RFR: 8218169 - [AOT] Segmentation fault when running java with AOTed Graal in -Xcomp mode on windows

[Bob Vandette]

Thanks, I’ll make the change.

Do you know which mach5 tier, if any, performs AOT testing on Windows?

Bob.


> On Feb 7, 2019, at 12:31 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> Hi Bob,
> 
> Very nice fix. Can you use #if INCLUDE_AOT instead of _WIN64 based on your description?
> 
> Thanks,
> Vladimir
> 
> On 2/7/19 7:15 AM, Bob Vandette wrote:
>> Please review this fix for a SEGV occurring when AOT is used on Windows.
>> PROBLEM:
>> The problem is caused by the fact that we're getting an implicit exception from the .text
>> segment of an AOT generated library but the generated code in the DLL does not have
>> any structured exception sections or unwind tables. The normal hotspot CodeCache works
>> around this limitation by registering the entire code cache with RtlAddFunctionTable. In order
>> to do this for AOT generated code, a DynamicCodeData structure would need to be generated
>> in the text segment of the AOT library.
>> BUG:
>> https://bugs.openjdk.java.net/browse/JDK-8218169
>> WEBREV:
>> http://cr.openjdk.java.net/~bobv/8218169
>> SOLUTION:
>> Rather than modify the AOT implementation to generate a Windows specific data structure that
>> requires a jmp out of the DLL code and into Hotspots exception handler, I chose a simpler solution
>> that installs a VectoredException handler. This VectoredException handler is only installed if AOT
>> is enabled.
>> This handler examines the pc of the exception. If this pc is determined to be in either the
>> codeCache or in AOT generated code, we pass control to the existing exception handler otherwise
>> we allow the system to continue searching for other exception handlers.
>> There were problems in the past with the use of VEH but at that time we made exclusive use of
>> VEH and did not use them in conjunction with SEH.  Since I am only passing control to our
>> existing handler when the pc is from one of our code sections, other code in the system can
>> continue to use SEH.
>> For more details, please see the bug comments.
>> Bob.