RFR: 8348828: Windows dll loading now resolves symlinks [v9]

[Benjamin Peterson]

On Fri, 17 Oct 2025 22:25:44 GMT, Benjamin Peterson <duke at openjdk.org> wrote:

>> Deep in the bowels of `System.loadLibrary`, `File.getCanonicalPath()` is called on the target library file before it is passed to the system library loading APIs. In JDK-8003887, `File.getCanonicalPath` was altered to resolve symlinks on Windows. This had unintended consequences for passing a symlink to `System.loadLibrary` on Windows. The underlying Windows `LoadLibrary` API inspects the file name passed to it and adds a `.dll` extension if the it is not already present. Thus, if `System.loadLibrary` was given a symlink to a file and that file didn't have a `.dll` extension, `LoadLibrary` try to load nonexistent file and fail.
>> 
>> Fix this problem by appending a `.` to library paths in Windows' `os::dll_load`. This trailing dot inhibits `LoadLibrary`'s own appending behavior.
>
> Benjamin Peterson has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 15 additional commits since the last revision:
> 
>  - add test showing loading symlinked libraries with various combinations
>  - revert dll_load fix
>  - Merge branch 'master' into nativelibraries-fix
>  - add cast
>  - use os::malloc
>  - Merge branch 'master' into nativelibraries-fix
>  - fix compilation
>  - fix grammar
>  - add dot in os::dll_load rather than NativeLibraries.java
>  - Merge remote-tracking branch 'origin/master' into nativelibraries-fix
>  - ... and 5 more: https://git.openjdk.org/jdk/compare/ab30fa02...09de5608

Did any thoughts come back from security?

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PR Comment: https://git.openjdk.org/jdk/pull/24694#issuecomment-3540027643