Bug #78881 [Ver]: "Can't preload unlinked class" if class extends Exception
Edit report at https://bugs.php.net/bug.php?id=78881&edit=1
ID: 78881
Updated by: cmb@php.net
Reported by: mlocati at gmail dot com
Summary: "Can't preload unlinked class" if class extends
Exception
Status: Verified
Type: Bug
Package: opcache
Operating System: Windows
PHP Version: 7.4.0
Assigned To: cmb
Block user comment: N
Private report: N
New Comment:
The problem is that internal class entries are stored on the heap,
and the position of the heap is randomized by ASLR on Windows, so
there seems to be nothing we can do (at least for PHP 7.4 due to
BC restrictions).
Previous Comments:
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[2019-12-10 12:16:45] michael dot vorisek at email dot cz
This should be fixed in PHP internally. \Exception class is maybe the most extended one and
preloading one or more extended \Exception classes is more than expected.
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[2019-12-04 08:54:17] nikic@php.net
I've added an improved error in https://github.com/php/php-src/commit/7cbf31a3c754961e0ebfd5022191c1c9080effdb.
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[2019-12-04 08:45:51] nikic@php.net
This is expected: On Windows, due to ASLR, internal classes are unknown for the purposes of
preloading.
I think the only thing we can do here is a) improve the error message (it should not be
"unknown reason") and b) documented this limitation.
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[2019-11-28 23:06:10] cmb@php.net
Thanks for reporting!
------------------------------------------------------------------------
[2019-11-28 17:51:06] mlocati at gmail dot com
Description:
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I have this file, saved as J:\tmp\MyException.php
<?php
class MyException extends Exception {}
I have this file, saved as J:\tmp\preload.php
<?php
opcache_compile_file('J:\\tmp\\MyException.php');
I have this file, saved as J:\tmp\php.ini:
log_errors = On
display_startup_errors = On
extension_dir=C:\Dev\PHP7.4\ext
zend_extension=opcache
opcache.enable_cli=1
opcache.preload=J:\tmp\preload.php
I have downloaded PHP 7.4.0 for Windows, 32 bits, thread safe, to C:\Dev\PHP7.4
If I run this command from the Windows terminal:
C:\Dev\PHP7.4\php.exe -c J:\tmp\php.ini -v
Here's the output:
PHP Warning: Can't preload unlinked class MyException: Unknown reason in
J:\tmp\MyException.php on line 2
Warning: Can't preload unlinked class MyException: Unknown reason in J:\tmp\MyException.php on
line 2
PHP 7.4.0 (cli) (built: Nov 27 2019 10:15:52) ( ZTS Visual C++ 2017 x86 )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
with Zend OPcache v7.4.0, Copyright (c), by Zend Technologies
If I edit the J:\tmp\MyException.php, removing "extends Exception", the output is:
PHP 7.4.0 (cli) (built: Nov 27 2019 10:15:52) ( ZTS Visual C++ 2017 x86 )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
with Zend OPcache v7.4.0, Copyright (c), by Zend Technologies
So, it seems that preload doesn't work if a class extends Exception...
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Edit this bug report at https://bugs.php.net/bug.php?id=78881&edit=1
Thread (8 messages)