review for 7088020: SEGV in JNIHandleBlock::release_block (original) (raw)

Vladimir Kozlov vladimir.kozlov at oracle.com
Fri Sep 9 12:01:05 PDT 2011

Looks good.

Vladimir

Tom Rodriguez wrote:

Thanks. Fixed.

tom On Sep 9, 2011, at 11:28 AM, Vladimir Kozlov wrote:

In stubGeneratorsparc.cpp last ,false parameter is not removed.

Vladimir Tom Rodriguez wrote: So I've backed off from changing generateexceptionthrow to perform the alignment. Given that we've seen no problems with alignment in the existing callees I have to assume they are already being called properly aligned. So instead I've added alignment code in code that throws it. I'll file a separate bug for the general issue that we should have more explicitly code for checking the alignment of calls into the runtime on x64. I've updated the webrev. I kept the stubgenerator deletions since they seemed like a good thing. tom On Sep 8, 2011, at 9:29 AM, Tom Rodriguez wrote: On Sep 8, 2011, at 3:09 AM, Christian Thalinger wrote:

I don't understand that comment:

+ // FIXME: this probably needs to alignment logic It's a typo in a comment John asked me to add. The unsafe handler also needs alignment but I wasn't sure how to reproduce a failure so I didn't want to touch it. To be honest my whole change make me a little nervous. The current stubs all apparently work ok which suggests they are always called from contexts that are properly aligned. The only way to do alignment is to extend the caller frame, which is really only safe in some contexts. It should always be safe to adjust SP in the method handle code calls so I think I should just do some stack alignment just before jumping to the throwWMTEentry. Part of the problem is that we don't have any strict alignment checks when calling into the runtime. We just happen to die because the part of the JNI code was using movdqa against rbp. Anyway, I'm going to play with this a bit more. tom -- Christian On Sep 8, 2011, at 5:40 AM, Tom Rodriguez wrote:

Strangely the WMT cases all seemed to work fine but another test was failing. Running with +WalkStackALot showed that I wasn't moving the return address so I propagated the frame adjustment outside the enter/leave.

tom On Sep 7, 2011, at 2:24 PM, Vladimir Kozlov wrote:

Where r12 is restored? It contains coop base.

Vladimir Tom Rodriguez wrote: http://cr.openjdk.java.net/~never/7088020 150 lines changed: 88 ins; 50 del; 12 mod; 10143 unchg 7088020: SEGV in JNIHandleBlock::releaseblock Reviewed-by: The throwWrongMethodTypeException stub on x64 needs to align the stack before calling into the runtime or it might crash. I also noticed that two stubs were dead which made an extra argument dead so I cleaned that up at the same time. Tested on linux-amd64 with new regression test and failing tests from report.

More information about the hotspot-compiler-dev mailing list