[jdk11u-dev] RFR: 8315380: AsyncGetCallTrace crash in frame::safe_for_sender [v3]

[Severin Gehwolf]

On Thu, 17 Apr 2025 06:59:37 GMT, Jaroslav Bachorik <jbachorik at openjdk.org> wrote:

>> This change is fixing the problem in `frame_aarch64.cpp`, function `safe_for_sender`, where we have this code
>> 
>> 
>> bool unextended_sp_safe = unextended_sp < thread->stack_base();
>> 
>> 
>> While this captures one possibility of not being safe, it omits the check for `unextended_sp` falling within the stack space.
>> 
>> The proposed change then is
>> 
>> 
>> bool unextended_sp_safe = (unextended_sp < thread->stack_base() && \
>>                              sp >= thread->stack_base() - thread->stack_size());
>> 
>> 
>> This is actually just making sure the behaviour is the same as in JDK 15+ (since [JDK-8238988](https://bugs.openjdk.org/browse/JDK-8238988)) where the `unextended_sp` is checked for being within the stack limits.
>> 
>> 
>> The change is not accompanied by a JTReg test because I was not able to craft one triggering the issue reliably.
>> 
>> Existing tests from tier1-tier4 were run on a linux-aarch64 system with no new failures observed.
>
> Jaroslav Bachorik has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use 'thread->stack_end()'

src/hotspot/cpu/aarch64/frame_aarch64.cpp line 4:

> 2:  * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
> 3:  * Copyright (c) 2014, 2021, Red Hat Inc. All rights reserved.
> 4:  * Copyrithg (c) 2025, Datadog, Inc. All rights reserved.

Suggestion:

 * Copyright (c) 2025, Datadog, Inc. All rights reserved.


I tend to agree that this doesn't really need a copyright update.

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PR Review Comment: https://git.openjdk.org/jdk11u-dev/pull/3003#discussion_r2049215654