RFR[11u]: backport 8218966: AArch64: String.compareTo() can read memory after string

[Dmitry Samersoff]

Dmitrij,

Looks good to me.

-Dmitry

On 21.08.19 20:53, Dmitrij Pochepko wrote:
> Hi,
> 
> please review backport of JDK-8218966 "AArch64: String.compareTo() can
> read memory after string" [1]
> 
> The original patch [1] does not apply cleanly with 2 failed hunks [2]
> because of JDK-8206895 [3] (not in jdk11u), which changed 2 "cmp"
> instructions to 2 "subs" instructions. Patch for [3] was introduced to
> handle potential immediate constant overflow, but for current patch
> these constants are within acceptable range because of [4], which is
> already present in 11u and no additional code changes are required. The
> only difference between current and original patch is that "cmp -> subs"
> change is taken into account.
> 
> new patch:
> http://cr.openjdk.java.net/~dpochepk/8218966.backport.11u/webrev.01/
> 
> testing:
> - tier1 hotspot jtreg tests passed
> - jck-runtime passed
> - new tests, which demonstrate this issue is also passed after patch is
> applied
> 
> Thanks,
> Dmitrij
> 
> 
> [1] original patch: http://hg.openjdk.java.net/jdk/jdk/rev/82fd8793ba5e,
> original bug: https://bugs.openjdk.java.net/browse/JDK-8218966, original
> review:
> https://mail.openjdk.java.net/pipermail/aarch64-port-dev/2019-May/007367.html
> 
> 
> [2] rejects of original apply:
> http://cr.openjdk.java.net/~dpochepk/8218966.backport.11u/webrev.01/stubGenerator_aarch64.cpp.rej
> 
> 
> [3] https://bugs.openjdk.java.net/browse/JDK-8206895, patch:
> http://hg.openjdk.java.net/jdk/jdk/rev/7be0084191ed
> 
> [4] https://bugs.openjdk.java.net/browse/JDK-8206265, patch
> http://hg.openjdk.java.net/jdk-updates/jdk11u-dev/rev/44483330f7cf
> 
>