On 27/08/2016 7:35 AM, Chris Plummer wrote:
Hi Dmitry,
Although the fix is addressing the specific issue described in the bug,
what about the general issue of referencing gdata after a call to
cbEarlyVMDeath(). Do more references to gdata need to be protected?
Also, is there the possibility of a multi-threading race condition here?
Could gdata be cleared by another thread after it is checked?
Certainly. This really isn't fixing anything just adding a bailout check
before the crashing code. We can still crash and not be any the wiser as
to why.
Not sure I really see the point of doing this instead of closing this as
a dup of JDK-8134103 and fixing things properly.
David
thanks,
Chris
On 8/26/16 4:00 AM, Dmitry Samersoff wrote:
Everybody,
Please review the fix.
http://cr.openjdk.java.net/~dsamersoff/JDK-8163994/webrev.02/
*Problem*
Under some circumstances, when JVMTI_ERROR_WRONG_PHASE(112) is received,
jvmtiAllocate could be called after call to cbEarlyVMDeath.
cbEarlyVMDeath set gdata->jvmti to NULL, so jvmtiAllocate crashes.
The problem appears only once in nightly testing and I was not able to
reproduce it locally.
*Solution*
Guard added to jvmtiAllocate to get meaningful error message instead of
crash.
These fix doesn't fix root cause - JVMTI_ERROR_WRONG_PHASE problem is
going to be addressed under JDK-8134103.
-Dmitry
