Bug #70428 [Fbk->ReO]: Opcache crashes with SIGSEGV

Edit report at https://bugs.php.net/bug.php?id=70428&edit=1

 ID:                 70428
 Updated by:         [email protected]
 Reported by:        christian at rishoj dot net
 Summary:            Opcache crashes with SIGSEGV
-Status:             Feedback
+Status:             Re-Opened
 Type:               Bug
 Package:            opcache
 Operating System:   Ubuntu 14.04
 PHP Version:        5.6.12
 Block user comment: N
 Private report:     N



Previous Comments:
------------------------------------------------------------------------
[2015-12-23 10:56:33] viking at xakep dot ru

And no errors when
opcache.interned_strings_buffer=0

------------------------------------------------------------------------
[2015-12-23 10:45:37] viking at xakep dot ru

you don't need to call any functions, just create new instance. This isolated code always crashes with configuration

opcache.use_cwd=1
opcache.validate_timestamps=1
opcache.memory_consumption=128
opcache.log_verbosity_level=2
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=4000
opcache.revalidate_freq=60
opcache.fast_shutdown=1
opcache.enable_cli=1


but only after first crash in non-sharable code

call stack

#0  0x000000000076058a in _zend_mm_alloc_int ()
#1  0x000000000077b7b6 in init_op_array ()
#2  0x00000000007713ad in zend_do_begin_function_declaration ()
#3  0x000000000074d654 in zendparse ()
#4  0x0000000000751228 in compile_file ()
#5  0x00000000006045f2 in phar_compile_file ()
#6  0x00007f2ebf01fa99 in compile_and_cache_file.constprop.17 () from /opt/aol/production/php56/ext/opcache.so
#7  0x00007f2ebf0207d2 in persistent_compile_file () from /opt/aol/production/php56/ext/opcache.so
#8  0x0000000000751397 in compile_filename ()
#9  0x000000000082baa3 in ZEND_INCLUDE_OR_EVAL_SPEC_CV_HANDLER ()
#10 0x00000000007bdbe8 in execute_ex ()
#11 0x0000000000778e03 in zend_call_function ()
#12 0x000000000079ef35 in zend_call_method ()
#13 0x000000000067c10a in zif_spl_autoload_call ()
#14 0x0000000000778d66 in zend_call_function ()
#15 0x00000000007796b2 in zend_lookup_class_ex ()
#16 0x0000000000779d92 in zend_fetch_class_by_name ()
#17 0x00000000007d4209 in ZEND_FETCH_CLASS_SPEC_CONST_HANDLER ()
#18 0x00000000007bdbe8 in execute_ex ()
#19 0x00000000007897a0 in zend_execute_scripts ()
#20 0x0000000000728562 in php_execute_script ()
#21 0x00000000004350b0 in main ()

------------------------------------------------------------------------
[2015-12-23 10:08:18] [email protected]

@viking:
> $this->{self::TEST_CONST}();
That will cause PHP to call testConst() repeatedly until the process eventually runs out of stack space and crashes. This is expected behavior.

Do you have a test case that is related to @christian's problem with opcache and the opcache.interned_strings_buffer setting?

------------------------------------------------------------------------
[2015-12-23 08:57:15] viking at xakep dot ru

No, it not that bug. So this is one, but floating reproduction. Always reproduce after first crash of php_fpm
TestClass.php >>
<?php
class TestClass {
	public function __get($field)
	{}

	public function someMethodName()
	{
		return $this->someMethodName;
	}
}
?>
-----------------------
baseClass.php >>
spl_autoload_register(function($className){
	$fileName = $className . '.php';
	include $fileName;
});
class baseClass extends TestClass{
	const TEST_CONST = 'testConst';
	private function testConst()
	{
		if ( true) {
			$this->{self::TEST_CONST}();

		}
	}
}
$class = new baseClass();
?>


php 5.6.12 on 3.10.0-229.7.2.el7.x86_64

------------------------------------------------------------------------
[2015-12-21 09:34:38] christian at rishoj dot net

Thanks, but are you sure this test case reproduces the opcache bug?

It causes the PHP CLI interpreter to crash with SIGSEGV regardless of whether opcache is enabled or not. 

Also, judging from a back trace, the crash does not not seem to involve the opcache.

------------------------------------------------------------------------


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