CALL and SWITCH executors segfault View as Markdown

Sebastian Bergmann wrote:

Tonight I wanted to do some benchmarks with PHP 4.3.11, PHP 5.0.4, and
the three (CALL, GOTO, SWITCH) executors of PHP 5.1 with both GCC 3.4.4
and GCC 4.0.1 to get a feeling for the improvements in the VM for
PHP 5.1.

Initial results are here [1].

Both the CALL and SWITCH executors segfault for me on my Linux system
when running the ZendEngine2/bench.php script.

The benchmark part that causes the segfault in both cases is the
Ackermann function.

--
[1] http://sebastian-bergmann.de/stuff/benchmark.txt

--
Sebastian Bergmann http://www.sebastian-bergmann.de/
GnuPG Key: 0xB85B5D69 / 27A7 2B14 09E4 98CD 6277 0E5B 6867 C514 B85B 5D69

Hi Sebastian,

The problem in stack overflow.
We will see how this can be fixed without performance lost.

Do you use x86 (non x86-64)?
What is your ./configure options?

Thanks. Dmitry.

-----Original Message-----
From: news [mailto:news@sea.gmane.org] On Behalf Of Sebastian Bergmann
Sent: Monday, June 13, 2005 12:49 AM
To: internals@lists.php.net
Subject: [PHP-DEV] CALL and SWITCH executors segfault

Tonight I wanted to do some benchmarks with PHP 4.3.11, PHP
5.0.4, and the three (CALL, GOTO, SWITCH) executors of PHP
5.1 with both GCC 3.4.4 and GCC 4.0.1 to get a feeling for
the improvements in the VM for PHP 5.1.

Both the CALL and SWITCH executors segfault for me on my
Linux system when running the ZendEngine2/bench.php script.

Below is the backtrace for the GOTO executor:

(gdb) r Zend/bench.php
Starting program: /usr/local/src/php/php-5.1/sapi/cli/php
Zend/bench.php
simple 0.294
simplecall 0.778
simpleucall 1.147
simpleudcall 1.379
mandel 1.223
mandel2 1.494

Program received signal SIGSEGV, Segmentation fault.
execute (op_array=0x826ffe0) at zend_vm_execute.h:3834
3834 memset(EX(CVs), 0, sizeof(zval**) *
op_array->last_var);
(gdb) bt
#0 execute (op_array=0x826ffe0) at zend_vm_execute.h:3834
#1 0x0816d534 in execute (op_array=0x812dcc0) at
zend_vm_execute.h:3989 . . . #871 0x0816d534 in execute
(op_array=0x8285194) at zend_vm_execute.h:3989 #872
0x0812fa34 in zend_execute_scripts (type=8, retval=0x0, file_count=3)
at /usr/local/src/php/php-5.1/Zend/zend.c:1077
#873 0x080ecb4d in php_execute_script (primary_file=0xbffff7a0)
at /usr/local/src/php/php-5.1/main/main.c:1670

#874 0x081d3b4a in main (argc=2, argv=0xbffff874)
at /usr/local/src/php/php-5.1/sapi/cli/php_cli.c:1036

Below is the backtrace for the SWITCH executor:

(gdb) r Zend/bench.php
Starting program: /usr/local/src/php/php-5.1/sapi/cli/php
Zend/bench.php
simple 0.316
simplecall 0.779
simpleucall 1.170
simpleudcall 1.389
mandel 1.384
mandel2 1.630

Program received signal SIGSEGV, Segmentation fault.
execute (op_array=0x8273fe0) at zend_vm_execute.h:53
53 memset(EX(CVs), 0, sizeof(zval**) *
op_array->last_var);
(gdb) bt
#0 execute (op_array=0x8273fe0) at zend_vm_execute.h:53
#1 0x0816f7b8 in execute (op_array=0x812dcc0) at
zend_vm_execute.h:211 . . . #875 0x0816f7b8 in execute
(op_array=0x8289194) at zend_vm_execute.h:211 #876 0x0812fa34
in zend_execute_scripts (type=8, retval=0x0, file_count=3) at
/usr/local/src/php/php-5.1/Zend/zend.c:1077
#877 0x080ecb4d in php_execute_script
(primary_file=0xbffff7a0) at
/usr/local/src/php/php-5.1/main/main.c:1670
#878 0x081d464a in main (argc=2, argv=0xbffff874) at
/usr/local/src/php/php-5.1/sapi/cli/php_cli.c:1036

--
Sebastian Bergmann
http://www.sebastian-bergmann.de/
GnuPG Key: 0xB85B5D69 / 27A7 2B14 09E4 98CD 6277 0E5B 6867
C514 B85B 5D69