Edit report at https://bugs.php.net/bug.php?id=71129&edit=1
ID: 71129
User updated by: maroszek at gmx dot net
Reported by: maroszek at gmx dot net
Summary: Segmentation fault on ZTS Embed SAPI
Status: Re-Opened
Type: Bug
Package: Reproducible crash
-Operating System: OS X 11.11
+Operating System: OS X 10.11
PHP Version: 7.0.0
Block user comment: N
Private report: N
New Comment:
This really seems to be related to signaling, which seems to behave different on OS X.
Disabling max_executing_time (or adding a simple return; in zend_bailout) seems to workaround the
problem.
Line for the crash.cpp sample
> php_embed_module.ini_entries = "max_execution_time=0\n\0";
Do you know if the signal handler (zend_timeout) needs to be called in the same thread as the timed
out script? (This does not seem to be the case for OS X)
There seems to be a known bug in SIGPROF on OS X, but as far as i have understood, it should be
fixes for El Capitan and therefore not the problem in my case. (http://research.swtch.com/macpprof)
Previous Comments:
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[2015-12-21 13:02:36] maroszek at gmx dot net
Most often the request does not block but throws the error immediately. Therefore OS X might be
*faster* somewhere and have a race condition, which checks for the timeout...
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[2015-12-21 12:20:28] ab@php.net
Hi,
yeah, reverted because i've seen there are some issues with CLI and it is definitely leaking in
the main thread on any SAPI. Also this is not appropriate for the NTS builds. Have to do yet another
round to collect all the cases, also in regard to #71115.
With the timeout - your code doesn't change the default ini, so it's 30 seconds. With an
empty script that should never be the case, because the request should just run through and exit.
But something blocks in the request, whether some lock or whatever, so then it hands 30 seconds and
then gets bailed out. For Mac, there are for sure some native tools which possible would do a better
job?
Thanks.
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[2015-12-21 11:52:04] maroszek at gmx dot net
I have seen that you have reverted the patch. Did you have any more information why it fails on OS
X?
But I think my segfault does not relate to the other mentioned bug, because this one was already
present in PHP 5.x. (AFAIK the other bug depends on the new PHP7 zend_strings ref count...)
My current theory:
Some timer does not behave corretly and falsely detects a script timeout. (the original bug) This
leads to an invalid cleanup or a double free/double cleanup.
Unfortunately valgrind under OS X does not detect any issues... drd/helgrind detects some issues,
but i haven't validated those yet and as some of them are present in linux aswell so they might
be just more false positives.
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[2015-12-21 11:11:20] ab@php.net
Automatic comment on behalf of ab
Revision: http://git.php.net/?p=php-src.git;a=commit;h=53bfb6618d13083b769014cbdcb845f787a7cf28
Log: Revert "Partially fix bug #71129"
------------------------------------------------------------------------
[2015-12-20 14:35:54] ab@php.net
@maroszek thanks for the check, a patch is now commited. I'm setting the status onto feedback
as you have yet more issues.
Unfortunately I've no Mac to test it. But how it sounds like, the crash and the timeout issues
are two separate things. As from your code, the requests should not be hanging but just running
through, so no timeouts are expected. Though, as you've already said, Mac will use another
threading library, so maybe it could condition the issue, but just a guess. You probably should
debug through and check which request are not running through and why. Maybe there's a way to
reproduce this on Linux as well.
So set this to feedback, but i'd rather suggest to indeed close this one and to open another
ticket for the exact timeout issue you experience. Please feel free to do so if you think it's
ok.
Thanks.
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