ID: 39460
User updated by: ben at thelemite dot freeserve dot co dot uk
-Summary: Crash when using 64-bit fields
Reported By: ben at thelemite dot freeserve dot co dot uk
-Status: Feedback
+Status: Open
Bug Type: MSSQL related
Operating System: Solaris 10
PHP Version: 5.2.0
New Comment:
Firstly I seem to have narrowed it down a little further. Crashes only
occur when the first 64-bit field occurs in column 2 (as in my test
table). If I rearrange the table to something like
TestTable {
id, int
value1, int
value2, bigint
}
suddenly it doesn't crash anymore. very, very weird.
anyway, the requested backtrace:-
php_mssql_get_column_content_with_type+0x2b8(6c0178, 2, 604998, 3e,
6140d8, 61357c)
_mssql_fetch_batch+0x244(0, 6037c8, ffffffff, 0, 2, 523858)
zif_mssql_query+0x2a4(2, 604ae0, ffffffff, 6c0178, 2, ffbfed60)
zend_do_fcall_common_helper_SPEC+0x6f0(ffbfee08, ffbfee08, 1, 688e20,
ffbfee08, 66d9e0)
execute+0x10c(6418d8, 40, 523818, ffbff0dc, 168, 748c)
zend_do_fcall_common_helper_SPEC+0x204(ffbff1e0, 35ebd8, 1, 6418d8,
ffbff1e0, 1)
execute+0x10c(689008, 40, 523818, ffbff3b4, 78, 748c)
zend_do_fcall_common_helper_SPEC+0x204(ffbff3e0, ffbff3e0, 1, 0, 0,
ffbff4a8)
execute+0x10c(5fffa0, ffbffc70, 1e8ff0, ffbff4ac, 4, 2279ac)
zend_execute_scripts+0xe0(7c54, 0, 3, ffbff598, 523598, ffbffc70)
php_execute_script+0x260(ffbffc70, 74, 2d00, 74657374, 0, ffbffa48)
main+0xfb8(2, ffbffd0c, ffbffd18, 50bf40, 0, 0)
_start+0x5c(0, 0, 0, 0, 0, 0)
Previous Comments:
------------------------------------------------------------------------
[2006-11-10 12:58:31] [EMAIL PROTECTED]
Thank you for this bug report. To properly diagnose the problem, we
need a backtrace to see what is happening behind the scenes. To
find out how to generate a backtrace, please read
http://bugs.php.net/bugs-generating-backtrace.php for *NIX and
http://bugs.php.net/bugs-generating-backtrace-win32.php for Win32
Once you have generated a backtrace, please submit it to this bug
report and change the status back to "Open". Thank you for helping
us make PHP better.
------------------------------------------------------------------------
[2006-11-10 12:55:39] ben at thelemite dot freeserve dot co dot uk
Just to clarify; it segfaults both in apache mod and cli. SQL Server
2003 is being used. built using gcc 3.4.6, and mssql is built-in (not
DSO loaded)
------------------------------------------------------------------------
[2006-11-10 12:44:31] ben at thelemite dot freeserve dot co dot uk
Description:
------------
Executing SELECT * queries on tables that contain 64-bit values (such
as bigints) cause a seg fault. Segfault occurs in
php_mssql_get_column_content_with_type within php_mssql.c
It's probably system dependent but has been verified on a separate
Solaris 10 setup.
Note the following things though:
1) Running queries containing 64-bit fields that do not contain the
primary key do not seem to cause the crash, e.g: "SELECT value from
TestTable", but individually selecting fields does, e.g: "SELECT
id,value". Bizzarely "SELECT value,id" doesn't cause a crash.
2) There seems to be some weird allocation issues going on that I have
not been able to get to the bottom of. In
php_mssql_get_column_content_with_type there is:
case SQLFLT8:
ZVAL_DOUBLE(result, (double) floatcol8(offset));
break;
If I change it to:
case SQLFLT8:
{
DBFLT8 res_buf;
memcpy(&res_buf, &floatcol8(offset), 8);
ZVAL_DOUBLE(result, res_buf);
}
break;
It cures the problem! But (very bizzarely), the following code still
crashes:
res_buf = *(DBFLT8 *)dbdata(mssql_ptr->link,offset);
ZVAL_DOUBLE(result, res_buf);
BUT... It does not crash at the point of reading the data into res_buf.
It's crashes when something is done with the value! (Possibly FreeTDS
is corrupting the stack?).
Help!
SunOS 5.10 Generic_118833-17 sun4u sparc SUNW,Ultra-60
PHP 5.1.6 (cli) (built: Oct 26 2006 15:30:54) [same on 5.2.0 as well
though]
FreeTDS 0.63
Reproduce code:
---------------
Table I have been using for experimenting:-
TestTable {
id, int
value, bigint
}
PHP code to generate crash:-
$link = mssql_connect("MyServer","MyUser","MyPassword");
$q = mssql_query("SELECT * from TestTable");
echo $q;
Expected result:
----------------
Resource id #X
Actual result:
--------------
nothing (segfaults when run from CLI)
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=39460&edit=1
