Bug #65784 [Com]: Segfault with finally
| From: | crussell52 at gmail dot com | Date: | Mon, 25 Nov 2013 20:33:44 +0000 |
| Subject: | Bug #65784 [Com]: Segfault with finally | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-182933@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=65784&edit=1
ID: 65784
Comment by: crussell52 at gmail dot com
Reported by: r dot wilczek at web-appz dot de
Summary: Segfault with finally
Status: Open
Type: Bug
Package: *General Issues
Operating System: Linux
PHP Version: 5.5.4
Block user comment: N
Private report: N
New Comment:
core-dump info from my example:
#0 zval_delref_p (execute_data=0xb7f12234) at /opt/src/apache2.4/php-5.5.5/Zend/zend.h:409
#1 zend_pzval_unlock_func (execute_data=0xb7f12234) at
/opt/src/apache2.4/php-5.5.5/Zend/zend_execute.c:72
#2 _get_zval_ptr_var (execute_data=0xb7f12234) at
/opt/src/apache2.4/php-5.5.5/Zend/zend_execute.c:186
#3 ZEND_ASSIGN_SPEC_CV_VAR_HANDLER (execute_data=0xb7f12234) at
/opt/src/apache2.4/php-5.5.5/Zend/zend_vm_execute.h:36995
#4 0x012b7496 in execute_ex (execute_data=0xb7f12234) at
/opt/src/apache2.4/php-5.5.5/Zend/zend_vm_execute.h:363
#5 0x007f3f35 in xdebug_execute_ex (execute_data=0xb7f12234) at
/opt/src/apache2.4/xdebug-2.2.3/xdebug.c:1437
#6 0x012cf5cf in ZEND_INCLUDE_OR_EVAL_SPEC_VAR_HANDLER (execute_data=0xb7f12160) at
/opt/src/apache2.4/php-5.5.5/Zend/zend_vm_execute.h:13418
#7 0x012b7496 in execute_ex (execute_data=0xb7f12160) at
/opt/src/apache2.4/php-5.5.5/Zend/zend_vm_execute.h:363
#8 0x007f3f35 in xdebug_execute_ex (execute_data=0xb7f12160) at
/opt/src/apache2.4/xdebug-2.2.3/xdebug.c:1437
#9 0x01286fe5 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at
/opt/src/apache2.4/php-5.5.5/Zend/zend.c:1320
#10 0x0122a3cf in php_execute_script (primary_file=0xbfd233c0) at
/opt/src/apache2.4/php-5.5.5/main/main.c:2489
#11 0x0132812b in php_handler (r=0x9eb98c8) at
/opt/src/apache2.4/php-5.5.5/sapi/apache2handler/sapi_apache2.c:667
#12 0x08098037 in ?? ()
Previous Comments:
------------------------------------------------------------------------
[2013-11-25 20:16:54] crussell52 at gmail dot com
The following script in php 5.5.5 demonstrates this problem.
Note, my testing indicates that all of these conditions must be true:
1. Exception is thrown in try block.
2. An Exception is thrown AND handled during execution of
the corresponding finally block.
3. The return value must be referenced.
-----------------
class Executor
{
public function go()
{
try
{
// 1. Throw exception in try block.
throw new Exception("Failed to do something!");
return true;
}
finally
{
// 2. Throw and handle exception within finally block.
// Note, this step could occur in a function/method which
// is called within the finally block.
try
{
throw new Exception("Failed to clean up.");
}
catch (Exception $E) { /* Ignore */ }
}
}
}
$Executor = new Executor();
// 3. Reference the return value.
$value = $Executor->go();
-----------------
#3 is interesting and threw me off a bit while trying to come up
with a reproduction script. See the following variations and
outcome:
$value = $Executor->go(); // fail
echo $Executor->go(); // fail
$Executor->go(); // success
------------------------------------------------------------------------
[2013-10-15 11:54:52] php-bugs at lists dot php dot net
No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Re-Opened". Thank you.
------------------------------------------------------------------------
[2013-10-03 11:53:28] r dot wilczek at web-appz dot de
Here you are ...
/* @var $sql string */
/* @var $expr SomeInterface */
/* @var $ctxt AnotherInterface */
$trx = $this->ctxt->beginTransaction(); // an interface
$memento = $this->ctxt->getMemento(); // can be anything
try {
$this->ctxt->persist(); // don't return or throw exception
return $this->execute($expr, $sql); // return scalar[] or throw exception
} finally {
$this->ctxt->setMemento($memento); // don't return or throw exception
$trx->rollback(); // don't return or throw exception
}
Don't know, if this helps.
What I forgot to mention was, that the segfault occurs, when there is an exception thrown from
within the try-block.
------------------------------------------------------------------------
[2013-10-01 22:58:15] nikic@php.net
Could you please post the code as it is actually used (just the part containing the finally)? Your
backtrace indicates that the segfault happens during an argument send, but your code samples do not
include any function calls with arguments.
------------------------------------------------------------------------
[2013-09-29 12:26:34] r dot wilczek at web-appz dot de
(The second core-dump is created without xdebug, to keep things simple)
------------------------------------------------------------------------
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