review for 7103380: assertion failure with -XX:+PrintNativeNMethods

[Vladimir Kozlov]

Looks good.

Vladimir

Tom Rodriguez wrote:
> http://cr.openjdk.java.net/~never/7103380
> 11 lines changed: 10 ins; 0 del; 1 mod; 1028 unchg
> 
> 7103380: assertion failure with -XX:+PrintNativeNMethods
> Reviewed-by:
> 
> Running with -XX:+PrintNativeNMethods I hit the assert:
> 
> #  assert(limit == NULL || limit <= nm->code_end()) failed: in bounds
> 
> The problem is that old instructions in the code buffer after the real
> code, so the disassembler attempts to disassemble off the end of the
> buffer.  This is because alignment of the end CodeSections is
> performed by looking at the predecessor of the current section.
> Fixing the alignment to always align the beginning and end seems to
> fan out causing other problems.  Instead I added some logic similar to
> the existing fill logic to fill any remaining space in the
> destination.  The reason native wrappers fall afoul of this is that
> the don't have a stub section.  Tested with -XX:+PrintNativeNMethods.
>