PING: RFR: 8234624: jstack mixed mode should refer DWARF

[Dmitry Samersoff]

Hello Yasumasa,

Please,

1. Consider to use mmap for reading elf sections.

2. Please move all platfrom-specific parts of native code to a separate
file/directory. Current patch will brake AARCH64 build.

3. I didn't find any tests here. How did your test the changes?


libproc_impl.c

131: If is not necessary, free handles NULLPTR gracefully.


-Dmitry


On 04.12.19 03:54, Yasumasa Suenaga wrote:
> PING: Could you review it?
> 
>   JBS: https://bugs.openjdk.java.net/browse/JDK-8234624
>   webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8234624/webrev.01/
> 
> This bug is targeted to JDK 14.
> 
> 
> Thanks,
> 
> Yasumasa
> 
> 
> On 2019/11/28 21:39, Yasumasa Suenaga wrote:
>> Hi,
>>
>> I refactored LinuxAMD64CFrame.java . It works fine in
>> serviceability/sa tests and
>> all tests on submit repo
>> (mach5-one-ysuenaga-JDK-8234624-2-20191128-0928-7059923).
>> Could you review new webrev?
>>
>>    http://cr.openjdk.java.net/~ysuenaga/JDK-8234624/webrev.01/
>>
>> The diff from previous webrev is here:
>>    http://hg.openjdk.java.net/jdk/submit/rev/4bc47efbc90b
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> On 2019/11/25 14:08, Yasumasa Suenaga wrote:
>>> Hi all,
>>>
>>> Please review this change:
>>>
>>>    JBS: https://bugs.openjdk.java.net/browse/JDK-8234624
>>>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8234624/webrev.00/
>>>
>>>
>>> According to 2.7 Stack Unwind Algorithm in System V Application
>>> Binary Interface AMD64
>>> Architecture Processor Supplement [1], we need to use DWARF in
>>> .eh_frame or .debug_frame
>>> for stack unwinding.
>>>
>>> As JDK-8022183 said, omit-frame-pointer is enabled by default since
>>> GCC 4.6, so system
>>> library (e.g. libc) might be compiled with this feature.
>>>
>>> However `jhsdb jstack --mixed` does not do so, it uses base pointer
>>> register (RBP).
>>> So it might be lack of stack frames.
>>>
>>> I guess JDK-8219201 is caused by same issue.
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>> [1]
>>> https://software.intel.com/sites/default/files/article/402129/mpx-linux64-abi.pdf
>>>