Integrated: 8293660: Fix frame::sender_for_compiled_frame frame size assert

[Aleksey Shipilev]

On Mon, 12 Sep 2022 17:56:17 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> The condition and assert messages are contradicting each other here:
> 
> 
> frame frame::sender_for_compiled_frame(RegisterMap* map) const {
>   ...
>   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
>   intptr_t* sender_sp = unextended_sp() + _cb->frame_size();
> 
> 
> I found this in x86_32 Loom port, where a entry generator bug caused zero-sized frames. I believe the assert message is correct, and the condition is not: sender SP should be different from (unextended) SP. In fact, if allowed to proceed, the tests can then fail the later assert, assuming `sp() == unextended_sp()`:
> 
> 
>   assert(sender_sp != sp(), "must have changed");
> 
> 
> This code predates OpenJDK history, and assert was copy-pasted in this form to many arches. 
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `tier1`

This pull request has now been integrated.

Changeset: 60f59a4a
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/60f59a4a8808abf1a8896ca122a1f8120c9f5527
Stats:     8 lines in 8 files changed: 0 ins; 0 del; 8 mod

8293660: Fix frame::sender_for_compiled_frame frame size assert

Reviewed-by: dlong, kvn

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PR: https://git.openjdk.org/jdk/pull/10242