RFR(S): 8008357: [sampling] assert(sender_blob->is_runtime_stub() || sender_blob->is_nmethod()) failed: Impossible call chain

[Rickard Bäckman]

Hi,

trying again, can I please have two reviews on this change?
Some small changes after offline discussion. 

The webrev is available here:
http://cr.openjdk.java.net/~rbackman/8008357.u1/

Thanks
/R

On Mar 5, 2013, at 8:07 AM, Rickard Bäckman wrote:

> Anyone have time to look at this?
> 
> Thanks
> /R
> 
> On Mar 1, 2013, at 10:27 AM, Rickard Bäckman wrote:
> 
>> Hi all,
>> 
>> here comes another update to frame.safe_for_sender. 
>> If the PC at a place where the stack doesn't match the _frame_size we sometimes read an invalid return PC. 
>> In this case we read one that pointed into the Safepoint blob. 
>> 
>> We now pretty much guarded for all kind of blobs in safe_for_sender,
>> so I've changed the method to not assert in the end but to do it the same was as the frame_sparc.cpp did it. Everything that is not
>> a nmethod at the end of the method is not safe. 
>> 
>> I've also changed another check for a frame_size == 0 to frame_size <= 0 to make it somewhat more safer.
>> 
>> The bug: http://bugs.sun.com/view_bug.do?bug_id=8008357
>> Webrev: http://cr.openjdk.java.net/~rbackman/8008357/
>> 
>> This webrev is for HS24.
>> 
>> Thanks
>> /R
>