On Mon, 14 Jul 2025 15:33:35 GMT, Jorn Vernee <jver...@openjdk.org> wrote:

> Issue copied from the JBS issue:
> 
> When an upcall stub accepts a by-value struct, and the struct is passed by 
> the underlying ABI as a pointer to a temporary copy on the caller's stack 
> (for instance on Windows when the struct doesn't fit into a single register), 
> a scope is created for the duration of the upcall, to which the memory 
> segment for this struct is attached.
> 
> However, if such a scope is created for the upcall, any other unrelated 
> pointer argument will _also_ be attached to the same scope. This is 
> incorrect, as unrelated pointer arguments should be attached to the global 
> scope. The underlying issue is that, when deciding whether a particular 
> argument needs to be attached to the scope, we check if _any_ of the argument 
> needs to be attached to the created scope.
> 
> This PR fixes the issue by calling `boxAddress.needsScope()` in 
> `BindingSpecializer::emitBoxAddress`, which checks only if that particular 
> argument needs to be attached to the upcall scope.
> 
> I've also renamed the 'global' `needsScope` method, which checks whether 
> _any_ of the arguments need a scope, to `anyArgNeedsScope` for clarity.
> 
> Testing: `jdk_foreign` test suite on Mac/Windows/Linux x64, and Mac/Linux 
> aarch64

This pull request has now been integrated.

Changeset: 9dc62825
Author:    Jorn Vernee <jver...@openjdk.org>
URL:       
https://git.openjdk.org/jdk/commit/9dc62825b5e7300542d22df0b87b79116f3562d3
Stats:     44 lines in 3 files changed: 39 ins; 0 del; 5 mod

8362169: Pointer passed to upcall may get wrong scope

Reviewed-by: mcimadamore

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

PR: https://git.openjdk.org/jdk/pull/26295

Reply via email to