RFR: 8144885: agent/src/os/linux/libproc.h needs to support Linux/SPARC builds

[Dmitry Samersoff]

Mikael,

1.

asm/ptrace.h is not an option as it (typically) doesn't define
PTRACE_GETREGSET.

The best approach IMHO is to check for PTRACE_GETREGSET in  {unistd.h,
sys/ptrace.h, linux/ptrace.h) at configure time and define appropriate
macro.


2.

Other part of problem is where register set is defined there are couple
of places where the system describes platform register set (sys/user.h,
asm/ptrace.h, sys/procfs.h, linux/elf.h etc). These definitions are
more-or-less compatible but not exactly the same.

Unfortunately SA uses all possible variants interchangeable. (see
JDK-8141101)

Personally, I would prefer to use one from asm/ptrace.h

-Dmitry


On 2015-12-08 21:05, Mikael Vidstedt wrote:
> 
> The problem is that this needs to be backporting to jdk8u where there
> is no devkit, and more importantly, even if there were I believe we
> would see the same issue: the types needed are not made available by
> including sys/ptrace.h on this platform. I believe we can choose
> between linux/ptrace.h or asm/ptrace.h. The former feels slightly
> better.
> 
> Cheers, Mikael
> 
>> On Dec 8, 2015, at 03:15, Dmitry Samersoff
>> <dmitry.samersoff at oracle.com> wrote:
>> 
>> Jerry,
>> 
>>> In which case the devkit needs fixing I think, not the code.
>> 
>> I'm second to David.
>> 
>> It's better to not include linux/* headers explicitly.
>> 
>> -Dmitry
>> 
>> 
>>> On 2015-12-08 08:23, David Holmes wrote:
>>>> On 8/12/2015 2:59 PM, Gerald Thornbrugh wrote: Hi David,
>>>> 
>>>> Yes, I believe this is a devkit issue.  Mikael and I have been
>>>> working to get JDK9 building in JPRT with the lab Linux/SPARC
>>>> machines that use a devkit and this change was needed. I will
>>>> update the bug detailing this as a devkit issue.
>>> 
>>> In which case the devkit needs fixing I think, not the code.
>>> 
>>> Cheers, David
>>> 
>>>> Thanks!
>>>> 
>>>> Jerry
>>>>> Hi Jerry,
>>>>> 
>>>>>> On 8/12/2015 8:58 AM, Gerald Thornbrugh wrote: Hi
>>>>>> Everyone,
>>>>>> 
>>>>>> Please review this small change which fixes a JDK9
>>>>>> Linux/SPARC build problem in
>>>>>> "hotspot/agent/src/os/linux/libproc.h” so the correct
>>>>>> “ptrace.h” include file will be used during the build 
>>>>>> process.
>>>>>> 
>>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8144885 
>>>>>> <https://bugs.openjdk.java.net/browse/JDK-8144885> Webrev:
>>>>>> http://cr.openjdk.java.net/~gthornbr/8144885/webrev/ 
>>>>>> <http://cr.openjdk.java.net/~gthornbr/8144885/webrev/>
>>>>> 
>>>>> As far as I can see both versions of ptrace.h exist on linux
>>>>> x86 and linux sparc distributions, so it is not at all clear
>>>>> why this change is needed. Is it perhaps an issue with a
>>>>> devkit?
>>>>> 
>>>>> Thanks, David
>>>>> 
>>>>>> Thanks,
>>>>>> 
>>>>>> Jerry
>> 
>> 
>> -- Dmitry Samersoff Oracle Java development team, Saint Petersburg,
>> Russia * I would love to change the world, but they won't give me
>> the source code.


-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* I would love to change the world, but they won't give me the sources.