Request for review (S): 7141637: JSR 292: MH spread invoker crashes with NULL argument on x86_32

[Christian Thalinger]

On Jan 31, 2012, at 8:07 PM, Volker Simonis wrote:

> Hi,
> 
> as the test in the webrev demonstrates, the MH spread invoker
> will crashes the VM if invoked with a NULL argument on x86_32
> platforms.
> 
> This is because nn 32-bit Intel platforms, the spread invoker
> uses the 'rsi' register as temporary. But because 'rsi' also
> contains the 'saved_last_sp' on x86_32 platforms, 'rsi' has to be
> temporary saved on the stack.  If this saving is done before a
> failing 'NULL' check in the spread adapter, the following
> excpetion handling routine will be confused by the extra value on
> the stack, because it expects to find the return address here.
> 
> To fix this problem, I've exchanged the usage of the temporary
> registers 'rsi' and 'rdi' in the spread adapter such that we only
> have to save the value of 'rsi' to the stack after the NULL check
> was done:
> 
> http://cr.openjdk.java.net/~simonis/SpreadNullArg/

Thanks for the detailed bug report and the fix.  I filed:

7141637: JSR 292: MH spread invoker crashes with NULL argument on x86_32

and created and webrev just for the record:

http://cr.openjdk.java.net/~twisti/7141637/

The changes look good, I fixed a typo and moved the test into the right directory.

-- Chris

> 
> Regards,
> Volker
> 
> PS: please don't forget to update the test directory name after a
> bug id was assigned to this issue.