(jdk10) RFR(xxs): 8176872: [s390] wrong pc shown in error logs

[Thomas Stüfe]

Hi David,

On Tue, Apr 4, 2017 at 9:25 AM, David Holmes <david.holmes at oracle.com>
wrote:

> Hi Thomas,
>
> On 4/04/2017 3:54 AM, Thomas Stüfe wrote:
>
>> Hi Dmitry, David,
>>
>> sorry for dropping the ball on this one. Here the latest version - I
>> only fixed the cosmetics Dmitry requested:
>>
>> http://cr.openjdk.java.net/~stuefe/webrevs/8176872-s390-wron
>> g-pc-in-errorlogs/jdk10-webrev.02/webrev/
>>
>
> Looks okay. I'm a little unsure about only fixing this in the shared code
> for non-s390. But I guess we can deal with other platforms later.
>
>
Not sure what you mean, but a common solution for all posix platforms would
be even easier. Instead of fixing the s390 signal handler and the secondary
signal handler for all posix platforms, one could adjust the pc at the
entry of error reporting, in VMError::report_and_die(). But that would
require an #ifndef WIN32 and you guys frown upon ifdefs, so that is why I
avoided this solution.

But lets commit this solution, and if other platforms should ever have the
same problem, we can modify the code.

..Thomas


> Thanks,
> David
> -----
>
> Thanks for reviewing!
>>
>> Kind Regards, Thomas
>>
>> On Sun, Mar 26, 2017 at 12:22 PM, Dmitry Samersoff
>> <dmitry.samersoff at oracle.com <mailto:dmitry.samersoff at oracle.com>> wrote:
>>
>>     Thomas,
>>
>>     Looks good to me,
>>
>>     We may consider to always use info->si_addr.
>>
>>     Nits:
>>
>>     vmError_posix.cpp
>>
>>     118:
>>       Please change uc ? ... to   (uc == NULL) ? ...
>>
>>     122: (and os_linux_s390.cpp:513)
>>
>>       Space missed after (address) ...
>>
>>
>>     -Dmitry
>>
>>
>>     On 2017-03-21 16:40, Thomas Stüfe wrote:
>>     > Hi all,
>>     >
>>     > please take a look at this tiny fix. It fixes the pc shown as
>> faulting
>>     > address for SIGILL and SIGFPE in hs_err files.
>>     >
>>     > https://bugs.openjdk.java.net/browse/JDK-8176872
>>     <https://bugs.openjdk.java.net/browse/JDK-8176872>
>>     >
>>     http://cr.openjdk.java.net/~stuefe/webrevs/8176872-s390-wron
>> g-pc-in-errorlogs/jdk10-webrev.00/webrev/
>>     <http://cr.openjdk.java.net/~stuefe/webrevs/8176872-s390-wro
>> ng-pc-in-errorlogs/jdk10-webrev.00/webrev/>
>>     >
>>     > When determining the crash pc, in all posix platform signal
>>     handlers pc is
>>     > taken from the context. However, context.pc on zlinux points to the
>>     > instruction *after* the faulting op. The correct way, according to
>>     POSIX,
>>     > would be to take the address from siginfo_t->si_addr for signals
>>     SIGILL,
>>     > SIGFPE.
>>     >
>>     > (actually, this patch would make sense for all POSIX platforms,
>>     but only
>>     > s390 seems to show this error, so I leave the patch local to s390.)
>>     >
>>     > Kind Regards, Thomas
>>     >
>>
>>
>>     --
>>     Dmitry Samersoff
>>     Oracle Java development team, Saint Petersburg, Russia
>>     * I would love to change the world, but they won't give me the
>> sources.
>>
>>
>>