From: buschmann at nidsa dot net
Operating system: Windows 10 Pro 64bit
PHP version: 8.0.0beta2
Package: JIT
Bug Type: Bug
Bug description:PHP 8.0 beta2 crashes with default JIT flags due to hardware incompatibility
Description:
------------
During the test of PHP 8 on all our applications I changed my
development machine from PHP 7.4.9 to PHP 8.
The overall configuration is the same as on the test server.
PHP crashes immediatly when running any script (opcache_gui.php for
example).
The configuration for JIT was as recommended:
opcache.jit_buffer_size=16M
opcache.jit=1205
In the apache error log the following showed up:
[Sun Aug 23 16:10:14.639607 2020] [mpm_winnt:notice] [pid 13272:tid 904]
AH00428: Parent: child process 12228 exited with status 3221225501 --
Restarting.
Error 3221225501 is 0xc000001d and means "Illegal instruction"
The root cause is that the crashing machine has no AVX instructions
available (Celeron G1840) and opcache.jit was set at 1205 where the "1"
indicates "enable AVX instruction generation" as mentioned in the WIKI.
It is quite common to encounter machines with no AVX instructions:
Celerons, ATOM, elder Server generations such as XEON x5570,
non-x86-architectures etc.
It should be possible to use the same configuration on different
hardware without a specific change.
The optimization parameter C=1 (enable AVX instruction generation)
should not always generate AVX-instructions, but only when they are
available in the hardware and otherwise fall back to non-AVX-JIT.
From the WIKI it is not clear, which AVX instruction set is used and
required for this optimization (AVX-1? or AVX2?, AVX512 can be ruled out
for now).
This error disappeared by setting opcache.jit=0205
PHP should detect the capabilities of the hardware before using
unsupported advanced CPU optimization Flags.
Environment:
- Windows 10 64bit Pro
- Apache 2.46 64bit from apachelounge
- php 8 beta2 64bit thread safe from php.net QA download
- php loaded as a module with php_module
Actual result:
--------------
Crash dump follows:
Report for
httpd__PID__10812__Date__08_24_2020__Time_04_00_39PM__171__Second_Chance_Exception_C000001D.dmp
Type of Analysis Performed Crash Analysis
Machine Name WINHB16
Operating System Windows 10 - 18363
Number Of Processors 2
Process ID 10812
Process Image N:\Apache\Apache24\bin\httpd.exe
Command Line httpd -X
System Up-Time 9 day(s) 22:20:25
Process Up-Time 00:01:26
Processor Type X64
Process Bitness 64-Bit
Faulting Thread
Entry point libhttpd!ap_run_generate_log_id+3ab0
Create time 24.08.2020 15:59:14
Time spent in user mode 0 Days 0:0:0.0
Time spent in kernel mode 0 Days 0:0:0.0
Arg 1
Arg 2
Arg 3
Arg 4
Source
0x000010000300fe2e 000023724a95000 0000237`245e42e0
000023724a95000 000023724a68000
0x0000023724a15300 0000237245e42e0 0000237`24a95000
000023724a68000 000000000000003
0x0000023724a95000 000023724a95000 0000237`24a68000
000000000000003 000000000000000
0x00000237245e42e0 000023724a68000 0000000`00000003
000000000000000 000000000000000
0x0000023724a95000 000000000000003 0000000`00000000
000000000000000 000023724a90660
0x0000023724a68000 000000000000000 0000000`00000000
000023724a90660 0000237245e42e0
0x00000003 000000000000000 000023724a90660
0000237245e42e0 000000000000000
CLR Information
Exception Information
In
httpd__PID__10812__Date__08_24_2020__Time_04_00_39PM__171__Second_Chance_Exception_C000001D.dmp
the assembly instruction at 0x00001000`0300fe2e which does not
correspond to any known native module in the process has caused an
unknown exception (0xc000001d) on thread 98
--
Edit bug report at https://bugs.php.net/bug.php?id=80014&edit=1
--
Fix committed: https://bugs.php.net/fix.php?id=80014&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=80014&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=80014&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=80014&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=80014&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=80014&r=support
Expected behavior: https://bugs.php.net/fix.php?id=80014&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=80014&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=80014&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=80014&r=globals
PHP version support discontinued: https://bugs.php.net/fix.php?id=80014&r=phptooold
Daylight Savings: https://bugs.php.net/fix.php?id=80014&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=80014&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=80014&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=80014&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=80014&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=80014&r=mysqlcfg