jdk8-aarch32: Crashing when running test case ParallelProbes.java

Thu Nov 10 11:49:10 UTC 2016

Stack trace shows that ObjectMonitor::enter performs some illegal 
acesss, triggering segfault.

As a second chance, are various combinations of UseFastLocking and 
UseBiasedLocking changes the behavior?

I'm asking because I recall some bugfix that I had no time to properly 
prepare. That bug have exactly same symptoms, crash in vm runtime 
locking code after platform "fast" locks failed to do something.

And as a last chance, is something differ from applying next patch? It 
fixes fast path locking code by using rscratch2 instead rscratch1 (which 
is lock_reg also below)

> diff -r 1de174b764f9 -r 3d0ebcac084a src/cpu/aarch32/vm/sharedRuntime_aarch32.cpp
> --- a/src/cpu/aarch32/vm/sharedRuntime_aarch32.cpp      Thu Nov 03 13:12:50 2016 +0300
> +++ b/src/cpu/aarch32/vm/sharedRuntime_aarch32.cpp      Thu Nov 10 14:41:09 2016 +0300
> @@ -2053,7 +2053,7 @@
>
>      // Atomic swap old header if oop still contains the stack lock
>      Label succeed;
> -    __ cmpxchgptr(lock_reg, old_hdr, obj_reg, rscratch1, succeed, &slow_path_unlock);
> +    __ cmpxchgptr(lock_reg, old_hdr, obj_reg, rscratch2, succeed, &slow_path_unlock);
>      __ bind(succeed);
>
>      // slow path re-enters here
>

Thanks,
Anton

On 11/10/2016 02:20 PM, Chi Vo wrote:
> Hi all,
>
> This issue still occurred with ‎-XX:-UseBiasedLocking option.
>
> Thanks & Best Regards,
> Chi Vo
>
> Sent from my BlackBerry 10 smartphone.
>   Original Message
> From: Anton Kozlov
> Sent: Thursday, November 10, 2016 18:04
> To: Chi Vo; Sergey Nazarkin
> Cc: aarch32-port-dev
> Subject: Re: jdk8-aarch32: Crashing when running test case ParallelProbes.java
>
> Hi, all,
>
> looks familar.
> Chi, could you add -XX:-UseBiasedLocking option?
>
> Thanks,
> Anton
>
> On 11/10/2016 02:00 PM, Chi Vo wrote:
>> Hi Sergey Nazarkin,
>>
>> Stack trace of the crash:
>>
>> [New LWP 26548]
>> [New LWP 26530]
>> [New LWP 26542]
>> [New LWP 26531]
>> [New LWP 26551]
>> [New LWP 26535]
>> [New LWP 26545]
>> [New LWP 26544]
>> [New LWP 26536]
>> [New LWP 26546]
>> [New LWP 26538]
>> [New LWP 26543]
>> [New LWP 26550]
>> [New LWP 26539]
>> [New LWP 26537]
>> [New LWP 26552]
>> [New LWP 26541]
>> [New LWP 26540]
>> [New LWP 26549]
>> [New LWP 26547]
>> [Thread debugging using libthread_db enabled]
>> Using host libthread_db library
>> "/lib/arm-linux-gnueabihf/libthread_db.so.1".
>> Core was generated by `/home/pi/workspace/openjdk/./j2re-image/bin/java
>> -Dtest.src=/home/pi/workspace/'.
>> Program terminated with signal SIGABRT, Aborted.
>> #0 0x76df4f70 in __GI_raise (sig=sig at entry=6) at
>> ../nptl/sysdeps/unix/sysv/linux/raise.c:56
>> 56 ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
>> (gdb) bt
>> #0 0x76df4f70 in __GI_raise (sig=sig at entry=6) at
>> ../nptl/sysdeps/unix/sysv/linux/raise.c:56
>> #1 0x76df6324 in __GI_abort () at abort.c:89
>> #2 0x758acee8 in os::abort(bool) () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #3 0x75917b64 in VMError::report_and_die() () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #4 0x758b1952 in JVM_handle_linux_signal () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #5 0x758ac140 in signalHandler(int, siginfo_t*, void*) () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #6 <signal handler called>
>> #7 0x758a7424 in ObjectMonitor::enter(Thread*) () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #8 0x758e865a in ObjectSynchronizer::slow_enter(Handle, BasicLock*,
>> Thread*) () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #9 0x758d33fe in SharedRuntime::complete_monitor_locking_C(oopDesc*,
>> BasicLock*, JavaThread*) () from
>> /home/pi/workspace/openjdk/j2re-image/lib/aarch32/client/libjvm.so
>> #10 0x734b5500 in ?? ()
>> Backtrace stopped: previous frame identical to this frame (corrupt stack?)
>> (gdb)
>>
>> If you want to get core file. Please contact me.
>>
>> Thanks & Best Regards,
>> Chi Vo
>>
>> On Thu, Nov 10, 2016 at 5:10 PM, Sergey Nazarkin <snazarkin at azul.com> wrote:
>>
>>> Hi Chi Vo,
>>>
>>> Could you provide stack trace of the crash? I see no reason for race
>>> condition here since the method doesn’t update any global variable.
>>>
>>>
>>> Sergey Nazarkin
>>>
>>>
>>>
>>>
>>>> On 10 Nov 2016, at 12:49, Chi Vo <thegeek108 at gmail.com> wrote:
>>>>
>>>> Hi All,
>>>>
>>>> Hotspot crashing when I running test case
>>>> */jdk/test/java/nio/file/Files/probeContentType/ParallelProbes.java*
>>>>
>>>> As my analysis, the probeContentType is static method so It is class
>>> level.
>>>> In this case, we allow many threads access it without synchronize. so It
>>>> should be protected by synchronizing to avoid any inconsistent data or
>>> also
>>>> corrupt data. I test this patch and it works fine.
>>>>
>>>> diff -r dbe7e2abe8b2 -r c9e2721b4711
>>>> 02.src/01.aarch32_jdk8u/jdk/src/share/classes/java/nio/file/Files.java
>>>> --- a/02.src/01.aarch32_jdk8u/jdk/src/share/classes/java/nio/
>>> file/Files.java
>>>> Fri
>>>> Oct 07 15:23:45 2016 +0700
>>>> +++ b/02.src/01.aarch32_jdk8u/jdk/src/share/classes/java/nio/
>>> file/Files.java
>>>> Tue
>>>> Oct 25 10:56:47 2016 +0700
>>>> @@ -1610,7 +1610,7 @@
>>>> * If a security manager is installed and it denies an
>>>> unspecified
>>>> * permission required by a file type detector
>>> implementation.
>>>> */
>>>> - public static String probeContentType(Path path)
>>>> + public synchronized static String probeContentType(Path path)
>>>> throws IOException
>>>> {
>>>> // try installed file type detectors
>>>>
>>>> Please help take a look my patch.
>>>>
>>>> Thanks you with best regards,
>>>> Chi Vo
>>>
>>>
>>
>>