ", '\177' <repeats 138 times>..., len = 0, maxlen = 256, cursor = 0}        edata = (ErrorData *)
0x83ab3a0       oldcontext = 0x83d1f00 
---Type <return> to continue, or q <return> to quit---
#5  0x08202bd2 in exec_execute_message (portal_name=0x8421a6c "", max_rows=1)    at postgres.c:1825        usecs =
89073       dest = DestRemoteExecute        receiver = (DestReceiver *) 0x8421b78        portal = 0x842c114
completed= 1 '\001'        completionTag = "ROLLBACK\000:ж©Ф\033\030\bэ:ж©m\032B\b\004\000\000\000%\n
\b╓\201?\b\000\001\000\000Х:ж©Ё\031\030\b\000\000\000\001э:ж©\004\000\000\000\224\035\030\b"       start_t = {tv_sec =
1155432847,tv_usec = 699143}        stop_t = {tv_sec = 1155432847, tv_usec = 788216}        save_log_duration = 0 '\0'
     save_log_min_duration_statement = 0        save_log_statement_stats = 0 '\0'        execute_is_fetch = 0 '\0' 
#6  0x0820498a in PostgresMain (argc=4, argv=0x83d2754,    username=0x83d2658 "cas_user_tmp") at postgres.c:3268
portal_name= 0x8421a6c ""        max_rows = 1        flag = -1        dbname = 0x83dd198 "cas"        userDoption = 0x0 
---Type <return> to continue, or q <return> to quit---        secure = 0 '\0'        errs = 0        debug_flag = -1
   guc_names = (List *) 0x0        guc_values = (List *) 0x0        ctx = PGC_USERSET        gucsource = PGC_S_CLIENT
    am_superuser = 0 '\0'        tmp = 0x83d232c ""        firstchar = 69        stack_base = 0 '\0'
input_message= {data = 0x8421a6c "", len = 5, maxlen = 256,  cursor = 5}        local_sigjmp_buf = {{__jmpbuf =
{138325712,137883360, 1, -1076478888,      -1076479248, 136332736}, __mask_was_saved = 1, __saved_mask = {__val = {
  1073347075, 4294967294, 0, 0, 0, 0, 0, 7004, 0, 8, 0, 0, 138225460,        138224272, 138223360, 3218488264,
4294967295,138223360, 3085359680,        3084618868, 138225440, 138224272, 3084378772, 138326168, 3085312352,
200,138249720, 138241528, 3085367328, 137883360, 1, 3218488344}}}}        send_rfq = 0 '\0' 
#7  0x081d3528 in BackendRun (port=0x83eaed0) at postmaster.c:2856        status = 0        remote_host =
"127.0.0.1\000ж╥\000ЮФ╥\004\aГ╥\004\aГ╥xAж©bЦщ╥\004\aГ╥\00---Type<return> to continue, or q <return> to quit--- 

0\000\000\000hAж©╠\201*\b<\032Г╥\000\000\000\000\004\aГ╥\002\024\000\000\000\024\000\000\000\000\000\000\000ЮФ╥╪\177=\bо]3\b\000ЮФ╥
ХФ╥\000шФ╥hAж©\b\212з╥
ХФ╥\005\000\000\000\000\000\000\000xEж©И╗ш╥\000ЮФ╥ЬAж©дБщ╥\210Aж©\000ЮФ╥\004\aГ╥\224Бв╥ЬAж©bЦщ╥\004\aГ╥\000\000\000\000\002\024\000\000\005\000\000\000<\032Г╥\000\000\000\000\004\aГ╥\003\024\000\000\000\024\000\000\000\000\000\000"...
      remote_port = "32989\000ж©╥\220У╥ГEш╥FD\a\bЭDж©И╗ш╥\000ЮФ"        remote_ps_data =
"127.0.0.1(32989)\000╚х\233pq©\233\034чФ╥p<ж©.фУ╥\000\000\000\000\000\000\000\000╦qЖ╥\000\000\000\000\000\000\000\000\003\000\000\000P<ж©ьoЖ╥\000\000\000\000\b©;\bL=ж©\"еУ╥\b©;\b\001\000\000\000дGж©ю!=\b╦\031ж╥Жiж╥╦qЖ╥╪tЖ╥\000\000\000\000дGж©\001\000\000\000\000ЮФ╥юlЖ╥ю!=\bл=ж©O\000Д╥ю!=\b\000\000\000\200\001\000\000\220\000\000\000\000
1\001\000Ю\236>\b\004\000\000\000\003\000\000\000ЬФ╥\000ЮФ╥ ЬФ╥юlЖ╥═=ж©"...        av = (char **) 0x83d2754
maxac= 10        ac = 4        protobuf = "-v196608\000<ж©\000\024\000\000ЪЪЪЪ\000\000\000\000ПТ$\234\000\000\000"
 i = 4 
#8  0x081d2b3f in BackendStartup (port=0x83eaed0) at postmaster.c:2500        bn = (Backend *) 0x83dd0c8        pid = 0
#9  0x081d0bc9 in ServerLoop () at postmaster.c:1230        timeout = {tv_sec = 59, tv_usec = 948000}
---Type <return> to continue, or q <return> to quit---        selres = 1        i = 0        port = (Port *) 0x83eaed0
     rmask = {fds_bits = {8, 0 <repeats 31 times>}}        readmask = {fds_bits = {24, 0 <repeats 31 times>}}
nSockets= 5        now = 1155432807        last_touch_time = 1155432686        earlier = {tv_sec = 1155432686, tv_usec
=49004}        later = {tv_sec = 1155432765, tv_usec = 301709} 
#10 0x081d0474 in PostmasterMain (argc=1, argv=0x83bb000) at postmaster.c:941        opt = -1        status = 0
userDoption= 0x0        i = 64 
#11 0x081821d8 in main (argc=1, argv=0x83bb000) at main.c:265        pw = (struct passwd *) 0xb7f66cc0
pw_name_persist= 0xb7e6e000 "\\}\021" 


Any ideas ? Or I should try to narrower the problem ?... (it is not very easy
for my application)...

Initially I thought that the problem can be due to JDBC, but it doesn't
seem so... In any case, since JDBC for PG is pure java and is using libpq,
Posgres shouldn't crash.

Thanks,
Regards,    Sergey

*******************************************************************
Sergey E. Koposov
Max Planck Institute for Astronomy/Sternberg Astronomical Institute
Tel: +49-6221-528-349
Web: http://lnfm1.sai.msu.ru/~math
E-mail: math@sai.msu.ru