#23078 [Asn]: overload, switch, array square bracket construct

ID: 23078 User updated by: bugs dot php dot net at wizzard dot org -Summary: overload and switch Reported By: bugs dot php dot net at wizzard dot org Status: Assigned Bug Type: Scripting Engine problem -Operating System: FreeBSD 4.8-RC (recent) +Operating System: FreeBSD 4.8-RC PHP Version: 4.3.2-RC (latest CVS) Assigned To: andrei New Comment: It appears that the same kind of problem occurs when using the square bracket construct on class attributes. To demonstrate the problem, replace the "problem_function" in the first code sample with the one below. function problem_function() { $this->var[] = 'foo'; return TRUE; } Backtrace: (gdb) run testcase4.php Starting program: /usr/local/bin/php testcase4.php Program received signal SIGSEGV, Segmentation fault. fetch_overloaded_element (result=0x830e0a0, op1=0x830e0b0, op2=0x830e0c0, Ts=0xbfbfdbe8, type=1, retval=0xbfbfdc20, overloaded_element_type=1) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:701 701 overloaded_element.element = *get_zval_ptr(op2, Ts, &EG(free_op2), type); (gdb) bt #0 fetch_overloaded_element (result=0x830e0a0, op1=0x830e0b0, op2=0x830e0c0, Ts=0xbfbfdbe8, type=1, retval=0xbfbfdc20, overloaded_element_type=1) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:701 #1 0x8142a4b in zend_fetch_dimension_address (result=0x830e0a0, op1=0x830e0b0, op2=0x830e0c0, Ts=0xbfbfdbe8, type=1) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:724 #2 0x8146f19 in execute (op_array=0x8305924) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:1267 #3 0x814adab in execute (op_array=0x8305024) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:1640 #4 0x81365f8 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend.c:864 #5 0x810aaea in php_execute_script (primary_file=0xbfbff8fc) at /usr/ports/www/mod_php4/work/php-4.3.1/main/main.c:1573 #6 0x81532b6 in main (argc=2, argv=0xbfbff968) at /usr/ports/www/mod_php4/work/php-4.3.1/sapi/cli/php_cli.c:746 #7 0x80637ca in _start () Previous Comments: ------------------------------------------------------------------------ [2003-04-07 04:41:04] sniper@php.net Assigning to Andrei who wrote this thing, he can decide if it's worth to fix this. ------------------------------------------------------------------------ [2003-04-07 01:01:05] bugs dot php dot net at wizzard dot org It seems that in a class with overloading enabled, inside a method, if you switch based on a declared attribute, PHP segfaults. Another FreeBSD user in #PHP on freenode was able to confirm the problem, using the following test code. I've worked out the test case using the CGI binary, but I've also confirmed that it happens through the APXS2 SAPI. In that case, the errors from apache are: [notice] child pid 72051 exit signal Segmentation fault (11) - and/or - httpd in free(): warning: chunk is already free The __get and __set methods are defined here as dummies just so overloading will truly be enabled. I'm assuming they would not be called because $var is pre-defined. Test Code: <?php class demo { var $var; function demo() { $this->var = FALSE; return TRUE; } function problem_function() { switch( $this->var ) { case 'foo': break; } return TRUE; } function __get($name, &$value) { return TRUE; } function __set($name, $value) { return TRUE; } } overload('demo'); $obj = new demo(); $obj->problem_function(); ?> Backtrace: (gdb) bt #0 overload_get_property (property_reference=0xbfbfdfe0) at /usr/ports/www/mod_php4/work/php-4.3.1/ext/overload/overload.c:363 #1 0x8144e07 in get_overloaded_property (T=0xbfbfdfd4) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:929 #2 0x814e2a3 in execute (op_array=0x8301ea4) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:92 #3 0x814adab in execute (op_array=0x8301424) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend_execute.c:1640 #4 0x81365f8 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /usr/ports/www/mod_php4/work/php-4.3.1/Zend/zend.c:864 #5 0x810aaea in php_execute_script (primary_file=0xbfbffd0c) at /usr/ports/www/mod_php4/work/php-4.3.1/main/main.c:1573 #6 0x81532b6 in main (argc=3, argv=0xbfbffd70) at /usr/ports/www/mod_php4/work/php-4.3.1/sapi/cli/php_cli.c:746 #7 0x80637ca in _start () More: (gdb) f 0 #0 overload_get_property (property_reference=0xbfbfdfe0) at /usr/ports/www/mod_php4/work/php-4.3.1/ext/overload/overload.c:363 363 if (Z_TYPE_P(overloaded_property) == OE_IS_OBJECT) { (gdb) p overloaded_property $1 = (zend_overloaded_element *) 0x5a5a5a62 (gdb) p *overloaded_property Error accessing memory address 0x5a5a5a62: Bad address. PHP Config Args: './configure' '--with-apxs2=/usr/local/sbin/apxs' '--with-tsrm-pth' '--with-config-file-path=/usr/local/etc' '--enable-versioning' '--with-regex=system' '--without-gd' '--without-mysql' '--with-gd=/usr/local' '--enable-gd-native-ttf' '--with-freetype-dir=/usr/local' '--with-jpeg-dir=/usr/local' '--with-png-dir=/usr/local' '--with-zlib' '--with-bz2=/usr' '--with-mcrypt=/usr/local' '--with-mhash=/usr/local' '--with-imap=/usr/local' '--with-mysql=/usr/local' '--with-expat-dir=/usr/local' '--with-gettext=/usr/local' '--enable-debug' '--prefix=/usr/local' 'i386-portbld-freebsd4.8' ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=23078&edit=1