review for 7104960: JSR 292: +VerifyMethodHandles in product JVM can overflow buffer
tom.rodriguez at oracle.com
Fri Nov 4 13:08:29 PDT 2011
On Nov 4, 2011, at 10:54 AM, Tom Rodriguez wrote:
> On Nov 3, 2011, at 10:49 PM, John Rose wrote:
>> That's good.
>> The xtty output should delimit the attribute values with single quotes:
>> - xtty->print_cr("<sect index=%d used=" ...
>> + xtty->print_cr("<sect index='%d' used='" …
> Yep. I'll fix that.
I also wasn't terminating one of the elements correctly. I ran an xml parser over the output to confirm that was syntactically well formed.
>> Perhaps the xml-spewing code should be a method on CodeBuffer itself, so we can log other such bits (stub routines, interpreter, adapters) when we feel like it.
> That's a good idea. I may add a few others if it's easy.
I added log_sections_sizes. It would be nice if this were all a lot more automatic but we'd have to rearrange CodeBuffer and friends to do it.
>> -- John
>> On Nov 3, 2011, at 4:51 PM, Tom Rodriguez wrote:
>>> 73 lines changed: 42 ins; 6 del; 25 mod; 14873 unchg
>>> 7104960: JSR 292: +VerifyMethodHandles in product JVM can overflow buffer
>>> The code buffers on limits on sparc didn't properly account for space
>>> required then the code cache and libjvm.so were farther apart than an
>>> int so it would slightly overflow it's buffer. It would crash because
>>> the CodeCache became corrupted instead of reporting that it
>>> overflowed. I modified the overflow detection logic to work even in
>>> product. It doesn't check on every operation as it does in debug
>>> mode, it just vierifies at the end that it hasn't overflowed. I also
>>> extended the ForceUnreachable logic to work on sparc and turned it
>>> into a diagnostic so it can be tested in product. I added logging
>>> code to report buffer usage and reset the values on sparc and x86. If
>>> left about 4k of buffer in product mode and 20k in debug mode.
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