RFR(s): 8074860: Structured Exception Catcher missing around CreateJavaVM on Windows

Thomas Stüfe thomas.stuefe at gmail.com
Wed Mar 11 15:40:33 UTC 2015

Hi all,

please review this smallish change:

bug:  https://bugs.openjdk.java.net/browse/JDK-8074860

This change adds SEH guards around JNI_CreateJavaVM(). Without the change,
on Windows, the VM initialization runs without crash protection: crashes
will terminate VM immediately without writing an error log; also, any
techniques relying on signals will not work, e.g. SafeFetch().

This was partly solved before on a case-by-case base by wrapping code
sections which may crash in their own __try/__except wrappers - e.g. CPU
feature probing.

The change guards the whole of JNI_CreateJavaVM invocation in
__try/__except. Unfortunately, for that to compile, I needed to introduce a
wrapper around JNI_CreateJavaVM and move the whole of JNI_CreateJavaVM to a
new function "JNI_CreateJavaVM_inner".

This fix also gets rid of various workarounds which were used before to
guard code sections.

Thanks for reviewing!

Oh, on a side note: I tried to figure out if threads which are attached
from the outside via JNI AttachCurrentThread() are in any way guarded with
SEH protection. Newly created threads are guarded because they run thru
java_start() in os_windows.cpp, which adds SEH guards to all frames below.
But for attached threads, I did not find any SEH guards - or maybe I am
blind? What does that mean for java code running inside attached threads?


Thomas Stuefe

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