[11] RFR(S): 8148871: Possible wrong expression stack depth at deopt point

[Tobias Hartmann]

Hi Yumin,

thanks for looking at this.

On 01.03.2018 03:11, yumin qi wrote:
> I am not reviewing the change, just wonder if you could modify the comment in the function:
> 
>  605 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
>  606 
>  607   // We are already active int he special DeoptResourceMark any ResourceObj's we
>  608   // allocate will be freed at the end of the routine.
> 
> It looks a typo in the comment.  'int he' -> 'in the'

Good catch, I'll fix that comment before pushing.

Best regards,
Tobias


> On Wed, Feb 28, 2018 at 2:43 PM, <dean.long at oracle.com <mailto:dean.long at oracle.com>> wrote:
> 
>     This looks good.
> 
>     dl
> 
> 
>     On 2/28/18 5:25 AM, Tobias Hartmann wrote:
> 
>         Hi,
> 
>         please review the following patch:
>         https://bugs.openjdk.java.net/browse/JDK-8148871
>         <https://bugs.openjdk.java.net/browse/JDK-8148871>
>         http://cr.openjdk.java.net/~thartmann/8148871/webrev.00/
>         <http://cr.openjdk.java.net/~thartmann/8148871/webrev.00/>
> 
>         The problem is that the stack verification code uses the interpreter oop map to get the
>         stack size
>         of the next instruction. However, for calls, the oop map contains the state *after* the
>         instruction.
>         With next_mask_expression_stack_size = 0, the result of 'next_mask_expression_stack_size -
>         top_frame_expression_stack_adjustment' is negative and verification fails. For details, see my
>         comment in the bug [1].
> 
>         The fix is to add a special case for invoke bytecodes and use the parameter size instead of
>         the oop
>         map in that case. Tested with hs-tier1/2 with -XX:+VerifyStack (I hit 8198826 which I'll fix
>         with
>         another patch).
> 
>         Thanks,
>         Tobias
> 
>         [1]
>         https://bugs.openjdk.java.net/browse/JDK-8148871?focusedCommentId=14160003&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14160003
>         <https://bugs.openjdk.java.net/browse/JDK-8148871?focusedCommentId=14160003&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14160003>
> 
> 
>