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

[Mikael Vidstedt]

On 2015-12-08 21:58, Mikael Vidstedt wrote:
>> On Dec 8, 2015, at 20:08, David Holmes <david.holmes at oracle.com> wrote:
>>
>>> On 9/12/2015 4:05 AM, 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.
>> Sorry I'm not convinced. What is the issue with using sys/ptrace.h (which should exist on your build platforms and your devkit)?
> It simply doesn't export the type we need on SPARC (struct pt_regs or whatever it's called, I don't have the code in front of me right now). I don't know why, it simply doesn't :)

Also note that there's a similar #ifdef+#include for aarch64 a few lines 
further down:

#if defined(sparc) || defined(sparcv9) || defined(ppc64)
#define user_regs_struct pt_regs
#endif
#if defined(aarch64)
#include <asm/ptrace.h>
#define user_regs_struct user_pt_regs
#endif So the problem doesn't seem to be unique to SPARC. Given that 
asm/ptrace.h is used here it's probably better to use asm/ptrace.h on 
SPARC as well for consistency. This whole logic in the SA seems to be a 
mess at best, but I'm not sure cleaning it up is in scope for this 
change. How about filing an enhancement for that? Cheers, Mikael


>
> Cheers,
> Mikael
>
>> Thanks,
>> David
>>
>>> 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.