Re: RFR(S): 8028412 - AsyncGetCallTrace() is broken on x86 in JDK7u40

[serguei.spit...@oracle.com]

On 11/27/13 2:32 AM, Markus Gronlund wrote:

Hi Sergei,

I have already worked with Nik on this issue and got his confirmation on the fix.

Cool!

Thanks,
Serguei

Thanks

Markus

*From:*Serguei Spitsyn
*Sent:* den 27 november 2013 11:31

*To:* Markus Gronlund; hotspot-compiler-...@openjdk.java.net; hotspot-runtime-...@openjdk.java.net; serviceability-dev

*Cc:* Oleg Mazurov; Nikolay Molchanov

*Subject:* Re: RFR(S): 8028412 - AsyncGetCallTrace() is broken on x86 in JDK7u40

Hi Markus,

The fix looks Ok.

It'd be helpful if Oleg and the Solaris Studio guys could confirm this fix works fine for them.

I've added Oleg and Nik to the CC-list.
They might request a link to the Solaris or Linux binaries.

Thanks,
Serguei


On 11/27/13 1:47 AM, Markus Gronlund wrote:

    Greetings,

    Kindly asking for reviews for the following change:

    Bug: https://bugs.openjdk.java.net/browse/JDK-8028412

    Webrev: http://cr.openjdk.java.net/~mgronlun/8028412/webrev01/
    <http://cr.openjdk.java.net/%7Emgronlun/8028412/webrev01/>

    Description:

    AsynchGetCallTrace() uses platform specific code for stack frame
    traversals.

    On x86, there currently exist a defensive construct that
    practically disallows stack traversal over entry_frame code stubs,
    such as StubRoutine(1) frames:

    src/cpu/x86/vm/frame_x86.cpp b/src/cpu/x86/vm/frame_x86.cpp:

    bool frame::safe_for_sender(JavaThread* thread)  {

    ...

    if (!Interpreter::contains(_pc) && _cb->frame_size() <= 0) {
      //assert(0, "Invalid frame_size");

     return false;
    }

    ...

    Since entry frames (such as StubRoutine(1)) have a frame size of
    0, the code returns prematurely.

    Fix is to move this frame size check post handling of
    is_entry_frame(),  where the code_stubs are processed.

    Testing completed:

    Sun Studio Profiler reproducer testcase

    SpecJBB2005

    Kitchensink

    Thanks
    Markus