RFR: 8339242: Fix overflow issues in AdlArena [v4]

[Kim Barrett]

On Thu, 5 Sep 2024 14:31:28 GMT, Casper Norrbin <duke at openjdk.org> wrote:

>> Hi everyone,
>> 
>> This PR addresses an issue in `adlArena` where some allocations lack checks for overflow. This could potentially result in successful allocations when called with unrealistic values.
>> 
>> The fix includes:
>> 
>> - Adding assertions to check for potential overflow.
>> - Reordering some operations to guard against overflow.
>
> Casper Norrbin has updated the pull request incrementally with one additional commit since the last revision:
> 
>   review suggestions

Changes requested by kbarrett (Reviewer).

src/hotspot/share/adlc/adlArena.cpp line 141:

> 139: 
> 140: //------------------------------realloc----------------------------------------
> 141: size_t pointer_delta(const void *left, const void *right) {

Function ought to be static.

-------------

PR Review: https://git.openjdk.org/jdk/pull/20774#pullrequestreview-2284536292
PR Review Comment: https://git.openjdk.org/jdk/pull/20774#discussion_r1746465313