RFR(xxs): 8185706: Native callstacks unreliable under Windows x64

[Thomas Stüfe]

Thank you, Zhengyu!

On Thu, Aug 10, 2017 at 3:09 PM, Zhengyu Gu <zgu at redhat.com> wrote:

> Look good to me.
>
> -Zhengyu
>
> On 08/10/2017 08:35 AM, Thomas Stüfe wrote:
>
>> Ping... May I please have a second review?
>>
>> Thank you!
>>
>> On Wed, Aug 2, 2017 at 11:17 AM, Thomas Stüfe <thomas.stuefe at gmail.com>
>> wrote:
>>
>> Hi all,
>>>
>>> may I please have a review for this small fix.
>>>
>>> Issue: https://bugs.openjdk.java.net/browse/JDK-8185706
>>> Webrev: http://cr.openjdk.java.net/~stuefe/webrevs/8185706-
>>> Native-callstacks-unreliable-under-Windows-x64/webrev.00/webrev/
>>>
>>> This can be seen as an addon to https://bugs.openjdk.java.n
>>> et/browse/JDK-8022335. Ioi Lam did a good job analyzing the original
>>> problem. On windows x64, the native compiler generates code which does
>>> not
>>> use the frame pointer (regardless whether we set -Oy-). Only in rare
>>> cases
>>> a frame pointer is used - e.g. for alloca()-functions - and, as Ioi
>>> pointed
>>> out, no guarantee either that RBP is actually the frame pointer.
>>>
>>> So, in os <http://ld8443:8080/source/s?defs=os&project=integ-hotspot-X
>>> >::
>>> platform_print_native_stack
>>> <http://ld8443:8080/source/s?defs=platform_print_native_stac
>>> k&project=integ-hotspot-X>()
>>> we walk the stack using StackWalk64(), extract the pc from each frame and
>>> print that, like normal windows coding. However, we still test for the
>>> frame pointer being NULL, and abort stack tracing if it is. This causes
>>> stack dumping to fail quite often, and unnecessarily.
>>>
>>> For example, test: java.exe -XX:ErrorHandlerTest=12
>>>
>>> Sometimes it works, but more out of accident - as Ioi pointed out in this
>>> mail thread: http://mail.openjdk.java.net/p
>>> ipermail/hotspot-runtime-dev/2
>>> 013-August/009063.html. If there are java frames above the crashing
>>> native frame, we still may have RBP set to some value (does not matter
>>> which) and os
>>> <http://ld8443:8080/source/s?defs=os&project=integ-hotspot-X>::
>>> platform_print_native_stack
>>> <http://ld8443:8080/source/s?defs=platform_print_native_stac
>>> k&project=integ-hotspot-X>()
>>> does not abort frame printing.
>>>
>>> Kind Regards, Thomas
>>>
>>>
>>>
>>>